Mathematical modeling of spacecraft guidance and control system in 3D space orbit transfer mission

Spacecraft performance in an orbital maneuver relies on guidance and control systems which manage the thrust direction within orbit transfer. In this article, the guidance and control approach for spacecraft having a 3D orbit transfer mission is proposed. To derive the optimal variation of steering angles with initial and terminal constraints on the space orbits, a mathematics polynomial function of the guidance command with unknown coefficients is introduced, one of which is determined to achieve the transfer accuracy requirement between space orbits. Genetic Algorithm is employed in finding optimal variation of guidance command and the optimal initial states within the transfer. The attitude control system is also modeled to evaluate the spacecraft response with respect to generated commands by the guidance system. Gas thrusters are considered as attitude actuators for space mission and linear controller with pulse-width pulse-frequency modulator and unconstrained control allocation is employed for controlling steering angles. Results indicate that the presented approach for guidance and control system fairly satisfies the mission requirement.