Engelbert Westkämper

Combining evolutionary computation and dynamic programming for solving a dynamic facility layout problem

This paper presents an algorithm combining dynamic programming and genetic search for solving a dynamic facility layout problem. While the quadratic assignment formulation of this problem has been deeply investigated there are very few papers solving it for departments of unequal size. We describe a model which can cope with unequal sizes, which may change from one period in time to the next. For each period a genetic algorithm evolves a population of layouts while the dynamic programming provides the evaluation of the fitness of the layouts.

Geometric Segmentation and Object Recognition in Unordered and Incomplete Point Cloud

In applications of optical 3D-measurement techniques segmentation and outlier elimination in point clouds is a tedious and time-consuming task. In this paper, we present a very robust and efficient procedure of segmentation, outlier elimination, and model fitting in point clouds. For an accurate and reliable estimation of the model parameters, we apply orthogonal distance fitting (ODF) algorithms that minimize the square sum of the geometric error distances. The model parameters are grouped and simultaneously estimated in terms of form, position, and rotation parameters, hence providing a very advantageous algorithmic feature for segmentation and object recognition. We give an application example for the proposed procedure which is applied to an unordered and incomplete point cloud containing multiple objects taken by laser radar.

Production Planning and Control with Learning Technologies: Simulation and Optimization of Complex Production Processes

Publisher Summary Since the early 1970s, order processing has increasingly been supported by engineering data processing (EDP) systems in German-speaking countries. This tremendously fast development in data processing has created the ability to cover the entire order processing chain, from customer request to delivery (invoicing). This chapter is based on order management, a new and general approach to production planning and control (PPC) in a turbulent environment. Its basis is the tight link between planning and execution activities in the order management cycle, and it includes an additional learning step. Because of a more reliable manufacturing forecast, more realistic production plans and therefore increased security in planning would follow. This is particularly important when establishing economically successful production in a turbulent environment. This chapter deals with the rough planning components at the individual site of a production network based on neural networks. In contrast to the classical planning procedure that is based on a constant lead-time, artificial neural networks (ANNs) allow planning with variable lead times, depending on the given situation. This chapter shows all of the requirements for such an approach to planning and its limits. The EDP system developed in the course of these tasks is drafted as an “add-on” to the companys existing PPC systems and is realized as a prototype.

Individuelle Softwareunterstützung für jeden Ingenieur: Advanced Engineering Platform for Production

Kurzfassung Die zukünftige Produktionstechnik erfordert neue Arbeitsweisen von Ingenieuren. Sie zeichnen sich durch Mobilität, Interdisziplinarität und Kooperation aus. In diesem Beitrag wird als Antwort auf diese Anforderungen eine Plattform vorgestellt, welche die technologische Voraussetzung und die Umgebung zur Unterstützung dieser neuen Arbeitsweisen bietet. Damit wird ein Beitrag zur Steigerung der Effizienz und der Festigung der Wettbewerbsfähigkeit produzierender Unternehmen geleistet.

Manufacturing in Networks - Competitive Advantages for Virtual Enterprises

Typical aspects of global competition are the regionally different production factors and varying demands on product function, quality and performance. Success is not only a matter of consistent market orientation but increasingly depends on regional contributions to production and employment. Crucial success factors are cooperation, the availability of components in a country, the use of the existing infrastructure, etc. Thus, many companies are building up international production capacities or shifting them to foreign regional markets to sell their products not only at home but also in international markets. They form global networks to which independent partners contribute their individual core competencies.

Design to Life Cycle by Value-Oriented Life Cycle Costing

Industrial products basically have to satisfy the customers’ wants and needs as a basic input as well as technical and ecological requirements while providing maximum economic benefit throughout the life cycle. In the early stages of design and development all these requirements have to be considered in terms of their long-term impacts on the entire product life cycle. The approach discussed in this paper combines quality and value-driven tools with the methodology of life cycle costing including the assessment of environmental aspects. While traditional cost optimising was successful by streamlining operations and returning to core competencies, this approach allows for sustainable cost optimisation in the early stages of product development and correlates with quality planning as well as ecologic product assessment. Based on the Value-Oriented Life Cycle Costing method, product components are evaluated over their life cycle to identify those components incurring high life cycle costs compared to their functional value. In order to achieve an efficient and effective design to life cycle the methods of Quality Function Deployment and Value Analysis are aligned with the methods of Life Cycle Costing and Life Cycle Assessment to be integrated into a comprehensive approach. This paper describes the theoretical background and explains the practical implementation based on a case study. The results of the practical analysis conducted illustrate the optimisation potential to be realised when implementing the approach in comparison to traditional design solutions.

Task-oriented programming of large redundant robot motion

Abstract Large robots are a new domain of advanced robotics. Examples of their application fields are tasks like operations on large free-form surfaces, especially aircraft cleaning and removing paint from hulls. They are equipped with a programmable robot control comparable to a control system used for industrial robots. However, conventional teach-in methods are not able to manage the complexity of programming large redundant robot operation on free-form geometries. The Fraunhofer IPA has developed an innovative off-line programming system that allows the creation of robot motion programs which satisfy time and energy optimization criteria. This system helps to avoid collisions within the workspace and to fulfill conditions that arise from the robot kinematics and dynamics. This advanced programming system has been successfully used to generate motion programs for the world’s largest mobile robot, the aircraft cleaning manipulator SKYWASH. In this context offline programs for eleven different types of aircraft have been developed.

A Reference Model for Factory Engineering and Design

Today factories can be considered as products, which contribute to value creation by efficient transformation of resources into high-adding value products and which have to be continuously adapted. The engineering of future factories requires digital tools to support the life cycle phases from investment planning to ramp-up and scientific-based integrated highly-dynamic data management systems. This paper presents a Reference Model for holistic Factory Engineering and Design and a Grid-based Factory Data Management, centred on a generic Factory Data Model based on state-of-the-art Grid, workflow and digital manufacturing technologies. The developed planning environ-ment, its architecture, the employed technologies, the estimated benefits and a validation scenario are presented and integrated in a Roadmap of current and future research activities in the field of factory engineering and design.

A Method for Multi-Scale Modeling of Production Systems

This paper presents our first research steps aiming at the development of a method for multi-scale modeling of production systems. Thereby the importance to support the modeling process is stated and the motivation for the development of such a method is pointed out. This is followed by the analysis of the state of the art concepts for developing a method to model complex systems. The approach to model a system with less experience and effort and the process of multi-scale modeling of a production system are firstly introduced. It concludes with the selection of suitable enabling technologies and a roadmap.

Automatische Segmentierung von Messpunktwolken in regelgeometrische Elemente (Automatic Segmentation of Measurement Point Clouds to Geometric Primitives)

Abstract Die zu verarbeitenden Messpunktwolken werden auch in der Mikrosystemtechnik durch die Verfügbarkeit leistungsfähiger moderner Sensorik wie z.B. der Mikro-Computertomographie immer größer. Vorgestellt wird ein Verfahren, mit dem Messpunktwolken vollautomatisch in einzelne Teilpunktwolken, die regelgeometrische Elemente beschreiben, segmentiert werden können. In die Teilpunktwolken lassen sich dann für Vermessungen mit Fit-Verfahren die entsprechenden Objekte einpassen.