【作者】 王磊；

【导师】 何平； 葛升民；

【作者基本信息】 哈尔滨工业大学 ， 控制科学与工程， 2013， 博士

【摘要】 本论文以具有可展开天线的同步轨道通信卫星为研究对象，解决卫星平台和挠性天线之间具有的动力学耦合问题。研究工作从理论层面提出了动力学去耦合控制的概念和方法，在工程应用层面，对卫星平台与挠性天线动力学去耦合控制的实现展开了深入细致的研究。在工程上，挠性卫星的姿态控制问题还没有彻底得到解决，已经提出的一些方法在具有大型挠性天线的卫星上应用均存在一些不足，所以需要研究新的方案。挠性卫星姿态动力学与控制问题的关键是卫星平台与挠性天线之间存在动力学耦合，并且这种耦合的动力学可控制性很差。在这种情形下，仅仅从控制器设计方面寻求提高姿态控制性能的收效是有限的。目前挠性卫星姿态控制的研究工作多数局限于此，所以不能解决问题。为了解决具有大型挠性天线卫星的控制问题，本文另辟蹊径，采取措施改变控制对象特性，提高被控制对象动力学的可控制性，从而获得更好的控制系统性能。具体工作如下：在深入分析挠性天线与卫星平台动力学特性的基础之上，提出了一个新的概念——动力学去耦合控制，并依据这个概念设计了一个用于连接挠性天线和卫星平台的机构——去耦机构。去合机构的引入在根本上改变了挠性卫星动力学的可控制性。针对具有去耦机构且带有大型挠性天线的卫星建立了动力学模型。推导证明了去耦机构确实能够降低系统动力学耦合。利用对比的方法分析了去耦合与非去耦合系统的能控性程度和能观性程度，定性说明了去耦合系统之所以能够改善卫星平台和挠性天线控制特性的原因。将卫星平台与挠性天线的动力学方程联立，计算去耦合控制系统的特征值迁移性，定量说明了系统控制特性的改善程度。按照工程实现的约束条件，完成了卫星姿态控制系统设计。控制系统采取了预补偿控制和去耦控制的结构。分别以天线相对于惯性空间的绝对角速度和天线相对卫星平台的相对转角为内外回路反馈信号，构成双回路控制系统，以低带宽外回路隔离天线振动，高带宽内回路抑制摩擦力矩。对整星系统的分析说明了此控制系统具有良好的去耦合特性。对去耦合控制与非去耦合控制进行控制性能仿真对比，仿真结果说明去耦合控制满足系统对指向精度和稳定度的要求。进一步，利用整星质心位置不确定条件下的动力学方程，并增加相应的非线性环节来构成较完善的仿真模型，以此为基础来验证去耦合控制系统在不确定因素影响下的有效性，并通过该模型中参数的大范围摄动来检验控制系统的鲁棒性。总之，论文针对具有大型可展开天线卫星开展了卫星平台与天线去耦合控制研究，提出了去耦合控制的新概念，设计完成了去耦合控制的新系统，获得了满意的结果。文中提出的新理论对于挠性卫星姿态控制具有一定的理论意义，所设计的控制系统对我国具有大型可展开天线卫星的工程应用具有一定的参考价值。更多还原

【Abstract】 This dissertation is a pre-research project of civil aerospace, to study asynchronous orbit communication satellite with a deployable antenna, for solving thedynamics coupling problem of satellite platform and flexible antenna. Theoretically, thework starts with a new concept and control method of reducing dynamical coupling, theintensive research are carried out on engineering standard.In the view of engineering, flexible satellite attitude control problem has not beencompletely resolved as presented solutions all have some disadvantages to apply to thesatellite with large flexible antenna. It is needed to develop new solutions.The key nut of the flexible satellite attitude control is dynamical coupling ofsatellite platform and antenna, and coupling dynamics is always accompanied with poorcontrollability. Simply counting on controller design, to improve the performance ofattitude control system, is fruitless in this predicament. Unfortunately, current researchworks of flexible satellite attitude control are mostly localized to this way, so theproblem can not be resolved successfully.To cope with the difficulty of controlling satellite with large flexible antenna, thiswork finds its way by taking measures to change the to be controlled object, to improveits dynamical controllability. Then, better conttrol performace is obtained. Specificworks are as follows.Fundamentally, upon deep investigating the characterisatic of dynamics of flexibleatenna and satellite platform, a new control method of reducing dynamical coupling isproposed. Based on this concept, a coupling-reduction-mechanism for flexible antennaconnected to satellite platform is designed. The introduction ofcoupling-reduction-mechanism fundamentally changes the dynamical controllability ofsatellite.Dynamical model of a satellite with large flexible antenna connected to platformby coupling-reduction-mechanism is established. Derivation proves thecoupling-reduction-mechanism can reduce the degree of dynamical coupling.Comparative analysis of coupling-reduction and coupling control shows the degree ofcontrollability and observability. This tells qualitatively the reason ofcoupling-reduction-mechanism makes the satellite platform and flexible antenna becontrolled more easily. By combining dynamics equations of the satellite platform andflexible antenna, the entire satellite eigenvalue mobility is calculated, which indicatesquantitively that the controllability has been greatly improved.In accordance with engineering implementation constraints, an attitude controlsystem using scheme of pre-compensation and coupling-reduction is designed. The antenna angular position measurement relative to the satellite platform is the outer loopfeedback signal, and the inner loop employs the angular velocity of the antenna withrespect to inertial space. This constitutes a dual loop control system. Low bandwidthouter loop is to isolate antenna vibration, and high bandwidth inner loop to suppressfriction torque. Analysis of entire satellite demonstrates that the control system has agreat coupling-reduction performance.The control performance of coupling-reduction and coupling control system iscompared. The simulation datum show that the coupling-reduction control methodcould meet the system pointing accuracy and stability requirements. Furtherly, by usingdynamics model under condition of the centroid position uncertainty and addingcorresponding nonlinear elements, a more real model is established, to validate theeffectiveness of coupling-reduction control system under the influence of uncertainfactors. The robustness of the control system is verified with parameters perturbation inwide range in the model.In conclusion, this work carrys out the reserch on coupling-reduction control tosatellites with large deployable antenna, a new concept of control to reduce dynamicscoupling is proposed, and the new control system of coupling-reduction with satisfatoryperformance is designed. The putout theories in this dissertation are of theoreticalsignificance for some flexible satellite attitude control, and the designed control systemhas certain practical referential value for national satellite with large deployable antennain engineering.更多还原