An Efficient Test Methodology for Combustion Engine Testing: Methods for Increasing Measurement Quality and Validity at the Engine Test Bench

Improving fuel efficiency while meeting relevant emission limits set by emissions legislation is among the main objectives of engine development. Simultaneously the development costs and development time have to be steadily reduced. For these reasons, the high demands in terms of quality and validity of measurements at the engine test bench are continuously rising. This paper will present a new methodology for efficient testing of an industrial combustion engine in order to improve the process of decision making for combustion-relevant component setups. The methodology includes various modules for increasing measurement quality and validity. Modules like stationary point detection to determine steady state engine behavior, signal quality checks to monitor the signal quality of chosen measurement signals and plausibility checks to evaluate physical relations between several measurement signals ensure a high measurement quality over all measurements. For increasing measurement validity, engine setting parameters are permanently monitored to ensure exact and consistent engine adjustments according to the test plan. Furthermore, embedded 0D engine simulations are used to correct undesired setting parameter deviations in order to create a consistent data base used for model-based optimization (DoE) and combustion-relevant component decisions. The methodology was verified by a measurement campaign carried out at an industrial engine. The new methodology is reducing potential incorrect measurements that have to be repeated. In addition, it ensures that only valid measurements are taken for model-based techniques (DoE) that have been 0D-corrected if necessary. Test bench time can be shortened, leading to a reduction in and better utilization of development costs as well.