Adaptive servo controller design using a disturbance observer

The authors propose an adaptive speed controller with a disturbance observer for a servomotor control system. The overall control system consists of three elements: a forward speed controller; a parameter identifier; and a disturbance observer. The servomotor system, using a two degree-of-freedom concept, can improve the characteristics of closed loop systems by suppressing the disturbance torque. Moreover, the system can be applied to time-varying systems by employing a parameter identifier. The authors show the performance of the proposed controller through experimental results