Convergence of Physical Testing and Simulation - ATFx simplifies Data Exchange

In the context of vehicle development, physical tests are increasingly being replaced by powerful simulation tools. But also in future, physical tests must continue to provide real data for the development of virtual models and the final validation of the vehicles. Simulation and physical testing must therefore complete each other over the long term.

However, the efficient exchange of data between various tool chains in simulation and those in physical testing is a challenge for many users. This applies in particular when the data coming from simulation has to be unambiguously comparable with that from physical testing. It is obvious that in this situation a uniform data exchange format is required.

Unfortunately, the exchange of data is not an issue in which companies want to invest a lot. Therefore, the data exchange format must be based on standards that are already available in the industry and have proven themselves in practice. In terms of tool integration and daily use, it is important that the data exchange format is easy to implement and maintain.

ATFx is a data exchange format that meets exactly these requirements. It is part of the ASAM ODS standard and allows both metadata and measured or calculated values to be transported. In terms of structure, ATFx is an XML file with which the context of measured or calculated data can be completely described. The format can refer to other data in binary files (e.g. MDF4) or to file attachments. In this way, huge amount of data can be exchanged between different simulation and measurement systems in such a way that all parties can correctly interpret the information.

A good example of how to apply ATFx is the data exchange format FDX, which was defined by the VDA Working Group “Functional Data Exchange”. FDX supports the structured transmission of so-called functional data (e.g. maps, characteristic curves, characteristic values). It describe the characteristic properties (= functions) of vehicle components (e.g. shock absorbers). Functional data is typically derived from discrete measurements (= testing). It is an important basis for the design and ongoing improvement of simulation models as part of virtual vehicle development.

Meta information plays an important role in functional data. They provide engineers with detailed information about the respective vehicle component and how its functional data was measured, calculated or estimated. Without this information, the functional data of a component would be meaningless.

Accordingly, the prerequisite for the smooth exchange of functional data is a jointly defined meta data model. For FDX it is derived from an ASAM ODS-compliant model template (= application model), namely the application model of openMDM®. Its full compatibility with the ASAM ODS standard ensures that all ODS-compatible applications can read and uniformly interpret the FDX data.

In the field of testing, there already have long been a large number of tools on the market that can export and import ATFx files. In the meantime, some providers of simulation tools have also expanded their applications in this direction. This makes data exchange between test and simulation increasingly easier. At the same time, quality and availability of data for simulation improves.

Companies that want to set up a central repository for exchanging, sharing and comparing data from simulation with that from physical testing can use the components of the open source framework openMDM®. Several providers around the globe offer appropriate software tools and services that ensure the efficient implementation of openMDM®-based applications.

Practice has shown that the consistent use of standards for test data management, such as ASAM ODS, ATFx and openMDM®, sustainably improves the interoperability between different tool chains. And that applies to all virtual and physical test domains in vehicle development.