GB2223870A

GB2223870A - Security apparatus

Info

Publication number: GB2223870A
Application number: GB8822290A
Authority: GB
Inventors: David William Shipley; Howard Morgan Clarke
Original assignee: Individual
Current assignee: Individual
Priority date: 1988-09-22
Filing date: 1988-09-22
Publication date: 1990-04-18
Also published as: GB2223870B; GB8822290D0

Abstract

The apparatus is for detecting interference with an object e.g. a vehicle 1 and comprises a plurality of detectors e.g. ultrasonic range finding detectors 2-11 on the vehicle and directed towards its wheels or the ground. They register a different output if an unauthorized object is passed through their beam. Such detection is memorized in a central unit 13, and its occurrence is indicated on the unit when the latter is interrogated by a remote unit 17. <IMAGE>

Description

Security Apparatus The invention relates to security apparatus for detecting interference with an object, in particular though not exclusively a vehicle.

A current security problem is that of an explosive device placed in or under a vehicle with the intention of blowing up the vehicle when the driver enters it or drives it away.

The object of the present invention is to provide security apparatus with which interference with a vehicle for example can be detected.

Security apparatus according to the invention for detecting interference with an object to be protected comprises: means for detecting presence of an unauthorized object within a defined space associated with the object; a central unit to which the detection means is connected and including: memory means for memorizing occurrence of a detection by the detection means, sensory means for receiving an interrogation message, output means for indicating occurrence of a detection; and a remote interrogation unit for co-operating with the central unit via the sensory means to cause the output means to indicate the occurrence of a detection in case thereof.

The object to be protected may be a fixed installation or a vehicle. In either case, the defined space may be the space interior to the installation or vehicle and/or a peripheral space. In the case of a road vehicle, it is the space beneath the vehicle which is of particular interest. The detection means for this may be of various types, for instance proximity detectors, electromagnetic detectors or in particular transceiving detectors of the range finding type. Where this type of detector is used, a plurality of detectors are preferably arranged around the periphery of the underbody of the vehicle to scan a "skirt" surrounding the space between the vehicle and the road. Any interference by way of. placing an explosive device on the underbody will involve intrusion through this skirt.

The range finding detectors are preferably arranged to detect deviation from a quiescent state in which they are receiving reflections from a fixed surface, such deviation occurring on interference by way of intrusion into the space beneath the vehicle. The fixed surface may be the road for instance or a part of the vehicle such as a wheel. Ultrasonic range finding transceivers are particularly suitable.

The sensory means and remote interrogation unit may co-operate by a variety of communication means such as radio transmission. However, infra red communication is particularly suitable. The communication may be two way, in that the output means sends its indication to the remote unit for display there. However, it is preferred that the communication be one way in that the remote unit sends an interrogation signal, in response to which the output means in the form of a visual display indicates whether an interference has been detected.

Preferably the interrogation unit and the sensory means are a matched pair, conveniently operating at an individual modulation of infra-red transmission. The visual display may be arranged to indicate not only that there has been an interference but which transceiver detected it.

The detection means may in addition or alternatively be arranged to detect intrusion within the installation, the vehicle or its engine compartment,for example by means of a doppler effect sensor.

The detection means may additionally include door opening detection switches.

To help understading of the invention, a specific embodiment thereof will now be described with reference to the accompanying drawings in which: Figure 1 is a side view of a vehicle fitted with security apparatus of the invention; Figure 2 is a front view of the vehicle of Figure 1; and Figure 3 is a block diagram of the security apparatus.

The vehicle 1, a car, is fitted with ten ultrasonic, narrow beam range finding transceivers 2-11 of the type manufactured by Polaroid Corporation. These are arranged as follows: Transceiver 2 is fitted to the under body of the vehicle at the nearside front (n/s/f) wheel and directed towards the nearside rear (n/s/r) wheel.

Transceiver 3 is fitted at the nearside rear (n/s/r) wheel and directed towards the nearside front (r/s/f) wheel.

Transceiver 4 is at the offside front (o/s/f) wheel and directed towards the offside rear (o/s/r) wheel.

Transceiver 5 is at the o/s/r wheel and directed towards the o/s/f wheel.

Transceiver 6 is in front of the n/s/f wheel and directed towards the o/s/f wheel.

Transceiver 7 is in front of the o/s/f wheel and directed towards the n/s/f wheel.

Transceiver 8 is behind the n/s/r wheel and directed towards the o/s/r wheel.

Transceiver 9 is behind the o/s/r wheel and directed towards the n/s/r wheel.

Transceiver 10 is fitted centrally behind the front bumper and directed downwards at the road.

Transceiver 11 is fitted centrally in front of the rear bumper and directed downwards at the road.

The transceivers radiate ultrasonic sound in a pattern shown by the arrows A in Figure 3 and the shaded areas B in Figures 1 and 2.

These define a skirt extending substantially around the entire vehicle between its underbody and the ground. If anything such as a hand placing an explosive device passes through the skirt it will cause one or other of the transceivers and possibly more than one, to detect a range different to that which it normally detects in its quiescent state. Once a change of state has been registered, a timer is triggered, so that only changes longer than a set period are registered, to avoid the alarm being tripped by leaves, cats, and the like.

The transceivers are all wired via cables 12 to a central unit 13. This includes circuitry for powering the transceivers and monitoring their output. The normal, quiescent, output of each transceiver is compared with its present output and if there is a variation, this is memorized in a memory within the central unit 13 as a detection of an interference by the particular transceiver.

Associated with the central unit is an LED display 14 having LED(s) arranged in a pattern corresponding to that of the position of transceivers. The display is arranged in co-operation with the memory to light the LED(s) relevant to interferences detected on interrogation, as described below.

Additionally connected to the central unit 13, and having corresponding LED(s) in the display 14, are a doppler effect sensor 15 for detecting movement within the vehicle and door switches 16 for detecting opening of the doors. Further switches may be provided for the boot and bonnet.

Interrogation of the central unit is via a hand held interrogation unit 17. It includes a modulated infra red emitter. The central unit has a corresponding receiver 18 and associated tuned demodulator. If the emitter's frequency is equal to that of the demodulator, indicating that the user of the interrogation unit 17 has the correct unit for the particular central unit 13, the display is switched ON to indicate to the user whether or not there has been an interference with his vehicle. Thus the user is able to check whether his vehicle has been interferred with without touching the vehicle and possibly setting off any explosive device deposited in it.

The apparatus can be reset only by means of a coded message from the interrogation unit when the user leaves his vehicle. The display incorporates a further LED which illuminates in the event of tampering with the apparatus.

The invention is not intended to be restricted to the details of the above described embodiment. For instance, the LED illuminating in event of tampering could be replaced by one illuminating only if the apparatus has not been tampered with.

Further, the apparatus could be adapted to sound an alarm when interference was detected.

Claims

1. Security apparatus for detecting interference with an object to be protected comprising: means for detecting presence of an unauthorized object within a defined space associated with the object; a central unit to which the detection means is connected and including: memory means for memorizing occurrence of a detection by the detection means, sensory means for receiving an interrogation message, output means for indicating occurrence of a detection; and a remote interrogation unit for co-operating with the central unit via a sensory means to cause the output means to indicate the occurrence of a detection in case thereof.

2. Security apparatus as claimed in claim 1, wherein the detecting means comprises a plurality of individual detectors.

3. Security apparatus as claimed in claim 2, wherein the detectors are range finding detectors, arranged to detect deviation from a quiescent state reflecting from fixed items in or around the defined space on intrusion into the defined space.

4. Security apparatus as claimed in claim 1, claim 2 or claim 3, wherein the object to be protected is a road vehicle and the detecting means is arranged around the periphery of the underbody of the vehicle to scan a skirt surrounding the space between the vehicle and the road.

5. Security apparatus as claimed in claim 4 as appendant to claim 3, wherein selected ones of the range finding detectors are directed from the vehicle body to a wheel thereof and others are so directed to the ground.

6. Security apparatus as claimed in claim 5, wherein the detectors are ultrasonic transceivers.

7. Security apparatus as claimed in claim 4, claim 5 or claim 6, wherein the detecting means includes supplementary detectors in the form of an internal doppler effect sensor and/or bonnet/boot opening detection switches.

8. Security apparatus as claimed in any preceding claim, wherein the sensory means and the remote interrogation unit co-operate by infra-red communication.

9. Security apparatus as claimed in claim 8, wherein the interrogation unit and the sensory means comprise a matched pair co-operating at an individual modulation of infra-red transmission therebetween.

10. Security apparatus as claimed in any preceding claim, wherein the communication between the sensory means and the remote interrogation unit is two way and the output means is incorporated in the interrogation unit.

11. Security apparatus as claimed in any one of claims 1 to 9, wherein the remote interrogation unit and the sensory means are adapted for one way communication from the former to the latter, the output means being incorporated in the interrogation unit.

12. Security apparatus as claimed in any one of claims 2, 3 or 4 to 11 as appendant to claim 2, wherein the output means is arranged to indicate which of the plurality of detectors detected intrusion into the defined space.

13. Security apparatus as claimed in any preceding claim, wherein the central unit includes a timer initiated by a detection for timing the intrusion and disabling memorization of short term intrusions.

14. Security apparatus as claimed in any preceding claim, wherein the interrogation unit and the central unit are adapted to co-operate in resetting the apparatus for initiating detection.

15. Security apparatus substantially as-hereinbefore described with reference to the accompanying drawings.