Vakuumgreifer : Flexibilitätssteigerung durch Anpassung an das Teilespektrum

Die Montage stellt nach wie vor einen Kernbereich zukünftiger Rationalisierungsmaßnahmen innerhalb der Produktion dar. Dabei kommen robotergeführten Greifern und Montagewerkzeugen eine große Bedeutung zu. Durch den Trend zur Typen- und Variantenvielfalt bei gleichzeitiger Abnahme der Losgröße und die daraus resultierende Zunahme unterschiedlicher Baugrößen der Elemente und Bauteile steigen auch die Anforderungen an die Flexibilität des Greifers. Nicht ein Greifer für ein Bauteil sondern ein flexibler Greifer für verschiedene Bauteilgrößen ist das Ziel der Greiferentwicklung und -auslegung. Im folgenden wird ein flexibler Greifer zur Montage von Paßscheiben vorgestellt

A systematic approach to automated gear assembly

Automated assembly of gear wheels requires exact orientation of the tooth profiles in order to avoid collision and damage during the joining process. Various tactile and contactless methods can be applied for the orientation of gear wheels. A systematic overview of these methods is compiled in the presented paper. As a conclusion of research carried out at the Institute for Machine Tools, setups for contactless orientation detection using inexpensive senor devices show significant advantages. Application of these methods and sensor concepts contributes to the realization of economical operation of automated assembly systems

Montagezelle zur Getriebemontage

Am Institut für Werkzeugmaschinen (IfW) der Universität Stuttgart wird im Rahmen des von der Deutschen Forschungsgemeinschaft getragenen Sonderforschungsbereichs 158 "Die Montage im flexiblen Produktionsbetrieb" eine flexible, automatisierte Montagezelle zur Getriebemontage aufgebaut. Im vorliegenden Beitrag wird Aufbau und Betrieb der Montagezelle beschrieben

Predicting the solubility of pharmaceutical cocrystals in solvent/anti-solvent mixtures

In this work, the solubilities of pharmaceutical cocrystals in solvent/anti-solvent systems were predicted using PC-SAFT in order to increase the efficiency of cocrystal formation processes. Modeling results and experimental data were compared for the cocrystal system nicotinamide/succinic acid (2:1) in the solvent/anti-solvent mixtures ethanol/water, ethanol/acetonitrile and ethanol/ethyl acetate at 298.15 K and in the ethanol/ethyl acetate mixture also at 310.15 K. The solubility of the investigated cocrystal slightly increased when adding small amounts of anti-solvent to the solvent, but drastically decreased for high anti-solvent amounts. Furthermore, the solubilities of nicotinamide, succinic acid and the cocrystal in the considered solvent/anti-solvent mixtures showed strong deviations from ideal-solution behavior. However, by accounting for the thermodynamic non-ideality of the components, PC-SAFT is able to predict the solubilities in all above-mentioned solvent/anti-solvent systems in good agreement with the experimental data

Fake News on Social Media: The (In)Effectiveness of Warning Messages

Warning messages are being discussed as a possible mechanism to contain the circulation of false information on social media. Their effectiveness for this purpose, however, is unclear. This article describes a survey experiment carried out to test two de

Embedding Mathematical Techniques in System Engineering

Some of the reasons why formal methods have not been widely accepted in practice are analyzed. This analysis provides the basis for a more modest approach to embedding mathematical and formal techniques into the system design process: identifying points in traditional design methodologies where formal reasoning can be convincingly introduced. A general outline of the approach is given, its use being illustrated by overviews of three different research activities. Keywords: Formal methods; dynamic simulation; object-oriented design; traditional design methods. 1 Formal Methods' Chronic Crisis The quest for abstraction and structuring concepts has been one of the driving forces in the development of programming languages and design methods. It is generally accepted that such concepts increase productivity, reduce the amount of errors made, and support maintenance and reuse. And the list of their advantages could be continued. The recent success of object-oriented concepts is merely one..

How explicit are the barriers to failure in safety arguments?

Safety cases embody arguments that demonstrate how safety properties of a system are upheld. Such cases implicitly document the barriers that must exist between hazards and vulnerable components of a system. For safety certification, it is the analysis of these barriers that provide confidence in the safety of the system. The explicit representation of hazard barriers can provide additional insight for the design and evaluation of system safety. They can be identified in a hazard analysis to allow analysts to reflect on particular design choices. Barrier existence in a live system can be mapped to abstract barrier representations to provide both verification of barrier existence and a basis for quantitative measures between the predicted barrier behaviour and performance of the actual barrier. This paper explores the first stage of this process, the binding between explicit mitigation arguments in hazard analysis and the barrier concept. Examples from the domains of computer-assisted detection in mammography and free route airspace feasibility are examined and the implications for system certification are considered