Synergetic Static-Dynamic Self-Gravity Compensation for Space-Borne Gravitational Wave Detectors Based on Dynamic Full-Link Simulation System

Self-gravity compensation is essential for maintaining the low-disturbance environment of the test mass (TM) in space-borne gravitational wave detectors. Existing studies have mainly focused on self-gravity analysis and compensation design under static configurations, with limited attention to time-varying disturbances induced by moving assemblies. To address this issue, this paper investigates the dynamic self-gravity variation caused by Moving Optical Sub-Assembly (MOSA) rotation and proposes a synergetic static-dynamic self-gravity compensation strategy. Built upon high-precision self-gravity calculation and optimization modeling, the proposed strategy suppresses gravitational imbalance through the coordinated allocation of multiple balance masses (BMs). It first establishes a static compensation baseline and then extends it to a synergetic dynamic compensation framework accounting for MOSA rotation, with static and dynamic constraints treated in a unified physical BM-based compensation framework. A dedicated two-stage hybrid optimization framework (TSHOF) is adopted to optimize the BM configuration while reducing mass redundancy. The proposed scheme is validated through optimization results analysis and static boundary sampling, and further evaluated at the system level using a dynamic full-link simulation system under more realistic on-orbit conditions. Within the considered simulation framework, the optimized BMs configuration satisfies both static and dynamic requirements, while the self-gravity acceleration noise remains below 2 × 10 -16 m/s 2 /Hz 1/2 over 1mHz-0.1Hz under coupled dynamic conditions, thereby satisfying the mission noise budget.