GB2342162A

GB2342162A - Object identification apparatus

Info

Publication number: GB2342162A
Application number: GB9923170A
Authority: GB
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: 2000-04-05
Anticipated expiration: 2019-09-30
Also published as: GB2342162B; AU6109499A; GB9923170D0; WO2000019236A1

Abstract

An object identification apparatus comprises sensing means such as an infrared detector (14) which senses the presence of an object such as an intruder or vehicle in the operative field of the apparatus and generates a control signal in response to the sensed presence of an object. A signal source such as a radar module (16) is made operative in response to the control signal so as to derive a signal influenced by the object eg by detecting a reflected radar signal. A microprocessor (24) processes the derived signal for subsequent identification of the object. The identity of the object may be transmitted to a hand-held receiver with a display by a transmitter (18) or directly by connection to a data communication line. The sensing means (14) may be remote and transmit the control signal to the signal source (16). Local and remote detectors may include heat, motion, vibration, acoustic and magnetic sensors.

Description

2342162

013JECT IDENTTFICATION APPARATUS DESCRIPTION'

The present invention relates to object identification apparatus and in particular to 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 is generally arranged to operate both during the hours of darkness and daylight and is 1 0 '"D 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 C activated upon detection of the presence of, for example, the intruder.

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.

k-I ID ID 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 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.

According to the present invention there is provided an object identification 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 si,,,nal to derive a sianal influenced by the object and means for processing the derived signal for subsequent identification of the object.

In one embodiment. the apparatus is provided as a single unit comprising both the sensinc means and the signal source.

In another embodiment, the sensor means is provided in a unit separate from the d sianal source.

sai t 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 Z__ -- 1 requirements can dictate that a particularly compact, and readily portable, and thus easily 20 hidden and disguised, apparatus can be provided.

Preferablv the sianal source is arranced to emit a continuous wave si-nal or 1 t -- - interrupted continuous wave signal such as pulsed signal.

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.

Advantageously, the signal source is arranged to be powered-up by the control signal.

Preferably, the apparatus includes coding means for coding a signal delivered from the means for processing the derived signal.

In accordance "ith a particular advantage, the signal delivered is arranged to have been analysed and classified within the apparatus for eventual presentation to a user on a data display, and, preferably, in plain text.

Ad-,,antaoeously, 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 1 C for receipt by a remote receiver. The remote receiver may be arranged to receive and display information relating to the identity of the object.

Advantageously, the apparatus comprises a self-contained unit with an onboard power supply and, particularly advantageously, can comprise a relatively small, portable and hand-held ground sensing radar system, particularly useful for remote ound sensing C1 _er The present invention is described further hereinafter, by way of example only, with reference to the accompanying drawings in which:

0 - Figure 1 is a block diagram representing identification apparatus according to one embodiment of the present invention; Figure 2 is a perspective view of an embodiment of the present invention mounted on a tripod; Fi-ure 3 is a block diagram representing identification apparatus according to another embodiment of the present invention; and Fi-ure 4 is a block diagram representing identification apparatus according to a c -- -4further 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 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 IS.

Within the main housing 12 there is mounted a signal detector 20 for detecting an 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 sianal as delivered from the signal conditioning circuit 22 and serving to achieve at least some degree of object identification.

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 C 11 C' micro-processor 24. A further signal line 28 leads from the micro- processor 24 to the signal conditionine circuit 22 and the sianal conditioninc, circuit 22 has a sianal line 30 extending to receive the output from the Doppler radar module 16.

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 include a signal monitoring line 334 by which initial set-up of the apparatus can be achieved I.P C 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 Fl,"Lire 2 illustrates an embodiment of the present invention in vdiich the features found in Figure I are identified by the same reference numerals. Figure 2 represents a I I perspective view of one embodiment of the apparatus of the present invention and which is mounted at an appropriate location on a tripod.

As can be appreciated from Figure 2, the present invention can be embodied in a C particularly compact, and readily portable, manner for use in any particular location,%-ithout 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 C of movement of the object. The detection of this signal by the signal detector 20 serves 0 to irutiate activation of both the Doppler radar module 16, the signal conditioning circuit C 11 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 si!2nal delivered from the si(Ynal detector 20 via the si(:Ynal lines 26, 28 and 30, the Doppler radar module 16 is activated to operate in either of the 1, J or K microwave frequency 25 bands and transmits a continuous wave or interrupted continuous wave signal which is C, 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 receivinu the reflected si,,nal, the Doppler radar modLIle 16 serves to mlx the reflected signal with the transmitted signal and the aforementioned difference frequency signal is then generated as an output and supplied via signal line 330 to the signal conditioning circuit 22.

At the si-nal conditioning circuit 22. the signal delivered over si-nal line 30 is IP amplified and further controlled by means of an automatic gain control circuit operati g n under micro-processor control and as forming part of the signal conditioning circuit 22.

Z Subsequently, the amplified and controlled signal is delivered to an anal o gue/di gital converter for subsequent analysis by the microprocessor 24. The aforementioned step of analogue/digital conversion can be conducted by an appropriate 0:_1 anal o aue/dig ital converter located either within the si-nal conditioninLy circuit arran-ement C> 22 or the micro-processor 24.

The micro-processor 24 is arranged to carry out a series of Fast FoUner 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 microprocessor 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 of the vehicle type and speed.

Once full signal analysis has been completed in the micro-processor 24, a message is created identifincr at least the classification of the object detected and, in the illustrated embodiment, is subsequently encoded, for example using the Post Office Code Standardization Advisory Group (POCSAG) format, and delivered to the output signal transmitter IS which preferably comprises a R-F 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 carnying the receiver with an indication of at least the classification and direction of the object that has been detected.

In one example. the pa(ger can serve to draw its user's attention to the fact that a message has been received from the object identification apparatus 10 and, subsequent to decoding, is available for receipt.

z:1 In an alternative, and higher specification, embodiment. the Doppler radar module

16 is arranged to produce two Doppler signals that are 90' 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 identifV the direction of movement of an object towards, or away from, the apparatus. Further, the number of likely false alarms 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 will be seen, a pair of headphones 36 can be connected to the signal conditioning circuit 0 0 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 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 3 14 is provided as a separate unit from the housing mounting the signal detector, the radar device and the signal processing means.

Within Fig. 3), the features also found in Fig. I are identified by related reference numerals but with the reference numeral 3 inserted to distinguish from the features of Fior ThLis. as %%-III be appreciated. an infra-red detector 314 is arranged for 1\ 1 JJ) 1 communication with a UHF modulation/transmission unit 338 bly means of a signal I"nk)40 so as to form a remotely located sensor arrangement 346.

This sensor arrangement 3 46 generally corresponds in functional terms to the passive infra-red detector 14 of the embodiment of Fig. 1 but. as will be appreciated, rather than bein- hard-wired to the si-nal detector 20 of Fig. 1, the infra-red sensor arranaement Z zz -ed to be located as a separate unit in the remote manner such that the si-nal)46 's arran., 1 received from the passive infra-red detector 3 14 is transmitted by means of the modulator/transmitter unit 3338 by way of the antenna illustrated in Fig. 3 to an antenna 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 1 CP detector 20 of the embodiment of Fig. 1.

In this manner, the infra-red sensor unit 346 can be located at any appropriate distance from the main housing unit 3 10 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 3 10 so as to increase the coverage provided by the present invention.

The remainina elements of the embodiment of Fia. 3, i.e. the sianal conditioning circuit 322, the microprocessor 324, the signal lines 326 and 328, the signal line 330, the signal output line _332, the signal monitodri. line 3)34, the set of headphones 3)6, and the c 0 P output signal transmitter 18 all correspond to the related features of the embodiment of Fig. 1.

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 0 -- 3 14 to the UHF transmitter/modulator 3) 8.

line 340 from the passage of infra-red detector-3 The transmitted sicynal is received by the UHF receiver/demodulator unit 342 and is 0delivered via the si-nal line 344 to the si(Mal detector module 320 and subsequently Of processed in the same manner as the si nal received b, the signal detector module - -9the 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.

For example, a device of any particular shape,ldimensions can be employed and any appropriate sensor means 14 for detecting the presence of personnel or vehicles such as seismic, magnetic, tnp wire, or appropriate signal source 16 can be employed along "kith the most appropriate signal conditioning and micro-processor arrangement. depending C) In 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 alterriatively be transmitted to a PSTN line for subsequent transmission to a standard commercial pager units or can be transmitted to a hand-held receiver.

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 clearly indicate the adaptability of apparatus embodying the invention and havincy regard to specific environmental requirements that might arise.

The svstem 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 2 5 hOUSed within the main bodv of the sensor unit, a remote detector 414b arran(yed to be located remote from the main unit and arran-ed to transmit its triorcyer signal to a VHF or UHF transceiver 442 housed within the main body and also a tamper detector unit 414c arran-ed to provide a trigger sianal should the apparatus be tampered with.

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 of the target or vibrations generated by the tar,(get and, as a further example, magnetic sensing means could provide the trigger signal to the si(,nal 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 4'224 with an appropriate output signal. The analvsis 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 In 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 ID the likely identity of the target objects.

Of course, as a further alternative, the main unit of the system can be provided with 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,

Z' C.

that the present invention advantageously provides for a portable/handheld unit comprising a self-contained ground sensing radar system. This system exhibits a variety "D 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 D 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.

As mentioned in relation to Figure 4 embodiment the detection arrangement for C triggering the radar module can relV upon heat sensing, motion detection. vibration sensing 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.

Each embodiment of the present invention can therefore advantageously provide Z for the use of radar for remote around sensing, the use of a detection source for triggering C Z Z the radar. the transmission and subsequent display of target-relevant data in a text format 1 - and all in relation to a small portable/hand-held unit.

- 5

Claims

- 12CLAIMS

Object iden 'fi sensor means for sensing the ti ication apparatus compri 1.

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 control signal to derive a signal influenced by the object and of the object.

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

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

4. Apparatus as claimed in claim 1 or 2, wherein the signal source is arranged 0 to emit an interrupted continuous wave signal.

5. Apparatus as claimed in claim 33 or 4, wherein the signal source is arranged to emit a microwave signal.

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

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

p -- 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.

9. Apparatus as claimed in claim 8, wherein the micro-processor is arranged 13 - to conduct Fast Fourier Transforms on the signal received from the analogue/diaital converter.

10. Apparatus as claimed in claim 8 or 9, wherein the micro-processor is 5 arranaed to perform auto-correlation on the received s12nal.

Il. Apparatus as claimed in any one of claims I -10 and inclUding coding means for codin(, a si,,nal delivered from the means for processing the derived signal.

12. Apparatus as claimed in any one of claims I A 1, wherein the means for processing the derived signal is arranged to be powered-up by receipt of said control Z: W ZID siornal.

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

14. Apparatus as claimed in claim 1-3), wherein the transmitter is arranged for transmitting a signal for receipt by a remote receiver.

C) 1 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.

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.

IS. Apparatus as claimed in Claim 17, wherein the said transmitting means of the said sensing means unit comprises an r.f. signal transmitting means.

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

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

Z 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.

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