Abstract: This paper deals with the design of observer-based controller for high-performance speed-controlled servo drives that employ incremental encoders for sensing of the motor shaft position. The suggested extended observer is designed by introducing the additional integration state variable within the ordinary identity observer in order to enable, even in the presence of a constant or slow varying load torque disturbance, the estimation of shaft speed and filtering of position signal contaminated by the quantization noise due to a limited resolution of position transducer. The useful procedures for setting of controller parameters and adjustment of observer gains are proposed.
Key words: Automatic control, digital control, servo drive, speed control, incremental encoder, observer.