Design and Control Strategy for a 5 DOF Above-Elbow Prosthetic Arm

This paper presents a five degree of freedom (DOF) prosthetic arm that is designed for above-elbow (AE) amputees to increase their mobility in daily life activities. The mechanical design and control strategy of the prosthetic arm are proposed. The proposed prosthetic arm is assumed to be controlled using a combination of a muscle electromyogram (EMG) based controller and a task oriented kinematics based controller. A fuzzy rule based EMG controller that uses the EMG signals of residual arm muscles is designed to control the prosthesis elbow and hand motion. The residual upper arm and the prosthesis elbow joint kinematics are used as input information for the kinematics based controller to control the prosthesis 2 DOF wrist and forearm motion. An artificial neural network based classifier that classifies the daily life activities based on the joint kinematics has been designed for the kinematics based controller. After the classification, the inverse kinematic technique is applied to calculate the desired wrist and forearm angles in order to realize the classified task. The kinematics of the arm was acquired with a motion capture system while performing the selected activities. The effectiveness of the proposed controller is evaluated through experiments.