MLUPS functions without contact or friction. With the large current power, mcu control core, laser interferometer position feedback, the stage meets the precision requirements hardware. The positioning system includes two-level positioning system—one-phase coarse positioning and two-phase fine positioning. Based on mathematical model, the immune PI controller is proposed in terms of magnetic edge effect, current harmonic and nonlinear characteristics of magnetic field. By designing target function, antigen affinity, antibodies affinity, mutation, immune algorithm optimizes parameters and memory cells. The stage working range is 10mm, the simulation result shows that the positioning precision is ±10 nm; the positioning time is 50 ms. The stage has a good performance in robustness

The LAMOST fiber positioning system is installed in focal panel. Thermal deformation influences focal panel and fiber positioning precision greatly. The heat transfer mathematical model of focal panel is established with the analysis of the focal panel structure. A single step motor heat under the normal work is detected. By using finite element analysis software Ansys the temperature distribution of the focal panel is calculated, which provides the basis for the next step calculation of the focal panel thermal deformation.