Model based TDC offset estimation from motored cylinder pressure data

Research output: Chapter in Book/Report/Conference proceedingPaper in conference proceeding

Abstract

Finding the correct top dead center (TDC) offset for an internal combustion engine is harder than it seems. This paper introduces a novel method to find the TDC offset based on a simple assumption that the heat loss power through the combustion chamber walls is constant for motored cycles in a narrow crank angle interval around TDC. The proposed method uses nonlinear least squares optimization to find the combination of specific heat ratio and TDC offset that makes the heat loss power as constant as possible. The standard deviation of the TDC estimate is approximately 0.05° crank angle (CA) when using a crank resolution of 0.2°CA for the measurements. The bias of the TDC estimate is in the 0-0.02°CA range both when comparing to measurements with a TDC sensor and with simulated motored cycles. The method can be used both for calibration and on-board diagnostics purposes e.g. during cranking, fuel cut-off or engine switch-off.

Details

Authors
Organisations
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Energy Engineering

Keywords

  • Cylinder pressure, Estimation, Least squares estimation, LLS, NLLS, TDC offset
Original languageEnglish
Title of host publicationIFAC Proceedings Volumes
Pages241-247
Number of pages7
Volume42
Edition26
ISBN (Electronic)1474-6670
Publication statusPublished - 2009
Publication categoryResearch
Peer-reviewedYes
Event2009 IFAC Workshop on Engine and Powertrain Control, Simulation and Modeling, E-COSM'09 - Rueil-Malmaison, France
Duration: 2009 Nov 302009 Dec 2

Conference

Conference2009 IFAC Workshop on Engine and Powertrain Control, Simulation and Modeling, E-COSM'09
CountryFrance
CityRueil-Malmaison
Period2009/11/302009/12/02