Nonmechanical and multiview 3D measurement microscope for workpiece with large slope and complex geometry

Area of Science:

• Metrology
• Optical Engineering
• Mechanical Engineering

Background:

• Traditional optical measurement methods struggle with the complex geometry and large slopes of cutting tools and drill bits.
• Accurate 3D parameter measurement is crucial for tool performance and manufacturing quality.

Purpose of the Study:

• To develop a novel, accurate 3D measurement method for cutting tools and drill bits.
• To overcome limitations of existing optical measurement techniques for complex geometries.

Main Methods:

• A multiview rotation scanning technique combined with non-mechanical focus variation using a liquid lens.
• Image acquisition in the axial direction during workpiece rotation.
• Focus measure operators to determine depth values for each pixel.
• A multiview registration algorithm to generate a 3D point cloud.

Main Results:

• Successfully measured 3D parameters, including rake and clearance angles, for gears, screw taps, and drills.
• Achieved high accuracy with axial measurement reaching 2.4 μm (2σ).
• The method demonstrated lateral shift-free and consistent light intensity, enhancing measurement reliability.

Conclusions:

• The proposed liquid lens-based multiview scanning method offers a superior solution for 3D measurement of complex tools.
• This technique provides high accuracy and reliability, overcoming the limitations of conventional optical methods.
• Enables precise characterization of critical tool parameters for improved manufacturing and performance.