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The attitude stabilization problem for rigid spacecraft in the presence of inertial uncertainties, external disturbances, actuator saturations, and actuator faults is addressed in this paper. First, a novel fast terminal sliding mode manifold is designed to avoid the singularity problem while providing high control ability. In addition, fast terminal sliding mode control laws are proposed to make the spacecraft system trajectory fast converge onto the fast terminal sliding mode surface and finally evolve into small region in finite time, which cannot be achieved by the previous literatures. Based on the real sliding mode context, a practical adaptive fast terminal sliding mode control law is presented to guarantee attitude stabilization in finite time. Also, simulation results are presented to illustrate the effectiveness of the control strategies. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
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The problem of attitude control for a spacecraft model which is nonlinear in dynamics with inertia uncertainty and external disturbance is investigated in this paper. Two sliding mode controllers are proposed to force the state variables of the closed‐loop system to converge to the origin in finite time. Specially, the second control design consists of the estimation of the uncertainty and disturbance by adaptive method and thus it achieves the decrease of undesired chattering effectively. Also, simulation results are presented to illustrate the effectiveness of the control strategies. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
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Yuxin Su 《国际强度与非线性控制杂志
》2017,27(6):1039-1040
》2017,27(6):1039-1040
This note points out that Theorems 1 and 2 in Zhu, Xia, Fu (Int. J. Robust Nonlinear Control 2011 21 (6):686–702) are incorrect. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
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This paper deals with the robust finite time tracking of desired trajectories for a wide group of robotic manipulators in spite of unknown disturbances, uncertainties, and saturations of actuators while only manipulator's positions are available and its velocities are not measurable physically. A new form of chattering‐free second order fast nonsingular terminal sliding mode control scheme is introduced to design input torques for fulfilling the determined tracking objective in the adjustable total finite settling time. The proposed control algorithm is incorporated with two nonlinear observers to estimate disturbances and velocities of joints within finite settling times. The global finite time stability of the closed‐loop manipulator is analytically proved. Finally, a numerical simulation is carried out to verify the effectiveness of the designed input torques. Copyright © 2017 John Wiley & Sons, Ltd. 相似文献
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This paper investigates the control problem of finite‐time attitude synchronization and tracking for a group of rigid spacecraft in the presence of environmental disturbances. A new fast terminal sliding manifold is developed for multiple spacecraft formation flying under the undirected graph topology. On the basis of the finite‐time control and adaptive control strategies, two novel decentralized finite‐time control laws are proposed to force the spacecraft attitude error dynamics to converge to small regions in finite time, and adaptive control is applied to reject the disturbance. The finite‐time convergence and stability of the closed‐loop system can be guaranteed by Lyapunov theory. Simulation examples are provided to illustrate the feasibility of the control algorithm. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
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This article proposes fault‐tolerant finite‐time attitude tracking control of a rigid spacecraft actuated by four reaction wheels without unwinding problem in the presence of external disturbances, uncertain inertia parameter, and actuator faults. First, a novel antiunwinding finite‐time attitude tracking control law is derived with a designed control signal which works within a known actuator‐magnitude constraint using a continuous nonsingular fast terminal sliding mode (NFTSM) concept. Second, a finite‐time disturbance observer (FTDO) is introduced to estimate a lumped disturbance due to external disturbances, uncertain inertia parameter, actuator faults, and input saturation. Third, a composite controller is developed which consists of a feedback control based on the continuous NFTSM method and compensation term based on the FTDO. The global finite‐time stability is proved using Lyapunov stability theory. Moreover, the singularity and unwinding phenomenon are avoided. Simulation results are conducted under actuator constraints in the presence of external disturbances, inertia uncertainty, and actuator faults and results are illustrated to show the effectiveness of the proposed method. In addition, to show the superiority of the proposed control method over the recently reported control methods, comparative analysis is also presented. 相似文献
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The attitude tracking of a rigid spacecraft is approached in the presence of uncertain inertias, unknown disturbances, and sudden actuator faults. First, a novel integral terminal sliding mode (ITSM) is designed such that the sliding motion realizes the action of a quaternion‐based nonlinear proportional‐derivative controller. More precisely, on the ITSM, the attitude dynamics behave equivalently to an uncertainty‐free system, and finite‐time convergence of the tracking error is achieved almost globally. A basic ITSM controller is then designed to ensure the ITSM from onset when an upper bound on the system uncertainties is known. Further, to remove this requirement, adaptive techniques are employed to compensate for the uncertainties, and the resultant adaptive ITSM controller stabilizes the system states to a small neighborhood around the sliding surface in finite time. The proposed schemes avoid the singularity intrinsic to terminal sliding mode‐based controllers and the unwinding phenomenon associated with some quaternion‐based controllers. Numerical examples demonstrate the advantageous features of the proposed algorithm. Copyright © 2017 John Wiley & Sons, Ltd. 相似文献
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为实现非线性系统输出对期望轨迹的有限时间内精确跟踪,提出一种有限时间鲁棒控制算法。通过设计一种无到达过程的时变终端滑模面,在保证有限时间收敛的基础上,消除了传统滑模控制中固有的稳态误差,实现系统输出对期望轨迹的精确跟踪。设计了自适应更新律补偿由参数摄动导致的系统扰动,增强系统对内部未知参数摄动的鲁棒性。对比仿真结果表明:时变终端滑模控制比线性滑模控制的轨迹跟踪时间快41. 5%;线性滑模控制器下的轨迹跟踪稳态误差为0. 005,时变滑模控制器使轨迹跟踪的稳态误差降为0,实现精确跟踪。 相似文献
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The fixed‐time relative position tracking and attitude synchronization control problem of a spacecraft fly‐around mission for a noncooperative target in the presence of parameter uncertainties and external disturbances is investigated. Firstly, a novel and coupled relative position and attitude motion model for a noncooperative fly‐around mission is established. Subsequently, a novel nonsingular fast terminal sliding mode (NFTSM) surface is developed, and the explicit estimation of the convergence time independent of initial states is provided. Fair and systematic comparisons among several typical terminal sliding modes show that the designed NFTSM has faster convergence performance than the fast terminal sliding mode. Then, a robust integrated adaptive fixed‐time NFTSM control law with no precise knowledge of the mass and inertia matrix and disturbances by combining the nonsingular terminal sliding mode technique with an adaptive methodology is proposed, which can eliminate the chattering phenomenon and guarantee that the relative position and attitude tracking errors can converge into the small regions containing the origin in fixed time. Finally, numerical simulations are performed to demonstrate the effectiveness of the proposed control schemes. 相似文献
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This paper addresses the global stability and robust attitude tracking problem of a near polar orbit satellite subject to unknown disturbances and uncertainties. It is assumed that the satellite is fully actuated by a set of reaction wheels (RW) as control actuators because of their relative simplicity, versatility and high accuracy. The terminal sliding mode control (TSMC) approach is utilized in a two‐level architecture to achieve control objectives. In the lower layer a detumbling‐like controller is designed which guarantees the finite‐time detumbling and tracking of the desired angular velocities and based on this result a robust attitude tracking controller is designed in the upper layer to achieve 3‐axis attitude tracking in the presence of unknown disturbances and bounded uncertainties. Robust stability and tracking properties of designed controllers are proved using the Lyapunov theory. Finally, a set of numerical simulation results are provided to illustrate the effectiveness and performance of the proposed control method. 相似文献
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针对反作用飞轮安装存在偏差的过驱动航天器姿态跟踪问题, 提出一种有限时间姿态补偿控制策略. 通过设计自适应滑模控制器保证实现对不确定性转动惯量与外部干扰的鲁棒控制, 同时实现对飞轮安装偏差的补偿控制, 并应用Lyapunov 稳定性理论证明了该控制器能够在有限时间内实现姿态跟踪控制. 最后, 将该控制器应用于某型航天器的姿态跟踪控制, 仿真结果验证了所提出方法的有效性. 相似文献
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Jing Na Muhammad Nasiruddin Mahyuddin Guido Herrmann Xuemei Ren Phil Barber 《国际强度与非线性控制杂志
》2015,25(16):3045-3071
》2015,25(16):3045-3071
This paper studies adaptive parameter estimation and control for nonlinear robotic systems based on parameter estimation errors. A framework to obtain an expression of the parameter estimation error is proposed first by introducing a set of auxiliary filtered variables. Then three novel adaptive laws driven by the estimation error are presented, where exponential error convergence is proved under the conventional persistent excitation (PE) condition; the direct measurement of the time derivatives of the system states are avoided. The adaptive laws are modified via a sliding mode technique to achieve finite‐time convergence, and an online verification of the alternative PE condition is introduced. Leakage terms, functions of the estimation error, are incorporated into the adaptation laws to avoid windup of the adaptation algorithms. The adaptive algorithm applied to robotic systems permits that tracking control and exact parameter estimation are achieved simultaneously in finite time using a terminal sliding mode (TSM) control law. In this case, the PE condition can be replaced with a sufficient richness requirement of the command signals and thus is verifiable a priori. The potential singularity problem encountered in TSM controls is remedied by introducing a two‐phase control procedure. The robustness of the proposed methods against disturbances is investigated. Simulations based on the ‘Bristol‐Elumotion‐Robotic‐Torso II’ (BERT II) are provided to validate the efficacy of the introduced methods. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
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为了消除干扰力矩和结构不确定性对卫星姿态控制性能的影响,本文提出了一种基于新型干扰观测器的非奇异终端二阶滑模控制方法.首先,文章设计了一种基于跟踪微分器的干扰观测器,来对卫星系统中的不确定项进行估计,利用估计值进行补偿,并保证估计误差在有限时间内收敛.在此基础上,文章设计一个非奇异终端滑模面,当系统到达滑模面时,姿态误差可以在有限时间内收敛,并利用二阶滑模趋近律设计控制器,保证系统在有限时间到达滑模面.在干扰观测器误差未完全收敛时,滑模控制器可以对存在的扰动进一步抑制,实现姿态跟踪系统的有限时间稳定,并通过李雅普诺夫方法严格证明了其稳定性.最后,仿真结果表明,干扰估计值误差可以在有限时间内收敛,证明了该控制方法对存在的干扰是具有较好的鲁棒性. 相似文献
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非奇异终端滑模控制（NTSMc）能够实现误差的有限时间收敛,但一般NTSMC的控制律采用高增益项来消除系统不确定性的影响,具有较强的保守性．为了降低这种保守性,本文采用复合白适应律对系统的不确定参数进行估计,按照估计值设计复合自适应非奇异终端滑模控制（CANTSMC）,对不确定参数引起的系统动态进行补偿．本方案曾经应用于电动舵机,以补偿不确定参数对模型动态性能的影响．本文证明了闭环稳定性,以及输出跟踪误差在有限时间内的收敛性．通过仿真验证了该方法的有效性． 相似文献
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In this paper, multi surface sliding cooperative control scheme is presented and new multiple sliding surfaces are proposed. It is proven that, for the setup that each agent is described by a chain of integrators, where the last integrator is perturbed by a bounded disturbance, leader–follower consensus can be achieved on these sliding surfaces if the communication graph has a directed spanning tree. Also, sliding variables can be driven to the sliding surfaces in fast finite time by the nonsmooth control law. The fast finite‐time Lyapunov stability theorem, the terminal sliding control technique, and the adding a power integrator design approach are used in our proposed control. Simulation results demonstrate the effectiveness of the proposed scheme. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
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针对一类非线性多变量被控对象的控制问题,设计了一种基于自适应2阶终端滑模的自主控制方法．与传统滑模控制方法相比,该控制方案保留了其结构简单、鲁棒性强的优点,并有效削弱了传统滑模控制引发的抖振问题．利用基于李亚普诺夫的分析方法进行闭环系统的稳定性分析,确保了闭环系统的稳定性以及控制误差有限时间收敛．通过在3自由度控制实验平台上进行姿态镇定和跟踪实验,表明本文所提出的控制方法具有良好的姿态控制效果. 相似文献
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For the high precise tracking control purpose of a cable‐driven manipulator under lumped uncertainties, a novel adaptive fractional‐order nonsingular terminal sliding mode control scheme based on time delay estimation (TDE) is proposed and investigated in this paper. The proposed control scheme mainly has three elements, ie, a TDE element applied to properly compensate the lumped unknown dynamics of the system resulting in a fascinating model‐free feature; a fractional‐order nonsingular terminal sliding mode (FONTSM) surface element used to ensure high precision in the steady phase; and a combined reaching law with adaptive technique adopted to obtain fast convergence and high precision and chatter reduction under complex lumped disturbance. Stability of the closed‐loop control system is analyzed with the Lyapunov stability theory. Comparative simulations and experiments were performed to demonstrate the effectiveness of our proposed control scheme using 2‐DOF (degree of freedom) of a cable‐driven manipulator named Polaris‐I. Corresponding results show that our proposed method can ensure faster convergence, higher precision, and better robustness against complex lumped disturbance than the existing TDE‐based FONTSM and continuous FONTSM control schemes. 相似文献