Research On Trajectory Planning Of Astronaut In Weightlessness Environment

With the development of aerospace technology,the progress of computer,automation and other fields of science and technology,as well as the maturity of human space technology,people’s research in the field of aerospace is more and more extensive,and the requirements of astronauts are also higher and higher.Astronauts not only need to enter space,but also need to complete a variety of complex tasks in space,and in space to complete the operation is more difficult and dangerous,the use of efficient operation mode will make the operation more safe,so the research on how to perform the mission in the best way in space becomes particularly important,this paper through the simulation study on the ground for astronauts A suitable and feasible method of operation training is put forward.Based on kinematics and dynamics,the trajectory planning of special tasks is completed.A multi-objective optimization method about time,energy and impact is proposed.The multi-objective trajectory optimization is carried out in joint space.Finally,the motion capture system is used to track the astronauts on the ground The training was captured and evaluated.The contents of this paper are as follows:Through the analysis of human anatomy and physiology,the wrist joint complex,elbow joint complex and shoulder joint complex are elaborated in detail.According to the physiological structure of human arm under spacesuit,the equivalent motion chain of both arms is extracted,and the forward and inverse kinematics of astronaut arm are analyzed by D-H method and GABP neural network method respectively,and the simulation results are verified.Considering the influence of pressurized spacesuit and weightlessness in space on the motion,the drag moment hysteresis model of Spacesuit Joint is proposed.The dynamic model of astronaut’s upper limb is established by Lagrange method.The influence of spacesuit without suit,with suit without pressure and with suit charged on astronaut’s motion is compared and analyzed,and verified by simplified three degree of freedom theoretical model.Monte Carlo method is used to solve the working space of single arm and double arm cooperation of astronauts in space weightlessness environment.For the operation space and joint space,the quintic polynomial interpolation method and the 4-1-4 order polynomial interpolation method are respectively used for trajectory planning,so as to realize the non impact motion from beginning to end.In this paper,a 7-order B-spline curve method is used to construct trajectories in joint space for one loading task,and a multi-objective optimization function with time,energy and impact as objectives is established.The non dominated sorting genetic algorithm(NSGA-II)is used for multi-objective optimization of astronaut operation trajectory.According to the experience,the optimal solution is selected from the Pareto solution set to obtain the required trajectory.The algorithm can reduce energy and impact on the basis of reducing time.The simulation experiment of operation training is carried out under the motion capture system(NOKOV).The optimal trajectory is taken as the standard for simulation teaching.The action capture system is used to capture the training actions of the experimenters.The time,energy and impact consumed in each movement process are obtained by seeker software.Finally,the evaluation function is used to evaluate and analyze each training process According to the evaluation criteria and the teaching process,the posture was adjusted for continuous training.