Smart Optical Shape Sensor Using Electronically Controlled Lens and Laser Line Illumination Scanning

Abstract

Proposed is a smart single viewing axis optical laser line illumination-based 3-D shape sensor that uses an electronically controlled variable focus lens (ECVFL) for 3-D optical beamforming. Specifically, the novel sensor design deploys laser line illumination scanning and camera-based spatial image processing of the target illuminated laser line spot that leads to a faster 3-D shape reconstruction versus the previously demonstrated point scanned ECVFL-based 3-D shape sensor. The proposed sensor is experimentally demonstrated using a liquid ECVFL and transverse direction motion mechanics to successfully 3-D map 40-mm depth steep surface profile objects with a mean measurement error of <5%. The line illumination sensor demonstrates a 53 times shorter 3-D mapping time per scanned point when compared with the point-scan-based sensor. The proposed 3-D shape sensor is suitable for scenarios where high transverse resolution inspections is required of objects having holes, crevices, or other complex external structures.