该报告的内容按编队卫星飞行的星间绝对距离测量与时间统一、编队构型的精确控制两部分独立展开。编队测量方面：完成了星间相对导航、精确定位的方案设计，主要是基于飞秒激光飞行时间的绝对距离测量方法与基于压电偏摆镜的锁相环路实现的。利用由主星发射的三路独立的飞秒激光绝对距离测量获得子星靶标的3个微米精度的绝对信息，其中微米精度是由飞秒激光的高时间分辨本领决定的；利用压电偏摆镜的锁相环路建立了星间自由光通信链路，使得测距激光脉冲能够实时跟踪自由漂浮的子卫星角锥棱镜。给出了基于飞秒激光的相对导航以及基于压电偏摆镜的跟瞄系统锁相环路的设计方案并基于已有条件测试了压电偏摆装置的稳定性，设计了跟瞄与测距系统集成方案，为三路测距与跟瞄、并实现精确定位的实验演示验证打下了基础。实验上，针对小卫星搭载的需求，建立了一台高稳定性、高集成度、全保偏结构的掺铒光纤飞秒激光源，测距、跟瞄与星间时钟统一的工作将主要依赖该飞秒激光源展开。编队控制方面：分析了编队卫星的动力学机理。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，分析了不同动力学模型的特点，确立了不同应用场合下动力学模型的选取准则。然后，考虑到微小卫星质量与载荷限制导致携带燃料有限，而编队初始化是个能耗较大的变轨过程，基于Gauss伪谱法为编队初始化过程设计了最优轨迹。最后，研究了卫星编队构型保持控制问题。首先确定了主从式的卫星编队协同控制结构。在该控制结构下，基于非线性相对轨道模型，分别采用传统滑模控制方法、自适应滑模控制方法设计了构型保持控制器，并对所设计的控制算法进行了仿真验证，验证了所设计控制算法的鲁棒性。%The report demonstrates a precision inter-satellite distance measurement and control technology for satellite formation flying. For precision inter-satellite distance measurement, relative-navigation method of satellites is designed. Based on 3 separate femtosecond laser distance measurements, we can get 3 independent distance from the steering mirrors to the common retro-reflector with sub micro-meter precision. A free space laser communication link based on piezo steering mirrors are built, which facilitate automatically lock the laser beaming pointing to the center of retro-reflector in the satellite. The stability of the beam acquisition, targeting and pointing system is tested experimentally. The integrated system with femtosecond laser, beam pointing phase locked loop and distance measurement facility are designed aimed at retrieve the position of cooperative target in real time. In experiment, a high stability, compact and all polarization maintaining Erbium femtosecond fiber laser is developed aimed at space applications, which can be used as laser source for satellite based laser distance measurement, targeting and high precision clock distribution. For formation control, the dynamies fundamental of the SFF was studied. The basic characteristics of formation flying of the satellites was based on the dynamies of two spacecraft near by eaeh other. Various dynamics models were analyzed with analytieal methods. Then a selective guide line of dynamics model of the SFF was established. Secondly , Considering the mass and payload of micro-satellite is relatively small, the ability of carrying the fuel is limited and the process of the satellite formation initialization has a relatively large fuel consumption, this thesis focus on the design of a fuel-optimal maneuver strategy by using the Gauss pseudospectral to achieve the process of the satellite formation initialization. Finally,the control methods for formation configuration of the SFF were studied. a leader-follower control architecture enabling coordination was selected. Based on the general nonlinear model, nonlinear robust control methods which adopted sliding mode control(SMC) 、Adaptive sliding mode control(ASMC) were designed respectively. The simulation results denoted that: SMC and ASMC control can achieve the task requirement within the set time, and have good robustness against the model uncertainty and model parameters’ variation.
展开▼
