Littérature scientifique sur le sujet « Driver-Range-Interaction »

For expanding the application scope of car-following, based on the basic idea of the noncontact interaction of the objects in physics, establish an attention field model to describe the driving behavior. Firstly, propose the time distance concept to describe the degree of driver perception to the front one-dimensional space and extend its application range to the two-dimensional space. Secondly, connect the point which has the same time distance to constitute the equipotential line of drivers’ attention field equipotent, and establish a model to describe it. Thirdly, define the effective range of the driver’s psychological field with the feature of the driver’s visual distance range increasing and the angle decreasing. Finally, design the calculation method to collect projection of the object in the psychological field scope and calculate the curve points to determine the object’s intensity of psychological field. Preliminarily build the driving behavior model and use the numerical simulation method to simulate the simple transport scenarios; initially verify the validity of the model.

SummaryThere has been little research into the interaction between fraud offences and mental health. Fraud is perpetrated on a massive scale and a number of offenders will have psychiatric pathology either as a primary driver of the offence or as an associated phenomenon that will require psychiatric care and treatment. This article reviews the broad range of psychiatric conditions that have been associated with fraud offending, comments on management and discusses methods of psychiatric assessment in fraud offences.

As a part of the Intelligent Vehicle Highway System (IVHS), Advanced Traveler Information Systems (ATIS) will offer tomorrow's drivers significantly expanded capabilities for getting where they want to go safely and efficiently. Vehicle-based navigation systems combined with information on highway conditions and services have the potential for improving driver performance. Though ATIS may offer considerable advantages, the system design must be consistent with the primary tasks of controlling and operating the vehicle. This paper describes an attempt to identify the likely interaction between what a driver must do to operate the vehicle safely while at the same time using the various ATIS systems. As such, it is an attempt to visualize what driving with these advanced systems will be like and to translate that vision into standard human factors task analytic techniques. Though a broad range of ATIS systems and functions were addressed in this project, this paper will address the macro-level task analyses that resulted from the examination of 165 tasks related to ATIS use.

Neurons transmit long-range biochemical signals between cell bodies and distant axonal sites or termini. To test the hypothesis that signaling molecules are hitchhikers on axonal vesicles, we focused on the c-Jun NH2-terminal kinase (JNK) scaffolding protein Sunday Driver (syd), which has been proposed to link the molecular motor protein kinesin-1 to axonal vesicles. We found that syd and JNK3 are present on vesicular structures in axons, are transported in both the anterograde and retrograde axonal transport pathways, and interact with kinesin-I and the dynactin complex. Nerve injury induces local activation of JNK, primarily within axons, and activated JNK and syd are then transported primarily retrogradely. In axons, syd and activated JNK colocalize with p150Glued, a subunit of the dynactin complex, and with dynein. Finally, we found that injury induces an enhanced interaction between syd and dynactin. Thus, a mobile axonal JNK–syd complex may generate a transport-dependent axonal damage surveillance system.

Interactive processes are omnipresent in fields dealing with automation of complex technical processes, allowing a wide range of application scenarios of assistance systems to support human operators. However, the definition and description of the interaction strongly depends on the application. The description of Human-Process-Interaction (HPI) in most cases is the key for the development of interaction models leading to a framework for the development of assistance systems. The goal of such assistance systems is to support human operators, or human factors, and thereby improve the considered process in parallel. For the purpose of creating a framework for the development of assistance systems, the Situation-Operator-Model (SOM) approach is applied. The SOM approach is capable of modeling HPI in a net-like structure representing the complex environment (or process) and human interactions. By this formal modeling of HPI for the development of human-centered assistance systems based on the underlying modeled interaction is available. In this contribution illustrative examples of different applications for the proposed approach are given by a cognitive, individualized driver assistance system for lane changing maneuvers, by the assessment of operator decisions in air traffic control as well as the operator supervision in semi-automated production process.

The paper shows a possibility of the tuning mechanical system by means of two pneumatic springs in a differential configuration connected with a throttle valve. The springs are inserted into the lead mechanism and connected to its parts, and to its supporting platform. The vibrations, transferred from the kinematic excitation of the base, are intended to be minimized. The vibration isolation by means of pneumatic springs is available in many technical systems, e.g. in supports of heavy machinery as well as in systems characterized by the human interaction, such as driver seats, ambulance couchettes, etc. The pneumatic springs provide the option of adaption of the stiffness, and herewith the adaption of the natural frequency of the system according to the exciting frequency. In cases of application of the object vibration isolation, they can change the load characteristics in a relative large range. In the studied case of the differential spring configuration, the springs are connected with an air pipe to the throttle valve. The air being exchanged during the motion period comes through the valve, the cross-section of which determines the time delay of the pneumatic sub-system thus creating a hysteresis of load characteristic of the spring support. This brings an additional, controllable damping to such a system that is profitable in most vibration isolation cases.

The connected vehicle systems (CVS) aim to provide drivers with information in a timely and reliable way to improve transportation safety. With the emerging wireless communication technologies, the vehicles will be equipped with the ability to communicate with each other about the surrounding traffic situations by exchanging vehicle status and motion data via Dedicated Short-Range Communications (DSRC) network (Kenney, 2011). With the assistance of the cooperative collision warnings, the impact of designed warning parameters on driver performance is increasingly important. Existing empirical studies have studied the warning timing and warning reliability in determining the effectiveness of the collision warning systems in advanced driver assistance systems (ADAS). In terms of warning timing, the studies in reached consistent conclusions that early warnings induced more timely braking and longer braking process, resulted in higher trust of the warning systems, and reduced collision rates (for example, Abe & Richardson, 2006a; Lee, McGehee, Brown, & Reyes, 2002; Yan, Xue, Ma, & Xu, 2014; Yan, Zhang, & Ma, 2015; Wan, Wu, and Zhang, 2016). In terms of the warning reliability, research has shown that warnings with a higher reliability increased driver’s trust of the warning systems, led to higher frequency in warning responses, and reduced crash rates (for example, Abe, Itoh, & Yamamura, 2009; Bliss & Acton, 2003; Maltz & Shinar, 2007; Sullivan, Tsimhoni, & Bogard, 2008). However, the interaction effects of warning lead time and warning reliability on driver performance was not examined especially under the connected vehicle settings. The current research investigated the interaction effects of warning lead time (2.5s vs. 4.5s), warning reliability (73% vs. 89%), and speech warning style (command vs. notification) on driver performance and subjective evaluation of warnings in CVS. A driving simulator study with thirty-two participants was conducted to simulate a connected vehicle environment with missing warnings due to the failures in the data transmission within the communication network of the CVS. The results showed command warnings led to a smaller collision rate compared to notification warnings with the warning lead time of 2.5s, whereas notification warnings resulted in a smaller collision rate compared to command warning with the warning lead time of 4.5s. These results suggested notification warnings should be selected when warning lead time is longer and warning reliability is higher, which resulted in higher safety benefits and higher subjective ratings. Command warnings could be selected when warning lead time is shorter since they led to more safety benefits. However, such selection has to be made with caution since command warnings may limit drivers’ response type and were perceived as less helpful than notification warnings.

This research aims to show the effectiveness of Operator Event Sequence Diagrams (OESDs) in the normative modelling of vehicle automation to human drivers’ handovers and validate the models with observations from a study in a driving simulator. The handover of control from automation to human operators has proved problematic, and in the most extreme circumstances catastrophic. This is currently a topic of much concern in the design of automated vehicles. OESDs were used to inform the design of the interaction, which was then tested in a driving simulator. This test provided, for the first time, the opportunity to validate OESDs with data gathered from videoing the handover processes. The findings show that the normative predictions of driver activity determined during the handover from vehicle automation in a driving simulator performed well, and similar to other Human Factors methods. It is concluded that OESDs provided a useful method for the human-centred automation design and, as the predictive validity shows, can continue to be used with some confidence. The research in this paper has shown that OESDs can be used to anticipate normative behaviour of drivers engaged in handover activities with vehicle automation in a driving simulator. Therefore, OESDs offer a useful modelling tool for the Human Factors profession and could be applied to a wide range of applications and domains.

A performance-based approach to the interaction of geometric design, speed, and safety is considered given the availability of two key documents: the Highway Safety Manual and Modeling Operating Speed: Synthesis Report. A historical look at the concept of design speed shows that although the definition of design speed has changed on more than one occasion, the same basic philosophy that related design speed to a safe speed is still reflected in current policy in supplemental guidance related to the selection of design speed. A conservative approach to establishing design criteria, used to address the range of driver, vehicle, and roadway conditions and capabilities that a designer must consider, is demonstrated. Operating speeds are shown to be higher than design speeds for design speeds of approximately 55 mph or less. This outcome may be considered undesirable, but that categorization seems to be based more on subjective judgments of what is desirable than on actual safety findings. Finally, the idea of speed management through the use of roadway geometrics (i.e., geometric designs that influence driver selection of operating speed)—one component of self-enforcing, self-explaining roadway design—is explored. Findings uncover possible challenges to implementing this idea. Five related questions are addressed: (a) What is known about the relationships between road geometry and operating speeds? (b) To what degree does road geometry influence operating speeds? (c) How are safety and security influenced by road geometry? (d) What are the potential impacts on large vehicles? and (e) What is the nature of the speed–safety trade-off?

Der globale Klimawandel gehört zu einem der wichtigsten Themen, die in Politik, Wirtschaft und Wissenschaft diskutiert werden. Der Reduzierung des weltweiten CO2-Ausstoßes wird dabei ein besonderer Stellenwert beigemessen. Auch im Transportsektor wird eine Verringerung der CO2-Emissionen angestrebt. Um dieses Ziel zu erreichen sollte die Nachhaltigkeit im Transportwesen erhöht werden. Elektrofahrzeuge können enorm zu diesem Ziel beitragen. Dies setzt voraus, dass sie während ihrer gesamten Nutzungsphase mit Strom aus regenerativen Energien geladen werden. In diesem Zusammenhang ist es wichtig, auch bei der Produktion auf eine möglichst hohe Nachhaltigkeit zu achten. Das bedeutet, dass die Ressourcen, die zur Produktion eines Elektrofahrzeugs (zum Beispiel Energieressourcen oder eingesetzte Materialien für die Batterieproduktion) möglichst gering gehalten werden sollten. Daher wird empfohlen, die maximale Kapazität einer Batterie und somit die verfügbare Reichweite eines Elektroautos gemäß der tatsächlichen Reichweitenanforderungen der Fahrer auszulegen. Dies bedeutet jedoch, dass Elektroautofahrer mit vergleichbar geringeren Reichweiten umgehen müssen als beim Verbrennerfahrzeug. Zusätzlich ist das Wiederherstellen der Reichweitenressourcen, also das Nachladen des Elektrofahrzeugs, mit höherem Aufwand verbunden als das Nachtanken eines Verbrennerfahrzeugs, da es heutzutage vergleichbar weniger öffentliche Schnelllademöglichkeiten gibt und das Nachladen relativ viel Zeit in Anspruch nimmt. Daher wird die Interaktion mit den Reichweitenressourcen eines Elektrofahrzeugs als relativ herausfordernd wahrgenommen. Dies führt dazu, dass die reichweitenbezogene Nutzerzufriedenheit und das Reichweitenerleben der Fahrer beeinträchtigt und die verfügbaren Reichweitenressourcen nicht optimal ausgenutzt werden. Darüber hinaus wird die limitierte Reichweite von Elektrofahrzeugen häufig auch als eine der wichtigsten Barrieren für die generelle Akzeptanz und Nutzung von Elektrofahrzeugen diskutiert. Um das Potenzial eines Elektrofahrzeugs hinsichtlich der Erhöhung der Nachhaltigkeit im Transportsektor voll auszuschöpfen ist es daher unerlässlich, Möglichkeiten zu finden um diese Barriere unter Beachtung der Anforderungen des Fahrers zu überwinden. Ergänzend zu technischen Lösungen wie zum Beispiel der Weiterentwicklung der Batterietechnology oder der Implementierung einer größeren Anzahl von öffentlichen Schnelllademöglichkeiten, sollten weitere Strategien entwickelt werden um das Reichweitenerleben der Elektroautofahrer zu verbessern und sie zu einer möglichst effizienten Ausreizung der verfügbaren Reichweitenressourcen zu befähigen. Reichweitenstress ist ein wichtiges Konzept in diesem Zusammenhang. Reichweitenstress ist besonders relevant in der Interaktion mit Elektrofahrzeugen auf Grund des relativ begrenzten Zugangs zu Schnellladestationen und relativ langer Ladedauern. Das Konzept ist aber auch auf anderen Arten der Mensch-Technik-Interaktion im Transportsektor übertragbar (z.B. auch auf Verbrennerfahrzeuge). Im Rahmen der vorliegenden Dissertation wird davon ausgegangen, dass sich Reichweitenstress und das breiter definierte Phänomen Reichweitenangst negativ auf die Zufriedenheit mit der Reichweite und der effizienten Nutzung von Elektrofahrzeugen auswirken. Um den maximalen Nachhaltigkeitseffekt von Elektrofahrzeugen ausschöpfen zu können, müssen daher Möglichkeiten gefunden werden um den erlebten Reichweitenstress zu verringern und der Entstehung von Stress vorzubeugen. Die vorliegende Dissertation trägt zu diesem Ziel bei, indem sie ein detailliertes Verständnis zu Reichweitenstress und dem Einfluss verschiedener Resilienzfaktoren im Rahmen von 5 Zeitschriftenartikeln (4 veröffentlich, 1 zur Veröffentlichung eingereicht) zur Verfügung stellt. Resilienzfaktoren meint dabei Faktoren, welche die Fähigkeit des Fahrers mit kritischen Situationen umzugehen erhöhen und somit das Erleben von Stress verringern. Das erste Forschungsziel dieser Arbeit bestand darin, das Konzept Reichweitenstress zur Beschreibung des Reichweitenerlebens in kritischen Reichweitensituationen (d.h., Situationen mit geringem Reichweitenpuffer) zu etablieren, ein theoretisches Rahmenmodell zur Erklärung von Reichweitenstress und möglichen Einflussfaktoren zur Verfügung zu stellen sowie eine Methode zur Erfassung von Reichweitenstress im experimentellen Kontext zu prüfen. Die Ergebnisse der Arbeit konnten zeigen, dass sich das Konzept Reichweitenstress dafür eignet, das Erleben der Fahrer zu beschreiben. Das bereits existierende Modell zur adaptiven Reichweitenkontrolle wurde auf den speziellen Fall einer Fahrt in einer kritischen Reichweitensituation angewendet und um das Konzept Reichweitenstress sowie möglicher, aus der Literatur abgeleiteter, Einflussfaktoren erweitert. Dies ermöglicht es, potenzielle stressreduzierende Faktoren abzuleiten um diese empirisch in einem Feldexperiment zu untersuchen, welches im Rahmen dieser Dissertation weiterentwickelt und getestet wurde. Es konnte gezeigt werden, dass es möglich ist, eine kritische Reichweitensituation in einem Feldexperiment herzustellen. Die Nutzung einer Coverstory ist in diesem Zusammenhang zu empfehlen (z.B. längere Strecke kommunizieren als dann tatsächlich gefahren werden muss). Das zweite Forschungsziel bestand darin, den Einfluss potenzieller Resilienzfaktoren auf den erlebten Reichweitenstress empirisch zu untersuchen. Basierend auf dem weiterentwickelten Modell der adaptiven Reichweitenkontrolle wurden mehrere Faktoren abgeleitet, die einen Einfluss auf das Reichweitenerleben haben sollten: (1) Wissen über Einflussfaktoren auf die Reichweitenentwicklung oder Wissen über Möglichkeiten zum energie-effizienten Fahren, (2) praktische Fahrerfahrung mit Elektrofahrzeugen sowie das Erleben einer kritischen Reichweitensituation, (3) Persönlichkeitseigenschaften wie zum Beispiel Kontrollüberzeugungen im Umgang mit Technik und schließlich (4) technische Systemeigenschaften wie zum Beispiel die wahrgenommene Verlässlichkeit des im Fahrzeug integrierten Systems zur Reichweitenschätzung. Die Ergebnisse zeigten, dass die Vermittlung von relevanten Informationen zur Reichweite eines Elektrofahrzeugs das Reichweitenerleben zum Teil verbessern kann. Insbesondere detaillierte Informationen zum energie-effizienten Fahren haben das Potenzial um Reichweitenstress zu verringern. Daher sollten dem Fahrer diese Informationen auf vielfältigen Wegen zur Verfügung gestellt werden. Dies könnte zum Beispiel über Informationsbroschüren, im Rahmen theoretischer Trainings zur Verbesserung der Interaktion mit dem Elektrofahrzeug, bereits vor dem Kauf durch den Berater oder eventuell sogar im Rahmen der theoretischen Fahrschulausbildung geschehen. Ein weiterer vielversprechender Ansatz wäre die Bereitstellung der relevanten Informationen direkt während der Fahrt durch Informations-, Assistenz- und Tutorsysteme. Praktische Fahrerfahrung sowie das Erleben und erfolgreiche Bewältigen einer kritischen Reichweitensituation in einer relativ geschützten Umgebung konnten Reichweitenstress ebenfalls verringern. Daher wird empfohlen Probefahrten mit Elektrofahrzeugen sowie Praxistrainings anzubieten, die im Idealfall auch eine unterstützte Fahrt in einer kritischen Reichweitensituation beinhalten sollten. Durch das aktive Auseinandersetzen mit den Grenzen der Reichweite kann ein Lernprozess angestoßen werden, der zu einem effizienteren Umgang mit den Reichweitenressourcen des Fahrzeugs führt. Auch in diesem Kontext bieten Assistenzsysteme im Fahrzeug ein großes Potenzial. Sie sollten so gestaltet sein, dass sie einen aktiven Umgang mit der Reichweite sowie eine kritische Auseinandersetzung mit der Reichweitendynamik ermöglichen und fördern. In der vorliegenden Dissertation konnte gezeigt werden, dass Persönlichkeitsmerkmal wie hohe Emotionale Stabilität und hohe Kontrollüberzeugungen im Umgang mit Technik mit einem geringeren erlebten Reichweitenstress zusammenhängen. Dies hat vor allem theoretische Implikationen und kann dazu beitragen, relative Unterschiede zwischen Individuen zu verstehen. Zudem konnte gezeigt werden, dass technische Systemeigenschaften wie die wahrgenommene Verlässlichkeit des Systems zur Reichweitenschätzung (z.B. zu Grunde liegender Algorithmus, Aktualität und Genauigkeit der angezeigten Reichweiteninformationen) ein wichtiger Faktor im Zusammenhang mit reduziertem Reichweitenstress darstellt. Daher sollte darauf geachtet werden, die verbliebene Reichweite eines Elektrofahrzeugs möglichst genau und verlässlich zu schätzen (z.B. Integration möglichst vieler Einflussfaktoren in den Algorithmus zur Reichweitenschätzung) sowie gut verständlich und nachvollziehbar zu präsentieren. Das dritte Forschungsziel bestand schließlich darin, die Relevanz des Konzepts Reichweitenstress auch jenseits des experimentellen Settings zu überprüfen. Bisherige Forschung konnte zeigen, dass der alltägliche Umgang mit Elektrofahrzeugen eher durch das Vermeiden kritischer Reichweitensituationen gekennzeichnet ist. Daher stellte sich die Frage, ob Reichweitenstress und der Einfluss der Resilienzfaktoren auch im Alltagserleben eine Rolle spielt. Die Ergebnisse einer Langzeit-Feldstudie konnten zeigen, dass Reichweitenstress in Form von Sorgen oder Bedenken bezüglich der Reichweite durchaus relevant im täglichen Umgang mit Elektrofahrzeugen ist. Zudem konnte gezeigt werden, dass die identifizierten Resilienzfaktoren (z.B. praktische Fahrerfahrung und technische Systemeigenschaften) auch unter alltäglichen Bedingungen das Erleben von Reichweitenstress verringern können. Zusammenfassend lässt sich sagen, dass Reichweitenstress ein relevantes Konzept im Zusammenhang mit der Interaktion mit Elektrofahrzeugen darstellt. Das Erleben von Reichweitenstress kann durch verschiedene Resilienzfaktoren wie zum Beispiel relevante Wissenselemente und Erfahrungen positiv beeinflusst werden. Aus den Ergebnissen lassen sich Strategien und Design-Empfehlungen für Informations- und Assistenzsysteme ableiten. Dadurch kann das Reichweitenerleben verbessert und ein effizienter Umgang mit der Reichweite gefördert werden. Dies trägt schließlich auch dazu bei, die Zufriedenheit mit Elektrofahrzeugen sowie deren Akzeptanz zu verringern. Somit kann ein Beitrag zur Erhöhung der Nachhaltigkeit im Transportsektor geleistet werden. Das Elektrofahrzeug stellt in dem Zusammenhang nur ein Beispiel für Systeme dar, die einen Umgang mit begrenzten Ressourcen erfordern. Die theoretischen Konzepte, Annahmen, Ergebnisse sowie Schlussfolgerungen der vorliegenden Dissertation können auch auf andere Formen der Mensch-Maschine-Interaktion übertragen werden, welche sich dadurch auszeichnen, dass eine Interaktion mit dem technischen System zu einer Verringerung der Ressourcen führt. Diese Arbeit kann also auch einen Betrag dazu leisten, den Stress und die mentale Beanspruchung beim Umgang mit diesen Systemen zu verringern sowie den effizienten Umgang mit begrenzten Ressourcen zu verbessern.:I Synopsis 1 Sustainability in the Context of Road Transport 2 The Challenge of Battery Electric Vehicles‘ Limited Range and the Contribution of the Present Dissertation 3 Overview of the Dissertation 4 Interaction with Battery Electric Vehicles' Range 4.1 Psychological Reference Values for the Regulation of Range Resources 4.2 The Adaptive Control of Range Resources (ACOR) Model 5 User Experience in Critical Range Situations 5.1 The Concept of Range Stress - Conceptual Framework and Empirical Investigation 5.1.1 Range Stress as One Facet of Drivers’ Experience in Critical Range Situations 5.1.2 Adaption of the ACOR Model with the Focus on Range Stress 5.1.3 Empirical Investigation of Range Stress and the Effects of Resilience Factors 5.2 Reduction of Range Stress - Influence of Inter-Individual Differences and Technical System Characteristics 5.2.1 The Influence of Domain Specific Knowledge on Range Stress 5.2.2 The Influence of Practical Driving Experience on Range Stress 5.2.3 The Influence of Personality Traits and Technical System Characteristics on Range Stress 5.3 Everyday Range Stress - Relevance of Range Stress and Resilience Factors in the Daily Interaction with Battery Electric Vehicles 6 Research Objectives of the Dissertation 6.1 Research Objective 1: Providing a Conceptual Framework and Validating a Methodology to Examine Range Stress and the Influence of Resilience Factors 6.2 Research Objective 2: Examining the Influence of Range-Related Knowledge, Practical Driving Experience, Personality Traits and Technical System Characteristics on Range Stress 6.3 Research Objective 3: Investigation of Range Stress and Specific Resilience Factors in the Everyday Usage of Battery Electric Vehicles 7 Overview of the Methodology 7.1 Field-Experimental Studies to Investigate Range Stress in a Critical Range Situation 7.1.1 General Setup of the Field Studies 7.1.2 Specific Characteristics of the Particular Field Studies 7.2 Long-Term Field Trial to Investigate Range Stress in Everyday BEV Interaction 8 Discussion and Critical Reflection of the Results 8.1 Research Objective 1: Providing a Conceptual Framework and Validating a Methodology to Examine Range Stress and the Influence of Resilience Factors 8.1.1 The Adapted ACOR Model (ACOR-c) with the Focus on Range Stress 8.1.2 Empirical Investigation of Range Stress in a Field-Experimental Setting 8.2 Research Objective 2: Examining the Influence of Range-Related Knowledge, Practical Driving Experience, Personality Traits and Technical System Characteristics on Range Stress 8.2.1 Influence of Range-Related Knowledge on Range Stress 8.2.2 Influence of Practical Driving Experience on Range Stress 8.2.3 Subjective Range Competence as Relevant Factor for Drivers’ Range Experience 8.2.4 Influence of Personality Traits and Technical System Characteristics on Range Stress 8.3 Research Objective 3: Investigation of Range Stress and Specific Resilience Factors in the Everyday Usage of Battery Electric Vehicles 9 Implications of the Results 9.1 Implications for the Conceptual Framework and the Methodology 9.2 Implications Regarding Range-Related Knowledge, Practical Driving Experience, Personality Traits and Technical System Characteristics 9.3 Implications Regarding Range Stress in the Everyday Interaction with Battery Electric Vehicles 10 Conclusion 11 References II Preliminary Study: Understanding the impact of electric vehicle driving experience on range anxiety III Paper 1: First-time experience of critical range situations in BEV use and the positive effect of coping information IV Paper 2: User experience with electric vehicles while driving in a critical range situation – a qualitative approach V Paper 3: Individual differences in BEV drivers’ range stress during first encounter of a critical range situation VI Paper 4: Positive influence of practical electric vehicle driving experience and range related knowledge on drivers' experienced range stress VII Paper 5: Which factors can protect against range stress in everyday usage of battery electric vehicles? Towards enhancing sustainability of electric mobility systems VIII Curriculum Vitae IX Publications

European users have eagerly adopted novel forms of digital media and related information and communications technologies (Stanton, 2001), making them a part of their increasingly varied and segmented cultures (Brown, Green, & Harper, 2001). For example, the young are active consumers of music, videos, movies, and games; businessmen on the other hand need more and more working tools and applications that enable connectivity when they are on the move. A not very dissimilar scenario is envisaged on troops in action where work on tactical and strategic information and mission management, command, and control, including real-time mission replanning, are essential. All these users rely on the Internet, i-TV, and mobile phones, and they have adapted all of these into the fabric of their lifestyles, or in short, their mobile life. But, functionality cannot be the main driver for design as mobile life is also deeply founded upon shared values and worldviews of the users, pleasure, enjoyment, culture, safety, trust, desire, and so forth (Rheingold, 1993). For example, WAP (wireless application protocol) technologies seemed to provide a powerful tool to the mobile worker. However, it is well known the fraud of WAP mainly due to the scarce usability, high usage cost, and inadequate range of the services provided together with intrinsic limitations of the device itself (insufficient memory storage, low battery autonomy, poor screen resolution, etc. [Cereijo Roibás, 2001]). However, some WAP applications have been widely used by Italian users. The success of this system of applications is due to its efficiency, effectiveness, and relevance for some specific work purposes. Each of the services will be analysed, describing the expected use of each service and the actual use of it by Italian users.

The Steer-By-Wire (SBW) paradigm for vehicle control offers many advantages over traditional use of mechanical steering systems but comes at the cost of loss of proprioception (“road feel”). To this end, haptic interfaces for SBW systems have been proposed to restore the intimacy of interactive control back to the driver. However, the degree of realism for the interaction is dependent on the fidelity of the underlying computational vehicle dynamics model. Hence we focus on quantitative comparative testing of the role of vehicle dynamics modeling fidelity for haptic SBW tasks. Additionally the SBW paradigm can simplify implementation of shared/collaborative control (steering) of the underlying mechanical system (vehicle). Possibilities range from sharing of control between multiple individual users or between user and automation technology. Performance evaluation of 3 modes of shared control vs. individual control of driving was carried out and preliminary analysis of results is presented in the paper.

A method for modeling the dynamics of industrial pumping systems is presented. The approach extends existing models for aero-engine like applications to capture dynamic features of interest in industrial, ground-based, applications. Those include the driver-driven (e.g., turbine-pump or compressor) interaction, the driver speed regulation subsystem, and their impact on stability. The method utilizes a lumped parameter modeling approach that involves developing and analyzing a set of nonlinear ordinary differential equations which describe the system dynamics. A model of a baseline industrial pumping system comprised of a turbine driving a process compressor is formulated first. Components in the compressor flow path include an inlet duct, a plenum, and a discharge valve. The resulting model captures the system’s instability onset point, the post-stall behavior, and the sensitivity to system parameters. Two non-dimensional groups are found to play a dominant role in characterizing the overall dynamics: the ratio of fluid compliance to fluid inertia on the compressor side (B-parameter), and the ratio of the mechanical inertia of the rotating assembly to the fluid inertia. Low values of the B-parameter have a strong stabilizing effect and are associated with high frequency surge oscillations. In contrast, low values of the mechanical to fluid inertia ratio have a stabilizing effect only in a limited region of the compressor operating range, and have little effect on surge frequency. For the baseline system considered in this study, stabilizing effects of these two ratios were observed at values less than 0.4 and 0.2 respectively. The baseline system model is then expanded to include a turbine speed controller. This allows examination of large transient events such as station shutdown and the phenomena of turbine hunting. It is found that the parameters of the turbine speed controller can affect the stability during such transients, but have little impact on the post-stall behavior.

The paper discusses the possible interaction between combustion instabilities and induction times of droplets (and sprays) to autoignition. It is shown that acoustic pressure/temperature oscillations significantly affect the induction times of n-heptane droplets. This may play an additional role in low frequency dynamics and might be the main driver of high frequency dynamics. Experiments on single droplets in an acoustic field were used to validate numerical simulations on the autoignition of large n-heptane droplets. The simulations were then extended towards technical droplet sizes and a gas turbine typical pressure range of 17 bar. It was found that the acoustic-scale changes of the pressure and temperature result in significant changes of the ignition delay. Applying numerical calculations to micro-sized droplets enabled to study the thermo-acoustic effects under conditions approximating real gas-turbines. The findings reveal the importance of thermo-acoustic effects on ignition processes in the instability-driving mechanisms of combustion and indicate that “acoustics-ignition”-interactions must be taken into account for low-frequency as well as for high-frequency dynamics; this in addition to the flow and mixture perturbations which are well known to drive combustion instabilities in gas-turbines.

Sequential combustion constitutes a major technological step-change for gas turbines applications. This design provides higher operational flexibility, lower emissions and higher efficiency compared to today’s conventional architectures. Like any constant pressure combustion system, sequential combustors can undergo thermoacoustic instabilities. These instabilities potentially lead to high-amplitude acoustic limit cycles, which shorten the engine components’ lifetime and therefore reduce their reliability and availability. In case of a sequential system, the two flames are mutually coupled via acoustic and entropy waves. This additional inter-stages interaction markedly complicates the already challenging problem of thermoacoustic instabilities. As a result, new and unexplored system dynamics are possible. In this work, experimental data from our generic sequential combustor are presented. The system exhibits many different distinctive dynamics, as function of the operation parameters and of the combustor arrangement. This paper investigates a particular bifurcation, where two thermoacoustic modes synchronize their self-sustained oscillations over a range of operating conditions. A low-order model of this thermoacoustic bifurcation is proposed. This consists of two coupled stochastically driven non-linear oscillators, and is able to reproduce the peculiar dynamics associated with this synchronization phenomenon. The model aids in understanding what the physical mechanisms that play a key role in the unsteady combustor physics are. In particular, it highlights the role of entropy waves, which are a significant driver of thermoacoustic instabilities in this sequential setup. This research helps to lay the foundations for understanding the thermoacoustic instabilities in sequential combustion systems.

Siemens H-Class. Siemens has developed the world-largest H-class Gas Turbine (SGT™) that sets unparalleled standards for high efficiency, low life cycle costs and operating flexibility. With a power output of 340+ MW, the SGT5–8000H gas turbine will be the primary driver of the new Siemens Combined Cycle Power Plant (SCC™) for the 50 Hz market, the SCC5–8000H, with an output of 530+ MW at more than 60% efficiency. After extensive lab and component testing, the prototype has been shipped to the power plant for an 18-month validation phase. In this paper, the compressor technology, which was developed for the Siemens H-class, is presented through its development and validation phases. Reliability and Availability. The compressor has been extensively validated in the Siemens Berlin Test Facility during consecutive engine test programs. All key parameters, such as mass flow, operating range, efficiency and aero mechanical behavior meet or exceed expectations. Six-sigma methodology has been exploited throughout the development to implement the technologies into a robust design. Efficiency. The new compressor technology applies the Siemens advanced aerodynamics design methodology based on the high performance airfoil (HPA) systematic which leads to broader operation range and higher efficiency than a standard controlled diffusion airfoil (CDA) design. Operational Flexibility. The compressor features an IGV and three rows of variable guide vanes for improved turndown capability and improved part load efficiency. Serviceability. The design has been optimized for serviceability and less complexity. Following the Siemens tradition, all compressor rotating blades can be replaced without rotor lift or destacking. Evolutionary Design Innovation. The compressor design incorporates the best features and experience from the operating fleets and technology innovation prepared through detailed research, analysis and lab testing in the past decade. The design tools are based on best practices from former Siemens KWU and Westinghouse with enhancements allowing for routine front-to-back compressor 3D CFD multistage analysis, unsteady blade row interaction, forced response analyses and aero-elastic analysis.

This paper examines the lock-in hypothesis of non-synchronous vibration (NSV) in a high speed multistage axial compressor. The unsteady Reynolds-averaged Navier-Stokes (URANS) equations and modal approach based structural dynamic equations are solved. A low diffusion E-CUSP approximate Riemann solver with a 3rd order WENO scheme for the inviscid fluxes and a 2nd order central differencing for the viscous terms are employed. The structural vibration of the blades are solved by a set of modal equations that are fully coupled with the flow equation. The rigid blade simulations are conducted to examine the main driver of NSV. A 1/7th annulus sector of IGV-rotor-stator is used with a time shifted phase lag BC at circumferential boundaries. A dominant excitation frequency caused by the traveling tip vortices are captured. The excitation frequency is not on the engine order. The simulation is then switched to fluid structure interaction that allows the blades to vibrate freely under the flow excitations. The matching of aerodynamic forcing frequency with the structure response frequency seems indicating that the NSV of this compressor is a limit cycle oscillation (LCO) excited by aerodynamic forcing, not caused by flow frequency/phase locked to structural frequency. The rotating speed is varied within a RPM range, in which the rig test detected the NSV. The unsteady flows with rigid blades are simulated first at several RPMs. The simulation indicates that the structure response follows the frequency of the flow excitations existing in the rigid blades. At least under the simulated conditions, the NSV does not appear to be a lock-in phenomenon, which has the flow frequency lock-in to the structure natural frequency.