Jonathan Chauvin

Modelling and control of the air system of a turbocharged gasoline engine

This paper investigates the modelling and the control of a turbocharged air system of a gasoline engine. The purpose of the work described here is to propose a new control strategy based on an original physical model of the system. This first part describes the development of a simple model of the system. Based on a complete representation of the system, some simplifications and assumptions are proposed in order to obtain a model with the adequate level of complexity for an integration in a control law. We describe a model based innovative control strategy. Experimental results are proposed on a 4 cylinder turbocharged gasoline engine. Conclusions stress the possibility of taking into account the model of this system by a simple, yet efficient in practice, control law.

Periodic input estimation for linear periodic systems: Automotive engine applications

In this paper, we consider periodic linear systems driven by T0-periodic signals that we desire to reconstruct. The systems under consideration are of the form [emailxa0protected]?=A(t)x+A0(t)w(t), y=C(t)x, [emailxa0protected]?R^n, [emailxa0protected]?R^m, [emailxa0protected]?R^p, (m=

Control of a turbocharged Diesel engine fitted with high pressure and low pressure exhaust gas recirculation systems

Exhaust gas recirculation is an effective way for reducing nitric oxides emissions in Diesel engine achieving low temperature combustion (LTC). Two strategies can be applied to recirculate burnt gas in a turbocharged Diesel engine using the high pressure loop or the low pressure loop. This paper describes a generic model based control structure for Diesel engines with dual-loop exhaust gas recirculation (EGR) and variable geometry turbocharger. An observer is designed to estimate the exhaust gas flow coming from the high pressure loop or from the low pressure loop. These estimates are used for the intake burnt gas fraction control. This approach avoids direct measurement or implementation of additional sensors. In addition, a generic model based control based on motion planning is adapted to the low pressure EGR system. The main advantage of the approach is that turbocharger and exhaust gas recirculation systems controllers have a limited number of calibration parameters. The observer and controller results are presented and validated on a LTC-Diesel engine with a dual-loop EGR system.

Online optimal control of a parallel hybrid with costate adaptation rule

Abstract This paper focuses on online control energy management strategy for a parallel hybrid architecture. The strategy is developed from the optimal control theory, using Pontryagins Minimum Principle (PMP). The resulting Equivalent Consumption Minimization Strategy (ECMS) is implemented in real time and tested in simulation and in an experimental environment (HyHiL test bench). In particular, the adaptation of one control parameter, playing the role of a Lagrange multiplier, is analyzed in terms of stability and effectiveness.

Controlling the start of combustion on an HCCI diesel engine

In this paper we propose a control strategy to improve stability of the combustion of HCCI engines during sharp transients. This approach complements existing airpath and fuelpath controllers, and aims at accurately controlling the start of combustion (soc). For that purpose, injection time is adjusted based on a simple Knock Integral Model and real time intake manifold signals. Experimental results are presented, which stress the relevance of the approach.

Airpath control of a SI engine with Variable Valve Timing actuators

We address the control of the airpath of a turbocharged SI engine equipped with variable valve timing (VVT) actuators. VVT devices are used to produce internal exhaust gas recirculation, providing beneficial effects in terms of consumption and pollutant emissions reduction. However, VVT actuators affect the fresh air charge in the cylinders. This has an impact on the torque output (leading to driveability problems), and on the air/fuel ratio (AFR) (leading to pollution peaks). To compensate these undesirable effects, a new approach is proposed. We model the intake dynamics as a first order system using a balance equation in which the VVT actuators play the role of a measured disturbance in the volumetric efficiency of the aspiration phenomenon. In view of practical implementation, two types of modeling errors are considered. We address them by an integral term and an observer. Convergence is proven. This strategy is sufficient to control the engine air mass. As a consequence, the AFR management is improved. These points are supported by experimental results.

Air Path Estimation for a Turbocharged SI Engine with Variable Valve Timing

In the context of increasingly stringent pollution standards, engine pollutant emission reduction is a great challenge for spark ignition (SI) engines. The very narrow operating zone of the three-way catalyst necessitates a good control of the air/fuel equivalence ratio and therefore a good estimation of the aspirated air mass. We consider in this study a turbocharged SI engine equipped with variable valve timing actuators (VVT). This device acts as a disturbance by impacting on the air mass flow through the inlet valves. This impact can be estimated from real-time measurement. Two observers of the aspirated air mass are then proposed in this paper. After proving convergence in the two cases, we carry out comparisons based on simulation results.

MODELING AND CONTROL OF A DIESEL HCCI ENGINE

This article focuses on the control of a Diesel engine airpath. We propose a detailed description of the airpath of a Diesel HCCI engine supported by experimental results. Moreover, we propose a simple, yet innovative, motion planning control strategy. At the light of this study, we can flnally conclude, with supportive results, that motion planning is indeed an appropriate solution for controlling the airpath dynamics.

Real-Time Combustion Parameters Estimation for HCCI-Diesel Engine Based on Knock Sensor Measurement

Abstract Future internal combustion engine technologies require an accurate combustion monitoring and control. This can be performed through high frequency recordings of cylinder pressure. However, this solution is limited by the sensor cost and reliability. Another method consist in reconstructing combustion related variables from indirect measurements. In this paper, we propose a combustion indicator estimation method from the vibration trace of the engine block recorded with a standard knock sensor. The relevance of such a method is demonstrated through experimental results on an HCCI engine application.

Impact of EGR on Turbocharger Control on a Diesel Engine with two EGR loops

Abstract This paper considers a Diesel engine fitted with a variable geometry turbocharger and two EGR circuits. It describes how a turbocharger control strategy based on motion planning and feedback linearization can take account of the impact of exhaust gas recirculation (EGR) on the system. The analysis of the system trajectories of a reduced model shows that the EGR has a deep impact on the operating range of the turbocharger. This effect can be introduced at the same time as a constraint in the trajectory and in the inversion of the reduced model. Experimental results demonstrate the efficiency of this strategy.