一种精确鲁棒的刚体航天器特征轴旋转控制策略(英文)

特征轴旋转表征了两个方位之间的最短角路径,通常被看做是一种拟最小时间的快速姿态机动策略。本文在动力学方程中考虑了外部扰动和系统参数不确定性,基于时变滑模控制技术(TVSMC)研究了刚体航天器特征轴旋转的鲁棒控制问题。首先,通过一个TVSMC算法揭示了所提出鲁棒特征轴旋转策略的主要特点,并且证明了全局滑模的特点和闭环系统的稳定性,给出了特征轴旋转的必要条件。然后,为了抑制全局抖振,提高控制精度,提出了一种基于扰动观测器的时变滑模控制(DOTVSMC)算法。其中,采用边界层方法来削弱抖振并设计了扰动观测器来补偿不期望的影响。在航天器的姿态表征参数选择上,采用了没有冗余性的修正罗德里格斯参数(MRP)。最后,采用数值仿真来验证提出方法的有效性,并采用调宽调频(PWPF)技术来调制开关推力器。     

采用框架角受限控制力矩陀螺的航天器姿态机动控制

以框架角受限的金字塔构型控制力矩陀螺(CMG)为执行机构,研究了航天器欧拉姿态机动控制问题.考虑控制力矩及航天器角速度约束等因素,对已有的姿态机动控制律进行了改进,使其能实现绕欧拉轴的大角度姿态机动.同时考虑力矩陀螺框架角受限情况,通过适当加入空转指令对框架角进行重构,设计了复合控制形式的控制力矩陀螺操纵律,并通过过渡...     

Composite anti-disturbance position and attitude control for spacecrafts with parametric uncertainty and flexible vibration

The rendezvous and proximity operations with respect to a tumbling non-cooperative target pose high requirement for the position and attitude control accuracy of servicing spacecraft.However, multiple disturbances including parametric uncertainties, flexible vibration, and unknown nonlinear dynamics degrade the control performance significantly. In order to enhance the system anti-disturbance ability, this paper proposes a composite anti-disturbance control law for the spacecraft position and at...     

航天器自适应快速非奇异终端滑模容错控制

针对存在外部干扰、转动惯量矩阵不确定、控制器饱和以及执行器故障的航天器姿态跟踪控制问题,提出了基于自适应快速非奇异终端滑模的有限时间收敛控制方案。通过引入能够避免奇异点的具有有限时间收敛特性的快速非奇异终端滑模面,设计了满足多约束的有限时间姿态跟踪容错控制器,并利用参数自适应方法使控制器设计不依赖于系统惯量信息和外部干扰的上界。此外,所设计的控制器显式考虑了执行器输出力矩的饱和幅值特性,使航天器在饱和幅值的限制下完成姿态跟踪控制任务,并且无须进行在线故障估计。Lyapunov稳定性分析表明：在外部干扰、转动惯量矩阵不确定、控制器饱和以及执行器故障等约束条件下,所设计的控制器能够保证闭环系统的快速收敛性,而且对控制器饱和与执行器故障具有良好的容错性能。数值仿真校验了该控制器在姿态跟踪控制中的优良性能。     

Robust attitude coordinated control for spacecraft formation with communication delays

In this paper,attitude coordinated tracking control algorithms for multiple spacecraft formation are investigated with consideration of parametric uncertainties,external disturbances,communication delays and actuator saturation.Initially,a sliding mode delay-dependent attitude coordinated controller is proposed under bounded external disturbances.However,neither inertia uncertainty nor actuator constraint has been taken into account.Then,a robust saturated delay dependent attitude coordinated control law is further derived,where uncertainties and external disturbances are handled by Chebyshev neural networks (CNN).In addition,command filter technique is introduced to facilitate the backstepping design procedure,through which actuator saturation problem is solved.Thus the spacecraft in the formation are able to track the reference attitude trajectory even in the presence of time-varying communication delays.Rigorous analysis is presented by using Lyapunov-Krasovskii approach to demonstrate the stability of the closed-loop system under both control algorithms.Finally,the numerical examples are carried out to illustrate the efficiency of the theoretical results.     

相对失控翻滚目标悬停的自适应模糊滑模控制

研究了含有系统不确定性和外部干扰的追踪器相对失控翻滚目标悬停的六自由度耦合控制问题。首先,在追踪器本体坐标系中建立了非线性的六自由度耦合的一体化动力学模型,将悬停控制问题转化为相对位置和相对姿态控制问题。再基于模糊逼近原理设计了一种自适应的模糊滑模控制器,该控制器能够有效克服系统的模型不确定性和外部干扰的影响,并能消除传统的抖振问题。由Lyapunov方法导出了模糊自适应律并证明了闭环系统的稳定性。数值仿真验证了所提的自适应模糊滑模控制器的有效性。     

执行器故障的挠性航天器姿态滑模容错控制

针对挠性航天器执行器卡死与失效故障的姿态稳定控制问题,提出一种改进型滑模容错控制策略.与传统的滑模控制相比,该方法能削弱传统滑模控制中抖振现象对姿态控制精度的影响,且它采用自适应技术在线估计系统中的不确定参数,从而保证控制性能对外部干扰、不确定甚至时变转动惯量具有良好的鲁棒性.该控制器并不需要任何在线或离线的故障信息,...     

Adaptive Integral-type Sliding Mode Control for Spacecraft Attitude Maneuvering Under Actuator Stuck Failures

A fault tolerant control (FTC) design technique against actuator stuck faults is investigated using integral-type sliding mode control (ISMC) with application to spacecraft attitude maneuvering control system. The principle of the proposed FTC scheme is to design an integral-type sliding mode attitude controller using on-line parameter adaptive updating law to compensate for the effects of stuck actuators. This adaptive law also provides both the estimates of the system parameters and external disturbances such that a prior knowledge of the spacecraft inertia or boundedness of disturbances is not required. Moreover, by including the integral feedback term, the designed controller can not only tolerate actuator stuck faults, but also compensate the disturbances with constant components. For the synthesis of controller, the fault time, patterns and values are unknown in advance, as motivated from a practical spacecraft control application. Complete stability and performance analysis are presented and illustrative simulation results of application to a spacecraft show that high precise attitude control with zero steady-error is successfully achieved using various scenarios of stuck failures in actuators.     

Backstepping design of missile guidance and control based on adaptive fuzzy sliding mode control

This paper presents an integrated missile guidance and control law based on adaptive fuzzy sliding mode control. The integrated model is formulated as a block-strict-feedback nonlinear system, in which modeling errors, unmodeled nonlinearities, target maneuvers, etc. are viewed as unknown uncertainties. The adaptive nonlinear control law is designed based on backstepping and sliding mode control techniques. An adaptive fuzzy system is adopted to approximate the coupling nonlinear functions of the system, and for the uncertainties, we utilize an online-adaptive control law to estimate the unknown parameters. The stability analysis of the closed-loop system is also conducted. Simulation results show that, with the application of the adaptive fuzzy sliding mode control, small miss distances and smooth missile trajectories are achieved, and the system is robust against system uncertainties and external disturbances.     

应用旋转矩阵的卫星姿态输出反馈机动控制

针对卫星姿态机动控制问题,提出一种只利用向量测量信息的无角速度反馈的输出反馈控制方法。卫星姿态的指向直接通过旋转矩阵进行描述,而不是先进行参数化过程,避免了由欧拉角、修正的罗德里格参数（MRPs）与四元数等姿态描述方式产生的奇异问题与退绕问题。首先,通过向量测量信息与一组期望姿态向量,引入一个新的姿态指向误差向量,并对其性质进行分析。其次,进一步结合主导滤波器的思想,设计了无需角速度信息的卫星姿态机动控制器,并应用Lyapunov理论,对闭环系统的全局稳定性进行了严格的证明。最后,对所提出的控制算法进行了数值仿真,其结果验证了所设计的输出反馈控制算法的可行性和有效性。     

Decentralized attitude synchronization tracking control for multiple spacecraft under directed communication topology

This paper studies the attitude synchronization tracking control of spacecraft formation flying with a directed communication topology and presents three different controllers. By introducing a novel error variable associated with rotation matrix, a decentralized attitude synchronization controller, which could obtain almost global asymptotical stability of the closed-loop system, is developed. Then, considering model uncertainties and unknown external disturbances, we propose a robust adaptive attitude synchronization controller by designing adaptive laws to estimate the unknown parameters. After that, the third controller is proposed by extending this method to the case of time-varying communication delays via Lyapunov–Krasovskii analysis. The distinctive feature of this work is to address attitude coordinated control with model uncertainties, unknown disturbances and time-varying delays in a decentralized framework, with a strongly connected directed information flow. It is shown that tracking and synchronization of an arbitrary desired attitude can be achieved when the stability condition is satisfied. Simulation results are provided to demonstrate the effectiveness of the proposed control schemes.     

Decentralized adaptive sliding mode control of a space robot actuated by control moment gyroscopes

An adaptive sliding mode control(ASMC) law is proposed in decentralized scheme for trajectory tracking control of a new concept space robot.Each joint of the system is a free ball joint capable of rotating with three degrees of freedom(DOF).A cluster of control moment gyroscopes(CMGs) is mounted on each link and the base to actuate the system.The modified Rodrigues parameters(MRPs) are employed to describe the angular displacements,and the equations of motion are derived using Kane's equations.The controller for each link or the base is designed separately in decentralized scheme.The unknown disturbances,inertia parameter uncertainties and nonlinear uncertainties are classified as a ‘‘lumped" matched uncertainty with unknown upper bound,and a continuous sliding mode control(SMC) law is proposed,in which the control gain is tuned by the improved adaptation laws for the upper bound on norm of the uncertainty.A general amplification function is designed and incorporated in the adaptation laws to reduce the control error without conspicuously increasing the magnitude of the control input.Uniformly ultimate boundedness of the closed loop system is proved by Lyapunov's method.Simulation results based on a three-link system verify the effectiveness of the proposed controller.     

空空导弹大角度姿态反作用喷气控制

为研究具有大离轴角及越肩发射能力的先进空空导弹初始段敏捷转弯方法,研究了装有反作用喷气控制系统的空空导弹的大角度姿态过失速机动控制律。反作用喷气控制系统用来提供大角度敏捷转弯时大攻角飞行的控制力矩。利用时间尺度分离的方法将导弹的姿态动力学和运动学系统分别看作快子系统和慢子系统。用李亚普诺夫方法设计了慢子系统控制律,利用滑动模态方法设计了快子系统控制律,在该控制律作用下,导弹闭环系统不仅是稳定的而且其动态品质也可以得到保证。分析了控制系统的鲁棒性,结果表明所提控制方法能够有效消除空空导弹大角度姿态机动时转动惯量变化以及各种力矩干扰的影响。最后给出了一个实例来说明姿态控制在空空导弹敏捷转弯中的应用。     

Adaptive nonlinear guidance law considering control loop dynamics

A new adaptive nonlinear guidance law is proposed here. The fourth order state equation for integrated guidance and control loop is formulated taking into consideration the target uncertainties and control loop dynamics. The state equation is further changed into the normal form by nonlinear coordinate transformation. Using the normal form of state equation, an adaptive nonlinear guidance law is proposed to compensate for the uncertainties in both target acceleration and control loop dynamics. The proposed law adopts the sliding mode control approach with adaptation for unknown bound of uncertainties. The present approach can effectively solve the existing guidance problem against target maneuver and the limited performance of control loop. We have provided the stability analyses and performed simulations comparing favorably our approach to the state of the art.     

对失控航天器在轨服务的自适应滑模控制器设计

为实现对自由翻滚的失控目标航天器进行在轨服务,基于二阶滑模控制算法设计了相对位置与姿态耦合的自适应控制器。考虑相对转动对相对平动的耦合作用,建立了两航天器对接端口间相对位置与姿态耦合的动力学模型,并在此基础上设计了自适应Super twisting控制器,以减弱已知界限的有界干扰所产生的震颤效应,使闭环系统在有限时间内收敛到平衡点。利用李雅普诺夫方法证明了有界干扰下的闭环系统稳定性,并对收敛时间的上界进行了估计。仿真结果表明,与Super twisting算法相比,所设计的自适应二阶滑模控制器对参数不确定性及线性增长有界干扰具有较强的鲁棒性,且控制精度满足在轨服务的任务需求。     

基于旋转矩阵的预设时间航天器编队姿态协同控制

由多个航天器组成的编队系统对复杂的环境往往具有较高的适应性和容错性,能更高效率地完成单航天器难以完成的任务。因此主要针对多航天器系统的姿态协同控制问题,提出一种基于旋转矩阵的预设时间控制算法。首先,为了避免航天器姿态建模的奇异性和模糊性问题,采用旋转矩阵对航天器的姿态进行统一描述,同时结合有向的通信拓扑对航天器姿态协同控制系统进行建模。其次,为赋予系统可控的收敛速度,提出一种基于滑模的预设时间控制算法。该算法的引入使得航天器编队系统的收敛时间可以在合理的范围内任意给定。此外,为了实现系统对参数摄动和外部干扰的鲁棒性,采用神经网络和自适应算法对不确定性进行在线估计与补偿。最后,通过理论分析和数值仿真验证了所提预设时间控制算法的有效性。     

倾斜转弯高超声速飞行器滑模变结构解耦控制

针对在倾斜转弯时高超声速飞行器自动驾驶仪设计中系统参数不确定和干扰严重、各通道之间存在强烈耦合的问题,提出了一种全局积分滑模变结构解耦控制方法.该方法基于滑动模态对匹配的参数不确定和外界干扰的不变性原理,采用了一种全局积分型的滑模面,使系统在初始阶段就处于滑模态,同时通过滑模函数反馈削弱参数摄动及干扰产生的滑模误差,实现了各输出之间的全程解耦和鲁棒稳定.仿真结果证实了所提方法具有良好的跟踪性能和鲁棒性,能满足高超声速飞行器倾斜转弯协调控制的要求.     

Twistor-based synchronous sliding mode control of spacecraft attitude and position

A synchronous control of relative attitude and position is required in separated ultra-quiet spacecraft, such as drag-free, disturbance-free, and distributed spacecraft. Thus, a twistor-based synchronous sliding mode control is investigated in this paper to solve the control problem of relative attitude and position among separated spacecraft modules. The twistor-based control design and the stability proof are implemented using the Modified Rodrigues Parameter (MRP). To evaluate the effectiveness of the proposed control method, this paper presents a case study of separated spacecraft flying control considering the mass uncertainty and external disturbances. In addition, a simulation study of the Proportional-Derivative (PD) control is also presented for comparison. The results indicate that the twistor-based sliding mode controller can ensure global asymptotic stability. The states converge fast with ultra-precision and ultra-stability in both the attitude and position. Moreover, the proposed twistor-based sliding mode control system is robust to the mass uncertainty and external disturbances.     

A composite control scheme for attitude maneuvering and elastic mode stabilization of flexible spacecraft with measurable output feedback

This paper treats the question of attitude maneuver control and elastic mode stabilization of a flexible spacecraft based on adaptive sliding mode theory and active vibration control technique using piezoelectric materials. More precisely, a modified positive position feedback (PPF) scheme is developed to design the PPF compensator gains in a more systematical way to stabilize the vibration modes in the inner loop, in which a cost function is introduced to be minimized by the feedback gains subject to the stability criterion at the same time. Based on adaptive sliding mode control theory, a discontinuous attitude control law is derived to achieve the desired position of the spacecraft, taking explicitly into account the mismatched perturbation and actuator constraints. In the attitude control law, an adaptive mechanism is also embedded such that the unknown upper bound of perturbation is automatically adapted. Once the controlled attitude control system reaches the switching hyperplane, the state variables can be driven into a small bounded region. An additional attractive feature of the attitude control method is that the structure of the controller is independent of the elastic mode dynamics of the spacecraft, since in practice the measurement of flexible modes is not easy or feasible. The proposed control strategy has been implemented on a flexible spacecraft. Both analytical and numerical results are presented to show the theoretical and practical merit of this approach.     

刚体航天器姿态跟踪系统的自适应积分滑模控制

 采用自适应滑模控制(ASMC)技术进行姿态跟踪系统设计时,切换增益的整定不需要外部干扰及惯量阵不确定性的上界信息。但现有自适应滑模控制方法存在过度适应问题,产生的切换增益远大于控制所需值。为解决该问题,在自适应滑模控制框架内开展了刚体航天器姿态跟踪控制研究。首先对切换增益自适应机制进行分析,揭示了造成过度适应问题的原因。然后利用积分滑模控制的全局滑模特点,消除了初始跟踪误差对自适应过程的影响,提出了一种自适应积分滑模姿态跟踪控制方法。理论分析和仿真结果表明该方法能够有效减小切换增益。