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A Real-Time 3D Range Image Sensor based on a novel Tip-Tilt-Piston Micro-mirror and Dual Frequency Phase Shifting

Abstract

Structured light is a robust and accurate method for 3D range imaging in which one or more light patterns are projected onto the scene and observed with an off-axis camera. Commercial sensors typically utilize DMD- or LCD-based LED projectors, which produce good results but have a number of drawbacks, e.g. limited speed, limited depth of focus, large sensitivity to ambient light and somewhat low light efficiency.
We present a 3D imaging system based on a laser light source and a novel tip-tilt-piston micro-mirror. Optical interference is utilized to create sinusoidal fringe patterns. The setup allows fast and easy control of both the frequency and the phase of the fringe patterns by altering the axes of the micro-mirror. For 3D reconstruction we have adapted a Dual Frequency Phase Shifting method which gives robust range measurements with sub-millimeter accuracy.
The use of interference for generating sine patterns provides high light efficiency and good focusing properties. The use of a laser and a bandpass filter allows easy removal of ambient light. The fast response of the micro-mirror in combination with a high-speed camera and real-time processing on the GPU allows highly accurate 3D range image acquisition at video rates.

Category

Academic article

Client

  • SINTEF AS / 102002634

Language

English

Author(s)

Affiliation

  • SINTEF Digital / Smart Sensor Systems
  • SINTEF Digital / Microsystems and Nanotechnology

Date

17.03.2015

Year

2015

Published in

Proceedings of SPIE, the International Society for Optical Engineering

ISSN

0277-786X

Publisher

SPIE - The International Society for Optics and Photonics

Volume

9393

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