Mobile Coordinate Measuring Machine for Large Workpiece Precision

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Solution Overview

Problem

Conventional coordinate measuring machines are inefficient for measuring large objects like aircraft parts due to low measuring rates and inability to accurately measure non-orthogonal or uneven surfaces, particularly in cavities such as boreholes.

Innovation Solution

A mobile, portable coordinate measuring machine (CMM) with fixation and dynamic positioning capabilities, using tactile or optical sensors, and advanced damping mechanisms to ensure precise spatial coordination, along with autonomous placement and compensation for surface irregularities, allowing accurate measurement of large workpieces and cavities.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a stationary coordinate measuring machine is used to measure local structures, then measurement accuracy is improved, but the measuring rate deteriorates and the device cannot measure large objects

Engineering Contradiction:

Improvemeasurement accuracyVSAvoidmeasuring rate

Core Design Contradiction:

Measurement precisionVSProductivity

Solution Approach 1:

The patent applies the dynamics principle by transforming the stationary CMM into a mobile device that can move along the surface of large workpieces. The CMM includes movable components such as a mobile platform with wheels or tracks, allowing it to travel to different measurement locations on large objects like aircraft fuselages, thereby maintaining measurement capability while increasing productivity and accessibility.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent segments the measurement task by dividing the large workpiece into multiple local areas that can be measured sequentially. The mobile CMM moves from one measurement location to another, collecting data in segments across the entire surface of large objects, which resolves the contradiction between measuring large objects and maintaining measurement precision.

Inventive Principle:

Principle #1Segmentation

2Ease of operation

If a hand held coordinate measuring device is used for measuring cavities, then mobility is improved, but positioning accuracy deteriorates due to non-orthogonal or uneven surfaces

Engineering Contradiction:

ImprovemobilityVSAvoidpositioning accuracy

Core Design Contradiction:

Ease of operationVSMeasurement precision

Solution Approach 1:

The patent replaces mechanical positioning systems with optical or laser-based tracking systems. These non-contact measurement systems use light fields to determine the position and orientation of the mobile CMM, eliminating the need for mechanical coupling elements and providing accurate positioning even on non-orthogonal or uneven surfaces.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the measurement parameters by using optical fields instead of mechanical contact. The optical tracking system measures parameters such as light reflection angles and time-of-flight to determine spatial coordinates, which allows accurate positioning without relying on mechanical orthogonality or surface flatness.

Inventive Principle:

Principle #35Parameter changes

3Stability of the object's composition

If mechanical coupling elements are used to position the device, then positioning stability is improved, but the device cannot eliminate measurement errors from non-orthogonal surfaces

Engineering Contradiction:

Improvepositioning stabilityVSAvoidmeasurement error elimination

Core Design Contradiction:

Stability of the object's compositionVSMeasurement precision

Solution Approach 1:

The patent replaces mechanical coupling elements with optical or laser tracking systems that use light fields to establish spatial relationships. This substitution eliminates measurement errors caused by non-orthogonal surfaces because the optical system can accurately measure and compensate for surface irregularities without requiring mechanical orthogonality.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent implements feedback mechanisms where the optical tracking system continuously monitors the position and orientation of the mobile CMM, and the system automatically compensates for deviations caused by non-orthogonal or uneven surfaces. This closed-loop feedback ensures measurement precision while maintaining mobility.

Inventive Principle:

Principle #23Feedback

Data Source

PatentEP2885602B1Method and system for determining spatial coordinates with a mobile coordinate measuring machine

Publication Date: 2023.01.18 HEXAGON TECH CENT GMBH

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AI summary

The invention pertains to a method for determining at least one spatial coordinate of a measurement point of a local structure (2,2') of an object (3), providing a mobile coordinate measuring machine (1), the method comprising at least placing the mobile coordinate measuring machine (1) on a surface (30) of the object (3) to be measured, approaching the measurement point with a sensing head (21,26), and determining at least one spatial coordinate of the at least one measurement point, characterized by establishing a defined spatial relation between the coordinate measuring machine (1) and the local structure (2,2')/ wherein the defined spatial relation is established by means of a mechanical fixation of the coordinate measuring machine (1) to the object (3), and/or a continuous determination of position and orientation of the coordinate measuring machine (1) relative to the object (3). The invention furthermore pertains to a mobile coordinate measuring machine (1) and a computer programme product for execution of said method.