Obstacle detection and spectral discrimination using multi-wavelength motionless wide angle laser scanning

Area of Science:

• Optics and Photonics
• 3D Sensing Technologies
• Spectroscopy

Background:

• Traditional laser scanning systems often have limitations in angular coverage and simultaneous multi-wavelength analysis.
• Accurate 3D coordinate acquisition and material identification are crucial for various applications, including robotics and remote sensing.

Purpose of the Study:

• To develop and demonstrate a static laser scanning system capable of wide-angle coverage using a novel cylindrical quasi-cavity waveguide.
• To integrate discrete laser spectroscopy for enhanced object characterization, including 3D positioning and surface material identification.

Main Methods:

• Utilized laser triangulation with 20 laser beams from a cylindrical quasi-cavity waveguide for 3D ranging.
• Employed a system of linear equations and principal ray plotting to calculate distances and angles.
• Integrated 640nm and 785nm laser diodes for discrete laser spectroscopy, with reflected light captured by a CCD imager.
• Calibrated the system using constrained non-linear optimization for instrumental parameters.

Main Results:

• Achieved distance accuracies exceeding 93% for measurements over 5 meters indoors.
• Demonstrated simultaneous spectral measurements from the same point using both red and infrared laser diodes.
• Successfully discriminated between natural objects based on differences in reflected light intensity.

Conclusions:

• The developed system offers a robust solution for wide-angle 3D scanning and material identification.
• The integration of multi-wavelength spectroscopy enhances object characterization, providing both 3D coordinates and surface material insights.
• This technology has potential applications in fields requiring detailed object analysis from a single measurement point.