Nonlinear kinematics of space parallel robot with Bricard mechanism

The space parallel robot with Bricard mechanism (SPRBM) is a complex mechanical device used for capturing free-floating space debris. It consists of a 3-RRS (Revolute-Revolute-Spherical Joints) parallel mechanism and a Bricard mechanism. Space debris can be captured by the interior space of the SPRBM. Compared with the conventional manipulator system, the SPRBM can capture a target with an arbitrary shape and motion state if the target can be enwrapped by the mechanism. In addition, it does not impose any stringent requirement on the locations of the capture points on the debris. However, the SPRBM has complex configurations and therefore nonlinear kinematics. This paper presents a detailed kinematics analysis of the SPRBM. The analysis involves the degrees of freedom, singularity, forward and inverse kinematics, workspace, and the trajectory planning method. These analyses and the results provide the fundamentals for modeling and controlling the SPRBM.