A hybrid method for microgravity simulation of space robotic manipulator

According to structural characteristics of a space robotic manipulator with 7 DOFs (degrees of freedom) which can be used for space station assembly, a hybrid method for microgravity simulation for the 7-DOF manipulator on the ground is proposed. The presented method is a combination of air-bearing support and static balancing. Gravity of the middle segment of the 7-DOF manipulator is compensated by air-bearing support. And two static balancing mechanisms are designed to compensate the gravity of both ends of the 7-DOF manipulator, i.e. the shoulder and wrist, respectively. The microgravity ground-based facility using the hybrid method allows the 7-DOF manipulator to perform movement in three dimensions. Therefore, in the simulated microgravity environment, the positioning accuracy of the end-effector of the 7-DOF manipulator can be measured, and experiments of target capture also can be carried out on the ground. The microgravity ground-based facility of the 7-DOF manipulator is modeled with ADAMS, and its performance is studied. Simulation results demonstrate the feasibility of the proposed microgravity simulation method for the 7-DOF space robotic manipulator.