Referring to Fig. 1, the AHG has five rotational joints and a moving grip. Joint 1 represents the shoulder base and its axis of motion is z0 position. This joint provides a rotational θ1 angular motion around z0 axis in x0y0 plane. Joint 2 is identified as the shoulder and its axis is perpendicular to Joint 1 axis. It provides an angular motion θ2 in x1y1 plane. z axes of Joint 3 (Elbow) and Joint 4 (Wrist) are parallel to Joint 1 z axis, They provide θ3 and θ4 angular motions in x2y2 and x3y3 planes respectively. Joint 5 is identified as the grip. Its z4 axis is vertical to z3 axis and it provides θ5 angular motion in x4y4 plane. This merger involves a number of hand movement kinematics of the AHG. Each movement involves a number of DOF kinematics whether the motion is up or down.
This AHG movement is limited to X ~ Y movement only. However, the objective of this study is to have an easy controllability of the movement of the fingers in order to get precise angle of each finger movement. To have a smooth and safe movement of arm and fingers, a gear system is applied. A powerful gear system is undeniably important to efficiently move this AHG or even to carry any heavy loads .