Dynamic Modeling And Contorl Analysis For Suspended Type Astronauts Low-gravity Simulation System

The ground training of astronauts is the important preparation for the manned space mission. To Apollo mission as a symbol, in the task requires more accurate moving trace, wide range of motion and excellent operation skills to the astronauts.Based on this, simulation of low gravity environment in the ground and training of astronauts movement skills becomes more important. CHINA, the United States,Russia and the European Union Aerospace Power in the low ground gravity simulation of a large number of studies, the astronaut extravehicular activities in low gravity simulation rely mainly on floating and weightlessness flight other passive methods, astronaut training time and velocity restricted are not enough to meet the needs of future missions. With the progress of motor, sensor and control technology, in the astronaut extravehicular activity training by suspension method active tracking astronaut motion, provide high precision gravity compensation system can be achieved.Firstly, the gravity compensation model is established in this thesis for the multi rigid chain model of the astronauts and the complete compensation constraint is obtained. Under the constraint condition of compensation, limited compensation number, as well as he direction and solution of a group of single cable gravity compensation model can be obtained. It can be correspondingly proposed the implementation of the principle of single cable gravity compensation astronauts in motion. Analysis of the astronaut training in the state of motion,complete suspension astronauts low gravity simulation system design, determine the single cable gravity compensation can be high fidelity is achieved to enable astronauts to walk, run and carry out space maneuver of low gravity simulation training.Secondly, according to the two states of astronaut movement, the corresponding astronaut and the dynamic model of the suspension system is established. The dynamic model and control target of servo system are unified for the research of the dynamic control method. Moreover, through the digital simulation model of completed the dynamics characteristic analysis and verification, it can be concluded astronaut-dynamic suspension system the presence of unknown disturbance, coupling and nonlinear dynamic characteristics.At last, according to the dynamic model, a stable nonlinear servo controller is designed with partial feedback linearization method. Dynamic simulation model isbuilt in the ADAMS simulation system. In the MATLAB in the establishment of the servo controller, combined by simulation experiment platform, for astronauts exercise in the trunk centroid tracking experiment, analysis of the controller performance to demonstrate the correctness of the system design.