Cooperative braking control method and braking electronic control unit

Abstract

The invention relates to a cooperative braking control method. The method comprises the steps that a brake pedal signal is received; determining a target braking force based on the brake pedal signal; and according to the target braking force, the temperature of the brake disc and the temperature of the driving motor, the reverse torque of the hydraulic braking system and / or the driving motor is determined so that the vehicle can be braked. The invention further relates to a braking electronic control unit, a computer readable storage medium, a computer program product and a decoupling braking system.

Description

Technical Field

[0001] The present application relates to the field of brake electronic control, and more specifically, to a collaborative brake control method for a vehicle, a brake electronic control unit, a computer-readable storage medium, a computer program product, and a decoupling brake system. Background Art

[0002] When a vehicle uses a hydraulic brake system to brake, if the brake disc temperature is very high, hydraulic braking will not work, which is very dangerous in some cases. For example, when driving on a winding mountain road for a long time, the driver tends to step on the brake pedal deeply, so the brake disc temperature will rise rapidly, resulting in a decrease in braking performance. In addition, overheating of the brake disc will also affect the service life of the hydraulic brake system. Summary of the invention

[0003] The inventors of the present application realized that when the brake disc of a vehicle overheats and cannot provide sufficient braking force, by utilizing the reverse torque (or reverse torque) of the motor for braking, or combining the reverse torque of the motor with hydraulic braking (i.e., the reverse torque of the motor as a supplement or replacement for hydraulic braking), the overheating of the brake disc can be reduced, thereby extending the service life of the hydraulic brake system.

[0004] In addition, when the brake electronic control unit ECU in the decoupled braking system (such as the intelligent integrated braking system IPB or the intelligent decoupled braking system DPB) is working normally, the force applied by the driver to the brake pedal will not act directly on the brake wheel cylinder through the brake master cylinder, but will be assisted by the brushless motor BLM in the brake electronic control unit ECU. The force generated by the brushless motor will act on the hydraulic plunger and pump the brake fluid into the brake wheel cylinder, thereby generating braking force.

[0005] When the hydraulic module of the brake electronic control unit ECU fails, the decoupled brake system will enter the mechanical backup mode. In this mode, all hydraulic control-related software functions will fail, and the force applied by the driver on the brake pedal will directly act on the brake master cylinder and inject the brake fluid into the brake wheel cylinder, thereby forming a braking force. In this mode, due to the lack of power assistance from the brushless motor, the force applied by the driver on the brake pedal directly acts on the brake master cylinder, so the brake pedal will be very hard and difficult to step on, and it will be difficult to generate sufficient braking force. In one embodiment of the present application, when the hydraulic module of the brake electronic control unit fails and enters the mechanical backup mode, the braking force in the mechanical backup mode is increased by sending a request for reverse torque to the drive motor.

[0006] According to one aspect of the present application, a collaborative braking control method is provided, the method comprising: receiving a brake pedal signal; determining a target braking force based on the brake pedal signal; and determining a reverse torque to use a hydraulic braking system and / or a drive motor to brake a vehicle based on the target braking force, a brake disc temperature, and a drive motor temperature.

[0007] As a supplement or alternative to the above-mentioned scheme, in the above-mentioned method, determining the reverse torque of the hydraulic braking system and / or the drive motor to brake the vehicle based on the target braking force, the brake disc temperature and the drive motor temperature includes: when the brake disc temperature is lower than a first temperature threshold, or when the drive motor temperature is higher than a second temperature threshold, or in an emergency braking condition, only using the hydraulic braking system to brake the vehicle, wherein the second temperature threshold is greater than the first temperature threshold.

[0008] As a supplement or alternative to the above-mentioned scheme, in the above-mentioned method, determining the use of the reverse torque of the hydraulic braking system and / or the drive motor to brake the vehicle based on the target braking force, the brake disc temperature and the drive motor temperature also includes: when the brake disc temperature is greater than or equal to the first temperature threshold but less than the second temperature threshold, using both the hydraulic braking system and the reverse torque of the drive motor to brake the vehicle.

[0009] As a supplement or alternative to the above-mentioned scheme, in the above-mentioned method, using both the hydraulic braking system and the reverse torque of the drive motor to brake the vehicle includes: determining the braking torque T1 that the hydraulic braking system can provide based on the brake disc temperature; and sending a reverse torque request T2 for the drive motor to the vehicle control unit VCU, wherein the reverse torque request T2 = the target braking force - the braking torque T1.

[0010] As a supplement or alternative to the above-mentioned scheme, in the above-mentioned method, determining the use of the reverse torque of the hydraulic braking system and / or the drive motor to brake the vehicle based on the target braking force, the brake disc temperature and the drive motor temperature also includes: when the brake disc temperature is greater than or equal to the second temperature threshold, only using the reverse torque of the drive motor to brake the vehicle.

[0011] According to another aspect of the present application, a brake electronic control unit is provided, which includes: a receiving device for receiving a brake pedal signal; a determining device for determining a target braking force based on the brake pedal signal; and a brake control device for determining a reverse torque of a hydraulic braking system and / or a drive motor to brake a vehicle based on the target braking force, the brake disc temperature, and the drive motor temperature.

[0012] As a supplement or alternative to the above-mentioned scheme, in the above-mentioned brake electronic control unit, the brake control device is configured to: when the temperature of the brake disc is lower than a first temperature threshold, or when the temperature of the drive motor is higher than a second temperature threshold, or in an emergency braking condition, only the hydraulic brake system is used to brake the vehicle, and the second temperature threshold is greater than the first temperature threshold.

[0013] As a supplement or alternative to the above scheme, in the above-mentioned brake electronic control unit, the brake control device is configured to: when the brake disc temperature is greater than or equal to the first temperature threshold but less than the second temperature threshold, use both the hydraulic brake system and the reverse torque of the drive motor to brake the vehicle.

[0014] As a supplement or alternative to the above scheme, in the above brake electronic control unit, the brake control device is configured to: determine the braking torque T1 that the hydraulic brake system can provide based on the brake disc temperature; and send a reverse torque request T2 for the drive motor to the vehicle control unit VCU, and the reverse torque request T2 = the target braking force - the braking torque T1.

[0015] As a supplement or alternative to the above solution, in the above brake electronic control unit, the brake control device is configured to: when the brake disc temperature is greater than or equal to the second temperature threshold, only the reverse torque of the drive motor is used to brake the vehicle.

[0016] As a supplement or alternative to the above-mentioned scheme, in the above-mentioned brake electronic control unit, the brake control device is configured to: enter a mechanical backup mode when the hydraulic module of the brake electronic control unit fails; and send a request for a reverse torque for the drive motor in the mechanical backup mode to provide additional braking force.

[0017] According to another aspect of the present application, a computer-readable storage medium is provided, wherein the medium includes instructions, and the instructions execute the above method when executed.

[0018] According to another aspect of the present application, a computer program product is provided, comprising a computer program, and when the computer program is executed by a processor, the method described above is implemented.

[0019] According to another aspect of the present application, a decoupling braking system is provided, wherein the decoupling braking system comprises the braking electronic control unit as described above.

[0020] The collaborative braking control scheme and the brake electronic control unit of the embodiments of the present application determine the use of the hydraulic braking system and / or the reverse torque of the drive motor to brake the vehicle based on the target braking force, brake disc temperature and drive motor temperature, which helps to solve the problem of insufficient braking force due to brake disc overheating - reducing the risks caused by brake disc overheating, extending the service life of the braking system under extreme operating conditions, and increasing braking redundancy to improve system robustness.

[0021] In addition, additionally requesting the drive motor to provide supplementary braking force in the mechanical standby mode can help overcome the problem of difficulty in generating sufficient braking force in the mechanical standby mode and increase the braking force in the mechanical standby mode. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The above and other objects and advantages of the present application will become more fully apparent from the following detailed description in conjunction with the accompanying drawings, wherein the same or similar elements are represented by the same reference numerals.

[0023] Figure 1 A schematic flow chart of a coordinated braking control method according to an embodiment of the present application is shown;

[0024] Figure 2 A schematic diagram of the structure of a brake electronic control unit according to an embodiment of the present application is shown; and

[0025] Figure 3 A schematic diagram of state changes of a brake electronic control unit according to an embodiment of the present application is shown. DETAILED DESCRIPTION

[0026] Figure 1 FIG. 1 is a flow chart of a cooperative braking control method 1000 according to an embodiment of the present application. Figure 1 As shown, the coordinated braking control method 1000 includes:

[0027] In step S110, a brake pedal signal is received;

[0028] In step S120, a target braking force is determined based on the brake pedal signal; and

[0029] In step S130 , a reverse torque of the hydraulic brake system and / or the drive motor is determined to brake the vehicle according to the target braking force, the brake disc temperature, and the drive motor temperature.

[0030] In one embodiment, the "brake pedal signal" in step S110 is generated by the force applied by the driver on the brake pedal and the angular displacement sensor. Based on the brake pedal signal, the target braking force of the vehicle can be determined by conversion or other means.

[0031] In step S130, the reverse torque of the hydraulic brake system and / or the drive motor is determined to brake the vehicle according to the target braking force, the brake disc temperature, and the drive motor temperature. In one embodiment, step S130 includes: when the brake disc temperature is lower than a first temperature threshold, or when the drive motor temperature is higher than a second temperature threshold, or in an emergency braking condition, only the hydraulic brake system is used to brake the vehicle, wherein the second temperature threshold is greater than the first temperature threshold.

[0032] In one embodiment, the above step S130 may further include: when the temperature of the brake disc is greater than or equal to the first temperature threshold but less than the second temperature threshold, using both the hydraulic brake system and the reverse torque of the drive motor to brake the vehicle. As an example, using both the hydraulic brake system and the reverse torque of the drive motor to brake the vehicle may include: determining the braking torque T1 that the hydraulic brake system can provide based on the brake disc temperature; and sending a reverse torque request T2 for the drive motor to the vehicle control unit VCU, wherein the reverse torque request T2 = the target braking force - the braking torque T1.

[0033] For example, assuming that the target braking force input by the driver is 10 units, and because the temperature of the brake disc exceeds the first temperature threshold and is lower than the second temperature threshold, the system is in a state of using both the hydraulic brake system and the reverse torque of the drive motor at the same time.

[0034] Based on the temperature of the brake disc, assuming that it is determined that the hydraulic brake system can only generate 4 units of braking force, then the (brake electronic control unit) will request the vehicle control unit VCU to provide 6 units of braking force (reverse torque) through the drive motor. If the VCU concludes that the current drive motor can provide 6 units of braking force based on the motor temperature and other parameters, then the system is normal. If the current drive motor can only provide 4 units of braking force, it means that the VCU cannot respond fully, but this does not affect the current system state and the request for 6 units of braking force from the motor. In this case, the hydraulic brake unit will provide the highest hydraulic braking force based on the actual maximum braking force that the motor can provide, and the brake disc temperature will not be considered. That is, the hydraulic system will provide the highest braking force that can be generated at present, and try to meet the overall demand for 10 units of braking force.

[0035] In one embodiment, the step S130 may further include: when the brake disc temperature is greater than or equal to the second temperature threshold, only using the reverse torque of the drive motor to brake the vehicle.

[0036] In short, in this embodiment, when the brake disc temperature is within the normal range (for example, below the first temperature threshold), hydraulic braking should have the highest priority (only hydraulic braking, except for the cooperative regenerative braking CRBS condition), and as the brake disc temperature increases (for example, above the first temperature threshold but below the second temperature threshold), the reverse torque of the drive motor will partially participate in braking. When the brake disc temperature exceeds the second temperature threshold, the drive motor will independently output the braking torque.

[0037] In addition, it is easy for a person skilled in the art to understand that the cooperative braking control method 1000 provided in the above one or more embodiments of the present application can be implemented by a computer program. For example, the computer program is included in a computer program product, and when the computer program is executed by a processor, the cooperative braking control method 1000 of one or more embodiments of the present application is implemented. For another example, when a computer-readable storage medium (such as a USB flash drive) storing the computer program is connected to a computer, running the computer program can execute one or more embodiments of the present application and the cooperative braking control method 1000.

[0038] refer to Figure 2 , Figure 2 FIG. 2 shows a schematic diagram of the structure of a brake electronic control unit 2000 according to an embodiment of the present application. Figure 2 As shown, the brake electronic control unit 2000 includes: a receiving device 210, a determining device 220 and a brake control device 230. The receiving device 210 is used to receive a brake pedal signal; the determining device 220 is used to determine a target braking force based on the brake pedal signal; and the brake control device 230 is used to determine the reverse torque of the hydraulic brake system and / or the drive motor to brake the vehicle according to the target braking force, the brake disc temperature and the drive motor temperature.

[0039] In one embodiment, the receiving device 210 is configured to receive the force applied by the driver on the brake pedal and the "brake pedal signal" generated by the angular displacement sensor. Based on the brake pedal signal, the determining device 220 can be configured to determine the target braking force of the vehicle by conversion or other means (such as table lookup, formula calculation, etc.).

[0040] In one embodiment, the brake control device 230 is configured to use only the hydraulic brake system to brake the vehicle when the brake disc temperature is lower than a first temperature threshold, or when the drive motor temperature is higher than a second temperature threshold, or in an emergency braking condition, wherein the second temperature threshold is greater than the first temperature threshold.

[0041] In one embodiment, the brake control device 230 may be further configured to: when the brake disc temperature is greater than or equal to the first temperature threshold but less than the second temperature threshold, use both the hydraulic brake system and the reverse torque of the drive motor to brake the vehicle. For example, the brake control device 230 may determine the braking torque T1 that the hydraulic brake system can provide based on the brake disc temperature; and send a reverse torque request T2 for the drive motor to the vehicle control unit VCU, wherein the reverse torque request T2 = the target braking force - the braking torque T1.

[0042] In one embodiment, the brake control device 230 may be further configured to brake the vehicle using only the reverse torque of the drive motor when the brake disc temperature is greater than or equal to the second temperature threshold.

[0043] The hydraulic module of the brake electronic control unit ECU generally enters the mechanical backup mode when it fails. At this time, the brake control device 230 can also be configured to send a request for the reverse torque of the drive motor in the mechanical backup mode to provide additional braking force. This can help overcome the problem of difficulty in generating sufficient braking force in the existing mechanical backup mode, increase braking redundancy and improve system robustness.

[0044] The above-mentioned brake electronic control unit 2000 can be integrated into various types of decoupled (type) brake systems, including but not limited to intelligent integrated brake system IPB or intelligent decoupled brake system DPB. For example, the intelligent decoupled brake system (DPB) combines the advantages of modular brake system and integrated brake system, and has the characteristics of small size, light weight, high installation flexibility, and good NVH performance. The decoupled brake redundancy solution composed of the vehicle body electronic stability system can meet the higher requirements of autonomous driving in the future. The intelligent integrated brake system (IPB) integrates the brake booster and the vehicle body electronic stability system, and can meet the requirements of autonomous driving brake redundancy when combined with the redundant brake unit RBU.

[0045] Figure 3 FIG. 2 shows a schematic diagram of the state transition of a brake electronic control unit according to an embodiment of the present application. Figure 3 As shown, the brake electronic control unit may have multiple states: hydraulic braking state S310, motor braking and hydraulic braking coordinated state S320, motor braking state S330, mechanical backup state (without motor braking) S340, and mechanical backup state (with motor braking) S350. When condition 311 is met, the state S310 is changed to state S320, and when condition 312 is met, the state S320 is changed to state S310.

[0046] In one or more embodiments, condition 311 may include: the brake disc temperature is greater than the first temperature threshold but less than the second temperature threshold. Condition 312 may include: the brake disc temperature is less than the first temperature threshold, or the (drive) motor temperature is higher than the second temperature threshold, or the vehicle is currently in emergency braking (for example, emergency braking is performed by ABS or the vehicle electronic stability system ESP, etc.).

[0047] Continue to refer Figure 3 , when condition 321 is met, the state S320 is changed to state S330, and when condition 322 is met, the state S330 is changed to state S320. When condition 315 is met, the state S310 is changed to state S340, and when condition 316 is met, the state S340 is changed to state S310. When condition 325 is met, the state S320 is changed to state S340, and when condition 326 is met, the state S340 is changed to state S320. When condition 335 is met, the state S330 is changed to state S340, and when condition 336 is met, the state S340 is changed to state S330. When condition 348 is met, the state S340 is changed to state S350, and when condition 349 is met, the state S350 is changed to state S340. In addition, when condition 319 is satisfied, the state changes from state S330 to state S310.

[0048] In one or more embodiments, condition 321 may include: the brake disc temperature is greater than the second temperature threshold. Condition 322 may include: the brake disc temperature is less than the second temperature threshold but greater than the first temperature threshold, or the motor temperature is greater than the first temperature threshold. Condition 315 may include: the hydraulic pressure is closed (e.g., due to solenoid valve failure). Condition 316 may include: the hydraulic brake system is restored and the brake disc temperature is less than the first temperature threshold. Condition 325 may include: the hydraulic pressure is closed (e.g., due to solenoid valve failure). Condition 326 may include: the hydraulic brake system is restored and the brake disc temperature is less than the second temperature threshold but greater than the first temperature threshold. Condition 335 may include: the hydraulic pressure is closed (e.g., due to solenoid valve failure). Condition 336 may include: the hydraulic brake system is restored and the brake disc temperature is greater than the second temperature threshold. Condition 348 may include: the hydraulic pressure is closed (e.g., due to solenoid valve failure) and the motor can provide reverse torque. Condition 349 may include: the hydraulic pressure is closed (e.g., due to solenoid valve failure) and the motor cannot provide reverse torque. Condition 319 may include: the brake disc temperature is less than a first temperature threshold, or the motor temperature is higher than a second temperature threshold, or the motor cannot provide reverse torque (cannot perform motor braking), or is in an emergency braking state.

[0049] It should be noted that Figure 3The state transition diagram shown here is only used as an example, not a limitation. In the final implementation, those skilled in the art can also adapt and optimize according to actual needs (such as the current existing logic).

[0050] In summary, the collaborative braking control scheme and the brake electronic control unit of the embodiments of the present application determine the use of the hydraulic braking system and / or the reverse torque of the drive motor to brake the vehicle based on the target braking force, brake disc temperature and drive motor temperature, which helps to solve the problem of insufficient braking force due to overheating of the brake disc - reducing the risks caused by overheating of the brake disc, extending the service life of the braking system under extreme operating conditions, and increasing braking redundancy to improve system robustness.

[0051] In addition, additionally requesting the drive motor to provide supplementary braking force in the mechanical standby mode can help overcome the problem of difficulty in generating sufficient braking force in the mechanical standby mode and increase the braking force in the mechanical standby mode.

[0052] The above examples mainly illustrate the cooperative braking control method and the brake electronic control unit and other schemes of the embodiments of the present application. Although only some of the implementation methods of the present application are described, it should be understood by those skilled in the art that the present application can be implemented in many other forms without departing from its subject matter and scope. Therefore, the examples and implementations shown are regarded as illustrative rather than restrictive, and the present application may cover various modifications and substitutions without departing from the spirit and scope of the present application as defined in the claims.

Claims

1. A coordinated braking control method, It is characterized in that The method comprises: receiving a brake pedal signal; determining a target braking force based on the brake pedal signal; and The reverse torque of the hydraulic brake system and / or the drive motor is determined according to the target braking force, the brake disc temperature, and the drive motor temperature to brake the vehicle.

2. The method according to claim 1, in, Determining the reverse torque of the hydraulic brake system and / or the drive motor to brake the vehicle according to the target braking force, the brake disc temperature, and the drive motor temperature includes: When the brake disc temperature is lower than a first temperature threshold, or when the drive motor temperature is higher than a second temperature threshold, or in an emergency braking condition, only the hydraulic brake system is used to brake the vehicle, wherein the second temperature threshold is greater than the first temperature threshold.

3. The method according to claim 2, in, Determining the reverse torque of the hydraulic brake system and / or the drive motor to brake the vehicle according to the target braking force, the brake disc temperature, and the drive motor temperature further includes: When the brake disc temperature is greater than or equal to the first temperature threshold but less than the second temperature threshold, the vehicle is braked using both the hydraulic brake system and the reverse torque of the drive motor.

4. The method according to claim 3, in, Using both the hydraulic brake system and the reverse torque of the drive motor to brake the vehicle includes: Determining a braking torque T1 that can be provided by the hydraulic brake system based on the brake disc temperature; and A reverse torque request T2 for the drive motor is sent to a vehicle control unit VCU, where the reverse torque request T2 = the target braking force - the braking torque T1.

5. The method according to claim 3, in, Determining the reverse torque of the hydraulic brake system and / or the drive motor to brake the vehicle according to the target braking force, the brake disc temperature, and the drive motor temperature further includes: When the brake disc temperature is greater than or equal to the second temperature threshold, only the reverse torque of the drive motor is used to brake the vehicle.

6. A brake electronic control unit, It is characterized in that The brake electronic control unit comprises: A receiving device, used for receiving a brake pedal signal; a determining device for determining a target braking force based on the brake pedal signal; and The brake control device is used to determine the reverse torque of the hydraulic brake system and / or the drive motor to brake the vehicle according to the target braking force, the brake disc temperature and the drive motor temperature.

7. The brake electronic control unit according to claim 6, in, The brake control device is configured as follows: When the brake disc temperature is lower than a first temperature threshold, or when the drive motor temperature is higher than a second temperature threshold, or in an emergency braking condition, only the hydraulic brake system is used to brake the vehicle, wherein the second temperature threshold is greater than the first temperature threshold.

8. The brake electronic control unit according to claim 7, in, The brake control device is configured as follows: When the brake disc temperature is greater than or equal to the first temperature threshold but less than the second temperature threshold, the vehicle is braked using both the hydraulic brake system and the reverse torque of the drive motor.

9. The brake electronic control unit according to claim 8, in, The brake control device is configured as follows: Determining a braking torque T1 that can be provided by the hydraulic brake system based on the brake disc temperature; as well as A reverse torque request T2 for the drive motor is sent to a vehicle control unit VCU, where the reverse torque request T2 = the target braking force - the braking torque T1.

10. The brake electronic control unit according to claim 8, in, The brake control device is configured as follows: When the brake disc temperature is greater than or equal to the second temperature threshold, only the reverse torque of the drive motor is used to brake the vehicle.

11. The brake electronic control unit according to any one of claims 6 to 10, in, The brake control device is configured to: enter a mechanical backup mode when a hydraulic module of the brake electronic control unit fails; and send a request for reverse torque of the drive motor in the mechanical backup mode to provide supplementary braking force.

12. A computer-readable storage medium, It is characterized in that The medium includes instructions which, when executed, perform the method of any one of claims 1 to 5.

13. A computer program product comprising a computer program, It is characterized in that When the computer program is executed by a processor, the method according to any one of claims 1 to 5 is implemented.

14. A decoupling braking system, It is characterized in that The decoupling brake system comprises a brake electronic control unit as claimed in any one of claims 6 to 11.

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