Simultaneous two-dimensional velocity and distance measurements based on laser triangulation

TL;DR

This paper introduces novel methods for simultaneous 2D velocity and distance measurements using laser triangulation, enhancing lateral resolution and enabling dynamic surface analysis with high accuracy.

Contribution

The work presents new theoretical models and measurement techniques that extend laser triangulation capabilities to include lateral velocity and improved axial distance sensing.

Findings

Achieved relative error and uncertainty of 10^{-4} in measurements

Validated methods through experiments on a moving metal specimen

Enhanced lateral resolution by an order of magnitude

Abstract

Laser triangulation sensors are widely used in industry for surface inspection due to simple setup, micron precision and low cost. Conventional laser triangulation methods only enable axial distance measurement limiting further applications, and their lateral resolution is limited by surface microstructure. For overcoming these issues, based on the geometric optics we propose novel theoretical models and methods to achieve lateral velocity measurement. Moreover, a novel axial distance measurement method using edge detection is presented, which can increase the lateral resolution by the order of one magnitude. The performance of the proposed methods are validated through simultaneous orthogonal velocity and distance measurements on a moving established metal specimen, showing the relative error and relative uncertainty can reach 10^{-4}. The versatility of this multi degree of freedom measurement method paves the way for its broad application across all laser triangulation systems. Therefore, this simultaneous two-dimensional velocity and distance sensing approach can propel advancements in dynamic behavior discipline, including but not limited to motion mechanology and fluid mechanics.