Research On The Ground Passive Suspension Systems For The Large-Scale Space End Effector

With the development of space technology, the large arm is successful use in space, and become important tool for the assemble, transport and maintenance. Space manipulators are the end effector of arm, and it is useful tools for human to explore the universe. The level of space manipulators technology represents the level of a country's science and technology. 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.Firstly, The suspension method has been compared with the other methods of gravity compensation, according to the result, the author has designed the suspension equipment for the gravity compensation, which can simulate the 6-DOFs capturing motion considerably. The key issue of the suspension equipment for gravity compensation is presented by static and dynamic analysis of gravity compensation of passive suspension method, that the friction force and the dimensions of the pulley. Rational design of pulley can effectively improve the accuracy of the simulation of microgravity.Through the resolution of the unbalance torque of the rotating mechanism, the author presents the rule that the unbalance torque is variational with the pitching angle. A compensating method for unbalance torque resulted from the platform deforming of the air-bearing testbed acted on gravity is presented,that is making a tiny distance between the mass-center and the center of rotation of the platform in the vertical direction so as to offset the unbalance torque resulted from the platform deforming.2-DOFs manipulator is designed, for the current space large-scale end effector. Based on the configuration of the manipulator, has determined the support project, also has designed connecting and walking mechanism of the manipulator which can successfully accomplish the joint motion in the plane and the rotation of the end effector. In the end, the ground testing equipment has used to test the capturing tolerance of the end effector. On this equipment, the snare-capturing, rigidizing and latching motion of the end effector has been tested. According to the result of the experiments, the ground testing equipment has the capability to simulate the motion of the end effector.Via the analysis of the experiment results, the author presents the means to simplify the mathematics model for the calculation of the capturing tolerance, and presents a mathematical calculation method for the successful target capturing when the tolerance exits in all 6-DOFs motion directions.