Method, device and vehicle for improving brake energy recovery efficiency

Abstract

This invention discloses a method, device, and vehicle for improving braking energy recovery efficiency. Under normal system self-check and inspection conditions, braking energy recovery for the current ignition cycle will only end after the number of times the braking energy recovery torque request has not been executed reaches a preset threshold. In the event of abnormal system self-check and inspection conditions, braking energy recovery for the current ignition cycle will end immediately. This eliminates the possibility of braking energy recovery for the current ignition cycle ending due to accidental abnormalities, thereby improving the braking energy recovery efficiency of the vehicle while ensuring vehicle safety.

Description

Technical Field

[0001] This invention belongs to the field of automotive braking control, and specifically relates to a method, device, and vehicle for improving braking energy recovery efficiency. Background Technology

[0002] With the development of vehicle electrification, driving range has become a crucial factor for users when choosing a vehicle. Regenerative braking, as a technology to improve driving range, is increasingly being applied in vehicles. Regenerative braking refers to the process where, when a vehicle needs to decelerate, the electric drive system converts the vehicle's kinetic energy into electrical energy stored in the battery, while simultaneously providing some deceleration. How to convert more kinetic energy into electrical energy to increase driving range is a key research focus for OEMs.

[0003] CN112298077A discloses a method, apparatus, and electronic device for improving energy recovery efficiency, applied to a vehicle controller. The core of this invention is determining whether the current allowable energy recovery power of an electric vehicle meets the driver's electric braking requirements, and increasing the current allowable energy recovery power when it does not. This method specifically proposes a solution to improve braking energy recovery efficiency, but it primarily focuses on adjustments made at the torque response execution end. It does not address whether the drive motor responds to the braking energy recovery request torque or whether the responded torque matches the requested torque (i.e., whether the braking energy recovery request torque is executed). Typically, if, during the current ignition cycle, the drive motor fails to respond to the braking energy recovery request torque, or the responded torque is inconsistent with the requested torque, the brake controller (IBCU) assumes an unknown fault in the drive motor system. The brake controller will set the braking energy recovery request torque to 0, stopping braking energy recovery, thus resulting in energy loss during the current ignition cycle. Summary of the Invention

[0004] The purpose of this invention is to provide a method, apparatus, and vehicle for improving the efficiency of brake energy recovery, so as to improve the efficiency of vehicle brake energy recovery while ensuring vehicle safety.

[0005] The method for improving regenerative braking efficiency according to the present invention includes:

[0006] S1. After the vehicle is started and powered on, the braking system performs a self-test, receives the self-test result information of the respective systems sent by the vehicle controller, motor controller and battery management controller, and then executes S2.

[0007] S2. (Based on the self-test results) Determine if the system is normal. If yes, proceed to S3; otherwise, proceed to S12.

[0008] S3. Determine whether the recyclable torque has been received from the vehicle controller. If yes, execute S4; otherwise, continue executing S3.

[0009] S4. Determine whether the braking energy recovery conditions are met. If yes, proceed to S5; otherwise, continue with S4.

[0010] S5. When the brake pedal is depressed, determine the brake energy recovery request torque based on the recyclable torque and the brake pedal travel, and send the brake energy recovery request torque to the vehicle controller, and then execute S6.

[0011] S6. Determine whether the regenerative braking torque request has been executed. If yes, end the process; otherwise, execute S7.

[0012] S7. Determine whether the system inspection result information sent by the vehicle controller, motor controller and battery management controller has been received. If yes, proceed to S8; otherwise, continue to S7.

[0013] S8. (Based on the inspection results) Determine if the system is normal. If yes, proceed to S9; otherwise, proceed to S11.

[0014] S9. Set a temporary fault and increase the number of temporary faults by 1, then execute S10; where the initial value of the number of temporary faults is 0.

[0015] S10. Determine whether the number of temporary failures is greater than or equal to the preset threshold. If yes, execute S11; otherwise, return to execute S4.

[0016] S11. Set a permanent fault for the current ignition cycle, and then execute S12.

[0017] S12. Send 0 as the braking energy recovery request torque for the current ignition cycle to the vehicle controller (equivalent to stopping braking energy recovery), and then end.

[0018] Preferably, if both condition one and condition two are met simultaneously, then the regenerative braking torque request is executed; wherein,

[0019] Condition 1 is: the braking energy recovery torque received within the preset time Δt is not equal to 0.

[0020] Condition two is: a represents the current actual deceleration of the vehicle obtained through the inertial sensor, ap represents the deceleration generated by hydraulic pressure calculated based on the current master cylinder pressure, a1 represents the target deceleration of regenerative braking determined based on the current regenerative braking torque request, and b is a preset deceleration ratio threshold.

[0021] After the regenerative braking request torque is executed, the process to improve regenerative braking efficiency ends, but the subsequent steps of the regenerative braking function will be executed normally.

[0022] Preferably, if condition three or four is met, it indicates that the regenerative braking torque request has not been executed; wherein,

[0023] Condition 3 is: the braking energy recovery torque received within the preset time Δt is equal to 0.

[0024] Condition four is: the braking energy recovery torque received within the preset time Δt is not equal to 0, and

[0025] Preferably, after the vehicle is started and powered on, the vehicle controller, motor controller and battery management controller will each perform self-tests on their respective systems and send the self-test results to the brake controller.

[0026] Preferably, after all systems have performed a self-test and are normal, the vehicle controller will determine the recyclable torque based on the vehicle speed and send the recyclable torque to the brake controller.

[0027] Preferably, after the regenerative braking request torque is executed, the vehicle controller, motor controller, and battery management controller will each perform a system inspection and send the inspection results to the brake controller.

[0028] Preferably, if the current vehicle speed is greater than a preset vehicle speed threshold, it means that the braking energy recovery conditions are met.

[0029] Preferably, the preset vehicle speed threshold ranges from 8 km / h to 10 km / h (obtained based on actual vehicle braking comfort calibration), and the preset number of times threshold is equal to 3.

[0030] The apparatus for improving braking energy recovery efficiency according to the present invention includes a brake controller, a vehicle controller, a motor controller, and a battery management controller; the brake controller is programmed to execute the above-described method for improving braking energy recovery efficiency.

[0031] The vehicle described in this invention includes the aforementioned device for improving braking energy recovery efficiency.

[0032] Compared with the prior art, the present invention has the following advantages:

[0033] (1) Under normal system self-check and inspection conditions, the braking energy recovery of the current ignition cycle will only end after the number of times the braking energy recovery request torque is not executed (corresponding to the number of temporary faults) reaches a preset threshold; instead of immediately ending the braking energy recovery of the current ignition cycle whenever the braking energy recovery request torque is not executed. This eliminates the situation where the braking energy recovery of the current ignition cycle is ended due to accidental abnormalities, and improves the vehicle braking energy recovery efficiency while ensuring vehicle safety.

[0034] (2) In the event of abnormal self-check or inspection of the system, the braking energy recovery of the current ignition cycle will be terminated immediately to ensure vehicle safety.

[0035] (3) Before the number of times the brake energy recovery request torque is not executed reaches the preset threshold, the brake energy recovery request torque is not executed, but the system inspection is normal. A temporary fault will be set and the number of temporary faults will be recorded, so as to discover faults that the system has not identified and ensure safe driving of the vehicle.

[0036] (4) When determining whether the requested torque for regenerative braking is executed, the system considers not only the torque for regenerative braking execution, but also the actual deceleration of the vehicle, the deceleration generated by hydraulic pressure, and the deceleration of regenerative braking. This makes the judgment of regenerative braking faults more detailed and accurate. Attached Figure Description

[0037] Figure 1 This is a schematic diagram of a braking energy recovery system.

[0038] Figure 2 This is a flowchart of the method for improving braking energy recovery efficiency in this embodiment. Detailed Implementation

[0039] like Figure 1 As shown, the braking energy recovery system (which is prior art) includes a brake controller 2 (i.e., IBCU), a vehicle controller 3 (i.e., VCU), a motor controller 4 (i.e., MCU), a battery management controller 8 (i.e., BMS), a brake pedal 1, a drive motor with a reducer assembly 5, a drive shaft, a brake 7, and a power battery assembly 6.

[0040] Brake pedal 1 is a mechanical mechanism that determines whether the driver intends to brake and the braking intensity.

[0041] Brake controller 2 is connected to brake pedal 1 and determines the driver's braking intention based on the depth to which brake pedal 1 is depressed. The travel of brake pedal 1 (i.e., brake pedal travel) corresponds to the required deceleration of the vehicle, which is matched and confirmed based on vehicle and braking system parameters during vehicle matching. When the conditions for regenerative braking are met, brake controller 2, acting as an electro-hydraulic brake distribution controller, determines the requested torque for regenerative braking and sends it out.

[0042] The vehicle controller 3 serves as the information exchange hub between the power system and other controllers. It combines the internal self-test status of the power system to provide feedback on the recoverable torque of the braking energy recovery, receives the braking energy recovery request torque issued by the brake controller 2, and then provides feedback on the execution status of the braking energy recovery request torque.

[0043] The motor controller 4 and the drive motor with reducer assembly 5 serve as the execution end of the braking energy recovery function. According to the requirements issued by the vehicle controller 3, they perform energy recovery negative torque, and the drive motor with reducer assembly 5 performs power generation and generates negative torque.

[0044] The drive shaft connects the drive motor with reducer assembly 5 and the brake 7, and transmits the negative torque generated by the drive motor with reducer assembly 5 to the brake 7 to achieve vehicle deceleration.

[0045] The battery management controller 8 controls the charging and discharging of the power battery assembly 6, monitors the status of the power battery assembly 6, and feeds back to the vehicle controller 3.

[0046] Brake controller 2 can acquire signals such as current vehicle speed, brake pedal travel, and master cylinder pressure. Brake controller 2 can also receive self-test and inspection result information from the vehicle controller 3, motor controller 4, and battery management controller 8.

[0047] like Figure 2 As shown, the method for improving regenerative braking efficiency in this embodiment is executed by the brake controller 2, and specifically includes:

[0048] S1. After the vehicle is started and powered on, the braking system performs a self-test, receiving the self-test results from the vehicle controller 3, motor controller 4, and battery management controller 8, and then executes S2. After the vehicle is started and powered on, the vehicle controller 3, motor controller 4, and battery management controller 8 will each perform a self-test on their respective systems and send their self-test results to the brake controller 2; therefore, under normal circumstances, the brake controller 2 can receive the self-test results from the vehicle controller 3, motor controller 4, and battery management controller 8.

[0049] S2. (Based on the self-test results) Determine if the system is normal. If yes, proceed to S3; otherwise, proceed to S12.

[0050] S3. Determine whether the recyclable torque sent by the vehicle controller 3 has been received. If yes, proceed to S4; otherwise, continue with S3. After all systems have completed their self-tests, the vehicle controller 3 will determine the recyclable torque based on the vehicle speed (the determination method is prior art) and send the recyclable torque to the brake controller 2. Therefore, under normal circumstances, the brake controller 2 can receive the recyclable torque sent by the vehicle controller 3.

[0051] S4. Determine whether the braking energy recovery conditions are met. If yes, proceed to S5; otherwise, continue with S4.

[0052] If the current vehicle speed is greater than a preset speed threshold, it indicates that the conditions for regenerative braking are met. In this embodiment, the preset speed threshold is 9 km / h.

[0053] S5. When the brake pedal 1 is depressed, determine the brake energy recovery request torque (the determination method is prior art) based on the recyclable torque and the brake pedal travel, and send the brake energy recovery request torque to the vehicle controller 3, and then execute S6.

[0054] S6. Determine whether the regenerative braking torque request has been executed. If yes, end the process; otherwise, execute S7.

[0055] If both conditions one and two are met, then the regenerative braking torque request is executed.

[0056] Condition one is: the braking energy recovery torque received within a preset time Δt is not equal to 0. The preset time Δt is calibrated based on the actual vehicle performance of the drive motor.

[0057] Condition two is: a represents the current actual deceleration of the vehicle obtained through the inertial sensor, ap represents the deceleration generated by hydraulic pressure calculated based on the current master cylinder pressure, a1 represents the target deceleration of regenerative braking determined based on the current regenerative braking torque request, and b is the preset deceleration ratio threshold (obtained by experimentally calibrating the ratio of actual regenerative braking deceleration to target regenerative braking deceleration).

[0058] Condition 1 indicates that there is a torque response within a preset time Δt. To avoid the situation where the execution torque signal value issued by the motor controller 4 does not match the actual torque of the vehicle, condition 2 (indicating that the torque response is real) is added here.

[0059] If condition three or four is met, it means that the regenerative braking torque request was not executed; among them,

[0060] Condition 3 is: the braking energy recovery torque received within the preset time Δt is equal to 0.

[0061] Condition four is: the braking energy recovery torque received within the preset time Δt is not equal to 0, and

[0062] Condition 3 indicates that there is no response torque within the preset time Δt, and condition 4 indicates that although there is a torque response within the preset time Δt, the torque response is not real.

[0063] S7. Determine whether the system inspection results from the vehicle controller 3, motor controller 4, and battery management controller 8 have been received. If yes, proceed to S8; otherwise, continue with S7. After the regenerative braking request torque is executed, the vehicle controller 3, motor controller 4, and battery management controller 8 will each perform a system inspection and send their respective inspection results to the brake controller 2. Therefore, under normal circumstances, the brake controller 2 can receive the system inspection results from the vehicle controller 3, motor controller 4, and battery management controller 8. The purpose of the inspection is to confirm whether there is a fault that prevents the response to the regenerative braking request torque.

[0064] S8. (Based on the inspection results) Determine if the system is normal. If yes, proceed to S9; otherwise, proceed to S11.

[0065] S9. Set a temporary fault and increment the temporary fault count by 1, then execute S10. The initial value of the temporary fault count is 0.

[0066] S10. Determine whether the number of temporary failures is greater than or equal to a preset threshold. If yes, proceed to S11; otherwise, return to S4. In this embodiment, the preset threshold is 3.

[0067] S11. Set a permanent fault for the current ignition cycle, and then execute S12.

[0068] S12. Send 0 as the braking energy recovery request torque for the current ignition cycle to the vehicle controller 3, and then end.

[0069] This embodiment also provides an apparatus for improving regenerative braking efficiency, including a brake controller 2, a vehicle controller 3, a motor controller 4, and a battery management controller 8. The brake controller 2 is programmed to execute the above-described method for improving regenerative braking efficiency.

[0070] This embodiment also provides a vehicle that includes the above-described device for improving braking energy recovery efficiency.

Claims

1. A method for improving braking energy recovery efficiency, characterized in that, include: S1. After the vehicle is started and powered on, the braking system performs a self-test, receives the self-test result information of the respective systems sent by the vehicle controller (3), motor controller (4) and battery management controller (8), and then executes S2. S2. Determine if the system is functioning normally. If yes, execute S3; otherwise, execute S12. S3. Determine whether the recyclable torque sent by the vehicle controller (3) has been received. If yes, execute S4; otherwise, continue executing S3. S4. Determine whether the braking energy recovery conditions are met. If yes, proceed to S5; otherwise, continue with S4. S5. When the brake pedal (1) is pressed, the brake energy recovery request torque is determined according to the recyclable torque and the brake pedal travel, and the brake energy recovery request torque is sent to the vehicle controller (3), and then S6 is executed. S6. Determine whether the regenerative braking torque request has been executed. If yes, end; otherwise, execute S7. S7. Determine whether the system inspection result information sent by the vehicle controller (3), motor controller (4) and battery management controller (8) has been received. If yes, execute S8; otherwise, continue to execute S7. S8. Determine if the system is functioning normally. If yes, proceed to S9; otherwise, proceed to S11. S9. Set a temporary fault and increment the temporary fault count by 1, then execute S10; where the initial value of the temporary fault count is 0; S10. Determine whether the number of temporary failures is greater than or equal to the preset threshold. If yes, execute S11; otherwise, return to execute S4. S11. Set a permanent fault for the current ignition cycle, and then execute S12; S12, send 0 as the braking energy recovery request torque in the current ignition cycle to the vehicle controller (3), and then end.

2. The method for improving braking energy recovery efficiency according to claim 1, characterized in that: If both conditions one and two are met, then the regenerative braking torque request is executed; where, Condition 1 is: the braking energy recovery torque received within the preset time Δt is not equal to 0; Condition two is: a represents the current actual deceleration of the vehicle obtained through the inertial sensor, ap represents the deceleration generated by hydraulic pressure calculated based on the current master cylinder pressure, a1 represents the target deceleration of regenerative braking determined based on the current regenerative braking torque request, and b is a preset deceleration ratio threshold.

3. The method for improving braking energy recovery efficiency according to claim 2, characterized in that: If condition three or four is met, it means that the regenerative braking torque request was not executed; among them, Condition 3 is: the braking energy recovery torque received within the preset time Δt is equal to 0. Condition four is: the braking energy recovery torque received within the preset time Δt is not equal to 0, and 4. The method for improving braking energy recovery efficiency according to any one of claims 1 to 3, characterized in that: After the vehicle is started and powered on, the vehicle controller (3), motor controller (4) and battery management controller (8) will perform self-tests on their respective systems and send the self-test results to the brake controller (2).

5. The method for improving braking energy recovery efficiency according to claim 4, characterized in that: After all systems have performed a self-test and are in good working order, the vehicle controller (3) will determine the recyclable torque based on the vehicle speed and send the recyclable torque to the brake controller (2).

6. The method for improving braking energy recovery efficiency according to claim 5, characterized in that: After the regenerative braking request torque is executed, the vehicle controller (3), motor controller (4) and battery management controller (8) will perform inspections on their respective systems and send the inspection results to the brake controller (2).

7. The method for improving braking energy recovery efficiency according to claim 6, characterized in that: If the current vehicle speed is greater than the preset vehicle speed threshold, it means that the conditions for regenerative braking are met.

8. The method for improving braking energy recovery efficiency according to claim 7, characterized in that: The preset vehicle speed threshold ranges from 8 km / h to 10 km / h, and the preset number of times threshold is equal to 3.

9. A device for improving regenerative braking efficiency, comprising a brake controller (2), a vehicle controller (3), a motor controller (4), and a battery management controller (8); characterized in that: The brake controller (2) is programmed to perform the method for improving brake energy recovery efficiency as described in any one of claims 1 to 8.

10. A vehicle, characterized in that: Includes the apparatus for improving braking energy recovery efficiency as described in claim 9.

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