没有合适的资源?快使用搜索试试~ 我知道了~
资源推荐
资源详情
资源评论
太原理工大学硕士研究生学位论文
I
基于 MATLAB 四轮转向汽车操纵动力学及控制策略研究
摘 要
四轮转向汽车的出现,在很大程度上解决了前轮转向汽车固有的缺陷,
汽车低速行驶转向响应慢,且转弯半径较大;高速行驶转向稳定性差,安
全性能差。此外,四轮转向技术的出现大大提高了汽车的操纵稳定性。
近几十年来,现代控制理论发展迅速,针对四轮转向系统控制的研究
方法层出不穷,如:鲁棒控制、模糊控制以及基于神经网络控制等,但这
些方法都各有利弊。本文在 MATLAB 环境下,对四轮转向汽车进行转向系
统的控制,采用不同的控制方法,通过 MATLAB/Simulink 建立模块模型进
行仿真,通过编写 M 文件,得出四轮转向汽车操纵稳定性评价指标的响应
曲线,对曲线进行分析对比,从中找出最合适的控制方法。
在国家汽车工程师协会标准坐标系下(SAE 坐标系),对四轮转向汽
车进行动力学分析。建立三种不同自由度四轮转向汽车动力学模型,应用
数学与物理相关知识将动力学模型转化成运动学模型,根据现代控制理论
所学知识应用 MATLAB 编程将运动学模型转化为数学模型,其中数学模型
包括传递函数模型及状态方程模型,为四轮转向汽车的控制策略研究提供
理论基础。
本文基于所建立的汽车模型,结合轮胎模型,设计四轮转向系统的控
制策略,分析车辆稳定性控制研究的两个问题。在二自由度车辆模型的基
础上,对车辆的横摆角速度与稳定性的关系以及车辆的质心侧偏角与稳定
性的关系进行分析。对 MATLAB 以及 Simulink 的基本操作进行简单介绍,
除此以外,对二自由度四轮转向系统进行横摆角速度反馈控制,分别在时
太原理工大学硕士研究生学位论文
II
速为 30km/h 和 90km/h 进行仿真,并与其它控制方法进行仿真对比,对仿
真结果进行定性分析。
在 MATLAB/Simulink 环境中建立四轮转向系统最优仿真的模块模型。
首先应用现代控制理论的知识将运动微分方程转化成状态方程模型,通过
分析可控性矩阵和可观性矩阵是否满秩来判断系统的可控性与能观性,在
能控与能观的基础上,在 MATLAB 中建立仿真模块模型,得到操纵稳定性
的评价指标响应曲线,对模型仿真结果进行分析。
设计 PID 控制器、构建 PID 子系统以及设计系统参数。在前人的研究
基础上, 应用已学 知 识 建 立 分 数 阶 PID 控制得数学模型,在
MATLAB/Simulink 中建立四轮转向系统分数阶 PID 控制的模块模型,并得
到分析操纵稳定性的评价指标的响应曲线。
关键词:四轮转向,横摆角速度反馈,最优控制,分数阶 PID,操纵稳定性
太原理工大学硕士研究生学位论文
III
STUDY ON HANDLING DYNAMICS AND CONTROL
STRATEGY OF FOUR-WHEEL STEERING
VEHICLE IN MATLAB SOFTWARE ENVIRONMENT
ABSTRACT
The appearance of a four-wheel steering vehicle has solved the inherent
defects of the front wheel ones to the automobile to a large extent, which
response is slow and a type of turning radius is large in low speeds; the stability
and the safety performancing is poor in high speeds. In addition, the appearance
of the four-wheel steering technology greatly improves the stability of the
vehicles.
In recent decades, the modern control theory has been developed rapidly,
and there are many research methods to control a four-wheel steering system,
such as robust control, fuzzy control and neural network control. But each of
these approaches has its pluses and minuses. This paper adopted different
control methods for four-wheel steering vehicles in the MATLAB environment.
Through MATLAB/Simulink, the response curves of the four-wheel steering
stability evaluation index are obtained, and those curves are analyzed and
compared to find a most suitable control method.
The dynamic analysis of four-wheel steering vehicles is conducted in the
standard coordinate system of the national automobile engineers association
(SAE coordinate system). The paper established three different degrees of
freedom dynamic model of the four-wheel steering vehicle, transformed the
dynamic model into the kinematics one in mathematics and physics knowledges,
and transformed the kinematics one into a mathematical model according to the
太原理工大学硕士研究生学位论文
IV
knowledge of modern control theory, the mathematical model includes the
transfer function model and the state equation model, which provides the
theoretical basis for the research on the control strategy of the four-wheel
steering vehicle.
A four-wheel steering system control strategy is designed based on the
model of the two-freedom four-wheel steering vehicle with its tire model,and
the two problems of vehicle stability control research are analyzed. The basic
operation of MATLAB and Simulink is briefly introduced. On the basis of the
two-degree-of-freedom vehicle model, the relationship between the angular
velocity and stability of the vehicle and the relationship between the lateral
angle and the stability of the vehicle are analyzed. In addition, the two degrees
of freedom four-wheel steering system for horizontal pendulum angular velocity
feedback control, separately in the speed of 30 km/h and 90 km/h in simulation,
and compared with other control methods are simulated, which results are
qualitatively analyzed.
The optimal simulation module is established for four-wheel steering
system in the MATLAB/Simulink environment. First of all, the motion
differential trasforms into state equation model with modern control theory
knowledge. By analyzing the controllability matrix is full rank matrix and
considerable sex to determine the controllability of the system and can view, are
able to view and controllability, on the basis of model simulation module in
MATLAB, get the steering stability evaluation index response curve, the model
simulation results are analyzed.
The PID controller, the construction of PID subsystem and the design of
parameters are designed. On the basis of predecessors' researching, the
mathematical model of fractional PID control is established with using
application knowledges, and the module model of fractional PID control of
four-wheel steering system is established in MATLAB/Simulink, and the
太原理工大学硕士研究生学位论文
V
response curves of the evaluation index are obtained.
KEY WORDS: four-wheel steering, yaw angular velocity feedback, the optimal
control, the fractional order PID,
maneuvering stability
剩余84页未读,继续阅读
资源评论
2201_75761617
- 粉丝: 20
- 资源: 7339
上传资源 快速赚钱
- 我的内容管理 展开
- 我的资源 快来上传第一个资源
- 我的收益 登录查看自己的收益
- 我的积分 登录查看自己的积分
- 我的C币 登录后查看C币余额
- 我的收藏
- 我的下载
- 下载帮助
安全验证
文档复制为VIP权益,开通VIP直接复制
信息提交成功