Automatisierung der Testauswertung für Steuergerätesoftware

In the testing process of ECU software, often both stimuli and system reactions exist as time-dependent signals. This makes a comparison of time-dependent (output-)signal forms necessary for the comparative test of different versions or development artifacts (regression / back-to-back tests) of these systems. Existing approaches for the automation of such signal comparisons are based on simple difference calculations or on standard methods from the area of signal processing and do not provide satisfying results in the case of more complex applications. The newly developed difference matrix method surmounts the limitations of currently used standard methods. Because of its multistage approach, it makes an automated evaluation of the similarity of signal forms in compliance with practical requirements of the application area possible. This offers the possibility for an automated analysis of large parts of regression and back-to-back tests necessary during the development of ECU software. It also ensures a more cost effective test execution. Furthermore, the method allows the detection of various systematic errors, for example relative scaling and local shifts of signals. The automated evaluation method presented is currently being pilot-tested by the DaimlerChrysler Group. The experiences gained in this process are addressed as well.