An EPB hub test control method, system, device and storage medium

Abstract

The present application relates to an EPB hub test control method, system, device and storage medium. After entering the hub test mode, the vehicle's EPB wheels are clamped, and the EPB braking torque applied to the vehicle's EPB wheels is obtained in real time. During the process of clamping the vehicle's EPB wheels, the non-EPB wheels of the vehicle are braked simultaneously with the hydraulic braking torque corresponding to the real-time EPB braking torque. In the above steps during the hub test, by actively controlling the braking torque of the non-EPB wheels, it is ensured that the vehicle remains stationary during the EPB clamping process, avoiding slip or yaw caused by uneven braking force distribution, thereby ensuring the vehicle stability during the test process and greatly improving the safety during the test process. In addition, since the overall vehicle safety factor is improved, the hub rotation speed of the EPB wheels during the test process can be appropriately increased, thus greatly improving the passing rate of the EPB regulation detection.

Description

Technical Field

[0001] The present application relates to the technical field of vehicle off-line testing, and particularly relates to an EPB roller test control method, system, device and storage medium. Background Art

[0002] Currently, when each vehicle is assembled and off-line, it must pass through a roller table for parking braking force monitoring. When performing parking braking force detection, the roller (usually the rear wheel) under the axle equipped with EPB rotates, and the rollers of other wheels (usually the front wheels) do not rotate. Then, the EPB caliper is controlled to apply braking to the vehicle, and the resistance torque of the roller table is measured through a sensor. The resistance torque of the roller table = the braking torque of the vehicle, so as to verify whether the vehicle can pass the test.

[0003] In some related technologies, the following problems are likely to occur during the roller test of the vehicle:

[0004] (1) If the rotational speed of the roller is too low, during the EPB clamping process, it is easy to quickly stop the rotational speed of the wheel. At this time, the roller and the vehicle tire slide and rub, which is likely to cause sharp corner noise and local wear of the tire.

[0005] (2) If the rotational speed of the roller is too high, during the EPB clamping process, due to the deviation of the torque magnitude and torque phase of the clamping forces of the left and right tires, dangerous working conditions such as the vehicle swinging laterally or slipping out of the roller table will occur, affecting the safety and detection passing rate during the test. Summary of the Invention

[0006] The embodiments of the present application provide an EPB roller test control method, system, device and storage medium to solve the problem in the related technology that when the rotational speed of the roller is too high, it is easy to cause dangerous working conditions such as the vehicle swinging laterally or slipping out of the roller table, affecting the detection passing rate.

[0007] In a first aspect, an EPB roller test control method is provided, which includes:

[0008] When the wheel rotates at a high speed and the vehicle speed is zero, enter the roller test mode;

[0009] After entering the roller test mode, start clamping the EPB wheel of the vehicle, and obtain the EPB braking torque applied to the EPB wheel of the vehicle in real time;

[0010] During the process of clamping the EPB wheel of the vehicle, at the same time, brake the non-EPB wheel of the vehicle with the hydraulic braking torque corresponding to the real-time EPB braking torque.

[0011] In some embodiments, before clamping the EPB wheel of the vehicle, apply a target hydraulic braking torque to the non-EPB wheel of the vehicle; the target hydraulic braking torque is greater than the parking braking force limit value and less than the maximum load torque of the roller.

[0012] In some embodiments, during the process of clamping the vehicle's EPB wheel, the hydraulic braking torque is controlled to increase at a first slope, and the EPB braking torque is controlled to increase at a second slope;

[0013] The first slope is greater than the second slope, and the difference between the first slope and the second slope is within the designed range.

[0014] In some embodiments, obtaining the hydraulic braking torque corresponding to the real-time EPB braking torque includes the following steps:

[0015] Taking the value of the real-time EPB braking torque as the base value;

[0016] Obtaining the hub rotation speed and tire slip ratio corresponding to the real-time EPB braking torque; then compensating the base value based on the hub rotation speed and tire slip ratio to obtain the target value;

[0017] Taking the target value as the hydraulic braking torque.

[0018] In some embodiments, during the process of clamping the vehicle's EPB wheel, the following steps are further included:

[0019] Obtaining the real-time yaw angular velocity of the vehicle, and then comparing it with the designed threshold;

[0020] When the real-time yaw angular velocity is greater than the designed threshold, it indicates that there is a yaw risk, and at the same time, the hydraulic braking torque is controlled to increase by a preset increment at the current moment; the preset increment is 8 - 15% of the hydraulic braking torque corresponding to the EPB braking torque at the current moment.

[0021] In some embodiments, after the hydraulic braking torque is controlled to increase by the preset increment, if the real-time yaw angular velocity is still greater than the designed threshold, the EPB braking torque is also increased by the preset increment;

[0022] When the hydraulic braking torque is controlled to increase by the preset increment at the current moment and the real-time yaw angular velocity gradually drops below the designed threshold, the hydraulic braking torque is controlled to gradually release the preset increment.

[0023] In some embodiments, after the EPB braking torque is increased by the preset increment or after the hydraulic braking torque is controlled to increase by the preset increment at the current moment, if the real-time yaw angular velocity is still greater than the designed threshold, the hub platform is controlled to stop and all braking systems of the vehicle are locked.

[0024] In a second aspect, an EPB hub test control system is provided, and the EPB hub test control system includes:

[0025] An EPB controller, which is used to enter the hub test mode when the wheel rotates at a high speed and the vehicle speed is zero; and after entering the hub test mode, start clamping the vehicle's EPB wheel and obtain in real time the EPB braking torque applied to the vehicle's EPB wheel;

[0026] An ESC controller, which is signal - connected to the EPB controller through a CAN bus and receives the EPB braking torque;

[0027] A compensation module, which is used to calculate the corresponding hydraulic braking torque according to the real - time EPB braking torque during the process of clamping the vehicle's EPB wheel; and then control the ESC controller to brake the non - EPB wheels of the vehicle with the hydraulic braking torque.

[0028] In a third aspect, an EPB hub test control device is provided. The EPB hub test control device includes a processor, a memory, and an EPB hub test control program stored on the memory and executable by the processor. When the EPB hub test control program is executed by the processor, the steps of the above - mentioned EPB hub test control method are implemented.

[0029] In a fourth aspect, a computer - readable storage medium is provided. An EPB hub test control program is stored on the computer - readable storage medium. When the EPB hub test control program is executed by a processor, the steps of the above - mentioned EPB hub test control method are implemented.

[0030] The beneficial effects brought by the technical solution provided in this application include:

[0031] The embodiments of this application provide an EPB hub test control method, system, device, and storage medium. Since after entering the hub test mode, the vehicle's EPB wheel is clamped and the EPB braking torque applied to the vehicle's EPB wheel is obtained in real time; during the process of clamping the vehicle's EPB wheel, the non - EPB wheels of the vehicle are braked with the hydraulic braking torque corresponding to the real - time EPB braking torque. The above steps actively control the braking torque of the non - EPB wheels during the hub test to ensure that the vehicle always remains stationary during the EPB clamping process, avoiding slip or yaw caused by uneven braking force distribution, thereby ensuring the vehicle stability during the test process and greatly improving the safety during the test process; in addition, since the overall vehicle safety factor is improved, the hub rotation speed of the EPB wheel during the test process can be appropriately increased, thus greatly improving the passing rate of the EPB regulation detection. Description of the Drawings

[0032] To more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0033] Figure 1 It shows the contact situation between the EPB wheel and non - EPB of the vehicle on the roller test bench provided in the related art.

[0034] Figure 2 It is a general flowchart of the roller test control method provided by the embodiments of the present application.

[0035] Figure 3 It is a control flowchart for suppressing yaw provided by the embodiments of the present application. Specific Embodiments

[0036] To make the objectives, technical solutions, and advantages of the embodiments of the present application clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present application in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are some, but not all, of the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of the present application.

[0037] In accordance with the requirements of GB 7258 - 2017 "Technical Conditions for the Safe Operation of Motor Vehicles", when testing the braking performance by bench test, the total parking braking force should be not less than 20% of the vehicle's total weight in the test state (for vehicles with a total mass less than 1.2 times the curb weight, it should be not less than 15%). Therefore, every vehicle assembled and off - line by each vehicle manufacturing enterprise must undergo parking braking force monitoring on the roller bench. This article only focuses on the parking braking system for EPB vehicles.

[0038] The following problems are likely to occur during the roller test of the vehicle:

[0039] (1) If the rotational speed of the roller is too low, during the EPB clamping process, it is easy to quickly stop the rotational speed of the wheel. At this time, the roller and the vehicle tire slide and rub, which is likely to cause sharp - corner noise and local tire wear.

[0040] (2) If the rotational speed of the roller is too high, during the EPB clamping process, due to the deviation in torque magnitude and torque phase between the clamping forces of the left and right tires, dangerous working conditions such as vehicle lateral swing or slipping off the roller bench may occur, affecting the safety and detection passing rate during the test. Note:

[0041] Among them, the reasons for the deviation in the braking torque of the left and right wheels are as follows: The transmission efficiency of each EPB caliper and the friction coefficient of the caliper friction pads cannot be exactly the same all the time, which in turn causes the braking torques of the left and right tires to be different.

[0042] The reasons for the torque phase deviation are as follows: The back electromotive force at the moment when the EPB caliper starts is relatively large. To avoid impacting the vehicle network, generally, a staggered start control (staggered by about 20 - 60 ms) is performed on the left and right EPBs. Therefore, there is a phase difference in the braking torques of the left and right wheels.

[0043] In addition, several key points need to be clarified:

[0044] (1) The function of the EPB system (electronic parking brake system) is usually used for parking braking, which clamps the calipers of the rear wheels through electronic control. The drum test bench is used to simulate the vehicle driving conditions and test vehicle performance, such as braking, power system, etc. The vehicle tires are placed on the drum, and the drum rotates to simulate the road surface.

[0045] (2) The reasons for dangerous working conditions such as vehicle lateral swing or slipping off the drum test bench are as follows: When the EPB caliper clamps the rear wheels (assuming the EPB acts on the rear wheels), the front wheels may not be braked, resulting in uneven braking force distribution. The vehicle may yaw or slip on the drum.

[0046] (3) The drum test bench simulates the vehicle driving conditions and is used to detect braking performance, power output, etc. The vehicle tires are placed on the rotating drum, but the vehicle body remains stationary. Potential risks: If only the EPB applies braking force to specific wheels (usually the rear wheels), while other wheels (such as the front wheels) have no braking force, it will cause yaw or slip;

[0047] Yaw refers to the rotation of the vehicle around the vertical axis, while slip refers to the relative movement between the tire and the drum; Yaw moment imbalance means uneven braking force between the front and rear axles, and the vehicle may rotate around the vertical axis (yaw). The slip risk means that due to insufficient friction between the tire and the drum, relative sliding occurs, affecting the test accuracy and equipment safety.

[0048] (4) The front wheels are non - EPB wheels, and the ESC system needs to apply hydraulic braking force to these front wheels. This application does not exclude the vehicle configuration with front - wheel EPB, but more commonly, it is rear - wheel EPB. See Figure 1 , where the rear wheels are EPB and the front wheels are non - EPB wheels. During the test, the drum in contact with the rear - wheel EPB rotates.

[0049] See Figure 2 , on the first hand, this application proposes an EPB drum test control method for the above - mentioned problems, which includes the following steps:

[0050] Step 100: When the wheel rotates at high speed and the vehicle speed is zero, enter the roller test mode. That is, the trigger condition is that the EPB recognizes that the vehicle is in the roller test mode through sensors or diagnostic signals (such as detecting that the wheel rotates at high speed while the vehicle speed is zero, and the vehicle speed being zero means that the vehicle body does not move on the test platform, and only the EPB wheels of the vehicle rotate with the roller).

[0051] Step 200: After entering the roller test mode, start clamping the EPB wheels of the vehicle and obtain the EPB braking torque applied to the EPB wheels of the vehicle in real time. The EPB caliper clamps to apply the parking braking force to the rear wheels to simulate the test under real parking conditions.

[0052] Step 300: During the process of clamping the EPB wheels of the vehicle, brake the non-EPB wheels of the vehicle with the hydraulic braking torque corresponding to the real-time EPB braking torque at the same time. That is, the ESC applies precise braking force to the front wheels through the hydraulic system to offset the imbalance caused by the unilateral braking of the EPB, balance the braking force of the non-EPB wheels not covered by the EPB, and prevent yaw and slip.

[0053] By actively controlling the braking torque of the non-EPB wheels through the above steps, it is ensured that the vehicle always remains stationary during the EPB clamping process, avoiding slip or yaw caused by uneven braking force distribution, thus ensuring the vehicle stability during the test and greatly improving the safety during the test. In addition, since the overall vehicle safety factor is improved, the roller speed of the EPB wheels during the test can be appropriately increased, thus greatly improving the passing rate of the EPB regulations detection.

[0054] It should be understood that the EPB controller and the ESC controller need signal coordination and timing synchronization. The EPB clamping instruction and the non-EPB wheel braking instruction need to be strictly synchronized. The timing consistency is ensured through the CAN signal (such as 0.1ms-level time stamp) between the controllers. The EPB controller sends an instruction to the ESC to inform the current EPB braking torque magnitude, and then calculates the braking force of the non-EPB wheels. The EPB and the ESC transmit data such as braking torque and wheel speed through the CAN bus. The above process is a dynamic process. By obtaining the EPB braking torque applied to the EPB wheels of the vehicle in real time, applying the hydraulic braking torque in real-time synchronization, and dynamically adjusting the hydraulic braking torque, the dynamic balance of the braking torque is achieved in the roller test of the vehicle, adapting to different test conditions.

[0055] That is, yaw stability control: By balancing the braking forces of the front and rear axles, eliminate the rotational torque around the vehicle center and prevent the vehicle body from shifting.

[0056] Slip suppression: Adjust the hydraulic braking torque to ensure that there is effective friction between all tires and the roller, avoiding slipping.

[0057] Of course, the above control method can also be applied to the following test scenarios, such as braking performance test: verifying the effectiveness of the coordinated operation of the EPB and the service braking system.

[0058] Powertrain test: avoiding drive wheel slip during high torque output.

[0059] Four-wheel drive system test: coordinating the braking force of multiple axles to simulate stability under complex road conditions.

[0060] In some preferred embodiments, dynamic imbalance may occur during the initial stage of EPB clamping. To solve this problem, the following settings are also provided:

[0061] Step 200 further includes the following steps: before clamping the EPB wheels of the vehicle, applying a target hydraulic braking torque to the non-EPB wheels of the vehicle; the target hydraulic braking torque is greater than the parking braking force limit value and less than the maximum load torque of the roller.

[0062] The above steps achieve early intervention in braking. Before the EPB starts to clamp, the ESC system is used to apply a braking force to the non-EPB wheels in advance. The basic braking force can be established in advance to offset the dynamic imbalance that may occur during the initial stage of EPB clamping, ensuring that the braking force of the non-EPB wheels is sufficient to stabilize the vehicle alone, even if the EPB braking force is not fully effective. The braking force of the non-EPB wheels needs to exceed the parking braking force limit value specified in GB7258 (for example: the parking braking force needs to be ≥ 20% of the total vehicle mass).

[0063] Furthermore, the above steps are aimed at the situation where the vehicle deviates due to excessive unilateral braking force. During the test, excessive braking force differences between different axles can also cause instability; the above axles refer to the front axle and the rear axle; for this problem, the following settings are provided:

[0064] During the process of clamping the EPB wheels of the vehicle, control the hydraulic braking torque to increase at a first slope and control the EPB braking torque to increase at a second slope;

[0065] The first slope is greater than the second slope, and the difference between the first slope and the second slope is within the design range.

[0066] In this embodiment, the design of the first slope and the second slope realizes the control of the torque growth slope, that is, the growth rate of the braking torque of the non-EPB wheels needs to be faster than the growth rate of the EPB clamping force. Through the high dynamic response characteristics of the ESC hydraulic system (such as high-speed solenoid valve adjustment), rapid linear growth of the braking force is achieved (for example: the first slope is set to 1.2 - 1.5 times the second slope). This avoids instantaneous torque imbalance caused by excessive differences in the growth rates of the braking forces of the front axle and the rear axle during the EPB clamping process.

[0067] In addition, in this embodiment, the slope matching accuracy also needs to be ensured, and it is necessary to ensure that the braking force curves of the ESC and the EPB are strictly matched. The calibration method is as follows: calibrate the braking force slope parameters through bench tests, and establish a look-up table mapping in combination with parameters such as vehicle mass and wheelbase.

[0068] In some preferred embodiments, there are the following settings on how to calculate the hydraulic braking torque to compensate for the EPB braking torque and ensure the balance of the front and rear axle braking forces:

[0069] Obtain the hydraulic braking torque corresponding to the real-time EPB braking torque, including the following steps:

[0070] Take the value of the real-time EPB braking torque as the base value;

[0071] Obtain the hub rotation speed and tire slip ratio corresponding to the real-time EPB braking torque; then compensate the base value based on the hub rotation speed and tire slip ratio to obtain the target value;

[0072] Take the target value as the hydraulic braking torque.

[0073] The above realizes that, based on the vehicle dynamics model, considering factors such as axle load transfer and friction coefficient, the compensation torque is ensured to be accurate; based on the feedback of the hub rotation speed and tire slip ratio, the braking force of the non-EPB wheels is finely adjusted in real time to ensure the dynamic balance between the total braking torque and the hub driving torque.

[0074] In this application, there are also the following problems, over-braking risk: excessive braking force of the non-EPB wheels may cause hub overload or abnormal tire wear. The solution is to set a protection mechanism, that is, set an upper limit of the braking force (such as not exceeding 80% of the maximum bearing torque of the hub), and monitor it in real time through a pressure sensor.

[0075] In some preferred embodiments, due to the reason of the difference in the braking torque of the left and right wheels: the transmission efficiency of each EPB caliper and the friction coefficient of the caliper friction plate cannot be exactly the same all the time, which in turn causes the braking torques of the left and right tires to be different.

[0076] And due to the reason of the torque phase deviation: the back electromotive force at the moment of starting of the EPB caliper is relatively large. To avoid impacting the vehicle network, generally, a staggered start control is performed on the left and right EPBs (the stagger is about 20 - 60 ms), so there is a phase for the braking torques of the left and right wheels.

[0077] After controlling the braking force of the non-EPB wheels to compensate for the braking force of the EPB wheels, there will still be a risk of yaw. For ensuring safety, there are the following settings:

[0078] Refer to Figure 3 , during the process of clamping the EPB wheels of the vehicle, it further includes the following steps:

[0079] Obtain the real-time yaw rate of the vehicle and then compare it with the designed threshold value;

[0080] When the real-time yaw rate is greater than the designed threshold value, it indicates that there is a yaw risk. At the same time, control the hydraulic braking torque to increase according to the preset increment at the current moment; the preset increment is 8 - 15% of the hydraulic braking torque corresponding to the EPB braking torque at the current moment.

[0081] In this embodiment, yaw rate monitoring and intervention are realized.

[0082] The yaw rate threshold in the monitoring parameters is set to 0.5° / s (the specific value needs to be calibrated according to parameters such as the vehicle's center of mass height and wheelbase). The yaw rate signal is obtained through the inertial measurement unit (IMU) built in the ESC or an independent gyroscope. The trigger condition is: the yaw rate continuously exceeds the threshold (for example: for more than 100 ms). The intervention logic is: primary response: the EPB controller sends an emergency force increasing instruction to the ESC through the CAN bus, requiring the non - EPB wheel braking torque to increase by the preset increment (such as 10% of the current value).

[0083] Furthermore, after the control of the hydraulic braking torque is increased by the preset increment, if the real-time yaw rate is still greater than the designed threshold value, then the control of the EPB braking torque is also increased by the preset increment;

[0084] After the control of the hydraulic braking torque is increased by the preset increment at the current moment, when the real-time yaw rate gradually drops below the designed threshold value, control the hydraulic braking torque to gradually release the preset increment. In this embodiment, the secondary response is realized. That is, if the yaw rate does not converge, trigger the synchronous increase of the EPB clamping force to form combined front and rear axle braking. Exit condition: after the yaw rate drops below the threshold and stabilizes for 200 ms, gradually release the additional braking force.

[0085] Among them, the preset increment is dynamic and different in different situations. The preset increment has a proportional - integral relationship with the yaw rate deviation value. This relationship needs to be determined through real - vehicle calibration and will not be introduced in detail here because each real vehicle has different parameters and weights. Of course, to avoid frequent fluctuations in braking force, hysteresis control can be introduced, which is an existing technology.

[0086] Furthermore, communication failures may lead to the failure of ESC compensation. If the ESC does not respond to the EPB's force increasing request, redundant protection is required at this time. Therefore, the following settings are made:

[0087] When the controlled EPB braking torque is increased by a preset increment or when the controlled hydraulic braking torque is increased by the preset increment at the current moment, and the real-time yaw rate is still greater than the design threshold, the hub platform is controlled to stop, and all braking systems of the vehicle are locked. That is, the EPB can start to independently increase the clamping force (limited by the maximum clamping force of the mechanical structure), trigger the hub stop protocol and lock all braking systems.

[0088] The following points need to be noted to achieve this test:

[0089] Basic parameter calibration: including vehicle mass distribution, tire-hub friction coefficient, EPB / ESC response delay, etc.

[0090] Threshold calibration: By injecting yaw perturbations (such as unilateral hub acceleration), determine the critical value of the yaw rate threshold.

[0091] Verification of special scenarios: Extreme condition tests, simulate fault modes such as EPB clamping delay and ESC hydraulic failure, and verify the robustness of the protection strategy. Long-term tests, verify the stability of the braking force compensation strategy in continuous tests (such as avoiding overheating of the hydraulic system).

[0092] For the determination that the vehicle is in a stable state or static hold, the displacement of the vehicle on the hub needs to be ≤ 1 mm (measured by a laser displacement sensor).

[0093] The above test strategy settings achieve zero displacement constraint of the vehicle in the hub test; millisecond-level intervention on the yaw instability trend; double compatibility with regulatory requirements (GB 7258) and equipment safety limits through preloading of non-EPB wheel braking torque, dynamic compensation of non-EPB wheel braking torque, and closed-loop safety protection based on yaw rate. This strategy reflects the deep integration of multi-system collaborative control and fault-tolerant design, providing a standardized solution for high-precision vehicle testing.

[0094] In a second aspect, the present application also proposes an EPB hub test control system, and the EPB hub test control system includes:

[0095] An EPB controller, which is used to enter the hub test mode when the wheels are rotating at high speed and the vehicle speed is zero; and after entering the hub test mode, start to clamp the vehicle's EPB wheels and obtain the EPB braking torque applied to the vehicle's EPB wheels in real time;

[0096] An ESC controller, which is connected to the EPB controller through a CAN bus signal and receives the EPB braking torque;

[0097] A compensation module, which is used to calculate the corresponding hydraulic braking torque according to the real-time EPB braking torque during the process of clamping the vehicle's EPB wheel; and then control the ESC controller to brake the non-EPB wheels of the vehicle with the hydraulic braking torque.

[0098] Among them, the function implementation of each of the above module controllers corresponds to each step in the embodiment of the above EPB hub test control method, and its function and implementation process will not be elaborated here one by one.

[0099] In a third aspect, an embodiment of the present application provides an EPB hub test control device. The EPB hub test control device can be a device with data processing functions such as a personal computer (PC), a laptop computer, a server, a CPU, a host computer, etc.

[0100] In the embodiment of the present application, the EPB hub test control device may include a processor, a memory, a communication interface, and a communication bus.

[0101] Among them, the communication bus can be of any type and is used to interconnect the processor, the memory, and the communication interface.

[0102] The communication interface includes interfaces such as input / output (I / O) interfaces, physical interfaces, and logical interfaces for interconnecting the components inside the EPB hub test control device, as well as interfaces for interconnecting the EPB hub test control device with other devices (such as other computing devices or user devices). The physical interface can be an Ethernet interface, an optical fiber interface, an ATM interface, etc.; the user device can be a display (Display), a keyboard (Keyboard), etc.

[0103] The memory can be various types of storage media, such as random access memory (RAM), read-only memory (ROM), non-volatile RAM (NVRAM), flash memory, optical memory, hard disk, programmable ROM (PROM), erasable PROM (EPROM), electrically erasable PROM (EEPROM), etc.

[0104] The processor can be a general-purpose processor, which can call the EPB hub test control program stored in the memory and execute the EPB hub test control method provided in the embodiments of the present application. For example, the general-purpose processor can be a central processing unit (CPU). The method executed when the EPB hub test control program is called can refer to the various embodiments of the EPB hub test control method of the present application, which will not be elaborated here.

[0105] Fourthly, the embodiments of the present application further provide a computer-readable storage medium.

[0106] The EPB hub test control program is stored on the computer-readable storage medium of the present application. When the EPB hub test control program is executed by a processor, the steps of the EPB hub test control method as described above are implemented.

[0107] The method implemented when the EPB hub test control program is executed can refer to the various embodiments of the EPB hub test control method of the present application, which will not be elaborated here.

[0108] It should be noted that the serial numbers of the above embodiments of the present application are only for description and do not represent the advantages or disadvantages of the embodiments.

[0109] The terms "including" and "having" and any variations thereof in the specification, claims and drawings of the present application are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device that includes a series of steps or units is not limited to the listed steps or units, but optionally further includes steps or units not listed, or optionally further includes other steps or units inherent to these processes, methods, products or devices. The descriptions with terms such as "first", "second" and "third" are used to distinguish different objects, etc., which do not represent the sequence, nor do they limit that "first", "second" and "third" are different types.

[0110] In the description of the embodiments of the present application, terms such as "exemplary", "for example" or "for instance" are used to represent examples, illustrations or explanations. Any embodiment or design solution described as "exemplary", "for example" or "for instance" in the embodiments of the present application should not be construed as being more preferred or having more advantages than other embodiments or design solutions. Rather, the use of terms such as "exemplary", "for example" or "for instance" is intended to present relevant concepts in a specific manner.

[0111] In the description of the embodiments of the present application, unless otherwise specified, " / " means "or". For example, A / B may mean A or B. The "and / or" in the text is merely a description of the relationship between associated objects, indicating that there can be three relationships. For example, A and / or B may mean: A exists alone, A and B exist simultaneously, and B exists alone. In addition, in the description of the embodiments of the present application, "a plurality of" means two or more than two.

[0112] In some of the processes described in the embodiments of the present application, there are a plurality of operations or steps that appear in a specific order. However, it should be understood that these operations or steps may not be executed in the order in which they appear in the embodiments of the present application or may be executed in parallel. The serial numbers of the operations are only used to distinguish different operations, and the serial numbers themselves do not represent any order of execution. In addition, these processes may include more or fewer operations, and these operations or steps may be executed in order or in parallel, and these operations or steps may be combined.

[0113] Through the description of the above embodiments, those skilled in the art can clearly understand that the above-described embodiment methods can be implemented by means of software plus a necessary general hardware platform. Of course, they can also be implemented by hardware, but in many cases the former is a better implementation. Based on such an understanding, the technical solution of the present application, in essence, or the part that contributes to the prior art can be embodied in the form of a software product. This computer software product is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk) as described above and includes several instructions for causing a terminal device to execute the methods described in the various embodiments of the present application.

[0114] The above are only the preferred embodiments of the present application, and do not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made by using the content of the specification and drawings of the present application, or directly or indirectly applied in other related technical fields, shall be included in the patent protection scope of the present application by the same token.

Claims

1. An EPB hub test control method, characterized in that: It includes: When the wheel is spinning at high speed and the vehicle speed is zero, it enters the hub test mode; After entering the rotating hub test mode, the vehicle EPB wheel begins to be clamped, and the EPB braking torque applied to the vehicle EPB wheel is obtained in real time; In the process of clamping the EPB wheel of the vehicle, the non-EPB wheel of the vehicle is braked simultaneously with the hydraulic braking torque corresponding to the real-time EPB braking torque; Wherein, obtaining the real-time hydraulic braking torque corresponding to the EPB braking torque includes the following steps: The real-time value of the EPB braking torque is used as a basic value; the hub speed and tire slip ratio corresponding to the real-time EPB braking torque are obtained; then the basic value is compensated based on the hub speed and tire slip ratio to obtain a target value; and the target value is used as the hydraulic braking torque.

2. The EPB hub test control method according to claim 1, characterized in that: Before clamping the EPB wheel of the vehicle, a target hydraulic braking torque is applied to the non-EPB wheel of the vehicle; the target hydraulic braking torque is greater than the parking brake force limit and less than the maximum bearing torque of the rotating hub.

3. The EPB hub test control method according to claim 1, characterized in that: In the process of clamping the EPB wheel of the vehicle, controlling the hydraulic braking torque to increase at a first slope, and controlling the EPB braking torque to increase at a second slope; The first slope is greater than the second slope, and a difference between the first slope and the second slope is within a design range.

4. The EPB hub test control method according to claim 1, characterized in that: In the process of clamping the vehicle EPB wheel, the following steps are also included: Obtain the real-time yaw rate of the vehicle and then compare it with the designed threshold; When the real-time yaw angular velocity is greater than the design threshold, it indicates that there is a yaw risk, and at the same time the hydraulic braking torque is controlled to increase according to the preset increment at the current moment; the preset increment is 8-15% of the hydraulic braking torque corresponding to the EPB braking torque at the current moment.

5. The EPB hub test control method according to claim 4, characterized in that: When the control hydraulic braking torque is increased by a preset increment, and the real-time yaw angular velocity is still greater than the design threshold, the control EPB braking torque is also increased by the preset increment; When the hydraulic braking torque is controlled to be increased according to the preset increment at the current moment, the real-time yaw angular velocity gradually decreases to below the design threshold, and the hydraulic braking torque is controlled to be gradually released by the preset increment.

6. The EPB hub test control method according to claim 5, characterized in that: When the EPB braking torque is controlled to increase by the preset increment or when the hydraulic braking torque is controlled to increase by the preset increment at the current moment, the real-time yaw angular velocity is still greater than the design threshold, the hub platform is controlled to shut down and all braking systems of the vehicle are locked.

7. An EPB hub test control system, characterized in that: The EPB hub test control system includes: An EPB controller is used to enter a hub test mode when the wheel rotates at a high speed and the vehicle speed is zero; and after entering the hub test mode, start clamping the vehicle EPB wheel and obtain the EPB braking torque applied to the vehicle EPB wheel in real time; An ESC controller, which is connected to the EPB controller via a CAN bus signal and receives the EPB braking torque; A compensation module, which is used to calculate the corresponding hydraulic braking torque according to the real-time EPB braking torque during the process of clamping the EPB wheel of the vehicle; and then control the ESC controller to brake the non-EPB wheel of the vehicle with the hydraulic braking torque; Wherein, obtaining the real-time hydraulic braking torque corresponding to the EPB braking torque includes the following steps: The real-time value of the EPB braking torque is used as a basic value; the hub speed and tire slip ratio corresponding to the real-time EPB braking torque are obtained; then the basic value is compensated based on the hub speed and tire slip ratio to obtain a target value; and the target value is used as the hydraulic braking torque.

8. An EPB hub test control device, characterized in that: The EPB hub test control device includes a processor, a memory, and an EPB hub test control program stored in the memory and executable by the processor, wherein when the EPB hub test control program is executed by the processor, the steps of the EPB hub test control method as described in any one of claims 1 to 6 are implemented.

9. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores an EPB hub test control program, wherein when the EPB hub test control program is executed by a processor, the steps of the EPB hub test control method according to any one of claims 1 to 6 are implemented.

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