Multi-head frequency-modulated continuous-wave ranging for real-time speckle suppression

Area of Science:

• Optics
• Metrology
• Industrial Automation

Background:

• Optical frequency-modulated continuous-wave (FMCW) ranging offers high-precision, high-speed distance measurements crucial for factory automation.
• Speckle noise, caused by rough surfaces, degrades the precision of FMCW ranging by introducing measurement uncertainties.
• Real-time speckle suppression is essential for developing robust industrial displacement sensors.

Purpose of the Study:

• To develop and demonstrate a speckle suppression strategy for FMCW ranging systems.
• To improve the precision and reliability of real-time displacement measurements in industrial settings.
• To enable accurate ranging of targets with rough surfaces.

Main Methods:

• Implementation of a multi-head interferometer system based on FMCW ranging principles.
• Development and application of a signal selection algorithm to mitigate speckle-induced errors.
• Experimental validation of the speckle suppression technique.

Main Results:

• Significant reduction in excess uncertainty attributed to speckle noise.
• Demonstrated improvement in the precision of real-time displacement measurements.
• Successful suppression of speckle effects without complex methodologies.

Conclusions:

• The proposed multi-head interferometer with a signal selection algorithm effectively suppresses speckle in FMCW ranging.
• This technique enhances the precision of real-time displacement measurements for various materials.
• The strategy offers a pathway for advancing laser-based displacement sensing capabilities in industrial automation.