Research On Emergency Return Technology Of Space Manipulator Assisting Astronaut

With the ceaselessly deepening of human space exploring.It is increasingly frequent and difficult to implement space operating tasks.As a typical on-orbit operating tools,space manipulator has advantages of large span and operating flexibility,and can substitute or assist astronauts to accomplish some complex space operating tasks.But astronauts also need to go out of the spacecraft to accomplish some tasks such as spacecraft repairing and space rescue missions.Considering the strong radiation and high temperature variation in space environment,it takes great risks for astronauts to carry out tasks outside the spacecraft.When there is an accident,astronauts must be guaranteed to go back to the hatch in fixed minutes to ensure personal safety.Therefore,it is of great engineering value to carry out the research of space-manipulator-assisted astronaut emergency return to improve on-orbit servicing capacity.This paper focuses on the research of space-manipulator-assisted emergency return technique,designing a set of strategies of space-manipulator-assisted astronaut emergency return,achieving the goal of rescuing astronauts to the hatch by a space manipulator with arbitrary configuration.The main work is carried out as follows:Firstly,the design of simulation platform structure of space-manipulator-assisted emergency return is accomplished.The overall structure scenario is designed through the function and demand analysis of the simulation platform.The three-dimension scanning algorithm is used to obtain surface points on the working area.The working area is divided by classifying these points to finish the pretreatment of the astronaut,working area.The workspace of space manipulator is preprocessed by combining Monte Carlo method with collision detection algorithm to get the collision-free working space of space manipulator.Secondly,the configuration network construction of space manipulator aided planning.The regional configuration set of space manipulator is selected based on the space manipulator workspace.The collision-free configuration set of space manipulator is selected based on the collision-free workspace of space manipulator.The intermediate configuration set of space manipulator is achieved considering the division of astronaut's working area.The selection of each configuration set lay the foundation of the design of the space-manipulator-assisted astronaut emergency return.Thirdly,the design of space-manipulator-assisted astronaut emergency return strategy.On the basis of the rescue condition analysis of space-manipulator-assisted astronaut emergency return,the corresponding emergency return strategy is designed under different working conditions of astronaut and space manipulator,to ensure that the space manipulator with arbitrary configuration can rescue the astronaut at arbitrary position to the exit.Through numerical simulation,comparison and analysis of the expected trajectory and actual trajectory of emergency return,the correctness of the algorithm is verified.Finally,the experimental research of space-manipulator-assisted astronaut emergency return is carried out.The three-dimension visual simulation software of space-manipulator-assisted astronaut emergency return is built based on the VC++ and OpenGL simulation technique.On this basis,the three-dimension simulation experiment of specific rescue task is carried out to verify the correctness and feasibility of the proposed algorithm.