Air/Fuel Ratio and Residual Gas Fraction Control Using Physical Models for High Boost Engines with Variable Valve Timing

2002 ◽  
Author(s):  
Yoshishige Ohyama
Keyword(s):  
Physical Models ◽  
Variable Valve Timing ◽  
Valve Timing ◽  
Fuel Ratio ◽  
Residual Gas Fraction ◽  
Residual Gas ◽  
Variable Valve

Residual Gas Fraction Estimation for Model-Based Variable Valve Timing and Spark Advance Control

2004 ◽  
Author(s):  
Nicolo` Cavina ◽  
Fabrizio Ponti ◽  
Carlo Siviero ◽  
Rosanna Suglia
Keyword(s):  
Direct Injection ◽  
Management Strategies ◽  
Combustion Process ◽  
Gasoline Direct Injection ◽  
Variable Valve Timing ◽  
Valve Timing ◽  
Residual Gas Fraction ◽  
Residual Gas ◽  
Variable Valve ◽  
Exhaust Valves

As it is well known, the combustion process in Spark Ignition (SI) engines is strongly affected by the quality and quantity of the fluid within the cylinder at Intake Valve Closing (IVC). Residual gas affects the engine combustion processes (and therefore emissions and performance) through its influence on charge mass, temperature and dilution. Moreover, in Gasoline Direct Injection (GDI) engines, the amount of oxygen in the residual gas may be significant if the engine is operated in stratified charge mode (low loads and speeds), while almost no oxygen may be found in the residual gas during homogeneous-charge operation. In this paper, different approaches to residual gas fraction estimation are analyzed and compared. The main objective is to obtain a simple and reliable model also in presence of Variable Valve Timing (VVT, both on intake and exhaust valves) and External Gas Recirculation (EGR) systems, that could be used to control combustion duration and position. In fact, the two main contributions to residual gas fraction (backflow of the burned gas during the valve overlap period, and amount of gas trapped within the cylinder) are strongly affected by intake and exhaust valves timing, and EGR flow should be taken into account in order to determine the total exhaust gas mass within the cylinder at IVC. Therefore, estimation of residual gas mass and composition is crucial for designing VVT and EGR management strategies, integrated with optimal control of Spark Advance (and therefore of the combustion process). Experimental data have been acquired on a 3.2 liter V6 GDI engine, equipped with intake and exhaust VVT systems. Tests were performed throughout the engine operating range for different combinations of intake and exhaust valve timings, while varying EGR flow.

A Multi-Cylinder HCCI Engine Model for Control

2004 ◽  
Author(s):  
Jason S. Souder ◽  
Parag Mehresh ◽  
J. Karl Hedrick ◽  
Robert W. Dibble
Keyword(s):  
Design Process ◽  
Control Design ◽  
The Other ◽  
Variable Valve Timing ◽  
Valve Timing ◽  
Coupling Effects ◽  
Hcci Engine ◽  
Engine Model ◽  
Hcci Engines ◽  
Variable Valve

Homogeneous charge compression ignition (HCCI) engines are a promising engine technology due to their low emissions and high efficiencies. Controlling the combustion timing is one of the significant challenges to practical HCCI engine implementations. In a spark-ignited engine, the combustion timing is controlled by the spark timing. In a Diesel engine, the timing of the direct fuel injection controls the combustion timing. HCCI engines lack such direct in-cylinder mechanisms. Many actuation methods for affecting the combustion timing have been proposed. These include intake air heating, variable valve timing, variable compression ratios, and exhaust throttling. On a multi-cylinder engine, the combustion timing may have to be adjusted on each cylinder independently. However, the cylinders are coupled through the intake and exhaust manifolds. For some of the proposed actuation methods, affecting the combustion timing on one cylinder influences the combustion timing of the other cylinders. In order to implement one of these actuation methods on a multi-cylinder engine, the engine controller must account for the cylinder-to-cylinder coupling effects. A multi-cylinder HCCI engine model for use in the control design process is presented. The model is comprehensive enough to capture the cylinder-to-cylinder coupling effects, yet simple enough for the rapid simulations required by the control design process. Although the model could be used for controller synthesis, the model is most useful as a starting point for generating a reduced-order model, or as a plant model for evaluating potential controllers. Specifically, the model includes the dynamics for affecting the combustion timing through exhaust throttling. The model is readily applicable to many of the other actuation methods, such as variable valve timing. Experimental results validating the model are also presented.

Application of Multi-Objective Genetic Algorithm (MOGA) for Design Optimization of Valve Timing at Various Engine Speeds

2011 ◽  
Vol 264-265 ◽  
pp. 1719-1724 ◽  
Author(s):  
A.K.M. Mohiuddin ◽  
Md. Ataur Rahman ◽  
Yap Haw Shin
Keyword(s):  
Genetic Algorithm ◽  
Design Optimization ◽  
Robust Design Optimization ◽  
Primary Concern ◽  
Variable Valve Timing ◽  
Valve Timing ◽  
Engine Valve ◽  
Multi Objective ◽  
Multi Objective Genetic Algorithm ◽  
Variable Valve

This paper aims to demonstrate the effectiveness of Multi-Objective Genetic Algorithm Optimization and its practical application on the automobile engine valve timing where the variation of performance parameters required for finest tuning to obtain the optimal engine performances. The primary concern is to acquire the clear picture of the implementation of Multi-Objective Genetic Algorithm and the essential of variable valve timing effects on the engine performances in various engine speeds. Majority of the research works in this project were in CAE software environment and method to implement optimization to 1D engine simulation. The paper conducts robust design optimization of CAMPRO 1.6L (S4PH) engine valve timing at various engine speeds using multiobjective genetic algorithm (MOGA) for the future variable valve timing (VVT) system research and development. This paper involves engine modelling in 1D software simulation environment, GT-Power. The GT-Power model is run simultaneously with mode Frontier to perform multiobjective optimization.

Development of a Hydraulic Variable Valve Timing Control System with an Optimum Angular Position Locking Mechanism

2012 ◽  
Author(s):  
Takahiro Miura ◽  
Shunichi Aoyama ◽  
Kaoru Onogawa ◽  
Takaya Fujia ◽  
Tetsuro Murata ◽  
...  
Keyword(s):  
Control System ◽  
Angular Position ◽  
Variable Valve Timing ◽  
Valve Timing ◽  
Timing Control ◽  
Locking Mechanism ◽  
Variable Valve
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