Projection Pattern Creation Apparatus for 3D Measurement
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Solution Overview
Problem
Existing three-dimensional measuring apparatuses face challenges in accurately measuring objects due to pattern deformation caused by optical systems and positional relations, leading to blurred, stretched, or squashed patterns, which limits spatial resolution and measurement range.
Innovation Solution
A projection pattern creation apparatus that includes a deformation unit to reproduce and improve projection patterns based on optical system characteristics and positional relations, generating a second projection pattern that accounts for blur, stretching, and squashing, allowing for accurate three-dimensional measurement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a pattern is projected from the pattern projection device to an object, then three-dimensional measurement can be performed, but the pattern becomes blurred, stretched, or squashed due to optical system characteristics and positional relations, reducing measurement precision
Solution Approach 1:
The invention applies preliminary action by pre-calculating and applying deformation compensation to the projection pattern before it is projected. The deformation amount calculation unit computes the expected deformation based on optical system characteristics and positional relations, and the projection pattern creation unit modifies the pattern in advance to counteract the anticipated distortion. This ensures that even though the pattern will be deformed during projection, the deformation has already been compensated for, maintaining measurement precision.
Solution Approach 2:
The invention implements feedback through an iterative optimization process. The evaluation unit assesses the recognition reliability of patterns under various deformation conditions, and this evaluation feedback is used to adjust the projection pattern creation parameters. The system repeatedly calculates deformation amounts, creates modified patterns, evaluates their recognition reliability, and refines the pattern until optimal measurement precision is achieved, considering the expected optical distortions.
2Adaptability or versatility
If the pattern projection device is separated from the focused position to increase measurement range, then more objects can be measured, but the projected pattern becomes more blurred, reducing spatial resolution
Solution Approach 1:
The invention applies parameter changes by dynamically adjusting the projection pattern parameters based on the separation distance from the focused position. When the pattern projection device is moved away from the focus position to expand measurement range, the system calculates the resulting blur amount and modifies the projection pattern parameters (such as line width, spacing, and contrast) to compensate for the expected degradation. This allows the system to maintain spatial resolution even when operating outside the optimal focus position.
3Manufacturing precision
If the pattern is made finer to improve spatial resolution, then measurement precision increases, but the pattern becomes more susceptible to blur and deformation, reducing recognition reliability
Solution Approach 1:
The invention applies preliminary action by pre-calculating the blur amount based on the pattern's fine details and the optical system characteristics before projection. For finer patterns that are more susceptible to blur, the system computes the expected degradation and modifies the projection pattern in advance to compensate. This might involve adjusting contrast, widening critical features, or applying deconvolution techniques to counteract the anticipated blur, ensuring that fine patterns maintain recognition reliability despite their vulnerability to deformation.
Data Source
AI summary
A projection pattern creation apparatus is configured to capture an image of a projection pattern projected from a pattern projection device by an imaging device to measure a three-dimensional position and/or a shape of an object. The projection pattern creation apparatus includes: a projection pattern deformation unit configured to reproduce deformation when a projected projection pattern is included in an image captured by the imaging device on the basis of characteristics of optical systems of the pattern projection device and the imaging device, and/or a positional relation between the pattern projection device and the imaging device and generate a deformation projection pattern; and a first projection pattern improvement unit configured to generate a second projection pattern obtained by improving a first projection pattern, on a basis of a first deformation projection pattern generated when the first projection pattern is projected toward evaluation surfaces having different positions and inclinations.