Dynamic modeling and performance analysis of the 2PRU-PUU parallel mechanism

Abstract. This paper investigates the dynamic modeling and performance analysis of the 2PRU-PUU reconfigurable parallel mechanism (RPM); here, P, R, and U denote the prismatic, revolute, and universal joints, respectively. By altering one of the rotation axes of the reconfigurable universal joint in limb 3, the mechanism can be switched into two operation modes, 1R2T and 2R1T. The authors resort to the Lagrangian equations of the first kind to derive the dynamic model of the 2PRU-PUU RPM. The optimal driving force distribution is determined to solve the problem of the non-uniqueness solution in dynamic analysis. The dynamic formulations are verified with the results obtained in ADAMS software. The dynamic manipulability ellipsoid index, which offers a quantitative assessment of the ability in manipulating the end effector, is used to assess the dynamic performance of the mechanism. Then, the distribution characteristics of the rotational and translational dynamic performance of the RPM are derived.