Research On 3-D Gravity Compensation And Equipment Of Space Floating Objective Simulation

Space robots are useful tools for human to explore the universe and utilize the space resource. The level of space robot technology represents the level of a country's science, technology and economy. Constructing an experimental system to simulate the microgravity environment is an essential condition and a key technology for the study of space robots. This paper aims how to develop an accurate microgravity simulation system to verify the capture ability for floating object.The contents are as follows:1. The paper firstly summaries some approaches to generate microgravity environment by escaping gravity acceleration and cycling in the space orbit. Then, the paper introduces three main approaches and their facilities for function validation of space robot on the ground. The approaches are the suspension method, buoyancy method and air floating method which apply balance forces to cancel or compensate the gravity.2. The suspension method is compared with others. Defects of gravity compensation of passive suspension method are pointed out by static and dynamic analysis and by experiments. After that, a new means, halving mass of the suspension model, is proposed. Active and semi-active control method of gravity compensation can avoid the drag of friction and inertia in cable-mass passive system.3. The experiment method to simulate the space object floating in six degrees of freedoms (DOF) is proposed. The active and passive displacement mechanisms are presented. The dynamic model and the kinematic optimal-time control approach is studied. The numerical simulation of following motion shows the trajectory program is validated.4. The method to set buoyancy volumes and bring buoyancy center accord with the mass center in buoyancy method is studied. A method of equivalent dynamic simulation (1:1) by changing the model mass is proposed.5. After modeling the relation of gas leak with flow pressure and the geometric parameters of low friction cylinder, the approach of pneumatic gravity compensation is put forward, and a novel low friction cylinder is designed. Experiments show the novel cylinder is suitable to realize 3-D gravity compensation.6. The defects of cable-massed simulation satellite in the mass and inertia in several axes or directions are indicated. A 6-DOF air floating satellite based on the novel cylinder is designed. Pneumatic thrusters and its control system make the satellite floating like in space, and some experiments are done for its characteristics. Finally, the author schemes a platform for validating space capture function of space robot on the ground.The main innovations of the paper are as follows:It is of consequence to develop 3-D air floating simulation on the ground for space object through pneumatic gravity compensation. Using a low friction cylinder, a 3-D platform to simulate floating objective and a 6-DOF simulation satellite have been built. Those are of consequence for high precision microgravity physical simulation experiment. After research on similar scales of flow dynamics in...