Design of a Compliant Locking and Unlocking Mechanism Using a Problem Decomposition-Based Method

Abstract To address the challenges associated with designing a locking and unlocking mechanism for the radial connection and separation of launch vehicles and spacecraft, this article introduces an approach to mechanism design centered on problem decomposition and leverages this method to develop a new compliant locking and unlocking mechanism. The mechanism consists of a segmented flange-based variable-radius inner cylinder, a compliant scissor mechanism, a step-reducing bolt, a bolt quick ejection mechanism, a quick-release mechanism, a wedge block, and a rigid outer cylinder with U-shaped slots. The segmented flange-based variable-radius inner cylinder adjusts its radius for connection needs. The compliant scissor mechanism ensures synchronized flange segment movement, enabling reliable locking and unlocking with the outer cylinder. The step-reducing bolt shortens screwing time while ensuring depth. The quick ejection mechanism removes the connection force without unscrewing bolts, improving unlocking efficiency. The quick-release mechanism utilizes principles of dead-point and triangular amplification, offering high-speed movement. Kinematic and dynamic modeling of the quick-release mechanism is conducted, and a prototype is developed and tested to validate the functionality and feasibility of the mechanism.