AC servo motor position sensorless control using mechanical springs

This paper describes a position sensorless control technique on AC servo motor position control systems. We had previously presented a paper on the DC servo motor position sensorless control technique using mechanical springs. It was based on a point of view that mechanical springs form the key components for the observability. On the basis of the result obtained from the successful experiment, we assumed that the AC servo motor position sensorless control system applying the vector control method would be identical as in the case of the DC motor. Using vector control, the controller needs the data of the magnetic pole position on the rotor of the AC servo motor. By using the AC servo motor perfect position sensorless control technique, the controller should estimate both the magnetic pole position and mechanical position. In this paper, we demonstrate the estimation method for the latter as an initial step in the new control technology