X-ray Inspection Robot Positioning for Reject Reduction

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Solution Overview

Problem

Existing X-ray inspection systems often reject a significant number of good-quality products alongside poor-quality products, even when advanced rejection mechanisms are employed, due to the variability in processing time and position detection accuracy.

Innovation Solution

An X-ray inspection system that includes a conveying unit, an X-ray irradiation unit, a transmitted X-ray sensing unit, an image generation unit, a position information generation unit, a robot with a removal mechanism, and a control unit that uses a fixed-interval reference signal to accurately position the robot for removing poor-quality products, allowing it to move both orthogonally and parallel to the conveying direction, and adjusts conveying velocity based on the number of poor-quality products to optimize processing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a single arm-type rejection apparatus is provided for all inspection regions, then the device complexity is reduced, but the number of good-quality products rejected increases significantly

Engineering Contradiction:
Improverejection apparatus configurationVSAvoidnumber of good-quality products rejected
Core Design Contradiction:
Device complexityVSLoss of substance

Solution Approach 1:

The inspection region is divided into multiple segments (first inspection region and second inspection region), with separate rejection apparatuses assigned to each segment. This segmentation allows independent control of rejection actions in different regions, enabling precise rejection of poor-quality products while preserving good-quality products in other regions.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different rejection strategies are applied to different inspection regions based on local conditions. The first rejection apparatus handles poor-quality products in the first inspection region, while the second rejection apparatus handles poor-quality products in the second inspection region, allowing localized optimization of rejection accuracy.

Inventive Principle:
Principle #3Local quality

2Loss of substance

If multiple arm-type rejection apparatuses are provided for different inspection regions, then the number of good-quality products rejected is reduced, but the device complexity increases

Engineering Contradiction:
Improvenumber of good-quality products rejectedVSAvoidrejection apparatus configuration
Core Design Contradiction:
Loss of substanceVSDevice complexity

Solution Approach 1:

Each rejection apparatus is designed to handle multiple functions: detecting poor-quality products in its assigned inspection region, determining whether to reject based on predefined criteria, and executing the rejection action. This multi-functionality reduces the need for additional specialized components.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The rejection apparatus autonomously performs the complete rejection process for its assigned region: detecting poor-quality products, making rejection decisions based on inspection results, and executing rejection actions without requiring external intervention for each step.

Inventive Principle:
Principle #25Self-service

3Device complexity

If the robot moves the removal mechanism only in the direction orthogonal to conveying direction, then the device complexity is reduced, but the positioning precision for removing poor-quality products deteriorates

Engineering Contradiction:
Improverobot movement mechanismVSAvoidpositioning precision of removal mechanism
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The robot's removal mechanism is enabled to move in two dimensions: the direction orthogonal to the conveying direction (width direction) and the direction parallel to the conveying direction (length direction). This two-dimensional movement capability provides precise positioning in both横向 and longitudinal directions, accurately targeting poor-quality products for removal.

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

This system effectively reduces the number of good-quality products rejected by ensuring precise removal of poor-quality products and optimizing the conveying velocity to handle varying loads, thereby improving the overall efficiency and reliability of the inspection process.

Implementation Method 1

an X-ray irradiation unit that irradiates articles on the conveying unit with X-rays

Methodology Applied
Scientific EffectX-ray transmission: X-Ray

Implementation Method 2

a transmitted X-ray sensing unit that senses X-rays transmitted through the articles

Methodology Applied
Scientific EffectX-ray detection: X-Ray

Data Source

PatentEP4027135A1X-ray inspection system, x-ray inspection device, and x-ray inspection method
Publication Date: 2022.07.13 ISHIDA CO LTD
  • EP4027135A1 patent drawingFigure 1
  • EP4027135A1 patent drawingFigure 2
  • EP4027135A1 patent drawingFigure 3

AI summary

PROBLEM TO BE SOLVED BY THE INVENTION An object of the present invention is to suppress the number of rejected good-quality products in an X-ray inspection system in which articles assessed to be poor quality are rejected. SOLUTION A X-ray inspection system 100 includes a conveying unit 10 that continuously conveys inspected objects at random positions, an X-ray irradiator 22 that irradiates the conveying unit with X-rays, a line sensor 24 that senses X-rays transmitted through the inspected objects, an image generation unit 28b that generates a transmitted X-ray image based on a sensing result from the line sensor, an inspection unit 28c that inspects for poor quality in the inspected objects based on the transmitted X-ray image, a position information generation unit 28e that generates position information E relating to positions of the inspected objects on the conveying unit determined to be poor quality, a robot 30 that take the inspection objects P away from the conveying unit with a suction ejector, and a robot control unit 40 that controls the action of the robot. The robot control unit, based on the position information and a fixed-interval reference signal S issued every time the conveying unit advances a first distance, controls the action of the robot so that the suction ejector comes near to and takes away the inspected objects determined to be poor quality.