A transfer-positioning system with linear DC motor

This paper describes the design and control of a linear DC motor with discontinuous stator for transfer and positioning system. Normally, a moving coil type linear DC motor (LDM) for positioning system is designed with the magnet track assembly as a stationary member and the coil assembly as a moving member. In this paper, the authors designed the magnet assembly so as to be a moving member and the coil assembly to be a stationery member. The coil assembly (stator) is placed discontinuously along the rail assembly. The magnet track assembly is installed on the moving cart. The cart is operated by open loop control under transfer operation and by closed loop control at position control. A prototype unit is assembled and evaluation tests have been conducted. This system shows good performance at both operation transfer and position control.