Research on high precision magnetic suspension positioning platform

In order to improve the positioning accuracy of magnetic levitation positioning platform and realize high-speed and high-precision positioning, this paper adopts the planar four-wheel drive structure based on the idea of modularity. Based on this structure, the relationship between the command coordinates and the driving coordinates is deduced, and the movement and rotation dynamics model of the positioning platform is established. For the multi-input and multi-output coupling system of magnetic levitation positioning platform, the sliding mode control strategy based on exponential reaching law is proposed, and through simulation verification, compared to the traditional control method, magnetic levitation positioning platform can acquire fastness and stability. Finally, a three-degree-of-freedom magnetic levitation positioning platform is built. To achieve the positioning platform of the closed-loop feedback, the displacement of the positioning platform is detected in real time by the laser displacement sensors. From the experimental results, the platform's stroke is 50mm×50mm, after about 153ms, the platform stabilizes to 50mm in the X direction and after about 198ms, the platform stabilizes to 50mm in the Y direction, the repeated positioning accuracy in XY plane can be obtained within 5μm.