GB2500221A - Vehicle brake apparatus having a trailer with an electro-pneumatic valve, controlled based on a vehicle parameter signal - Google Patents
Vehicle brake apparatus having a trailer with an electro-pneumatic valve, controlled based on a vehicle parameter signal Download PDFInfo
- Publication number
- GB2500221A GB2500221A GB1204442.6A GB201204442A GB2500221A GB 2500221 A GB2500221 A GB 2500221A GB 201204442 A GB201204442 A GB 201204442A GB 2500221 A GB2500221 A GB 2500221A
- Authority
- GB
- United Kingdom
- Prior art keywords
- vehicle
- brake
- electro
- pneumatic valve
- trailer
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60T—VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL; ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES
- B60T8/00—Arrangements for adjusting wheel-braking force to meet varying vehicular or ground-surface conditions, e.g. limiting or varying distribution of braking force
- B60T8/17—Using electrical or electronic regulation means to control braking
- B60T8/1701—Braking or traction control means specially adapted for particular types of vehicles
- B60T8/1708—Braking or traction control means specially adapted for particular types of vehicles for lorries or tractor-trailer combinations
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60T—VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL; ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES
- B60T13/00—Transmitting braking action from initiating means to ultimate brake actuator with power assistance or drive; Brake systems incorporating such transmitting means, e.g. air-pressure brake systems
- B60T13/10—Transmitting braking action from initiating means to ultimate brake actuator with power assistance or drive; Brake systems incorporating such transmitting means, e.g. air-pressure brake systems with fluid assistance, drive, or release
- B60T13/58—Combined or convertible systems
- B60T13/581—Combined or convertible systems both hydraulic and pneumatic
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60T—VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL; ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES
- B60T13/00—Transmitting braking action from initiating means to ultimate brake actuator with power assistance or drive; Brake systems incorporating such transmitting means, e.g. air-pressure brake systems
- B60T13/10—Transmitting braking action from initiating means to ultimate brake actuator with power assistance or drive; Brake systems incorporating such transmitting means, e.g. air-pressure brake systems with fluid assistance, drive, or release
- B60T13/66—Electrical control in fluid-pressure brake systems
- B60T13/662—Electrical control in fluid-pressure brake systems characterised by specified functions of the control system components
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60T—VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL; ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES
- B60T13/00—Transmitting braking action from initiating means to ultimate brake actuator with power assistance or drive; Brake systems incorporating such transmitting means, e.g. air-pressure brake systems
- B60T13/10—Transmitting braking action from initiating means to ultimate brake actuator with power assistance or drive; Brake systems incorporating such transmitting means, e.g. air-pressure brake systems with fluid assistance, drive, or release
- B60T13/66—Electrical control in fluid-pressure brake systems
- B60T13/68—Electrical control in fluid-pressure brake systems by electrically-controlled valves
- B60T13/683—Electrical control in fluid-pressure brake systems by electrically-controlled valves in pneumatic systems or parts thereof
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60T—VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL; ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES
- B60T7/00—Brake-action initiating means
- B60T7/12—Brake-action initiating means for automatic initiation; for initiation not subject to will of driver or passenger
- B60T7/20—Brake-action initiating means for automatic initiation; for initiation not subject to will of driver or passenger specially for trailers, e.g. in case of uncoupling of or overrunning by trailer
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60T—VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL; ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES
- B60T8/00—Arrangements for adjusting wheel-braking force to meet varying vehicular or ground-surface conditions, e.g. limiting or varying distribution of braking force
- B60T8/18—Arrangements for adjusting wheel-braking force to meet varying vehicular or ground-surface conditions, e.g. limiting or varying distribution of braking force responsive to vehicle weight or load, e.g. load distribution
- B60T8/1887—Arrangements for adjusting wheel-braking force to meet varying vehicular or ground-surface conditions, e.g. limiting or varying distribution of braking force responsive to vehicle weight or load, e.g. load distribution especially adapted for tractor-trailer combinations
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60T—VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL; ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES
- B60T8/00—Arrangements for adjusting wheel-braking force to meet varying vehicular or ground-surface conditions, e.g. limiting or varying distribution of braking force
- B60T8/24—Arrangements for adjusting wheel-braking force to meet varying vehicular or ground-surface conditions, e.g. limiting or varying distribution of braking force responsive to vehicle inclination or change of direction, e.g. negotiating bends
- B60T8/248—Trailer sway, e.g. for preventing jackknifing
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60T—VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL; ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES
- B60T8/00—Arrangements for adjusting wheel-braking force to meet varying vehicular or ground-surface conditions, e.g. limiting or varying distribution of braking force
- B60T8/26—Arrangements for adjusting wheel-braking force to meet varying vehicular or ground-surface conditions, e.g. limiting or varying distribution of braking force characterised by producing differential braking between front and rear wheels
- B60T8/266—Arrangements for adjusting wheel-braking force to meet varying vehicular or ground-surface conditions, e.g. limiting or varying distribution of braking force characterised by producing differential braking between front and rear wheels using valves or actuators with external control means
- B60T8/267—Arrangements for adjusting wheel-braking force to meet varying vehicular or ground-surface conditions, e.g. limiting or varying distribution of braking force characterised by producing differential braking between front and rear wheels using valves or actuators with external control means for hybrid systems with different kind of brakes on different axles
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60T—VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL; ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES
- B60T8/00—Arrangements for adjusting wheel-braking force to meet varying vehicular or ground-surface conditions, e.g. limiting or varying distribution of braking force
- B60T8/32—Arrangements for adjusting wheel-braking force to meet varying vehicular or ground-surface conditions, e.g. limiting or varying distribution of braking force responsive to a speed condition, e.g. acceleration or deceleration
- B60T8/321—Arrangements for adjusting wheel-braking force to meet varying vehicular or ground-surface conditions, e.g. limiting or varying distribution of braking force responsive to a speed condition, e.g. acceleration or deceleration deceleration
- B60T8/323—Systems specially adapted for tractor-trailer combinations
Landscapes
- Engineering & Computer Science (AREA)
- Transportation (AREA)
- Mechanical Engineering (AREA)
- Braking Systems And Boosters (AREA)
- Regulating Braking Force (AREA)
Abstract
A brake apparatus 10 comprising a pneumatic brake actuation apparatus 14 for braking the trailer comprising an air supply 40 in fluid communication with an electro-pneumatic valve 44. The electro-pneumatic valve 44 is adapted to receive an electric brake control signal for controlling the air supply via the electro-pneumatic valve 44. The brake apparatus 10 including a control device 52 adapted to receive an electric input signal from the vehicle, and to determine the electric brake control signal from the electric input signal to operate the electro-pneumatic valve 44. The electric input signal relates to a parameter of the vehicle. The vehicle parameter may be one or more of vehicle road speed, hydraulic pressure of a hydraulic brake apparatus of the vehicle, an operation of a brake actuation switch and an operation of an ignition switch.
Description
1
Brake Apparatus
Technical Field
The invention relates to a brake apparatus for a vehicle coupleable to a trailer, a method 5 of operation thereof, and a computer program product for operation thereof.
Background
Modern tractors, such as agricultural tractors, may be fitted with a Constant Variable Transmission or a semi-automated transmission. With such vehicles engine braking can 10 be significant and a driver of the tractor may rely on engine braking to a large extent for deceleration of the tractor. The tractor may be often used with a trailer which may be several times the weight of the tractor when fully loaded.
It is known to provide the tractor with a hydraulic braking system, and the trailer with a 15 pneumatic braking system which is coupled to the tractor braking system with a hydro-pneumatic valve. The known hydro-pneumatic valve provides a way of mechanically converting a pressure in the hydraulic braking system to a pressure in the pneumatic braking system. Such a hydro-pneumatic valve can be used to transfer compressed air from the tractor to the trailer.
20
There are many problems associated with such an arrangement. One problem is that the known hydro-pneumatic valve does not take account of a change in road conditions, for example a steep decent, because it relies on the hydraulic pressure in the hydraulic braking system of the tractor as the driver operates the brake pedal. Overall using the
2
hydro-pneumatic valve to transfer compressed air to the trailer is not very controllable and it is difficult to achieve a sufficiently accurate air pressure supply for the trailer using such an arrangement. Such an air pressure may be stated by valve manufacturers to have an accuracy of ±10% from a required air pressure.
5
In general with such an arrangement the pneumatic pressure is not applied to the brakes of the trailer during pure engine braking and when the hydraulic brakes of the tractor are not applied. Without the trailer being braked to match the deceleration of the tractor shunting of the trailer into the tractor occurs. Since the trailer weight may be several 10 times that of the tractor this may be dangerous resulting in instability of the tractor and trailer to cause jack-knifing thereof.
Legislation is continuing to drive the requirements for tractor and trailer braking systems. Future legislation will require that air pressure is delivered to the trailer in 15 relation to the deceleration of the tractor. Over the years tractor braking technology has advanced to provide better brakes so that larger trailers can be towed and higher road speeds can be used safely. In contrast the trailer braking technology has not been developed to such an extent with the result that the level of control and consistency in the air pressure delivered to the trailer may not be sufficient. The known hydro-20 pneumatic valve may not be able to achieve the tight tolerances required by future legislation.
It is broadly an object of the present invention to address one or more of the above mentioned disadvantages of the previously known brake apparatus.
3
Summary
What is required is a brake apparatus which may reduce or minimise at least some of the above-mentioned problems.
5
According to a first aspect of the invention, there is provided a brake apparatus for a vehicle coupleable to a trailer, comprising:
a pneumatic brake actuation apparatus comprising an air supply in fluid communication with an electro-pneumatic valve, the electro-pneumatic valve adapted to 10 receive an electric brake control signal for controlling the air supply via the electro-pneumatic valve for braking the trailer, and a control device adapted to receive an electric input signal from the vehicle, and to determine the electric brake control signal from the electric input signal to operate the electro-pneumatic valve, wherein the electric input signal relates to a parameter of the 15 vehicle.
Such an apparatus provides the advantage of being able to take account of road conditions encountered by the vehicle or operating conditions of the vehicle by relating the operation of the electro-pneumatic valve to the parameter of the vehicle. This is 20 achieved by using the electric input signal, which relates to the parameter to control the electro-pneumatic valve. The result is that an improved level of control and consistency in the air pressure delivered to the trailer may be achieved. The apparatus may be used to take account of the road conditions experienced by the vehicle, such as a steep decent, which causes the electro-pneumatic valve to be operated to reduce or minimise
4
shunting of the trailer into the vehicle. Such an operation of the brake apparatus is safer particularly when a heavily loaded trailer is being towed. It will be appreciated that the air supply is typically from an air reservoir. Overall the brake apparatus has the capability to provide an improved braking of the vehicle and trailer which may provide 5 more responsive braking leading to shorter stopping distances than the prior art braking systems.
Preferably the parameter is related to one or more of a road speed of the vehicle, a hydraulic pressure of a hydraulic brake actuation apparatus of the vehicle, an operation 10 of a brake actuation switch, and an operation of an ignition switch. These parameters may be used individually to provide the electric input signal, or in a combination of more than one parameter. The brake actuation switch may be associated with a main brake of the vehicle, or an emergency brake of the vehicle.
15 Preferably the brake apparatus further includes a road speed sensor to determine the road speed and to provide the electric input signal. Preferably the control device is operable to determine a deceleration for the vehicle using the road speed sensor. Determining such a road speed and deceleration is advantageous because such additional information about the vehicle can be used to control the air pressure to the 20 trailer.
Preferably the brake apparatus further includes a pressure sensor to determine the hydraulic pressure and to provide the electric input signal. Determining such a hydraulic
5
pressure is advantageous because such additional information about the vehicle can be used to control the air pressure to the trailer.
Preferably the operation of the brake actuation switch, or the operation of the ignition 5 switch provides the electric input signal. Such an arrangement may be further used by the control device to determine a braking type which is experienced by the vehicle.
Preferably the control device is operable to determine the electric brake control signal from the electric input signal to operate the electro-pneumatic valve for providing a 10 substantially matched braking deceleration between the vehicle and the trailer. Such an arrangement seeks to minimise or reduce the shunting that may occur due to the trailer exerting a force on the vehicle as the vehicle is decelerated.
Preferably the electric brake control signal is operable to control the electro-pneumatic 15 valve for controlling the air supply therefrom which increases in pressure in proportion to a deceleration of the vehicle. In one embodiment the electro-pneumatic valve is operable to control the air supply therefrom which increases in pressure with a directly proportional relationship to the deceleration of the vehicle. Advantageously such an arrangement may permit the brake apparatus to comply with legislation.
20
According to a second aspect of the invention there is provided a method of operating a brake apparatus for a vehicle coupleable to a trailer, the brake apparatus comprising a pneumatic brake actuation apparatus comprising an air supply in fluid communication with an electro-pneumatic valve, and a control device, the method including:
6
measuring a parameter of the vehicle;
determining an electric input signal from the parameter;
receiving the electric input signal at the control device;
determining an electric brake control signal from the electric input signal; and 5 using the electric brake control signal to control the electro-pneumatic valve to control the air supply via the electro-pneumatic valve.
A method so arranged provides the advantage that the brake apparatus can take account of road conditions encountered by the vehicle or operating conditions of the vehicle by 10 relating the operation of the electro-pneumatic valve to the parameter of the vehicle. This is achieved by using the electric input signal, which relates to the parameter to control the electro-pneumatic valve. The result is that an improved level of control and consistency in the air pressure delivered to the trailer may be achieved using the method. The method may be used to take account of the road conditions experienced by 15 the vehicle, such as a steep decent, which causes the electro-pneumatic valve to be operated to reduce or minimise shunting of the trailer into the vehicle. Such a method of operating the brake apparatus is safer particularly when a heavily loaded trailer is being towed. Overall the method has the capability to provide an improved braking of the vehicle and trailer which may provide more responsive braking leading to shorter 20 stopping distances than the prior art braking systems.
Preferably the method further includes using the brake apparatus to provide a substantially matched braking deceleration between the vehicle and the trailer. Such a
7
method seeks to minimise or reduce the shunting that may occur due to the trailer exerting a force on the vehicle as the vehicle is decelerated.
Preferably the method further includes using the brake apparatus to provide the air 5 supply therefrom which increases in pressure in proportion to a deceleration of the vehicle. In one embodiment the method further includes using the brake apparatus to provide the air supply therefrom which increases in pressure with a directly proportional relationship to the deceleration of the vehicle. Advantageously such a method may permit the brake apparatus to comply with legislation.
10
Preferably the method further includes analysing a braking type of the vehicle. Such a method may further assist with determining operating conditions of the vehicle.
Preferably the method further includes determining the parameter from a vehicle 15 management system, a sensor of the vehicle and/or a brake actuation switch of the vehicle. The vehicle management system may comprise a CANbus system of the vehicle.
According to a third aspect of the invention there is provided a computer program 20 product for performing the method according to the second aspect of the invention.
According to an alternative characterisation of the invention there is provided a brake apparatus for a vehicle coupleable to a trailer, comprising:
8
a pneumatic brake actuation apparatus comprising an air supply in fluid communication with an electro-pneumatic valve, the electro-pneumatic valve adapted to receive an electric brake control signal for controlling the air supply via the electro-pneumatic valve for braking the trailer, and a control device adapted to receive an electric input signal from the vehicle, and to determine the electric brake control signal from the electric input signal to operate the electro-pneumatic valve, wherein the electric brake control signal is operable to control the electro-pneumatic valve for controlling the air supply therefrom which increases in pressure in proportion to a deceleration of the vehicle.
Any preferred or optional features of one aspect or characterisation of the invention may be preferred or optional feature of other aspects or characterisations of the invention.
Brief Description of the Drawings
Other features of the invention will be apparent from the following description of preferred embodiments shown by way of example only with reference to the accompanying drawings, in which;
Figure 1 shows a schematic diagram of a brake apparatus according to an embodiment of the invention;
Figure 2a is a graph showing voltage against air pressure to illustrate the operation of the electro-pneumatic valve shown in Figure 1;
Figure 2b is a graph showing deceleration against air pressure to illustrate the operation of the pneumatic brake actuation apparatus shown in Figure 1;
9
Figure 3 shows a flow chart for operation of the apparatus of in Figure 1; and Figure 4 shows a method according to an embodiment of the invention.
Detailed Description
5 Figure 1 shows a schematic diagram of a brake apparatus according to an embodiment of the invention, generally designated 10. In Figure 1 pneumatic pipes are shown with a solid line, hydraulic pipes are shown with a dashed line, and electrical connections are shown with a line comprising dashes and dots. The brake apparatus 10 is mounted to a vehicle, and a trailer can be coupled to the vehicle and the brake apparatus 10. The 10 brake apparatus 10 comprises a hydraulic brake actuation apparatus 12, and a pneumatic brake actuation apparatus 14. The hydraulic brake actuation apparatus 12 is for braking the vehicle and the pneumatic brake actuation apparatus 14 is for braking the trailer.
The hydraulic brake actuation apparatus 12 has right hand and left hand brake actuators 15 16, 18, and associated right hand and left hand brake master cylinders 20, 22 for producing a hydraulic pressure corresponding to the actuation of the brake actuators 16, 18. Each brake actuator 16, 18 is provided with a respective brake light switch 24, 26, which may be alternatively termed brake actuation switches. Each master cylinder 20, 22 operates right hand and left hand brake slave cylinders 28, 30 via respective 20 hydraulic pipes 32, 34 to provide braking to the vehicle.
A hydraulic shuttle valve 36 is provided between the hydraulic pipes 32, 34, and a hydraulic pressure transducer 38 is coupled to the hydraulic shuttle valve 36. The hydraulic shuttle valve 36 permits the hydraulic pressure transducer 38 to measure a
10
hydraulic pressure value within the hydraulic pipes 32, 34 based on whether the right hand side and left hand side brake actuators 16, 18 are used together or independently. The hydraulic pressure transducer 38 provides an electrical signal which is proportional to the hydraulic pressure within the hydraulic pipes 32, 34.
5
In another embodiment a single brake actuator is used instead of right hand side and left hand side brake actuators 16, 18. It will be understood that with a single brake actuator the shuttle valve 36 is not required, and the pressure transducer 38 is coupled to the hydraulic pipe associated with the single brake actuator.
10
The pneumatic brake actuation apparatus 14 comprises an air reservoir 40 which is maintained at an appropriate pressure level using compressed air from an air compressor 42 of the vehicle. An air dryer and filter 43 are provided between the air compressor 42 and the air reservoir 40. The air reservoir 40 is in fluid communication with an electro-15 pneumatic valve 44 which receives a supply of compressed air from the air reservoir 40 and is operable to deliver a required air pressure upon receipt of an electric brake control signal. The electro-pneumatic valve 44 is operable to control the compressed air supply from the air reservoir via the electro-pneumatic valve 44 to a relay valve 46, which is in fluid communication with a brake service coupling 48. According to known 20 arrangements the brake service coupling 48 is connectable to a pneumatic brake system of the trailer. It will be appreciated that the electro-pneumatic valve 44 regulates the supply of compressed air from the air reservoir 40 to the brake service coupling 48. The air reservoir 40 is also in parallel fluid communication with the relay valve 46 and an emergency brake coupling 50. According to known arrangements the emergency brake
11
coupling 50 is connectable to a pneumatic brake system of the trailer. The relay valve 46 operates to increase the air flow to the brake service coupling 48 under the control of the electro-pneumatic valve 44. In effect the electro-pneumatic valve 44 is used to control a higher air flow by operation of the relay valve 46. The valve 44 provides an 5 increased air flow so that the air pressure from electro-pneumatic valve 44 to the relay valve 46 is the same as the air pressure from the relay valve 46 to the brake service coupling 48. It will be understood that the electro-pneumatic valve 44 is an infinitely variable pressure regulator valve. In an alternative arrangement the relay valve 46 operates to provide a higher or lower air pressure. With such an arrangement the 10 electro-pneumatic valve 44 is used to control a higher air pressure or a lower air pressure by operation of the relay valve 46.
The brake apparatus 10 also includes a control device 52 which is adapted to receive an electric input signal from the vehicle, and provide the electric brake control signal to the 15 electro-pneumatic valve 44. The control device 52 has a processor, for example a micro processor, to receive the electric input signal and output the electric brake control signal to the electro-pneumatic valve 44. The electric brake control signal is in the form of a voltage determined by the control device in relation to the electric input signal. For example, to increase the output air pressure from the electro-pneumatic valve 44 a lower 20 voltage is required, and to decrease the output air pressure from the electro-pneumatic valve 44 a higher voltage is required, whereby the required change of voltage is determined by the processor.
12
The electric input signal relates to a parameter of the vehicle and may be received by the control device 52 from at least one of the brake light switches 24, 26, the pressure transducer 38, a park brake or emergency brake and switch 54, a road speed sensor 56, an Engine Control Unit (ECU) 58 of the vehicle, and an ignition switch 60. It will be 5 appreciated that the electrical input signal may be received by the control device 52 from the CANbus system of the vehicle. The switch 54 may alternatively be termed a brake actuation switch. The park brake or emergency brake may also be known as a secondary brake of the vehicle.
10 In the case of the electrical control signal being received from the brake light switches 24, 26, the pressure transducer 38, or the ignition switch 60, the control device 52 receives the electrical control signal and determines the voltage of the electric brake control signal to operate the electro-pneumatic valve to provide the required braking to the trailer. When the electrical control signal is received from the brake light switches 15 24, 26, the control device 52 determines that deceleration of the vehicle is occurring as a result of the vehicle brakes being operated rather than the deceleration being achieved by engine braking alone.
In the case of the electrical control signal being received from the park brake or 20 emergency brake switch 54 the failsafe mode of operation is an open line between the air reservoir 40 and the pneumatic braking system of the trailer via the electro-pneumatic valve 52. In another arrangement the park brake or emergency brake may be a hydraulically operated brake that may require an electric circuit to provide the electric input signal.
13
In the case of the electrical control signal being received from the road speed sensor 56, the control device 52 calculates a deceleration for the vehicle using data from the road speed sensor 56, and the control device 52 determines the voltage of the electric brake 5 control signal to operate the electro-pneumatic valve 44 to provide the required braking for the trailer. It will be appreciated that the road speed data may be received from the road speed sensor 56 via the ECU 58, which may already be present on the vehicle. The processor of the control device 52 continuously receives data from the road speed sensor 56 and software initiates a voltage change of the electric brake control signal 10 when the vehicle deceleration reaches a predetermined threshold. As the deceleration increases or decreases the voltage of the electric brake control signal changes accordingly, which in turn controls the air pressure from the electro-pneumatic valve 44.
It will be appreciated that the control device 52 may be operable using software such 15 that it maps the vehicle behaviour and determines deceleration above a predetermined threshold. In one arrangement the software only initiates a voltage change of the electric brake control signal when deceleration is above the predetermined threshold.
In the above brake apparatus 10, when the trailer receives the required air pressure from 20 the electro-pneumatic valve 44 it will brake at substantially the same rate as the tractor. In this manner the trailer will not impose any significant force on the tractor tow hitch that may otherwise change the rate of deceleration and braking of the tractor. With such an arrangement the tractor and trailer are braked at substantially the same rate.
14
Figure 2a is a graph showing voltage against air pressure to illustrate the operation of the electro-pneumatic valve 44 shown in Figure 1. The x-axis shows the air pressure at the brake service coupling 48. The y-axis shows an inverse voltage, measured as 1/V, of the electric brake control signal, so that the pressure is a maximum when the voltage is a 5 minimum. This is a failsafe arrangement so that if the voltage of the electric brake control signal is zero the electro-pneumatic valve provides a maximum pressure to the brake service coupling 48 so that the trailer braking system is operated. The graph shows a linear region 64 in the range 0.2 - 2, which represents a range of operation of about 0.5 - 4.5 V. The range between 0 - 0.5 V is avoided to reduce the effects of noise 10 that may occur around 0V. In the linear region 64 there is an inversely proportional relationship between the voltage of the electric brake control signal and the air pressure at the brake service coupling 48.
Figure 2b is a graph showing deceleration against air pressure to illustrate the operation 15 of the pneumatic brake actuation apparatus shown in Figure 1. The deceleration is the deceleration of the vehicle, which may be plotted as a measure of braking efficiency of the vehicle. The air pressure is the air pressure at the brake service coupling 48. The graph illustrates that using the brake apparatus 10 there is a directly proportional relationship between the deceleration of the vehicle and the air pressure at the brake 20 service coupling 48. It will be appreciated that the graph may change depending on ballast weights added or removed from the vehicle or the maximum permitted design speed of the vehicle as stated by the vehicle manufacturer. For example, the range 70 represents a vehicle with less weight, and the range 72 represents a vehicle with more weight. In general, the air pressure at the brake service coupling 48 will be directly
15
proportional to the rate of deceleration of the tractor, and the line 74 represents an average target relationship between deceleration of the tractor and air pressure at the brake service coupling 48. Where the deceleration of the vehicle is less than the predetermined threshold DT mentioned above, the proportionality between the 5 deceleration and the pressure measured at the brake service coupling 48 is not considered. In one example the predetermined threshold DT may be, for example, between 0 - 1 m/s , which means that if there is a slight shunting of the trailer into the vehicle or a slight force on the tow hitch of the vehicle as the vehicle is braked this is acceptable. In an ideal arrangement the vehicle and the trailer would be braked in an 10 identical manner so that they decelerate in an identical way. Such an ideal arrangement would mean that there is no force exerted at the tow hitch between the vehicle and the trailer when the hydraulic brake actuation apparatus 12 of the vehicle and a pneumatic brake actuation apparatus 14 of the trailer are operated. However, such an ideal arrangement may not exist in a real life arrangement, and it will be appreciated that the 15 brake apparatus 10 operates to substantially equalise or match the deceleration between the vehicle and the trailer.
In one arrangement the hydraulic brake actuation apparatus 12 and the braking effect provided by the engine is not used, and instead only the pneumatic brake actuation 20 apparatus 14 is operated. This may occur if, for example, there is a failure in the overall brake apparatus 10 such that the electro-pneumatic valve 44 is then operated in a failsafe manner so that the full pressure of the air reservoir 40 is sent to the brake service coupling 48 to operate the trailer brakes.
16
Figure 3 shows a flow chart for operation of the apparatus shown in Figure 1, generally designated 80. The flow chart 80, for example, represents the operation of software used to control the brake apparatus 10, which may be embedded in the control device 52 shown in Figure 1. In Figure 3, electric input signals from the vehicle are read to 5 analyse the type of braking, as shown at 82. These electric input signals may be a hydraulic pipe pressure signal, shown at 84, or an ignition switch signal, shown at 86, or an emergency/park brake signal, shown at 88, or a brake switch signal, shown at 90. With the emergency/park brake signal 88 a digital 0 - 12V signal from the emergency/park brake 54 is used. With the ignition switch signal 86 a digital 0 - 12V 10 signal from the ignition switch 60 is used. With the brake switch signal 90 a digital 0 -12V signal is used, which may be provided by a mechanical activation of the brake pedal 16, 18 or switched by pressure in the hydraulic pipes 32, 34 using the pressure transducer 38 to provide the variable voltage. A road speed is determined and a change in speed is calculated at 92. The speed signal may be received at 92 from a CANbus 15 encoded speed signal, shown at 94. The CANbus encoded speed signal is interpreted and then used to calculate change in speed of the vehicle, and thus deceleration. The electric input signals are used as shown at 96, together with preset vehicle specific parameters, shown at 98, to read from a lookup table, shown at 100, to determine an output voltage i.e. the electric brake control signal for operating the electro-pneumatic 20 valve 44, shown at 102. It will be appreciated that the operation 96 is performed at the control device 52. The output voltage controls the air pressure supplied to the trailer via the electro-pneumatic valve 44. The change of speed signal may be received at 82 and/or at 96. The hydraulic pipe pressure signal 84 may be received at 82 and/or at 96.
17
Overall at least one of the signals 84, 86, 88, 90, 92 is used at 96 to determine the output voltage for operating the electro-pneumatic valve 44 at 102.
It will be appreciated that the software program receives electrical input signals and 5 performs calculations based on them, which will be different from vehicle to vehicle. The software program uses the electric input signal to calculate a braking performance or efficiencyof the vehicle, and then uses the lookup table to arrive at the appropriate voltage to deliver to the electro-pneumatic valve 44. The intent of the driver is determined, such as whether to maintain vehicle speed on a gradient, or to reduce speed, 10 or to hold the vehicle at a standstill on an inclined road or a level road, or to apply the emergency/parking brake. The software program also provides emergency/park brake functions as required.
The software program may include self diagnostics capabilities, for example, by looking 15 at the electric input signals available and considering whether they lie within pre-set parameters that are reasonable and expected. The software program also checks for internal failures of sensors and valves within the electro-pneumatic valve 44. If faults are detected the software program initiates operation of the brakes of the trailer as a failsafe measure. The software program also includes a watchdog timer to mitigate the 20 effects that it may crash during use.
In addition to outputting a voltage to control the electro-pneumatic valve 44, the software program may also provide feedback to other systems of the vehicle or to other equipment fitted to the vehicle, as shown at 104. These outputs include a CANbus
18
signal to provide a status feedback to the vehicle regarding the operation of the pneumatic brakes of the trailer. These outputs also include a digital switched voltage dependent on the air pressure or pneumatic brake status to control a warning light/buzzer in the vehicle to provide an alert to the driver of the vehicle.
5
It will be appreciated that using the brake apparatus 10 an equalising braking effect is created between the vehicle and the trailer. As a reduction in speed of the vehicle is sensed the brake apparatus 10 operates so that the trailer reaches the target deceleration as quickly and safely as possible. The above embodiments enhance transport safety 10 when decelerating of the vehicle and trailer using the transmission as an engine brake. The brake apparatus 10 has the capability to provide an improved braking of the vehicle and trailer and to provide more responsive braking, which may lead to shorter stopping distances.
15 In one embodiment only the change in road speed signal 92 and/or the hydraulic pipe pressure signal 84 is received at 96 to determine the voltage of the electric brake control signal for operating the electro-pneumatic valve 44.
In general it will be understood that one or more of the hydraulic pipe pressure signal 20 84, the ignition switch signal 86, the emergency/park brake signal 88, the brake switch signal 90, and the road speed signal 92 may be received at 96 to determine the voltage of the electric brake control signal for operating the electro-pneumatic valve 44.
19
The brake apparatus 10 may be retrofitted to the vehicle. This may be a straight forward task because the control device 52 may be readily connectable to the vehicle CANbus to receive one or more of the electric input signals which are related to the parameter of the vehicle. Furthermore the electro-pneumatic valve 44 and the relay valve 46 are 5 readily connectable between the air reservoir 40 and the brake service coupling 48. An electrical connection may then be provided between the control device 52 and the electro-pneumatic valve 44 to complete the brake apparatus 10.
Figure 4 shows a method according to an embodiment of the invention, generally 10 designated 110. The method 110 is a method of operating a brake apparatus 10 for a vehicle coupleable to a trailer. The brake apparatus 10 comprising a pneumatic brake actuation apparatus 14 comprising an air supply 40 in fluid communication with an electro-pneumatic valve 44, and a control device 52. The method includes measuring a parameter of the vehicle, as shown at 112. Determining a parameter of the vehicle 112 15 may also include analysing a braking type of the vehicle. The method includes determining an electric input signal from the parameter, as shown at 114, The method includes receiving the electric input signal at the control device 52, as shown at 116. The method includes determining an electric brake control signal from the electric input signal, as shown at 118. The method includes using the electric brake control signal to 20 control the electro-pneumatic valve 44 to control the air supply 40 via the electro-pneumatic valve 44, as shown at 120.
The method further includes using the brake apparatus 10 to provide a substantially matched braking deceleration between the vehicle and the trailer, as shown at 122. The
20
method further includes using the brake apparatus 10 to provide the air supply therefrom which increases in pressure in proportion to a deceleration of the vehicle, as shown at 124. In one arrangement the brake apparatus 10 provides the air supply therefrom which increases in pressure with a directly proportional relationship to the 5 deceleration of the vehicle. The method may further include determining the parameter from a vehicle management system, a sensor of the vehicle and/or a brake actuation switch of the vehicle. The vehicle management system may comprise a CANbus system of the vehicle.
10 The above described method 110 may be performed by a computer program product. The computer program product may be encoded on a data carrier.
It will be appreciated that in the above embodiments reference is made to a vehicle which may be a tractor, such as an agricultural tractor, which is a towing vehicle.
15
In the above embodiments reference is made to receiving the electronic signal at the control device 52 from the vehicle CANbus system. It will be understood that there are other vehicle management systems that may be used. Accordingly, the method 110 and the computer program product may operate with such a vehicle management system.
21
Claims (18)
1. A brake apparatus for a vehicle coupleable to a trailer, comprising:
a pneumatic brake actuation apparatus comprising an air supply in fluid 5 communication with an electro-pneumatic valve, the electro-pneumatic valve adapted to receive an electric brake control signal for controlling the air supply via the electro-pneumatic valve for braking the trailer, and a control device adapted to receive an electric input signal from the vehicle, and to determine the electric brake control signal from the electric input signal to operate the 10 electro-pneumatic valve, wherein the electric input signal relates to a parameter of the vehicle.
2. A brake apparatus according to claim 1, wherein the parameter is related to one or more of a road speed of the vehicle, a hydraulic pressure of a hydraulic brake
15 actuation apparatus of the vehicle, an operation of a brake actuation switch, and an operation of an ignition switch.
3. A brake apparatus according to claim 2, and further including a road speed sensor to determine the road speed and to provide the electric input signal.
20
4. A brake apparatus according to claim 3, wherein the control device is operable to determine a deceleration for the vehicle using the road speed sensor.
22
5. A brake apparatus according to claim 2, and further including a pressure sensor to determine the hydraulic pressure and to provide the electric input signal.
6. A brake apparatus according to claim 2, wherein the operation of the brake 5 actuation switch, or the operation of the ignition switch provides the electric input signal.
7. A brake apparatus according to any preceding claim, wherein the control device is operable to determine the electric brake control signal from the electric input signal to
10 operate the electro-pneumatic valve for providing a substantially matched braking deceleration between the vehicle and the trailer.
8. A brake apparatus according to any preceding claim, wherein the electric brake control signal is operable to control the electro-pneumatic valve for controlling the air
15 supply therefrom which increases in pressure in proportion to a deceleration of the vehicle.
9. A brake apparatus according to claim 8, wherein the electro-pneumatic valve is operable to control the air supply therefrom which increases in pressure with a directly
20 proportional relationship to the deceleration of the vehicle.
10. A brake apparatus as substantially described herein with reference to Figures 1 -3 of the accompanying drawings.
23
11. A method of operating a brake apparatus for a vehicle coupleable to a trailer, the brake apparatus comprising a pneumatic brake actuation apparatus comprising an air supply in fluid communication with an electro-pneumatic valve, and a control device, the method including:
5 measuring a parameter of the vehicle;
determining an electric input signal from the parameter;
receiving the electric input signal at the control device;
determining an electric brake control signal from the electric input signal; and using the electric brake control signal to control the electro-pneumatic valve to 10 control the air supply via the electro-pneumatic valve.
12. A method according to claim 11, and further including using the brake apparatus to provide a substantially matched braking deceleration between the vehicle and the trailer.
15
13. A method according to claim 11 or 12, and further including using the brake apparatus to provide the air supply therefrom which increases in pressure in proportion to a deceleration of the vehicle.
20
14. A method according to claim 13, and further including using the brake apparatus to provide the air supply therefrom which increases in pressure with a directly proportional relationship to the deceleration of the vehicle.
24
15. A method according to any of claims 11 - 14, and further including analysing a braking type of the vehicle.
16. A method according to any of claims 11 - 15, and further including determining the parameter from a vehicle management system, a sensor of the vehicle and/or a brake actuation switch of the vehicle.
17. A method as substantially described herein with reference to Figure 3 or 4 of the accompanying drawings.
18. A computer program product for performing the method according to any of claims 11 - 17.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB1204442.6A GB2500221A (en) | 2012-03-14 | 2012-03-14 | Vehicle brake apparatus having a trailer with an electro-pneumatic valve, controlled based on a vehicle parameter signal |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB1204442.6A GB2500221A (en) | 2012-03-14 | 2012-03-14 | Vehicle brake apparatus having a trailer with an electro-pneumatic valve, controlled based on a vehicle parameter signal |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| GB201204442D0 GB201204442D0 (en) | 2012-04-25 |
| GB2500221A true GB2500221A (en) | 2013-09-18 |
Family
ID=46026484
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB1204442.6A Withdrawn GB2500221A (en) | 2012-03-14 | 2012-03-14 | Vehicle brake apparatus having a trailer with an electro-pneumatic valve, controlled based on a vehicle parameter signal |
Country Status (1)
| Country | Link |
|---|---|
| GB (1) | GB2500221A (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP3121075A1 (en) * | 2015-07-22 | 2017-01-25 | Haldex Brake Products Aktiebolag | Pull-off valve |
| IT201800007776A1 (en) * | 2018-08-02 | 2020-02-02 | Cnh Ind Italia Spa | INTELLIGENT HYDRAULIC TRAILER BRAKE VALVE |
| CN111372827A (en) * | 2017-11-21 | 2020-07-03 | 哈尔德克斯制动产品股份公司 | Brake system |
| EP4281344B1 (en) | 2021-01-19 | 2025-02-05 | AGCO International GmbH | Trailer brake control system |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0319970A2 (en) * | 1987-12-08 | 1989-06-14 | Rudolf Paukner | Brake device for trailers |
| GB2363435A (en) * | 2000-06-17 | 2001-12-19 | Knorr Bremse Systeme | Transfering vehicle parameters for electronic brake control |
| CA2342388A1 (en) * | 2001-03-28 | 2002-09-28 | Jack Costa | Improved tractor trailer air braking system |
| GB2374389A (en) * | 2001-04-10 | 2002-10-16 | Edward James Yaxley | Towed vehicle over-run braking system intensifying unit triggered by brake light circuit |
| WO2003043863A1 (en) * | 2001-11-19 | 2003-05-30 | Knorr-Bremse Systeme für Nutzfahrzeuge GmbH | Method and device for controlling an abs brake system of a vehicle |
| GB2384838A (en) * | 2002-02-02 | 2003-08-06 | Knorr Bremse Systeme | Anti-lock braking of a vehicle with a self-steerable axle and an axle control valve for isolating a higher modulator pressure |
-
2012
- 2012-03-14 GB GB1204442.6A patent/GB2500221A/en not_active Withdrawn
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0319970A2 (en) * | 1987-12-08 | 1989-06-14 | Rudolf Paukner | Brake device for trailers |
| GB2363435A (en) * | 2000-06-17 | 2001-12-19 | Knorr Bremse Systeme | Transfering vehicle parameters for electronic brake control |
| CA2342388A1 (en) * | 2001-03-28 | 2002-09-28 | Jack Costa | Improved tractor trailer air braking system |
| GB2374389A (en) * | 2001-04-10 | 2002-10-16 | Edward James Yaxley | Towed vehicle over-run braking system intensifying unit triggered by brake light circuit |
| WO2003043863A1 (en) * | 2001-11-19 | 2003-05-30 | Knorr-Bremse Systeme für Nutzfahrzeuge GmbH | Method and device for controlling an abs brake system of a vehicle |
| GB2384838A (en) * | 2002-02-02 | 2003-08-06 | Knorr Bremse Systeme | Anti-lock braking of a vehicle with a self-steerable axle and an axle control valve for isolating a higher modulator pressure |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP3121075A1 (en) * | 2015-07-22 | 2017-01-25 | Haldex Brake Products Aktiebolag | Pull-off valve |
| CN111372827A (en) * | 2017-11-21 | 2020-07-03 | 哈尔德克斯制动产品股份公司 | Brake system |
| IT201800007776A1 (en) * | 2018-08-02 | 2020-02-02 | Cnh Ind Italia Spa | INTELLIGENT HYDRAULIC TRAILER BRAKE VALVE |
| EP4281344B1 (en) | 2021-01-19 | 2025-02-05 | AGCO International GmbH | Trailer brake control system |
| EP4281338B1 (en) | 2021-01-19 | 2025-02-12 | AGCO International GmbH | Trailer brake control system |
Also Published As
| Publication number | Publication date |
|---|---|
| GB201204442D0 (en) | 2012-04-25 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CA2935989C (en) | Method for controlling a brake device in a traction vehicle-trailer combination and brake device controlled according to said method | |
| CN108349471B (en) | Method for setting the brake pressure of a vehicle and braking system for carrying out the method | |
| AU2012319104B2 (en) | A towing vehicle controller providing brake control to a towed vehicle and method | |
| EP2512890B1 (en) | Method for signalling a brake process at a trailer vehicle, control device for this purpose, and lighting system, trailer vehicle brake system and trailer vehicle with said control device | |
| CN107848515B (en) | ABS strategy for hybrid brake actuators | |
| US20160068144A1 (en) | Method for braking a traction vehicle-trailer combination with reduced trailer braking force as a function of the response of the abs of the traction vehicle | |
| KR20180104018A (en) | Electronically controllable pneumatic brake system for utility vehicle and method for electronically controlled pneumatic brake system | |
| US11485334B2 (en) | Supplemental deceleration using electronic parking brake in fully integrated braking systems | |
| CN204870981U (en) | Automatically controlled braking system of EBS gas braking | |
| EP3284643B1 (en) | Hydraulic trailer brake circuit for adjustable gain and improved stability | |
| US11661047B2 (en) | Method for controlling a pneumatic braking system of a trailer vehicle | |
| CN108349466A (en) | The method of brake pressure at the wheel drag of air-operated control for adjusting vehicle, braking equipment and vehicle for executing this method | |
| EP3275746B1 (en) | Trailer brake pilot control circuit and method of control thereof | |
| JPH01237255A (en) | Overload alarm device for trailer brake | |
| GB2500221A (en) | Vehicle brake apparatus having a trailer with an electro-pneumatic valve, controlled based on a vehicle parameter signal | |
| US11724676B2 (en) | Trailer detection and control module | |
| Kant | Sensotronic brake control (SBC) | |
| US20230415721A1 (en) | Method for operating an electropneumatic parking brake system, and electropneumatic parking brake system | |
| US12325403B2 (en) | Brake system for commercial vehicle | |
| JP4654420B2 (en) | Trailer snakeing prevention method and system | |
| WO2002051682A1 (en) | Method and system for brakes of utility vehicles | |
| EP4534367A1 (en) | Improved hydraulic arrangement for a tractor-trailer system | |
| KR20250096829A (en) | Electro-pneumatic structural unit and electro-pneumatic brake device including dual redundancy mode and braking slip control |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| WAP | Application withdrawn, taken to be withdrawn or refused ** after publication under section 16(1) |