基于滑模自适应的飞行器鲁棒姿态控制

摘要

针对一类不确定非线性系统,基于李亚普诺夫稳定性理论提出了滑模自适应算法.算法的核心为:将系统分为标称模型和包含建模误差、参数变化、干扰及未建模动态等在内的混合干扰项,用自适应控制实时逼近具有不确定性特征的系统输入系数,用鲁棒控制使系统的混合干扰在有限时间内减小到一个小范围内,用滑模控制最终消除不确定非线性系统的跟踪误差.不仅使系统有较好的鲁棒性,而且消除了传统滑模控制中系统输入的抖振现象.对微型飞行器的姿态控制系统进行了仿真研究,仿真结果验证了算法的有效性.%Taking aim at a class of uncertain nonlinear systems, a sliding mode adaptive control algorithm based on Lyapunov's stability theory was proposed. It is essence that: the system is divided into nominal model and lumped disturbance term which is composed of modeling error, parameter uncertainties, disturbances and unmodeled dynamics. Coefficient of the system input with uncertain character is approached in real time by adaptive control, the lumped disturbance is reduced to an acceptant bound within finite time by robust control, the tracking errors of the uncertain nonlinear system are eleminated ultimately by sliding mode control. The scheme has a good robustness for the uncertain nonlinear system and overcomes the chattering in the control input of conventional sliding mode control. The attitude control of micro air vehicle was simulated. Simulation result shows the validity of the proposed method.