Host: The Japan Society of Mechanical Engineers
Name : The 15th International Conference on Motion and Vibration(MoViC 2020)
Date : September 09, 2020 - September 11, 2020
As robot arms used in industrial factories are required high-speed operations and precise positionings in order to improve work efficiency and accuracy, their residual vibration is one of the crucial problems in automation industry. Many robot arms use a reduction gear such as a harmonic drive for each joint. Since the harmonic drive is small in backlash but low in rigidity in rotational motion, most residual rotational vibrations are due to the spring-like behavior of the reduction gear. Moreover, since many robot arms have multiple joints, multiple vibration modes occur. However, most of the previous studies treat merely a fundamental mode vibration, and higher modes are merely suppressed under closed-loop control. In this study, we proposed a reference input of a finite-time settling function, called rotational vibration manipulation function, to suppress the residual rotational oscillation of the robot arm with the reduction gear as a rotational spring under open-loop control. The manipulation function is used in feedforward control for one-time rest-to-rest motion in various operational times. We performed simulations to discuss specific operational times that suppresses the both residual vibrations in the fundamental and secondary modes of a horizontal 2DOF robot arm simultaneously.
