A Low-Speed Functional-by-Wire Vehicle Service Braking Redundancy Control Method and System

Abstract

The present invention relates to a redundant control method and system for the driving brake of a low-speed functional by-wire vehicle. The method includes: C1. When the vehicle is traveling on the road, based on the vehicle AD controller, the vehicle braking deceleration data information is acquired in real time; C2. Based on the vehicle braking deceleration data information, the real-time vehicle deceleration is obtained. If the real-time vehicle braking deceleration is equal to zero, the vehicle controller periodically sends an EMB release instruction message to the EMB controller to make the EMB actuator in a released state; C3. If the real-time vehicle braking deceleration is greater than zero and less than the maximum braking deceleration, the vehicle controller sends a braking instruction to the MCU through the Lagrange interpolation algorithm, and the MCU controls the driving motor to brake. The present invention can not only ensure the safety of vehicle driving, but also make the braking process more intelligent and smooth, improving the user's riding experience.

Description

Technical Field

[0001] The present invention relates to the technical field of vehicle braking, and in particular to a redundancy control method and system for the service braking of a low-speed functional by-wire vehicle. Background Art

[0002] With the rapid development of technology, the intelligence of vehicles is also constantly evolving. Consequently, the safety issues of vehicles have increasingly become the focus of our attention. The safety of vehicles is closely related to the braking system. The braking system is one of the most critical safety devices during vehicle driving, capable of effectively controlling the vehicle speed and stopping distance, and avoiding accidents. If the braking system fails or malfunctions, the vehicle will be unable to stop properly, resulting in serious consequences. Therefore, the performance and reliability of the braking system play a crucial role in vehicle safety. The continuous innovation and development of the braking system can improve the braking performance of vehicles, reduce accidents, and safeguard people's lives and property safety.

[0003] A braking redundancy system refers to the use of multiple independent braking devices in the braking systems of vehicles, aircraft, and other transportation means to improve the reliability and safety of the entire braking system, including a braking hydraulic system, a mechanical braking system, an electronic control braking system, etc. The braking hydraulic system transmits the braking force to the actuator through hydraulic transmission, and the mechanical braking system achieves braking by means of mechanical connectors. According to current vehicle models statistics, the service braking of low-speed functional by-wire vehicles still uses the traditional hydraulic braking system, without achieving braking redundancy, and there has been no significant improvement in response timeliness and vehicle braking safety. Summary of the Invention

[0004] In view of the above deficiencies of the prior art, the present invention provides a redundancy control method and system for the service braking of a low-speed functional by-wire vehicle, which can not only ensure the safety of vehicle driving, but also make the braking process more intelligent and smooth, improving the user's riding experience.

[0005] To achieve the above object and other related objects, the technical solutions provided by the present invention are as follows:

[0006] A redundancy control method for the service braking of a low-speed functional by-wire vehicle, the method comprising:

[0007] C1. When the vehicle is driving on the road, based on the vehicle AD controller, the vehicle braking deceleration data information is acquired in real time;

[0008] C2. Based on the vehicle braking deceleration data information, the real-time vehicle deceleration is obtained. If the real-time vehicle braking deceleration is equal to zero, the vehicle controller periodically sends an EMB release instruction message to the EMB controller to make the EMB actuator in a released state;

[0009] C3. If the real-time vehicle braking deceleration is greater than zero and less than the maximum braking deceleration, the vehicle control unit sends a braking instruction to the MCU through the Lagrange interpolation algorithm. The MCU controls the drive motor to brake. At the same time, the vehicle control unit periodically sends an EMB instruction event message to the EMB controller, making the EMB actuator in a periodically controlled state;

[0010] C4. If the real-time vehicle braking deceleration is greater than the maximum braking deceleration, the vehicle control unit sends the maximum braking instruction to the MCU. The MCU controls the drive motor to brake. At the same time, the vehicle control unit sends a continuous EMB clamping instruction event message to the EMB controller, making the EMB actuator in a continuous clamping state.

[0011] Further, in step C3, the Lagrange interpolation algorithm includes:

[0012] C31. Based on the vehicle braking deceleration data information, since the vehicle braking deceleration and the vehicle braking force are linearly related, establish a vehicle braking force function:

[0013] β(α) = k1α + k2,

[0014] where α is the vehicle braking deceleration, β is the vehicle braking force function, and k1 and k2 are constant coefficients, obtaining vehicle braking force sampling points (α0, β0), (α1, β1),..., (α n , β n );

[0015] C32. Based on the vehicle braking force sampling points (α0, β0), (α1, β1),..., (α n , β n ), establish a Lagrange interpolation function:

[0016]

[0017] where F(x) is the Lagrange interpolation function and h i (x) is the interpolation basis function;

[0018] C33. Based on the Lagrange interpolation function F(x), output the vehicle braking force data information.

[0019] Further, the interpolation basis function h i (x) is:

[0020] where α i is the vehicle braking deceleration.

[0021] Further, in step C3, when the motor is free of faults, the EMB controller includes a front axle EMB controller and a rear axle EMB controller. When both the front axle EMB controller and the rear axle EMB controller are free of faults, the EMB actuator is in a controlled state.

[0022] Further, regardless of whether the front axle EMB controller has a fault, if a fault is detected in the rear axle EMB controller, it reports to the vehicle controller.

[0023] Further, when the front axle EMB controller has no fault, a preset braking deceleration is set. If the real-time vehicle braking deceleration is less than the preset braking deceleration, the vehicle controller sends an instruction to the front axle EMB controller to make the EMB actuator in a controlled state.

[0024] Further, when a fault occurs in the motor and the front axle EMB controller also has a fault, if it is checked that the rear axle EMB controller has no fault, the vehicle controller sends an EMB clamping instruction message to the EMB controller, and the EMB actuator will be in a clamped state.

[0025] To achieve the above object and other related objects, the present invention also provides a low-speed functional by-wire vehicle service braking redundancy control system, and the system includes:

[0026] A vehicle controller, which is a receiving node for real-time vehicle braking deceleration and a sending node for control strategies;

[0027] An AD controller, connected to the vehicle controller, for real-time obtaining vehicle braking deceleration data information and uploading the information to the vehicle controller;

[0028] An MCU, connected to the vehicle controller, which is an execution node for receiving instructions sent by the vehicle controller and performing actions;

[0029] An EMB controller, connected to the MCU, which is an execution node for receiving instructions sent by the MCU and performing braking actions;

[0030] An EMB actuator, connected to the EMB controller, which is an actuator for receiving instructions sent by the EMB controller and performing braking actions.

[0031] Further, the system further includes a motor, which is an actuator for receiving instructions sent by the MCU and performing braking actions.

[0032] The present invention has the following positive effects:

[0033] 1. The present invention predicts and supplements the data during the vehicle braking process by using the Lagrange interpolation algorithm, thereby making the braking process smoother and improving the riding experience of users.

[0034] 2. The present invention ensures the normal operation of the EMB controller and can take timely solutions when a failure occurs by using the communication method that the vehicle control unit periodically sends messages to other controllers.

[0035] 3. The present invention ensures the normal operation of the EMB during the vehicle driving process, thereby improving the safety of the vehicle. Description of the Drawings

[0036] Figure 1 It is a schematic diagram of the method flow of the present invention;

[0037] Figure 2 It is a schematic diagram of the system framework of the present invention. Detailed Embodiments

[0038] The following describes exemplary embodiments of the present disclosure in conjunction with the drawings. Various details of the embodiments of the present disclosure are included to assist in understanding, and they should be considered merely exemplary. Therefore, those of ordinary skill in the art should recognize that various changes and modifications can be made to the embodiments described herein without departing from the scope and spirit of the present disclosure. Similarly, for clarity and conciseness, the description of well-known functions and structures is omitted below.

[0039] Embodiment 1: As Figure 1 shown, a redundancy control method for the service braking of a low-speed functional by-wire vehicle, the method includes:

[0040] C1. When the vehicle is driving on the road, based on the vehicle AD controller, the vehicle braking deceleration data information is obtained in real time;

[0041] C2. Based on the vehicle braking deceleration data information, the real-time vehicle deceleration is obtained. If the real-time vehicle braking deceleration is equal to zero, the vehicle control unit periodically sends an EMB release instruction message to the EMB controller to make the EMB actuator in the release state;

[0042] C3. If the real-time vehicle braking deceleration is greater than zero and less than the maximum braking deceleration, the vehicle control unit sends a braking instruction to the MCU through the Lagrange interpolation algorithm, the MCU controls the drive motor to brake, and at the same time the vehicle control unit periodically sends an EMB instruction event message to the EMB controller to make the EMB actuator in the periodic controlled state;

[0043] C4. If the real-time vehicle braking deceleration is greater than the maximum braking deceleration, the vehicle controller sends a maximum braking command to the MCU. The MCU controls the drive motor to brake. At the same time, the vehicle controller sends a continuous EMB clamping command event-type message to the EMB controller, causing the EMB actuator to be in a continuous clamping state.

[0044] In this embodiment, in step C3, the Lagrange interpolation algorithm includes:

[0045] C31. Based on the vehicle braking deceleration data information, since there is a linear relationship between the vehicle braking deceleration and the vehicle braking force, establish a vehicle braking force function:

[0046] β(α) = k1α + k2,

[0047] where α is the vehicle braking deceleration, β is the vehicle braking force function, and k1 and k2 are constant coefficients, obtaining vehicle braking force sampling points (α0, β0), (α1, β1),..., (α n , β n );

[0048] C32. Based on the vehicle braking force sampling points (α0, β0), (α1, β1),..., (α n , β n ), establish a Lagrange interpolation function:

[0049]

[0050] where F(x) is the Lagrange interpolation function and h i (x) is the interpolation basis function;

[0051] C33. Based on the Lagrange interpolation function F(x), output the vehicle braking force data information.

[0052] In this embodiment, the interpolation basis function h i (x) is:

[0053] where α i is the vehicle braking deceleration.

[0054] In this embodiment, in step C3, when the motor is fault-free, the EMB controller includes a front axle EMB controller and a rear axle EMB controller. When both the front axle EMB controller and the rear axle EMB controller are fault-free, the EMB actuator is in a controlled state.

[0055] In this embodiment, regardless of whether the front axle EMB controller has a fault, if a fault is detected in the rear axle EMB controller, it is reported to the vehicle controller.

[0056] In this embodiment, the front axle EMB controller has no fault, and a preset braking deceleration is set. If the real-time vehicle braking deceleration is less than the preset braking deceleration, the vehicle controller sends an instruction to the front axle EMB controller to make the EMB actuator in a controlled state.

[0057] In this embodiment, when the motor fails, the front axle EMB controller also fails. If it is checked that the rear axle EMB controller has no fault, the vehicle controller sends an EMB clamping instruction message to the EMB controller, and the EMB actuator will be in a clamped state.

[0058] Embodiment 2: On the basis of the low-speed functional by-wire vehicle driving braking redundancy control method in Embodiment 1, the present invention will be further described and illustrated below.

[0059] For electric by-wire vehicles below 1000 kg, a mature drive solution is to directly connect the drive motor to the drive axle, which can perform energy regeneration and generate a braking effect; the conventional braking system still uses traditional hydraulic braking as the driving braking, without braking redundancy, and currently the power source power of the master cylinder occupies a relatively high level, it is difficult to arrange the hydraulic power source, the brake fluid pollutes the environment, the hydraulic pipeline occupies the battery space and there are various layout challenges, and the assembly and maintenance cost of the by-wire hydraulic braking system is relatively high, which affects its popularization and use in application scenarios with a total weight less than 1000 kg and a running speed of 30 km / h or less.

[0060] As Figure 2 shown, in order to achieve the above and other related purposes, the present invention also provides a low-speed functional by-wire vehicle driving braking redundancy control system, and the system includes:

[0061] A vehicle controller, which is a node for receiving the real-time vehicle braking deceleration and issuing a control strategy;

[0062] An AD controller, connected to the vehicle controller, for obtaining the vehicle braking deceleration data information in real time and uploading the information to the vehicle controller;

[0063] An MCU, connected to the vehicle controller, which is an execution node for receiving the instruction sent by the vehicle controller and performing an action;

[0064] An EMB controller, connected to the MCU, which is an execution node for receiving the instruction sent by the MCU and performing a braking action;

[0065] An EMB actuator, connected to the EMB controller, which is an actuator for receiving the instruction sent by the EMB controller and performing a braking action.

[0066] In this embodiment, the system further includes a motor, which is used to receive the instructions issued by the MCU and an actuator for performing braking actions.

[0067] In summary, the present invention can not only ensure the safety of vehicle driving, but also make the braking process more intelligent and smooth, improving the user's riding experience.

[0068] The above specific embodiments do not constitute a limitation on the protection scope of the present disclosure. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present disclosure shall be included within the protection scope of the present disclosure.

Claims

1. A redundancy control method for the service brake of a low-speed functional by-wire vehicle, characterized in that The method includes: C1. When the vehicle is running on the road, based on the vehicle AD controller, the vehicle braking deceleration data information is obtained in real time; C2. Based on the vehicle braking deceleration data information, the real-time vehicle deceleration is obtained. If the real-time vehicle braking deceleration is equal to zero, the vehicle controller periodically sends an EMB release instruction message to the EMB controller to make the EMB actuator in the release state; C3. If the real-time vehicle braking deceleration is greater than zero and less than the maximum braking deceleration, the vehicle controller sends a braking instruction to the MCU through the Lagrange interpolation algorithm, and the MCU controls the drive motor to brake. At the same time, the vehicle controller periodically sends an EMB instruction event message to the EMB controller to make the EMB actuator in the periodic controlled state; C4. If the real-time vehicle braking deceleration is greater than the maximum braking deceleration, the vehicle controller sends the maximum braking instruction to the MCU, and the MCU controls the drive motor to brake. At the same time, the vehicle controller sends a continuous EMB clamping instruction event message to the EMB controller to make the EMB actuator in the continuous clamping state; The Lagrange interpolation algorithm includes: C31. Based on the vehicle braking deceleration data information, since the vehicle braking deceleration and the vehicle braking force are linearly related, a vehicle braking force function is established: β(α) = k1α + k2, where α is the vehicle braking deceleration, β is the vehicle braking force function, k1 and k2 are constant coefficients, and the vehicle braking force sampling points (α0, β0), (α1, β1),..., (α n , β n ) are obtained; C32. Based on the vehicle braking force sampling points (α0, β0), (α1, β1),..., (α n , β n ), a Lagrange interpolation function is established: ， Among them, F(x) is the Lagrange interpolation function, and h i (x) is the interpolation basis function; C33. Based on the Lagrange interpolation function F(x), the vehicle braking force data information is output; The interpolation basis function h i (x) is ， where α i is the vehicle braking deceleration. In step C3, when the motor has no fault, the EMB controller includes a front axle EMB controller and a rear axle EMB controller. When both the front axle EMB controller and the rear axle EMB controller have no fault, the EMB actuator is in a controlled state.

2. The low-speed functional by-wire vehicle driving brake redundancy control method according to claim 1, wherein: Regardless of whether the front axle EMB controller has a fault, if it is detected that the rear axle EMB controller has a fault, it is reported to the vehicle controller.

3. The redundant control method for the driving braking of a low-speed functional by-wire vehicle according to claim 1, characterized in that: The front axle EMB controller has no fault, and a preset braking deceleration is set. If the real-time vehicle braking deceleration is less than the preset braking deceleration, the vehicle controller sends an instruction to the front axle EMB controller to make the EMB actuator in the controlled state.

4. The redundant control method for the driving braking of a low-speed functional by-wire vehicle according to claim 1, wherein: When the motor fails and the front axle EMB controller also fails, and it is checked that the rear axle EMB controller has no fault, the vehicle controller sends an EMB clamping instruction message to the EMB controller, and the EMB actuator will be in the clamping state.

5. A system for implementing the redundant control method for the driving braking of a low-speed functional by-wire vehicle according to any one of claims 1-4, characterized in that, The system includes: A vehicle controller, which is a node for receiving the vehicle braking deceleration in real time and issuing a control strategy; An AD controller, connected to the vehicle controller, for obtaining the vehicle braking deceleration data information in real time and uploading the information to the vehicle controller; An MCU, connected to the vehicle controller, which is an execution node for receiving the instruction sent by the vehicle controller and performing actions; An EMB controller, connected to the MCU, which is an execution node for receiving the instruction sent by the MCU and performing braking actions; An EMB actuator, connected to the EMB controller, which is an actuator for receiving the instruction issued by the EMB controller and performing braking actions.

6. The low-speed functional by-wire vehicle service braking redundancy control system according to claim 5, characterized in that: The system further includes a motor, which is an actuator for receiving the instruction issued by the MCU and performing braking actions.

Images