New ASAM Standards Raise ECU Calibration To Higher Level by Capturing Expert Knowledge

HOEHENKIRCHEN, GERMANY, 2016 – The process of ECU Calibration is driven by highly-specialized domain experts, who have a lot of system, controls and software knowledge. In the best case, this knowledge is documented via semi-formal methods in documents, spread sheets or programming scrips. In the worst-case, the knowledge exists within individual experts only and is passed on to others on-the-job. Some companies in the automotive industry started internal projects to develop in-house description methods and tools to capture this business-critical knowledge. However, the development is costly and has shown mixed results.

ASAM has tackled this problem with experts from twelve member companies from across the automotive industry by developing two new standards:

ASAM MCD-2 CERP (Calibration Expert System Rule and Product Format) covers the use-cases to describe ECU Calibration parameter dependencies and plausibility checks. Modern ECUs can have several ten thousand Calibration parameters, curves and maps, which depend on product properties and have interdependencies among each other. As a first step, the Standard defines a product model, which allows to describe product-specific parameters such as the number of cylinders of an engine or the emission law to which the engine has to comply with. These parameters are typically not stored in ECUs. Based upon OTX (ISO 13209), the Standard then allows as a second step to describe dependencies of Calibration parameters with product model parameters and other Calibration parameters. Since the OTX programming language is Turing-complete, it is possible to write complex check routines including branches, loops, conditions and mathematic calculations. ASAM MCD-2 CERP adds Calibration-specific routines such as access to Calibration parameter data (according to ASAM MCD-2 MC), Calibration runtime data (ECU values, units) and the product model data. Additionally, sophisticated check functions and procedures are defined to compare and validate data.

ASAM CPX (Calibration Process Exchange Format) covers the Use-Case of describing Calibration test sequences and processes. The industry increasingly demands that this critical process knowledge is documented, is usable by other people, and that its execution can be automated as much as possible. ASAM CPX is an extension of OTX (ISO 13209), which provides the necessary functionality. For example, the Standard provides programmatic access to Calibration and Measurement data on the ECU, access to meta information about this data (from A2L files), functions for controlling the execution of Measurement tests and Simulation models, and specific mathematical functions. Further extensions of OTX even allow to use flow charts and state machines to describe the Calibration process.

ASAM tool vendors are currently in the process to develop tools based on these new standards. As soon as they become available, automotive companies have a chance to raise their ECU development process to a higher level. Calibration processes and Calibration parameter dependencies can be formally described, automatically executed or checked, and easily passed on to other experts or business partners. Expert knowledge becomes independent from persons or tools, can be put into libraries and is available to quickly setup new Calibration projects. The increasing complexity of ECUdevelopment becomes better manageable with these expert systems. They have the potential to shorten the development time, improve Calibration quality and to overall reduce the costs of ECU development.

The standards are available for immediate download for ASAM members or purchase for non-members.

About ASAM e.V.
 

ASAM e.V. coordinates the development of technical standards. These standards define protocols, data models, file formats and application programming interfaces (APIs) for the use in the development and testing of automotive electronic control units. A large amount of popular tools in the areas of Simulation, Measurement, Calibration and test automation are compliant to ASAM standards. Compliance shall guarantee interoperability of tools from different vendors, allow data exchange without the need for converters, and facilitate the exchange of unambiguous Specification between customers and suppliers.

Founded in 1998 as a German association, ASAM has today more than 200 international members, including major OEMs in Germany, France, Great Britain, US, Japan, and China. ASAM has a portfolio of 24 standards among them the well established MCD (measuring, Calibration, Diagnostics)-standards with a market distribution of up to 80% worldwide. The infrastructural standards of ASAM are used by many of the big international OEM