자율주행 안전 (SOTIF) 용어 정리

해당 포스팅은 차량 자율주행 안전 표준인 SOTIF 의 정의된 용어 중 Scenario 에 관한 내용을 정리합니다.

Term	Description
use case	description of a suite of related scenarios Note 1 to entry: A use case can include the following information about the system: - one or several scenarios; - the functional range (e.g. maximum allowed speed, maximum allowed deceleration); - the desired behaviour; - the system boundaries; - assumptions on the environment and human operation Note 2 to entry: The use case description typically does not include a detailed list of all relevant scenarios for this use case. Instead a more abstract description of these scenarios is used.
scenario	description of the temporal relationship between several scene in a sequence of scenes with goals and values within a specified situation, influenced by actions and events. Note 1 to entry: Every scenario starts with an initial scene. Actions and events, as well as goals and values, can be specified to characterise this temporal relationship within a scenario. In contrast to a scene, a scenario spans a certain amount of time.
scene	snapshot of the environment including the scenery, dynamic elements, and all actors' and observers' self-representations, and the relationships among those entities. Note 1 to entry: A scene can include environmental elements (state, time, weather, lighting and other surrounding conditions), road infrastructure or internal elements (road or interior geometry, topology, quality, traffic signs, barriers, etc.) and objects/actors (static, dynamic, movable, interactions, maneuvres if applicable) Note 2 to entry: An all-encompassing scene (i.e. an objective scene or ground truth) incorporating all entities (e.g. scenery, dynamic elements, actors) can only be modelled in simulation. In the real-world, scenes are perceived by sensors. The scene perceived by the ego vehicle or human driver is an incomplete, inaccurate, uncertain and potentially erroneous projection of ground truth.
situation	all relevant conditions, options and determinants for the choice of an appropriate behaviour of the system under consideration at a particular point in time Note 1 to entry: A situation is derived from the scene by an information selection and augmentation process that is based on transient (e.g. mission-specific) as well as permanent goals and values. Hence, a situation is always subjective as it represents an element's point of view.
action	single act or behaviour that is executed by any actor in a scene Note 1 to entry: The temporal sequence of actions/events and scene specify a scenario. EXAMPLE Ego vehicle activates the hazard warning lights. Note 2 to entry: In the context of this definition, an actor can be a person, another system or any element in interaction with the considered function.
event	occurrence at a point in time Note 1 to entry: The temporal sequence of actions/events and scenes specify a scenario. EXAMPLE 1 Tree falling on a street 50m ahead of a vehicle. EXAMPLE 2 Traffic light turning green at a given time