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To meet future pollutant emissions standards, it is crucial to be able to estimate the cycle by cycle in-cylinder mass and the composition of the combustion chamber charge. This charge consists of residual gases from the previous cycle, fresh air and fuel. Consequently, the estimation of the fresh air mass based on total in-cylinder mass is a function of residual gas fraction. This estimation is essential to compute the fuel mass to be injected. This paper proposes an algorithm, based on physical equations, which estimates the in-cylinder total mass based on cylinder pressure. A residual gas model, which computes the burned gas fraction, is then used to determine the fresh air mass. The paper shows that the algorithm, tested on a Spark Ignited engine, is very robust to noise. To test the estimator several parameters are varied: valve timing, cylinder pressure sampling period, residual gas fraction, cylinder pressure offset and exhaust gas temperature.

To meet future pollutant emissions standards, it is crucial to be able to estimate the composition of the combustion chamber charge on a cycle by cycle basis. This charge consists of fresh air, fuel and residual gas from the previous cycle. Unfortunately, the residual gas fraction cannot be directly measured. Therefore, a model of residual gas fraction as a function of engine parameters and operating parameters has been developed. The model has been calibrated with exhaust pipe hydrocarbon measurements using a successive dilution method.

To meet future pollutant emissions standards, it is crucial to be able to estimate the cycle by cycle composition of the combustion chamber charge. This charge consists of fresh air, fuel and residual gas from the previous cycle. Unfortunately, the residual gas fraction cannot be directly measured. Therefore, a model of residual gas fraction as a function of engine parameters and operating parameters has been developed. The model has been calibrated with exhaust pipe hydrocarbon measurements using a successive dilution method.

Torque based engine control seems to be the trend for the future for powertrain management (automatic gearbox, hybrid vehicles). Today, torque estimation is best achieved using cylinder pressure transducers. This paper proposes a method to achieve a good accuracy of the torque using Bézier curves to reconstruct the cylinder pressure peak from the low frequency embedded pressure measurements. As is, IMEP cannot be used on a cycle to cycle basis for engine torque control, due to the very high cycle to cycle variability of SI engines. To improve the quality of the IMEP feedback data, this paper proposes a moving horizon filtering method.

The optimization of fuel efficiency and the minimization of the residual gas fraction require individual cylinder control of the amounts of inducted air mass and injected fuel mass. Determination of an individual cylinder air/fuel ratio (AFR) regulator is based on the measured AFR for each cylinder, using 4 proportional UEGO sensors. The innovative character of this study describes a unified and robust individual cylinder AFR estimator, using a single measuring point: a proportional oxygen sensor located in the exhaust manifold. The model used for the estimator is a state model such that the dimension of the state and measurement matrices are unique, whatever the manifold configuration and the sensor position (confluence point or exhaust manifold: unified model), the engine speed (robust model).

The aim of the project described in this paper is to control the behavior and trajectory of a vehicle when different parameters - such as the lift and/or the aerodynamic parameters - change, i.e., increase or decrease. The problem is tackled, whatever the mode of propulsion of the vehicle ( combustion engine or electric motor and wheel transmission - or reactor ). This paper describes one way of developing the architecture of such a system for the control of the functions of route guidance, of the changes in attitude which lead to a modification of the aerodynamic forces according to the speed variations and more generally the vehicle's dynamics. An active system based on torque and slip controls of each wheel allows the control of rolling. The wheel propulsion mode and freewheel mode are considered in a similar way. The function of attitude correction uses an active system controlling a hydraulic jack mounted in the suspension.

This article presents the results obtained in regulating complex physical systems of low time- constants-often less than a second or even a tenth of a second. Special emphasis is placed on unstable systems -or those that may become such in certain working conditions. These systems which are difficult to regulate require special precautions in real industrial uses. Different algorithms such as controls using PID (Proportional plus Integrator plus Derivator controller) or pole placement, adaptive controls or, in some cases generalised predictive controls, have been tested and compared. In the case of adaptive controls, special care is given to the problem of parameter initialization which is often crippling for such uses as the ones described here. A compromise between implementation and operation costs, calculation time, performance, etc, must be found. Our application is a real industrial example: the braking system of a vehicle.