介绍了风云3号(FY-3, C星)太阳辐射监测仪采用的自主设计的精指向自解锁星载太阳指向器。该指向器是一个绕双轴旋转的指向平台, 其由驱动单元、执行机构、编码器、太阳敏感器等实现主动例行工作与被动冗余相结合的在轨太阳指向策略。为避免运输、发射等过程的冲击振动对其性能及寿命影响, 指向器具有自由度锁止及释放功能, 可以实现发射前的自由度锁止及入轨后的自由度释放。文中给出了指向器的结构组成、指向精度设计过程以及寿命实验结果。FY-3(C星)于2013年10月成功发射, 太阳辐射监测仪的太阳指向器入轨后成功解锁, 目前为止已经在轨连续运行17个月, 在轨指向精度为±0.05°, 其承载的太阳辐射监测仪获取了大量高精度有价值的太阳辐射数据。该精指向自解锁星载太阳指向器可为未来风云系列及其它卫星载荷指向机构设计提供应用基础。

This paper introduces the accurate pointing and auto-unlocking sun tracker on the Fengyun-3(FY-3, C)satellite designed by ourselves. The auto-unlocking sun tracker is rotating around the biaxial tracking platform, consisting of a drive unit, an encoder, a sun sensor, mechanical positioning elements etc. It realizes the on-orbit pointing strategy by both active routine and passive redundancy. In order to avoid the influences of vibration and shock in transporting and launching the satellite on the performance and lifetime of the satellite, the pointing device has a degree of freedom for locking and releasing function, and achieves the function that locking freedom before the launch and releasing freedom after the launch. The paper describes the structures of the pointing device, the design process of precise pointing and the result of life test. FY-3 (C) was successfully launched in October 2013. the sun tracker of solar radiation monitor has unlocked successfully when it was into the orbit. It has run continuously for 17 months in the orbit, and showing the orbit pointing accuracy within ±0.05 °. The tracker loaded the solar radiation monitor has accessed a large number of high precision and valuable solar radiation data. The accurate pointing and auto-unlocking sun tracker provides foundation for FY system satellites and other satellite loads in design of pointing devices.