Orthogonal-Camera Vision for Contactless Part Straightness Measurement

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Solution Overview

Problem

Existing optical inspection systems for geometrically regular parts face challenges such as limited accuracy in defect detection, mechanical complexity leading to malfunctions, incomplete surface coverage, mechanical damage risks, and mechanical wear, especially when measuring straightness without rotating the object.

Innovation Solution

A vision system using two video cameras positioned at 90 degrees to acquire images along orthogonal directions, applying the Pythagorean theorem for precise straightness measurement during the component's flight time, eliminating mechanical contact and optimizing system size and lighting efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If traditional optical inspection systems use single-camera setups or mechanical rotating devices to measure straightness, then the measurement capability is provided, but the measurement precision is limited and mechanical complexity increases

Engineering Contradiction:
Improvestraightness measurement precisionVSAvoidsystem mechanical complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent replaces mechanical rotating devices and single-camera mechanical scanning systems with a dual-camera optical system that captures images simultaneously from two orthogonal directions. This substitution eliminates mechanical moving parts while achieving precise straightness measurement through optical means, directly resolving the contradiction between measurement precision and mechanical complexity

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent introduces a second spatial dimension by positioning cameras at 90 degrees to each other, capturing images along orthogonal directions. This dimensional approach enables simultaneous measurement of straightness in multiple axes without mechanical rotation, improving measurement precision while avoiding the complexity of mechanical scanning systems

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Measurement precision

If mechanical contact methods are used to measure straightness, then measurement is achieved, but mechanical wear and damage risks increase

Engineering Contradiction:
Improvestraightness measurement accuracyVSAvoidmechanical wear and damage
Core Design Contradiction:
Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The patent replaces mechanical contact measurement methods with non-contact optical imaging using dual cameras. This substitution eliminates physical contact between measurement devices and inspected parts, preventing mechanical wear and damage while maintaining high measurement precision through optical capture of part geometry

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Measurement precision

If complete surface coverage inspection is implemented, then defect detection accuracy improves, but inspection time increases

Engineering Contradiction:
Improvedefect detection accuracyVSAvoidinspection time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent divides the inspection task into two simultaneous orthogonal views captured by separate cameras. Each camera captures a specific directional projection of the part, and the combination of these segmented views provides complete surface coverage information without requiring sequential scanning, thus improving defect detection accuracy while maintaining fast inspection speed

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system performs preliminary action by capturing both orthogonal images simultaneously in a single inspection cycle rather than sequentially. This preliminary capture of complete directional information eliminates the need for repeated scanning or rotation, achieving comprehensive surface coverage inspection without time loss

Inventive Principle:
Principle #10Preliminary action

4Measurement precision

If dual-camera orthogonal imaging is implemented, then straightness measurement precision improves, but system size increases

Engineering Contradiction:
Improvestraightness measurement precisionVSAvoidsystem footprint
Core Design Contradiction:
Measurement precisionVSArea of stationary object

Solution Approach 1:

The patent utilizes the third spatial dimension by positioning cameras at vertical orthogonal directions (90 degrees to each other). This vertical stacking arrangement allows both cameras to be housed in a compact configuration along the Z-axis rather than spreading them out horizontally, thereby improving measurement precision through orthogonal views while minimizing the system's horizontal footprint

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

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

Enables accurate, instant classification of parts as good or waste with reduced mechanical wear, ensuring high precision and efficiency while minimizing system size and maintaining clear imaging.

Implementation Method 1

the surface of the article is optically scanned with light beams coming from different circumferential positions. Non-specular light reflected from the surface is detected

Methodology Applied
Scientific EffectLight reflection: Reflection

Implementation Method 2

a backlight apparatus (3, 4) synchronized with the cameras (1, 2), turning on during the flight time of the geometrically regular inspectable part

Methodology Applied
Scientific EffectLight emission: Light

Data Source

PatentEP4603793A1Vision system and process for measuring the straightness of geometrically regular inspectable parts
Publication Date: 2025.08.20 ROMANĂ’, FRANCESCO
  • EP4603793A1 patent drawingFigure 1~2
  • EP4603793A1 patent drawingFigure 3~4
  • EP4603793A1 patent drawing

AI summary

A vision system is described for measuring the straightness of geometrically regular inspectable parts, comprising two video cameras (1, 2) positioned mutually at 90 degrees, a feeding apparatus (10), a photocell (20) to identify the approach of the part to a viewing, VOA, a backlight apparatus (3, 4), a central processing unit, CPU, an algorithm based on the Pythagorean theorem to be able to measure univocally the straightness of the parts, a mechanical diversion apparatus (30) in the channel (11) to direct the parts towards the good or waste bin, wherein the step for measuring the straightness of the parts takes place during the flight time, allowing an instant classification as good or to be rejected. A vision process for measuring the straightness of geometrically regular inspectable parts is also described.