Extension velocity limiter for the ring of an elastically adaptive peripheral docking mechanism

Abstract

The docking ring of an elastically adaptive docking mechanism on the initial contact signal is extended by spring-loaded mechanisms of the rods in order to improve capture conditions. In the process, it reaches a high velocity, which applies unacceptably high impact loads to the docking interface. This paper discusses an extension velocity limiter for the docking ring, its analytical model, and a brief procedure for calculating its parameters. It describes a simplified model for ring extension during initial contact, and a method for determining viscous friction coefficient of the ball-screw pair of the docking mechanism, which is a parameter in the model. It presents the procedure, results and comparison of simulations of the docking ring extension both with the use of the proposed retarder and without it. It is demonstrated that the use of the velocity limiter permits to meet the requirements of the International Standard for pulsed loads on the passive interface. The paper describes a design option for velocity limiter that has acceptable mass and dimensions. Keywords: spacecraft docking, elastically adaptive docking mechanism, retraction device, velocity limiter, mechanical governor