【作者】 朱良宽；

【导师】 马广富；

【作者基本信息】 哈尔滨工业大学 ， 控制科学与工程， 2008， 博士

【摘要】 自20世纪50年代以来,随着航天技术的迅猛发展,挠性航天器姿态控制问题得到了密切的关注和广泛的研究。挠性航天器姿态控制系统是一个多输入多输出、耦合的不确定非线性系统,为了完成姿态控制任务,要求所设计的控制规律具有较高的鲁棒性以及参数自适应能力。本学位论文结合国家自然科学基金项目“一类挠性航天器主动振动鲁棒控制技术研究”(60774062)和高等学校博士学科点专项科研项目“挠性多体结构卫星主动振动控制技术研究”(20050213010),从理论和应用两个方面针对挠性航天器姿态鲁棒非线性控制算法进行了深入和细致的研究。主要完成以下几个方面的工作:针对存在惯量参数不确定、外干扰力矩的挠性航天器姿态控制问题,提出一种动态输出反馈鲁棒姿态控制方案。首先,基于挠性航天器动力学模型,给出状态反馈姿态控制器设计方法;在此基础上,提出动态输出反馈鲁棒控制器设计方法;进一步,为了降低设计的保守性,提出一种自适应参数设计方法,并基于Lyapunov方法给出了系统稳定性证明。理论分析表明,所构建的姿态控制器是模型参数独立的(即不依赖于航天器的转动惯量),并且不需要预知外干扰力矩的上界。仿真表明所提出的控制方案可以保证挠性航天器完成姿态控制任务,同时有效地抑制了挠性附件的振动,对于转动惯量的摄动及外干扰力矩具有很好的鲁棒性。针对带有非线性(饱和/死区特性)输入的挠性航天器姿态控制问题,提出一种自适应变结构输出反馈控制方案。首先,给出一类不确定系统的变结构输出反馈控制器的设计步骤;在此基础上,针对控制输入存在饱和/死区特性的非线性输入问题,给出滑模存在条件以及变结构输出反馈渐近稳定控制器和指数稳定控制器;为了降低设计的保守性,提出一种自适应参数设计方法,基于Lyapunov方法分析了滑动模态的存在性及稳定性;最后,将本章提出的控制方法应用于挠性航天器的姿态控制,仿真结果表明,尽管存在输入非线性,所提方案不但可以保证完成姿态控制任务,而且可以有效抑制挠性结构的振动,对参数不确定性具有很强的鲁棒性。针对存在模型不确定性因素的挠性航天器姿态机动问题,提出一种主动控制策略。首先,基于T-S模糊滑模控制技术设计了姿态机动控制器,为了抑制挠性结构的振动,设计了应变速率反馈补偿器(SRF)以增加挠性结构的阻尼,使振动能够很快地衰减;其次,提出一种基于模糊逻辑补偿思想的鲁棒主动控制策略,理论分析和仿真结果表明,该算法可以取得较好的控制效果;最后,针对采用推力器作为执行机构的挠性航天器提出一种自适应滑模控制姿态控制算法,结合脉冲调宽调频(PWPF)技术应用到喷气推力器的控制中,使其产生所需要的控制力矩脉冲序列。仿真结果表明所提出的控制策略对挠性航天器惯量参数具有自适应能力,对扰动具有良好的鲁棒性。针对带有执行机构动态特性的挠性航天器姿态跟踪问题,基于后步滑模及主动振动控制技术提出一种鲁棒主动控制策略。首先,采用自适应后步法结合主动振动控制技术设计了姿态跟踪鲁棒控制器,基于Lyapunov方法分析了系统的渐近稳定性;在此基础上,显性地考虑了执行机构动态特性问题,将整个设计过程分为两个步骤:第一步采用滑模控制技术设计了变结构虚拟控制器,给出自适应控制律的设计方法;第二步,将后步法与滑模控制技术相结合,设计了姿态跟踪鲁棒控制器,给出飞轮电压的输入算法及稳定性分析;最后,将提出的控制方法应用于挠性航天器的姿态跟踪控制,通过数值仿真对所提方法的可行性与有效性进行分析和验证。更多还原

【Abstract】 With the development of aerospace technology, attitude control problem of flexible spacecraft has received considerable attention and comprehensive investigation ever since the fifties of the last century. Attitude control system of spacecraft is a coupling and uncertain nonlinear system with multi-input and multi-output. In order to accomplish the attitude control missions, the control law should have robust capability to attenuate disturbances and be able to adapt to parameters. Under this background, the robust control algorithms of flexible spacecraft are deeply studies on theory and application for the attitude control system of spacecraft in the dissertation, which is funded by the Research Fund for the Doctoral Program of Higher Education of China Item—“Large flexible multi-bodies structure spacecraft active vibration control technology”(20050213010) and National Natural Science Foundation of China—“Study on Active Vibration Control of Flexible Spacecraft”(60774062). The main contents of this dissertation are as follows:A robust control scheme based on dynamic output feedback control is proposed for the attitude control problem of a flexible spacecraft in the presence of parametric uncertainty, external disturbances. Firstly, the controller design of state feedback is proposed for the dynamic model of flexible spacecraft; Furthermore, the robust dynamic output feedback method is proposed. Moreover, an adaptive attitude controller is presented to decrease the conservativeness and the stability of the system is analyzed via Lyapunov method. The designed controller is independent with the model parameters, i.e., it is independent with the inertial parameters of flexible spacecraft, and it doesn’t have to know the upper bound of the out disturbance torque. Numerical simulations are performed to show that rotational maneuver and vibration suppression are accomplished in spite of the presence of disturbance torque and parametric uncertainty.A robust control algorithm for stabilization of a flexible spacecraft is investigated in the presence of parametric uncertainty, external disturbances and control input saturation/dead-zone nonlinearity. Firstly, the design process of the variable structure output feedback controller for a class of uncertain system is presented. Furthermore, the existent condition of sliding and the asymptotically and exponentially stable design methods are proposed for constructing the controller to stabilize uncertain system. Moreover, the developed controller is achieved through adaptive variable structure output feedback control without the limitation of knowing the bounds of the uncertainties and perturbations in advance and the existence of the sliding surfaces is analyzed via Lyapunov method. The simulation results show that the precise attitude control and vibration suppression can be accomplished using the derived controller for both cases with and without adaptive control, and it is robust to the uncertainty of the parameters.For the large angle attitude maneuvering problem of flexible with inertia parameter uncertainty, disturbances, a hybrid robust active control scheme is presented combined with the active vibration suppression technique based on piezoelectric materials. Firstly, based on T-S fuzzy control technique, a robust fuzzy attitude control scheme is given, in which the asymptotic stability is shown using a Lyapunov analysis. For actively suppressing the induced vibration, strain rate feedback control methods are provided by using piezoelectric materials as additional sensors and actuators such that the vibration can be damping down quickly. Secondly, a hybrid robust control method based on fuzzy logic compensator is provided. Compared with the T-S fuzzy controller, it has less computation cost. Thirdly, another hybrid robust control method is proposed based on sliding and active vibration control technique. In addition, to avoid chattering, pulse-width pulse-frequency (PWPF) modulation is adopted for the thruster control, which makes the thrusters to be operated in a close to linear manner and also can suppress the relatively large amplitude vibrations excited by, for example, rapid maneuver. The simulation results demonstrate the feasibility and effectiveness of the proposed method.A robust active control approach is presented for the attitude tracking control and vibration damping of a spacecraft with actor dynamics. Firstly, based on the sliding mode control (SMC) and backstepping technique, a new attitude tracking controller is derived to control the attitude motion of spacecraft, the stability of the system is analyzed via Lyapunov method and the reaction wheel dynamics is also considered from the real applications point of view. The whole design process is divided into two steps: the first step is to use sliding control technique to design suppositional adaptive variable structure controller; and the second step is to design attitude tracking controller based on SMC and backstepping technique. Numerical simulations are performed to show that both tracking maneuver and vibration suppression can be accomplished effectively.更多还原