Robust Load Disturbance Torque Estimation for a Permanent Magnet DC Motor Drive System

Direct current motors are an integral part of many systems. An important factor in the design of these systems is the disturbance torque on the motor\u27s shaft. This disturbance torque can negatively affect the performance of the motor and the overall system. Knowledge of the disturbance can aid in compensating for these negative effects, which enhances the robustness of the system to changes in the load. Estimation has become a feasible means of acquiring the value of such a disturbance. Various methods for the design of a robust disturbance torque estimator are presented here. The designs are robust in the sense that the estimation is insensitive to the presence of model uncertainties and/or noise. The estimators are designed to estimate both constant and non-constant, low-frequency disturbance torques. The designs are tested using a permanent magnet DC motor. An in-line torque sensor is used for validation