Language：Japanese   Publishing type：Research paper (conference, symposium, etc.)  

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Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：SAE International  

A major challenge for internal combustion engine vehicles is reduction of CO₂ emissions. Hybrid vehicle demand has recently increased as a countermeasure. However, in hybrid vehicles, the frequency of motor and engine usage varies depending on the driver's driving style, even when driving the same vehicle on the same route. As a result, CO₂ emissions can differ significantly between drivers. Analyzing the impact of driving characteristics on CO₂ emissions can contribute to improving the efficiency of engine and motor control in vehicles, leading to further reductions in CO₂ emissions. Therefore, this paper examines the impact of different driver behaviors on CO₂ emissions in hybrid vehicles. In this study, two drivers were asked to follow a preceding vehicle on real roads, and various data were collected during these drives. Conducting the experiments on actual roads allowed us to obtain results that closely reflect real-world driving conditions, thereby enhancing the relevance of the findings. The use of hybrid vehicles, which are rapidly gaining popularity, in these experiments is considered particularly valuable. Among the two drivers, significant differences in inter-vehicular distance (the distance between the preceding vehicle and the driver’s vehicle) were observed. Consequently, this study focused on how such differences affect CO₂ emissions and successfully demonstrated that inter-vehicular distance, a quantitative indicator of driving behavior, influences CO₂ emissions in hybrid vehicles. The results showed that drivers who maintained a larger intervehicular distance tended to produce lower CO₂ emissions. This outcome was influenced by differences in driving resistance and the amount of engine usage. Drivers who maintained a larger inter-vehicular distance tended to experience lower driving resistance. Additionally, regarding engine usage time, drivers who kept a larger inter-vehicular distance spent more time driving using only the electric motor. As a result, the engine's operating time was reduced, leading to lower CO₂ emissions.

DOI： 10.4271/2025-01-0404.

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Language：English   Publishing type：Research paper (international conference proceedings)  

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Language：English   Publishing type：Research paper (international conference proceedings)  

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Language：English   Publishing type：Research paper (international conference proceedings)  

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Language：Japanese   Publishing type：Research paper (scientific journal)  

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Language：English   Publishing type：Research paper (international conference proceedings)  

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Language：English   Publishing type：Research paper (international conference proceedings)  

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Language：Japanese   Publishing type：Research paper (conference, symposium, etc.)  

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：AIP Publishing  

DOI： 10.1063/5.0205280

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Language：Japanese   Publishing type：Research paper (scientific journal)  

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Language：English   Publishing type：Research paper (international conference proceedings)  

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Language：Japanese   Publishing type：Research paper (conference, symposium, etc.)  

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Language：English   Publishing type：Research paper (international conference proceedings)  

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Language：Japanese   Publishing type：Research paper (conference, symposium, etc.)  

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Language：Japanese   Publishing type：Research paper (conference, symposium, etc.)  

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Language：English   Publishing type：Research paper (international conference proceedings)  

Three-way catalysts are used in gasoline vehicles for simultaneous purifying nitrogen oxide, carbon monoxide, and hydrocarbon in recent years. However, the reduction of ammonia emission generated in the three-way catalyst is pressing issue. In EURO 7, ammonia will also be subject to the Real Driving Emissions regulation, and its emissions must be reduced. Previous studies have shown that ammonia emissions are higher under fuel-rich conditions, suggesting that differences in driving behavior have a significant impact on ammonia emissions in real-world driving, which includes various driving environments. In this study, driving tests were conducted on a direct-injection gasoline vehicle equipped with a three-way catalyst and Portable Emission Measurement System and Sensor-based Emission Measurement System to investigate the actual ammonia emissions on actual roads. Sensor-based Emission Measurement System includes the system that can measure ammonia and nitrogen monoxide concentrations independently with high accuracy. Two drivers were used to analyze the effects of different driving behaviors on ammonia emissions. The results showed that ammonia emissions in real world driving largely affected by the lean-rich conditions of three-way catalyst and increased for the driver who drove more aggressively because he/she entered, and fuel cut conditions and the rich condition more frequently during deceleration and acceleration.

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Language：English   Publishing type：Research paper (international conference proceedings)  

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Language：English   Publishing type：Research paper (international conference proceedings)  

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Language：Japanese   Publishing type：Research paper (conference, symposium, etc.)  

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Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：SAE International  

DOI： 10.4271/2023-01-0379

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Language：English   Publishing type：Research paper (international conference proceedings)  

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Language：Japanese   Publishing type：Research paper (scientific journal)  

DOI： 10.11351/jsaeronbun.55.295

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Springer Nature  

This study assessed the on-road gaseous and particulate emissions from a gasoline direct injection (GDI) hybrid electric vehicle (HEV) using portable emissions measurement systems (PEMS). Testing was conducted, while the vehicle was exercised over three routes with different topological and environmental characteristics, representing urban, highway, and mountain (high-altitude) driving conditions. The gaseous emissions (NOx, CO, THC, and CO2) were found to be the highest during mountain driving compared to urban and highway driving. PM mass and soot mass emissions were comparable between the Downtown LA (urban driving conditions) and Mt Baldy (rural driving conditions with altitude changes) routes but higher compared to Highway route. NOx emissions and soot mass emissions over all test routes exhibited reasonably good correlations with vehicle acceleration but poor correlations with road grade.

DOI： 10.1007/s40825-023-00225-0

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Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1016/j.cej.2022.139937

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Language：Japanese   Publishing type：Research paper (conference, symposium, etc.)  

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Language：English   Publishing type：Research paper (international conference proceedings)  

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Language：English   Publishing type：Research paper (international conference proceedings)  

In recent years, particulate matter (PM) emitted from direct-injection gasoline vehicles is becoming an increasingly concerning problem. In addition, it is often reported that ammonia (NH3) is emitted from gasoline vehicles equipped with a three-way catalyst. These emissions might be largely emitted especially when driving in on-road driving conditions. In this study, we investigated the emissions, NOx, NH3, and PM/PN (particulate number) of a light-duty direct-injection gasoline vehicle when driving on actual roads. Using a small direct-injection gasoline vehicle equipped with a threeway catalyst, experiment was conducted 8 times on the same route, and these emissions were measured. In this study, vehicle specific power (VSP) was introduced, which can be calculated using vehicle parameters, vehicle speed, and road gradient. The effects of parameters acquired through on-board diagnostics (OBD) port and VSP on emissions were investigated. Based on these measurements, "where" and "how much" NOx, NH3, and PM/PN were emitted were emphasized. As a result, it was clarified that a large amount of NOx is emitted after the fuel is cut during deceleration, NH3 is emitted when the air-fuel ratio becomes rich, and PM/PN is emitted during rapid acceleration of the vehicle. Cross-correlation function is also introduced to identify parameters that has similar properties to avoid redundancy when analyzing the causes and effects of the exhaust gas emissions.

DOI： 10.4271/2022-01-0572.

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Elsevier  

As the push to reduce air pollutants and carbon dioxide for global warming continues, there is increasing interest in the development and deployment of battery electric vehicles for heavy-duty applications as one of the critical
and challenging steps of a broader effort to fully electrify the transportation sector. This study evaluated and
quantified the energy consumption rates and energy regeneration rates for three heavy-duty battery electric
vehicles (a step van, a yard tractor, and a class 8 truck) using driving cycle tests with a heavy-duty vehicle chassis
dynamometer. Information in this area is currently very limited, and yet it is critical to understanding how
effective heavy-duty battery electric vehicles will be for a wide range of applications as the electrification of the
heavy-duty vehicle market continues to expand. Energy consumption rates ranged from 0.37 and 2.71 kWh/km
for most vehicle/cycle combinations. On a diesel liter energy-equivalent basis, the heavy-duty vehicles had
approximately 3 to 6 times better energy consumption rates compared to comparable diesel vehicles, with weight
normalized energy consumption rates also comparing favorably to the current and future greenhouse gas/fuel
economy standards for equivalent diesel vehicles. Based on battery capacities ranging from 80 to 215 kWh, the
vehicle ranges varied from 38.18 km to 171.2 km, with ranges of 115.9 km to 171.2 km for most types of driving
and lower ranges of 38.18 to 42.20 km for sustained grade cycles. Overall, the advantage of improved energy
consumption rates coupled with improvements that can be expected for battery technology and vehicle range,
provide promise for expanded use of heavy-duty vehicles going into the future.

DOI： 10.1016/j.ijepes.2022.108100

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Springer Nature  

Wear and deformation occur in the body seat of diesel fuel injector nozzles, thereby affecting fuel spray behaviors and injection characteristics. In this study, the effects of body seat temperature, test duration, temperature increase duration, tempering temperature, and tempering duration on the nozzle body seat are investigated using an injector testing device. Surface roughness measurements using a nano search microscope and hardness measurements of the nozzle body seat are performed to investigate the textural and physical characteristics of the nozzle body seat. In addition, optical measurements via optical microscopy and field emission scanning electron microscopy are performed to investigate the topographical information and microstructure of the nozzle body seat. The results show that the increase in wear and deformation is related to the higher test temperature and duration. Additionally, the tempering technique can suppress the deformation of the nozzle body seat.

DOI： 10.1007/s12239-022-0021-2

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Language：Japanese   Publishing type：Research paper (conference, symposium, etc.)  

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Language：English   Publishing type：Research paper (international conference proceedings)  

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Language：Japanese   Publishing type：Research paper (conference, symposium, etc.)  

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Language：English   Publishing type：Research paper (international conference proceedings)  

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Language：Japanese   Publishing type：Research paper (conference, symposium, etc.)  

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Language：Japanese   Publishing type：Research paper (conference, symposium, etc.)  

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Language：Japanese   Publishing type：Research paper (scientific journal)  

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Language：Japanese   Publishing type：Research paper (conference, symposium, etc.)  

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Language：English   Publishing type：Research paper (scientific journal)  

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Language：Japanese   Publishing type：Research paper (conference, symposium, etc.)  

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Language：Japanese   Publishing type：Research paper (conference, symposium, etc.)  

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Language：Japanese   Publishing type：Research paper (conference, symposium, etc.)  

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Language：Japanese   Publishing type：Research paper (conference, symposium, etc.)  

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Language：English   Publishing type：Research paper (conference, symposium, etc.)  

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Language：Japanese   Publishing type：Research paper (conference, symposium, etc.)  

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Language：English   Publishing type：Research paper (international conference proceedings)  

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Language：Japanese   Publishing type：Research paper (scientific journal)  

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Language：Japanese   Publishing type：Research paper (scientific journal)  

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Language：English   Publishing type：Research paper (international conference proceedings)  

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Language：English   Publishing type：Research paper (conference, symposium, etc.)  

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Language：Japanese   Publishing type：Research paper (conference, symposium, etc.)  

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Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1177/1468087420908164

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Language：English   Publishing type：Research paper (international conference proceedings)  

Every year, exhaust gas regulations are getting stricter with the intention to solve the average air pollution problem, however, local roadside pollution is still a pressing issue. In order to solve this local roadside pollution problem, it is necessary to evaluate and/or predict “where” and “how much” pollutants such as NOx are emitted. To predict the local roadside pollution, it is necessary to collect emissions data from various kinds of vehicles driving on realworld and analyze them. In recent years, Real Driving Emission regulations using PEMS (Portable Emission Measurement System) have been introduced mainly in Europe. A typical PEMS configuration can weigh close to 100 kg however, and its weight affects the driving conditions of vehicles running on actual roads. In this study, we focused on the analysis of real-world emissions using SEMS (Sensorbased Emission Measurement System). Whereas PEMS is a method of sampling and analyzing exhaust gas, SEMS directly attaches a NOx sensor and PM sensor to the exhaust pipe and measures the concentration. Although SEMS has a limited number of items that can be measured compared to PEMS, other analysis is possible by devising the analysis method. This paper focuses on the analysis method of real-world emissions using SEMS and aims to examine the analysis method of CO2 emission concentration, exhaust gas flowrate, and local roadside emissions from the measured value of SEMS. In addition, an example of applying this analysis method using on-road test data of a diesel passenger car equipped with SEMS is shown. The NOx sensor can measure not only the NOx concentration but also the O2 concentration and air-fuel ratio. It is clarified that the CO2 concentration at wet condition can be calculated with high accuracy by using the measured values of the O2 concentration. Also, the exhaust flowrate is obtained by combining the intake air flow rate acquired through the vehicle's OBD and the air-fuel ratio measured by the NOx sensor. At that time, the exhaust gas density is also calculated based on the air-fuel ratio, so that the exhaust flowrate can be calculated with higher accuracy.

DOI： 10.4271/2020-01-0381

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Language：English   Publishing type：Research paper (scientific journal)  

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Language：English   Publishing type：Research paper (scientific journal)  

CI engines provide higher thermal efficiency compared to other internal combustion engines. On the other hand large amounts of smoke and NOx are produced during combustion. Smoke and NOx can be reduced by applying Premixed Charge Compression Ignition (PCCI) combustion. Unfortunately, the problems of PCCI combustion include unstable start of combustion and limited operating range. The multi-pulse ultrahigh pressure injection allows fuel to control PCCI combustion. The objective of offset orifice nozzle is to improve mixture formation and shorten spray penetration in order to increase thermal efficiency and control PCCI combustion. The offset orifice nozzle was designed by shift orifice aliment from into the sac center to edge of sac follow swirl direction. Counter bore design was applied to offset orifice nozzle in order to keep the constant orifice length as standard nozzle. This paper investigates the effect of nozzle orifice design on combustion characteristics under multi pulse ultra high pressure injection and PCCI combustion conditions. The experiments were carried out on a single cylinder engine at 0.55 MPa gross IMEP at 1,750 rpm. The injection pulses were 3 pulses equally mass main injection at 150, 200, 250, 300 and 350 MPa injection pressure. In case of standard nozzle orifice, 1st, 2nd pulse are PCCI followed by diffusive combustion in every injection pressure. For offset orifice nozzle orifice at 150 and 200 MPa 1st, 2nd pulse are also PCCI combustion. However when injection pressure is over 200 MPa, the 2nd pulse of rate of heat release become diffusive combustion. The offset orifice nozzle resulted in increased thermal efficiency, NOx and smoke. However significant differences between the smoke of offset orifice nozzle and standard nozzle were not found under injection pressure 300 and 350 MPa. The offset orifice nozzle also resulted in decrease CO and THC.

DOI： 10.4271/2019-32-0522.

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Language：English   Publishing type：Research paper (international conference proceedings)  

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Language：Japanese   Publishing type：Research paper (conference, symposium, etc.)  

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Language：Japanese   Publishing type：Research paper (conference, symposium, etc.)  

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER  

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Language：English   Publishing type：Research paper (conference, symposium, etc.)  

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Language：Japanese   Publishing type：Research paper (scientific journal)  

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Language：Japanese   Publishing type：Research paper (conference, symposium, etc.)  

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Language：English   Publishing type：Research paper (international conference proceedings)  

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Language：English   Publishing type：Research paper (international conference proceedings)  

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER  

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Language：English   Publishing type：Research paper (international conference proceedings)  

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Language：Japanese   Publishing type：Research paper (conference, symposium, etc.)  

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Language：Japanese   Publishing type：Research paper (conference, symposium, etc.)  

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Language：Japanese   Publishing type：Research paper (conference, symposium, etc.)  

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Language：Japanese   Publishing type：Research paper (conference, symposium, etc.)  

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Language：Japanese   Publishing type：Research paper (conference, symposium, etc.)  

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Language：English   Publishing type：Research paper (international conference proceedings)  

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER  

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Language：English   Publishing type：Research paper (international conference proceedings)  

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Language：English   Publishing type：Research paper (conference, symposium, etc.)  

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Language：Japanese   Publishing type：Research paper (scientific journal)  

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Language：Japanese   Publishing type：Research paper (conference, symposium, etc.)  

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Language：Japanese   Publishing type：Research paper (conference, symposium, etc.)  

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Language：Japanese   Publishing type：Research paper (conference, symposium, etc.)  

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Language：Japanese   Publishing type：Research paper (conference, symposium, etc.)  

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Language：Japanese   Publishing type：Research paper (conference, symposium, etc.)   Publisher：一般社団法人 日本機械学会  

DOI： 10.1299/jsmemecj.2017.G0700402

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DOI： 10.1007/s12206-017-0852-3

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Language：English   Publishing type：Research paper (international conference proceedings)  

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Springer  

DOI： 10.1007/s12239-017-0064-y

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Language：Japanese   Publishing type：Research paper (conference, symposium, etc.)  

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER  

DOI： 10.1016/j.fuproc.2017.04.018

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Language：English   Publishing type：Research paper (conference, symposium, etc.)  

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Language：Japanese   Publishing type：Research paper (conference, symposium, etc.)  

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Language：English   Publishing type：Research paper (conference, symposium, etc.)  

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Language：Japanese   Publishing type：Research paper (conference, symposium, etc.)  

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Language：English   Publishing type：Research paper (international conference proceedings)  

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Language：Japanese   Publishing type：Research paper (conference, symposium, etc.)  

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Language：Japanese   Publishing type：Research paper (conference, symposium, etc.)  

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DOI： 10.4271/2015-01-2012

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Language：Japanese   Publishing type：Research paper (conference, symposium, etc.)  

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Language：Japanese   Publishing type：Research paper (bulletin of university, research institution)  

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Language：Japanese   Publishing type：Research paper (conference, symposium, etc.)  

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Language：Japanese   Publishing type：Research paper (conference, symposium, etc.)  

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Language：Japanese   Publishing type：Research paper (conference, symposium, etc.)  

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Language：English   Publishing type：Research paper (conference, symposium, etc.)   Publisher：自動車技術会  

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Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：公益社団法人自動車技術会  

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Language：English   Publishing type：Research paper (international conference proceedings)  

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Language：Japanese   Publishing type：Research paper (conference, symposium, etc.)  

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Language：Japanese   Publishing type：Research paper (conference, symposium, etc.)  

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Language：English   Publishing type：Research paper (international conference proceedings)  

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Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：公益社団法人自動車技術会  

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Language：English   Publishing type：Research paper (scientific journal)  

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Language：Japanese   Publishing type：Research paper (conference, symposium, etc.)   Publisher：公益社団法人自動車技術会，一般社団法人日本機械学会  

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Language：Japanese   Publishing type：Research paper (conference, symposium, etc.)   Publisher：公益社団法人自動車技術会  

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Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：Society of Automotive Engineers of Japan, SAE International  

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Language：Japanese   Publishing type：Research paper (conference, symposium, etc.)   Publisher：公益社団法人大気環境学会  

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Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：公益社団法人自動車技術会  

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Language：Japanese   Publishing type：Doctoral thesis  

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Language：Japanese   Publishing type：Master’s thesis  

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Language：Japanese   Publishing type：Internal/External technical report, pre-print, etc.  

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Language：Japanese   Publishing type：Internal/External technical report, pre-print, etc.   Publisher：一般社団法人日本機械学会  

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Language：Japanese   Publishing type：Article, review, commentary, editorial, etc. (scientific journal)   Publisher：一般社団法人日本機械学会  

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Language：Japanese   Publishing type：Internal/External technical report, pre-print, etc.   Publisher：一般社団法人日本機械学会  

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Language：Japanese   Publishing type：Internal/External technical report, pre-print, etc.  

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Language：Japanese   Publishing type：Internal/External technical report, pre-print, etc.  

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