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Until recently, U.S. government efforts to dramatically reduce emissions, greenhouse gases and vehicle fuel consumption have primarily focused on passenger car applications. Similar aggressive reductions need to be extended to heavy vehicles such as delivery trucks, buses, and motorhomes. However, the wide range of torques, speeds, and powers that such vehicles must operate under makes it difficult for any current powertrain system to provide the desired improvements in emissions and fuel economy. Hybrid electric powertrains provide the most promising, near-term technology that can satisfy these requirements. This paper highlights the configuration and benefits of a hybrid electric powertrain capable of operating in either a parallel or series mode. It describes the hybrid electric components in the system, including the electric motors, power electronics and batteries.

This paper describes how the 21st Century Truck Initiative supports the U.S. Army's transformation to a lighter, more mobile force to meet future National Security needs while helping commercial users develop economically viable technologies to lower costs and reduce demands for foreign fuel. The paper will also show how the National Automotive Center's systems engineering approach supports the selection of emerging technologies to support the transformation process.

This paper provides an overview of the Hybrid Electric Commercially Based Tactical Truck (COMBATT), a collaborative program between the U.S. Army Tank-automotive and Armaments Command's (TACOM) National Automotive Center (NAC) and the DaimlerChrysler Hybrid Electric Vehicle Platform Engineering Group. As part of the 21st Century Truck Initiative, the COMBATT platforms represent the class 2b (light) trucks. The platforms contain all of the utility and enhanced off-road capability features of the baseline COMBATT platform plus the second generation of a hybrid propulsion system incorporating an integral auxiliary power supply. The hybrid feature increases fuel efficiency, expands operational capability by providing a limited range electric propulsion mode, and enables an extended auxiliary electrical power supply capability. The auxiliary power supply provides up to 20kW of continuous electric power and 30kW of peak electric power for on- or off-board applications.

The utilization of commercially based technologies has the ability to greatly reduce the time and cost of military vehicle development. Commercially based technologies also enable the transition of a high level of capability into the military vehicle inventory and to the Army's ultimate customer, the soldier. The Army's National Automotive Center (NAC) has created SmarTruck, a light truck platform enhanced for military concept exploration. SmarTruck is outfitted with telematics, safety, and non-lethal weapon systems technology. It is a prime example of the NAC's central focus, which is dual-use commercial technology transfer. At the core of success for SmarTruck is the application of telematics technologies including embedded diagnostics, advanced electronic architectures, tele-maintenance, and wireless communications.

This no-idle climate control (NICC) system designed for heavy commercial and military vehicles (class 8 line haulers) will decrease emissions, cost, and fuel usage without sacrificing crew comfort. The system is designed for the sleeper cabin of the commercial trucks and crew compartment of the military trucks. During the night, truck drivers tend to idle the engine in order to provide heating or cooling while they sleep. This system will provide that comfort at approximately 13% of the fuel usage. Military personnel will also benefit by the ability to supply heating or cooling to the crew compartment during silent watch operations. This quiet solution to crew comfort along with the reduction in pollution and energy consumption will position this NICC system for commercial success.

Hybrid electric propulsion is a viable, realistic, near-term technology that can dramatically increase the fuel efficiency of commercial and military ground vehicles. Hybrid vehicles also benefit from exhaust emission reductions and the availability of an on-board source of mobile high power electrical energy for auxiliary systems.

Modern natural gas-to-liquids (GTL) conversion processes (Fischer-Tropsch liquid fuels (FTL)) offers an attractive means for making synthetic liquid fuels. Military diesel and jet fuels are procured under Commercial Item Description (CID) A-A-52557 (based on ASTM D 975) and MIL-DTL-83133/MIL-DTL-5624 (JP-8/JP-5), respectively. The Single Fuel Forward (single fuel in the battlefield) policy requires the use of JP-8 or JP-5 (JP-8/5). Fuel properties crucial to fuel system/engine performance/operation are identified for both old and new tactical/non-tactical vehicles. The 21st Century Truck program is developing technology for improved safety, reduced harmful exhaust emissions, improved fuel efficiency, and reduced cost of ownership of future military and civilian ground vehicles (in the heavy duty category having gross vehicle weights exceeding 8500 pounds).[1]

To reach its objective of reducing vehicle fuel consumption by 50 percent, the development of the 21st Century Truck (21T) will address all the aspects of truck design contributing to the achievement of that goal. [1] This paper will address one of these aspects, specifically vehicle parasitic loss reduction with special emphasis on drive train losses, concentrating on the potential benefits of replacing mechanical coolant (water) and oil pumps with electrically powered pumps.

This paper will describe the Army's Vehicle Intelligence Program and discuss some of the VI technologies being considered for use within the Army's Tactical Wheeled Vehicle fleet. It will describe some initial modeling efforts that focus on the fuel efficiency impacts of selected VI technologies and will suggest the impacts of an integrated and networked fleet with regard to logistics. Lastly, it will identify several areas of AVIP research that are being considered in the near term. All of these programs impact directly on the 21st Century (21T) Truck program. [1]

Alternative fuels made from materials other than petroleum are available for use in alternative fueled vehicles (AFVs) and some conventional vehicles. Liquid fuels such as biodiesel could be used in U.S. Army or other Military/Federal Government compression ignition (CI) engine powered vehicles. The military combat/tactical fleet is exempt from Federal Government mandates to use alternative fueled vehicles and has adopted JP-8/JP-5 jet fuel as the primary military fuel. The Army non-tactical fleet and other Federal nonexempt CI engine powered vehicles are possible candidates for using biodiesel. Inclusion of biodiesel as an alternative fuel qualifying for alternative fueled vehicle credits for fleets required to meet AFV requirements has allowed for its use at 20 (minimum) percent biodiesel in petroleum diesel fuel. Alternative fuels are being considered for the 21st Century Truck (21T) program. [1]