Stephan Rudolph

University of Stuttgart · Institute of Aircraft Design

The packing of given hydraulic equipment together with the hydraulic piping is a challenging design task. Both the hydraulic domain and the geometry domain are highly intercoupled as the packing determines the exact location of the connection points and tangents for the pipes but also defines the installation spaces for the equipment to be position...

The development of electric gerotor pumps is a complex multiphysical optimization problem. To develop optimal systems, accurate simulation models are required to increase digital reliability. An important challenge is the accurate prediction of the pump behavior for extreme temperatures in automotive applications from −40 °C to 110 °C, where the vi...

Pipe design in 3D is typically characterized by competing objectives, since the different design objectives, such as the reduction of length, weight, number of bends, manufacturing cost and overall angle sum, are examples for such competing design goals, where one goal is often at the expense of the other. The origin of these competing design goals...

The implementation of a fully instrumented, automated and simulation-enabled engineering software platform capable of automating the currently still manual model-based systems engineering (MBSE) design process for physical systems architecture generation and optimization in an aircraft wing is presented. The software platform uses graph-based desig...

In engineering and architecture, different approaches have been developed that share the use of graph transformation to automate design processes or to search for design solutions by means of computational design synthesis. In order to give an overview of these approaches, we provide a review of articles published in the last decade. Forty-eight ar...

Vorwort Nur noch sieben Jahre bis 2030, dem Jahr, in dem wichtige Meilensteine der EU- und der deutschen Klimapolitik sowie vieler Industrieunternehmen auf dem Weg zu einer „net-zero“- Betriebsweise erreicht sein sollen! In dieser Zeit müssen die Konzepte entwickelt und zumindest großtechnisch erprobt werden, die uns dann im Zeitfenster 2045-2050 w...

The main focus of this paper is the integration of an integrated function modeling (IFM) framework in an engineering framework based on graph-based design languages (GBDLs). Over the last decade, GBDLs have received increasing attention as they offer a promising approach for addressing several important challenges in engineering, such as the freque...

The design rationale describes the justification of design decision or selection. To avoid unnecessary design iterations, a capturing and documentation of this rationale is highly desirable. In digital engineering processes it is of imminent importance not only to document the evaluation processes behind this rationale but to make them repeatable a...

System design in an aircraft is still a costly, manual and iterative approach. One major cost driver of changes in system installation are design efforts for creating new pipes in an earlier stage and the costs accumulated during the in service life. To reduce these costs and the time to market, an automation approach with an integrated design opti...

System design in an aircraft is still a costly, manual and iterative approach. One major cost driver of changes in system installation are design efforts for creating new pipes in an earlier stage and the costs accumulated during the in service life. To reduce these costs and the time to market, an automation approach with an integrated design opti...

In engineering, design decisions in one domain exhibit multiple consequences in other domains. These consequences result from the often more or less hidden coupling between the different design domains. In order to examine these consequences, models need to be created. In practice, this is challenging due to the exchange of data between different e...

In this paper, a combination of graph-based design and simulation-based engineering (SBE) into a new concept called Executable Integrative Product-Production Model (EIPPM) is elaborated. Today, the first collaborative process in engineering for all mechatronic disciplines is the virtual commissioning phase. The authors see a hitherto untapped poten...

Graph-based design languages have received increasing attention in the research community, because they offer a promising approach to address several major issues in engineering, e.g., the frequent manual data transfer between computer-aided design (CAD) and computer-aided engineering (CAE) systems. Currently, these issues prevent the realization o...

Over the last 20 years design automation using the concept of so-called graph-based design languages has grown in the Similarity Mechanics Group at the University of Stuttgart from its early infancy to nowadays real-world industrial applications. Due to the availability of a translation machine for these design languages in form of a so-called desi...

For the last two decades, a novel mechanical system has received increasing attention—the inerter. An inerter is a system that can store mechanical energy for a rather short amount of time and behaves analogously to a capacitor in electrical engineering. Until today, only a few inerter applications have been reported. In a vehicle suspension, an in...

This paper presents a novel approach to include a holistic description of abstract physics in a digital engineering framework. Physical phenomena realize the numerous functions of technical systems and are an important link between rather abstract product functions and the concrete product geometry and material. Until now, a possibility to integrat...

In a market-driven economy, the availability of an evaluation of the manufacturability cost and economic efficiency right on from the early design phase is a competitive advantage. For this reason, a methodology is proposed in this work which enhances the planning capabilities and efficiency by automatic provision of steel constructions with manufa...

In this paper, the authors elaborate a combination of graph-based design and simulation-based engineering into a new concept called Executable Integrative Product-Production Model (EIPPM). Today, the first collaborative process in engineering for all mechatronic disciplines is the virtual commissioning phase. Therefore, Digital Twins (DT) are model...

In order to best match individual customer requirements in gearbox applications, customer-tailored gearboxes are a desirable solution. That leads to the demand for a truly individualized product development. In order to keep costs down despite an increasing product variability, novel digital design methods which automate the design process and avoi...

In a market-driven economy, the availability of an evaluation of the manufacturability cost and economic efficiency right on from the early design phase is a competitive advantage. For this reason, a methodology is proposed in this work which enhances the planning capabilities and efficiency by automatic provision of steel constructions with manufa...

The paper describes a physics based reconstruction algorithm for the generation of clean, parametric, beam like native CAD structures from density based topology optimization (TO) results. As an algorithmic key element in this process, a physics based stress tensor criteria available from density based TO results is used in the automated TO result...

Graph-based design languages aim at the holistic digital design and representation of complex industrial products. These languages are based on the structure of natural languages, in which the vocabulary and the rules define a language grammar. The translation of the abstract graph-based design language into multiple specific domain-dependent engin...

Model-Based Systems Engineering (MBSE) structures the design process in form of a V-Model. Along the V-Model, the tasks of model creation, editing and design change propagation to maintain model consistency requires manually much time, effort and cost. While formal languages such as the Unified Modeling Language (UML) or the Systems Modeling Langua...

Scope of this research is a holistic, completely digital representation of product development processes. The proposed process is implemented by graph-based design languages based on diagrams of Unified-Modelling-Language. The unique approach allows an automatic generation and evaluation of multiple product variants and is illustrated by the develo...

Der Bericht ist ausschließlich als PDF-Dokument erschienen! Drei Konferenzen in einer, auf 1.874 Seiten finden Sie jede Menge aller neueste Informationen zum Thema Gears. Die beiden anderen Konferenzen waren: 3rd International Conference on High Performance Plastic Gears 2019 und 3rd International Conference on Gear Production 2019 Achtung: Dieser...

Graph-based design languages are presented as a method to encode and automate the complete design process and the final optimization of the product or complex system. The Unified Modeling Language (UML) is used to represent the design language which models the design process. A design language consists of a vocabulary (i.e. the digital building blo...

Most modern digital approaches to engineering are based on models and their model transformations. Most of these model transformations are mathematically speaking non-bijective mappings – so-called projections – where some information of the original model is lost during the mapping. From a theoretical point of view it is therefore of great interes...

Graph-based design languages in UML (Unified Modeling Language) are presented as a method to encode and automate the complete design process and the final optimization of the product or complex system. A design language consists of a vocabulary (digital building blocks) and a set of rules (digital composition knowledge) along with an executable seq...

Today, the product development process is characterized by increasing diversity. A trend towards customer-tailored products can be observed. This trend demands new processes for product development and manufacturing. Increasing product individuality up to lot size one can be faced with methods, which automate the design process and avoid redundant...

‘Industrie 4.0’ based production systems are likely to change the way future products are manufactured. As information technology gains influence on these systems there is a chance of higher flexibility due to decentralized logic and artificial intelligence. All this leads to a higher complexity and also indeterminism is feasible. Therefore simulat...

For several decades, a wide-spread consensus concerning the enormous importance of an in-depth clarification of the specifications of a product has been observed. A weak clarification of specifications is repeatedly listed as a main cause for the failure of product development projects. Requirements, which can be defined as the purpose, goals, cons...

In recent years the research concerning the representation of product functions has intensified again. Current studies exhibit a growing interest of design engineers to apply such representations in their daily practice. Simultaneously, a growing interest concerning graph-based methods for the digital representation of product models and the pro...

Car Manufacturers are subject to continuous and fundamental changes. Already today increasing time pressure, rising complexity and a soaring cost pressure require a shorter time to market. As assembly planning is one of car manufacturers' core competence an innovative approach to adapt the processes is needed. This paper presents the early idea of...

Today, the product development process is characterized by increasing diversity. A trend towards customer-tailored products can be observed. This trend demands new processes for product development and manufacturing. Increasing product individuality up to lot size one can be faced with methods, which automate the design process and avoid redundant...

Graph-based design languages are used in this work to implement individualized mass customization. Using coffee machines as examples, the individualization of the product architecture and geometry is demonstrated. Combined with a user interface, a “coffee maker language” is shown to automate the design process including topological and parametric p...

Combining subsystems to build a fully integrated product is a challenging task in complex systems design. The integration of flow components requires a fast creation and validation of different pipe route variants. In this article an algorithm for the automated generation of pipe routes in a given installation space is presented. The pipe route gen...

This second in a series of three papers [1,2] describes the combination of an analytical model with a rule-based approach. The abstract design vocabulary is assembled by the a sequence of rules, making up a design language. After describing the subsystems in the first paper, in this paper the modeling of the FireSat payload is the starting point. T...

Product engineering involves designing and dimensioning a product, including geometric modeling and scientific simulation and analysis to fulfill predetermined requirements. Therefore, the engineering design effort requires a multidisciplinary analysis that is based on a multitude of different models, each of which require a different kind of repre...

In this third paper of the series [1,2] about satellite design languages, the detailed geometry and simulation modeling is described. The definition of the FireSat subsystems in different design languages is presented in the first paper. In the second part, novel analytical design evaluations resulting from these means are shown. This paper focuses...

This paper describes the formal representation approach used in the scope of a large-scale research project aiming at the holistic, completely digital representation and automated computability of the product life-cycle (PLC). The distinctive approach consists in the novel methodology of visual, graph-based design languages expressed in UML (Unifie...

Im digitalen Entwurf müssen verschiedene Teilsysteme ausgelegt und miteinander gekoppelt werden. Zur Beherrschung der Komplexität kann die Entwurfshandlung in Einzelschritte zerlegt werden. Analysiert man die mathematischen Dimensionen der zu integrierenden Teilsysteme im gemeinsamen Teil des Entwurfsraums, so lassen sich bevorzugte Entwurfssequenz...

Increasing complexity in spacecraft design requires new ways for comprehensive problem formulation. Graph-based design languages are an innovative response to this challenge. Using the Unified Modeling Language (UML), design languages are a formal, executable description of the design knowledge. The FireSat mission given in the textbook [1] from We...

The conceptual design phase in the design of complex systems such as satellite propulsion systems heavily relies on an exploration of the feasible design space. This exploration requires both: topological changes in the potential system architecture and consistent parametrical changes in the dimensioning of the existing system components. Since adv...

Zusammenfassung: Im Entwurf komplexer Systeme werden meist viele der zentralen Entscheidungen ohne umfassende Kenntnis aller damit zusammen-hängenden Folgen getroffen. Eine der Ursachen hierfür ist, dass diese Kenntnis eine manuell sehr aufwändige Ausarbeitung der damit verbundenen Entwurfs-alternativen erfordert. Dagegen können in einer graphenbas...

Im Entwurf von SCR-Systemen (Selective Catalytic Reaction, SCR) zur Abgasnachbehandlung ist die Beherrschung der Anwendungs- und Variantenvielfalt eine Herausforderung. Insbesondere im Off-Highway-Bereich ist der Entwickler mit verschiedensten Fahrzeugvarianten bei unterschiedlichsten Lastkollektiven konfrontiert. Zudem machen strenge Emissionsrich...

KNOWLEDGE-BASED DESIGN OF SCR-SYSTEMS USING GRAPH-BASED DESIGN LANGUAGES The ability to cope with different applications and system variants is a big challenge when designing exhaust aftertreatment systems. Especially in the off-highway application area designers are faced with many different vehicle variants featuring lots of different load profi...

Using the FireSat mission from literature (see Larson 1999), the satellite design process is analyzed. Prior to this analysis, the physical and functional properties of the satellite system are encoded in a graph-based design language. During the automated design language compilation process several graph representations are generated. These graph...

The use of graph-based design languages in UML for complex system design is motivated. The FireSat mission from literature is modeled in different UML classes representing the systems, subsystems and parts of the satellite. A rule-based creation mechanism for the instances is shown along with an executable activity diagram for the definition of the...

Zusammenfassung: Es wird ein generelles Schema für die Anwendung graphen-basierter Entwurfssprachen im Entwurf komplexer Systeme vorgestellt. In einem Beispielszenario werden für das Kommunikationssystem eines Satelliten verschie-dene Varianten untersucht. Dazu werden Bauteil-und Subsystemanalysen durch-geführt. Hierbei wird gezeigt, dass die Entwu...

The coupling of physical effects and the rising complexity of modern aircraft necessitate an intense collaboration of disciplinary specialists in preliminary airplane design. Additionally, a growing number of suppliers and outsourced design activities aggravate the design processes even further. Novel multidisciplinary design environments intend to...

Due to the multidisciplinary nature of satellite design and the mostly proprietary formats of engineering software tools, a multitude of heterogeneous computer models are employed during satellite design. A unified central product model can guarantee data consistency and manage the interdependencies between the different isolated models. This paper...

The design language allows the construction of a variety of airplane designs. The syntax of the design language relies on the standardized Unified Modeling Language (UML) and con-sists of an object-oriented vocabulary (i.e. points, lines, profiles, wings, etc.) comparable to building blocks, and design rules (i.e. building laws) which represent the...

Similarity theory in form of the Pi-Theorem guarantees for any dimensionally homogeneous function the existence of a dimensionless similarity function of dimensionless parameters. Similarity theory is known for its successful applications in science and engineering. Classical applications of similarity theory in engineering mostly exploit the fact...

Classical topology optimization aims at achieving a problem suited material distribution in a structure by identification of lightly loaded areas and local element-wise reduction of stiffness. The resulting topologic layout often contains small substructures which are complicated to manufacture, hence requiring an additional manual smoothing during...

In this paper the application of graph grammar based design languages is presented. Design languages consist of a set of vocabulary and a set of rules. The design graph generated by the design language is a priori not restrained to any specific design domain. Therefore it is a formal representation of the design object. This allows to apply modific...

Shortening the design cycle, faster time-to-market, reduction of development costs, more intelligent products and intelligent production are the buzzwords which characterize the current trends in our industries subject to global competition. While in the past many downstream activities in engineering design and mass production have already been sub...

The exterior design of cars is considered to be a highly creative task typically executed by experienced human designers. Based on a case study of the Audi car family, both a careful analysis of the humanassisted exterior design process has been assessed, as well as the syntax, semantics and pragmatics of a formal, graph-based engineering design la...

This paper presents a methodology for the conceptual design synthesis and subsequent automated structural analysis of the material topology in composite structures. The long-term goal of this approach is to obtain a conceptual design language which is able to generate a multitude of composite structure topologies along with an automated analysis. T...

Grammars have been used for the generation of various product designs (e.g. coffeemakers, transmission towers, etc.). Like any other formal language in computer science, the correctness of the designs generated during the translation process possesses the three distinct aspects of syntax, semantic and pragmatic. While compilers can check the syntax...

Currently available tools for classical topology optimization of structures have proven valuable in conceptual design. These tools may provide design direction very early in the design cycle. However, the results subsequently need to be interpreted and translated by an engineer into a consistent CAD-model. This research focuses on the topological d...

Material flows are often encountered in the area of manufacturing processes. Simulation tools for the simulation of such material flows are used widely in the industry to predict and optimize the throughput in preposition of factory alterations or (re-)constructions. The simulation process itself is made up by an iterative sequence of modeling and...

It is commonly agreed on that the overall quality of an engineering design object mainly depends on the decisions taken in the early conceptual stage of the design process. This paper presents an innovative formalism, called “design grammars” that seems to be well suited for the conceptual design of space stations. It is shown how the design gramma...

The paper deals with the application of engineering design grammars for a satellite design process. The situation of today's satellite design facilities is addressed and the need for an automated design process support is explained.The suggested method is to use graph grammars as a new representation of design. A design compiler acts as a ‘front-en...

Towards the future goal of providing a unified computer aided engineering design framework, engineering design languages are an already available option. Their application allows to formalize the computer aided design synthesis and analysis process. Design languages serve as a computable abstraction of design representation and synthesis processes...

A core aspect of systems engineering is the system design based on coupling and sensitivity analyses of submodules which are combined together. If the submodule properties are presented as equations, i.e. as constraints between the module design parameters in symbolic form, knowledge processing techniques by means of graph theoretic methods provide...

A genetic algorithm is used for the topology design of feed-forward neural networks. The generated neural network topology populations are then trained to approximate non-linear relationships of multiple variables. A specifically designed fitness function using the epistemological principle of dimensional homogeneity is used for the evaluation of t...

Significant reduction of helicopter blade-vortex interaction (BVI) noise is currently one of the most advanced research topics in the helicopter industry. This is due to the complex flow, the close aerodynamic and structural coupling, and the interaction of the blades with the trailing edge vortices. Analytical and numerical modelling techniques ar...

An adaptive neural control concept for the deployment of a tethered re-entry capsule is presented. The control concept applies an indirect neural controller that combines two neural networks, a controller network and a plant model network. While the controller network is initialized by means of multiple conventional linear quadratic regulator desig...

One of the major obstacles towards the realization of automated creative design lies in the restricting design representation frames explicitly or implicitly imposed by common means for design representation. In this paper it is proposed to extend these frames by impro-ving the design representation with a description technique that is more suitabl...

Design by compilation of a design language is a new paradigm in the solution of the problem of conceptual car design. It is inspired by the concept of natural languages, such as German or English. Natural languages are defined by their vocabulary and a set of grammar rules, which form the language grammar and define the structure of all syntactical...

Pattern recognition is an important aspect of image processing. Image features are computed from image objects and subsequently used by an object classificator to map (and therefore classify) image objects into their corresponding object classes. To avoid misclassification the image features used should be selected in such a way that they represent...

Traditionally the engineering modeling process is based on first principles, which usually yields large, complex and detailed models of a dynamic system. As an alternative, classical system identification procedures often produce simple (linear) models ignoring additional domain knowledge. In this context, numerical models, e.g. multi-body models o...

Feature extraction is a major processing step in pattern recognition. To classify similar objects into the correct object class the selected image features should represent the desired objects invariance. This means any two objects, which are similar according to the given similarity postulate, should have identical features so that the classificat...