AU6109499A

AU6109499A - Object identification apparatus

Info

Publication number: AU6109499A
Application number: AU61094/99A
Authority: AU
Inventors: Leonard Robinson
Original assignee: Arkonia Systems Ltd
Current assignee: Exensor Technology Ltd
Priority date: 1998-09-30
Filing date: 1999-09-30
Publication date: 2000-04-17
Also published as: GB2342162B; WO2000019236A1; GB9923170D0; GB2342162A

Description

WO 00/19236 PCT/GB99/03254 OBJECT IDENTIFICATION APPARATUS DESCRIPTION The present invention relates to object identification apparatus and in particular to 5 apparatus which can at least discriminate between different forms of object whether animate or otherwise. Object identification apparatus is commonly used for security purposes so as to, for example, identify an intruder whether on foot or perhaps within a vehicle. Such apparatus 10 is generally arranged to operate both during the hours of darkness and daylight and is commonly employed to at least record the presence of an intruder within the operative field of the apparatus. In addition, and in real time, an alarm system can be arranged to be activated upon detection of the presence of, for example, the intruder. 15 Such known apparatus commonly comprises a radar-based system. The radar is permanently switched-on for the purpose of object detection/identification and a user has to interpret target information as displayed on a Cathode Ray Tube display. The system is bulky and so is generally housed in a building or large transportable housing/container. 20 Such apparatus is therefore disadvantageous and restricted due to the manner in which a user has to interpret the results provided and due to problems associated with its size and lack of portability and adaptability. For example, the known apparatus is quite often readily visible to a would-be intruder. Also, such known apparatus is not readily moveable or adaptable to different environments and often has relatively high power 25 requirements which likewise limit the location at which the apparatus can be positioned and also the manner in which it can be moved and manipulated. The present invention therefore seeks to provide an object, i.e. target, identification apparatus having advantages over known such apparatus. 30 According to the present invention there is provided an object identification WO 00/19236. PCT/GB99/03254 -2 apparatus comprising sensing means for sensing the presence of an object in the operative field of the apparatus and arranged to generate a control signal responsive to the sensed presence of the object, a signal source operative in response to receipt of the said control signal to derive a signal influenced by the object and means for processing the derived 5 signal for subsequent identification of the object. In one embodiment, the apparatus is provided as a single unit comprising both the sensing means and the signal source. 10 In another embodiment, the sensor means is provided in a unit separate from the said signal source. Advantageously, a plurality of sensor means units are provided which can be separately located and used in tandem so as to increase the coverage and range of the 15 apparatus. The invention is particularly advantageous in that, since the signal source need only be activated upon generation of the control signal by the sensing means, power requirements can dictate that a particularly compact, and readily portable, and thus easily 20 hidden and disguised, apparatus can be provided. Preferably the signal source is arranged to emit a continuous wave signal or interrupted continuous wave signal such as pulsed signal. 25 As such, the signal source may be arranged to emit a microwave signal and can comprise a radar module wherein the said derived signal influenced by the object comprises the reflected radar signal. Such signals can serve advantageously to scan the operative field of the apparatus. 30 Advantageously, the signal source is arranged to be powered-up by the control signal.

WO 00/19236 PCT/GB99/03254 -3 Preferably, the apparatus includes coding means for coding a signal delivered from the means for processing the derived signal. In accordance with a particular advantage, the signal delivered is arranged to have 5 been analysed and classified within the apparatus for eventual presentation to a user on a data display and, preferably, in plain text. Advantageously, the means for processing the derived signal is arranged to be powered-up by receipt of said control signal. 10 Further, the apparatus may include a transmitter arranged for transmitting a signal for receipt by a remote receiver. The remote receiver may be arranged to receive and display information relating to the identity of the object. 15 Advantageously, the apparatus comprises a self-contained unit with an on-board power supply and, particularly advantageously, can comprise a relatively small, portable and hand-held ground sensing radar system, particularly useful for remote ground sensing. The present invention is described further hereinafter, by way of example only, 20 with reference to the accompanying drawings in which: Figure 1 is a block diagram representing identification apparatus according to one embodiment of the present invention; 25 Figure 2 is a perspective view of an embodiment of the present invention mounted on a tripod; Figure 3 is a block diagram representing identification apparatus according to another embodiment of the present invention; and 30 Figure 4 is a block diagram representing identification apparatus according to a WO 00/19236 PCT/GB99/03254 -4 further embodiment of the present invention. Turning first to Figure 1, a block diagram of object identification apparatus 10 embodying the present invention is shown. The apparatus comprises a main housing 12 5 having mounted thereon an infra-red sensor, and in particular a passive infra-red detector 14. a signal source and reflected signal detector preferably comprising a Doppler radar module 16 and a output signal transmitter 18. Within the main housing 12 there is mounted a signal detector 20 for detecting an 10 output from the passive infra-red detector 14, a signal conditioning circuit 22 for receiving the output from the Doppler radar module 16 and a micro-processor 24 for processing a signal as delivered from the signal conditioning circuit 22 and serving to achieve at least some degree of object identification. 15 The passive infra-red detector 14 is connected to the signal detector 20 by the signal line 25 and the signal detector 20 is, in turn, connected by signal line 26 to the micro-processor 24. A further signal line 28 leads from the micro-processor 24 to the signal conditioning circuit 22 and the signal conditioning circuit 22 has a signal line 30 extending to receive the output from the Doppler radar module 16. 20 A signal output line 32 connects the micro-processor to the output signal transmitter 18. As an option, but illustrated within the embodiment of Figure 1, the apparatus can 25 include a signal monitoring line 34 by which initial set-up of the apparatus can be achieved by means of an operator employing, for example, a set of headphones 36. Also, the apparatus 10 includes an on-board power supply mounted within the housing (not shown). 30 Figure 2 illustrates an embodiment of the present invention in which the features WO 00/19236 PCT/GB99/03254 -5 found in Figure 1 are identified by the same reference numerals. Figure 2 represents a perspective view of one embodiment of the apparatus of the present invention and which is mounted at an appropriate location on a tripod. 5 As can be appreciated from Figure 2, the present invention can be embodied in a particularly compact, and readily portable, manner for use in any particular location without being readily detected by a would-be intruder. In operation, the preferably wide-angle passive infra-red detector 14 is mounted on 10 top of the main housing 12 as illustrated in Figure 2 and, in the illustrated embodiment, is arranged to be continually powered from the on-board power supply. The passive infra-red detector 14 serves to detect the heat that might be emitted from, for example, a human or vehicle body, and such detection serves to generate a signal which can be delivered via signal line 25 to the signal detector 20. The signal delivered can also indicate the direction 15 of movement of the object. The detection of this signal by the signal detector 20 serves to initiate activation of both the Doppler radar module 16, the signal conditioning circuit 22 and the micro-processor 24. Until such time as the signal detector 20 receives the aforementioned incoming signal from the passive infra-red detector 14, the Doppler radar module, signal conditioning circuit and micro-processor remain in a powered-down, or at 20 least a standby, mode. Upon power-up of the Doppler radar module 16 responsive to an activation control signal delivered from the signal detector 20 via the signal lines 26, 28 and 30, the Doppler radar module 16 is activated to operate in either of the I, J or K microwave frequency 25 bands and transmits a continuous wave or interrupted continuous wave signal which is intended to be reflected by the object, i.e. a human or vehicle body that first emitted the heat sensed by the passive infra-red detector. If the object is moving, a change in phase between the signal transmitted from the Doppler radar module 16 and the signal reflected back thereto occurs and serves to establish a difference, or so-called Doppler, frequency. 30 Upon receiving the reflected signal, the Doppler radar module 16 serves to mix the WO 00/19236 PCT/GB99/03254 -6 reflected signal with the transmitted signal and the aforementioned difference frequency signal is then generated as an output and supplied via signal line 30 to the signal conditioning circuit 22. 5 At the signal conditioning circuit 22, the signal delivered over signal line 30 is amplified and further controlled by means of an automatic gain control circuit operating under micro-processor control and as forming part of the signal conditioning circuit 22. Subsequently, the amplified and controlled signal is delivered to an 10 analogue/digital converter for subsequent analysis by the micro-processor 24. The aforementioned step of analogue/digital conversion can be conducted by an appropriate analogue/digital converter located either within the signal conditioning circuit arrangement 22 or the micro-processor 24. 15 The micro-processor 24 is arranged to carry out a series of Fast Fourier Transforms (FFTs) on the digital representation of the signal and controlled within the signal conditioning circuit 22. By use of an auto-correlation function provided within the micro processor 24, a pattern recognition process can be carried out which serves to at least classify the object as either a human body or a vehicle and can also provide an indication 20 of the vehicle type and speed. Once full signal analysis has been completed in the micro-processor 24, a message is created identifying at least the classification of the object detected and, in the illustrated embodiment, is subsequently encoded, for example using the Post Office Code 25 Standardization Advisory Group (POCSAG) format, and delivered to the output signal transmitter 18 which preferably comprises a RF transmitter. The message is then transmitted as a RF signal which can be received by a remotely located receiver device, for example a pager, so as to provide an individual carrying the receiver with an indication of at least the classification and direction of the object that has been detected. 30 In one example, the pager can serve to draw its user's attention to the fact that a WO 00/19236 PCT/GB99/03254 -7 message has been received from the object identification apparatus 10 and, subsequent to decoding, is available for receipt. In an alternative, and higher specification, embodiment, the Doppler radar module 5 16 is arranged to produce two Doppler signals that are 900 out of phase, so-called in-phase and quadrature signals, which are subsequently processed through the signal conditioning circuit 22 as discussed above. This more advanced in-phase and quadrature system provides additional advantages in that it can readily identify the direction of movement of an object towards, or away from, the apparatus. Further, the number of likely false alarms 10 is considerably reduced since oscillating obstructions, such as tree branches etc. are identifiable as false readings. In the illustrated embodiment of Figure 1, an arrangement is included to assist with the set-up of the detection range and can also be used for local monitoring purposes. As 15 will be seen, a pair of headphones 36 can be connected to the signal conditioning circuit 22. When required, the passive infra-red detector 14 can be overridden in response to the connection of the headphones 36 to the signal conditioning circuit 22. Further, this connection of the headphones is also arranged to allow for a continual supply of power to the Doppler radar module 16 and then allows an operative to establish an appropriate 20 operating range and also to monitor the Doppler frequency signal directly so as to assist with subsequent classifications of detected objects. Fig. 3 illustrates an alternative embodiment to the present invention in which the passive infra-red detector 314 is provided as a separate unit from the housing mounting the 25 signal detector, the radar device and the signal processing means. Within Fig. 3. the features also found in Fig. 1 are identified by related reference numerals but with the reference numeral 3 inserted to distinguish from the features of Fig. 1. 30 Thus, as will be appreciated, an infra-red detector 314 is arranged for WO 00/19236 PCT/GB99/03254 -8 communication with a UHF modulation/transmission unit 338 by means of a signal link 340 so as to form a remotely located sensor arrangement 346. This sensor arrangement 346 generally corresponds in functional terms to the 5 passive infra-red detector 14 of the embodiment of Fig. 1 but, as will be appreciated, rather than being hard-wired to the signal detector 20 of Fig. 1, the infra-red sensor arrangement 346 is arranged to be located as a separate unit in the remote manner such that the signal received from the passive infra-red detector 314 is transmitted by means of the modulator/transmitter unit 338 by way of the antenna illustrated in Fig. 3 to an antenna 10 associated with a UHF receiver and demodulation unit 342, the output signal which is delivered by means of line 344 to a signal detector 320 which corresponds to the signal detector 20 of the embodiment of Fig. 1. In this manner, the infra-red sensor unit 346 can be located at any appropriate 15 distance from the main housing unit 310 and, indeed, a plurality of such passive infra-red sensor arrangement 346 can be provided for use in combination with the signalling arrangement mounted within the housing 310 so as to increase the coverage provided by the present invention. 20 The remaining elements of the embodiment of Fig. 3, i.e. the signal conditioning circuit 322, the microprocessor 324, the signal lines 326 and 328, the signal line 330, the signal output line 332, the signal monitoring line 334, the set of headphones 336, and the output signal transmitter 318 all correspond to the related features of the embodiment of Fig. 1. 25 In operation, it will therefore be appreciated that upon detection of a heat source, for example such as a person or a vehicle, the detection signal travels by way of the signal line 340 from the passage of infra-red detector 314 to the UHF transmitter/modulator 338. The transmitted signal is received by the UHF receiver/demodulator unit 342 and is 30 delivered via the signal line 344 to the signal detector module 320 and subsequently processed in the same manner as the signal received by the signal detector module 20 of WO 00/19236 PCT/GB99/03254 -9 the embodiment of Fig. 1. The embodiment of Fig. 3 therefore offers further adaptability and flexibility of operation over and above the embodiment of Fig. 1. 5 For example, a device of any particular shape/dimensions can be employed and any appropriate sensor means 14 for detecting the presence of personnel or vehicles such as seismic, magnetic, trip wire, or appropriate signal source 16 can be employed along with the most appropriate signal conditioning and micro-processor arrangement, depending 10 upon the likely environment in which the apparatus is to be used. Also, the apparatus need not only be supplied by an on-board power supply. Further, the encoded message delivered from the micro-processor via the signal output line 32 can alternatively be transmitted to a PSTN line for subsequent transmission to a standard commercial pager units or can be transmitted to a hand-held receiver. 15 Further, the apparatus may incorporate an r.f. receiver module to allow it to be controlled as part of a system containing any required number of such apparatus. Figure 4 illustrates a further embodiment of the present invention and serves to 20 clearly indicate the adaptability of apparatus embodying the invention and having regard to specific environmental requirements that might arise. The system of Figure 4 can employ optional detector units for serving to trigger the radar module housed within a main unit and which can comprise a local detector 414a 25 housed within the main body of the sensor unit, a remote detector 414b arranged to be located remote from the main unit and arranged to transmit its trigger signal to a VHF or UHF transceiver 442 housed within the main body and also a tamper detector unit 414c arranged to provide a trigger signal should the apparatus be tampered with. 30 As with the other embodiments of the present invention, the detectors, for example local detector 414a or remote detector 414b can be arranged to detect movement or heat WO 00/19236 PCT/GB99/03254 - 10 of the target or vibrations generated by the target and, as a further example, magnetic sensing means could provide the trigger signal to the signal detector 420. As with the other illustrated embodiments, the signal serving to trigger the radar 5 module 416 is delivered as part of a wake-up control arrangement and, once operational, the radar module 416 serves to supply a signal conditioning unit 422 and subsequent spectrum analysis and pattern recognition units 424 with an appropriate output signal. The analysis and recognition units 424 serve to supply a message generator 448 which, in the embodiment according to Figure 4, delivers an output signal which, subsequent to 10 modulation, is passed to the VHF/UHF transceiver 442 for transmission to a remote display unit which can be arranged to display appropriate text information providing for the likely identity of the target objects. Of course, as a further alternative, the main unit of the system can be provided with 15 such an appropriate text display such that, should a remote detector 414b be provided, the transceiver 442 merely comprise a receiver. It will therefore now be appreciated from reference to the foregoing description, that the present invention advantageously provides for a portable/hand-held unit 20 comprising a self-contained ground sensing radar system. This system exhibits a variety of specific advantageous features which distinguish it from known target identification apparatus. In particular, and as will be appreciated from the above, detector units, which may be located within the main unit of the sensor or remote therefrom, are provided to act as triggers for the radar modules and the target object is subsequently subjected to 25 classification by means of a pattern recognition arrangement within the main unit. The target classification, and further information such as direction of movement, is eventually presented to the user in a text format on a data display which, again, can be either local to the main unit or remotely located therefrom. 30 As mentioned in relation to Figure 4 embodiment the detection arrangement for triggering the radar module can rely upon heat sensing, motion detection, vibration sensing WO 00/19236 PCT/GB99/03254 - 11 such as by way of an acoustic detector and indeed magnetic sensing. Such arrangements prove particularly suitable for use in relation to the small portable/hand held unit now achievable in accordance with the present invention. 5 Each embodiment of the present invention can therefore advantageously provide for the use of radar for remote ground sensing, the use of a detection source for triggering the radar, the transmission and subsequent display of target-relevant data in a text format and all in relation to a small portable/hand-held unit. 10 15 20 25 30

Claims

1. Object identification apparatus comprising sensor means for sensing the presence of an object in the operative field of the apparatus and arranged to generate a 5 control signal responsive to the sensed presence of the object, a signal source operative in response to receipt of the control signal to derive a signal influenced by the object and means for processing the derived signal for subsequent identification of the object.

2. Apparatus as claimed in claim 1, wherein the means for sensing the 10 presence of an object comprises an infra-red detector.

3. Apparatus as claimed in claim 1 or 2, wherein the signal source is arranged to emit a continuous-wave signal. 15

4. Apparatus as claimed in claim 1 or 2, wherein the signal source is arranged to emit an interrupted continuous wave signal.

5. Apparatus as claimed in claim 3 or 4, wherein the signal source is arranged to emit a microwave signal. 20

6. Apparatus as claimed in any one of claims 1-5, wherein the signal source comprises a radar module and the said derived signal influenced by the object comprises the reflected radar signal. 25

7. Apparatus as claimed in any one of claims 1-6, wherein the signal source is arranged to be powered-up by the control signal.

8. Apparatus as claimed in any one of claims 1-7, wherein the means for processing the derived signal includes an analogue/digital converter and a micro-processor. 30

9. Apparatus as claimed in claim 8, wherein the micro-processor is arranged WO 00/19236 PCT/GB99/03254 - 13 to conduct Fast Fourier Transforms on the signal received from the analogue/digital converter.

10. Apparatus as claimed in claim 8 or 9, wherein the micro-processor is 5 arranged to perform auto-correlation on the received signal.

11. Apparatus as claimed in any one of claims 1-10 and including coding means for coding a signal delivered from the means for processing the derived signal. 10

12. Apparatus as claimed in any one of claims 1-11, wherein the means for processing the derived signal is arranged to be powered-up by receipt of said control signal.

13. Apparatus as claimed in any one of claims 1-12 and including a transmitter 15 for transmitting a signal obtained from the means for processing the derived signal.

14. Apparatus as claimed in claim 13, wherein the transmitter is arranged for transmitting a signal for receipt by a remote receiver. 20

15. Apparatus as claimed in any one of claims 1-14 and comprising a self contained unit with an on-board power supply.

16. Apparatus as claimed in any one of Claims 1-14, wherein said sensing means is provided in a unit separate from the said signal source. 25

17. Apparatus as claimed in Claim 16, wherein the said sensing means unit includes transmitting means for transmitting the said control signal to a receiving means of the said signal source. 30

18. Apparatus as claimed in Claim 17, wherein the said transmitting means of the said sensing means unit comprises an r.f. signal transmitting means. WO 00/19236 PCT/GB99/03254 -14

19. Apparatus as claimed in Claim 16, 17 or 18, and including a plurality of the said sensing means units.

20. Apparatus as claimed in any one of claims 1-19. wherein the sensing means 5 is arranged to be continually powered.

21. An object identification apparatus substantially as hereinbefore described with reference to, and as illustrated in, Figures 1 and 2, and Figures 3 and 4 of the accompanying drawings. 10 15 20 25 30