Design and Experiment of Constant-Force Grippers

• Main Authors: Jung-YuanWang, 王俊元
• Other Authors: Chao-Chieh Lan
• Format: Others
• Language: zh-TW
• Published: 2012
• Online Access: http://ndltd.ncl.edu.tw/handle/14395135934897920840

碩士 === 國立成功大學 === 機械工程學系碩博士班 === 101 === This research presents the design, simulation, and experiment of compliant grippers that can provide a constant gripping force to handle objects of various stiffness and size. Maintaining a proper gripping force is a challenging task of grippers used for manipulating delicate objects with uncertain sizes and stiffnesses. To avoid damage and provide a stable grip of an object, force feedback is often required so that the gripping force can be directly or indirectly regulated. Without using additional sensors and control, the proposed grippers passively maintain a constant contact force between fingertip and an object given a pre-specified force magnitude. Two types of grippers are designed to generate a nearly constant contact force regardless of object stiffness and size. The first gripper consists of a symmetric flexible mechanism that can generate a constant torque regardless of input rotation. The constant torque is converted to a constant force through an adjustable lever arm and then transmitted to fingertips. The other is designed to have a constant input force generated by a constant-force mechanism. Transmitted through a statically balanced mechanism, a constant gripping force is obtained at the fingertip. After a formulation to find the optimal gripper shape, both designs are verified by comparing with simulation results. Prototypes are illustrated with experimental demonstrations. These novel grippers are expected to serve as a reliable alternative for object manipulation.