A MODEL-BASED APPROACH FOR DETERMINING DATA QUALITY METRICS IN COMBUSTION PRESSURE MEASUREMENT

Measuring and monitoring the cylinder pressure in relation to the instantaneous cylinder volume allows the engineer to gain a great deal of information about the quality and efficiency of the energy conversion process taking place inside the cylinder. Many useful metrics can be derived or extracted from the pressure curve and these parameters are well established. This article forms the basis to propose a set of basic combustion data metrics that can be used to establish the quality of measured data. The proposed indicators can be used to establish fitness for purpose of the proposed system set-up for various measurement applications, prior to undertaking the critical measurement task. In addition, these metrics can be used or monitored during system run time, to ensure consistent data quality throughout short-or long-term test procedures, in addition to allowing identification of measurement drift or step change factors that could affect data quality over time. This article shows the application of DoE-based testing and a model-based approach in order to establish the response of newly developed metrics when stimulated with target error variations. The output could be used to understand the variation and interactions of the newly developed metrics, and also to understand if they would be usable for the application suggested. It was found that not all of the results that were tested could be utilized, but the test and measurement environment, plus the unique application of model-based testing, facilitated an efficient working environment to support future development work.