TOPEXPERT: Automated and virtual calibration as keys to success

31. March 2016 | Software & Testing Solutions

To meet the strong competition in the worldwide vehicle markets, the complexity of modern engines and their respective engine control units has increased drastically over the last few decades. An exploding amount of hardware variants, several hundred function groups, and up to 40,000 calibration parameters are state of the art and define the daily work of the designated engineers. In contrast to that, development cycles and budget as well as the amount of available project vehicles have been reduced continuously.
To overcome these challenges, new approaches in all contributing parts of the development process are required. It’s necessary not only to do things right, but also to do the right things at the right time. This is expressed, for example, in the idea of consequently moving reasonable parts of the work to earlier stages in the development process. The concept is widely known as “Road 2 Rig 2 Desktop”.

Vehicle calibration work is shifted to the chassis dynamometer or test bed facilities. Test bench tasks are processed and solved by means of “in-the-loop”-solutions – such as model-, hardware- and software-inthe- loop (MiL, HiL, SiL, etc.) or even full simulation. It is directly obvious that all of these steps require a reasonable amount of knowledge about the behavior of those components that are necessary to be removed while stepping back along the process. As a replacement, data-driven and physical models fill the gaps.


Benefits of the TOPEXPERT environment

FEV’s excellence in virtual calibration additionally manifests itself in our TOPEXPERT framework. It smartly connects the diversity of all the expertise and knowhow of FEV’s engineers to the benefit of the user. This ranges from FEVcal, the new solution for Design of Experiment, over domain-specific tools, to the general Framework for Automated Calibration and Evaluation (FACE) and Vehicle Test Automation (VTA). All these are built on the basis of a generalized software architecture and thus ensure close integration of all TOPEXPERT tools. The user experiences a unified handling and usability based on a guided calibration approach by means of workflows. Allactions are performed in terms of activities, which are assembled in task- and domain-tailored combinations. This eases the learning and makes the interaction with the tools fluent, intuitive for the respective field of usage, and, on request, specifically adapted to directly match the customer’s needs.

Hands-on TOPEXPERT – One calibration in a day

A very important aspect of any software with a complex technological background is its capability to make the theory as easy as possible to apply, even for less experienced users. One of many examples is the interaction of VTA, FACE, and FEV’s test bench automation system TCM. It serves the goal of fully automated boost pressure governor calibration. Operation points for required step response measurements are selected by VTA automatically and the respective tests are performed with TCM. After finishing a required set of measurements, the acquired data is seamlessly evaluated with FACE. Sections of importance are determined, plant identification is performed and the final PID controller parameters are optimized. These results are pushed into smooth calibration maps and their closed loop performance is directly validated by VTA after a final calibration data set is exported. In this way, the typically manual and iterative task of parameter tuning is solved by means of a tailored model-based solution and leads, in its fully automated fashion, to massively increased efficiency.


Plant identification and parameter optimization


Actuator linearization