Effect of Transfer Function Order of Thruster Actuators on Satellite Attitude Control

In this paper, effect of order of the thruster transfer function is investigated for a single-axis attitude control of a rigid satellite using two sets of opposing thrusters. The thruster dynamics is modeled by a pure delay in series with an arbitrary-order transfer function (TF) consisting of similar first-order lags. For this purpose, bang-bang controllers, bang-bang with dead zone, Schmitt-trigger and PWPF modulator are used in the analysis. The thruster dynamics order is selected using existing empirical thruster profiles. Considering the empirical profiles, usually a TF’s order lower than 2 is not recommended. Simulation results show that the TF’s order may be considered as an uncertainty applied to the attitude control problem and its sensitivity analysis.