On the computation of motion resolution for robotic manipulators

The purpose of this paper is to propose a new mathematical framework for examining the motion resolution of robotic manipulators. The term motion resolution refers to the smallest possible increase in end-effector motion when compared to actuator displacements. The proposed resolution model is different from other established mechanisms analysis concepts such as manipulability, velocity amplification factor, or the kinematic Jacobian condition number. To examine the effects of small motion increments in the robot workspace or joint space, a forward and inverse model are discussed. The framework is applicable to both serial and parallel robots, and the characteristics of these models are discussed. Moreover, several case studies are presented to highlight numerical examples and data interpretation for motion resolution models. The numerical examples are based on a 2-DOF planar parallel manipulator, a 3-RRR parallel planar manipulator, and a Stewart-Gough platform.