Scenarios for Development, Test and Validation of Automated Vehicles (1801.08598v3)

Abstract: The ISO 26262 standard from 2016 represents the state of the art for a safety-guided development of safety-critical electric/electronic vehicle systems. These vehicle systems include advanced driver assistance systems and vehicle guidance systems. The development process proposed in the ISO 26262 standard is based upon multiple V-models, and defines activities and work products for each process step. In many of these process steps, scenario based approaches can be applied to achieve the defined work products for the development of automated driving functions. To accomplish the work products of different process steps, scenarios have to focus on various aspects like a human understandable notation or a description via time-space variables. This leads to contradictory requirements regarding the level of detail and way of notation for the representation of scenarios. In this paper, the authors present requirements for the representation of scenarios in different process steps defined by the ISO 26262 standard, propose a consistent terminology based on prior publications for the identified levels of abstraction, and demonstrate how scenarios can be systematically evolved along the phases of the development process outlined in the ISO 26262 standard.

• The paper presents a systematic scenario-based framework that replaces distance-based validation, streamlining development processes for automated vehicles.
• It introduces a multi-level scenario representation—from functional to concrete—to support rigorous specification, testing, and validation under ISO 26262.
• The study shows that applying scenario reduction techniques, like equivalence class partitioning, can significantly reduce complexity and cost in the validation process.

Analysis of "Scenarios for Development, Test and Validation of Automated Vehicles"

The paper "Scenarios for Development, Test and Validation of Automated Vehicles" by Till Menzel, Gerrit Bagschik, and Markus Maurer provides a structured framework for the development of automated vehicles, leveraging the ISO 26262 standard. This research discards the notion of distance-based validation due to its economic impracticality at higher automation levels, proposing instead a scenario-based approach.

Objectives and Methodology

The core idea proposed by the authors is the systematic derivation and use of scenarios to aid in the development, test, and validation process of automated vehicles. The authors identify that scenarios can be applied across the entire V-model-based development process, from high-level concept stages through to detailed test and validation phases. They emphasize the necessity of addressing different levels of abstraction in scenario representation—functional, logical, and concrete.

The paper outlines how these scenario representations can be used to derive work products necessary for the development of automated driving systems adhering to the ISO 26262 standard. Each abstraction level serves a specific purpose within the development cycle:

• Functional Scenarios: Used during the concept phase, providing a high-level, linguistic representation that is human-readable, facilitating expert discussions.
• Logical Scenarios: Utilized during system development to describe parameters in formal notation with defined value ranges, thereby translating linguistic descriptions into a format conducive to technical specification and requirement derivation.
• Concrete Scenarios: Applied during the testing phase. These convert logical scenarios into executable test cases via specific, discrete parameter values, ensuring consistency and reproducibility in testing.

Numerical and Claims Analysis

The authors present their approach as a more tractable and economically feasible method compared to traditional distance-based approaches. The systematic use of scenarios allows for an efficient validation process by significantly reducing the infinite parameter space to a more manageable set, selected through techniques like equivalence class partitioning and boundary value analysis. This reduction in complexity directly implies cost and time efficiencies in the validation process of higher-level automated systems.

Implications

Practically, this approach supports the ongoing development of SAE Level 3 and 4 vehicles by providing a clear, systematic framework for scenario creation and evolution. Theoretically, it contributes to a more consistent definition and understanding of 'scenarios' in the context of automated vehicle development, tackling the previously ambiguous and fragmented use of the term across different domains and studies.

Future Prospects

Looking forward, the authors suggest the need for innovative methods and tools to automate the generation and conversion of scenarios from functional to concrete along the development process. Such advancements would enhance the implementation of safe and reliable automated driving systems. Additionally, integrating existing data formats with the proposed scenario frameworks and refining scenario generation methodologies remain key areas for future investigation. The continuous evolution of these methodologies will likely have a significant impact on the development lifecycle of automated vehicles.

In conclusion, the paper presents a viable avenue for improving the safety and validation processes of automated vehicles, aligning with the structured rigor necessary for compliance with international safety standards. This structured approach addresses key challenges in the field and opens pathways for further advancements in both research and practical implementations.