A control method for a four-wheel independent steering vehicle

Abstract

The invention provides a control method for a four-wheel independent steering vehicle. The method comprises the steps that (A) an ideal vehicle steering model, a front wheel steering angle observer, an interference boundary estimation link, a rear wheel steering angle slide-mode controller and a yawing moment slide-mode controller are preset; (B) a mass center deflection angle and a yawing angular speed of the vehicle are measured in real time, and a front wheel steering angle estimated value at a corresponding moment is obtained through computation; (C) the front wheel steering angle estimated value is computed in real time, the real-time mass center deflection angle and the real-time yawing angular speed are computed, and a real-time control error between the mass center deflection angle and the yawing angular speed can be obtained through computation; (D) a real-time interference boundary parameter is obtained through computation in the interference boundary estimation link; and (E) in combination with the real-time front wheel steering angle estimated value, the real-time interference boundary parameter and the control error, a real-time rear wheel steering angle and yawing moment are obtained through computation, and the vehicle is controlled. The method has the advantages that the defect that vehicle stability is reduced due to sensor failures can be overcome; control effects are good; and the stability is high.

Description

Technical field

[0001] The invention relates to the field of vehicle steering control, in particular to a control method of a four-wheel independent steering vehicle. Background technique

[0002] The handling and stability of the vehicle is an important performance related to the safe driving of the vehicle. Four-wheel steering (4WS) technology is an important component of the active chassis control system, and is the development trend of modern vehicles to improve handling stability and active safety. Control strategy is an important research aspect of 4WS technology. By adjusting the rear wheel angle to control the vehicle's center of mass slip angle and yaw rate, it can effectively improve the vehicle's high-speed driving stability and low-speed maneuverability. So far, for the 4WS control problem of active rear wheel steering, people have proposed methods such as feedforward control, yaw rate feedback control, neural network control, etc. that are proportional to the front ...

Examples

Embodiment 1

[0109] Such as figure 1 As shown, the control method for a four-wheel independent steering vehicle provided in this embodiment includes the following steps:

[0110] A. Preset ideal vehicle steering model, front wheel angle estimation initial value, front wheel angle observer, interference boundary estimation link, rear wheel angle sliding mode controller and yaw moment sliding mode controller;

[0111] The construction process of the ideal vehicle steering model is as follows:

[0112] Establish the following vehicle steering kinematics model:

[0113]

[0114] Where: m is the mass of the whole vehicle; v x , V y Respectively represent the velocity components of the vehicle's centroid velocity V on the x and y axes; Respectively represent the acceleration components of the vehicle's centroid velocity V on the x and y axes; γ is the vehicle yaw rate, It represents the yaw acceleration; a and b are the distances from the center of mass of the car to the front and rear axles, respecti...

Technical field

[0001] The invention relates to the field of vehicle steering control, in particular to a control method of a four-wheel independent steering vehicle. Background technique

[0002] The handling and stability of the vehicle is an important performance related to the safe driving of the vehicle. Four-wheel steering (4WS) technology is an important component of the active chassis control system, and is the development trend of modern vehicles to improve handling stability and active safety. Control strategy is an important research aspect of 4WS technology. By adjusting the rear wheel angle to control the vehicle's center of mass slip angle and yaw rate, it can effectively improve the vehicle's high-speed driving stability and low-speed maneuverability. So far, for the 4WS control problem of active rear wheel steering, people have proposed methods such as feedforward control, yaw rate feedback control, neural network control, etc. that are proportional to the front ...

Examples

Embodiment 1

[0109] Such as figure 1 As shown, the control method for a four-wheel independent steering vehicle provided in this embodiment includes the following steps:

[0110] A. Preset ideal vehicle steering model, front wheel angle estimation initial value, front wheel angle observer, interference boundary estimation link, rear wheel angle sliding mode controller and yaw moment sliding mode controller;

[0111] The construction process of the ideal vehicle steering model is as follows:

[0112] Establish the following vehicle steering kinematics model:

[0113]

[0114] Where: m is the mass of the whole vehicle; v x , V y Respectively represent the velocity components of the vehicle's centroid velocity V on the x and y axes; Respectively represent the acceleration components of the vehicle's centroid velocity V on the x and y axes; γ is the vehicle yaw rate, It represents the yaw acceleration; a and b are the distances from the center of mass of the car to the front and rear axles, respecti...

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