Vibration control of two-mass system with low inertia ratio considering practical use

Abstract

In some industrial motor-drive systems, a torsional vibration is often generated because of an elastic element in torque transmission. Such a mechanical system is modeled as a two-mass system and it is well-known that the suppressing vibration of a low inertia ratio two-mass system where the motor inertia is larger than the load inertia is very difficult. This paper proposes a speed control system of a low-inertia ratio system, taking into account not only the dynamic responses but also a robust stability. The proposed control system is based on the H∞ control theory and the resonance ratio control due to the feedback of the estimated shaft torque. Combining the H∞ controller with the resonance ratio controller, the control system with high robust stability can be obtained comparing with the conventional resonance ratio control. The variable feedback gain system and the construction of the disturbance observer are discussed in order to reject the effects of noise. The simulated and experimental results show that the proposed speed control system is useful for the two-mass system with low inertia ratio. ©1998 Scripta Technica, Electr Eng Jpn, 125(2): 1–9, 1998