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Determining TDC Position Using Symmetry and Other Methods
Technical Paper
2004-01-1458
ISSN: 0148-7191, e-ISSN: 2688-3627
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English
Abstract
It is important to determine the phasing of a measured cylinder pressure trace and crank angle with high accuracy. The reason is that erroneous determination of the position of TDC is a major error source when calculating properties such as heat release etc. A common way to determine the TDC position is to study motored cycles. Heat transfer makes the task more complicated, since it shifts the position of the maximum pressure away from TDC.
In this paper a new method for determining the TDC position is proposed that does not require any additional sensors other than a cylinder pressure sensor and an incremental encoder. The idea is to find a point that the cylinder pressure from a motored cycle is symmetric around, since the volume is close to symmetric on either side of TDC. The new method and four published methods are tested and evaluated. Cylinder pressure data used for comparison are from simulations of a SAAB Variable Compression engine. The investigation shows that the methods have an error that is in the range of 0.1° or less, but are sensitive to errors in geometry and heat transfer information. The symmetry method is less sensitive to these errors than most of the other methods, and is not affected by an offset or gain error in the cylinder pressure signal. It is also the least sensitive method with respect to noise.
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Citation
Nilsson, Y. and Eriksson, L., "Determining TDC Position Using Symmetry and Other Methods," SAE Technical Paper 2004-01-1458, 2004, https://doi.org/10.4271/2004-01-1458.Also In
References
- Rocco V. DI diesel engine in-cylinder pressure data analysis under TDC setting error SAE Technical Paper 930595 1993
- Brown W.L. Methods for evaluating requirements and errors in cylinder pressure measurements SAE Technical Paper 670008 1967
- Staś Marek J. Thermodynamic determination of TDC in piston combustion engines SAE Technical Paper 960610 1996
- Tazerout M. Le Corre O. Rousseau S. TDC determination in IC engines based on the thermodynamic analysis of the temperature-entropy diagram SAE Technical Paper 1999-01-1489 1998
- Morishita Mitsue Kushiyama Tadashi An improved method for determining the TDC position in a pv-diagram (first report) SAE Technical Paper 970062 1997
- Drangel H. Reinmann R. The variable compression (SVC) and the combustion control (scc) - two ways to improve fuel economy and still comply with world-wide emission requirements SAE Technical Paper 2002-02-0996 2002
- Hribernik Ales Statistical determination of correlation between pressure and crankshaft angle during indication of combustion engines SAE Technical Paper 982541 1998
- Pinchon Ph. Calage thermodynamique du point mort haut des moteurs a piston Revue de l'institut francais du pet-role 39 1 93 111 January 1984
- Heywood J. B. Internal Combustion Engine Fundamentals McGraw-Hill series in mechanical engineering McGraw-Hill 1988
- Woschni G. A universally applicable equation for the instantaneous heat transfer coefficient in the internal combustion engine SAE Technical Paper 670931 1967
- Nilsson Ylva Eriksson Lars A new formulation of multi-zone combustion engine models Karlsruhe, Germany IFAC Workshop: Advances in Automotive Control 2001
- Eriksson Lars CHEPP - a chemical equilibrium program package for matlab SAE Technical Paper 2004-04-0066 2004
- Nilsson Ylva Cylinder volume function for SVC engines Technical report Department of Electrical Engineering 2001 http://www.fs.isy.liu.se/Publications/
- Stone R. Introduction to Internal Combustion Engines SAE International third 1999