Accession Number : ADP009078

Title :   Quantifying Gun Barrel Curvature: From Derivation of the Basic Formulas to Evaluating Derivatives, Estimating Errors, and Selecting Measurement Intervals.

Corporate Author : ARMY ARMAMENT RESEARCH DEVELOPMENT AND ENGINEERING CENTER WATERVLIET NY CLOSE COMBAT ARMAMENTS CENTER

Personal Author(s) : Finlayson, David F.

Report Date : SEP 1993

Pagination or Media Count : 16

Abstract : Following a discussion on the need to measure the curvature of gun barrels are given the derivations of the unit tangent and normal vectors; and the definitions of the binormal vector, and the curvature and torsion of a space curve. Formulas for curvature and torsion and the tangent, normal, and binormal vectors are given in terms of cartesian coordinate derivatives. The derivatives in these formulas must be evaluated numerically using measurements of the deviation from straightness of the barrel centerlines. Various methods for obtaining derivative formulas (e.g. Taylor's series, and differentiating interpolating polynomials derived by finite difference and least squares methods) and the requirements of a derivative formula are given origins and definitions of types of error are given as an introduction to error estimation and measurement interval selection. Finally a new method for selecting derivative formulas and measurement intervals based on the treatment of error as a random variable is introduced.

Descriptors :   *CURVATURE, *GUN BARRELS, CARTESIAN COORDINATES, ERRORS, INTERVALS, MEASUREMENT, POLYNOMIALS, RANDOM VARIABLES, REQUIREMENTS, SELECTION, TANGENTS, TORSION, TAYLORS SERIES, FINITE DIFFERENCE THEORY.

Subject Categories : Guns

Distribution Statement : APPROVED FOR PUBLIC RELEASE