Optimal Design of Underactuated Fingers

Introduction

This chapter presents the optimal design of underactuated fingers considering several issues among which the force isotropy of the grasp, i.e., its ability to generate a uniform pressure on the object seized, its stability, and the Cartesian directions of contact forces. First, the force isotropy property is defined and a method to achieve the latter is presented. Its robustness with respect to undesired variations of the design parameters is also discussed. Second, guidelines to minimize or completely avoid ejection are presented as well as their influence on the desired optimality. The occurrence of the situations where one phalanx force is negative should be decreased (prevention is impossible as established in Section 4.2.7, at least with our model of underactuated fingers) and the ejection should be avoided.