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

ObjectiveIn order to solve the problems that the steering wheel cannot achieve pure rolling during the steering process of the multi-axle vehicle linkage steering mechanism, resulting in the increase of tire friction and low steering accuracy during steering, the kinematics and dynamics of a multi-axis linkage steering mechanism with virtual constraints were studied.MethodsThe 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 round of 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.ResultsThe error between the numerical simulation results and the simulation results was within a reasonable range, which verified the accuracy of the dynamic model. In order to further reduce the driving torque and steering accuracy of the hydraulic cylinder, the improved NSGA-Ⅲ algorithm was used to optimize the steering arm and wheel hinge points of the steering mechanism, and the error of the optimized rear rotation angle was within 1.4°, and the driving torque of the hydraulic cylinder after optimization was reduced by 210 N·m, which was 3.1% less than that before optimization. The research results provide reference for the design of multi-axle vehicle steering system.