Study On The Docking Mechanism For Uncooperative Space Target

Space rendezvous and docking technique is a very important technology in the field of aerospace, such as personal transportation, material supply, maintenance and space rescue, capturing the failed spacecraft, it is also an indispensable technology for Chinese plan to loading on moon. The docking targets can be divided into two kinds, cooperative targets and uncooperative targets, due to the way used to capture them. Since it has been installed cooperate sign device and docking mechanism on the targets in the case of cooperative docking, it becomes much easier to capture the targets and dock. On the contrary, when it comes to uncooperative docking, there is no cooperate sign device and docking mechanism specially set as well as information exchange, which brings difficulties for docking. However, the uncooperative docking has the advantage of strong adaptability and wide application, and some foreign countries even have made related ground and space test while China is still at the initial stage. As a result, it has enormous significant to take research on uncooperative targets.This article takes satellites in geosynchronous orbit as research objects, and takes research on the docking mechanism which is used to capture satellites. On the base of investigation from both abroad and domestics, it is defined to choose satellites'apogee engine as docking interfaces. Since the size and shape of this kind of engines is in a narrow range, and their nozzles are generally embedded conical structure, the nozzles are suit to identify and capture. Based on the size, shape and initial docking condition of the nozzles, the author designs a docking mechanism that is consisted by an umbrella-shaped damping-oriented mechanism and three mechanical fingers.As soon as finishing program design, the author goes on taking theoretical analysis for the docking mechanism. In the facet of kinematic analysis, based on the size-range and shape of the nozzles, he gets the finger trajectory needed for docking, then, according the trajectory, he makes converse solution and gets the length of every lines which should be accurate so as to successfully capture the uncooperative targets. When it refers to the facet of dynamic analysis, based on Lagrangian dynamic equation, the author makes analysis from the viewpoint of energy, this method is suit to analysize the mechanism made by lots of parts. The dynamic analysis is also the theoretical foundation for the following simulation. The kinematic simulation analysis of space docking mechanism for uncooperative targets has demonstrated the process of docking, verified the correctness of the design, while the dynamic analysis has shown the contact force during docking and the process of becoming stability, then comparing the analysis result with the docking mechanism's based on underactuated theory which has prove the advantage of this design. What is more, based on the load condition of each part which is got form dynamic analysis, this design goes on modifying structure and taking optimization for all parts. Finally, under the prerequisite of meeting the requirement of docking, the optimized design improves the loading condition of the docking mechanism, greatly reduces the mass of the whole machine. At last, modifying all parts according to the results of optimization, simulating the virtual prototyping again as well as taking overload simulation, which also prove the correctness of this design.