Chassis braking method, apparatus, system, and storage medium

Abstract

The application relates to the field of vehicle brake control and discloses a chassis brake method, device, system and storage medium, which are used for improving brake safety and reducing brake cost. The chassis brake method comprises the following steps: monitoring the working state of a chassis brake system; when the working state of the chassis brake system is normal, controlling an electronic stability controller to brake through a wire control master controller; and when the working state of the chassis brake system is abnormal, identifying a failed target object in the chassis brake system and determining a brake strategy based on the failed target object to brake.

Description

Technical Field

[0001] This invention relates to the field of vehicle braking control, and more particularly to a chassis braking method, device, system, and storage medium. Background Technology

[0002] In autonomous driving design, to reduce the risk of vehicle braking system failure, braking redundancy is usually implemented in the vehicle.

[0003] Current brake redundancy designs typically involve dual communication, dual power supply, dual sensors, and dual actuators, meaning that a backup is prepared for each module in the chassis braking system. This design is not only structurally complex but also costly. Summary of the Invention

[0004] The main objective of this invention is to provide a chassis braking method, device, system, and storage medium to solve the problem of high cost in dual-redundant braking design, improve braking safety, and reduce braking costs.

[0005] The first aspect of this invention provides a chassis braking method applied to a vehicle's chassis braking system. The chassis braking system includes a drive-by-wire master controller, an electronic parking brake, a vehicle control unit, an electronic stability controller, and a redundant braking controller. The method includes: monitoring the operating status of the chassis braking system; when the operating status of the chassis braking system is normal, controlling the electronic stability controller to perform braking via the drive-by-wire master controller; when the operating status of the chassis braking system is abnormal, identifying a failed target object in the chassis braking system; and determining a braking strategy based on the failed target object to perform braking.

[0006] In one feasible implementation, monitoring the operating status of the chassis braking system includes: monitoring whether the electronic stability controller generates a first failure signal, the first failure signal indicating a communication failure, power failure, brake cylinder failure, or output feedback failure of the electronic stability controller; monitoring whether the vehicle control unit generates a second failure signal, the second failure signal indicating a communication failure, power failure, or negative torque recovery failure of the vehicle control unit; monitoring whether the drive-by-wire master controller generates a third failure signal, the third failure signal indicating a communication failure or power failure of the drive-by-wire master controller; monitoring whether the redundant brake controller generates a fourth failure signal, the fourth failure signal indicating a communication failure or power failure of the redundant brake controller; when the vehicle activates the autonomous driving function, triggering a self-test command for the electronic parking brake, monitoring whether the electronic parking brake generates a fifth failure signal, the fifth failure signal indicating a signal generator failure of the electronic parking brake; if the first failure signal, the second failure signal, the third failure signal, the fourth failure signal, or the fifth failure signal are detected, then the operating status of the chassis braking system is determined to be abnormal; otherwise, the operating status of the chassis braking system is determined to be normal.

[0007] In one feasible implementation, monitoring whether the electronic stability controller generates a first failure signal includes: detecting a heartbeat signal output by the electronic stability controller; if no heartbeat signal occurs within the heartbeat cycle, it is determined that the electronic stability controller has experienced a communication failure and a power failure; detecting the requested braking pressure and the actual braking pressure received by the electronic stability controller; if the difference between the actual braking pressure and the requested braking pressure is greater than a first threshold and the cylinder pressure of the brake cylinder is less than a second threshold, it is determined that the brake cylinder of the electronic stability controller has failed, the brake cylinder including a master cylinder and wheel cylinders; detecting the requested braking stroke and the actual braking stroke received by the electronic stability controller; if the first difference between the requested braking stroke and the actual braking stroke is greater than a third threshold and the duration is greater than a first preset duration, it is determined that the output feedback of the electronic stability controller has failed; when the electronic stability controller experiences a communication failure, a power failure, a brake cylinder failure, or an output feedback failure, a first failure signal is generated.

[0008] In one feasible implementation, monitoring whether the vehicle control unit generates a second failure signal includes: detecting a heartbeat signal output by the vehicle control unit; if no heartbeat signal appears within the heartbeat cycle, determining that the vehicle control unit has experienced a communication failure and a power failure; detecting a requested negative torque and a received feedback negative torque issued by the vehicle control unit; if a second difference between the requested negative torque and the feedback negative torque is greater than a fourth threshold and the duration is greater than a second preset duration, determining that the vehicle control unit has experienced a negative torque recovery failure; and generating a second failure signal when the vehicle control unit experiences a communication failure, a power failure, or a negative torque recovery failure.

[0009] In one feasible implementation, monitoring whether the main controller for drive-by-wire generates a third failure signal includes: detecting a heartbeat signal sent by the main controller for drive-by-wire to the redundant braking controller; if no heartbeat signal appears within the heartbeat cycle, determining that the main controller for drive-by-wire has experienced a communication failure and a power failure; and generating a third failure signal when the main controller for drive-by-wire experiences a communication failure or a power failure.

[0010] In one feasible implementation, monitoring whether the redundant braking controller generates a fourth failure signal includes: detecting a heartbeat signal sent by the redundant braking controller to the main controller by wire; if no heartbeat signal appears within the heartbeat cycle, determining that the redundant braking controller has experienced a communication failure and a power failure; and generating a fourth failure signal when the redundant braking controller experiences a communication failure or a power failure.

[0011] In one feasible implementation, the step of triggering a self-test command for the electronic parking brake when the vehicle starts the autonomous driving function, and monitoring whether the electronic parking brake generates a fifth failure signal, includes: triggering a self-test command for the electronic parking brake when the vehicle starts the autonomous driving function; if the electronic parking brake cannot send parking information or receive parking feedback according to the self-test command, then a fifth failure signal is generated.

[0012] In one feasible implementation, the step of determining a braking strategy based on the failed target object and performing braking includes: when the failed target object is the electronic stability controller, sending a negative torque request to the vehicle control unit through the drive-by-wire master controller, and controlling the vehicle motor to execute the negative torque request to perform braking through the vehicle control unit; when the failed target object is the vehicle control unit, controlling the electronic stability controller to perform braking through the drive-by-wire master controller; when the failed target object is the drive-by-wire master controller, triggering the electronic parking brake to perform braking through the redundant braking controller; when the failed target object is the redundant braking controller, controlling the electronic stability controller to perform braking through the drive-by-wire master controller; and when the failed target object is the electronic parking brake, prohibiting the vehicle from entering automatic driving mode and sending a warning message for manual braking.

[0013] In one feasible implementation, when the failed target object is the electronic stability controller, after sending a negative torque request to the vehicle control unit through the drive-by-wire master controller and controlling the vehicle motor to execute the negative torque request for braking through the vehicle control unit, the method further includes: if the deceleration corresponding to the negative torque request is greater than the deceleration corresponding to the maximum negative torque of the vehicle motor, then triggering the electronic parking brake to perform synchronous braking through the drive-by-wire master controller.

[0014] In one feasible implementation, when the failed target object is the vehicle control unit, after controlling the electronic stability controller to brake through the drive-by-wire master controller, the method further includes: if the electronic stability controller malfunctions, triggering the electronic parking brake through the drive-by-wire master controller.

[0015] A second aspect of the present invention provides a chassis braking device, comprising: a monitoring module for monitoring the operating status of the chassis braking system, wherein the operating status is normal or abnormal; a control module for controlling the electronic stability controller to perform braking via the drive-by-wire master controller when the operating status of the chassis braking system is normal; an identification module for identifying a failed target object in the chassis braking system when the operating status of the chassis braking system is abnormal; and a braking module for determining a braking strategy and performing braking based on the failed target object.

[0016] In one feasible implementation, the monitoring module includes: a first monitoring unit for monitoring whether the electronic stability controller generates a first failure signal, the first failure signal indicating a communication failure, power failure, brake cylinder failure, or output feedback failure of the electronic stability controller; a second monitoring unit for monitoring whether the vehicle control unit generates a second failure signal, the second failure signal indicating a communication failure, power failure, or negative torque recovery failure of the vehicle control unit; a third monitoring unit for monitoring whether the drive-by-wire master controller generates a third failure signal, the third failure signal indicating a communication failure or power failure of the drive-by-wire master controller; and a fourth monitoring unit for... The system includes a fifth monitoring unit, which monitors whether the redundant braking controller generates a fourth failure signal, indicating a communication failure or power failure of the redundant braking controller; a fifth monitoring unit, which triggers a self-test command for the electronic parking brake when the vehicle activates the autonomous driving function, and monitors whether the electronic parking brake generates a fifth failure signal, indicating a failure of the signal generator of the electronic parking brake; and a determination unit, which determines that the chassis braking system is in an abnormal operating state if the first failure signal, the second failure signal, the third failure signal, the fourth failure signal, or the fifth failure signal are detected, otherwise determines that the chassis braking system is in a normal operating state.

[0017] In one feasible implementation, the first monitoring unit is specifically used to: detect the heartbeat signal output by the electronic stability controller; if no heartbeat signal appears within the heartbeat cycle, it is determined that the electronic stability controller has experienced communication failure and power failure; detect the requested braking pressure and actual braking pressure received by the electronic stability controller; if the difference between the actual braking pressure and the requested braking pressure is greater than a first threshold and the cylinder pressure of the brake cylinder is less than a second threshold, it is determined that the brake cylinder of the electronic stability controller has failed, the brake cylinder including the master cylinder and the wheel cylinder; detect the requested braking stroke and actual braking stroke received by the electronic stability controller; if the first difference between the requested braking stroke and the actual braking stroke is greater than a third threshold and the duration is greater than a first preset duration, it is determined that the output feedback of the electronic stability controller has failed; when the electronic stability controller experiences communication failure, power failure, brake cylinder failure, or output feedback failure, a first failure signal is generated.

[0018] In one feasible implementation, the second monitoring unit is specifically used to: detect the heartbeat signal output by the vehicle control unit; if no heartbeat signal appears within the heartbeat cycle, determine that the vehicle control unit has experienced communication failure and power failure; detect the requested negative torque and received feedback negative torque issued by the vehicle control unit; if the second difference between the requested negative torque and the feedback negative torque is greater than a fourth threshold and the duration is greater than a second preset duration, determine that the negative torque recovery of the vehicle control unit has failed; and generate a second failure signal when the vehicle control unit experiences communication failure, power failure, or negative torque recovery failure.

[0019] In one feasible implementation, the third monitoring unit is specifically used to: detect the heartbeat signal sent by the main controller to the redundant braking controller; if no heartbeat signal appears within the heartbeat cycle, determine that the main controller has failed in communication and power supply; and generate a third failure signal when the main controller fails in communication or power supply.

[0020] In one feasible implementation, the fourth monitoring unit is specifically used to: detect the heartbeat signal sent by the redundant braking controller to the main controller by wire; if no heartbeat signal appears within the heartbeat cycle, determine that the communication of the redundant braking controller has failed and the power supply has failed; when the communication of the redundant braking controller fails or the power supply fails, generate a fourth failure signal.

[0021] In one feasible implementation, the fifth monitoring unit is specifically used to: trigger a self-test command for the electronic parking brake when the vehicle starts the autonomous driving function; if the electronic parking brake cannot send parking information or receive parking feedback according to the self-test command, then generate a fifth failure signal.

[0022] In one feasible implementation, the braking module includes: a first braking unit, configured to send a negative torque request to the vehicle control unit via the drive-by-wire master controller when the failed target object is the electronic stability controller, and control the vehicle motor to perform braking by the vehicle control unit; a second braking unit, configured to control the electronic stability controller to perform braking by the drive-by-wire master controller when the failed target object is the vehicle control unit; a third braking unit, configured to trigger the electronic parking brake to perform braking by the redundant braking controller when the failed target object is the drive-by-wire master controller; a fourth braking unit, configured to control the electronic stability controller to perform braking by the drive-by-wire master controller when the failed target object is the redundant braking controller; and a sending unit, configured to prevent the vehicle from entering automatic driving mode and send a warning message for manual braking when the failed target object is the electronic parking brake.

[0023] In one feasible implementation, the chassis braking device further includes a fifth braking unit, which is used to trigger the electronic parking brake for synchronous braking via the drive-by-wire controller if the deceleration corresponding to the negative torque request is greater than the deceleration corresponding to the maximum negative torque of the vehicle motor.

[0024] In one feasible implementation, the chassis braking device further includes a sixth braking unit, which is used to trigger the electronic parking brake through the main controller if the electronic stability controller malfunctions.

[0025] A third aspect of the present invention provides a chassis braking system, comprising: a drive-by-wire master controller, an electronic parking brake, a vehicle control unit, an electronic stability controller and a redundant brake controller, a memory and at least one processor, wherein the memory stores instructions; the at least one processor invokes the instructions in the memory to cause the chassis braking system to perform the aforementioned chassis braking method.

[0026] A fourth aspect of the present invention provides a computer-readable storage medium storing instructions that, when executed on a computer, cause the computer to perform the aforementioned chassis braking method.

[0027] The technical solution provided by this invention monitors the working status of the chassis braking system. When the chassis braking system is functioning normally, the electronic stability controller is controlled by the drive-by-wire master controller to apply brakes. When the chassis braking system is malfunctioning, a failed target object in the chassis braking system is identified, and a braking strategy is determined based on the failed target object for braking. In this embodiment of the invention, the working status of each module in the chassis braking system is monitored. When each module is functioning normally, the drive-by-wire master controller applies brakes through the electronic stability controller. When a module malfunctions, a failed target object is identified, and a braking strategy is formulated based on other normally functioning targets in the chassis braking system for braking, thereby improving braking safety, eliminating the need for a dual braking system, and reducing braking costs. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the chassis braking system in an embodiment of the present invention;

[0029] Figure 2 This is a schematic diagram of one embodiment of the chassis braking method in this invention;

[0030] Figure 3 This is a schematic diagram of another embodiment of the chassis braking method in this invention;

[0031] Figure 4 This is a schematic diagram of one embodiment of the chassis braking device in this invention;

[0032] Figure 5 This is a schematic diagram of another embodiment of the chassis braking device in this invention. Detailed Implementation

[0033] This invention provides a chassis braking method, apparatus, device, and storage medium to improve braking safety and reduce braking costs.

[0034] The terms “first,” “second,” “third,” “fourth,” etc. (if present) in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms “comprising” or “having,” and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0035] To facilitate understanding, the chassis braking system will be explained first, such as... Figure 1 As shown, the chassis braking system 100 includes a drive-by-wire (DBW) controller 101, an electric parking brake (EPB) 102, a vehicle control unit (VCU) 103, an electronic stability control (ESC) 104, a redundant brake controller 105, a memory 106, and at least one processor 107. The memory 106 stores instructions, and the processor 107 can call the instructions in the memory 106. DBW 101 is communicatively connected to the redundant brake controller 105. EPB 102 is communicatively connected to both DBW 101 and the redundant brake controller 105. EPB 102 is also communicatively connected to ESC 104. DBW 101, VCU 103, ESC 104, and the redundant brake controller 105 communicate via a controller area network (CAN).

[0036] The functions of each module in the chassis braking system are as follows:

[0037] 1. Functions of DBW 101: 1) Issue braking request; 2) Issue negative torque request; 3) Issue parking request; 4) Monitor the status of redundant brake controller 105; 5) Monitor the status of chassis actuators.

[0038] 2. Function of EPB 102: Execute parking request.

[0039] 3. Function of VCU 103: Execute the negative torque request issued by DBW 101.

[0040] 4. Function of ESC 104: Execute the braking request issued by DBW 101.

[0041] 5. Functions of the redundant brake controller 105: 1) Monitor the status of DBW 101; 2) Trigger a parking request; 3) Issue a negative torque recovery request.

[0042] 6. Memory 106: Store instructions.

[0043] 7. Processor 107: Calls instructions from memory.

[0044] The redundant brake controller 105 can not only decelerate and brake the vehicle through negative torque recovery, but also achieve the parking control effect of DBW101, performing emergency braking in case of DBW101 malfunction, thus improving safety. It should be noted that the functions of each module listed above are only partial and do not limit the complete functionality of each module.

[0045] When the chassis braking system is working properly, DBW 101 controls ESC 104 to apply the brakes. When the chassis braking system is not working properly, the chassis braking system identifies the failed target object. The failed target object is any one of DBW 101, EPB 102, VCU 103, ESC 104 and redundant brake controller 105.

[0046] When the failed target object is DBW 101, the redundant brake controller 105 controls EPB 102 to brake; when the failed target object is EPB 102, the vehicle is prohibited from entering automatic driving mode, and a warning message for manual braking is sent to initiate manual braking; when the failed target object is VCU 103, DBW 101 controls ESC 104 to brake; when the failed target object is ESC 104, DBW 101 controls VCU 103 to brake; when the failed target object is redundant brake controller 105, DBW 101 controls ESC 104 to brake. This allows braking to be performed using other unfailed objects in the chassis braking system when a failed object occurs, improving braking safety. It eliminates the need to back up every module in the chassis braking system, reducing the braking costs associated with redundant design.

[0047] The specific process of the embodiments of the present invention is described below. It should be understood that the executing entity of the present invention can be a chassis braking device or a vehicle terminal that controls the operation of the chassis braking system; no specific limitation is made here. The embodiments of the present invention are illustrated using a vehicle terminal (hereinafter referred to as the terminal) as the executing entity.

[0048] Please see Figure 2 One embodiment of the chassis braking method in this invention includes:

[0049] 201. Monitor the working status of the chassis braking system.

[0050] The terminal monitors the working status of the chassis braking system, which includes DBW, EPB, VCU, ESC and redundant brake controller, and the modules are interconnected.

[0051] The functions of each module in the chassis braking system are as follows:

[0052] 1. Functions of DBW: 1) Issue braking request; 2) Issue negative torque request; 3) Issue parking request; 4) Monitor the status of redundant brake controller; 5) Monitor the status of chassis actuator.

[0053] 2. EPB function: Execute parking request.

[0054] 3. VCU function: Execute the negative torque request issued by DBW.

[0055] 4. The function of ESC: to execute the braking request issued by DBW.

[0056] 5. Functions of the redundant brake controller: 1) Monitor the status of the DBW; 2) Trigger a parking request; 3) Issue a negative torque recovery request.

[0057] The redundant brake controller can not only decelerate and brake the vehicle through negative torque recovery, but also achieve the parking control effect of DBW (Device-Driven Braking), performing emergency braking in case of DBW malfunction to improve safety. It should be noted that the functions of each module listed above are only partial and do not limit the complete functionality of each module.

[0058] When all modules in the chassis braking system can apply the corresponding functions, the terminal determines that the chassis braking system is in normal working condition. When a module in the chassis braking system cannot fully apply the corresponding functions, the terminal determines that the chassis braking system is in abnormal working condition.

[0059] 202. When the chassis braking system is in normal working condition, the electronic stability controller is controlled by the main controller for braking.

[0060] When the chassis braking system is in normal working condition, the terminal controls the ESC to brake via the DBW. The ESC includes the master cylinder, wheel cylinders, connecting lines and brakes. Specifically, when the terminal determines that braking is required based on the information collected by the vehicle sensors, it sends a braking request to the ESC via the DBW. The braking request includes a braking control signal, and the ESC controls the brakes to brake the vehicle based on the control signal.

[0061] 203. When the chassis braking system is in an abnormal working state, identify the failed target object in the chassis braking system.

[0062] When the chassis braking system is in an abnormal working state, the terminal identifies the failed target object in the chassis braking system. The failed target object refers to the module that cannot fully apply the above-mentioned corresponding functions. The failed target object is any one of DBW, EPB, VCU, ESC and redundant brake controller.

[0063] 204. Determine the braking strategy based on the failed target object and apply braking accordingly.

[0064] After the terminal identifies the failed target object, it combines control based on the functions of modules other than the failed target object to generate a braking strategy for braking. For example, when the failed target object is ESC, since EPB has a parking function and can stop the vehicle, and VCU has the function of executing negative torque of the motor and can control the vehicle to decelerate to a stop, EPB or VCU can be used to replace ESC for braking.

[0065] In this embodiment of the invention, the working status of each module in the chassis braking system is monitored. When each module is working normally, the DBW brakes through ESC. When a module malfunctions, the failed module is identified, and a braking strategy is formulated based on other normally functioning modules in the chassis braking system to improve braking safety. This eliminates the need for a dual braking system and reduces braking costs.

[0066] Please see Figure 3 Another embodiment of the chassis braking method in this invention includes:

[0067] 301. Monitor whether the electronic stability controller generates a first failure signal. The first failure signal indicates communication failure, power failure, brake cylinder failure, or output feedback failure of the electronic stability controller.

[0068] The terminal monitors the ESC from multiple aspects. Firstly, the terminal detects the heartbeat signal output by the ESC. The heartbeat signal is a data packet sent at a set frequency. If no heartbeat signal appears within the heartbeat cycle, it is determined that the ESC's communication has failed and its power supply has failed.

[0069] Secondly, the terminal detects the requested braking pressure and the actual braking pressure received by the ESC. If the difference between the actual braking pressure and the requested braking pressure is greater than the first threshold and the cylinder pressure of the brake cylinder is less than the second threshold, then it is determined that the brake cylinder of the ESC has failed. The brake cylinder includes the master cylinder and the wheel cylinder.

[0070] Specifically, pressure sensors are installed at both the master cylinder and wheel cylinders. The terminal converts the braking request received by the ESC into a requested braking pressure, and then multiplies the requested braking pressure by a first preset coefficient to obtain a first threshold. The actual braking pressure of the master cylinder is collected. If the difference between the requested braking pressure and the actual braking pressure is greater than the first threshold, the real-time pressure values ​​of the master cylinder and wheel cylinder are detected. If the real-time pressure values ​​of both the master cylinder and wheel cylinder are less than the second threshold, the terminal determines that the master cylinder and wheel cylinder of the ESC have failed.

[0071] For example, if the braking request is for 100% of the braking stroke, and the converted braking pressure is for 100% of the pressure limit, with a preset coefficient of 0.3, then the first threshold is a pressure limit of 30%, while the actual braking pressure of the master cylinder is a pressure limit of 60%. The difference between the requested braking pressure and the actual braking pressure is a pressure limit of 40%, which is greater than the first threshold. At this time, the real-time pressure values ​​of the master cylinder and wheel cylinders are collected. If the real-time pressure values ​​of the master cylinder and wheel cylinders are less than the second threshold, such as 10 bar, then the terminal determines that the master cylinder and wheel cylinders of the ESC have failed.

[0072] Thirdly, the terminal detects the requested braking stroke and the actual braking stroke received by the ESC. If the first difference between the requested braking stroke and the actual braking stroke is greater than the third threshold and the duration is greater than the first preset duration, then the output feedback of the ESC is determined to be invalid.

[0073] Specifically, a sensor is installed on the brake. The ESC receives a request for braking stroke. The terminal multiplies the requested braking stroke by a second preset coefficient to obtain a third threshold. The actual braking torque is collected by the sensor and converted into a corresponding proportion of the actual braking stroke. The difference between the requested braking stroke and the actual braking stroke is calculated. If the difference calculation result is greater than the third threshold, the terminal monitors whether the difference between the requested braking stroke and the actual braking stroke is always greater than the third threshold within a first preset time period. If so, the terminal determines that the output feedback of the ESC has failed.

[0074] When a communication failure, power failure, brake cylinder failure, or output feedback failure is detected by the ESC, the terminal controls the ESC to generate a first failure signal.

[0075] 302. Monitor whether the vehicle control unit generates a second failure signal, which indicates a communication failure, power failure, or negative torque recovery failure of the vehicle control unit.

[0076] The terminal monitors the VCU from multiple aspects. Firstly, the terminal detects the heartbeat signal output by the VCU. If no heartbeat signal appears within the heartbeat cycle, it is determined that the VCU's communication has failed and its power supply has failed.

[0077] Secondly, the terminal detects the requested negative torque and the received feedback negative torque issued by the VCU. If the second difference between the requested negative torque and the feedback negative torque is greater than the fourth threshold and the duration is greater than the second preset duration, then it is determined that the negative torque recovery of the VCU has failed.

[0078] When the VCU experiences communication failure, power failure, or negative torque recovery failure, the terminal controls the VCU to generate a second failure signal.

[0079] 303. Monitor whether the main controller of the drive-by-wire generates a third failure signal. The third failure signal indicates a communication failure or power failure of the main controller of the drive-by-wire.

[0080] The DBW and the redundant braking controller communicate via CAN. The terminal detects the heartbeat signal sent by the DBW to the redundant braking controller. If no heartbeat signal appears within the heartbeat cycle, it is determined that the DBW has failed in communication and power. When the DBW fails in communication or power, the terminal controls the DBW to generate a third failure signal.

[0081] 304. Monitor whether the redundant braking controller generates a fourth failure signal. The fourth failure signal indicates a communication failure or power failure of the redundant braking controller.

[0082] Similarly, the terminal detects the heartbeat signal sent by the redundant braking controller to the DBW. If no heartbeat signal appears within the heartbeat cycle, it is determined that the redundant braking controller has failed in communication and power. When the redundant braking controller fails in communication or power, the terminal controls the redundant braking controller to generate a fourth failure signal.

[0083] 305. When the vehicle activates the autonomous driving function, a self-test command for the electronic parking brake is triggered to monitor whether the electronic parking brake generates a fifth failure signal. The fifth failure signal indicates that the signal generator of the electronic parking brake has failed.

[0084] When the vehicle activates the autonomous driving function, the terminal triggers the EPB's self-test command. The self-test command is for the EPB to send parking information and receive parking feedback. If the EPB cannot send parking information or receive parking feedback according to the self-test command, the terminal controls the EPB to generate a fifth failure signal.

[0085] 306. If the first failure signal, second failure signal, third failure signal, fourth failure signal or fifth failure signal is detected, the chassis braking system is determined to be in an abnormal working state; otherwise, the chassis braking system is determined to be in a normal working state.

[0086] 307. When the chassis braking system is in normal working condition, the electronic stability controller is controlled by the main controller for braking.

[0087] Step 307 in this embodiment is the same as step 202, and will not be repeated here.

[0088] 308. When the chassis braking system is in an abnormal working state, identify the failed target object in the chassis braking system.

[0089] When the chassis braking system is in an abnormal operating state, the terminal identifies the failed target object in the chassis braking system. The failed target object is any one of DBW, EPB, VCU, ESC and redundant brake controller.

[0090] 309. When the failed target is the electronic stability controller, a negative torque request is sent to the vehicle control unit through the main controller by drive, and the vehicle control unit controls the vehicle motor to execute the negative torque request for braking.

[0091] When the failed target is ESC, the terminal sends a negative torque request to VCU through DBW. VCU controls the motor to decelerate according to the negative torque request until the vehicle stops. At the same time, it also controls DBW to upload fault information to the autonomous driving computing unit of the service center through CAN.

[0092] Furthermore, if the deceleration corresponding to the negative torque request is greater than the deceleration corresponding to the maximum negative torque of the vehicle motor, the terminal sends a parking signal through the DBW to trigger the EPB to brake. During the EPB braking process, the terminal controls the brake lights to flash and sets the vehicle gear to P. After the vehicle stops, the DBW stops sending parking signals.

[0093] 310. When the failed target is the vehicle control unit, the electronic stability controller is controlled to brake via the drive-by-wire master controller.

[0094] When the failed target object is the VCU, the terminal controls the ESC to brake via the DBW. The braking method is as described in step 202 and will not be repeated here. After the vehicle stops, the terminal controls the DBW to upload the fault information to the autonomous driving computing unit of the service center via CAN.

[0095] Furthermore, if the ESC also malfunctions, the terminal sends a parking signal via the DBW to trigger the EPB to brake. During braking, the terminal controls the brake lights to flash and sets the vehicle to P gear. After the vehicle stops, the DBW stops sending parking signals.

[0096] It should be noted that, since the redundant brake controller, like the DBW, can issue braking requests and communicate with the ESC, it can replace the DBW to perform braking in this step.

[0097] 311. When the failed target is the main controller of the drive-by-wire system, a parking signal is sent through the redundant brake controller to trigger the electronic parking brake for braking.

[0098] When the target object that fails is DBW, the terminal sends a parking signal through DBW to trigger EPB to perform synchronous braking. During the EPB braking process, the terminal controls the brake lights to flash and sets the vehicle gear to P. After the vehicle stops, DBW stops sending parking signals.

[0099] After the vehicle stops, the terminal control redundant brake controller uploads fault information to the autonomous driving computing unit of the service center via CAN.

[0100] 312. When the failed target object is a redundant braking controller, the electronic stability controller is controlled by the main controller by the drive-by-wire controller to perform braking.

[0101] When the failed target is a redundant braking controller, the terminal controls the ESC to brake via the DBW. The braking method is as described in step 202 and will not be repeated here. After the vehicle stops, the terminal controls the DBW to upload fault information to the autonomous driving computing unit of the service center via CAN.

[0102] 313. When the target object that fails is the electronic parking brake, the vehicle is prohibited from entering the automatic driving state, and a warning message to send manual braking is issued.

[0103] When the failed target object is EPB, the terminal detects whether the vehicle is in autonomous driving mode. If not, the vehicle is prohibited from entering autonomous driving mode. If so, a warning message for manual braking is sent until the driver takes over the vehicle.

[0104] Before the driver takes over the vehicle, a negative torque request can be sent to the VCU via the DBW, and the VCU can then control the vehicle's motors to execute the negative torque request for braking.

[0105] Furthermore, when the number of failed target objects is greater than 1, the non-failed objects are aggregated into a set of non-failed objects. The terminal extracts the objects that are coordinated braking and belong to the chassis braking system in steps 309-313, respectively, to obtain the first braking object set, the second braking object set, the third braking object set, the fourth braking object set, and the fifth braking object set. The set of non-failed objects is matched with the first braking object set, the second braking object set, the third braking object set, the fourth braking object set, and the fifth braking object set in sequence. If the match is successful, the braking strategy corresponding to the successfully matched braking object set is determined as the target braking strategy for braking. Successful matching means that all objects in the braking object set exist in the set of non-failed objects.

[0106] For example, when the failed target objects are DBW and EPB, the set of unfailed objects obtained by summarizing the unfailed objects includes VCU, ESC, and redundant brake controller. The terminal extracts the objects that cooperate in braking and belong to the chassis braking system in steps 309-313, and obtains the first braking object set including DBW and VCU, the second braking object set including DBW / redundant brake controller and ESC, the third braking object set including redundant brake controller and EPB, the fourth braking object set including DBW and ESC, and the fifth braking object set including DBW and VCU. It can be seen from the matching that the set of unfailed objects matches the second braking object set. Therefore, braking is performed according to the strategy corresponding to the second braking object set.

[0107] In this embodiment of the invention, the working status of each module in the chassis braking system is monitored. When each module is working normally, the DBW brakes through ESC. When a module malfunctions, the failed object is identified, and a braking strategy is formulated based on other normally functioning objects in the chassis braking system to improve braking safety. There is no need to set up a redundant backup braking system, which reduces braking costs. In the case of multiple failed objects, the corresponding braking strategy is matched according to the non-failed objects to further improve safety.

[0108] The chassis braking method in the embodiments of the present invention has been described above. The chassis braking device in the embodiments of the present invention will be described below. Please refer to [link / reference]. Figure 4 One embodiment of the chassis braking device in this invention includes:

[0109] Monitoring module 401 is used to monitor the working status of the chassis braking system, which is either normal or abnormal.

[0110] Control module 402 is used to control the electronic stability controller to brake through the main controller when the chassis braking system is in normal working condition.

[0111] The identification module 403 is used to identify the failed target object in the chassis braking system when the working state of the chassis braking system is abnormal.

[0112] Braking module 404 is used to determine a braking strategy based on the failed target object and perform braking.

[0113] In this embodiment of the invention, the working status of each module in the chassis braking system is monitored. When each module is working normally, the drive-by-wire controller performs braking through the electronic stability controller. When a module malfunctions, the failed module is identified, and a braking strategy is formulated based on other normally functioning modules in the chassis braking system to improve braking safety. This eliminates the need for a dual braking system and reduces braking costs.

[0114] Please see Figure 5 Another embodiment of the chassis braking device in this invention includes:

[0115] Monitoring module 401 is used to monitor the working status of the chassis braking system, which is either normal or abnormal.

[0116] Control module 402 is used to control the electronic stability controller to brake through the main controller when the chassis braking system is in normal working condition.

[0117] The identification module 403 is used to identify the failed target object in the chassis braking system when the working state of the chassis braking system is abnormal.

[0118] Braking module 404 is used to determine a braking strategy based on the failed target object and perform braking.

[0119] Optionally, the control module 402 includes:

[0120] The first monitoring unit 4021 is used to monitor whether the electronic stability controller generates a first failure signal. The first failure signal indicates communication failure, power failure, brake cylinder failure or output feedback failure of the electronic stability controller.

[0121] The second monitoring unit 4022 is used to monitor whether the vehicle control unit generates a second failure signal. The second failure signal indicates communication failure, power failure, or negative torque recovery failure of the vehicle control unit.

[0122] The third monitoring unit 4023 is used to monitor whether the main controller of the drive-by-wire generates a third failure signal. The third failure signal indicates a communication failure or power failure of the main controller of the drive-by-wire.

[0123] The fourth monitoring unit 4024 is used to monitor whether the redundant braking controller generates a fourth failure signal, which indicates a communication failure or power failure of the redundant braking controller.

[0124] The fifth monitoring unit 4025 is used to trigger the self-test command of the electronic parking brake when the vehicle starts the autonomous driving function, and to monitor whether the electronic parking brake generates a fifth failure signal. The fifth failure signal indicates that the signal generator of the electronic parking brake has failed.

[0125] The determining unit 4026 is used to determine that the working state of the chassis braking system is abnormal if a first failure signal, a second failure signal, a third failure signal, a fourth failure signal, or a fifth failure signal is detected; otherwise, it determines that the working state of the chassis braking system is normal.

[0126] Optionally, the first monitoring unit 4021 is specifically used for:

[0127] The system detects the heartbeat signal output by the electronic stability controller (ESC). If no heartbeat signal is detected within the heartbeat cycle, it determines that the ESC has experienced a communication failure and a power failure. It also detects the requested braking pressure and the actual braking pressure received by the ESC. If the difference between the actual braking pressure and the requested braking pressure is greater than a first threshold and the cylinder pressure of the brake cylinder is less than a second threshold, it determines that the brake cylinder of the ESC has failed. The brake cylinder includes the master cylinder and wheel cylinders. Furthermore, it detects the requested braking stroke and the actual braking stroke received by the ESC. If the first difference between the requested braking stroke and the actual braking stroke is greater than a third threshold and the duration is greater than a first preset duration, it determines that the output feedback of the ESC has failed. When the ESC experiences communication failure, power failure, brake cylinder failure, or output feedback failure, a first failure signal is generated.

[0128] Optionally, the second monitoring unit 4022 is specifically used for:

[0129] The system detects the heartbeat signal output by the vehicle control unit. If no heartbeat signal appears within the heartbeat cycle, it determines that the vehicle control unit has failed in communication and power. It also detects the requested negative torque and the received feedback negative torque issued by the vehicle control unit. If the second difference between the requested negative torque and the feedback negative torque is greater than the fourth threshold and the duration is greater than the second preset duration, it determines that the negative torque recovery of the vehicle control unit has failed. When the vehicle control unit fails in communication, power, or negative torque recovery, a second failure signal is generated.

[0130] Optionally, the third monitoring unit 4023 is specifically used for:

[0131] The system detects the heartbeat signal sent from the main controller to the redundant brake controller; if no heartbeat signal is detected within the heartbeat cycle, it determines that the main controller has failed in both communication and power supply; when the main controller fails in either communication or power supply, a third failure signal is generated.

[0132] Optionally, the fourth monitoring unit 4024 is specifically used for:

[0133] The system detects the heartbeat signal sent by the redundant braking controller to the main controller by wire; if no heartbeat signal is detected within the heartbeat cycle, it is determined that the redundant braking controller has failed in communication and power supply; when the redundant braking controller fails in communication or power supply, a fourth failure signal is generated.

[0134] Optionally, the fifth monitoring unit 4025 is specifically used for:

[0135] When the vehicle activates the autonomous driving function, a self-test command for the electronic parking brake is triggered. If the electronic parking brake fails to send parking information or receive parking feedback according to the self-test command, a fifth failure signal is generated.

[0136] Optionally, the braking module 404 includes:

[0137] The first braking unit 4041 is used to send a negative torque request to the vehicle control unit through the main controller by the drive-by-wire controller when the failed target object is the electronic stability controller, and then control the vehicle motor to perform braking by the vehicle control unit to execute the negative torque request.

[0138] The second braking unit 4042 is used to control the electronic stability controller to brake when the failed target object is the vehicle control unit;

[0139] The third braking unit 4043 is used to trigger the electronic parking brake through the redundant braking controller when the failed target object is the main controller of the drive-by-wire system.

[0140] The fourth braking unit 4044 is used to control the electronic stability controller to perform braking through the main controller when the failed target object is a redundant braking controller.

[0141] The sending unit 4045 is used to prevent the vehicle from entering the automatic driving state and send a warning message for manual braking when the failed target object is the electronic parking brake.

[0142] Optionally, the chassis braking device also includes a fifth braking unit 4046, which is used to trigger electronic parking brake for synchronous braking through the drive-by-wire main controller if the deceleration corresponding to the negative torque request is greater than the deceleration corresponding to the maximum negative torque of the vehicle motor.

[0143] Optionally, the chassis braking system also includes a sixth braking unit 4047, which is used to trigger the electronic parking brake via the main controller if the electronic stability controller malfunctions.

[0144] In this embodiment of the invention, the working status of each module in the chassis braking system is monitored. When each module is working normally, the drive-by-wire controller performs braking through the electronic stability controller. When a module malfunctions, the failed object is identified, and a braking strategy is formulated based on other normally functioning objects in the chassis braking system to improve braking safety. There is no need to set up a redundant backup braking system, which reduces braking costs. In the case of multiple failed objects, the corresponding braking strategy is matched according to the non-failed objects, further improving safety.

[0145] The present invention also provides a computer-readable storage medium, which may be a non-volatile computer-readable storage medium or a volatile computer-readable storage medium, wherein the computer-readable storage medium stores instructions that, when the instructions are executed on a computer, cause the computer to perform the steps of the chassis braking method.

[0146] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0147] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0148] The above-described embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A chassis braking method applied to a vehicle's chassis braking system, said chassis braking system comprising a drive-by-wire master controller, an electronic parking brake, a vehicle control unit, an electronic stability controller, and a redundant brake controller, characterized in that, The chassis braking method includes: Monitor the operating status of the chassis braking system; When the chassis braking system is in normal working condition, the electronic stability controller is controlled by the main controller for braking. When the chassis braking system is in an abnormal working state, identify the failed target object in the chassis braking system; The braking strategy is determined based on the failed target object, including: when the failed target object is the electronic stability controller, a negative torque request is sent to the vehicle control unit through the drive-by-wire master controller, and the vehicle control unit controls the vehicle motor to execute the negative torque request for braking; when the failed target object is the vehicle control unit, the electronic stability controller is controlled by the drive-by-wire master controller for braking; when the failed target object is the drive-by-wire master controller, the electronic parking brake is triggered by the redundant brake controller for braking; when the failed target object is the redundant brake controller, the electronic stability controller is controlled by the drive-by-wire master controller for braking; when the failed target object is the electronic parking brake, the vehicle is prohibited from entering automatic driving mode, and a warning message for manual braking is sent.

2. The chassis braking method according to claim 1, characterized in that, The monitoring of the operating status of the chassis braking system includes: Monitor whether the electronic stability controller generates a first failure signal, the first failure signal indicating communication failure, power failure, brake cylinder failure or output feedback failure of the electronic stability controller; Monitor whether the vehicle control unit generates a second failure signal, the second failure signal indicating a communication failure, power failure, or negative torque recovery failure of the vehicle control unit; Monitor whether the main controller of the wire generates a third failure signal, the third failure signal indicating a communication failure or power failure of the main controller of the wire; Monitor whether the redundant braking controller generates a fourth failure signal, the fourth failure signal indicating a communication failure or power failure of the redundant braking controller; When the vehicle activates the autonomous driving function, a self-test command is triggered to monitor whether the electronic parking brake generates a fifth failure signal. The fifth failure signal indicates that the signal generator of the electronic parking brake has failed. If the first failure signal, the second failure signal, the third failure signal, the fourth failure signal, or the fifth failure signal is detected, the chassis braking system is determined to be in an abnormal operating state; otherwise, the chassis braking system is determined to be in a normal operating state.

3. The chassis braking method according to claim 2, characterized in that, The monitoring of whether the electronic stability controller generates a first failure signal includes: The heartbeat signal output by the electronic stability controller is detected. If no heartbeat signal appears within the heartbeat cycle, it is determined that the electronic stability controller has failed in communication and power supply. The electronic stability controller detects the requested braking pressure and the actual braking pressure received. If the difference between the actual braking pressure and the requested braking pressure is greater than a first threshold and the cylinder pressure of the brake cylinder is less than a second threshold, then it is determined that the brake cylinder of the electronic stability controller has failed. The brake cylinder includes a master cylinder and wheel cylinders. The electronic stability controller detects the requested braking stroke and the actual braking stroke received by the electronic stability controller. If the first difference between the requested braking stroke and the actual braking stroke is greater than a third threshold and the duration is greater than a first preset duration, then the output feedback of the electronic stability controller is determined to be faulty. When the electronic stability controller experiences communication failure, power failure, brake cylinder failure, or output feedback failure, a first failure signal is generated.

4. The chassis braking method according to claim 2, characterized in that, The monitoring of whether the vehicle control unit generates a second failure signal includes: The heartbeat signal output by the vehicle control unit is detected. If no heartbeat signal appears within the heartbeat cycle, it is determined that the communication of the vehicle control unit has failed and the power supply has failed. The vehicle control unit detects the requested negative torque and the received feedback negative torque. If the second difference between the requested negative torque and the feedback negative torque is greater than the fourth threshold and the duration is greater than the second preset duration, then it is determined that the negative torque recovery of the vehicle control unit has failed. A second failure signal is generated when the vehicle control unit experiences communication failure, power failure, or negative torque recovery failure.

5. The chassis braking method according to claim 2, characterized in that, The monitoring of whether the master controller generates a third failure signal includes: Detect the heartbeat signal sent by the main controller for drive-by-wire to the redundant brake controller; If no heartbeat signal is detected within the heartbeat cycle, it is determined that the communication and power supply of the main controller are both faulty. A third failure signal is generated when the communication or power supply of the main controller fails.

6. The chassis braking method according to claim 2, characterized in that, The monitoring of whether the redundant braking controller generates a fourth failure signal includes: Detect the heartbeat signal sent by the redundant braking controller to the main controller by drive; If no heartbeat signal is detected within the heartbeat cycle, it is determined that the redundant braking controller has failed in communication and power supply. A fourth failure signal is generated when the redundant braking controller experiences a communication failure or a power failure.

7. The chassis braking method according to claim 2, characterized in that, When the vehicle activates the autonomous driving function, a self-test command is triggered for the electronic parking brake to monitor whether the electronic parking brake generates a fifth failure signal, including: When the vehicle activates the autonomous driving function, the electronic parking brake self-test command is triggered; If the electronic parking brake fails to send parking information or receive parking feedback according to the self-test command, a fifth failure signal is generated.

8. The chassis braking method according to claim 1, characterized in that, When the failed target is the electronic stability controller, after the drive-by-wire master controller sends a negative torque request to the vehicle control unit, and the vehicle control unit controls the vehicle motor to execute the negative torque request for braking, the method further includes: If the deceleration corresponding to the negative torque request is greater than the deceleration corresponding to the maximum negative torque of the vehicle motor, then the electronic parking brake is triggered by the drive-by-wire controller to perform synchronous braking.

9. The chassis braking method according to claim 1, characterized in that, When the failed target is the vehicle control unit, after the electronic stability controller is controlled to brake by the master controller by the drive-by-wire controller, the following steps are also included: If the electronic stability controller malfunctions, the electronic parking brake will be triggered by the main controller for drive-by.

10. A chassis braking device, characterized in that, The chassis braking device includes: The monitoring module is used to monitor the working status of the chassis braking system, which is either normal or abnormal. The control module is used to control the electronic stability controller to brake through the main controller when the chassis braking system is in normal working condition. The identification module is used to identify the failed target object in the chassis braking system when the working state of the chassis braking system is abnormal. The braking module is used to determine a braking strategy based on the failed target object and perform braking. The braking module includes: a first braking unit, used to send a negative torque request to the vehicle control unit through the drive-by-wire master controller when the failed target object is the electronic stability controller, and to control the vehicle motor to perform braking by the vehicle control unit; a second braking unit, used to control the electronic stability controller to perform braking by the drive-by-wire master controller when the failed target object is the vehicle control unit; a third braking unit, used to trigger the electronic parking brake to perform braking by the redundant brake controller when the failed target object is the drive-by-wire master controller; a fourth braking unit, used to control the electronic stability controller to perform braking by the drive-by-wire master controller when the failed target object is the redundant brake controller; and a sending unit, used to prevent the vehicle from entering the automatic driving state and send a warning message for manual braking when the failed target object is the electronic parking brake.

11. A chassis braking system, characterized in that, The chassis braking system includes: a drive-by-wire master controller, an electronic parking brake, a vehicle control unit, an electronic stability controller, a redundant brake controller, a memory, and at least one processor, wherein the memory stores instructions; The at least one processor invokes the instructions in the memory to cause the chassis braking system to perform the chassis braking method as described in any one of claims 1-9.

12. A computer-readable storage medium storing instructions thereon, characterized in that, When the instructions are executed by the processor, they implement the chassis braking method as described in any one of claims 1-9.

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