HMMWV Variable Vehicle Cone Index (VCI)

The Marine Corps requires the High Mobility Multipurpose Wheeled Vehicle (HMMWV) to have a not-to-exceed Vehicle Cone Index (VCI) of 25. Leveraging a preliminary design study already conducted, Texas Research Institute Austin, Inc. (TRI/Austin) proposes to develop a Variable VCI System to detect the shape of the tire deformation and adjust the tire pressure to the optimal tire footprint using the Central Tire Inflation System. The proposed device is based on sensors embedded in the run-flat, with no modifications to the vehicle tire. The proposed sensing method is low cost, simple, rugged and environmentally and temperature tolerant to insure long working life without required maintenance. Relationships will be established between soil conditions, tire pressure, deflection/deformation, traction, and efficiency. Energy harvesting for system power and wireless data transmission methods will be thoroughly explored. TRI will team with AM General and Hutchison, Inc. to achieve integration of the proposed system with the HMMWV, Central Tire Inflation System (CTIS), Wheel, and Run-flat. Phase I will demonstrate the feasibility of the Variable VCI System by design and testing a demonstrator prototype. Phase II plans include mature prototype development and performance validation, with a final report incorporating a plan for transition to Phase III.