Accurate high-speed thermal 3D shape measurement of transparent objects

Area of Science:

• Optical measurement technologies
• Thermal imaging
• 3D metrology

Background:

• Traditional 3D measurement methods struggle with transparent, glossy, or black surfaces.
• Previous thermal 3D sensing methods required surface preparation and had long measurement times (seconds).

Purpose of the Study:

• To introduce a high-speed thermal 3D sensor for significantly faster 3D shape acquisition.
• To enable 3D measurements of challenging materials without surface preparation.
• To improve the applicability of thermal 3D sensing in industrial settings like quality assurance and production lines.

Main Methods:

• Optically generating structured heat patterns on object surfaces.
• Utilizing a stereo mid-wave infrared camera setup to capture re-emitted thermal patterns.
• Developing a novel high-speed sensor architecture to reduce measurement duration.

Main Results:

• Achieved a tenfold reduction in measurement time, down to 0.1 seconds.
• Demonstrated comparable accuracy to previous thermal 3D sensors.
• Presented successful 3D measurements of static objects with high thermal conductivity.
• Performed the first dynamic 3D measurement of a transparent object using this technique.

Conclusions:

• The high-speed thermal 3D sensor offers a significant advancement for rapid 3D metrology.
• This technology overcomes limitations of previous methods, enabling faster and more versatile 3D shape measurements.
• The sensor shows promise for real-time applications in quality control and dynamic industrial processes.