Name
Abstract | ||
|---|---|---|
In this paper, we propose a control strategy to improve the combustion efficiency of Spark Ignited engines. More precisely, we adapt the spark ignition time according to variations of thermodynamic conditions of the combustion chamber during transients. Sensitivity of a simple proposed combustion model (ordinary differential equations governing the flame propagation phenomenon) is used to compute an open-loop control law. An end-point matching condition is formulated to guarantee that the middle of combustion occurs at an optimal time. Simulation results stress the relevance of the approach. timing based on static look-up tables accounting for the current working point. This approach assumes that the engine has reached some steady-state conditions. This is obviously wrong during transients when the thermodynamic parameters mismatch at the beginning of the combustion creates an offset (lead or lag) in the middle of combustion timing. Physically, the spark ignition time (sit) has a major synchronization effect on the whole combustion timeline. Theoretically, it is thus possible to use it to reach an ideal CA50 despite the discussed offsets in the thermodynamical parameters. To compute the relevant updates in sit, we formulate a tar- get reaching problem for a set of two non-linear differential equations over a variable time interval which depends on the sit. Equivalently, after a time change, this problem is turned into a shooting problem. At first order, a sensitivity analysis provides an explicit solution. After some inverse change of variables, an explicit procedure is obtained to determine the update in the sit to compensate the discussed offsets. In this very preliminary work, we wish to prove the concept that a phenomenological model can be exploited to complement static look-up tables during transients. Interestingly, this approach does not require any in-cylinder sensor. This point is supported by numerical results obtained with the AMESim Simulation software. Further work will include experimental validation. |
Year | DOI | Venue |
|---|---|---|
2008 | 10.1109/CDC.2008.4739262 | CDC |
Keywords | Field | DocType |
combustion,differential equations,internal combustion engines,open loop systems,combustion chamber,combustion efficiency,end-point matching condition,flame propagation phenomenon,open-loop combustion timing control,ordinary differential equations,spark-ignited engine,thermodynamic conditions | Combustion,Differential equation,Ignition system,Spark (mathematics),Combustion chamber,Ordinary differential equation,Computer science,Control theory,Homogeneous charge compression ignition,Open-loop controller | Conference |
ISSN | Citations | PageRank |
0743-1546 | 1 | 0.35 |
References | Authors | |
0 | 3 | |
Name | Order | Citations | PageRank |
|---|---|---|---|
| Mathieu Hillion | 1 | 1 | 0.35 |
| Jonathan Chauvin | 2 | 105 | 14.57 |
| Nicolas Petit | 3 | 88 | 20.29 |