Ultrasonic Weld Probe Positioning for Robot Inspection Accuracy

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Solution Overview

Problem

Current robot systems for inspecting joined bodies face challenges in achieving high inspection accuracy, particularly in accurately determining the position and quality of welds due to deviations from design positions and misalignment, which prolongs the inspection process.

Innovation Solution

A processing system that uses a detector with ultrasonic wave transmission and reflection to calculate the center position of welds, adjusts its position based on movement distances to reduce the distance between the detector and the weld center, and corrects the prescribed position using reference distances calculated from previous adjustments to improve accuracy and efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If the robot system uses fixed prescribed positions for detector placement, then the inspection process is simple and fast, but the inspection accuracy decreases due to deviations from design positions and misalignment

Engineering Contradiction:
Improveinspection accuracyVSAvoidinspection time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The system performs preliminary position adjustments by calculating the actual weld center position from intensity data and adjusting the detector position before the main inspection process. This preliminary action ensures accurate positioning without requiring time-consuming adjustments during the actual inspection, thus resolving the contradiction between inspection accuracy and inspection time.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system uses feedback from intensity data obtained during probing to calculate the actual weld center position. This feedback mechanism allows the system to automatically adjust the detector position based on real-time measurement data, improving inspection accuracy while maintaining efficient automated operation without manual intervention.

Inventive Principle:
Principle #23Feedback

2Measurement precision

If the system performs position adjustment for every inspection, then the inspection accuracy is maintained, but the inspection time increases

Engineering Contradiction:
Improveposition accuracyVSAvoidinspection efficiency
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

The system performs position adjustment only when necessary, based on calculated deviations from the prescribed position. Instead of adjusting for every inspection unconditionally, the system applies adjustment only when the deviation exceeds acceptable thresholds, thus maintaining position accuracy while avoiding unnecessary time consumption and improving overall inspection efficiency.

Inventive Principle:
Principle #16Partial or excessive action

3Measurement precision

If the detector is positioned exactly at the weld center, then the inspection accuracy is maximized, but the system complexity increases due to continuous position adjustment requirements

Engineering Contradiction:
Improvedetector positioning accuracyVSAvoidposition adjustment system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The system uses the intensity data obtained during the probing process itself to calculate the weld center position and perform necessary adjustments. The inspection process serves its own positioning needs by utilizing the same data for both quality assessment and position correction, eliminating the need for separate complex positioning systems and reducing overall system complexity while maintaining high positioning accuracy.

Inventive Principle:
Principle #25Self-service

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 enhances inspection accuracy while reducing the time required for the inspection process by accurately positioning the detector closer to the weld center, even when welds deviate from design positions, and accounts for misalignment and fluctuation in movement distances.

Implementation Method 1

The probe includes a transmission of an ultrasonic wave and a detection of a reflected wave

Methodology Applied
Scientific EffectUltrasonic wave transmission and reflection: Ultrasound

Data Source

PatentEP4123301A1Processing system, robot system, control device, processing method, control method, program, and storage medium
Publication Date: 2023.01.25 KK TOSHIBA
  • EP4123301A1 patent drawingFigure 1
  • EP4123301A1 patent drawingFigure 2
  • EP4123301A1 patent drawingFigure 3A~3C

AI summary

A processing system (1) sets a detector (22) to a prescribed position. The detector (22) includes a plurality of detection elements (22a) arranged along a first direction and a second direction. The second direction crosses the first direction. The processing system (1) causes the detector (22) to perform a probe of a weld portion (53) of a joined body (50). The probe includes a transmission of an ultrasonic wave (US) and a detection of a reflected wave (RW). The processing system (1) calculates a center position of the weld portion (53) in a first plane along the first and second directions based on intensity data. The intensity data is of an intensity of the reflected wave (RW) obtained by the probe. The processing system (1) performs a position adjustment of moving the detector (22) along the first plane to reduce a distance between the center position and a position of the detector (22) in the first plane.