Is a Linear Axis Really Required When Assembling Parts to a Moving Conveyor?

Abstract

Assembly tasks at a conveyor are usually executed using a robot that is mounted on a linear axis. In this way the robot is moved in parallel to the conveyor, such that control is almost as with a fixed object. Control without such a linear axis is more demanding as the conveyor motion has to be overlaid to the normal motion of the robot arm. This requires high path accuracy instead of high pose accuracy. In addition there are kinematic restrictions and a more difficult fault management that have to be considered.