Publication

Modeling & Simulation, Testing & Validation (MSTV)
2018

PRACTICAL FEATURES EXTRACTED FROM FULL SURFACE TERRAIN SCANS

by Brian Liswell

Abstract

Test course characterization has long relied on single-line profile measurements which provide elevation as a function of distance. These profiles are analyzed to provide various statistics and metrics. While these metrics can be useful, single-line profiles will always lead to a limited characterization. A vehicle has multiple concurrent inputs from the ground, inducing not just vertical excitations but also pitching, rolling, and twisting displacements (amongst others). Improvements in profiling equipment have enabled the ability to sample and characterize the entire surface. This paper identifies two characterization methods which take advantage of a full surface scan. The first uses orthogonal transverse modes which could either be extracted with Singular Value Decomposition (SVD) or be predefined polynomials. The second extracts a concurrent profile under each wheel for a given vehicle axle spacing and track width. Orthogonal basis vectors are then projected onto the concurrent profiles to extract the heave, pitch, roll, and twist inputs from the ground into the vehicle.