Design And Control Of Universal Underactuated Manipulator

As an important end-effector,underactuated manipulator has always been the focus of research.Because the driving units of under-actuated manipulator are less than the degrees of freedom,its adaptive ability is poor and grasping force control is difficult.In view of this,a general under-actuated manipulator with good adaptive ability and controllable grasping force is developed in this thesis.The manipulator is mounted at the end of the cooperative robot.It can not only grasp objects of different shapes adaptively,but also grasp objects of different hardness nondestructively.At the same time,the development of this kind of manipulator has certain reference significance for the further development of general under-actuated manipulator.This topic comes from the enterprise project "Research on Material Grabbing Manipulator Based on Collaborative Robot".The main contents of this thesis are as follows:(1)The structure of under-actuated manipulator is designed,including finger mechanism,posture adjustment mechanism,transmission mechanism and frame;The kinematics and statics of underactuated manipulator during grasping are analyzed theoretically by using D-H method and virtual work principle.(2)Aiming at the uniformity of grasping force,genetic algorithm is used to determine the optimal parameters of under-actuated finger,and on this basis,the parameters of driving motor are further determined.Monte Carlo method is used to simulate the workspace of under-actuated finger and determine the range of finger motion.The motion and force of the manipulator during the grasping process are analyzed by simulation,and the stability of the manipulator is verified.The strength and stiffness of the key parts of the manipulator are verified by simulation.(3)The control system based on DSP is designed.The microprocessor,power chip,force sensor and stepper motor driver are selected.The hardware circuits of some key control modules are designed,including power module,DC motor driver module,sensor module and communication module.The human-machine control interface and control system software are designed.(4)A prototype of under-actuated manipulator is developed and the force sensor is calibrated.The uniformity,adaptability and controllability of grasping force under different grasping modes are verified by experiments.