Vehicle braking control method and device, vehicle and storage medium

Abstract

The invention relates to the technical field of vehicle braking, and discloses a vehicle braking control method and device, a vehicle and a storage medium. According to the vehicle braking control method, a pedal braking signal is received, and if it is determined that a vehicle is in an auxiliary braking activation state, the wheel speed state of the vehicle is obtained; if the wheel speed state is an effective state, acquiring a pedal depth parameter and a wheel speed parameter; and target auxiliary braking force is determined according to the pedal depth parameter and the wheel speed parameter, and the electronic parking braking assembly is controlled to execute auxiliary braking operation according to the target auxiliary braking force. When it is determined that the vehicle is in the auxiliary braking activation state, the electronic parking braking assembly can be activated to automatically intervene in rear wheel auxiliary braking under the condition that only mechanical braking exists, and the timeliness of vehicle braking is guaranteed. Meanwhile, the depth of the brake pedal and the wheel speed are comprehensively considered to determine the auxiliary braking force, the rationality of braking force distribution is improved, and the stability of the vehicle is guaranteed.

Description

Technical Field

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

[0002] In order to improve the performance of vehicles, more and more models are equipped with a one-box brake-by-wire system, which integrates traditional boosters, vacuum pumps, and electronic stability programs (ESP). In the prior art, the brake-by-wire system requires the solenoid valve, motor, and electronic control unit (ECU) to work together to generate brake assistance. Therefore, if there is a problem with the solenoid valve, motor, or ECU, or the solenoid valve or motor cannot operate, the brake-by-wire assistance will fail. At this time, the braking of the entire vehicle depends entirely on the mechanical braking of the driver stepping on the brake pedal, and the braking deceleration is reduced, which increases the vehicle's braking time and poses a safety hazard. At this time, if you consider triggering the electronic parking brake function to increase the deceleration, you need to manually pull up the electronic parking brake switch, which is inconvenient to operate and cannot provide brake assistance in time. In addition, it is difficult to reasonably distribute the braking force through manual control, which is prone to the risk of loss of control due to excessive electronic parking brake force. Summary of the invention

[0003] Based on this, it is necessary to provide a vehicle braking control method, device, vehicle and storage medium to address the above technical problems, so as to solve the problems of inconvenient vehicle braking control operation and unreasonable braking force distribution in the prior art.

[0004] A vehicle braking control method, comprising: receiving a pedal brake signal, and if it is determined that the vehicle is in an auxiliary brake activation state, obtaining a wheel speed state of the vehicle; If the wheel speed state is a valid state, then obtaining a pedal depth parameter and a wheel speed parameter; A target auxiliary braking force is determined according to the pedal depth parameter and the wheel speed parameter, and the electronic parking brake assembly is controlled to perform an auxiliary braking operation according to the target auxiliary braking force.

[0005] A vehicle brake control device, comprising: an auxiliary brake activation module, configured to receive a pedal brake signal, and if determining that the vehicle is in an auxiliary brake activation state, obtain a wheel speed state of the vehicle; A parameter acquisition module, for acquiring a pedal depth parameter and a wheel speed parameter if the wheel speed state is a valid state; The auxiliary braking force determination module is used to determine a target auxiliary braking force according to the pedal depth parameter and the wheel speed parameter, and control the electronic parking brake assembly to perform an auxiliary braking operation according to the target auxiliary braking force.

[0006] A vehicle comprises an electronic parking brake assembly and a controller communicatively connected to the electronic parking brake assembly, wherein the controller is used to implement the vehicle braking control method as claimed in any one of claims 1 to 7.

[0007] A computer-readable storage medium stores computer-readable instructions. When the computer-readable instructions are executed by one or more processors, the one or more processors execute the vehicle braking control method as described above.

[0008] In the above-mentioned vehicle braking control method, device, vehicle and storage medium, the vehicle braking control method receives a pedal braking signal, and if it is determined that the vehicle is in an auxiliary braking activation state, the vehicle's wheel speed state is obtained; if the wheel speed state is in an effective state, the pedal depth parameter and the wheel speed parameter are obtained; the target auxiliary braking force is determined according to the pedal depth parameter and the wheel speed parameter, and the electronic parking brake component is controlled to perform an auxiliary braking operation according to the target auxiliary braking force. The present invention needs to determine that the vehicle is in an auxiliary braking activation state when the driver steps on the brake pedal, so that the electronic parking brake component is activated to automatically intervene in the rear wheel auxiliary braking when there is only mechanical backup braking. The superposition of mechanical braking and rear wheel auxiliary braking can increase the braking deceleration and ensure the timeliness of vehicle braking. At the same time, when the wheel speed state is in an effective state, the present invention comprehensively considers the brake pedal depth and the size of the wheel speed to determine the auxiliary braking force, which can effectively prevent the safety hazards caused by vehicle instability, improve the rationality of braking force distribution, and ensure braking stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative labor.

[0010] Figure 1 is a flow chart of a vehicle braking control method according to an embodiment of the present invention; Figure 2 It is a structural schematic diagram of a vehicle braking control device in one embodiment of the present invention. DETAILED DESCRIPTION

[0011] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are 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 creative work are within the scope of protection of the present invention.

[0012] In one embodiment, if Figure 1 As shown, a vehicle braking control method is provided, comprising the following steps S10-S30: S10: receiving a pedal brake signal, and if it is determined that the vehicle is in an auxiliary brake activation state, obtaining a wheel speed state of the vehicle.

[0013] Understandably, when the driver brakes by means of the brake pedal, the controller receives a pedal brake signal and determines whether the vehicle is in an auxiliary brake activation state. The pedal brake signal is a signal generated when the driver steps on the brake pedal to indicate the need to decelerate or stop. The auxiliary brake activation state refers to a state in which the vehicle allows the activation of the electronic parking brake function for auxiliary braking, that is, a vehicle in the auxiliary brake activation state can achieve automatic intervention of the electronic parking brake. When it is determined that the vehicle is in the auxiliary brake activation state, the wheel speed state of the vehicle is obtained, and it is determined whether the wheel speed state is in a valid state. The wheel speed state of the vehicle is state information used to indicate whether the vehicle can accurately monitor the wheel speed, including a valid state and a failed state. When the wheel speed state of the vehicle is in a valid state, it indicates that the vehicle can monitor the real-time wheel speed value through the wheel speed sensor and the real-time wheel speed value is true. When the wheel speed state of the vehicle is in a failed state, it indicates that the vehicle cannot monitor the real-time wheel speed value through the wheel speed sensor or the monitored real-time wheel speed value is distorted.

[0014] S20: If the wheel speed state is a valid state, then obtain a pedal depth parameter and a wheel speed parameter.

[0015] Understandably, during the driving process of the vehicle, the wheel has a certain wheel speed in the pure rolling state. The braking process of the wheel from pure rolling to parking is a gradual process, which goes through three stages: pure rolling, rolling and sliding, and pure sliding. When the wheel is subjected to braking force, relative sliding will occur between the wheel and the ground, but this sliding cannot exceed a certain limit, otherwise it will cause a sharp drop in friction and cause the wheel to lock. Under the premise that the wheel speed state of the vehicle is in a valid state, the pedal depth parameter and the wheel speed parameter are obtained. On the one hand, different auxiliary braking forces can be determined according to different pedal depths, and on the other hand, the sliding component of the wheel during the braking process can be evaluated according to the real-time wheel speed value of the vehicle to avoid vehicle loss of control due to wheel locking. The pedal depth parameter refers to the depth value of the brake pedal being stepped on, and different pedal depths correspond to different mechanical braking forces. The wheel speed parameter refers to the real-time wheel speed value of the wheel during the braking process.

[0016] S30, determining a target auxiliary braking force according to the pedal depth parameter and the wheel speed parameter, and controlling the electronic parking brake assembly to perform an auxiliary braking operation according to the target auxiliary braking force.

[0017] Understandably, different pedal depths correspond to different mechanical braking forces, and also require different auxiliary braking forces. Mechanical braking force refers to the braking force generated by the brake pedal being stepped on, and auxiliary braking force is the braking force generated by the electronic parking brake function. That is, the greater the pedal depth, the greater the corresponding mechanical braking force, the greater the auxiliary braking force required, and the greater the superposition of the mechanical braking force and the auxiliary braking force. However, the greater the superposition of the mechanical braking force and the auxiliary braking force, the greater the risk of wheel locking. The probability of wheel locking at different wheel speeds with the same braking force is different. Based on the real-time wheel speed value, the sliding component of the wheel during braking can be evaluated, and the auxiliary braking force can be further adjusted. Therefore, the target auxiliary braking force is determined based on the pedal depth parameter and the wheel speed parameter, and the electronic parking brake assembly is controlled to perform the auxiliary braking operation according to the target auxiliary braking force. The target auxiliary braking force is the braking force that the electronic parking brake assembly actually needs to provide for superposition on the mechanical braking force. When the electronic parking brake assembly performs auxiliary braking operations, it electronically controls the motor to drive the brake caliper of the rear wheel, so that the brake pads and brake discs are in close contact, thereby generating friction. The magnitude of the friction force is the magnitude of the target auxiliary braking force.

[0018] This embodiment receives a pedal brake signal, and if it is determined that the vehicle is in an auxiliary brake activation state, the vehicle's wheel speed state is obtained; if the wheel speed state is in an effective state, the pedal depth parameter and the wheel speed parameter are obtained; the target auxiliary braking force is determined according to the pedal depth parameter and the wheel speed parameter, and the electronic parking brake component is controlled to perform an auxiliary braking operation according to the target auxiliary braking force. This embodiment needs to determine that the vehicle is in an auxiliary brake activation state when the driver steps on the brake pedal, so that the electronic parking brake component is activated to automatically intervene in the rear wheel auxiliary braking when only mechanical braking is in effect. The superposition of mechanical braking and rear wheel auxiliary braking can increase the braking deceleration and ensure the timeliness of vehicle braking. At the same time, this embodiment comprehensively considers the brake pedal depth and wheel speed to determine the auxiliary braking force when the wheel speed state is in an effective state, which can effectively prevent the safety hazards caused by vehicle instability, improve the rationality of braking force distribution, and ensure braking stability.

[0019] In one embodiment, in step S10, that is, after obtaining the wheel speed state of the vehicle, the process further includes: S101. If the wheel speed state is a failure state, a preset standard braking force is determined as a target auxiliary braking force, and an electronic parking brake assembly is controlled to perform an auxiliary braking operation according to the target auxiliary braking force.

[0020] Understandably, when the wheel speed state of the vehicle is in a failed state, the vehicle cannot monitor the real real-time wheel speed value through the wheel speed sensor, and it is also impossible to accurately assess the risk of wheel locking during braking. At this time, the preset standard braking force is directly determined as the target auxiliary braking force, and the electronic parking brake assembly is controlled to perform auxiliary braking operations according to the target auxiliary braking force. The preset standard braking force is the auxiliary braking force that the pre-calibrated electronic parking brake assembly needs to provide in the event of wheel speed failure. The preset standard braking force is a fixed value calibrated by the actual vehicle and is not affected by the pedal depth parameters and wheel speed parameters. The preset standard braking force can be regarded as a minimum value of an auxiliary braking force, that is, the minimum auxiliary braking force that the electronic parking brake assembly can provide at the test vehicle speed (such as 5~120km / h) that will not cause wheel locking.

[0021] In this embodiment, if the wheel speed fails when the electronic parking brake function automatically intervenes, the preset standard braking force is directly determined as the target auxiliary braking force to ensure that the vehicle can be safely decelerated or stopped.

[0022] In one embodiment, step S10, that is, after receiving the pedal brake signal, includes: S102, upon receiving a backup brake switching signal, determining that the vehicle is in a backup brake activation state, and judging whether the vehicle state parameters meet a preset auxiliary brake condition; the backup brake switching signal is generated when the brake-by-wire system detects that the solenoid valve and / or the motor cannot operate; S103: If the vehicle state parameter satisfies a preset auxiliary braking condition, determine that the vehicle is in an auxiliary braking activation state.

[0023] It is understandable that after receiving the pedal brake signal, in order to determine whether the vehicle is in the auxiliary brake activation state, it is necessary to determine whether the vehicle is in the backup brake activation state on the one hand, and on the other hand, it is necessary to determine whether the vehicle state parameters meet the preset auxiliary brake conditions. The backup brake activation state refers to the state in which the vehicle's wire control brake system does not work and relies entirely on mechanical braking. When determining whether the vehicle is in the backup brake activation state, the controller determines whether a backup brake switching signal is received. If the backup brake switching signal is received, it is determined that the vehicle is in the backup brake activation state. If the backup brake switching signal is not received, it is determined that the vehicle is not in the backup brake activation state, and no subsequent vehicle state parameter determination is required. When the vehicle is equipped with a wire control brake system (One-box), if the solenoid valve or motor fails to operate, the wire control brake assist will fail. At this time, the vehicle braking relies entirely on the backup brake, that is, the mechanical brake when the driver steps on the brake pedal. Therefore, the wire control brake system generates a backup brake switching signal when it detects that the solenoid valve and / or motor cannot operate by identifying the working state of structures such as the solenoid valve and the motor, and continuously sends the backup brake switching signal to the controller in a loop. The backup brake switching signal is a signal used to indicate that the vehicle is degraded to pure mechanical braking due to the failure of the wire control brake system.

[0024] On the premise that it is determined that the vehicle is in the backup brake activation state, it is further determined whether the vehicle state parameters meet the preset auxiliary braking conditions. If the vehicle state parameters meet the preset auxiliary braking conditions, it is determined that the vehicle is in the auxiliary brake activation state. If the vehicle state parameters do not meet the preset auxiliary braking conditions, it is determined that the vehicle is not in the auxiliary brake activation state and the electronic parking brake function cannot be used for auxiliary braking. Vehicle state parameters refer to information used to describe and characterize the vehicle's motion state and hardware working state, such as vehicle speed. The preset auxiliary braking conditions are pre-set conditions for determining whether the electronic parking brake function is allowed to be automatically triggered to provide additional braking force for the mechanical brake, such as a preset vehicle speed threshold condition that the vehicle speed needs to meet.

[0025] On the one hand, this embodiment determines that the vehicle needs to trigger the electronic parking brake function for auxiliary braking by receiving the backup brake switching signal. On the other hand, it determines that the vehicle's electronic parking brake function can be triggered normally by the vehicle state parameters satisfying the preset auxiliary braking conditions, thereby ensuring the rigor and rationality of the auxiliary brake activation state judgment.

[0026] In one embodiment, step S102, i.e., determining whether the vehicle state parameter satisfies the preset auxiliary braking condition, includes: S1021, obtaining real-time voltage parameters, real-time vehicle speed parameters, and electronic parking brake status; S1022: When it is determined that the real-time voltage parameter reaches a preset voltage threshold, the real-time vehicle speed parameter reaches a preset vehicle speed threshold, and the electronic parking brake state is a brake release state, determine that the vehicle state parameter satisfies a preset auxiliary braking condition.

[0027] Understandably, in order to ensure that the electronic parking brake function can be triggered normally and provide auxiliary braking force, the vehicle state parameters include real-time voltage parameters, real-time vehicle speed parameters and electronic parking brake state, and the preset auxiliary braking conditions set corresponding to the vehicle state parameters include preset voltage thresholds, preset vehicle speed thresholds and specific braking states. The preset voltage threshold is a preset voltage range value used to limit the triggering of the electronic parking brake function. When the real-time voltage parameter does not reach the preset voltage threshold, the electronic parking brake function may not be able to provide braking force through electronic control. The preset vehicle speed threshold is a preset critical value of the vehicle speed used to limit the triggering of the electronic parking brake function. When the real-time vehicle speed parameter does not reach the preset vehicle speed threshold, the vehicle can achieve deceleration or parking only by mechanical braking, so there is no need to trigger the electronic parking brake function to provide braking force. The electronic parking brake state includes a brake release state and a brake working state, and the specific braking state refers to the electronic parking brake state being a brake release state. The electronic parking brake function can only be triggered when it is in the brake release state to provide auxiliary braking force of different sizes. If the electronic parking brake state is the braking working state, it indicates that the electronic parking brake function has been triggered and cannot be triggered again to provide auxiliary braking force.

[0028] In one embodiment, the default value of the preset voltage threshold is set to 8-18 volts, the default value of the preset vehicle speed threshold is set to 5 km / h, and the specific braking state is the brake release state. When the real-time voltage parameter is between 8-18 volts, the real-time vehicle speed parameter reaches above 5 km / h, and the electronic parking brake state is the brake release state, it is determined that the vehicle state parameter meets the preset auxiliary braking condition, that is, the vehicle allows the electronic parking brake function to be automatically triggered to provide additional auxiliary braking force for the mechanical brake.

[0029] This embodiment performs preset auxiliary braking condition judgment from three aspects: voltage, vehicle speed and electronic parking brake status, which can comprehensively and accurately evaluate whether the vehicle status is suitable for the electronic parking brake to provide auxiliary braking force, thereby realizing the reasonable intervention of the electronic parking brake function.

[0030] In one embodiment, in step S30, that is, determining the target auxiliary braking force according to the pedal depth parameter and the wheel speed parameter, includes: S301, when the pedal depth parameter reaches a preset pedal depth threshold, determining an initial auxiliary braking force according to the pedal depth parameter; S302: Determine a wheel slip ratio according to the wheel speed parameter, and determine a target auxiliary braking force according to the initial auxiliary braking force and the wheel slip ratio.

[0031] Understandably, in order to reasonably distribute the auxiliary braking force of the electronic parking brake function, this embodiment pre-matches and calibrates the different auxiliary braking forces that need to be superimposed at different pedal depths under actual vehicle experimental conditions, and generates a deep brake boost data table. Each pedal depth value in the deep brake boost data table corresponds to a calibrated auxiliary braking force value, and the corresponding relationship between the pedal depth value and the calibrated auxiliary braking force value may be linear or nonlinear, and needs to be calibrated according to the actual vehicle situation.

[0032] In the process of determining the target auxiliary braking force, it is first necessary to determine whether the pedal depth parameter reaches the preset pedal depth threshold. The preset pedal depth threshold is a preset minimum critical value of the pedal depth for determining the need to provide auxiliary braking force. If the pedal depth parameter has not reached the preset pedal depth threshold, it indicates that the driver may have accidentally touched the brake pedal and no auxiliary braking force is required. When the pedal depth parameter reaches the preset pedal depth threshold, the initial auxiliary braking force is determined based on the pedal depth parameter. The initial auxiliary braking force refers to the calibrated auxiliary braking force value that matches the pedal depth parameter found in the depth brake boost data table.

[0033] After determining the initial auxiliary braking force, it is also necessary to determine the wheel slip ratio according to the wheel speed parameter, and determine the target auxiliary braking force according to the initial auxiliary braking force and the wheel slip ratio. The wheel slip ratio refers to the proportion of the wheel slip component in braking, which can be calculated by the formula "wheel slip ratio = (wheel speed-vehicle speed) / vehicle speed × 100%". Since there is a conversion relationship between wheel speed and vehicle speed, the wheel slip ratio can be determined according to the wheel speed parameter. Since the auxiliary braking force in this embodiment is the superimposed braking force acting on the rear wheel provided by the electronic parking brake function, the wheel slip ratio in this embodiment is the rear wheel slip ratio. When the wheel slip ratio is zero, the lateral adhesion coefficient is the largest, the vehicle's anti-skid ability is the strongest, and the directional stability during braking is the best. As the wheel slip ratio increases, the lateral adhesion coefficient decreases. When the wheel is completely locked and dragged, the lateral adhesion coefficient is close to zero, and the vehicle's braking stability is the worst. If the initial auxiliary braking force is directly used as the target auxiliary braking force, it may cause wheel locking. Therefore, it is necessary to adjust the initial auxiliary braking force according to the wheel slip ratio to determine the final target auxiliary braking force.

[0034] This embodiment determines the target auxiliary braking force by comprehensively considering the initial auxiliary braking force and the wheel slip rate on the basis of determining the initial auxiliary braking force based on the pedal depth parameter, thereby improving the rationality of the target auxiliary braking force and avoiding wheel locking.

[0035] In one embodiment, step S302, i.e., determining the wheel slip ratio according to the wheel speed parameter, and determining the target auxiliary braking force according to the initial auxiliary braking force and the wheel slip ratio, includes: S3021, controlling the real-time braking force of the electronic parking brake assembly to gradually increase, determining a wheel slip rate according to a wheel speed parameter corresponding to the real-time braking force, and judging whether the wheel slip rate reaches a preset slip rate threshold; S3022: when the real-time braking force increases to the initial auxiliary braking force and the wheel slip rate is less than the preset slip rate threshold, determining the initial auxiliary braking force as the target auxiliary braking force; S3023. When the real-time braking force has not yet increased to the initial auxiliary braking force and the wheel slip rate is greater than or equal to the preset slip rate threshold, the real-time braking force is reduced by the preset braking force, and the real-time braking force after the preset braking force is reduced is determined as the target auxiliary braking force.

[0036] Understandably, after the initial auxiliary braking force is determined according to the pedal depth parameter, the target auxiliary braking force is determined on the basis of the initial auxiliary braking force. First, the real-time braking force of the electronic parking brake assembly is controlled to gradually increase, and the wheel slip ratio is determined according to the wheel speed parameter corresponding to the real-time braking force. The real-time braking force refers to the auxiliary braking force generated by the electronic parking brake assembly in real time. The real-time braking force is zero when the electronic parking brake state is the brake release state. The electronic parking brake assembly has a slow increase process when providing the auxiliary braking force, that is, the positive power supply makes the real-time braking force gradually increase from zero to the initial auxiliary braking force, and the electronic parking brake state changes from the brake release state to the brake working state. During the increase of the auxiliary braking force, the wheel speed parameter of the wheel will also change. Therefore, the real-time wheel speed value is collected by the wheel speed sensor and the corresponding wheel slip ratio is calculated. The wheel slip ratio at this time can reflect the influence of the real-time braking force on the braking stability. Secondly, it is necessary to determine whether the wheel slip ratio reaches the preset slip ratio threshold. As the wheel slip ratio increases, the lateral adhesion coefficient decreases, and the braking stability of the vehicle deteriorates. The preset slip rate threshold is a preset maximum critical value of the wheel slip rate for measuring the risk of wheel locking. For example, when the default value of the preset slip rate threshold is set to 20%, the braking stability is the best.

[0037] When the real-time braking force increases to the initial auxiliary braking force and the wheel slip rate is less than the preset slip rate threshold, it indicates that there is no risk of wheel locking under the superposition of the initial auxiliary braking force and the mechanical braking force. Therefore, the initial auxiliary braking force is determined as the target auxiliary braking force, and the electronic parking brake assembly is controlled to maintain the initial auxiliary braking force to perform the auxiliary braking operation. Before the real-time braking force has not increased to the initial auxiliary braking force, the wheel slip rate is greater than or equal to the preset slip rate threshold, indicating that there is a risk of wheel locking under the superposition of the mechanical braking force and the real-time braking force of the electronic parking brake assembly. At this time, it is necessary to reduce the real-time braking force by the preset braking force, determine the adjusted wheel slip rate according to the wheel speed parameter corresponding to the real-time braking force after the preset braking force is reduced, and re-judge whether the adjusted wheel slip rate reaches the preset slip rate threshold. The preset braking force is a pre-set braking force size used for each adjustment of the real-time braking force according to the wheel slip rate. When the adjusted wheel slip rate is less than the preset slip rate threshold, the real-time braking force after reducing the preset braking force is determined as the target auxiliary braking force, and the electronic parking brake assembly is controlled to perform an auxiliary braking operation according to the target auxiliary braking force.

[0038] This embodiment implements a dynamic adjustment strategy for auxiliary braking force based on a preset slip rate threshold, maintaining the braking force to obtain the best braking effect when the wheel slip rate is moderate, and reducing the braking force to prevent wheel locking when the wheel slip rate is too high. This embodiment dynamically adjusts and allocates a reasonable target auxiliary braking force, so that the wheel slip rate is kept within an ideal range, ensuring the stability and safety of the braking process.

[0039] In one embodiment, in step S30, that is, after controlling the electronic parking brake assembly to perform the auxiliary braking operation according to the target auxiliary braking force, the step further includes: S303, when it is detected that the pedal brake signal disappears and / or a backup brake cancellation signal is received, the electronic parking brake state of the electronic parking brake assembly is controlled to switch to a brake release state; the backup brake cancellation signal is generated when the online control brake system detects that the solenoid valve and / or motor that cannot operate resumes normal operation.

[0040] It can be understood that the controller monitors whether the pedal brake signal disappears and whether the backup brake cancellation signal is received during the period when the controller controls the electronic parking brake component to perform the auxiliary braking operation according to the target auxiliary braking force. If the pedal brake signal disappears, indicating that the driver has released the brake pedal, the electronic parking brake state of the electronic parking brake component is controlled to switch to the brake release state. That is, the reverse power supply causes the real-time braking force to gradually decrease from the target auxiliary braking force to zero, and the electronic parking brake state is restored from the brake working state to the brake release state, and the vehicle exits the auxiliary brake activation state.

[0041] The backup brake cancellation signal is generated when the brake-by-wire system detects that the solenoid valve and / or motor that cannot move has resumed normal operation. The brake-by-wire system generates a backup brake cancellation signal when it detects that the solenoid valve and / or motor that cannot move has resumed normal operation by identifying the working status of structures such as the solenoid valve and the motor. At this time, the backup brake switching signal is no longer continuously sent to the controller in a loop, but a backup brake cancellation signal is sent once. The backup brake cancellation signal is a signal used to indicate that the brake-by-wire system has resumed its function and the electronic parking brake no longer needs to intervene in the mechanical brake for assistance. Similarly, if the backup brake cancellation signal is received, the electronic parking brake state of the electronic parking brake assembly is controlled to switch to the brake release state. That is, the reverse power supply causes the real-time braking force to gradually decrease from the target auxiliary braking force to zero, and the electronic parking brake state is restored from the brake working state to the brake release state, and the vehicle exits the auxiliary brake activation state.

[0042] After the electronic parking brake automatically intervenes to provide auxiliary braking force, this embodiment realizes automatic exit through signal monitoring, thereby achieving reasonable coordination of the electronic parking brake, mechanical brake and wire control brake systems, avoiding unnecessary braking intervention, and improving the intelligence of braking control.

[0043] It should be understood that the order of execution of the steps in the above embodiment does not necessarily mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiment of the present invention.

[0044] In one embodiment, a vehicle braking control device is provided, which corresponds one-to-one to the vehicle braking control method in the above embodiment. Figure 2 As shown, the vehicle braking control device includes an auxiliary braking activation module 10, a parameter acquisition module 20 and an auxiliary braking force determination module 30. The functional modules are described in detail as follows: The auxiliary brake activation module 10 is used to receive a pedal brake signal, and if it is determined that the vehicle is in an auxiliary brake activation state, obtain the wheel speed state of the vehicle; A parameter acquisition module 20, for acquiring a pedal depth parameter and a wheel speed parameter if the wheel speed state is a valid state; The auxiliary braking force determination module 30 is used to determine a target auxiliary braking force according to the pedal depth parameter and the wheel speed parameter, and control the electronic parking brake assembly to perform an auxiliary braking operation according to the target auxiliary braking force.

[0045] In one embodiment, the auxiliary brake activation module 10 includes: The wheel speed failure auxiliary braking unit is used to determine a preset standard braking force as a target auxiliary braking force if the wheel speed state is a failure state, and control the electronic parking brake component to perform an auxiliary braking operation according to the target auxiliary braking force.

[0046] In one embodiment, the auxiliary brake activation module 10 further includes: A vehicle state parameter judgment unit is used to determine that the vehicle is in a backup brake activation state and to judge whether the vehicle state parameter meets a preset auxiliary brake condition when receiving a backup brake switching signal; the backup brake switching signal is generated when the brake-by-wire system detects that the solenoid valve and / or the motor cannot operate; The auxiliary brake activation state determining unit is used to determine that the vehicle is in an auxiliary brake activation state if the vehicle state parameter meets a preset auxiliary brake condition.

[0047] In one embodiment, the auxiliary brake activation module 10 further includes: A state parameter acquisition unit, used to acquire real-time voltage parameters, real-time vehicle speed parameters and electronic parking brake status; The state parameter judgment unit is used to determine that the vehicle state parameter meets the preset auxiliary braking condition when it is determined that the real-time voltage parameter reaches the preset voltage threshold, the real-time vehicle speed parameter reaches the preset vehicle speed threshold and the electronic parking brake state is a brake release state.

[0048] In one embodiment, the auxiliary braking force determination module 30 includes: an initial auxiliary braking force determining unit, configured to determine an initial auxiliary braking force according to the pedal depth parameter when the pedal depth parameter reaches a preset pedal depth threshold; The target auxiliary braking force determination unit is used to determine the wheel slip ratio according to the wheel speed parameter, and to determine the target auxiliary braking force according to the initial auxiliary braking force and the wheel slip ratio.

[0049] In one embodiment, the auxiliary braking force determination module 30 further includes: a wheel slip ratio determination unit, configured to control the real-time braking force of the electronic parking brake assembly to gradually increase, determine the wheel slip ratio according to a wheel speed parameter corresponding to the real-time braking force, and determine whether the wheel slip ratio reaches a preset slip ratio threshold; a first braking force determining unit, configured to determine the initial auxiliary braking force as a target auxiliary braking force when the real-time braking force increases to the initial auxiliary braking force and the wheel slip rate is less than the preset slip rate threshold; The second braking force determination unit is used to reduce the real-time braking force by a preset braking force when the real-time braking force has not yet increased to the initial auxiliary braking force and the wheel slip rate is greater than or equal to the preset slip rate threshold, and determine the real-time braking force after the preset braking force is reduced as the target auxiliary braking force.

[0050] In one embodiment, the auxiliary braking force determination module 30 further includes: The auxiliary brake cancellation unit is used to control the electronic parking brake state of the electronic parking brake assembly to switch to a brake release state when it detects that the pedal brake signal disappears and / or receives a backup brake cancellation signal; the backup brake cancellation signal is generated when the online control brake system detects that the solenoid valve and / or motor that cannot operate has resumed normal operation.

[0051] The specific definition of the vehicle brake control device can be found in the definition of the vehicle brake control method above, which will not be repeated here. Each module in the above-mentioned vehicle brake control device can be implemented in whole or in part by software, hardware and a combination thereof. The above-mentioned modules can be embedded in or independent of the processor in the computer device in the form of hardware, or can be stored in the memory of the computer device in the form of software, so that the processor can call and execute the operations corresponding to the above modules.

[0052] In one embodiment, a vehicle is provided, the vehicle including an electronic parking brake assembly and a controller that is communicatively connected to the electronic parking brake assembly. The controller may include only a vehicle controller, i.e., a vehicle control unit (VCU), or only an electronic parking brake assembly controller, or may include both a vehicle controller and an electronic parking brake assembly controller that are communicatively connected. The controller may be a computer device, a microprocessor, or a microcontroller, and may implement various complex control strategies. For the specific definition of the controller, please refer to the definition of the vehicle braking control method above, which will not be repeated here. Each module in the above controller may be implemented in whole or in part by software, hardware, and a combination thereof. Each of the above modules may be embedded in or independent of the processor in the controller in hardware form, or may be stored in the memory in the controller in software form, so that the processor may call and execute the operations corresponding to each of the above modules.

[0053] In one embodiment, the controller is configured to implement the following steps: receiving a pedal brake signal, and if it is determined that the vehicle is in an auxiliary brake activation state, obtaining a wheel speed state of the vehicle; If the wheel speed state is a valid state, then obtaining a pedal depth parameter and a wheel speed parameter; A target auxiliary braking force is determined according to the pedal depth parameter and the wheel speed parameter, and the electronic parking brake assembly is controlled to perform an auxiliary braking operation according to the target auxiliary braking force.

[0054] In one embodiment, one or more computer-readable storage media storing computer-readable instructions are provided. The readable storage media provided in this embodiment include non-volatile readable storage media and volatile readable storage media. The readable storage media store computer-readable instructions, and when the computer-readable instructions are executed by one or more processors, the following steps are implemented: receiving a pedal brake signal, and if it is determined that the vehicle is in an auxiliary brake activation state, obtaining a wheel speed state of the vehicle; If the wheel speed state is a valid state, then obtaining a pedal depth parameter and a wheel speed parameter; A target auxiliary braking force is determined according to the pedal depth parameter and the wheel speed parameter, and the electronic parking brake assembly is controlled to perform an auxiliary braking operation according to the target auxiliary braking force.

[0055] A person of ordinary skill in the art can understand that all or part of the processes in the above-mentioned embodiments can be implemented by instructing the relevant hardware through computer-readable instructions. The computer-readable instructions can be stored in a non-volatile readable storage medium or a volatile readable storage medium. When the computer-readable instructions are executed, they can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to memory, storage, database or other media used in the embodiments provided by the present invention may include non-volatile and / or volatile memory. Non-volatile memory may include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM) or flash memory. Volatile memory may include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in many forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous link (Synchlink) DRAM (SLDRAM), memory bus (Rambus) direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM), etc.

[0056] Those skilled in the art can clearly understand that for the convenience and simplicity of description, only the division of the above-mentioned functional units and modules is used as an example. In actual applications, the above-mentioned functions can be distributed and completed by different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above.

[0057] The embodiments described above are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be included in the protection scope of the present invention.

Claims

1. A vehicle braking control method, characterized in that: include: receiving a pedal brake signal, and if it is determined that the vehicle is in an auxiliary brake activation state, obtaining a wheel speed state of the vehicle; If the wheel speed state is a valid state, then obtaining a pedal depth parameter and a wheel speed parameter; A target auxiliary braking force is determined according to the pedal depth parameter and the wheel speed parameter, and the electronic parking brake assembly is controlled to perform an auxiliary braking operation according to the target auxiliary braking force.

2. The vehicle braking control method according to claim 1, characterized in that: After obtaining the wheel speed state of the vehicle, the method further includes: If the wheel speed state is a failure state, a preset standard braking force is determined as a target auxiliary braking force, and the electronic parking brake assembly is controlled to perform an auxiliary braking operation according to the target auxiliary braking force.

3. The vehicle braking control method according to claim 1, characterized in that: After receiving the pedal brake signal, the method includes: Upon receiving the backup brake switching signal, determining that the vehicle is in a backup brake activation state, and judging whether the vehicle state parameters meet the preset auxiliary brake conditions; the backup brake switching signal is generated when the wire control brake system detects that the solenoid valve and / or the motor cannot operate; If the vehicle state parameter satisfies a preset auxiliary braking condition, it is determined that the vehicle is in an auxiliary braking activation state.

4. The vehicle braking control method according to claim 3, characterized in that: The determining whether the vehicle state parameter satisfies the preset auxiliary braking condition includes: Obtain real-time voltage parameters, real-time vehicle speed parameters and electronic parking brake status; When it is determined that the real-time voltage parameter reaches a preset voltage threshold, the real-time vehicle speed parameter reaches a preset vehicle speed threshold, and the electronic parking brake state is a brake release state, it is determined that the vehicle state parameter meets the preset auxiliary braking condition.

5. The vehicle braking control method according to claim 1, characterized in that: The determining the target auxiliary braking force according to the pedal depth parameter and the wheel speed parameter comprises: When the pedal depth parameter reaches a preset pedal depth threshold, determining an initial auxiliary braking force according to the pedal depth parameter; A wheel slip ratio is determined according to the wheel speed parameter, and a target auxiliary braking force is determined according to the initial auxiliary braking force and the wheel slip ratio.

6. The vehicle braking control method according to claim 5, characterized in that: The determining of the wheel slip ratio according to the wheel speed parameter, and determining the target auxiliary braking force according to the initial auxiliary braking force and the wheel slip ratio, comprises: Controlling the real-time braking force of the electronic parking brake assembly to gradually increase, determining a wheel slip rate according to a wheel speed parameter corresponding to the real-time braking force, and judging whether the wheel slip rate reaches a preset slip rate threshold; When the real-time braking force increases to the initial auxiliary braking force and the wheel slip rate is less than the preset slip rate threshold, determining the initial auxiliary braking force as the target auxiliary braking force; When the real-time braking force has not yet increased to the initial auxiliary braking force and the wheel slip rate is greater than or equal to the preset slip rate threshold, the real-time braking force is reduced by the preset braking force, and the real-time braking force after the preset braking force is reduced is determined as the target auxiliary braking force.

7. The vehicle braking control method according to any one of claims 1 to 6, characterized in that: After the controlling the electronic parking brake assembly to perform the auxiliary braking operation according to the target auxiliary braking force, the method further includes: When it is detected that the pedal brake signal disappears and / or a backup brake cancellation signal is received, the electronic parking brake state of the electronic parking brake assembly is controlled to switch to a brake release state; the backup brake cancellation signal is generated when the online control brake system detects that the solenoid valve and / or motor that cannot operate has resumed normal operation.

8. A vehicle brake control device, characterized in that: include: an auxiliary brake activation module, configured to receive a pedal brake signal, and if determining that the vehicle is in an auxiliary brake activation state, obtain a wheel speed state of the vehicle; A parameter acquisition module, for acquiring a pedal depth parameter and a wheel speed parameter if the wheel speed state is a valid state; The auxiliary braking force determination module is used to determine a target auxiliary braking force according to the pedal depth parameter and the wheel speed parameter, and control the electronic parking brake assembly to perform an auxiliary braking operation according to the target auxiliary braking force.

9. A vehicle, characterized in that: The invention comprises an electronic parking brake component and a controller which is communicatively connected with the electronic parking brake component, wherein the controller is used to implement the vehicle braking control method according to any one of claims 1 to 7.

10. A computer-readable storage medium storing computer-readable instructions, characterized in that: When the computer-readable instructions are executed by one or more processors, the one or more processors are caused to perform the vehicle braking control method according to any one of claims 1 to 7.

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