Abstract
Since the reduction gears of motors in robotic arms have rotational stiffness, residual free vibration occurs in robotic arms after the motor stops. Therefore, it cannot shift to the next operation until it is completed by vibration and causes decline in working efficiency. As method to suppress vibration is the input shaping method, the input shaping method is effective for suppression of residual vibration in machining tools. However, this method can be applied only to time-invariant system. Since robotic arms operate changing a posture, natural frequency changes. We model robotic arms with two flexibility and consider notch filter to intercept two natural frequency in a frequency domain. Therefore we change into the mode coordinate system from the physical coordinate system and consider conservation of energy of equation of motion, an improved is proposed for suppression of residual vibration to time-variant systems. The effectiveness of the proposed method is verified through simulation.
