Design and verification of a piezoelectric-driven locking and handover mechanism for space-based gravitational wave detection

Space inertial sensors, comprising a test mass and its surrounding framework, are pivotal for high-precision gravitational wave detection. The precise locking and handover of the test mass are crucial, particularly during launch and orbital insertion phases. Given the necessity for ultra-stable locking mechanisms in space inertial sensors to ensure mission success, this paper presents a novel locking and handover mechanism driven by a rotating piezoelectric motor and lead screw. This mechanism ensures stable support and accurate handover of the test mass. Finite element simulations were performed to evaluate the static performance and modal response of the mechanism, confirming its stability under a preload of 1200 N and its ability to avoid resonance with rocket launch frequencies. A testing platform was constructed to validate the performance of the design. Experimental results demonstrate a maximum locking force of 1313.3 ± 3.1 N, a typical force resolution of 15.4 ± 3.6 N, a movement range of 10.0 ± 0.7 mm, and a typical displacement resolution of 1.7 ± 0.8 μm. Both simulation and experimental outcomes indicate that this design successfully integrates high preload locking with precise force and displacement control. This work represents a significant advancement in space mechanism design by combining high preload stability with micrometer-level precision.