Background

[0001] The present invention relates to vehicle braking. It finds particular application in conjunction with braking a vehicle during a failure and will be described with particular reference thereto. It will be appreciated, however, that the invention is also amenable to other applications.

[0002] Drivers of modern air braked vehicles increasingly rely on advanced driver assistance systems for braking. When there is any type of failure in the braking system, there is currently only a limited amount of actions that can be taken by a brake controller to maintain braking by the driver assistance system.

[0003] The present invention provides a new and improved apparatus and method for braking a vehicle during a failure of a driver assistance system.

Summary

[0004] In one aspect of the present invention, it is contemplated that a vehicle braking system for a vehicle combination includes a first brake axle including a first actuatable brake, a second brake axle including a second actuatable brake, a third brake axle including a third actuatable brake, a first valve controlling actuation of the first actuatable brake and actuation of the second actuatable brake, and a second valve controlling actuation of the second actuatable brake and actuation of the third actuatable brake. Brief Description of the Drawings

[0005] In the accompanying drawings which are incorporated in and constitute a part of the specification, embodiments of the invention are illustrated, which, together with a general description of the invention given above, and the detailed description given below, serve to exemplify the embodiments of this invention.

[0006] FIGURE 1 illustrates a schematic representation of a vehicle braking system in accordance with one embodiment of an apparatus illustrating principles of the present invention; and

[0007] FIGURE 2 is an exemplary methodology of braking the vehicle in

accordance with one embodiment illustrating principles of the present invention.

Detailed Description of Illustrated Embodiment

[0008] With reference to FIGURE 1, a simplified component diagram of a combination vehicle 10 including an exemplary braking system 12 is illustrated in

accordance with one embodiment of the present invention. In the illustrated embodiment, the combination vehicle 10 is an articulated vehicle including a first portion 14 (e.g., a tractor portion) and a second portion 16 (e.g., a trailer portion).

[0009] The combination vehicle 10 includes a plurality of axles 20 (e.g., brake axles).

For example, three (3) axles 20i ₎₂₎₃ (collectively 20) are shown in the illustrated embodiment. The first and second axles 20i ₎₂ are included on the tractor portion 14 of the vehicle 10, and the axle 20 ₃ is included on the trailer portion 16 of the vehicle 10. On one embodiment, the first axle 20i is a steer axle on the tractor portion 14; the second axle 20i is a drive axle on the tractor portion 14; and the third axle 20 ₃ is a trailer axle on the trailer portion 16. It is to be understood that any number of axles in any configuration distributed between the tractor portion 14 and the trailer portion 16 of the vehicle 10 are contemplated. [0010] Each of the axles 20 includes at least one respective actuatable brake 22. For example, the first axle 20i includes first actuatable brakes 22i (e.g., actuatable brakes 22i,i and 22i ₎₂ ); the second axle 20 ₂ includes second actuatable brakes 22 ₂ (e.g., actuatable brakes 22 ₂₎ i and 22 ₂₎₂ ); and the third axle 20 ₃ includes third actuatable brakes 22 ₃ (e.g., actuatable brakes 22 ₃ ,i and 22 ₃₎₂ ). The brakes 22 ; 22i, ₂ ; 22 ₂ ,i, 22 ₂₎₂ ; and 22 ₃ ,i, 22 ₃₎₂ are collectively referenced as 22.

[0011] The first axle 20i and the first actuatable brake 22i are included in a first brake group 24i. The second axle 20 ₂ and the second actuatable brake 22 ₂ are included in both the first brake group 24i and a second brake group 24 ₂ . The third axle 20 ₃ and the third actuatable brake 22 ₃ are included in the second brake group 24 ₂ .

[0012] A first valve 26i controls actuation of the first and second actuatable brakes

22i ₎₂ (e.g., the first brake group 24i), and a second valve 26 ₂ controls actuation of the second and third actuatable brakes 22 ₂₎₃ (e.g., the first brake group 24i). In one embodiment, the first and second valves 26i ₎₂ (collectively 26) are both in the tractor portion 14 of the vehicle 10. However, other embodiments in which at least one of the valves 26 is on the trailer portion 16 of the vehicle 10 are contemplated. In any embodiment, it is contemplated that the first valves 26i ₎₂ are solenoid valves.

[0013] It is also contemplated the first and second valves 26 are control valves that receive both a pneumatic control signal at respective pneumatic control signal ports 30i ₎₂ (collectively 30) and respective electronic control signal ports 32i ₎₂ (collectively 32).

[0014] A foot brake valve 34 (e.g., pedal) is depressed by an operator of the vehicle

10 to cause at least one of the brakes 22 to be actuated (e.g., to brake the vehicle 10) during a manual braking event. A pressure of a pneumatic fluid delivered from a foot brake delivery port 36 of the foot brake valve 34 is fluidly communicated (e.g., transmitted) to the respective pneumatic control signal ports 30i ₎₂ of the first and second valves 26 as respective pneumatic control signals. The pneumatic control signals fluidly delivered to the respective pneumatic control signal ports 30i ₎₂ are based on how much the operator depresses the foot brake valve 34. Braking of the vehicle 10 achieved in response to the foot brake valve 34 being depressed by the operator is referred to as a manual braking event. Therefore, in this embodiment, the first and second valves 26 receive pneumatic control signals during the manual braking event and the respective pneumatic control signals are manually controlled by application of the foot brake valve 34 by the operator.

[0015] An electrical delivery port 40 of an electronic control unit 42 (ECU) electrically communicates with the respective electronic control signal ports 32i ₎₂ of the first and second valves 26. During an automatic braking event (e.g., an adaptive cruise control (ACC) braking event, an antilock brake system (ABS) braking event, etc.), the ECU 42 electrically communicates (e.g., transmits) electronic signals from the electrical ECU delivery port 40 to the respective electronic control signal ports 32i ₎₂ of the first and second valves 26 as respective electronic control signals to cause at least one of the brakes 22 to be actuated (e.g., to brake the vehicle 10). Since the electronic control signals are

communicated during an automatic braking event, these signals are referred to as

automatically controlled braking signals. In one embodiment, it is contemplated the ECU 42 is an anti-lock braking system (ABS) controller that transmits the electronic control signals to the first and second valves 26 during an ABS event (i.e., an automatic braking event).

[0016] During normal operation, at least one of the foot brake valve 34 and the ECU

42 transmits the pneumatic control signals and/or the electronic control signals to the respective control ports 30, 32 of both the first and second valves 26i ₎₂ . The first valve 26i transmits a pneumatic fluid from a first valve supply port (not shown) to a first valve delivery port 44i based on the control signals received at the pneumatic and electronic control ports 30i, 32i, respectively. Similarly, the second valve 26 ₂ transmits the pneumatic fluid from a second valve supply port (not shown) to a second valve delivery port 44 ₂ based on the control signals received at the pneumatic and electronic control ports 30 ₂ , 32 ₂ , respectively. The control signals received at the pneumatic and electronic control ports 30i, 32i, respectively, control operation of the first valve 26i independently of each other. Similarly, the control signals received at the pneumatic and electronic control ports 30 ₂ , 32 ₂ , respectively, control operation of the second valve 26 ₂ independently of each other.

[0017] For example, if neither the pneumatic control signal nor the electronic control signal is received at the respective control ports 30i, 32i, the first valve 26i does not transmit the pneumatic fluid from the first valve supply port (not shown) to the first valve delivery port 44i. Otherwise, if at least one of the pneumatic control signal and the electronic control signal is received at the respective control ports 30i, 32i, the first valve 26i does transmit the pneumatic fluid from the first valve supply port (not shown) to the first valve delivery port 44i. It is contemplated that the amount of pneumatic fluid (e.g., the pressure of the pneumatic fluid) transmitted from the first valve supply port (not shown) to the first valve delivery port 44i is based on (e.g., proportional or linearly proportional to) the pressure of the pneumatic fluid at the pneumatic control port 30i. On the other hand, while the amount of pneumatic fluid (e.g., the pressure of the pneumatic fluid) transmitted from the first valve supply port (not shown) to the first valve delivery port 44i is based on the electronic control signal being present at the control port 32, it is not contemplated to be a proportional relationship.

[0018] The second valve 26 ₂ operates in a similar manner to the first valve 26 ₂ with regard to transmitting the pneumatic fluid from the second valve supply port (not shown) to the second valve delivery port 44 ₂ based on the pneumatic and electronic control signals at the control ports 30 ₂ , 32 ₂ , respectively.

[0019] Each of the actuatable brakes 22i ₎₂₎₃ includes a respective control port 46i ₎₂₎₃

(e.g., a pneumatic control port). The control port 46i fluidly communicates with the first valve delivery port 44i; the control port 46 ₂ fluidly communicates with both the first valve delivery port 44i and the second valve delivery port 44 ₂ ; and the control port 46 ₃ fluidly communicates with the second valve delivery port 44 ₂ .

[0020] The brakes 22i ₎₂₎₃ actuate based on the pressure of the pneumatic fluid present at the respective control ports 46i ₎₂₎₃ . More specifically, the first and second actuatable brakes 22i ₎₂ actuate based on the pneumatic pressure at the delivery port 44i of the first valve 26i; and the second and third actuatable brakes 22 ₂₎₃ actuate based on the pneumatic pressure at the delivery port 44 ₂ of the second valve 26 ₂ . Since the second control port 46 ₂ fluidly communicates with both the delivery port 44i of the first valve 26i and the delivery port 44i of the second valve 26 ₂ , the second actuatable brakes 22 ₂ actuate based on either the pneumatic pressure at the delivery port 44i of the first valve 26i or the pneumatic pressure at the delivery port 44 ₂ of the second valve 26 ₂ . For example, the second actuatable brakes 22 ₂ actuate based on the higher of the pneumatic pressures at the delivery ports 44i ₎₂ . In another embodiment, another valve (e.g., a double-check valve) (not shown) arbitrates between the pneumatic pressure at the delivery port 44i and the pneumatic pressure at the delivery port 44 ₂ for actuating the second actuatable brakes 22 ₂ .

[0021] In the event of a malfunction (e.g., failure), insufficient pneumatic pressure may be available at the first valve delivery port 44i to actuate the first and second brakes 22i ₎₂ when desired. For example, a leak may reduce the supply pressure of the pneumatic fluid available to pass from the first valve supply port (not shown) to the first valve delivery port 44i. Alternatively, the first valve 26i may simply fail to change states and pass the pneumatic fluid from the first valve supply port (not shown) to the first valve delivery port 44i even when at least one of the appropriate control signals requesting the fluid

communication between the first valve supply port (not shown) and the first valve delivery port 44i is present at the control ports 30i, 32i.

[0022] A malfunction may also cause insufficient pneumatic pressure to be available at the second valve delivery port 44 ₂ to actuate the second and third brakes 22 ₂₎₃ when desired. For example, a leak may reduce the supply pressure of the pneumatic fluid available to pass from the second valve supply port (not shown) to the second valve delivery port 44 ₂ . Alternatively, the second valve 26 ₂ may simply fail to change states and pass the pneumatic fluid from the second valve supply port (not shown) to the second valve delivery port 44 ₂ even when at least one of the appropriate control signals requesting the fluid communication between the second valve supply port (not shown) and the second valve delivery port 44 ₂ is present at the control ports 30 ₂ , 32 ₂ .

[0023] Because the second actuatable brakes 22 ₂ actuate based on either the pneumatic pressure at the delivery port 44i or the pneumatic pressure at the delivery port 44 ₂ , the second actuatable brakes 22 ₂ actuate when either the first valve 26i or the second valve 26 ₂ transmit the pneumatic fluid from the respective valve supply port (not shown) to the respective valve delivery port 44i ₎₂ . Therefore, although a malfunction causing insufficient pneumatic pressure to be available at one of the first valve delivery port 44i and the second valve delivery port 44 ₂ may cause one of the first brakes 22i and the third brakes 22 ₃ to be actuated, it is contemplated that sufficient pneumatic pressure will still be available at the other of the first valve delivery port 44i and the second valve delivery port 44 ₂ to actuate the other of the first brakes 22i and the third brakes 22 ₃ .

[0024] Since the second brakes 22 ₂ are actuated even when a malfunction causes either the first valve 26i or the second valve 26 ₂ to not transmit the pneumatic fluid from the respective valve supply port (not shown) to the respective valve delivery port 44 _i)2 , two (2) of the three (3) brakes 22i ₎₂₎₃ are actuated during such a malfunction. For example, if a malfunction causes the first valve 26i to not transmit sufficient pneumatic fluid from the valve supply port (not shown) to the valve delivery port 44i to actuate the first and second brakes 22 _i)2 , it is contemplated that the second valve 26 ₂ still transmits sufficient pneumatic fluid from the valve supply port (not shown) to the valve delivery port 44 ₂ to actuate the second and third brakes 22 ₂₎₃ . Similarly, if a malfunction causes the second valve 26 ₂ to not transmit sufficient pneumatic fluid from the valve supply port (not shown) to the valve delivery port 44 ₂ to actuate the second and third brakes 22 ₂₎₃ , it is contemplated that the first valve 26i still transmits sufficient pneumatic fluid from the valve supply port (not shown) to the valve delivery port 44i to actuate the first and second brakes 22i ₎₂ .

[0025] The first valve 26i, the second valve 26 ₂ , the brake pedal 34, and the ECU 42 act as a means for independently controlling the first group 24i of the actuatable brakes 22 _i)2 and the second group 24 ₂ of the actuatable brakes 22 ₂₎₃ , where one of the actuatable brakes 22 ₂ is included in both the first and second groups 24i ₎₂ of the actuatable brakes 22, and where one of the first and second groups 24 _i)2 of the actuatable brakes 22i ₎₃ is continued to be controlled if the other of the first and second groups 24 _i)2 of the actuatable brakes 22i ₎₃ fails to be controlled.

[0026] With reference to FIGURE 2, an exemplary methodology of the system shown in FIGURE 1 for braking a vehicle combination is illustrated. As illustrated, the blocks represent functions, actions and/or events performed therein. It will be appreciated that electronic and software systems involve dynamic and flexible processes such that the illustrated blocks and described sequences can be performed in different sequences. It will also be appreciated by one of ordinary skill in the art that elements embodied as software may be implemented using various programming approaches such as machine language, procedural, object-oriented or artificial intelligence techniques. It will further be appreciated that, if desired and appropriate, some or all of the software can be embodied as part of a device's operating system.

[0027] With reference to FIGURES 1 and 2, the method starts in at step 210. Then, in a step 212, a vehicle braking event begins. For example, the braking event begins when at least one of i) the operator of the vehicle 10 depresses the pedal 34 to transmit pneumatic control signals to the pneumatic control ports 30 of the respective valves 26 to initiate a manual braking event and ii) the ECU 42 transmits electronic control signals to the electronic control ports 32 of the respective valves 26 to initiate an automatic braking event.

[0028] In a step 214, the ECU 42 monitors the brakes 22 to determine if the brakes

22 are actuated as demanded by the at least one of the manual braking event and the automatic braking event. If it is determined in the step 214 that the brakes 22 are actuated as demanded (e.g., no failure has occurred to either the valves 26 or the brakes 22), control passes to a step 216 to determine if the at least one braking event has ended. If it is determined in the step 216 that the at least one braking event has ended, control passes to a step 220 to end the method. Otherwise, if it is determined in the step 216 that the at least one braking event has not ended, control returns to the step 214.

[0029] If it is determined in the step 214 that the brakes 22 in one of the brake groups

24i ₎₂ are not actuated as demanded (e.g., a failure has occurred in either the valves 26 or the brakes 22), control passes to a step 222 to continue actuating the at least one of the other brake groups 24i ₎₂ . Control then passes to the step 216 to determine if the at least one braking event has ended.

[0030] While the present invention has been illustrated by the description of embodiments thereof, and while the embodiments have been described in considerable detail, it is not the intention of the applicants to restrict or in any way limit the scope of the appended claims to such detail. Additional advantages and modifications will readily appear to those skilled in the art. Therefore, the invention, in its broader aspects, is not limited to the specific details, the representative apparatus, and illustrative examples shown and described. Accordingly, departures may be made from such details without departing from the spirit or scope of the applicant's general inventive concept.