Abstract:

Most of current mechanical grippers are rigid-structured and have poor adaptive ability to target objects. In order to achieve adaptive grasping, the under-actuated mechanisms are usually employed, leading to complicated structure and controlling difficulty. On the other hand, such under-actuated grippers are generally designed for a specific target object. A soft pneumatic robotic gripper which is easy to be controlled and has strong adaptive ability is designed in this paper. The three-finger soft pneumatic robotic gripper achieves grasping tasks through cooperation of three fiber-reinforced soft bending actuators. It can accomplish the no-damage grasping of fragile items because of the compressibility of gas and the elasticity of soft actuators. After selecting appropriate parameters, soft actuators are manufactured by injecting silicon into 3D-printed molds. With 3D-printed connecting base, air-impermeability of the whole equipment can be guaranteed. The experiments are designed as: Grasping different kinds of object with different size by cooperation between the soft pneumatic gripper and UR robot arm. The results of experiments indicate that this developed gripper can realize the expected no-damage grasping function and has the features such as universal grasping, strong adaptive ability, and easy of control.

Key words: fiber-reinforced structure, soft actuator, soft gripper, adaptive grasping