Recent advances in the active magnetic control of satellites

Abstract

The paper covers main recent results in the active magnetic attitude control of satellites. Three main implementation situations are outlined. Angular velocity damping opens the problem as the auxiliary control task. Next, implementation with other actuators and passive stabilization concepts is considered. Magnetic attitude control is restricted in the direction: control torque cannot be applied along the magnetic induction vector. Other actuators or environmental properties may enhance the control, providing control authority along the restricted axis. This comes at the cost of restricted attitude motion. Passive gravitational stabilization, spin stabilization and dual spin satellites present main cases. The satellite may acquire the local vertical and one axis inertial attitude that represent important cases. The most challenging and practically promising situation is the fully magnetic three axis attitude control. This reduces the hardware requirements for the attitude control system to the minimum. However, this also comes at the cost of a restriction on the control torque vector and low attitude accuracy and time-response. Feedback law with proper control gains tuning, sliding control and optimization techniques are considered for this problem.

Time-Periodic Spacecraft Attitude Control with the Use of Slewing Permanent Magnets

“…Attitude control is a subtask of SC motion control [1]. Attitude control system can use diffe rent actuators, for example reaction wheels, electromagnetic torquers, thrusters, control moment gyros and other modifications of these systems [1][2][3]. Electromagnetic torquers are frequently used for SC because they allow the system to control the SC attitude motion using only onboard electrical energy, which can be renewed in orbit.…”

“…For example, Refs. [7,11,12] demonstrate that the ASPMs consume three times less electric energy than electromagnets with "mobile control" [8] and an order of magnitude less than conventional electromagnetic stabilization [1][2][3].…”

“…The following reference frames were used: the inertial reference frame (IRF), orbital reference frame (ORF), body frame reference frame (BFRF) [1], magnetic dipole reference frame (MDRF) [3,14].…”

Development of the methodological approaches for the attitude control system of the Earth remote sensing satellite in the conditions of the onboard equipment partial failures

“…Special algorithms that use MGTR's with other actuators and passive stabilization concepts had been considered in paper [2]. Therefor one of the options for such a combined use was the use of the RW in one channel instead of a MGTR (with the orthogonal arrangement of the RW along the three main axes of inertia of the spacecraft).…”

“…Therefor one of the options for such a combined use was the use of the RW in one channel instead of a MGTR (with the orthogonal arrangement of the RW along the three main axes of inertia of the spacecraft). This control algorithm is proposed to turn on the RW and MGTRs simultaneously [2]. In this case a control problem may arise due to the large difference between the torque generated by the RW's and MGTR's.…”