Modeling and Control of Hybrid Magnetic Levitation for Spinning Rotor Gauge

For the permanent magnet-electromagnetic hybrid magnetic levitation system of the spinning rotor gauge, the influence of the permanent magnet in the magnetic levitation structure is considered.The magnetic field distribution in the axial direction of magnetic levitation is calculated, and the frequency domain model of the hybrid magnetic levitation system is established.The permanent magnet current stiffness coefficient and the permanent magnet displacement stiffness coefficient are designed to characterize the influence of coil current, the distance between the rotor and the lower coil and the permanent magnet parameters on the hybrid magnetic levitation system, and to limit and specify the design of the sus-pension system according to these two parameters.An analog proportional-integral-differential control circuit is designed for suspension control.Finally, according to this control model, the pressure measurement experiment is carried out with the measuring head under vacuum.Experimental results show that the pressure measurement of 9×10^-5~1Pa can be completed under the control of the proportional-integral-differential control circuit of the hybrid magnetic levitation model according to the design.