Statics and Grasp Stiffness Analysis of an Underactuated Cable-Truss Mechanism

Abstract

Although much literature is available on the statics and grasp stiffness analysis of underactuated mechanisms, little research has been done on them of the underactuated cable-truss mechanism. The underactuated cable-truss mechanism grasps the target in the form of envelopment. Considering the grasping characteristics of the mechanism, the research on the relationship between the grasping force and the driving force is extremely important, as well as the study of the grasp stiffness. The statics analysis of an underactuated cable-truss mechanism, constituted by five cable-truss units, was given by means of combining with the vector method and the principle of virtual work in this paper. To prove the correctness of the analysis, the simulation was presented. The stiffness of the cable-truss unit was defined and the curve, showing the influence of the proportion relationship between the essential parameters to the stiffness, was obtained. Then, the stiffness of the mechanism was discussed.