Closed-loop guidance laws for low-thrust spacecrafts

This paper attempts to compare the two methods of Takagi-Sugeno (TS) fuzzy logic and neighbouring optimal control (NOC), for closed-loop guidance laws of low-thrust spacecraft system equations. At first, the open-loop optimal guidance is considered as the optimal thrust steering program that will transfer the vehicle from an inclined low earth orbit to a high earth orbit. Secondly, proper closed-loop guidance laws are achieved, as the novelty of this work, to examine the robustness of the two methods with respect to min-effort criterion for low-thrust spacecrafts. This performance index will be better than customary min-time and will be investigated as a new trend in this field for closed-loop guidance. The results illustrate the viability and efficiency of TS and NOC methods as closed-loop guidance laws for low-thrust orbital manoeuvres regarding the robustness of this guidance against disturbances. Finally, results illustrate a better method to achieve closed-loop guidance for low-thrust spacecraft manoeuvres.