航天器姿态跟踪有限时间饱和控制

针对卫星姿态跟踪系统, 在无扰动和有扰动的情况下, 利用双曲正切函数和辅助系统设计两个有限时间饱和控制器. 双曲正切函数可以严格地保证卫星姿态跟踪系统的控制输入是有界的. 通过李雅普诺夫理论可以证明, 系统在两个控制器的作用下既是渐近稳定的又是有限时间稳定的, 系统可以快速收敛到平衡点. 数值仿真进一步表明了所提出的有限时间控制器的有效性.

     

多航天器系统分布式固定时间输出反馈姿态协同跟踪控制

针对角速度信息不可测条件下的多航天器系统姿态协同跟踪控制问题,提出一种基于积分滑模的分布式固定时间姿态协同跟踪控制方法.基于bi-limit齐次性理论设计一种新型的固定时间收敛的积分滑模面.为估计出不可测的航天器信息,提出一种固定时间观测器,同时为减少航天器间的通信信息流,引入滑模估计器估计领航者的姿态信息.结合固定时...     

基于super-twisting算法的多航天器姿态有限时间分布式协同控制

针对受外界干扰和执行器故障影响的多航天器姿态协同控制问题,本文设计了一种基于干扰观测器的分布式协同supper-twisting滑模控制器.首先,将各航天器的外界干扰和执行器故障看作一个集总干扰,设计自适应滑模干扰观测器对其进行估计.其次,将supper-twisting算法和积分滑模面相结合,设计一种基于多航天器姿态...     

导弹姿态的自抗扰有限时间控制

针对导弹模型同时具有不确定性和执行机构饱和受限的问题, 首先针对模型不确定性, 将质心运动方程的非线性影响、耦合影响、外部环境干扰视为总干扰, 并设计扩展状态观测器对其进行实时估计; 然后针对舵偏角和角速度存在饱和受限的问题, 设计辅助系统和限幅微分器; 最后结合反演和有限时间稳定系统理论, 设计有限时间控制器, 以保证整个闭环系统在受限条件下能收敛到参考信号. 数值仿真结果表明, 所设计的控制器与理论分析结果一致, 是可行而有效的.

     

输入饱和受限下的刚体飞行器姿态系统的有限时间镇定

研究存在输入饱和受限下的飞行器姿态控制问题, 提出一种有限时间姿态镇定方案. 针对基于修改的Rodriguez 参数模型的飞行器姿态控制系统, 基于齐次性理论和饱和控制器设计方法, 并充分利用系统的模型结构特征, 设计一类饱和的有限时间姿态控制器, 使得姿态可以在有限时间内被镇定到平衡点. 仿真结果验证了所设计姿态控制器的有效性.

     

多导弹时间协同分布式导引律设计

为了实现多导弹协同攻击同一目标, 提出一种时间协同分布式导引律设计方法, 该方法对于无角度约束和有角度约束的情况均适用. 首先, 以各导弹子系统作为网络同构节点建立了多导弹时间协同制导模型, 该模型以各导弹剩余时间信息附加预定偏置量为输出; 然后, 以调整子系统间输出误差为目的, 设计了系统的分布式控制方案, 并结合一般协同控制系统的收敛性条件, 分析了导弹寻的导引的特殊性, 给出了保证多导弹时间协同的通信拓扑条件; 最后, 通过仿真结果验证了所提出方法的有效性.

     

考虑推力器安装偏差的航天器姿态机动有限时间控制

针对航天器快速姿态机动控制问题,考虑存在参数不确定性、外部干扰、推力器安装偏差以及控制输入饱和受限的多约束条件下,提出了一类自适应终端滑模有限时间控制方法,显式地引入推力器输出的饱和幅值,确保闭环系统在有限时间内快速收敛到滑模面的邻域内;同时,通过引入参数自适应学习律,使得控制器的设计不依赖于参数不确定性、外部干扰以及推力器安装偏差信息;此外,基于Lyapunov稳定性定理对所提出的控制器进行了理论分析.并通过给定某型航天器参数进行了数值仿真,结果表明在考虑多约束情况下,系统具有较快的收敛速度,且具有很好的动态性能,从而验证了所设计方案的有效性、可行性.     

多导弹分布式协同制导与反步滑模控制方法

针对多弹三维协同攻击机动目标的要求, 提出一种基于网络同步原理的协同制导方法. 该算法给出了导弹3 个方向的速度, 并基于运动学关系转化为总速度、弹道倾角和弹道偏角指令. 基于反步法将控制器设计过程转化为3 步, 分别为速度及弹道角子系统、气动角子系统和角速率子系统设计, 各子系统采用滑模控制. 控制器设计中采用扩展状态观测器对气动参数摄动和外部扰动进行估计, 并在控制器中进行补偿. 仿真结果验证了控制器的跟踪特性及导弹的协同攻击效果.

     

基于旋转矩阵描述的航天器无角速度测量姿态跟踪无源控制

利用系统无源性和旋转矩阵性质研究无角速度测量下的姿态跟踪控制问题. 为了避免姿态参数的奇异性和模糊性, 提出基于三维特殊正交群(SO(3)) 的控制策略. 首先利用旋转矩阵建立姿态跟踪误差方程, 然后分析了系统的内在无源性, 从而揭示了闭环系统的稳定性. 当角速度无法获得时, 利用新的无源滤波提出一种无角速度测量控制律, 并给出了严格的Lyapunov 稳定性分析. 最后, 通过数值仿真验证了所提出的控制方法的有效性.

     

基于积分滑模的航天器有限时间姿态容错控制

针对存在执行机构故障和外部干扰的刚体航天器姿态稳定系统,本文提出了基于积分滑模的容错控制策略,实现了姿态有限时间稳定.首先,利用齐次系统相关理论,设计了一类饱和有界的基础控制律,保证了不存在执行机构故障和干扰情况下的姿态有限时间稳定.在此基础上,利用积分滑模和自适应技术设计了一种有限时间姿态鲁棒容错控制方案,对执行机构故障和干扰进行有效的补偿;该方案能够快速地实现姿态高精度稳定,并抑制系统抖振现象.最后,将本文提出的姿态容错控制方案进行数值仿真与对比,验证了方案的有效性与优越性.     

考虑状态约束的航天器编队分布式姿态协同跟踪控制

针对有向通信拓扑结构下的航天器编队姿态协同控制问题,提出一种基于反步法的分布式姿态协同跟踪控制律.在仅有部分跟随航天器可以获取动态领航航天器信息的情况下,利用多层神经网络的逼近特性对系统的非线性不确定性进行估计.同时,考虑到航天器编队的姿态协同跟踪控制性能,构造Barrier Lyapunov函数,使得状态变量保持在预设的约束区间内,进而实现对姿态跟踪误差的约束.根据代数图论和Lyapunov理论,证明跟随航天器的姿态跟踪误差最终有界.仿真分析表明了所提出控制方法的有效性.     

Distributed finite-time attitude containment control for multiple rigid bodies

Distributed finite-time attitude containment control for multiple rigid bodies is addressed in this paper. When there exist multiple stationary leaders, we propose a model-independent control law to guarantee that the attitudes of the followers converge to the stationary convex hull formed by those of the leaders in finite time by using both the one-hop and two-hop neighbors’ information. We also discuss the special case of a single stationary leader and propose a control law using only the one-hop neighbors’ information to guarantee cooperative attitude regulation in finite time. When there exist multiple dynamic leaders, a distributed sliding-mode estimator and a non-singular sliding surface were given to guarantee that the attitudes and angular velocities of the followers converge, respectively, to the dynamic convex hull formed by those of the leaders in finite time. We also explicitly show the finite settling time.     

多智能体系统的有限时间包含控制研究

在固定有向拓扑结构下,研究了具有多个静态或动态领导者的多智能体有限时间包含控制问题;假设领导者之间不存在信息的交互,提出基于快速终端滑模的控制算法,该算法驱使跟随者的运动轨迹在有限时间收敛到由领导者组成的凸包中;进一步,考虑实际应用中跟随者状态不能在线获得的情况,提出基于有限时间观测器的包含控制协议;利用图论和Lyapunov有限时间稳定性理论,给出了有限时间包含控制的充分条件;最后通过仿真示例,验证了算法的有效性.     

Adaptive attitude tracking control for rigid spacecraft with finite-time convergence

In this paper, the finite-time attitude tracking control problem for rigid spacecraft with external disturbances and inertia uncertainties is addressed. First, a novel fast nonsingular terminal sliding mode surface (FNTSMS) without any constraint is designed, which not only avoids the singularity problem, but also contains the advantages of the nonsingular terminal sliding mode (NTSM) and the conventional sliding-mode together. Second, the proposed FNTSM control laws (FNTSMCLs) by employing FNTSMS associated with adaptation provide finite-time convergence, robustness, faster, higher control precision. The proposed FNTSMCLs in light of novel adaptive control architecture are continuous. Thus, they are chattering-free. Finally, simulation results are presented to illustrate effectiveness of the control strategies. In addition, digital simulations of satellite Hubble Space Telescope (HST) are presented to verify the practical feasibility of the reorientation/ slew maneuvers mission.     

Decentralised finite-time attitude synchronisation and tracking control for rigid spacecraft

The problem of finite-time attitude synchronisation and tracking for a group of rigid spacecraft nonlinear dynamics is investigated in this paper. First of all, in the presence of environmental disturbance, a novel decentralised control law is proposed to ensure that the spacecraft attitude error dynamics can converge to the sliding surface in finite time; then the final practical finite-time stability of the attitude error dynamics can be guaranteed in small regions. Furthermore, a modified finite-time control law is proposed to address the control chattering. The control law can guarantee a group of spacecraft to attain desired time-varying attitude and angular velocity while maintaining attitude synchronisation with other spacecraft in the formation. Simulation examples are provided to illustrate the feasibility of the control algorithm presented in this paper.     

Nonsingular terminal sliding mode based finite-time control for spacecraft attitude tracking

This paper studies finite-time attitude tracking control problem of a rigid spacecraft system with external disturbances and inertia uncertainties. Firstly, a new finite-time attitude tracking control law is designed using nonsingular terminal sliding mode concepts. In the absence and presence of external disturbances and inertia uncertainties, this controller can drive the attitude and angular velocity tracking errors to reach zero in finite time. Secondly, a finite-time disturbance observer is introduced to estimate the disturbance, and a composite controller is developed which consists of a feedback control based on nonsingular terminal sliding mode method and compensation term based on finite-time disturbance observer. Finite-time convergence of attitude tracking errors and the stability of the closed-loop system is ensured by the Lyapunov approach. Numerical simulations on attitude control of spacecraft are also given to demonstrate the performance of the proposed controllers.     

Global finite-time attitude consensus tracking control for a group of rigid spacecraft

The problem of finite-time attitude consensus for multiple rigid spacecraft with a leader–follower architecture is investigated in this paper. To achieve the finite-time attitude consensus, at the first step, a distributed finite-time convergent observer is proposed for each follower to estimate the leader's attitude in a finite time. Then based on the terminal sliding mode control method, a new finite-time attitude tracking controller is designed such that the leader's attitude can be tracked in a finite time. Finally, a finite-time observer-based distributed control strategy is proposed. It is shown that the attitude consensus can be achieved in a finite time under the proposed controller. Simulation results are given to show the effectiveness of the proposed method.     

多枚倾斜转弯导弹的滚转通道之分布式有限时间姿态协调控制

对多枚倾斜转弯(BTT)导弹设计滚转通道自动驾驶仪时,基于分布式协调控制理论,本文提出了一类分布式有限时间姿态协调控制器.由于BTT导弹的气动参数变化强烈、机动要求高,要求控制器响应速度高,抗干扰能力强.本文基于有限时间控制技术,并结合多智能体系统的协调控制理论,对多枚BTT导弹滚转通道提出了一种分布式有限时间姿态协调控制律.在该控制律作用下,所有的BTT导弹通过相互协调,其滚转角可以在有限时间内达到一致并为给定的参考指令信号.仿真结果表明了该方法的有效性.     

Velocity-free adaptive nonsingular fast terminal sliding mode finite-time attitude tracking control for spacecraft

Aiming at the attitude tracking control problem of rigid spacecraft under the condition of unmeasurable angular velocity information, a velocity-free adaptive nonsingular fast terminal sliding mode finite-time tracking control method is proposed. The finite-time extended-state observer is used to estimate the attitude tracking speed errors and the integrated disturbances. Combined with the above control method, a fast nonsingular terminal sliding mode controller with attitude measurement is designed and the adaptive technology is introduced to compensate for the influence of observation errors on the controller. The finite-time convergence of the observer and the control method was demonstrated based on Lyapunov theory, and the effectiveness of the proposed method is verified by numerical simulations.