Klaus Zeman

CONSISTENCY CHECKING OF MECHATRONIC DESIGN MODELS

During all phases of the design process there is a need to build models. Hierarchical models are very important tools for complex activities such as engineering design. In engineering of high performance products, mathematical modeling and simulation, i.e. experimenting with computer-based models, is an increasingly important technique for solving problems, evaluating solutions and making decisions. However, large design models may contain thousands of model elements. Designers easily get overwhelmed maintaining the correctness of such design models over time. Not only is it hard to detect new errors when the model changes but it is also hard to keep track of known errors. In the software engineering community this problem is known as a consistency problem and errors in models are known as inconsistencies. This paper presents an approach for consistency checking of mechatronic design models.

Non Circular Arc Temper Rolling Model Considering Radial And Circumferential Work Roll Displacements

Compared to usual cold rolling conditions the length of contact between work roll and strip is very short in case of temper rolling. As a consequence, work roll flattening becomes critical even for small contact pressures, and the simplifying assumption of a “circular arc” contour of the deformed work roll cannot be justified anymore. A new temper rolling model is presented applying a non circular arc theory using a semi‐analytical procedure for the calculation of the elastic work roll deformations based on numerical superposition of influence functions. In addition to the radial displacements of the work roll, also the circumferential displacements, generated mainly by the shear stresses acting on the work roll surface, are taken into account. The circumferential displacements heavily affect the relative speed (slip speed) between the surfaces of work roll and strip, this speed being a crucial input parameter for any friction law. Hence, the evolution of the shear stresses in the roll gap is re‐affected ...

Hierarchical Structuring of Mechatronic Design Models

Abstract Synergies and integration in design set a mechatronic system apart from a traditional, multi-disciplinary system. On the other hand, the increased complexity of mechatronic systems, resulting from the benificial interaction of components from various domains, requests the use of an appropriate design methodology in order to recognize the functionality and performance of a solution already at an early stage of the mechatronic design process and to shorten development time. The mechatronic pillar model outlined in this paper deals with a systematic approach of modeling mechatronic systems by establishing an appropriate model hierarchy. This helps to keep the overview over such systems and to make the interactions, interdependencies and interfaces more transparent.

DesignSpace: an infrastructure for multi-user/multi-tool engineering

The engineering and maintenance of large (software) systems is an inherently collaborative process that involves diverse engineering teams, heterogeneous development artifacts, and different engineering tools. While teams have to collaborate continuously and their artifacts are often related, the tools they use are nearly always independent, single-user applications. These tools range from programming to modeling tools and cover a wide range of engineering disciplines. However, relations among the artifacts across these tools often remain undocumented and are handled in an adhoc manner. Keeping these artifacts in sync continues to be a key engineering challenge. In this paper, we present our vision of the DesignSpace, a novel engineering infrastructure for integrating diverse development artifacts and their relations. The DesignSpace supports distributed collaboration, a wide range of tools and development, maintenance, and evolution services including incremental consistency checking and transformation.

Reduced-order modelling of self-excited, time-periodic systems using the method of Proper Orthogonal Decomposition and the Floquet theory

The mathematical models of dynamical systems become more and more complex, and hence, numerical investigations are a time-consuming process. This is particularly disadvantageous if a repeated evaluation is needed, as is the case in the field of model-based design, for example, where system parameters are subject of variation. Therefore, there exists a necessity for providing compact models which allow for a fast numerical evaluation. Nonetheless, reduced models should reflect at least the principle of system dynamics of the original model. In this contribution, the reduction of dynamical systems with time-periodic coefficients, termed as parametrically excited systems, subjected to self-excitation is addressed. For certain frequencies of the time-periodic coefficients, referred to as parametric antiresonance frequencies, vibration suppression is achieved, as it is known from the literature. It is shown in this article that by using the method of Proper Orthogonal Decomposition (POD) excitation at a parametric antiresonance frequency results in a concentration of the main system dynamics in a subspace of the original solution space. The POD method allows to identify this subspace accurately and to set up reduced models which approximate the stability behaviour of the original model in the vicinity of the antiresonance frequency in a satisfying manner. For the sake of comparison, modally reduced models are established as well.

Understanding the relationship of information in mechatronic design modeling

Understand the information flow during engineering processes of mechatronic systems is an important point for competitive mechatronic engineering. The paper gives an overview about product models used in mechatronic design and analyzes also the flow of information through tools. Furthermore, there is also the need for considering model consistency because if objects and models are independently created and maintained by the various disciplines then correctness is no longer guaranteed. The same is true for objects or models that are transferred from one discipline to another, from one abstraction level to another, or from one design phase to the next one --- if such objects or models are subsequently modified on both ends just as proposed in simultaneous engineering.

Model-Based approach for the reliability prediction of mechatronic systems on the system-level

In general, mechatronic products merge solutions from different engineering disciplines and therefore a mechatronic design process must integrate multiple disciplines as well. There is a critical lack of tools supporting the inter-disciplinary aspects of the development process of mechatronic products, especially in the conceptual design phase. A general approach for the creation of mechatronic system models as well as a simulation-based design process based on system-level simulations was elaborated. Simulations on the system-level are different from those on the discipline-level. They should contribute to a better understanding of the overall system under consideration by the evaluation of system-specific (global) properties that cannot be evaluated on a discipline-specific level. In this paper a model-based approach for the reliability prediction of mechatronic systems on the system-level is presented.

Elasto‐Plastic Simulation Concepts For Profile Transfer And Flatness Prediction In Flat Hot Rolling

For the prediction of the material flow behavior of wide strips in hot and cold rolling, highly sophisticated procedures are essential, which are able to couple the deformation of the strip and the elastic response of the rolls. Especially for thin, wide strips, where the aspect ratio width over thickness is extremely unfavorable for standard FEM‐calculations, the determination of profile transfer and flatness obviously leads to extremely high calculation times with commercial FEM‐programs. Therefore, a tailor‐made FEM‐code for the efficient simulation of the elasto‐plastic material flow inside the roll gap has been developed. The underlying formalism for the strip‐routines is based on pseudo‐steady‐state streamline‐update techniques for the stress‐field, coupled iteratively with the principle of virtual power for the determination of the velocity field and the contact stress distribution between strip and work roll. Coupling of the strip models with the routines for elastic roll stack deflection is a pre...

CONCEPTUAL DESIGN OF MECHATRONIC SYSTEMS AS A RECURRING ELEMENT OF INNOVATION PROCESSES

Abstract In this research work the authors reflect some aspects of state-of-the-art innovation management and product development processes. Furthermore the paper concentrates on an analysis of the phase of conceptual design with a focus on mechatronic design and on product life cycle engineering. The conceptual design phase is an underlying process of innovation, but some steps are recurring in both stages, so one can also use particular know how from conceptual design for other phases of product development and vice versa. The presented considerations for conceptual design of mechatronic systems are not finished yet, some weak points have to be eliminated in the future.

Evaluation of Modular Design Concepts of Complex Mechatronic Systems

Synergies and integration in design set a mechatronic system apart from a traditional, multi-disciplinary system. This paper proposes a method for the modularization and evaluation of different mechatronic design concepts in the early stages of product development processes. In order to consider the specific aspects of complex systems, a design metric is presented, which assists the design engineer in finding the best solution concept. For the description and evaluation of a complex mechatronic system, it is essential to decompose the total system into a hierarchical structure of mechatronic sub-modules. The number of levels in the decomposition, as well as the number of mechatronic modules involved, is indicative of the complexity of the design task.Copyright