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Identification, Quantification and Reduction of Sources of Variability in Vehicle Emissions and Fuel Economy Measurements
ISSN: 0148-7191, e-ISSN: 2688-3627
Published February 01, 1979 by SAE International in United States
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A major problem in Vehicle Exhaust Emissions and Fuel Economy Testing has been the variability in the measurements. An extensive test program was undertaken to identify and quantify the sources of variation. The test program was designed using four test vehicles on five CTE-50 Clayton Dynamometer cells whereby four repeats for each combination were provided for a total of 80 CVS-C/H Emissions and F.E. Tests. During each test a total of 23 test variables were monitored and recorded in real time. Nine other variables were also observed for a total of 32 variables: 5 vehicle related variables, 16 engine related, 4 dynamometer variables, 3 driver related, and 4 environment variables.
The paper reports various results of this experiment and describes an instrumentation package that was developed for “on-line” data recording. A brief discussion of the software used for “off-line” processing of the voluminous data as well as several statistical analysis techniques which were developed especially for identifying and quantifying the sources of variation, are included. The benefits which result from reduced test variability, namely lower test cost because of improved test efficiency and increased confidence in results, are pointed out.
CitationSheth, N. and Rice, T., "Identification, Quantification and Reduction of Sources of Variability in Vehicle Emissions and Fuel Economy Measurements," SAE Technical Paper 790232, 1979, https://doi.org/10.4271/790232.
- “Analysis of the Measuring and Testing Procedures for Motor Vehicle Exhaust Emissions Regulated in Europe and the U.S.A.,” Research Department, Volkswagen, Wolfsburg, Germany, June 1977.
- Juneja, W.K., Horchler, D.D. and Haskew, H. M., “A Treatise on Exhaust Emission Test Variability,” SAE Paper 770136, SAE International Automotive Engineering Congress and Exposition, Detroit, February 1977.
- Lipsion, C. and Sheth, N.J., “Statistical Design and Analysis of Engineering Experiments,” McGraw-Hill Book Company, Copyright 1973.