Eberhard Abele

Zukunft der Produktion: Herausforderungen, Forschungsfelder, Chancen

Der Produktionsstandort Deutschland kann sich im globalen Wettbewerb nur behaupten, wenn die Unternehmen auf die zukunftigen Anforderungen eingestellt sind. Das vorliegende Buch zeigt ausgehend von den Megatrends, welche Aktionsfelder die Produktionsforschung in den nachsten zehn Jahren bearbeiten muss, um vorne dabei zu sein. Sei es der demografische Wandel, neue Technologien, Klimawandel, Ressourcenknappheit oder Mobilitat; jeder dieser Einflussfaktoren verlangt gezielte Anpassungen in der Produktion und im Unternehmen. Das Buch beschreibt, wie diese aussehen sollten: Neue Produkte und Markte, Paradigmenwechsel in Organisation und Management, neue Fertigungstechnologien, nachhaltige Prozesse. Auf jede Herausforderung gibt es Antworten und Handlungsempfehlungen. Ein unverzichtbares Buch fur Fuhrungskrafte, die Zukunft mitgestalten.

Wear Mechanism when Machining Compacted Graphite Iron

Abstract The industrial application of compacted graphite iron in the automotive industry is taking a rather long time due to its uneconomic machinability, because of a significant decrease in tool life. After six years of holistic research of the PTW in cooperation with foundries, manufactures and material scientists, the wear mechanism was understood and clarified: Sulphur in the microstructure of compacted graphite iron has direct influence on the formation of a manganese-sulphur layer on the cutting edge. For machining gray cast iron this layer protects the cutting edge against abrasive wear. Therefore the design of cutting tools for the machining of CGI must consider the absence of manganese-sulphur layer.

Measuring flexibility in investment decisions for manufacturing systems

Investment decisions for manufacturing systems are primarily based on three characteristics: cost of purchase and operation, cycle time in connection with maximum capacity and achievable work piece quality. However, such considerations neglect another important criterion: the flexibility that allows a manufacturing system to adapt to future production requirements and structures. The major barrier in integrating flexibility into the decision-making process is the difficulty to measure and compare it due to upcoming production scenarios that are not ultimately definable. Therefore, this paper presents a methodical concept for the evaluation of manufacturing systems using real options in order to incorporate flexibility in the decision-making process.

Material aspects of chip formation in HSC machining

Abstract Investigations in the past have shown, that chip formation changes by increasing cutting speed, because most of the experimental work had been carried out in the original material stage. In contrary to this new machining investigations were made on an aluminium alloy at different heat treatment states. This investigations confirm that precipitation hardening is the key in changing from continuous to segmented chip formation and not only the cutting parameters. By applying this new knowledge, the relationship between chip formation and cutting forces was examined.

Analyzing Energy Consumption of Machine Tool Spindle Units and Identification of Potential for Improvements of Efficiency

This paper describes the results of the analyses of a representative machine tool spindle unit and the thereof identified potentials for increasing the energy efficiency. This is done within the project “EnergieMSP”, whose aim it is to develop an energy optimized spindle unit with an adapted electric drive train. The holistic analysis of the system is done in a machine tool to determine the consumption of pressurized air, the energy demand for the tool change and hydraulic stand-by losses. The frictional losses in the bearings and rotary union and the electrical drive train where separately investigated at test benches.

Development and design of an active work piece holder driven by piezo actuators

The use of piezo actuators in machine tools is a current topic. There are many research works which show the advantages of this kind of actuators in various fields around machining. In this paper an active work piece holder is presented, which is designed for reducing the dynamic displacement between the tool and the work piece relatively. The paper shows the design process for the fixture, the finite element analysis of the mechanical parts and the actuators. Also a specially designed power amplifier is presented which fits best to the needs of voltage and frequency range of the active work piece holder. First experimental results are shown.

Architecture for Multilevel Monitoring and Control of Energy Consumption

Guaranteeing energy efficient operation of production systems through a-priori optimization is an extremely complex task. We therefore propose an alternative approach where controls can decide locally if an energy reduction is possible and set components to energy-optimal states. In this paper we present results from the research group ECOMATION describing the information flow that generates energy control loops on different levels based on model information and an appropriate communication and control infrastructure. The communication mechanisms and control structures in production systems and machines are presented which allow using models automatically and coherently on all required levels of detail and abstraction.

Creating Stability Lobe Diagrams during Milling

Abstract Motorized spindles are in common use in high-speed milling. The dynamic behavior of the spindle depends on the actual number of revolutions and the temperature. The performance of the spindle during milling, particularly, the behavior concerning chatter, is crucially affected by the speed dependent dynamic behavior of the mechanical system. This paper presents the reasons for the speed-sensitive stiffness and the shifting stability lobes. A new method of measuring and calculating the dynamic behavior during milling by means of sub-space-state-space-identification methods is introduced. Finally, the computed stability lobe diagrams are compared with experimentally determined stability lobe diagrams.

Cartesian compliance model for industrial robots using virtual joints

Industrial robots represent a promising, cost-saving and flexible alternative for machining applications. Due to the kinematics of a vertical articulated robot the system behavior is quite different compared to a conventional machine tool. The robot’s stiffness is not only much smaller but also position dependent in a non-linear way. This article describes the modeling of the robot structure and the identification of its parameters with focus on the analysis of the system’s stiffness. Therefore a method for the calculation of the Cartesian stiffness based on the polar stiffness and the use of the Jacobian matrix is introduced. Furthermore, so called virtual joints are used. With this method it is possible to model each joint of the robot with three degrees of freedom. Beside the gear stiffness the method allows the consideration of the tilting rigidity of the bearing and the link deformations to improve the model accuracy. Based on the results of the parameter identification and the calculation of the Cartesian stiffness the experimental model validation is done.

Learning factory design: a competency-oriented approach integrating three design levels

Developing competencies of employees on all hierarchy levels is a crucial prerequisite to enable fast problem solving and adaption to changing market conditions. Action-oriented learning approaches in learning factories show promising results, though a systematic approach for the design of learning factory courses and systems is missing. This article presents such a systematic approach for the competency-oriented development of learning factories integrating the conceptual design levels ‘learning factory’, ‘teaching module’ and ‘learning situation’. The presented approach enables an effective competency development in learning factories by addressing problems of intuitively designed learning systems. As a result learning factories, teaching modules and single teaching–learning situations meeting industries’ requirements can be realised with less effort and an increased success in applied competencies in real situations.