Broad-Spectrum Triangulation Profiling for Specular 3D Measurement
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Laser triangulation measurement requires a collimated laser with narrow spectrum, leading to poor imaging of specularly reflected objects and high costs, while spectral confocal imaging has a complex light path and high cost due to the use of a spectrometer.
Innovation Solution
A method using a broad spectrum light source with a dispersion lens and high resolution imaging lens to focus light at different heights, combined with a displacement moving mechanism and data processing system to measure 3D profiles, eliminating the need for a spectrometer and allowing for high compatibility and accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a collimated laser with narrow spectrum is used for laser triangulation measurement, then the measurement can be performed with simple equipment, but the imaging quality of specularly reflected objects deteriorates and the system becomes sensitive to angle changes
Solution Approach 1:
The patent changes the spectral parameter from narrow spectrum (laser) to broad spectrum light source, and changes the beam configuration from collimated to divergent. This parameter change allows the system to maintain both simplicity and improved imaging quality for specularly reflected objects, as the broad spectrum enables better angular compatibility while the divergent beam reduces sensitivity to angle changes.
2Measurement precision
If a spectral confocal imaging measurement system is used to improve imaging quality and angle compatibility, then the measurement precision improves, but the device complexity and cost increase significantly
Solution Approach 1:
The patent extracts and eliminates the spectrometer from the system, which is the key component that causes high complexity and cost in spectral confocal imaging. By using a broad spectrum light source with a divergent beam and a simple imaging lens, the system achieves improved imaging quality without requiring the complex spectral analysis hardware, thus reducing device complexity and cost.
Solution Approach 2:
The patent creates a universal measurement system that can handle both specularly reflected objects and inclined surfaces using a single broad spectrum light source and imaging lens configuration. This multi-functional capability eliminates the need for separate specialized components required by spectral confocal systems, thereby simplifying the overall device while maintaining high measurement precision.
3Measurement precision
If a spectral confocal sensor with a spectrometer is used, then the measurement accuracy improves, but the system volume and acquisition cost increase
Solution Approach 1:
The patent removes the spectrometer and associated spectral analysis components from the system, which are the primary contributors to increased system volume. The simplified architecture using a broad spectrum light source with a divergent beam and a single imaging lens achieves the required measurement accuracy with significantly reduced system volume, making the device more compact and cost-effective.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The method achieves high measurement precision with a large tolerance angle, reducing system volume and cost, and can measure specularly reflected objects and inclined surfaces, combining the advantages of both laser triangulation and spectral confocal systems.
Implementation Method 1
the dispersion lens focuses colored light with different colors of the divergent beam at different heights of the measured object plane
Implementation Method 2
the dispersion lens focuses colored light with different colors of the divergent beam at different heights of the measured object plane
Implementation Method 3
the high resolution imaging lens focuses the reflected light beam to the imaging detector for imaging
Implementation Method 4
the imaging detector and the data processing system are configured to convert an optical signal into an electric signal
Data Source
AI summary
Disclosed is a method for measuring a triangular profile based on a broad spectrum light source, including the following steps: first, building a triangular laser measurement model; putting a calibrator in the triangular laser measurement model, measuring object plane coordinates (x, z) of the calibrator by virtue of a measuring instrument, moving the calibrator many times to acquire object plane coordinates of a plurality of groups of calibrators and corresponding image plane coordinates, so as to obtain a coefficient-determined relational expression of a two-variable linear function; and finally, putting a measured object in the triangular laser measurement model, acquiring, by an imaging detector, image plane coordinates (u, v) of a measured object plane, calculating a coordinate z of the measured object plane through the relational expression of the function, driving, by a displacement moving mechanism, the measured object to move relative to an optical axis of a focused light beam in a perpendicular direction to measure a coordinate y, and splicing an object plane profile (x, z) in a displacement distance to obtain a whole object plane profile of the measured object, so as to obtain a 3D size of the whole measured object. The present invention features a large tolerance angle, high compatibility, and a high measurement accuracy, and the volume and cost are greatly reduced.