Energy recovery method, vehicle, and storage medium

Abstract

The application provides an energy recovery method, a vehicle and a storage medium, and belongs to the field of vehicles. The method comprises the following steps: acquiring a vehicle unstable state coefficient when the vehicle recovers energy; determining a maximum regenerative braking force that can keep the vehicle body stable when the vehicle recovers energy according to the vehicle unstable state coefficient; and braking and recovering energy by using the maximum regenerative braking force that can keep the vehicle body stable. According to the method, the maximum regenerative braking force that can keep the vehicle body stable when the vehicle recovers energy can be determined according to the vehicle unstable state coefficient, and the braking and energy recovery are performed by using the maximum regenerative braking force that can keep the vehicle body stable. In this way, the energy recovery can be maximized while keeping the vehicle body stable, and the efficiency of the vehicle body stability and the energy recovery is considered.

Description

Technical Field

[0001] This application relates to the field of vehicles, and more specifically, to an energy recovery method, vehicle, and storage medium in the field of brake-by-wire chassis vehicles. Background Technology

[0002] The brake energy recovery system mainly recovers excess energy released by the vehicle during braking or coasting when the driver presses the brake pedal or when both the accelerator and brake pedals are released. This energy is then converted into electrical energy by a generator and stored in the battery for subsequent vehicle driving, greatly reducing resource waste.

[0003] Most of the regenerative braking systems in related technologies can only recover a certain amount of energy, resulting in excessive energy loss. Furthermore, when the vehicle is performing regenerative braking, pressing the brake pedal will engage the regenerative braking system. However, when the regenerative braking system disengages, it can easily cause a sudden change in the torque of the regenerative braking system, resulting in a jerky feeling in the vehicle, poor stability, poor control, and a poor user experience. Summary of the Invention

[0004] This application provides an energy recovery method, a vehicle, and a storage medium. The method can utilize the maximum regenerative braking force that can maintain vehicle stability for braking and energy recovery, thereby maintaining vehicle stability while maximizing energy recovery, balancing vehicle stability and energy recovery efficiency, and improving the user experience.

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

[0006] The above technical solution can determine the maximum regenerative braking force that can maintain vehicle stability during energy recovery based on the vehicle's instability coefficient. By utilizing the maximum regenerative braking force that can maintain vehicle stability for braking and energy recovery, the vehicle can maintain stability while maximizing energy recovery, thus balancing vehicle stability and energy recovery efficiency and improving the user experience.

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

[0008] The above technical solution can obtain the maximum regenerative braking force that can maintain vehicle stability based on the magnitude of the vehicle's instability coefficient, so that the maximum regenerative braking force that can maintain vehicle stability can be used for braking and energy recovery in the future.

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

[0010] The above technical solution can obtain the vehicle's instability coefficient based on the vehicle's actual state, so as to determine the maximum regenerative braking force that can keep the vehicle body stable during energy recovery based on the vehicle's instability coefficient.

[0011] In combination with the first aspect and the above implementation, in some possible implementations, after braking and energy recovery using the maximum regenerative braking force that can maintain vehicle stability, the method further 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] The above technical solution enables the braking mechanism of each wheel to output the target braking force to compensate for the insufficient braking force required by the vehicle when the maximum regenerative braking force is less than the required braking force, thereby achieving vehicle braking.

[0013] In combination with the first aspect and the above implementation methods, in some possible implementation methods, the step of controlling the braking mechanism of each wheel to output the target braking force includes: acquiring the current braking force of each wheel; and controlling the caliper motor in the corresponding braking mechanism to output the target current based on the current braking force of each wheel and the corresponding target braking force.

[0014] The above technical solution can control the output target current of the caliper motor 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 implementation methods, in some possible implementation methods, before controlling the braking mechanism of each wheel to output the target braking force, the method further includes: inputting the required braking force, the maximum regenerative braking force and the slip ratio of each wheel into a closed-loop processing model, wherein the closed-loop processing model outputs the target braking force of the corresponding wheel.

[0016] The above technical solution enables data processing based on the closed-loop processing algorithm in the closed-loop processing model, thereby calculating the target braking force for each vehicle, so as to facilitate subsequent control of the braking force of each wheel.

[0017] In combination with the first aspect and the above 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, the method further includes: identifying whether the caliper motor of each wheel has failed; when at least one caliper motor failure is identified, inputting the required braking force for vehicle energy recovery, the maximum regenerative braking force, and the slip ratio of the wheel corresponding to each non-failed caliper motor into a closed-loop processing model, wherein the closed-loop processing model outputs the target braking force of the wheel corresponding to each non-failed caliper motor.

[0018] The above technical solution enables the input of the required braking force, maximum regenerative braking force, and slip ratio of the wheel corresponding to each non-failed caliper motor into the closed-loop processing model when the caliper motor fails, based on the actual situation. This allows the calculation of the target braking force for the wheel corresponding to each non-failed caliper motor, so that the subsequent braking mechanism can output the corresponding target braking force.

[0019] In conjunction with the first aspect and the above implementation methods, in some possible implementation methods, the closed-loop processing model utilizes a closed-loop processing algorithm for data processing. 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 rate of the vehicle is not detected and the slip ratio is not a longitudinal slip ratio, using the braking force difference as the target braking force; if the actual yaw rate of the vehicle is detected and the slip ratio is not a longitudinal slip ratio, calculating the target braking force based on the angular velocity difference between the actual yaw rate and the target yaw rate and the braking force difference; otherwise, calculating the target braking force based on the braking force difference and the longitudinal slip ratio.

[0020] The above technical solution enables data processing based on the closed-loop processing algorithm in the closed-loop processing model, thereby calculating the target braking force according to the actual situation, so as to facilitate the subsequent control of the braking force of each wheel.

[0021] Secondly, an energy recovery device is provided, comprising: an acquisition module for acquiring the vehicle instability coefficient during energy recovery; a determination module for determining the maximum regenerative braking force that can maintain vehicle stability during energy recovery based on the vehicle instability coefficient; and a processing module for performing braking and energy recovery using the maximum regenerative braking force that can maintain vehicle stability.

[0022] Thirdly, a vehicle is provided, the vehicle comprising: a memory, a processor, and a computer program stored in the memory and executable on the processor, the processor executing the program to implement the energy recovery method as described in the above embodiments.

[0023] Fourthly, a computer-readable storage medium is provided that stores computer program code, which, when executed on a computer, causes the computer to perform the energy recovery method described in the first aspect or any possible implementation thereof. Attached Figure Description

[0024] Figure 1 This is a flowchart of the energy recovery method provided in the embodiments of this application;

[0025] Figure 2 This is a block diagram of the energy recovery device provided in the embodiments of this application;

[0026] Figure 3 This is a schematic diagram of the vehicle structure provided in the embodiments of this application. Detailed Implementation

[0027] The technical solutions in this application will be clearly and thoroughly described below with reference to the accompanying drawings. In the description of the embodiments of this application, unless otherwise stated, " / " means "or," for example, A / B can mean A or B. "And / or" in the text is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Furthermore, in the description of the embodiments of this application, "multiple" refers to two or more than two.

[0028] Hereinafter, the terms "first" and "second" are used for descriptive purposes only and should not be construed as implying or suggesting 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 that feature.

[0029] The following will combine Figure 1 The energy recovery methods are described in detail.

[0030] Figure 1 This is a flowchart of an energy recovery method provided in an embodiment of this application.

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

[0032] In step S101, the vehicle instability coefficient during vehicle energy recovery is obtained.

[0033] It is understandable that since vehicle instability may occur during energy recovery, and the vehicle instability coefficient is formed based on the importance of the factors affecting vehicle stability, the instability coefficient includes but is not limited to lateral acceleration, VDC (Vdc vehicle running dynamic control system) triggering state and ABS (Antilock Brake System) triggering state. Therefore, the embodiments of this application can obtain the vehicle instability coefficient when energy recovery is triggered.

[0034] It should be noted that the chassis structure of the vehicle in this embodiment mainly includes four EMB (Electromechanical Brake System) actuators, which can independently control the four wheels. The EMB is an actuator driven by a caliper motor and installed on the caliper of the braking mechanism. It is a device that brakes the vehicle directly using the braking mechanism without the need for brake fluid or other media. The EMB replaces the traditional hydraulic brake for the main braking, and its application range is expanded.

[0035] In this embodiment of the application, obtaining the vehicle instability 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; and obtaining the vehicle instability coefficient based on one or more of the lateral acceleration, VDC trigger state, and ABS trigger state.

[0036] It is understood that in this embodiment of the application, the vehicle instability coefficient can be obtained according to the actual state of the vehicle, so as to determine the maximum regenerative braking force that can keep the vehicle body stable during energy recovery based on the vehicle instability coefficient.

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

[0038] (1) The method for obtaining the vehicle's instability coefficient based on lateral acceleration is as follows:

[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 combine the vehicle's instability state coefficient to correct the vehicle's energy recovery capability and 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 instability state coefficient. The slope of the first curve is s. The first curve decreases according to time and slope s. The vehicle instability state coefficient can be obtained by identifying the first curve. The maximum value of the first curve is the first preset coefficient, which 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 at a slope t. The vehicle instability coefficient is allowed to recover to the first preset coefficient only when the threshold u is reached. The slope of the vehicle instability coefficient recovery is v. Thus, the vehicle instability coefficient can be recovered with a delay through the first counter, avoiding frequent fluctuations in the stability factor caused by changes in lateral acceleration and improving the stability of vehicle control. Here, w, s, t, u, and v are all matching parameters.

[0041] (2) The method for obtaining the vehicle instability coefficient based on the VDC trigger state is as follows:

[0042] When the VDC function is triggered, it indicates that the vehicle is at risk of instability. Therefore, it is necessary to adjust the vehicle's energy recovery capability in conjunction with the vehicle's instability coefficient to avoid 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 instability coefficient. The slope of the second curve is e. The second curve decreases according to time and slope e. The vehicle instability 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 disabled, the second counter is controlled to increase at a slope g. The vehicle instability coefficient is only allowed to recover to the second preset coefficient when the threshold h is reached. The slope of the vehicle instability coefficient recovery is f. Thus, the vehicle instability coefficient can be recovered with a delay through the second counter, avoiding frequent fluctuations in the stability factor caused by the VDC function triggering and improving the stability of vehicle control. Here, e, f, g, and h are all matching parameters.

[0044] (3) The method for obtaining the vehicle instability coefficient based on the ABS trigger state is as follows:

[0045] When the ABS function is triggered, it indicates that the vehicle is at risk of instability. Therefore, it is necessary to adjust the vehicle's energy recovery capability in conjunction with the vehicle's instability coefficient to avoid instability. At this time, a pre-calibrated third curve can be obtained. The third curve is calibrated based on the ABS function trigger state and the corresponding vehicle instability coefficient. The slope of the third curve is 'a'. The third curve decreases according to time and slope 'a'. By identifying the third curve, the vehicle instability coefficient can be obtained. 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 deactivated, the third counter is controlled to increase at a slope c. The vehicle instability coefficient is only allowed to recover to the third preset coefficient when it reaches a threshold d. The slope of the vehicle instability coefficient recovery is b. This delay in recovering the vehicle instability coefficient through the third counter avoids frequent fluctuations in the stability factor caused by the ABS function triggering, thus improving the stability of vehicle control. Here, a, b, c, and d are all matching parameters.

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

[0048] In step S102, the maximum regenerative braking force that can maintain vehicle stability during energy recovery is determined based on the vehicle instability coefficient.

[0049] It is understood that since different vehicle instability coefficients correspond to different vehicle stability states, the braking force required to stabilize the vehicle body is different. In this application embodiment, the maximum braking force to maintain vehicle body stability can be determined based on the vehicle instability coefficient, and used as the maximum regenerative braking force.

[0050] Specifically, regenerative braking converts some of the vehicle's kinetic energy into electrical energy during deceleration (braking or downhill driving). This converted electrical energy is stored in storage devices such as various batteries, supercapacitors, and high-speed flywheels, ultimately increasing the electric vehicle's driving range or preparing it for later acceleration. The regenerative braking system activates when the electric vehicle decelerates, cruises on a highway with the accelerator pedal released, or stops with the brake pedal pressed. During normal deceleration, the regenerative braking torque is generally maintained at maximum load. When the electric vehicle is cruising at high speed, its drive motor typically operates under constant power conditions, and the driving torque is inversely proportional to the drive motor's speed or the vehicle's speed.

[0051] In this embodiment of the application, determining the maximum regenerative braking force that can maintain vehicle stability during energy recovery based on the vehicle instability coefficient includes: obtaining the initial regenerative braking force during vehicle energy recovery; if the vehicle instability coefficient is less than a coefficient threshold, then using the initial regenerative braking force as the maximum regenerative braking force that can maintain vehicle stability; if the vehicle instability coefficient is greater than or equal to the coefficient threshold, then correcting the initial regenerative braking force based on the vehicle instability coefficient to obtain the maximum regenerative braking force that can maintain vehicle stability.

[0052] The coefficient threshold can be specifically calibrated and is not specifically limited. In this embodiment, the initial regenerative braking force can be determined based on the vehicle's required braking force and its maximum regenerative capacity. The minimum value of the braking force corresponding to the required braking force and the vehicle's maximum regenerative capacity is used as the initial regenerative braking force. The vehicle's required braking force is the braking force corresponding to the actual travel of the brake pedal when it is triggered, representing the braking force the driver expects the vehicle to generate. The formula for calculating the braking force corresponding to the maximum regenerative capacity is:

[0053] T = a × M × r,

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

[0055] It is understood that the embodiments of this application can determine the maximum regenerative braking force that can maintain the stability of the vehicle body based on the vehicle instability coefficient and the initial regenerative braking force, thereby taking into account the stability control of the vehicle body when performing energy recovery.

[0056] Specifically, due to differences in vehicle instability coefficients, such as when the vehicle body is unstable, the amount of energy recovered during regenerative braking varies. To avoid energy waste, the initial regenerative braking force can be adjusted based on the vehicle's instability coefficient to obtain the maximum regenerative braking force that can maintain vehicle stability. If the vehicle instability coefficient is less than a threshold, the initial regenerative braking force is used as the maximum regenerative braking force to maintain vehicle stability. If the vehicle instability coefficient is greater than or equal to the threshold, it indicates that the vehicle body is in an unstable state, and the initial regenerative braking force is adjusted based on the vehicle instability coefficient to obtain the maximum regenerative braking force that can maintain vehicle stability. For example:

[0057] When the vehicle instability coefficient is greater than the vehicle instability state coefficient threshold, the difference between the current vehicle instability coefficient and the vehicle instability state coefficient threshold is obtained. The correction value of the initial regenerative braking force is determined based on the difference of the vehicle instability state coefficient. The maximum regenerative braking force that can maintain vehicle stability is determined by correcting the initial regenerative braking force based on the vehicle instability state coefficient.

[0058] Therefore, in the embodiments of this application, the correspondence between the vehicle's instability coefficient difference and the correction value of the initial regenerative braking force can be pre-calibrated. For example, when the vehicle's instability coefficient difference is A, the corresponding correction value of the initial regenerative braking force can be obtained by querying the correspondence table, 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, if the vehicle instability coefficient calculated based on the above actual situation is 8, and the set threshold for the vehicle instability coefficient is 5, then the vehicle instability coefficient difference is 3. Assuming the initial regenerative braking force is 20 N·m, by consulting the correspondence table between the vehicle instability coefficient difference and the correction value of the initial regenerative braking force, it can be determined that when the vehicle instability coefficient difference is 3, the corresponding correction value of the initial regenerative braking force is 5. Since the vehicle instability coefficient difference is large, the initial regenerative braking force needs to be appropriately increased. Therefore, the corresponding maximum regenerative braking force is 25 N·m.

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

[0061] It is understood that the embodiments of this application utilize the maximum regenerative braking force that can maintain vehicle stability for braking and energy recovery, which can maintain vehicle stability while maximizing energy recovery, thus balancing the efficiency of vehicle stability and energy recovery.

[0062] In this embodiment of the application, after braking and energy recovery using the maximum regenerative braking force that can maintain vehicle stability, the method further includes: detecting the vehicle's required braking force; if the maximum regenerative braking force is less than the required braking force, controlling the braking mechanism of each wheel to output the target braking force to compensate for the difference between the vehicle's required braking force and the maximum regenerative braking force.

[0063] It is understood that, in the embodiments of this application, when the maximum regenerative braking force is detected to be less than the required braking force, the required compensation braking force is evenly distributed to each wheel, 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 this embodiment of the application, controlling the braking mechanism of each wheel to output a target braking force includes: acquiring the current braking force of each wheel; and controlling the caliper motor in the corresponding braking mechanism to output a target current based on the current braking force and the corresponding target braking force.

[0065] It is understood that, in the embodiments of this application, the target current output by the caliper motor can be controlled according to the target braking force and the corresponding current braking force. 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 decreased.

[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 normal state or when one or more caliper motors are in failure state. In particular, when it is detected that the steering wheel always turns to one side or the brake disc vibrates as a whole when the vehicle is braking, it can be determined that the caliper motor is in failure, without specific limitation.

[0067] As one possible approach, before controlling the braking mechanism of each wheel to output the target braking force, the following steps are also included: inputting the required braking force, the maximum regenerative braking force, and the slip ratio of each wheel into the closed-loop processing model, and the closed-loop processing model outputs the target braking force for the corresponding wheel.

[0068] It is understood that the embodiments of this application can process data based on the closed-loop processing algorithm in the closed-loop processing model, thereby calculating 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 detected that no caliper motor has failed, the vehicle's instability coefficient, required braking force, the difference between the vehicle's required braking force and the maximum regenerative braking force, and the maximum regenerative braking force are input into the closed-loop processing model, and the target braking force for each wheel is output, as follows:

[0070] (1) When the vehicle meets the requirements for regenerative braking, if the maximum regenerative braking force of the regenerative braking is greater than or equal to the required braking force of the vehicle, and the vehicle instability coefficient is less than the coefficient threshold, then 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 the vehicle instability coefficient is greater than or equal to the coefficient threshold, the maximum regenerative braking force is corrected by the vehicle instability 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 consists of two parts: the maximum regenerative braking force and the target braking force of each wheel. When the vehicle instability coefficient is less than the coefficient threshold, the maximum regenerative braking force will not change with the change of the vehicle instability coefficient. The target braking force of each wheel is calculated from the 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 braking energy recovery is less than the required braking force of the vehicle, when the vehicle's instability coefficient is greater than or equal to the coefficient threshold, the maximum regenerative braking force will change according to the change of the vehicle's instability coefficient (when the vehicle's instability coefficient increases, the maximum regenerative braking force decreases; when the vehicle's instability coefficient decreases, the maximum regenerative braking force increases). The change value is compensated by the target braking force of each wheel. That is, the target braking force of each wheel is calculated by the difference between the vehicle's required braking force and the maximum regenerative braking force.

[0074] As another possible approach, before controlling the braking mechanism of each wheel to output the target braking force, the following steps are also included: identifying whether there are wheels with caliper motor failures; 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 ratio of the wheel corresponding to each non-failed caliper motor are input into the closed-loop processing model, and the closed-loop processing model outputs the target braking force for the wheel corresponding to each non-failed caliper motor.

[0075] It is understood that, when the caliper motor fails, the required braking force, maximum regenerative braking force, and slip ratio of the wheel corresponding to each non-failed caliper motor are input into the closed-loop processing model according to the actual situation, thereby calculating the target braking force of the wheel corresponding to each non-failed caliper motor, 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 for the wheel corresponding to the failed caliper motor can be calculated based on the slip ratio 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 can be performed on the non-failed wheel based on the target yaw rate and the actual yaw rate, so that the caliper motor can generate the target braking force.

[0077] Specifically, if the system detects that the steering wheel consistently deflects to one side or the brake disc vibrates throughout the vehicle during braking, it can be determined that the caliper motor has failed. Upon detecting the failure of any caliper motor, the system inputs signals such as the vehicle's instability coefficient, required braking force, braking force difference, maximum regenerative braking force, current braking force of each wheel, vehicle speed, steering wheel angle, and yaw rate into the closed-loop processing model. The model then outputs the target braking force for each wheel, including the following cases:

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

[0079] Specifically, to avoid inaccuracies in calculating the target yaw rate when the vehicle is unstable, this embodiment of the application obtains the deviation-compensated steering wheel angle, current vehicle speed, characteristic vehicle speed, wheelbase, and the steering angle between the steering wheel angle and the wheel angle during the calculation. The target yaw rate is calculated based on these factors, thereby improving the accuracy of the target yaw rate calculation. Furthermore, the calculation method of this embodiment can also be applied to the calculation of the target yaw rate in a stable state, offering better applicability. The formula for the target yaw rate is as follows:

[0080]

[0081] Where 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. The characteristic vehicle speed is a parameter used to describe the vehicle's understeer characteristics. When the vehicle speed reaches a preset value, the vehicle's steady-state angular velocity gain (the ratio of yaw rate to front wheel angle, also known as steering sensitivity) reaches its maximum value.

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

[0083] In this embodiment of the application, the closed-loop processing model uses a closed-loop processing algorithm for data processing. 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 rate of the vehicle is not detected and the slip ratio is not the longitudinal slip ratio, the braking force difference is used as the target braking force; if the actual yaw rate of the vehicle is detected and the slip ratio is not the longitudinal slip ratio, the target braking force is calculated based on 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 based on the braking force difference and the longitudinal slip ratio.

[0084] It is understood that the embodiments of this application can process data based on the closed-loop processing algorithm in the closed-loop processing model, thereby calculating 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, embodiments of this application can also combine yaw rate and / or longitudinal slip ratio to correct the target braking force, for example:

[0086] (1) When the actual yaw rate is greater than the target yaw rate, obtain the angular velocity difference between the actual yaw rate and the target yaw rate; calculate the target braking force of the corresponding wheel based on the braking force difference and the angular velocity difference.

[0087] The actual yaw rate has positive and negative values, so the vehicle attitude can be determined based on the sign of the actual yaw rate. For example, a positive actual yaw rate can be pre-calibrated to indicate a tilt to the left, and a negative actual yaw rate can be pre-calibrated to indicate a tilt to the right, etc., which can be specifically calibrated.

[0088] Therefore, the correspondence between the angular velocity difference and the braking force difference can be pre-calibrated in the embodiments of this application. 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 each wheel can be determined according to the sign of the actual yaw rate.

[0089] For example, when a tilt to the left requires correction, the braking force difference between the left and right wheels can be determined based on the difference in angular velocity. That is, by assigning different target braking forces to the two wheels, the vehicle body can be kept stable. Assuming the driver requests a braking force of 100 N·m and the braking difference is 10 N·m, then the target braking force for the left wheel can be 90 N·m, and the target braking force for the right wheel can be 100 N·m, etc. Of course, the braking force of the left wheel can also be appropriately reduced to avoid the wheel stopping and affecting the vehicle body stability correction. For example, the target braking force for the left wheel can be 88 N·m, and the target braking force for the right wheel can be 98 N·m, etc.

[0090] (2) The target braking force is corrected based on the longitudinal slip ratio. For example, a larger longitudinal slip ratio indicates a lower wheel lateral force adhesion coefficient, so the corresponding target braking force needs to be smaller to avoid sideslip; a smaller longitudinal slip ratio indicates a higher wheel lateral force adhesion coefficient, so the corresponding target braking force can be larger. Therefore, in this embodiment, the correction amount of the braking force difference can be determined based on the longitudinal slip ratio, and the target braking force is calculated based on the correction amount and the braking force difference.

[0091] For example, when the detected slip ratio is longitudinal slip ratio and the longitudinal slip ratio is 30%, the wheel lateral force adhesion coefficient is low, requiring an appropriate reduction in the target braking force. Based on the correspondence table between the longitudinal slip ratio and the braking force difference, the correction amount for the braking force difference can be determined. For instance, by consulting the table, it can be determined that the correction amount corresponding to a longitudinal slip ratio of 30% is 5. When the braking force difference is 20N, the corresponding target braking force is 15N.

[0092] In this embodiment of the application, when any caliper motor failure is detected, the method further includes: obtaining the number and location of caliper motor failures; matching the target speed limit of the vehicle based on 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 is understood that the embodiments of this application can limit the vehicle speed according to the actual situation when any caliper motor fails, so that the vehicle speed reaches a safe range, thereby improving vehicle safety.

[0094] Specifically, the system identifies the number of caliper motor failures in the vehicle. When any one caliper motor fails, the vehicle speed is limited to any speed within a first speed range, such as 60 kph. When two caliper motors fail, the speed is limited to any speed within a second speed range, such as 10 kph, where the maximum value within the second speed range is less than the minimum value within the first speed range. When all three caliper motors fail, the vehicle will brake using only the remaining caliper motor or through regenerative braking to bring it to a complete stop. Power will be promptly cut off after the vehicle comes to a stop to improve vehicle safety.

[0095] It should be noted that when any caliper motor failure is detected, the system can also display corresponding speed limit reminders on the vehicle's display screen and / or issue voice prompts for speed limit reminders based on the actual condition of the caliper motors of each wheel of the vehicle. For example, it can display prompts such as "Braking malfunction, speed needs to be reduced to 60kph" or "Braking malfunction, please pull over." No specific limitations are made here.

[0096] In summary, the embodiments of this application can determine the maximum regenerative braking force that can maintain vehicle stability during energy recovery based on the vehicle's instability coefficient, and use the maximum regenerative braking force that can maintain vehicle stability for braking and energy recovery. This can maintain vehicle stability while maximizing energy recovery, balancing vehicle stability and energy recovery efficiency, and improving the user experience.

[0097] Figure 2 This is a schematic diagram of the structure of an energy recovery device provided in an embodiment of this application.

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

[0099] The acquisition module 100 is used to acquire the vehicle instability coefficient during energy recovery; the determination module 200 is used to determine the maximum regenerative braking force that can maintain vehicle stability during energy recovery based on the vehicle instability coefficient; and the processing module 300 is used to perform braking and energy recovery using the maximum regenerative braking force that can maintain vehicle stability.

[0100] In this embodiment of the application, the determining module 200 is further configured to: obtain the initial regenerative braking force when the vehicle recovers energy; if the vehicle instability coefficient is less than the coefficient threshold, then take the initial regenerative braking force as the maximum regenerative braking force; if the vehicle instability coefficient is greater than or equal to the coefficient threshold, then correct the initial regenerative braking force according to the vehicle instability coefficient to obtain the maximum regenerative braking force.

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

[0102] In this embodiment of the application, the processing module 300 is further configured 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 this embodiment, the processing module 300 is further configured to: obtain the current braking force of each wheel; and control the output target current of the caliper motor in the corresponding braking mechanism according to the current braking force and the corresponding target braking force.

[0104] In this embodiment, the processing module 300 is further configured to: input the required braking force, maximum regenerative braking force and slip ratio of each wheel into the closed-loop processing model, and the closed-loop processing model outputs the target braking force of the corresponding wheel.

[0105] In this embodiment of the application, the processing module 300 is further configured to: identify whether the caliper motor of each wheel has failed; when at least one caliper motor has failed, input the required braking force, the maximum regenerative braking force, and the slip ratio of the wheel corresponding to each non-failed caliper motor into the closed-loop processing model, and the closed-loop processing model outputs the target braking force of the wheel corresponding to each non-failed caliper motor.

[0106] In this embodiment, the closed-loop processing model uses a closed-loop processing algorithm for data processing. 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 rate of the vehicle is not detected and the slip ratio is not the longitudinal slip ratio, using the braking force difference as the target braking force; if the actual yaw rate of the vehicle is detected and the slip ratio is not the longitudinal slip ratio, calculating the target braking force based on the angular velocity difference between the actual yaw rate and the target yaw rate and the braking force difference; otherwise, calculating the target braking force based on the braking force difference and the longitudinal slip ratio.

[0107] In summary, the embodiments of this application can determine the maximum regenerative braking force that can maintain vehicle stability during energy recovery based on the vehicle's instability coefficient, and use the maximum regenerative braking force that can maintain vehicle stability for braking and energy recovery. This can maintain vehicle stability while maximizing energy recovery, balancing vehicle stability and energy recovery efficiency, and improving the user experience.

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

[0109] The memory 301, the processor 302, and the computer program stored on the memory 301 and capable of running on the processor 302.

[0110] When the processor 302 executes the program, it implements the braking control method provided in the above embodiments.

[0111] Furthermore, the vehicle also includes:

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

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

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

[0115] If the memory 301, processor 302, and communication interface 303 are implemented independently, then the communication interface 303, memory 301, and processor 302 can be interconnected via a bus to complete communication between them. 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 address bus, data bus, control bus, etc. For ease of representation, Figure 3 The bus is represented by a single thick line, but this does not mean that there is only one bus or one type of bus.

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

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

[0118] This embodiment also provides a computer-readable storage medium storing computer program code. When the computer program code is run on a computer, the computer executes the above-described related method steps to implement the energy recovery method provided in the above embodiment.

[0119] In this embodiment, the device, computer-readable storage medium, computer program product, or chip are all used to execute the corresponding methods provided above. Therefore, the beneficial effects they can achieve can be referred to the beneficial effects in the corresponding methods provided above, and will not be repeated here.

[0120] Through the above description of the embodiments, those skilled in the art will understand that, for the sake of convenience and brevity, only the division of the above functional modules is used as an example. In actual applications, the above 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 this application, it should be understood that the disclosed apparatus and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of modules or units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another device, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between devices or units may be electrical, mechanical, or other forms.

[0122] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. An energy recovery method, wherein a vehicle independently controls each wheel based on an electromechanical braking system, characterized in that, The method includes: The vehicle instability coefficient during energy recovery is obtained, wherein the vehicle instability coefficient is determined based on a pre-calibrated curve and one or more of the following: lateral acceleration, vehicle dynamic control system trigger state, and anti-lock braking system trigger state. The pre-calibrated curve is a curve showing the relationship between one or more of the following: lateral acceleration, vehicle dynamic control system trigger state, and anti-lock braking system trigger state and the vehicle instability coefficient. The maximum regenerative braking force that can maintain vehicle stability during energy recovery is determined based on the vehicle instability coefficient. Braking and energy recovery are performed using the maximum regenerative braking force that can maintain vehicle stability. Detect the required braking force of the vehicle; If the maximum regenerative braking force is less than the required braking force, then the braking mechanism of each wheel is controlled to output the target braking force to compensate for the difference between the vehicle's required braking force and the maximum regenerative braking force. The required braking force, maximum regenerative braking force, and slip ratio of each wheel during vehicle energy recovery are input into the closed-loop processing model, which outputs the target braking force for the corresponding wheel. The closed-loop processing model uses a closed-loop processing algorithm for data processing, wherein the closed-loop processing algorithm includes: Obtain the 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 ratio is not the longitudinal slip ratio, the difference in braking force will be used as the target braking force. If the actual yaw rate of the vehicle is detected and the slip ratio is not the longitudinal slip ratio, the target braking force is calculated based on the difference in angular velocity between the actual yaw rate and the target yaw rate and the difference in braking force; otherwise, the target braking force is calculated based on the difference in braking force and the longitudinal slip ratio. Specifically, the target yaw rate is calculated based on the steering wheel angle value after deviation compensation, the current vehicle speed, the characteristic vehicle speed, the wheelbase, and the steering ratio between the steering wheel angle and the wheel angle. The characteristic vehicle speed is a parameter used to describe the understeer characteristics of the vehicle.

2. The method according to claim 1, characterized in that, The determination of the maximum regenerative braking force that can maintain vehicle stability during energy recovery based on the vehicle instability coefficient includes: Obtain the initial regenerative braking force during vehicle energy recovery; If the vehicle instability coefficient is less than the coefficient threshold, then the initial regenerative braking force is taken as the maximum regenerative braking force. If the vehicle instability coefficient is greater than or equal to the coefficient threshold, the initial regenerative braking force is corrected based on the vehicle instability coefficient to obtain the maximum regenerative braking force.

3. The method according to claim 1, characterized in that, The braking mechanism that controls each wheel to output the target braking force includes: Obtain the current braking force for each wheel; The caliper motor in the corresponding braking mechanism is controlled to output the target current based on the current braking force and the corresponding target braking force of each wheel.

4. The method according to claim 1, characterized in that, Before the braking mechanism of each wheel outputs the target braking force, it also includes: Identify whether the caliper motor of each wheel is malfunctioning; When at least one caliper motor failure is detected, the required braking force, maximum regenerative braking force, and slip ratio of the wheel corresponding to each non-failed caliper motor are input into the closed-loop processing model. The closed-loop processing model outputs the target braking force of the wheel corresponding to each non-failed caliper motor.

5. A vehicle, characterized in that, The vehicle includes: a memory, a processor, and a computer program stored in the memory and executable on the processor, the processor executing the program to implement the energy recovery method as described in any one of claims 1 to 4.

6. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program that, when executed, implements the energy recovery method as described in any one of claims 1 to 4.

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