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Early activation of catalyst by quickly raising the temperature of the catalyst is effective in reducing exhaust gas during cold starts. One such technique of early activation of the catalyst by raising the exhaust temperature through substantial retardation of the ignition timing is well known. The present research focuses on the realization of quick warm-up of the catalyst by using a method in which the engine is fed with a large volume of air by feedforward control and the engine speed is controlled by retarding the ignition timing. In addition, an intake air flow control method that comprises a flow rate correction using an adaptive sliding mode controller and learning of flow rate correction coefficient has been devised to prevent control degradation because of variation in the flow rate or aging of the air device. The paper describes the methods and techniques involed in the implementation of a quick warm-up system with improved adaptability.

Time-resolved and local ambient gas entrainment processes in intermittent gas jets with a range of injection conditions were evaluated by a LIFA (Laser-Induced Fluorescence of Ambient gas) technique. The gas injection conditions tested were: mean discharge velocity, um; mean discharge turbulence intensity, u′m; kinematic viscosity of the gas jet, ν; specific gravity of the gas jet, ρj; and of the ambient gas, ρa. Experimental results showed that the entrainment of jets are enhanced with higher eddy kinematic viscosity, νt, measured by a hot wire anemometer. In conclusion, the mean jet concentration was approximated with only one parameter, (ρj/ρa)D2/[(ν+νt)Δt].

The new 2.0L gasoline engine for ACCORD Plug-in Hybrid was developed as a next-generation Honda engine series. This engine's features are low fuel consumption and good emission performance. Variable valve Timing and Electric Control (VTEC) system is applied to this engine, so we can have two characteristic cams, output cam and fuel economy (FE) cam. Output cam is narrow duration, used for power and engine starting. FE cam is wide duration, so it can get Atkinson cycle effect by late intake valve close timing (IVC). Cooled exhaust gas recirculation (Cooled-EGR) is applied to this engine. Low fuel consumption is achieved by combining VTEC and cooled EGR. We made the improvement of control systems. First is the new control which can secure the pressure difference before and behind the EGR valve. As a result, EGR flow control performance is improved. Second is improvement of torque control. It can predict an engine torque decrease when ignition retard is carried out.

Recently, emission regulations have been strict in many countries, and it is very difficult technical issue to reduce emissions of diesel cars. In order to reduce the emissions, various combustion technologies such as Massive EGR, PCCI, Rich combustion, etc. have been researched. The combustion technologies require precise control of the states of in-cylinder gas (air mass flow, EGR rate etc.). However, a conventional controller such as PID controller could not provide sufficient control accuracy of the states of in-cylinder gas because the air-pass system controlled by an EGR valve, a throttle valve, a variable nozzle turbo, etc. is a multi-input, multi-output (MIMO) coupled system. Model predictive control (MPC) is well known as the advanced MIMO control method for industrial process. Generally, the sampling period of industrial process is rather long so there is enough time to carry out the optimization calculation for MPC.

Bioethanol is being used as an alternative fuel throughout the world based on considerations of reduction of CO2 emissions and sustainability. It is widely known that ethanol has an advantage of high anti-knock quality. In order to use the ethanol in ethanol-blended gasoline to control knocking, the research discussed in this paper sought to develop a fuel separation system that would separate ethanol-blended gasoline into a high-octane-number fuel (high-ethanol-concentration fuel) and a low-octane-number fuel (low-ethanol-concentration fuel) in the vehicle. The research developed a small fuel separation system, and employed a layout in which the system was fitted in the fuel tank based on considerations of reducing the effect on cabin space and maintaining safety in the event of a collision. The total volume of the components fitted in the fuel tank is 6.6 liters.

This paper describes a technology for reducing cold hydrocarbons (HCs) emissions during cold engine start-up. The technology consists of a new HC adsorption system and a method for detecting the deterioration of adsorption performance of the HC adsorber. This active type HC adsorption system is added to Honda's current SULEV system technologies (high performance catalysts, catalyst quick warm-up control, and high accuracy A/F control), for further reduction of cold HC emissions at start-up. In addition, a new sensor has been developed to detect humidity in the exhaust gas, which in turn is used to predict performance deterioration of the HC adsorber. During FTP (Federal Test Procedure) testing, this emission control system has achieved a reduction of more than 70% in cold HC emissions during cold start, and a reduction of about 60% in NMOG weighted mean (WM) value, as compared to without the HC adsorption system.

The Honda Accord is the world's first automobile meeting the SULEV category criteria in the LEV-II exhaust emissions standards. An improved accuracy engine control system and catalyst account for the automobile's extremely low emissions. The accuracy engine control system includes double adaptive air-fuel ratio feedback loops composed of STR (Self-Tuning Regulator), for primary air-fuel ratio control, and PRISM (Prediction and Identification Sliding Mode Control), for secondary O2 feedback. The basic algorithm of the latter was presented at SAE 20001). However, two issues required further PRISM algorithm improvements in order to apply the double adaptive loops to an actual vehicle. One such achievement is both the compensation for engine dynamic characteristics by PRISM and the avoidance of the reciprocal interference with two adaptive loops.

Recently, much research has been carried out on secondary O2 feedback which performs control based on the output from a secondary O2 sensor (HEGO sensor). In this research it has been found that, regardless of catalyst aging conditions, the HEGO sensor output indicates 0.6 V when the catalyst reduction rate is maintained at the optimum level. Therefore, based on this relationship, we designed an accurate secondary O2 feedback with the aim of reducing emissions by stabilizing the HEGO sensor output to 0.6 V. In order to realize this control, it was necessary to solve the three problems of nonlinear catalyst characteristics, dead time characteristics, and changes in dynamic characteristics due to catalyst aging conditions. Therefore, these problems were solved using the modeling approach of robust control and a new robust adaptive control named Prediction and Identification Type Sliding Mode Control.

There has been strong public demand for reduced hazardous exhaust gas emissions and improved fuel economy for automobile engines. In recent years, a number of innovative solutions that lead to a reduction in fuel consumption rate have been developed, including in-cylinder direct injection and lean burn combustion technologies, as well as an engine utilizing a large volume of exhaust gas recirculation (EGR). Furthermore, a homogeneous charge compression ignition (HCCI) engine is under development for actual application. However, one of the issues common to these technologies is less stable combustion, which causes difficulty in engine management. Additionally, it is now mandatory to provide an onboard diagnosis (OBD) system. This requires manufacturers to develop a technology that allows onboard monitoring and control of the combustion state. This paper reports on an innovative combustion diagnostic method using an in-cylinder pressure sensor.

Diesel combustion and exhaust gas emissions under transient operation (when fuel amounts abruptly increased) were investigated under a wide range of operating conditions with a newly developed gas sampling system. The relation between gas emissions and piston wall temperatures was also investigated. The results indicated that after the start of acceleration NOx, THC and smoke showed transient behaviors before reaching the steady state condition. Of the three gases, THC was most affected by piston wall temperature; its concentration decreased as the wall temperature increased throughout the acceleration except immediately after the start of acceleration. The number of cycles, at which gas concentrations reach the steady-state value after the start of acceleration, were about 1.2 times the cycle constant of the piston wall temperature for THC, and 2.3 times for smoke.

Amidst the rising demand to reduce CO2 and other greenhouse gas emissions in recent years, gasoline homogeneous-charge compression ignition (HCCI) has gained attention as a technology that achieves both low NOx emissions and high thermal efficiency by means of lean combustion. However, gasoline HCCI has low robustness toward intracylinder temperature variations, therefore the problems of knocking and misfiring tend to occur during transient operation. The authors verified the transient operation control of HCCI by using a 4-stroke natural aspiration (NA) gasoline engine provided with direct injection (DI) and a variable valve timing and a lift electronic control system (VTEC) for intake air and exhaust optimized for HCCI combustion. This report describes stoichiometry spark ignition (SI) to which external exhaust gas recirculation (EGR) was introduced, HCCI ignition switch control, and changes in the load and number of engine revolutions in the HCCI region.

Low NOx and soot free premixed diesel combustion can be realized by increasing ignition delays in low oxygen atmospheres, as well as the combustion here also depends on fuel ignitability. In this report single intermittent spray combustion with primary reference fuels and a normal heptane-toluene blend fuel under several oxygen concentrations in a constant volume combustion vessel was analyzed with high-speed color video and pressure data. Temperature and KL factor distributions are displayed with a 2-D two-color method. The results show that premixing is promoted with a decrease in oxygen concentration, and the local high temperature regions, above 2200 K, as well as the duration of their appearance decreases with the oxygen concentration. With normal heptane, mild premixed diesel combustion can be realized at 15 vol% oxygen and there is little luminous flame.