Nonlinear dynamics analysis of shift manipulator for robot driver considering multiple revolute clearance joints and variable load

Clearance joints and variable load have a great influence on the dynamic performance of shift manipulator for robot driver. In this article, a dynamics model of clearance joint and a simulation method of variable load are proposed to analyze the influence of clearance joint and variable load on the dynamic performance of shift manipulator. Firstly, a hybrid nonlinear contact force model is established to describe the normal contact force of revolute clearance joint, and a modified Coulomb friction model is used to describe the tangential contact force of revolute clearance joint. On this basis, a virtual prototype dynamics model of shift manipulator with multiple revolute clearance joints is established. Then a power transmission model of shift manipulator including the variable load model at the end of shift manipulator is established. The time-varying and nonlinear characteristics of the load in gear engaging direction are simulated by neural network. Finally, the influences of different clearance dimension and variable load on the dynamic performance of shift manipulator are analyzed. Experiment and simulation results show the validity of the presented analysis, which provides a basis for further structure optimization of shift manipulator.