电动助力转向系统建模与仿真分析-机械工程专业论文.docxVIP

重庆大学硕士学位论文中文摘要 重庆大学硕士学位论文 中文摘要 I I 摘 要 汽车转向系统是影响汽车操纵稳定性 行驶安全性和驾驶舒适性的关键部件 在追求高效节能 高舒适性和高安全性的今天 电动助力转向系统EPS作为 一种全新的汽车动力转向系统 以其节能 环保 更佳的操纵特性和转向路感 成为动力转向技术研究的焦点 本文结合 EPS 的结构和动力学特性 建立起 EPS 的动力学模型和空间状态模 型 通过对 EPS 系统控制特性的分析研究 提出了 PID 和 Fuzzy-PID 的控制方法 并结合三自由度的整车模型考虑侧倾影响和 Fiala 轮胎模型建立了 EPS 仿真 模型 进行了采用 PID 及 Fuzzy-PID 两种控制策略下的 EPS 系统性能仿真 分析汽 车在转向行驶时轮胎载荷的变化 汽车纵 横向加速度的变化 以及车速 转向 系刚度 前后轮侧偏刚度比 前后悬架侧倾角刚度比等对转向系统的影响 分析 了在阶跃输入下的汽车横摆角速度频率响应 结果表明 相对于普通汽车 装有 电动助力转向系统的汽车响应速度更快 具有更好的操纵稳定性 相对于普通 PID 控制 采用 Fuzzy-PID 控制可使系统动态性能更好 系统响应更迅速 超调量更 小 稳定更快 关键词 电动助力转向 动态特性 仿真 控制策略 重庆大学硕士学位论文英文摘要 重庆大学硕士学位论文 英文摘要 II II ABSTRACT Vehicle Steering System is a pivotal parts which has big influence on vehicle’s control stability, drive safety and comfort. Electric Power Steering, is a new high-tech which follows the development of modern automobile, has advantages both in energy saving, environmental protecting, drive safety, making higher steering performance, better road feeling, has shown its tremendous direction. Based on the structure and the dynamic characteristics of electric power steering system (EPS), the control strategy and algorithm of electric power steering system is analyzed and the mathematical model the state space model is established. Through the further research based on other domestic university, this paper bring forward PID control and Fuzzy-PID control, combined with three freedom full vehicle model (considered drift angular) and Fiala tire model, and the EPS simulation model is finally established. Through the model we established, the dynamic characteristics of EPS was conducted due to disturbance of the road condition, such as the variety of the tire load during steering, the variety of longitudinal and latitude acceleration, the factors, such as the vehicle speed, the stiffness of the steering system which influence steering system, is also analyzed. Also, the simulation results is carried out by system model applied with PID and Fuzzy-PID control strategy respectively, the