Energy recovery method, vehicle and storage medium

Abstract

The invention provides an energy recovery method, a vehicle and a storage medium, the method is applied to the field of vehicles, and the method comprises the steps that a vehicle unstable state coefficient during vehicle energy recovery is obtained; the maximum regenerative braking force capable of keeping a vehicle body stable during vehicle energy recovery is determined according to the vehicle unstable state coefficient; the maximum regenerative braking force capable of keeping a vehicle body stable is used for braking and energy recovery. According to the method, the maximum regenerative braking force capable of keeping the vehicle body stable during vehicle energy recovery can be determined according to the vehicle unstable state coefficient, braking and energy recovery are conducted through the maximum regenerative braking force capable of keeping the vehicle body stable, energy recovery can be conducted to the maximum extent while the vehicle body stable can be kept, and the energy recovery efficiency is improved. And the vehicle body stability and the capacity recovery efficiency are both considered.

Description

Technical Field

[0001] The present application relates to the field of vehicles, and more specifically, to an energy recovery method, a vehicle and a storage medium in the field of wire-controlled chassis vehicle braking. Background Art

[0002] The brake energy recovery system mainly recovers excess energy released by the vehicle during braking or coasting when the driver steps on the brake pedal or the accelerator pedal and the brake pedal are released, converts it into electrical energy through a generator and stores it in the battery for subsequent vehicle driving, greatly reducing the waste of resources.

[0003] Most of the braking energy recovery systems in the related technology can only perform quantitative energy recovery, resulting in excessive energy loss, and when the vehicle is performing coasting energy recovery, the brake pedal is pressed and the braking energy recovery intervenes. However, when the braking energy recovery exits, it is easy to cause a sudden change in the coasting energy recovery torque, which can cause the vehicle to feel jerky, have poor stability, poor control effect, and poor experience. Summary of the invention

[0004] The present application provides an energy recovery method, a vehicle and a storage medium. The method can utilize the maximum regenerative braking force that can maintain the stability of the vehicle body for braking and energy recovery, thereby maintaining the stability of the vehicle body while recovering energy to the greatest extent, taking into account the efficiency of vehicle body stability and energy recovery, and improving the user experience.

[0005] In a first aspect, an energy recovery method is provided, the method comprising: obtaining a vehicle unstable state coefficient during vehicle energy recovery; determining a maximum regenerative braking force that can maintain vehicle body stability during vehicle energy recovery based on the vehicle unstable state coefficient; and utilizing the maximum regenerative braking force that can maintain vehicle body stability for braking and energy recovery.

[0006] Through the above technical scheme, the maximum regenerative braking force that can maintain the stability of the vehicle body during vehicle energy recovery can be determined according to the vehicle's unstable state coefficient, and the maximum regenerative braking force that can maintain the stability of the vehicle body can be used for braking and energy recovery. While maintaining the stability of the vehicle body, energy recovery can be performed to the greatest extent, taking into account both the stability of the vehicle body and the efficiency of energy recovery, thereby improving the user experience.

[0007] In combination with the first aspect, in some possible implementations, determining the maximum regenerative braking force that can maintain vehicle body stability when the vehicle recovers energy based on the vehicle unstable state coefficient includes: obtaining the initial regenerative braking force when the vehicle recovers energy; if the vehicle unstable state coefficient is less than a coefficient threshold, using the initial regenerative braking force as the maximum regenerative braking force; if the vehicle unstable state coefficient is greater than or equal to the coefficient threshold, correcting the initial regenerative braking force based on the vehicle unstable state coefficient to obtain the maximum regenerative braking force.

[0008] Through the above technical solution, the maximum regenerative braking force that can maintain the stability of the vehicle body can be obtained according to the size of the vehicle's unstable state coefficient, so as to facilitate subsequent braking and energy recovery using the maximum regenerative braking force that can maintain the stability of the vehicle body.

[0009] In combination with the first aspect and the above-mentioned implementation methods, in some possible implementation methods, obtaining the vehicle's unstable state coefficient during vehicle energy recovery includes: obtaining one or more of the lateral acceleration of the vehicle during energy recovery, the vehicle dynamic control system triggering state, and the anti-lock braking system triggering state; obtaining the vehicle's unstable state coefficient based on one or more of the lateral acceleration, the vehicle dynamic control system triggering state, and the anti-lock braking system triggering state.

[0010] Through the above technical solution, the vehicle unstable state coefficient can be obtained according to the actual state of the vehicle, so as to subsequently determine the maximum regenerative braking force that can maintain vehicle body stability when the vehicle recovers energy according to the vehicle unstable state coefficient.

[0011] In combination with the first aspect and the above-mentioned implementation methods, in some possible implementation methods, after using the maximum regenerative braking force that can maintain the stability of the vehicle body for braking and energy recovery, it also includes: detecting the required braking force of the vehicle; if the maximum regenerative braking force is less than the required braking force, controlling the braking mechanism of each wheel to output a target braking force to compensate for the difference between the required braking force of the vehicle and the maximum regenerative braking force.

[0012] Through the above technical solution, when the maximum regenerative braking force is less than the required braking force, the braking mechanism of each wheel can be controlled to output the target braking force to compensate for the insufficient braking force required by the vehicle, so as to achieve braking of the vehicle.

[0013] In combination with the first aspect and the above-mentioned implementation methods, in some possible implementation methods, the control of the braking mechanism of each wheel to output the target braking force includes: obtaining the current braking force of each wheel; controlling the caliper motor in the corresponding braking mechanism to output the target current according to the current braking force of each wheel and the corresponding target braking force.

[0014] Through the above technical solution, the output target current of the caliper motor can be controlled according to the target braking force and the current braking force, so as to achieve braking of the vehicle.

[0015] In combination with the first aspect and the above-mentioned implementation methods, in some possible implementation methods, before controlling the braking mechanism of each wheel to output the target braking force, it also includes: inputting the required braking force during vehicle energy recovery, the maximum regenerative braking force and the slip rate of each wheel into a closed-loop processing model, and the closed-loop processing model outputs the target braking force of the corresponding wheel.

[0016] Through the above technical solution, data can be processed based on the closed-loop processing algorithm in the closed-loop processing model, so as to calculate the target braking force of each vehicle, so as to facilitate the subsequent control of the braking force of each wheel.

[0017] In combination with the first aspect and the above-mentioned implementation methods, in some possible implementation methods, before controlling the braking mechanism of each wheel to output the target braking force to compensate for the insufficient braking, it also includes: identifying whether the caliper motor of each wheel has failed; when it is identified that at least one caliper motor has failed, the required braking force during vehicle energy recovery, the maximum regenerative braking force, and the slip rate of each non-failed caliper motor corresponding to the wheel are input into a closed-loop processing model, and the closed-loop processing model outputs the target braking force of each non-failed caliper motor corresponding to the wheel.

[0018] Through the above technical solution, when the caliper motor fails, the required braking force for vehicle energy recovery, the maximum regenerative braking force, and the slip rate of each non-failed caliper motor corresponding to the wheel can be input into the closed-loop processing model according to the actual situation, thereby calculating the target braking force of each non-failed caliper motor corresponding to the wheel, so that the subsequent braking mechanism can output the corresponding target braking force.

[0019] In combination with the first aspect and the above-mentioned implementation methods, in some possible implementation methods, the closed-loop processing model uses a closed-loop processing algorithm to perform data processing, wherein the closed-loop processing algorithm includes: obtaining the braking force difference between the required braking force and the maximum regenerative braking force; if the actual yaw angular velocity of the vehicle is not detected and the slip rate is not the longitudinal slip rate, using the braking force difference as the target braking force; if the actual yaw angular velocity of the vehicle is detected and the slip rate is not the longitudinal slip rate, calculating the target braking force according to the angular velocity difference between the actual yaw angular velocity and the target yaw angular velocity and the braking force difference, otherwise calculating the target braking force according to the braking force difference and the longitudinal slip rate.

[0020] Through the above technical solution, data can be processed based on the closed-loop processing algorithm in the closed-loop processing model, so as to calculate the target braking force according to the actual situation, so as to facilitate the subsequent control of the braking force of each wheel.

[0021] In a second aspect, an energy recovery device is provided, which includes: an acquisition module for acquiring a vehicle non-stable state coefficient during vehicle energy recovery; a determination module for determining a maximum regenerative braking force that can maintain vehicle body stability during vehicle energy recovery based on the vehicle non-stable state coefficient; and a processing module for utilizing the maximum regenerative braking force that can maintain vehicle body stability for braking and energy recovery.

[0022] In a third aspect, a vehicle is provided, comprising: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the energy recovery method as described in the above embodiment.

[0023] In a fourth aspect, a computer-readable storage medium is provided, which stores a computer program code. When the computer program code runs on a computer, the computer executes the energy recovery method in the above-mentioned first aspect or any possible implementation of the first aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 is a flow chart of the energy recovery method provided in an embodiment of the present application;

[0025] Figure 2 is a block diagram of an energy recovery device provided in an embodiment of the present application;

[0026] Figure 3 It is a schematic diagram of the structure of a vehicle provided in an embodiment of the present application. DETAILED DESCRIPTION

[0027] The technical solution in the present application will be described clearly and in detail below in conjunction with the accompanying drawings. In the description of the embodiments of the present application, unless otherwise specified, " / " means or, for example, A / B can mean A or B: "and / or" in the text is only a description of the association relationship of associated objects, indicating that there can be three relationships, for example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. In addition, in the description of the embodiments of the present application, "multiple" means two or more than two.

[0028] In the following, the terms "first" and "second" are used for descriptive purposes only and are not to be understood as suggesting or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features.

[0029] The following will be combined Figure 1 The energy recovery method is explained in detail.

[0030] Figure 1 This is a flow chart of an energy recovery method provided in an embodiment of the present application.

[0031] For example, Figure 1 As shown, the method includes:

[0032] In step S101, the vehicle non-steady state coefficient during vehicle energy recovery is obtained.

[0033] It can be understood that since the vehicle may become unstable during energy recovery, the vehicle unstable state coefficient is formed according to the importance of the factors affecting the vehicle stability. The instability coefficient includes but is not limited to lateral acceleration, VDC (Vdc vehicle running dynamic control system) trigger state and ABS (Antilock Brake System) trigger state. Therefore, the embodiment of the present application can obtain the vehicle unstable state coefficient when energy recovery is triggered.

[0034] It should be noted that the chassis structure of the vehicle in the embodiment of the present application mainly includes four EMB (Electromechanical Brake System) actuators, which can independently control the four wheels; EMB is an actuator driven by a caliper motor and installed on the caliper of the brake mechanism. It is a device that directly brakes the vehicle with the brake mechanism without the need for a medium such as brake fluid; EMB replaces traditional hydraulic brakes and is used for main braking, and its scope of use has been expanded.

[0035] In an embodiment of the present application, obtaining a vehicle unstable state coefficient during vehicle energy recovery includes: obtaining one or more of the lateral acceleration, VDC trigger state, and ABS trigger state during vehicle energy recovery; obtaining the vehicle unstable state coefficient based on one or more of the lateral acceleration, VDC trigger state, and ABS trigger state.

[0036] It can be understood that in the embodiment of the present application, the vehicle unstable state coefficient can be obtained according to the actual state of the vehicle, so as to facilitate the subsequent determination of the maximum regenerative braking force that can maintain vehicle body stability during vehicle energy recovery based on the vehicle unstable state coefficient.

[0037] Specifically, the vehicle unstable state coefficient includes but is not limited to obtaining the vehicle unstable state coefficient according to one or more of the lateral acceleration, the VDC trigger state and the ABS trigger state, and the specific method is as follows:

[0038] (1) The method for obtaining the vehicle unstable state coefficient based on the lateral acceleration is:

[0039] When the lateral acceleration signal is valid and the absolute value of the lateral acceleration is greater than the threshold w, it indicates that the vehicle is at risk of instability. Therefore, it is necessary to correct the vehicle's energy recovery capability in combination with the vehicle's unstable state coefficient to avoid vehicle instability. At this time, a pre-calibrated first curve can be obtained. The first curve is calibrated based on the lateral acceleration and the corresponding vehicle's unstable state coefficient. The slope of the first curve is s. The first curve decreases according to time and the slope s. The vehicle's unstable state coefficient can be obtained by identifying the first curve. The maximum value of the first curve is the first preset coefficient, and the first preset coefficient is obtained during calibration.

[0040] When the lateral acceleration signal is valid and the absolute value of the lateral acceleration is greater than the threshold w, the first counter is set to 0. When the lateral acceleration signal is valid and the absolute value of the lateral acceleration is less than or equal to the threshold w, the first counter is controlled to start increasing with a slope t. When the threshold u is reached, the vehicle's unstable state coefficient is allowed to recover to the first preset coefficient. The slope of the vehicle's unstable state coefficient when it recovers is v, so that the first counter can be used to delay the recovery of the vehicle's unstable state coefficient, avoiding frequent fluctuations in the stability factor caused by changes in the lateral acceleration, and improving the stability of vehicle control. Among them, w, s, t, u, and v are all matching parameters.

[0041] (2) The method for obtaining the vehicle unstable state coefficient according to the VDC trigger state is:

[0042] When the VDC function is triggered, it indicates that the vehicle is at risk of instability. Therefore, it is necessary to correct the vehicle's energy recovery capability in combination with the vehicle's unstable state coefficient to avoid vehicle instability. At this time, a pre-calibrated second curve can be obtained. The second curve is calibrated based on the VDC trigger state and the corresponding vehicle's unstable state coefficient. The slope of the second curve is e. The second curve decreases according to time and the slope e. The vehicle's unstable state coefficient can be obtained by identifying the second curve. The maximum value of the second curve is the second preset coefficient, which is obtained during calibration.

[0043] When the VDC function is triggered, the second counter is set to 0. When the VDC function is turned off, the second counter is controlled to start increasing with a slope of g. When the threshold h is reached, the vehicle unstable state coefficient is allowed to recover to the second preset coefficient. The slope of the vehicle unstable state coefficient recovery is f, so that the vehicle unstable state coefficient can be delayed by the second counter to avoid frequent fluctuations in the stability factor caused by the VDC function triggering, thereby improving the stability of vehicle control. Among them, e, f, g, and h are all matching parameters.

[0044] (3) The method of obtaining the vehicle unstable state coefficient according to the ABS trigger state is:

[0045] When the ABS function is triggered, it indicates that the vehicle is at risk of becoming unstable. Therefore, it is necessary to correct the vehicle's energy recovery capability in combination with the vehicle's unstable state coefficient to avoid vehicle instability. At this time, a pre-calibrated third curve may be obtained. The third curve is calibrated based on the ABS function triggering state and the corresponding vehicle's unstable state coefficient. The slope of the third curve is a. The third curve decreases according to time and slope a. The vehicle's unstable state coefficient may be obtained by identifying the third curve. The maximum value of the third curve is the third preset coefficient, which is obtained during calibration.

[0046] When the ABS function is triggered, the third counter is set to 0. When the ABS function is turned off, the third counter is controlled to start increasing with a slope c. When the threshold d is reached, the vehicle unstable state coefficient is allowed to recover to the third preset coefficient. The slope of the vehicle unstable state coefficient recovery is b, so that the vehicle unstable state coefficient can be delayed to recover through the third counter, avoiding frequent fluctuations of the stability factor caused by the ABS function triggering, and improving the stability of vehicle control. Among them, a, b, c, d are all matching parameters.

[0047] (4) When multiple vehicle unstable state coefficients are obtained from the lateral acceleration, VDC trigger state, and ABS trigger state, the smallest vehicle unstable state coefficient is used as the final vehicle unstable state coefficient.

[0048] In step S102, the maximum regenerative braking force that can maintain vehicle body stability during vehicle energy recovery is determined according to the vehicle unstable state coefficient.

[0049] It can be understood that since different vehicle unstable state coefficients correspond to different vehicle stable states, the braking force required to stabilize the vehicle body is different. The embodiment of the present application can determine the maximum braking force to maintain the stability of the vehicle body according to the vehicle unstable state coefficient as the maximum regenerative braking force.

[0050] Specifically, regenerative braking is the conversion of part of the vehicle's kinetic energy into electrical energy during deceleration braking (braking or downhill), and the converted electrical energy is stored in storage devices, such as various batteries, supercapacitors and high-speed flywheels, which ultimately increases the mileage of electric vehicles or is used for later acceleration. When the electric vehicle decelerates, releases the accelerator pedal to cruise on the road, or presses the brake pedal to stop, the regenerative braking system is activated. During normal deceleration, the torque of regenerative braking is generally maintained at the maximum load state; when the electric vehicle is cruising at high speed, its drive motor is usually operated at a constant power state, and the drive torque is inversely proportional to the speed of the drive motor or the vehicle speed.

[0051] In an embodiment of the present application, the maximum regenerative braking force that can maintain vehicle body stability when the vehicle recovers energy is determined based on the vehicle's unstable state coefficient, including: obtaining the initial regenerative braking force when the vehicle recovers energy; if the vehicle's unstable state coefficient is less than a coefficient threshold, using the initial regenerative braking force as the maximum regenerative braking force that can maintain vehicle body stability; if the vehicle's unstable state coefficient is greater than or equal to the coefficient threshold, correcting the initial regenerative braking force based on the vehicle's unstable state coefficient to obtain the maximum regenerative braking force that can maintain vehicle body stability.

[0052] Among them, the coefficient threshold can be specifically calibrated and is not specifically limited; the embodiment of the present application can determine the initial regenerative braking force according to the required braking force of the vehicle and the maximum regenerative capacity of the vehicle, and the minimum value of the braking force corresponding to the required braking force and the maximum regenerative capacity of the vehicle is used as the initial regenerative braking force, wherein the required braking force of the vehicle is the braking force corresponding to the actual stroke when the brake pedal is triggered, indicating the braking force that the driver expects the vehicle to generate, and the calculation formula of the braking force corresponding to the maximum regenerative capacity is:

[0053] T=a×M×r,

[0054] Among them, T represents the braking force corresponding to the maximum regenerative capacity, a represents the deceleration, which refers to the acceleration to which an object is subjected when it decelerates, M is the mass of the vehicle, and r is the rolling radius of the wheel.

[0055] It is understandable that the embodiment of the present application can determine the maximum regenerative braking force that can maintain vehicle body stability based on the vehicle's unstable state coefficient and the initial regenerative braking force, thereby taking into account vehicle body stability control when performing energy recovery.

[0056] Specifically, due to the different unstable state coefficients of the vehicle, such as when the vehicle body is unstable, the amount of energy recovered by the vehicle during braking energy recovery is different. In order to avoid energy waste, the initial regenerative braking force can be corrected according to the unstable state coefficient of the vehicle to obtain the maximum regenerative braking force that can keep the vehicle body stable. If the unstable state coefficient of the vehicle is less than the coefficient threshold, the initial regenerative braking force is used as the maximum regenerative braking force that can keep the vehicle body stable; if the unstable state coefficient of the vehicle is greater than or equal to the coefficient threshold, it means that the vehicle body is in an unstable state, and the initial regenerative braking force is corrected according to the unstable state coefficient of the vehicle to obtain the maximum regenerative braking force that can keep the vehicle body stable, for example:

[0057] When the vehicle instability coefficient is greater than the vehicle unstable state coefficient threshold, the difference between the current vehicle instability coefficient and the vehicle unstable state coefficient threshold is obtained, and a correction value of the initial regenerative braking force is determined according to the vehicle unstable state coefficient difference, so as to correct the initial regenerative braking force according to the vehicle unstable state coefficient to determine the maximum regenerative braking force that can maintain vehicle body stability.

[0058] Therefore, the embodiment of the present application can pre-calibrate the correspondence between the vehicle's instability coefficient difference and the correction value of the initial regenerative braking force. For example, when the vehicle's instability coefficient difference is A, the corresponding relationship table is queried to obtain the corresponding correction value of the initial regenerative braking force, which is aN·m. The maximum regenerative braking force can be obtained by correcting the initial regenerative braking force based on the correction value.

[0059] For example, the vehicle unstable state coefficient calculated according to the above actual situation is 8, and the set vehicle unstable state coefficient threshold is 5, then the vehicle unstable coefficient difference is 3, assuming that the initial regenerative braking force is 20N·m, query the correspondence table between the vehicle unstable coefficient difference and the correction value of the initial regenerative braking force, it can be determined that when the vehicle unstable coefficient difference is 3, the corresponding correction value of the initial regenerative braking force is 5. Since the vehicle unstable coefficient difference is large, it is necessary to appropriately increase the initial regenerative braking force. Therefore, the corresponding maximum regenerative braking force is 25N·m.

[0060] In step S103 , braking and energy recovery are performed using the maximum regenerative braking force that can maintain vehicle body stability.

[0061] It can be understood that the embodiment of the present application utilizes the maximum regenerative braking force that can maintain vehicle body stability for braking and energy recovery, which can maintain vehicle body stability while recovering energy to the greatest extent, taking into account both vehicle body stability and energy recovery efficiency.

[0062] In an embodiment of the present application, after braking and energy recovery are performed using the maximum regenerative braking force that can maintain vehicle body stability, it also includes: detecting the required braking force of the vehicle; if the maximum regenerative braking force is less than the required braking force, controlling the braking mechanism of each wheel to output a target braking force to compensate for the difference between the required braking force of the vehicle and the maximum regenerative braking force.

[0063] It can be understood that the embodiment of the present application can evenly distribute the required compensation braking force to each wheel when it is detected that the maximum regenerative braking force is less than the required braking force, so as to control the braking mechanism of each wheel to output the target braking force to compensate for the insufficient braking force required by the vehicle, so as to achieve braking of the vehicle.

[0064] In an embodiment of the present application, controlling the brake mechanism of each wheel to output a target braking force includes: obtaining the current braking force of each wheel; and controlling the caliper motor in the corresponding brake mechanism to output a target current according to the current braking force and the corresponding target braking force.

[0065] It can be understood that the embodiment of the present application can control the target current output by the caliper motor according to the target braking force and the corresponding current braking force, wherein when the target braking force is greater than the current braking force, the target current is increased; when the target braking force is less than the current braking force, the target current is reduced.

[0066] It should be noted that before controlling the braking mechanism of each wheel to output the target braking force, the target braking force of each wheel can be calculated based on the caliper motor in different states, such as when each caliper motor is in a normal state or when one or more caliper motors fail. Among them, when it is identified that the steering wheel always deviates to one side or the brake disc shakes as a whole when the vehicle brakes, it can be determined that the caliper motor has failed without specific limitation.

[0067] As a possible implementation method, before controlling the braking mechanism of each wheel to output the target braking force, it also includes: inputting the required braking force during vehicle energy recovery, the maximum regenerative braking force and the slip rate of each wheel into a closed-loop processing model, and the closed-loop processing model outputs the target braking force of the corresponding wheel.

[0068] It is understandable that the embodiments of the present application can process data based on the closed-loop processing algorithm in the closed-loop processing model to calculate the target braking force of the corresponding wheel, so as to facilitate the subsequent control of the braking force of each wheel.

[0069] Specifically, when it is identified that any caliper motor has not failed, the vehicle unstable state coefficient, the required braking force, the braking force difference between the required braking force and the maximum regenerative braking force of the vehicle, the maximum regenerative braking force and other signals are input into the closed-loop processing model, and the target braking force of each wheel is output, as follows:

[0070] (1) When the vehicle meets the requirements for braking energy recovery, if the maximum regenerative braking force of the braking energy recovery is greater than or equal to the required braking force of the vehicle, and the vehicle unstable state coefficient is less than the coefficient threshold, the maximum regenerative braking force is used for energy recovery and braking;

[0071] (2) If the maximum regenerative braking force of the braking energy recovery is greater than or equal to the required braking force of the vehicle, but when the vehicle unstable state coefficient is greater than or equal to the coefficient threshold, the maximum regenerative braking force is corrected using the vehicle unstable state coefficient, and the corrected maximum regenerative braking force is used for energy recovery and braking;

[0072] (3) If the maximum regenerative braking force of the braking energy recovery is less than the required braking force of the vehicle, the required braking force of the vehicle is composed of the maximum regenerative braking force and the target braking force of each wheel. When the vehicle unstable state coefficient is less than the coefficient threshold, the maximum regenerative braking force will not change with the change of the vehicle unstable state coefficient. The target braking force of each wheel is calculated by the braking force difference between the required braking force of the vehicle and the maximum regenerative braking force;

[0073] (4) If the maximum regenerative braking force of the brake energy recovery is less than the required braking force of the vehicle, when the vehicle unstable state coefficient is greater than or equal to the coefficient threshold, the maximum regenerative braking force will change according to the change of the vehicle unstable state coefficient (the maximum regenerative braking force will decrease when the vehicle unstable state coefficient increases; the maximum regenerative braking force will increase when the vehicle unstable state coefficient decreases), and its change value will be compensated by the target braking force of each wheel, that is, the target braking force of each wheel is calculated by the braking force difference between the required braking force of the vehicle and the maximum regenerative braking force.

[0074] As another possible implementation method, before controlling the braking mechanism of each wheel to output the target braking force, it also includes: identifying whether there is a wheel with a failed caliper motor; when at least one caliper motor failure is identified, the required braking force for vehicle energy recovery, the maximum regenerative braking force, and the slip rate of each non-failed caliper motor corresponding to the wheel are input into a closed-loop processing model, and the closed-loop processing model outputs the target braking force of each non-failed caliper motor corresponding to the wheel.

[0075] It can be understood that when the caliper motor fails, the embodiment of the present application can input the required braking force for vehicle energy recovery, the maximum regenerative braking force, and the slip rate of each non-failed caliper motor corresponding to the wheel into a closed-loop processing model according to actual conditions, thereby calculating the target braking force of each non-failed caliper motor corresponding to the wheel, so that the subsequent braking mechanism can output the corresponding target braking force.

[0076] It should be noted that, when the caliper motor of one of the vehicle's wheels fails, the target braking force of the wheel corresponding to the failed caliper motor can be calculated based on the slip rate of the non-failed wheel and the driver's requested braking force; in addition, when the braking force of the vehicle's caliper motor is insufficient, current compensation of the non-failed wheel can be performed based on the target yaw angular velocity and the actual yaw angular velocity, so that the caliper motor can generate the target braking force.

[0077] Specifically, when it is detected that the steering wheel always deflects to one side or the brake disc shakes as a whole when the vehicle brakes, it can be determined that the caliper motor has failed. When any caliper motor failure is detected, the vehicle's unstable state coefficient, required braking force, braking force difference, maximum regenerative braking force, current braking force of each wheel, vehicle speed, steering wheel angle, yaw rate and other signals are input into the closed-loop processing model to output the target braking force of each wheel, including the following situations:

[0078] (1) When the steering wheel angle is constant, the target braking force is sufficient to make the vehicle produce a certain actual yaw velocity but will not produce a longitudinal slip rate; the closed-loop processing model calculates the target yaw velocity based on the steering wheel angle, yaw velocity, and vehicle speed input signals; when the actual yaw velocity is greater than the target yaw velocity, the difference between the actual yaw velocity and the target yaw velocity is used as the control variable to calculate the target braking force of the wheel corresponding to the non-failure caliper motor.

[0079] Specifically, in order to avoid the problem of inaccuracy in the target yaw rate calculation when the vehicle is in an unstable state, the embodiment of the present application obtains the steering wheel angle value after deviation compensation, the current vehicle speed, the characteristic vehicle speed, the wheelbase and the steering between the steering wheel angle and the wheel angle during the specific calculation, and calculates the target yaw rate based on the steering wheel angle value after deviation compensation, the current vehicle speed, the characteristic vehicle speed, the wheelbase and the steering between the steering wheel angle and the wheel angle, thereby improving the accuracy of the target yaw angle calculation, and the calculation method of the embodiment of the present application can also be applied to the calculation of the target yaw rate in a stable state, with better applicability. Among them, the formula for the target yaw rate is as follows:

[0080]

[0081] Among them, w is the target yaw rate, a is the steering wheel angle value after deviation compensation, V1 is the current vehicle speed, V2 is the characteristic vehicle speed, l is the wheelbase, and α is the steering ratio between the steering wheel angle and the wheel angle, i.e. the steering characteristic. Among them, the characteristic vehicle speed is a parameter used to describe the understeering characteristics of the vehicle. When the vehicle speed reaches the preset value, the vehicle steady-state angular velocity gain (the ratio of the yaw rate to the front wheel angle, also known as steering sensitivity) reaches the maximum value.

[0082] (2) When the steering wheel angle is constant, the target braking force can generate a longitudinal slip rate, regardless of whether the vehicle generates a yaw angular velocity. At this time, the closed-loop processing model calculates the target braking force of the wheel corresponding to the non-failed caliper motor based on the required braking force during vehicle energy recovery, the maximum regenerative braking force, and the slip rate of each wheel corresponding to the non-failed caliper motor.

[0083] In an embodiment of the present application, a closed-loop processing model performs data processing using a closed-loop processing algorithm, wherein the closed-loop processing algorithm includes: obtaining a braking force difference between a required braking force and a maximum regenerative braking force; if the actual yaw velocity of the vehicle is not detected and the slip rate is not a longitudinal slip rate, using the braking force difference as a target braking force; if the actual yaw velocity of the vehicle is detected and the slip rate is not a longitudinal slip rate, calculating the target braking force based on the angular velocity difference between the actual yaw velocity and the target yaw velocity and the braking force difference, otherwise calculating the target braking force based on the braking force difference and the longitudinal slip rate.

[0084] It is understandable that the embodiment of the present application can process data based on the closed-loop processing algorithm in the closed-loop processing model, so as to calculate the target braking force according to the actual situation, so as to facilitate the subsequent control of the braking force of each wheel.

[0085] Specifically, the embodiment of the present application may also correct the target braking force in combination with the yaw rate and / or the longitudinal slip rate, for example:

[0086] (1) when the actual yaw angular velocity is greater than the target yaw angular velocity, obtaining an angular velocity difference between the actual yaw angular velocity and the target yaw angular velocity; and calculating a target braking force of the corresponding wheel according to the braking force difference and the angular velocity difference;

[0087] The actual yaw rate has positive and negative signs, so the vehicle body posture can be determined based on the positive and negative signs of the actual yaw rate. For example, a positive actual yaw rate is pre-calibrated to indicate a tilt to the left, and a negative actual yaw rate is pre-calibrated to indicate a tilt to the right, etc. This can be specifically calibrated.

[0088] Therefore, the embodiment of the present application can pre-calibrate the corresponding relationship between the angular velocity difference and the braking force difference. For example, when the angular velocity difference is A, the corresponding correction value of the braking force difference is aN·m, and the target braking force of the wheel on each side can be determined according to the positive or negative actual yaw angular velocity.

[0089] For example, when the left tilt needs to be corrected, the braking force difference of the left and right wheels can be determined according to the angular velocity difference, that is, by assigning different target braking forces to the wheels on both sides, the body can be kept stable; assuming that the driver's requested braking force is 100N·m and the braking difference is 10N·m, the target braking force of the left wheel can be 90N·m, the target braking force of the right wheel can be 100N·m, and so on; of course, the braking force of the left wheel can also be appropriately reduced to avoid the wheel braking affecting the body stability correction. For example, the target braking force of the left wheel can be 88N·m, and the target braking force of the right wheel can be 98N·m, and so on.

[0090] (2) The target braking force is corrected according to the longitudinal slip ratio. For example, the larger the longitudinal slip ratio, the lower the wheel lateral force adhesion coefficient, so the corresponding target braking force needs to be smaller to avoid skidding; the smaller the longitudinal slip ratio, the higher the wheel lateral force adhesion coefficient, so the corresponding target braking force can be larger. Therefore, the embodiment of the present application can determine the correction amount of the braking force difference according to the longitudinal slip ratio, and calculate the target braking force according to the correction amount and the braking force difference.

[0091] For example, when the current slip rate is detected to be the longitudinal slip rate and the longitudinal slip rate is 30%, the wheel lateral force adhesion coefficient is low, and the target braking force needs to be appropriately reduced. According to the correction amount correspondence table of the longitudinal slip rate and the braking force difference, the correction amount of the braking force difference can be determined. For example, by looking up the correspondence table, it can be determined that the correction amount corresponding to the longitudinal slip rate of 30% is 5, and when the braking force difference is 20N, the corresponding target braking force is 15N.

[0092] In an embodiment of the present application, when any caliper motor failure is identified, it also includes: obtaining the number and location of caliper motor failures; matching the target speed limit of the vehicle according to the number and / or location of caliper motor failures; and limiting the maximum speed of the vehicle to within the target speed limit.

[0093] It can be understood that the embodiments of the present application can limit the speed of the vehicle according to actual conditions when any caliper motor fails, so that the speed of the vehicle is within a safe range, thereby improving the safety of the vehicle.

[0094] Specifically, the number of failed caliper motors of the vehicle is identified. When any one caliper motor is identified as failed, the speed limit is any speed within the first speed range, such as 60kph; when any two caliper motors are identified as failed, the speed limit is any speed within the second speed range, such as 10kph, and the maximum value within the second speed range is less than the minimum value within the first speed range; when any three caliper motors are identified as failed, the vehicle will brake with the only remaining caliper motor or assist in braking to a stop through motor energy recovery, and cut off the power in time after stopping to improve the safety of the vehicle.

[0095] It should be noted that when any caliper motor failure is identified, the corresponding speed limit reminder can be displayed on the vehicle's display screen based on the actual condition of the caliper motor of each wheel of the vehicle, and / or the speed limit reminder can be voice broadcast, such as: "There is an abnormal braking situation, and the speed needs to be reduced to 60kph" or "There is an abnormal braking situation, please pull over" and other prompt messages, without specific limitation here.

[0096] In summary, the embodiments of the present application can determine the maximum regenerative braking force that can maintain the stability of the vehicle body when the vehicle recovers energy according to the vehicle's unstable state coefficient, and use the maximum regenerative braking force that can maintain the stability of the vehicle body for braking and energy recovery. It can maintain the stability of the vehicle body while recovering energy to the greatest extent, taking into account the efficiency of vehicle body stability and energy recovery, and improving the user experience.

[0097] Figure 2 It is a structural schematic diagram of an energy recovery device provided in an embodiment of the present application.

[0098] For example, Figure 2 As shown, the device may include: an acquisition module 100 , a determination module 200 and a processing module 300 .

[0099] Among them, the acquisition module 100 is used to obtain the vehicle's unstable state coefficient during vehicle energy recovery; the determination module 200 is used to determine the maximum regenerative braking force that can maintain the stability of the vehicle body during vehicle energy recovery based on the vehicle's unstable state coefficient; the processing module 300 is used to use the maximum regenerative braking force that can maintain the stability of the vehicle body for braking and energy recovery.

[0100] In an embodiment of the present application, the determination module 200 is further used to: obtain the initial regenerative braking force during vehicle energy recovery; if the vehicle's unstable state coefficient is less than the coefficient threshold, the initial regenerative braking force is used as the maximum regenerative braking force; if the vehicle's unstable state coefficient is greater than or equal to the coefficient threshold, the initial regenerative braking force is corrected according to the vehicle's unstable state coefficient to obtain the maximum regenerative braking force.

[0101] In an embodiment of the present application, the acquisition module 100 is further used to: obtain one or more of the lateral acceleration of the vehicle during energy recovery, the trigger state of the vehicle dynamic control system, and the trigger state of the anti-lock braking system; obtain the vehicle unstable state coefficient based on one or more of the lateral acceleration, the trigger state of the vehicle dynamic control system, and the trigger state of the anti-lock braking system.

[0102] In the embodiment of the present application, the processing module 300 is further used to: obtain the required braking force of the vehicle; if the maximum regenerative braking force is less than the required braking force, control the braking mechanism of each wheel to output the target braking force to compensate for the difference between the required braking force and the maximum regenerative braking force of the vehicle.

[0103] In the embodiment of the present application, the processing module 300 is further used to: obtain the current braking force of each wheel; and control the output target current of the caliper motor in the corresponding brake mechanism according to the current braking force and the corresponding target braking force.

[0104] In the embodiment of the present application, the processing module 300 is further used to: input the required braking force, maximum regenerative braking force and slip rate of each wheel during vehicle energy recovery into a closed-loop processing model, and the closed-loop processing model outputs the target braking force of the corresponding wheel.

[0105] In an embodiment of the present application, the processing module 300 is further used to: identify whether the caliper motor of each wheel has failed; when it is identified that at least one caliper motor has failed, the required braking force for vehicle energy recovery, the maximum regenerative braking force, and the slip rate of each non-failed caliper motor corresponding to the wheel are input into a closed-loop processing model, and the closed-loop processing model outputs the target braking force of each non-failed caliper motor corresponding to the wheel.

[0106] In an embodiment of the present application, the closed-loop processing model uses a closed-loop processing algorithm to perform data processing, wherein the closed-loop processing algorithm includes: obtaining the braking force difference between the required braking force and the maximum regenerative braking force; if the actual yaw velocity of the vehicle is not detected and the slip rate is not the longitudinal slip rate, using the braking force difference as the target braking force; if the actual yaw velocity of the vehicle is detected and the slip rate is not the longitudinal slip rate, calculating the target braking force based on the angular velocity difference between the actual yaw velocity and the target yaw velocity and the braking force difference, otherwise calculating the target braking force based on the braking force difference and the longitudinal slip rate.

[0107] In summary, the embodiments of the present application can determine the maximum regenerative braking force that can maintain the stability of the vehicle body when the vehicle recovers energy according to the vehicle's unstable state coefficient, and use the maximum regenerative braking force that can maintain the stability of the vehicle body for braking and energy recovery. It can maintain the stability of the vehicle body while recovering energy to the greatest extent, taking into account the efficiency of vehicle body stability and energy recovery, and improving the user experience.

[0108] Figure 3 A schematic diagram of the structure of a vehicle provided in an embodiment of the present application. The vehicle may include:

[0109] A memory 301 , a processor 302 , and a computer program stored in the memory 301 and executable on the processor 302 .

[0110] When the processor 302 executes the program, the braking control method provided in the above embodiment is implemented.

[0111] Furthermore, the vehicle also includes:

[0112] The communication interface 303 is used for communication between the memory 301 and the processor 302 .

[0113] The memory 301 is used to store computer programs that can be run on the processor 302 .

[0114] The memory 301 may include a high-speed RAM (Random Access Memory) memory, and may also include a non-volatile memory, such as at least one disk memory.

[0115] If the memory 301, the processor 302 and the communication interface 303 are implemented independently, the communication interface 303, the memory 301 and the processor 302 can be connected to each other through a bus and communicate with each other. The bus can be an ISA (Industry Standard Architecture) bus, a PCI (Peripheral Component Interconnect) bus or an EISA (Extended Industry Standard Architecture) bus, etc. The bus can be divided into an address bus, a data bus, a control bus, etc. For ease of representation, Figure 3 Only one thick line is used in the diagram, but this does not mean that there is only one bus or only one type of bus.

[0116] Optionally, in a specific implementation, if the memory 301, the processor 302 and the communication interface 303 are integrated on a chip, the memory 301, the processor 302 and the communication interface 303 can communicate with each other through an internal interface.

[0117] The processor 302 may be a CPU (Central Processing Unit), or an ASIC (Application Specific Integrated Circuit), or one or more integrated circuits configured to implement the embodiments of the present application.

[0118] This embodiment also provides a computer-readable storage medium, in which a computer program code is stored. When the computer program code is executed on a computer, the computer executes the above-mentioned related method steps to implement an energy recovery method provided by the above-mentioned embodiment.

[0119] Among them, the device, computer-readable storage medium, computer program product or chip provided in this embodiment is used to execute the corresponding method provided above. Therefore, the beneficial effects that can be achieved can refer to the beneficial effects in the corresponding method provided above, and will not be repeated here.

[0120] Through the description of the above implementation methods, technical personnel in the relevant field can understand that for the convenience and simplicity of description, only the division of the above-mentioned functional modules is used as an example. In actual applications, the above-mentioned functions can be assigned to different functional modules as needed, that is, the internal structure of the device can be divided into different functional modules to complete all or part of the functions described above.

[0121] In the embodiments provided in the present application, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic, for example, the division of modules or units is only a logical function division, and there may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another device, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0122] The above contents are only specific implementation methods of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. An energy recovery method, in which a vehicle independently controls each wheel based on an electronic mechanical braking system, characterized in that: The method comprises: Obtaining the vehicle non-steady state coefficient when the vehicle recovers energy; Determining, according to the vehicle unstable state coefficient, a maximum regenerative braking force that can maintain vehicle body stability when the vehicle recovers energy; The maximum regenerative braking force capable of maintaining vehicle body stability is utilized for braking and energy recovery.

2. The method according to claim 1, characterized in that The determining, according to the vehicle unstable state coefficient, the maximum regenerative braking force that can maintain vehicle body stability during vehicle energy recovery includes: Obtaining the initial regenerative braking force when the vehicle recovers energy; If the vehicle unstable state coefficient is less than a coefficient threshold, the initial regenerative braking force is used as the maximum regenerative braking force; If the vehicle unstable state coefficient is greater than or equal to a coefficient threshold, the initial regenerative braking force is corrected according to the vehicle unstable state coefficient to obtain the maximum regenerative braking force.

3. The method according to claim 1, characterized in that The obtaining of the vehicle non-stable state coefficient during vehicle energy recovery includes: Obtaining one or more of the lateral acceleration of the vehicle during energy recovery, the triggering state of the vehicle dynamic control system, and the triggering state of the anti-lock braking system; The vehicle unstable state coefficient is obtained according to one or more of the lateral acceleration, the vehicle dynamic control system triggering state and the anti-lock braking system triggering state.

4. The method according to claim 1, characterized in that: After braking and recovering energy using the maximum regenerative braking force capable of maintaining vehicle stability, the method further includes: detecting a required braking force of the vehicle; If the maximum regenerative braking force is less than the required braking force, the braking mechanism of each wheel is controlled to output a target braking force to compensate for the difference between the required braking force of the vehicle and the maximum regenerative braking force.

5. The method according to claim 4, characterized in that The step of controlling the brake mechanism of each wheel to output a target braking force comprises: Obtaining the current braking force of each wheel; The caliper motor in the corresponding brake mechanism is controlled to output a target current according to the current braking force of each wheel and the corresponding target braking force.

6. The method according to claim 4, characterized in that Before controlling the brake mechanism of each wheel to output the target braking force, the method further includes: The required braking force, the maximum regenerative braking force and the slip ratio of each wheel during vehicle energy recovery are input into a closed-loop processing model, and the closed-loop processing model outputs a target braking force for the corresponding wheel.

7. The method according to claim 4, characterized in that Before controlling the brake mechanism of each wheel to output the target braking force, the method further includes: Identifying whether a caliper motor of each wheel fails; When at least one caliper motor failure is identified, the required braking force for vehicle energy recovery, the maximum regenerative braking force, and the slip rate of the wheel corresponding to each non-failed caliper motor are input into a closed-loop processing model, and the closed-loop processing model outputs the target braking force of each wheel corresponding to the non-failed caliper motor.

8. The method according to claim 6 or 7, characterized in that: The closed-loop processing model performs data processing using a closed-loop processing algorithm, wherein the closed-loop processing algorithm includes: obtaining a braking force difference between the required braking force and the maximum regenerative braking force; If the actual yaw rate of the vehicle is not detected and the slip rate is not the longitudinal slip rate, taking the braking force difference as the target braking force; If the actual yaw rate of the vehicle is detected and the slip rate is not the longitudinal slip rate, the target braking force is calculated according to the angular velocity difference between the actual yaw rate and the target yaw rate and the braking force difference; otherwise, the target braking force is calculated according to the braking force difference and the longitudinal slip rate.

9. A vehicle, characterized in that: The vehicle comprises: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the energy recovery method according to any one of claims 1 to 8.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, and when the computer program is executed, the energy recovery method according to any one of claims 1 to 8 is implemented.

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