US20110030672A1 - Solar Collection Apparatus and Methods Using Accelerometers and Magnetics Sensors - Google Patents
Solar Collection Apparatus and Methods Using Accelerometers and Magnetics Sensors Download PDFInfo
- Publication number
- US20110030672A1 US20110030672A1 US12/901,289 US90128910A US2011030672A1 US 20110030672 A1 US20110030672 A1 US 20110030672A1 US 90128910 A US90128910 A US 90128910A US 2011030672 A1 US2011030672 A1 US 2011030672A1
- Authority
- US
- United States
- Prior art keywords
- mirror
- accelerometer
- tracking apparatus
- axis
- solar radiation
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
- 230000005291 magnetic effect Effects 0.000 title claims abstract description 33
- 238000000034 method Methods 0.000 title description 9
- 230000005855 radiation Effects 0.000 claims abstract description 44
- 230000007246 mechanism Effects 0.000 claims abstract description 21
- 230000033001 locomotion Effects 0.000 claims abstract description 18
- 239000003990 capacitor Substances 0.000 claims description 2
- 230000008878 coupling Effects 0.000 claims 2
- 238000010168 coupling process Methods 0.000 claims 2
- 238000005859 coupling reaction Methods 0.000 claims 2
- 238000010586 diagram Methods 0.000 description 12
- 230000003287 optical effect Effects 0.000 description 6
- 238000004891 communication Methods 0.000 description 4
- 230000000712 assembly Effects 0.000 description 3
- 238000000429 assembly Methods 0.000 description 3
- 230000008859 change Effects 0.000 description 3
- 239000012141 concentrate Substances 0.000 description 3
- 238000005516 engineering process Methods 0.000 description 3
- 230000005484 gravity Effects 0.000 description 3
- 238000010438 heat treatment Methods 0.000 description 3
- 238000012360 testing method Methods 0.000 description 3
- 230000001133 acceleration Effects 0.000 description 2
- 230000005540 biological transmission Effects 0.000 description 2
- 239000011521 glass Substances 0.000 description 2
- 239000013529 heat transfer fluid Substances 0.000 description 2
- 230000010354 integration Effects 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 239000004065 semiconductor Substances 0.000 description 2
- 229920002799 BoPET Polymers 0.000 description 1
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 1
- DGAQECJNVWCQMB-PUAWFVPOSA-M Ilexoside XXIX Chemical compound C[C@@H]1CC[C@@]2(CC[C@@]3(C(=CC[C@H]4[C@]3(CC[C@@H]5[C@@]4(CC[C@@H](C5(C)C)OS(=O)(=O)[O-])C)C)[C@@H]2[C@]1(C)O)C)C(=O)O[C@H]6[C@@H]([C@H]([C@@H]([C@H](O6)CO)O)O)O.[Na+] DGAQECJNVWCQMB-PUAWFVPOSA-M 0.000 description 1
- BQCADISMDOOEFD-UHFFFAOYSA-N Silver Chemical compound [Ag] BQCADISMDOOEFD-UHFFFAOYSA-N 0.000 description 1
- 230000004913 activation Effects 0.000 description 1
- 239000008186 active pharmaceutical agent Substances 0.000 description 1
- 239000000853 adhesive Substances 0.000 description 1
- 230000001070 adhesive effect Effects 0.000 description 1
- 230000003466 anti-cipated effect Effects 0.000 description 1
- 230000008901 benefit Effects 0.000 description 1
- 230000003750 conditioning effect Effects 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000004146 energy storage Methods 0.000 description 1
- 239000000835 fiber Substances 0.000 description 1
- 239000000446 fuel Substances 0.000 description 1
- 239000005431 greenhouse gas Substances 0.000 description 1
- 239000001257 hydrogen Substances 0.000 description 1
- 229910052739 hydrogen Inorganic materials 0.000 description 1
- 230000000977 initiatory effect Effects 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 230000007774 longterm Effects 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 238000012544 monitoring process Methods 0.000 description 1
- 230000006855 networking Effects 0.000 description 1
- 230000001699 photocatalysis Effects 0.000 description 1
- 239000004033 plastic Substances 0.000 description 1
- 229920006267 polyester film Polymers 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 230000004044 response Effects 0.000 description 1
- 230000035945 sensitivity Effects 0.000 description 1
- 229910052709 silver Inorganic materials 0.000 description 1
- 239000004332 silver Substances 0.000 description 1
- 229910052708 sodium Inorganic materials 0.000 description 1
- 239000011734 sodium Substances 0.000 description 1
- 239000000758 substrate Substances 0.000 description 1
- 230000001360 synchronised effect Effects 0.000 description 1
- 238000012549 training Methods 0.000 description 1
- 238000012546 transfer Methods 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Images
Classifications
-
- E—FIXED CONSTRUCTIONS
- E04—BUILDING
- E04D—ROOF COVERINGS; SKY-LIGHTS; GUTTERS; ROOF-WORKING TOOLS
- E04D13/00—Special arrangements or devices in connection with roof coverings; Protection against birds; Roof drainage; Sky-lights
- E04D13/03—Sky-lights; Domes; Ventilating sky-lights
- E04D13/033—Sky-lights; Domes; Ventilating sky-lights provided with means for controlling the light-transmission or the heat-reflection, (e.g. shields, reflectors, cleaning devices)
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F24—HEATING; RANGES; VENTILATING
- F24S—SOLAR HEAT COLLECTORS; SOLAR HEAT SYSTEMS
- F24S23/00—Arrangements for concentrating solar-rays for solar heat collectors
- F24S23/70—Arrangements for concentrating solar-rays for solar heat collectors with reflectors
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F24—HEATING; RANGES; VENTILATING
- F24S—SOLAR HEAT COLLECTORS; SOLAR HEAT SYSTEMS
- F24S30/00—Arrangements for moving or orienting solar heat collector modules
- F24S30/40—Arrangements for moving or orienting solar heat collector modules for rotary movement
- F24S30/45—Arrangements for moving or orienting solar heat collector modules for rotary movement with two rotation axes
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F24—HEATING; RANGES; VENTILATING
- F24S—SOLAR HEAT COLLECTORS; SOLAR HEAT SYSTEMS
- F24S50/00—Arrangements for controlling solar heat collectors
- F24S50/20—Arrangements for controlling solar heat collectors for tracking
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L31/00—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
- H01L31/04—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof adapted as photovoltaic [PV] conversion devices
- H01L31/054—Optical elements directly associated or integrated with the PV cell, e.g. light-reflecting means or light-concentrating means
- H01L31/0547—Optical elements directly associated or integrated with the PV cell, e.g. light-reflecting means or light-concentrating means comprising light concentrating means of the reflecting type, e.g. parabolic mirrors, concentrators using total internal reflection
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F24—HEATING; RANGES; VENTILATING
- F24S—SOLAR HEAT COLLECTORS; SOLAR HEAT SYSTEMS
- F24S30/00—Arrangements for moving or orienting solar heat collector modules
- F24S2030/10—Special components
- F24S2030/13—Transmissions
- F24S2030/133—Transmissions in the form of flexible elements, e.g. belts, chains, ropes
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F24—HEATING; RANGES; VENTILATING
- F24S—SOLAR HEAT COLLECTORS; SOLAR HEAT SYSTEMS
- F24S30/00—Arrangements for moving or orienting solar heat collector modules
- F24S2030/10—Special components
- F24S2030/15—Bearings
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
- Y02B10/00—Integration of renewable energy sources in buildings
- Y02B10/20—Solar thermal
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E10/00—Energy generation through renewable energy sources
- Y02E10/40—Solar thermal energy, e.g. solar towers
- Y02E10/47—Mountings or tracking
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E10/00—Energy generation through renewable energy sources
- Y02E10/50—Photovoltaic [PV] energy
- Y02E10/52—PV systems with concentrators
Definitions
- the present invention relates to systems and methods for utilizing the energy of the Sun, and more particularly, to systems and methods for tracking the Sun to re-direct and concentrate incident solar radiation for lighting, heating and photovoltaic applications.
- FIG. 1 illustrates one example of a prior art device that utilizes a parabolic dish mirror 10 with a central axis 12 that is pointed generally toward the Sun 14 .
- Incident solar radiation 22 is received and reflected by the parabolic dish mirror 10 and concentrated at its focus 16 , where a thermal target (not illustrated) can be mounted so that it can be heated.
- the parabolic dish mirror 10 is supported for independent movement by a two-axis tracking support 18 mounted atop a supporting structure 20 such as a tower.
- Optical encoders (not illustrated) associated with the tracking support 18 provide signals indicative of the direction and amount of rotation of the parabolic dish mirror 10 so that motor drives and a control system (not illustrated) can be used to track the Sun and increase the efficiency of the energy transfer.
- FIG. 2 illustrates another example of a prior art device similar to the device of FIG. 1 except that the device of FIG. 2 utilizes a parabolic trough mirror 30 .
- Dashed line 32 illustrates a common plane of the focal line 36 of the parabolic trough mirror 30 and the Sun 14 .
- a single axis tracking support 38 carries the parabolic trough mirror 30 and is mounted atop a tower 40 .
- Incident light rays from the Sun such as 42 are collected and reflected by the parabolic trough mirror 30 and concentrated on a pipe (not illustrated) that extends along the focal line 36 . This allows a heat transfer fluid such as water or liquid sodium to be heated.
- FIG. 3 illustrates another prior art device that utilizes a heliostat flat mirror 50 that receives incident light rays 52 from the Sun 14 and reflects them against a thermal target 58 atop a tower 59 .
- Another tower 54 carries a two-axis tracking support 56 which supports a flat mirror 50 .
- Drive and control mechanisms allow the flat mirror 50 to be independently moved about a rotate axis 60 (azimuth) and about a tilt axis 62 (elevation) to ensure that the Sun's rays are reflected onto the target 58 as the Sun moves across the sky.
- a solar tracking apparatus has a mirror or other reflecting surface for collecting and reflecting incident solar radiation.
- the mirror is supported for independent motion about a pair of axes.
- An accelerometer generates signals representative of an amount and direction of motion of the mirror about each of the axes.
- Motors or other drive mechanisms independently drive the mirror about each of the axes.
- a tracking device provides information about the current position of the Sun.
- a control is connected to the accelerometer, the motors and the tracking device for maintaining a predetermined optimum orientation of the mirror as the Sun moves across the sky.
- one or more magnetic field sensors are used to sense rotation around an approximately vertical axis and one or more accelerometers are used to sense tilt around an approximately horizontal axis to provide signals indicative of heliostat mirror position in a coordinate system to a control system.
- the control system allows for precise positioning of a heliostat mirror and the directing of solar energy in a desired direction.
- three orthogonal magnetic field sensors are used to sense rotation around an approximately vertical axis and three orthogonal accelerometers are used to sense tilt around an approximately horizontal axis to provide signals indicative of heliostat mirror position in a coordinate system to a control system.
- the control system allows for precise positioning of a heliostat mirror and the directing solar energy in a desired direction.
- FIGS. 1-3 illustrate examples of prior art solar radiation collecting and redirecting devices.
- FIG. 4 illustrates a first embodiment of the present invention that utilizes a flat mirror to heat a target.
- FIG. 5 illustrates a second embodiment of the present invention that utilizes an array of mirrors to reflect solar radiation through a skylight.
- FIG. 6 illustrates an alternate embodiment wherein an array of flat tracking mirrors reflects incident solar radiation through the windows of a house to provide light and heat.
- FIG. 7 illustrates another embodiment that utilizes an array of heliostat mirrors to heat a thermal target.
- FIG. 8 illustrates another embodiment that utilizes a plurality of heliostat mirrors to reflect solar radiation onto a high temperature photovoltaic panel.
- FIG. 9 is a block diagram of another embodiment in which a network controller controls a plurality of mirror nodes.
- FIG. 10 illustrates another embodiment in which a heliostat mirror is positioned to reflect incident solar radiation onto a target via a vertical array of photo-sensors.
- FIG. 11 is a block diagram illustrating one embodiment of the mirror controller network node of the embodiment of FIG. 4 .
- FIG. 12 is a flow diagram illustrating one embodiment of a method of operation of the control of FIG. 11 .
- FIG. 13 is a flow diagram of another embodiment of a method of operation of a solar tracking 20 device in accordance with the present invention.
- FIG. 14 is a front isometric view of another embodiment that utilizes a weight-tensioned device to pivot the mirror.
- FIG. 15 is a back isometric view of the embodiment illustrated in FIG. 14 .
- FIG. 16 is a front elevation view of the embodiment illustrated in FIG. 14 .
- FIG. 17 is a back elevation view of the embodiment illustrated in FIG. 14 .
- FIG. 18 is a side elevation view of the embodiment illustrated in FIG. 14 .
- FIG. 19 is an exploded back isometric view of the embodiment illustrated in FIG. 14 .
- FIG. 20 is a vertical sectional view (stepped cut) of the embodiment illustrated in FIG. 14 showing internal components thereof.
- FIG. 21 illustrates another embodiment that employs magnetic sensors and accelerometers.
- FIG. 22 is a block diagram of the control system of the embodiment of FIG. 21 .
- FIG. 23 is a block diagram of control circuitry.
- FIG. 24 is a flow chart of data integration of magnetic sensor and accelerometer data and their resolution.
- FIG. 4 illustrates a first embodiment of the present invention that utilizes a flat mirror to heat a target.
- a solar tracking apparatus has a reflective surface in the form of a mirror 70 for collecting and reflecting incident solar radiation 82 from the Sun 14 .
- the mirror in this embodiment has a planar configuration, although this embodiment could be adapted to use other mirror configurations including parabolic dish, parabolic trough, etc. in order to concentrate the incident solar radiation.
- the mirror could be conventional silver coated glass, or could be plastic, or could be Mylar® polyester film on a support substrate, or some other form of reflective material that is durable, lightweight and inexpensive.
- the mirror 70 ( FIG. 4 ) is supported by a pair of pivot mechanisms 72 for independent motion about a pair of tilt axes 88 and 90 .
- the pivot mechanisms 72 are mounted atop a support or tower 76 .
- An accelerometer 74 generates signals representative of an amount and direction of motion of the mirror about each of the axes 88 and 90 . In effect the Earth's gravity is sensed and used to provide an indication of the current orientation of the mirror 70 .
- Electric motors 78 (only one of two illustrated) independently drive the mirror 70 about each of the axes utilizing, for example, a worm gear 80 and a circular rack gear 81 .
- a mirror controller network node 86 includes a tracking device, typically an electronic processor, that provides information about the current position of the Sun 14 .
- the mirror controller network node 86 also includes a control that is connected to the accelerometer 74 , the motors 78 and the tracking device for maintaining a predetermined optimum orientation of the mirror as the Sun moves across the sky.
- the architecture and method of operation of the mirror controller network node 86 are discussed hereafter in greater detail.
- Incident solar radiation with an angle of incidence 96 is reflected off the surface of the mirror 70 at an angle of reflection 94 so that it strikes a thermal target 84 such as a container or conduit of a heat transfer fluid or an array of photovoltaic cells.
- the accelerometer 74 ( FIG. 4 ) is preferably a micro-electro-mechanical systems (MEMS) accelerometer device. Utilizing micro-fabrication techniques a position sensor component and signal conditioning circuit can be fabricated on a single integrated circuit chip. Such MEMS accelerometer devices are relatively inexpensive, durable and sufficiently accurate for purposes of manufacturing commercial embodiments of the present invention. Suitable MEMS accelerometer devices are the KXM52-1040 dual-axis (XY) MEMS accelerometer device and the KXM52-1 050 tri-axis (XYZ) MEMS accelerometer device, both of which are commercially available from Kionix, Inc., 36 20 Thronwood Drive, Ithica, N.Y. 14850 USA. See U.S. Pat. Nos.
- ADXL321 two-axis
- ADXL330 three-axis MEMS accelerometer devices, both of which are commercially available from Analog Devices, Inc., One 25 Technology Way, Norwood, Mass. 02062 USA. See U.S. Pat. Nos. 6,837,107 granted Jan. 4, 2005 to Green and 6,845,665 granted Jan. 25, 2005 also to Green, both of which are assigned to Analog Devices, Inc., the entire disclosures of which are hereby incorporated by reference.
- the AMI602 which would also serve in this application, is also from Aichi and is a 6-axis motion sensor which incorporates 3-axis magnetometer and 3-axis accelerometer.
- the controller IC of the AMI602 consists of a circuit for sensor elements, an amplifier capable of compensating each sensors offset and setting appropriate sensitivity values, a temperature sensor, a 12 bitAD converter, an PC serial output circuit, a constant voltage circuit for power control and an 8032 micro-processor controlling each circuit.
- the pivot mechanisms 72 are configured and arranged so that throughout the useful range of tracking tilts, the accelerometer 74 is not rotated in an unknown fashion about a vertical axis. If the accelerometer is rotated about a vertical axis, the pointing direction of the mirror 70 becomes ambiguous or indeterminate.
- a magnetic sensor in an alternate embodiment avoids this problem, as discussed later.
- Modern compass MEMS devices which combine accelerometers with magnetic compass sensors are known in the art, and allow the array to be corrected for tilt, and such a device could be used in place of the accelerometer 74 .
- the accelerometer 74 need not be directly mounted to the mirror but could be coupled thereto through a mechanical or optical linkage.
- the pivot mechanisms 72 could be replaced with an alternate pivot mechanism such as a ball and socket or flexible joint, instead of those employing independently movable mechanical pivots.
- the mirror 70 need not strictly rotate about two axes, as is the case with the embodiment of FIG. 4 wherein rotation of the mirror 70 about one axis rotates the other axis. It will be appreciated that it is not necessary that both axes of tilt are substantially in the same horizontal plane when the mirror 70 is in a normal or horizontal orientation.
- mirror 70 can be driven besides the electric motor 78 and gears 80 and 81 , such as hydraulic and pneumatic systems.
- the mirror 70 need not move in azimuth and elevation, it being sufficient that it be capable of independent movement about two non-parallel axes.
- FIG. 5 illustrates a second embodiment of the present invention that utilizes an array 104 of individual mirrors 106 to reflect solar radiation 110 through a skylight 102 on the roof of a building 100 to provide internal lighting.
- the mirrors 106 may each be independently supported and moved as illustrated in FIG. 4 or they may be simultaneously supported and moved by a common tracking system so that reflected light 114 strikes a fixed angle target mirror 112 and is reflected as downwardly projected light 116 .
- the skylight 102 may be of the type sold under the SOLATUBE® trademark which employs a conduit with a highly reflective surface.
- a hot mirror 118 may be inserted in to the reflected light transmission path to reflect away the infrared component during the summer to avoid unwanted heating of the interior of the building 100 .
- FIG. 6 illustrates an alternate embodiment wherein an array 144 of flat tracking mirrors 142 reflect incident solar radiation 146 as reflected radiation 148 that passes through the window 140 of a house to provide light and heat. Again the mirrors 142 are supported and moved in the fashion described in connection with FIG. 4 .
- FIG. 7 illustrates another embodiment that utilizes an array 170 of heliostat mirrors 168 to heat a thermal target 162 .
- the amount of incident solar radiation 164 that is redirected as reflected solar radiation 166 is maximized by mounting an accelerometer 160 on each heliostat mirror 168 and using its signals, along with tracking information to tilt each mirror 168 about its two-axis tilting support 172 .
- FIG. 8 illustrates another embodiment that utilizes a plurality of heliostat mirrors 206 equipped as described in connection with FIG. 4 in order to re-direct a maximum amount of incident solar radiation 202 as reflected radiation 204 onto a high temperature photovoltaic panel 200 .
- FIG. 9 is a block diagram of another embodiment in which a network controller 222 controls a plurality of mirror nodes 220 .
- the network controller 222 may be connected to the mirror nodes 220 by a network link 226 which may be wired or wireless, fiber optic, laser or any other well known data communications scheme.
- a network link 226 which may be wired or wireless, fiber optic, laser or any other well known data communications scheme.
- One example is the ZIGBEETM data link. Bluetooth links or other wireless means could be used as well according to the scale of the application.
- An optional mirror node training interface 224 is provided that can be used to load the network controller 222 with tracking data from local or remote sources that give the predicted location of the Sun throughout the day for a given latitude, longitude, date and time.
- This information is used by the controller to compare the actual position of the mirrors with their optimum positions so that they can be moved to maximize the collection and/or concentration of solar radiation.
- this information may be preprogrammed into the network controller 222 or the mirror controller network node 86 ( FIG. 4 ).
- the present invention differs from conventional heliostats that require a vertical tracking axis.
- the Sun is tracked in both azimuth and elevation, however, tracking is required in both axes as neither component is separately derived.
- FIG. 10 illustrates another embodiment in which a heliostat mirror 246 is positioned to re-direct incident solar radiation 250 as reflected solar radiation 252 to strike a target 248 utilizing mechanisms similar to those described in connection with FIG. 4 .
- a vertical array of photo-sensors 240 detect reflected radiation 252 and their signals are used to position the mirror 246 so that the reflected radiation will strike the target 248 .
- a Sun hood 254 may be used with each photo-sensor 240 to prevent it from detecting significant amounts of incident solar radiation 250 .
- the spacing 242 between the photo-sensors 240 can be optimized relative to the dimension 244 of the mirror 246 .
- FIG. 11 is a block diagram illustrating one embodiment of mirror controller network node 86 of the embodiment of FIG. 4 .
- a PIC micro-computer based control 300 provides the basic intelligence and control through appropriate input/output interfaces. Position information is received from the accelerometer 302 . First and second axis motors 304 and 306 are appropriately driven. AC power or some other power source 310 such as solar or battery power provides power to the control 300 . In order for the mirror to be optimally pointed, it is necessary for the control 300 to compare the actual position of the mirror to the current position of the Sun and make the appropriate adjustments.
- Data regarding the predicted location of the Sun is pre-programmed into the control 300 , in which case a user interface (not illustrated) is necessary for a user to enter the correct latitude, longitude, date and time during initial set up.
- This interface could be a keypad or a connection to a PC or PDA, for example.
- a Global Positioning System (GPS) and time base receiver 312 may be connected to the control 300 to provide this information.
- GPS Global Positioning System
- a wired or wireless network link 308 connects the control to a remote location for monitoring or control.
- FIG. 12 is a flow diagram illustrating one embodiment of a method of operation of the control of FIG. 11 .
- the starting parameters are acquired, including latitude and longitude, time, tilt axis orientation to the North, and the estimated azimuth and elevation of the mirror. Latitude, longitude and time can be obtained via the network.
- the processor calculates the position of the Sun.
- the control uses signals from the accelerometer, and data from a look up table, the control calculates the movement of the mirror about each axis necessary to achieve the optimum orientation.
- the motors are driven by the control the move the mirror as needed to obtain the optimum orientation. If the accelerometer signals do not indicate mirror motion, an ERROR message is generated and transmitted and/or displayed.
- the control continues to track the Sun in order to engage the target.
- FIG. 13 is a flow diagram of another embodiment of a method of operation of a solar tracking device in accordance with the present invention.
- FIGS. 14-20 illustrate another embodiment of the present invention that utilizes weight-tensioned mechanisms to pivot the mirror.
- the embodiment 400 includes a planar square mirror 402 whose corners are supported by four cable hook corners 404 .
- a small yoke 406 ( FIGS. 15 and 19 ) has a square surface which is secured to the center of the rear side of the mirror 402 by suitable adhesive. Small yoke 406 is connected for independent rotation about two axes to a tall yoke 408 by a cross piece 410 .
- the base of the tall yoke 408 is secured by screws 412 and nuts 414 ( FIG. 19 ) to a cylindrical cap plate 416 .
- the cylindrical cap plate 416 is mounted on the upper end of a support structure in the form of a hollow vertical support post 418 .
- a lower tension wire 420 ( FIG. 18 ) has one end connected to the uppermost cable hook corner 404 and its other end connected to the lowermost cable hook corner 404 .
- An upper tension wire 422 ( FIGS. 18 and 19 ) has an intermediate segment wrapped around an upper drive pulley 424 ( FIG. 20 ) and its ends connected to respective ones of the laterally spaced cable hook corners 404 .
- the lower tension wire 420 is connected to a lower counter-weight drive assembly 426 ( FIG. 20 ).
- the upper tension wire 422 is connected to an upper counter-weight drive assembly 428 on which the upper drive pulley 424 is mounted.
- the lower tension wire 420 passes through large rectangular apertures 430 ( FIG. 18 ) on opposite sides of the lower portion of the support post 418 .
- the upper tension wire 422 passes through large rectangular apertures 432 formed on opposite sides of the upper portion of the support post 418 , and spaced ninety degrees from the apertures 430 .
- the intermediate segment of the lower tension wire is wrapped around a lower drive pulley 434 ( FIG. 20 ) mounted on the lower counter-weight drive assembly 426 .
- the lower counter-weight drive assembly 426 includes a lower micro-motor 436 ( FIG. 20 ), a lower rotation restraint mechanism 438 , a shaft connector 440 , and a lower worm gear drive 442 . These mechanisms allow the lower tension wire 420 to be driven by the lower drive pulley 434 to pivot the mirror 402 about a horizontal axis. Similar mechanisms in the upper counter-weight drive assembly 428 allow the upper drive pulley 424 to drive the upper tension wire back and forth to pivot the mirror 402 about a tilted (off vertical) axis.
- the lower counter-weight drive assembly 426 includes a cylindrical drive mount 444 ( FIG. 20 ) and a ring-shaped counter-weight 446 .
- the cylindrical drive mount 444 has oval apertures 448 ( FIG. 14 ) formed on opposite sides thereof to allow ingress and egress of the lower tension wire 420 .
- the lower and upper counter-weight drive assemblies 426 and 428 are capable of reciprocal vertical motion within the bore of the support post 418 .
- a control circuit (not illustrated) receives input from a MEMS accelerometer as previously described and causes the micro-motors of the lower and upper counter-weight drive assemblies 426 and 428 to move the mirror 402 into the optimum position for reflecting solar radiation onto a target (not illustrated in FIGS. 14-20 ), such as a photovoltaic array, heat exchanger, etc.
- a heliostat mirror ( 1000 ) is supported by a vertical tubular support ( 1002 ).
- a motorized tilt mechanism (not shown) provides rotation around an approximately horizontal axis ( 1004 ) for tracking solar elevation.
- a second motorized rotation mechanism (not shown) provides rotation around an approximately vertical axis ( 1006 ) for tracking the sun ( 1018 ) in azimuth across the sky.
- the mirror need not be flat but might have some curvature in one or more directions to allow the solar energy to be brought to a tight focus.
- a sensor and control package ( 1008 ) can be mounted anywhere on the mirror or the supporting structure. Preferably, all the sensors and controls are integrated into a single package to reduce cost and the need for interconnecting cables.
- the sensor and control package needs to be mounted so that it is subject to both tilt and rotation during mirror positioning.
- One or more magnetic sensors 1010 are used to sense the earth's magnetic field ( 1012 ) to determine rotational position around an approximately vertical axis.
- One or more accelerometers included in the sensor package 1008 are used to sense the gravity vector ( 1014 ) and determine rotational position around an approximately horizontal tilt axis 1004 .
- the magnetic sensor may be a three-axis magnetic field sensor which provides x, y, and z data in response to measurement of the earth's magnetic field.
- a separate sensor such as the Honeywell HMC5843 available from Honeywell International Inc., 101 Columbia Road, Morristown, N.J. 07962 or the AK8973S available from Asahi Kasei Microsystems (AKM Semiconductor) at 1731 Technology Drive, San Jose, Calif. 95110, are examples which would serve.
- a combined integrated circuit including both three-axis accelerometer and three-axis compass such as the AMI602 6-axis motion sensor which incorporates 3-axis magnetometer and 3-axis accelerometer (available from Aichi Steel Corporation at 1 Wano-wari, Arao-machi, Tokai-shi, Aichi-ken, 476-8666 Japan) or the STMicroelectronics LSM303DLH geomagnetic module combining magnetic-field and linear-acceleration sensing would serve.
- a combined sensor unit is used, separate magnetic sensors 1010 are dispensed with as both the gravitic vector 1014 and the magnetic vector 1012 are measured by the combined unit.
- the sensor and control package can be mounted behind an uncoated transparent section of glass mirror.
- Optical sensors to determine the position of the sun can be integrated into the sensor and control package.
- the same suite of optical sensors can further be used to determine the relative position of the solar energy target.
- Various means of building optical sensors to sense light direction are known in the art.
- photovoltaic cells can be integrated into the sensor and control package or optionally mounted in an adjacent fashion ( 1011 ). Batteries or capacitors can be used to store the energy from the photovoltaic cells to provide power to operate both motorized rotation axes. Alternatively wired power (not shown) can be used.
- a wireless link ( 1016 ) or a wired link (not shown) can be used to remotely control each mirror and exchange data between each mirror's control system and a centralized control facility. If a wireless link is employed, a mesh networking topology is preferably used to allow data and control signals to be communicated across a heliostat array of large area extent. A large heliostat array might be usefully employed to produce hydrogen fuel by photo-catalytic means.
- Control signals from the mirror control system to each motorized rotation axis might be by wireless means. For lowest possible cost and long terms reliability it is desirable to reduce the number of cables, wires, and connectors as possible. Power to run the axis rotation motors may be provided by a hardwired means while control might be provided by wireless means. Rotation motors may alternatively each have their own small photovoltaic panel and energy storage means.
- FIG. 22 illustrates a block diagram of the control system for the embodiment of FIG. 21 .
- a controller block ( 2216 ) receives data from magnetic sensors ( 2200 ) which sense rotation around an approximately vertical axis and acceleration sensors ( 2202 ) to sense tilt around an approximately horizontal axis to provide signals indicative of heliostat mirror position.
- photo sensors ( 2204 ) may be used to establish the position of the heliostat relative to the sun, or to a target with an optical beacon.
- the option of using photovoltaics to power the system is illustrated including photovoltaic cells ( 2218 ), a power-conditioning block ( 2220 ), and a power storage unit ( 2222 ) which in turn communicates and supplies power to the controller block ( 2216 ).
- the controller block ( 2216 ) is illustrated with a communication link via a ZigBee module ( 2214 ) which in turn is in communication with a mesh network ( 2224 ) allowing coordination of the local system with a remote solar array controller ( 2226 ).
- the dashed line represents an alternative energy source ( 2230 ) by usual wired connection to the energy grid, a local generator, or other energy supply.
- An optional wireless link ( 2232 ) is also shown for data relay between the controller block and the motor control electronics if separate power is available.
- FIG. 23 illustrates a detailed block diagram of exemplary components of magnetic sensors and accelerometers and their relationship to the axis motors of an embodiment similar to FIG. 21 .
- an integrated circuit system 2314 contains both magnetic sensors and accelerometers and their appropriate circuitry.
- the integrated circuit 2314 is an AMI602 6-axis sensor with integrated amplifier, 12-bit analog-digital converter and an 8032 microprocessor controlling the circuits of the integrated circuit 2314 .
- Three sensors measure values for magnetic orientation relative to the earth's magnetic field on an X axis 2318 , a Y axis 2320 , and a Z axis 2320 .
- Three accelerometer sensors measure acceleration at the same time along the X axis 2324 , Y axis 2326 , and Z axis 2328 . These sensor signals are processed through a converter into digital data transmitted to a microcontroller 2310 .
- the microcontroller 2310 is a 64-pin PIC 18F6722 available from Microchip Technology Inc., 2355 West Chandler Blvd., Chandler, Ariz., USA 85224-6199.
- the microcontroller 2310 communicates with the AMI602 integrated circuit 2314 through a standard I 2 C bus 2323 .
- a real-time clock chip 2316 also communicates with the microcontroller 2310 on the I 2 C bus 2323 .
- the real-time clock chip 2316 is a DS 1340 C with built-in calendar and clock, available from Maxim/Dallas Semiconductor, at Maxim Integrated Products, Inc., 120 San Gabriel Drive, Sunnyvale, Calif. 94086.
- the microcontroller 2310 also receives digital GPS time base information from an optional GPS/time base receiver 2312 ; alternatively it may receive data streams from an onboard clock 2316 and perform look-up operations using an on-board or remote data lookup table.
- An optional ZigBee communication module 2319 and the optional GPS/time base receiver 2312 communicate to the microcontroller 2310 by means of an on-board universal synchronous/asynchronous receiver/transmitter, or USART 2321 .
- the microcontroller 2310 is capable of sending pulse-width modulated data on two output pins, P 3 A and P 3 D, shown in FIG. 23 as a combined PWM port 2325 . Motor control commands are transmitted by means of the PWM port 2325 to a first axis motor 2327 controlling the horizontal axis of the solar collector, and a second axis motor 2329 controlling the vertical axis thereof.
- FIG. 24 is a flow chart of the control logic.
- the microprocessor may derive delta values for each axis to align the mirror 1000 ( FIG. 21 ) with the sun 1018 ( FIG. 21 ). These delta values are in turn used to compute motor commands to drive the horizontal axis motor 2326 and the vertical axis motor 2334 in FIG. 23 .
- the control cycle begins with a step 2402 of getting the real-time clock value and a following step 2404 of looking up the sun's real-time position and translating to azimuth and elevation values.
- a test step 2406 is done to determine whether the sun is over the horizon or not; if it is not, the mirrors are parked (step 2408 ) and a sleep timer is initiated (step 2410 ).
- the system is placed in a sleep state 2412 until such time as a sleep timer interrupt 2401 occurs.
- the sleep timer interrupt may be caused by passage of a specified period, or by an external signal, or a pre-defined clock moment, or by a photo-sensor trigger event, for example. If test step 2406 determines the sun is over the horizon, the system must then get the zero baseline value for the accelerometers (step 2414 ) and their current values (step 2416 ).
- Step 2418 it gets baseline values for the magnetic sensors (step 2418 ) on three axes, and their current values (step 2420 ). Based on these values the system computes current azimuth and elevation in Step 2422 , and compares them to the required azimuth and elevation in step 2424 . A test is then done in Step 2426 to determine whether the delta between the required azimuth and elevation and their present values is below a pre-defined tolerance threshold. If the delta is within tolerable limits the motors are halted (step 2428 ) and the sleep timer initiation step 2410 is executed.
- Step 2430 the system must then compute the amount of change required in azimuth and elevation (step 2430 ) and translate that change into a change for the horizontal axis and the vertical axis (step 2432 ). These values must in turn be translated into motor control values in Step 2434 resulting in motor control transmissions sent to the first axis motor 2326 ( FIG. 23 ) and the second axis motor 2328 ( FIG. 23 ) in Step 2436 .
Abstract
A mirror or other reflecting surface is used for collecting and reflecting incident solar radiation. The mirror is supported for independent motion about a pair of axes. An accelerometer generates signals representative of an amount and direction of motion of the mirror about each of the axes. Motors or other drive mechanisms independently drive the mirror about each of the axes. A tracking device provides information about the current position of the Sun. A control is connected to the accelerometer, the motors and the tracking device for maintaining a predetermined optimum orientation of the mirror as the Sun moves across the sky. Position sensors that sense the position of the mirror relative to the earth's magnetic field may also be employed.
Description
- This application is a Continuation-in-Part of U.S. application Ser. No. 11/763,267 of Mark S. Olsson, filed Jun. 14, 2007.
- This application also claims benefit under 35 USC Sections 119(e) and 120 to the filing date of U.S. Provisional Application Ser. No. 60/807,456 filed by Mark S. Olsson on Jul. 14, 2006.
- The present invention relates to systems and methods for utilizing the energy of the Sun, and more particularly, to systems and methods for tracking the Sun to re-direct and concentrate incident solar radiation for lighting, heating and photovoltaic applications.
- Increased usage of renewable energy sources such as solar radiation is important in reducing dependence upon foreign sources of oil and decreasing green house gases. Devices have been developed in the past that track the motion of the Sun to re-direct and concentrate incident solar radiation.
FIG. 1 illustrates one example of a prior art device that utilizes aparabolic dish mirror 10 with acentral axis 12 that is pointed generally toward the Sun 14. Incidentsolar radiation 22 is received and reflected by theparabolic dish mirror 10 and concentrated at itsfocus 16, where a thermal target (not illustrated) can be mounted so that it can be heated. Theparabolic dish mirror 10 is supported for independent movement by a two-axis tracking support 18 mounted atop a supportingstructure 20 such as a tower. Optical encoders (not illustrated) associated with thetracking support 18 provide signals indicative of the direction and amount of rotation of theparabolic dish mirror 10 so that motor drives and a control system (not illustrated) can be used to track the Sun and increase the efficiency of the energy transfer. -
FIG. 2 illustrates another example of a prior art device similar to the device ofFIG. 1 except that the device ofFIG. 2 utilizes aparabolic trough mirror 30. Dashedline 32 illustrates a common plane of thefocal line 36 of theparabolic trough mirror 30 and the Sun 14. A singleaxis tracking support 38 carries theparabolic trough mirror 30 and is mounted atop atower 40. Incident light rays from the Sun such as 42 are collected and reflected by theparabolic trough mirror 30 and concentrated on a pipe (not illustrated) that extends along thefocal line 36. This allows a heat transfer fluid such as water or liquid sodium to be heated. The heating efficiency can be improved by mechanisms (not illustrated) that cause theparabolic trough mirror 30 to pivot and track the Sun.FIG. 3 illustrates another prior art device that utilizes a heliostatflat mirror 50 that receivesincident light rays 52 from the Sun 14 and reflects them against athermal target 58 atop atower 59. Anothertower 54 carries a two-axis tracking support 56 which supports aflat mirror 50. Drive and control mechanisms (not illustrated) allow theflat mirror 50 to be independently moved about a rotate axis 60 (azimuth) and about a tilt axis 62 (elevation) to ensure that the Sun's rays are reflected onto thetarget 58 as the Sun moves across the sky. There are many variations of the foregoing devices, but to date, none has been widely adopted due to the complexity, reliability, accuracy and/or expense of the tracking mechanisms. - In accordance with the present invention a solar tracking apparatus has a mirror or other reflecting surface for collecting and reflecting incident solar radiation. The mirror is supported for independent motion about a pair of axes. An accelerometer generates signals representative of an amount and direction of motion of the mirror about each of the axes. Motors or other drive mechanisms independently drive the mirror about each of the axes. A tracking device provides information about the current position of the Sun. A control is connected to the accelerometer, the motors and the tracking device for maintaining a predetermined optimum orientation of the mirror as the Sun moves across the sky.
- According to another aspect of the present invention, one or more magnetic field sensors are used to sense rotation around an approximately vertical axis and one or more accelerometers are used to sense tilt around an approximately horizontal axis to provide signals indicative of heliostat mirror position in a coordinate system to a control system. The control system allows for precise positioning of a heliostat mirror and the directing of solar energy in a desired direction.
- According to another aspect of the present invention, three orthogonal magnetic field sensors are used to sense rotation around an approximately vertical axis and three orthogonal accelerometers are used to sense tilt around an approximately horizontal axis to provide signals indicative of heliostat mirror position in a coordinate system to a control system. The control system allows for precise positioning of a heliostat mirror and the directing solar energy in a desired direction.
-
FIGS. 1-3 illustrate examples of prior art solar radiation collecting and redirecting devices. -
FIG. 4 illustrates a first embodiment of the present invention that utilizes a flat mirror to heat a target. -
FIG. 5 illustrates a second embodiment of the present invention that utilizes an array of mirrors to reflect solar radiation through a skylight. -
FIG. 6 illustrates an alternate embodiment wherein an array of flat tracking mirrors reflects incident solar radiation through the windows of a house to provide light and heat. -
FIG. 7 illustrates another embodiment that utilizes an array of heliostat mirrors to heat a thermal target. -
FIG. 8 illustrates another embodiment that utilizes a plurality of heliostat mirrors to reflect solar radiation onto a high temperature photovoltaic panel. -
FIG. 9 is a block diagram of another embodiment in which a network controller controls a plurality of mirror nodes. -
FIG. 10 illustrates another embodiment in which a heliostat mirror is positioned to reflect incident solar radiation onto a target via a vertical array of photo-sensors. -
FIG. 11 is a block diagram illustrating one embodiment of the mirror controller network node of the embodiment ofFIG. 4 . -
FIG. 12 is a flow diagram illustrating one embodiment of a method of operation of the control ofFIG. 11 . -
FIG. 13 is a flow diagram of another embodiment of a method of operation of asolar tracking 20 device in accordance with the present invention. -
FIG. 14 is a front isometric view of another embodiment that utilizes a weight-tensioned device to pivot the mirror. -
FIG. 15 is a back isometric view of the embodiment illustrated inFIG. 14 . -
FIG. 16 is a front elevation view of the embodiment illustrated inFIG. 14 . -
FIG. 17 is a back elevation view of the embodiment illustrated inFIG. 14 . -
FIG. 18 is a side elevation view of the embodiment illustrated inFIG. 14 . -
FIG. 19 is an exploded back isometric view of the embodiment illustrated inFIG. 14 . -
FIG. 20 is a vertical sectional view (stepped cut) of the embodiment illustrated inFIG. 14 showing internal components thereof. -
FIG. 21 illustrates another embodiment that employs magnetic sensors and accelerometers. -
FIG. 22 is a block diagram of the control system of the embodiment ofFIG. 21 . -
FIG. 23 is a block diagram of control circuitry. -
FIG. 24 is a flow chart of data integration of magnetic sensor and accelerometer data and their resolution. - The entire disclosure of U.S. patent application Ser. No. 11/763,267 of Mark S. Olsson, filed Jun. 14, 2007, and published Jan. 17, 2008 as US-2008-0011288-A1 is hereby incorporated by reference.
-
FIG. 4 illustrates a first embodiment of the present invention that utilizes a flat mirror to heat a target. A solar tracking apparatus has a reflective surface in the form of amirror 70 for collecting and reflecting incidentsolar radiation 82 from the Sun 14. The mirror in this embodiment has a planar configuration, although this embodiment could be adapted to use other mirror configurations including parabolic dish, parabolic trough, etc. in order to concentrate the incident solar radiation. The mirror could be conventional silver coated glass, or could be plastic, or could be Mylar® polyester film on a support substrate, or some other form of reflective material that is durable, lightweight and inexpensive. - The mirror 70 (
FIG. 4 ) is supported by a pair ofpivot mechanisms 72 for independent motion about a pair of tilt axes 88 and 90. Thepivot mechanisms 72 are mounted atop a support ortower 76. Anaccelerometer 74 generates signals representative of an amount and direction of motion of the mirror about each of theaxes mirror 70. Electric motors 78 (only one of two illustrated) independently drive themirror 70 about each of the axes utilizing, for example, aworm gear 80 and acircular rack gear 81. A mirrorcontroller network node 86 includes a tracking device, typically an electronic processor, that provides information about the current position of theSun 14. The mirrorcontroller network node 86 also includes a control that is connected to theaccelerometer 74, themotors 78 and the tracking device for maintaining a predetermined optimum orientation of the mirror as the Sun moves across the sky. The architecture and method of operation of the mirrorcontroller network node 86 are discussed hereafter in greater detail. Incident solar radiation with an angle ofincidence 96 is reflected off the surface of themirror 70 at an angle ofreflection 94 so that it strikes athermal target 84 such as a container or conduit of a heat transfer fluid or an array of photovoltaic cells. - The accelerometer 74 (
FIG. 4 ) is preferably a micro-electro-mechanical systems (MEMS) accelerometer device. Utilizing micro-fabrication techniques a position sensor component and signal conditioning circuit can be fabricated on a single integrated circuit chip. Such MEMS accelerometer devices are relatively inexpensive, durable and sufficiently accurate for purposes of manufacturing commercial embodiments of the present invention. Suitable MEMS accelerometer devices are the KXM52-1040 dual-axis (XY) MEMS accelerometer device and the KXM52-1 050 tri-axis (XYZ) MEMS accelerometer device, both of which are commercially available from Kionix, Inc., 36 20 Thronwood Drive, Ithica, N.Y. 14850 USA. See U.S. Pat. Nos. 6,149,190 granted Nov. 21, 2000 to Galvin et al. and 6,792,804 granted Sep. 21, 2004 to Adams et al., both of which are assigned to Kionix, Inc., the entire disclosures of which are hereby incorporated by reference. Also suitable are the ADXL321 (two-axis) and ADXL330 (three-axis) MEMS accelerometer devices, both of which are commercially available from Analog Devices, Inc., One 25 Technology Way, Norwood, Mass. 02062 USA. See U.S. Pat. Nos. 6,837,107 granted Jan. 4, 2005 to Green and 6,845,665 granted Jan. 25, 2005 also to Green, both of which are assigned to Analog Devices, Inc., the entire disclosures of which are hereby incorporated by reference. - While it is possible over certain rotational limits, with appropriate calibration and alignment to use single axis sensors, it is desirable to use three axis sensors for both magnetic field and gravity. It is anticipated with ongoing reductions in the cost of sensors and greater system integration that three axis sensors will be widely available at low cost. For example, an Aichi Steel Corporation, Electro-Magnetic Products, AMI601 sensor would be suitable for this application. See http://www.aichi-mi.com/3_products/ami%20catalogue%20e.pdf.
- The AMI602, which would also serve in this application, is also from Aichi and is a 6-axis motion sensor which incorporates 3-axis magnetometer and 3-axis accelerometer. The controller IC of the AMI602 consists of a circuit for sensor elements, an amplifier capable of compensating each sensors offset and setting appropriate sensitivity values, a temperature sensor, a 12 bitAD converter, an PC serial output circuit, a constant voltage circuit for power control and an 8032 micro-processor controlling each circuit.
- Again referring to
FIG. 4 , thepivot mechanisms 72 are configured and arranged so that throughout the useful range of tracking tilts, theaccelerometer 74 is not rotated in an unknown fashion about a vertical axis. If the accelerometer is rotated about a vertical axis, the pointing direction of themirror 70 becomes ambiguous or indeterminate. The addition of a magnetic sensor in an alternate embodiment avoids this problem, as discussed later. Modern compass MEMS devices which combine accelerometers with magnetic compass sensors are known in the art, and allow the array to be corrected for tilt, and such a device could be used in place of theaccelerometer 74. - It will be understood that a wide variation of modifications of the embodiment illustrated in
FIG. 4 are possible. For example, theaccelerometer 74 need not be directly mounted to the mirror but could be coupled thereto through a mechanical or optical linkage. Thepivot mechanisms 72 could be replaced with an alternate pivot mechanism such as a ball and socket or flexible joint, instead of those employing independently movable mechanical pivots. Thus themirror 70 need not strictly rotate about two axes, as is the case with the embodiment ofFIG. 4 wherein rotation of themirror 70 about one axis rotates the other axis. It will be appreciated that it is not necessary that both axes of tilt are substantially in the same horizontal plane when themirror 70 is in a normal or horizontal orientation. Other forms of motor means for driving themirror 70 can be employed besides theelectric motor 78 and gears 80 and 81, such as hydraulic and pneumatic systems. Themirror 70 need not move in azimuth and elevation, it being sufficient that it be capable of independent movement about two non-parallel axes. -
FIG. 5 illustrates a second embodiment of the present invention that utilizes anarray 104 ofindividual mirrors 106 to reflectsolar radiation 110 through askylight 102 on the roof of abuilding 100 to provide internal lighting. This greatly increases the amount of solar radiation otherwise directly entering the interior of the building through theskylight 102 as illustrated by incident light rays 108. Themirrors 106 may each be independently supported and moved as illustrated inFIG. 4 or they may be simultaneously supported and moved by a common tracking system so that reflected light 114 strikes a fixedangle target mirror 112 and is reflected as downwardly projected light 116. Theskylight 102 may be of the type sold under the SOLATUBE® trademark which employs a conduit with a highly reflective surface. Optionally ahot mirror 118 may be inserted in to the reflected light transmission path to reflect away the infrared component during the summer to avoid unwanted heating of the interior of thebuilding 100. -
FIG. 6 illustrates an alternate embodiment wherein anarray 144 of flat tracking mirrors 142 reflect incidentsolar radiation 146 as reflectedradiation 148 that passes through thewindow 140 of a house to provide light and heat. Again themirrors 142 are supported and moved in the fashion described in connection withFIG. 4 . -
FIG. 7 illustrates another embodiment that utilizes anarray 170 of heliostat mirrors 168 to heat athermal target 162. The amount of incidentsolar radiation 164 that is redirected as reflectedsolar radiation 166 is maximized by mounting anaccelerometer 160 on eachheliostat mirror 168 and using its signals, along with tracking information to tilt eachmirror 168 about its two-axis tilting support 172. -
FIG. 8 illustrates another embodiment that utilizes a plurality of heliostat mirrors 206 equipped as described in connection withFIG. 4 in order to re-direct a maximum amount of incidentsolar radiation 202 as reflectedradiation 204 onto a high temperaturephotovoltaic panel 200. -
FIG. 9 is a block diagram of another embodiment in which a network controller 222 controls a plurality of mirror nodes 220. The network controller 222 may be connected to the mirror nodes 220 by a network link 226 which may be wired or wireless, fiber optic, laser or any other well known data communications scheme. One example is the ZIGBEE™ data link. Bluetooth links or other wireless means could be used as well according to the scale of the application. An optional mirror node training interface 224 is provided that can be used to load the network controller 222 with tracking data from local or remote sources that give the predicted location of the Sun throughout the day for a given latitude, longitude, date and time. This information is used by the controller to compare the actual position of the mirrors with their optimum positions so that they can be moved to maximize the collection and/or concentration of solar radiation. Alternatively this information may be preprogrammed into the network controller 222 or the mirror controller network node 86 (FIG. 4 ). - The present invention differs from conventional heliostats that require a vertical tracking axis. In the present invention, the Sun is tracked in both azimuth and elevation, however, tracking is required in both axes as neither component is separately derived.
-
FIG. 10 illustrates another embodiment in which aheliostat mirror 246 is positioned to re-direct incidentsolar radiation 250 as reflectedsolar radiation 252 to strike atarget 248 utilizing mechanisms similar to those described in connection withFIG. 4 . A vertical array of photo-sensors 240 detect reflectedradiation 252 and their signals are used to position themirror 246 so that the reflected radiation will strike thetarget 248. ASun hood 254 may be used with each photo-sensor 240 to prevent it from detecting significant amounts of incidentsolar radiation 250. The spacing 242 between the photo-sensors 240 can be optimized relative to thedimension 244 of themirror 246. -
FIG. 11 is a block diagram illustrating one embodiment of mirrorcontroller network node 86 of the embodiment ofFIG. 4 . A PIC micro-computer basedcontrol 300 provides the basic intelligence and control through appropriate input/output interfaces. Position information is received from theaccelerometer 302. First andsecond axis motors other power source 310 such as solar or battery power provides power to thecontrol 300. In order for the mirror to be optimally pointed, it is necessary for thecontrol 300 to compare the actual position of the mirror to the current position of the Sun and make the appropriate adjustments. Data regarding the predicted location of the Sun is pre-programmed into thecontrol 300, in which case a user interface (not illustrated) is necessary for a user to enter the correct latitude, longitude, date and time during initial set up. This interface could be a keypad or a connection to a PC or PDA, for example. Optionally, a Global Positioning System (GPS) andtime base receiver 312 may be connected to thecontrol 300 to provide this information. A wired orwireless network link 308 connects the control to a remote location for monitoring or control. -
FIG. 12 is a flow diagram illustrating one embodiment of a method of operation of the control ofFIG. 11 . Initially instep 314 the starting parameters are acquired, including latitude and longitude, time, tilt axis orientation to the North, and the estimated azimuth and elevation of the mirror. Latitude, longitude and time can be obtained via the network. Instep 316 the processor calculates the position of the Sun. Instep 318, using signals from the accelerometer, and data from a look up table, the control calculates the movement of the mirror about each axis necessary to achieve the optimum orientation. Instep 320, the motors are driven by the control the move the mirror as needed to obtain the optimum orientation. If the accelerometer signals do not indicate mirror motion, an ERROR message is generated and transmitted and/or displayed. Instep 322, the control continues to track the Sun in order to engage the target. -
FIG. 13 is a flow diagram of another embodiment of a method of operation of a solar tracking device in accordance with the present invention. -
FIGS. 14-20 illustrate another embodiment of the present invention that utilizes weight-tensioned mechanisms to pivot the mirror. Theembodiment 400 includes a planarsquare mirror 402 whose corners are supported by fourcable hook corners 404. A small yoke 406 (FIGS. 15 and 19 ) has a square surface which is secured to the center of the rear side of themirror 402 by suitable adhesive.Small yoke 406 is connected for independent rotation about two axes to atall yoke 408 by across piece 410. The base of thetall yoke 408 is secured byscrews 412 and nuts 414 (FIG. 19 ) to acylindrical cap plate 416. Thecylindrical cap plate 416 is mounted on the upper end of a support structure in the form of a hollowvertical support post 418. - A lower tension wire 420 (
FIG. 18 ) has one end connected to the uppermostcable hook corner 404 and its other end connected to the lowermostcable hook corner 404. An upper tension wire 422 (FIGS. 18 and 19 ) has an intermediate segment wrapped around an upper drive pulley 424 (FIG. 20 ) and its ends connected to respective ones of the laterally spacedcable hook corners 404. Thelower tension wire 420 is connected to a lower counter-weight drive assembly 426 (FIG. 20 ). Theupper tension wire 422 is connected to an uppercounter-weight drive assembly 428 on which theupper drive pulley 424 is mounted. Thelower tension wire 420 passes through large rectangular apertures 430 (FIG. 18 ) on opposite sides of the lower portion of thesupport post 418. Theupper tension wire 422 passes through largerectangular apertures 432 formed on opposite sides of the upper portion of thesupport post 418, and spaced ninety degrees from theapertures 430. The intermediate segment of the lower tension wire is wrapped around a lower drive pulley 434 (FIG. 20 ) mounted on the lowercounter-weight drive assembly 426. - Each of the
counter-weight drive assemblies 426 and 428 (FIG. 19 ) has a similar construction, and therefore, only one need be described. The lowercounter-weight drive assembly 426 includes a lower micro-motor 436 (FIG. 20 ), a lowerrotation restraint mechanism 438, ashaft connector 440, and a lowerworm gear drive 442. These mechanisms allow thelower tension wire 420 to be driven by thelower drive pulley 434 to pivot themirror 402 about a horizontal axis. Similar mechanisms in the uppercounter-weight drive assembly 428 allow theupper drive pulley 424 to drive the upper tension wire back and forth to pivot themirror 402 about a tilted (off vertical) axis. The lowercounter-weight drive assembly 426 includes a cylindrical drive mount 444 (FIG. 20 ) and a ring-shapedcounter-weight 446. Thecylindrical drive mount 444 has oval apertures 448 (FIG. 14 ) formed on opposite sides thereof to allow ingress and egress of thelower tension wire 420. - The lower and upper
counter-weight drive assemblies support post 418. A control circuit (not illustrated) receives input from a MEMS accelerometer as previously described and causes the micro-motors of the lower and uppercounter-weight drive assemblies mirror 402 into the optimum position for reflecting solar radiation onto a target (not illustrated inFIGS. 14-20 ), such as a photovoltaic array, heat exchanger, etc. - Referring now to
FIG. 21 , a heliostat mirror (1000) is supported by a vertical tubular support (1002). A motorized tilt mechanism (not shown) provides rotation around an approximately horizontal axis (1004) for tracking solar elevation. A second motorized rotation mechanism (not shown) provides rotation around an approximately vertical axis (1006) for tracking the sun (1018) in azimuth across the sky. The mirror need not be flat but might have some curvature in one or more directions to allow the solar energy to be brought to a tight focus. A sensor and control package (1008) can be mounted anywhere on the mirror or the supporting structure. Preferably, all the sensors and controls are integrated into a single package to reduce cost and the need for interconnecting cables. In this case, the sensor and control package needs to be mounted so that it is subject to both tilt and rotation during mirror positioning. One or moremagnetic sensors 1010 are used to sense the earth's magnetic field (1012) to determine rotational position around an approximately vertical axis. One or more accelerometers included in thesensor package 1008 are used to sense the gravity vector (1014) and determine rotational position around an approximatelyhorizontal tilt axis 1004. The magnetic sensor may be a three-axis magnetic field sensor which provides x, y, and z data in response to measurement of the earth's magnetic field. - A separate sensor such as the Honeywell HMC5843 available from Honeywell International Inc., 101 Columbia Road, Morristown, N.J. 07962 or the AK8973S available from Asahi Kasei Microsystems (AKM Semiconductor) at 1731 Technology Drive, San Jose, Calif. 95110, are examples which would serve. Alternatively a combined integrated circuit including both three-axis accelerometer and three-axis compass, such as the AMI602 6-axis motion sensor which incorporates 3-axis magnetometer and 3-axis accelerometer (available from Aichi Steel Corporation at 1 Wano-wari, Arao-machi, Tokai-shi, Aichi-ken, 476-8666 Japan) or the STMicroelectronics LSM303DLH geomagnetic module combining magnetic-field and linear-acceleration sensing would serve. Where a combined sensor unit is used, separate
magnetic sensors 1010 are dispensed with as both thegravitic vector 1014 and themagnetic vector 1012 are measured by the combined unit. - For maximum durability, the sensor and control package can be mounted behind an uncoated transparent section of glass mirror. Optical sensors to determine the position of the sun can be integrated into the sensor and control package. The same suite of optical sensors can further be used to determine the relative position of the solar energy target. Various means of building optical sensors to sense light direction are known in the art. Optionally, photovoltaic cells can be integrated into the sensor and control package or optionally mounted in an adjacent fashion (1011). Batteries or capacitors can be used to store the energy from the photovoltaic cells to provide power to operate both motorized rotation axes. Alternatively wired power (not shown) can be used. A wireless link (1016) or a wired link (not shown) can be used to remotely control each mirror and exchange data between each mirror's control system and a centralized control facility. If a wireless link is employed, a mesh networking topology is preferably used to allow data and control signals to be communicated across a heliostat array of large area extent. A large heliostat array might be usefully employed to produce hydrogen fuel by photo-catalytic means.
- Control signals from the mirror control system to each motorized rotation axis might be by wireless means. For lowest possible cost and long terms reliability it is desirable to reduce the number of cables, wires, and connectors as possible. Power to run the axis rotation motors may be provided by a hardwired means while control might be provided by wireless means. Rotation motors may alternatively each have their own small photovoltaic panel and energy storage means.
-
FIG. 22 illustrates a block diagram of the control system for the embodiment ofFIG. 21 . InFIG. 22 , a controller block (2216) receives data from magnetic sensors (2200) which sense rotation around an approximately vertical axis and acceleration sensors (2202) to sense tilt around an approximately horizontal axis to provide signals indicative of heliostat mirror position. Optionally, photo sensors (2204) may be used to establish the position of the heliostat relative to the sun, or to a target with an optical beacon. InFIG. 22 , the option of using photovoltaics to power the system is illustrated including photovoltaic cells (2218), a power-conditioning block (2220), and a power storage unit (2222) which in turn communicates and supplies power to the controller block (2216). Further, inFIG. 22 , the controller block (2216) is illustrated with a communication link via a ZigBee module (2214) which in turn is in communication with a mesh network (2224) allowing coordination of the local system with a remote solar array controller (2226). The dashed line represents an alternative energy source (2230) by usual wired connection to the energy grid, a local generator, or other energy supply. The controller block (2216), by means of emitted control signals, governs the activation of a motor drive (2208) which in turn controls two axes, one approximately vertical (2210) and one approximately horizontal (2212). An optional wireless link (2232) is also shown for data relay between the controller block and the motor control electronics if separate power is available. -
FIG. 23 illustrates a detailed block diagram of exemplary components of magnetic sensors and accelerometers and their relationship to the axis motors of an embodiment similar toFIG. 21 . InFIG. 23 anintegrated circuit system 2314 contains both magnetic sensors and accelerometers and their appropriate circuitry. InFIG. 23 theintegrated circuit 2314 is an AMI602 6-axis sensor with integrated amplifier, 12-bit analog-digital converter and an 8032 microprocessor controlling the circuits of theintegrated circuit 2314. - Three sensors measure values for magnetic orientation relative to the earth's magnetic field on an
X axis 2318, aY axis 2320, and aZ axis 2320. Three accelerometer sensors measure acceleration at the same time along theX axis 2324,Y axis 2326, andZ axis 2328. These sensor signals are processed through a converter into digital data transmitted to amicrocontroller 2310. InFIG. 23 , themicrocontroller 2310 is a 64-pin PIC 18F6722 available from Microchip Technology Inc., 2355 West Chandler Blvd., Chandler, Ariz., USA 85224-6199. Themicrocontroller 2310 communicates with the AMI602integrated circuit 2314 through a standard I2C bus 2323. A real-time clock chip 2316 also communicates with themicrocontroller 2310 on the I2C bus 2323. InFIG. 23 the real-time clock chip 2316 is a DS 1340C with built-in calendar and clock, available from Maxim/Dallas Semiconductor, at Maxim Integrated Products, Inc., 120 San Gabriel Drive, Sunnyvale, Calif. 94086. - The
microcontroller 2310 also receives digital GPS time base information from an optional GPS/time base receiver 2312; alternatively it may receive data streams from anonboard clock 2316 and perform look-up operations using an on-board or remote data lookup table. An optionalZigBee communication module 2319 and the optional GPS/time base receiver 2312 communicate to themicrocontroller 2310 by means of an on-board universal synchronous/asynchronous receiver/transmitter, orUSART 2321. Themicrocontroller 2310 is capable of sending pulse-width modulated data on two output pins, P3A and P3D, shown inFIG. 23 as a combinedPWM port 2325. Motor control commands are transmitted by means of thePWM port 2325 to afirst axis motor 2327 controlling the horizontal axis of the solar collector, and asecond axis motor 2329 controlling the vertical axis thereof. -
FIG. 24 is a flow chart of the control logic. By calculating the present orientation of the sun and the measured present orientation of the line-of-direction axis of the mirror such as 1000 inFIG. 21 , the microprocessor may derive delta values for each axis to align the mirror 1000 (FIG. 21 ) with the sun 1018 (FIG. 21 ). These delta values are in turn used to compute motor commands to drive thehorizontal axis motor 2326 and the vertical axis motor 2334 inFIG. 23 . InFIG. 24 the control cycle begins with astep 2402 of getting the real-time clock value and a followingstep 2404 of looking up the sun's real-time position and translating to azimuth and elevation values. Atest step 2406 is done to determine whether the sun is over the horizon or not; if it is not, the mirrors are parked (step 2408) and a sleep timer is initiated (step 2410). The system is placed in asleep state 2412 until such time as a sleep timer interrupt 2401 occurs. The sleep timer interrupt may be caused by passage of a specified period, or by an external signal, or a pre-defined clock moment, or by a photo-sensor trigger event, for example. Iftest step 2406 determines the sun is over the horizon, the system must then get the zero baseline value for the accelerometers (step 2414) and their current values (step 2416). Likewise, it gets baseline values for the magnetic sensors (step 2418) on three axes, and their current values (step 2420). Based on these values the system computes current azimuth and elevation inStep 2422, and compares them to the required azimuth and elevation instep 2424. A test is then done inStep 2426 to determine whether the delta between the required azimuth and elevation and their present values is below a pre-defined tolerance threshold. If the delta is within tolerable limits the motors are halted (step 2428) and the sleeptimer initiation step 2410 is executed. If the delta exceeds tolerable limits the system must then compute the amount of change required in azimuth and elevation (step 2430) and translate that change into a change for the horizontal axis and the vertical axis (step 2432). These values must in turn be translated into motor control values inStep 2434 resulting in motor control transmissions sent to the first axis motor 2326 (FIG. 23 ) and the second axis motor 2328 (FIG. 23 ) inStep 2436. - It will be clear to one skilled in the art that the use of other particular sensors and other configurations will also prove workable. The particular components described are mentioned as examples of different embodiments.
- While several preferred embodiments of the present invention have been described, and some variations thereof, further modifications will occur to those skilled in the art. For example, any of the embodiments described herein can utilize accelerometers alone, or accelerometers and magnetic sensors. Therefore the protection afforded the subject in invention should only be limited in accordance with the following claims.
Claims (35)
1. A solar tracking apparatus, comprising:
means for collecting and reflecting incident solar radiation;
means for supporting the solar radiation collecting and reflecting means for independent motion about a pair of axes; accelerometer means for generating signals representative of an amount and direction of motion of the solar radiation collecting and reflecting means about each of the axes;
motor means for independently driving the solar radiation collecting and reflecting means about each of the axes;
tracking means for providing information about the current position of the Sun; and
control means connected to the accelerometer means, the motor means and the tracking means for maintaining a predetermined optimum orientation of the solar radiation collecting and reflecting means as the Sun moves across the sky.
2. The solar tracking apparatus of claim 1 wherein the solar radiation collecting and reflecting means is configured for concentrating incident solar radiation.
3. The solar tracking apparatus of claim 1 wherein the accelerometer means is mounted on the solar radiation collecting and reflecting means.
4. The solar tracking apparatus of claim 1 wherein the support means includes a pair of pivot mechanisms.
5. The solar tracking apparatus of claim 1 wherein the accelerometer means includes a MEMS accelerometer device
6. The solar tracking apparatus of claim 1 wherein the motor means includes first and second electric motors and first and second drive linkages for coupling the electric motors, respectively, to the support means.
7. The solar tracking apparatus of claim 1 wherein the solar radiation collecting and reflecting means is supported so that both axes are substantially in the same horizontal plane when the solar radiation collecting and reflecting means is in a horizontal orientation.
8. The solar tracking apparatus of claim 7 wherein the solar radiation collecting and reflecting means is a mirror with a configuration selected from the group consisting of planar, parabolic and parabolic trough.
9. The solar tracking apparatus of claim 1 and further comprising means for sensing a reference position of the solar radiation collecting and reflecting means relative to the earth's magnetic field vector and for generating signals representative of the reference position and supplying them to the control means.
10. The solar tracking apparatus of claim 9 wherein the accelerometer means and the reference position sensing means are provided by three-axis sensors.
11. A heliostat mirror pointing system employing both accelerometer and magnetic sensors to determine mirror position relative to the earth's gravitational vector and the earth's magnetic field vector.
12. The heliostat mirror pointing system of claim 11 wherein one axis of rotation is approximately vertical.
13. The heliostat mirror pointing system of claim 11 wherein one axis of rotation is approximately horizontal.
14. The heliostat mirror pointing system of claim 11 wherein the magnetic sensor is used to sense rotation around said vertical axis.
15. The heliostat mirror pointing system of claim 11 wherein the accelerometer sensor is used to sense rotation around said horizontal axis.
16. The heliostat mirror pointing system employing 3-axis magnetic sensors to determine mirror position relative to the earth's magnetic field vector.
17. The heliostat mirror pointing system of claim 16 wherein one axis of rotation is approximately vertical.
18. The heliostat mirror pointing system of claim 16 wherein one axis of rotation is approximately horizontal.
19. The heliostat mirror pointing system of claim 16 wherein the magnetic sensor is used to sense rotation around horizontal and vertical axis.
20. A heliostat mirror control system employing both accelerometer and magnetic sensors to determine mirror position relative to the earth's gravitational vector and the earth's magnetic field vector.
21. The heliostat mirror control system of claim 20 wherein said control system is a member of a mesh network.
22. The heliostat mirror control system of claim 20 wherein said control system uses a wireless control means
23. The heliostat mirror control system of claim 20 wherein photovoltaic devices are used to provide power to said control system.
24. The heliostat mirror control system of claim 20 wherein photovoltaic devices are used to store energy in one or more capacitors to provide power for said control system.
25. The heliostat mirror control system of claim 20 wherein photovoltaic devices are used to store energy in one or more rechargeable batteries to provide power for said control system.
26. A solar tracking apparatus, comprising:
a reflective surface for collecting and reflecting incident solar radiation;
a pivot mechanism that supports the reflective surface for independent motion about a pair of axes;
an accelerometer that generates signals representative of an amount and direction of motion of the reflective surface about each of the axes;
at least one motor coupled to independently drive the reflective surface about each of the axes;
a data source that provides information about the current position of the Sun; and
a control circuit connected to the accelerometer, the motor and the data source for maintaining a predetermined optimum orientation of the reflecting surface as the Sun moves across the sky.
27. The solar tracking apparatus of claim 26 wherein the reflective surface is configured for concentrating incident solar radiation.
28. The solar tracking apparatus of claim 26 wherein the accelerometer is mounted on the reflective surface.
29. The solar tracking apparatus of claim 26 wherein the reflective surface is supported by a pair of pivot mechanisms.
30. The solar tracking apparatus of claim 26 wherein the accelerometer is a MEMS accelerometer device.
31. The solar tracking apparatus of claim 29 wherein the apparatus includes first and second electric motors and first and second drive linkages for coupling the electric motors to corresponding ones of the pair of pivot mechanisms.
32. The solar tracking apparatus of claim 26 wherein the reflective surface is supported so that both axes are substantially in the same horizontal plane when the reflective surface is in a horizontal orientation.
33. The solar tracking apparatus of claim 26 wherein the reflective surface is a mirror with a configuration selected from the group consisting of planar, parabolic and parabolic trough.
34. The solar tracking apparatus of claim 26 and further comprising means for sensing a reference position of the solar radiation collecting and reflecting means relative to the earth's magnetic field vector and for generating signals representative of the reference position and 4 supplying them to the control circuit.
35. The solar tracking apparatus of claim 34 wherein the accelerometer and the reference position sensing means are provided by three-axis sensors.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US12/901,289 US20110030672A1 (en) | 2006-07-14 | 2010-10-08 | Solar Collection Apparatus and Methods Using Accelerometers and Magnetics Sensors |
Applications Claiming Priority (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US80745606P | 2006-07-14 | 2006-07-14 | |
US11/763,267 US20080011288A1 (en) | 2006-07-14 | 2007-06-14 | Solar Collection Apparatus and Methods Using Accelerometers and Magnetic Sensors |
US12/901,289 US20110030672A1 (en) | 2006-07-14 | 2010-10-08 | Solar Collection Apparatus and Methods Using Accelerometers and Magnetics Sensors |
Related Parent Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US11/763,267 Continuation-In-Part US20080011288A1 (en) | 2006-07-14 | 2007-06-14 | Solar Collection Apparatus and Methods Using Accelerometers and Magnetic Sensors |
Publications (1)
Publication Number | Publication Date |
---|---|
US20110030672A1 true US20110030672A1 (en) | 2011-02-10 |
Family
ID=43533819
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US12/901,289 Abandoned US20110030672A1 (en) | 2006-07-14 | 2010-10-08 | Solar Collection Apparatus and Methods Using Accelerometers and Magnetics Sensors |
Country Status (1)
Country | Link |
---|---|
US (1) | US20110030672A1 (en) |
Cited By (22)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20100243032A1 (en) * | 2007-11-02 | 2010-09-30 | Nobuyoshi Mori | Sunlight Collecting System |
US20110108019A1 (en) * | 2008-08-18 | 2011-05-12 | Pratt & Whitney Rocketdyne., Inc. | Heliostat joint |
CN102628687A (en) * | 2012-04-28 | 2012-08-08 | 浙江海洋学院 | Ship horizontal attitude indicator |
EP2530744A3 (en) * | 2011-06-01 | 2013-04-24 | David Erz | Solar device with reflector device |
ES2422806R1 (en) * | 2012-03-12 | 2013-12-12 | Ingemetal En S A | SYSTEM, PROCEDURE AND INFORMATIC PROGRAM OF CALIBRATION OF THE POSITIONING OF MIRRORS IN HELIOSTATS |
CN103471265A (en) * | 2013-08-19 | 2013-12-25 | 高椿明 | Sunlight directional reflection control device based on time-sharing competition mechanism and control method thereof |
US20140123645A1 (en) * | 2012-11-02 | 2014-05-08 | Topper Sun Energy Technology Co., Ltd. | Pull control apparatus of solar tracking power generation mechanism |
EP2773911A1 (en) * | 2011-11-04 | 2014-09-10 | STN Super Travel Net Oy | Solar energy harvesting |
EP2905567A4 (en) * | 2012-10-02 | 2015-08-12 | Rodrigo Benito Resa | Eco-sustainable dryer for agricultural produce |
US20150226461A1 (en) * | 2012-08-07 | 2015-08-13 | Logos Technologies, Llc | Solar energy collection utilizing heliostats |
WO2016007011A1 (en) * | 2014-07-10 | 2016-01-14 | ROSINGA, Gerardus Marcellus | Heliostat system and method |
US9471050B2 (en) | 2013-01-15 | 2016-10-18 | Wovn, Inc. | Solar tracker and related methods, devices, and systems |
EP3088818A1 (en) * | 2015-04-27 | 2016-11-02 | Teknikran Soluciones Para Gruas, S.L. | Tilting structure for solar panels |
US20170250649A1 (en) * | 2016-02-26 | 2017-08-31 | Panasonic Boston Laboratory | In-plane rotation sun-tracking for concentrated photovoltaic panel |
US9857040B1 (en) * | 2015-08-20 | 2018-01-02 | X Development Llc | Kinematically linked optical components for light redirection |
EP3396855A1 (en) | 2017-04-25 | 2018-10-31 | Vestel Elektronik Sanayi ve Ticaret A.S. | Light-tracking apparatus and method |
CN109708323A (en) * | 2018-03-16 | 2019-05-03 | 厦门东方远景科技股份有限公司 | Normal direction advises directing mirror array |
RU193079U1 (en) * | 2019-07-01 | 2019-10-14 | Федеральное государственное автономное образовательное учреждение высшего образования "Новосибирский национальный исследовательский государственный университет" (Новосибирский государственный университет, НГУ) | Ultra Small Spacecraft Orientation Module |
FR3086038A1 (en) * | 2018-09-18 | 2020-03-20 | Freville Stades Et Arenas Equipements | MULTIPLE SYSTEM OF OBJECTS REFLECTING THE LIGHT OF THE SUN, IN ORDER TO REDIRECT IT TO THE LAWN OF A SPORTS STADIUM |
US11063553B2 (en) | 2008-11-17 | 2021-07-13 | Kbfx Llc | Solar carports, solar-tracking carports, and methods |
US11283393B2 (en) * | 2008-11-17 | 2022-03-22 | Kbfx Llc | Movable building crown |
EP3942223A4 (en) * | 2019-03-21 | 2023-03-15 | Frederick Guy | An electromagnetic radiation collecting and directing device |
Citations (40)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3105486A (en) * | 1960-11-16 | 1963-10-01 | United Aircraft Corp | Mirror petal modulator |
US3466119A (en) * | 1965-04-10 | 1969-09-09 | Giovanni Francia | Multiple mirrored apparatus utilizing solar heat |
US3501664A (en) * | 1967-07-28 | 1970-03-17 | Nasa | Angular position and velocity sensing apparatus |
US4034735A (en) * | 1976-02-04 | 1977-07-12 | Waldrip Ralph L | Solar energy system |
US4061130A (en) * | 1975-04-28 | 1977-12-06 | Gonzalez Eduardo E | Solar energy device |
US4090070A (en) * | 1976-03-26 | 1978-05-16 | Commissariat A L'energie Atomique | Solar pointer |
US4154219A (en) * | 1977-03-11 | 1979-05-15 | E-Systems, Inc. | Prismatic solar reflector apparatus and method of solar tracking |
US4195905A (en) * | 1978-03-23 | 1980-04-01 | Hansen Paul A | Automatic biaxial sun tracking mechanism for solar energy utilization devices |
US4202321A (en) * | 1978-05-30 | 1980-05-13 | Volna William M | Solar tracking device |
US4295621A (en) * | 1980-03-18 | 1981-10-20 | Rca Corporation | Solar tracking apparatus |
US4365618A (en) * | 1980-12-05 | 1982-12-28 | Dedger Jones | Heliostatic solar energy conversion system |
US4440150A (en) * | 1982-01-25 | 1984-04-03 | Atlantic Richfield Company, Inc. | Heliostat control |
US4922088A (en) * | 1987-09-21 | 1990-05-01 | Technology Network, Inc. | Automatic solar lighting apparatus having a solar following sensor |
US4979492A (en) * | 1989-03-03 | 1990-12-25 | Kei Mori | Solar ray collecting device |
US5374939A (en) * | 1993-07-07 | 1994-12-20 | Pullen V; William J. | Radiation gathering and focusing apparatus |
US5600124A (en) * | 1991-12-03 | 1997-02-04 | Berger; Alexander | Sun tracker system for a solar assembly |
US5632823A (en) * | 1996-01-29 | 1997-05-27 | Sharan; Anand M. | Solar tracking system |
US5798517A (en) * | 1994-05-19 | 1998-08-25 | Berger; Alexander | Sun tracker system for a solar assembly |
US6617506B2 (en) * | 2001-03-29 | 2003-09-09 | Keiji Sasaki | Power generation equipment using sunlight |
US6704607B2 (en) * | 2001-05-21 | 2004-03-09 | The Boeing Company | Method and apparatus for controllably positioning a solar concentrator |
US6725173B2 (en) * | 2000-09-02 | 2004-04-20 | American Gnc Corporation | Digital signal processing method and system thereof for precision orientation measurements |
US20040079863A1 (en) * | 2001-03-28 | 2004-04-29 | Lasich John Beavis | Solar tracking system |
US20050126560A1 (en) * | 2003-12-10 | 2005-06-16 | The Boeing Company | Solar collector and method |
US20050139210A1 (en) * | 2003-11-04 | 2005-06-30 | Martin Eickhoff | Parabolic trough collector |
US20050157411A1 (en) * | 2004-01-16 | 2005-07-21 | Mario Rabinowitz | Advanced micro-optics solar energy collection system |
US6926440B2 (en) * | 2002-11-01 | 2005-08-09 | The Boeing Company | Infrared temperature sensors for solar panel |
US6960717B2 (en) * | 2001-10-16 | 2005-11-01 | American Signal Company | Adjustable solar panel |
US20060054162A1 (en) * | 2004-09-03 | 2006-03-16 | Romeo Manuel L | Solar tracker |
US20060107992A1 (en) * | 2000-06-23 | 2006-05-25 | Sanpauer Reflekt | Solar power plant |
US20060118105A1 (en) * | 2004-12-02 | 2006-06-08 | Hon Wai M | Solar power station |
US20060169315A1 (en) * | 2005-02-01 | 2006-08-03 | Alexander Levin | Modular photovoltaic solar power system |
US20060193066A1 (en) * | 2005-02-01 | 2006-08-31 | Prueitt Melvin L | Concentrating solar power |
US20060243319A1 (en) * | 2005-04-29 | 2006-11-02 | Arizona Public Service Company | Clustered solar-energy conversion array and method therefor |
US7152495B2 (en) * | 2002-12-19 | 2006-12-26 | Honeywell International, Inc. | System and method for adaptive cancellation of disturbances |
US7252084B2 (en) * | 2004-06-28 | 2007-08-07 | Lucent Technologies Inc. | Solar tracking system |
US7339731B2 (en) * | 2005-04-20 | 2008-03-04 | Meade Instruments Corporation | Self-aligning telescope |
US7526402B2 (en) * | 2005-04-19 | 2009-04-28 | Jaymart Sensors, Llc | Miniaturized inertial measurement unit and associated methods |
US20090188487A1 (en) * | 2008-01-29 | 2009-07-30 | Tilt Solar Llc | Self ballasted celestial tracking apparatus |
US20090260619A1 (en) * | 2008-04-20 | 2009-10-22 | The Boeing Company | Autonomous heliostat for solar power plant |
US20100043777A1 (en) * | 2008-08-25 | 2010-02-25 | Ormat Technologies Inc. | Solar collector system |
-
2010
- 2010-10-08 US US12/901,289 patent/US20110030672A1/en not_active Abandoned
Patent Citations (41)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3105486A (en) * | 1960-11-16 | 1963-10-01 | United Aircraft Corp | Mirror petal modulator |
US3466119A (en) * | 1965-04-10 | 1969-09-09 | Giovanni Francia | Multiple mirrored apparatus utilizing solar heat |
US3501664A (en) * | 1967-07-28 | 1970-03-17 | Nasa | Angular position and velocity sensing apparatus |
US4061130A (en) * | 1975-04-28 | 1977-12-06 | Gonzalez Eduardo E | Solar energy device |
US4034735A (en) * | 1976-02-04 | 1977-07-12 | Waldrip Ralph L | Solar energy system |
US4090070A (en) * | 1976-03-26 | 1978-05-16 | Commissariat A L'energie Atomique | Solar pointer |
US4154219A (en) * | 1977-03-11 | 1979-05-15 | E-Systems, Inc. | Prismatic solar reflector apparatus and method of solar tracking |
US4195905A (en) * | 1978-03-23 | 1980-04-01 | Hansen Paul A | Automatic biaxial sun tracking mechanism for solar energy utilization devices |
US4202321A (en) * | 1978-05-30 | 1980-05-13 | Volna William M | Solar tracking device |
US4295621A (en) * | 1980-03-18 | 1981-10-20 | Rca Corporation | Solar tracking apparatus |
US4365618A (en) * | 1980-12-05 | 1982-12-28 | Dedger Jones | Heliostatic solar energy conversion system |
US4440150A (en) * | 1982-01-25 | 1984-04-03 | Atlantic Richfield Company, Inc. | Heliostat control |
US4922088A (en) * | 1987-09-21 | 1990-05-01 | Technology Network, Inc. | Automatic solar lighting apparatus having a solar following sensor |
US4979492A (en) * | 1989-03-03 | 1990-12-25 | Kei Mori | Solar ray collecting device |
US5600124A (en) * | 1991-12-03 | 1997-02-04 | Berger; Alexander | Sun tracker system for a solar assembly |
US5374939A (en) * | 1993-07-07 | 1994-12-20 | Pullen V; William J. | Radiation gathering and focusing apparatus |
US5798517A (en) * | 1994-05-19 | 1998-08-25 | Berger; Alexander | Sun tracker system for a solar assembly |
US5632823A (en) * | 1996-01-29 | 1997-05-27 | Sharan; Anand M. | Solar tracking system |
US20060107992A1 (en) * | 2000-06-23 | 2006-05-25 | Sanpauer Reflekt | Solar power plant |
US6725173B2 (en) * | 2000-09-02 | 2004-04-20 | American Gnc Corporation | Digital signal processing method and system thereof for precision orientation measurements |
US20040079863A1 (en) * | 2001-03-28 | 2004-04-29 | Lasich John Beavis | Solar tracking system |
US6617506B2 (en) * | 2001-03-29 | 2003-09-09 | Keiji Sasaki | Power generation equipment using sunlight |
US6704607B2 (en) * | 2001-05-21 | 2004-03-09 | The Boeing Company | Method and apparatus for controllably positioning a solar concentrator |
US6960717B2 (en) * | 2001-10-16 | 2005-11-01 | American Signal Company | Adjustable solar panel |
US6926440B2 (en) * | 2002-11-01 | 2005-08-09 | The Boeing Company | Infrared temperature sensors for solar panel |
US7152495B2 (en) * | 2002-12-19 | 2006-12-26 | Honeywell International, Inc. | System and method for adaptive cancellation of disturbances |
US20050139210A1 (en) * | 2003-11-04 | 2005-06-30 | Martin Eickhoff | Parabolic trough collector |
US20050126560A1 (en) * | 2003-12-10 | 2005-06-16 | The Boeing Company | Solar collector and method |
US20050157411A1 (en) * | 2004-01-16 | 2005-07-21 | Mario Rabinowitz | Advanced micro-optics solar energy collection system |
US7252084B2 (en) * | 2004-06-28 | 2007-08-07 | Lucent Technologies Inc. | Solar tracking system |
US20060054162A1 (en) * | 2004-09-03 | 2006-03-16 | Romeo Manuel L | Solar tracker |
US20060118104A1 (en) * | 2004-12-02 | 2006-06-08 | Hon Wai M | Solar power station |
US20060118105A1 (en) * | 2004-12-02 | 2006-06-08 | Hon Wai M | Solar power station |
US20060169315A1 (en) * | 2005-02-01 | 2006-08-03 | Alexander Levin | Modular photovoltaic solar power system |
US20060193066A1 (en) * | 2005-02-01 | 2006-08-31 | Prueitt Melvin L | Concentrating solar power |
US7526402B2 (en) * | 2005-04-19 | 2009-04-28 | Jaymart Sensors, Llc | Miniaturized inertial measurement unit and associated methods |
US7339731B2 (en) * | 2005-04-20 | 2008-03-04 | Meade Instruments Corporation | Self-aligning telescope |
US20060243319A1 (en) * | 2005-04-29 | 2006-11-02 | Arizona Public Service Company | Clustered solar-energy conversion array and method therefor |
US20090188487A1 (en) * | 2008-01-29 | 2009-07-30 | Tilt Solar Llc | Self ballasted celestial tracking apparatus |
US20090260619A1 (en) * | 2008-04-20 | 2009-10-22 | The Boeing Company | Autonomous heliostat for solar power plant |
US20100043777A1 (en) * | 2008-08-25 | 2010-02-25 | Ormat Technologies Inc. | Solar collector system |
Cited By (31)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US8379310B2 (en) * | 2007-11-02 | 2013-02-19 | Konica Minolta Opto, Inc. | Sunlight collecting system |
US20100243032A1 (en) * | 2007-11-02 | 2010-09-30 | Nobuyoshi Mori | Sunlight Collecting System |
US20110108019A1 (en) * | 2008-08-18 | 2011-05-12 | Pratt & Whitney Rocketdyne., Inc. | Heliostat joint |
US11283393B2 (en) * | 2008-11-17 | 2022-03-22 | Kbfx Llc | Movable building crown |
US11063553B2 (en) | 2008-11-17 | 2021-07-13 | Kbfx Llc | Solar carports, solar-tracking carports, and methods |
EP2530744A3 (en) * | 2011-06-01 | 2013-04-24 | David Erz | Solar device with reflector device |
WO2012164003A3 (en) * | 2011-06-01 | 2013-05-02 | David Erz | Solar device having a reflector device and reflector device |
EP2773911A1 (en) * | 2011-11-04 | 2014-09-10 | STN Super Travel Net Oy | Solar energy harvesting |
US9739506B2 (en) * | 2011-11-04 | 2017-08-22 | Solixi Oy | Solar energy harvesting |
US20140305490A1 (en) * | 2011-11-04 | 2014-10-16 | STN SuperTravelNet Oy | Solar energy harvesting |
EP2773911A4 (en) * | 2011-11-04 | 2015-04-15 | Stn Super Travel Net Oy | Solar energy harvesting |
ES2422806R1 (en) * | 2012-03-12 | 2013-12-12 | Ingemetal En S A | SYSTEM, PROCEDURE AND INFORMATIC PROGRAM OF CALIBRATION OF THE POSITIONING OF MIRRORS IN HELIOSTATS |
CN102628687A (en) * | 2012-04-28 | 2012-08-08 | 浙江海洋学院 | Ship horizontal attitude indicator |
US20150226461A1 (en) * | 2012-08-07 | 2015-08-13 | Logos Technologies, Llc | Solar energy collection utilizing heliostats |
EP2905567A4 (en) * | 2012-10-02 | 2015-08-12 | Rodrigo Benito Resa | Eco-sustainable dryer for agricultural produce |
US20140123645A1 (en) * | 2012-11-02 | 2014-05-08 | Topper Sun Energy Technology Co., Ltd. | Pull control apparatus of solar tracking power generation mechanism |
US9471050B2 (en) | 2013-01-15 | 2016-10-18 | Wovn, Inc. | Solar tracker and related methods, devices, and systems |
US9488968B2 (en) | 2013-01-15 | 2016-11-08 | Wovn, Inc. | Energy distribution system and related methods, devices, and systems |
CN103471265A (en) * | 2013-08-19 | 2013-12-25 | 高椿明 | Sunlight directional reflection control device based on time-sharing competition mechanism and control method thereof |
WO2016007011A1 (en) * | 2014-07-10 | 2016-01-14 | ROSINGA, Gerardus Marcellus | Heliostat system and method |
EP3088818A1 (en) * | 2015-04-27 | 2016-11-02 | Teknikran Soluciones Para Gruas, S.L. | Tilting structure for solar panels |
US9857040B1 (en) * | 2015-08-20 | 2018-01-02 | X Development Llc | Kinematically linked optical components for light redirection |
US10801684B2 (en) | 2015-08-20 | 2020-10-13 | X Development Llc | Kinematically linked optical components for light redirection |
US20190052223A1 (en) * | 2016-02-26 | 2019-02-14 | Panasonic Boston Laboratory | In-plane rotation sun-tracking for concentrated photovoltaic panel |
US20170250649A1 (en) * | 2016-02-26 | 2017-08-31 | Panasonic Boston Laboratory | In-plane rotation sun-tracking for concentrated photovoltaic panel |
EP3396855A1 (en) | 2017-04-25 | 2018-10-31 | Vestel Elektronik Sanayi ve Ticaret A.S. | Light-tracking apparatus and method |
CN109708323A (en) * | 2018-03-16 | 2019-05-03 | 厦门东方远景科技股份有限公司 | Normal direction advises directing mirror array |
FR3086038A1 (en) * | 2018-09-18 | 2020-03-20 | Freville Stades Et Arenas Equipements | MULTIPLE SYSTEM OF OBJECTS REFLECTING THE LIGHT OF THE SUN, IN ORDER TO REDIRECT IT TO THE LAWN OF A SPORTS STADIUM |
EP3942223A4 (en) * | 2019-03-21 | 2023-03-15 | Frederick Guy | An electromagnetic radiation collecting and directing device |
US11808415B2 (en) | 2019-03-21 | 2023-11-07 | Frederick R. Guy | Electromagnetic radiation collecting and directing device |
RU193079U1 (en) * | 2019-07-01 | 2019-10-14 | Федеральное государственное автономное образовательное учреждение высшего образования "Новосибирский национальный исследовательский государственный университет" (Новосибирский государственный университет, НГУ) | Ultra Small Spacecraft Orientation Module |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US20110030672A1 (en) | Solar Collection Apparatus and Methods Using Accelerometers and Magnetics Sensors | |
US20080011288A1 (en) | Solar Collection Apparatus and Methods Using Accelerometers and Magnetic Sensors | |
US8528541B2 (en) | Solar collection apparatus and methods | |
Salgado-Conrado | A review on sun position sensors used in solar applications | |
US8324547B2 (en) | Solar tracking and concentration device | |
US9182470B2 (en) | Inclinometer for a solar array and associated systems, methods, and computer program products | |
JP4964857B2 (en) | Solar tracking device and tracking method thereof | |
US8381718B1 (en) | Actuator for controlling rotation about two axes using a single motor | |
US8426792B2 (en) | Solar reflector apparatus with independently controlled bail-arms | |
WO2009091339A2 (en) | A method and apparatus for automatic tracking of the sun | |
US20090320827A1 (en) | Solar array tracker controller | |
US8481906B2 (en) | Tilting/tracking system for solar devices | |
JP2003240356A (en) | Sun tracking system | |
US20110209696A1 (en) | Three point solar tracking system and method | |
US10598755B2 (en) | Solar monitoring system for measuring solar radiation intensity | |
US20140174503A1 (en) | Energy convertor/concentrator system | |
WO2012077285A1 (en) | Heliostat and solar-light condensing system | |
WO2017187445A1 (en) | Sun position detector and method of sensing sun position | |
US20130032135A1 (en) | Apparatuses and Methods for Determining and Changing the Orientation of Solar Energy Capture Devices | |
JP3315108B1 (en) | Seesaw type solar power generation water heater system | |
EP2534431A2 (en) | Scalable and rapidly deployable master-slave method and apparatus for distributed tracking solar collector and other applications | |
CN206619030U (en) | A kind of reflection unit for being used to track light source | |
KR200329018Y1 (en) | Light focusing solar cell capable of tracing sunlight | |
JP4253194B2 (en) | Method for installing solar panel of concentrating solar power generation device | |
JP3209221U (en) | Light source tracking device |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AS | Assignment |
Owner name: SEEKTECH, INC., CALIFORNIA Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:OLSSON, MARK S.;REEL/FRAME:025627/0647 Effective date: 20101020 |
|
STCB | Information on status: application discontinuation |
Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION |