汽车稳定性控制算法仿真研究

发布时间：2018-09-06 16:42

【摘要】：汽车在急转弯时的稳定性一直是影响汽车高速安全行驶时的一项重要内容。当汽车在高速行驶时转弯或变更车道时,汽车会在很大的离心力作用下产生横摆运动,当地面附着系数较低时,汽车会立即发生侧滑,而且侧滑一旦产生,路面对汽车的横向作用将迅速减弱,驾驶员通过方向盘对汽车的控制效果也会变的非常不明显,汽车将迅速失去稳定性。对汽车稳定性影响的因素有很多,包括车辆的结构、参数、车辆行驶速度、初始运行状态、路面附着情况和方向盘转角等,因此,汽车转向时的稳定性控制器设计是一个较为复杂的非线性问题。本文根据国内外对汽车稳定性的研究现状,介绍了汽车稳定控制系统的国内外研究现状以及工作原理,并分析了汽车产生侧滑的原因,选取了针对汽车稳定性的两个控制参数并提出了控制策略,并通过遗传优化PID控制算法对其进行了研究。本文主要包括了以下几方面研究内容:1.分析了汽车侧滑发生的原因,然后根据理想汽车二自由度模型研究了横摆角速度和质心侧偏角对汽车稳定性的影响,并选取了横摆角速度和质心侧偏角作为汽车稳定性控制系统的控制参数,通过这两个控制参数如何对汽车的行驶状态进行判断,然后制定了相应的控制策略。2.在ADAMS/Car中建立了整车主要部分的虚拟模型并最后组合为整车虚拟样车的模型,在MATLAB/Simulink中通过不同功能的模块搭建控制系统的仿真框图,通过MATLAB和ADAMS的联合仿真技术实现了多体动力学系统和闭环控制系统的协同仿真。3.研究了PID控制算法和遗传优化PID控制算法,通过在MATLAB/Simulink上搭建的仿真框图分别对这两种算法进行了仿真分析和结果对比。4.在遗传优化PID控制算法下,还比较了不同的车辆结构参数对汽车稳定性控制参数的影响。通过联合仿真可以看出,遗传优化PID控制算法比PID控制算法有着更好的控制效果,横摆角速度和质心侧偏角的幅值和超调量都有着明显的减小,显著提高了汽车转向时的稳定性。整车质量和质心位置对汽车稳定性控制参数都有着较为明显的影响。
[Abstract]:The stability of automobile when turning sharply is always an important content that affects the safety of automobile driving at high speed. When the automobile turns or changes lane at high speed, the automobile will produce yaw motion under the action of great centrifugal force. When the adhesion coefficient is low, the automobile will immediately sideslip, and once the sideslip occurs, the road surface will be changed. The lateral effect on the vehicle will be weakened rapidly, and the control effect of the driver on the vehicle through the steering wheel will become very obvious. The vehicle will lose its stability rapidly. Therefore, the design of stability controller for automobile steering is a complicated nonlinear problem. According to the research status of automobile stability at home and abroad, this paper introduces the research status and working principle of automobile stability control system at home and abroad, analyzes the causes of automobile side slip, and selects two kinds of stability controller for automobile. The control parameters and control strategies are proposed and studied by genetic optimization PID control algorithm. The main contents of this paper are as follows: 1. The causes of vehicle sideslip are analyzed. Then the effects of yaw rate and center of mass sideslip angle on vehicle stability are studied according to the two-degree-of-freedom model of ideal vehicle. The yaw rate and center-of-mass side-slip angle are selected as the control parameters of the vehicle stability control system. Through these two control parameters, how to judge the driving state of the vehicle, and then the corresponding control strategy is formulated. 2. In ADAMS/Car, the virtual model of the main parts of the vehicle is established and finally combined into the model of the whole vehicle virtual prototype. In MATLAB/Simulink, the simulation block diagram of the control system is built by modules with different functions, and the co-simulation of multi-body dynamics system and closed-loop control system is realized by the joint simulation technology of MATLAB and ADAMS. 3. The PID control algorithm and genetic optimization PID control algorithm are studied, and the simulation block diagram is built on MATLAB/Simulink. The simulation results of the two algorithms are analyzed and compared. 4. The influence of different vehicle structure parameters on vehicle stability control parameters is also compared under the genetic optimization PID control algorithm. Both the amplitude and overshoot of the sideslip angle of the center of mass decrease obviously, and the stability of the vehicle is improved remarkably. The vehicle quality and the position of the center of mass have obvious influence on the vehicle stability control parameters.
【学位授予单位】：上海工程技术大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：U461.6

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