Optical Dual Laser Based Sensor Denoising for OnlineMetal Sheet Flatness Measurement Using Hermite Interpolation

Area of Science:

• Materials Science and Engineering
• Metrology and Measurement Science

Background:

• Accurate flatness measurement of metal sheets is essential for quality control in steel coil processing.
• Existing methods face challenges with noise from vibrations and mechanical events during production.

Purpose of the Study:

• To develop and validate an innovative system for real-time, robust surface estimation of flattened metal sheets.
• To improve the accuracy and efficiency of flatness sensing in industrial environments.

Main Methods:

• Utilized a system with two line lasers and a 2D camera for laser plane triangulation.
• Employed Hermite cubic interpolation for real-time surface estimation and high-frequency noise removal.
• Validated the system using synthetic data simulating noise and real-world data from a steel mill.

Main Results:

• Achieved instantaneous, robust estimation of surface height derivatives using dual lasers.
• Demonstrated effective high-frequency noise removal through Hermite cubic interpolation.
• Showcased at least a 41% improvement in surface reconstruction accuracy compared to conventional filtering methods.

Conclusions:

• The proposed dual-laser system offers a significant advancement in real-time metal sheet flatness sensing.
• The system provides robust and accurate surface estimation, outperforming traditional techniques.
• This technology enhances quality control in metal sheet production by minimizing noise and improving measurement precision.