四轮转向梯形机构优化设计及目标函数选取

Optimum design of four wheel steering trapezium and selection of objective function

针对智能车的转向梯形机构,对其空间结构及一些参数进行了合理的简化。提出了新的优化目标函数,利用MATLAB优化工具箱,采用遗传算法,调用Ga模块对转向梯形的目标函数进行最优化设计,并与常见的目标函数进行对比分析,找出瞬时回转中心变化的基本规律。结果表明:当转向轮转向角在较小范围内变化时,转向瞬心基本上在一条直线上波动,与Akermann原理特征相符;在大转向角范围内,瞬时回转中心偏离这条线越来越远,基本不符合Akermann原理。为转向梯形机构优化设计提供了更精确的方法。

Aiming at the steering trapezium mechanism of intelligent vehicle,the space structure and some parameters aresimplified reasonably.The optimization objective function is proposed,by using the MATLAB optimization toolbox,usinggenetic algorithm,called Ga module optimization design for the objective function of steering trapezoid,and compared withthe common objective function,find out the basic laws of the change of instantaneous center of rotation.The results showthat when the steering angle of the steering wheel changes in a small range,the steering instantaneous center fluctuatesbasically in a straight line,which is consistent with the characteristics of the Akermann principle.In the range of largesteering angle,the instantaneous center of rotation deviates from this line more and more far and basically does not conformto the principle of Akermann.It provides a more accurate method for the optimal design of the steering trapezium mechanism.