基于新型滑模控制方法的再入飞行器姿态控制律设计

Design of a novel sliding mode controller for the attitude control of reentry vehicle

设计了一种新型滑模控制方法,该方法不但能对已有的控制律进行鲁棒性改进,而且能有效抑制抖振现象。在该方法的设计过程中,首先基于已有的控制律和标称系统,设计了一种新型的动态滑模面,然后对超扭曲算法进行改进,得出了一种快速、连续且有限时间收敛的算法,并首次将其作为新型趋近律,该趋近律与滑模面相结合能够大大增强现有控制律的鲁棒性,而且滑模的切换律是连续的,因此大大降低了系统的抖振。将以上方法应用于再入飞行器的姿态跟踪控制中,有效增强了已有控制律的鲁棒性,实现了大干扰情况下对姿态系统的稳定控制。通过仿真,验证了该方法在提高系统鲁棒性和降低抖振方面的有效性。

A novel sliding mode control method was proposed in this paper,which is not only capable of improving the robust-ness of the existing control law,but can also effectively attenuate chattering.In the design process,a novel dynamic sliding mode surface was designed firstly based on the nominal system and the existing control law.Then the super-twisted algorithm was improved.A fast continuous and finite time convergence algorithm was obtained,which was adopted as the novel reaching law for the first time. The reaching law combined with the sliding mode surface can greatly enhance the robustness of the existing control law.In addition, since the sliding mode switching law is continuous,the chattering was greatly attenuated. The proposed method was then applied to attitude tracking control of reentry vehicle and the robustness of the existing control law was effectively enhanced under large dis-turbance.Finally,the effectiveness of the method was demonstrated through simulation.