Hybride optical sensor for 2D/3D objekt inspektion (IOS23)

A project, financed by the Baden-Württemberg Stiftungs gGmbH, in collaboration with IPVS (Univ. Stuttgart), that realizes a sensor for industrial product inspection based on a hybrid system of diffractive-refractive optics and realtime image processing on a FPGA.

Rapidly advancing automation - also in the scope of Industry 4.0 - leads to increased demands on production-integrated quality inspection and process control. Optical measuring principles are increasingly being used for this due to their speed, non-contact use and high accuracy. The sensor to be developed and investigated within the scope of the project should enable both 2D and 3D measurements of technical objects at high speed and with high accuracy.


The concept is based on object-adapted fringe projection, telecentricity through diffractive optics and smart camera with deconvolution (FPGA). Based on triangulation, the object to be measured is illuminated with fringe patterns adapted to its topography. The pattern is generated via an LC spatial light modulator (SLM). Deviations of the surface are measured by distorting the patterns. Telecentric imaging optics are achieved cost-effectively by using a large diffractive lens (DOE). The aberrations that occur are compensated by the smart camera (FPGA) with deconvolution-based image enhancement. Coherent light source illumination introduces adverse speckle noise. This is to be reduced by dynamic computer-generated holograms (CGH). The principle here is the shifting of the spot position and averaging. In addition, a holographic multi-point sensor system reduces the measurement uncertainty caused by the image sensor.

Poster IOS23
Photo: Faulhaber

Publications

  1. 1. A. Faulhaber et al., “Hybrid telecentric triangulation sensor system with real-time field-dependent deconvolution,” in Optical Measurement Systems for Industrial Inspection XI, in Optical Measurement Systems for Industrial Inspection XI, vol. 11056. International Society for Optics and Photonics, 2019, p. 1105613. doi: 10.1117/12.2525568.
  2. 2. A. Faulhaber, M. Gronle, S. Haberl, T. Buchholz, T. Haist, and W. Osten, “Dynamically scanned spot projections with digital holograms for reduced measurement uncertainty in laser triangulation systems,” in AOPC 2019: Optical Sensing and Imaging Technology, H. Gong, J. E. Greivenkamp, J. Tanida, Y. Jiang, J. Lu, and D. Liu, Eds., in AOPC 2019: Optical Sensing and Imaging Technology. SPIE, Dec. 2019. doi: 10.1117/12.2548075.
  3. 3. A. Faulhaber et al., “Dynamic holography for speckle noise reduction in hybrid measurement system,” in LASER BEAM SHAPING XVIII, in LASER BEAM SHAPING XVIII, vol. 10744. SPIE-INT SOC OPTICAL ENGINEERING, 2018, p. 107440J. doi: 10.1117/12.2320486.

Financed by:

Logo BW Stiftung

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