Vibration control of flexible arm by multiple observer structure

This paper describes vibration control of a flexible arm by multiple-observer structure using the accelerations of the arm. In general, a flexible arm has several oscillation modes. In the model of a flexible arm described as a two-mass resonant system, the reaction torque feedback makes the flexible arm system stable. In the N-mass resonant system, it is known that the reaction torque feedback makes all oscillation modes, only the reaction torque feedback is not enough to make the system stable. Resonance ratio control with the arm disturbance observer has been proposed. The arm disturbance observer is able to suppress the disturbance applied to the tip, but it is not sufficient for the disturbance applied to other points on the arm. The aim is to make the control system robust to arm inertia variation and disturbance. This paper proposes vibration control of flexible arm by acceleration feedback, and disturbance rejection by multiple-observer structure using the acceleration of the arm. The validity of the proposed method is shown by simulations and experiments.