Dual-Limb Coordinate Measurement for Mobile Precision Inspection

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Solution Overview

Problem

Conventional Coordinate Measuring Machines (CMMs) are heavy, inflexible, and often require dedicated metrology laboratories, limiting their mobility and ability to perform in-line quality control with high precision.

Innovation Solution

A lightweight CMM design featuring a first and second limb with respective sets of joints and links, equipped with sensors for metrology-grade data acquisition, allowing for precise measurement and flexible installation options, including mobile configurations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If conventional CMM designs are used to ensure measurement precision, then measurement accuracy is improved, but device weight and complexity increase

Engineering Contradiction:
Improvemeasurement accuracyVSAvoiddevice weight
Core Design Contradiction:
Measurement precisionVSWeight of moving object

Solution Approach 1:

The CMM device is divided into multiple independent limbs (first limb with probing element, second limb with coupling interface), each capable of functioning semi-independently. This segmentation allows the use of lighter materials and reduced structural complexity in each limb while maintaining overall measurement precision through coordinated operation and sensor fusion.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The coupling interface on the second limb serves multiple functions: it provides mechanical coupling between limbs for structural stability, enables the second limb to function as a probing element for dual-sided measurements, and allows flexible configuration options. This multi-functionality reduces the need for additional specialized components, thereby reducing overall device weight.

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

2Reliability

If conventional CMM designs are used to ensure stability, then measurement reliability is improved, but mobility and installation flexibility deteriorate

Engineering Contradiction:
Improvemeasurement reliabilityVSAvoidmobility and installation flexibility
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The CMM device transitions from a static, fixed installation design to a dynamic, reconfigurable system. The limbs can be independently positioned and configured, allowing the device to adapt to different measurement scenarios and installation locations. The coupling interface enables dynamic reconfiguration where either limb can serve as the primary probing element depending on the measurement task.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The device allows changes in operational parameters by switching which limb functions as the probing element. The system can operate in different modes (first limb probing, second limb probing, or coordinated operation) based on the measurement requirements, enabling adaptation to various environments without sacrificing measurement reliability.

Inventive Principle:
Principle #35Parameter changes

3Measurement precision

If conventional CMM designs are used to achieve precision, then measurement accuracy is improved, but device complexity and portability worsen

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

Solution Approach 1:

The measurement system is segmented into two independent limbs with their own sensor sets and control capabilities. Each limb can perform measurements independently or in coordination, reducing the need for complex mechanical structures and interconnections. This modular approach simplifies the overall system architecture while maintaining precision through redundant measurement paths.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Each limb is equipped with its own sensors and can independently determine the position and orientation of the workpiece. The limbs can self-calibrate and self-adjust during operation, reducing the need for external calibration equipment and complex control systems. The coupling interface allows the limbs to share measurement data and coordinate their operations autonomously.

Inventive Principle:
Principle #25Self-service

Data Source

PatentEP4538636A1Coordinate measurement system having at least two limbs
Publication Date: 2025.04.16 HEXAGON INNOVATION HUB GMBH
  • EP4538636A1 patent drawingFigure 1a~1b
  • EP4538636A1 patent drawingFigure 2a~4b
  • EP4538636A1 patent drawingFigure 5a~5b

AI summary

The invention relates to a coordinate measuring machine (CMM) for determining spatial coordinate data of an object point on a workpiece. The CMM comprising, a first limb, a probing element, a second limb, and a coupling interface. The probing element provides probing data regarding an interaction between a sensing area and the object point. The first limb connects the sensing area to a first proximal end. The coupling interface is configured to provide coupling data regarding an interaction between a coupling area and a reference point having a defined spatial relationship to the object point. The second limb connects the sensing area to a second proximal end mechanically constrained to the first proximal end. The CMM is configured to (i) access the actual pose of the sensing area, (ii) access an actual pose of the coupling area, (iii) provide coupling pose change data based on the actual pose of the coupling area and the coupling data, (iv) provide the coordinate data of the object point based on the actual pose of the sensing area, the probing data and the coupling pose change data.