Design and dynamic analysis of high-speed over-constrained deployable mechanisms with low load sensitivity

High-speed deployable mechanisms often utilize the flexible deformation of components to assist in overcoming mechanical dead points. However, under uncertain external loads, the deformation behavior of conventional flexible deployable mechanisms often exhibits a strong dependency on external loads. This paper proposes a flexible deployable mechanism based on over-constrained design. First, a flexible multibody dynamic model based on the Absolute Nodal Coordinate Formulation (ANCF) is established and validated. The study elucidates the guiding role of the over-constrained design on the deformation path of the leading-edge flexible link, forcing the mechanism’s deformation behavior to depend primarily on driving parameters, thereby significantly reducing its sensitivity to external load fluctuations. Dynamic simulations indicate that this configuration effectively eliminates motion lag and enhances locking reliability, while reducing the transient locking impact by over 40% and increasing the fundamental frequency of the locked configuration from 36  Hz to over 90  Hz. Finally, scaled prototype experiments confirm the feasibility of regulating flexible deformation through geometric parameters. This study provides a new design approach for high load adaptability high-speed deployable mechanisms.