Structure Design And Control Of Several Freedoms Mechanical Fingers Driven By Pneumatic Artificial Muscles

Wi th the develop ment of the ind ustrial me cha nization and auto matic intelligent, all areas have made great progress, and robot research is one of the most popular objects and has made great progress. The robots are divided into industrial robot and intelligent bionic robot, which have been expanded from the original industry to the health care industry, service industry, agriculture and other fields, and will be pervasive in every family. Pneumatic manipulator is studied in this paper. Compared to general robot, pneumatic manipulator is driven by a new type of running structure, namely pneumatic artificial muscles, having the advantage of simple structure, large power/weight ratio, great safety as well as good flexibility. Pneumatic artificial muscle has been widely applied in biomimetic robots, medical rehabilitation robot and service robot. Under this background, the relevant researches of pneumatic artificial muscle became the favors of the researchers.In this paper, according to the man hands’ characteristics of structure and movement, the manipulator with multiple freedoms driven by pneumatic artificial muscle is designed. The whole structure of manipulator is included by four same fingers, one thumb and one palm. Each finger has three degrees of freedom, which is made up of three joints and some fittings. Pulleys in the finger joints are pulled by the wire ropes which is connected to pneumatic artificial muscle, thus the finger joints can move and rotate, realizing humanoid hand function with a good imitation of nature.In this paper, the main work is as follows:The characteristics of hand structure and hand movement are analyzed, and the manipulator with multiple freedoms driven by pneumatic artificial muscle is designed through the 3D modeling software of UG. The size of the manipulator is 1.5 times bigger than that of man hand, and the manipulator is included by the thumb, the fingers and the palm. The analysis of direct kinematics solution and inverse kinematics solution are performed at the index finger of the manipulator. According the solution results, the finger’s tip movement range can be obtained by MATLAB. The three degrees of freedom of each finger is as follows: flexion and rotation range of the near knuckle of finger is nearly from 0°to 80°, the middle knuckle is nearly from 0°to 90°, the far knuckle is nearly from 0° to 60°.According to the working principle of the pneumatic circuit and control principle of hardware, selection of pneumatic components and hardware is performed, and the movement control principle and the control method of the single joint are analyzed, and the software of the control interface is designed and edited.The whole test rig of pneumatic artificial muscle manipulator is built, and the tracking response experiment of the single joint and the whole manipulator experiment are performed through the control interface, obtaining the movement range of each joint. Then the rationality of the structure of the manipulator and Human-like and flexibility of the manipulator is verified.