Design and Some Experimental Results of the U-Type Permanent Magnet Three-Phase Linear Motor Based Position Control System with the Backstepping Technique Based Disturbance Observer

Nowadays, permanent magnet linear motors are widely used in high accuracy CNCs, because they make the linear moving without the mechanical system, that transfers rotating moving to linear moving, therefore the accuracy in position control of the system is improved. Among them, U-type permanent magnet three-phase linear motors are more widely used because there are not attractive forces in these motors and the thrust force is high. However, the nonlinearity of the motor and the force disturbances that are caused by the end effect, load, slot tooth, high order harmonic waves still reduce the accuracy in position control of the system. In order to solve this problem, this paper presents the design of the U-Type permanent magnet three-phase linear motor based position control system with the Backstepping technique based disturbance observer. The proposed position control system is experimented on the DSP based experimental system, which uses DSP TMS 320F2812. The experimental results show that the performance of the proposed position control system has high accuracy, that meets the commands of the high precision CNC machines in the industry.