Immune PI Controller on Magnetic Levitating Ultra Precision Stage
Xue Peng Liu, Xiao Hong Hao, Dong Sheng Zhang, Bin Wang · Key engineering materials · 2013
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