Design of a Robot End-Effector Grabbing Mechanism Based on a Bionic Snake Mouth

Inspired by the bite and swallowing function of a snake’s mouth, a robot end‐effector grabbing mechanism was designed. The grabbing movement is realized by the ‘bite’ function of the bionic snake mouth actuator, and the ‘swallowing’ function insures a continuous grip on the object. To implement the continuous grip function of the new robot end‐effector, the complex motion of a snake’s mouth is simplified into three basic movements based on the anatomy of a snake’s mouth and with a combination of bionics and engineering. The upper jaw consists of a double four‐bar linkage mechanism and the lower jaw mechanism implementing a lateral expansion function are the two elements of the robot end‐effector. The relationship model and the corresponding curves of the actuating force and gripping force are necessary to implement an open‐loop control of the robot end‐effector. Through analysis and simulation, linkage parameters are determined to implement the desired motion.