For a SI engine, algorithms for intake air estimation closed-loop control of EGR and for the cylinder individual estimation of air-fuel ratio have been proposed. The estimation of intake air allows the replacement of the air-mass sensor, it considers fuel vapor, exhaust gas residual, and external exhaust gas recirculation. Closed-loop control of the EGR rate can be achieved by calculating the coefficient of variation of mean indicated pressure, and by controlling it to a pre-specified value. While operating the engine at the limit of driveability during vehicle life-time, the calibration effort is considerably reduced. In spite of the stochastic nature of the combustion events a good control performance can be obtained by adaptive feed-forward control. The estimation of air-fuel ratio based on cylinder pressure signals allows lambda control and the detection of maldistribution. This is of special interest during situations when no sensor signal of the EGO sensor is available, e.g. during warm-up, or for control objectives or situations of lambdas not equal 1, i.e. when no quantitative measure of the lambda-deviation can be provided by the switching EGO sensor. Additionally, lambda can be estimated for each cylinder separately. Cylinder pressure based closed-loop control strategies allow to compensate for manufacturing tolerances, changing ambient conditions and aging, thus engine performance can be maintained during vehicle life-time. Further applications of cylinder pressure sensors for SI engines are the optimized cold start behavior and warm-up of the catalytic converter. Fault detection algorithms like for misfire and knock can be considerably simplified and improved, calibration expense can be reduced. The implemented algorithms proved the considerable potential of cylinder pressure based engine management systems for meeting and maintaining future engine specifications and requirements.
Control of mixture composition using cylinder pressure sensors
Regelung der Gemischbildung auf Basis eines Zylinderdrucksensors
2001
8 Seiten, 9 Bilder, 20 Quellen
Conference paper
English
Control of Mixture Composition Using Cylinder Pressure Sensors
SAE Technical Papers | 2001
|Control of mixture composition using cylinder pressure sensors
Automotive engineering | 2001
|2001-01-3382 Control of Mixture Composition Using Cylinder Pressure Sensors
British Library Conference Proceedings | 2001
|British Library Conference Proceedings | 2000
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