Inverse dynamics and servomotor parameter estimation of a 2-DOF spherical parallel mechanism

A novel reconfigurable 5-DOF hybrid manipulator-TriVariant-B is composed of a 2-DOF spherical parallel mechanism which is serially connected with a 3-DOF open-loop kinematic chain undergoing one translation and two rotations by a prismatic joint. The merit of this design is that a relatively large workspace/limb-stroke ratio can be achieved thanks to the decomposition of the fixed point rotation and the relative translation. In this paper, on the basis of inverse dynamic formulation of the 2-DOF spherical parallel mechanism, an approach is proposed for estimating the servomotor parameters including moment of inertia, rated speed and the maximum torque in a quick manner. The approach has been employed for the development of a prototype for frame cutting process.