Variable Cycle Stripe Pattern Projector for 3D Shape Measurement

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Solution Overview

Problem

Conventional three-dimensional shape measurement apparatuses using the phase shift method face challenges in handling a wide range of distances to measurement targets efficiently, often requiring multiple devices and resulting in prolonged measurement times due to the need for raster-scanning with parallel light.

Innovation Solution

A three-dimensional shape measurement apparatus that includes a camera adjusted to focus on the measurement target and a projector capable of projecting a variable stripe pattern, with the cycle of the stripe pattern being adjusted based on the measurement distance to optimize measurement accuracy and time.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If parallel light is subjected to raster-scanning to handle a wide range of distance, then the measurement distance range is improved, but the measurement time increases significantly

Engineering Contradiction:

Improvemeasurement distance rangeVSAvoidmeasurement time

Core Design Contradiction:

Adaptability or versatilityVSLoss of time

Solution Approach 1:

The patent replaces the mechanical raster-scanning system with a direct projection system. Instead of mechanically scanning parallel light across the measurement target, the invention projects stripe patterns directly onto the target at various distances, eliminating the need for mechanical scanning movements and significantly reducing measurement time while maintaining wide distance range capability

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent employs dynamic adjustment of the stripe pattern cycle based on measurement distance. The system automatically adapts the pattern parameters in real-time according to the distance being measured, optimizing measurement efficiency across different distance ranges without requiring mechanical reconfiguration or scanning

Inventive Principle:

Principle #15Dynamics

2Device complexity

If a fixed focal length optical system is used, then the device structure is simplified, but the measurement distance range is restricted

Engineering Contradiction:

Improveoptical system structureVSAvoidmeasurement distance range

Core Design Contradiction:

Device complexityVSAdaptability or versatility

Solution Approach 1:

The patent changes the parameter of stripe pattern cycle dynamically based on measurement distance. By adjusting the pattern cycle parameter rather than the optical system's physical parameters, the system achieves adaptation to different distances while maintaining a simple fixed focal length optical structure

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent creates a universal measurement system that can handle multiple distance ranges using a single fixed focal length optical configuration. The system achieves multi-functionality by adapting the projection pattern parameters rather than requiring multiple optical systems or adjustable focal length mechanisms

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Measurement precision

If multiple types of three-dimensional shape measurement apparatus are used to measure targets at different distances, then the measurement accuracy for each target type is improved, but the device complexity and cost increase

Engineering Contradiction:

Improvemeasurement accuracyVSAvoidnumber of measurement devices

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent creates a single universal measurement apparatus that can accurately measure targets at various distances by dynamically adjusting the stripe pattern cycle. This eliminates the need for multiple specialized devices while maintaining measurement accuracy across different distance ranges

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The system dynamically adapts the projection pattern parameters based on the measurement distance, allowing a single device to optimize its performance for different target distances. This dynamic adaptation enables one apparatus to replace multiple fixed-configuration devices

Inventive Principle:

Principle #15Dynamics

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 allows for efficient measurement across a wide range of distances while minimizing the increase in measurement time, by setting the stripe pattern cycle to balance contrast and conversion accuracy, thus reducing measurement errors and improving overall measurement efficiency.

Implementation Method 1

a projector that projects a stripe pattern

Methodology Applied

Scientific EffectLight: Light

Implementation Method 2

an apparatus that measures a three-dimensional shape using a principle of a phase shift method

Methodology Applied

Scientific EffectPhase shift method: Interference

Data Source

PatentUS20240384985A1Three-dimensional shape measurement apparatus, control method, and non-transitory computer-readable recording medium

Publication Date: 2024.11.21 KONICA MINOLTA INC

AI summary

A three-dimensional shape measurement apparatus includes: a camera adjusted to bring a measurement target into focus; and a projector that projects a stripe pattern. A cycle of the stripe pattern projected by the projector is variable.