Command generation techniques for elimination of residual vibrations for robotic applications

One method used to reduce or eliminate residual vibrations is to modify the input signal by using previously determined system parameters. In order to eliminate the residual vibration completely, these system parameters must be known very accurately. In real systems, achieving such accuracy may not always be possible. To address this problem and to provide a solution, a new residual vibration elimination method is introduced in this thesis. It has been proven to be useful especially in cases of uncertain system parameters that are estimated or predicted. It is shown that the technique is capable of handling high levels of uncertainty and is able to successfully eliminate or reduce residual vibrations in flexible robotic systems. In this approach, the desired position of the system is primarily divided into two or more equal parts for each of which a sectional input command is generated. In generation of each of the input signal, cycloid-plus-ramped and versine-plus-ramp functions are used. This reference input is composed of three key functions. Each part is travelled by each of the three functions within the same travel time. Provided that the specified move time and the total distance are unchanged, vibration can be eliminated by adjusting excursion distance of each function. The thesis presents theoretical and experimental results of the techniques applied to flexible robotic systems; a comparative study of robustness performance is also provided. The presented simulation and experimental results show that the residual vibrations are considerably decreased with a high degree of robustness in the presence of estimation related uncertainty regarding system parameters.