Kinetostatics modeling and analysis of parallel continuum manipulators

Abstract

Parallel continuum manipulators (PCMs) have increasingly attracted attentions in the field of mechanism and robotics, owing to their inherent merits, such as compliance in structure, reduction of backlash, and easiness in implementation. This paper presents a general approach for the kinetostatics modeling and analysis of spatial PCMs. A discretization-based technique is employed for the nonlinear large-deflection problems of the coupled slender flexible links in these flexible parallel manipulators. Benefiting from the mechanism approximation to the force-deflection characteristics of the flexible links, the kinetostatics models of the PCMs can be established analytically in the realm of robot kinematics/statics, rather than continuum mechanics. Moreover, a closed-form solution to the gradient of these nonlinear algebraic equations can be derived, such that gradient-based searching algorithms can be implemented to efficiently determine the equilibrium configurations in a variety of given conditions. A prototype of a three-limb 6-DOF PCM is developed, on which validation experiments are conducted. And the results verify the effectiveness of the proposed method for the kinetostatics modeling and analysis of parallel continuum manipulators.