CMM Probe Shielding and Coil Alignment for Precise Scanning

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Solution Overview

Problem

Existing coordinate measuring machine (CMM) scanning probes face challenges in ease of assembly and improved operating characteristics, such as crosstalk and interference between components, which affect the accuracy of three-dimensional position measurements.

Innovation Solution

A scanning probe configuration for CMMs that includes a stylus suspension module, stylus position detection module, and signal processing and control circuitry, utilizing inductive sensing principles with a shield configuration to isolate the sensor from external interference and ensure precise positional measurements.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a mechanical contact probe with inductive position detector is used for three-dimensional position measurement, then measurement capability is provided, but crosstalk and interference between components occur affecting measurement accuracy

Engineering Contradiction:
Improvethree-dimensional position measurement accuracyVSAvoidcrosstalk and interference between components
Core Design Contradiction:
Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

A non-conductive shield configuration is introduced as an intermediary element between the field generating coil configuration and the sensing coil configurations. This shield acts as a mediator that blocks electromagnetic interference and crosstalk while allowing the magnetic field to pass through, thereby improving measurement accuracy without compromising the functional relationships between components

Inventive Principle:
Principle #24Intermediary (Mediator)

2Device complexity

If sensor configurations are positioned close to each other for compact probe design, then device compactness is improved, but electromagnetic interference between sensor components increases

Engineering Contradiction:
Improveprobe compactnessVSAvoidelectromagnetic interference between sensor components
Core Design Contradiction:
Device complexityVSObject-affected harmful factors

Solution Approach 1:

The non-conductive shield configuration serves as a protective intermediary that enables close positioning of sensor components while preventing electromagnetic interference. The shield's positioning members allow the shield to be placed strategically between components, maintaining compact probe design while blocking harmful electromagnetic interactions

Inventive Principle:
Principle #24Intermediary (Mediator)

3Adaptability or versatility

If multiple coil configurations are integrated in the probe for comprehensive position detection, then measurement functionality is enhanced, but assembly complexity increases

Engineering Contradiction:
Improveposition detection functionalityVSAvoidassembly complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The non-conductive shield configuration is designed with multiple functions: it provides electromagnetic shielding, structural support through positioning members, and alignment reference for coil configurations. This multi-functional design reduces the need for separate components, thereby simplifying assembly while maintaining comprehensive position detection functionality

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

Solution Approach 2:

The shield configuration integrates multiple shielding functions and structural support functions into a single component rather than using separate shields and supports. This merging of functions reduces the number of parts and simplifies the assembly process while maintaining all necessary measurement capabilities

Inventive Principle:
Principle #5Merging (Combining)

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

The solution enhances the accuracy and reliability of three-dimensional position measurements by reducing crosstalk and interference, thereby improving the operational characteristics and assembly efficiency of the CMM scanning probes.

Implementation Method 1

A field generating coil configuration generates a changing magnetic flux encompassing the disruptor element and coils

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

A non-conductive shield configuration reduces crosstalk and interference between the field generating coil configuration and the sensing coil configurations

Methodology Applied
Scientific EffectElectromagnetic shielding: Faraday Cage

Data Source

PatentEP4202354B1Shielding for sensor configuration and alignment of coordinate measuring machine probe
Publication Date: 2025.08.20 MITUTOYO CORP
  • EP4202354B1 patent drawingFigure 1
  • EP4202354B1 patent drawingFigure 2
  • EP4202354B1 patent drawingFigure 3

AI summary

A scanning probe for a coordinate measurement machine includes a stylus suspension module, a stylus position detection module, a disruptor configuration, and a signal processing and control circuitry module. The stylus position detection module includes a sensor configuration, which comprises various coils, and a shield configuration that is located around the sensor configuration and comprises electrically conductive material for shielding the sensor configuration. The stylus position detection module is mounted to the stylus suspension module utilizing a module mounting configuration, which enables the relative position of the sensor configuration to be adjusted for alignment during the assembly of the scanning probe.