The aim of this work package is to determine the measurement uncertainty sources attributed to freeform geometries, and to develop accurate mathematical models for use in D-MTs. This includes the (i) evaluation of the D-MTs, (ii) the experimental comparison of the deviations of freeform geometries to prismatic standards, and (iii) the creation of virtual reference artefacts for representative freeform standards.

The work package is divided into four tasks

1.1. aims to review and select existing artefacts, and design and manufacture new artefacts with complex freeform geometries representing features of products in advanced manufacturing.

1.2. aims to develop appropriate virtual reference artefacts (i.e. softgauges) based on datasets from simulations of representative freeform geometries.

1.3. aims to develop appropriate mathematical models for D-MTs of measurement standards (physical from Task 1.1 and virtual from Task 1.2), of CMMs, and of MTs applicable for determination of the uncertainty of freeform measurements using both optical and tactile sensors.

1.4.  aims to collate already established terms and define new terms from the field of D-MTs for freeform metrology and create a glossary of terms.

The aim of this work package is to evaluate the behaviour and inherent properties of at least three different types of optical sensors integrated into CMMs and MTs. This will include the determination of the influence of (i) surface characteristics, (ii) surface tilt and (iii) curvature on the interaction between the optical sensors for freeform and prismatic geometries, as well as the development of reliable mathematical models for D‑MTs.

The work package is divided into four tasks:

2.1. aims to plan and perform the characterisation of different sensors required for formulating mathematical models.

2.2. aims to create mathematical models for the sensors studied in Task 2.1. Either physics-based models with characterised error sources and probability distributions or data driven methods, such as statistical analyses and machine learning concepts will be used for the mathematical model formulation.

2.3. aims to integrate the sensor models from Task 2.2 into the D-MTs of CMMs either from those already existing or those developed in Task 1.3, in order to improve the uncertainty estimation of the metrology system.

2.4.  aims to integrate the sensor models from Task 2.2 into the D-MTs of MTs either from those already existing or those developed in Task 1.3., in order to improve the uncertainty estimation of the on-machine measuring systems.

The aim of this work package is to develop methods for the traceable parametrisation of the models used for measurement uncertainty evaluation in D-MTs. This will include the identification of suitable measurement standards and procedures for the parameterisation of D-MTs and the development of parameterisation strategies for (i) freeform geometry measurements and (ii) for optical sensor measurements. Specifically, WP3 will develop traceable measurements of freeform on i) CMMs with tactile and optical sensors, and ii) MTs with integrated optical sensors. For MTs, traditional multi-axis and newer configurations will be addressed.

The work package is divided into three tasks:

3.1.  aims to select the most appropriate measurement standards with prismatic and freeform geometries, as well as optical measurement instruments (e.g. laser tracer, laser tracker, EGPS, Laser scanner, etc.) that are traceable to the SI metre, and then use them for the identification of D-MTs parametrisation strategies for geometric errors. Additional parametrisation strategies will be also investigated for D-MTs related to dynamic errors, probing systems, etc.

3.2. aims to determine the parameters of the implemented D-MTs from WP1 and WP2 for both CMMs and multi-axis MTs in order to ensure their traceability to the SI, in particular on prismatic/freeform geometries. The identification of the parameters of the D-MT models uses the selected measurement standards and D-MT parametrisation strategies from Task 3.1. The identified parameters will then be used to build reduced traceable D-MT models with an optimised number of parameters.

3.3. aims to test and verify the conformance of each reduced traceable D-MT model from Task 3.2 using industrial freeform specimens.

The aim of this work package is to evaluate and optimise the performances of the D-MTs and methods developed in WP1 to WP3 for economically efficient application in advanced manufacturing This will include case studies comparing optical and tactile measurements using freeform geometries and prismatic parts in order to (i) verify D-MT application and (ii) to produce good practice guidelines for D-MT use. And provide substantial novel information as base for the development of good practice guidelines.

The work package is divided into four tasks:

4.1. aims to define strategies to evaluate the performance of D-MTs, in order to optimise their use with respect to needs in advanced manufacturing. This includes the need for computationally efficient implementations as well as time- and cost-efficient methods to parametrise the D-MTs.

4.2. aims to produce case studies for the use of D-MTs for tactile and optical sensors in coordinate measurements of freeform geometries. The case studies will include comparisons of freeform and prismatic geometries.

4.3. aims to apply the D-MTs from WP1 and WP2 to 3 optical sensors and 2 different freeform geometry parts on CMMs and in MTs. The calculated measurement uncertainty will be analysed and compared to reference data from probed measurement standards.

4.4. Aims to produce 2 good practice guidelines for the reliable and trustworthy application of D‑MTs for both freeform measurements/optical sensors in advanced metrology applications.