WO2009075615A1

WO2009075615A1 - Vehicle immobilization system and a method of immobilizing a vehicle

Info

Publication number: WO2009075615A1
Application number: PCT/SE2007/001106
Authority: WO
Inventors: Lars Johansson; Mikael Karlsson
Original assignee: Volvo Lastvagnar AB
Current assignee: Volvo Truck Corp
Priority date: 2007-12-12
Filing date: 2007-12-12
Publication date: 2009-06-18
Anticipated expiration: 2010-06-12

Abstract

There is provided a vehicle immobilization system (180, 230) for a vehicle (10). The vehicle (10) includes a powertrain with an upper part (80) and a lower part (90). The upper power train part (80) has a source of motive power (130) and a gearbox (100) coupled thereto. The upper powertrain part (80) is operable to provide motive power from an output of the gear box (100) to the lower power train part (90) of the vehicle (10) for propelling the vehicle (10) when the immobilization system is in its inactivated state. Beneficially, the immobilization system (180) is operable to apply at least one brake (180, 230) to the upper power train (80) to immobilize the vehicle (10). The at least one brake (180, 230) applied to the upper power train part (80) includes an engine brake (180) and/or a gearbox brake (230).

Description

Vehicle immobilization system and a method of immobilizing a vehicle

Field of the invention

The present invention relates to vehicle immobilization systems, for example to vehicle immobilization systems for hindering theft of vehicles equipped with such systems. Moreover, the present invention also concerns methods of immobilizing vehicles by employing aforesaid vehicle immobilization systems. Furthermore, the present invention also relates to software products stored and/or conveyed on a data carrier, the software products being executable on computing hardware for implementing aforesaid methods of immobilizing vehicles. Additionally, the present invention concerns vehicles equipped with such immobilization systems.

Background of the invention

Road vehicles represent items of considerable value and are therefore often a focus for theft. Moreover, heavy commercial vehicles are often carrying cargos of considerable value which are of potential interest to criminal organisations. Furthermore, heavy commercial vehicles in the hands of unauthorized individuals can inflict potentially enormous damage if driven in a reckless manner. In one or more of the aforementioned situations, it is desirable to be able to immobilize a vehicle to mitigate theft or damage to the vehicle.

Immobilization systems are known, for example as described in a published international PCT application no. PCT/US99/14915 (WO 00/15480). In this international application, there is disclosed a safety-enhancing automatic air parking brake lock system which is alleged to eliminate accidental and inadvertent disengagement of an air parking brake of a vehicle. The lock system is susceptible to being easily installed in a brake system having a manually operated loading valve. When the valve is open, air is supplied to an air parking brake mechanism for releasing the air parking brake. Conversely, when the valve is closed, air pressure is relieved for disengaging the air parking brake. The aforesaid lock system is implemented by including a solenoid valve in-line between an air source and loading valve. Moreover, the solenoid valve has an exhaust vent which is operable to release air-line pressure between the solenoid valve and the loading valve in an event that the solenoid valve is de-energized. The solenoid valve is wired into an ignition switch of the vehicle so that the solenoid valve is de-energized when the ignition is turned to its "off" position, thereby closing the solenoid valve to block the air supply to the loading valve; the air pressure between the solenoid valve and the loading valve is then released through the exhaust vent of the solenoid valve. The loading valve is operable to automatically close when its upstream pressure falls below a pre-determined value, thereby releasing the air pressure between the loading valve and the air brake through the vent of the closed loading valve. Thus, depending upon initially whether or not the loading valve is closed, turning off the ignition of the vehicle causes the air parking brake to engage or maintain its engagement and thereby inhibits movement of wheels of the vehicle until the parking brake is purposely reset.

Contemporary vehicle immobilizer systems generally concentrate on two aspects:

(a) authentication of a driver's authorization to drive the vehicle, for example by exchanging identification codes electronically, by voice recognition, by biometric analysis to mention a few known examples;

(b) brakes of the vehicle remained engaged and/or ignition of an engine of the vehicle is disable unless it is identified in (a) above that a correct code or identity has been presented by the driver.

These aforesaid contemporary immobilizer systems generally are implemented in sophisticated electronic modules, often operating under software control.

A third party attempting to steal a vehicle equipped with aforesaid immobilizer system is potentially faced with two choices:

(i) to mimic characteristics of an authorized driver to gain control of the vehicle by working cooperatively with the sophisticated electronic modules thereby not inflicting any change to the vehicle but otherwise gaining control of the vehicle; and/or

(ii) bypassing the immobilizer system by "hot wiring", replacing whole immobilizer units with substitutes programmed in favour of the third party, or simply using brut force such as lifting the vehicle onto a trailer using a crane or towing the vehicle by force.

It will be appreciated that a higher degree of complexity for the sophisticated electronic modules associated with immobilization systems renders unauthorized intervention by third parties more difficult. This unfortunately focuses the attention of third parties on more brut- force approaches.

In order to address a technical problem of theft posed by such brut-force methods, there is a need for yet more sophisticated immobilization systems which are more complex to circumvent by third parties. Summary of the invention

An object of the present invention is to provide a vehicle immobilization system which is more effective to resist vehicle theft.

According to the first aspect of the invention, in order to address the object of the present invention, there is provided a vehicle immobilization system as claimed in appended claim 1.

The invention of advantage in that a greater degree of immobilization is capable of being achieved by applying one of more brakes to the upper powertrain part.

Optionally, in the vehicle immobilization system, the at least one brake includes at least one of: an engine brake associated with the source of motive power, and a gearbox brake associated with the gearbox. Such upper powertrain brakes are more difficult to circumvent than wheel brakes and are therefore potentially more effective in immobilizing the vehicle; thieves would not normally expect there to be additional immobilization measures in addition to wheel immobilization measures.

More optionally, in the vehicle immobilization system, the source of motive power includes a piston-cylinder combustion engine, wherein the engine brake is implemented by configuring the combustion engine to function as an air pump for compressing a volume of gas to generate a retarding force to hinder movement of the vehicle when the immobilization system is in its activated state.

More optionally, in the vehicle immobilization system, the gearbox brake is operable to engage one or more cog wheels in the gear box to hinder rotational power communication through the gear box when the immobilization system is in its activated state.

Optionally, in the vehicle immobilization system, the immobilization system includes a position measurement arrangement for determining a position of the vehicle for use in combination with immobilizing the vehicle.

Optionally, in the vehicle immobilization system, the at least one brake is implemented by employing components operable to provide or communicate motive power when the vehicle is in operation also for providing a retarding force for immobilization purposes when the vehicle is immobilized. Such an implementation of the immobilization system is especially beneficially in that existing parts of the vehicle are synergistically applied also to implement immobilization measures.

According to a second aspect of the invention, there is provided a method of immobilizing a vehicle as claimed in appended claim 7.

Optionally, when implementing the method, the at least one brake includes an engine brake associated with the source of motive power, and a gearbox brake associated with the gearbox.

More optionally, when implementing the method, the source of motive power includes a piston-cylinder combustion engine, wherein the engine brake is implemented by configuring the combustion engine to function as an air pump for compressing a volume of gas to generate a retarding force to hinder movement of the vehicle when the vehicle is in an immobilized state.

More optionally, when implementing the method, the gearbox brake is operable to engage one or more cog wheels in the gear box to hinder rotational power communication through the gear box when the vehicle is in its immobilized state.

More optionally, the method includes a step of determining a position of the vehicle using a position measurement arrangement for determining a position of the vehicle for use in combination with immobilizing the vehicle.

More optionally, when implementing the method, the engine brake is implemented by employing components operable to provide or communicate motive power in a non- immobilized state also for providing a retarding force for immobilization purposes.

According to a third aspect of the invention, there is provided a vehicle operable to employ a method pursuant to the second aspect of the invention.

According to a fourth aspect of the invention, there is provided a software product stored on a data carrier, the software product being executable on computing hardware for implementing the method pursuant to the second aspect of the invention. It will be appreciated that features of the invention are susceptible to being combined in any combination without departing from the scope of the invention as defined by the appended claims.

Description of the diagrams

Embodiments of the present invention will now be described, by way of example only, with reference to the following diagrams wherein:

Figure 1 is an illustration of a vehicle including a vehicle immobilization system pursuant to the present invention operable to invoke a vehicle engine brake, also known as a Volvo Engine Brake (VEB) or Volvo Compression Brake (VCB), and/or a gearbox brake;

Figure 2 is an illustration of a function of a vehicle engine brake;

Figure 3 and 4 are schematic diagrams illustrating a practical implementation of the vehicle engine brake of Figure 2; and

Figure 5 is a schematic diagram of a gear box of the vehicle of Figure 1 , the gear box being configurable to implement a gearbox brake for immobilizing the vehicle.

Description of embodiments of the invention

In overview, the present invention is concerned with vehicle immobilization systems which are operable to immobilize vehicles by directly hindering rotation of their engines and/or motors and/or gearboxes, optionally in addition to interrupting supply of fuel and/or energy supply to the engines and/or motors. Such a profound degree of immobilization is intended to mitigate a risk of gross brut-force methods being adopted by third parties to steal the vehicles, for example by vehicle towing operations, which would often destroy various wheel brakes of a vehicle. On account of conventional contemporary practice being to concentrate solely on wheel brakes and fuel-interruption immobilization, third parties confronted with vehicles immobilized pursuant to the present invention would experience considerable practical difficulties and potentially would not be able to quickly circumvent associated immobilization measures. Referring to Figure 1, there is shown a vehicle indicated generally by 10 including a front tractor unit 20 including a driver cabin, and a rear trailer unit 30 for carrying a cargo to be transported. Optionally, the trailer unit 30 is detachable from the tractor unit 20. Moreover, the rear trailer unit 30 is optionally pivotally coupled to the tractor unit 20. Optionally, the tractor unit 20 provides motive power to its wheels.

The front tractor unit 20 includes a pair of steerable front wheels 50 equipped with disc brakes 60 and parking brakes 70. There is further included a powertrain comprising an upper powertrain part 80 and a lower powertrain part 90 for propelling the vehicle 10 when in operation. The upper powertrain part 80 includes a source of motive power 130 and a gearbox 100 including adjustable gears; optionally, the gearbox 100 can be an ATM (Automated Manual Transmission) which is designed so as to remain in a non-neutral engaged state when the vehicle 10 is in a parked state. The gearbox 100 is coupled between a differential gear 110 of the pair of rear wheels 120 and the source of motive power, i.e. a motor and/or engine 130 of the vehicle 10.

The motor and/or engine 130 is optionally implemented as at least one of:

(a) a piston-cylinder internal combustion engine, for example an Otto engine configured to burn diesel fuel, bio-diesel fuel, petrol, liquid petroleum gas (LPG), methane, hydrogen;

(b) a turbine engine, for example a gas turbine engine;

(c) a hybrid engine including both a combustion engine and an electric motor, optionally mutually coupled via an energy storage device; and

(d) an electric motor electrically coupled to a fuel cell arrangement operable to generate electrical power directly from oxidation of fuel.

In highly advanced versions of the vehicle 20, at least one of the gear box 100 and the motor/engine 130 are integrated in proximity of the set of wheels 50, 120. For example, when the motor and/or engine 130 is implemented as a series hybrid engine, the front set of wheels 50 and/or the rear set of wheels 120 can include switched reluctance traction motors therein or in close proximity thereto. The pair of double wheels 120 also furnished with disc brakes 160 and parking brakes 170.

In operation, the disc brakes 60, 160 are employed for slowing the vehicle 10 when in motion at high speeds, whereas the parking brakes 70, 170 are employed when the vehicle 10 is substantially stationary, for example parked on a steeply inclined slope of a hill. The parking brakes 70, 170 are beneficially implemented as a form of drum brakes. Whereas the disc brakes 70, 170 are designed to dissipates large amounts of thermal energy when invoked when the vehicle 10 is in motion, for example many kilowatts of thermal energy derived from movement of the vehicle 10 and its cargo, the parking brakes 70, 170 are designed to provide a very firm grip on the wheels 50, 120 respectively when the vehicle 10 is in a stationary situation, but do not need to dissipate large amounts of energy in operation.

The vehicle 10 is beneficially provided with a form of vehicle engine brake denoted by 180. An example of a vehicle engine brake is a proprietary Volvo engine brake (VEB) or Volvo combustion brake (VCB). The engine brake 180 is operable to provide a retarding force on an output shaft of the engine and/or motor 130 coupled via the gear box 100 and the differential gear 110 to the wheels 120. In order for this retarding force provided by the vehicle engine brake 180 to be effective at the wheels 120, the gear box 100 needs to be in a coupled state from its rotational input shaft to its rotational output shaft when the vehicle 10 is in motion or parked. The vehicle engine brake 180 is beneficial in that the engine/motor 130 is designed to be continuously cooled to remove power dissipation therein during normal operation thereof, for example by water cooling, and is thereby generally capable of dissipating kinetic energy associated with motion of the vehicle 10, thereby potentially avoiding unnecessary wear of the disc brakes 60, 160.

The vehicle 10 further includes a management unit 200 which is responsible for supervising operation of the engine and/or motor 130. The management unit 200 is especially important for hybrid vehicles wherein the engine and/or motor 130 includes a combustion engine, a motor/generator and a rechargeable battery configured to implement regenerative braking for recharging the battery as well as supervising recharging of the battery. The management unit 200 is also operable to control fuel injection via a fuel control unit into the combustion engine, for example for controlling generation of soot and/or NOx therein when in operation.

The management unit 200 is also operable to provide a vehicle operating system for creating a driving interface environment for a driver of the vehicle 10, for example coupled in communication with a driving console of the vehicle 10 whereat the driver inputs driving commands when driving and steering the vehicle 10. Moreover, the management unit 200 is coupled in communication with the gear box 100, with the fuel control unit and with the vehicle engine brake 180. Such communication is beneficially implemented via a CAN data bus or similar. Optionally, the front set of wheels 50 is steered using a servo actuator controlled via the management unit 200, namely "drive-by-wire" control in order to afford enhanced driver comfort when controlling a trajectory of the vehicle 10. The vehicle 10 further comprises a security module 210 optionally coupled in communication with a wireless interface 220 for determining a GPS satellite-derived position reference for the vehicle 10 and/or a GPRS position reference for the vehicle 10 based upon mobile telephone, namely cell-net, infrastructure. The wireless interface 220 is also optionally coupled in operation in communication with a fleet operator control centre managing a fleet of vehicles including the vehicle 10.

Optionally, the gear box 100 is also designed to include immobilization features. For example, when the gear box 100 is susceptible to being immobilized by selectively actuating its cog wheels so as to mutually engage in a manner which prevents input and output shafts of the gearbox 100 being rotated relative to a casing of the gear box 100. The cog wheels are thereby synergistically capable of providing motive power transmission during normal operation, as well as immobilization when the vehicle 10 is in a stationary state, for example in a parked state. Such an immobilization function provided by the gear box 100 will hereafter be referred to as a gearbox brake (GB) and is denoted by 230 in Figure 1. The gearbox brake 230 will be described in more detail later.

Operation of the vehicle 10 will now be described in general overview.

When in a parked state, the disc brakes 60, 160, the parking brakes 70, 170 as well as the vehicle engine brake 180 and/or the gearbox brake 230 are engaged to prevent the vehicle 10 from being towed away or otherwise moved, namely fully immobilized. Additionally, the fuel control unit of the engine 130 is optionally deactivated so that fuel injection into the engine 130 is prevented. Beneficially, the vehicle engine brake 180 is implemented in a mechanical manner which does not depend upon a provision of electrical power, thereby preventing third parties from simply disabling the vehicle engine brake 180 merely by disconnecting a battery of the vehicle 10; similar considerations apply also to the gearbox brake 230. Beneficially, actuators within the gear box 100 are operated using compressed air provided from a compressed air reservoir, wherein the engine and/or motor 130 is rotationally coupled to an air pump for maintaining the air reservoir provided with compressed air. Alternatively, or additionally, one or more actuators for controlling operation of the gear box 100 are hydraulically operated using a compressed servo liquid such as oil.

The disc brakes 60, 160 and the parking brake 70, 170 are beneficially operated by compressed air, or compressed servo liquid such as oil; the brakes 60, 160, 70, 170 are thereby all engaged in an absence of sufficient compressed air pressure or servo liquid pressure available within the vehicle 10, namely when the motor and/or engine 130 of the vehicle 10 is inactive.

A third party attempting to steal the vehicle 10 when in a parked state by towing it away would conventionally attempt to firstly disengage the brakes 60, 160, 70, 170 and then secondly tow the vehicle 10 away. However, the third party would not normally anticipate provision also of the vehicle engine brake 180 and/or the gearbox brake 230. Having discovered the vehicle 10 to be virtually impossible to tow, the third party would then attempt to "hot-wire" bypass the engine management unit 200 to start the engine and/or motor 130 only to find that the engine and/or motor 130 had also been immobilized. In a time duration that it would take for the third party to devise a method of bypassing, namely "hot wiring", the vehicle engine brake 180, there would be potentially services such police available to intervene on account of the security module 210 having communicated one or more messages via its wireless interface 220 to a fleet operator control centre that the vehicle 10 had been tampered with, together with a coordinate reference for the vehicle 10 as determined by the GPS or GPRS position measurement arrangement of the vehicle 10. The fleet operator control centre is beneficially operable to decide whether or not the situation were unexpected or not, and to summon assistance such as a police presence as deemed appropriate.

It is conventionally considered that the brakes 60, 160, 70, 170 together with disabling the fuel control unit of the engine 130 is sufficient to immobilize the vehicle 10. However, thieves are becoming increasingly sophisticated such that such conventional contemporary immobilization measures are not now a guarantee against theft. A conventional approach to enhancing security is to employ more complex keys and interfacing between the security module 210 and/or the management unit 200, for example encrypted exchange of enabling pass-words. Such an approach does not however anticipate thieves simply bypassing such measures and utilizing brut-force approaches. On account of the vehicle engine brake 180 being a mechanical device, thieves stripping out the security module 210 still have to contend with a problem that the vehicle engine brake 180 is engaged by default when the vehicle 10 is parked with its engine and/or motor deactivated. Use of the gearbox brake 230 further frustrates such thieves.

In normal use, when the vehicle 10 is being driven by a driver authorised by the fleet operator control centre, the driver offers a key to the management unit 200 which receives a first code K1 from the key. The management unit 200 in cooperation with the security module 210 can optionally perform one or more verification functions: (a) the management unit 200 in cooperation with the security module 210 are operable to compare the first code K1 with a security code K2 earlier provided to the management unit 200 in cooperation with the security module 210 in respect of the vehicle 10; if the codes K1 and K2 are in agreement, the management unit 200 in cooperation with the security module 210 are then operable to deactivate immobilization of the vehicle 10;

(b) the management unit 200 in cooperation with the security module 210 are operable to communicate the code K1 by wireless, for example in encrypted format, to the fleet operator control centre to confirm back by wireless that the code K1 is valid, whereafter the management unit 200 in cooperation with the security module 210 are then operable to deactivate immobilization of the vehicle 10; and

(c) the code K1 in the key is previously composed to include biometrical parameters of the driver such that the key is individualised to the driver; when the driver offers the key to the management unit 200 in cooperation with the security module 210, the driver also allows the management unit 200 in cooperation with the security module 210 to biometrically measure the driver, for example by fingerprint analysis and/or facial feature analysis derived from a digital camera image from a camera mounted in a cab of the vehicle 10; thereafter, the management unit 200 in cooperation with the security module 210, either locally or in collaboration with the fleet operator control centre, are then operable to deactivate immobilization of the vehicle 10 in an event that the key K1 and biometrically measured characteristics of the driver are consistent.

The code K1 can optionally be a combination of a code stored electronically and/or mechanically upon the key together with a numerical or alpha-numerical code which the driver enters upon a keyboard included in the cab of the vehicle 10; the keyboard is coupled in communication with the management unit 200 and/or the security module 210.

The vehicle immobilization system as described in the foregoing is susceptible to considerably frustrating thieves attempting to steal the vehicle 10.

An implementation of the vehicle engine brake 180 will now be described with reference to Figures 2a and 2b wherein a combustion cylinder with its associated piston and con-rod are denoted by 300, 310, 320 respectively. The engine 130 is provided with one or more of such cylinder 300 and associated piston 310 wherein their one or more con-rods 320 are coupled to a crank shaft (not shown in Figure 2) which is operable in turn to actuate inlet and outlet valves 330, 340 respectively of the cylinder 300. The cylinder 300 also includes a fuel injector 350 whose fuel injection into the cylinder 300 under normal driving conditions is controlled by the aforementioned fuel control unit of the engine 130.

The engine 130 further comprises an inlet manifold 380 operating a pressure P1 and an outlet manifold 390 operable to function at a pressure P2 and vented via a mechanical pressure valve 395 operable to ensure that the pressure P2 does not exceed an upper threshold pressure level value Pth.

Figure 2a corresponds to a downward stroke of the piston 310 in the cylinder 300 as denoted by an arrow 400, whereas Figure 2b corresponds to an upward stroke of the piston 310 in the cylinder 300 as denoted by 410. The piston 310 is operable to reciprocate between a dead-centre top position denoted by 360, and a dead-centre bottom position denoted by 370. Moreover, the inlet and outlet valves 330, 340 are disposed in fluid communication with the inlet and outlet manifolds 380, 390 respectively.

When the vehicle 10 is immobilized and the engine 130 is not in operation, the vehicle engine brake 180 functions as an air pump:

(a) to suck air at the pressure P1 from the inlet manifold 380 via the inlet valve 330 into the cylinder 300 when the piston 310 is executing a downward stroke as illustrated in Figure 2a, the inlet valve 330 being at least partially open and the outlet valve 340 being closed; and

(b) to pump compressed air from the cylinder 300 via the outlet valve 340 into the outlet manifold 390 at the pressure P2 when the piston 310 is executing an upward stroke as illustrated in Figure 3b.

When the vehicle 10 is being towed by thieves with its vehicle engine brake 180 active, the engine 130 pumps air into the outlet manifold 390 which results in the outlet manifold 390 experiencing an increase in pressure and temperature therein. The mechanical valve 395 functions as a pressure release valve to prevent the outlet manifold 390 being pressurized excessively. The outlet manifold 390 is designed to withstand high operating temperatures under normal operation of the engine 130 when hot exhaust gases from the cylinder 300 are vented via the outlet manifold 390.

Under normal operation of engine 130 when propelling the vehicle 10, both valves 330, 340 are closed when the piston 310 is forced on its downward stroke in response the injected fuel being burned in the cylinder 300 to generate mechanical work from the engine 130. Moreover, the valve outlet valve 340 is opened for a part of period that the piston 310 is near its bottom dead centre to exhaust combustion gases from the cylinder 300 after which the inlet valve 330 opens to admit air into the cylinder 300.

It will be appreciated that very different control of the valves 330, 340 is required in relation to cam-shaft angle depending upon whether the engine 130 is employed in its normal fuel- burning mode of operation or its vehicle engine brake mode of operation. Moreover, so that operation of the vehicle engine brake 180 should not be circumvented merely by thieves "hot wiring" the management unit 200 or the security module 210, the vehicle engine brake 180 is beneficially implemented in a mechanical manner such that timing controls of the valves 330, 340 is mechanically alterable.

Referring to Figure 3, there is shown a timing shaft denoted by 500 which is coupled with the aforesaid craft shaft. The timing shaft 500 includes an annular timing member 510 associated with each cylinder 300 of the engine 130. The timing member 510 rotates in a direction as denoted by an arrow 520. Moreover, the timing member 510 includes a major lobe 530, and minor lobes 540, 550; the minor lobes 540, 550 are mutually disposed circa 60° apart, such that a midpoint X of the minor lobes 540, 550 is substantially on an opposite side of the timing member 510 to the major lobe 350 as illustrated. A pivotally-mounted cam follower 600 is operable via its contact roller 610 to abut onto the timing member 510, the cam follower 600 being coupled via a member 620 to control opening and closing of the valves 330, 340 normally held firmly closed by way of forces applied by helical springs 650, 660 respectively. Abutment of the cam follower 600 is controlled by pressure of a pressured oil supply in the engine 130 which adjusts a separation y.

The minor lobes 540, 550 are employed to implement the aforesaid vehicle engine brake (VEB) 180, whereas the major lobe 530 is operable to actuate the valves 330, 340 during normal active driving operation of the engine 130 when it delivers motive power. The distance y between the timing member 510 and the cam follower 600 is adjusted between a separation Y₁ in Figure 3 and a separation y₂ in Figure 4 to switch between vehicle engine brake (VEB) mode and operating engine mode in response to actuating oil pressure. When the engine 130 is non-operating, oil pressure falls causing the engine 130 to mechanically automatically assume its vehicle engine brake mode.

When the engine and/or motor 130 is implemented as gas turbine unit, the vehicle engine brake (VEB) 130 is beneficially implemented as a spring-biased actuated member which obstructs rotation of the turbine when the vehicle 10 is in its immobilized state, namely with the vehicle engine brake 180 engaged; when the engine and/or motor 130 is to be operated to propel the vehicle 10 under a normal driving situation, the actuated member is retracted so that the turbine is able to rotate in an unobstructed manner.

When the engine and/or motor 130 is implemented as a parallel hybrid power train comprising both a combustion engine and an electric motor/generator, the vehicle engine brake 180 substantially as depicted in Figures 2 to 4 is implemented for the engine brake 180 in the hybrid combustion engine, optionally together with the electric motor/generator having at least one of: its winding shorted together to provide extra drag, a spring-biased actuator is engaged to prevent a stator of the motor/generator from rotating.

When the engine and/or motor 130 is implemented as configuration of fuel cells and one or more electric motors, the vehicle engine brake 180 when active is implemented by at least one of: electrically disconnecting an electric output of the fuel cells from the one or more electric motors, obstructing motion of one or more stators of the one or more electric motors, blocking and/or bypassing provision of fuel and/or oxidizing agent to electrodes of the fuel cells.

In the foregoing, it will be appreciated that when the driver parks the vehicle 10 and leaves the vehicle 10, a vehicle immobilization system including the security module 210 and the management unit 200 in combination with the vehicle engine brake 180 and/or the gearbox brake 230 is operable to immobilize the vehicle 10 by applying the brakes 60, 70, 160, 170 together with the vehicle engine brake 180 and/or the gearbox brake 230 and disabling the fuel injection module of the engine 130. Such immobilization mitigates a risk that a thief or similar steals or tows away the vehicle 10. However, faced with such immobilization, criminals are more inclined to capture the driver and then force the driver to drive the vehicle 10 to a remote location whereat the cargo of the vehicle 10, for example, can be removed, for example to other vehicles for further illegal distribution.

Another manner, as elucidated in the foregoing, is that the driver is a criminal and cooperates with a criminal organisation to make it appear that the vehicle 10 has been stolen and its cargo removed; in other words, for total security, not only a measures against physical theft of the vehicle 10 necessary, but also measures to hinder the driver in an event of an authorized movement of the vehicle 10 occurring.

Optionally, the wireless interface 220 includes a GPS or GPRS apparatus for determining a spatial position of the vehicle 10. The security module 210 in cooperation with the wireless interface 220 is operable to periodically report, by wireless communication, information concerning operation of the vehicle 10 back to the fleet operation control centre. In an event that the vehicle 10 deviates along its expected route by more than a threshold distance, the control centre is capable by wireless communication to the wireless interface 220 and subsequently via the security module 210 to cause the vehicle engine brake 180 and/or the gearbox brake 230 to be applied to immobilize the vehicle 10 once the driver of the vehicle 10 has safely brought the vehicle 10 to a standstill. In order to drive the vehicle 10 further, the driver then needs to contact the control centre to explain why a deviation has occurred. Optionally, before the engine vehicle brake 180 and/or the gearbox brake 230 of the vehicle 10 is remotely applied by the control centre when the vehicle 10 has been safely brought to a standstill by the driver, the control centre sends the driver a warning message to the vehicle 10; such a warning is beneficially at least one of a visual and audio warning.

In the foregoing, it will be appreciated that the vehicle engine brake 180 and the gearbox 230 are distinct from the disc brakes 60, 160 and the parking brakes 70, 170 in that disc and parking brakes 60, 160, 70, 170 form a part of the lower powertrain 90, whereas the gearbox brake 230 and the vehicle engine brake 180 form a part of the upper powertrain 80. As elucidated earlier, for the vehicle engine brake 180 to be effective, there is requirement that the gear box 100 remains coupled between its input and output shafts or equivalent when vehicle immobilization pursuant to the present invention is invoked. However, even in an event that the gear box 100 is in neutral, the vehicle engine brake 180 is effective at hindering a thief trying to drive away the vehicle 10 by "hot wiring" and thereby activating the engine and/or motor 130.

The present invention is also concerned with methods of immobilizing vehicles using the vehicle engine brake (VEB) 180. Moreover, when such immobilization involves actions invoked by computer control, the present invention is also concerned with software products stored on data carriers, wherein the software products are susceptible to being executed by computer hardware for implementing these vehicle engine brake immobilization methods.

The aforementioned gearbox brake 230 shown in Figure 1 will now be further elucidated with reference to Figure 5. The gear box 100 shown schematically in Figure 5 is of the type called automated manual transmission (ATM) which is an unsynchronized manual gearbox with automatic control. The gear box 100 includes in sequence from the engine and/motor 130 to a differential gear 110: a splitter 800, a main section 810 and a range section 820. The splitter 800 includes an input shaft 850 coupled to a rotational output from the engine and/or motor 130. Moreover, the range section 820 includes an output shaft 860 for providing output power from the gear box 100 to the differential gear 110.

The splitter 800 comprises a first coupler 870 having three alternative configurations: A1 , B1 and C1. Moreover, the main section 810 includes a second coupler 880 having three alternative configurations: A2, B2, C2. Furthermore, the main section 810 includes a third coupler 890 having three alternative configurations: A3, B3 and C3. Lastly, the range section 820 includes a fourth coupler 900 having two alternative configurations: A4 and C4.

The gear box 100 includes the aforesaid input shaft 850, a side shaft 920, a main gearbox shaft 930, a reverse gear intermediate shaft 940 and the aforesaid output shaft 860. The shafts 850, 860, 920, 930, 940 rotate when in operation to communicate motive power therethrough. A first drive cog wheel 950 is mounted along the input shaft 850. An end of the input shaft 850 remote from the engine and/or motor 130 has a centre clutch plate 960 mounted thereto as illustrated. The side shaft 920 has mounted in sequence therealong: a second gear drive cog wheel 1000, a third drive cog wheel 1010, a fourth drive cog wheel 1020, a fifth drive cog wheel 1030 and a sixth drive cog wheel 1040. The drive cog wheels 1000, 1010, 1020, 1030, 1040 are of progressively reducing diameter, wherein the second cog wheel 1000 is largest in diameter and the sixth cog wheel 1040 is of smallest diameter. The first drive cog wheel 950 is in certain circumstances capable of rotating independently relative to the input shaft 850; moreover, the first drive cog wheel 950 is coupled to an upper clutch plate 1100 forming a part of the first coupler 870. Associated with the sixth cog wheel 1040 is a seventh drive cog wheel 1050 operable to cooperate with the sixth cog wheel 1040 as illustrated.

The main gearbox shaft 930 includes in sequence therealong from its end nearest to the centre clutch plate 960: an eighth drive cog wheel 1160 between the first coupler 870 and the second coupler 880, ninth and tenth drive cog wheels 1170, 1180 respectively between the second and third couplers 880, 890, an eleventh drive cog wheel 1190 between the third and fourth couplers 890, 900 respectively, and a twelfth drive cog wheel 1200 forming an inner cog wheel of a planetary drive gear of the range section 820. The second, third, fourth, fifth, sixth, and seventh cog wheels 1000, 1010, 1020, 1030, 1150 respectively are arranged to cooperate with the eighth, ninth, tenth, eleventh, twelfth cog wheels 950, 1160, 1170, 1180, 1190 respectively for transmitting motive power through the gear box 100. Moreover, the cog wheels 950 to 1190 are of progressively increasing diameter, wherein the cog wheel 950 is of smallest diameter and the cog wheel 1190 is of largest diameter as illustrated. The eighth cog wheel 1160 is coupled to a lower clutch plate 1300 of the first coupler 870 and to an upper clutch plate 1310 of the second coupler 880. The ninth cog wheel 1170 is coupled to a lower clutch plate 1320 of the second coupler 880. The tenth cog wheel 1180 is coupled to an upper clutch plate 1330 of the third coupler 890. The eleventh cog wheel 1190 is coupled to a lower clutch plate 1340 of the third coupler 890. The main gearbox shaft 930 also includes central clutch plates 1400, 1410, and an upper clutch plate 1420 associated with the second, third and fourth couplers 880, 890, 900 respectively as illustrated.

The range section 820 includes a planetary gear including the twelfth cog wheel 1200 functioning as a sun gear, four planetary cog wheels 1510 rotationally mounted offset onto a member 1500 coupled to the output shaft 860 as a planet gear, and a ring gear 1520 coupled to a central clutch plate 1550. The four cog wheels 1510 are operable to rotate to accommodate rotations of the twelfth cog wheel 1200 and the ring gear 1520. A lower clutch plate 1560 of the fourth coupler 900 is supported on a non-rotational bearing surface 1570.

The aforesaid configurations A1 , A2, A3, A4 correspond to the centre clutch plates 960, 1400, 1410, 1550 of the first, second, third and fourth couplers 870, 880, 890, 900 respectively being coupled to their upper clutch plates 1100, 1310, 1330, 1420 respectively. Moreover, the aforesaid configurations C1 , C2, C3, C4 correspond to the centre clutch plates 960, 1400, 1410, 1550 of the first, second, third and fourth couplers 870, 880, 890, 900 respectively being coupled to their lower clutch plates 1300, 1320, 1340, 1560 respectively. Furthermore, the aforesaid configurations B1 , B2, B3 correspond to the centre clutch plates 960, 1400, 1410 of the first, second and third couplers 870, 880, 890 respectively being in an uncoupled state. Thus, the first coupler 870 in the configuration B1 corresponds to the gear box 100 being decoupled from the engine and/or motor 130, namely in a "neutral" state.

Table 1 illustrates normal gear configurations for the gear box 100 shown in Figure 5 when the vehicle 10 is in motion.

Table 1: Normal driving operation of the gear box 100

The forward gears in Table 1 are not listed in a descending or ascending order of gearing ratio provided. However, pursuant to the present invention, certain configurations of the couplers 870, 880, 890, 900 are susceptible to resulting in the gear box 100 being in an immobilized state, namely the output shaft 860 being completely unable to rotate. Table 2 provides a list of configurations resulting in immobilization of the gear box 100, namely for implementing the gearbox brake 230.

Table 2: Immobilized states of the gear box 100

When the first coupler 870 is in the configuration A1 , the vehicle engine brake 180 is operable to cooperate with the gearbox brake 230 to immobilize the vehicle 10. Alternatively, when the first coupler 870 is in the configuration C1 , the gearbox brake 230 is able to provide immobilization whilst enabling the engine and motor 130 to be started, for example when initially legitimately disabling immobilization of the vehicle 10. Such a feature is advantageous when the couplers 870, 880, 890, 900 are operated using compressed air, and an air compressor for providing the compressed air is driven by the engine and/or motor 130.

When the vehicle 10 is to be immobilized, the couplers 870, 880, 890, 900 beneficially automatically assume configurations as outlined in Table 2. Certain of the configurations in Table 2 are especially advantageous on account of step-down gearing being applied via the planetary gear associated with the fourth coupler 900 for providing an extra degree of immobilization, for example to even more effectively resist brute towing of the vehicle 10.

Expressions such as "has", "is", "include", "comprise", "consist of, "incorporates" are to be construed to include additional components or items which are not specifically defined; namely, such terms are to be construed in a non-exclusive manner. Moreover, reference to the singular is also to be construed to also include the plural. Furthermore, numerals and other symbols included within parentheses in the accompanying claims are not to be construed to influence interpreted claim scope but merely assist in understanding the present invention when studying the claims.

Modifications to embodiments of the invention described in the foregoing are susceptible to being implemented without departing from the scope of the invention as defined by the appended claims.

Optionally, in order to immobilize the vehicle 10, the vehicle engine brake 180 and/or the gearbox brake 230 are applied, irrespective of whether or not one or more or the disc brakes 60, 160 and the parking brakes 70, 170 are applied.

Claims

1. A vehicle immobilization system (180, 230) for a vehicle (10), said vehicle (10) comprising a powertrain with an upper part (80) and a lower part (90), said upper powertrain part (80) comprising a source of motive power (130) and a gear box (100) coupled thereto, said upper powertrain part (80) being operable to provide motive power from an output of said gear box (100) to the lower power train part (90) of said vehicle for propelling said vehicle (10) when said immobilization system is in its inactivated state,

characterized in that

said immobilization system (180) is operable to apply in its activated state at least one brake (180, 230) to said upper power train part (80) to immobilize said vehicle (10).

2. A vehicle immobilization system (180, 230) as claimed in claim 1, wherein said at least one brake (180, 230) includes at least one of: an engine brake (180) associated with said source of motive power (130), and a gearbox brake (230) associated with said gearbox (100).

3. A vehicle immobilization system (180, 230) as claimed in claim 1 or 2, wherein said source of motive power (130) includes a piston-cylinder combustion engine, wherein said engine brake (180) is implemented by configuring said combustion engine to function as an air pump for compressing a volume of gas to generate a retarding force to hinder movement of the vehicle (10) when said immobilization system is in its activated state.

4. A vehicle immobilization system (180, 230) as claimed in claim 2 or 3, wherein said gearbox brake (230) is operable to engage one or more cog wheels (1010, 1160, 1030, 1180, 1040, 1150, 1190) in said gear box (100) to hinder rotational power communication through said gear box (100) when said immobilization system (180, 230) is in its activated state.

5. A vehicle immobilization system (180, 230) as claimed in any one of claims 1 to 4, wherein said immobilization system (180, 230) includes a position measurement arrangement for determining a position of the vehicle (10) for use in combination with immobilizing said vehicle (10).

6. A vehicle immobilization system (180, 230) as claimed in any one of claims 1 to 5, wherein said at least one brake (180, 230) is implemented by employing components operable to provide or communicate motive power when said vehicle (10) is in operation also for providing a retarding force for immobilization purposes when said vehicle (10) is immobilized.

7. A' method of immobilizing a vehicle (10), said vehicle (10) comprising a powertrain with an upper part (80) and a lower part (90), said upper powertrain part (80) comprising a source of motive power (130) and a gear box (100) coupled thereto, said upper powertrain part (80) being operable to provide motive power from an output of said gear box (100) to the lower power train part (90) of said vehicle for propelling said vehicle (10) when said immobilization system is in its inactivated state,

characterized in that

said method includes a step of immobilizing said vehicle (10) by applying at least one brake (180, 230) to the upper powertrain part (80).

8. A method as claimed in claim 7, wherein said at least one brake (180, 230) includes at least one of: an engine brake (180) associated with said source of motive power (130), and a gearbox brake (230) associated with said gearbox (100).

9. A method as claimed in claim 8, wherein said source of motive power (130) includes a piston-cylinder combustion engine, wherein said engine brake (180) is implemented by configuring said combustion engine to function as an air pump for compressing a volume of gas to generate a retarding force to hinder movement of the vehicle (10) when said vehicle (10) is in an immobilized state.

10. A method as claimed in claim 8 or 9, wherein said gearbox brake (230) is operable to engage one or more cog wheels in said gear box (100) to hinder rotational power communication through said gear box (100) when said vehicle (10) is in its immobilized state.

11. A method as claimed in claim 7, 8, 9 or 10, including a step of determining a position of said vehicle (10) using a position measurement arrangement for determining a position of the vehicle (10) for use in combination with immobilizing said vehicle (10).

12. A method as claimed in claim 8, 9 or 10, wherein said engine brake (180) is implemented by employing components operable to provide or communicate motive power in a non-immobilized state also for providing a retarding force for immobilization purposes.

13. A vehicle (10) operable to employ a method as claimed in any one of claims 7 to 12.

14. A software product stored on a data carrier, said software product being executable on computing hardware for implementing the method as claimed in any one of claims 7 to 12.