Robust position control of DC servomotors using fuzzy reasoning

In position control for DC servomotors using the equivalent disturbance torque observer, the position control ability is affected by the estimation error of torque observer. We propose the robust position control of DC servomotors using fuzzy reasoning to consider the estimation error. In order to compensate the estimation error, we combine the equivalent disturbance torque observer and a feedback controller. The influence of estimation error is restrained by the feedback controller introducing fuzzy reasoning. The reason why we introduce fuzzy control is that the estimation error for the observer is highly nonlinear and it cannot be detected by a linear error estimator. In this case, it is very convenient to use fuzzy reasoning to identify the estimation error. The simulation and experimental results confirm the validity of the proposed control technique.