Mechanism Design And Motion Control Realization Of Seven Freedoms Robotic Arm Driven By Pneumatic Artificial Muscles

With the development of industrial mechanization, automation and the advantages of pneumatic technology, pneumatic manipulator has been widely used in various industries. Pneumatic muscle actuator (PMA) is a new type of pneumatic actuator, which has simple construction, highest power/weight ratio, good flexibility. So it has broadly used in the area of biomorphic robotics, bionic medicine, service robot and so on. Robotic arm, which is driven by PMA, has good flexibility. And it has many advantages in many fields. The joints'turning adjusting, position control and remote control are the most important problems in the system of the pneumatic robotic arm. In this paper, a new pneumatic robotic arm is improved based on the original pneumatic robotic arm, and the key technology of the new arm is studied. Then, the key technology is detail checked by the experiment results. The main research works of this paper are as follows:Combined with real measured data,and based on considering the ends influence, rubber elasticity of PMA and friction between rubber tube and braided cords, the relationship among the output force, stress and muscle length is obtained. A relatively simple but integrated mathematic model of the PMA output force is built. The mathematic model is proved by using Kinematical Analysis.One seven degrees of freedom robotic arm driven by pneumatic artificial muscles is designed, which includes wrist, elbow and shoulder. The wrist and elbow adopt Hooke's joint to realize hand up and down, right and left, and forearm curved and twisted. The shoulder joint has three independent executing agencies to realize the entire arm rotating, flexion and lifting movements. The rationality of the arm is verified through the motion simulation, and each joint theory angle is obtained. Through kinematics analysis, the relationship between joint angle and the end of robotic arm is obtained.In this paper, PID controller is used in the joint closed-loop control. The feasibility and effectiveness of the PID controller is proved by the experiments. However, the PID controller response time is too long and doesn't satisfy the need of trajectory planning for mechanical arm, the adaptive and self-learning single neuron adaptive PID controller is designed to improve motion performance of the joint. Experiments show that a good joint's position accuracy and a short response time are achieved.The remote control system is designed based on a wireless transceiver nRF905 and 51 microcontroller chip, which can be used in the pneumatic mechanical arm. The control area of remote control system and the movement of pneumatic muscle manipulator joint were studied. The results indicate that using the remote control system, in the area of 100m indoor, can be able to remotely control better, and reliable operation.