In LAMOST project, the reflecting Schmidt plate (MA) and the spherical primary mirror (MB) are constructed with segmented mirrors. MA consists of 24 submirrors and MB consists of 37 submirrors. Three position actuators are mounted on the back of each submirror to support the submirror and maintain the co-focus of the submirrors. The position actuators are the critical components in the system. They must make precise movements under large loads. A set of position actuators for one submirror and its electronics system in the lab will be presented in this paper. The character of one actuator and the networking of handling its position will be described in the paper in detail. Adopt the field bus technology to combine these position actuators into a distributed control system.

This paper gives a function description of the distributed system and an implementation and the performance of the experimental subsystem.