Abstract
This paper provides an examples based on four-axle steering mechanism of QY80 Auto-crane, in the example the trapezium mechanisms of each axle and the rocker mechanism are taken as one spatial system. This paper presents a new method which applies multi-rigid body system kinematics theory to analyze spatial motion of the steering mechanism. Basing on the kinematics analysis, this paper builds up the mathematical model of optimization for the spatial four-axle steering mechanism of Road Vehicles, then, the minimization adoptive random search method is employed to develop an optimization design microcomputer program, and finally optimizes each design variable, obtains optimum result which has been used in the process of production.