ASAM OpenCRG®

ASAM OpenCRG®

DATASHEET
Title
Curved Regular Grid
Domain
Simulation
Current Version
1.2.0
Release Date
30 Sep 2020
Application Areas
  • Description of road surfaces
  • Endurance simulation
  • Driving simulation
  • Traffic simulation
Specification Content
  • File format specification
  • C API description
  • MATLAB API description
File Formats
  • crg

(The download of the standard ASAM OpenCRG is free of charge)

ASAM OpenCRG defines a file format for the description of road surfaces. It was originally developed to store high-precision elevation data from road surface scans. The primary use for this data is in tire, vibration or driving simulation. Precise elevation data allows realistic endurance simulation of vehicle components or the entire vehicle. For driving simulators, it allows a realistic 3D-rendering of the road surface. The file format can also be used for other types of road surface properties, e.g. for the friction coefficient or grey values.  

The standard describes a method to store the data in a specific layout, called "curved regular grid" (abr. CRG). The advantages of this method are high memory efficiency, low computation time for file generation and data processing in simulation tools, and high accuracy of positioning the data onto road networks.

The basic principle for describing the road surface is to place the data into a grid along a road reference line. Line segments are described by a start position and heading angle. The grid is produced by longitudinal cuts (columns) and lateral cuts (rows) along consecutive line segments. Each cell in this grid has a value, typically the elevation. The road center line also includes the end position, which can be used to detect and correct a potential drift of the placement of the data on roads.

ASAM OpenCRG defines ASCII and binary file formats with clear-text headers. The header contains road parameters for the reference line and the overall configuration of the longitudinal sections, a definition of the data format (ASCII and binary), the sequence of data which is expected in the trailing data block, and modifier and option parameters. Furthermore, OpenCRG-files may contain references to other files (typically containing the actual data) to handle different parameters for the same data set.

Data from ASAM OpenCRG can be included in OpenDRIVE road network descriptions. The dynamic content of driving simulations, such as vehicle maneuvers, can be described with ASAM OpenSCENARIO. The three standards complement each other and cover the static and dynamic content of in-the-loop vehicle simulation applications.

The standard is delivered with software libraries in ANSI-C and MATLAB. The libraries for both languages contain functions for reading CRG files, and for modifying and evaluating the imported data. In addition to that, the MATLAB library contains functions to generate, analyze and visualize the data.


Standard Authors

Audi, BMW AG, Daimler AG, Porsche AG, Volkswagen AG, 3D Mapping Solutions GmbH, Cruden B.V., OTSL Inc., VIRES Simulationstechnologie GmbH.


Older Version

ASAM was entrusted with the further development of OpenCRG in 2018 (READ MORE). The first version released by ASAM is OpenCRG V1.2.0. For a matter of completeness, we are providing the predecessor version "OpenCRG V1.1.2" on our website:

OpenCRG V1.1.2. was published by VIRES Simulationstechnologie GmbH. This version is the intellectual property of VIRES Simulationstechnologie GmbH. ASAM e.V. does not assume any liability for completeness, correctness or other issues. For liability claims, questions or other matters, please contact VIRES Simulationstechnologie GmbH at info(at)vires.com. 


DATASHEET
Title
Curved Regular Grid
Domain
Simulation
Current Version
1.2.0
Release Date
30 Sep 2020
Application Areas
  • Description of road surfaces
  • Endurance simulation
  • Driving simulation
  • Traffic simulation
Specification Content
  • File format specification
  • C API description
  • MATLAB API description
File Formats
  • crg
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