An Analysis On The Key Issues Of Optimal Design In Steering Trapezium

Steering trapezoid is an important part of steering mechanism,the ideal steering trapezoid has the ability to let all of the wheels turn around the same instantaneous turning center.However,steering trapezium can't guarantee that all the wheels are pure rolling motion in the actual steering process.Steering trapezium has had interference on steering movements.It Causes wheel slip angle,accelerates tire wear,affects the transmission of force and motion,and further impacts the steering performance of automobile.Therefore,trapezoidal parameter is the key of optimized design.Based on the Ackerman steering and elastic tires,this paper Considered car steering motion characteristics to establish a mathematical model composed by steering trapezium and elastic tires,and combined with the actual work conditions of the steering wheel,proposed a objective function based on tire wear,used of MATLAB to optimization,in order to get a better trapezoidal parameter.Overall,this article mainly studies the following three aspects.Firstly,this paper analyzed Ackerman steering in planar projection method,then the kinematic and dynamic models of Steering trapezoid and elastic tires were set up,illustrated the ideal kinematics and actual kinematic properties based on the trapezoid model,and the practical and theoretical steering angle of inside steering wheel during steering.After then,analyzed tire slip angle caused by trapezoidal motion interference in numerical method based on the system composed by steering trapezoid and elastic tires.Then based on the tire brush model,this article summarized the achievements of previous study on tire wear,and found the relationship between slip angle and tire wear.Last constructed deviation function which reflected the relationship between the trapezoidal interference and tire wear.Secondly,the paper investigated the weighting function which reflected the car's actual steering condition,analyzed of weight function from two aspects of the theoretical derivation and statistical data:focused on what's the meaning of the weight function in theory and practice,and summarized and analyzed others steering wheel angle distribution data in the actual steering process;Then this article studied the distribution characteristics of steering angle on the bases of the theoretical analysis and statistical data;After then proposed a new weighting function which reflected the actual working condition of steering wheel.Finally,this paper set up an objective function was based on tire wear,which was composed by deviation function and weight function.In this article,a real car was taken as an example to use MATLAB optimization toolbox for solving the problem of optimization design of the steering trapezoid,and comparing with other methods,the method was superior to them.