Automatic following in a sheet metal bending process

Abstract

Sheet metal bending is a common task in industry manufacturing. Traditionally, a sheet metal is slightly held by a human operator when it is being bent. However, due to shortage of human workers, the bending process is replaced by a robotic system. To have a smooth bending process, a robot system is required to follow the sheet metal while it is being bent and immediately grasp it while the bending process is finished. Thus, the goal of this paper is to assure that the gripper of a robot is able to follow a metal sheet's movement. In other words, while the sheet metal is being bent by a bending machine, the robot can reach this sheet as soon as it has been completely bent. In the system, we use a laser range finder to detect the distance between the sheet and robot and then apply PID control to achieve sheet metal following. In the experiment, we used a DENSO robot to validate the method. The result showed that the robot was able to follow the sheet.