High Speed Positioning System Considering Coulomb Friction and Inertia Variation

Abstract

In a conventional positioning system, when the position error becomes small, the motor cannot obtain enough deceleration torque. Hence, the position response becomes slow.
In order to overcome this problem, this paper proposed a new high speed positioning system of an AC servo-motor considering unknown coulomb friction, inertia variation and windup phenomenon. In this paper, the sum of coulomb friction load and inertia variation are estimated by disturbance observer. The proposed method always uses the maximum acceleration torque, the deceleration torque and maximum speed.