Design of High Precision and High Stability Magnetic Torquer System for Gravity Gradient Satellite

Gravity gradient satellite is a type of real ultra-quiet satellite, and it has a very high requirement for its own stability because of the installation of high-precision load devices such as accelerometers. Conventional rotational actuators, such as momentum wheels, will bring high acceleration and frequency noise to the attitude control process, so the magnetic torquer is usually selected as the main actuator for the attitude control of gravity gradient satellites. Due to the ultra-quiet requirements, the precision and stability of the magnetic torquer are also required strictly. In this paper, a magnetic torquer with precision of better than 1% is designed for a gravity gradient satellite. The factors affecting the magnetic control precision are analyzed, and the implementation method to improve the precision of the magnetic torquer is given. According to the stability of the control system, the optimization analysis of control parameters is carried out, the current sampling method is improved, and the stability and precision of the system are verified by experiments. The on-orbit data show that the precision of the whole satellite magnetic control system can reach 2%», and the environmental micro-vibration level at the high-precision accelerometer during the operation of the satellite attitude control system can reach E-ll m/s
²
, which ensures the precise and reliable operation of the entire satellite attitude control.