Phase Shift Measurement Pattern for Topographic Profilometry
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Solution Overview
Problem
Conventional topographical measurement methods require multiple image recordings to achieve unambiguity in phase images, leading to increased measurement time and complexity, especially in time-critical applications like mobile profilometry.
Innovation Solution
A method and device that project a sequence of measurement patterns with periodically modulated phase shift patterns and stationary value sequences, allowing independent evaluation of phase shift and modulation, reducing the number of necessary image recordings by using a redundant value sequence that can be decoded separately from the phase image.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If multiple measurement patterns with phase shift patterns are projected onto the object, then measurement precision is improved, but measurement time increases
Solution Approach 1:
The patent combines phase shift patterns with value sequence patterns into a single measurement pattern that can be evaluated independently. This merging allows extraction of both phase information and uniqueness information from one pattern, reducing the total number of patterns needed while maintaining measurement precision
Solution Approach 2:
The measurement pattern serves multiple functions simultaneously: it provides phase information for topographical measurement and contains value sequences for unambiguous identification. This multi-functionality eliminates the need for separate patterns for each purpose, reducing measurement time
2Measurement precision
If multiple measurement patterns are projected to achieve unambiguity, then measurement precision is improved, but device complexity increases
Solution Approach 1:
The patent merges phase encoding and value sequence encoding into a single measurement pattern structure. This combination allows the system to achieve unambiguous measurements without requiring multiple separate pattern projection systems, thereby reducing device complexity
Solution Approach 2:
The measurement pattern is segmented into independently evaluable portions: phase shift pattern components and value sequence components. This segmentation allows independent evaluation of each component, simplifying the overall measurement system while maintaining unambiguous measurement capability
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
This approach significantly reduces measurement time by at least a third, making it more efficient and suitable for time-critical applications, while maintaining the integrity of phase images and providing fault tolerance through error correction.
Implementation Method 1
two-dimensional recording of the light reflected from the front of the wheel from a direction other than the direction of light projection by an image converter
Data Source
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AI summary
The method involves projecting a sequence of multiple measurement patterns (3) onto an object (1) by a projection unit (2), where each measurement pattern contains a periodically modulated phase shifting pattern modulated with a value sequence. The phase shifting patterns have a phase shift relative to one another, where the value sequences are stationarily fixed relative to one another. An independent claim is also included for an apparatus for topographic measurement of an object.