Dynamics modeling and active disturbance rejection control method of translation in a magnetically suspended universally stabilized platform

In response to the urgent demand for high-precision and high-stability pointing control technology of satellite platforms for complex space missions such as space laser communication, research has been conducted on the configuration design and control method of a spherical magnetically suspended universally stabilized platform (MSUSP). Firstly, the omnidirectional stable suspension characteristics of the MSUSP were analyzed, and a space structure with a right-angled equilateral triangular pyramid configuration was designed. Coordinate transformation was used to decouple the magnetic bearing rotor translation, and a three-degree-of-freedom dynamic model of the spherical magnetic bearing was created. Based on this, in order to achieve stable control of the magnetic bearing rotor under external disturbance conditions, a three-channel self-disturbance rejection controller based on coordinate transformation was designed, which treated the unmodeled dynamics and external disturbances between each channel as merged disturbances for tracking and compensation, thereby improving the speed and stability of the controller under disturbance conditions. The effectiveness and superiority of the suggested method were demonstrated by the analysis of simulation results, which revealed that this method significantly improved the anti-interference performance of the magnetic bearing rotor under various frequency sinusoidal disturbances and reduced the step response time for translational motion by 42.86% when compared to traditional methods.