Back EMF compensation of a linear motor stage with a passive RFC mechanism

Abstract

The vibration of system base in a linear motor motion stage has been reduced with passive reaction force compensation (RFC) mechanism of movable magnet track type. However, the reaction force of the mover makes the magnet track oscillate so that the settling time of the mover may be increased due to induced back EMF of the mover coil. This paper presents a back EMF compensation of a linear motor stage with a movable magnet track using RBF (radial basis function) neural network. The linear motor stage with the passive RFC mechanism is mathematically modeled and the effect of the back EMF of the mover coil is investigated with simulations. A RBF neural network control is applied to compensate the back EMF of the mover coil and uncertain friction effect of the motion stage. Finally, the effectiveness of the back EMF compensation method is verified by both simulations and experiments of a linear motor stage with the RFC mechanism. © 2014 The Japan Society of Mechanical Engineers.