GB2621840A

GB2621840A - Trailer brake control system

Info

Publication number: GB2621840A
Application number: GB2212224.6A
Authority: GB
Inventors: Fry Matthew; Pahl Stefan
Original assignee: Knorr Bremse Systeme fuer Nutzfahrzeuge GmbH
Current assignee: Knorr Bremse Systeme fuer Nutzfahrzeuge GmbH
Priority date: 2022-08-23
Filing date: 2022-08-23
Publication date: 2024-02-28
Also published as: GB202212224D0

Abstract

A trailer vehicle anti-tow or anti theft system comprises a brake control module 13 for controlling the application and/or release of a brake pressure to a trailer wheel. The brake control module 13 (e.g. an electronic braking system EBS modulator) is able to receive signals output from sensors indicative of motion of the trailer, for example wheel speed sensors 5-8, GPS information over a 5V CAN bus from a telematics unit, load sensors 43-46 measuring a pressure profile on an axle of the trailer and/or an acceleration sensor detecting longitudinal acceleration. When a control is set to active (e.g. anti-theft system activated) and the module 13 receives signals indicative of motion, the module 13 applies a brake pressure to the trailer wheels. The pressure applied may be a low-pressure test pulse to check the trailer has moved, and/or a series of pulsed brake applications to warn the driver to stop the vehicle. If braking is not then applied by the user, a full brake activation may be made to bring the vehicle to standstill. The system may provide a permanent error message from the trailer to an attached truck logging information about the theft or movement of the trailer.

Description

Trailer Brake Control System The invention relates to a trailer brake control system, in particular an anti-tow away or anti theft system.

Trailers of commercial vehicle combinations will often be parked outside of a secured yard of the transport company, which provides a window of opportunity for unauthorized movement of those vehicles. A number of technical solutions have been developed to protect a trailer from being stolen or to reduce its attractiveness or simply to prevent it being towed. At a basic level, such solutions are simple mechanical locks that can be applied to the coupling of the trailer to prevent the trailer from being coupled to a truck.

More advanced anti-theft solutions have been developed which typically use an arrangement offering control over the parking braking system of the trailer. GB2417764 discloses a parking brake which is applied by removal of fluid pressure from the spring actuator. The valve is moved to a second condition in which fluid pressure is prevented from being applied to the spring actuator to release the parking brake, until the valve is reset manually.

EP3481685 discloses a vehicle braking system comprising a spring brake control assembly and an immobiliser valve which is movable between brake release position in which the spring brake control assembly is operable to cause the flow of pressurised fluid into the spring brake chamber or to vent the spring brake chamber to a low pressure region, and an immobilise position in which the spring brake control assembly is operable to connect the spring brake chamber to a low pressure region but cannot be operated to cause the flow of pressurised fluid into the spring brake chamber.

These systems provide a permanent application of the parking braking system that can only be set and reset when a set of criteria would be fulfilled. Generally all such systems do have to rely on the existing infrastructure within the Trailer braking system so that the connections between the components which form the braking system are relatively easy accessible.

There are also solutions based on GSM and/or GPS hardware. An example of this is US2015217727 which discloses an approach which uses an embedded security system installed on the trailer which transmit data from a refrigerated trailer such as the trailer's present position, a speed of the trailer, a temperature set point in the trailer, a return air temperature, a discharge air temperature, an operating mode, a unit mode, an alarm status, an hours of operation indication, a fuel quantity, a fuel consumption rate and total, a status of a door, a battery voltage, and other sensed information. In response, the remote control system can communicate with and/or send commands back to the trailer. The security system can he part of the refrigeration control unit or a standalone system and can track unauthorized movement of the trailer. GSM and GPS systems on trailers have not been widely adopted due to the additional costs for operators and they are relatively easy to disable if then-presence is known.

Therefore such systems do provide a certain protection against theft of trailers, but only to an extent that spontaneous theft of parked vehicles might he successfully avoided. Anyone with knowledge about the infrastructure of trailer braking systems or the GSM and GPS systems, which is likely to be most of those involved in the process of stealing and disposing of a trailer, can overcome these security solutions too easily.

The present invention therefore seeks to provide an anti-tow away or anti theft solution for a trailer that can reduce the attractiveness of the trailer to a potential thief without significantly increasing the cost of the trailer to the builder or user.

According to the invention there is provided a trailer vehicle control system, comprising a brake control module for controlling the application and/or release of a brake pressure to a wheel of a trailer, which brake control module can receive signals output from wheel speed sensors on the trailer, the trailer vehicle control system further comprising a control, wherein when the control is set to active and the brake control module receives signals from the wheel speed sensors indicative of motion of the trailer, the brake control module applies a brake pressure to the wheels of the trailer.

The principle underlying the invention is that the braking ECU or brake control module of the trailer can detect whether the vehicle is being driven when the anti-theft or anti tow system is supposed to be inhibiting the driving of the vehicle.

When that status is detected the brake control module can reacts in an automated, predefined way that can he configured by the trailer OEM in dependence on the equipment that is available within the trailer vehicle.

Preferably, the output of one or more wheel speed sensors is monitored to detect motion of the trailer. In a preferred embodiment the control system makes a series of brake applications with variable intensity, in particular one or more pulsed brake application followed by a full brake application. Preferably, if a telcmatics unit is fitted to the trailer, the brake control module can transmit a specific message from the braking ECU to the telematics unit that could be used to inform the vehicle owner.

Preferably, the control system can disable non-safety relevant auxiliary equipment in the trailer. Preferably, the control system can provide a permanent error message from the trailer to the truck. Preferably, it could lead to a message being displayed to a user that is executing a diagnostic session on the braking ECU of that Trailer at a later point in time containing some clear information about the theft.

The anti-theft system of the invention advantageously increases the prospect of successfully preventing the loss of a trailer vehicle. In contrast to existing systems which are easy to bypass, this system will activate many measures that make the vehicle inoperable or at least difficult to operate._The system would therefore not only be a passive system in a way that it activates the anti-theft system but would also detect and react to a manipulation of the infrastructure of the trailer braking system.

Alternatively or additionally to monitoring wheel speed sensors, UPS information on the 5V CAN from the telematics would show movement on the street and/or typical pressure profile on the load sensing port would indicate that the vehicle is being driven.

Advantageously the detection criteria and the system reaction can be recorded and therefore be available for later investigation.

Exemplary embodiments of the invention will now be described in greater detail with reference to the drawings in which: Fig. 1 shows a known trailer electronic braking system Fig. 2 shows schematically the electrical connection in a further embodiment of the invention Figure 1 shows a trailer electronic braking system in which the utility vehicle trailer has a stecrable front axle with front wheels 1, 2 and a rear axle with rear wheels 3, 4. Rotational wheel speed sensors 5-8 are in each case assigned to the front wheels 1.2 and the rear wheels 3, 4, and arc connected by way of electric lines 9-12 with an electropneumatic brake pressure control module 13 (EBS module) which is primarily assigned to the rear axle brakes. One brake 14-17 is in each case assigned to the front wheels 1, 2 and the rear wheels 3, 4, which brake 14-17 can be applied by means of brake cylinders 18, 19 of the front axle or spring-loaded brake cylinders 20, 21 of the rear axle.

The braking system of the trailer vehicle can be connected by way of three connections, specifically a pneumatic supply line connection 22, a pneumatic control line connection 23 and an electric control connection 24, with the braking system of a tractor or a further trailer. The electric control line 24 provides the ISO 11992 CAN data connection.

The supply line connection 22 is connected by way of a return valve 25 and a parking valve 26 with an air brake reservoir 27. From the air brake reservoir 27, a pneumatic line 28,30 leads to a supply input of the pressure control module 13 and ABS valve 32. In addition, a pneumatic line 29 branches off the parking valve 26 to the pressure control module 13. A pneumatic line 30 extends between the parking valve 26 and the air brake reservoir 27.

The ABS valve 32 is assigned jointly to both brake cylinders 18, 19 of the front axle and is connected with the brake cylinder 18 by way of a pneumatic line 33 and with the brake cylinder 19 by way of a pneumatic line 34. The ABS valve 32 has two electric control inputs which are connected by way of "one" electric line 35 shown here only schematically with the pressure control module 13.

Furthermore, the ABS valve 32 has a pneumatic control input 36 which is connected by way of a return valve 37 with the pneumatic control connection 23. The pneumatic control input 36 is also connected by way of a pneumatic control line 38 with a pneumatic control input of the pressure control module 13. The pressure control module 13 has an integrated pressure sensor (not shown) which measures the pressure in the pneumatic control line 38, that is, the control pressure present at the pneumatic control input 36 of the ABS valve, which control pressure is identical to the maximal pressure which can be controlled into the brake cylinders 18, 19.

The pressure control module 13 has pneumatic outputs 39-42 which are connected by way of assigned pneumatic lines with the spring brake cylinders 20 or 21.

Furthermore, pneumatic axle load sensors or air bellows 43,44 are provided at the rear axle and permit a determination of the axle load, particularly of the dynamic axle load during braking and starting. The axle load sensors or air bellows 43, 44 are connected by way of pneumatic lines with the pressure control module 13. Correspondingly the pressure in airbags 45, 46 provided at the front axle, which here are electrically controlled, may be detected by the transducer 47. However, the axle load sensors 45,46 are not absolutely necessary.

To provide stability control a lateral acceleration sensor 50 is provided, which may also be integrated with a yaw sensor, and the output of the lateral acceleration sensor is fed to the pressure control module/ECU 13. Typically the lateral acceleration sensor 50 is integrated into the pressure control module/ECU 13. In the event that lateral acceleration on the trailer is detected, the pressure control module can provide for increased brake force at the front and/or rear axles. When the lateral acceleration sensor 50 detects lateral acceleration on the trailer in which it is installed, the sensor generates a signal setting the stability control to active.

With respect to the embodiment described to Figure 1, the ABS valve 32 may be replaced with an electro-pneumatic valve where the electric control line 35 consists of a commutation means preferably CAN and an electric power source.

The pressure control module 13 receives data from the wheel speed sensors on the trailer and also receives a signal indicating whether the brake pedal in the vehicle cab is depressed or not, as well as the brake pressure demand. In addition to the ISO 7638 electrical connection shown, trailers can also have an ISO 1185 electrical connection for supplying power to indicator lights and the trailer stop lights.

In an alternative installation of the braking system shown schematically in Figure 2 in a trailer 400. The front end of the trailer, denoted by kingpin 401, is provided with a separate ISO 12098 connector 402 and ISO 7638 connector 403. The ISO 7638 connector 403 is provided with an electronic control unit 404. The electronic control unit 404 is connected by way of an electrical and CAN bus connection 405 to the trailer EBS 406 and by way of electrical connection 407 to a splitter 408, which is also connected to the ISO12098 connector 402 and which provides the connection to the trailer lighting system. The trailer lighting system The trailer lighting system, which is symmetrically arranged on the trailer, comprises rear light clusters 409, which clusters include the brake, reversing and night lights, top 410 and bottom 411 rear marker lights, four side marker Eats 412 and a front marker light 413 the system is provided with the ISO 7638 and, optionally, ISO 1185 (or alternately IS012098) connections being connected to an electronic control module. The electronic control module can be located at the trailer headboard and receive the brake and running gear control signals from the Truck-Trailer CAN bus. The trailer electronic module is further connected to a first trailer brake CAN bus, to which the trailer brake module (equivalent to EBS module 13) is connected The trailer brake module is further connected to wheel speed sensors and Auxiliary I/O.

In this embodiment, the trailer is provided with an internal CAN bus, in particular a 5V CAN bus, to enable auxiliary devices or functions to he installed such as a trailer information module, tyre pressure monitoring system or trailer access point. The internal bus is connected to the trailer electronic pressure module.

The ISO 11992 standard defines a maximum speed on the bus at 125 Kb/s as the signal on that CAN bus has a range from 0 to the truck battery voltage. As trailers are disconnected and reconnected frequently, there is inevitably damage to the connectors resulting in attenuation of the voltage. On the known systems, a 5V CAN bus is unsuitable for connection to a truck due to this damage as the signal will he attenuated from too low a level to provide a reliable signal over the life time of the system.

The connection between the electronic control module and the module and is however permanent upon installation. The absence of any connection damage leads to much reduced signal attenuation on the CAN bus connections so the 5V CAN bus can be used. Moreover, the speed of the data signals on this CAN bus can also be increased to 250Kb/s or higher, which in turn enables much more data to be placed on the CAN bus. This enables the introduction of further functionality on the trailer such as obstruction detection or lane control.

The trailer internal CAN bus enables auxiliary devices or functions to be installed such as a trailer information module, tyre pressure monitoring system or trailer access point such as that disclosed in 0B2499459. The trailer internal bus is connected to the electronic control module.

The electronic control module comprises a power management function, the CAN bus connections and the warning light circuit connection. The control logic for the trailer brake system is located in this module rather than in the brake control module.

When the anti-theft system is activated via a secure CAN message or other secure signal directly to the EBS modulator thc brake control module (13) of the trailer applies the parking brake system for the trailer and may also store that status internally or alternatively make use of a trailer access point, if installed. It would both keep the parking braking system exhausted (i.e. applied) as well as the desired status of the anti theft system stored as activated until the anti-theft system is deactivated via a secure CAN message or other secure signal by an authorised user.

The brake control module monitors the outputs of the wheel speed sensors on the wheels of the trailer. If the brake control module detects wheel speed of one or more wheels signals when the anti theft system has an activated status and the wheel speed siganls are within a plausible tolerance between the individual sensors, the brake control module can assume that the vehicle is being driven and/or being used in an unauthorised way. Preferably, the signals are taken from all the wheel speed sensors on the trailer to provide security against false activation.

The brake control module can then act in one or more of a number of ways. These methods could be programmed into the brake control module by the trailer OEM, which advantageously will not require additional hardware on the trailer.

In a first embodiment, when vehicle speed is detected under an anti-theft ACTIVE condition, the brake control module will pulse the trailer brakes a set number of times, for example 10 times, to warn the driver and to therefore lead the driver to stop the vehicle. If the vehicle nonetheless continues driving and reaches the configured Full Brake Limit (with an exemplary range between 9-30 km/h and a preferred value of 28 km/h) a full brake activation will be made on the trailer. The vehicle will be braked to standstill and held for 20 seconds. This function can then be disabled for the remainder of the power cycle of the trailer. If during the 20 seconds holding period the driver applies a Wake pressure of more than say 5 bar, the function is reset to its initial state and will operate as described before. If the vehicle cannot be stopped with the full brake activation, this function should be disabled. In other words the requested brake activation is removed after 40 seconds to avoid overheating of the brakes. When the vehicle stops the function will be reset and will operate as described as above. When the function is activated or disabled the yellow warning lamp on the truck will be illuminated and during the braking phases the tractor can be signalled over the IS011992 CAN bus to illuminate the stop lights on the trailer. Alternatively or additionally, the RED Lamp could be illuminated. As the RED lamp indicates STOP Now, and on many vehicles will cause the dashboard to emit an audible warning signal. If the vehicle is driven with the anti-theft deactivated and later during driving the antitheft is detected as activated and the speed exceeds 30 km/h for 30 seconds the detection of the anti theft system active shall be treated as defect and the function disabled. Again, the yellow warning or red lamp will be illuminated.

It would also be possible for the brake control module to send a specific message to a connected telematics system that would then be immediately transmitted to the vehicle owner so that they would be alerted to unauthorized usage of the vehicle.

In the event of unauthorised driving being detected with the anti theft system set to active, it would additionally or alternatively be possible for certain auxiliary functions under the control of the brake control module, such as lift-axle control, automatic load distribution functions or cornering aids, to be disabled. It would further also be possible to actuate a lock function for a steering axle if the trailer has one. Each of these steps will reduce the attractiveness of the trailer to a potential thief.

In a further embodiment, the control system further comprises a longitudinal acceleration sensor, the output of which can he measured by the brake control module. The braking system would (as described before) use at least one of the aforementioned possibilities as an indication for a vehicle movement. If one or more of those detection possibilities (movement indicators) would indicate a vehicle movement, the braking system would initiate a test pulse on all wheels. That test pulse is executed with a relatively low (load dependent) braking pressure. In case of the vehicle really being driven, such a test pulse will cause a certain deceleration that can he measured or detected by the longitudinal acceleration sensor. Since that acceleration can only occur during driving the detection of driving would be more reliable.

It would further be possible for the brake control module to send an error message via the CAN bus to the truck to cause an error message to be displayed that the trailer should not he driven any further. This error message can be regarded as permanent in that an event can be stored in the TEBS microcontroller; these events are not erasable but will persist for many 100 of km of use. Eventually the event may then drop off the list based on newer events dropping into the log on the TEBS microcontroller.

It would also be possible for information regarding the unauthorized usage to be stored by the brake control module, which would he accessible to a technician carrying out a diagnostic session at a later time to inform them about the unauthorized use of the vehicle.

At this time, the standards in force are ISO 1185:2003 ISO 7638-1/2:2018, ISO 11992:2021 and 1S012098:2020.

Claims

Claims 1. A trailer vehicle control system, comprising a brake control module for controlling the application and/or release of a brake pressure to a wheel of a trailer, which brake control module can receive signals output from sensors on the trailer indicative of motion of the trailer, the trailer vehicle control system further comprising a control, wherein when the control is set to active and the brake control module receives signals from the sensors indicative of motion of the trailer, the brake control module applies a brake pressure to the wheels of the trailer.
2. A trailer vehicle control system according to Claim I, wherein the sensors indicative of motion comprise one or more wheel speed sensors, GPS information on a 5V CAN from a telematics system and/or measuring a pressure profile on a load sensing port of the trailer vehicle control system.
3. A trailer vehicle control system according to Claim I or Claim 2, wherein the control system makes a series of brake applications with variable intensity.
4. A trailer vehicle control system according to Claim 3, wherein the brake control module actuates one or more pulsed brake applications followed by a full brake application.
A trailer vehicle control system according to any one of Claims I to 4, wherein a telematics unit is fitted to the trailer and the brake control module can transmit a specific message from the braking ECU to the telematics unit, which message can be transmitted to the vehicle owner.
6. A trailer vehicle control system according to any one of Claims 1 to 5, wherein the control system can disable non-safety relevant auxiliary equipment in the trailer.
7. A trailer vehicle control system according to any one of Claims 1 to 6, wherein the control system can provide a permanent error message from the trailer to the truck.
8. A trailer vehicle control system according to Claim 7, wherein the control system leads to a message being displayed to a user that is executing a diagnostic session on the braking ECU of that Trailer at a later point in time containing some clear information about the theft or movement of the vehicle.
9. A trailer vehicle control system according to any one of Claims 1 to 8, wherein when vehicle speed is detected under an anti-theft ACTIVE condition, the brake control module can pulse the trailer brakes a set number of times, to warn the driver and to therefore lead the driver to stop the vehicle.
10. A trailer vehicle control system according to Claim 9, wherein the number of pulses applied is in the range of 2 to 20, in particular 10.
11. A trailer vehicle control system according to Claims 9 and 10, wherein if the vehicle nonetheless continues driving and reaches a configured full brake limit a full brake activation will be made on the trailer.
12. A trailer vehicle control system according to Claim 11, wherein the full brake limit has a range between 9-30 km/h, preferably 28 km/h)
13. A trailer vehicle control system according to Claims 1 to 12, wherein the vehicle is braked to standstill and held for 20 seconds.
14. A trailer vehicle control system according to any one of Claims 9 to 13, wherein the function can then be disabled for the remainder of the power cycle of the trailer.
15. A trailer vehicle control system according to Claim 13 or Claim 14, wherein if during the 20 seconds holding period a brake pressure of more than predetermined level is applied, the function is reset to its initial state.
16. A trailer vehicle control system according to any one of Claims 1 to 15, wherein the control system further comprises an acceleration sensor arranged to detect longitudinal acceleration of the trailer.
17. A trailer vehicle control system according to any one of Claims 1 to 16, wherein the control system initiates a test pulse on all wheels upon detection of motion of the trailer vehicle.
18. A trailer vehicle control system according to Claim 17, wherein the test pulse is executed with a relatively low braking pressure, in particular a load dependent pressure.
19. A trailer vehicle control system according to Claim 17 or Claim 18, wherein the test pulse causes a certain deceleration that can be detected by the longitudinal acceleration sensor.