中继卫星天线指向控制策略研究

The Antenna Pointing Control Strategy Study of Tracking and Data Relay Satellite

首先根据中继卫星系统中中继卫星跟踪用户星的要求,定义了中继卫星天线坐标系,推导出了中继卫星天线对用户星的跟踪规律,通过该跟踪规律可以推出中继卫星跟踪用户星时天线方位和俯仰轴转角,为了保证中继卫星与用户星之间的通信,中继卫星单址天线需要精确的指向用户星;然后详细描述了天线指向控制概念,并且设计了星上自主控制方案,星上自主控制方案由捕获和自动跟踪模式组成,一方面设计了天线捕获过程,另一方面对自动跟踪模式的天线步进逻辑进行了合理选择;最后根据推导的跟踪规律,以不同轨道的用户星作为跟踪目标,对所设计的天线指向控制系统进行了数学仿真,并且通过对仿真结果的分析验证了中继卫星单址天线指向性能。

Tracking and Data Relay Satellite System (TDRSS) is one of the hot spots in aerospace engineering recently. Firstly, the antenna coordinate system of the Tracking and Data Relay Satellite(TDRS) is defined and the tracking laws from the user satellites to the TDRS are derived according to the requirement of the TDRSS. The antenna's azimuth and elevation angles can be derived through the tracking laws when the TDRS is tracking the user satellites. In order to ensure the correspondence between the TDRS and the user satellites, the SA (Single-Access) antennas of the TDRS need to point the user satellites accurately. The antenna pointing control concepts are described, and the on-board autonomous control scheme is designed. The on-board autonomous control scheme is composed of acquisition and autotrack modes. On one hand the acquisition process of the SA antenna is designed, and on the other hand, the antenna step logic of the autotrack mode is properly selected. Finally, the mathematic simulation of the antenna pointing control system designed in this paper is conducted in the case of taking the user satellites in different orbits as tracking objects according to tracking laws derived before, and the SA antenna pointing performance of the TDRS is demonstrated by the analysis of the simulation results.