Design And Control Of The Robot Arm Actuated By Pneumatic Mucsles

The robot arm actuated by pneumatic muscles is one kind of the robot arm with good compliance and it is superior to other robot arms in some cases. For the robot arm system actuated by pneumatic muscles, the joint stiffness regulation, the joint position control, and the finger grasping force control are three key techniques. In this dissertation, the three techniques are studied and some effective methods are proposed. Moreover, a robot arm prototype system actuated by pneumatic muscles is designed to verify those proposed methods. Main works of this dissertation are as follows:The scheme of the robot arm prototype system is presented and this system is composed of three subsystems, i.e. forearm, wrist and gripper. Moreover, the detailed implemented scheme is proposed and the prototype system, which includes the software and hardware, are debugged.For the joint stiffness regulation, the static drive model of pneumatic muscle is improved and stiffness characteristic of the joint is analyzed. The detailed work includes:An improved static drive model of pneumatic muscle is proposed, it can compensate the complicated errors due to various factors by adjusting the contraction ratio. On the basis of the model, the static drive model of the joint is introduced. An indirect measurement method of the joint stiffness is proposed by measuring the static parameters of the joint, and its detailed equation of the joint stiffness is given. Some experiments are performed to validate these works and the results show their effectiveness.For the joint position control, the detailed work includes:Theoretical analysis and experiments proved that PID controller for the joint position control is feasible, effective, However its slow response time doesn't satisfy the need of the trajectory planning for the 4 DOF articulated robot, and so the author proposed to adopt the adaptive and self-learning single neuron PSD controller to improve motion performance of the joint, the controller can adjust adaptively all four parameters, i.e. proportion, integral, differential and gain simultaneously. Experiments show that a good joint position accuracy and a short step response time are achieved.For the finger grasping force control, the detailed work includes:The structure of humanoid two-fingers gripper is designed. The theoretical model of the finger grasping force is developed. The effect of the initial input pressure and the initial...