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The design and the supervision of hybrid electric vehicles (HEV) are strongly coupled. The mutual influence between the optimal components sizing and the optimal operating points choice makes the problem complex. This was previously exposed in literature for spark ignition (SI) HEV. In this paper, we address the same issue for diesel HEV. In this case, the energy management strategy must take nitrogen oxides (NOx) emissions into account in addition to fuel consumption. This paper presents an optimal supervision strategy and its impact on the electric components sizing. The energy management strategy is based on the equivalent consumption minimization strategy (ECMS) using Pontryagin's minimum principle. It allows an adjustable trade-off between NOx and fuel consumption to be minimized. It was validated experimentally with a hardware-in-the-loop test bed.

The present paper deals with the activities and the results achieved under a cooperative research project between IFP, D2T, LMS, G2Elab and Renault focused on Hardware-in-the-Loop (HIL) applications to hybrid power-trains conception and assessment. The main goal of this study is the evaluation of hybrid propulsion concepts and the benefits of different degrees of hybridization in a flexible architecture, by using a chain of simulation platforms: from the co-simulation to the high-dynamic engine-in-the-loop test bed, through a virtual version of the last one. The activity assessed the potentialities in terms of fuel consumption reduction and the challenges in terms of pollutants emissions of micro and full-hybrid application for light-duty vehicle based on gasoline engine: over several road load cycles as NEDC, FTP72, ARTEMIS.

The paper presents a new control strategy to compensate the mutual influence of multiple injections in diesel and HCCI engines. The approach is based on a control-oriented model of the process, which represents the dependencies between injection timing, rail pressure, and masses injected. The model is conveniently inverted to yield the injection timing required to obtain a desired mass pattern. The model-based compensator developed is calibrated against measurements taken both on a dedicated injection bench and on a HCCI engine test bench. The compensator is then implemented in the control unit of the latter and validated against measurements of fuel consumption.

This paper presents the development of torque-based engine control strategies for a downsized SI engine, from simulation design to final validation on a demonstration car. One main issue to reach performance, fuel consumption and pollutant emission demands is in-cylinder mass observation and control. A simulation-based approach is first presented to design accurate observers from a reference simulator. In this study, a multivariable and non-linear control has been developed and focused on in-cylinder mass trajectories. It has been tested on a real time Software-In-the-Loop platform before a complete validation and calibration on the test bed. Finally, the complete torque-based engine control has been successfully integrated on the vehicle.

Nowadays, (engine) downsizing using turbocharging appears as a major way for reducing fuel consumption. With this aim in view, the air actuators (throttle, Turbo WasteGate) control is needed for an efficient engine torque control especially to reduce pumping losses and to increase efficiency. This work proposes Nonlinear Model Predictive Control (NMPC) of the air actuators for turbocharged SI engines where the predictions are achieved by a neural model. The results obtained from a test bench of a Smart MCC engine show the real time applicability of the proposed method based on on-line linearization and the good control performances (good tracking, no overshoot) for various engine speeds.

On diesel engines, a discrepancy between the air fuel ratio (AFR) of the cylinders can lead to a decrease of full load performances, an increase of pollutant and noise emissions and has an effect on the aftertreatment efficiency. A cylinder individual AFR estimator has been developed using Kalman filter techniques. This estimator is based on a physical model of the exhaust, and intended to be implemented in an engine management system. The time delay of the exhaust system, including the sensor, can be identified online. When applied on testbed acquisitions, the estimator gives good results over the whole operating range of the engine.

Torque balancing for diesel engines is important to eliminate generated vibrations and to correct injected quantity disparities between cylinders. The vibration phenomenon is important at low engine speed and at idling. To estimate torque production from each cylinders, the instantaneous engine speed from the crankshaft is used. Currently, an engine speed measurement every 45° crank angle is sufficient to estimate torque balance and to correct it in an adaptive manner by controlling the mass injected into each cylinder. The contribution of this article is to propose a new approach of estimation of the indicated torque of a DI engine based on a nonstationary linear model of the system. On this model, we design a linear observer to estimate the indicated torque produced by each cylinder. In order to test it, this model has been implemented on a HiL platform and tested on simulation and with experimental data.

This paper presents a new approach of Air Fuel Control (AFR) control strategy based on non-linear dynamics models of the engine air and fuel processes. Higher demands for lower engine exhaust emissions require a more accurate control of the air-fuel ratio during transient operations. A model-based air-fuel ratio control was applied to a production multipoint port injection engine with the initial constraint to keep the original sensors and actuators. The control strategy contains real-time engine models which describe air, fuel and sensors dynamics. In the final step, the control structure was implemented on a production car and evaluated on a chassis dynamometer. Several experiments with different transient conditions have shown reduced air-fuel ratio excursions in magnitude and duration compared to the standard strategy. Moreover, the calibration process was considerably easier than usual and required less testing on the car.