Abstract: | The speed control ability of dc servomotors is affected by parameter variations and disturbance torque. In this paper, a robust speed control method for dc servomotors with a disturbance torque observer and a feedback controller is proposed. The disturbance torque observer is used for the compensation of parameter variations and disturbance. The feedback gain is adjusted in the aspect of stability by an adaptive gain law based on Lyapunov's direct method and is used to restrain the influence of estimation error for the disturbance observer. A robust current control scheme for a voltage source PWM inverter with disturbance observer is also presented, since current control ability affects the control performance of dc servomotors. The validity of this control scheme is verified by numerical simulations and experiments. © 1999 Scripta Technica, Electr Eng Jpn, 126(3): 30–40, 1999 |