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DIGItal MAterials CharacterisatioN proof-of-process auto assembly

Periodic Reporting for period 1 - DIGIMAN (DIGItal MAterials CharacterisatioN proof-of-process auto assembly)

Reporting period: 2017-01-01 to 2018-06-30

DIGIMAN aims to develop a blueprint design for next generation fully automated cell assembly & testing of Intelligent Energy’s Air Cooled fuel cell stacks. The programme outcomes will demonstrate operational and supply chain cost reduction via seamless integration of digital manufacturing techniques (Industry 4.0 compliant) and advanced manufacturing technology, with a fully automated uplift to existing engineered assembly processes. The blueprint design will allow build-to-print machine readiness with scalable production capacity to more than 50,000 fuel cell stacks per annum by 2020. The project will raise the manufacturing readiness level (MRL4 to MRL6) by introducing enhanced design for assembly, automated processes for assembly, inspection, and test, coupled with materials acceptance standards.
CEA-LITEN coordinates the project and provides in depth understanding and characterization of Gas Diffusion Layers. Pretexo leads dissemination activities. Intelligent Energy is technical lead and provides the manufacturing know how and the design of the pre-existing semi-automation for its stack. Toyota Motor Europe is the voice-of-the-customer and shares scientific knowledge towards automotive manufacturing KPIs. Freudenberg leads on GDL properties and processing, whilst academic partner Warwick Manufacturing Group leads the proof-of-process (PoP) demonstration equipment’s development with digital simulation and modelling of the blueprint design solution via a ‘digital twin’.
DIGIMAN’s key outputs will be:
• creation of a robust platform for PEM fuel cell stack production
• establishment of best practice requirements for automotive fuel cell stack production
• demonstration of operational and supply chain cost reduction
• to offer seamless integration of digital manufacturing techniques with advanced automated production technology
• to enable build-to-print machine configuration with ready to scale production capacity
• to supply a capability roadmap to meet requirement of more than 50,000 fuel cell stacks per annum by 2020
The KPIs for fully automated stack assembly and test have been issued. Work has started on the methods to reduce the duration of handover tests and conditioning cycles and a design-of-experiment to include 6 different approaches to accelerating the handover tests have been developed. A stack for each conditioning regime has been assembled. A candidate automated handling system to support stack transfer between test stations and allow multi-channel parallel testing has been identified.
Non-destructive thermal diffusivity scanning method were found to be highly sensitive to heterogeneities in GDLs materials. Thermal diffusivity has been assessed and a good agreement was found between the wider area QC scanning techniques and the localized measurement of thermal diffusivity. The Digital Quality Control of GDLs has progressed with roll good optimization and digitalization for the digital mapping of ocular (via camera-based inspection) and structural (via thermal scan) defects.
To correlate defects and performance, GDL samples with and without defects have been generated, properties such as thickness, permeability, resistivity, and thermal diffusivity have been measured, and stack tests have been done. Preliminary results indicate a dependency of the AC64 performance to the in-plane permeability.
The handling requirements for GDL encompassing supply chain packaging through to presentation for automated assembly of AC64 cells have been identified. The mapped process flow reflects the value chain from the ‘upstream’ GDL raw material manufacturer to the ‘downstream’ end user.
Based on IE’s experience, key technical requirements have been established for the Blueprint design and will be validated by the PoP Demonstrator. Representative mock up rigs have been developed and have established component & material handling characteristics and their packaging. Process engineering outcomes (to date) have allowed de-risking of the Blueprint design by facilitating PoP demonstration. Process engineering activities have also mocked up inline high-speed cell testing and demonstrated the target <5 seconds capability (albeit pass / fail only).
Data links/harvesting capability has been established. Cause data is now captured automatically via the semi-automated cell assembly capability and its already in place fully automated stack assembly. Although analysis is currently manually performed by expert staff, effects data from cell and stack test is automatically harvested. For the uplifted automation OPC UA connectivity has been specified for the outputting cause data to the digital cause & effects model. For data from none automated processes IE has developed a web based application which allows the manual data input (by bespoke configured tablets) and is currently being trialed by said expert staff.
The project consortium has finalized all planned deliverables, milestones, communication, and dissemination actions for the first 18 months.
Progress beyond SoA
• Innovative floatation methods for pick and place handling and mechanical pre-alignment of none rigid and (90%) porous materials such as GDLs have been developed with untethered vacuum carriers capable of smart ‘fire and forget’ motion and positioning control allowing direct lamination of liner mounted adhesive film eliminating gasket-to-gasket or plate-to-plate pitch errors.
• Automated defect inspection resulting in a machine-readable digital QC protocol have been developed to guide the singulating and sorting processes for the GDL.
Expected results until the end of the project
• PoP Demo design and development activities completed for Static and Dynamic Process Modules; equipment installed and dry cycle tested. Discrete Event Simulation work involving PoP demo modules and track, GDL lineside conversion, fuel cell test, stack assembly and test. PoP production relevant environment facility established at IE with cell, stack build and validation testing programme leading to MRL6 validation; digital twin to result in ‘build to print’ readiness for the Blueprint design.
• Extended content included in the Digital QC protocol. Protocol transferred to steps “singulation” and “sorting” and concept of lineside conversion verified via a digital case study.
Potential impacts
• The innovation floatation handling and untethered vacuum clamping methods will offer assemble-ability for light-weighted fuel cell stacks and future ultra-light weight materials. Incorporated automotive best practices offer drop-in compatible production lines or direct ship to line delivery of fuel cell stacks and systems. The developed schemas for cause data / effects data harvesting via emerging Industry 4.0 compatible methods will enable mining of ‘big data’, from which, the to be developed digital cause & effects modelling tool will be able to detect previously undetectable data trends and unforeseen causations of fuel cell stack performance and durability degradation.