Multi-objective optimization of multi-axis linkage steering mechanism based on improved NSGA-Ⅲ

XIONG Hengkang; KANG Shaopeng; YANG Jing; QIANG Hongbin; LIU Kailei

doi:10.16578/j.issn.1004.2539.2025.12.007

Abstract：[Objective]In order to solve the problems that the steering wheel cannot achieve pure rolling during the steering process of the multi-axis vehicle linkage steering mechanism,resulting in the increase of friction and low steering accuracy,the kinematics and dynamics of a multi-axis linkage steering mechanism with virtual constraints were studied.[Methods]The kinematic analysis of the steering mechanism was carried out by the coordinate transformation method,and the relation between the coordinates of the hinge point of each component and the change of the first axis rotation angle was constructed,so as to obtain the imaginary displacement angle of each component.Based on the virtual work principle,the dynamic model of the steering mechanism was established,so as to solve the output torque of the hydraulic cylinder.Based on Matlab software,the dynamic simulation analysis of the steering mechanism was carried out,and the Adams software was used to verify the change curve of the output torque of the hydraulic cylinder and the rotation angle of the first axis.In order to further reduce the driving torque and improve the steering accuracy of the hydraulic cylinder,the improved NSGA-Ⅲ was used to optimize the steering arm and wheel hinge points of the steering mechanism.[Results]The error between the numerical simulation results and the simulation results is within a reasonable range,which verifies the accuracy of the dynamic model.After the improved NSGA-Ⅲoptimization,the error of the rotation angle is within 1.4°,and the driving torque of the hydraulic cylinder is reduced by 210 N∙m,which is 3.1%less than that before optimization.The research results provide reference for the design of multi-axis vehicle steering system.