Effect of camera temperature variations on stereo-digital image correlation measurements

Area of Science:

• Optical Measurement Techniques
• Metrology
• Experimental Mechanics

Background:

• Stereo-digital image correlation (stereo-DIC) relies on stable camera parameters for accurate measurements.
• Environmental factors like temperature can cause drift in camera intrinsic and extrinsic parameters.
• Unaccounted parameter changes lead to errors in measured displacements and strains.

Purpose of the Study:

• To experimentally investigate the influence of temperature variations on stereo-DIC measurements.
• To quantify the magnitude of displacement and strain errors induced by temperature changes.
• To propose methods for mitigating temperature-related errors in stereo-DIC systems.

Main Methods:

• Utilized a stereo-DIC system to continuously measure a stationary quartz glass plate.
• Varied camera and ambient temperatures to observe their effects.
• Quantified surface displacements and strains under controlled temperature conditions.

Main Results:

• Temperature variations demonstrably influence stereo-DIC measurements.
• Altered camera parameters (intrinsic and extrinsic) due to temperature changes cause significant errors.
• Displacement and strain errors showed a clear correlation with temperature fluctuations, estimated at 30-50 με/°C for the tested setup.

Conclusions:

• Temperature variations are a critical factor affecting stereo-DIC accuracy, particularly in non-laboratory settings.
• The study confirms that temperature-induced errors in stereo-DIC are quantifiable and correlate with temperature changes.
• Two practical solutions are proposed to minimize the adverse effects of camera temperature variations on measurement precision.