考虑输入饱和的多航天器系统姿轨耦合分布式协同跟踪控制

基于一致性理论,研究了多航天器系统相对轨道及姿态耦合的分布式协同控制问题。在仅有部分跟随航天器可获取领航航天器信息的情形下,针对各跟随航天器存在未建模动态以及外部环境干扰等问题,利用双曲正切函数的性质,提出了考虑输入饱和的分布式自适应协同控制律。首先,对于领航航天器具有时变状态的情形,为每个跟随航天器设计了3个滑模估计器,对领航航天器的状态进行估计。其次,针对跟随航天器间相对速度和角速度难以测量的问题,设计仅需领航航天器状态的切比雪夫神经网络自适应更新律。最后,设计考虑输入饱和的分布式自适应协同控制律保证各跟随航天器跟踪动态领航航天器。仿真结果表明了该算法的有效性、可行性。     

Polynomial networks based adaptive attitude tracking control for NSVs with input constraints and stochastic noises

This paper proposes a backstepping technique and Multi-dimensional Taylor Polynomial Networks (MTPN) based adaptive attitude tracking control strategy for Near Space Vehicles (NSVs) subjected to input constraints and stochastic input noises. Firstly, considering the control input has stochastic noises, and the attitude motion dynamical model of the NSVs is actually modeled as the Multi-Input Multi-Output (MIMO) stochastic nonlinear system form. Furthermore, the MTPN is used to estimate the unknown system uncertainties, and an auxiliary system is designed to compensate the influence of the saturation control input. Then, by using backstepping method and the output of the auxiliary system, a MTPN-based robust adaptive attitude control approach is proposed for the NSVs with saturation input nonlinearity, stochastic input noises, and system uncertainties. Stochastic Lyapunov stability theory is utilized to analysis the stability in the sense of probability of the entire closed-loop system. Additionally, by selecting appropriate parameters, the tracking errors will converge to a small neighborhood with a tunable radius. Finally, the numerical simulation results of the NSVs attitude motion show the satisfactory flight control performance under the proposed tracking control strategy.     

考虑状态约束的弹性高超声速飞行器自适应饱和容错控制

针对弹性高超声速飞行器跟踪控制问题进行研究,主要考虑状态约束、输入饱和、执行器故障等约束条件.首先,将弹性模态、外界干扰和模型参数不确定性归结为一类带有未知上界的系统干扰.其次,根据被动容错思想,针对速度和高度子系统分别设计抗饱和自适应容错控制器,通过引入双曲正切函数和新型屏障李雅普诺夫函数分别处理了输入饱和与状态约束...     

同轴探针对称激励矩形波导模式谱图研究

文章用输入阻抗方法探讨同轴探针中心对称激励矩形波导在多模传输时所能激发的传输模式。说明采取一定的措施,可以避免产生某些高次模式。并应用分式线性变换检测法,以精心设计的实验验证了理论分析的正确性。     

Robust fault-tolerant attitude control for satellite with multiple uncertainties and actuator faults

In this paper, the satellite attitude control system subject to parametric perturbations,external disturbances, time-varying input delays, actuator faults and saturation is studied. In order to make the controller architecture simple and practical, the closed-loop system is transformed into a disturbance-free nominal system and an equivalent disturbance firstly. The equivalent disturbance represents all above uncertainties and actuator failures of the original system. Then a robust controller is...