弹性飞翼无人机自适应反步终端滑模姿态控制

Adaptive terminal sliding mode attitude control law of elastic flying wing UAV with backstepping

针对存在非线性、强耦合、参数不确定性及外部扰动的大展弦比飞翼布局无人机刚/弹耦合动力学模型,提出了基于反步思想的自适应范数型终端滑模姿态控制策略.首先,基于李雅普诺夫稳定理论,利用反步方法设计系统的虚拟控制量和实际控制量.其次,在虚拟控制中,采用自适应范数型滑模消除不确定项和刚/弹耦合项,并在反馈中采用非线性增益提高系统的鲁棒性和动态特性;在实际控制中,引入鲁棒自适应终端滑模项消除不确定项、刚/弹耦合项与扰动的影响,既解决了虚拟量求导的计算膨胀和实际控制量抖振问题,又提高了系统的控制精度和鲁棒性.最后,基于李雅普诺夫理论证明了跟踪误差收敛到任意小邻域.仿真结果表明：该控制方法对模型不确定性、气动弹性及阵风等外扰影响具有鲁棒性,能够实现高精度的姿态跟踪控制.

An attitude control strategy based adaptive terminal sliding mode backstepping was proposed for the flying wing layout and unmanned aerial vehicle（UAV） rigid/elastic coupled dynamic model with the nonlinear,strong coupling,parameter uncertainties and external disturbance.Firstly,the actual control and the virtual control were designed with the backstepping design system derived directly from applying Lyapunov stability theory.Secondly,in virtual control,it employed the adaptive norm switch sliding mode to eliminate the negative effects from the uncertainties and resilient-rigid coupling.Furthermore,it utilized integral item of feedback system to reinforce robustness and dynamic characteristic.In the actual control input,it injected the robust adaptive terminal sliding mode to eliminate the uncertainty and disturbance effects and solved the calculating explosion problems of back stepping method and control buffeting problems,improved the control accuracy and robustness of the system.Finally,according to Lyapunov theory,it proves that the tracking error astringes to arbitrarily small field.The simulation results indicate that the method has robustness to the model uncertainty,aero elasticity,gust and external disturbance effect and can realize high precision position tracking control.