N121-002 TITLE: HMMWV Variable Vehicle Cone Index (VCI)

TECHNOLOGY AREAS: Ground/Sea Vehicles

ACQUISITION PROGRAM: Program Manager Motor Transportation, HMMWV, ACAT 1C

OBJECTIVE: The HMMWV ORD clarification, dated 22 July 2010, requires the HMMWV to have a not-to-exceed Vehicle Cone Index (VCI) of 25 (Threshold). The VCI of the HMMWV in its current configuration is approximately 31 at 15,500 lbs. The objective of this SBIR is to develop a system that will enable the HMMWV to achieve the Threshold VCI of 25 at the GVW of 15,500 lbs. Additionally, it is desired to be able to vary the VCI "on-the go" to provide for rapid transitions between different surfaces, such as soft soils and hard surfaces.

DESCRIPTION: Soil strengths are described in terms of Rating Cone Index (RCI), as soils get softer (mud, snow, sand, silts, etc) the RCI gets lower. A vehicle�s VCI describes the capability of a vehicle, as determined by test methods, to traverse a given soil a in single or multiple passes. To traverse a soil with an RCI of 20, a vehicle must have a VCI of 20 (or less). Since VCI is largely dependent on the contact patch of the tire and vehicle axle weight, varying the tire contact patch will also vary the VCI.

PHASE I: The contractor will investigate concepts for varying the HMMWV VCI on the fly based on soil and road conditions. The contractor will develop an analytical model to compare different concepts to include projected performance, reliability, maintainability. The contractor shall estimate hardware, installation and maintenance costs. The contractor will present the alternatives at the end of Phase I and make a recommendation for a Phase II demonstration.

PHASE II: The contractor will develop a prototype of the variable VCI system and evaluate it on a Government Furnish HMMWV. The modified HMMWV will be tested to validate the performance, reliability and maintainability of the variable VCI system.

PHASE III: A successful variable VCI system will follow a dual transition path. Some systems will be integrated onto HMMWVs that are deployed in mission areas that require variable VCI, while the overall system design will transition into the HMMWV RECAP program to facilitate that vehicle�s need to traverse multiple soils.

PRIVATE SECTOR COMMERCIAL POTENTIAL/DUAL-USE APPLICATIONS: The need to rapidly and safely traverse multiple soil types exists in many industries including agricultural, mining, oil exploration and forestry. Additionally, commercial recreation endeavors such as off-road vehicle competition and winter sports activities could benefit from a system that varies vehicle VCI.

REFERENCES:
(1) AGRICULTURAL ENGINEERING: AGRICULTURAL MECHANIZATION, Vincent A. Dodd, Patrick M.Grace

(2) CORRELATION OF MOBILITY CONE INDEX WITH FUNDAMENTAL ENGINEERING O PROPERTIES OF SOIL, Bohzad Rohani and George Y. Baladi, U. S. Army Engineer Waterways Experiment Station, Vicksburg, MS

(3) CENTRAL TIRE INFLATION SYSTEMS MANAGING THE VEHICLE TO SURFACE, Society of Automotive Engineers

KEYWORDS: Tire Contact Patch; Vertical Cone Index; Soil Rating Cone Index; Central Tire Inflation System; Soil Stability; Vehicle Mobility

** TOPIC AUTHOR (TPOC) **

DoD Notice:   Between November 9 and December 11, 2011, you may talk directly with the Topic Authors to ask technical questions about the topics. Their contact information is listed above. For reasons of competitive fairness, direct communication between proposers and topic authors is not allowed starting December 12, 2011, when DoD begins accepting proposals for this solicitation.

However, proposers may still submit written questions about solicitation topics through the DoD's SBIR/STTR Interactive Topic Information System (SITIS), in which the questioner and respondent remain anonymous and all questions and answers are posted electronically for general viewing until the solicitation closes. All proposers are advised to monitor SITIS (12.1 Q&A) during the solicitation period for questions and answers, and other significant information, relevant to the SBIR 12.1 topic under which they are proposing.

If you have general questions about DoD SBIR program, please contact the DoD SBIR Help Desk at (866) 724-7457 or email weblink.