Coordinate Measuring System With Thermal Expansion Compensation

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Solution Overview

Problem

Conventional coordinate measuring systems face challenges in accurately determining workpiece dimensions due to temperature-induced distortions, requiring lengthy tempering processes to achieve homogeneous temperature conditions, which is inefficient for precise measurements.

Innovation Solution

A coordinate measuring system equipped with temperature sensors and a computing device that calculates temperature-corrected 3D coordinates by considering actual temperature distributions and expansion coefficients, allowing for real-time compensation of thermal deformations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If the workpiece is tempered to achieve homogeneous temperature distribution, then measurement precision is improved, but the measurement time is significantly increased

Engineering Contradiction:
Improvemeasurement precisionVSAvoidpreparation time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The system performs preliminary temperature measurement and distribution analysis before the actual measurement process. By detecting the initial temperature state and using this information to calculate thermal expansion effects, the system can compensate for temperature-induced distortions without requiring the workpiece to reach thermal equilibrium, thus eliminating the need for lengthy tempering processes while maintaining measurement precision

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system changes the approach from physically altering the workpiece temperature (tempering) to mathematically adjusting the measurement data. By using temperature sensors to detect the actual temperature distribution and applying thermal expansion coefficients to calculate and compensate for dimensional changes, the system achieves accurate measurements at any temperature state without requiring the workpiece to be tempered to a specific temperature

Inventive Principle:
Principle #35Parameter changes

2Measurement precision

If conventional temperature compensation methods are used, then measurement accuracy is maintained, but the complexity of the measurement process is increased

Engineering Contradiction:
Improvemeasurement accuracyVSAvoidprocess complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The measurement system performs self-compensation by automatically detecting its own temperature state and independently calculating the thermal expansion effects. The system uses integrated temperature sensors and built-in computational algorithms to automatically adjust measurement data, eliminating the need for external tempering equipment or complex manual compensation procedures, thus reducing overall process complexity while maintaining 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

Enables high-precision measurements by reducing preparation time and accounting for inhomogeneous temperature distributions, providing accurate dimensional data without the need for lengthy tempering processes.

Implementation Method 1

at least one temperature sensor (5, 5A, 5B) that is configured to determine one or more actual temperature values of the object

Methodology Applied
Scientific EffectThermal radiation: Thermal Radiation

Implementation Method 2

the computing device is configured to determine, based on the determined 3D coordinates of the measurement points, on the provided temperature data and on the expansion coefficients, tempered coordinates of the object

Methodology Applied
Scientific EffectThermal expansion: Thermal Expansion

Data Source

PatentEP4202352B1Coordinate measuring system
Publication Date: 2025.08.27 HEXAGON INNOVATION HUB GMBH
  • EP4202352B1 patent drawingFigure 1a~1b
  • EP4202352B1 patent drawingFigure 2a~2b
  • EP4202352B1 patent drawingFigure 3

AI summary

The invention pertains to a coordinate measuring system for determining 3D coordinates of an object (2), comprising a coordinate measuring device (1) comprising an arrangement of sensors configured to generate measurement data from which 3D coordinates of measurement points on the object are derivable, and a computing device configured to determine, based on the measurement data, 3D coordinates of the measurement points, and for storing nominal data of the object in a data storage, the nominal data comprising nominal dimension data of the object for a pre-defined temperature, wherein the nominal data comprises one or more expansion coefficients of the object, the coordinate measuring system comprises at least one temperature sensor (5A, 5B) that is configured to determine actual temperature values of the object, the at least one temperature sensor is configured to generate temperature data based on the determined actual temperature values and to provide the temperature data to the computing device; and the computing device is configured to determine, based on the determined 3D coordinates of the measurement points, on the provided temperature data and on the expansion coefficients, tempered coordinates of the object, wherein the determined actual temperature values of the object deviate from the pre-defined temperature, and the tempered coordinates are three-dimensional coordinates that the object would have at a tempered state in which the object uniformly has the pre-defined temperature.