多输入–多输出非线性系统的特征模型及在挠性卫星姿态控制中的应用

研究多输入–多输出（MIMO）高阶非仿射非线性系统的特征建模问题.首先证明了MIMO高阶非仿射非线性系统的特征模型可用二阶时变差分方程组描述,并给出了特征模型的建模误差.然后设计了基于特征模型的自适应模糊广义预测控制器,利用Lyapunov方法分析了闭环系统的稳定性.由于控制结构中使用了分层模糊逻辑系统,从而极大减少了模糊规则和可调参数的个数,提高了控制的实时性.通过对挠性卫星姿态控制的仿真研究验证了所给控制方案的有效性,可实现高精度的姿态控制,且该方法具有较强的鲁棒性.

Characteristic model for multi-input-multi-output nonlinear systems and its application in flexible satellite attitude control

The characteristic modeling is investigated for multi-input and multi-output higher-order non-affine nonlinear systems. First, we prove that the characteristic model for the above systems can be expressed by a system of quadratic timevarying difference equations and estimate the characteristic modeling errors. Next, we design an adaptive fuzzy generalized predictive controller based on this characteristic model, and analyze the stability of the closed-system using Lyapunov method. Because hierarchical fuzzy logic systems are employed in the control architecture, the number of fuzzy rules and adjustable parameters in a fuzzy logic controller are reduced greatly, thus improving the real-time operation performances of the control. Finally, the results from the control simulation on a flexible satellite attitude validate that the proposed control scheme is effective and has the advantages of high steady-state precision and strong robustness.