Electric thruster configuration design optimization for geostationary satellites with robotic manipulators

This paper proposes a novel electric thruster configuration design optimization scheme to implement efficient station-keeping operations for geostationary satellites. In this work, the electric thrusters are equipped with 4-DOF robotic manipulators to provide flexible control thrust in space, which consumes much less propellant than the conventional station-keeping process using fixed-position electric thrusters. To effectively determine the firing right ascensions and firing durations of each electric thruster during the station-keeping process, a novel station-keeping control strategy is developed in view of the low-thrust feature of electric thrusters and the flexible pointing capacity of robotic manipulators. A low-thrust station-keeping period includes one two-day orbit determination period and six two-day control periods, where the initial orbital elements are determined in the orbit determination period, and the electric thrusters fire to compensate the perturbations in the control periods. Based on the control strategy, the electric thruster configuration design optimization problem is formulated to minimize the total propellant consumption via optimizing the robotic manipulator joint swivel angles and firing durations simultaneously, subject to several practical engineering constraints including the station-keeping accuracy, angular momentum dumping, collision between electric thruster and solar array, and electric thruster plume. Finally, the proposed electric thruster configuration design optimization scheme is applied to real-world station-keeping problems. The simulation results show that the geostationary satellites can be successfully maintained in an assigned station-keeping window using the robotic manipulators based low-thrust station-keeping control strategy. Moreover, the optimized electric thruster configuration with robotic manipulators can save 31.58% propellant consumption compared with that of the conventional configuration owing to the favorable flexibility of control thrust, which demonstrates the effectiveness and practicality of this work.