Operation Capability Analysis and Experiments of Underactuated Compliant Multi-Fingered Hands

In this paper, operation capabilities of underactuated compliant robot hands have been investigated based on the shape stability analysis of underactuated compliant fingers and operation modes analysis of human hands. It is shown that the operation modes of robot hands can be classified into two major classes, namely, enveloping grasp mode and pinch mode. For the two operation modes, two principles are respectively presented with regard to the mechanical design issues of the underactuated robot hands. According to the principles presented in this paper, a robot hand prototype with four underactuated compliant fingers has been fabricated. On the robot hand prototype, enveloping grasp capability of underactuated compliant robot hands has been verified by many experiments. For precision operations, a proposition is presented and it is shown that the prototype should be further improved.