Vibration Control of Flexible Manipulator taking Friction-depending Disturbance into account

Recently, a lot of studies for vibration control of flexible manipulators have been reported. In 2 mass resonant system, “Resonance ratio control” is one of effective control methods. However, in this method, the robustness against the arm disturbance decreases. To improve this issue, the resonance ratio control with the arm disturbance observer is proposed. The arm disturbance observer is powerful. But, it is not robust enough to suppress friction-depending disturbance. There exists stick-slip friction effect when the arm moves slowly. The arm disturbance observer cannot compensate such a friction effect, and the vibration due to the stick-slip motion is induced. This paper proposes vibration control of flexible manipulator taking friction-depending disturbance into account. Here, the command generation is divided into two stages. First, friction is estimated by the arm disturbance observer. Second, the friction-depending disturbance can be rejected with the estimation result. The validity of the proposed method is also shown by simulations and experiments.