3D Probe Measurement Settings for Hand-Shake Error Minimization

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Solution Overview

Problem

Existing three-dimensional shape measuring systems face precision issues due to position displacement of the probe, such as hand shake errors, leading to inaccuracies in measuring the shape and posture of a measurement target.

Innovation Solution

The system adjusts exposure time and the number of imaging instances to minimize position measurement errors, using markers to calculate and set optimal imaging parameters based on pixel values and error reduction strategies, ensuring precise measurements even with probe displacement.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the probe is held manually during measurement, then ease of operation is improved, but position measurement precision deteriorates due to hand shake errors

Engineering Contradiction:
Improveease of operationVSAvoidposition measurement precision
Core Design Contradiction:
Ease of operationVSMeasurement precision

Solution Approach 1:

The patent converts the harmful effect of hand shake into a measurable signal by using imaging devices to capture marker positions during probe movement. The system measures the actual displacement caused by hand shake and compensates for it through coordinate transformation and error correction algorithms, thereby maintaining measurement precision while allowing manual operation.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The system implements feedback by continuously monitoring marker positions through imaging devices and using this information to correct probe position measurements in real-time. The measured hand shake displacement is fed back into the coordinate transformation process to compensate for positioning errors, ensuring accurate three-dimensional shape measurement despite manual operation.

Inventive Principle:
Principle #23Feedback

2Measurement precision

If exposure time is increased to reduce positioning error, then measurement precision is improved, but productivity deteriorates due to longer imaging time

Engineering Contradiction:
Improvepositioning errorVSAvoidproductivity
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

The patent changes the parameter of exposure time to optimize the balance between measurement precision and productivity. By adjusting exposure time within an optimal range, the system reduces positioning error while avoiding excessive imaging time that would reduce productivity. This parameter optimization allows the system to achieve high-precision measurements efficiently.

Inventive Principle:
Principle #35Parameter changes

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 high-precision measurement of three-dimensional shapes by reducing position measurement errors, improving the accuracy of probe positioning and shape measurement, even when position displacement occurs.

Implementation Method 1

an imaging part configured to capture an image including a plurality of markers

Methodology Applied
Scientific EffectPhotoelectric Effect: Photoelectric Effect

Data Source

PatentEP3564618B1Three-dimensional shape measuring system and measuring time setting method
Publication Date: 2022.05.11 OMRON CORP
  • EP3564618B1 patent drawingFigure 1
  • EP3564618B1 patent drawingFigure 2
  • EP3564618B1 patent drawingFigure 3

AI summary

An exposure time is set (step 11), and a position of a probe (2) is measured a plurality of times (step 12). A position measurement error is calculated in a plurality of patterns of average numbers of times (step 13). A correspondence table of measuring times and the positioning errors being calculated is calculated (step 14). A correspondence table being prepared of measuring times and hand shake errors is used to calculate a correspondence table of measuring times and (hand shake errors + the positioning errors) for the exposure time being set (step 15). For all exposure times being candidates to be set, steps 11 to 15 are repeated to calculate a correspondence table of measuring times and position measurement errors (step 16). One of the exposure times and one of the average numbers of times, at which a position measurement error reaches the minimum, are set (step 17).