热约束下近空间飞行器预设性能抗噪控制

Prescribed performance and anti-noise control of near space vehicle with thermal constraint

近空间高速飞行器再入过程中,巨大的飞行速度将使其面对复杂气动、高温及噪声等严酷的载荷环境。为缓解高速飞行器的热防护结构设计压力,确保再入过程中飞行器的结构与材料安全,从弹道与控制系统设计角度出发,给出近空间高速再入飞行器攻角约束下的高性能自适应非线性预设性能控制方案,对飞行器进行主动的力热载荷安全管理。首先根据飞行器大面积热流工程模型解算全弹道飞行的攻角约束,结合指数型预设性能函数基于状态受限控制理论对攻角的动态响应过程进行设计,并使用新型前馈Sigmoid非线性跟踪微分器来处理反演控制中的微分爆炸问题;之后引入基于级联的新型扩张状态观测器以抑制传统高增益观测器的峰值现象,通过非线性增益调节机制提高其抗噪能力;并对上述控制系统进行了Lyapunov稳定性证明,从理论上确保了飞行器再入过程中热防护结构强度的安全性。最后给出了本文控制方案与鲁棒-自抗扰控制系统的仿真对比结果。结果表明,本文的控制方案能够确保攻角在预设的性能边界内满足飞行器的力热载荷约束,且在工程噪声环境下具有更稳妥的鲁棒安全保障与更优的指令跟踪性能。

Near space hypersonic vehicle will under harsh load such as complex aerodynamics,high temperature and noise in the reentry process due to its supersonic velocity.In order to alleviate the design pressure of thermal protection system on high-speed aircraft and ensure the structural and material safety during reentry process,from the perspective of trajectory and control system design,a high-performance adaptive nonlinear prescribed performance control scheme under the angle of attack constraint is given to do the thermal and mechanical loads management actively.First,the angle of attack constraint of the full ballistic flight is solved according to the engineering model of large-area heat flux,and the dynamic response process of angle of attack is designed based on the prescribed performance control theory combined with the exponential function.To avoid the explosion of the complexity problem in the backstepping procedure,a new feedforward nonlinear sigmoid tracking differentiator is introduced to improve the chattering and peak phenomenon of traditional tracking differentiator in ADRC theory.Then a new nonlinear extended state observer based on cascade is introduced to suppress the peak phenomenon of the traditional high gain observer,nonlinear gain adjustment mechanism is introduced to improve the anti-noise ability of the extended state observer.The Lyapunov stability of above control system is proved to ensure the safety of the thermal protection system during reentry process theoretically.Finally,the simulation comparison between the prescribed performance control system and the robust ADRC system are given.The results show that the prescribed performance control system can ensure AOA within the prescribed boundary to meet the demand on the thermal and mechanical load constraints,and also has more reliable robust security guarantee with better command tracking performance in the engineering noise environment.