Mechanical modeling and parameter analysis of the docking process for probe-drogue docking mechanisms

The on-orbit probe-drogue berthing docking of two spacecraft can effectively reduce impact force and adjust for initial deviations. However, its dynamic response and influence behaviors of design parameters are extremely concerning but difficult to obtain because of its complicated structure. In this paper, a fast mechanical modeling (FMM) method is proposed to obtain the dynamic response of probe-drogue docking mechanisms during spacecraft berthing missions. Regarding the quasi-static docking process, complex dynamic docking behaviors are simplified and decoupled. The FMM method divides docking into three contact processes based on the scene of contact; it analyzes the deviation adaptive docking principle of this type of docking mechanism by establishing the kinematics and mechanics models of active and passive parts. The finite element simulations and experiments of probe-drogue berthing docking were used to compare with the proposed FMM. The comparison results of different initial deviation conditions indicate that the FMM method guarantees computation accuracy and increases computation speed by two orders of magnitude, which greatly reduces computation costs. Then this efficient FMM method was utilized to analyze the influence of key parameters, such as friction coefficient and cone angle, on the contact force and driving force of the docking mechanism. The conclusions of the parameter analysis of probe-drogue berthing docking can be used to reduce contact force and accelerate iterative design as a reference for the design of this kind of docking mechanisms, making the docking process optimized and reliable.