Mechanical adaptability analysis of underactuated mechanisms

- In order to quantitatively analyze the mechanical adaptability of underactuated mechanisms, a measure is proposed.
- The measure is used for the prediction of underactuated grasping process and the evaluation of mechanical adaptability.
- Three typical compliant underactuated mechanisms are compared in terms of the inherent adaptability.
- The adaptive behaviors of different underactuated mechanisms are analyzed.

Underactuated mechanisms have been implemented in a good number of automation mechanical systems due to their adaptability. There are few measures to quantitatively analyze the mechanical adaptability, although it has been mentioned repeatedly as one of the highlights of underactuated mechanisms in literatures. This paper presents a quantitative analysis methodology for the mechanical adaptability of underactuated mechanisms. Different from compliance, namely the reciprocal of stiffness, the adaptability is presented as an ability of mechanical motion under environment constraint. To quantitatively analyze the adaptive behavior of underactuated mechanisms, a measure based on the relation of force and motion is proposed. The measure is used for the prediction of underactuated grasping process and the evaluation of mechanical adaptability. Meanwhile, we apply this measure to compare the inherent adaptability of three typical compliant underactuated mechanisms, and to analyze the adaptive behavior of other underactuated mechanisms in different structure types.