皮卫星质量特性测量和配重优化

Measurement of pico-satellite's mass properties and counterweight optimization

卫星质量特性主要包括卫星的质量、质心、转动惯量和惯性积等,是影响卫星精确姿控的一个重要因素.皮卫星能源和姿控能力有限,对皮卫星偏心量和转动惯量提出了相关要求.以"皮星一号A"卫星为例,首先采用三支点称重法和三线摆法测量了卫星的原始偏心量和原始转动惯量,然后采用遗传算法对该卫星配重块个数、尺寸及其安装位置进行配重优化.配重后测量发现:"皮星一号A"卫星偏心量小于0.5mm,皮卫星转动惯量Jyy>Jxx>Jzz,配重质量约为0.34kg,在满足姿控系统质量特性要求的前提下实现了配重质量轻量化.皮卫星在轨下传的地球照片说明皮卫星姿控成功.

Mass properties of satellite include mass, centroid, moment of inertia, product of iner- tia, etc. It is an important security factor for the satellite to achieve attitude control precisely. The pico-satellite has limited ability of energy and attitude control which put forward relevant re- quirements on its mass properties. Firstly, three pivot weighing method and trifilar torsional pendulum were applied to measure the initial amount of centroidal deviation and the initial mo- ment of inertia. Then, genetic algorithm was employed to optimize the counterweights of the pi- co-satellite. Through measuring the mass properties of the pico-satellite after counterweight, it was found that all relevant conditions were satisfied. The amount of centroidal deviation was less than 0.5 mm, the moment of inertia met requirement of Jyy〉Jxx〉Jzz, and the counterweight was about 0.34 kg. On the premise of meeting requirements of mass properties of attitude control system, lightweight design was realized. Finally, the picture of the earth taken by pico-satellite verified the success of attitude control.