Crane Control System with an Industrial Robot

Most of existing industrial robots have much smaller load capacity than their own weight. Therefore it is very difficult for a robot to handle a heavy work such as a steel frame in a construction site. The purpose of this research is to develop a crane control system which can operate heavy works with a small-size robot. In this system a heavy work is suspended by a crane and a robot handles the work. A flexible arm is attached to the robot to avoid impulsive force on grasping the vibrating work. In this system, the robot is position-controlled, while the crane is velocity-controlled by the feedback signal from a strain gauge pasted on the flexible arm. Experiments with an industrial robot proved that this system is very efficient in the utilizing of robots for handling heavy works.