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Roland Lachmayer

Bio: Roland Lachmayer is an academic researcher from Leibniz University of Hanover. The author has contributed to research in topics: New product development & Computer science. The author has an hindex of 12, co-authored 211 publications receiving 822 citations.


Papers
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Patent
27 Feb 1998
TL;DR: In this paper, a headlamp has a saucer-shaped reflector with two focuses, and an adjustable screen is located between the reflector and a lens, which can be adjusted into positions providing high-beam and low-beam light.
Abstract: A headlamp has a saucer-shaped reflector (1) with two focuses. A light source (2) is positioned at an inner focus. An adjustable screen (4) is located between the reflector and a lens (3), and can be adjusted into positions providing high-beam and low-beam light. A bracket (5) has an area below the adjustable screen that serves as a shielding element for light beams from the light source, and as a holder for a remote-controlled adjusting device (6).

48 citations

Journal ArticleDOI
TL;DR: A short overview on highly dynamic front lighting systems and the essential technologies for their realization and different approaches are compared and evaluated regarding their applications for headlamp systems.
Abstract: Abstract The introduction of adaptive front lighting systems for vehicles has increased road safety and drivers’ comfort significantly within the last years. A next step in this development is the realization of higher resolution systems to further increase the functionality of vehicle headlamps toward fully adaptive front lighting systems. In this paper, we present a short overview on highly dynamic front lighting systems and the essential technologies for their realization. Different approaches are compared and evaluated regarding their applications for headlamp systems. As an example for on-road projection systems, a laser-based scanning unit is set up and evaluated.

31 citations

Journal ArticleDOI
TL;DR: A literature-based network model of how modular product structures affect firm’s economics across the design-to-manufacturing life cycle phases is presented, revealing that in design, an increase of commonality drove component reuse leading to lower development costs per unit and in production, it was found that a smaller variety of components allowed less process variety, leading to fewer and more optimized processes and therefore lower production costs.
Abstract: Research in modularization of product families reveals numerous individual cause and effect impacts of modularity on a firm. There are clearly many interrelated positive and negative economic impacts arising from different activities of the firm impacted by the modular product structures. This makes the construction of an economic business case for modularity difficult, where often the benefits are reduced indirect costs. This paper presents a literature-based network model of how modular product structures affect firm's economics across the design-to-manufacturing life cycle phases. It shows how (1) changes on modularity properties may lead to (2) different effects within the product's life cycle phases that (3) have an economic impact on the firm. For instance, modularization can prolong development time of a platform, while shortening the subsequent development times of product variants and lowering manufacturing costs. To validate the proposed model, the given effect chains were compared by industrial experts against nine case study modularization projects by marking effects that were experienced and observed in their projects. The results first revealed that in design, an increase of commonality drove component reuse leading to lower development costs per unit. Second, in procurement, it was found that increased modularity caused better predictability, less purchasing orders, and better purchasing conditions that ultimately lead to lower costs. Third, in production, it was found that a smaller variety of components allowed less process variety, leading to fewer and more optimized processes and therefore lower production costs. We present these cause and effect impacts of modularity as drivers for quantifying the economic impact of modularity.

23 citations

Journal ArticleDOI
TL;DR: In this paper, the effect of particle damping on laser powder bed fusion (LPBF) manufactured beam structures made of AlSi10Mg is evaluated in terms of performance curves for different beam parameter sets.
Abstract: Damping mechanisms are a crucial factor for influencing the vibration behavior of dynamic systems. In many applications vibrations are undesirable and need to be reduced by appropriate measures. For instance, vibrations in vehicles can reduce driving comfort or in civil engineering resonance damage can occur in constructions. An interesting and cost-effective way of increasing damping is particle damping. In modern processes of additive manufacturing, like laser powder bed fusion (LPBF), unmelted powder can be left inside a structure on purpose after making and thus producing integrated particle dampers already. Additively manufactured particle damping has not yet reached the industrial level because there are no detailed specifications for the design process. This includes the modelling of (non-linear) dynamic properties, based on numerous design parameters. The state of the art reveals that the effect of particle damping has been convincingly demonstrated, but transferability of the obtained information is still limited. In this paper the effect of particle damping is investigated experimentally with LPBF manufactured beam structures made of AlSi10Mg. Particle damping is evaluated in terms of performance curves for different beam parameter sets. The aim is to help the designer, who needs to keep amplitudes in certain range to estimate the damping of the potential particle damper via the given performance curves. Damping is determined via experimental modal analysis by impulse excitation. The response is evaluated in the frequency domain using the Circle-Fit method with a focus on the beams first bending mode of vibration. Beyond that, a significantly increased damping could be verified up to the seventh bending mode covering a frequency range between 600 Hz and 18 kHz. Damping through particle-filled cavities shows up to 20 times higher damping compared to the same component with fused powder.

23 citations


Cited by
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01 Jan 2016
TL;DR: In this paper, the authors present the principles of optics electromagnetic theory of propagation interference and diffraction of light, which can be used to find a good book with a cup of coffee in the afternoon, instead of facing with some infectious bugs inside their computer.
Abstract: Thank you for reading principles of optics electromagnetic theory of propagation interference and diffraction of light. As you may know, people have search hundreds times for their favorite novels like this principles of optics electromagnetic theory of propagation interference and diffraction of light, but end up in harmful downloads. Rather than enjoying a good book with a cup of coffee in the afternoon, instead they are facing with some infectious bugs inside their computer.

2,213 citations

08 Nov 2014
TL;DR: A knowledge representation schema for design called design prototypes is introduced and described to provide a suitable framework to distinguish routine, innovative, and creative design.
Abstract: A prevalent and pervasive view of designing is that it can be modeled using variables and decisions made about what values should be taken by these variables. The activity of designing is carried out with the expectation that the designed artifact will operate in the natural world and the social world. These worlds impose constraints on the variables and their values; so, design could be described as a goal-oriented, constrained, decision- making activity. However, design distinguish- es itself from other similarly described activities not only by its domain but also by additional necessary features. Designing involves exploration, exploring what variables might be appropriate. The process of explo- ration involves both goal variables and deci- sion variables. In addition, designing involves learning: Part of the exploration activity is learning about emerging features as a design proceeds. Finally, design activity occurs within two contexts: the context within which the designer operates and the context produced by the developing design itself. The designer’s perception of what the context is affects the implication of the context on the design. The context shifts as the designer’s perceptions change. Design activity can be now characterized as a goal-oriented, con- strained, decision-making, exploration, and learning activity that operates within a con- text that depends on the designer’s percep- tion of the context.

1,697 citations

Journal Article
TL;DR: This study reviews several of the most commonly used inductive teaching methods, including inquiry learning, problem-based learning, project-basedLearning, case-based teaching, discovery learning, and just-in-time teaching, and defines each method, highlights commonalities and specific differences, and reviews research on the effectiveness.
Abstract: Traditional engineering instruction is deductive, beginning with theories and progressing to the applications of those theories Alternative teaching approaches are more inductive Topics are introduced by presenting specific observations, case studies or problems, and theories are taught or the students are helped to discover them only after the need to know them has been established This study reviews several of the most commonly used inductive teaching methods, including inquiry learning, problem-based learning, project-based learning, case-based teaching, discovery learning, and just-in-time teaching The paper defines each method, highlights commonalities and specific differences, and reviews research on the effectiveness of the methods While the strength of the evidence varies from one method to another, inductive methods are consistently found to be at least equal to, and in general more effective than, traditional deductive methods for achieving a broad range of learning outcomes

1,673 citations

Journal ArticleDOI
01 Jan 1977-Nature
TL;DR: Bergh and P.J.Dean as discussed by the authors proposed a light-emitting diode (LEDD) for light-aware Diodes, which was shown to have promising performance.
Abstract: Light-Emitting Diodes. (Monographs in Electrical and Electronic Engineering.) By A. A. Bergh and P. J. Dean. Pp. viii+591. (Clarendon: Oxford; Oxford University: London, 1976.) £22.

1,560 citations