Topology Analysis and Decoupling Design of 3-RSR Antenna Parallel Mechanism

The topological structure of 3-RSR antenna parallel mechanism (PM) is special. The spherical joint (S) in each chain is in the middle of the chain, which makes its topological analysis difficult. According to the topology structure design method of PMs based on the position and orientation characteristics (POC) theory, the main topology structure characteristics (POC sets, degree of freedom (DOF), coupling degree) of the 3-RSR antenna PM are analyzed. The coupling degree of the PM obtained as k= indicates that only the numerical solution of direct displacement can be obtained, which is unfavourable to the sequential kinematic synthesis and dynamic analysis. Therefore, the structure decoupling design of the antenna PM is carried out, and its optimized configuration with coupling degree k=0 is obtained, which is very beneficial to kinematic analysis of the PM.