EP1538579A1 - Method and device for power saving in battery driven movement detectors. - Google Patents

Abstract

A scanning method for a movement detector (1) in which the movement detector generates a measurement signal (100b) for detection of the movement or presence (100a) of an object. Depending on the ambience light signal (5b), the movement detector is switched over between an operating mode for detection-readiness and a power saving mode for reduction of power demand of the supply source (105). Independent claims are included for the following (1) A movement detector (2) A system for movement detection (3) An appliance installation or machine.

Description

TECHNICAL AREA

The invention relates to the field of autonomously operated electrical appliances and installations and in particular on battery-powered devices of domestic installation technology. It starts with a scanning process, a Motion detector, a system and an installation according to the preamble of the independent claims.

STATE OF THE ART

Motion detectors are devices that keep people in one as possible capture defined area or solid angle. she are mainly used in the installation technology. They are preferred for controlling light sources, Fans, heaters or other electrical equipment used. Does a person move to a sensor? To, it is via a relay or a semiconductor switch z. B. turned on a lamp. The sensors are based on an infrared detector, the corresponding the radiated temperature of a moving Body generates a signal. Typically, these are Hardwired devices and the low-voltage power supply operated.

In U.S. Pat. 4'982'176 will be a Außenbeleuchtungsund Alarm system with a passive infrared motion detector disclosed. The system is powered by a battery fed, which is rechargeable via solar cells. Of the Battery operation of the lighting or the alarm is from an electronic control activated only if the motion detector has detected a moving object. In addition, activating the system by day can help a daylight detector can be prevented. Activities to reduce the power consumption in the motion detector are none provided.

In EP 1 278 047 A2 a scanning method for Flowmeters specified in which a sampling rate in Reduced dependence of a residual life of the supply source becomes. This can be at the expense of measuring accuracy the life of the supply source can be increased.

In JP 10246662 A, Patent Abstract is an electronic Watermeter disclosed in which a magnetic sensor is present, the sampling rate in response to the sensor signal is adjusted. To reduce energy consumption the sampling rate is lowered when the sensor signal stable or largely unchanged, and increased when changes in the sensor signal occur. A Reduction of energy consumption depending on others Parameter and in particular a residual life of the Power source is not provided.

In WO 98/52061 a meter or gas meter is specified, in which the battery state of charge is monitored and the time is determined when the battery replaces shall be. The determination of the remaining battery capacity or remaining life are u. a. underlying: one Counting the days of operation of the battery since its commissioning; a battery self-discharge; a standby Consumption of the measuring device; a count, how often certain Operating modes of the meter were performed; one on Statistics or empirical values based extrapolation the presumed future energy consumption; as well as one Safety margin to bridge the time between Battery alarm and battery replacement. Activities to extend battery life none seized.

PRESENTATION OF THE INVENTION

The object of the present invention is a method and a device for extending the service life to specify an autonomous motion detector. This task According to the invention by the features of the independent Claims solved.

In a first aspect, the invention consists in one Scanning method for a motion detector, wherein at least a power-consuming component of the motion detector at least temporarily from an autonomous source of supply is fed, wherein the motion detector is a measurement signal for detecting the movement or presence of an object and an ambient light signal from a photosensitive element is generated for the detection of ambient light, wherein the motion detector is dependent on the ambient light signal between an operating mode for detection readiness and an energy saving mode for reducing the Power consumption of the power source is switched. By The procedure becomes the power consumption of a motion detector with at least partially autonomous power supply reduced without the measurement reliability of the motion detector must be restricted. This will be done achieved that the motion detector or at least one power-consuming component of the motion detector only then wakes up and thus the motion detector in Willingness to measure will be offset if, due to the Ambient light signal is established that the result of the Movement or presence measurement actually to Control of the actuator to be used.

The embodiment according to claim 2a ensures that is controlled by the ambient light signal power saving circuit superior to the measurement signal acquisition of the Motion detector is operated. According to claim 2b is the motion detector operated particularly energy efficient. According to Claim 2c are the essential in the energy saving mode or all power consuming components off and / or switched to standby.

The embodiment according to claim 3 has the advantage that the ambient light signal is detected where an actuator depending on a person or object registration and controlled by a natural or artificial ambient light shall be.

Claim 4 relates to an embodiment in which the Monitoring the ambient light from the control unit of the Motion detector itself is controlled and the monitoring ensured by the control unit also in the energy saving mode becomes.

The embodiment according to claim 5 has the advantage that depends on the type of actuator to be controlled the Energy saving mode activated in day mode or in night mode can be.

By the sampling method according to claim 6, the power consumption of the motion detector are lowered even further.

In a further aspect, the invention relates to a motion detector, comprising measuring means and a control unit for generating and evaluating a measurement signal for detection the movement or presence of an object as well as a autonomous power source for at least temporary power at least one current-consuming component of the motion detector, wherein a photosensitive element for producing an ambient light signal in response to a Ambient light is present, further wherein the motion detector an operating mode for detection readiness and an energy saving mode for reducing the power consumption of Supply source and switching means for automatic Switching the motion detector between the operating mode and the energy saving mode depending on a size of the Ambient light signal are present.

The invention also relates to a system comprising a Motion detector as previously described and one through the Motion detector controlled actuator or a device, a Installation or a machine comprising such Motion detector.

Further embodiments, advantages and applications of the invention arise from dependent claims as well as from the Now following description and the figures.

BRIEF DESCRIPTION OF THE DRAWINGS Show it

Fig. 1

a block diagram of a battery powered motion detector with radio connection to an actuator;

Fig. 2

a first power saving operation of the motion detector with an alternating day and night mode of operation;

Fig. 3

a power consumption of the motion detector in Function of the sampling rate of its motion sensor;

Fig. 4

schematically a second power saving operation of Motion detector with reduced sampling rate; and

Fig. 5

schematically a third power-saving operation of Motion detector with approval of sampling gaps.

In the figures, the same parts are given the same reference numerals Mistake.

WAYS FOR CARRYING OUT THE INVENTION

Fig. 1 shows schematically a battery powered wireless Motion or presence detector 1. The detector 1 includes measuring means 100, 101, 102 and a control unit 103 for generating and evaluating a measurement signal 100b, with which the movement or presence 100a of an object is detectable. The detector 1 comprises an autonomous supply source 105 for at least temporary feeding at least a power consuming component 100, 101, 102, 103, 104 of the detector 1. The object to be detected may a person, an animal, a bicycle, a car o. Ä. act. The motion detector 1 is for example a Passive infrared detector 1 (PIR), but can also be an active Infrared detector based on infrared reflection, an active Ultrasonic detector based on ultrasonic reflection or Doppler effect, an acoustic sound detector, be an active microwave detector or the like. With 100 is the widely used passive infrared detector called the comprises two pyroelectric crystals A, A ', which are opposite in polarity Polarity are interconnected. The crystals A, A 'give due to the heat radiation 100a one moved thermal object a characteristic electric Measuring signal 100b from that with a field effect transistor, comprising drain D, collector and source S, the capacitive Ground GND is coupled, pre-amplified, in the signal amplifier 101 further amplified, in the A / D converter 102 in a digital Signal converted and finally in the microcontroller 103 is evaluated. Especially for retrofit applications, in remote installation locations without direct network access or in systems that have a plurality of sensors and actuators 2, will be a separate installation of the Detector 1 required by the actuator 2. Here is the sensor part 1 can be operated with a battery 105 and the switching command from the sensor 1 to the actuator 2 through a wireless connection 3 are transmitted. Therefor the detector 1 a transmitter 104 and the actuator 2 a Receiver 204 based on radio waves, Microwaves, acoustic waves o. Ä. Can work. Furthermore, the actuator 2 includes its own microcontroller 203 and a switch 200, in particular a relay or a semiconductor switch 200 for controlling a light source, a blind, a fan, an air conditioner, a heater or other electrical appliances.

In addition, a photosensitive element 5 is present detected by the ambient light 5a and a corresponding Ambient light signal 5b to the motion detector 1 and in particular its microcontroller 103 is forwarded. Suppress conventional battery powered motion detectors 1 then the trip command to the actuator 2 or the Relay 2, without going into a special power-saving mode switch. In the known state of the art, so the Actuation of the actuator 2 depending on the movement signal 100b of the motion detector 1 and the ambient light signal 5a of the element 5. According to the invention, however, the ambient light signal 5a directly used the motion detector 1 as a function of the ambient light signal 5b between an operating mode 7 for detection readiness and an energy saving mode 8 for reducing the power consumption I the supply source 105 of the motion detector 1 switch. Switching takes place automatically and triggered by the Ambient light signal 5b. Set the switching means 103b that is, a control circuit 103b that is within or also can be arranged outside the control unit 103 and with their help by switching between operating mode 7 and power saving mode 8 extends the battery life is. In this case, the control circuit switches in dependence of Size of the ambient light signal and does not diminish in any Assure the measurement reliability of the motion detector 1.

In general, the control unit 103 comprises the switching means 103b and in particular the microcontroller 103. In energy-saving mode 8, each measuring device 100 is preferably 100, 101, 102 switched off or switched to standby and the Control unit 103 is switched to standby insofar, that they are for a repeated measurement of ambient light 5a automatically and only as far as necessary can be activated. Especially need motion sensor 100, data acquisition part or signal processing unit 101, 102, evaluation electronics 103 for the personal identification and communication part 104 only to be active if in the environment a predefinable Brightness, whether dark or light, is present. If this is not the case, z. B. the microcontroller 103rd be switched into a low power mode 8 and only for the For example, measure the brightness once per second to be woken up. The rest of the electronics can be 100-104 stay switched off during this time.

Advantageously, the switching means 103b comprise comparator means for comparing the ambient light signal 5b with a predefinable brightness threshold value 60; 61, 62 and calculating means for determining operating mode 7 or energy-saving mode 8 in function of the comparison. Preferably activate Switching means 103b the energy saving mode 8 then, if by the motion detector 1, a light switch 200 are controlled should and the ambient light signal 5b above the brightness threshold 60; 61, 62 lies or if by the motion detector 1 is an ambient light 5a to be activated Installation 200, especially a sun blind or activated or daylight-dependent ventilation during the day, Air conditioning or office installation, to be controlled and the ambient light signal 5b below the brightness threshold 60; 61, 62 is located.

Fig. 2 shows an embodiment of a motion detector 1 for activating a light switch 2. Shown is the brightness curve 6 as a function of Time of day t. When exceeding a threshold value of 60 am Tomorrow will switch to daytime energy-saving mode 8 and so that the motion detector 1 is deactivated. In the evening at Falling below the brightness threshold 60 is in the Night operating mode 7 switched and the motion detector 1 activated. To toggle during the transition phases to avoid a hysteresis is introduced in such a way that in the morning the threshold is 61, increased by one Trigger, and in the evening the threshold 62, humbled by one Trigger, serves as switching criterion. About the annual mean can such a battery powered motion detector 1 about half of the time in day mode 8 are operated. The battery life can be drastically reduced extend. Here is a numerical example: Power consumption in Night operating mode 7: 27 mA; Power consumption in the daily energy-saving module 8: 4 mA; average power consumption 15.5 mA at half day / night operation. The battery life extends by almost a factor of two, without consideration of additional self-discharge and Aging of the battery 105.

The autonomous power source 105 may be any battery power, also a rechargeable battery or a rechargeable battery be. The battery 105 may also outside the Motion detector 1 may be arranged. The photosensitive Element 5 may be a photocell, a photoresistor (LDR = light dependent resistor), phototransistor o. Ä. Be. Advantageously, the photosensitive element 5 is in the range the motion detector 1 and / or one of the motion detector. 1 controlled actuator 2 is arranged. It can be especially in Motion detector 1 or optionally in the actuator 2 itself be arranged.

According to FIG. 1, in wireless communication between Detector 1 and actuator 2 in addition to Hinkommunikation 3 to Command transmission to the actuator 2 also a return communication 4 to the detector 1 be present. The return communication 4 serves to order from the actuator 2 to the detector. 1 tell how good the send connection works and if necessary, the transmission power to an optimum level level and in particular lower.

The subject of the invention is also a system for motion detection, comprising a motion detector 1 as before described and controlled by the motion detector 1 Actuator 2, as well as a device, an installation or a machine comprising such a motion detector. 1

In a further aspect, the invention relates to a scanning method for a motion detector 1, wherein at least a power consuming component 100, 101, 102, 103, 104 of the motion detector 1 at least temporarily from an autonomous supply source 105 is fed, wherein the Motion detector 1 a measurement signal 100b for detecting the Movement or presence 100a of an object and of a photosensitive element 5 an ambient light signal 5b is generated for the detection of ambient light 5a, wherein Further, in dependence of the ambient light signal 5b of Motion detector 1 between an operating mode 7 for Detektionsbereitschäft and an energy saving mode 8 for reduction the power consumption I of the supply source 105 is switched becomes. For this purpose in the following some embodiments.

The motion detector can be independent of the measurement signal 100b in the operating mode 7 or energy-saving mode 8 are added. The energy-saving mode can be activated by default. In particular, in the energy saving mode 8 at least one of at least one power-consuming component 100, 101, 102, 103, 104 of the motion detector 1, in particular each of power consuming components 100, 101, 102, 103, 104, switched off or switched to standby. It is preferred the ambient light 5 a in the area of the motion detector 1 and / or an actuator controlled by the motion detector 1 2 measured; it can be daylight 5a and / or Artificial light 5a act.

Preference is given by a control unit 103 of the motion detector 1 repeats a measurement of the ambient light 5a initiated and the resulting ambient light signal 5b with a brightness threshold 60; 61, 62 compared, the is in particular hysteresis and depending on the Comparison of the operating mode 7 or the energy-saving mode 8 activated. In energy saving mode 8, the control unit 103 so far switched to stand-by that they automatically and only as necessary for the repeated measurement of ambient light 5a is activated. In the microcontroller 103 is running a clock, for example, every 1 s or 10 s the microcontroller 103 awakens and initiates measurement. In energy-saving mode 8 So runs the control unit 103 only in one Minimum configuration required for periodic or repeated Monitoring the environment for brightness 5a and occasional Wake up the entire motion detector 1 serves.

In the embodiment of FIG. 2 is the motion detector 1, a light switch 200 is controlled and due to the Comparison of energy saving mode 8 activated when the brightness threshold 60; 61, 62 exceeded by the ambient light 5a becomes. The comparison is thus carried out so that the motion detector 1 in daylight largely inactive and is ready for detection in the dark. alternative can from the motion detector 1 in an ambient light 5a too activating installation 200, in particular a sun blind 200 or daytime activated ventilation, air conditioning or office installation, be controlled and due the comparison of the energy saving mode 8 are activated when the brightness threshold 60; 61, 62 from ambient light 5a is fallen short of.

In addition, to reduce the power consumption I of the supply source 105, a sampling rate f ₁ , f ₂ , f ₃ can be reduced with a decreasing residual life of the supply source 105 (FIGS. 3, 4). Alternatively or additionally, a sampling rate f, 13 can be left unchanged and intermittent sampling gaps 14 can be permitted (FIG. 5).

In detail, FIG. 3 shows the power consumption I of a data acquisition system 101-103 or microcontroller 103 as a function the sampling rate or clock frequency f. The total power consumption I, 11 consists of a base load 10 and a part dependent on the sampling frequency f. The Base load 10 consists of the power consumption of the microcontroller 103 in sleep mode, the consumption of the amplifier 101 and the sensor 100 (if not switched off can be) as well as from leakage currents of other components together. The frequency-dependent part substantially decreases proportional and at high frequencies f disproportionately to the frequency f. So can the power consumption I one Data acquisition system 101-103, e.g. an analog / digital converter 102, approximately halved when the sampling rate f is reduced by a factor of two.

The relevant sampling rates f of the infrared motion detector 1 for the evaluation and detection of a person are in a frequency range between approximately 0.1 Hz and 10 Hz. A detection system 1 must therefore theoretically be at least twice the sampling rate, ie at least 20 Hz, operate. For an optimal evaluation even 75 Hz is used here. This increases the reliability of motion detection by the motion detector 1. However, as the life of the battery 105 finishes, it may be more important to ensure a prolonged operational readiness even at the expense of reduced reliability in the detection of persons. 4 shows an example in which a predicted battery life T _E of 5 years is achieved with a conventional sampling rate of f ₁ = 75 Hz. If, after 4 years, the sampling rate is reduced from f ₁ = 75 Hz to f ₂ = 60 Hz, the service life is extended to just under 6 years, and with further reduction to f ₃ = ₄₅ Hz, over 6 years. The system 1 can thus be operated for a longer time with a relatively slightly reduced detection reliability until the capacity of the battery 105 is completely used up.

5 shows an alternative or supplementary scanning method, where a scan is performed in burst mode becomes. In general, a signal is given by equidistant or at least continuous scans 12 detected. However, if the power consumption I of a system 1 should be reduced, so the sample can also be in one Burst Mode 13 can be performed by capturing or Scanning gaps 14 are allowed. The sampling rate f remains unchanged, but is temporarily suspended or interrupted. The burst mode 13 can be basically independent operated by a remaining life of the battery 105 become.

Power consumption I can be reduced all the more, the longer the coverage gaps 14 are selected in burst mode 13 become. The loss is that traceability of the motion signal 100b becomes worse and mainly prolonged the reaction or response time until a movement 100a can be detected. One good compromise exists when a ratio dead time 14 or sleep mode 14 at waking time is chosen so that persons not unguarded or unnoticed one to be controlled Area can happen. This is a dead time 14th or acquisition gap 14 from 100 ms to a few 100 ms in general tolerable. However, the burst mode 13 can also with increasing battery life ever longer sampling gaps Allow 14 so that the battery life at ever lower availability over long periods of time remains intermittently available.

The scanning methods according to FIGS. 4 and 5 are freely combinable with the method according to the invention and in particular with each other. Overall, a minimum sampling rate over a minimum period should be ensured in any case for detecting moving persons, cyclists, cars o. Ä. The reduction of the sampling frequency f ₁ , f ₂ , f ₃ and the admission of sampling gaps 14 will also be determined depending on a spatial area to be monitored, a field of view and in dependence of several motion detectors 1.

LIST OF REFERENCE NUMBERS

1

Autonomous motion detector

100

Motion sensor, pyroelectric detector, passive infrared detector (PIR)

100a

Motion signal, presence signal, heat radiation

100b

measuring signal

101

signal amplifier

102

A / D converter

103

Control unit, microcontroller, μC, microprocessor

103b

switching

104

Communication part, transmitter, transceiver

105

autonomous power source, battery

2

actuator

200

Light switch, blind control

203

Control unit, microcontroller, μC, microprocessor

204

Communication part, receiver, transceiver

3

Hinkommunikation, command direction

4

rear communication

5

photosensitive element, photoresistor, phototransistor

5a

Ambient light, daylight, artificial light

5b

Ambient light signal

6

brightness curve

60

Threshold for brightness, trigger

61

Brightness threshold plus hysteresis

62

Brightness threshold minus hysteresis

7

Operating mode, night operating mode

8th

Energy saving mode, day operating mode

9

Power consumption, energy consumption

10

Power consumption baseload

11

Total power consumption

12

Continuous scanning

13

intermittent (burst-mode) sampling

14

sampling gaps

A, A '

pyroelectric crystals

A / D

analog / digital

D

drain

S

source

GND

Ground, grounding

f, f ₁ , f ₂ , f ₃

Sampling rate, clock frequency

I

power consumption

t

Time of day, time

T

Battery life (in years)

T _E

predicted battery life

Claims (14)

Sampling method for a motion detector (1), wherein at least one current-consuming component (100, 101, 102, 103, 104) of the motion detector (1) is at least temporarily fed by an autonomous supply source (105), wherein the motion detector (1) a measurement signal ( 100b) for detecting the movement or presence (100a) of an object and of a photosensitive element (5) an ambient light signal (5b) for detecting ambient light (5a) is generated, characterized in that in dependence on the ambient light signal (5b) of the motion detector ( 1) between an operating mode (7) for detection readiness and an energy-saving mode (8) for reducing the power consumption (I) of the supply source (105) is switched. Scanning method according to claim 1, characterized in that a) the motion detector (1) is set independently of the measuring signal (100b) in the operating mode (7) or energy saving mode (8) and / or b) the energy-saving mode is activated by default and / or c) in the energy saving mode (8) at least one of the at least one current-consuming component (100, 101, 102, 103, 104) of the motion detector (1), in particular each of the power consuming components (100, 101, 102, 103, 104), off or switched to standby. Scanning method according to one of the preceding claims, characterized in that a) the ambient light (5a) is measured in the region of the motion detector (1) and / or an actuator (2) controlled by the motion detector (1) and / or b) the ambient light (5a) is daylight and / or artificial light. Scanning method according to one of the preceding claims, characterized in that a) repeatedly initiating a measurement of the ambient light (5a) by a control unit (103) of the motion detector (1) and comparing the resulting ambient light signal (5b) with a brightness threshold value (60; 61, 62) which is in particular hysteretic, b) is activated as a function of the comparison of the operating mode (7) or the energy-saving mode (8), and c) in the energy saving mode (8), the control unit (103) is switched to stand-by insofar that it can be activated automatically and only as necessary for the repeated measurement of the ambient light (5a). Scanning method according to claim 4, characterized in that a) a light switch (200) is controlled by the motion detector (1) and is activated on the basis of the comparison of the energy saving mode (8) when the brightness threshold value (60; 61, 62) is exceeded by the ambient light (5a) or b) by the motion detector (1) in an ambient light (5a) to be activated installation (200), in particular a sun blind (200) or daytime activated ventilation, air conditioning or office installation, is controlled and activated due to the comparison of the energy saving mode (8), if the brightness threshold value (60; 61, 62) is undershot by the ambient light (5a). Scanning method according to one of the preceding claims, characterized in that in order to reduce the power consumption (I) of the supply source (105) a) a sampling rate (f ₁ , f ₂ , f ₃ ) is reduced with a decreasing residual life of the supply source (105) and / or b) a sampling rate (f, 13) is left unchanged and intermittent sampling gaps (14) are allowed. Motion detector (1) comprising measuring means (100, 101, 102) and a control unit (103) for generating and evaluating a measurement signal (100b) for detecting the movement or presence (100a) of an object and an autonomous supply source (105) for at least temporary Feeding at least one current-consuming component (100, 101, 102, 103, 104) of the motion detector (1), further comprising a photosensitive element (5) for generating an ambient light signal (5a) in response to an ambient light (5a), characterized that a) the motion detector (1) has an operating mode (7) for detection readiness and an energy saving mode (8) for reducing the power consumption (I) of the supply source (105) and b) switching means (103b) for automatically switching over the motion detector (1) between the operating mode (7) and the energy saving mode (8) depending on a size of the ambient light signal (5b) are present. Motion detector (1) according to claim 7, characterized in that a) in the energy saving mode (8) of each measuring means (100, 101, 102) is switched off or switched to standby and the control unit (103) is so far switched to standby that they automatically for a repeated measurement of the ambient light (5a) and only as far as necessary can be activated and / or b) the control unit (103) comprises the switching means (103b) and in particular a microcontroller (103). Motion detector (1) according to one of claims 7-8, characterized in that a) the switching means (103b) comprise comparator means for comparing the ambient light signal (5b) with a predefinable brightness threshold value (60; 61, 62) and b) the switching means (103b) comprise computing means for determining the operating mode (7) or energy-saving mode (8) as a function of the comparison. Motion detector (1) according to claim 9, characterized in that the switching means (103b) activate the energy saving mode (8) when a) by the motion detector (1) a light switch (200) to be controlled and the ambient light signal (5b) above the brightness threshold (60; 61, 62) is or b) by the motion detector (1) in an ambient light (5a) to be activated installation (200), in particular a sun blind (200) or daytime activatable ventilation, air conditioning or office installation to be controlled and the ambient light signal (5b) below the brightness threshold (60 ; 61, 62). Motion detector (1) according to one of claims 7-10, characterized in that a) the measuring means (100, 101, 102) a motion sensor (100), a signal processing unit (101, 102), in particular a signal amplifier (101) and an A / D converter (102), and communication means (104) for controlling a Include actuator (2) and b) in particular that the motion sensor (100) is designed for the detection of human, animal and / or vehicle and is preferably a passive infrared detector (1). Motion detector (1) according to one of claims 7-11, characterized in that a) the supply source (105) is a battery supply (105) of the motion detector (1), in particular a rechargeable battery, and / or b) the photosensitive element (5) is arranged in the region of the motion detector (1) and / or an actuator (2) controlled by the motion detector (1) and / or c) means for wireless return communication (4) from the actuator (2) to the motion detector (1) and for adapting a transmission power of the motion detector (1) are present at a required level of performance. Motion detection system comprising a motion detector (1) according to any one of claims 7-12 and a controlled by the motion detector (1) actuator (2). Device, installation or machine comprising one Motion detector (1) according to one of claims 7-12.

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