Use of human-robot collaboration to enhance process monitoring of mechanical joining

Abstract

This paper presents a new form of setting process monitoring for mechanical joining implemented into a human-robot collaboration. The used lightweight robot can be manipulated in an intuitive way. We developed an easy to use hand guiding opportunity for cobots from Universal Robots by providing an URCap. This way such a cobot can be manipulated quickly and precisely with ease by any operator new to the system within minutes. It enables an economic use of hand guiding with an additional hand guiding device. With this device the teach pendant is not needed during the regular operations which simplifies the usage of the cobot. The integrated sensors (primarily a force-torque sensor) collect data, which gives information about the setting process. Several errors (e.g. no rivet head support, angle offset, gap between the sheets) were carried out on a test setup while recording the data for evaluation. The resulting force/torque-time graphs give indication of the occurring error. As a result the classified error can be immediately displayed to the operator for recognizing the need for reworking. In combination with an error avoidance algorithm the overall quality of the product can be sustainably improved.