To meet increasingly stringent emission regulations modern internal combustion engines require highly accurate control of the air-to-fuel ratio. The performance of the conventional air-to-fuel ratio feedback loop is limited by the combustion delay between fuel injection and engine exhaust, and by the transport delay for the exhaust gas to propagate to the air-to-fuel ratio sensor location. The ...

in spark ignition (si) engines, the accurate control of air fuel ratio (afr) in the stoichiometric value is required to reduce emission and fuel consumption. the wide operating range, the inherent nonlinearities and the modeling uncertainties of the engine system are the main difficulties arising in the design of afr controller. in this paper, an optimization-based nonlinear control law is anal...

Maximization of the fuel economy of the lean burn spark ignition (SI) engine strongly depends on precise air-fuel ratio control. A great challenge associated with the air-fuel ratio feedback control is the large variable time delay in the exhaust system. In this paper, a systematic development of an air-fuel ratio controller based on post lean NOx trap (LNT) oxygen sensor feedback using linear ...

This paper puts forward one kind of air-fuel ratio control method with PI controller. With the help of MATLAB/SIMULINK software, the mathematical model of air-fuel ratio control system for distributorless CNG engine is constructed. The objective is to maintain cylinder-to-cylinder air-fuel ratio at a prescribed set point, determined primarily by the state of the ThreeWay-Catalyst (TWC), so that...

The present study focuses on the effect of air-fuel ratio on the performance of four cylinder hydrogen fueled direct injection internal combustion engine. GT-Power was utilized to develop the model for direct injection engine. Air-fuel ratio was varied from rich limit to a lean limit. The rotational speed of the engine was varied from 1250 to 4500 rpm. The acquired results shown that the air fu...

simulation of metallurgical processes has been the subject of intense research due to the reduced number of experiments required for controlling the process as well as time and energy savings it allows. in gas carburizing of steel parts, the amount of carbon at the surface of carburized parts is the most important specification of the process in terms of achieving the desired metallurgical prop...

In spark ignition (SI) engines, the accurate control of air fuel ratio (AFR) in the stoichiometric value is required to reduce emission and fuel consumption. The wide operating range, the inherent nonlinearities and the modeling uncertainties of the engine system are the main difficulties arising in the design of AFR controller. In this paper, an optimization-based nonlinear control law is a...

A high pressure combined air-fuel injection system is designed and tested for an experimental free liquid-piston engine compressor. The application discussed utilizes available high pressure air from the compressor’s reservoir, and high pressure fuel to mix and then inject into a combustion chamber. This paper addresses the modeling, design and control for this particular high-pressure air-fuel...