Abstract
The speed control ability of dc servomotors is affected by parameter variations and disturbance torque. Mathematical plant model is usually used for control, however, accurate parameter measurement is very difficult and parameters vary with operating conditions, for example, temperature or saturation effects. Consequently, motor control methods using the disturbance torque observer which compensates parameter variations and disturbance torque has been proposed, high-performance control of servomotor has been achieved. However, estimated disturbance torque by the disturbance torque observer has estimation error, therefore the control method taking account of estimation error is necessary.In this paper, the robust speed control method for a dc servomotor with a disturbance torque observer and a feedback controller is proposed. The disturbance torque observer is used for compensating parameter variations and disturbance torque. The influence of estimation error for disturbance torque is restrained by the feedback controller introducing fuzzy reasoning. The feedback again adaptive law in the feedback controller is constructed on the basis of the speed error information.The useful features and validity of proposed control method are confirmed by computer simulations.
