临近空间飞行器的滑模变结构解耦控制

Sliding Mode Decoupling Control of Near-Space Vehicle

建立了临近空间滑翔飞行器六自由度运动模型,针对模型具有的快时变、强耦合、强非线性和不确定性特点,应用动态逆方法和滑模变结构控制方法分别设计了内环解耦控制器和外环鲁棒控制器,实现了解耦性与鲁棒性的有机结合,显著提高了控制系统性能。内环采用反馈线性化方法实现了姿态运动模型的伪线性化;外环滑模变结构控制器采用等速趋近律,采用饱和函数法抑制抖振现象,有效抑制外界干扰和参数偏差。仿真结果表明:基于动态逆的滑模变结构控制系统可以准确跟踪攻角、侧滑角和倾侧角指令,对外界干扰和参数偏差具有较强的鲁棒性。

The six degrees of freedom （Six -DoF） near- space glide vehicle model is obtained. This vehicle model is time variant, coupling, highly nonlinear and uncertain parameters included. To combine the decou- pling and robustness and improve the performance of control system, a multi - input-multi - output sliding mode decoupling controller is proposed. The controller includes two parts, one is the inner loop decoupling controller and the other is the outer loop robustness controller. The inner - loop controller based on dynamic inversion is designed, by which input-output linearization of rotation motion model is achieved. The outer-loop sliding mode controller based on sign function is designed, and it is robust to outside interference and pa- rameter uncertainties. The saturation function is applied to reduce the chatter of the slide mode. The simula- tion studies are conducted for the response of the commands of angle of attack, sideslip angle and bank angle. The controller is evaluated for robustness with respect to interference and parameter uncertainties by using sim- ulations. Simulation studies demonstrate that the proposed controller is robust with respect to interference and parametric uncertainty and meets the performance requirements with acceptable control inputs.