DocumentCode :
36360
Title :
Reducing Cyclic Variability While Regulating Combustion Phasing in a Four-Cylinder HCCI Engine
Author :
Hellstrom, Erik ; Larimore, Jacob ; Jade, Shyam ; Stefanopoulou, Anna G. ; Li Jiang
Author_Institution :
Dept. of Mech. Eng., Univ. of Michigan, Ann Arbor, MI, USA
Volume :
22
Issue :
3
fYear :
2014
fDate :
May-14
Firstpage :
1190
Lastpage :
1197
Abstract :
The cyclic variability (CV) at late phasing conditions in autoignition engines with high residuals limits the operating range of such advanced combustion strategies. A model has been recently proposed by the authors that captures the experimental observations of CV in lean autoignition combustion in a single-cylinder engine. The model is here tuned to multicylinder engine data and is used to design controllers that reduce the CV. The dynamics are only stable for certain amounts of residual gas. At late phasing, with low amounts of residual gas, a cascade of period-doubling bifurcations occur leading to seemingly chaotic behavior. The deterministic dynamics are also mixed with significant levels of noise in the residual gas fraction. The approach to reduce CV is to control the fuel injection timing, which is an effective way of influencing the combustion phasing in the individual cylinders, with feedback from the combustion phasing. A PI controller and a reduced-order linear quadratic Gaussian (LQG) controller are designed and evaluated in experiments. Integral action is utilized for maintaining the average combustion phasing between open loop and closed loop, which is shown to be essential for a proper evaluation because of the high sensitivity of CV on the combustion phasing close to unstable operation. A quantitative analysis of the experimental results show that CV is notably reduced for various levels of residual gas fraction at one speed and load. The standard deviation of the combustion phasing is reduced by 17% on average over the open-loop behavior, which results in a 15% smaller coefficient of variation of the indicated work.
Keywords :
PI control; bifurcation; control system synthesis; fuel systems; ignition; internal combustion engines; linear quadratic Gaussian control; CV; LQG controller; PI controller; autoignition engines; combustion phasing regulation; controller design; cyclic variability; four-cylinder HCCI engine; fuel injection timing control; homogeneous charge compression ignition; late phasing conditions; lean autoignition combustion; period-doubling bifurcations; reduced-order linear quadratic Gaussian controller; residual gas fraction; Combustion; Eigenvalues and eigenfunctions; Engines; Fuels; Mathematical model; Timing; Valves; Bifurcation; internal combustion engines; linear feedback control systems; nonlinear dynamical systems; stability; stability.;
fLanguage :
English
Journal_Title :
Control Systems Technology, IEEE Transactions on
Publisher :
ieee
ISSN :
1063-6536
Type :
jour
DOI :
10.1109/TCST.2013.2271355
Filename :
6558764
Link To Document :
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