吸气式高超声速飞行器鲁棒非奇异Terminal滑模反步控制

摘要

A new nonlinear disturbance observer based Terminal sliding mode backstepping controller is proposed for flexible air-breathing hypersonic vehicles with parameter perturbations and external disturbances.The longitudinal vehicle model considering the elastic mode is expressed as strict feedback form.On the basis of traditional backstepping method,the nonsingular fast Terminal sliding mode is introduced to control the pitch angle and pitch rate,thus optimizing the control structure and enabling the system with finite time convergence property.A new nonlinear disturbance observer developed from tracking differentiator is then introduced to estimate and compensate the uncertainties including the derivatives of virtual control laws to improve the robustness of the controller,which avoids the explosion of differentiation terms.The system tracking error is proven to converge to zero in finite time with Lyapunov stability theory.Simulations demonstrate the effectiveness of tracking input commands with the designed controller in the presence of uncertainties.%针对含有参数摄动、外界干扰的吸气式高超声速飞行器弹性模型,设计了一种基于新型非线性干扰观测器的Terminal滑模反步控制器.将考虑弹性模态的飞行器纵向模型表示为严格反馈形式,在传统反步法的基础上采用非奇异快速Terminal滑模控制俯仰角与俯仰角速率,优化了反步法的控制结构,并实现了系统的有限时间收敛.基于跟踪微分器设计了一种新型非线性干扰观测器,并与本文所提滑模反步方法相结合,通过对包括虚拟控制量微分信号在内的不确定性进行估计与补偿,进一步提高了控制器的鲁棒性,同时解决了“微分膨胀”问题.基于Lyapunov稳定性理论证明了系统的跟踪误差于有限时间收敛至零.仿真结果表明,该控制器在存在不确定性的情况下,可以实现对参考输入的稳定跟踪.