Abstract: Direct Torgue Control system (DTC) is a new AC servo system after the invention of Vector Control of AC Motor It has many advantages, but in low speed operation, the deviation of stator resistance R 1 makes the performance poor A description is given of a resistane fuzzy observer employing fuzzy control theorg, which can get a more precise value of R 1 through real-time calcalation The experiments show that the fuzzy observer is effective

Key words: fuzzy systems, torque-control, AC-servomechanisms