Regenerative braking control method, device and equipment and storage medium

Abstract

The invention discloses a regenerative braking control method and device, equipment and a storage medium. The method comprises the steps that dynamic ramp demand time is determined according to target regenerative braking torque; determining an end ramp starting speed according to the regenerative braking deceleration and the dynamic ramp demand time; when the regenerative braking of the vehicle is in the holding stage state and the real-time vehicle speed is smaller than or equal to the initial speed of the end slope, the vehicle enters the end slope state; according to the dynamic slope demand time, the ending slope initial braking force and the braking state real-time sensing parameters, mixed curve algorithm smooth fitting is carried out to obtain output decreasing regenerative braking force; and performing regenerative braking force decreasing control according to the output decreasing regenerative braking force until the regenerative braking state is quitted. The working condition adaptability is improved by dynamically setting the slope demand time, the system coordination is improved by smoothly fitting the braking force through the mixed curve algorithm, and the control smoothness when the regenerative braking system exits is effectively improved.

Description

Technical Field

[0001] This application relates to the field of vehicle braking energy recovery technology, specifically to a regenerative braking control method, device, equipment, and storage medium. Background Technology

[0002] In automatic cruise control, deceleration is highly predictable, with frequent prolonged periods of low-intensity deceleration, providing an ideal working environment for regenerative braking. The basic principle of regenerative braking is to switch the drive motor to generator mode during braking, converting the vehicle's kinetic energy into electrical energy and storing it in the battery, thereby effectively extending the driving range and reducing energy consumption. In regenerative braking, the total braking force is shared by the electric motor (regenerative braking force) and hydraulic friction braking force. To maximize energy recovery, the control system follows a "regenerative braking priority" principle, utilizing the electric motor for braking recovery as much as possible while meeting the driver's braking needs. Only when the electric motor's braking force is insufficient (e.g., when the motor torque is saturated or during high-speed braking) or when regenerative braking is ineffective (e.g., at extremely low speeds) will the hydraulic braking system supplement the difference in braking force. Regenerative braking in automatic cruise control effectively recovers energy and improves the vehicle's driving range.

[0003] A key challenge currently facing regenerative braking systems in vehicle autopilot mode is how to smoothly transition from regenerative braking to hydraulic braking when disengaging regenerative braking to a low speed. This process is known as regenerative braking exit control or ramp termination, which involves gradually reducing the regenerative braking force until regenerative braking is disengaged. Existing ramp termination control strategies typically employ a simple linear exit method based on a fixed vehicle speed threshold. That is, when the vehicle speed falls below a certain preset exit threshold, the system linearly reduces the regenerative braking force within a preset fixed ramp time until regenerative braking is disengaged.

[0004] However, in existing ramp termination control strategies, the fixed exit speed threshold leads to poor adaptability of the braking system to different operating conditions. For example, at different cruising speeds, the vehicle deceleration during braking varies significantly, making it difficult for a fixed exit speed threshold to maintain smooth control under all conditions. Furthermore, linear regenerative braking exit methods rely on simple timing control and lack a dynamic compensation mechanism based on real-time vehicle status. Insufficient coordination with hydraulic braking during exit also results in uneven braking exit. Therefore, existing technologies suffer from poor braking control smoothness during regenerative braking system exit under automatic cruise control, requiring improvement. Summary of the Invention

[0005] This application provides a regenerative braking control method, device, equipment, and storage medium, which can solve the technical problem of poor braking control smoothness when the regenerative braking system disengages under automatic cruise control in the prior art.

[0006] In a first aspect, embodiments of this application provide a regenerative braking control method, including: When a regenerative braking request is received, the system enters the regenerative braking state and determines the dynamic ramp demand time based on the target regenerative braking torque. The starting speed of the final ramp is determined based on the regenerative braking deceleration and the dynamic ramp demand time. When the vehicle regenerative braking is in the holding phase and the real-time vehicle speed is less than or equal to the starting speed of the end slope, it enters the end slope state. If the regenerative braking deceleration is greater than or equal to the deceleration threshold, the output decreasing regenerative braking force is obtained by smooth fitting of the hybrid curve algorithm based on the dynamic slope demand time, the initial braking force of the end slope and the real-time sensor parameters of the braking state. The regenerative braking force is reduced according to the output decreasing regenerative braking force until the regenerative braking state is exited. Among them, the real-time sensing parameters of braking status include real-time vehicle speed, real-time braking force, and real-time vehicle deceleration.

[0007] In conjunction with the first aspect, in one implementation, determining the dynamic ramp demand time based on the target regenerative braking torque includes: The conversion factor is determined based on the tire rolling radius; The gradient baseline value is determined based on the slope calibration value and the S-curve weight; The maximum torque gradient is determined based on the slope calibration value, gradient reference value, and conversion coefficient. The dynamic ramp demand time is determined based on the target regenerative braking torque and the maximum torque gradient. Among them, the target regenerative braking torque is less than or equal to the maximum regenerative braking torque, and the maximum regenerative braking torque is determined based on the current vehicle mass.

[0008] In conjunction with the first aspect, in one implementation, a hybrid curve algorithm is used to smoothly fit the dynamic slope demand time, the initial braking force at the end of the slope, and the real-time sensing parameters of the braking state to obtain the output decreasing regenerative braking force, including: The actual braking force step size is determined based on the dynamic slope demand time, the initial braking force at the end of the slope, and the real-time sensor parameters of the braking status. The cumulative step length is obtained by summing the actual braking force step length of each control cycle, and the slope position is determined based on the cumulative step length. The mixing curve factor is obtained by fitting the mixing curve based on the slope location; The output decreasing regenerative braking force for the current control cycle is determined based on the mixing curve factor.

[0009] In conjunction with the first aspect, in one implementation, the actual braking force step size is determined based on real-time sensing parameters of the dynamic slope demand time, the initial braking force at the end of the slope, and the braking state, including: The fixed number of deceleration steps is determined based on the dynamic slope demand time and control cycle. The fixed braking force step length is determined based on the fixed deceleration step number and the initial braking force at the end of the ramp. The variable deceleration time is determined based on the real-time vehicle speed and real-time vehicle deceleration. The number of variable deceleration steps is determined based on the variable deceleration time and the remaining control cycle. The variable braking force step size is determined based on the variable deceleration step number and the real-time braking force of the previous control cycle. The actual braking force step length is determined based on the maximum value of the fixed braking force step length and the variable braking force step length.

[0010] In conjunction with the first aspect, in one implementation, the mixing curve factor is obtained by fitting a mixing curve based on the slope position, including: The S-curve position is obtained by polynomial curve fitting of the slope position, and the S-curve factor is determined based on the S-curve position and S-curve weight. The linear curve factor is determined based on the slope location and the linear curve weight. The mixed curve factor is determined based on the S-curve factor and the linear curve factor.

[0011] In conjunction with the first aspect, in one implementation, determining the final ramp start speed based on the regenerative braking deceleration and the dynamic ramp demand time includes: The starting speed for ending the ramp is determined based on the regenerative braking deceleration, the dynamic ramp demand time, and the regenerative braking exit speed.

[0012] In conjunction with the first aspect, in one embodiment, the regenerative braking control method further includes: If the regenerative braking deceleration is less than the deceleration threshold, the output decreasing regenerative braking force is calculated based on the initial braking force at the end of the ramp and the real-time sensing parameters of the braking state using a control cycle decreasing algorithm.

[0013] In conjunction with the first aspect, in one embodiment, the regenerative braking control method further includes: The pre-filling start speed is determined based on the initial speed of the end ramp, the regenerative braking deceleration, and the set pre-filling time. The speed hysteresis is determined based on the regenerative braking deceleration and the set buffer time. Determine the initial velocity of the hold phase based on the velocity hysteresis and the initial velocity of the final ramp; The reset speed of the end slope is determined based on the velocity hysteresis, the pre-filling start speed, and the end slope start speed. When the real-time vehicle speed exceeds the end slope reset speed, reset all status flags and exit the corresponding status.

[0014] In conjunction with the first aspect, in one embodiment, the regenerative braking control method further includes: When the real-time vehicle speed is less than or equal to the ramp reset speed, a pre-filling judgment is performed; If the pre-filling judgment indicates that the real-time vehicle speed is greater than the starting speed of the end ramp but less than or equal to the starting speed of the pre-filling, the vehicle enters the pre-filling state. When the pre-filling judgment indicates that the real-time vehicle speed is less than or equal to the starting speed of the end slope, it enters the residual force holding state.

[0015] In conjunction with the first aspect, in one embodiment, the regenerative braking control method further includes: When the real-time vehicle speed is less than or equal to the starting speed of the holding phase, the vehicle enters the holding phase state.

[0016] In conjunction with the first aspect, in one embodiment, the regenerative braking control method further includes: When the ramp ends, the minimum value among the output decreasing regenerative braking force, the output decreasing regenerative braking force of the previous control cycle, and the maximum regenerative braking force is taken as the final output decreasing regenerative braking force of the current control cycle.

[0017] In conjunction with the first aspect, in one embodiment, the regenerative braking control method further includes: A regenerative braking request is generated when the requested braking torque is less than a preset torque threshold, the real-time vehicle speed is greater than a stationary speed threshold, and adaptive cruise control and automatic braking are activated.

[0018] In conjunction with the first aspect, in one embodiment, the regenerative braking control method further includes: When exiting the regenerative braking state, reset all status flags and exit the corresponding state.

[0019] In conjunction with the first aspect, in one embodiment, the regenerative braking control method further includes: The regenerative braking control torque is determined based on the regenerative braking force and the tire rolling radius. Regenerative braking control is performed based on the regenerative braking control torque.

[0020] Secondly, embodiments of this application provide a regenerative braking control device, comprising: The regenerative braking control module is used to enter the regenerative braking state when a regenerative braking request is received, and to determine the dynamic slope demand time based on the target regenerative braking torque. The exit condition determination module is used to determine the starting speed of the exit ramp based on the regenerative braking deceleration and the dynamic ramp demand time. The exit control force calculation module is used to enter the end slope state when the vehicle regenerative braking is in the holding phase and the real-time vehicle speed is less than or equal to the starting speed of the end slope. If the regenerative braking deceleration is greater than or equal to the deceleration threshold, the output decreasing regenerative braking force is obtained by smooth fitting the hybrid curve algorithm based on the dynamic slope demand time, the initial braking force of the end slope and the real-time sensor parameters of the braking state. The regenerative braking exit module is used to control the regenerative braking force reduction based on the output decreasing regenerative braking force until the regenerative braking state is exited. Among them, the real-time sensing parameters of braking status include real-time vehicle speed, real-time braking force, and real-time vehicle deceleration.

[0021] In conjunction with the second aspect, in one embodiment, the regenerative braking control device includes a dynamic ramp time calculation module, which is used for: The conversion factor is determined based on the tire rolling radius; The gradient baseline value is determined based on the slope calibration value and the S-curve weight; The maximum torque gradient is determined based on the slope calibration value, gradient reference value, and conversion coefficient. The dynamic slope requirement time is determined based on the preset maximum braking torque, the target regenerative braking torque, and the maximum torque gradient.

[0022] In conjunction with the second aspect, in one embodiment, the regenerative braking control device includes a hybrid curve braking force fitting module, which is used for: The actual braking force step size is determined based on the dynamic slope demand time, the initial braking force at the end of the slope, and the real-time sensor parameters of the braking status. The cumulative step length is obtained by summing the actual braking force step length of each control cycle, and the slope position is determined based on the cumulative step length. The mixing curve factor is obtained by fitting the mixing curve based on the slope location; The output decreasing regenerative braking force for the current control cycle is determined based on the mixing curve factor.

[0023] In conjunction with the second aspect, in one embodiment, the regenerative braking control device includes a low deceleration control module, which is used for: If the regenerative braking deceleration is less than the deceleration threshold, the output decreasing regenerative braking force is calculated based on the initial braking force at the end of the ramp and the real-time sensing parameters of the braking state using a control cycle decreasing algorithm.

[0024] Thirdly, embodiments of this application provide a regenerative braking control device, which includes a processor, a memory, and a regenerative braking control program stored in the memory and executable by the processor, wherein when the regenerative braking control program is executed by the processor, it implements the steps of the regenerative braking control method described above.

[0025] Fourthly, embodiments of this application provide a computer-readable storage medium storing a regenerative braking control program, wherein when the regenerative braking control program is executed by a processor, it implements the steps of the regenerative braking control method described above.

[0026] The beneficial effects of the technical solutions provided in this application include: By determining the dynamic ramp demand time using the target braking torque and then determining the ramp termination initiation speed based on that time, the ramp termination initiation speed can be dynamically adjusted according to operating conditions, making the ramp termination control strategy applicable to various conditions. Furthermore, by using a hybrid curve algorithm to smoothly fit and calculate the decreasing regenerative braking force during the ramp termination phase based on real-time sensor parameters of the initial braking force and braking state, the coordination between the regenerative braking exit process and the hydraulic braking can be enhanced. This application improves operating condition adaptability through dynamic ramp demand time and enhances system coordination through hybrid curve algorithm smooth fitting, effectively improving the control smoothness when the regenerative braking system exits during automatic cruise control. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 This is a flowchart illustrating the first embodiment of the regenerative braking control method of this application; Figure 2 This is a flowchart illustrating the process of determining the dynamic slope demand time in an embodiment of this application. Figure 3 This is a control logic flowchart of the overall state machine architecture of this application; Figure 4 This is a schematic diagram of the smooth fitting process of the hybrid curve algorithm in this application; Figure 5 This is a detailed flowchart of step S402 in this application; Figure 6 This is a detailed flowchart of step S404 in this application; Figure 7This is a functional module diagram of an embodiment of the regenerative braking control device of this application; Figure 8 This is a schematic diagram of the hardware structure of the regenerative braking control device involved in the embodiments of this application. Detailed Implementation

[0029] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present application.

[0030] It should be understood that the illustrative drawings are not drawn to scale. The flowcharts used in this invention illustrate operations implemented according to some embodiments of the invention. It should be understood that the operations in the flowcharts may be implemented out of order, and steps without logical contextual relationships may be reversed or performed simultaneously. Furthermore, those skilled in the art, guided by the content of this invention, may add one or more other operations to the flowcharts, or remove one or more operations from the flowcharts. Some block diagrams shown in the drawings are functional entities and do not necessarily correspond to physically or logically independent entities. These functional entities may be implemented in software, in one or more hardware modules or integrated circuits, or in different network and / or processor systems and / or microcontroller systems.

[0031] The terms "first," "second," etc., used in the embodiments of this invention are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a technical feature defined with "first" or "second" may explicitly or implicitly include at least one of those features.

[0032] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of the invention. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a mutually exclusive, independent, or alternative embodiment. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0033] First, some of the technical terms used in this application will be explained to help those skilled in the art understand this application.

[0034] End of ramp state: refers to the process by which a vehicle, under regenerative braking control, gradually exits regenerative braking and switches to hydraulic braking when its speed decreases to the point where it is difficult to continue recovering kinetic energy.

[0035] To make the objectives, technical solutions, and advantages of this application clearer, the embodiments of this application will be described in further detail below with reference to the accompanying drawings.

[0036] In a first aspect, embodiments of this application provide a regenerative braking control method.

[0037] In one embodiment, reference is made to Figure 1 , Figure 1 This is a schematic flowchart of the first embodiment of the regenerative braking control method of this application. Figure 1 As shown, the regenerative braking control method includes: S101. Upon receiving a regenerative braking request, enter the regenerative braking state and determine the dynamic slope demand time based on the target braking torque. S102. Determine the starting speed of the final ramp based on the regenerative braking deceleration and the dynamic ramp demand time. S103. When the vehicle regenerative braking is in the holding phase and the real-time vehicle speed is less than or equal to the starting speed of the end slope, it enters the end slope state. If the regenerative braking deceleration is greater than or equal to the deceleration threshold, the output decreasing regenerative braking is obtained by smooth fitting the hybrid curve algorithm based on the dynamic slope demand time, the initial braking force of the end slope and the real-time sensing parameters of the braking state. S104. Perform regenerative braking force reduction control based on the output decreasing regenerative braking force until the regenerative braking state is exited. Among them, the real-time sensing parameters of braking status include real-time vehicle speed, real-time braking force, and real-time vehicle deceleration.

[0038] Specifically, in this embodiment, when the braking system receives a regenerative braking request, the system enters the regenerative braking state and dynamically calculates the slope demand time in real time based on the target regenerative braking torque.

[0039] Specifically, a regenerative braking request is generated when the requested braking torque is less than a preset torque threshold, the real-time vehicle speed is greater than a stationary speed threshold, and adaptive cruise control and automatic braking are activated. The vehicle then enters regenerative braking mode after generating the regenerative braking request.

[0040] By setting multiple conditions for entering the regenerative braking state, the embodiment can avoid comfort problems or safety hazards caused by accidental activation of regenerative braking. For example, when the driver needs to take over the vehicle or perform emergency braking, the system does not enter the regenerative braking state, but instead uses hydraulic braking to ensure braking response speed.

[0041] In calculating the dynamic slope demand time, the example first determines the conversion coefficient based on the tire rolling radius; then determines the gradient reference value based on the slope calibration value and S-curve weight; next, determines the maximum torque gradient based on the slope calibration value, gradient reference value, and conversion coefficient; and finally determines the dynamic slope demand time based on the target regenerative braking torque and the maximum torque gradient.

[0042] The above calculation process calculates the slope's required time, ensuring that the slope's required time meets the current operating conditions.

[0043] In this embodiment, considering that under the same cruise state, the deceleration behavior of the vehicle is usually relatively stable, the target regenerative braking torque for each regenerative braking control cycle is determined based on the recovery force request of the corresponding previous cycle.

[0044] Then, in the embodiment, during the regenerative braking process of the vehicle, based on the calculated dynamic slope demand time and the measured regenerative braking deceleration, the starting speed of the exit slope for regenerative braking can be further dynamically calculated.

[0045] The starting speed at the end of the ramp is determined based on the regenerative braking deceleration, the dynamic ramp demand time, and the regenerative braking exit speed.

[0046] The embodiment calculates the dynamic ramp demand time based on the target regenerative braking torque and sets the conditions for entering the ramp termination state based on the dynamic ramp demand time. This ensures the adaptability of regenerative braking control to the current operating conditions during the ramp termination state and improves the smoothness of vehicle braking during the exit from regenerative braking. It solves the problem in existing technologies where a fixed exit speed threshold leads to poor control smoothness because the braking system struggles to adapt to different operating conditions at varying cruising speeds due to significant differences in vehicle deceleration during braking.

[0047] The embodiment then sets up a multi-level state control machine, and the various judgment thresholds of the state control machine are calculated through the following steps: The pre-filling start speed is determined based on the initial speed of the end ramp, the regenerative braking deceleration, and the set pre-filling time. The speed hysteresis is determined based on the regenerative braking deceleration and the set buffer time. Determine the initial velocity of the hold phase based on the velocity hysteresis and the initial velocity of the final ramp; The reset speed of the end ramp is determined based on the velocity hysteresis, the pre-filling start speed, and the end ramp start speed.

[0048] Based on the calculated judgment thresholds, the control states of the state controller include regenerative braking state, pre-filling state, residual force holding state, holding stage state, and final ramp state, and each control state is performed according to the following logic: Upon receiving a regenerative braking request, it enters the regenerative braking state; When the real-time vehicle speed exceeds the end slope reset speed, reset all status flags and exit the corresponding status. When the real-time vehicle speed is less than or equal to the ramp reset speed, a pre-filling judgment is performed; If the pre-filling judgment indicates that the real-time vehicle speed is greater than the starting speed of the end ramp but less than or equal to the starting speed of the pre-filling, the vehicle enters the pre-filling state. When the pre-filling judgment indicates that the real-time vehicle speed is less than or equal to the starting speed of the end slope, it enters the residual force holding state; In the pre-filled state or residual force holding state, when the real-time vehicle speed is less than or equal to the starting speed of the holding phase, the vehicle enters the holding phase state. When the vehicle regenerative braking is in the holding phase and the real-time vehicle speed is less than or equal to the starting speed of the end ramp, it enters the end ramp state. When exiting the regenerative braking state, reset all status flags and exit the corresponding state.

[0049] Through the above multi-level state protection, the embodiment can ensure vehicle control safety, effectively improve operating condition adaptability, and ensure smooth withdrawal of regenerative braking force.

[0050] Then, in the ramp state, the embodiment sets two sub-states: one is the standard sub-state under normal conditions, in which the output decreasing regenerative braking force is obtained by smooth fitting through the hybrid curve algorithm; the other is the low deceleration sub-state, in which the output decreasing regenerative braking force is calculated through the control cycle decreasing algorithm.

[0051] In this embodiment, the regenerative braking deceleration is compared with a deceleration threshold to determine which sub-state to enter. When the regenerative braking deceleration is greater than or equal to the deceleration threshold, the system enters the standard sub-state; when the regenerative braking deceleration is less than the deceleration threshold, the system enters the low deceleration sub-state.

[0052] It should be noted that the regenerative braking deceleration and deceleration threshold are both taken as positive values ​​in this judgment, rather than as negative values ​​in a reference frame with the vehicle direction as the positive direction.

[0053] Under the standard sub-state, the smooth fitting process of the mixing curve algorithm is as follows: First, the actual braking force step size is determined based on the dynamic slope demand time, the initial braking force at the end of the slope, and the real-time sensing parameters of the braking state. Since the hybrid curve algorithm combines fixed deceleration slope parameters (controlled by a linear slope) and variable deceleration slope parameters (a polynomial-fitted curve), the fixed braking force step size and the variable braking force step size need to be calculated separately before determining the actual braking force step size.

[0054] The fixed deceleration step size is determined first by the dynamic slope demand time and control cycle, then by combining the initial braking force at the end of the slope to determine the fixed braking force step size. The real-time deceleration step size is determined first by calculating the variable deceleration time based on the real-time vehicle speed and deceleration, then by calculating the variable deceleration time and remaining control cycle, and finally by combining the real-time braking force from the previous control cycle to determine the variable braking force step size. The actual control step size is then the maximum value of the fixed and variable braking force step sizes.

[0055] Then, in the embodiment, the actual braking force step length of each control cycle is accumulated to obtain the cumulative step length, and the ramp position is determined based on the cumulative step length; the hybrid curve factor is obtained by fitting the hybrid curve based on the ramp position; and the output decreasing regenerative braking force of the current control cycle is determined based on the hybrid curve factor.

[0056] The embodiment estimates the actual control step size for each cycle by combining real-time sensing parameters of the braking state, and uses them for hybrid curve control in the next cycle. This allows for real-time adjustment during the exit of regenerative braking control, ensuring a smooth exit of regenerative braking.

[0057] In the process of fitting the hybrid curve, the embodiment uses polynomial fitting to determine the position of the S-curve and combines it with the S-curve weights to determine the S-curve factor. Then, the S-curve factor is added to the linear curve factor determined based on the slope position and the linear curve weights to obtain the hybrid curve factor. After transforming and mapping the hybrid curve factor, the output decreasing regenerative braking force of the current control cycle is obtained.

[0058] Then, by continuously calculating the output decreasing regenerative braking force for each cycle, a smooth exit of regenerative braking is achieved.

[0059] In the low deceleration sub-state, to prevent control instability due to insufficient sensor resolution, the embodiment adopts a decrement algorithm based on the control cycle.

[0060] The periodic-based deceleration algorithm calculates the decrease in regenerative braking force for each control cycle using a pre-calibrated control duration and cycle, gradually exiting regenerative braking. Generally, the change in regenerative braking force in the periodic-based deceleration algorithm is relatively gradual to ensure the overall braking stability of the vehicle.

[0061] The embodiment uses a periodic decreasing algorithm to perform special processing under low deceleration conditions, thus ensuring stability under low deceleration.

[0062] In this embodiment, the dynamic ramp demand time is determined by the target braking torque, and the starting speed of the end ramp is determined based on the dynamic ramp demand time. This allows for dynamic adjustment of the end ramp starting speed based on operating conditions, making the end ramp control strategy applicable to various conditions. By using a hybrid curve algorithm to smoothly fit the initial braking force and real-time braking state parameters of the end ramp, the output decreasing regenerative braking force during the end ramp stage is calculated, enhancing the coordination between the regenerative braking exit process and the hydraulic braking. This application improves operating condition adaptability through the dynamic ramp demand time and enhances system coordination through the hybrid curve algorithm smooth fitting, effectively improving the control smoothness when the regenerative braking system exits during automatic cruise control.

[0063] Furthermore, in one embodiment, the regenerative braking control method includes: A regenerative braking request is generated when the requested braking torque is less than a preset torque threshold, the real-time vehicle speed is greater than a stationary speed threshold, and adaptive cruise control and automatic braking are activated.

[0064] Specifically, in this embodiment, the vehicle's intelligent driving system activates the regenerative braking system to recover energy only when the vehicle is in automatic cruise control and automatic braking mode. That is, when the braking torque requested by the intelligent driving system is less than a set threshold (e.g., -0.1), the real-time vehicle speed is greater than the stationary speed threshold (the vehicle is not stationary), and the adaptive cruise control and automatic braking states are activated, a regenerative braking request is generated, the regenerative braking request flag is set to true, and the braking system enters the regenerative braking state.

[0065] In this embodiment, by limiting the entry conditions for regenerative braking, comfort issues or safety hazards caused by accidental activation of regenerative braking can be avoided. For example, when the driver needs to take over the vehicle or perform emergency braking, the system does not enter regenerative braking mode, but instead uses hydraulic braking to ensure braking response speed.

[0066] Furthermore, in one embodiment, Figure 2 This is a flowchart illustrating the process of determining the dynamic slope demand time according to an embodiment of this application, as shown below. Figure 2 As shown, the dynamic ramp demand time is determined based on the target regenerative braking torque, including: S201. Determine the conversion factor based on the tire rolling radius; S202. Determine the gradient baseline value based on the slope calibration value and the S-curve weight; S203. Determine the maximum torque gradient based on the slope calibration value, gradient reference value, and conversion coefficient; S204. Determine the dynamic slope demand time based on the target regenerative braking torque and the maximum torque gradient; Among them, the target regenerative braking torque is less than or equal to the maximum regenerative braking torque, and the maximum regenerative braking torque is determined based on the current vehicle mass.

[0067] Further, in one embodiment, determining the starting speed of the final ramp based on the regenerative braking deceleration and the dynamic ramp demand time includes: The starting speed for ending the ramp is determined based on the regenerative braking deceleration, the dynamic ramp demand time, and the regenerative braking exit speed.

[0068] Specifically, after entering the regenerative braking state, it is necessary to determine the target regenerative braking torque and the maximum regenerative braking torque, and then calculate the dynamic slope demand time based on the target regenerative braking torque and the maximum regenerative braking torque, so as to ensure that the subsequent slope termination state can adapt to the current working conditions.

[0069] The target regenerative braking torque is determined based on the recovery force request from the previous cycle. This setting is because, in the vehicle's autopilot mode, to provide better passenger comfort, more stable deceleration is required; therefore, the braking control requirements between adjacent deceleration cycles are relatively close during autopilot.

[0070] It should be noted that, in addition to its application in regenerative braking disengagement control under automatic cruise control, the method proposed in this application can also be applied to other regenerative braking controls based on the core concept of this application. However, the difference in applying this application to other regenerative braking controls is that the target regenerative braking torque is no longer determined based on the recovery force request of the previous cycle, but can be determined by combining the current real-time vehicle speed and real-time deceleration.

[0071] For functional safety reasons, the embodiment also includes a maximum regenerative braking torque. The formula is expressed as:

[0072] in, Indicates the maximum regenerative braking force. Indicates the tire's rolling radius. The maximum vehicle deceleration set for functional safety limitations is generally [value missing]. , This refers to the current overall vehicle quality.

[0073] In calculating the dynamic ramp demand time, considering the difference between the front and rear wheels, a conversion factor needs to be determined in advance, expressed by the formula:

[0074] in, Indicates the front axle distribution factor. Indicates the rolling radius of the front wheels. This indicates the rolling radius of the rear wheel.

[0075] Then, the gradient baseline value is determined based on the slope calibration value and the S-curve weights, expressed by the formula:

[0076] in, Indicates the gradient baseline value. This indicates the slope (calibrated value) before the motor exits. This represents the weighting factor (standardized value) adjusted according to the application, i.e., the S-curve weight, with values ​​ranging from... Within the range, 0 represents linear and 1 represents S-shaped.

[0077] Then, based on the slope calibration value, gradient reference value, and conversion coefficient, the maximum torque gradient can be determined, expressed by the formula:

[0078] in, This represents the maximum torque gradient.

[0079] Then, the dynamic ramp time requirement is calculated based on the target regenerative braking torque and the maximum torque gradient. It's important to note that the target regenerative braking torque cannot exceed the maximum regenerative braking torque. Therefore, the formula is:

[0080] in, Represents the maximum regenerative braking torque, and represents the target regenerative braking torque. This indicates the time required for dynamic slope.

[0081] Finally, the starting velocity of the slope is calculated based on the dynamic slope demand time, expressed by the formula:

[0082] in, Indicates the initial velocity of the ending ramp. Indicates regenerative braking deceleration. This indicates the set regenerative braking exit speed.

[0083] In this embodiment, the dynamic ramp demand time is calculated using the target regenerative braking torque, and the conditions for entering the ramp termination state are set based on the dynamic ramp demand time. This ensures the adaptability of regenerative braking force control to the current operating conditions in the ramp termination state and improves the smoothness of vehicle braking during the exit from regenerative braking.

[0084] Furthermore, in one embodiment, the ending ramp reset speed and the corresponding ending ramp reset method are set as follows: The pre-filling start speed is determined based on the initial speed of the end ramp, the regenerative braking deceleration, and the set pre-filling time. The speed hysteresis is determined based on the regenerative braking deceleration and the set buffer time. Determine the initial velocity of the hold phase based on the velocity hysteresis and the initial velocity of the final ramp; The reset speed of the end slope is determined based on the velocity hysteresis, the pre-filling start speed, and the end slope start speed. When the real-time vehicle speed exceeds the end slope reset speed, reset all status flags and exit the corresponding status.

[0085] Furthermore, in one embodiment, the pre-filling determination process is as follows: When the real-time vehicle speed is less than or equal to the ramp reset speed, a pre-filling judgment is performed; If the pre-filling judgment indicates that the real-time vehicle speed is greater than the starting speed of the end ramp but less than or equal to the starting speed of the pre-filling, the vehicle enters the pre-filling state. When the pre-filling judgment indicates that the real-time vehicle speed is less than or equal to the starting speed of the end slope, it enters the residual force holding state.

[0086] Furthermore, in one embodiment, the condition for determining the holding stage is as follows: In the pre-filled state or residual force holding state, when the real-time vehicle speed is less than or equal to the starting speed of the holding phase, the vehicle enters the holding phase state.

[0087] Furthermore, in one embodiment, the regenerative braking method further includes: When exiting the regenerative braking state, reset all status flags and exit the corresponding state.

[0088] Specifically, Figure 3 This is the control logic flowchart of the overall state machine architecture of this application, combined with... Figure 3 As can be seen, the regenerative braking process employs multi-level state control to ensure the safety and stability of the control process. In this embodiment, the judgment thresholds for each state in the state machine are determined based on the determined initial speed of the final ramp.

[0089] In this embodiment, the pre-filling starting speed is determined based on the starting speed of the ending ramp, the regenerative braking deceleration, and the set pre-filling time, expressed by the following formula:

[0090]

[0091] in, Indicates the initial pre-filling speed. This indicates the change in vehicle speed during the pre-filling stage. This indicates the set pre-filling time.

[0092] The velocity hysteresis is determined based on the regenerative braking deceleration and the set buffer time, expressed by the following formula:

[0093] in, Indicates velocity hysteresis. This indicates the set buffer time, and the maximum speed hysteresis value is limited to [value missing]. .

[0094] The initial velocity of the hold phase is determined based on the velocity hysteresis and the initial velocity of the final ramp, expressed by the following formula:

[0095] in, This indicates maintaining the initial speed of the phase.

[0096] Then, based on the judgment thresholds for each state set above, the ramp reset speed is terminated as follows:

[0097] in, Indicates the final ramp reset speed. This indicates the reset hysteresis value set.

[0098] Then, based on the pre-set thresholds, combined with Figure 3 From the control logic flowchart of the overall state machine architecture, the state transition process of the embodiment is as follows: When regenerative braking is activated, if the real-time vehicle speed is less than or equal to the end ramp reset speed, pre-filling judgment begins. If the real-time vehicle speed is greater than the end ramp start speed but less than or equal to the pre-fill start speed, the vehicle enters the pre-filling state; if the real-time vehicle speed is less than or equal to the end ramp start speed, the vehicle enters the residual force holding state.

[0099] During the pre-filling judgment process, when the real-time vehicle speed is greater than the starting speed of the end ramp but less than or equal to the starting speed of pre-filling, the vehicle enters the pre-filling state. This state is to ensure that the hydraulic braking system can respond promptly during the subsequent end ramp stage by activating the hydraulic braking system in advance. Furthermore, if the real-time vehicle speed is already less than or equal to the starting speed of the ramp during the pre-filling judgment, the vehicle enters the residual force holding state. In this state, residual braking force is maintained to ensure a smooth transition in the subsequent process.

[0100] Then, the state machine continues to judge the real-time vehicle speed. When the real-time vehicle speed is less than or equal to the starting speed of the holding phase, it enters the holding phase state; otherwise, it directly outputs regenerative force. In the holding phase state, the system freezes the regenerative braking force to prepare for the end of the ramp phase, and when the real-time vehicle speed decreases to the starting speed of the end ramp (less than or equal to the starting speed of the end ramp), it transitions to the end ramp state.

[0101] The ramp-ending phase comprises two sub-states. One sub-state is the standard algorithm sub-state, employing a hybrid curve algorithm based on both fixed and variable deceleration ramps. The other sub-state is the low-deceleration algorithm sub-state, which uses a decreasing algorithm based on the control cycle when the regenerative braking deceleration falls below a threshold, preventing control instability caused by insufficient sensor resolution at low speeds. For example, the standard algorithm sub-state is typically used during normal deceleration, while the low-deceleration algorithm sub-state is typically used in low-speed scenarios such as traffic jams.

[0102] In addition, if during the entire process, when the vehicle speed is detected to be greater than the reset speed of the end ramp (this may be because the vehicle is accelerating again to prepare to enter normal driving state, or the vehicle speed increases after entering the downhill), then it is necessary to reset the various status flags related to the end ramp and exit the corresponding state, so as to facilitate subsequent re-judgment and entry into the end ramp.

[0103] Finally, after exiting regenerative braking, the status information needs to be saved as a reference value for the next regenerative braking cycle. Additionally, whether exiting after braking is complete or after entering normal driving, all status flags need to be reset and the corresponding status exited to facilitate subsequent reassessment and entry into the final ramp. In this embodiment, multi-level state protection can ensure vehicle control safety, effectively improve operating condition adaptability, and ensure smooth withdrawal of regenerative braking force.

[0104] Furthermore, in one embodiment, Figure 4 This is a schematic diagram of the smooth fitting process of the hybrid curve algorithm in this application, as shown below. Figure 4 As shown, the decreasing regenerative braking force is obtained by smoothing and fitting a hybrid curve algorithm based on the dynamic slope demand time, the initial braking force at the end of the slope, and the real-time sensing parameters of the braking state. This includes: S401. Determine the actual braking force step size based on the dynamic slope demand time, the initial braking force at the end of the slope, and the real-time sensing parameters of the braking status. S402. Accumulate the actual braking force step length of each control cycle to obtain the cumulative step length, and determine the slope position based on the cumulative step length. S403. Obtain the mixed curve factor by fitting the mixed curve based on the slope location; S404. Determine the output decreasing regenerative braking force of the current control cycle based on the mixing curve factor.

[0105] Furthermore, in one embodiment, Figure 5 This is a detailed flowchart of step S402 in this application, as shown below. Figure 5 As shown, the actual braking force step size is determined based on the dynamic slope demand time, the initial braking force at the end of the slope, and the real-time sensing parameters of the braking state, including: S501. Determine the fixed deceleration steps based on the dynamic slope demand time and control cycle. S502. Determine the fixed braking force step length based on the fixed deceleration step number and the initial braking force at the end of the ramp. S503. Determine the variable deceleration time based on the real-time vehicle speed and real-time vehicle deceleration; S504. Determine the number of variable deceleration steps based on the variable deceleration time and the remaining control cycle; S505. Determine the variable braking force step size based on the variable deceleration step number and the real-time braking force of the previous control cycle. S506. Determine the actual braking force step length based on the maximum value of the fixed braking force step length and the variable braking force step length.

[0106] Furthermore, in one embodiment, Figure 6 This is a detailed flowchart of step S404 in this application, as shown below. Figure 6 As shown, the mixing curve factors are obtained by fitting the mixing curve based on the slope location, including: S601. Perform polynomial curve fitting on the slope position to obtain the S-curve position, and determine the S-curve factor based on the S-curve position and S-curve weight. S602. Determine the linear curve factor based on the slope location and the linear curve weight; S603. Determine the mixed curve factor based on the S-curve factor and the linear curve factor.

[0107] Specifically, in the process of smoothly fitting and calculating the output of decreasing regenerative braking force using the hybrid curve algorithm, it is first necessary to determine the actual braking force step size for each cycle. In this process, since the embodiment adopts a hybrid curve algorithm that combines fixed deceleration ramp parameters (controlled by linear slope) and variable deceleration ramp parameters (a curve fitted by polynomial), it is necessary to calculate the fixed braking force step size and the variable braking force step size separately.

[0108] In the process of calculating the fixed braking force step length, the fixed deceleration step number is first determined based on the dynamic slope demand time and control cycle:

[0109] in, Indicates a fixed number of deceleration steps. Indicates the control cycle.

[0110] Then, the fixed braking force step length is calculated based on the fixed deceleration steps and the initial braking force at the end of the ramp. The formula is as follows:

[0111] in, Indicates the fixed braking force step size. This indicates the braking force during the holding phase (i.e., the initial braking force at the end of the slope, but for accurate measurement, the braking force measured during the holding phase is used). Its purpose is to prevent the step size from becoming zero, which would render the formula meaningless.

[0112] Then, for the variable braking force step size, the current variable deceleration time needs to be calculated first. The variable deceleration time can be calculated based on the real-time vehicle speed and real-time vehicle deceleration, as expressed by the formula:

[0113] in, Indicates the variable deceleration time. Indicates real-time vehicle speed. Indicates the real-time vehicle deceleration. This is a constant, and its value can be set to 0.001 to prevent the result from returning to zero. To set a vehicle deceleration threshold to prevent When the value is small, the calculation result is too large.

[0114] Then, the number of variable deceleration steps is determined based on the variable deceleration time and the remaining control cycle:

[0115] in, Indicates the number of variable deceleration steps. Indicates the remaining control cycle.

[0116] The variable braking force step size is determined based on the remaining control cycle and the real-time braking force of the previous control cycle:

[0117] in, Indicates the variable braking force step size. This indicates the real-time braking force in the previous control cycle.

[0118] Finally, the actual braking force step size for each cycle is the maximum value of the fixed braking force step size and the variable braking force step size:

[0119] in. This indicates the actual braking force step length.

[0120] After establishing the actual braking force step size for each control cycle in real time, the cumulative step size can be determined by summing. Then, based on the cumulative step size, the current slope position is determined, expressed by the formula:

[0121] in, Indicates the location of the slope. Indicates the cumulative step size. This indicates that the phased braking force will be maintained.

[0122] Then, based on the slope location, the embodiment determines the S-curve position through polynomial curve fitting, as follows:

[0123] in, and The coefficients (calibrated values) of the polynomial curve are shown in the example. The value is 2. The value is 3.

[0124] Then, the S-curve factor is determined based on the S-curve position and S-curve weight, and the linear curve factor is determined based on the slope position and linear curve weight. The two factors are then added together to obtain the mixed curve factor, expressed by the following formula:

[0125]

[0126] in, Indicates the mixing curve factor. Indicates the weight of the S-curve. This represents the weight of a linear curve.

[0127] Finally, by converting the slope position of the mixed curve factor into regenerative braking force, the output decreasing regenerative braking force of the current control cycle can be calculated.

[0128] In this embodiment, the actual control step size for each cycle is estimated by combining real-time sensing parameters of the braking state. The cumulative step size is then obtained by accumulating the real-time control step sizes, and a hybrid curve algorithm is used to smoothly fit the cumulative step size. Dynamic fitting is performed to calculate the regenerative braking force at the end of the ramp phase, effectively enhancing the coordination between regenerative braking and hydraulic braking during the regenerative braking exit process and improving the smoothness of the regenerative braking exit process.

[0129] Furthermore, in one embodiment, the regenerative braking control method provides special handling for low deceleration, including: If the regenerative braking deceleration is less than the deceleration threshold, the output decreasing regenerative braking force is calculated based on the initial braking force at the end of the ramp and the real-time sensing parameters of the braking state using a control cycle decreasing algorithm.

[0130] Specifically, in scenarios such as traffic jams, the vehicle's speed and deceleration are relatively small, which may lead to insufficient sensor resolution. To prevent control instability at low deceleration, the embodiment incorporates special handling as follows: Regenerative braking deceleration when entering the final ramp phase. Less than the deceleration threshold In this case, the ramp ends using a low deceleration algorithm, which is a deceleration algorithm based on the control cycle.

[0131] The control cycle-based decrement algorithm first requires initializing parameters based on real-time sensing parameters of the braking state. When the system decides to begin exiting regenerative braking (when the regenerative braking deceleration is less than the deceleration threshold), it immediately records the current regenerative braking torque value as the starting point of the entire exit process.

[0132] Next, the decrement step size needs to be determined. The decrement step size is based on engineering calibration. Generally, the calibration step size can be determined by presetting the total control duration and control cycle, combined with the recorded current regenerative braking torque value.

[0133] In each control cycle, the regenerative braking torque value is gradually reduced according to the calibrated step size, and a minimum value is set as the completion judgment threshold. When the torque is lower than this value, it is considered that the operation has been completely disengaged and can be directly reset to zero, avoiding prolonged small outputs due to calculation accuracy issues.

[0134] At the same time, in order to ensure that the total braking force remains unchanged, this process must be closely synchronized with the hydraulic braking system.

[0135] In each control cycle, when the regenerative torque decreases, the hydraulic braking system must synchronously increase the corresponding braking torque. Furthermore, the command to increase the braking torque needs to be sent to the hydraulic control unit (such as ESP) in advance to compensate for its inherent mechanical response delay.

[0136] Generally, in control cycle-based decreasing algorithms, the step size in each control cycle is small to avoid abrupt changes during the exit from regenerative braking; essentially, it trades time for stability. It ensures control stability by sacrificing dynamic adaptability during low-deceleration control. In low-speed, low-deceleration conditions, the system's dynamic adaptability requirements are actually low. For example, in traffic jams where vehicles decelerate slowly, the switching process between regenerative and hydraulic braking can proceed gradually, without requiring high dynamic adaptability between the two. The control cycle-based decreasing algorithm ensures control stability of the regenerative braking system under low-speed, low-deceleration conditions.

[0137] Furthermore, it should be noted that in some other embodiments, in addition to determining whether to enter the control cycle-based deceleration algorithm based on the vehicle deceleration when entering the end slope state, the control mode can also be switched to the control cycle-based deceleration algorithm after the vehicle speed is less than the set threshold during the hybrid curve control process, so as to ensure the smoothness of the final exit stage.

[0138] In this embodiment, a special processing method based on a periodic decreasing algorithm is set up for low deceleration conditions to ensure the stability of low deceleration and improve the smoothness of regenerative braking exit under low deceleration.

[0139] Furthermore, in one embodiment, the regenerative braking control method also includes an output limiting mechanism, which comprises: When the ramp ends, the minimum value among the output decreasing regenerative braking force, the output decreasing regenerative braking force of the previous control cycle, and the maximum regenerative braking force is taken as the final output decreasing regenerative braking force of the current control cycle.

[0140] Specifically, to prevent the braking force from rebounding during the end of the ramp, the embodiment also includes an output limiting mechanism and a state holding mechanism.

[0141] In the output limiting mechanism, before outputting regenerative braking force to the motor, the calculated output decreasing regenerative braking force, the output decreasing regenerative braking force of the previous control cycle, and the maximum regenerative braking force are compared, and the minimum value is taken as the final regenerative braking force output to the motor to ensure that the regenerative braking force of each cycle will not be greater than that of the previous cycle.

[0142] The state preservation mechanism saves the current result for use in the next cycle.

[0143] In this embodiment, by setting an output limiting mechanism, the phenomenon of braking force rebound during the end of the ramp can be effectively prevented, further ensuring control smoothness and improving user experience.

[0144] Furthermore, in one embodiment, the regenerative braking control method further includes: The regenerative braking control torque is determined based on the regenerative braking force and the tire rolling radius. Regenerative braking control is performed based on the regenerative braking control torque.

[0145] Specifically, during the entire regenerative braking control process, considering the different rolling radii of the front and rear wheels, the embodiment also needs to multiply the regenerative braking force by the tire rolling radius to convert it into control torque, and then output it to the corresponding control motor for regenerative braking control, so as to ensure the consistency of regenerative braking control in multi-wheel coordinated control. For example, in a four-wheel drive vehicle, the regenerative braking control torque corresponding to the front and rear axles is calculated based on the rolling radii of the front and rear wheels respectively, so as to ensure the consistency of regenerative braking control in a four-wheel drive vehicle.

[0146] In this embodiment, by converting the regenerative braking force into a control torque, the consistency of regenerative braking control in multi-wheel coordinated control can be guaranteed, and the smoothness of regenerative braking control under multi-wheel coordinated control can be ensured.

[0147] In summary, the beneficial effects of this application include: By limiting the conditions for entering regenerative braking, it is possible to avoid comfort issues or safety hazards caused by accidental activation of regenerative braking. For example, when the driver needs to take over the vehicle or perform emergency braking, the system does not enter regenerative braking mode, but instead uses hydraulic braking to ensure braking response speed.

[0148] The dynamic ramp demand time is calculated using the target regenerative braking torque, and the conditions for entering the ramp termination state are set based on this dynamic ramp demand time. This ensures the adaptability of regenerative braking force control to the current operating conditions during the ramp termination state.

[0149] Multi-level condition protection can ensure vehicle control safety and effectively improve adaptability to operating conditions.

[0150] The actual control step size for each cycle is estimated by combining real-time sensing parameters of the braking state. The cumulative step size is then obtained by accumulating the real-time control step sizes, and a hybrid curve algorithm is used to smoothly fit the cumulative step size. Dynamic fitting is performed to calculate the regenerative braking force during the ramp-end phase, effectively enhancing the coordination between regenerative braking and hydraulic braking during regenerative braking exit.

[0151] By setting up a periodic decreasing algorithm for special handling under low deceleration conditions, the stability of low deceleration is ensured.

[0152] By setting an output limiting mechanism, braking force rebound during the slope termination can be effectively prevented.

[0153] By converting regenerative braking force into control torque, the consistency of regenerative braking control in multi-wheel coordinated control can be ensured, thus guaranteeing the smoothness of regenerative braking control under multi-wheel coordinated control.

[0154] Secondly, embodiments of this application also provide a regenerative braking control device.

[0155] In one embodiment, reference is made to Figure 7 , Figure 7 This is a functional module diagram of an embodiment of the regenerative braking control device of this application. Figure 7 As shown, the regenerative braking control device includes: The regenerative braking control module 701 is used to enter the regenerative braking state when a regenerative braking request is received, and to determine the dynamic slope demand time based on the target regenerative braking torque. The exit condition determination module 702 is used to determine the starting speed of the end slope based on the regenerative braking deceleration and the dynamic slope demand time. The exit control force calculation module 703 is used to enter the end slope state when the vehicle regenerative braking is in the holding phase and the real-time vehicle speed is less than or equal to the starting speed of the end slope. If the regenerative braking deceleration is greater than or equal to the deceleration threshold, the output decreasing regenerative braking force is obtained by smooth fitting of the hybrid curve algorithm based on the dynamic slope demand time, the initial braking force of the end slope and the real-time sensing parameters of the braking state. The regenerative braking exit module 704 is used to control the regenerative braking force reduction based on the output decreasing regenerative braking force until the regenerative braking state is exited. Among them, the real-time sensing parameters of braking status include real-time vehicle speed, real-time braking force, and real-time vehicle deceleration.

[0156] Furthermore, in one embodiment, the regenerative braking control device further includes a dynamic ramp time calculation module, used for: The conversion factor is determined based on the tire rolling radius; The gradient baseline value is determined based on the slope calibration value and the S-curve weight; The maximum torque gradient is determined based on the slope calibration value, gradient reference value, and conversion coefficient. The dynamic ramp demand time is determined based on the target regenerative braking torque and the maximum torque gradient. Among them, the target regenerative braking torque is less than or equal to the maximum regenerative braking torque, and the maximum regenerative braking torque is determined based on the current vehicle mass.

[0157] Furthermore, in one embodiment, the regenerative braking control device further includes a hybrid curve braking force fitting module, used for: The actual braking force step size is determined based on the dynamic slope demand time, the initial braking force at the end of the slope, and the real-time sensor parameters of the braking status. The cumulative step length is obtained by summing the actual braking force step length of each control cycle, and the slope position is determined based on the cumulative step length. The mixing curve factor is obtained by fitting the mixing curve based on the slope location; The output decreasing regenerative braking force for the current control cycle is determined based on the mixing curve factor.

[0158] Furthermore, in one embodiment, the regenerative braking control device further includes a new module for: The fixed number of deceleration steps is determined based on the dynamic slope demand time and control cycle. The fixed braking force step length is determined based on the fixed deceleration step number and the initial braking force at the end of the ramp. The variable deceleration time is determined based on the real-time vehicle speed and real-time vehicle deceleration. The number of variable deceleration steps is determined based on the variable deceleration time and the remaining control cycle. The variable braking force step size is determined based on the variable deceleration step number and the real-time braking force of the previous control cycle. The actual braking force step length is determined based on the maximum value of the fixed braking force step length and the variable braking force step length.

[0159] Furthermore, in one embodiment, the regenerative braking control device further includes a new module for: The S-curve position is obtained by polynomial curve fitting of the slope position, and the S-curve factor is determined based on the S-curve position and S-curve weight. The linear curve factor is determined based on the slope location and the linear curve weight. The mixed curve factor is determined based on the S-curve factor and the linear curve factor.

[0160] Furthermore, in one embodiment, the regenerative braking control device further includes a low deceleration control module, used for: The starting speed for ending the ramp is determined based on the regenerative braking deceleration, the dynamic ramp demand time, and the regenerative braking exit speed.

[0161] Furthermore, in one embodiment, the regenerative braking control device further includes a new module for: If the regenerative braking deceleration is less than the deceleration threshold, the output decreasing regenerative braking force is calculated based on the initial braking force at the end of the ramp and the real-time sensing parameters of the braking state using a control cycle decreasing algorithm.

[0162] Furthermore, in one embodiment, the regenerative braking control device further includes a new module for: The pre-filling start speed is determined based on the initial speed of the end ramp, the regenerative braking deceleration, and the set pre-filling time. The speed hysteresis is determined based on the regenerative braking deceleration and the set buffer time. Determine the initial velocity of the hold phase based on the velocity hysteresis and the initial velocity of the final ramp; The reset speed of the end slope is determined based on the velocity hysteresis, the pre-filling start speed, and the end slope start speed. When the real-time vehicle speed exceeds the end slope reset speed, reset all status flags and exit the corresponding status.

[0163] Furthermore, in one embodiment, the regenerative braking control device further includes a new module for: When the real-time vehicle speed is less than or equal to the ramp reset speed, a pre-filling judgment is performed; If the pre-filling judgment indicates that the real-time vehicle speed is greater than the starting speed of the end ramp but less than or equal to the starting speed of the pre-filling, the vehicle enters the pre-filling state. When the pre-filling judgment indicates that the real-time vehicle speed is less than or equal to the starting speed of the end slope, it enters the residual force holding state.

[0164] Furthermore, in one embodiment, the regenerative braking control device further includes a new module for: When the real-time vehicle speed is less than or equal to the starting speed of the holding phase, the vehicle enters the holding phase state.

[0165] Furthermore, in one embodiment, the regenerative braking control device further includes a new module for: When the ramp ends, the minimum value among the output decreasing regenerative braking force, the output decreasing regenerative braking force of the previous control cycle, and the maximum regenerative braking force is taken as the final output decreasing regenerative braking force of the current control cycle.

[0166] Furthermore, in one embodiment, the regenerative braking control device further includes a new module for: A regenerative braking request is generated when the requested braking torque is less than a preset torque threshold, the real-time vehicle speed is greater than a stationary speed threshold, and adaptive cruise control and automatic braking are activated.

[0167] Furthermore, in one embodiment, the regenerative braking control device further includes a new module for: When exiting the regenerative braking state, reset all status flags and exit the corresponding state.

[0168] Furthermore, in one embodiment, the regenerative braking control device further includes a new module for: The regenerative braking control torque is determined based on the regenerative braking force and the tire rolling radius. Regenerative braking control is performed based on the regenerative braking control torque.

[0169] The functions of each module in the above-mentioned regenerative braking control device correspond to the steps in the above-mentioned regenerative braking control method embodiment, and their functions and implementation processes will not be described in detail here.

[0170] Thirdly, embodiments of this application provide a regenerative braking control device. This device can be a vehicle-mounted ECU (electronic control unit) or other device with data processing capabilities, and can execute the steps of the following regenerative braking control method: When a regenerative braking request is received, the system enters the regenerative braking state and determines the dynamic ramp demand time based on the target regenerative braking torque. The starting speed of the final ramp is determined based on the regenerative braking deceleration and the dynamic ramp demand time. When the vehicle regenerative braking is in the holding phase and the real-time vehicle speed is less than or equal to the starting speed of the end slope, it enters the end slope state. If the regenerative braking deceleration is greater than or equal to the deceleration threshold, the output decreasing regenerative braking force is obtained by smooth fitting of the hybrid curve algorithm based on the dynamic slope demand time, the initial braking force of the end slope and the real-time sensor parameters of the braking state. The regenerative braking force is reduced according to the output decreasing regenerative braking force until the regenerative braking state is exited. Among them, the real-time sensing parameters of braking status include real-time vehicle speed, real-time braking force, and real-time vehicle deceleration.

[0171] Furthermore, the regenerative braking control method that the regenerative braking control device can execute also includes: The conversion factor is determined based on the tire rolling radius; The gradient baseline value is determined based on the slope calibration value and the S-curve weight; The maximum torque gradient is determined based on the slope calibration value, gradient reference value, and conversion coefficient. The dynamic ramp demand time is determined based on the target regenerative braking torque and the maximum torque gradient. Among them, the target regenerative braking torque is less than or equal to the maximum regenerative braking torque, and the maximum regenerative braking torque is determined based on the current vehicle mass.

[0172] Furthermore, the regenerative braking control method that the regenerative braking control device can execute also includes: The actual braking force step size is determined based on the dynamic slope demand time, the initial braking force at the end of the slope, and the real-time sensor parameters of the braking status. The cumulative step length is obtained by summing the actual braking force step length of each control cycle, and the slope position is determined based on the cumulative step length. The mixing curve factor is obtained by fitting the mixing curve based on the slope location; The output decreasing regenerative braking force for the current control cycle is determined based on the mixing curve factor.

[0173] Furthermore, the regenerative braking control method that the regenerative braking control device can execute also includes: The fixed number of deceleration steps is determined based on the dynamic slope demand time and control cycle. The fixed braking force step length is determined based on the fixed deceleration step number and the initial braking force at the end of the ramp. The variable deceleration time is determined based on the real-time vehicle speed and real-time vehicle deceleration. The number of variable deceleration steps is determined based on the variable deceleration time and the remaining control cycle. The variable braking force step size is determined based on the variable deceleration step number and the real-time braking force of the previous control cycle. The actual braking force step length is determined based on the maximum value of the fixed braking force step length and the variable braking force step length.

[0174] Furthermore, the regenerative braking control method that the regenerative braking control device can execute also includes: The S-curve position is obtained by polynomial curve fitting of the slope position, and the S-curve factor is determined based on the S-curve position and S-curve weight. The linear curve factor is determined based on the slope location and the linear curve weight. The mixed curve factor is determined based on the S-curve factor and the linear curve factor.

[0175] Furthermore, the regenerative braking control method that the regenerative braking control device can execute also includes: The starting speed for ending the ramp is determined based on the regenerative braking deceleration, the dynamic ramp demand time, and the regenerative braking exit speed.

[0176] Furthermore, the regenerative braking control method that the regenerative braking control device can execute also includes: If the regenerative braking deceleration is less than the deceleration threshold, the output decreasing regenerative braking force is calculated based on the initial braking force at the end of the ramp and the real-time sensing parameters of the braking state using a control cycle decreasing algorithm.

[0177] Furthermore, the regenerative braking control method that the regenerative braking control device can execute also includes: The pre-filling start speed is determined based on the initial speed of the end ramp, the regenerative braking deceleration, and the set pre-filling time. The speed hysteresis is determined based on the regenerative braking deceleration and the set buffer time. Determine the initial velocity of the hold phase based on the velocity hysteresis and the initial velocity of the final ramp; The reset speed of the end slope is determined based on the velocity hysteresis, the pre-filling start speed, and the end slope start speed. When the real-time vehicle speed exceeds the end slope reset speed, reset all status flags and exit the corresponding status.

[0178] Furthermore, the regenerative braking control method that the regenerative braking control device can execute also includes: When the real-time vehicle speed is less than or equal to the ramp reset speed, a pre-filling judgment is performed; If the pre-filling judgment indicates that the real-time vehicle speed is greater than the starting speed of the end ramp but less than or equal to the starting speed of the pre-filling, the vehicle enters the pre-filling state. When the pre-filling judgment indicates that the real-time vehicle speed is less than or equal to the starting speed of the end slope, it enters the residual force holding state.

[0179] Furthermore, the regenerative braking control method that the regenerative braking control device can execute also includes: When the real-time vehicle speed is less than or equal to the starting speed of the holding phase, the vehicle enters the holding phase state.

[0180] Furthermore, the regenerative braking control method that the regenerative braking control device can execute also includes: When the ramp ends, the minimum value among the output decreasing regenerative braking force, the output decreasing regenerative braking force of the previous control cycle, and the maximum regenerative braking force is taken as the final output decreasing regenerative braking force of the current control cycle.

[0181] Furthermore, the regenerative braking control method that the regenerative braking control device can execute also includes: A regenerative braking request is generated when the requested braking torque is less than a preset torque threshold, the real-time vehicle speed is greater than a stationary speed threshold, and adaptive cruise control and automatic braking are activated.

[0182] Furthermore, the regenerative braking control method that the regenerative braking control device can execute also includes: When exiting the regenerative braking state, reset all status flags and exit the corresponding state.

[0183] Furthermore, the regenerative braking control method that the regenerative braking control device can execute also includes: The regenerative braking control torque is determined based on the regenerative braking force and the tire rolling radius. Regenerative braking control is performed based on the regenerative braking control torque.

[0184] Reference Figure 8 , Figure 8 This is a schematic diagram of the hardware structure of the regenerative braking control device involved in the embodiments of this application. In the embodiments of this application, the regenerative braking control device may include a processor, a memory, a communication interface, and a communication bus.

[0185] The communication bus can be of any type and is used to interconnect the processor, memory, and communication interface.

[0186] The communication interface includes input / output (I / O) interfaces, physical interfaces, and logical interfaces used for interconnecting devices within the regenerative braking control equipment, as well as interfaces used for interconnecting the regenerative braking control equipment with other devices (such as other computing devices or user equipment). Physical interfaces can be Ethernet interfaces, fiber optic interfaces, ATM interfaces, etc.; user equipment can be displays, touch screens, etc.

[0187] Memory can be various types of storage media, such as random access memory (RAM), read-only memory (ROM), non-volatile RAM (NVRAM), flash memory, optical storage, hard disk, programmable ROM (PROM), erasable PROM (EPROM), electrically erasable PROM (EEPROM), etc.

[0188] The processor can be a general-purpose processor, which can call the regenerative braking control program stored in memory and execute the regenerative braking control method provided in the embodiments of this application. For example, the general-purpose processor can be a central processing unit (CPU). The method executed when the regenerative braking control program is called can be referred to in the various embodiments of the regenerative braking control method of this application, and will not be repeated here.

[0189] Those skilled in the art will understand that Figure 8 The hardware structure shown does not constitute a limitation of this application and may include more or fewer components than shown, or combine certain components, or have different component arrangements.

[0190] Fourthly, embodiments of this application also provide a computer-readable storage medium.

[0191] This application provides a computer-readable storage medium storing a regenerative braking control program, wherein when executed by a processor, the regenerative braking control program implements the following steps of a regenerative braking control method: When a regenerative braking request is received, the system enters the regenerative braking state and determines the dynamic ramp demand time based on the target regenerative braking torque. The starting speed of the final ramp is determined based on the regenerative braking deceleration and the dynamic ramp demand time. When the vehicle regenerative braking is in the holding phase and the real-time vehicle speed is less than or equal to the starting speed of the end slope, it enters the end slope state. If the regenerative braking deceleration is greater than or equal to the deceleration threshold, the output decreasing regenerative braking force is obtained by smooth fitting of the hybrid curve algorithm based on the dynamic slope demand time, the initial braking force of the end slope and the real-time sensor parameters of the braking state. The regenerative braking force is reduced according to the output decreasing regenerative braking force until the regenerative braking state is exited. Among them, the real-time sensing parameters of braking status include real-time vehicle speed, real-time braking force, and real-time vehicle deceleration.

[0192] Furthermore, when the regenerative braking control program is executed by the processor, the regenerative braking control method that can be implemented also includes: The conversion factor is determined based on the tire rolling radius; The gradient baseline value is determined based on the slope calibration value and the S-curve weight; The maximum torque gradient is determined based on the slope calibration value, gradient reference value, and conversion coefficient. The dynamic ramp demand time is determined based on the target regenerative braking torque and the maximum torque gradient. Among them, the target regenerative braking torque is less than or equal to the maximum regenerative braking torque, and the maximum regenerative braking torque is determined based on the current vehicle mass.

[0193] Furthermore, when the regenerative braking control program is executed by the processor, the regenerative braking control method that can be implemented also includes: The actual braking force step size is determined based on the dynamic slope demand time, the initial braking force at the end of the slope, and the real-time sensor parameters of the braking status. The cumulative step length is obtained by summing the actual braking force step length of each control cycle, and the slope position is determined based on the cumulative step length. The mixing curve factor is obtained by fitting the mixing curve based on the slope location; The output decreasing regenerative braking force for the current control cycle is determined based on the mixing curve factor.

[0194] Furthermore, when the regenerative braking control program is executed by the processor, the regenerative braking control method that can be implemented also includes: The fixed number of deceleration steps is determined based on the dynamic slope demand time and control cycle. The fixed braking force step length is determined based on the fixed deceleration step number and the initial braking force at the end of the ramp. The variable deceleration time is determined based on the real-time vehicle speed and real-time vehicle deceleration. The number of variable deceleration steps is determined based on the variable deceleration time and the remaining control cycle. The variable braking force step size is determined based on the variable deceleration step number and the real-time braking force of the previous control cycle. The actual braking force step length is determined based on the maximum value of the fixed braking force step length and the variable braking force step length.

[0195] Furthermore, when the regenerative braking control program is executed by the processor, the regenerative braking control method that can be implemented also includes: The S-curve position is obtained by polynomial curve fitting of the slope position, and the S-curve factor is determined based on the S-curve position and S-curve weight. The linear curve factor is determined based on the slope location and the linear curve weight. The mixed curve factor is determined based on the S-curve factor and the linear curve factor.

[0196] Furthermore, when the regenerative braking control program is executed by the processor, the regenerative braking control method that can be implemented also includes: The starting speed for ending the ramp is determined based on the regenerative braking deceleration, the dynamic ramp demand time, and the regenerative braking exit speed.

[0197] Furthermore, when the regenerative braking control program is executed by the processor, the regenerative braking control method that can be implemented also includes: If the regenerative braking deceleration is less than the deceleration threshold, the output decreasing regenerative braking force is calculated based on the initial braking force at the end of the ramp and the real-time sensing parameters of the braking state using a control cycle decreasing algorithm.

[0198] Furthermore, when the regenerative braking control program is executed by the processor, the regenerative braking control method that can be implemented also includes: The pre-filling start speed is determined based on the initial speed of the end ramp, the regenerative braking deceleration, and the set pre-filling time. The speed hysteresis is determined based on the regenerative braking deceleration and the set buffer time. Determine the initial velocity of the hold phase based on the velocity hysteresis and the initial velocity of the final ramp; The reset speed of the end slope is determined based on the velocity hysteresis, the pre-filling start speed, and the end slope start speed. When the real-time vehicle speed exceeds the end slope reset speed, reset all status flags and exit the corresponding status.

[0199] Furthermore, when the regenerative braking control program is executed by the processor, the regenerative braking control method that can be implemented also includes: When the real-time vehicle speed is less than or equal to the ramp reset speed, a pre-filling judgment is performed; If the pre-filling judgment indicates that the real-time vehicle speed is greater than the starting speed of the end ramp but less than or equal to the starting speed of the pre-filling, the vehicle enters the pre-filling state. When the pre-filling judgment indicates that the real-time vehicle speed is less than or equal to the starting speed of the end slope, it enters the residual force holding state.

[0200] Furthermore, when the regenerative braking control program is executed by the processor, the regenerative braking control method that can be implemented also includes: When the real-time vehicle speed is less than or equal to the starting speed of the holding phase, the vehicle enters the holding phase state.

[0201] Furthermore, when the regenerative braking control program is executed by the processor, the regenerative braking control method that can be implemented also includes: When the ramp ends, the minimum value among the output decreasing regenerative braking force, the output decreasing regenerative braking force of the previous control cycle, and the maximum regenerative braking force is taken as the final output decreasing regenerative braking force of the current control cycle.

[0202] Furthermore, when the regenerative braking control program is executed by the processor, the regenerative braking control method that can be implemented also includes: A regenerative braking request is generated when the requested braking torque is less than a preset torque threshold, the real-time vehicle speed is greater than a stationary speed threshold, and adaptive cruise control and automatic braking are activated.

[0203] Furthermore, when the regenerative braking control program is executed by the processor, the regenerative braking control method that can be implemented also includes: When exiting the regenerative braking state, reset all status flags and exit the corresponding state.

[0204] Furthermore, when the regenerative braking control program is executed by the processor, the regenerative braking control method that can be implemented also includes: The regenerative braking control torque is determined based on the regenerative braking force and the tire rolling radius. Regenerative braking control is performed based on the regenerative braking control torque.

[0205] It should be noted that the sequence numbers of the embodiments in this application are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0206] The terms "comprising" and "having," and any variations thereof, in the specification, claims, and accompanying drawings of this application are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to such process, method, product, or apparatus. The terms "first," "second," and "third," etc., are used to distinguish different objects, etc., and do not indicate a sequence, nor do they limit "first," "second," and "third" to different types.

[0207] In the description of the embodiments in this application, terms such as "exemplary," "for example," or "for example" are used to indicate examples, illustrations, or explanations. Any embodiment or design described as "exemplary," "for example," or "for example" in the embodiments of this application should not be construed as being more preferred or advantageous than other embodiments or designs. Specifically, the use of terms such as "exemplary," "for example," or "for example" is intended to present the relevant concepts in a specific manner.

[0208] In the description of the embodiments of this application, unless otherwise stated, " / " means "or". For example, A / B can mean A or B. The "and / or" in the text is merely a description of the relationship between related objects, indicating that there can be three relationships. For example, A and / or B can mean: A exists alone, A and B exist simultaneously, and B exists alone. In addition, in the description of the embodiments of this application, "multiple" means two or more.

[0209] In some processes described in the embodiments of this application, multiple operations or steps are included in a specific order. However, it should be understood that these operations or steps may not be executed in the order they appear in the embodiments of this application, or they may be executed in parallel. The sequence number of the operation is only used to distinguish different operations, and the sequence number itself does not represent any execution order. In addition, these processes may include more or fewer operations, and these operations or steps may be executed sequentially or in parallel, and these operations or steps may be combined.

[0210] Through the above description of the embodiments, those skilled in the art can clearly understand that the methods of the above embodiments can be implemented by means of software plus necessary general-purpose hardware platforms. Of course, they can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk) as described above, and includes several instructions to cause a terminal device to execute the methods of the various embodiments of this application.

[0211] The above are merely preferred embodiments of this application and do not limit the patent scope of this application. Any equivalent structural or procedural transformations made using the content of this application's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this application.

Claims

1. A regenerative braking control method characterized by, The method comprises the following steps: When a regenerative braking request is received, entering a regenerative braking state, determining a dynamic ramp demand time according to a target regenerative braking torque; Determining an end ramp start speed according to a regenerative braking deceleration and the dynamic ramp demand time; When the vehicle regenerative braking is in a holding phase state and a real-time vehicle speed is less than or equal to the end ramp start speed, entering an end ramp state, and if the regenerative braking deceleration is greater than or equal to a deceleration threshold, performing a hybrid curve algorithm smooth fitting according to the dynamic ramp demand time, an end ramp initial braking force and a braking state real-time sensing parameter to obtain an output decreasing regenerative braking force; Performing a regenerative braking force decreasing control according to the output decreasing regenerative braking force until exiting the regenerative braking state; The braking state real-time sensing parameter comprises a real-time vehicle speed, a real-time braking force and a real-time vehicle deceleration.

2. The regenerative braking control method according to claim 1, characterized by, The step of determining the dynamic ramp demand time according to the target regenerative braking torque comprises the following steps: Determining a conversion coefficient according to a tire rolling radius; Determining a gradient reference value according to a slope calibration quantity and an S curve weight; Determining a maximum torque gradient according to the slope calibration quantity, the gradient reference value and the conversion coefficient; Determining the dynamic ramp demand time according to a target regenerative braking torque and the maximum torque gradient; The target regenerative braking torque is less than or equal to a maximum regenerative braking torque, and the maximum regenerative braking torque is determined according to a current vehicle mass.

3. The regenerative braking control method according to claim 1, characterized by, The step of performing the hybrid curve algorithm smooth fitting according to the dynamic ramp demand time, the end ramp initial braking force and the braking state real-time sensing parameter to obtain the output decreasing regenerative braking force comprises the following steps: Determining an actual braking force step length according to the dynamic ramp demand time, the end ramp initial braking force and the braking state real-time sensing parameter; Accumulating the actual braking force step length of each control period to obtain a cumulative step length, and determining a ramp position according to the cumulative step length; Performing a hybrid curve fitting according to the ramp position to obtain a hybrid curve factor; Determining the output decreasing regenerative braking force of a current control period according to the hybrid curve factor.

4. The regenerative braking control method according to claim 3, characterized by, The step of determining the actual braking force step length according to the dynamic ramp demand time, the end ramp initial braking force and the braking state real-time sensing parameter comprises the following steps: Determining a fixed deceleration step number according to the dynamic ramp demand time and a control period; Determining a fixed braking force step length according to the fixed deceleration step number and the end ramp initial braking force; Determining a variable deceleration time according to the real-time vehicle speed and the real-time vehicle deceleration; Determining a variable deceleration step number according to the variable deceleration time and a remaining control period; Determining a variable braking force step length according to the variable deceleration step number and the real-time braking force of a previous control period; Determining the actual braking force step length according to a maximum value of the fixed braking force step length and the variable braking force step length.

5. The regenerative braking control method according to claim 3, characterized by, The step of performing the hybrid curve fitting according to the ramp position to obtain the hybrid curve factor comprises the following steps: Performing a polynomial curve fitting on the ramp position to obtain an S curve position, and determining an S curve factor according to the S curve position and an S curve weight; Determining a linear curve factor according to the ramp position and a linear curve weight; Determining the hybrid curve factor according to the S curve factor and the linear curve factor.

6. The regenerative braking control method according to claim 1, characterized by, The end ramp start speed is determined according to the regenerative braking deceleration and the dynamic ramp demand time, and the method further comprises: The end ramp start speed is determined according to the regenerative braking deceleration, the dynamic ramp demand time and the regenerative braking exit vehicle speed.

7. The regenerative braking control method according to claim 1, characterized by, The method further comprises: If the regenerative braking deceleration is less than a deceleration threshold, the output regenerative braking force is calculated according to the end ramp initial braking force and real-time sensing parameters of a braking state based on a control cycle decreasing algorithm.

8. The regenerative braking control method according to claim 1, characterized by, The method further comprises: The pre-charging start speed is determined according to the end ramp start speed, the regenerative braking deceleration and a set pre-charging time; The speed hysteresis is determined according to the regenerative braking deceleration and a set buffer time; The holding stage start speed is determined according to the speed hysteresis and the end ramp start speed; The end ramp reset speed is determined according to the speed hysteresis, the pre-charging start speed and the end ramp start speed; When the real-time vehicle speed is greater than the end ramp reset speed, the state flags are reset and the corresponding state is exited.

9. The regenerative braking control method according to claim 8, characterized by, The method further comprises: When the real-time vehicle speed is less than or equal to the ramp reset speed, pre-charging judgment is performed; If the pre-charging judgment shows that the real-time vehicle speed is greater than the end ramp start speed and less than or equal to the pre-charging start speed, the pre-charging state is entered; When the pre-charging judgment shows that the real-time vehicle speed is less than or equal to the end ramp start speed, the residual force holding state is entered.

10. The regenerative braking control method according to claim 8, characterized by, The method further comprises: When the real-time vehicle speed is less than or equal to the holding stage start speed, the holding stage state is entered.

11. The regenerative braking control method according to claim 1, characterized by, The method further comprises: In the end ramp state, the minimum value among the output regenerative braking force, the output regenerative braking force of the last control cycle and the maximum regenerative braking force is taken as the final output regenerative braking force of the current control cycle.

12. The regenerative braking control method according to claim 1, characterized by, The method further comprises: When the requested braking torque is less than a preset torque threshold, the real-time vehicle speed is greater than a static state speed threshold, and the adaptive cruise control state and the automatic braking state are activated, the regenerative braking request is generated.

13. The regenerative braking control method according to claim 1, characterized by, The method further comprises: When the regenerative braking state is exited, the state flags are reset and the corresponding state is exited.

14. The regenerative braking control method according to claim 1, characterized by, The method further comprises: The regenerative braking control torque is determined according to the regenerative braking force and the tire rolling radius; The regenerative braking control is performed according to the regenerative braking control torque.

15. A regenerative braking control device characterized by comprising: The method further comprises: The regenerative braking control module is configured to enter the regenerative braking state when the regenerative braking request is received, and to determine the dynamic ramp demand time according to the target regenerative braking torque; The exit condition determination module is configured to determine the end ramp start speed according to the regenerative braking deceleration and the dynamic ramp demand time; The exit control force calculation module is configured to enter the end ramp state when the vehicle regenerative braking is in the holding stage state and the real-time vehicle speed is less than or equal to the end ramp start speed, and to calculate the output regenerative braking force according to the dynamic ramp demand time, the end ramp initial braking force and real-time sensing parameters of a braking state based on a mixed curve algorithm smooth fitting if the regenerative braking deceleration is greater than or equal to a deceleration threshold. The regenerative braking exit module is configured to perform regenerative braking force decrement control according to the output regenerative braking force decrement until the regenerative braking state is exited. The real-time braking state sensing parameters include real-time vehicle speed, real-time braking force and real-time vehicle deceleration.

16. The regenerative braking control device according to claim 15, characterized by The regenerative braking control device comprises a dynamic slope time calculation module configured to: determine a conversion coefficient according to a tire rolling radius; determine a gradient reference value according to a slope calibration value and an S-curve weight; determine a maximum torque gradient according to the slope calibration value, the gradient reference value and the conversion coefficient; determine a dynamic slope demand time according to a preset maximum braking torque, a target regenerative braking torque and the maximum torque gradient.

17. The regenerative braking control device according to claim 15, characterized by The regenerative braking control device comprises a hybrid curve braking force fitting module configured to: determine an actual braking force step according to the dynamic slope demand time, an end slope initial braking force and real-time braking state sensing parameters; accumulate the actual braking force step of each control cycle to obtain a cumulative step, and determine a slope position according to the cumulative step; perform hybrid curve fitting according to the slope position to obtain a hybrid curve factor; determine an output regenerative braking force decrement of a current control cycle according to the hybrid curve factor.

18. The regenerative braking control device according to claim 15, characterized by The regenerative braking control device comprises a low deceleration control module configured to: if the regenerative braking deceleration is less than a deceleration threshold, perform control cycle decrement algorithm-based calculation according to an end slope initial braking force and real-time braking state sensing parameters to obtain an output regenerative braking force decrement.

19. A regenerative braking control device characterized by comprising: The regenerative braking control device comprises a processor, a memory, and a regenerative braking control program stored on the memory and executable by the processor, wherein when the regenerative braking control program is executed by the processor, the steps of the regenerative braking control method according to any one of claims 1 to 14 are implemented.

20. A computer-readable storage medium, characterized in that, The computer readable storage medium stores a regenerative braking control program, wherein when the regenerative braking control program is executed by a processor, the steps of the regenerative braking control method according to any one of claims 1 to 14 are implemented.

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