Fringe Density Reduction of Relative Phase Difference in Laser Interferometry Measurement of Gear Tooth Flank

Abstract

High density of fringe pattern in laser interferometry measurement of form deviation of gear tooth flank makes the S/N ratio of measured signal lower. The concatenation of that signal for discrete phase difference becomes then difficult. In this paper, a method for reducing the density of fringes by data processing is proposed for the case, that the 3-dimensional target form of the objective tooth flank is specified by the design drawing. The simulated relative phase difference between involute helicoid and this target tooth flank is subtracted from the measured relative phase difference. This process corresponds, as if the target tooth flank form was used as the reference of the measurement, instead of the former reference of involute helicoid. The density of fringe pattern therefore becomes lower and the further data processing becomes surer and easier. The result of this proposal raises the reliability of the data processing to reconstruct the 3-dimensional tooth form deviation of gears.