Sensorless DC motor drive via optimal observer‐based servo control

This paper proposes an alternative design of a sensorless DC motor drive via optimal observer‐based servo control. Without the speed sensor, the extended Luenberger observer is implemented to estimate the rotor speed of the DC motor in the presence of the disturbance torque. With this knowledge of the speed estimated from the observer, the servo state‐feedback controller can drive such a rotor speed to follow the desired one. The stability and performance of the DC drive system can be guaranteed by the optimal control which minimizes the H 2 norm of the closed‐loop feedback control and observer system. The simulation and experiment studies are demonstrated for the effectiveness of the proposed control methodology in a practical approach for the sensorless DC drive.