【作者】 王兆魁；

【导师】 张育林；

【作者基本信息】 国防科学技术大学 ， 航空宇航科学与技术， 2006， 博士

【摘要】 分布式卫星技术是空间技术发展的新方向,可能带来航天器应用方式的重大变革。分布式卫星协同控制是分布式卫星系统的关键技术,涉及轨道动力学、自主导航控制、执行器和敏感器、计算和数据处理等多个领域。本文从动力学和控制系统的角度,对分布式卫星系统的协同控制方法开展了研究。首先分析了分布式卫星的动力学机理。以近距离航天器相对运动方程为基础,分析了编队飞行的基本特性,定义了椭圆绕飞编队构型的统一描述参数;通过理论分析和数值仿真,分析了不同编队飞行动力学模型的特点,确立了不同应用场合下动力学模型的选取准则。其次,研究了分布式卫星构型控制问题。分布式卫星的协同控制必须在一定的控制结构下进行,论文首先确定了分布式卫星协同控制的分层协作控制结构。然后,在分层协作控制结构的原则下,提出了基于二次冲量控制的单星环绕编队构型初始化方法和相应的多星环绕编队构型初始化策略,可保证分布式卫星构型初始化在一个轨道周期内完成;提出了基于切换增益衰减因子的变切换增益变结构控制律,实现了高精度的分布式卫星构型保持鲁棒控制,较好地克服了误差收敛时间和控制精度的矛盾;针对缺失轨道径向控制力的情况,设计了变结构构型保持控制律,提出了基于线性离散不确定系统保性能控制的滑动面设计方法,解决了存在不匹配不确定性的线性离散系统变结构控制问题。以二次规划为手段,研究了分布式卫星的构型变换路径规划问题,建立了燃料消耗最优、燃料均匀性最优、燃料量和均匀性综合最优的分布式卫星整体构型变换优化准则,提出了单颗环绕星失效情况下的编队失效重组策略。分布式卫星构型初始化、构型保持和构型变换的研究,构成了完整的分布式卫星协同控制方案。随后,研究了分布式卫星应用系统设计问题。提出了分布式空间目标监视系统概念,对空间目标光学可见性进行了分析,根据任务要求设计了分布式卫星系统的轨道和构型。研究了目标敏感器的探测原理和方法,提出了星图预处理的最佳分割阈值确定准则和星点提取测量的交叉投影算法,在此基础上,通过直接检测法和基于格拉布斯准则的检测法分别实现了移动目标的检测。最后,建立了分布式卫星实时仿真平台和分布式空间目标监视半实物仿真系统。实时仿真平台包含高精度的轨道动力学模型、推进器模型和敏感器模型,可对协同控制任务进行分布式的实时仿真。对分布式卫星协同控制方法和分布式空间目标监视系统任务的系统仿真验证了相关方法的正确性。更多还原

【Abstract】 Distributed satellites system (DSS) is a new research field of space technology, may lead to revolution in the applications of the spacecraft. Coordination and control of the DSS is a key technology to enable distributed satellite, referring to technology in orbital dynamics, auto navigation and control, sensors and actors, data processing and computation etc. In this thesis, the problem of coordination and control of DSS was studied from aspects of dynamics and control.First, The dynamics fundamental of the DSS was studied. The basic characteristic of formation flying of the satellites in the DSS was based on the dynamics of two spacecraft near by each other. Then a set of parameters used to describe formation configuration were defined. Various dynamics models were analyzed with analytical and numerical methods. Then a selective guide line of dynamics model of the DSS was established.Secondly, the control methods for formation configuration of the DSS were studied. The coordination and control of multi-satellite DSS must be implemented under a control architecture, so a layer control architecture enabling coordination and control of multi-satellite DSS was selected. Under the architecture, a scheme of formation initialization using two impulses was presented, and a control strategy was concluded to guarantee that the initialization of the multi-satellite DSS could be completed in one orbital period. A new reaching law with an attenuation multiplier to the switch gain of sliding mode varied structure control (VSC) was presented. The robust precise formation keeping of the DSS was realized based on the control law, and the conflict between control time and control precision was conquered using the control law. A control scheme without radial control for the DSS formation keeping was presented, the controller was designed based on a new VSC method, which used the optimal Guaranteed Cost Control (GCC) methods of the uncertain discrete time system to design sliding surface of the VSC, and the problem of the VSC of linear discrete system with mismatched uncertainty was resloved. The path plan problem of the DSS reconfiguration was studied with a quadric programming method, the objective functions for optimization of the DSS reconfiguration were presented, including fuel consumption optimization, equality of fuel consumption optimization and the optimization of both fuel consumption and equality. In addition, a DSS reconfiguration strategy with one satellite fault was presented in study of the DSS reconfiguration. Then an overall scheme of coordination and control of DSS was established based on the study of formation initialization, formation keeping and formation reconfiguration.Then design of typical DSS system was studied. The concept of distributed space surveillance system was presented, the elements and detection method for space target sensor were studied, and the orbit and configuration of the system were designed. The optical characteristic of space target was studied, a strategy for star image preprocess was presented, and a new algorithm for locating star point was presented by a two-step projection checking method. Then the moving target was checked with a direct method and a mthod based on the Grubbs law.Finally, a distributed real-time simulation environment for common DSS and a distributed hardware-in-loop simulation environment for space surveillance were built, inclding models of high precision orbital dynamics, typical thrustors and sensors. Simulation for coordination and control of DSS and distributed space surveillance mission were made to validate the methods studied in the thesis.更多还原