GB2053516A - Programmable Vehicle - Google Patents

Abstract

A surveillance vehicle guards high risk targets and has wheels or endless tracks 4 and 6 on hull 2. A radar antenna 10 lies at the hull rear, and a remote control mode antenna 12 lies at the front of the hull. Vehicle sensors are mounted on top of boom 14 pivoted by ram 16 which is pivotally mounted on hull 2. The vehicle sensors comprise an infra- red search light 18, a television camera 20, radar 22, an infra-red detector 24, and a gun microphone 26. A UHF antenna 28 is provided for television and sound transmission. The sensors are mounted on a head 30 which is rotatably mounted on boom 14. The vehicle patrols a predetermined route by following control commands generated by a programmed guidance routine. At intervals, it stops and scans its surroundings. If a change is detected, it calls the operator and transmits the relevant information. The operator then controls the vehicle to take a closer look. If the alarm is false, the operator can return the vehicle to its predetermined route. <IMAGE>

Description

SPECIFICATION A Vehicle Technical Field The present invention relates to a vehicle.

In this Specification the term "vehicle" includes an apparatus which can travel on land, in the water or in the air, or closely above the ground as is the case with a vehicle that rides on a self produced air cushion. The term "vehicle" is intended to include an apparatus which can travel in any one or more of the aforementioned modes.

The invention is particularly concerned with, but not exclusively limited to, a surveillance vehicle which can be used to guard high risk targets such as large military installations, petrochemical plants, pipelines, power stations and border posts. Previously these targets could be guarded by only two methods, both of which have certain disadvantages. The first method is to protect the perimeter of the site with electronic alarm systems designed to detect unauthorised entry. These systems are extremely expensive, particularly when installed on large sites, and these systems are still relatively unsophisticated and consequently frequently generate a false alarm. In addition, operational and cost considerations may preclude the use of these systems to protect targets such as military or civil aircraft which need to be parked at dispersal points, or pipelines laid in open country.

The second method involves the use of security personnel to patrol the site while maintaining visual surveillance. Although a patrol guard's senses are considerably more efficient than any electronic device, the efficiency and alertness of a human guard can be seriously impaired by tiredness, boredom and inclement weather, particularly towards the end of a long shift. A significant disadvantage to the use of human guards is however the risk of physical violence, because a guard may be attacked and silenced before he can raise an alarm. With the prevalence of terrorism, insurgency and highjacking the vulnerability to attack of a human guard is a very real threat.

A partial compromise has been attempted by the installation of closed circuit television systems to provide surveillance at a remote and secure location. Unfortunately, it has been shown that security personnel cannot be expected to watch T.V. monitors efficiently for more than approximately one hour, and that the staff member can view effectively only a limited number of different monitors. To summarise, it is now thought that large scale closed circuit T.V. installations may be have some deterrent value but that they are not really cost effective. In addition, television systems only enable the viewer to see what is happening at a particular remote location or locations, and does not provide him with any other sensory input.

Statement of Invention The invention envisages a vehicle which is programmable to travel along and survey a preselected route independently of a control station, and to report to the control station any change in environment from a preselected normal or safe condition.

The vehicle may be equipped with night vision equipment and radar and sensors to sense infrared emitting targets and siesmic disturbances caused by pedestrians or vehicles which are not visibie.

The vehicle sensors may be arranged to transmit information only when a change in the environment is detected thereby enhancing the efficiency of the operator so that one operator can monitor several vehicles either on the same site or at separate locations. Because the vehicle can reconnoitre any required route such as for example the perimeter of a site to be guarded, it is possible to avoid the high capital costs of installing a permanent surveillance installation. As previously mentioned the vehicle traveis along a preselected route independently of any control commands, and requires the operator to decide only whether or not any detected change in the environment is a genuine alarm situation requiring action.

In addition to surveying one or more of the aforementioned high risk targets, the vehicle is suitable for duties such as for example riot control, fire fighting, surveillance in hazardous atmospheres i.e. when nuclear radiation is present, and as a forward observation post in military applications.

Description The vehicle comprises a semimonocoque hull moulded from 5/1 6" high impact polyethylene plastic with a welded channel steel frame. Motive power is provided by a D.C. electric motor driving all six wheels through a gearbox, torque converter and a pair of clutches. Power for traction and all onboard services is provided by high capacity maintenance free lead acid batteries.

The basic vehicle carries a microprocessor based logic and control system with a large memory capacity which directs the pre-programmed patrol path and monitors all system functions. Interface equipment connects onboard sensors with the logic and control electronics whilst multichannel telemetry and telecommand radio links relay sensor data to the operator and permit him to take control of the vehicle should the need arise.

Each vehicle can be equipped with a variety of different sensors to suit particular mission requirements. Typical sensor packages might include a T.V. camera with a low light or night viewing capability; a highly directional gun microphone; an F.M.C.W. radar with a 3600 field, a B.S.R. and passive infra-red sensors with more narrow fields of view. Geophones, magnetic anomaly detectors and products of combustion sensors can also be fitted for specialised applications.

Mission Profiles The onboard microprocessor (mini computor) allows the vehicle to function in several modes.

Patrol Mode In this mode the vehicle patrols a predetermined route by following control commands generated by a programmed and internally stored guidance routine. At frequent intervals the vehicle stops and scans its surroundings. If any significant change in its environment is detected the vehicle calls the operator and then transmits the relevant information to the terminal equipment. Should the operator be unable to decide from the displayed information whether the alarm is genuine he can override the patrol mode and select the remote control mode.

Remote Control Mode In this mode all vehicle functions are under the control of the operator who, by means of a simple control panel, can drive the vehicle to take a closer look at anything that has attracted its attention. If the alarm proves false the operator can re-select the patrol mode, or, if genuine, can take the appropriate action.

Survival and Energy Maintenance Modes In addition to its prime mission roles, each vehicle calls its operator at regular intervals to guard against attacks on the control centre and also monitors all onboard system functions for breakdowns or assaults on the vehicle itself. In applications where such attacks are more likely, aluminium or composite armour can be fitted and non-lethal defence mechanisms can be employed e.g. C.S. or mace dispensers, curdlers, etc.

For military applications a hostile target indicator can be carried on the vehicle. Any attack on the vehicle which results in less than its complete destruction arms and fires the defence mechanisms whilst an emergency transmission notifies the operator. Failure of any vehicle to call the operator within a predetermined time limit automatically initiates an alarm transmission from the remote terminal equipment.

Power consumption of all onboard services is constantly monitored so that sufficient power is conserved to enable the vehicle to return to its recharging point. Normally the internal supplies are sufficient for an 8 hour shift although the provision of an optional onboard petrol generating set can accommodate unusual or extended mission profiles.

Terminal Equipment The terminal equipment associated with the vehicle comprises a small control panel, a T.V.

monitor together with a V.D.U. for displaying system status and messages from the vehicle. An optional speech facility can also be provided whilst a line printer and V.T.R. can be used to log each shift.

Because of the compact nature of the equipment the complete system can be easily transported whilst the ease of programming facilitates re-depolyment in a new location in a matter of hours.

Summary The vehicle of the invention can provide a flexible and cost effective surveillance system that can be applied to many security roles. It combines the efficiency and intelligence of the human operator with the benefits bestowed by modern electronic sensors without either the cost penalties incurred by deployment of the latter in large fixed installations or the inherent fallabilities of the human patrol guard.

Operating Modes-Detailed Description 1. Manual Mode In this mode certain vehicle functions may be controlled by a local command guidance box which is plugged into the rear of the vehicle via a short cable. The L.C.G. box allows the vehicle to be driven off a transported for mission depolyment or to recover a disabled vehicle. The L.C.G. box is also used to guide the vehicle when programming a patrol.

2. Manual Mode (Programming) When mode 2 is selected the vehicle must be situated at its patrol origin point.

For operation without leader cable guidance one of two alternative navigation packages may be fitted to enable the vehicle to patrol the desired route with operator intervention. On sites where the route to be followed does not demand absolute dead reckoning navigation (i.e. cross track errors of less than +2 metres), a navigation package based upon a flux-gate magnetometer can be used.

The navigation package includes a dedicated 8 bit microcomputer which receives heading information from the flux-gate compass and from port and starboard wheel rotation sensors and thus yields predicted cartesian co-ordinates relative to a datum. The co-ordinate of the starting datum (the patrol origin point) is input manually and the vehicle is then driven off along the desired route.

All control commands from L.C.G. box are written into R.A.M. together with the digital output from the wheel encoders and the vehicle headings resulting from the control commands. At each surveillance point the vehicle is halted and a "surveillance sweep" command is entered on the L.C.G.

box.

3. Patrol Mode Selection of the patrol mode is normally performed by a real time clock in the terminal equipment which is connected to the vehicle by the forward umbilical. Charging of the onboard batteries is discontinued and the M.P.U. runs a debugging monitor routine. This is followed by a status check on ail surveillance sensors and the vehicle's power buses. If all is in order the M.P.U. outputs "vehicle Ready" and demands a handshake from the operator. The umbilical disconnects and the vehicle then runs its patrol programme. The traction motor is fed via tyristor controls which provide controlled acceleration.

Turns are accomplished by declutching the drive to one set of wheels. Zero speed turns are also possible to permit manouevering in confined spaces. Guidance commands read from memory together with the distance run and the desired vehicle headings are computed in 3-terms so that the M.P.U.

performs continuous correction of any deviation from the average desired vehicle heading and ground track. Repeated D.F. "fixes" on the radio beacons are used by the M.P.U. to monitor navigational accuracy. This closed loop system greatly minimises ground track and bearing errors so that the probable miss distance from any reference point is only a few metres after patrol segments of several kilometres.

In terms of absolute positional accuracy, algorithmically derived headings from a flux-gate/wheel sensor package cannot (with current state-of-the-art technology) be expected to achieve cartesian coordinates with a resolution better than + one metre. This is because of the diurnal variation in the earth's magnetic field (amounting to about > in this part of the globe) and due to errors in heading arising from vehicular undulation. Even with three axis inertial navigation packages (precluded in this application on grounds of cost) heading accuracies better than one degree cannot be predicted at this time.

Heading and track deviations resulting from data processing errors are eliminated because the main 16 bit M.P.U. runs a continuous C.R.C. error correction monitor. Since route programmes use comparatively few data bits at very slow rates, bearing and distance run bytes are repeated twice and an immediate parity check is performed. Because processor utilisation is so low advantage is taken of the M.P.U. capacity to perform error checking on all data movements.

The use of volatile memory is justified because of the low-capacity required for most mission profiles (typically 8-1 6K) and the provision of "safe" power supplies. Refresh is safeguarded by providing a stand-by supply during those times when crashdown is more probable e.g. during re-charge of the prime system battery and when the prime battery is approaching its end point voltage. Power failure interrupt control logic is provided on the M.P.U. card for this purpose.

Extended mission profiles are accommodated by plugging expansion R.A.M. cards into the M.P.U.

bus. The comparatively low M.T.B.F. predictions for both tape and disc system memories when used in such environments precludes their use in the vehicle and it is envisaged that bubble memories will be used on later marks of the vehicle. The use of R.A.M. also enhances the systems flexibility since it allows rapid re-programming whenever necessary although, once written, all programmes should be dumped onto minifloppy. A disc drive and controller is therefore a strongly recommended optional base station facility so that a dump can be performed via the vehicle's umbilical once route learning is completed. Where the vehicle is expected to remain in one operational environment for some time the R.A.M. cards can be replaced with P.R.O.M. for added security.

The main 1 6 bit M.P.U. is a harsh environment version primarily intended for military applications.

The wide range of support hardware available and its compatability with the products from more than 100 other manufacturers was an important factor governing the choice of M.P.U. for the mark 2 vehicle although it is possible to utilise other operating systems if required by special operational considerations.

Upon reaching a surveillance point the vehicle halts and runs a surveillance routine (normally in P.R.O.M.). The head is indexed (randomly) to 0 or 300 degrees and, after a settling delay, all sensor output inhibits are lifted. If no target returns are received the head stays in that position for a predetermined number of surveillance clock cycles before the sensors are inhibited and the head is indexed to the next sector (usually a 60 degree pan but dependent upon camera and sensor fields of view). This cycle is repeated until either the surveillance routine is completed or a target return is received. If this latter condition is realised the sensor(s) generate an interrupt and keys the appropriate channel of the onboard telemetry transmitter.The channel identification code is transmitted for one second before the appropriate sensor output is coupled to a separate transmitter assigned to the sensors. Receipt of a channel ident at the base station generates an audible warning and causes the V.D.U. to print the appropriate text e.g. "vehicle 7-1 have an acoustic contact". Sensors with speechband outputs i.e. doppler sensors (M.W.D.; F.M.C.W. radars; B.S.R.'s such as Oasis or Shrimp) or geophones, microphones, P.l.R.'s and M.A.D.'s utilise a conventional R.T. transmitter (VHF or UHF) whilst video returns are transmitted by a separate wideband transmitter. If required speech band returns can be modulated on a sub-carrier of the video transmitter instead.

Whiist mobile, only certain surveillance sensors can be fully powered up (to avoid spurious returns due to the vehicle's motion) but any that are can interrupt the patrol when a target is detected.

The sensor return is transmitted until an override command is transmitted to the vehicle or mode 4 is selected. At the end of a surveillance sweep the head is indexed to the vehicle centre line.

Alternative Navigation Package Where the patrol route demands positional accuracy better than can be achieved with a flux-gate "nav-pack" an alternative vehicle guidance system can be fitted. This system relys upon the deliniation of the route by a series of active or passive markers that function in the same way as "cats eyes" markers on roads although, in this case, non optical markers are used. On those vehicles utilising a B.S.R. as the primary long range surveillance sensor this device is used in a dual mode. When patrolling, the B.S.R. is used as a narrow beam beacon that projects a cone of microwave energy ahead of the vehicle. In the case of passive route markers, irradiation by the beacon causes a retransmission of a phase shifted signal which is detected in the "receive" intervals between the transmission of the pulsed beacon signal.This reflected signal is sensed by the B.S.R. to generate course headings under control of the main computer. In programming mode the vehicle is located over the course marker at the patrol origin point and rotated until aligned with the next course marker. The beacon then scans ahead of the vehicle and once accquisition of the next marker is achieved the vehicle can be moved off.

The long range scan is used on straight line course segments to acquire several successive markers (which are spaced to match the range gating of the beacon) but terminal guidance onto a marker (or closely spaced series of markers in the case of a route segment with many course changes) is achieved by a short range scan from either the primary radar or from an auxilliary beacon dedicated to this task.

This secondary beacon is used exclusively where the surveillance role does not require a B.S.R.

As with the flux-gate "nav-pack" the headings from the beacon radar pack are stored with distance-over-ground inputs to produce a programme that is capable of repetition in the patrol mode.

Because a model of the desired route is stored internally together with real time inputs for each route segment, any deviation from normality (as might occur with sabotage or displacement of the markers) is detected and generates the appropriate response.

Active markers incorporate a battery powered transponder. When not illuminated by the vehicle beacon the markers are in a stand-by (no battery drain) mode but reception of the pulsed microwave signal from the search radar causes them to transmit an acquisition signal back to the vehicle. Because an active microwave or radio frequency source is employed in the markers, significant improvements in S/N ratio are obtained and operation in an E.C.M. environment becomes more positive.

4. Remote Control Mode If, on receipt of a target return, the operator is unsure whether the contact is genuine or not he can select the fourth (remote control) mode and assume command of the vehicle. Receipt of a telecommand carrier signal (of more than 5 sec. duration) generates an interrupt of either patrol or surveillance sweep operations. At the same time the vehicle begins to write into an empty R.A.M. block guidance telecommands and resulting vehicle headings. A minimum of ten channels are provided for telecommand as follows 1. Forward 6. Tilt 2. Reverse 7. Zoom (option) 3. Left 8. Head elevate and retract (option) 4. Right 9. Handshake 5. Pan 10. Override.

Additional optional channels can be provided to control other functions. By writing all remote control guidance commands the vehicle records its path away from the programmed route. If no telecommand signals are received for a pre-set interval (usually 1 5 secs.) as, for example, when the operator completes his "off route" inspection or if L.O.S. occurs due to dead spots, screening, etc. then the vehicle reads this data and feeds reciprocal headings (via the M.P.U.) and guidance signals to the traction controller. The vehicle thus returns to the patrol route and reverts to mode 3 operation. If operational conditions such as rough ground may cause errors in the back track to the start point the vehicle can be equipped with an optional homing aid in the form of active or passive markers which can be dropped when mode 4 is selected. These provide an accurate fix from which the programmed route can be resumed.

Energy Maintenance and Survival Monitor In modes 1-4 a continuous monitor with priority interrupts and dedicated subroutine checks vehicle status. The three main power buses (M.P.U., traction and sensors/interfaces) are monitored by a power monitor card which interrupts any mode to report "low battery".

If running in mode 3 a sub routine can be initiated to allow the vehicle to seek a re-charge point or, if an onboard generator is fitted, to hold the programme whilst re-charging takes place.

Defence Sensors Defence sensors fitted as standard include C.C. wiring on all looms and intertia switches on the double walled equipment and traction bays. Inputs from these Gross Attack Damage (G.A.D.) sensors generate a priority interrupt in modes 3 and 4, cause transmission of an alarm signal and arm any defence countermeasures. If the G.A.D. input is not cancelled within 1 5 seconds all counter-measures fire. Optional defence sensors include a hostile target indicator and manalert which senses the presence of anyone who closely approaches the vehicle.

Tactile Sensors An input from the front bumper interrupts mode 3 and initiates a sub-routine. The vehicle stops, reverses one metre, indexes the head to the centre line and tilts the camera to the full "eyes down" position (--450). The routine also keys the telemetry transmitter which sends the "I have a tactile contact" code prefixed by the vehicle identification. In mode 4 a rear bumper contact (when in reverse) stops the vehicle and transmits the T.C. code.

In mode 5 the tactile inputs function as follows: Front contact = reverse and random turn Side strake contacts = turn away from the obstacle Vehicle Displacement Sensor In modes 3 or 4 this sensor keys the telemetry transmitter to report "vehicle displacement" whenever a pitch or roll of more than 450 is sensed. Should such a displacement occur in mode 3 the input is also interpreted as a G.A.D. input and selects mode 5.

Current Monitors If either the traction motor or any head servo exceed normal surge current ratings, as for example, would occur if stalled, the current monitors generate an interrupt (in mode 3) and reports to the base station. Accidental obstruction of the vehicle of the head is therefore sensed and would normally be corrected by selecting mode 4. If, however, no action is taken to correct the abnormal condition within a predetermined time the M.P.U. interprets the input as G.A.D. This guards against deliberate attempts to halt the vehicle or restrict head movement.

5. Survival Mode If the vehicle selects mode 5 following any G.A.D. input that is not cancelled, two alternative survival procedures can be adopted. If the M.P.U. is still on line (data out on the mode 5 port within, say, 5 seconds) a reciprocal course heading is selected and the Traction Controller is commanded to jump from "loiter" speed to "sprint". Since the vehicle may be running blind tactile inputs take priority as previously described. If the telecommand receiver is still on line this panic retreat can be overridden by selecting mode 4 thus allowing a more orderly withdrawal.

If however, the M.P.U. cannot output data to the mode 5 port and mode 4 cannot be selected (control and communications damage) the vehicle powers down all buses except those supplying any defence countermeasures.

Vehicle/Base Communications To avoid the complication and cost of high data rate machine code communications between the M.P.U. and the base station V.D.U., direct connection between these elements is normally only possible via the vehicle umbilical during "off watch" periods. At all other times all messages from the vehicle are restricted to a number of predetermined texts which are transmitted by the onboard telemetry transmitter. Receipt of a telemetry code word causes display of the appropriate text stored in P.R.O.M.

within the V.D.U. Air time is thus kept to a minimum and since the codes can easily be changed the security of the link is enhanced. Each code word is formatted as 8 bits for the vehicle identification prefix followed by 8 bits for the message text.

The standard vocabulary is as follows:- 1. (Vehicle number): "on watch". (transmitted immediately prior to umbilical disconnect).

2. Prefix: '1 have a tactile contact" 3. Prefix: "Vehicle Displacement" 4. Prefix: "Low Ba ttery" 5. Prefix: "Power bus overload" 6. Prefix: ''Ack....Mode 4 selected" 7. Prefix: "Reverting to Mode 3" (transmitted after a Mode 4 excursion, an override or after recharge) 8.Prefix: "G.A.D. Input-Selecting Mode 5" 9.--15. Prefix: "/ have a contact" (Seven message texts assigned to the specific surveillance sensors) 16. Prefix: "Control acknowledge " (handshake request) Note:- Video returns from the camera are transmitted direct to the base station where they are processed by a field programmable video detector such as the Grundig V.C. 75 which provides its own alarm and outputs to a conventional display. The video display is divided into a predetermined number of fields (up to 32x32) and the unit detects movement that occurs within a chosen zone.

If, for special mission profiles, direct access to the M.P.U. is required the standard telemetry and telecommand radios can be replaced by a "SPARQ" data link and additional onboard memory. This provides a secure duplex communications link between the vehicle and the remote terminal thus allowing a trained operator to communicate in a high level language and greatly extending the number of message texts, graphics and other information that could be displayed Whilst such a facility might be useful is specialised applications such sophistication is not considered desirable for the majority of mission profiles where one of the principle benefits of the vehicle system is that although the equipment is complex highly skilled operators are not required.

To compensate in some measure for the limited standard vocabulary optional base station equipment can be provided to display graphics such as route maps with super-imposed vehicle locations (from vehicle tracking receivers).

Operator Disciplines Before any operator can assume control he must first "check-in" by inserting his ID card into the control console and enter his personal ID code on the alpha-numeric keyboard. The terminal equipment logs this action on the V.D.U. and prints out the signing on with time and date. This action also releases the controls to the operator. In normal use an operator would assume control well before scheduled patrols were due to begin. Vehicle status lights displayed on the V.D.U. would normally be indicating that the vehicle was off watch and that re-charging of the vehicle batteries was in progress. The operator then selects the desired operating mode (normally 3) and awaits the powering up and status check sequence demanded by the real time clock.

During the diagnostic monitor run any errors are displayed and an unskilled operator can check the system manual to determine what action to take. On completion the vehicle announces its status by outputting "(vehicle code) Ready -Acknowledge". This latter request is the first handshake required during the mission. Subsequent handshakes are requested at random intervals and the operator must reply within a pre-set time window by pressing the handshake button on his telecommand transmitter and then entering his personal ID number on the V.D.U. keyboard, (these ID's are not displayed or printed for obvious reasons). If an operator does not perform the requested handshake the terminal equipment initiates a two stage alarm sequence.Initially, a loud audible warning sounds in the base station and if not cancelled the equipment transmits (by conventional methods) an alarm message to the appropriate actioning authority. During the first stage alarm period the vehicle interrupts its mode 3 programme and waits for a preset period before selecting mode 5.

Facilities can be provided to allow an operator to input a duress code in place of his personal ID code which results in an immediate (silent) alarm transmission.

Specifications The vehicles are essentially custom built to suit specific roles.

The following specifications relate to a vehicle intended for operation on reasonably level ground (e.g. airfield patrol).

Main Dimensions (approx.) Length 2.28 metres Width 1.4 metres Height (less head and antennas) 0.86 metres Height (head lowered) 1.92 metres Height (head elevated) 2.75 metres Weight varies with sensor package and mission profile but typically 286 Kg.

Mechanical (hull) The backbone of the vehicle is a ladder construction chassis around which is formed a bodyshell of high density vacuum moulded polyethylene. The chassis and body are designed to flex to offer the least possible impact resistance when meeting an obstacle. The underside of the hull is reinforced by an aluminium plate to protect it from sharp rocks.

The hull topside supports the head pantograph and provision is made for mounting an F.M.C.W.

radar or further B.S.R. on the rear decking together with the telemetry antennae.

Mechanical (running gear) The vehicle is powered by a small D.C. 2 H.P. electric motor which drives through a torque converter and gearbox to a pair of clutches. Each clutch output shaft is coupled via a chain drive to each of the driven axles which carry six wheels (three per side). Each wheel carries a soft and flexible ribbed balloon tyre giving an extremely low ground pressure.

The vehicle is skid steered by declutching the drive to one set of wheels. Apart from bestowing on the vehicle an exceptional cross country all-terrain performance the balloon tyres and sealed hull amphibious operation should patrol requirements dictate (i.e. patrol of cooling water intake channels at power stations on the coast). This motive power and steering arrangement bestows on the vehicle a loiter speed of 5 Km/H; and a 1 800 turn on a 1 in 3 gradient capability. The vehicle can accommodate a step obstacle height of 1 8 cm. Motors up to 6HP can be fitted to allow execution of 1 800 slew turns on 1 in 1 slopes if required although mission duration without recharging is impaired.

With the aforementioned running gear (2HP) a traction battery pack of high energy (22 watt hours/lb) batteries will provide an 8 hour mission capability with surveillance/patrol ratios as high as 0:1; i.e. constant patrol.

Where the lowest possible ground pressure is required together with improved stepheight clearance the tyres and wheels can be shed with special tracks based upon a design originated at the A.F.V. Research Establishment. Moulded in one piece these tracks provide exceptional grip in marshy or dessert terrain and in soft snow conditions.

Electrical The M.P.U. and related support equipment is designed for severe environment use and will operate reliably over M.l.L. spec. temperature ranges.

Operating frequencies for video, telemetry and telecommand transmissions can be provided to suit local regulations but certain preferred bands are normally used. Military Frequencies can also be specified.

The standard video transmitter has a 5W peak output giving a nominal range of 2 kilometres with vertical UHF whips. Range is dependant upon terrain and environment but high power transmitters (up to 70W) are available to special order.

Input is 1 V peak positive CCIR standard 625 lines. Nominal current consumption 1 A at 12-16 V d.c. The transmitter has an integral ni-cad back-up battery for emergency use giving 1 hour transmission.

Telemetry and Telecommand Preferred frequencies.

Either High Band VHF or UHF. Low Band UHF can be specified for certain applications. 1-5W onput as standard. High power available to special order.

Suggested Sensor Packages Sensors fitted to the vehicles perform two separate functions. Defence Sensors are provided to protect the vehicle from deliberate sabotage or accidental damage. Surveillance Sensors are provided to permit the vehicle to execute its reconnaissance role and may be varied to suit particular mission profiles.

Defence Sensors As previously described four groups of defence sensor are provided in the basic vehicle configuration. These are: 1. Gross Attack Damage Sensors.

2. Tactile Sensors (Front and rear bumpers and side strakes).

3. Displacement Sensors.

4. Current Monitors.

For high risk mission profiles two other optional defence sensor packages might be considered.

5. Manalert. This bio-sensor detects the EMG signature of human muscle activity and gives warning of anyone who closely approaches the vehicle. (Normally used only when vehicles are parked "off watch" and undercover).

6. G.S. 20 Radar. A low power X-Band C.W. radar that provides instantaneous indication of the direction of hostile fire relative to the vehicle.

Where several vehicles are to be deployed on one site each vehicle may be equipped with a form of I.F.F.

Surveillance Sensors Provision is normally made for up to seven surveillance sensors of which one -TV. is always fitted and the remainder are chosen to suit operational requirements. The television camera can however be specified according to customers choice and can range from medium resolution types 625 lines, 50 fields, (Light levels down to 20 lux at f/2; dynamic range 1:5000; resolution 400 lines; SN ratio 38 db), to any of the wide range of very low light level units available with S.l.T. tubes, image intensifiers, etc. Where image convertor optics are specified an l.R. spot light can also be fitted. Visible light target designation can be accomplished by provision of a "Streamlite" very high intensity 0.1.

spot. The high current consumption of both IR and visible search lights necessitate the fitting of an additional high capacity battery to supply the vehicle's No. 3 power bus.

For operation on reasonably level ground (mission profiles like airfield perimeters, border patrol, etc.) the following mix of surveillance sensors might be considered:- 1. Gun microphone 2. F.M.C.W. radar type 1 65F360 coverage.

Target detectiont Crawling man 1 6M Walking man 30M Vehicle 60M Taxiing aircraft 1 30M 3. Battlefield Surveillance Radar The primary long range sensor, the pulsed doppler B.S.R.~provides vehicles with the capability of identifying vehicle targets at ranges up to 4000 M and man targets up to 1000 M. Automatically range gated during the surveillance sweep, the type of BSR fitted would depend upon operational environments. For airfield perimeter duties or operation in desert/snow field conditions (low clutter areas) a BSR with an artificial clutter reference such as the MESL Oasis would normally be specified.

Operation in wooded or urban areas with high clutter reflections can be accommodated by use of clutter locked BSR's such as the GEC Shrimp. Oasis B.S.R.'s are modified to perform the dual role of surveillance sensor and navigation beacon as previously described.

4. Geophone Sensor For additional detection of the movement of personnel and wheeled or tracked vehicles during a surveillance sweep, vehicles can be fitted with a Protec Shield geophone and signal processing unit.

The siesmic head is emplaced by a servo ram under the vehicle. The Plessey 1 A 8 geophone sensor may be fitted as an alternative to the Shield unit.

Two spare surveillance channels are provided in the sensor interface and these could be utilised by fitting sensors with non-speech band outputs like Passive Infra-red sensors or Magnetic Anomaly Detectors. Channels one to four can connect sensors with audio pass band outputs (50 Hz to 3 kHz) to the telemetry transmitter on receipt of a target return so that an operator can evaluate the target signature in his headset.

Within reasonable constraints of physical size and power consumption almost any sensor package may be specified for use with the vehicle system.

Defence Countermeasures For operation in hostile environments and for special duties like riot control, vehicles may be armed with non-lethal defences. Standard options include a) CS or Mace projectors.

b) A shockstick array on each quadrant of the vehicle.

c) Liquid dye dispenser.

d) P.A. system with re-entrant horn speakers rated for Curdler operation.

e) 35 mm still camera for suspect identification (supplements base station V.T.R.).

The vehicle chassis is provided with hardpoints and is stressed to accept certain offensive countermeasure equipment for EOD tasks and other special duties. Tactical roles (e.g. forward reconnaissance) are facilitated by the vehicles low profile, small radar cross section and low IR, acoustic and magnetic signatures.

Figures in the Drawings One vehicle of the invention will now be described by way of example with reference to the accompanying illustrative drawings in which: Figure 1 is a perspective view of a surveillance vehicle in its operational position, and Figure 2 is a side view of the vehicle of Figure 1 with its sensors in the folded-down position.

Detailed Description of Drawings Referring to the drawings, the vehicle includes a hull 2 mounted on two endless tracks 4 and 6 which extend along opposite sides of the hull. When not in use, the umbilical 8 for charging the vehicle batteries is stored at the front of the hull 2. An antenna 1 0 for FMCW radar is located at the rear of the hull, and an antenna 12 for receiving commands when the vehicle is in the remote control mode is located in the forward region of the vehicle.

The vehicle sensors are mounted on top of an elongate boom 14 which is pivotally mounted at its lower end to the forward region of the hull. This boom 14 can be pivoted between its operational position illustrated in Figure 1 and its folded-down position illustrated in Figure 2 by means of an actuating ram 1 6. The sensors comprise an infra-red search light 18, a television camera 20, BS radar 22, a passive infra-red detector 24, and a gun microphone 26. 28 is a UHF co-linear antenna for television and sound transmission. These sensors are mounted on a head 30 which is itself rotatably mounted on the boom 14, so that the head can swing or pan through an arc of 2000.

The detailed construction and various modes of operation of this vehicle are as previously described in this Specification.

Claims (14)

Claims

1. A vehicle programmable to travel along and survey a preselected route independently of a control station, and to report to the control station any change in environment from a preselected normal or safe condition.

2. A vehicle as claimed in Claim 1, equipped with appropriate sensors.

3. A vehicle as claimed in Claim 2, in which said sensors are adapted are adapted to sense infrared emitting targets and siesmic disturbances.

4. A vehicle as claimed in Claim 2 or Claim 3, in which said sensors are arranged to transmit information only when a change in the environment is detected.

5. A vehicle as claimed in any preceding Claim, carrying a microprocessor based logic and control system.

6. A vehicle as claimed in Claim 5, in which the said logic and control system has a large memory capacity to direct a pre-programmed patrol path and to monitor all system functions.

7. A vehicle as claimed in Claim 5 or Claim 6 as dependent upon any one of Claims 2 to 4, including interface equipment connecting onboard sensors with the logic and control electronics.

8. A vehicle as claimed in any one of Claims 2 to 7, including multichannel telemetry and telecommand radio links to relay sensor data to an operator.

9. A vehicle as claimed in any one of Claims 5 to 8, in which said logic and control system is operable to allow the vehicle to function in a selected one of a plurality of modes.

1 0. A vehicle as claimed in Claim 9, in which one of said modes is a patrol mode as hereinbefore defined.

1 A vehicle as claimed in Claim 9, in which one of said modes is a remote control mode as hereinbefore defined.

12. A vehicle as claimed in Claim 9, in which one of said modes is a survival and energy maintenance mode as hereinbefore defined.

13. A vehicle as claimed in Claim 9, in which one of said modes is a manual mode as hereinbefore defined.

14. A vehicle as claimed in any preceding Claim, and equipped with radar.

1 5. A vehicle as claimed in any preceding Claim, and equipped with night vision equipment.

1 6. A vehicle substantially as herein described and shown in the accompanying drawings.