Vehicle and automatic driving redundancy brake control method thereof

Abstract

The invention relates to the technical field of vehicles, in particular to a vehicle and an automatic driving redundant braking control method thereof, and aims to solve the problems that when a main braking unit of an existing vehicle fails, a backup braking unit cannot control motor braking for power recovery; and a backup brake unit does not have a manual driving assistance function of a main brake unit, so that a driver is strenuous to brake, and unnecessary potential safety hazards may be caused. In order to achieve the purpose, the vehicle automatic driving redundant braking control method comprises the steps that third braking force of the vehicle is determined according to first braking force for braking of a driver and second braking force for automatic driving; and controlling the vehicle to brake according to the third braking force. The redundant braking can control the braking of the motor, and power recovery can be carried out during the redundant braking; in addition, the redundant braking can also be used for carrying out power-assisted compensation on the braking of the driver, so that the braking of the driver is relatively labor-saving when the driver intervenes in the braking, and unnecessary potential safety hazards are avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of vehicles, and particularly provides a vehicle and an automatic driving redundant braking control method therefor. Background Art

[0002] With the development of 4G and 5G communication technologies, the automatic driving of vehicles has gradually become possible. In order to meet the safety requirements of the braking system for automatic driving at L3 level and above, it is necessary to improve the safety of the braking system by adding redundancy.

[0003] The current solution is to improve the safety of the braking system by adding a backup hydraulic control unit. Specifically, as Figure 1 shown, the main braking unit and the backup braking unit are directly connected to the automatic driving controller through a deceleration interface. When the main braking unit fails, the backup braking unit will take over the control and decelerate the vehicle by establishing hydraulic pressure.

[0004] However, the backup braking unit can only achieve hydraulic braking and cannot use electric motor braking for braking, that is, it cannot use electric motor braking for power recovery. In addition, the backup braking unit does not have the manual driving assistance function of the main braking unit. When the driver intervenes, when the braking force that the driver needs to step on is greater than the braking force of the backup braking unit, the pedal braking force can play a braking role, resulting in relatively strenuous braking for the driver and possibly causing unnecessary safety hazards.

[0005] Therefore, there is an urgent need for a vehicle and an automatic driving redundant braking control method therefor to solve the above technical problems. Summary of the Invention

[0006] The present invention aims to solve the above technical problems, that is, to solve the problems that when the main braking unit fails in an existing vehicle, the backup braking unit cannot control electric motor braking for power recovery; the backup braking unit does not have the manual driving assistance function of the main braking unit, resulting in relatively strenuous braking for the driver and possibly causing unnecessary safety hazards.

[0007] In a first aspect, the present invention provides an automatic driving redundant braking control method for a vehicle, and the control method includes the following steps:

[0008] Determine a third braking force of the vehicle according to a first braking force of the driver's braking and a second braking force of the automatic driving;

[0009] Control the vehicle to brake according to the third braking force.

[0010] In a specific embodiment of the above automatic driving redundant braking control method for a vehicle, "determine the third braking force of the vehicle according to the first braking force of the driver's braking and the second braking force of the automatic driving" includes:

[0011] The larger of the first braking force and the second braking force is the third braking force.

[0012] In the specific implementation of the above vehicle autonomous driving redundant braking control method, "controlling the vehicle to brake according to the third braking force" includes:

[0013] Controlling the vehicle to perform electric motor braking and hydraulic braking according to the third braking force, wherein the priority of the electric motor braking is higher than that of the hydraulic braking.

[0014] In the specific implementation of the above vehicle autonomous driving redundant braking control method, "controlling the vehicle to perform electric motor braking and hydraulic braking according to the third braking force" includes:

[0015] If the braking torque corresponding to the third braking force is less than or equal to the maximum recoverable torque of the motor, controlling the vehicle to perform the electric motor braking according to the braking torque corresponding to the third braking force.

[0016] In the specific implementation of the above vehicle autonomous driving redundant braking control method, "controlling the vehicle to perform electric motor braking and hydraulic braking according to the third braking force" further includes:

[0017] If the braking torque corresponding to the third braking force is greater than the maximum recoverable torque, controlling the electric motor braking to brake according to the maximum recoverable torque, and controlling the hydraulic braking to brake according to the part by which the braking torque corresponding to the third braking force exceeds the maximum recoverable torque.

[0018] In a second aspect, the present invention provides a vehicle, which includes a central controller, a pedal detection component, an autonomous driving controller and a wheel speed detection component. The pedal detection component, the wheel speed detection component and the autonomous driving controller are all communicatively connected to the central controller; when redundant braking is required during the autonomous driving process of the vehicle;

[0019] The pedal detection component is used to detect the pedal braking force and transmit it to the central controller. The wheel speed detection component is used to detect the wheel speed and transmit it to the central controller. The autonomous driving controller can transmit the deceleration of the autonomous driving to the central controller;

[0020] The central controller can determine the first braking force of the driver's braking according to the pedal braking force; the central controller can also determine the second braking force of the autonomous driving braking according to the wheel speed, the deceleration and the weight of the vehicle;

[0021] The central controller can also determine a third braking force of the vehicle according to the first braking force and the second braking force; and control the vehicle to brake according to the third braking force.

[0022] In the above specific implementation manner of the vehicle, "the central controller can also determine a third braking force of the vehicle according to the first braking force and the second braking force" includes:

[0023] The central controller selects the larger one of the first braking force and the second braking force as the third braking force.

[0024] In the above specific implementation manner of the vehicle, the vehicle includes a motor and a backup hydraulic braking unit, both of which are communicatively connected to the central controller; "the central controller controls the vehicle to brake according to the third braking force" includes:

[0025] The central controller controls the motor and the backup hydraulic braking unit to brake according to the third braking force, wherein the braking priority of the motor is higher than that of the backup hydraulic braking unit.

[0026] In the above specific implementation manner of the vehicle, "the central controller controls the motor and the backup hydraulic braking unit to brake according to the third braking force" includes:

[0027] If the braking torque corresponding to the third braking force is less than or equal to the maximum recoverable torque of the motor, the central controller controls the motor to perform electric braking according to the braking torque corresponding to the third braking force.

[0028] In the above specific implementation manner of the vehicle, "the central controller controls the motor and the backup hydraulic braking unit to brake according to the third braking force" further includes:

[0029] If the braking torque corresponding to the third braking force is greater than the maximum recoverable torque, the central controller controls the motor to perform electric braking according to the maximum recoverable torque, and controls the backup hydraulic braking unit to perform hydraulic braking according to the part by which the braking torque corresponding to the third braking force exceeds the maximum recoverable torque.

[0030] In the case of adopting the above technical solution, the vehicle automatic driving redundant braking control method of the present invention includes: determining the third braking force of the vehicle according to the first braking force of the driver's braking and the second braking force of the automatic driving; controlling the vehicle to brake according to the third braking force. Controlling the vehicle to perform electric motor braking and hydraulic braking according to the third braking force, wherein the priority of the electric motor braking is higher than that of the hydraulic braking. During the automatic driving process, the redundant braking control method can enable both the driver's braking and the automatic driving braking to participate, and control the electric motor braking and the hydraulic braking to brake according to the determined third braking force. This redundant braking control method can control the electric motor braking and can perform power recovery during redundant braking; moreover, this redundant braking control method can also determine the third braking force of the vehicle according to the first braking force of the driver's braking, can assist and compensate the driver's braking, and can make it easier for the driver to perform intervention braking, avoiding unnecessary safety hazards. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The following describes the preferred embodiments of the present invention with reference to the drawings, in which:

[0032] Figure 1 is a schematic structural diagram of a vehicle automatic driving braking system in the prior art.

[0033] Figure 2 is the flow chart of the main steps of the vehicle automatic driving redundant braking control method provided in Embodiment 1 of the present invention Figure 1 ;

[0034] Figure 3 is the flow chart of the main steps of the vehicle automatic driving redundant braking control method provided in Embodiment 1 of the present invention Figure 2 ;

[0035] Figure 4 is the flow chart of the detailed steps of the vehicle automatic driving redundant braking control method provided in Embodiment 1 of the present invention;

[0036] Figure 5 is the schematic structural diagram of the vehicle automatic driving redundant braking control system provided in Embodiment 2 of the present invention;

[0037] Figure 6 is the flow chart of the detailed steps of the vehicle automatic driving redundant braking control method provided in Embodiment 2 of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0038] The following describes the preferred embodiments of the present invention with reference to the drawings. Those skilled in the art should understand that these embodiments are only used to explain the technical principles of the present invention and are not intended to limit the protection scope of the present invention.

[0039] It should be noted that in the description of the present invention, the terms indicating the direction or positional relationship such as "upper", "lower", "left", "right", "inner", "outer", etc. are based on the direction or positional relationship shown in the drawings. This is only for convenience of description and does not indicate or imply that the device or component must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0040] In addition, it should be noted that in the description of the present invention, unless otherwise clearly specified and limited, the terms "installation", "setting", "connection" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected, or indirectly connected through an intermediate medium, and can also be the communication inside two components. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0041] In order to solve the problem that when the main braking unit of an existing vehicle fails, the backup braking unit cannot control the electric motor braking for power recovery; the backup braking unit does not have the manual driving assistance function of the main braking unit, resulting in the driver having to apply more effort when braking, which may cause unnecessary safety hazards.

[0042] Embodiment 1

[0043] This embodiment discloses a redundant braking control method for vehicle autonomous driving. The vehicle is specifically an electric vehicle or a hybrid electric vehicle, that is, the vehicle has an electric motor, and the electric motor can be used as the power source of the vehicle. In addition, the vehicle has an autonomous driving function and can use electric motor braking and hydraulic braking during braking. That is, the vehicle can use electric motor braking for power recovery during braking.

[0044] The vehicle includes an autonomous driving controller and a main braking unit. During autonomous driving, normally, the autonomous driving controller controls the active braking unit to perform braking. If the main braking unit fails during the autonomous driving process of the vehicle, the redundant braking control method is executed. As Figure 2 shown, the redundant braking control method for vehicle autonomous driving includes the following steps:

[0045] S1. Determine the third braking force of the vehicle according to the first braking force of the driver's braking and the second braking force of autonomous driving;

[0046] S2. Control the vehicle to brake according to the third braking force.

[0047] Specifically, as Figure 3As shown, the vehicle autonomous driving redundant braking control method further includes step S0, where S0 is to obtain the first braking force of the driver's braking and the second braking force of autonomous driving.

[0048] The specific acquisition method of the first braking force is to obtain the pedal stroke through a pedal stroke sensor or other pedal stroke detection components, and then the central controller calculates the first braking force based on the pedal stroke. It can also be that other pedal detection components detect the torque or braking force of the pedal, and then the central controller calculates the first braking force. The specific acquisition method of the second braking force is to detect the wheel speed of the vehicle through a wheel speed sensor and obtain the deceleration of the vehicle's autonomous driving through the autonomous driving controller, and then calculate and obtain the second braking force based on the wheel speed, deceleration, and the weight of the vehicle (which can be obtained in advance, and the specific acquisition method will not be elaborated here). However, only when the autonomous driving controller of autonomous driving sends an autonomous driving braking request to the central controller, the central controller will calculate the second braking force.

[0049] Among them, "determining the third braking force of the vehicle according to the first braking force of the driver's braking and the second braking force of autonomous driving" specifically includes:

[0050] The larger of the first braking force N1 and the second braking force N2 is the third braking force N3. That is, if the first braking force N1 is greater than the second braking force N2, then N3 = N1; if the second braking force N2 is greater than the first braking force N1, then N3 = N2.

[0051] Among them, "controlling the vehicle to brake according to the third braking force" specifically includes: controlling the vehicle to perform electric braking and hydraulic braking according to the third braking force, where the priority of electric braking is higher than that of hydraulic braking. More specifically, "controlling the vehicle to perform electric braking and hydraulic braking according to the third braking force" specifically includes: if the braking torque corresponding to the third braking force is less than or equal to the maximum recoverable torque of the motor, then control the vehicle to perform electric braking according to the braking torque corresponding to the third braking force. If the braking torque corresponding to the third braking force is greater than the maximum recoverable torque, then control the electric braking to brake according to the maximum recoverable torque, and control the hydraulic braking to brake according to the part by which the braking torque corresponding to the third braking force exceeds the maximum recoverable torque.

[0052] Regarding the maximum recoverable torque of the motor, it should be noted that it is not a fixed value; it is a value that changes in real time, and is specifically related to the battery's charge and the performance of the motor, etc. Therefore, when comparing with the maximum recoverable torque, it is necessary to first obtain the maximum recoverable torque, and the specific acquisition method is a conventional method in the art, which will not be elaborated in the present invention.

[0053] Such as Figure 4As shown in the figure, when redundant braking is required during the automatic driving of a vehicle, the redundant braking control method for the automatic driving of the vehicle specifically includes the following detailed steps:

[0054] S00. Obtain the pedal travel, and then calculate the first braking force according to the pedal travel.

[0055] S01. When the automatic driving controller of the automatic driving sends an automatic driving braking request, obtain the wheel speed of the vehicle, the deceleration of the automatic driving, and the weight of the vehicle, and then calculate and obtain the second braking force according to the wheel speed, deceleration, and weight of the vehicle.

[0056] S11. Determine whether the first braking force is greater than the second braking force. If the first braking force is greater than the second braking force, proceed to step S12; if the second braking force is greater than the first braking force, proceed to step S13.

[0057] S12. Make the third braking force equal to the first braking force, and then proceed to step S21.

[0058] S13. Make the third braking force equal to the second braking force, and then proceed to step S21.

[0059] S21. Determine whether the braking torque corresponding to the third braking force is greater than the maximum recoverable torque of the motor. If so, proceed to step S22; if not, proceed to step S23.

[0060] S22. Control the electric motor to brake according to the maximum recoverable torque, and control the hydraulic brake to brake according to the part by which the braking torque corresponding to the third braking force exceeds the maximum recoverable torque.

[0061] S23. Control the vehicle to perform electric motor braking according to the braking torque corresponding to the third braking force.

[0062] Embodiment 2

[0063] This embodiment discloses a vehicle, which is specifically an electric vehicle or a hybrid electric vehicle, that is, the vehicle has an electric motor, and the electric motor can be used as the power source of the vehicle. In addition, the vehicle has an automatic driving function, and electric motor braking and hydraulic braking can be used during braking. That is, the vehicle can recover power by using electric motor braking during braking.

[0064] As Figure 5 shown in the figure, the vehicle includes a central controller, a pedal detection component, a wheel speed detection component, an automatic driving controller, a main braking unit, and a backup hydraulic braking unit. The central controller is specifically a part of the vehicle central control system. The backup hydraulic braking unit is communicatively connected to the central controller, and the central controller can control the backup hydraulic braking unit to perform hydraulic braking. The electric motor is also communicatively connected to the central controller, and the central controller can control the electric motor to perform electric motor braking for power recovery.

[0065] During the automatic driving process of the vehicle, under normal circumstances, the automatic driving controller controls the active braking unit to perform braking. When the main braking unit fails, redundant braking is adopted, that is, the central controller controls the backup hydraulic braking unit and the motor to perform braking.

[0066] The pedal detection component, the wheel speed detection component, and the automatic driving controller are all communicatively connected to the central controller.

[0067] The pedal detection component is used to detect the pedal braking force and transmit the detected pedal to the central controller. The pedal detection component is specifically a pedal travel sensor, which can detect the pedal travel and then obtain the pedal braking force according to the pedal travel. The pedal detection component can also be a pedal torque detection component, which specifically detects the torque of the pedal and then obtains the pedal braking force according to the torque; the pedal detection component can also be a pressure detection component, which specifically detects the hydraulic pressure of the pedal hydraulic oil circuit and then obtains the pedal braking force according to the hydraulic pressure.

[0068] The wheel speed detection component is specifically a wheel speed sensor, which is specifically used to detect the wheel speed and transmit the detected wheel speed to the central controller. When redundant braking is required during the automatic driving process, the automatic driving controller can generate a deceleration and transmit the deceleration to the central controller.

[0069] The central controller can determine the first braking force of the driver's braking according to the pedal braking force. The central controller can also determine the second braking force of the automatic driving braking according to the wheel speed, the deceleration, and the weight of the vehicle. The method for the central controller to calculate the second braking force of the automatic driving according to the wheel speed, the deceleration, and the weight of the vehicle (which can be obtained in advance, and the specific obtaining method will not be elaborated) is the prior art, and the specific calculation method will not be elaborated in the comparison of the present invention.

[0070] The central controller can also determine the third braking force of the vehicle according to the first braking force and the second braking force; and control the vehicle to perform braking according to the third braking force.

[0071] Among them, "the central controller can also determine the third braking force of the vehicle according to the first braking force and the second braking force" includes:

[0072] The central controller selects the larger of the first braking force and the second braking force as the third braking force. That is, if the first braking force N1 is greater than the second braking force N2, the central controller makes N3 = N1; if the second braking force N2 is greater than the first braking force N1, the central controller makes N3 = N2.

[0073] Among them, "the central controller controls the vehicle to perform braking according to the third braking force" includes:

[0074] The central controller controls the motor and the backup hydraulic braking unit to perform braking according to the third braking force, where the braking priority of the motor is higher than that of the backup hydraulic braking unit. Specifically, "the central controller controls the motor and the backup hydraulic braking unit to perform braking according to the third braking force" specifically includes: If the braking torque corresponding to the third braking force is less than or equal to the maximum recoverable torque of the motor, the central controller controls the motor to perform electric braking according to the braking torque corresponding to the third braking force. If the braking torque corresponding to the third braking force is greater than the maximum recoverable torque, the central controller controls the motor to perform electric braking according to the maximum recoverable torque, and controls the backup hydraulic braking unit to perform hydraulic braking according to the part by which the braking torque corresponding to the third braking force exceeds the maximum recoverable torque.

[0075] Regarding the maximum recoverable torque of the motor, it should be noted that it is not a fixed value; it is a value that changes in real time, and is specifically related to the battery charge and the performance of the motor, etc. Therefore, when comparing the maximum recoverable torque, it is necessary to first obtain the maximum recoverable torque, and the specific obtaining method is a conventional method in the art, which will not be elaborated in the present invention.

[0076] When redundant braking is required during vehicle autonomous driving, such as Figure 6 As shown, the specific control method for vehicle autonomous driving braking specifically includes the following detailed steps:

[0077] S001. The pedal detection component detects the pedal braking force and transmits the detected pedal braking force to the central controller, and then the central controller calculates the first braking force according to the pedal braking force.

[0078] S002. The wheel speed detection component detects the wheel speed and transmits the detected wheel speed to the central controller; the autonomous driving controller sends the deceleration of autonomous driving to the central controller; the central controller calculates and obtains the second braking force according to the wheel speed, deceleration and the weight of the vehicle.

[0079] S003. The central controller determines whether the first braking force is greater than the second braking force. If the first braking force is greater than the second braking force, step S004 is performed; if the second braking force is greater than the first braking force, step S005 is performed.

[0080] S004. The central controller makes the third braking force equal to the first braking force, and then step S006 is performed.

[0081] S005. The central controller makes the third braking force equal to the second braking force, and then step S006 is performed.

[0082] S006. The central controller determines whether the braking torque corresponding to the third braking force is greater than the maximum recoverable torque of the motor. If not, step S007 is performed; if so, step S008 is performed.

[0083] S007. The central controller controls the motor to perform electric braking according to the braking torque corresponding to the third braking force.

[0084] S008. The central controller controls the motor to perform electric braking according to the maximum recoverable torque, and controls the backup hydraulic braking unit to perform hydraulic braking according to the part by which the braking torque corresponding to the third braking force exceeds the maximum recoverable torque.

[0085] So far, the technical solution of the present invention has been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it is easy for those skilled in the art to understand that the protection scope of the present invention is obviously not limited to these specific embodiments. Without departing from the principle of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the protection scope of the present invention.

Claims

1. A redundant braking control method for vehicle autonomous driving, characterized in that, The method includes the following steps: Determine a third braking force of the vehicle according to a first braking force of the driver's braking and a second braking force of the autonomous driving; Control the vehicle to brake according to the third braking force.

2. The vehicle autonomous driving redundant braking control method according to claim 1, wherein "Determine a third braking force of the vehicle according to a first braking force of the driver's braking and a second braking force of the autonomous driving" includes: The larger one of the first braking force and the second braking force is the third braking force.

3. The vehicle autonomous driving redundant braking control method according to claim 2, wherein "Control the vehicle to brake according to the third braking force" includes: Control the vehicle to perform electric motor braking and hydraulic braking according to the third braking force, wherein the priority of the electric motor braking is higher than that of the hydraulic braking.

4. The vehicle autonomous driving redundant braking control method according to claim 3, wherein "Control the vehicle to perform electric motor braking and hydraulic braking according to the third braking force" includes: If the braking torque corresponding to the third braking force is less than or equal to the maximum recoverable torque of the motor, control the vehicle to perform the electric motor braking according to the braking torque corresponding to the third braking force.

5. The vehicle autonomous driving redundant braking control method according to claim 4, wherein, "Control the vehicle to perform electric motor braking and hydraulic braking according to the third braking force" further includes: If the braking torque corresponding to the third braking force is greater than the maximum recoverable torque, control the electric motor braking to brake according to the maximum recoverable torque, and control the hydraulic braking to brake according to the part by which the braking torque corresponding to the third braking force exceeds the maximum recoverable torque.

6. A vehicle, characterized in that, It includes a central controller, a pedal detector, an autonomous driving controller and a wheel speed detector, and the pedal detector, the wheel speed detector and the autonomous driving controller are all communicatively connected to the central controller; when redundant braking is required during the autonomous driving of the vehicle; The pedal detector is used to detect the pedal braking force and transmit it to the central controller, the wheel speed detector is used to detect the wheel speed and transmit it to the central controller, and the autonomous driving controller can transmit the deceleration of the autonomous driving to the central controller; The central controller can determine a first braking force of the driver's braking according to the pedal braking force; the central controller can also determine a second braking force of the autonomous driving braking according to the wheel speed, the deceleration and the weight of the vehicle; The central controller can also determine a third braking force of the vehicle according to the first braking force and the second braking force; and control the vehicle to brake according to the third braking force.

7. The vehicle according to claim 6, characterized in that, "The central controller can also determine a third braking force of the vehicle according to the first braking force and the second braking force" includes: The central controller selects the larger one of the first braking force and the second braking force as the third braking force.

8. The vehicle autonomous driving redundant braking control method according to claim 7, characterized in that, The vehicle further includes an electric motor and a backup hydraulic braking unit, and both are communicatively connected to the central controller; "the central controller controls the vehicle to brake according to the third braking force" includes: The central controller controls the electric motor and the backup hydraulic braking unit to brake according to the third braking force, wherein the priority of the electric motor braking is higher than that of the backup hydraulic braking unit.

9. The vehicle autonomous driving redundant braking control method according to claim 8, wherein, "The central controller controls the electric motor and the backup hydraulic braking unit to brake according to the third braking force" includes: If the braking torque corresponding to the third braking force is less than or equal to the maximum recoverable torque of the motor, the central controller controls the motor to perform electric braking according to the braking torque corresponding to the third braking force.

10. The vehicle autonomous driving redundant braking control method according to claim 9, characterized in that, "The central controller controls the motor and the backup hydraulic braking unit to perform braking according to the third braking force" further includes: If the braking torque corresponding to the third braking force is greater than the maximum recoverable torque, the central controller controls the motor to perform electric braking according to the maximum recoverable torque, and controls the backup hydraulic braking unit to perform hydraulic braking according to the part by which the braking torque corresponding to the third braking force exceeds the maximum recoverable torque.

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