基于奥迪q5的四轮转向系设计及运动仿真【含论文、CAD图纸、catia三维图、开题报告、任务书、答辩PPT、文献翻译】

基于奥迪Q5的四轮转向系设计

及运动仿真

摘  要

四轮转向系统利用行驶中的某些信息来控制后轮的转角输入，主要目的是增强汽车高速行驶时的操纵稳定性，提高汽车低速行驶时的操纵灵活性。

文中介绍了四种类型的四轮转向系统，为控制前后轮的协调偏转，提供了七种控制策略。根据已有的研究，设计了一种电控电动式的四轮转向系统，对其主要结构进行了介绍。

基于奥迪Q5的基本参数，设计了齿轮齿条式的前轮转向机构和后轮转向机构。基于阿克曼转向原理，运用Matlab优化工具箱对所设计的转向梯形机构进行尺寸优化。

本文建立了线型二自由度四轮转向汽车模型，推导出其运动微分方程。基于前后转角比例转向的控制策略，借助Matlab/Simulink对四轮转向和前轮转向汽车进行了运动仿真。

关键词：四轮转向；转向系设计；转向梯形优化；运动仿真

Design and Simulation of Four-Wheel Steering System Based On Audi Q5

Abstract

The four-wheel steering system utilizes some information from the vehicle to control the rotation angle of the rear wheel, in order to enhance the car handling stability at high speed, and improve the control flexibility at low speed.

Four types of four-wheel steering system are introduced respectively in this paper,. To achieve coordinated deflection of the front and rear wheels, seven kinds of control strategies are recommended. According to the existing research, a four-wheel steering system with electric-control and electric-power is designed, and its main structure is described.

Based on Audi Q5, the rack-and-pinion steering mechanism of the front and rear axles are designed respectively. The size of steering trapezoidal mechanism is optimized by using the Matlab optimization toolbox built on Ackerman principle.

The 2DOF linear four-wheel steering vehicle model is presented and the movement differential equation is deduced in this paper. The movement of four-wheel steering and front wheel steering vehicle are simulated with the help of Matlab/Simulink based on the control strategy of proportionable angles of front and rear wheels.

Key Words：Four-wheel steering, Steering system design, Optimization of steering trapezoid, Motion simulation