Docking Dynamics Simulation Of Spacecraft With Peripheral Docking Mechanisms

Rendezvous and docking technology is essential in space-assembly,space-succor,outer space-exploration and so on, and is also a key technology of the second step of Chinese manned spaceflight. Building rendezvous and docking simulation system is an important way for studying rendezvous and docking technology. By employing the development of the RVD simulation system as the research background, the main work of this dissertation is to study the docking dynamics of spacecraft with Peripheral Docking Mechanisms and to develop the docking dynamics simulation system (DDSS). The main achievements obtained in this dissertation are as follows.1. Mathematical descriptions of the complex shape of docking mechanisms are established. 20 kinds of designed contact points, which exist when the capture rings approach and capture each other, are given. Another 20 kinds of non-designed contact points are given for the first time. Contact determining algorithm of all the above contact types is given using Z-Buffer Algorithm for 3-D observation, and simulation results show high accordance with results of Vector-Associated method. Simulation for non-designed contact mode with random initial conditions has been done too, and statistics from the simulation indicates that it is important to predict non-designed contact points in practical RVD efforts.2. Relative dynamics equations of spacecraft and docking mechanism for each phase of the docking process are built by Newton-Euler method. In the equations, the buffer system is simplified as a 6-DOF spring-damper model. Contact force is treated as a non-linear spring and act in a continuous way. Separation force is modeled as well.3. Scheme of varying integrating steps and integration algorithm are given after analysizing the difficulties of solving the capture phase dynamics equations, and the flow chart of the whole docking process simulation is given; The need and design principles of the docking dynamics simulation system is analyzed, basic structure and modules of the system are detailed, and the software is demonstrated.4. Simulation model for capture and buffer phase is built based on ADAMS software, in the model, capture ring is accurately built with full consideration of actual geometrical feature, buffer system is modeled the same as that of DDSS, and ADAMS impact model. Is adopted. The whole model contains parts,applied force,measures,sensors,simulation script and so on.5. Numerous simulations are done with different initial docking misalignment by ADAMS software and DDSS: (1) Influence of the contact Columbus friction to simulation results is inspected; (2) ADAMS results are compared with that of DDSS, both the results validate each other; (3) Simulation results show good capture ability of...