Velocity estimation in digital controlled DC servo drives

This paper deals with the design of the extended observer in a digital control system for a DC servomotor. The suggested extended observer is able both to estimate the shaft speed and to filter the quantized signal from the position transducer. The developed observer enables proper estimation of the plant state variables, even in the case of the constant or a slow varying load torque disturbances. Useful procedures for the adjustment of observer gains are proposed and verified.