Helmet accommodation analysis using 3D laser scanning

A method used to determine the probable population accommodation of a helme t sizing system is described. The method involves the use of 3D laser scann ing, as a means of measuring helmet standoff distance (distance between the inside of the helmet and the skull), and the selection of a representative sample of test subjects. The laser scanner and the software developed to c alculate standoff distance proved to be an excellent tool for the assessmen t of helmet fit. The main advantages include ease of use and visualization of problem areas. This 3D-analysis method gives designers objective evidenc e of the need for design changes as well as an idea of what these changes s hould be. A comparison was made between standoff distance results obtained from the scanner and those obtained using a physical measurement method (a probe). Although discrepancies were found between the two, sources of error s intrinsic to both methods make it difficult to determine which of the two methods yielded the truest standoff distance. Analysis of the comparison d ata shows laser scanning to be slightly more conservative than the probe me thod for standoff distance purposes, i.e. erring on the side of safety. (C) 2000 Published by Elsevier Science Ltd. All rights reserved.