Electro-optical contour measuring system

摘要

A non-contacting, electro-optical system adapted automatically to measure the contours of helicopter rotor blades and other shaped objects at high speed and with a high degree of accuracy. An object to be measured is held in a fixture with its contoured surface presented to an electro-optical triangulation rangefinder assembly supported on a carriage that is caused to step incrementally from one end of the object to the other. The assembly is constituted by a pivoted laser beam illuminator and a pivoted automatic tracker mounted for rotation at spaced pivot points on a carriage beam, the line extending between these points forming a triangulation baseline. At each carriage step, the assembly is activated to cause the illuminator to swing through a sector whereby the laser beam spot scans across the surface of the object being tested from one edge to the other. The angles assumed by the illuminator and those assumed by the tracker in the course of a scan are determined and fed to a computer in which the value of the baseline is stored, the computer calculating the changing spot location by triangulation. This scanning operation is repeated at every step from one end of the object to the other, thereby mapping the entire contour of the surface.