Key Technologies Of The Astronauts EVA Operation Training Equipment In Microgravity Environment

Due to the microgravity environment of space, astronauts’extravehicular operation is quite different from that on the earth. For high reliability, the astronauts’ extravehicular operations need training on the ground. Meanwhile, some security measures also need tested before it put into use. To develop a training equipment in simulated microgravity environment in laboratory for astronauts is very important. In this paper, we designed a microgravity simulation system of3-dof for astronauts operating training through static air pressure flotation. Kinematics and dynamics characteristics of the system were analyzed, and air flow within the bearing was also simulated by Fluent software.The complete design of the astronauts three degrees of freedom of micro-gravity operation training system is finished in the paper. Space station model and the astronauts wearing space suits were respectively placed on the flotation platform. The electrical connector assembly operations component (push-pull operation) and bolt and nut assembly operations component (reversing operation) are installed on the space station simulator, which is available to let the astronauts who stand in the other flotation platform to do push-pull and reverse operation training; a air film appears between the floating table and the support platform when the two flotation units are supplied with air, so that the air bearing table could move and rotate freely on the platform, so that the microgravity state of motion in three degrees of freedom is simulated.In this paper, the kinematics and dynamics simulation for the interaction between the space station system and spacesuit system is finished. How the speed in translational motion, rotational motion as well as the two composite movement is conversed in different coordinate through mathematical method is elaborated, the flotation kinematics equations and the dynamic equations in the two-dimensional plane are established; corresponded3-D model of the experimental platform is also be established, using ADAMS software, displacement, velocity, acceleration curve of the air-bearing table under the push-pull operation condition and the reverse operation condition is obtained.The plane static pressure flotation leads the compressed air which is from external source into the throttle holes in the gap of the plane motion so as to establish hydrostatic support. Mathematical model of the process is described through fluid dynamics method. Pressure, density, flow velocity contours in the air orifice and air cavity were obtained by using the FLUENT simulation software, then calculating bearing capacity, so the relationship between the bearing geometric parameters such as gas cavity diameter, depth, bearing outside diameter, orifice diameter and bearing capacity was obtained.In order to verify the theoretical research, experiments on the bearing capacity characteristic were carried out. The carrying capacity of the air bearing in different air pressures was obtained. Experiments validated the simulation analysis. The paper provides the foundation to the development of multi-degree of freedom space microgravity ground simulation technology, and provides a basis for further development and application of flotation technology as well.