Design and analysis of direct teaching robot for human-robot cooperation

The interest in the human-robot cooperative robot has been increased, because it can work together cooperating with human being through physical interaction in the same space. The purpose of this paper is to develop direct teaching robot with high speed and high precision, which enables operator with no robotic experience to easily and conveniently teach robot the task trajectory. In the paper, 7-axis manipulator is designed through analysis of workspace and stiffness of each component are analyzed at each joint. Comparing to stiffness value at each joint, we optimize the link shape. Also, maximum displacement error is calculated at the end-effector using the stiffness of each joint and payload. In addition, applying this x-axis and y-axis stiffness of each joint to kinematic calculation, we achieve the precise kinematic calibration in the various postures.