DIGITAL IMAGE CORRELATION FOR OFF-ROAD MOBILITY

Digital Image Correlation (DIC) technology developed for off-road vehicle dynamics at the University of Pretoria, South Africa, was recently assessed for all-season and all-terrain viability through a Foreign Technology Assessment Support (FTAS) program at the US Army Engineer Research and Development Center-Cold Regions Research and Engineering Laboratory (ERDC-CRREL) in Hanover, New Hampshire (NH). Advancements in camera technology have brought on the proliferation of inexpensive, high resolution and high frame-rate cameras. At the same time the increase in computational power of computers has allowed algorithms to determine the depth of a scene and enable the near real-time tracking of features on an image. These advancements have enabled the application of DIC to measure surface and velocity profiles as well as deformation from a reference state (for terrain or for tires). In large off-road vehicle dynamics DIC can be used to improve maneuverability of vehicles by monitoring the road or terrain surface before and after the tire passes. From these measurements the initial road roughness and the deformation of the terrain can be determined to provide an indication of the terrain trafficability. DIC can also be used to determine the motion of the vehicle or tire, which can aid in vehicle safety systems via slip angle and traction performance.

This paper details the application of DIC on a military vehicle to measure terrain deformation and vehicle motion on varied terrain with the final aim of providing additional information to the driver or vehicle control system for performance optimization; and ultimately for providing feedback on mobility or terrain information for situational awareness at the driver or theater level. The technology was tested and validated using the CRREL Instrumented Vehicle (CIV) and two military vehicles; an unarmored High Mobility Multipurpose Wheeled Vehicle (HMMWV) (M1097) and a 20-ton Heavy Expanded Mobility Tactical Truck (HEMTT). Testing with the HEMTT on snow, ice, water, asphalt, concrete and vegetated ground will be shown to illustrate use of the technology on large military vehicles on a variety or surfaces.