Vehicle brake control method, device and vehicle

Abstract

The application discloses a vehicle brake control method and device and a vehicle. The method comprises the following steps: acquiring the vehicle speed, wheel speed, wheel slip rate and wheel acceleration of the vehicle under the condition that the anti-lock braking function of the vehicle is started; controlling the brake caliper of the electronic parking brake system of the vehicle to be adjusted to a first target state according to the vehicle speed, wheel slip rate and wheel acceleration; determining a target deceleration based on the wheel speed and a degradation strategy, wherein the degradation strategy is used to determine the degradation rule of the brake deceleration under multiple wheel speed failure states; and adjusting the brake caliper from the first target state to a second target state according to the target deceleration. The application solves the technical problem of low accuracy, poor safety and stability of the vehicle brake control method provided by the related art.

Description

Technical Field

[0001] The present invention relates to the field of vehicle braking control, and in particular to a vehicle braking control method, device and vehicle. Background Art

[0002] Vehicle braking consists of three levels of braking: service braking, emergency braking (Crash Dynamic Pulse, CDP), and the rear-wheel anti-lock function of the Electronic Park Brake (EPB). Service braking has the highest priority, while the rear-wheel anti-lock function of the EPB system has the lowest priority. If the service brake fails, the emergency braking function of the Electronic Stability Control (ESC) can be used to build pressure on all four wheels. If the emergency brake fails, the driver can manually pull up the EPB switch to activate the rear-wheel anti-lock function of the EPB system. However, existing technologies have low vehicle braking control accuracy, which can easily lead to poor control effects, that is, poor vehicle safety and stability.

[0003] From the above analysis, it can be seen that there is currently no effective solution to the problems of low accuracy, poor vehicle safety and stability of the vehicle braking control methods provided by the above-mentioned related technologies. Summary of the Invention

[0004] The embodiments of the present invention provide a vehicle braking control method, device and vehicle to at least solve the technical problems of low accuracy, poor vehicle safety and stability of the vehicle braking control method provided by the related art.

[0005] According to one aspect of an embodiment of the present invention, a vehicle braking control method is provided, comprising:

[0006] When the rear wheel anti-lock braking function of the vehicle is turned on, the vehicle speed, wheel speed, wheel slip rate and wheel acceleration are obtained; according to the vehicle speed, wheel slip rate and wheel acceleration, the brake caliper of the vehicle's electronic parking brake system is controlled to be adjusted to a first target state; based on the wheel speed and the degradation strategy, the target deceleration is determined, wherein the degradation strategy is used to determine the degradation rules of the braking deceleration under multiple wheel speed failure states; according to the target deceleration, the brake caliper is adjusted from the first target state to the second target state.

[0007] Optionally, the vehicle braking control method further includes: in response to the vehicle speed being greater than a first threshold and the switch control lever of the electronic parking brake system being in the on position for a duration greater than a second threshold, controlling the vehicle to activate a rear wheel anti-lock braking function.

[0008] Optionally, the wheel speed includes the wheel center speed and the wheel angular velocity, and obtaining the wheel slip rate and the wheel acceleration includes: calculating the wheel slip rate based on the wheel center speed, the wheel angular velocity and the wheel rolling radius; and calculating the wheel acceleration using the change in wheel speed in multiple time segments.

[0009] Optionally, controlling the brake caliper of the vehicle's electronic parking brake system to adjust to a first target state based on the vehicle speed, wheel slip and wheel acceleration includes: determining a first threshold value, a second threshold value, a third threshold value, a fourth threshold value and a fifth threshold value based on the vehicle speed, wherein the first threshold value is used to determine a target minimum threshold of the wheel acceleration, the second threshold value is used to determine a target recovery threshold of the wheel acceleration, the third threshold value is used to determine a target maximum threshold of the wheel acceleration, the fourth threshold value is used to determine a target minimum threshold of the wheel slip, and the fifth threshold value is used to determine a target maximum threshold of the wheel slip; determining the first target state based on the wheel slip, wheel acceleration, the first threshold value, the second threshold value, the third threshold value, the fourth threshold value and the fifth threshold value; controlling the brake caliper of the vehicle's electronic parking brake system to adjust to the first target state.

[0010] Optionally, based on the wheel slip rate, the wheel acceleration, the first threshold value, the second threshold value, the third threshold value, the fourth threshold value and the fifth threshold value, determining the first target state includes: in response to the wheel acceleration being greater than or equal to the first threshold value and the wheel slip rate being less than or equal to the fourth threshold value, determining the first target state as the first clamping state; in response to the wheel acceleration being greater than or equal to the second threshold value and the wheel slip rate being less than or equal to the fifth threshold value, determining the first target state as the second clamping state; in response to the wheel acceleration being less than the third threshold value, determining the first target state as the released state; in response to the wheel acceleration being less than the second threshold value and the wheel slip rate being greater than the fifth threshold value, determining the first target state as the released state.

[0011] Optionally, multiple wheel speed failure states include: a first state, indicating that the wheel speed corresponding to at least one rear wheel of the vehicle has failed and the wheel speeds corresponding to other wheels have not failed; a second state, indicating that the wheel speeds corresponding to two front wheels of the vehicle have failed and the wheel speeds corresponding to other wheels have not failed; a third state, indicating that the wheel speeds corresponding to one rear wheel and one front wheel of the vehicle have failed and the wheel speeds corresponding to other wheels have not failed; a fourth state, indicating that the wheel speeds corresponding to any three wheels of the vehicle have failed and the wheel speeds corresponding to other wheels have not failed; a fifth state, indicating that the wheel speeds corresponding to four wheels of the vehicle have failed.

[0012] Optionally, determining the target deceleration based on the wheel speed and the degradation strategy includes: performing a failure detection on the wheel speed to obtain a detection result; and determining the target deceleration according to the detection result and multiple wheel speed failure states.

[0013] Optionally, the vehicle braking control method further includes: in response to the vehicle's throttle opening being greater than a third threshold, controlling the vehicle to turn off a rear wheel anti-lock braking function.

[0014] According to another aspect of an embodiment of the present invention, there is further provided a vehicle brake control device, comprising:

[0015] An acquisition module is used to obtain the vehicle speed, wheel speed, wheel slip rate and wheel acceleration when the rear wheel anti-lock braking function is turned on; a control module is used to control the brake caliper of the vehicle's electronic parking brake system to adjust to a first target state according to the vehicle speed, wheel slip rate and wheel acceleration; a determination module is used to determine the target deceleration based on the wheel speed and the degradation strategy, wherein the degradation strategy is used to determine the degradation rules of the brake deceleration under multiple wheel speed failure states; and an adjustment module is used to adjust the brake caliper from the first target state to the second target state according to the target deceleration.

[0016] Optionally, the vehicle braking control method further includes: an activation module for controlling the vehicle to activate a rear wheel anti-lock braking function in response to a vehicle speed being greater than a first threshold and a switch control lever of the electronic parking brake system being in the activation position for a duration greater than a second threshold.

[0017] Optionally, the above-mentioned acquisition module is also used for: the wheel speed includes the wheel center speed and the wheel angular velocity, and obtaining the wheel slip rate and wheel acceleration includes: calculating the wheel slip rate based on the wheel center speed, the wheel angular velocity and the wheel rolling radius; and calculating the wheel acceleration using the change in wheel speed in multiple time segments.

[0018] Optionally, the above-mentioned control module is also used to: control the brake caliper of the vehicle's electronic parking brake system to adjust to a first target state according to the vehicle speed, wheel slip rate and wheel acceleration, including: determining a first threshold value, a second threshold value, a third threshold value, a fourth threshold value and a fifth threshold value according to the vehicle speed, wherein the first threshold value is used to determine the target minimum threshold of the wheel acceleration, the second threshold value is used to determine the target recovery threshold of the wheel acceleration, the third threshold value is used to determine the target maximum threshold of the wheel acceleration, the fourth threshold value is used to determine the target minimum threshold of the wheel slip rate, and the fifth threshold value is used to determine the target maximum threshold of the wheel slip rate; determine the first target state based on the wheel slip rate, wheel acceleration, the first threshold value, the second threshold value, the third threshold value, the fourth threshold value and the fifth threshold value; control the brake caliper of the vehicle's electronic parking brake system to adjust to the first target state.

[0019] Optionally, the above-mentioned determination module is also used to: determine the first target state based on the wheel slip rate, the wheel acceleration, the first threshold value, the second threshold value, the third threshold value, the fourth threshold value and the fifth threshold value, including: in response to the wheel acceleration being greater than or equal to the first threshold value and the wheel slip rate being less than or equal to the fourth threshold value, determining the first target state as the first clamping state; in response to the wheel acceleration being greater than or equal to the second threshold value and the wheel slip rate being less than or equal to the fifth threshold value, determining the first target state as the second clamping state; in response to the wheel acceleration being less than the third threshold value, determining the first target state as the released state; in response to the wheel acceleration being less than the second threshold value and the wheel slip rate being greater than the fifth threshold value, determining the first target state as the released state.

[0020] Optionally, the above-mentioned determination module is also used for: multiple wheel speed failure states include: a first state, indicating that the wheel speed corresponding to at least one rear wheel of the vehicle has failed and the wheel speeds corresponding to other wheels have not failed; a second state, indicating that the wheel speeds corresponding to two front wheels of the vehicle have failed and the wheel speeds corresponding to other wheels have not failed; a third state, indicating that the wheel speeds corresponding to one rear wheel and one front wheel of the vehicle have failed and the wheel speeds corresponding to other wheels have not failed; a fourth state, indicating that the wheel speeds corresponding to any three wheels of the vehicle have failed and the wheel speeds corresponding to other wheels have not failed; a fifth state, indicating that the wheel speeds corresponding to four wheels of the vehicle have failed.

[0021] Optionally, the above-mentioned determination module is further used to: determine the target deceleration based on the wheel speed and the degradation strategy, including: performing failure detection on the wheel speed to obtain a detection result; and determining the target deceleration according to the detection result and multiple wheel speed failure states.

[0022] Optionally, the vehicle braking control method further includes: a shut-down module configured to control the vehicle to shut down a rear wheel anti-lock braking function in response to a throttle opening of the vehicle being greater than a third threshold.

[0023] According to another aspect of an embodiment of the present invention, a vehicle is provided, characterized in that it includes an on-board memory and an on-board processor, the on-board memory stores a computer program, and the on-board processor is configured to run the computer program to execute any one of the aforementioned vehicle braking control methods.

[0024] In an embodiment of the present invention, first, when the rear wheel anti-lock braking function of the vehicle is turned on, the vehicle speed, wheel speed, wheel slip rate and wheel acceleration are obtained. Then, based on the vehicle speed, wheel slip rate and wheel acceleration, the brake caliper of the vehicle's electronic parking brake system is controlled to be adjusted to a first target state. Then, based on the wheel speed and the degradation strategy, a target deceleration is determined, wherein the degradation strategy is used to determine the degradation rules of the braking deceleration under multiple wheel speed failure states. Finally, based on the target deceleration, the brake caliper is adjusted from the first target state to a second target state. By combining the vehicle speed, wheel speed, wheel slip rate, wheel acceleration and the degradation strategy to brake the brake caliper of the electronic parking brake system, the purpose of ensuring the vehicle's braking deceleration and vehicle stability during the vehicle braking control process is achieved, thereby achieving the technical effect of improving the vehicle braking control accuracy and enhancing the vehicle safety and stability, thereby solving the technical problems of low accuracy, poor vehicle safety and stability of the vehicle braking control method provided by the related art. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0026] Figure 1 1 is a hardware structure block diagram of a vehicle terminal for a vehicle braking control method according to an embodiment of the present invention;

[0027] Figure 2 is a flow chart of a vehicle braking control method according to an embodiment of the present invention;

[0028] Figure 3 is a schematic diagram of a vehicle braking control process according to an embodiment of the present invention;

[0029] Figure 4 is a structural block diagram of an optional vehicle brake control device according to an embodiment of the present invention;

[0030] Figure 5 is a structural block diagram of another optional vehicle brake control device according to an embodiment of the present invention;

[0031] Figure 6 This is a structural block diagram of another optional vehicle braking control device according to an embodiment of the present invention. DETAILED DESCRIPTION

[0032] In order to enable those skilled in the art to better understand the solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of the present invention.

[0033] It should be noted that the terms "first", "second", etc. in the description and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0034] According to an embodiment of the present invention, a method embodiment of a vehicle braking control method is provided. It should be noted that the steps shown in the flowchart of the accompanying drawings can be executed in a computer system such as a set of computer executable instructions, and although a logical order is shown in the flowchart, in some cases, the steps shown or described can be executed in an order different from that shown here.

[0035] Figure 1 is a hardware structure block diagram of a vehicle terminal for a vehicle braking control method according to an embodiment of the present invention, such as Figure 1 As shown, the vehicle terminal 10 (or a mobile device 10 that is communicatively associated with the vehicle) may include one or more processors 102 (the processor 102 may include but is not limited to a processing device such as a microcontroller unit (MCU) or a programmable logic device (Field Programmable Gate Array, FPGA)), a memory 104 for storing data, and a transmission device 106 for communication functions. In addition, it may also include: a display device 110, an input / output device 108 (i.e., an I / O device), a universal serial bus (USB) port (which may be included as one of the ports of a computer bus, not shown in the figure), a network interface (not shown in the figure), a power supply (not shown in the figure), and / or a camera (not shown in the figure). It will be understood by those skilled in the art that Figure 1 The structure shown is only for illustration and does not limit the structure of the vehicle terminal 1. For example, the vehicle terminal 10 may also include Figure 1 More or fewer components than shown, or with Figure 1 Different configurations shown.

[0036] It should be noted that the one or more processors 102 and / or other data processing circuits may be embodied in whole or in part as software, hardware, firmware, or any other combination thereof. Furthermore, the data processing circuit may be a single independent processing module, or may be fully or partially integrated into any of the other components in the vehicle terminal 10 (or mobile device).

[0037] The memory 104 can be used to store software programs and modules of application software, such as the program instructions / data storage device corresponding to the vehicle braking control method in the embodiment of the present invention. The processor 102 executes various functional applications and data processing by running the software programs and modules stored in the memory 104, thereby implementing the above-mentioned vehicle braking control method. The memory 104 may include high-speed random access memory and may also include non-volatile memory, such as one or more magnetic storage devices, flash memory, or other non-volatile solid-state memory. In some examples, the memory 104 may further include memory remotely located relative to the processor 102, and these remote memories may be connected to the vehicle terminal 10 via a network. Examples of the above-mentioned network include, but are not limited to, the Internet, corporate intranets, local area networks, mobile communication networks, and combinations thereof.

[0038] The transmission device 106 is used to receive or transmit data via a network. A specific example of the aforementioned network may include a wireless network provided by the communications provider of the vehicle terminal 10. In one embodiment, the transmission device 106 includes a network interface controller (NIC), which can be connected to other network devices via a base station to enable communication with the Internet. In another embodiment, the transmission device 106 may be a radio frequency (RF) module, which is used to communicate with the Internet wirelessly.

[0039] Under the above operating environment, the embodiment of the present invention provides the following Figure 2 The vehicle braking control method shown, Figure 2 FIG. 1 is a flow chart of a vehicle braking control method according to an embodiment of the present invention. Figure 2 As shown above Figure 2 The illustrated embodiment may include at least the following implementation steps, which may be the technical solution implemented by steps S21 to S24.

[0040] Step S21, when the rear wheel anti-lock braking function of the vehicle is turned on, obtaining the vehicle speed, wheel speed, wheel slip rate and wheel acceleration;

[0041] Step S22, controlling the brake caliper of the vehicle's electronic parking brake system to adjust to a first target state according to the vehicle speed, wheel slip rate, and wheel acceleration;

[0042] Step S23, determining a target deceleration based on the wheel speed and the degradation strategy, wherein the degradation strategy is used to determine a degradation rule for the braking deceleration in a state where multiple wheel speeds fail;

[0043] Step S24: adjusting the brake caliper from the first target state to the second target state according to the target deceleration.

[0044] In the optional technical solutions provided by steps S21 to S24 above, the rear wheel anti-lock braking (Rear Wheel Unlocker, RWU) function can be used to prevent the rear wheels of the vehicle from locking during emergency braking. Specifically, when the vehicle brakes suddenly, the braking system monitors the tire rotation speed through sensors. When it is determined based on the rotation speed value that the rear wheel is about to lock, the anti-lock braking system (Anti-lock Braking System, ABS) can automatically adjust the braking force and quickly apply and release the braking pressure to keep the rear wheel rotating to avoid locking.

[0045] In the optional technical solutions provided in steps S21 to S24 above, the method for obtaining the vehicle speed may include, but is not limited to, directly reading from the vehicle's speedometer, obtaining using an on-board navigation system, or reading using an on-board diagnostic tool (OBD). The method for obtaining the wheel speed may include, but is not limited to, obtaining using an anti-lock braking system (ABS) sensor or an independent wheel speed sensor. The wheel slip ratio may be calculated based on the vehicle's driving speed and wheel rotational speed and can be used to assess wheel-to-road adhesion and determine the vehicle's traction and braking force. It is also understood that the wheel slip ratio can be calculated by monitoring vehicle driving data using an electronic control system such as the vehicle's ABS system or traction control system (TCS). The wheel acceleration may be calculated based on the vehicle's driving speed (including, but not limited to, initial driving speed and real-time driving speed) and driving time and can be used to control the vehicle's motion by changing wheel rotational speed and steering. It is also understood that the wheel acceleration may be measured using vehicle dynamics sensors (such as a speed sensor or inertial measurement unit).

[0046] In the optional technical solutions provided in steps S21 to S24 above, the electronic parking brake system can be used to maintain the vehicle's stationary position in a parked state to prevent the vehicle from slipping or accidentally moving. It should also be noted that the equipment of the electronic parking brake system may include, but is not limited to: an electronic parking switch, which can be used to activate or deactivate the electronic parking brake system; an electronic control unit (ECU): which can be used to receive and process information from other sensors and control the electronic parking brake system; a handbrake switch, which can be used to manually activate and release the electronic parking brake system; an electronic parking module, which can be used to control the operation of the electronic parking brake system (such as braking and releasing); a motor or electromagnet, which can be used to apply or release braking force to keep the vehicle in a parked state; a sensor, which can be used to detect information such as the vehicle's tilt angle and speed to ensure the correct operation of the electronic parking brake system; and a warning device or sound prompt device, which can be used to remind the driver of the real-time operating status of the electronic parking brake system. The brake caliper can control the brake pads to clamp or release the brake disc via electronic signals, thereby implementing the parking and release functions. Specifically, when the vehicle is parked, the brake caliper clamps the brake pads to the brake disc, generating a certain friction force to secure the vehicle in the parked position. When the vehicle is released from the parking position, the brake caliper releases the brake disc, allowing the vehicle to move freely. The first target state can be one of the following: a clamped state and a released state.

[0047] In the optional technical solutions provided in steps S21 to S24 above, the degradation strategy can be a strategy for controlling the braking deceleration during the vehicle braking control process predetermined by a technician, and can be determined based on vehicle data (including but not limited to: vehicle speed, wheel speed, wheel slip rate, wheel acceleration). The multiple wheel speed failure states can include but are not limited to: single wheel speed failure, multiple wheel speed failures on the same side, and multiple wheel speed failures on the opposite side. The target deceleration can be determined based on the real-time braking deceleration, or can be predetermined by a technician. The second target state can be, but is not limited to: a low-force clamping state.

[0048] In an embodiment of the present invention, first, when the rear wheel anti-lock braking function of the vehicle is turned on, the vehicle speed, wheel speed, wheel slip rate and wheel acceleration are obtained. Then, based on the vehicle speed, wheel slip rate and wheel acceleration, the brake caliper of the vehicle's electronic parking brake system is controlled to be adjusted to a first target state. Then, based on the wheel speed and the degradation strategy, a target deceleration is determined, wherein the degradation strategy is used to determine the degradation rules of the braking deceleration under multiple wheel speed failure states. Finally, based on the target deceleration, the brake caliper is adjusted from the first target state to a second target state. By combining the vehicle speed, wheel speed, wheel slip rate, wheel acceleration and the degradation strategy to brake the brake caliper of the electronic parking brake system, the purpose of ensuring the vehicle's braking deceleration and vehicle stability during the vehicle braking control process is achieved, thereby achieving the technical effect of improving the vehicle braking control accuracy and enhancing the vehicle safety and stability, thereby solving the technical problems of low accuracy, poor vehicle safety and stability of the vehicle braking control method provided by the related art.

[0049] The above method of the embodiment of the present invention is further introduced below.

[0050] In an optional embodiment, the vehicle braking control method further includes:

[0051] Step S25 , in response to the vehicle speed being greater than the first threshold and the switch lever of the electronic parking brake system being in the on position for a duration greater than the second threshold, controlling the vehicle to activate the rear wheel anti-lock braking function.

[0052] In the technical solution provided by the present invention, as an optional implementation mode, when the real-time speed of the vehicle is greater than 5 km / h and the switch control lever of the electronic parking brake system is in the on position for a duration greater than 150 ms, the vehicle is controlled to activate the rear-wheel anti-lock braking function, thereby actively responding to the real-time status of the vehicle and timely controlling the vehicle to activate the rear-wheel anti-lock braking function, thereby improving the vehicle's braking control efficiency and enhancing the user's driving experience.

[0053] In an optional embodiment, in step S21, the wheel speed includes the wheel center speed and the wheel angular velocity, and obtaining the wheel slip rate and the wheel acceleration includes:

[0054] Step S211, calculating the wheel slip rate based on the wheel center speed, wheel angular velocity and wheel rolling radius;

[0055] Step S212: Calculate the wheel acceleration using the changes in wheel speed within multiple time segments.

[0056] In the technical solution provided by the present invention, as an optional implementation, let the wheel center speed be v, the wheel angular speed be ω, and the wheel rolling radius be r. According to the wheel center speed, the wheel angular speed, and the wheel rolling radius, the wheel slip rate δ of the rear wheel of the vehicle can be calculated as shown in the following formula (1):

[0057]

[0058] In the technical solution provided by the present invention, as another optional implementation, for the left rear wheel (right rear wheel) of the vehicle, 10 wheel speeds can be taken and divided into five groups for difference calculation to obtain the wheel acceleration of the left rear wheel (right rear wheel). Specifically, the time length of a time segment in multiple time segments is recorded as t, the initial wheel speed corresponding to the time segment at the start time is recorded as v1, and the final speed corresponding to the time segment at the end time is recorded as v2. According to the change in wheel speed within multiple time segments, the wheel acceleration a can be calculated as shown in the following formula (2):

[0059]

[0060] The following combination Figure 3 The above method is further explained.

[0061] Figure 3 FIG. 1 is a schematic diagram of a vehicle braking control process according to an embodiment of the present invention. Figure 3 As shown, during vehicle braking control, the wheel speed is first acquired and determined to be abnormal. If the wheel speed is abnormal, the rear anti-lock brake is downgraded based on a downgrade strategy, and the brake calipers of the electronic parking brake system are clamped with a low clamping force, thereby controlling the locked wheel to ensure vehicle stability and safety. When the wheel speed is normal, the vehicle speed is greater than 5 km / h, and the electronic parking brake system's switch pull-up time is greater than 150 ms, the wheel slip rate and wheel acceleration are calculated.

[0062] In an optional embodiment, in step S22, controlling the brake caliper of the electronic parking brake system of the vehicle to adjust to the first target state according to the vehicle speed, the wheel slip rate, and the wheel acceleration includes:

[0063] Step S221: determining a first threshold value, a second threshold value, a third threshold value, a fourth threshold value, and a fifth threshold value based on the vehicle speed, wherein the first threshold value is used to determine a target minimum threshold value for wheel acceleration, the second threshold value is used to determine a target recovery threshold value for wheel acceleration, the third threshold value is used to determine a target maximum threshold value for wheel acceleration, the fourth threshold value is used to determine a target minimum threshold value for wheel slip rate, and the fifth threshold value is used to determine a target maximum threshold value for wheel slip rate;

[0064] Step S222, determining a first target state based on the wheel slip rate, the wheel acceleration, the first threshold value, the second threshold value, the third threshold value, the fourth threshold value, and the fifth threshold value;

[0065] Step S223 , controlling the brake caliper of the vehicle's electronic parking brake system to adjust to a first target state.

[0066] Wherein, determining the first target state based on the wheel slip rate, the wheel acceleration, the first threshold value, the second threshold value, the third threshold value, the fourth threshold value, and the fifth threshold value includes:

[0067] Step S2221, in response to the wheel acceleration being greater than or equal to the first threshold value and the wheel slip ratio being less than or equal to the fourth threshold value, determining that the first target state is a first clamping state;

[0068] Step S2222: in response to the wheel acceleration being greater than or equal to the second threshold value and the wheel slip ratio being less than or equal to the fifth threshold value, determining that the first target state is the second clamping state;

[0069] Step S2223, in response to the wheel acceleration being less than a third threshold value, determining that the first target state is a released state;

[0070] Step S2224 : In response to the wheel acceleration being less than the second threshold value and the wheel slip ratio being greater than the fifth threshold value, determining that the first target state is the released state.

[0071] Still Figure 3 As shown, further, based on the real-time vehicle speed, the real-time wheel acceleration, the wheel acceleration threshold value (including the first threshold value, the second threshold value, and the third threshold value), and the wheel slip rate threshold value (including the fourth threshold value and the fifth threshold value), the dynamic brake clamping and release are judged. Specifically, for example, the first threshold value SSP is set based on three vehicle speed intervals: [0, 15] km / h, (15, 50] km / h, and greater than 50 km / h. WhlAcceltnLo -2m / s 2 , the second threshold value SSP WhlAcceltnHi -4m / s 2 , the third threshold SSP WhlAcceltnRec 8m / s 2 , the fourth threshold value SSP WhlSlLo 6%, the fifth threshold SSP WhlSlHi 20%, and you can also set the speed segment parameter SSP of the RWU function WehSpdBP (Unit: 0.1kph), the maximum time threshold for the brake caliper to clamp once SSP CntrRWAStpApp The minimum waiting time threshold SSP after the brake caliper is clamped once is 30ms CntrRWAAppHldThe minimum waiting time threshold SSP after the brake caliper is released is 100ms CntrRWARelHld is 20ms.

[0072] Still Figure 3 As shown, further, when the wheel acceleration is greater than or equal to the first threshold value and the wheel slip ratio does not exceed the fourth threshold value, the brake caliper of the electronic parking brake system is controlled to be in a clamped state; when the wheel acceleration is greater than or equal to the second threshold value and the wheel slip ratio does not exceed the fifth threshold value, the brake caliper of the electronic parking brake system is controlled to be in a clamped state; when the wheel acceleration is less than the third threshold value, the brake caliper of the electronic parking brake system is controlled to be in a released state; when the wheel acceleration is less than the second threshold value and the wheel slip ratio exceeds the fifth threshold value, the brake caliper of the electronic parking brake system is controlled to be in a released state.

[0073] In an optional embodiment, in step S23, multiple wheel speed failure states include: a first state, indicating that the wheel speed corresponding to at least one rear wheel of the vehicle has failed and the wheel speeds corresponding to other wheels have not failed; a second state, indicating that the wheel speeds corresponding to two front wheels of the vehicle have failed and the wheel speeds corresponding to other wheels have not failed; a third state, indicating that the wheel speeds corresponding to one rear wheel and one front wheel of the vehicle have failed and the wheel speeds corresponding to other wheels have not failed; a fourth state, indicating that the wheel speeds corresponding to any three wheels of the vehicle have failed and the wheel speeds corresponding to other wheels have not failed; a fifth state, indicating that the wheel speeds corresponding to four wheels of the vehicle have failed.

[0074] And, in step S23, determining the target deceleration based on the wheel speed and the degradation strategy includes:

[0075] Step S231, performing a failure detection on the wheel speed to obtain a detection result;

[0076] Step S232: Determine the target deceleration based on the detection result and the multiple wheel speed failure states.

[0077] In the technical solution provided by the present invention, as an optional implementation, the vehicle is a four-wheeled vehicle, and the multiple wheel speed failure states include: wheel speed failure of any front wheel, wheel speed failure of any rear wheel, wheel speed failure of both front wheels, wheel speed failure of both rear wheels, wheel speed failure of both front wheels and any rear wheel, wheel speed failure of three wheels (two front wheels and any rear wheel, or two rear wheels and any front wheel), and wheel speed failure of four wheels. Furthermore, after performing wheel speed failure detection and determining the wheel with wheel speed failure based on the multiple wheel speed failure states, the target deceleration is determined based on the degradation strategy, which can be shown in Table 1 below:

[0078] Table 1

[0079] Wheel with failed wheel speed Function Degradation strategy Either front wheel RWU function is not invalid Not downgraded Either rear wheel RWU function failure Braking control with a target deceleration of 0.1g Two front wheels RWU function failure Braking control with a target deceleration of 0.1g Two rear wheels RWU function failure Braking control with a target deceleration of 0.1g Any front wheel and any rear wheel RWU function failure Braking control with a target deceleration of 0.1g Three wheels RWU function failure Braking control with a target deceleration of 0.1g four wheels RWU function failure Braking control with a target deceleration of 0.1g

[0080] In the above optional embodiment, it can be understood that when the wheel speed of the two front wheels or any rear wheel is invalid, the RWU function of the vehicle fails. At this time, due to the failure of the vehicle wheel speed, the vehicle speed cannot be accurately determined, and it is necessary to perform degraded braking control on the rear wheels based on the degrading strategy, that is, braking control is performed at the target deceleration.

[0081] In an optional embodiment, the vehicle braking control method further includes:

[0082] Step S26 , in response to the throttle opening of the vehicle being greater than a third threshold, controlling the vehicle to disable the rear wheel anti-lock braking function.

[0083] Still Figure 3 As shown, further, when it is detected that the vehicle is in a special working condition, a special working condition handling strategy is executed. Specifically, when the accelerator pedal is pressed (that is, the accelerator pedal opening is greater than 0), the vehicle is controlled to turn off the rear wheel anti-lock braking function; when the brake pedal is pressed (that is, the brake pedal opening is greater than 0), the rear wheel anti-lock braking function of the vehicle is kept in the on state.

[0084] Still Figure 3 As shown, in the technical solution provided by the present invention, when the rear wheel anti-lock braking function of the vehicle is in the on state, a display signal can be sent to the vehicle's display device (such as the instrument panel) through the Controller Area Network (CAN) bus, so that the working indicator light corresponding to the electronic parking brake system is in a flashing state, thereby prompting the user of the vehicle's operating status.

[0085] The vehicle braking control method provided by the present invention can achieve the following technical effects: by monitoring the vehicle speed, wheel speed, wheel slip rate and wheel acceleration, and combining the degradation strategy, the brake caliper of the electronic parking brake system is adjusted to the target state, which not only improves the accuracy of vehicle braking control, but also improves the overall vehicle safety and stability, and enhances the user's driving experience.

[0086] In this embodiment, a vehicle brake control device is also provided. This device is used to implement the above-mentioned embodiments and preferred embodiments. Details already described will not be repeated here. As used below, a "module" refers to a combination of software and / or hardware that can implement a predetermined function. Although the devices described in the following embodiments are preferably implemented using software, implementation using hardware, or a combination of software and hardware, is also possible and contemplated.

[0087] Figure 4 is a structural block diagram of an optional vehicle brake control device according to an embodiment of the present invention, such as Figure 4 As shown, the device includes:

[0088] An acquisition module 401 is used to acquire the vehicle speed, wheel speed, wheel slip rate and wheel acceleration when the rear wheel anti-lock braking function is turned on.

[0089] a control module 402 for controlling a brake caliper of an electronic parking brake system of the vehicle to adjust to a first target state according to the vehicle speed, the wheel slip rate, and the wheel acceleration;

[0090] a determination module 403 for determining a target deceleration based on the wheel speed and a degradation strategy, wherein the degradation strategy is used to determine a degradation rule for the braking deceleration under multiple wheel speed failure states;

[0091] The adjustment module 404 is configured to adjust the brake caliper from a first target state to a second target state according to the target deceleration.

[0092] Optionally, Figure 5 is a structural block diagram of another optional vehicle brake control device according to an embodiment of the present invention, such as Figure 5 As shown, the device includes Figure 4 In addition to all the modules shown, the system further includes: an activation module 405 for controlling the vehicle to activate the rear wheel anti-lock braking function in response to the vehicle speed being greater than a first threshold and the switch control lever of the electronic parking brake system being in the activation position for a duration greater than a second threshold.

[0093] Optionally, the above-mentioned acquisition module 401 is also used for: the wheel speed includes the wheel center speed and the wheel angular velocity, and obtaining the wheel slip rate and the wheel acceleration includes: calculating the wheel slip rate according to the wheel center speed, the wheel angular velocity and the wheel rolling radius; and calculating the wheel acceleration using the change in the wheel speed in multiple time segments.

[0094] Optionally, the above-mentioned control module 402 is also used to: control the brake caliper of the vehicle's electronic parking brake system to adjust to a first target state according to the vehicle speed, wheel slip rate and wheel acceleration, including: determining a first threshold value, a second threshold value, a third threshold value, a fourth threshold value and a fifth threshold value according to the vehicle speed, wherein the first threshold value is used to determine the target minimum threshold of the wheel acceleration, the second threshold value is used to determine the target recovery threshold of the wheel acceleration, the third threshold value is used to determine the target maximum threshold of the wheel acceleration, the fourth threshold value is used to determine the target minimum threshold of the wheel slip rate, and the fifth threshold value is used to determine the target maximum threshold of the wheel slip rate; determine the first target state based on the wheel slip rate, wheel acceleration, the first threshold value, the second threshold value, the third threshold value, the fourth threshold value and the fifth threshold value; control the brake caliper of the vehicle's electronic parking brake system to adjust to the first target state.

[0095] Optionally, the above-mentioned determination module 403 is also used to: determine the first target state based on the wheel slip rate, the wheel acceleration, the first threshold value, the second threshold value, the third threshold value, the fourth threshold value and the fifth threshold value, including: in response to the wheel acceleration being greater than or equal to the first threshold value and the wheel slip rate being less than or equal to the fourth threshold value, determining that the first target state is the first clamping state; in response to the wheel acceleration being greater than or equal to the second threshold value and the wheel slip rate being less than or equal to the fifth threshold value, determining that the first target state is the second clamping state; in response to the wheel acceleration being less than the third threshold value, determining that the first target state is the released state; in response to the wheel acceleration being less than the second threshold value and the wheel slip rate being greater than the fifth threshold value, determining that the first target state is the released state.

[0096] Optionally, the above-mentioned determination module 403 is also used for: multiple wheel speed failure states include: a first state, indicating that the wheel speed corresponding to at least one rear wheel of the vehicle has failed and the wheel speeds corresponding to other wheels have not failed; a second state, indicating that the wheel speeds corresponding to two front wheels of the vehicle have failed and the wheel speeds corresponding to other wheels have not failed; a third state, indicating that the wheel speeds corresponding to one rear wheel and one front wheel of the vehicle have failed and the wheel speeds corresponding to other wheels have not failed; a fourth state, indicating that the wheel speeds corresponding to any three wheels of the vehicle have failed and the wheel speeds corresponding to other wheels have not failed; a fifth state, indicating that the wheel speeds corresponding to four wheels of the vehicle have failed.

[0097] Optionally, the determination module 403 is further configured to: determine the target deceleration based on the wheel speed and the degradation strategy, including: performing a failure detection on the wheel speed to obtain a detection result; and determining the target deceleration according to the detection result and multiple wheel speed failure states.

[0098] Optionally, Figure 6 is a structural block diagram of another optional vehicle brake control device according to an embodiment of the present invention, such as Figure 6 As shown, the device includes Figure 5 In addition to all the modules shown, the system further includes: a closing module 406 for controlling the vehicle to close the rear wheel anti-lock braking function in response to the throttle opening of the vehicle being greater than a third threshold.

[0099] It should be noted that the above modules can be implemented through software or hardware. For the latter, it can be implemented in the following ways, but not limited to: the above modules are all located in the same processor; or the above modules are located in different processors in any combination.

[0100] According to another aspect of an embodiment of the present invention, a vehicle is provided, characterized in that it includes an on-board memory and an on-board processor, the on-board memory stores a computer program, and the on-board processor is configured to run the computer program to execute any one of the aforementioned vehicle braking control methods.

[0101] Optionally, in the embodiment, the vehicle storage can be configured to store a computer program for performing the following steps:

[0102] Step S1, acquiring the vehicle speed, wheel speed, wheel slip ratio and wheel acceleration of the vehicle in the case that the wheel anti-lock function is started after the vehicle is started;

[0103] Step S2, controlling the brake caliper of the electronic parking brake system of the vehicle to adjust to a first target state according to the vehicle speed, wheel slip ratio and wheel acceleration;

[0104] Step S3, determining a target deceleration based on the wheel speed and a degradation strategy, wherein the degradation strategy is used to determine a degradation rule of brake deceleration in multiple wheel speed failure states;

[0105] Step S4, adjusting the brake caliper from the first target state to a second target state according to the target deceleration.

[0106] Optionally, in the embodiment, the vehicle storage can include but is not limited to a U disk, a read-only memory (ROM), a random access memory (RAM), a mobile hard disk, a magnetic disk or an optical disk and various computer program storage media.

[0107] Optionally, in the embodiment, the vehicle processor can be configured to perform the following steps by the computer program:

[0108] Step S1, acquiring the vehicle speed, wheel speed, wheel slip ratio and wheel acceleration of the vehicle in the case that the wheel anti-lock function is started after the vehicle is started;

[0109] Step S2, controlling the brake caliper of the electronic parking brake system of the vehicle to adjust to a first target state according to the vehicle speed, wheel slip ratio and wheel acceleration;

[0110] Step S3, determining a target deceleration based on the wheel speed and a degradation strategy, wherein the degradation strategy is used to determine a degradation rule of brake deceleration in multiple wheel speed failure states;

[0111] Step S4, adjusting the brake caliper from the first target state to a second target state according to the target deceleration.

[0112] Optionally, in the embodiment, the specific examples can refer to the examples described in the above embodiments and optional implementation manners, and the embodiment will not be described here.

[0113] The above embodiment numbers of the application are only for description, and do not represent the advantages and disadvantages of the embodiments.

[0114] In the above-mentioned embodiments of the present application, the description of each embodiment is focused on, and the part not described in detail in a certain embodiment can be referred to the relevant description of other embodiments.

[0115] In several embodiments provided by the present application, it should be understood that the disclosed technology can be implemented in other manners. The embodiments described above are merely exemplary, and the unit division is merely logical function division, and there can be other division manners in actual implementation. For example, a plurality of units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the displayed or discussed mutual couplings or direct couplings or communication connections can be indirect couplings or communication connections through some interfaces, and electrical or mechanical couplings or communication connections.

[0116] The units described as separate components can or can not be physically separate, and the components displayed as units can or can not be physical units, i.e., can be located in one place or distributed on a plurality of units. In actual implementation, some or all of the units can be selected according to actual needs to achieve the purposes of the embodiments.

[0117] In addition, each functional unit in the embodiments of the present application can be integrated in a processing unit, or each unit can exist physically, or two or more units can be integrated in one unit. The integrated unit can be implemented in the form of hardware or in the form of a software functional unit.

[0118] When the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on such an understanding, the technical solutions of the present application essentially or substantially, or all or part of the technical solutions can be embodied in the form of a software product. The computer software product is stored in a storage medium, and includes a plurality of instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in the embodiments of the present application. The foregoing storage medium includes: U disk, read-only memory (ROM), random access memory (RAM), mobile hard disk, magnetic disk or optical disk, and various media that can store program codes.

[0119] The above-mentioned are only preferred embodiments of the present application, and it should be pointed out that, for those skilled in the art, without departing from the principles of the present application, a number of improvements and refinements can be made, and these improvements and refinements should be regarded as the protection scope of the present application.

Claims

1. A vehicle braking control method, characterized in that: include: When the rear wheel anti-lock braking function of the vehicle is turned on, obtaining the vehicle speed, wheel speed, wheel slip rate and wheel acceleration; determining a first threshold value, a second threshold value, a third threshold value, a fourth threshold value, and a fifth threshold value based on the vehicle speed, wherein the first threshold value is used to determine a target minimum threshold value of the wheel acceleration, the second threshold value is used to determine a target recovery threshold value of the wheel acceleration, the third threshold value is used to determine a target maximum threshold value of the wheel acceleration, the fourth threshold value is used to determine a target minimum threshold value of the wheel slip rate, and the fifth threshold value is used to determine a target maximum threshold value of the wheel slip rate; determining a first target state based on the wheel slip ratio, the wheel acceleration, the first threshold value, the second threshold value, the third threshold value, the fourth threshold value, and the fifth threshold value; controlling a brake caliper of an electronic parking brake system of the vehicle to adjust to the first target state; determining a target deceleration based on the wheel speed and a degradation strategy, wherein the degradation strategy is used to determine a degradation rule for the braking deceleration under multiple wheel speed failure states; The brake caliper is adjusted from the first target state to a second target state based on the target deceleration.

2. The vehicle braking control method according to claim 1, characterized in that: The vehicle braking control method further includes: In response to the vehicle speed being greater than a first threshold and the switch control lever of the electronic parking brake system being in the on position for a duration greater than a second threshold, the vehicle is controlled to activate the rear wheel anti-lock braking function.

3. The vehicle braking control method according to claim 1, wherein: The wheel speed includes the wheel center speed and the wheel angular velocity, and obtaining the wheel slip rate and the wheel acceleration includes: Calculating the wheel slip rate according to the wheel center speed, the wheel angular velocity and the wheel rolling radius; The wheel acceleration is calculated using the changes in the wheel speed within multiple time segments.

4. The vehicle braking control method according to claim 1, wherein: Determining the first target state based on the wheel slip rate, the wheel acceleration, the first threshold value, the second threshold value, the third threshold value, the fourth threshold value, and the fifth threshold value includes: In response to the wheel acceleration being greater than or equal to the first threshold value and the wheel slip ratio being less than or equal to the fourth threshold value, determining that the first target state is a first clamping state; In response to the wheel acceleration being greater than or equal to the second threshold value and the wheel slip ratio being less than or equal to the fifth threshold value, determining that the first target state is a second clamping state; In response to the wheel acceleration being less than the third threshold value, determining that the first target state is a released state; In response to the wheel acceleration being less than the second threshold value and the wheel slip ratio being greater than the fifth threshold value, the first target state is determined to be the released state.

5. The vehicle braking control method according to claim 1, characterized in that: The multiple wheel speed failure states include: A first state indicates that the wheel speed corresponding to at least one rear wheel of the vehicle is invalid and the wheel speeds corresponding to other wheels are not invalid; The second state indicates that the wheel speeds corresponding to the two front wheels of the vehicle are invalid and the wheel speeds corresponding to the other wheels are not invalid; A third state indicates that the wheel speeds corresponding to one rear wheel and one front wheel of the vehicle are invalid and the wheel speeds corresponding to the other wheels are not invalid; A fourth state indicates that the wheel speeds corresponding to any three wheels of the vehicle are invalid and the wheel speeds corresponding to the other wheels are not invalid; The fifth state indicates that the wheel speeds corresponding to the four wheels of the vehicle are invalid.

6. The vehicle braking control method according to claim 5, characterized in that: Determining the target deceleration based on the wheel speed and the degradation strategy includes: Performing a failure detection on the wheel speed to obtain a detection result; The target deceleration is determined according to the detection result and the multiple wheel speed failure states.

7. The vehicle braking control method according to claim 1, characterized in that: The vehicle braking control method further includes: In response to an accelerator opening of the vehicle being greater than a third threshold, the vehicle is controlled to disable the rear wheel anti-lock braking function.

8. A vehicle brake control device, characterized in that: include: an acquisition module, configured to acquire the vehicle speed, wheel speed, wheel slip rate, and wheel acceleration of the vehicle when the rear wheel anti-lock braking function of the vehicle is turned on; a control module, configured to control a brake caliper of an electronic parking brake system of the vehicle to adjust to a first target state according to the vehicle speed, the wheel slip rate, and the wheel acceleration; a determination module, configured to determine a target deceleration based on the wheel speed and a degradation strategy, wherein the degradation strategy is configured to determine a degradation rule for the braking deceleration under multiple wheel speed failure states; an adjustment module, configured to adjust the brake caliper from the first target state to a second target state according to the target deceleration; The control module is further used to: determine a first threshold value, a second threshold value, a third threshold value, a fourth threshold value and a fifth threshold value according to the vehicle speed, wherein the first threshold value is used to determine a target minimum threshold value of the wheel acceleration, the second threshold value is used to determine a target recovery threshold value of the wheel acceleration, the third threshold value is used to determine a target maximum threshold value of the wheel acceleration, the fourth threshold value is used to determine a target minimum threshold value of the wheel slip rate, and the fifth threshold value is used to determine a target maximum threshold value of the wheel slip rate; determine the first target state based on the wheel slip rate, the wheel acceleration, the first threshold value, the second threshold value, the third threshold value, the fourth threshold value and the fifth threshold value; and control the brake caliper of the electronic parking brake system of the vehicle to adjust to the first target state.

9. A vehicle, characterized in that: The vehicle brake control method comprises an on-board memory and an on-board processor, wherein the on-board memory stores a computer program, and the on-board processor is configured to run the computer program to execute the vehicle brake control method according to any one of claims 1 to 7.

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