High Speed Positioning Method for Servo Motor Considering Friction Load Torque

Abstract

When the position error becomes small, in a conventional positioning system, its motor cannot obtain enough deceleration torque. Hence, the position response becomes slow. There is the other positioning system that is to design the position reference using a trapezoidal speed reference. When the load torque and the final goal position are known, this positioning system has a fine response. However, if the load torque and the final goal vary, its position response cannot have the desired response. In order to overcome these problems, this paper proposes a new high speed positioning system of AC servo motor considering both an unknown friction torque and a windup phenomenon. The proposed system always uses the maximum acceleration, deceleration torque and the maximum speed.