Research On The Grasper Based On Underactuated Mechanism

There is a contradiction among degree of freedom, drive, weight, agility, grasp ability and reliability of the robot grasper. Aiming at this reason, inside and outside researchers have done vast research. The underactuated mechanism is the machine that has lesser drivers compare with the amount of the degree of freedom. The robot grasper based on underactuated mechanism is simple and strongly grasp, the mechanism has the ability of adapting to the shape of the object. It can fold completely when the grasper snatches at the object, and solve the problem of robot grasper at present.This paper design a robot grasper based on the underactuated mechanism, it composed of four bar linkage and parallel limit machine. This grasper has the character of simple structure, light weight, strongly grasp and conveniently operate. This grasper has 3 fingers, use 4 drive elements to drive 11 DOF. In order to ensure the reliably grasp the position of the 3 fingers transferred adapting to the shape of the object. It can work on objects of different shape and size.The theory and drive mode of the underactuated robot grasper have been researched in this paper, and the mechanism has been designed and optimized. The grasper is driven by hydraulic pressure, has strong drive strength and simple structure. The research has been done on statics, dynamics and kinematics. Using the software ANSYS, the statics analysis and intensity analysis have been done on some of the parts. The emulation on dynamics and kinematics of the grasper grasp different object (as staff, ball, column) has been done. Tactile sensor based on PVDF has been designed. This sensor can measure the signal of feeling, slip and strength. It's proved by experiments that the sensor can satisfy the practical request and make good in work.By using Pro/E, 3D models for all parts are build, the relative relation of the movement parts are analysed, assemble sequence is drawn reasonablely and entity model of the underactuated grasper is creat. The kinematics characteristic and statics characteristic for the single finger of the robot grasper is analysised.