Military


XM1124 Hybrid Electric HMMWV

The XM1124 Hybrid Electric HMMWV is derived when the traditional mechanical drive train (engine, transmission and transfer case) is removed from a conventional M1113 Expanded Capability Series HMMWV and replaced with a hybrid electric drive train. The hybrid electric drive train consists of a motor-generator set, 2 drive motors, and a battery pack. The Hybrid drive train is in a series configuration, where the motor-generator set does not have a direct mechanical linkage to the wheels.

Compared to the convetional M1113, the Hybrid-Electric HMMWV had a higher top speed (85 versus 70 miles per hour), faster acceleration (7 versus 14 seconds), longer range (380 versus 275 miles), double the fuel economy, larger payload capacity, and 75 percent fewer emissions. The Hybrid-Electric HMMWV was also a portable power plant, capable of powering a mobile command post or field hospital.

Army interest in the HE HMMWV was predominantly in the areas of fuel consumption and logistical footprint reduction. Other areas of interest were the decreased thermal and acoustic signatures, as well as the availability of silent watch and silent mobility. The target for the HE program was to achieve the standard HMMWV mobility and payload (5,100 pounds), while also providing silent watch, silent mobility and the ability to produce a minimum of 33 kilowatts of continuous power.

In March 2002, PEI Electronics of Huntsville, Alabama, provided a Hybrid Electric HMMWV to support a demonstration to be carried out by soldiers of the 1-204th Air Defense Artillery Battalion, Mississippi Army Nationa Guard, at Newton, Mississippi. The intent of the demonstration was to show the capability and benefits of powering the Sentinal Radar from a new power source system, the Hybrid Electric HMMWV, in a live operational training exercise. The demonstration would include radar emplacement, start-up, and full power operation of the radar with the system's engine off (silent stealth mode, battery power only), and with the diesel engine running (alternator cycling in and out, re-charging the batteries). A Sentinel radar that was conventionally powered (mobile electric power unit) would hand-off an air defense mission to the new system's radar so it keeps providing ADA "air intelligence" to 2 operating Avenger batteries in an operational training exercise.

Four technology demonstrator vehicles were under contract, delivered in May 2002 for Government testing. Results of this testing was to be used to build documentation for a competitive source selection in 2003. In July 2003, the US Army projected a requirement for 1,500 HE HMMWVs for scout/RSTA use, as well as 19,000 HE HMMWV shelter carriers. A sole source AMG-FFP contract was issued in July 2003 and a Design-CPFF contract was issued in December 2003. The requirements were to decrease fuel consumption by 30 percent, provide 33 kW of continuous power, be transportable by C-130 aircraft, have multi-phase mobile power (AC/DC), maintain existing HMMWV capabilities (mobility, transportability, and payload), provide 2 level maintenance for prototypes, and design the vehicle with open Architecture for upgrades. Initial issues noted in continued testing included the vehicle's resistance water. 44 percent of incidents in the 4 demonstrator vehicles through July 2003 were the result of a problem with the hardware.

The FY04 budget funded Hybrid Electric (HE) Development of additional prototypes used in User Evaluation and to support logistics improvements to the HMMWV Family of Vehicles through the use of more recent engine technologies and maintainability improvements, which would result in decreased operational support costs and product improvements. FY04 and FY05 budgets funded continuation of the Hybrid Electric (HE) HMMWV program. The HE HMMWV Program represented a potential savings of 30% in O&S costs alone. The HE HMMWV was identified as a possible Objective Force platform in the Unit of Action and the Modernized HMMWV was to be considered as the interim platform for the Future Tactical Truck System (FTTS) Utility. HMMWV supported the Legacy-to-Objective transition path of the Transformation Campaign Plan (TCP), and the HE HMMWV supported the Objective Force.

The XM1124 vehicles went on to participate in the US Army's Tank Automotive Research, Development and Engineering Center's Air Assault Expeditionary Force Spiral B in 2005 and Spiral C in 2006. During one of these experimental events, the HE-HMMWV benefits for export power were demonstrated in experiments for an extended period of time (100 hours) of battalion tactical operations center operation. It was also demonstrated in a real-world situation when the HE-HMMWV provided emergency power to Fort Benning's electrical grid system when it went down.

As a result of participation in those experiments, TARDEC's Ground Vehicle Power and Mobility group sponsored the participation of an XM1124 Hybrid Electric HMMWV in the Air Assault Expeditionary Force Spiral D experiments. These experiments were conducted from 17 September 2007 through 8 November 2007, at Fort Benning, Georgia. The HE-HMMWV was used in these experiments as the Company Robotics Command and Control vehicle (ROBO C2).

The AAEF was intended to perform field-like experimentation and evaluation of Future Combat Systems Command, Control, Computer, Communications, Intelligence, Surveillance and Reconnaissance technologies and assess the impact on the Army's overall Brigade Combat Team mission capabilities. The AAEF Spiral D goals were:

  • Demonstrate to the Soldier the use of emerging C4ISR technologies and their utility in a battlefield scenario with a small mounted unit in a live field experiment within a BCT/Joint Task Force context. Within this context, comparisons were made between how battles are conducted with existing technologies, the "base case experiments," versus technologies projected for 2014, or "advanced case experiments."
  • Identify enabling capabilities that could be spiraled to the Current Force to address existing US Army Training and Doctrine Command/TARDEC Force Operating Capability gaps.
  • Conduct testing on candidate technologies and provide recommendations for spiraling, further testing or discarding.
  • Examine operational vertical maneuver of a small mounted force using surrogate aircraft and surrogate vehicles within a BCT/JTF context.

In Spiral D, the HE-HMMWV demonstrated the benefits of hybrid technology by providing "power on the move" to all C4ISR equipment mounted within the vehicle shelter. During the experiments, the HE-HMMWV provided C2 to several robotics systems, which included the Raven Unmanned Aerial Vehicle (UAV) and the Packbot Explorer.

The VIP Day and Open House followed the field experiments. The vehicle was used to demonstrate the ability to export electrical power. It provided simultaneous export power to the following vehicle exhibits: BAE System's Bradley advanced demonstrator, Lockheed Martin Corporation's C2AMMO satellite command station and 3 HMMWVs mounted with future C4ISR C2 systems. These systems required approximately 6 kilowatts of export power, while the HE-HMMWV's onboard ROBO C2 systems required an additional 2 kilowatts. Thus, a total of 8 kilowatts of onboard and export power were simultaneously provided by the HE-HMMWV.

A final report detailing the HE-HMMWV's performance was to be released by Soldier Battle Lab. The limited Military Utility Assessment obtained from the AAEF was significant in helping TARDEC engineers and scientists focus on new technologies in relation to Soldiers' needs. An AAEF Spiral E experiment is planned for November 2008.




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