Design of a Drag-Free Control System for Gravity Field Measurement Satellite Based on a Cusped Hall Electric Propulsion System

To obtain a more accurate gravity field model, gravity field measurement satellites use the drag-free control system to minimize the residual disturbance force of the satellite. To meet the drag-free control accuracy, these tasks propose the requirements of wide continuous throttling ability, low noise, and rapid response for the propulsion system, which acts as the actuator of the control system. This research takes a cusped Hall electric propulsion system as the research object and constructs a component-level propulsion system model based on experimental data. The drag-free control simulation system is designed. And the control simulation results show that the slow thrust response speed of the propulsion system limits the bandwidth of the control system, resulting in the control accuracy not meeting the mission requirements. To solve this problem, a thrust response speed optimization method based on coordinated control of input parameters of the propulsion system is proposed. The results show that the thrust response speed is improved and the bandwidth of the control system is increased after the coordinated control of the flow rate and the voltage, which makes the residual accelerations of the satellite meet the drag-free control requirements of the gravity field measurement satellite.