Three-axis Control of an Under-actuated Satellite Based on the Principles of Artificial Intelligence Using 2 Gimbal Actuators

In this paper, we design an intelligent active attitude control subsystem (ACS) including 2 reaction wheels (RW) to achieve 3-axis attitude control of an under-actuated satellite. Since the position and configuration of the control actuators plays an important role in the performance and behavior of the attitude control system, in this paper, we used artificial intelligence as a loop of the main control algorithm to calculate the optimal RWs configuration with respect to the user's command. Then the robotic joints are responsible to place the actuators in new optimal configuration (gimbal RW). So this variable configuration ACS provides maximum RWs momentum envelope coverage. Authors used the backstepping method as the main controller due to its robustness against uncertainties. Advantages of this method in comparison to the other Studies are its simultaneous and fast time response, negligible power consumption and latency in RW saturation. Analysis of the simulation results shows that the presented approach has an acceptable pointing accuracy of the attitude time response.