IMEP Estimation from Instantaneous Crankshaft Torque Variation

<div class="htmlview paragraph">Crankshaft torque fluctuation has been theoretically analyzed and possible sources of error have been reviewed in the cases of determining the indicated mean effective pressure (P<sub>mi</sub>) from measurement of the flywheel angular-speed fluctuation.</div> <div class="htmlview paragraph">The specific objective of this study was to develop a new approach to determine P<sub>mi</sub> from the crankshaft torque of a SI engine, and it has successfully proven that using an appropriate data processing for the angular-speed fluctuation, P<sub>mi</sub> in low- to medium-speed ranges can be estimated with very high accuracy in terms of 99% or higher coefficient of correlation to the in-cylinder pressure sensor.</div>