ASAM OpenSCENARIO® XML

ASAM OpenSCENARIO® XML

DATASHEET
Domain
Simulation
Current Version
1.2.0
Release Date
13 May 2022
Application Areas
  • Description of vehicle maneuvers
  • Driving simulation
  • Traffic simulation
Specification Content
  • XML schemata
File Formats
  • xosc
Scope
Dynamic scenario description
Current projects

(The download of ASAM OpenSCENARIO XML is free of charge)

ASAM OpenSCENARIO XML defines a file format for the description of the dynamic content of driving and traffic simulators. The primary use-case of ASAM OpenSCENARIO XML is to describe complex, synchronized maneuvers that involve multiple entities like vehicles, pedestrians and other traffic participants. The description of a maneuver may be based on driver actions (e.g. performing a lane change) or on trajectories (e.g. derived from a recorded driving maneuver). Other content, such as the description of the ego vehicle, driver appearance, pedestrians, traffic and environment conditions, is included in the standard as well.

The standard describes vehicle maneuvers in a storyboard, which is subdivided in stories, acts and sequences. A story can describe the driving maneuvers of one single vehicle or specify the dynamic behavior of several entities (e.g. vehicles perform a lane change once they reach a specific position). Stories consist of acts, which are triggered when a specific condition is met, such as exceeding a defined speed, reaching a defined distance to a vehicle ahead or going off-road. By using the notion of sequences, the standard allows to define the maneuvers of multiple vehicles in response to that. The maneuver of one car could be a lane change, overtaking another car or driving in a traffic jam while creating a corridor for emergency vehicles. The detailed driving behavior of the vehicle is described via events (i.e. when does it happen?) and actions (i.e. what happens?). Actions may be related to one vehicle and can include speed changes, lane changes or drive to a specified position. Routes and trajectories can be defined that the vehicle shall follow. Actions may also be related to the environment and can include the change of a traffic light or the occurrence of a traffic jam.

Maneuvers, actions, trajectories and other elements can be organized in catalogs and can be parameterized. Additionally, complete scenario descriptions support parameterization, which allows test automation without the need to create a large amount of scenario files.

The data for maneuver descriptions in ASAM OpenSCENARIO XML is organized in a hierarchical structure and serialized in an XML file format. The schema is provided with the standard. The XML file can be easily validated, edited, imported and exported by simulation tools and content editors. The format is technology and vendor independent. 

Maneuver descriptions are an essential part in an effort to test, validate and certify the safety of driver assistance systems and autonomous driving cars. The industry, certification agencies and government authorities jointly work on the definition of maneuver libraries, which can be used to ensure the safe operation of such systems. A publicly developed and vendor-independent standard, such as ASAM OpenSCENARIO XML, is well suited for this purpose. However, despite the clear and unambiguous maneuver descriptions through a standardized format, it is common understanding that simulation results will not necessarily be the same on different simulators.

The standard is used together with road network descriptions from ASAM OpenDRIVE and can use road surface profiles from ASAM OpenCRG. The three standards complement each other and cover the static and dynamic content of in-the-loop vehicle simulation applications.

 

ASAM OpenSCENARIO XML and DSL

ASAM OpenSCENARIO occupies a unique position among the ASAM OpenX standards in that there are two standards developed in parallel: ASAM OpenSCENARIO XML  and ASAM OpenSCENARIO DSL.

ASAM OpenSCENARIO XMLASAM OpenSCENARIO DSL
 
  • Defines XML schema for describing scenarios with synchronized maneuvers of vehicles, pedestrians, and other traffic participants
  • Supports specifying precise trajectories with a capability to parameterize and vary their properties
  • Structured format that can be validated, edited, imported, and exported by simulation tools and content editors
  • Tuned to support trigger-action scenario descriptions
  • Optimized for simple machine parsing and processing
 
 
  • Defines domain specific programming language for describing test scenarios of synchronized maneuvers of vehicles, pedestrians, other traffic participants and ADS function control
  • Supports specifying scenario intent at a higher level of abstraction along with KPIs, checks, & coverage metrics
  • Built-in abstract road descriptions
  • Designed to enable exploration of scenario/functionality space to identify potential unknowns
  • Optimized for composability to maximize scenario reuse
  • Designed as V&V programming language
  • Enables higher level of automated test generation at scale 
 

Differentiation
Each of these standards occupies a different position in the application toolchain. To help users determine the most appropriate standard for their use case, the standards are delineated by their primary use case. These use cases describe what the standard is intended for and are the basis for key considerations behind many design decisions. However, this primary use case is not exclusive, the standards may be (and are) used for a wide variety of additional use cases, with overlap, but these are not specified here.

Primary use cases:

  • ASAM OpenSCENARIO XML: Predictable highly precise scenarios that may be used with an external test specification for V&V
  • ASAM OpenSCENARIO DSL: Large-scale V&V of the safety and functionality of autonomous vehicles (AV) and advanced driver-assistance systems (ADAS)

Alignment
Continued alignment of the two standards is encouraged but not required by ASAM. It is not part of the formal roadmap of ASAM OpenSCENARIO. It is rather subject to the project participant's interests and will be driven by the market/members.

The main motivators of current participants for future & continued alignment are:

  • Joint use of the scenario standards with ASAM's other standards (e.g. ASAM OpenDRIVE®, ASAM OSI®). Sometimes both scenario standards are used in the same toolchain. 
  • Similar terminology and domain concepts ensure better shared understanding of the same concepts.
  • Generation of scenario descriptions from one version to another (e.g. from abstract OpenSCENARIO DSL scenario descriptions to concrete OpenSCENARIO XML descriptions)
  • Alignment of domain models between versions makes it easier for implementers by saving on implementation time, e.g., of misaligned features

Where will alignment be focused:

  • Alignment should take place between standards on any topic where domain concepts are impacted. This means any new features or significant modifications to existing features as soon as any implications for domain concepts are identified.
  • Core language development will not be subject to active alignment
  • Domain model (entities, actions) changes in either version will be approached jointly, however complete alignment is not required
  • Difference as of today: Alignment is neither migration nor conversion.

How will alignment take place

  • The project will make a 'best effort' to achieve joint consensus on direction of features or domain model concepts between the standards. Where deviations occur, these shall be documented.
  • The final decision process is independent between the standards. No overall consensus is required. Voting is constrained to enrolled participants of the projects or subgroups for the respective standards.

 


DATASHEET
Domain
Simulation
Current Version
1.2.0
Release Date
13 May 2022
Application Areas
  • Description of vehicle maneuvers
  • Driving simulation
  • Traffic simulation
Specification Content
  • XML schemata
File Formats
  • xosc
Scope
Dynamic scenario description
Current projects
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