To improve quality and efficiency of the manufacturing

This paper investigates residual vibrations of industrial SCARA robots in wafer handling applications. Due to rapid point-to-point movements, SCARA robot arms exhibit large vibrations after reaching the destination position. A mathematical model particularly suitable for residual vibration analysis is developed. The validity of the mathematical model is confirmed by the close match between experimental results and robot arm trajectories generated by the model. The root cause of residual vibrations is analyzed using the model. Based on the root cause analysis, a practical solution to suppress vibrations is proposed. The solution utilizes an acceleration smoother to smooth the commanded trajectory, and it can be easily implemented in practice without redesign the robot hardware or control system. Experimental results show over 40% reduction in both vibration amplitude and settling time.