CA2243409C - Manufacturing installation and processing operations - Google Patents
Manufacturing installation and processing operations Download PDFInfo
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- CA2243409C CA2243409C CA002243409A CA2243409A CA2243409C CA 2243409 C CA2243409 C CA 2243409C CA 002243409 A CA002243409 A CA 002243409A CA 2243409 A CA2243409 A CA 2243409A CA 2243409 C CA2243409 C CA 2243409C
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- vehicle
- articles
- arrangement according
- cpu
- signals
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- 238000009434 installation Methods 0.000 title claims abstract description 16
- 238000012545 processing Methods 0.000 title claims description 14
- 238000004519 manufacturing process Methods 0.000 title description 8
- 229910000831 Steel Inorganic materials 0.000 claims abstract description 16
- 239000010959 steel Substances 0.000 claims abstract description 16
- 238000003860 storage Methods 0.000 claims description 21
- 238000000034 method Methods 0.000 claims description 9
- 238000012937 correction Methods 0.000 claims description 8
- 238000005266 casting Methods 0.000 claims description 6
- 239000002184 metal Substances 0.000 claims description 5
- 230000004044 response Effects 0.000 claims description 5
- 230000001133 acceleration Effects 0.000 claims description 3
- 238000005096 rolling process Methods 0.000 description 9
- 230000032258 transport Effects 0.000 description 4
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 1
- 239000000956 alloy Substances 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- 238000005275 alloying Methods 0.000 description 1
- 230000005540 biological transmission Effects 0.000 description 1
- 238000012790 confirmation Methods 0.000 description 1
- 238000005520 cutting process Methods 0.000 description 1
- 230000001419 dependent effect Effects 0.000 description 1
- 238000000151 deposition Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000011156 evaluation Methods 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 229910052739 hydrogen Inorganic materials 0.000 description 1
- 239000001257 hydrogen Substances 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 239000005433 ionosphere Substances 0.000 description 1
- 230000008569 process Effects 0.000 description 1
- 230000008439 repair process Effects 0.000 description 1
- 230000001360 synchronised effect Effects 0.000 description 1
- 238000012360 testing method Methods 0.000 description 1
- 238000012795 verification Methods 0.000 description 1
Classifications
-
- G—PHYSICS
- G08—SIGNALLING
- G08G—TRAFFIC CONTROL SYSTEMS
- G08G1/00—Traffic control systems for road vehicles
- G08G1/20—Monitoring the location of vehicles belonging to a group, e.g. fleet of vehicles, countable or determined number of vehicles
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S5/00—Position-fixing by co-ordinating two or more direction or position line determinations; Position-fixing by co-ordinating two or more distance determinations
- G01S5/0009—Transmission of position information to remote stations
- G01S5/0018—Transmission from mobile station to base station
- G01S5/0027—Transmission from mobile station to base station of actual mobile position, i.e. position determined on mobile
-
- G—PHYSICS
- G05—CONTROLLING; REGULATING
- G05B—CONTROL OR REGULATING SYSTEMS IN GENERAL; FUNCTIONAL ELEMENTS OF SUCH SYSTEMS; MONITORING OR TESTING ARRANGEMENTS FOR SUCH SYSTEMS OR ELEMENTS
- G05B19/00—Programme-control systems
- G05B19/02—Programme-control systems electric
- G05B19/418—Total factory control, i.e. centrally controlling a plurality of machines, e.g. direct or distributed numerical control [DNC], flexible manufacturing systems [FMS], integrated manufacturing systems [IMS], computer integrated manufacturing [CIM]
- G05B19/4183—Total factory control, i.e. centrally controlling a plurality of machines, e.g. direct or distributed numerical control [DNC], flexible manufacturing systems [FMS], integrated manufacturing systems [IMS], computer integrated manufacturing [CIM] characterised by data acquisition, e.g. workpiece identification
-
- G—PHYSICS
- G05—CONTROLLING; REGULATING
- G05D—SYSTEMS FOR CONTROLLING OR REGULATING NON-ELECTRIC VARIABLES
- G05D1/00—Control of position, course or altitude of land, water, air, or space vehicles, e.g. automatic pilot
- G05D1/02—Control of position or course in two dimensions
- G05D1/021—Control of position or course in two dimensions specially adapted to land vehicles
- G05D1/0276—Control of position or course in two dimensions specially adapted to land vehicles using signals provided by a source external to the vehicle
- G05D1/0278—Control of position or course in two dimensions specially adapted to land vehicles using signals provided by a source external to the vehicle using satellite positioning signals, e.g. GPS
-
- G—PHYSICS
- G05—CONTROLLING; REGULATING
- G05D—SYSTEMS FOR CONTROLLING OR REGULATING NON-ELECTRIC VARIABLES
- G05D1/00—Control of position, course or altitude of land, water, air, or space vehicles, e.g. automatic pilot
- G05D1/02—Control of position or course in two dimensions
- G05D1/021—Control of position or course in two dimensions specially adapted to land vehicles
- G05D1/0276—Control of position or course in two dimensions specially adapted to land vehicles using signals provided by a source external to the vehicle
- G05D1/028—Control of position or course in two dimensions specially adapted to land vehicles using signals provided by a source external to the vehicle using a RF signal
- G05D1/0282—Control of position or course in two dimensions specially adapted to land vehicles using signals provided by a source external to the vehicle using a RF signal generated in a local control room
-
- G—PHYSICS
- G05—CONTROLLING; REGULATING
- G05B—CONTROL OR REGULATING SYSTEMS IN GENERAL; FUNCTIONAL ELEMENTS OF SUCH SYSTEMS; MONITORING OR TESTING ARRANGEMENTS FOR SUCH SYSTEMS OR ELEMENTS
- G05B2219/00—Program-control systems
- G05B2219/30—Nc systems
- G05B2219/31—From computer integrated manufacturing till monitoring
- G05B2219/31432—Keep track of conveyed workpiece, batch, tool, conditions of stations, cells
-
- 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
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P90/00—Enabling technologies with a potential contribution to greenhouse gas [GHG] emissions mitigation
- Y02P90/02—Total factory control, e.g. smart factories, flexible manufacturing systems [FMS] or integrated manufacturing systems [IMS]
Abstract
The absolute position of a vehicle (V) transporting articles between sites (SS) at an installation, e.g. stations of a steel works, is determined by satellite navigation signal and logged on a CPU with a database to ensure that the intended articles (SR) are processed on different sites as required.
Description
MANUFACTURING INSTALLATION
' AND PROCESSING OPERATIONS
The invention relates to the tracking of batches of articles undergoing successive processing steps in an overall manufacturing process at a manufacturing installation.
While the invention is capable of use in a wide variety of contexts, it is seen to good use in the tracking of steel slabs, blooms, billets and the Iike between the caster and successive rolling mills of a steel mill. For convenience, these pieces will be called by the single word "slabs" herein.
Following the casting of a batch of slabs of steel, metal or other alloy, it is imperative that the steel maker knows exactly what each slab is: what alloying elements it contains; when it was cast; its position within the steel mill, the intended end use or customer; and the like. This information is required for every slab produced and therefore each slab is allocated an identity, usually in the form of a number.
The steel maker may want to carry out a number of operations on certain slabs between the caster and the rolling mill, e.g. subdivide or slit them, diffuse hydrogen out of the slab, quality test them, send them straight for export or stock them etc.
Therefore each slab must be tracked and the identity must be maintained so as not to lose them or confuse them with other slabs. Due to the high volume of production and the short lead times for steel slabs, a paper record system of logging the position of each slab is not sufficient to allow effective control of the mill. It must of course be appreciated that a steelmill is a large area and that the slabs are stored in yards open to the environment.
US-A-4,b42,0i7 discloses an automated storage retrieval system for use at a pipe manufacturing facility wherein containers for the pipes are provided with transponders which are interrogated by transmitter/receiver arrangements located on cranes which _ 2 transport the containers containing the pipes. The results of the interrogation are stored in a computer which also monitors the loading and unloading operations of the cranes and monitors and controls the positions of the cranes on a gantry such an ' arrangement requires that identifiable containers are required for the batches of articles to be moved. Furthermore the identities of the batches of articles are not stored.
WO-A-91/10202 (Asyst Technologies Inc.) discloses a manufacturing installation comprising a plurality of processing stations each arranged to perform a processing step on a batch of articles to be manufactured, the installation also having storage stations made up of storage regions, and a vehicle for moving the batches between the processing stations and the storage regions, the installation having a CPU
provided with a database and arranged to track the moving of the batches by the vehicle, the installation having identifying code means and reading means arranged to read the identifying code means, the reading means and identifying code means being coupled to the CPU and arranged to automatically update the CPU with the positions of the batches.
Further background prior art is disclosed in GB -A-1377966, US-A-4956777, TP-A-52/007018, EP-A-428160, TP-A-60/214009, GB-A-2143395, GB-A-1278929 and GB-A-1070176.
In an earlier patent application PCT/GB95/00640, publication W095/26522, an arrangement and method for tracking batches of articles (e.g. steel slabs) is disclosed wherein the locations of the batches axe stored in a database and the locations are updated by a CPU arranged to receive position signals from a vehicle which transfers the batches between sites at the installation. The position signals are relative position signals obtained by sensing proximity to transponders located at each site and elsewhere on the routes to the sites.
It is one object of the present uivention is to provide an arrangement and method which does not require transponders or other local markers which indicate relative position.
According to the present invention, there is provided an arrangement for tracking articles, the arrangement comprising at least one steerable vehicle, said steerable vehicle having a determinable absolute position, said vehicle being arranged to carry articles between storage positions at an installation, position-sensing means located on the vehicle and arranged to sense the absolute position of the vehicle, and a CPU provided with a database recording the storage positions of the articles, the CPU
being arranged to update the database with new storage positions of the articles in response to signals from the position-sensing means.
According to the present invention, there is also provided a method of tracking articles at a steel works, wherein the articles are stored in storage areas, and which are moved between storage areas at the steelworks by a steerable vehicle which has a determinable absolute position, a CPU
having a database containing stored positions of the articles, the method including the step of updating the database with new positions of stored articles in response to signals from a position-sensing means, located on and arranged to sense the absolute position of the vehicle.
'fhe absolute position of the vehicle may for example by sensed by a position-sensing mea~is comprising a receiver arranged to receive satellite navigation signals and E~wm,~ssuy means arranged to determine the absolute position of the vehicle ti~ow timing information in the navigation signals.
Preferably the receiver is arranged to receive Global Positioning System (GPS) signals.
The GPS is based on a constellation of about 24 high altitude ( I 0,90() nautical miles) satellites which transmit accurately synchronised encoded timing signals. An appropriate receiver at an unknown point on the earth's surface can pick up signals from three or more (preferably four) of these satellites and calculate its distance from these satellites and hence its location by comparing the time indicated by its local clock with the transmission times of the received signals. The signals from the fourth satellite is used to correct errors in the receivers clock by applying that correction necessary to ensure that the four computed distances from the receiver to the respective satellites are mutually consistent. This error can be substantially reduced by a refinement known as the Differential Global Positioning System (DGPS) wherein a local stationary receiver at a known location also receives the GPS signals from the S
satellites and applies a correction to the position signal from the receiver in the unknown location, the correction being that necessary to correct the sensed position of the stationery receiver to its known true position. In a variant of this system , the stationary receiver is positioned at an arbitrary location and a correction signal is derived by comparing its instantaneous sensed position with its averaged sensed position.
The correction applied by the DGPS system compensates for errors due to variations in radio propagation speed resulting from changes in the ionosphere, and relies on the assumption that such variations will be the same for the stationery receiver and the receiver whose position is to be determined.
There is a risk that there will be interference by reflection of satellite navigational signals, e.g. from adjacent buildings. To avoid this shielding means may be provided, e.g. a further antenna, or a dead reckoning system may be incorporated into the system.
DGPS receivers and associated equipment are commercially available (e.g. from Trimble Navigation Europe, Hampshire UK) and can give position signals with a repeatability of the order of 0.1 metre.
Another means of absolute position sensing is an inertial navigation arrangement e.g.
based on integrated circuit accelerometers with means for double-integrating the acceleration signal, i.e. a position in space independent of any local reference.
Further preferred features are defined in the dependent claims.
In a preferred feature, the arrangement includes a CPU having a database which stores the identities of all the slabs by their positions in and around the steel mill or other WO 97!26588 PCTlGB97/00174 manufacturing installation. It- preferably has an input facility for updating and modifying data and can provide output to produce reports and to monitor progress. (It preferably also has a security system to allow access only to those who require it). ' This package can be integrated with the caster and rolling mill computers so that the database can receive instructions and confirm execution automatically, without human input.
In operation of a preferred embodiment the CPU will receive instructions from e.g. a casting computer by radio Link. The instructions will specify which slabs should be collected by the vehicles and where they are to be taken for storage or subsequent processing. The CPU will calculate the optimum storage site or position for these slabs and the optimum carrier for carrying out the transport, storing the information in the appropriate database. The CPU will transmit a radio signal to the computer interface of the selected vehicle to inform the operator that the slabs should be taken to the calculated optimum storage site. The radio signal will be received by an antenna on the vehicle, then demodulated and the required information displayed on the computer interface. When the vehicle arnves at a slab pile, it will verify its position using its DGPS receiver, and signal this to the CPU. The verification will be displayed by the computer interface within the vehicle. If the actual and instructed positions do not coincide, the computer interface will display that an error has been made, and will automatically update the CPU by a radio signal so that although an incorrect pile has been picked up, the positions of the slabs in either pile are still known. it is possible to override this or any automatic feature of the CPU and this would be flagged in a report printed at the end o f every shift.
In the preferred embodiment the vehicle driver then takes the slabs to the assigned ' station. When the vehicle arnves at that station it will check its position using its DGPS receiver and will transmit a further radio signal corresponding to its position within the mill. Confirmation that this is the correct position will be displayed on the _ WO 97/26588 PCTlGB97/00174 computer interface, and if it is not the correct position the operator will be informed and the CPU updated automatically by radio. In this way every slab may be tracked no ' matter what an operator does. The position by the DGPS maintains the integrity of the system whilst the immediate updating ensures that the CPU can be interrogated at any time for information concerning a given slab.
The invention has the following additional advantages in the particular context of a steel works:
- reducing steel mill inventory. With total slab tracking no slabs will be lost which in turn leads to more efficient casting because many times an entire cast has to be made again even if only one slab is lost;
- reducing vehicle movements. This will reduce lead times as slabs are placed in the nearest available position to their next process. This will also increase vehicle efficiency as the CPU identifies and recommends the batch closest to the vehicle as the next batch of articles to transport. This will also reduce the risk of human error, from either caster, rolling mill or other employees.
- reducing human input and thus the potential for human error. By electronically verifying the position and identity of slabs these can be automatically updated without any human involvement.
- avoiding the need to repair transmitting/receiving apparatus mounted on the vehicle where transponders are used and avoiding the possibility of damage to Local position markers (e.g. expensive transponders) which are not required in the present system.
WO 97/26588 PCT/GB97/0~174 - improved rolling. At ali time all slabs identities and locations are known.
This in turn leads to improvement in rolling schedules.
In order that the invention may be well understood a preferred embodiment will now be described with reference to the accompanying diagrammatic drawings in which:
Figure I is a schematic drawing of a steelworks;
Figure 2 is a schematic drawing of the DGPS arrangement;
Figure 2A shows schematically tile processing means and error correcting means of DGPS receiver 3, and Figure 2B shows a vertical position sensor of an alternative embodiment.
in the drawing a casting mould C is arranged to cast a batch B of steel slabs S which will require processing at a subsequent processing station PS. (The processing steps may be rolling as in a rolling mill, scarfing, cutting, heat treatment or the like.) Because of the way in which work is handled at a steel mill it is necessary to store batches B of slabs 5 between operations and this is done in one or more storage stations SS which are divided up into storage regions SR which are parking lots for the slabs which are transported between sites using one or more vehicles V.
Vehicle V moves the batches of slabs about the steelworks and is provided with a radio modem 2 linked to a DGPS receiver 3 in the vehicle. DGPS receiver 3 has a receiving antenna 6 which is arranged to receive satellite . navigation signals from at least four GPS satellites 9, 10, 1 l, 12 which are in high altitude orbit and were set up by the US
Department of Defence. Receiver 3 sends sensed position signals to a stationary radio modem 2 which transmits the sensed position via antenna A to a further radio modem (not shown) which has a similar antenna A and is coupled to a caster computer CC and optionally also rolling computers (not shown). Our evaluations have established that ' the accuracy can be less than one metre which is good enough to be considered as an absolute position. Radio modem 2 can also receive destination position signals and other instructions from the radio modem coupled to caster computer CC and can display these instructions on a display (not shown) in the vehicle V.
A CPU 1 is also coupled to the radio modem associated with caster computer CC
and maintains a database on hard drive D which stores the updated positions of all the slabs 5.
In operation, as shown in Figure 2, a radio signal is transmitted from the antenna A
associated with CPU 1 to a radio modem 2 coupled to a computer interface 3 of a vehicle V, setting out the code number of the location at which slabs are to be picked up and the corresponding slab identities and the code number of the destination station.
For example a batch may need to be moved from a storage area to a processing station. The vehicle then travels to the storage area and on arrival the DGPS
receiver 3 sends a radio signal via the radio modem 2 and antenna A to verify the vehicle position. If the sensed position corresponds to the assigned position the operator lifts the slabs and transports them to the destination station. He checks the position of that before depositing the load. He can check his route along the roadways and can identify his location in transit to a central control on request.
The position signals output from DGPS receiver 3 are corrected by an error signal transmitted from a stationary DGPS receiver 7 at a base station BS. This error signal ' is transmitted to antenna A on vehicle V from a radio modem (not shown) at the base station, via an antenna 8. The signals from DGPS receiver 7 are decoded in module 18 which outputs a position correction signal to processor module 19, which calculates the true position of the vehicle from the DGPS signals received from satellites Q9 to Q12 and from the correction signal. The position signal is output to radio modem 2.
The DGPS receiver 3 may be a DSMTM 8-channel receiver as supplied by Trimble navigation, the radio modems may be TRIOMTALKTM 450 modems from the same manufacturer, and the base station BS may be a GPS PATHFINDERTM base station, also as supplied by Trimble Navigation.
In the alternative embodiment of Figure 2B, a 3-axis accelerometer 20 replaces the DGPS receiver and sends 3 acceleration signals to a double integrator processor module 19A which outputs a position signal. If the installation is flat 2-axis signals should be sufficient.
The CPU which maintains the database need not be linked to the casting computer CC
but may communicate independently with the vehicle V. The database may be maintained by a computer on the vehicle or by the computers of all vehicles in order to provide a multiple backup.
The invention is applicable not only to articles which are identical within each batch but also to batches each comprising a number of different articles, in which case the identities of individual articles can be stored by preserving the relative positions and /or orientations of the articles within each batch as the batch is moved.
m
' AND PROCESSING OPERATIONS
The invention relates to the tracking of batches of articles undergoing successive processing steps in an overall manufacturing process at a manufacturing installation.
While the invention is capable of use in a wide variety of contexts, it is seen to good use in the tracking of steel slabs, blooms, billets and the Iike between the caster and successive rolling mills of a steel mill. For convenience, these pieces will be called by the single word "slabs" herein.
Following the casting of a batch of slabs of steel, metal or other alloy, it is imperative that the steel maker knows exactly what each slab is: what alloying elements it contains; when it was cast; its position within the steel mill, the intended end use or customer; and the like. This information is required for every slab produced and therefore each slab is allocated an identity, usually in the form of a number.
The steel maker may want to carry out a number of operations on certain slabs between the caster and the rolling mill, e.g. subdivide or slit them, diffuse hydrogen out of the slab, quality test them, send them straight for export or stock them etc.
Therefore each slab must be tracked and the identity must be maintained so as not to lose them or confuse them with other slabs. Due to the high volume of production and the short lead times for steel slabs, a paper record system of logging the position of each slab is not sufficient to allow effective control of the mill. It must of course be appreciated that a steelmill is a large area and that the slabs are stored in yards open to the environment.
US-A-4,b42,0i7 discloses an automated storage retrieval system for use at a pipe manufacturing facility wherein containers for the pipes are provided with transponders which are interrogated by transmitter/receiver arrangements located on cranes which _ 2 transport the containers containing the pipes. The results of the interrogation are stored in a computer which also monitors the loading and unloading operations of the cranes and monitors and controls the positions of the cranes on a gantry such an ' arrangement requires that identifiable containers are required for the batches of articles to be moved. Furthermore the identities of the batches of articles are not stored.
WO-A-91/10202 (Asyst Technologies Inc.) discloses a manufacturing installation comprising a plurality of processing stations each arranged to perform a processing step on a batch of articles to be manufactured, the installation also having storage stations made up of storage regions, and a vehicle for moving the batches between the processing stations and the storage regions, the installation having a CPU
provided with a database and arranged to track the moving of the batches by the vehicle, the installation having identifying code means and reading means arranged to read the identifying code means, the reading means and identifying code means being coupled to the CPU and arranged to automatically update the CPU with the positions of the batches.
Further background prior art is disclosed in GB -A-1377966, US-A-4956777, TP-A-52/007018, EP-A-428160, TP-A-60/214009, GB-A-2143395, GB-A-1278929 and GB-A-1070176.
In an earlier patent application PCT/GB95/00640, publication W095/26522, an arrangement and method for tracking batches of articles (e.g. steel slabs) is disclosed wherein the locations of the batches axe stored in a database and the locations are updated by a CPU arranged to receive position signals from a vehicle which transfers the batches between sites at the installation. The position signals are relative position signals obtained by sensing proximity to transponders located at each site and elsewhere on the routes to the sites.
It is one object of the present uivention is to provide an arrangement and method which does not require transponders or other local markers which indicate relative position.
According to the present invention, there is provided an arrangement for tracking articles, the arrangement comprising at least one steerable vehicle, said steerable vehicle having a determinable absolute position, said vehicle being arranged to carry articles between storage positions at an installation, position-sensing means located on the vehicle and arranged to sense the absolute position of the vehicle, and a CPU provided with a database recording the storage positions of the articles, the CPU
being arranged to update the database with new storage positions of the articles in response to signals from the position-sensing means.
According to the present invention, there is also provided a method of tracking articles at a steel works, wherein the articles are stored in storage areas, and which are moved between storage areas at the steelworks by a steerable vehicle which has a determinable absolute position, a CPU
having a database containing stored positions of the articles, the method including the step of updating the database with new positions of stored articles in response to signals from a position-sensing means, located on and arranged to sense the absolute position of the vehicle.
'fhe absolute position of the vehicle may for example by sensed by a position-sensing mea~is comprising a receiver arranged to receive satellite navigation signals and E~wm,~ssuy means arranged to determine the absolute position of the vehicle ti~ow timing information in the navigation signals.
Preferably the receiver is arranged to receive Global Positioning System (GPS) signals.
The GPS is based on a constellation of about 24 high altitude ( I 0,90() nautical miles) satellites which transmit accurately synchronised encoded timing signals. An appropriate receiver at an unknown point on the earth's surface can pick up signals from three or more (preferably four) of these satellites and calculate its distance from these satellites and hence its location by comparing the time indicated by its local clock with the transmission times of the received signals. The signals from the fourth satellite is used to correct errors in the receivers clock by applying that correction necessary to ensure that the four computed distances from the receiver to the respective satellites are mutually consistent. This error can be substantially reduced by a refinement known as the Differential Global Positioning System (DGPS) wherein a local stationary receiver at a known location also receives the GPS signals from the S
satellites and applies a correction to the position signal from the receiver in the unknown location, the correction being that necessary to correct the sensed position of the stationery receiver to its known true position. In a variant of this system , the stationary receiver is positioned at an arbitrary location and a correction signal is derived by comparing its instantaneous sensed position with its averaged sensed position.
The correction applied by the DGPS system compensates for errors due to variations in radio propagation speed resulting from changes in the ionosphere, and relies on the assumption that such variations will be the same for the stationery receiver and the receiver whose position is to be determined.
There is a risk that there will be interference by reflection of satellite navigational signals, e.g. from adjacent buildings. To avoid this shielding means may be provided, e.g. a further antenna, or a dead reckoning system may be incorporated into the system.
DGPS receivers and associated equipment are commercially available (e.g. from Trimble Navigation Europe, Hampshire UK) and can give position signals with a repeatability of the order of 0.1 metre.
Another means of absolute position sensing is an inertial navigation arrangement e.g.
based on integrated circuit accelerometers with means for double-integrating the acceleration signal, i.e. a position in space independent of any local reference.
Further preferred features are defined in the dependent claims.
In a preferred feature, the arrangement includes a CPU having a database which stores the identities of all the slabs by their positions in and around the steel mill or other WO 97!26588 PCTlGB97/00174 manufacturing installation. It- preferably has an input facility for updating and modifying data and can provide output to produce reports and to monitor progress. (It preferably also has a security system to allow access only to those who require it). ' This package can be integrated with the caster and rolling mill computers so that the database can receive instructions and confirm execution automatically, without human input.
In operation of a preferred embodiment the CPU will receive instructions from e.g. a casting computer by radio Link. The instructions will specify which slabs should be collected by the vehicles and where they are to be taken for storage or subsequent processing. The CPU will calculate the optimum storage site or position for these slabs and the optimum carrier for carrying out the transport, storing the information in the appropriate database. The CPU will transmit a radio signal to the computer interface of the selected vehicle to inform the operator that the slabs should be taken to the calculated optimum storage site. The radio signal will be received by an antenna on the vehicle, then demodulated and the required information displayed on the computer interface. When the vehicle arnves at a slab pile, it will verify its position using its DGPS receiver, and signal this to the CPU. The verification will be displayed by the computer interface within the vehicle. If the actual and instructed positions do not coincide, the computer interface will display that an error has been made, and will automatically update the CPU by a radio signal so that although an incorrect pile has been picked up, the positions of the slabs in either pile are still known. it is possible to override this or any automatic feature of the CPU and this would be flagged in a report printed at the end o f every shift.
In the preferred embodiment the vehicle driver then takes the slabs to the assigned ' station. When the vehicle arnves at that station it will check its position using its DGPS receiver and will transmit a further radio signal corresponding to its position within the mill. Confirmation that this is the correct position will be displayed on the _ WO 97/26588 PCTlGB97/00174 computer interface, and if it is not the correct position the operator will be informed and the CPU updated automatically by radio. In this way every slab may be tracked no ' matter what an operator does. The position by the DGPS maintains the integrity of the system whilst the immediate updating ensures that the CPU can be interrogated at any time for information concerning a given slab.
The invention has the following additional advantages in the particular context of a steel works:
- reducing steel mill inventory. With total slab tracking no slabs will be lost which in turn leads to more efficient casting because many times an entire cast has to be made again even if only one slab is lost;
- reducing vehicle movements. This will reduce lead times as slabs are placed in the nearest available position to their next process. This will also increase vehicle efficiency as the CPU identifies and recommends the batch closest to the vehicle as the next batch of articles to transport. This will also reduce the risk of human error, from either caster, rolling mill or other employees.
- reducing human input and thus the potential for human error. By electronically verifying the position and identity of slabs these can be automatically updated without any human involvement.
- avoiding the need to repair transmitting/receiving apparatus mounted on the vehicle where transponders are used and avoiding the possibility of damage to Local position markers (e.g. expensive transponders) which are not required in the present system.
WO 97/26588 PCT/GB97/0~174 - improved rolling. At ali time all slabs identities and locations are known.
This in turn leads to improvement in rolling schedules.
In order that the invention may be well understood a preferred embodiment will now be described with reference to the accompanying diagrammatic drawings in which:
Figure I is a schematic drawing of a steelworks;
Figure 2 is a schematic drawing of the DGPS arrangement;
Figure 2A shows schematically tile processing means and error correcting means of DGPS receiver 3, and Figure 2B shows a vertical position sensor of an alternative embodiment.
in the drawing a casting mould C is arranged to cast a batch B of steel slabs S which will require processing at a subsequent processing station PS. (The processing steps may be rolling as in a rolling mill, scarfing, cutting, heat treatment or the like.) Because of the way in which work is handled at a steel mill it is necessary to store batches B of slabs 5 between operations and this is done in one or more storage stations SS which are divided up into storage regions SR which are parking lots for the slabs which are transported between sites using one or more vehicles V.
Vehicle V moves the batches of slabs about the steelworks and is provided with a radio modem 2 linked to a DGPS receiver 3 in the vehicle. DGPS receiver 3 has a receiving antenna 6 which is arranged to receive satellite . navigation signals from at least four GPS satellites 9, 10, 1 l, 12 which are in high altitude orbit and were set up by the US
Department of Defence. Receiver 3 sends sensed position signals to a stationary radio modem 2 which transmits the sensed position via antenna A to a further radio modem (not shown) which has a similar antenna A and is coupled to a caster computer CC and optionally also rolling computers (not shown). Our evaluations have established that ' the accuracy can be less than one metre which is good enough to be considered as an absolute position. Radio modem 2 can also receive destination position signals and other instructions from the radio modem coupled to caster computer CC and can display these instructions on a display (not shown) in the vehicle V.
A CPU 1 is also coupled to the radio modem associated with caster computer CC
and maintains a database on hard drive D which stores the updated positions of all the slabs 5.
In operation, as shown in Figure 2, a radio signal is transmitted from the antenna A
associated with CPU 1 to a radio modem 2 coupled to a computer interface 3 of a vehicle V, setting out the code number of the location at which slabs are to be picked up and the corresponding slab identities and the code number of the destination station.
For example a batch may need to be moved from a storage area to a processing station. The vehicle then travels to the storage area and on arrival the DGPS
receiver 3 sends a radio signal via the radio modem 2 and antenna A to verify the vehicle position. If the sensed position corresponds to the assigned position the operator lifts the slabs and transports them to the destination station. He checks the position of that before depositing the load. He can check his route along the roadways and can identify his location in transit to a central control on request.
The position signals output from DGPS receiver 3 are corrected by an error signal transmitted from a stationary DGPS receiver 7 at a base station BS. This error signal ' is transmitted to antenna A on vehicle V from a radio modem (not shown) at the base station, via an antenna 8. The signals from DGPS receiver 7 are decoded in module 18 which outputs a position correction signal to processor module 19, which calculates the true position of the vehicle from the DGPS signals received from satellites Q9 to Q12 and from the correction signal. The position signal is output to radio modem 2.
The DGPS receiver 3 may be a DSMTM 8-channel receiver as supplied by Trimble navigation, the radio modems may be TRIOMTALKTM 450 modems from the same manufacturer, and the base station BS may be a GPS PATHFINDERTM base station, also as supplied by Trimble Navigation.
In the alternative embodiment of Figure 2B, a 3-axis accelerometer 20 replaces the DGPS receiver and sends 3 acceleration signals to a double integrator processor module 19A which outputs a position signal. If the installation is flat 2-axis signals should be sufficient.
The CPU which maintains the database need not be linked to the casting computer CC
but may communicate independently with the vehicle V. The database may be maintained by a computer on the vehicle or by the computers of all vehicles in order to provide a multiple backup.
The invention is applicable not only to articles which are identical within each batch but also to batches each comprising a number of different articles, in which case the identities of individual articles can be stored by preserving the relative positions and /or orientations of the articles within each batch as the batch is moved.
m
Claims (16)
1. ~An arrangement for tracking articles (15), the arrangement comprising at least one steerable vehicle (V), said steerable vehicle having a determinable absolute position, said vehicle being arranged to carry articles between storage positions at an installation, position-sensing means (3/19A,20) located on the vehicle and arranged to sense the absolute position of the vehicle, and a CPU (1) provided with a database recording the storage positions of the articles, the CPU being arranged to update the database with new storage positions of the articles in response to signals from the position-sensing means.
2. ~An arrangement according to claim 1 wherein the position-sensing means (3) comprises a receiver arranged to determine the absolute position of the vehicle from timing means (19) arranged to determine the absolute position of the vehicle from miming information in the navigation signals.
3. ~An arrangement according to claim 2 further comprising a stationary receiver (7) arranged to receive the navigation signals, error-calculating means (18) responsive to an output of the stationary receiver to calculate an error in the satellite navigation signals received by the vehicle's position sensing means and correcting means (19) responsive to the error to apply a correction to the sensed position.
4. ~An arrangement according to claim 2 or 3 wherein the navigation signals are high altitude GPS navigation sinals.
12~
12~
5. An arrangement according to any one of claims 2 to 4, further comprising shielding means arranged to reduce interference by locally reflected satellite navigation signals.
6. An arrangement according to any one of claims 2 to 5, wherein the position-sensing mans further comprises inertial navigation means (19A, 20) arranged to update the sensed position of the vehicle (V) during periods of poor or inaccurate reception of the satellite navigation signals.
7. An arrangement according to claim 5, wherein the inertial navigation means comprises an accelerometer (20) and means (19A) for double integrating an acceleration signal from the accelerometer to determine the position of the vehicle (V).
8. An arrangement according to claim 7, wherein the vehicle (V) is arranged to update the sensed position on reaching a predetermined reference position.
9. An arrangement according to any one of claims 1 to 8, wherein the vehicle (V) is provided with a transmitter (2) arranged to transmit sensed position information to the CPU
(1) which is located off the vehicle.
(1) which is located off the vehicle.
10. An arrangement according to any one of claims 1 to 9, wherein the vehicle (V) is manually steerable.
11. An arrangement according to claim 10, wherein the CPU
(1) is arranged to be updated automatically in response to an operator of the vehicle (V) picking up an article (5) from an incorrect location.
(1) is arranged to be updated automatically in response to an operator of the vehicle (V) picking up an article (5) from an incorrect location.
12. An arrangement according to any one of claims 1 to 11, wherein the installation is a metal handling or processing installation and wherein the articles (5) comprise at least one metal stock items, semi-manufactured metal articles finished metal articles.
13. An arrangement according to claim 12, wherein the installation is a steelworks, and a casting computer (CC) is arranged to generate and transmit to the CPU (1) instructions concerning movement of batches (B) of the articles (5).
14. A method of tracking articles at a steel works, wherein the articles (5) are stored in storage areas, and which are moved between storage areas at the steelworks by a steerable vehicle (V) which has a determinable absolute position, a CPU (1) having a database containing stored positions of the articles, the method including the step of updating the database with new positions of stored articles (5) in response to signals from a position-sensing means (3/19A, 20), located on and arranged to sense the absolute position of the vehicle.
15. A method according to claim 14, wherein the position-sensing means (3) comprises a receiver arranged to receive satellite navigation signals and processing means (19) arranged to sense the absolute position of the vehicle (V) form limiting information in the navigation singals.
16. A method according to claim 15 including the step of correcting an error in the absolute position in dependence upon a signal from a local stationary receiver (7) which is also arranged to receive signal satellite navigation signals.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB9601010A GB2309320B (en) | 1996-01-18 | 1996-01-18 | Manufacturing installation and processing operations |
| GB9601010.3 | 1996-01-18 | ||
| PCT/GB1997/000174 WO1997026588A1 (en) | 1996-01-18 | 1997-01-17 | Manufacturing installation and processing operations |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CA2243409A1 CA2243409A1 (en) | 1997-07-24 |
| CA2243409C true CA2243409C (en) | 2004-03-30 |
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ID=10787206
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002243409A Expired - Fee Related CA2243409C (en) | 1996-01-18 | 1997-01-17 | Manufacturing installation and processing operations |
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| EP (1) | EP0875024B1 (en) |
| AT (1) | ATE225529T1 (en) |
| AU (1) | AU720217B2 (en) |
| CA (1) | CA2243409C (en) |
| DE (1) | DE69716033T2 (en) |
| ES (1) | ES2183126T3 (en) |
| GB (1) | GB2309320B (en) |
| WO (1) | WO1997026588A1 (en) |
Families Citing this family (16)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5883817A (en) * | 1996-07-08 | 1999-03-16 | Trimble Navigation Limited | Method and apparatus for precise positioning of large structures |
| WO1999013353A1 (en) * | 1997-09-10 | 1999-03-18 | Siemens Nixdorf Informationssysteme Ag | Method and system for detecting and signalling a change in the location of an object |
| DE29908964U1 (en) * | 1999-05-21 | 2000-07-27 | Siemens Ag | Arrangement for transporting transport goods |
| JP2001174537A (en) * | 1999-12-21 | 2001-06-29 | Hitachi Ltd | Radio terminal position measuring method and terminal device by using it |
| US6240362B1 (en) | 2000-07-10 | 2001-05-29 | Iap Intermodal, Llc | Method to schedule a vehicle in real-time to transport freight and passengers |
| US6411897B1 (en) | 2000-07-10 | 2002-06-25 | Iap Intermodal, Llc | Method to schedule a vehicle in real-time to transport freight and passengers |
| AUPQ916600A0 (en) | 2000-08-03 | 2000-08-24 | James Hardie Research Pty Limited | Automated manufactured apparatus for aluminium window/door systems |
| WO2004021141A2 (en) * | 2002-08-30 | 2004-03-11 | Racom Products | Modular analog wireless data telemetry system adapted for use with web based location information distribution method and method for developing and disseminating information for use therewith |
| AU2003288909A1 (en) * | 2002-09-20 | 2004-04-08 | Racom Products, Inc. | Method for wireless data system distribution and disseminating information for use with web base location information |
| FI118394B (en) * | 2006-05-26 | 2007-10-31 | Savcor One Oy | A system and method for locating a GPS device |
| US20140033909A1 (en) * | 2012-08-03 | 2014-02-06 | Robert M. Murphy | Methods and apparatus to control movement of a component |
| US10246180B2 (en) * | 2014-05-20 | 2019-04-02 | Sikorsky Aircraft Corporation | Cooperative perception and state estimation for vehicles with compromised sensor systems |
| CN104310012A (en) * | 2014-09-29 | 2015-01-28 | 三一重型装备有限公司 | Intelligent scraper conveyor and monitoring system thereof |
| US9581449B1 (en) * | 2015-01-26 | 2017-02-28 | George W. Batten, Jr. | Floor patterns for navigation corrections |
| CN109607104B (en) * | 2018-12-03 | 2021-03-26 | Oppo（重庆）智能科技有限公司 | Material reminding method and material reminding system |
| DE102019218046A1 (en) * | 2019-11-22 | 2021-05-27 | Sms Group Gmbh | Satellite-based tracking of metallurgical vessels in a metal industrial plant |
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| GB1070176A (en) * | 1966-03-29 | 1967-06-01 | Conco Engineering Works Inc | Automatic warehousing system |
| US3646890A (en) * | 1969-11-28 | 1972-03-07 | Clark Equipment Co | Means for controlling automatically moved vehicle |
| GB1377966A (en) * | 1971-12-02 | 1974-12-18 | Werkzeugmasch Okt Veb | Mass production of workpieces especially gear wheels |
| US4006921A (en) * | 1975-06-10 | 1977-02-08 | Hydrotech International, Inc. | Pipe coupling |
| GB2090675B (en) * | 1978-01-19 | 1982-12-15 | Lely Nv C Van Der | A land vehicle having automatic steering control |
| US4642017A (en) * | 1982-09-30 | 1987-02-10 | Amca International Corporation | Automated in-process pipe storage and retrieval system |
| GB2143395B (en) * | 1983-05-14 | 1986-08-06 | Gen Electric Co Plc | Vehicle guidance and control system |
| JPS60214009A (en) * | 1984-04-06 | 1985-10-26 | Namuko:Kk | Interface for computer control |
| US4974166A (en) * | 1987-05-18 | 1990-11-27 | Asyst Technologies, Inc. | Processing systems with intelligent article tracking |
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| GB2221212A (en) * | 1988-07-25 | 1990-01-31 | Davy Morris Limited | Controlling stocking and de-stacking of containers |
| JPH087910Y2 (en) * | 1989-11-20 | 1996-03-06 | 株式会社エス・エヌ・ケイ | Memory cartridge for video game console |
| AU642638B2 (en) * | 1989-12-11 | 1993-10-28 | Caterpillar Inc. | Integrated vehicle positioning and navigation system, apparatus and method |
| US5610815A (en) * | 1989-12-11 | 1997-03-11 | Caterpillar Inc. | Integrated vehicle positioning and navigation system, apparatus and method |
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| JPH0519854A (en) * | 1991-07-12 | 1993-01-29 | Pioneer Electron Corp | Controller and monitor device for movement of moving body |
| AU7493894A (en) * | 1993-07-17 | 1995-02-13 | Georg Durrstein | Process for working exploitable territories |
| SE515499C2 (en) * | 1993-11-08 | 2001-08-13 | Telia Ab | Device for enabling communication and positioning in control system |
| GB2288299B (en) * | 1994-03-28 | 1998-04-01 | Heckett Multiserv Plc | Manufacturing installation and processing operations |
| US5512902A (en) * | 1994-04-18 | 1996-04-30 | Northrop Grumman Corporation | Stock locator system using GPS translator |
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- 1996-01-18 GB GB9601010A patent/GB2309320B/en not_active Expired - Fee Related
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1997
- 1997-01-17 CA CA002243409A patent/CA2243409C/en not_active Expired - Fee Related
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- 1997-01-17 AT AT97900696T patent/ATE225529T1/en not_active IP Right Cessation
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- 1997-01-17 EP EP97900696A patent/EP0875024B1/en not_active Expired - Lifetime
- 1997-01-17 DE DE69716033T patent/DE69716033T2/en not_active Expired - Fee Related
Also Published As
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|---|---|
| US6081231A (en) | 2000-06-27 |
| DE69716033T2 (en) | 2003-06-12 |
| EP0875024A1 (en) | 1998-11-04 |
| EP0875024B1 (en) | 2002-10-02 |
| AU1316197A (en) | 1997-08-11 |
| CA2243409A1 (en) | 1997-07-24 |
| DE69716033D1 (en) | 2002-11-07 |
| ATE225529T1 (en) | 2002-10-15 |
| GB9601010D0 (en) | 1996-03-20 |
| GB2309320B (en) | 1999-09-08 |
| WO1997026588A1 (en) | 1997-07-24 |
| ES2183126T3 (en) | 2003-03-16 |
| GB2309320A (en) | 1997-07-23 |
| AU720217B2 (en) | 2000-05-25 |
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Legal Events
| Date | Code | Title | Description |
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| EEER | Examination request | ||
| MKLA | Lapsed |
Effective date: 20140117 |