Fault detection device of vehicle brake system

Abstract

A method and system for determining a fault in a vehicle braking system is provided. An electronic information processor obtains a brake pedal signal from a brake pedal indicating a driver's braking intent and obtains a vehicle brake response status signal from a brake system feedback sensor. The electronic information processor determines a fault condition when (1) the brake pedal signal indicates no brake pedal motion and the vehicle brake response signal indicates the occurrence of a vehicle brake response, or when (2) the brake pedal signal indicates brake pedal motion and the vehicle brake response status signal indicates no occurrence of a vehicle brake response. The electronic information processor controls output of an audio or visual indication of the fault condition and / or controls braking operation of the vehicle in response to the fault condition.

Description

Technical Field

[0001] A vehicle braking system includes means for determining when the braking system is not operating properly. Background Art

[0002] A brake-by-wire vehicle brake pedal does not use a conventional connection to the other parts of the brake system, such as a mechanical connection to a vacuum brake system or a hydraulic brake system. In some brake-by-wire systems, sensors monitor how far the driver depresses the brake pedal. This distance is used to determine the amount of braking force required. A control unit or computer then determines how much hydraulic pressure is needed and uses an electric pump to generate that pressure and, for example, causes the caliper to push against the brake disc to stop the vehicle. Summary of the invention

[0003] When there is a mechanical connection between the brake pedal and the rest of the brake system, the driver feels a certain sensation through their foot and leg. When there is no mechanical connection between the brake pedal and the rest of the brake system, the driver feels a different sensation. It is desirable to replicate or simulate the feel of a conventional connection between the brake pedal and the brake system in a brake-by-wire (sometimes called fly-by-wire) vehicle brake pedal. Simulating this feel can be accomplished in a variety of ways. It is also desirable to ensure that the amount of braking force requested through the brake-by-wire brake pedal matches or otherwise correlates to the actual braking performed by the brake system.

[0004] Embodiments, aspects, and features described herein are directed, among other things, to a brake-by-wire vehicle brake pedal system that determines when a brake system is not operating properly.

[0005] One aspect includes a method for determining a fault in a vehicle braking system. The method includes receiving a brake pedal signal from a brake pedal sensor indicating a driver's braking intent; and receiving a vehicle braking response status signal from a brake system feedback sensor for at least one wheel of the vehicle. The method also includes determining, using an electronic information processor based on the brake pedal signal and the vehicle braking response status signal, that the vehicle braking system is in a fault state when (1) the brake pedal signal indicates no brake pedal movement and the vehicle braking response status signal indicates that a vehicle braking response has occurred, or when (2) the brake pedal signal indicates brake pedal movement and the vehicle braking response status signal indicates that no vehicle braking response has occurred. The method also includes providing at least one selected from the group consisting of: a visual or audio indicator indicating a fault state, and controlling operation of the vehicle in response to the fault state.

[0006] Another aspect includes a vehicle braking system for determining a fault in a vehicle braking system. The vehicle braking system includes a vehicle brake pedal sensor for providing a brake pedal signal from a brake pedal indicating a driver's braking intent; a brake system feedback sensor for providing a vehicle brake response status signal; and an electronic information processor. The electronic information processor is configured to receive the brake pedal signal and receive the vehicle brake response status signal, and determine a fault state when (1) the brake pedal signal indicates no brake pedal movement and the vehicle brake response status signal indicates that a vehicle braking response has occurred, or when (2) the brake pedal signal indicates brake pedal movement and the vehicle brake response status signal indicates that no vehicle braking response has occurred. The electronic information processor is also configured to provide at least one selected from the group consisting of: an audio or visual indication of the fault state, and controlling a braking operation of the vehicle in response to the fault state.

[0007] Other embodiments, features, and aspects will become apparent from the detailed description and accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 is a block diagram of a vehicle braking system according to some examples.

[0009] Figure 2 is a block diagram showing details of an electronic brake controller and its inputs according to one example.

[0010] Figure 3 is a perspective view of a brake pedal with a brake pedal force sensor assembly.

[0011] Figure 4 is a flow chart illustrating the operation of a vehicle braking system to determine a fault.

[0012] Figure 5 It is shown Figure 3 A block diagram of the details of the alternate brake pedal force sensor and electronic information processor is shown in FIG. DETAILED DESCRIPTION

[0013] Before any embodiment, aspect or feature is described in detail, it should be understood that these devices are not limited in their application to the construction details and component arrangements set forth in the following description or shown in the following drawings. Other embodiments, aspects and features are also possible and can be practiced or implemented in various ways.

[0014] Figure 1 A vehicle braking system 20 is shown for a vehicle 22 including a plurality of wheels 24a, 24b, 24c, 24d. The vehicle 22 includes a brake 28a, 28b, 28c, 28d associated with each wheel.

[0015] Figure 1 The arrangement includes a brake system feedback sensor 32a, 32b, 32c, 32d, which is arranged adjacent to each wheel 24a-24d to determine the actuation of each brake 28a, 28b, 28c, 28d. In one example, the brake system feedback sensor 32a-32d includes a hydraulic pressure sensor that senses the hydraulic pressure applied to each brake 28a-28d. Other arrangements are contemplated.

[0016] Figure 1 Also shown are a brake pedal force sensor assembly 40, a brake pedal position sensor 50, and an engine state or motor state sensor 54. The sensors 32a-32d, 40, 50, 54 provide inputs to an electronic controller 60. The electronic controller 60 provides outputs to a brake control system 64 connected to the vehicle brakes 28a-28d. The electronic controller 60 is also connected to a fault indicator 68 within the vehicle 22.

[0017] Figure 2 The electronic controller 60 is schematically shown in more detail. Figure 2 As shown, the electronic controller 60 is connected to a plurality of sensors 40, 54 via a communication bus 70. The vehicle communication bus 70 may be a controller area network ("CAN") bus, a CAN-FD (Flexible Data Rate) bus, a Flex-Ray bus, etc. In one embodiment, the sensors of the vehicle 22 include a brake pedal force sensor device 40, a brake pedal position sensor 50, an engine state sensor or a motor state sensor 54, and brake system feedback sensors 32a-32d.

[0018] like Figure 2 As shown, the electronic controller 60 includes an input / output interface 80, an electronic processing unit ("EPU") or electronic information processor 82, and one or more non-transitory memories or computer readable modules, such as random access memory ("RAM") 84 and read-only memory ("ROM") 88. The input / output interface 80 sends and receives data, including data from sensors, via the communication bus 70. It should be understood that the electronic controller 60 may include multiple processors, additional computer readable media modules, multiple I / O interfaces, and / or other additional components or modules (e.g., hardware, software, or a combination thereof).

[0019] The electronic information processor 82 receives information from the input / output interface 80 and processes the information by executing one or more instructions from a software module (also referred to as a "controller"). The instructions, modules, or controllers are stored in a non-transitory computer readable medium, such as ROM 88. The electronic controller 60 stores and retrieves information (e.g., information received from the communication bus 70 or information generated by instructions or modules executed by the electronic information processor 82 and sent to and from RAM 84). Non-transitory computer readable media include volatile memory, non-volatile memory, or a combination thereof. The computer readable medium stores operating system software, application programs and / or instructions, data, or a combination thereof. It should be understood that although Figure 2 Only a single electronic information processor 82, RAM 84, ROM 88 and input / output interface 80 are shown, but the electronic controller 60 may include multiple processing units, memory modules and / or input / output interfaces.

[0020] Although Figure 1-2 , the electronic controller 60 is shown as a separate component, but in some embodiments, the electronic controller 60 can be combined with other vehicle components. For example, the electronic controller 60 can be connected to other ECUs or controllers or additional or different sensors. The electronic controller 60 can also perform multiple functions, not just brake control and fault detection.

[0021] Figure 3 A vehicle brake pedal 90 is shown including a brake pedal force sensor arrangement 102. The brake pedal force sensor arrangement 40 includes a first brake pedal force sensor 94 and a second, alternate brake pedal force sensor 98.

[0022] Fault detection operation

[0023] Figure 4 A flow chart 100 is shown describing the operation of a fault detection device of the vehicle brake system 20. In operation, the electronic information processor 82 of the electronic controller 60 is configured to execute algorithms or programs received from the memory 84,88.

[0024] like Figure 4 As shown, in step 104, the electronic information processor 82 receives a brake pedal signal from the vehicle brake pedal sensor via the communication bus 70 and the input / output interface 80. The electronic information processor 82 proceeds to step 108. In one embodiment, the vehicle brake pedal sensor is a brake pedal position sensor 50, and the brake pedal signal is a brake pedal position signal.

[0025] At step 108 , the electronic information processor 82 receives the vehicle brake response status signal from one or a combination of the brake system feedback sensors 32 a - 32 d via the communication bus 70 and the input / output interface 80 or another connection. The electronic information processor 82 then proceeds to decision step 112 .

[0026] At decision step 112, the electronic information processor 82 determines whether the brake pedal signal from the brake pedal position indicates pedal movement. When the brake pedal signal indicates pedal movement / braking, the electronic information processor 82 proceeds to decision step 120. When the brake pedal signal does not indicate the driver's intention to brake, the electronic information processor proceeds to step 124.

[0027] When braking occurs, the electronic information processor proceeds to decision step 120. At decision step 120, the electronic information processor 82 determines whether the vehicle braking response status signal from the plurality of braking system feedback sensors 32a-32d indicates that braking has occurred. When the vehicle braking response status signal matches the brake pedal signal, the electronic information processor 82 returns to step 104 and repeats these steps. When the vehicle braking response status signal does not indicate that braking has occurred at decision step 120, the electronic information processor proceeds to step 130 and indicates a fault condition of the vehicle braking system. The fault condition signal is indicated by the fault indicator 68. In one arrangement, the electronic information processor 82 provides a signal to the fault indicator 68 via the input / output interface 80 and the communication bus 70.

[0028] Returning to decision step 112, when the brake pedal signal does not indicate brake pedal movement, the electronic information processor 82 proceeds to decision step 124. At decision step 124, the electronic information processor 82 determines whether the vehicle braking response status signal from one or more brake system feedback sensors 32a-32d indicates that vehicle braking has occurred. If not occurring and therefore corresponding to no pedal movement, the electronic information processor 82 returns to step 124 and repeats these steps. If braking has occurred and there has been no pedal movement at step 124, the electronic information processor 82 proceeds to step 130.

[0029] At step 130, the electronic information processor outputs a fault status signal. The fault status signal is indicated by the fault indicator 68. The fault indicator signal is at least one selected from the group consisting of a fault indicator signal provided visually on the instrument panel display and an audible ring tone or voice alarm provided on the vehicle audio system. In one embodiment, both the audible alarm and the visual alarm are provided.

[0030] In addition to or as an alternative to the fault condition indication at step 130, in another arrangement, the electronic information processor 82 also provides vehicle control signals to control the operation of the vehicle to minimize vehicle speed and / or ultimately stop the vehicle in an appropriate position due to the fault condition of the vehicle braking system 20.

[0031] Other arrangements are also contemplated. In one arrangement, the vehicle brake response status signal is sensed by a brake system feedback sensor 32a-32d in a hydraulic brake system disposed at at least one wheel 24a-24d. In another arrangement, the vehicle brake response status signal is sensed by a brake system feedback sensor 32a-32d that is part of an electromechanical brake system disposed at at least one wheel 24a-24d.

[0032] In one arrangement, the brake system feedback sensor 32a-32d comprises a brake pressure sensor. In another arrangement, the brake system feedback sensor is a plurality of brake system feedback sensors 32a-32d located at each vehicle brake 28a-28d, and an average value of the sensed vehicle brake response state signals is determined.

[0033] In one arrangement, the vehicle 22 is one selected from the group consisting of an electric vehicle, an internal combustion engine vehicle, and a hybrid vehicle. In another embodiment, the vehicle is an autonomous vehicle.

[0034] Figure 5 Shows Figure 3 140 of another arrangement of the brake pedal force sensor device 40 shown in the figure, which includes a pair of brake pedal force sensors 94, 98. The outputs of the first brake pedal force sensor 94 and the spare second brake pedal force sensor 98 are provided to an electronic information processor 182. The output can be provided by a direct connection or through a communication bus. The electronic information processor 182 compares the brake pedal force signals. When the signals are not similar, the electronic information processor 182 provides a signal to the fault status indicator 168 to indicate a fault of the brake pedal force sensors 94, 98. In response, a visual or audio indicator indicating the fault state is provided. The output can clearly indicate that the fault state is directed to the brake force sensors 94, 98. In other arrangements, the operation of the vehicle is controlled and ultimately terminated in response to the fault state. In summary, when the first brake pedal force sensor 94 and the second brake pedal force sensor 98 do not provide similar brake pedal force signals, the arrangement provides a fault indication to the brake pedal force sensor device. Thus, when the brake pedal force signal from the first brake pedal force sensor 94 differs from the brake pedal force signal from the second brake pedal force sensor 98 , the electronic information processor 182 is configured to provide a fault indication to the brake pedal force sensor device 140 .

[0035] In another arrangement, the method includes a vehicle brake pedal position sensor 50, one or more brake pedal force sensors 94, 98, and providing an engine status signal or a motor status signal from an engine status sensor or a motor status sensor 54. In one feature, the electronic information processor 82, 182 determines when the vehicle engine or the vehicle motor is at rest based on the engine status signal or the motor status signal from the engine status sensor or the motor status sensor 54. The engine status signal or the motor status signal can be displayed visually or provided on the vehicle dashboard. The electronic information processor 82, 182 can also provide an audio engine status signal or a motor status signal.

[0036] In addition, it should be understood that the words and terms used herein are for descriptive purposes and should not be considered limiting. "Including," "comprising," or "having" and variations thereof as used herein are intended to cover the items listed thereafter and their equivalents as well as additional items. The terms "mounted," "connected," and "coupled" are used broadly and cover direct and indirect mounting, connection, and coupling. Furthermore, "connected" and "coupled" are not limited to physical or mechanical connections or couplings, and may include electrical connections or couplings, whether direct or indirect. Furthermore, electronic communications and notifications may be performed using any known means, including wired connections, wireless connections, etc.

[0037] It should also be noted that multiple hardware- and software-based devices and multiple different structural components can be used to implement the embodiment. In addition, it should be understood that the embodiment may include hardware, software and electronic components or modules, which, for the purpose of discussion, may be shown and described as if most components are implemented only in hardware. However, those of ordinary skill in the art will recognize based on reading this specific embodiment that, in at least one embodiment, the electronic-based aspects of the embodiment can be implemented by software (e.g., stored on a non-transient computer-readable medium) that can be executed by one or more processors. Therefore, it should be noted that multiple hardware- and software-based devices and multiple different structural components can be used to implement the embodiment. For example, the "electronic information processor" and "controller" described in this specification may include standard processing components, such as one or more processors, one or more memory modules including non-transient computer-readable media, one or more input / output interfaces, and various connections (e.g., system buses) connecting various components. Software may include instructions and algorithms for executing the methods described herein.

Claims

1. A method for determining a fault condition in a vehicle braking system, the method comprising: receiving a brake pedal signal from a brake pedal sensor indicating a driver's braking intention; receiving a vehicle brake response status signal from a brake system feedback sensor for at least one wheel of the vehicle; Using an electronic information processor, based on the brake pedal signal and the vehicle brake response status signal, determining that the vehicle brake system is in a fault state when (1) the brake pedal signal indicates no brake pedal movement and the vehicle brake response status signal indicates that a vehicle brake response has occurred, or when (2) the brake pedal signal indicates brake pedal movement and the vehicle brake response status signal indicates that a vehicle brake response has not occurred; and At least one selected from the group consisting of providing a visual or audio indicator indicating a fault condition, and controlling operation of the vehicle in response to the fault condition. 2 . The method according to claim 1 , wherein the brake pedal signal is a brake pedal position signal, and the brake pedal sensor is a vehicle brake pedal position sensor for sensing a brake pedal position. 3 . The method according to claim 2 , wherein the vehicle brake response status signal is sensed by a brake system feedback sensor arranged in a hydraulic brake system at at least one wheel. 4 . The method of claim 1 , wherein the brake system feedback sensor is one of a plurality of brake system feedback sensors disposed at each wheel. The method of claim 4 , wherein the brake system feedback sensor comprises a brake pressure sensor.

6. The method of claim 1, wherein the vehicle is one of the group consisting of an electric vehicle, an internal combustion engine vehicle, and a hybrid vehicle.

7. The method according to claim 1, wherein the brake pedal sensor is implemented by a vehicle brake pedal position sensor, and the method includes providing a brake pedal force signal from a brake pedal force sensor arranged in the brake pedal, and providing an engine status signal or a motor status signal from an engine status sensor or a motor status sensor.

8. The method of claim 7, comprising determining, using an electronic information processor, when the vehicle engine or motor is at rest based on the engine status signal or the motor status signal.

9. The method according to claim 2 includes providing a brake pedal force sensor device, which includes a first brake pedal force sensor arranged in the brake pedal and a spare second brake pedal force sensor, wherein the method includes using the electronic information processor to provide a fault indication for the brake pedal force sensor device when the first brake pedal force sensor and the second brake pedal force sensor do not provide similar brake pedal force signals.

10. The method according to claim 1, wherein: The vehicle brake response status signal sensed by the brake system feedback sensor is part of an electromechanical brake system arranged at at least one wheel.

11. A vehicle braking system for determining a fault condition in a vehicle braking system, the vehicle braking system comprising: a vehicle brake pedal sensor for providing a brake pedal signal from a brake pedal indicating a driver's braking intention; A brake system feedback sensor for providing a vehicle brake response status signal; and An electronic information processor having: Receive brake pedal signal and receive vehicle brake response status signal, determining a fault condition when (1) the brake pedal signal indicates no brake pedal movement and the vehicle brake response status signal indicates a vehicle brake response has occurred, or when (2) the brake pedal signal indicates brake pedal movement and the vehicle brake response status signal indicates no vehicle brake response has occurred; and At least one selected from the group consisting of: providing an audio or visual indication of a fault condition, and controlling a braking operation of the vehicle in response to the fault condition.

12. The vehicle braking system of claim 11, wherein the vehicle brake pedal sensor comprises a vehicle brake pedal position sensor.

13. The vehicle braking system of claim 12, wherein the braking system feedback sensor is arranged at at least one wheel.

14. The vehicle braking system of claim 11, wherein the braking system feedback sensor is one of a plurality of braking system feedback sensors disposed at each wheel.

15. The vehicle braking system of claim 14, wherein the braking system feedback sensor comprises a brake pressure sensor for a hydraulic braking system.

16. The vehicle braking system of claim 14, wherein the braking system feedback sensor comprises a brake pressure sensor for an electromechanical braking system.

17. The vehicle brake system of claim 11, wherein the vehicle is one of the group consisting of an electric vehicle, an internal combustion engine vehicle, and a hybrid vehicle.

18. The vehicle braking system of claim 11, wherein the brake pedal sensor comprises a vehicle brake pedal position sensor, and the vehicle braking system comprises: a brake pedal force sensor disposed in the brake pedal to provide a brake pedal force signal to the electronic information processor, and An engine status sensor or a motor status sensor provides an engine status signal or a motor status signal to the electronic information processor.

19. The vehicle braking system of claim 18, wherein the electronic information processor is configured to determine when the vehicle engine or the vehicle motor is at rest based on the engine status signal or the motor status signal.

20. The vehicle braking system of claim 12, comprising: A brake pedal force sensor device includes a first brake pedal force sensor and a second backup brake pedal force sensor disposed in a brake pedal, and Wherein, when the brake pedal force signal from the first brake pedal force sensor is different from the brake pedal force signal from the second brake pedal force sensor, the electronic information processor is configured to provide a fault indication to the brake pedal force sensor device.

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