Modeling and control algorithm for power steering stability of electric vehicle

Abstract

The invention provides a modeling and control algorithm for power steering stability of an electric vehicle. The modeling and control algorithm comprises the following steps: establishing a mathematical model of a steering wheel system; establishing a mathematical model of a motor subsystem; establishing a mathematical model of a steering tie rod subsystem; and establishing a road model of a control algorithm of an EPS system. According to the invention, mathematical models of the steering wheel system, the motor subsystem and the steering tie rod subsystem are established according to the basic structure and the working principle of the EPS system, a P algorithm and a PD algorithm are adopted for auxiliary control, and the road model of the two algorithms is established; auxiliary control over the electric vehicle is achieved by adjusting a steering gear speed ratio, an electromagnetic torque coefficient and an auxiliary current gain coefficient in the road model, and experimental results show that through testing, the algorithm plays a positive role in improving the steering stability of the vehicle.

Description

technical field [0001] The invention belongs to the technical field of motor vehicle control, and in particular relates to a modeling and control algorithm for electric vehicle power steering stability. Background technique [0002] The steering system of a motor vehicle is one of the main automotive subsystems to ensure the driving of the vehicle. Its performance is directly related to the comfort and safety of the vehicle. The positive torque ensures the stability of the vehicle and increases the steering resistance of the driver, especially for large vehicles. The low-speed steering will make the driver work hard, which is not conducive to the driver's driving comfort. [0003] In order to improve this contradiction, the power steering system of automobiles began to appear. The steering system of the prior art has gone through several stages of mechanical, hydraulic and electro-hydraulic. Easy to leak, difficult steering control and other disadvantages; electric power st...

AI Technical Summary

Problems solved by technology

Kim, W et al. proposed a PID control signal filtering method (Kim et al.2016), and compared the PID control effect before and after filtering, but did not consider the size of the given current, so the single PID control has poor real-time performance. The system parameter setting is complex; some inventors have proposed fuzzy PID control based on signal filtering and system stability analysis. However, within the stable range of a single control variable, other variable parameters still cannot reach the optimal control effect, and the stability is not strong; therefore, how to optimize the control algorithm and improve the control stability of the EPS system is still the focus of research

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