Low-speed braking energy recovery method and low-speed braking energy recovery device

Abstract

The application discloses a low-speed braking energy recovery method and device. The low-speed braking energy recovery method comprises the following steps: a brake controller sends a brake pedal setting signal to a motor controller; the motor controller identifies whether the brake pedal setting signal is set; when the motor controller identifies that the driver applies the brake, the crawling torque starting to be requested below a calibrated vehicle speed threshold is closed; when the motor controller identifies that the driver applies the brake, the brake energy recovery capability value is periodically and continuously sent to the brake controller; after the brake energy recovery capability value is received, the brake controller periodically and continuously sends a brake energy recovery request to the motor controller until the vehicle speed is 0; when the motor controller identifies that the driver does not apply the brake and the vehicle speed meets the crawling torque opening condition of the calibrated vehicle speed threshold, the crawling torque is opened. The positive crawling torque is eliminated from the offset effect of the negative recovery torque, and the low-speed recovery efficiency is improved.

Description

Technical Field

[0001] This invention relates to the technical field of vehicles, specifically to a method and device for low-speed braking energy recovery. Background Technology

[0002] In vehicles equipped with energy recovery systems, energy recovery is typically initiated by the motor controller based on brake pedal signals during braking. However, at low speeds, especially below the calibrated threshold, the vehicle often still requires creep torque to ensure smooth crawling and acceleration. This creep torque is a positive drive torque, which cancels out the negative torque generated by brake energy recovery, resulting in a significant reduction in recovery efficiency at low speeds or even the inability to recover energy. Summary of the Invention

[0003] This invention aims to at least solve the problem in the prior art where the negative torque request for current regenerative braking and the positive torque of motor creep cancel each other out, resulting in the inability to perform regenerative braking at low vehicle speeds. To this end, this invention provides a low-speed regenerative braking method and a low-speed regenerative braking device.

[0004] According to a first aspect of the present invention, a low-speed braking energy recovery method is applied to a vehicle braking energy recovery system, the system including a brake controller and a motor controller, the low-speed braking energy recovery method comprising: The brake controller sends the brake pedal set signal to the motor controller; The motor controller identifies whether the brake pedal set signal is set; When the motor controller detects that the driver is applying the brakes, it shuts off the creep torque that was requested before the vehicle speed threshold was set. When the motor controller detects that the driver is applying the brakes, it periodically and continuously sends the brake energy recovery capability value to the brake controller. After receiving the regenerative braking capability value, the brake controller periodically and continuously sends regenerative braking requests to the motor controller until the vehicle speed is 0. When the motor controller detects that the driver has not applied the brakes and the vehicle speed meets the calibrated vehicle speed threshold, the creep torque is activated.

[0005] A low-speed braking energy recovery method according to an embodiment of the present invention has at least the following beneficial effects: During braking, the creep torque requested below the calibrated vehicle speed threshold is shut off, eliminating the offsetting effect of positive creep torque on negative recovery torque and improving recovery efficiency at low speeds. By continuously sending capability values ​​and requests until the vehicle speed reaches 0, the problem of expired recovery capability values ​​and interrupted recovery requests at low speeds in existing technologies is solved, enabling the vehicle to continue regenerating braking energy below the calibrated vehicle speed threshold until it comes to a complete stop, thus improving the vehicle's overall driving range.

[0006] According to some embodiments of the present invention, the brake pedal setting signal is a binary state signal characterizing whether the brake pedal is depressed.

[0007] According to some embodiments of the present invention, the brake controller sends a brake pedal set signal to the motor controller, including: The brake controller sends the brake pedal set signal to the motor controller via the vehicle's CAN bus; When the binary status signal is set, it indicates that the brake pedal is depressed; when the binary status signal is not set, it indicates that the brake pedal is not depressed.

[0008] According to some embodiments of the present invention, the period for the motor controller to periodically and continuously send the braking energy recovery capability value to the brake controller is T1, and the period for the brake controller to periodically and continuously send the braking energy recovery request to the motor controller is T2, and T1≤T2.

[0009] According to some embodiments of the present invention, the braking energy recovery capability value includes at least one of the maximum permissible recovery torque, the maximum permissible recovery power, and the sustainable recovery time.

[0010] According to some embodiments of the present invention, the closure of the creep torque requested when it begins below a calibrated vehicle speed threshold includes: The motor controller prohibits the generation of creep torque requests when the vehicle speed is lower than or equal to the calibrated vehicle speed threshold, and / or cancels currently generated creep torque requests.

[0011] According to some embodiments of the present invention, after receiving the regenerative braking capability value, the brake controller periodically and continuously sends a regenerative braking request to the motor controller, including: The brake controller generates a brake energy recovery request based on the brake energy recovery capability value and the brake pedal opening, and periodically sends it to the motor controller; When the vehicle speed is 0, the brake controller stops sending the brake energy recovery request.

[0012] According to some embodiments of the present invention, when the motor controller detects that the driver has not applied the brakes and the vehicle speed meets the creep torque activation condition of the calibrated vehicle speed threshold, activating the creep torque includes: When no braking is applied and the vehicle speed drops below the calibrated vehicle speed threshold, the motor controller resumes the creep torque request; or When no braking is applied and the vehicle speed meets the creep torque activation condition corresponding to the calibrated vehicle speed threshold, the motor controller outputs creep torque.

[0013] According to some embodiments of the present invention, the calibrated vehicle speed threshold is 2~5 km / h.

[0014] According to a second aspect of the present invention, a low-speed braking energy recovery device includes a brake controller and a motor controller. The brake controller includes: The brake pedal position signal sending module is used to send the brake pedal position signal to the motor controller. The brake pedal position signal is a binary state signal that indicates whether the brake pedal is depressed, which is different from the continuous position signal that indicates the amount of brake pedal depression. The regenerative braking request sending module is used to periodically and continuously send regenerative braking requests to the motor controller after receiving the regenerative braking capability value until the vehicle speed is 0. The motor controller includes: A brake pedal signal recognition module is used to identify whether the brake pedal set signal is set; The creep torque shut-off module is used to shut off the creep torque that is requested when the driver applies the brakes, which is below a calibrated vehicle speed threshold. The regenerative braking capability sending module is used to periodically and continuously send the regenerative braking capability value to the brake controller when the driver applies the brakes. The creep torque activation module is used to activate the creep torque when it is detected that the driver has not applied the brakes and the vehicle speed meets the calibrated vehicle speed threshold.

[0015] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. Attached Figure Description

[0016] The present invention will be further described below with reference to the accompanying drawings and embodiments, wherein: Figure 1 A simplified flowchart of a low-speed braking energy recovery method; Figure 2 This is a flowchart of a low-speed braking energy recovery method. Detailed Implementation

[0017] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0018] In the description of this invention, it should be understood that the orientation descriptions, such as up, down, etc., are based on the orientation or positional relationship shown in the drawings and are only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0019] In the description of this invention, "multiple" refers to two or more. The use of "first" and "second" is for distinguishing technical features only and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features or their sequential relationship.

[0020] In the description of this invention, unless otherwise explicitly defined, terms such as "set up," "install," and "connect" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this invention in conjunction with the specific content of the technical solution.

[0021] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described below are some embodiments of the present invention, not all embodiments.

[0022] Reference Figure 1 and Figure 2 A low-speed braking energy recovery method is applied to a vehicle braking energy recovery system. The system includes a brake controller and a motor controller. The low-speed braking energy recovery method includes: Step S100: The brake controller sends the brake pedal set signal to the motor controller; Step S200: The motor controller identifies whether the brake pedal set signal is set; Step S300: When the motor controller detects that the driver has applied the brakes, it shuts off the creep torque that was requested when the vehicle speed was below the calibrated threshold. Step S400: When the motor controller detects that the driver has applied the brakes, it periodically and continuously sends the brake energy recovery capability value to the brake controller. Step S500: After receiving the regenerative braking capability value, the brake controller periodically and continuously sends regenerative braking requests to the motor controller until the vehicle speed is 0. Step S600: When the motor controller detects that the driver has not applied the brakes and the vehicle speed meets the creep torque activation condition of the calibrated vehicle speed threshold, the creep torque is activated.

[0023] During braking, the creep torque request initiated below the calibrated vehicle speed threshold is deactivated, eliminating the offsetting effect of positive creep torque on negative regenerative torque and improving low-speed recovery efficiency. By continuously sending capability values ​​and requests until the vehicle speed reaches 0, the problem of expired low-speed regenerative capability values ​​and interrupted recovery requests in existing technologies is solved, enabling the vehicle to continue regenerating braking energy below 3 km / h until it comes to a complete stop, thus increasing the vehicle's range. Creep torque is restored when no braking is applied and the creep torque activation conditions are met, ensuring a normal driving experience during vehicle start-up, creeping, and after stopping.

[0024] Meanwhile, in existing control strategies, the regenerative braking capacity values ​​sent by the motor controller are often only sent at the initial stage of braking or are sent intermittently. The brake controller cannot continuously obtain effective capacity values ​​at low speeds, causing the regenerative braking request to be interrupted, and the vehicle cannot continue to recover energy before its speed drops to zero. Furthermore, existing brake pedal signals mostly use continuous position signals, which have response delays and are easily affected by sensor accuracy. This makes it difficult to immediately deactivate creep torque when the driver presses the brake pedal, further exacerbating the conflict between creep torque and regenerative torque.

[0025] Therefore, in step S100, the brake pedal set signal is a binary state signal indicating whether the brake pedal is depressed, rather than a continuous position signal. The motor controller can identify the driver's braking intention the moment the brake pedal is depressed, unaffected by the accuracy or calibration error of the position sensor. This shortens the delay in triggering the creep torque shutdown and regeneration request, resulting in faster response and higher reliability. The binary set signal triggers a combination of continuously sending capability values / requests until the vehicle speed reaches 0. These two elements work together to solve the technical problem of low-speed regeneration interruption and creep torque conflict.

[0026] More specifically, the brake controller sends a brake pedal set signal to the motor controller, including: The brake controller sends the brake pedal set signal to the motor controller via the vehicle's CAN bus. A binary status signal indicates that the brake pedal is depressed when it is set, and that the brake pedal is not depressed when it is not set. Utilizing the vehicle's CAN bus for transmission ensures reliable communication, good real-time performance, and compatibility with existing vehicle network architectures, eliminating the need for additional hardwiring.

[0027] Furthermore, the period for the motor controller to periodically and continuously send the regenerative braking capability value to the brake controller is T1, and the period for the brake controller to periodically and continuously send the regenerative braking request to the motor controller is T2, where T1 ≤ T2. This ensures that the capability value used by the brake controller when generating a regenerative braking request is the latest value, avoiding requests exceeding the motor's current actual regenerative braking capability. It also prevents motor overcurrent, battery overcharging / over-discharging, or sudden changes in regenerative braking torque caused by excessive requests, improving system safety. By limiting the periodicity, a timing coordination is formed where capability is updated first and requests are sent later, enhancing control stability. The sending period T1 is 10ms~50ms. 10ms~50ms ensures sufficient real-time capability value, meeting the need for rapid updates in low-speed regenerative braking control. Simultaneously, it avoids excessive load on the CAN bus or waste of controller computing resources due to excessively short periods.

[0028] According to some embodiments of the present invention, the regenerative braking capacity value includes at least one of the maximum permissible regenerative torque, the maximum permissible regenerative power, and the sustainable regenerative time. This enables the braking controller to fully understand the regenerative collection boundaries on the motor / battery side, thereby rationally allocating the regenerative torque. It maximizes energy recovery while protecting the battery and motor. It provides a quantitative basis for low-speed continuous regenerative braking, avoiding unreasonable requests due to overly simplistic capacity values.

[0029] Step S300 includes: The motor controller prohibits the generation of creep torque requests when the vehicle speed is below or equal to the calibrated vehicle speed threshold, and / or cancels currently generated creep torque requests. Prohibiting generation prevents new creep torque requests from being generated at the source. Canceling currently generated requests quickly clears existing creep torque, preventing its continued output. The combination of these two measures ensures that creep torque exits rapidly during braking, reducing the conflict time window with regenerative braking, and improving regenerative braking efficiency and smoothness.

[0030] Step S500 includes: The brake controller generates a brake energy recovery request based on the brake energy recovery capability value and the brake pedal opening, and sends it to the motor controller periodically. When the vehicle speed reaches 0, the brake controller stops sending regenerative braking requests. Combined with brake pedal opening, the regenerative braking request matches the driver's braking intention, resulting in a more linear braking feel. Based on the capability value, it ensures that the request does not exceed the system's regenerative braking boundary, protecting the motor and battery. Stopping sending requests at 0 speed prevents continued regenerative braking requests after stopping, which could lead to torque stagnation or vehicle vibration, ensuring safe and smooth stopping.

[0031] Step S600 includes: When no braking is applied and the vehicle speed drops below the calibrated speed threshold, the motor controller resumes the creep torque request; or When no braking is applied and the vehicle speed meets the creep torque activation condition corresponding to the calibrated vehicle speed threshold, the motor controller outputs creep torque.

[0032] This system ensures the vehicle resumes creeping motion after the driver releases the brake, conforming to traditional automatic transmission vehicle driving habits. It avoids permanent failure of the creeping function due to regenerative braking strategies, improving driving comfort. The system is deactivated during braking and activated when not braking, ensuring complete control logic.

[0033] According to some embodiments of the present invention, the calibrated vehicle speed threshold is 2~5 km / h. The calibrated vehicle speed threshold is 3 km / h, and can be calibrated according to vehicle model or calibration requirements. 3 km / h is a typical critical speed between low-speed creep and braking to a stop; below this threshold, the creep torque is deactivated and recovery continues, significantly improving the amount of energy recovered at low speeds. Calibration allows the solution to be adapted to different vehicle models, driving styles, and energy recovery strategies, improving versatility.

[0034] According to an embodiment of a low-speed braking energy recovery device of the second aspect of the present invention, the device includes a brake controller and a motor controller: The brake controller includes: The brake pedal set signal sending module is used to send the brake pedal set signal to the motor controller. The brake pedal set signal is a binary state signal that indicates whether the brake pedal is pressed, which is different from the continuous position signal that indicates the amount of brake pedal pressing. The regenerative braking request sending module is used to periodically and continuously send regenerative braking requests to the motor controller after receiving the regenerative braking capability value until the vehicle speed is 0. The motor controller includes: Brake pedal signal recognition module is used to identify whether the brake pedal set signal is set; The creep torque shut-off module is used to shut off the creep torque that is requested when the driver applies the brakes, which is below a calibrated vehicle speed threshold. The regenerative braking capability sending module is used to periodically and continuously send the regenerative braking capability value to the brake controller when the driver applies the brakes. The creep torque activation module is used to activate the creep torque when it is detected that the driver has not applied the brakes and the vehicle speed meets the calibrated vehicle speed threshold.

[0035] The brake pedal position signal sending module and the regeneration request sending module are located in the brake controller; the brake pedal signal recognition module, the creep torque deactivation module, the regeneration capability sending module, and the creep torque activation module are located in the motor controller. Clearly defining the functional module division of the two controllers facilitates the implementation of the overall vehicle electronic and electrical architecture.

[0036] Since this invention uses the brake pedal position signal, a binary state signal, as the trigger condition, the motor controller does not need to wait for the continuous position signal to exceed the calibrated threshold to identify the braking intention, thereby shutting off the creep torque the moment the brake pedal is pressed, shortening the conflict time window between the creep torque and the recovery torque.

[0037] Since the motor controller periodically and continuously sends the regenerative braking capability value, and the brake controller continuously sends regenerative braking requests until the vehicle speed reaches 0, the problem of regenerative braking failure caused by expired capability values ​​or interrupted requests in the low-speed range in the prior art is solved.

[0038] The synergistic effect of these features enables the vehicle to continue regenerating braking energy at speeds below 3 km / h until it comes to a stop, while also ensuring crawling functionality under non-braking conditions, achieving a comprehensive technical effect of improving driving range and ensuring driving smoothness.

[0039] This invention also provides a vehicle, including a memory, a processor, and a program stored in the memory and executable on the processor, wherein the program, when executed by the processor, implements a low-speed braking energy recovery method.

[0040] The processor can be implemented using a general-purpose central processing unit (CPU), microprocessor, application-specific integrated circuit (ASIC), or one or more integrated circuits, and is used to execute relevant programs to implement the technical solutions provided in the embodiments of this application.

[0041] The memory can be implemented in the form of read-only memory (ROM), static storage device, dynamic storage device, or random access memory (RAM). The memory can store the operating system and other applications. When the technical solutions provided in the embodiments of this specification are implemented through software or firmware, the relevant program code is stored in the memory and is called and executed by the processor.

[0042] The vehicle also includes the aforementioned low-speed braking energy recovery device. Specifically, the vehicle can be a private car, such as a sedan, SUV, MPV, or pickup truck. The vehicle can also be a commercial vehicle, such as a van, bus, small truck, or large semi-trailer. The vehicle can be a gasoline-powered vehicle or a new energy vehicle. When the vehicle is a new energy vehicle, it can be a hybrid vehicle or a pure electric vehicle.

[0043] According to an embodiment of the present invention, a computer-readable storage medium is stored thereon, which, when executed by a processor, implements the above-described low-speed braking energy recovery method.

[0044] The computer-readable storage medium of this invention can be any combination of one or more computer-readable media. The computer-readable medium can be a computer-readable signal medium or a computer-readable storage medium. The computer-readable storage medium can be, but is not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples of computer-readable storage media (a non-exhaustive list) include: an electrical connection having one or more wires, a portable computer disk, a hard disk, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage device, magnetic storage device, or any suitable combination thereof. In this invention, the computer-readable storage medium can be any tangible medium containing or storing a program that can be used by or in conjunction with an instruction execution system, apparatus, or device.

[0045] Computer-readable signal media may include data signals propagated in baseband or as part of a carrier wave, carrying computer-readable program code. Such propagated data signals may take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination thereof. Computer-readable signal media may also be any computer-readable medium other than computer-readable storage media, capable of sending, propagating, or transmitting programs for use by or in connection with an instruction execution system, apparatus, or device.

[0046] Program code contained on a computer-readable medium may be transmitted using any suitable medium, including but not limited to: wireless, wire, optical fiber, RF, etc., or any suitable combination thereof.

[0047] It should be understood that various parts of the present invention can be implemented in hardware, software, firmware, or a combination thereof. In the above embodiments, multiple steps or methods can be implemented in software or firmware stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, it can be implemented using any one or a combination of the following techniques known in the art: discrete logic circuits having logic gates for implementing logical functions on data signals, application-specific integrated circuits (ASICs) having suitable combinational logic gates, programmable gate arrays (PGAs), field-programmable gate arrays (FPGAs), etc.

[0048] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0049] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.

Claims

1. A method for low-speed braking energy recovery, characterized in that, An application in a vehicle braking energy recovery system, the system including a brake controller and a motor controller, wherein the low-speed braking energy recovery method includes: The brake controller sends the brake pedal set signal to the motor controller; The motor controller identifies whether the brake pedal set signal is set; When the motor controller detects that the driver is applying the brakes, it shuts off the creep torque that was requested before the vehicle speed threshold was set. When the motor controller detects that the driver is applying the brakes, it periodically and continuously sends the brake energy recovery capability value to the brake controller. After receiving the regenerative braking capability value, the brake controller periodically and continuously sends regenerative braking requests to the motor controller until the vehicle speed is 0. When the motor controller detects that the driver has not applied the brakes and the vehicle speed meets the calibrated vehicle speed threshold, the creep torque is activated.

2. The low-speed braking energy recovery method according to claim 1, characterized in that, The brake pedal setting signal is a binary state signal that indicates whether the brake pedal is pressed.

3. The low-speed braking energy recovery method according to claim 2, characterized in that, The brake controller sends a brake pedal set signal to the motor controller, including: The brake controller sends the brake pedal set signal to the motor controller via the vehicle's CAN bus; When the binary status signal is set, it indicates that the brake pedal is depressed; when the binary status signal is not set, it indicates that the brake pedal is not depressed.

4. The low-speed braking energy recovery method according to claim 1, characterized in that, The period for the motor controller to periodically and continuously send the braking energy recovery capability value to the brake controller is T1, and the period for the brake controller to periodically and continuously send the braking energy recovery request to the motor controller is T2, and T1≤T2.

5. The low-speed braking energy recovery method according to claim 1, characterized in that, The braking energy recovery capability value includes at least one of the following: maximum permissible recovery torque, maximum permissible recovery power, and sustainable recovery time.

6. The low-speed braking energy recovery method according to claim 1, characterized in that, The decision to disable the creep torque requested when it begins below a calibrated vehicle speed threshold includes: The motor controller prohibits the generation of creep torque requests when the vehicle speed is lower than or equal to the calibrated vehicle speed threshold, and / or cancels currently generated creep torque requests.

7. The low-speed braking energy recovery method according to claim 1, characterized in that, After receiving the regenerative braking capability value, the brake controller periodically and continuously sends regenerative braking requests to the motor controller, including: The brake controller generates a brake energy recovery request based on the brake energy recovery capability value and the brake pedal opening, and periodically sends it to the motor controller; When the vehicle speed is 0, the brake controller stops sending the brake energy recovery request.

8. The low-speed braking energy recovery method according to claim 1, characterized in that, When the motor controller detects that the driver has not applied the brakes and the vehicle speed meets the calibrated vehicle speed threshold, the creep torque is activated, including: When no braking is applied and the vehicle speed drops below the calibrated vehicle speed threshold, the motor controller resumes the creep torque request; or When no braking is applied and the vehicle speed meets the creep torque activation condition corresponding to the calibrated vehicle speed threshold, the motor controller outputs creep torque.

9. The low-speed braking energy recovery method according to claim 1, characterized in that, The calibrated vehicle speed threshold is 2~5 km / h.

10. A low-speed braking energy recovery device, characterized in that, The device includes a brake controller and a motor controller: The brake controller includes: The brake pedal position signal sending module is used to send the brake pedal position signal to the motor controller. The brake pedal position signal is a binary state signal that indicates whether the brake pedal is depressed, which is different from the continuous position signal that indicates the amount of brake pedal depression. The regenerative braking request sending module is used to periodically and continuously send regenerative braking requests to the motor controller after receiving the regenerative braking capability value until the vehicle speed is 0. The motor controller includes: A brake pedal signal recognition module is used to identify whether the brake pedal set signal is set; The creep torque shut-off module is used to shut off the creep torque that is requested when the driver applies the brakes, which is below a calibrated vehicle speed threshold. The regenerative braking capability sending module is used to periodically and continuously send the regenerative braking capability value to the brake controller when the driver applies the brakes. The creep torque activation module is used to activate the creep torque when it is detected that the driver has not applied the brakes and the vehicle speed meets the calibrated vehicle speed threshold.

Images