Abstract: Aiming at difficulties for conventional speed observer to reach high precision in DTC of servo induction motor，the paper designed fuzzy velocity observer.Since the fuzzy observer has a strong subjectivity in fuzzy control rules，self-learning fuzzy velocity observer is produced to present detailed algorithm process.Then，a DTC induction motor servo control simulation model is established，which adopts the self-learning fuzzy in velocity observer.Based on this，the paper built an experimental platform combining TI TMS320LF2407DSP with IPM.Experiment results showed that the proposed observer made well observation on the servo motor velocity，thus providing an idea for accurate positioning control of servo-motor.

Key words: Servo motor, DTC, Self-learning fuzzy logic, Velocity observer