Design of XYR Precision Positioning Platform Control System for Desktop Scanning Electron Microscope

This paper addresses the multi-degree-of-freedom control and precise positioning requirements of the desktop scanning electron microscope. Considering the diversity of the mechanical structure of the positioning platform and the compatibility of various types of motor drives, a set of XYR positioning platform control system is designed. This system is centered on the GD32 microcontroller and designs three motor control channels that support plug-and-play. Each channel is compatible with two-phase stepper motors and brushless DC motors. The software design adopts a modular programming approach, achieving dual closed-loop control based on PID for position and speed, covering functions such as motion control, real-time monitoring, and error compensation. Experimental results show that the positioning accuracy of the XYR axes of the designed positioning platform control system reaches ±5.94 μm, ±6.76 μm, and ±0.28° respectively; the repeat positioning accuracy reaches ±3.44 μm, ±3.12 μm, and ±0.36° respectively, meeting the usage requirements of the sample positioning platform for the desktop scanning electron microscope.