The SAE MOBILUS platform will continue to be accessible and populated with high quality technical content during the coronavirus (COVID-19) pandemic. x

Your Selections

Kawai, Terunao
Show Only

Collections

File Formats

Content Types

Dates

Sectors

Topics

Authors

Publishers

Affiliations

Events

   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Validation of Test Procedure for Measuring the Fuel Consumption of Production-Model FCVs

SAE International Journal of Advances and Current Practices in Mobility

National Traffic Safety & Enviro Lab.-Kenichiroh Koshika, Tetsuya Niikuni, Terunao Kawai
  • Journal Article
  • 2019-01-0382
Published 2019-04-02 by SAE International in United States
Factors affecting the measurement of the fuel consumption of FCVs were analyzed to reveal their sensitivity. The method for measuring fuel consumption described in WLTP is to measure the hydrogen consumption by using an electric precision balance and off-vehicle tanks (not on-vehicle tanks). This is unique compared with conventional vehicles such as petrol-engine vehicles and pure-electric vehicles. Therefore, we examined the sensitivities of the effect of hydrogen consumption determination, the effect of hydrogen supply pipe design, and the effect of hydrogen supply pipe management. The experiments were conducted with two production models of FCVs having different FC management systems. The effects were quantitatively evaluated by comparing the fuel consumption rate driving in WLTC.
This content contains downloadable datasets
Annotation ability available
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Development of Evaluation System for Exhaust Gas and Fuel Economy of Next-generation Hybrid Electric Vehicles

Meidensha Corporation-Masahiko Suzuki, Hiroshi Takahata
National Traffic Safety & Environment Lab.-Nobunori Okui, Terunao Kawai, Tetsuya Niikuni
Published 2013-10-14 by SAE International in United States
Next-generation vehicles which include Electric Vehicles (EV) and Hybrid Electric Vehicles (HEV) are researched and expected to reduce CO2 emissions in the future. Generally, the main factor to support high efficiency of EV and HEV is the idle stop, motor assistance and regenerative braking. The vehicle mechanism of HEV is complex, compared with conventional internal combustion engine vehicle.Certification test method of gas emissions and fuel consumption is used driving mode, which is currently reflecting the typical driving conditions in the market. And driving mode of certification test is established focusing on the reproducibility of driving by conventional internal combustion engine vehicles. It is necessary to consider that the driving mode for the vehicle used regenerative energy is reflected correctly. And high accuracy certification test method for next generation HEVs is necessary in order to evaluate exhaust gas and fuel economy.In this research, new test bench system which responded to a complicated HEV power-train system was produced, in order to investigate HEV test method including driving mode, certification test method for next generation HEV and the…
Annotation ability available
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Development of Evaluation System for Exhaust Gas and Fuel Economy of Next-Generation Hybrid Electric Vehicles

Meidensha-Masahiko Suzuki, Hiroshi Takahata
National Traffic Safety and Environment Laboratory-Nobunori Okui, Tetsuya Niikuni, Terunao Kawai
  • Technical Paper
  • 2012-08-0523
Published 2012-10-03 by Society of Automotive Engineers of Japan in Japan
Next-generation vehicles which include Electric Vehicles (EV) and Hybrid Electric Vehicles (HEV) are researched and expected to reduce CO₂ emissions in the future. High accuracy certification test method for next-generation HEVs is necessary in order to evaluate exhaust gas and fuel economy. In this research, new test bench system which responded to a complicated HEV powertrain system was produced. The bench system is able to reconstruct almost all of parallel HEV powertrain system in test room. The bench system is able to operate real internal combustion engine and real electric motor individually, and apply virtual drivetrain and vehicle. Therefore, the production of real vehicle is not needed for evaluation. The result of real-time simulation of HEV powertrain system in test bench is reported.
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Research of Adaptability to Battery Energy on Heavy-Duty Hybrid Electric Vehicle

National Traffic Safety & Enviro Lab.-Nobunori Okui, Tetsuya Niikuni, Terunao Kawai
Published 2012-09-10 by SAE International in United States
At interurban transportation, improvement of fuel economy of hybrid electric heavy-duty diesel vehicles, which assist drive-axle by using regeneration energy, is minimum, compared to heavy-duty diesel vehicles. One of the factors is that hybrid electric heavy-duty vehicles are not able to balance regeneration energy (input) and power energy (output) at high speed driving. One reason is not opportunity to operate of braking at high speed driving for the heavy-duty vehicle. In this research, we focus on the method used for the battery energy, and propose a new concept of hybrid electric system to efficiently utilize battery energy. That system consists of electrical booster for supercharging intake air into engine cylinder. We have confirmed the feasibility of the electric system of a new HEV concept by using the simulation I created.
Annotation ability available
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Research of Adaptability to Battery Energy on Hybrid Electric Heavy-Duty Vehicles

National Traffic Safety and Environment Laboratory-Nobunori Okui, Tetsuya Niikuni, Terunao Kawai
  • Technical Paper
  • 2012-08-0054
Published 2012-05-23 by Society of Automotive Engineers of Japan in Japan
At interurban transportation, improvement of fuel economy of hybrid electric heavy-duty diesel vehicles, which assist drive-axle by using regeneration energy, is minimum, compared to heavy-duty diesel vehicles. One of the factors is that hybrid electric heavy-duty vehicles are not able to balance regeneration energy (input) and power energy (output) at high speed driving. The reason that the vehicles at high speed driving is not chance braking timing. In this research, we focus on the method used for the battery energy, and propose a new concept of hybrid electric system to efficiently utilize battery energy. That system consists of electrical booster for supercharging intake air into engine cylinder. We have confirmed the feasibility of the electric system of a new HEV concept by using the simulation I created.
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Study on Evaluation Method for Battery Degradation in Plug-In Hybrid Electric Vehicles

Tetsuya Niikuni, Terunao Kawai, Kenichiroh Koshika
  • Technical Paper
  • 2011-08-0471
Published 2011-10-12 by Society of Automotive Engineers of Japan in Japan
Plug-in hybrid electric vehicles (PHEV) show much higher fuel economy values than those of hybrid electric vehicles (HEV). This advantage strongly depends on the performance of batteries in PHEVs. Battery performance declines over time. Nevertheless, there are no concrete methods to evaluate battery degradation. Battery degradation depends on battery usage and secular change. Therefore, the load conditions of battery tests need to reflect actual usage conditions of PHEVs. In this study, the load condition in a battery degradation test has been investigated. The influences of electrical and thermal loading in the capacity reduction of a test battery were compared.
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Actual Condition Survey and Optimized Approach of Energy Regenerative Braking Control for Electric Drive-Train Vehicles

National Traffic Safety and Environment Laboratory-Nobunori Okui, Tetsuya Niikuni, Terunao Kawai
  • Technical Paper
  • 2010-08-0679
Published 2010-09-29 by Society of Automotive Engineers of Japan in Japan
In order to improve the energy efficiency for electric drive-train vehicles such as EV, HEV and PHEV, it is necessary to optimize the regenerative braking control during deceleration of those vehicles. In this paper, regenerative braking control is estimated using commercial electric drive-train vehicles in an actual using condition. Based on these obtained data, the efficiency of a virtual vehicle, which allows 100% regenerative control, is predicted. Then, we explore the potential for the expansion of energy efficiency of electric drive-train vehicles. As a result, the layout of high efficient electric drive-train vehicle is that the regenerative motor is arranged in a front-rear wheel or a front wheel, and the mechanical brake is not used as much as possible. The regenerative efficiency of about 50% can be expected.
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Fuel Consumption Test Protocol Concept for Plug-in Hybrid Electric Vehicle

National Traffic Safety and Environment laboratory-Terunao Kawai, Tetsuya Niikuni
Published 2009-06-15 by SAE International in United States
A plug-in hybrid vehicle (PHEV) is recently developed technology and it will be put in the market in the near future. In existing hybrid electric vehicles (HEV), it was possible to suppress the petroleum consumption by regenerating the kinetic energy of vehicles during deceleration into electrical energy. A PHEV can use petroleum fuel as with traditional vehicles including HEV, and in addition, use the electrical energy supplied from the commercial power for running energy. That is, the existing HEV technology suppresses petroleum energy consumption. In contrast, the PHEV technology alternates part of vehicle drive petroleum energy with electric energy. Commercial electric generation can use many kinds of energy source other than the fossil oil. PHEV is a promising technology to reduce the well to wheel CO2 emission and one of the solutions for energy security issue. On the other hand, from the point of view of vehicle emission and fuel consumption performance evaluation, current test protocols cannot produce sufficient response to the peculiarities of PHEV, which use two kinds of energy source, such as petroleum…
Annotation ability available
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Characteristics of Plug-In Hybrid Electric Vehicle and Fuel Consumption Test Protocol Concept

National Traffic Safety and Environment Laboratory-Terunao Kawai, Tetsuya Niikuni, George W. Bush
  • Technical Paper
  • 2009-08-0178
Published 2009-05-20 by Society of Automotive Engineers of Japan in Japan
The current test protocols cannot produce sufficient response to the peculiarities of a plug-in hybrid vehicle (PHEV) which use two kinds of energy sources, such as petroleum fuel and electrical power and fuel consumption ratio which changes depending on the mileage. Since electric-motor vehicles (including PHEV) use electrical power to actually drive the vehicle, performance of the battery which stores electrical power has direct effect on PHEV performance. In this paper, the measurement methods for fuel consumption for PHEV and the concept of type approval test protocol for PHEV in Japan, which are currently being considered, will be discussed.
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Development of a Fuel Economy and Exhaust Emissions Test Method with HILS for Heavy-Duty HEVs

SAE International Journal of Engines

Hino Motors, Ltd.-Seiichi Yamaguchi
Isuzu Motors, Ltd.-Keiji Furumachi
  • Journal Article
  • 2008-01-1318
Published 2008-04-14 by SAE International in United States
The objective of this study was to develop a test method for heavy-duty HEVs using a hardware-in-the-loop simulator (HILS) to enhance the type-approval-test method. To achieve our objective, HILS systems for series and parallel HEVs were actually constructed to verify calculation accuracy. Comparison of calculated and measured data (vehicle speed, motor/generator power, rechargeable energy storage system power/voltage/current/state of charge, and fuel economy) revealed them to be in good agreement. Calculation error for fuel economy was less than 2%. To establish an HILS method, the following items were carried out: (a) Typical HEV models for the HILS system were proposed to enable them to be adapted to all types of heavy-duty HEVs which will be launched over the next few years in Japan; (b) Test procedures for HEV components such as engines, motors/generators and batteries were proposed to measure the parameters of HEV models; and (c) A verification procedure for the HILS system was developed.
Annotation ability available