TU Darmstadt / ULB / TUbiblio

How Stochastic can Help to Introduce Automated Driving

Wachenfeld, Walther Hans Karl (2017)
How Stochastic can Help to Introduce Automated Driving.
Technische Universität Darmstadt
Dissertation, Erstveröffentlichung

Kurzbeschreibung (Abstract)

Status Quo: Automated systems will replace the human operator at different tasks in everyday life. From today’s perspective, these new technologies offer predicted but also unknown benefits. However, as every other new technology, also automated systems will have drawbacks for some stakeholders in our society. As long as new technologies are within readiness levels of research, their impact is mostly negligible. The technology readiness level of automated driving in road traffic is pushed forward strongly by many researchers and developers all over the world. Consequently, the demand for safety assurance gets urgent. From today’s perspective, a concept that evaluates the safety of automated driving in an affordable and meaningful way is missing. However, this concept is necessary to enable the introduction of automated driving to public road traffic. Objectives: The objective of this thesis is to improve the understanding of the challenge for safety assurance on automated vehicles. Therefore a concept is aimed for, that estimates the safety impact for the stakeholders of automated driving. Estimations are always based on assumptions and suffer from uncertainty. For that reason the concept needs to consider and express the underlying assumptions and uncertainties. Methodology: The methodology for reaching the objectives is formed around the core assumption of the concept: The safety of an Object under Test can be described by the parameter of a probability distribution. This parameter connects the number of events that result from driving a distance with the safety performance of the OuT. Based on this core assumption a model for safety evaluation is developed iteratively. First of all the relevant stakeholders that are influenced by the technology are identified and analyzed. The second step identifies measurable requirements for the safety of automated vehicles from the stakeholder’s perspectives. Based on this preliminary work on the one hand a usage strategy is defined that controls the introduction of automated vehicles. On the other hand an examination strategy is developed to evaluate whether this strategy enables the automation to meet the requirements. In step four the usage strategy is examined for the Autobahn automation being one representative use case. The results, meaning testing effort and introduction possibilities, are compared and discussed. A refinement of stakeholders as well as requirements is performed. Such a refinement is necessary as only a more precise and subtle analysis will lead to a share between efforts and benefits of the introduction of automated vehicles that forms a basis for the discussion on the safety assurance challenge. Results: The results of the thesis can be grouped into four mayor insights. Firstly, the number of rare events like accidents can be handled as being a product of a random experiment that depends on a safety performance of a traffic participant and the number of driven kilometers. From today’s perspective a falsification of this approach was not found and thus builds a simple first approach. Secondly, the statistical proof of safety based on real-world driving is not economically feasible before mass application of the automated vehicle. Thirdly, refinement of the requirements is necessary and justifiable to reduce the safety requirements. Splitting up the requirements of society and vehicle users leads to reduced testing efforts and an uncertainty-based usage strategy. This uncertainty most likely will reduce during usage, thus also enabling a statistical statement on safety at one point in future. Lastly, a method consisting of evaluation criteria as well as an introduction simulation is developed to examine proposed usage strategies. Thereby the possible safety impacts of the usage are studied. Conclusion: As the safety of automated driving cannot be proven statistically before introduction, the introduction needs to be performed despite and under consideration of an estimated uncertainty. This does not mean that the introduced vehicles are less safe compared to their benchmark; however during introduction it will be uncertain. As long as the uncertainty stays above a threshold a usage strategy that is included into the safety assurance concept is necessary. Such a usage strategy would be cautious and based on regular observation of the events encountered by introduced vehicles. Several challenges have been identified for the developed introduction concept of automated vehicles. Based on these challenges further work should mainly address two topics: 1. The identification and collection of data that is necessary for concept application. 2. The answer of an unavoidable question: How much harm, caused by a human built machine, is acceptable for the exposed humans?

Typ des Eintrags: Dissertation
Erschienen: 2017
Autor(en): Wachenfeld, Walther Hans Karl
Art des Eintrags: Erstveröffentlichung
Titel: How Stochastic can Help to Introduce Automated Driving
Sprache: Englisch
Referenten: Winner, Prof. Dr. Hermann ; Grunwald, Prof. Dr. Armin
Publikationsjahr: 2017
Ort: Darmstadt
Datum der mündlichen Prüfung: 20 Dezember 2016
URL / URN: http://tuprints.ulb.tu-darmstadt.de/5949
Kurzbeschreibung (Abstract):

Status Quo: Automated systems will replace the human operator at different tasks in everyday life. From today’s perspective, these new technologies offer predicted but also unknown benefits. However, as every other new technology, also automated systems will have drawbacks for some stakeholders in our society. As long as new technologies are within readiness levels of research, their impact is mostly negligible. The technology readiness level of automated driving in road traffic is pushed forward strongly by many researchers and developers all over the world. Consequently, the demand for safety assurance gets urgent. From today’s perspective, a concept that evaluates the safety of automated driving in an affordable and meaningful way is missing. However, this concept is necessary to enable the introduction of automated driving to public road traffic. Objectives: The objective of this thesis is to improve the understanding of the challenge for safety assurance on automated vehicles. Therefore a concept is aimed for, that estimates the safety impact for the stakeholders of automated driving. Estimations are always based on assumptions and suffer from uncertainty. For that reason the concept needs to consider and express the underlying assumptions and uncertainties. Methodology: The methodology for reaching the objectives is formed around the core assumption of the concept: The safety of an Object under Test can be described by the parameter of a probability distribution. This parameter connects the number of events that result from driving a distance with the safety performance of the OuT. Based on this core assumption a model for safety evaluation is developed iteratively. First of all the relevant stakeholders that are influenced by the technology are identified and analyzed. The second step identifies measurable requirements for the safety of automated vehicles from the stakeholder’s perspectives. Based on this preliminary work on the one hand a usage strategy is defined that controls the introduction of automated vehicles. On the other hand an examination strategy is developed to evaluate whether this strategy enables the automation to meet the requirements. In step four the usage strategy is examined for the Autobahn automation being one representative use case. The results, meaning testing effort and introduction possibilities, are compared and discussed. A refinement of stakeholders as well as requirements is performed. Such a refinement is necessary as only a more precise and subtle analysis will lead to a share between efforts and benefits of the introduction of automated vehicles that forms a basis for the discussion on the safety assurance challenge. Results: The results of the thesis can be grouped into four mayor insights. Firstly, the number of rare events like accidents can be handled as being a product of a random experiment that depends on a safety performance of a traffic participant and the number of driven kilometers. From today’s perspective a falsification of this approach was not found and thus builds a simple first approach. Secondly, the statistical proof of safety based on real-world driving is not economically feasible before mass application of the automated vehicle. Thirdly, refinement of the requirements is necessary and justifiable to reduce the safety requirements. Splitting up the requirements of society and vehicle users leads to reduced testing efforts and an uncertainty-based usage strategy. This uncertainty most likely will reduce during usage, thus also enabling a statistical statement on safety at one point in future. Lastly, a method consisting of evaluation criteria as well as an introduction simulation is developed to examine proposed usage strategies. Thereby the possible safety impacts of the usage are studied. Conclusion: As the safety of automated driving cannot be proven statistically before introduction, the introduction needs to be performed despite and under consideration of an estimated uncertainty. This does not mean that the introduced vehicles are less safe compared to their benchmark; however during introduction it will be uncertain. As long as the uncertainty stays above a threshold a usage strategy that is included into the safety assurance concept is necessary. Such a usage strategy would be cautious and based on regular observation of the events encountered by introduced vehicles. Several challenges have been identified for the developed introduction concept of automated vehicles. Based on these challenges further work should mainly address two topics: 1. The identification and collection of data that is necessary for concept application. 2. The answer of an unavoidable question: How much harm, caused by a human built machine, is acceptable for the exposed humans?

Alternatives oder übersetztes Abstract:
Alternatives AbstractSprache

Wie jede Technologie, die vom Forschungsgegenstand zum Massenprodukt weiterentwickelt wird, birgt auch automatisiertes Fahren verschiedenste Vor- und Nachteile. Besonders die Frage der Sicherheit (Safety) der unterschiedlichen Stakeholder in der Gesellschafft ist zu beantworten. Obwohl aktuell eine Vielzahl von Forschern und Entwicklern an der Thematik des automatisierten Fahrens arbeiten, fehlt dennoch ein Konzept zur Bewertung der Sicherheit des öffentlichen Straßenverkehrs mit automatisiert fahrenden Fahrzeugen. Diese Arbeit schlägt ein solches Konzept zur Bewertung der Sicherheit vor. Das Konzept nimmt eine makroskopische Perspektive für die Sicherheitsbewertung ein, indem die Sicherheit des automatisierten Fahrens durch eine gefahrene Distanz und dabei aufgetretene Ereignisse (z.B. Unfälle) beschrieben wird. Dabei wird angenommen, dass die Verteilung der Ereignisse einer Wahrscheinlichkeitsverteilung für seltene diskrete Ereignisse folgt (Poisson-Verteilung). Der statistische Sicherheitsnachweis kann für aktuell bekannte Use-Cases des automatisierten Fahrens nicht wirtschaftlich erbracht werden. Besser zu sein als der heutige Straßenverkehr entspricht einer Sicherheitsanforderung, die mit dem heutigen Stand der Technik nicht bewiesen werden kann. Allerdings ist auch nicht nachzuweisen, dass der heutige Straßenverkehr an Sicherheit einbüßen würde, wenn das automatisierte Fahrzeug sich ähnlich sicher wie Fahranfänger verhalten würde. Da beides nicht nachgewiesen werden kann, ist die Sicherheitsanforderung zu verfeinern. Aus einer werden damit zwei Anforderungen: 1. Der Nutzer des automatisierten Fahrens fordert eine objektive Abschätzung der geringsten Sicherheit, der er bei Nutzung ausgesetzt wird. 2. Die Gesellschaft fordert, dass maximal eine zuvor definierte akzeptable Anzahl an Ereignissen in Verbindung mit automatisiertem Fahren entsteht. Das formalisierte, simulierte und ausgewertete Konzept nutzt Daten des heutigen Straßenverkehrs, sowie fiktive Testdaten um die Erfüllung beider Anforderungen sicherzustellen. Eine konkrete Einführungsstrategie ist das Ergebnis, die gezielt die Nutzung des automatisierten Fahrens limitiert und neu anfallende Informationen aus der Nutzung für eine iterative Anpassung der Limitierung einsetzt. Ein bestärkender Lernzyklus entsteht. Herausforderungen für die Anwendung und Weiterentwicklung des Konzepts werden diskutiert. Damit das beschriebene Konzept die Einführung automatisierten Fahrens unterstützt, sind vor allem zwei Themen in Zukunft zu bearbeiten: 1. Die Sammlung von detaillierten Daten für die Anwendung des Konzepts auf konkrete Use-Cases. 2. Die Beantwortung einer unausweichlichen Frage: Wie viel Schaden, hervorgerufen durch automatisiertes Fahren, ist akzeptabel für Menschen, die der Technologie ausgesetzt sind?

Deutsch
URN: urn:nbn:de:tuda-tuprints-59492
Sachgruppe der Dewey Dezimalklassifikatin (DDC): 600 Technik, Medizin, angewandte Wissenschaften > 620 Ingenieurwissenschaften und Maschinenbau
Fachbereich(e)/-gebiet(e): 16 Fachbereich Maschinenbau > Fachgebiet Fahrzeugtechnik (FZD)
16 Fachbereich Maschinenbau
Hinterlegungsdatum: 19 Feb 2017 20:55
Letzte Änderung: 19 Feb 2017 20:55
PPN:
Referenten: Winner, Prof. Dr. Hermann ; Grunwald, Prof. Dr. Armin
Datum der mündlichen Prüfung / Verteidigung / mdl. Prüfung: 20 Dezember 2016
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