Method of Vibration Suppression of the End-effector of Wafer Handling Robot Based on Optimal S-curve Profile

To solve the problem of low frequency vibration of wafer handling robot, a suppression method is presented based on the optimal S-curve profile. The low frequency vibration of the end-effector is suppressed by minimizing the amplitude of the vibration through optimizing the S-curve profile parameters in the amplitude equations, which are obtained by deducing the dynamic response approximate equations with parameterized S-curve profile input of the nonlinear time-varying system. Firstly, the models of the kinematics, the position error of end effector and the rigid-flexible coupling dynamics of wafer handling robot are built and the dynamic characteristics are analyzed as well. Following that, the approximate analytic solutions of the time domain dynamic response equations and the amplitude equations with parameterized S-curve profile input are deduced, by which the calculation method of the optimal S-curve profile is presented with the consideration of the dynamic characteristics of the wafer handling robot. Finally, the numerical simulations and the experiment are carried out to testify the effectiveness of the method presented. The experimental result shows that the amplitude of the low frequency vibration of the end-effector is reduced by 53.9% and 45% respectively in x, y directions.