近空间飞行器的DSF:vsat鲁棒快速Terminal滑模控制

Robust Tracking Control of Near Space Vehicle Based on Dynamic Saturation Function Fast Terminal Sliding-Mode

针对一类强耦合强非线性系统,依据趋近角的概念定义了新型动态饱和函数,并利用连续趋近方法证明了动态饱和函数的平衡面趋近性能.设计了基于动态饱和函数的快速Terminal滑模面,不仅确保了滑模到达过程,而且减少了参数导致的振颤和奇异问题,并依据Lyapunov稳定性理论设计了包含动态饱和函数的鲁棒跟踪控制律,而后证明了系统的有限时间收敛性.针对具有大飞行包络的变结构近空间飞行器,给出了不同飞行状态下的有效动力学系统描述,将先前提出的控制函数算法应用于飞行控制系统中,分别设计了快慢通道滑模面和相应的控制律,有效抑制了参数不确定性与外干扰对系统的影响.仿真结果证明了控制方案的有效性与鲁棒性.

A new dynamic saturation function is developed for a class of strong coupling and non- linear system according to the definition of approaching angle. Approaching ability is proved by continuous approximation of the dynamic saturation function. Then fast terminal sliding-mode hyperplane is advanced based on the function. Arriving process is assured, chattering and singularity caused by parameters is eliminated more effectively than switching hyperplane designed without dynamic saturation function. The robust tracking control law with the function is approved based on Lyapunov stability theory and finite time convergence is further verified. Finally, effective dynamic equations are developed under different flight conditions of variable structure near space vehicle. Application of above control method in flight control system is achieved by designing control hyperplanes and laws of fast and slow channels respectively. This new method compensates the disadvantages due to parameter uncertainty and outside disturbance. Simulation demonstrates the rationality and robustness.