扁平转子小型磁悬浮控制力矩陀螺磁轴承控制方法研究

轻小型磁悬浮控制力矩陀螺是高分辨率敏捷小卫星姿态控制的理想执行机构。在轻小型化约束下，为了提供足够的控制输出力矩，本研究提出的小型磁悬浮控制力矩陀螺采用扁平转子，转子轴向支承采用四磁极三自由度混合磁轴承，径向支承采用两自由度混合磁轴承。对于这种具有强耦合、强非线性特性的新结构磁轴承，目前未见有效的高速转子悬浮控制方法。本项目首先基于系统能量方程用拉格朗日方法建立考虑弹性模态的新结构五自由度混合磁轴承高速转子运动模型，揭示转子涡动、平动耦合特性与系统参数之间的关系，以及磁轴承与框架间相互作用机理，然后通过实验辨识分析磁轴承非线性、功放非线性、控制时滞等多源扰动特性对磁轴承控制系统性能的影响，最后提出新结构磁轴承高精度、低噪音、低功耗控制方法及其控制量在磁轴承各磁极中的分配算法并实验验证。

Small Magnetically Suspended Control Moment Gyro (SMSCMG) is the ideal attitude control actuator for high resolution small agile satellites. Under the limits of mass and size, in order to provide enough output control torque, the presented SMSCMG adopts oblate rotor, which is suspended with a four-pole 3-degree-of-freedom (DoF) axial magnetic bearing and a 2-DoF radial magnetic bearing. At present, there is not efficient high-speed rotor suspension control method for the new configuration magnetic bearings with strong coupling and nonlinear characteristics. In this project, firstly, the dynamic model of the 5-DoF rotor with bending modes is built up using Lagrange method based on the energy equations. The relationships between the system parameters and the whirling-shifting coupling characteristics, and the coupling between magnetic bearings and gimbal system are revealed. Secondly, the multi-source disturbances such as magnetic bearing nonlinearity, power amplifier nonlinearity, and control delay and their effects on the performance of magnetic bearings' control system are analyzed by means of experimental identification. Finally, the high precision, low noise, and low power-consumption control method together with its control allocation algorithm for the new kind magnetic bearing are presented, and validated by experiments.