Magnetic attitude control system for spin stabilized satellite

Abstract

An active magnetic attitude control system through spin stabilization has been simulated. The attitude control including control of the spin axis, damping of the nutation angle and control of the spin rate. These are implemented through three magnetic coils or torqrods as magnetic torquers. Commonly, two transverse axis actuators are used for controlling the spin rate and one longitudinal axis actuator is used for controlling the spin axis and the active damping of the nutation angle. In order to have a high degree of safety and reliability an algorithm has been provided, so that, if one of the transverse axis actuators or the longitudinal axis actuator encounters a problem for any reason, each of the mentioned operations could be fully controlled via two remaining actuators. According to the simulations and obtained results, if the longitudinal axis actuator fails, the total control of the satellite attitude will be achievable, adaptive, and effective, only when the two transverse axis actuators simultaneously control the satellite. Furthermore, for the control of the spin axis, in addition to using the longitudinal axis actuator, one of the transverse axis actuators can also be used, in which case, the control of the spin axis is accelerated and, in a way, the sluggish response of the satellite's magnetic attitude control system is somewhat recompensed. Also, the algorithm used for the control of the spin rate causes the spin rate of the transverse axes approach zero so that the nutation angle is damped through the active magnetic control.