A backup control method for a new energy vehicle brake-by-wire vehicle controller

Abstract

The present invention discloses a backup control method for a vehicle controller of a wire-controlled brake for a new energy vehicle, comprising the following steps: S1: when the wire-controlled brake system fails, the vehicle controller takes a fault action response mode to limit the speed of the vehicle; S2: the vehicle controller takes over the braking force, and the braking force is provided by the drive motor; S3: when the vehicle controller receives the brake pedal opening signal, the pedal opening is used as input, and the request torque for the drive motor is output, and the torque of the drive motor is used to simulate the braking force; S4: when the braking force of the drive motor is in the same direction as the vehicle speed, a "0" torque request is executed to prevent the vehicle from reversing through the braking force. The present invention can use the vehicle controller + drive motor as a brake backup without adding hardware structure, replace the backup of the original mechanical brake structure, reduce the wear of the brake system, and extend the life of the brake system. The modification is small, the vehicle upgrade is convenient, and there is no increase in hardware cost.

Description

Technical Field

[0001] The present invention belongs to the technical field of electric vehicle driving control, and in particular relates to a backup control method for a whole vehicle controller of a new energy vehicle brake-by-wire. Background Art

[0002] After nearly 10 years of research and development, my country's new energy vehicles have made great progress and are increasingly accepted by the market. Currently, new energy vehicles mainly include pure electric, hybrid and plug-in hybrid. The new three trends of automobiles are coming, and the research on self-driving cars is in full swing. my country's electric vehicle industry has developed rapidly and has become the world's leading country in electric vehicle reserves. It is moving towards the goal of the "new three trends" (electrification, intelligence, and networking) of future new energy vehicles.

[0003] At present, automotive wire control braking is the future development trend of automobile braking, with advantages such as simple structure and strong platform modularity. The main difference between wire control braking and traditional braking is that the brake pedal and the brake actuator are no longer rigidly connected, and the brake pedal only provides an analog electrical signal of the pedal opening. The failure forms of wire control braking are diverse and complex, and failure will lead to complete failure of the braking force. Therefore, the current wire control braking system still needs a mechanical brake structure as a system safety backup, which increases costs and restricts the development of technology. Summary of the invention

[0004] In view of the problems existing in the prior art, the present invention provides a backup control method for a vehicle controller of a wire-controlled brake-type vehicle of a new energy vehicle. After using the backup control method for a vehicle controller of a wire-controlled brake-type vehicle, it is possible to use the vehicle controller + drive motor as a brake backup without adding any hardware structure, thereby replacing the backup of the original mechanical brake structure, reducing the wear of the brake system, and extending the life of the brake system. It only requires updating the backup control strategy of the vehicle controller based on the existing on-board system, with minor changes, thus facilitating the upgrade of existing vehicles and without increasing hardware costs.

[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0006] A backup control method for a brake-by-wire vehicle controller of a new energy vehicle is provided, and the backup control method for a brake-by-wire vehicle controller of the new energy vehicle comprises the following steps:

[0007] S1: When the brake-by-wire system fails, the vehicle controller takes a fault action to limit the vehicle speed;

[0008] S2: The vehicle controller takes over the braking force, which is provided by the drive motor;

[0009] S3: When the vehicle controller receives the brake pedal opening signal, it uses the pedal opening as input and outputs the requested torque for the drive motor, using the torque of the drive motor to simulate the braking force;

[0010] S4: When the braking force of the drive motor is in the same direction as the vehicle speed, a "0" torque request is executed to prevent the vehicle from reversing due to the braking force.

[0011] In order to solve the technical problem, the further technical solution adopted by the present invention is:

[0012] Optionally, in the above-mentioned new energy vehicle brake-by-wire vehicle controller backup control method, in step S1, the vehicle controller takes fault response actions including: at least one of a limp home function, a speed limiting function and limiting the maximum capacity of the power system.

[0013] Optionally, in the above-mentioned new energy vehicle brake-by-wire vehicle controller backup control method, wherein, in step S1, after the vehicle controller receives the brake-by-wire system failure signal from step S1, the vehicle controller performs fault detection on the vehicle, and when it is detected that the vehicle has at least one of a limp-home function failure, a speed limiting function failure and a power system maximum capacity limiting failure, the vehicle executes low-speed driving.

[0014] Optionally, in the above-mentioned new energy vehicle wire control brake vehicle controller backup control method, wherein, in step S2, when the vehicle controller detects that the vehicle has at least one of a limp home function failure, a speed limiting function failure and a power system maximum capacity limiting failure, the vehicle controller controls the braking force, reduces the torque output of the drive motor, and the vehicle executes low-speed driving.

[0015] Optionally, in the above-mentioned backup control method of the vehicle controller of the new energy vehicle wire control brake, in step S3, the step of the vehicle controller receiving the brake pedal opening signal includes:

[0016] S31: collecting the accelerator pedal opening signal and the brake pedal opening signal, and sending them to the vehicle controller to assist in determining the driver's intention;

[0017] S32: Based on the driver's intention and the actual operation of the vehicle, the vehicle controller determines the fault situation;

[0018] S33: Based on the fault situation determined by the vehicle controller, the vehicle fault processing is executed. When the vehicle controller detects that the vehicle has at least one of a limp home function failure, a speed limiting function failure and a power system maximum capacity limiting failure, the vehicle executes low-speed driving.

[0019] Optionally, in the above-mentioned backup control method of the vehicle controller of the new energy vehicle wire control brake, when the vehicle is driving at a low speed, the vehicle is in the deceleration process, and the target deceleration rate is calibrated to a larger value to drive the motor to decelerate with the drag torque.

[0020] Optionally, in the above-mentioned backup control method of the vehicle controller of the new energy vehicle brake-by-wire, in step S4, the step of determining that the braking force of the drive motor is in the same direction as the vehicle speed comprises:

[0021] S41: The vehicle controller obtains the braking force of the drive motor and determines the vector direction of the braking force;

[0022] S42: The vehicle controller obtains the rotation speed of the drive motor and determines the rotation speed direction of the drive motor;

[0023] S43: When the rotational speed direction of the driving motor is consistent with the braking direction of the braking force, they are in the same direction, otherwise they are in different directions.

[0024] Optionally, the above-mentioned new energy vehicle wire control brake vehicle controller backup control method includes a redundant vehicle controller, a redundant drive motor and a redundant brake pedal, and the redundant controller and the vehicle controller, the redundant drive motor and the drive motor, and the redundant brake pedal and the brake pedal are all connected through a CAN communication bus.

[0025] Optionally, the above-mentioned new energy vehicle brake-by-wire vehicle controller backup control method, wherein the new energy vehicle brake-by-wire vehicle controller backup control method is applied to at least one of a pure electric vehicle, a hybrid electric vehicle and a plug-in hybrid electric vehicle.

[0026] The beneficial effects of the present invention are:

[0027] In the event that the wire-controlled braking system of the present invention fails, the vehicle controller takes a fault action response method to limit the speed of the vehicle; the vehicle controller takes over the braking force, which is provided by the drive motor; when the vehicle controller receives the brake pedal opening signal, the pedal opening is used as input to output the requested torque for the drive motor, and the torque of the drive motor is used to simulate the braking force; when the braking force of the drive motor is in the same direction as the vehicle speed, a "0" torque request is executed to prevent the vehicle from reversing through the braking force. Through the above-mentioned wire-controlled braking vehicle controller backup control method, the vehicle controller + drive motor can be used as a brake backup without increasing the hardware structure, replacing the backup of the original mechanical brake structure, reducing the wear of the brake system, and extending the life of the brake system. Only the vehicle controller backup control strategy needs to be updated on the basis of the existing on-board system, with small changes, convenient for upgrading existing vehicles, and no increase in hardware costs.

[0028] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention and implement it according to the contents of the specification, the following is a detailed description of the preferred embodiments of the present invention in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 is a flow chart of a backup control method for a vehicle controller of a new energy vehicle brake-by-wire according to this embodiment;

[0030] Figure 2 is a schematic diagram of a flow chart of determining a brake pedal opening degree signal received by a vehicle controller according to this embodiment;

[0031] Figure 3 is a schematic diagram of a process for determining that the braking force of the drive motor is in the same direction as the vehicle speed according to this embodiment;

[0032] Figure 4 It is a schematic diagram of the vehicle controller looking up a table to determine the torque requested for the drive motor according to the brake pedal opening after the wire control brake fails in this embodiment. DETAILED DESCRIPTION

[0033] The following is a specific embodiment of the present invention, and those skilled in the art can easily understand the advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented in other different ways, that is, different modifications and changes can be made without departing from the scope disclosed by the present invention. Example

[0034] like Figure 1-Figure 4 As shown, in an embodiment, a backup control method for a brake-by-wire vehicle controller of a new energy vehicle is provided, and the backup control method for a brake-by-wire vehicle controller comprises the following steps:

[0035] S1: When the brake-by-wire system fails, the vehicle controller takes a fault action to limit the vehicle speed;

[0036] S2: The vehicle controller takes over the braking force, which is provided by the drive motor;

[0037] S3: When the vehicle controller receives the brake pedal opening signal, it uses the pedal opening as input and outputs the requested torque for the drive motor, using the torque of the drive motor to simulate the braking force;

[0038] S4: When the braking force of the drive motor is in the same direction as the vehicle speed, a "0" torque request is executed to prevent the vehicle from reversing due to the braking force.

[0039] In the embodiment, in step S1, the vehicle controller takes a fault response action including at least one of a limp home function, a speed limiting function, and limiting the maximum capacity of the power system.

[0040] Further preferably, in step S1, when the vehicle controller receives the failure signal of the wire control brake system in step S1, the vehicle controller performs fault detection on the vehicle, and when it is detected that the vehicle has at least one of a limp home function failure, a speed limiting function failure and a power system maximum capacity limiting failure, the vehicle executes low-speed driving.

[0041] More preferably, in step S2, when the vehicle controller detects that the vehicle has at least one of a limp home function failure, a speed limiting function failure and a power system maximum capacity limiting failure, the vehicle controller controls the braking force, reduces the torque output of the drive motor, and the vehicle executes low-speed driving.

[0042] In the embodiment, in step S3, the step of the vehicle controller receiving the brake pedal opening signal includes:

[0043] S31: collecting the accelerator pedal opening signal and the brake pedal opening signal, and sending them to the vehicle controller to assist in determining the driver's intention;

[0044] S32: Based on the driver's intention and the actual operation of the vehicle, the vehicle controller determines the fault situation;

[0045] S33: Based on the fault situation determined by the vehicle controller, the vehicle fault processing is executed. When the vehicle controller detects that the vehicle has at least one of a limp home function failure, a speed limiting function failure and a power system maximum capacity limiting failure, the vehicle executes low-speed driving.

[0046] Further preferably, when the vehicle is traveling at a low speed, the vehicle is in a deceleration process, and the target deceleration is calibrated to a larger value to drive the motor to decelerate by dragging torque.

[0047] In the embodiment, in step S4, the step of determining that the braking force of the drive motor is in the same direction as the vehicle speed comprises:

[0048] S41: The vehicle controller obtains the braking force of the drive motor and determines the vector direction of the braking force;

[0049] S42: The vehicle controller obtains the rotation speed of the drive motor and determines the rotation speed direction of the drive motor;

[0050] S43: When the rotational speed direction of the driving motor is consistent with the braking direction of the braking force, they are in the same direction, otherwise they are in different directions.

[0051] In an embodiment, the backup control method of the wire-controlled brake vehicle controller also includes a redundant vehicle controller, a redundant drive motor and a redundant brake pedal, and the redundant controller and the vehicle controller, the redundant drive motor and the drive motor, and the redundant brake pedal and the brake pedal are all connected via a CAN communication bus.

[0052] Further preferably, the backup control method for the new energy vehicle brake-by-wire vehicle controller is applied to at least one of a pure electric vehicle, a hybrid electric vehicle and a plug-in hybrid electric vehicle.

[0053] The working process and working principle of the present invention are as follows:

[0054] The backup control method of the brake-by-wire vehicle controller of the present invention has the following working steps:

[0055] First, in the event of a brake-by-wire system failure, the vehicle controller takes a fault action response to limit the vehicle speed;

[0056] When the vehicle controller receives a failure signal from the brake-by-wire system, the vehicle controller performs fault detection on the vehicle. When at least one of a limp-home function failure, a speed limiting function failure, and a power system maximum capacity limiting failure is detected, the vehicle executes low-speed driving.

[0057] Secondly, the vehicle controller takes over the braking force, which is provided by the drive motor;

[0058] When the vehicle controller detects that the vehicle has at least one of a limp home function failure, a speed limit function failure, and a power system maximum capacity limit failure, the vehicle controller controls the braking force, reduces the torque output of the drive motor, and the vehicle drives at a low speed;

[0059] Next, when the vehicle controller receives the brake pedal opening signal, it uses the pedal opening as input to output the requested torque for the drive motor, and uses the torque of the drive motor to simulate the braking force;

[0060] The step of the vehicle controller receiving the brake pedal opening signal comprises:

[0061] The first step is to collect the accelerator pedal opening signal and the brake pedal opening signal, and send them to the vehicle controller to assist in determining the driver's intention;

[0062] The second step is to determine the fault situation through the vehicle controller based on the driver's intention and the actual vehicle operation status;

[0063] The third step is to execute vehicle fault processing based on the fault situation determined by the vehicle controller. When the vehicle controller detects that the vehicle has at least one of a limp home function failure, a speed limit function failure, and a power system maximum capacity limit failure, the vehicle executes low-speed driving;

[0064] Finally, when the braking force of the drive motor is in the same direction as the vehicle speed, a “0” torque request is executed to prevent the vehicle from reversing through the braking force;

[0065] The step of determining that the braking force of the drive motor is in the same direction as the vehicle speed comprises:

[0066] In the first step, the vehicle controller obtains the braking force of the drive motor and determines the vector direction of the braking force;

[0067] In the second step, the vehicle controller obtains the speed of the drive motor and determines the speed direction of the drive motor;

[0068] The third step is that when the rotational speed direction of the driving motor is consistent with the braking direction of the braking force, they are in the same direction, otherwise they are in different directions.

[0069] like Figure 4 As shown, under the premise of failure of the wire control brake system, according to the opening of the brake pedal, the vehicle controller determines the requested torque for the drive motor by looking up the table (for example, 80% brake pedal opening corresponds to 300Nm motor torque). When the speed reaches 0kph (vehicle prohibited), in order to prevent the vehicle from reversing (the drive motor reverses and outputs negative torque), the vehicle controller requests the drive motor to have a torque of "0", and then completes the parking.

[0070] The backup control components and connections of the brake-by-wire vehicle controller of the present invention are as follows:

[0071] It includes a redundant vehicle controller, a redundant drive motor and a redundant brake pedal. The redundant controller and the vehicle controller, the redundant drive motor and the drive motor, and the redundant brake pedal and the brake pedal are all connected through a CAN communication bus to form a backup control system;

[0072] The application scope of the backup control method of the wire control vehicle controller of the present invention is:

[0073] Applicable to at least one of pure electric vehicles, hybrid electric vehicles and plug-in hybrid electric vehicles.

[0074] The above descriptions are merely embodiments of the present invention, and are not intended to limit the patent scope of the present invention. Any equivalent structures made using the contents of the specification and drawings of the present invention, or directly or indirectly used in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A backup control method for a vehicle controller of a new energy vehicle wire control brake, characterized in that: The backup control method of the brake-by-wire vehicle controller comprises the following steps: S1: When the brake-by-wire system fails, the vehicle controller takes a fault action to limit the vehicle speed; S2: The vehicle controller takes over the braking force, which is provided by the drive motor; S3: When the vehicle controller receives the brake pedal opening signal, it uses the pedal opening as input and outputs the requested torque for the drive motor, using the torque of the drive motor to simulate the braking force; S4: When the braking force of the drive motor is in the same direction as the vehicle speed, a "0" torque request is executed to prevent the vehicle from reversing due to the braking force.

2. A backup control method for a vehicle controller of a new energy vehicle brake-by-wire according to claim 1, characterized in that: In step S1, the vehicle controller takes at least one of the following fault response actions: a limp home function, a speed limiting function, and limiting the maximum capacity of the power system.

3. A backup control method for a new energy vehicle brake-by-wire vehicle controller according to claim 2, characterized in that: In step S1, when the vehicle controller receives the failure signal of the wire control brake system in step S1, the vehicle controller performs fault detection on the vehicle. When it is detected that the vehicle has at least one of a limp home function failure, a speed limiting function failure and a power system maximum capacity limiting failure, the vehicle executes low-speed driving.

4. A backup control method for a new energy vehicle brake-by-wire vehicle controller according to claim 3, characterized in that: In step S2, when the vehicle controller detects that the vehicle has at least one of a limp home function failure, a speed limiting function failure and a power system maximum capacity limiting failure, the vehicle controller controls the braking force, reduces the torque output of the drive motor, and the vehicle executes low-speed driving.

5. The backup control method of the vehicle controller of the new energy vehicle brake-by-wire system according to claim 1 is characterized in that: In step S3, the vehicle controller receives the brake pedal opening signal, including: S31: collecting the accelerator pedal opening signal and the brake pedal opening signal, and sending them to the vehicle controller to assist in determining the driver's intention; S32: Based on the driver's intention and the actual operation of the vehicle, the vehicle controller determines the fault situation; S33: Based on the fault situation determined by the vehicle controller, the vehicle fault processing is executed. When the vehicle controller detects that the vehicle has at least one of a limp home function failure, a speed limiting function failure and a power system maximum capacity limiting failure, the vehicle executes low-speed driving.

6. A backup control method for a vehicle controller of a new energy vehicle brake-by-wire according to claim 5, characterized in that: When the vehicle is running at a low speed, the vehicle is in the process of deceleration, and the target deceleration is calibrated to a larger value to drive the motor to decelerate with the drag torque.

7. The backup control method for the whole vehicle controller of a new energy vehicle brake-by-wire system according to claim 1 is characterized in that: In step S4, the step of determining that the braking force of the drive motor is in the same direction as the vehicle speed includes: S41: The vehicle controller obtains the braking force of the drive motor and determines the vector direction of the braking force; S42: The vehicle controller obtains the rotation speed of the drive motor and determines the rotation speed direction of the drive motor; S43: When the rotational speed direction of the driving motor is consistent with the braking direction of the braking force, they are in the same direction, otherwise they are in different directions.

8. A backup control method for a vehicle controller of a new energy vehicle brake-by-wire according to claims 1 to 7, characterized in that: It includes a redundant vehicle controller, a redundant drive motor and a redundant brake pedal. The redundant controller and the vehicle controller, the redundant drive motor and the drive motor, and the redundant brake pedal and the brake pedal are all connected via a CAN communication bus.

9. A backup control method for a vehicle controller of a new energy vehicle brake-by-wire according to claim 8, characterized in that: The backup control method of the whole vehicle controller of the new energy vehicle wire control brake is applied to at least one of a pure electric vehicle, a hybrid electric vehicle and a plug-in hybrid electric vehicle.

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