Performance Influences and selection criteria for actuated joints on redundant parallel mechanisms—by two novel design examples

Abstract

The selection of actuated joints in the limbs of redundant parallel mechanisms (RPMs) is a critical design challenge, as the number of limbs typically exceeds the degree of freedom (DOF). Despite its importance, this issue has received limited attention in the literature. This paper addresses the gap by proposing two examples of 2-DOF RPMs with redundant limbs, analyzing the impact of different actuated joints on the performance of RPMs. One example is a spatial two-translation RPM, and the other is a planar one-translation and one-rotation RPM. The influence of various actuated joints on the kinematic, stiffness, and dynamic performance of these RPMs is thoroughly examined under two actuated joint schemes. A comparative analysis reveals that each scheme has distinct advantages and disadvantages, making them suitable for different applications. Based on this analysis, the paper proposes application scenario requirement-based selection criteria for actuated joints of RPMs. This work provides a clear procedure for actuated joint selection and offers valuable insights into the design and application of RPMs.