Scaling Laws of the Drag-free Control System Between Ground Model and Space Prototype

To address issues in the construction of the ground test platform and closed-loop control performance evaluation of the drag-free system in space gravitational wave detection, this paper proposes a verification method based on a ground composite semi-physical drag-free simulation system. A ground simulator for drag-free simulation is innovatively designed based on the configuration of a drag-free satellite with two test masses. The scaling laws between the space prototype and the ground simulator are determined by using the Pi theorem. The scaling laws are used as the design guide for the ground simulator. According to the principle of the drag-free satellite in the science mode, the drag-free controller is designed using the active disturbance rejection control (ADRC) algorithm, and the control scaling laws are established for the controller design of the ground simulator. The closed-loop similarity of the two systems is studied, and the simulation results indicate that the two systems exhibit similar closed-loop dynamic behavior. The drag-free controller of the space prototype can be transferred to the ground simulator for verification using control scaling laws.