A decoupled mechanism based on intersecting planes that can be considered as a parallel mechanism with two arms is presented in this paper. The end-effector is connected to the base through two planar serial arms. The new specific characteristics of novel mechanism allow the generation of a remote center of motion (RCM) possessing two decoupled rotational degrees-of-freedom (DoF) and a tanslational DoF. It has a simpler control scheme and a larger workspace due to the decoupling characteristics of this mechanism when compared with the RCM mechanism based on intersecting planes proposed by Li et al. This mechanism also eliminates the singularity inside its workspace that impairs the original mechanism. In the final part of this paper, through an analysis of the force transmission performance, we derive a method to adjust the length of the linkage to optimize its force transmission performance.
Journal of Mechanisms and Robotics Open Issues