A flexible self-adaptive underactuated hand with series passive joints

Abstract

Purpose This paper aims to propose a novel hand to bridge the gap between the traditional rigid robot hands and the soft hands to obtain a better grasping performance. Design/methodology/approach The proposed hand consists of three fingers. Each finger has 15 degrees of freedom and three phalanxes, which can bend in one direction when load is applied, but they are rigid toward the opposite direction at the initial position. The grasping process and simulations of the fingers are discussed in this paper. Both kinematic and dynamics analyses are performed to predict the performance of the hand. Subsequently, a prototype of the hand is developed for experiments. Findings Both kinematics and dynamics analyses indicate good grasping performance of the hand. Simulations and experiments confirm the feasibility of the finger design. The hand can execute hybrid grasping modes with more uniform force distribution and a larger workspace than traditional rigid fingers. The proposed hand has much potential in the industrial sector. Originality/value A new method to obtain better grasping performance and to bridge the gap between the rigid finger and the soft finger has been presented and verified. The hand combines the advantages of both the rigid phalanxes and the soft fingers. Compared with some traditional rigid fingers, the proposed design has a more uniform force distribution and a bigger workspace.