Ralf Stetter

University of Applied Sciences Ravensburg-Weingarten | RWU · Faculty of Mechanical Engineering

In industrial vehicle design processes, most companies have implemented model-based systems engineering (MBSE). As a consequence, design processes are nowadays not driven by documents, but by digital models of the vehicle to be developed and its components. These models exist on different levels of abstraction. The models on the requirements level...

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...

Automated guided vehicles undertake complex transportation tasks, for instance, in production and storage systems. In recent years, an increased focus on sustainability has occurred as the effects of ongoing climate change have become more apparent. Engineers are searching intensively for ways to design technical systems that are not only environme...

Both fault-tolerant design (FTD) and fault-tolerant control (FTC) are receiving increasing attention from the scientific community. Both intend to develop and implement solutions for accommodating faults which are inevitable in complex technical systems. However, up to no, little scientific activity was aimed at integrating those two promising appr...

Due to complex operation and surrounding conditions, faults are inevitable during the use of complex technical systems such as two-wheel scooters. This paper explains algorithms and methods which allow the accommodation of faults through the design and control of such systems on the functional level of product concretization. A main component of th...

In the area of industrial Internet of Things (IIoT), digital twins (DTs) are a powerful means for process improvement. In this paper the concept of a DT is explained and analysis possibilities throughout the life-cycle of a product and its production system are explored. The main part of this paper is focused on an approach to the analysis of manuf...

In the field of inner-city cargo transportation, solutions such as electrified cargo trailers are increasingly being used. To provide an intelligent drivetrain control system that improves driving dynamics and enables safety, it is necessary to know the characteristics of the trailer system. This includes the behavior of the tires. Existing investi...

Current batteries of battery electric vehicles (BEVs) require a battery management system (BMS) in order to enable a safe and long-lasting operation. The main functions of the battery management systems are a continuous monitoring of the voltage of each cell, a continuous monitoring of the battery temperature, the control of the charge current and...

Researchers around the globe have contributed for many years to the research field of fault-tolerant control; the importance of this field is ever increasing as a consequence of the rising complexity of technical systems, the enlarging importance of electronics and software as well as the widening share of interconnected and cloud solutions. This f...

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...

One of the main current threats for producing companies is the possibility of cyber-space attacks. Due to several reasons, industrial companies need to connect their plants over some kind of networks. Obviously, today many approaches from information technology (IT) exist which will greatly reduce the danger of attacks. Still, no producing company...

The main focus of this paper is the exploration of fault accommodation possibilities in the context of function development. Faults occur in complex technical systems and may lead, if no accommodation entities or processes are present, to catastrophic failure. Several entities and processes exist and are applied, but mainly on the concrete levels....

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...

Currently, a consensus in the scientific community can be observed that it is necessary to reduce the carbon footprint and the use of fossil resources in order to ensure the ongoing well-being of humanity and our planet. Battery electric vehicles (BEVs) can contribute to this reduction, as they can use energy from sustainable sources as well as sto...

The task of designing and planning an assembly system is complex and challenging. Today, planning results are often dependent on the experience and methodological skills of the planner as well as on the available planning tools available. Digital processes are used to accelerate the planning process and establish the best possible shared knowledge...

Since battery electric vehicle (BEV) sales are increasing, the calculation of necessary electric power supply, and energy consumption data, and vehicle range is important. The Worldwide harmonized Light vehicles Test Procedure (WLTP) currently in use can deliver data to collect comparable energy consumption data for different vehicles on defined ch...

Since several decades a widespread consensus concerning the enormous importance of an in-depth clarification of the specifications of a system can be observed. A weak clarification of specifications is repeatedly listed as a main cause for the failure of system development projects. Requirements, which can be defined as the purpose, goals, constrai...

Due to increasing sales figures, the energy consumption of battery-electric vehicles is moving further into focus. In addition to efficient driving, it is also important that the energy losses during AC charging are as low as possible for a sustainable operation. In many situations it is not possible or necessary to charge the vehicle with the maxi...

Since decades, researchers are developing methods, tools, and processes for the development of mechatronic systems. In the last decade, this field has widened, including, amongst others, aspects such as cyber-physical systems (CPS) or the internet of things (IoT). Still, little concrete guidance can be identified for engineers who have to decide wh...

Today, design engineers engaged in the development of a high-performance electrical drive-train are challenged by the multitude of possible topological choices and numerous mutually interconnected physical phenomena. Development teams around the globe struggle with this challenge; usually they employ several tools for simulation and topology optimi...

Fahrzeuge für die sog. letzte Meile sind wesentlicher Bestandteil von innerstädtischen Logistikkonzepten (vgl. Gumpert und Wiese 2017) und für die individuelle Mobilität. Bei der individuellen Mobilität können Nutzer idealerweise direkt zwischen verschiedenen Verkehrsmitteln wechseln – eine Möglichkeit hierfür ist ein balancierendes Zweiradfahrzeug...

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...

The current increase in road traffic in cities requires innovative, low-emission and flexible solutions for passenger transport on short distances. The main topic of this paper is a customer-oriented digital design process of a self-balanced scooter, which can be used as an individual last-mile means of transport between for example public means of...

In the last decades, virtual sensors have found increasing attention in the research community. Virtual sensors employ mathematical models and different sources of information such as actuator states or sensors, which are already existing in a system, in order to generate virtual measurements. Additionally, in recent years, the concept of virtual a...

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...

The reliability of technical systems can be greatly reduced if possible faults cannot be accommodated but lead to system shut-down with sometimes catastrophic consequences. The algorithms and systems of fault-tolerant control were developed in the last years into a powerful tool to accommodate such faults. Additionally, it became obvious that the d...

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...

This paper reports the application of the methods and tools of fault-tolerant design to an automated shifting system and their reflection and extension. Fault-tolerant design has emerged in the last years and is generally understood as a collection of strategies, methods, algorithms, tools and insights which are intended to support the development...

Models of technical systems are an essential means in design and product-development processes. A large share of technical systems, or at least subsystems, are directly or indirectly connected with the generation or transformation of energies. In design science, elaborated modelling approaches were developed for different levels of product concreti...

An advanced control of manufacturing and transportation systems forms a prominent research field with powerful algorithms developed in the last decades. Challenges still arise, if several automated guide vehicles (AGV) have to be coordinated. This paper focuses on the modelling and fault-tolerant control of multiple AGVs. The considered application...

This chapter discusses fault tolerant design. In the focus are the main aspects and components of fault-tolerant design. The discussion is arranged following a model of the levels of abstraction of a technical system. The presented insights concern requirements, the functional architecture, the physical structure as well as geometry and material.

This chapter extends the model predictive control framework to systems with flexible redundant and shared elements. Flexible redundant elements can increase the reliability and fault-tolerance; shared elements can increase the economic efficiency of automated processes. However, flexible redundant elements require elaborate control systems for task...

This chapter explains the principles of fault-tolerant control. Points of main emphasis are FTC for continuous processes and discrete event systems, fault identification, fault-tolerant controllers and the prognosis of faults.

This chapter summarises important insights concerning the methodical and model-based design of automated vehicles under special consideration of the fault-tolerant qualities of these automated vehicles.

This chapter describes the development and application of an innovative virtual sensor. The application is explained following the example of an automated guided vehicle. The explanation covers the mathematical model, the experimental verification and the experimental results.

The chapter explains a newly developed framework for the prescriptive fault-tolerant control of automated processes. This explanation includes descriptions of the assembly planning for the automated battery assembly system, the modelling of this system, the developed fault-tolerant control strategy and the application of this strategy.

This chapter explains a strategy for scheduling in assembly systems, which is based on an innovative algorithm for the estimation of the state of the battery of vehicles in automated processes. The chapter includes descriptions of the underlying research, the sample application, the state of the art in the concerned areas, the estimation of the bat...

This chapter concludes the other chapters of the book and summarises further research directions.

Flexibility and agility are central requirements for future manufacturing systems (especially assembly systems), because in most industries the product variety and the fluctuations in demand are still increasing. An increase of the degree of flexibility allows more efficient activities aiming at following the dynamically evolving markets. Such syst...

This book summarizes strategies, methods, algorithms, frameworks and systems for the fault-tolerant design and control of automated vehicles and processes. Intelligent systems may be able to accommodate inevitable faults, but this ability requires targeted design processes and advanced control systems. This book explains the respective elements inv...

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 recent years, more and more technical systems dispose of some form of intelligence which allows to control and diagnose the processes and states in such systems. One important prerequisite for both control and diagnosis is monitoring, i.e. a systematic observation, surveillance or recording of entities of a technical product or its surroundings...

Graph-based design languages offer a promising approach to address several major issues in engineering, e. g. the laborious manual transfer between CAD and CAE. Such languages generate a digital meta- or system model storing all relevant information about a design and feed this into any relevant CAE tool as needed to simulate and test the impact of...

This paper reports the development and application of an interval max-plus fault-tolerant control to a seat assembly system. Such systems will undergo a profound change, because novel seats for autonomous driving contain expanded safety systems and are more voluminous and heavy. Automated guided vehicles are a promising means of transportation in t...

This paper presents an approach to prediction of the Remaining Useful Life (RUL) for components of Automated Guided Vehicles (AGV). The focus is paid on the batteries which are a crucial element of these systems and influence the possible operation times considerably. For batteries, two aspects are taken into consideration, if the remaining useful...

In the paper, a new scheduling strategy for assembly systems consisting of cooperating Automated Guided Vehicles (AGVs) based on their remaining operational time is developed. The operational time is associated with state of charge and state of health of the AGV battery. While the latter is defined as a possible number of repetitions of a set of gi...

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...

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...

The current trend towards Industry 4.0 leads to several important aspects that concern future warehouse systems. The holistic digitalization efforts behind this trend may enable sustainable and resilient processes within warehouses and may increase their agility, but require elaborate control and diagnosis systems. This paper concentrates on one pr...

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...

In recent years, Automated Guided Vehicles (AGVs) have been playing an increasingly important role in producing industry and infrastructure and will soon arrive to other areas of human life such as the transportation of goods and people. However, several challenges still aggravate the operation of AGVs, which limit the amount of implementation. One...

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...

This paper illustrates a new engineering approach in the field of digital production planning using graph-based design languages. After introducing the overall process of graph-based production engineering, this contribution presents its most important characteristics. As a first step, the general concept of design languages is introduced; afterwar...

The paper deals with the design of virtual sensors of longitudinal forces as well as torques acting onto an automated guided vehicle. These virtual sensors are based on a measurement set associated with accelerations, velocities and yaw rate sensors mounted on the robot. Subsequently, the estimated forces and torques are used for diagnostic purpose...

The importance of the clarification of the objectives in the early stages of product development is often stressed in the scientific literature. It is primarily focused on the target search. Until today, methodological approaches were not the subject of consideration, which aim to determine the status quo of a product with regard to various aspects...

In the scientific field of systematic product development a wide range of helpful methods, guidelines and tools were generated and published in recent years. Until now little special attention was given to design guidelines aiming at supporting product development engineers to design products that allow and support monitoring functions. In this pap...

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...

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...

The paper addresses the issue of the state estimation problem of a class of discrete-event systems. The receding-horizon approach is employed to solve above problem. The system and its variables are described within the (max,+) algebra. Thus making possible to incorporate robustness within the overall framework. The paper also shows the transformat...

Graphenbasierte Entwurfssprachen sind eine neue Sichtweise auf die ganzheitliche Beschreibung von Produkten, die sich am Aufbau natürlicher Sprachen orientiert, in welcher Vokabeln und Regeln eine Grammatik bilden. In Verbindung mit graphenbasierten Entwurfssprachen steht mittlerweile ein leistungsfähiges Engineering-Framework zur Verfügung, das au...

In the scientific field of systematic product development a wide range of helpful methods, guidelines and tools were generated and published in recent years. Until now little special attention was given to design guidelines aiming at supporting product development engineers to design products that allow and support control or diagnosis functions. T...

The paper concerns fault-tolerant control of a real battery assembly system which is under a pilot implementation at RAFI GmbH Company (one of the leading electronic manufacturing service providers in Germany).The proposed framework is based on an interval analysis approach, which along with max-plus algebra, allows describing uncertain discrete ev...

Design research has resulted in a deepened understanding about the design process as well as characteristics and proceeding schemes of single designers and design teams. Additionally, numerous strategies, methods, and tools were developed in the last decades. Not all the results could be successfully applied in industrial practice. This chapter see...

The paper concerns fault-tolerant control of a real battery assembly system which is under a pilot implementation at RAFI GmbH Company (one of the leading electronic manufacturing service providers in Germany).The proposed framework is based on an interval analysis approach, which along with max-plus algebra, allows describing uncertain discrete ev...

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...