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Exhaust emissions behavior from a vehicle under road driving condition is affected by a driving force of a vehicle. It is impossible to measure the driving force by an existing torque meter under this on-road driving condition. This study reports the development and verification of the wheel torque meter which is possible to measure driving force under the on-road driving condition and has enough strength and accuracy. The wheel torque meter developed in this study consists of a torque detector with a strain gauge type torque transducer, a telemeter receiver and a data logger. The strain gauge type torque transducer is equipped between hub and wheel at the drive axle tire, because of the narrow width of this transducer, and it is possible to be placed against vehicle without significant conversion of the vehicle. Because of these characters, this transducer is possible to be used for an on-road driving vehicle.

In recent years, exhaust emissions regulations is increasingly enhanced on the non-road diesel engines, which are mainly used for agriculture, industrial and construction applications in world-wide area, in order to prevent air pollution on the earth. On the other hand, customers demand higher power in a tight packaging constraint to be competitive on the product that the engine is installed. We developed the all-new 1.3 liter non-road In-Direct Injection (IDI) diesel engine, which realized to balance the strict exhaust emissions regulations and user needs such as compact and higher power. This paper reviews the technologies to achieve the targets, higher power density and lower exhaust emissions on the newly-developed small IDI diesel engines.

The performance of various types of control systems for an electric governor of a diesel engine was examined. The amount of fuel injection of a diesel engine is usually controlled by an electric governor system in these decades, and a PID controller is installed for the electric governor. Even when the optimal parameters for PID controller are well tuned, it is difficult to keep constant rotation speed of the engine, because the applied load to generators may vary according to its running conditions. In this study, a neural network was applied to regulate the parameters in the PID controller for the axial-moving DC motor to control the amount of fuel injection. Experimental studies show that the parameter regulation system using neural network presented here showed good performance under various running conditions. Furthermore, it was shown that various types of training algorithms were applied to neural network control systems and their performance was compared.

Three types of control system for an electric governor of a diesel engine developed for generators were examined experimentally. The quantity of fuel injection of a diesel engine for generators is usually controlled by an electric governor system in these decades, and a PID controller has been installed for the electric governor. Even when the optimal parameters for PID controller are well tuned, it is difficult to keep constant rotating speed of the engine, because the applied load to generators may vary according to its running conditions. In this research, a neural network was applied to regulate the parameters in PI controller for the axial-moving DC motor to control the quantity of fuel injection. Experimental studies showed that the parameter regulation system using neural network presented here had good performance under various running conditions.

The authors have been developing a ceramic heat insulated natural gas engine, in which cooling losses are greatly reduced by using heat insulation structure on the combustion chamber walls. High thermal efficiency is achieved by being able to operate this engine at high compression ratios. This engine is intended to use in co-generation systems and hybrid vehicles. In the engine, a new combustion system has been developed to enable the use of compressed natural gas (CNG) as fuel supplied at low pressure. The system consists of a pre-chamber and a throat valve on the passage between the pre- and main- chambers in order to make the engine ignite smoothly. This system uses low-pressure fuel, injected into the pre-chamber when the throat valve is closed. A homogeneous charge and large amounts of EGR are used in the main chamber.

The horse power and emissions of a heat insulated engine with high heat insulation rate* over 70% was investigated, as a result, a deterioration of power and emissions has become clear to be caused by change of combustion in the tests. Therefore, the observation of the combustion process in high temperature air has been carried out in the engine by using a high speed camera. We have investigated the combustion process included progress of injected fuel spray, ignition, extension of flame, and formation of soot in a vessel charged with air of high temperature and pressure with the gas condition in an engine cylinder. The test result showed that diesel fuel did not penetrate straight forward in the high temperature air, and the tip of the jet stream spread in such a shape like a lump of cloud and the spray is ignited in a short ignition delay. The flame extended widely in the free jet stream, however we observed soot formations here and there in the flame.