No abstract

Industrial robot systems offer a flexible, adaptable basis due to their kinematics and their mobility An influencing variable, which is particularly relevant for processes with long process times, is the thermal heating and the associated thermal drift of the tool center point. The maximum deviation from the actual nominal position can reach up to ΔAPt = 1.5 mm. Currently, there are no procedures and methods established in practice which compensate the effects of thermal drift without expensive calibration measures and system downtime. In these investigations a system was developed which allows the reduction of thermally induced displacement by using controlled heating elements. The aim is to keep the entire robot system at a permanent, balanced temperature level. The heating elements are adapted to the geometry of the respective axis and heat the material to a temperature θ close to the steady state. A comparison of the drift through the heating system with the error occurring in normal operation shows that the drift of the heating system is comparable with the drift of normal heating. With the heating mats, a thermally induced error of ΔAPt = 0.234 mm can be generated within t = 20 min. While normal heating requires up to t = 600 min. The achieved error deviation of the drift of the self-heating to the heated variants is with ΔAP = 0.04 mm only minimal. The results can help to reduce the influence of thermal heating and the associated thermal drift of the TCP without using cost-intensive measures with additional hardware and software on external computers for compensating the errors.

Kurzfassung Neben den Investitionskosten und der Leistungsfähigkeit sind die Nutzungskosten und somit auch die Energieeffizienz relevante Faktoren für die Implementierung innovativer und nachhaltiger Technologien. Das Fraunhofer-Institut für Produktionsanlagen und Konstruktionstechnik (IPK) Berlin hat eine Energiebilanz für ein Fräsroboter-system erstellt. Darüber hinaus wurden der Einfluss von anwendungsspezifischen Schnittparametern sowie Pfadstrategien auf die energieoptimierte Nutzung des Systems untersucht. Die Ergebnisse dieser Untersuchung ermöglichen eine energieoptimierte Bahnplanung bereits in CAM-Systemen und können in Energiemanagement-systeme integriert werden. Insgesamt können die Ergebnisse helfen, die robotergeführte Bearbeitung für neue Industriebereiche zu qualiizieren.

Industrie 4.0 – die Produktion der Zukunft und die flexible Herstellung kundenindividueller Produkte: Doch neben der Nutzung von cyberphysikalischen Systemen und der intelligenten Vernetzung sind es am Ende noch immer die Fertigungstechnologien und Anlagensystem, die ein Bauteil herstellen. Neben den 3D-Druckverfahren, die das Portfolio an verfügbaren Herstellungsprozessen signifikant erweitern, bietet auch der Einsatz von Industrierobotern ein großes Potenzial, die Fertigung zu revolutionieren. Sich autonom bewegende und selbst organisierende Bearbeitungsmaschinen, die jeden Schritt der Produktion an beliebigen Stellen der Herstellungskette realisieren können, erscheinen realistisch. Der Fachartikel fasst zusammen, welche Potenziale und Möglichkeiten die robotergeführte Bearbeitung bereits heute bietet und welche Hindernisse es zu überwinden gilt.   Industry 4.0 – Production of the future and the flexible fabrication of customized products. But beside the use of cyber physical systems and the intelligent linkage of machine tools, the manufacturing technologies and machine tools are the core of each production chain. 3D-printing technologies for example significantly expand the portfolio of production technologies. Furthermore the usage of industrial robots for machining tasks can fundamentally change today’s production. Autonomously moving and self organized machine tools based on robot guided machining seem to be possible. The article sums up the potentials and possibilities of the robot guided machining and shows the current obstacles.

Robotic machining is an alternative to manufacturing processes that combines the technologies of a high-performance machine tool with the flexibility of a 6-axis jointed arm robot. With their large working area, industrial robots are of particular interest for processing large-volume components and large structures, like aircraft components. An influencing variable, which is particularly relevant for milling processes with industrial robots are the cutting force F and the resulting dimensional deviation D. Milling tests of titanium alloys were carried out with an industrial robot and the results compared with a conventional machine tool. Due to the low thermal conductivity and high chemical reactivity of the Ti-6Al-4V alloy, heat is generated and increases the temperature in the contact region of the cutting tool/work piece. That has an impact on the cutting tool wear and increases the cutting force F, and consequently, the dimensional deviation D and the machined surface quality. The aim of the investigations is to find a suitable parameter selection and machining strategy for machining titanium alloys with minimal deviation D and an appropriate surface finish.