Flexible Automation through Robot-Assisted Mechanical Joining in Small Batches

Abstract

Mechanical joining has become a fully automatable machining type regarding series production. In contrast, many process steps are currently carried out manually in the field of small batch manufacturing. Economic, but above all technological reasons prevent the introduction of highly adaptive solutions with which even small batches can be processed semi-automatically. For example, current joining tools are nowadays not able to detect any deviations before the actual joining process and to adjust the processes accordingly. Existing solutions can usually only eliminate certain sources of errors and are also only designed for use during the teaching phase. This teaching of industrial robots still can be performed by a limited number of trained professionals. Hand guiding or other more intuitive teaching approaches are mainly developed for collaborative robots, but currently available payloads are not suitable for most of the joining scenarios.Therefore, this paper presents an approach to automate joining processes in small batches. For this purpose, the joining tool is coupled to an industrial robot in the payload range of +200 kg and equipped with a hand guiding application. Via this, all necessary process parameters can be controlled and the movement of the robot can be guided. By means of a superimposed system, the robot movements are recorded, stored and can be replayed afterwards. In order to optimize the joining process and make optimum use of the advantage of the applied robot, the joining tool is equipped with additional sensor technology. This allows both positioning and material deviations to be detected before and during the joining process. Through adaptions to the actual conditions, the effects of deviations on the resulting joint quality can be reduced.