Robust speed servo system for wide speed range based on instantaneous speed observer and disturbance observer

Proposes a new robust speed servo system for a wide speed range including an ultra low speed range for a DC servo motor, which is based on the instantaneous speed observer and the disturbance observer. The proposed system has a two control strategy. First, this paper designs the instantaneous speed observer which uses the information of an armature current and an armature voltage. The proposed observer takes account of both the voltage drop of the power converter and the armature resistance variation. The second strategy is to realize both the robust speed control for disturbance torque and the adaptive speed control for inertia variation. For this strategy, this paper designs the disturbance observer based inertia identification algorithm. The total speed servo system becomes the robust speed servo system for a wide speed range.