WEDM Probe and Wire Calibration Using a Dual-Cavity Artifact

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Solution Overview

Problem

Existing WEDM systems lack effective methods for accurately calibrating the position of the touch probe and conductive wire relative to the machine coordinate system, leading to inefficiencies in machining complex components like aircraft propulsion system parts.

Innovation Solution

A machining system incorporating a wire electrical discharge machining assembly, a probe assembly, and a calibration artifact, with a controller that identifies and calibrates the positions of the touch probe and conductive wire using a calibration artifact to determine X, Y, and Z offsets, storing these offsets in memory for precise machining.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If traditional calibration methods are used for WEDM systems, then the machining process can proceed, but the calibration precision of the touch probe and conductive wire positions is insufficient

Engineering Contradiction:
Improvecalibration precisionVSAvoidcalibration system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent introduces a calibration artifact as an intermediary object with precisely engineered cavities (probe cavity and wire cavity) that serve as reference features. This artifact mediates between the measurement system and the workpiece, enabling accurate determination of the touch probe and conductive wire positions relative to the machine coordinate system without requiring complex direct measurement procedures

Inventive Principle:
Principle #24Intermediary (Mediator)

2Productivity

If manual calibration procedures are performed, then the system can be set up, but the calibration time is excessive

Engineering Contradiction:
Improvecalibration efficiencyVSAvoidcalibration time
Core Design Contradiction:
ProductivityVSLoss of time

Solution Approach 1:

The calibration artifact is pre-manufactured with precisely located cavities and reference features that encode the desired coordinate system relationships. By preparing this artifact in advance with built-in reference geometry, the system eliminates time-consuming manual measurement and calculation procedures during the actual calibration process, as the controller can directly compute offsets from the artifact's known geometry

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent replaces manual mechanical calibration procedures with an automated computational approach. The controller uses the artifact's known geometry and measured contact points to automatically calculate the touch probe and conductive wire positions, substituting human-operated mechanical alignment with algorithmic coordinate transformation based on the artifact locating parameters

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

3Reliability

If separate calibration procedures are used for the touch probe and conductive wire, then each component can be calibrated individually, but the overall calibration process becomes complex and time-consuming

Engineering Contradiction:
Improvecalibration accuracyVSAvoidcalibration process complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines the calibration of the touch probe and conductive wire into a single integrated process using one calibration artifact. The artifact contains both a probe cavity and a wire cavity that can be measured in sequence, allowing both components' positions to be determined relative to the same artifact locating parameters and machine coordinate system, thereby unifying what would otherwise be separate calibration procedures

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentEP4624083A1System and method for calibrating a machining system
Publication Date: 2025.10.01 PRATT & WHITNEY CANADA CORP
  • EP4624083A1 patent drawingFigure 1
  • EP4624083A1 patent drawingFigure 2
  • EP4624083A1 patent drawingFigure 3A~3C

AI summary

A machining system (20) includes a WEDM assembly (22), a probe assembly, a calibration artifact (66), and a controller. The WEDM assembly (22) includes a conductive wire. The conductive wire extends between and to an upper guide head and a lower guide head. The probe assembly includes a touch probe (46). The calibration artifact (66) includes an artifact body (68) forming a probe cavity (82) and a wire cavity (84). The controller is configured to identify a probe X-position and a probe Y-position of the touch probe (46) by controlling the WEDM assembly (22) to move the touch probe (46) to contact the calibration artifact (66) with the touch probe (46) disposed within the probe cavity (82), identify a wire X-position and a wire Y-position of the conductive wire by controlling the WEDM assembly (22) to move the conductive wire to contact the calibration artifact (66) with the conductive wire disposed within the wire cavity (84), and calibrate the machining system (20) by determining an X-offset and a Y-offset of the conductive wire relative to the touch probe and storing the X-offset and the Y-offset.