An instrument going from ‘Big Science’ to large-scale manufacturing

An instrument going from ‘Big Science’ to large-scale manufacturing

Frequency Scanning Interferometry (FSI) was invented to measure movements of the detectors in the Large Hadron Collider at CERN. Now a team at the UK’s National Physical Laboratory are developing a practical FSI based instrument for large-scale manufacturing. This may enable the next generation of aircraft with natural laminar flow wings and part-to-part interchangeable assembly. ReadRead more about An instrument going from ‘Big Science’ to large-scale manufacturing[…]

Unified Uncertainty for Optimal Quality Decisions

Unified Uncertainty for Optimal Quality Decisions

I talked about the advantages of a unified uncertainty-based approach to quality in manufacturing earlier this year at LAMDAMAP. I have now gone into more detail on why a hybrid approach is required. In my presentation at ENBIS in Naples, I have given examples of how MSA and SPC can fail to properly quantify uncertaintyRead more about Unified Uncertainty for Optimal Quality Decisions[…]

Unified Uncertainty-based Quality Improvement

Unified Uncertainty-based Quality Improvement

Within manufacturing different methodologies are used to quantify uncertainty. These include uncertainty evaluation (GUM), measurement systems analysis (MSA) and statistical process control (SPC). The different methods are used at different stages. GUM is used for instrument calibrations, MSA is used for factory measurements and SPC is used for the production processes. Each is well adapted toRead more about Unified Uncertainty-based Quality Improvement[…]

Method for traceable coordinate measurements

Method for traceable coordinate measurements

I’ve worked a lot with large-scale coordinate measurements in aircraft and spacecraft assembly. These measurements are typically not fully traceable and their accuracy is limited by environmental effects, especially temperature. For the next generation of aerospace structures, these limitations will need to be overcome to achieve natural laminar flow and part-to-part interchangeability. We need a measurement system that addressesRead more about Method for traceable coordinate measurements[…]

Calibration of a large scale 3D attitude sensor

Calibration of a large scale 3D attitude sensor

Researchers at Tianjin University have developed an attitude sensor, located within the reflector target for a total station. This enables large scale 6 degrees-of-freedom measurements. I provided some support with the calibration procedure, described in this open access paper. Paper Title: Integrated calibration of a 3D attitude sensor in large-scale metrology Authors: Yang Gao1, Jiarui Lin1, 2,Linghui Yang1,Read more about Calibration of a large scale 3D attitude sensor[…]

Methods for thermally compensated measurements of large structures

Methods for thermally compensated measurements of large structures

Thermal deformations are often the dominant source of uncertainty for high accuracy measurements of large structures. This open access paper published in the International Journal of Metrology and Quality Engineering presents a hybrid approach to compensation for the resulting errors. This involves temperature measurements at discrete points on the part which is undergoing thermal deformation. Finite Element Analysis (FEA) isRead more about Methods for thermally compensated measurements of large structures[…]

Sensitivity Coefficients in Uncertainty Budgets

Sensitivity Coefficients in Uncertainty Budgets

This article follows on my previous introductions to uncertainty and uncertainty budgets. It goes into more detail about some of the more tricky aspects of uncertainty budgets. I first explain what sensitivity coefficients are and then use examples to show exactly how sensitivity coefficients can be calculated and used within an uncertainty budget. Read the full article publishedRead more about Sensitivity Coefficients in Uncertainty Budgets[…]