基于自适应反步的DGMSCMG框架伺服系统控制方法

针对双框架磁悬浮控制力矩陀螺(DGMSCMG)内、外框架伺服系统耦合力矩及传动机构的非线性传动特性影响框架角速率精度的问题,提出一种基于自适应反步的非线性鲁棒控制器的设计方法。首先分别就双框架伺服系统耦合力矩及框架传动机构的非线性传动特性对系统稳定性和角速率精度的影响进行分析;其次利用反步理论,通过构造适当的Lyapunov函数并逐级反推得到控制律,保证参数估值的收敛性和系统的全局稳定性;最后通过仿真分析并以小型DGMSCMG系统为对象进行实验,结果表明:与电流前馈控制比较,所提出的自适应反步控制方法,既增强双框架伺服系统的扰动抑制能力,又提高框架角速率精度。

Adaptive backstepping control method used in DGMSCMG gimbal servo system

To overcome the problem of the precision of gimbal angular speed control brought by the coupling torque between inner and outer gimbal of double gimbal magnetically suspended control moment gyroscope (DGMSCMG) and the nonlinear transmission characteristics of the transmission gear, a nonlinear robust controller based on adaptive backstepping control method is proposed. Firstly, the effects of the double gimbal coupling torque and the nonlinear transmission characteristics of the transmission gear on the stability of the system and the precision of gimbal angular speed are analyzed. Secondly, based on backstepping theory, the control law is recursively deduced by constructing the suitable Lyapunov function, which ensures convergence of parameter estimation and global stability of the adaptive system. Finally, simulation analysis and experiment with small DGMSCMG show that the disturbance restraint ability of double gimbal servo system and the precision of gimbal angular speed are significantly improved by the proposed method, compared with current feed-forward control.