Synchronous control for a dual linear motor of moving gantry machining centers based on improved sliding mode variable structure and decoupling control

For the problem that a dual linear motor servo system on the X-axis of gantry moving machining centers is not synchronized during the driven process, this paper proposed an improved variable structure control and decoupling control approach. Firstly, the decoupling control could compensate for the force caused by mechanical coupling, because of dual parallel linear motors that are physically coupled with a mechanism. After that, for the one linear motor servo system, an improved variable structure control is designed, in order to improve the anti-jamming and robust of system. The results of simulation show that the proposed scheme is effective. Not only the synchronization accuracy is upgraded but also the chattering problem of the ideal sliding mode is avoided.