Robotising maintenance of TBM cutting tools 14 May 2013
NeTTUN News Release
- Basic designs for a mechanised system of robotised maintenance of TBM cutting tools have been completed as part of a European Commission-funded research and development project. Work will now focus on the detailed design and manufacture of a working prototype system.
Inside the TBM hyperbaric chamber
- The project brings together 21 industry partners, led by French TBM manufacturer NFM Technologies, with the aim of collaboratively addressing key scientific and technical aspects of tunnel construction. The specialised underground construction sector is viewed as a key element in delivering huge current and future demand for sustainable infrastructure.
- At a six-monthly meeting in Paris the partner companies and organisations, collectively known as New Technologies for Tunnelling and Underground Works (NeTTUN), presented a progress update to the European Commission Project Technical Advisers. The European Union is funding two thirds of the project's €15 million budget.
- Research scope includes a number of TBM and underground-related sub-projects, with Works Package 6 aimed at using dedicated robotics to perform TBM cutterhead maintenance operations, primarily in a pressurised environment.
- "The obvious benefits of this solution are, first, to reduce the risk to operators currently exposed to work in confined areas under repeated cycles of compression and decompression, and second, to increase the overall excavation efficiency by dramatically reducing the time spent on cutterhead maintenance operations," said Ashleigh Ogier, NeTTUN Project Support Officer at NFM Technologies.
- The R&D work performed by NeTTUN covers the complete development of the robotics system, and, as a final step, its implementation and field testing in an actual TBM.
- The NeTTUN robotics work package involves the following partners: NFM, DFKI (Robotics Innovation Centre, Germany), and Razel (a French construction company). Expert advice is being contributed by Dr Donald Lamont, leading international Health & Safety expert in tunnel construction and operational safety. Other NeTTUN end-users are also contributing details of their experience in pressurised tunnelling and the maintenance constraints that are currently applicable.
Work on this sub-project started by defining the end-user needs and requirements. From this, an operational concept of the envisaged system was outlined via brainstorming sessions with the project partners. Multiple solutions were considered, assessed, and compared. The design work consists of three major developments:
• the maintenance robot;
• new cutting tools adapted to a robotised intervention;
• handling methods for worn and new cutter tools.
EC is funding NeTTUN R&D project
- Basic designs and multiple-solution investigations were carried out for the deployer part of the robot. These concepts were evaluated and compared based on mechanical criteria, bulk characteristics, and achievable reliability. Comparative studies and kinematic/dynamic simulations of the different concepts led to the choice concerning the necessary number of degrees of freedom (dof).
- Totally new concepts of disc cutter and drag bit mounting brackets are required in order to simplify the robot operation and reduce its complexity. Through a parallel design process, several disc cutter concepts were designed, together with corresponding grippers. All of these solutions were evaluated in cooperation with the project partners. This process included kinematic simulations of the tool gripping/locking/unlocking procedure, and workspace analysis of the complete robot in a TBM virtual environment. One solution was selected as having the highest combined ranking and its detailed mechanical design was completed. As a further step, detailed analytical and finite element stress analyses were conducted in order to validate the chosen models. The same process is being followed for the drag bits.
- Space analysis of the TBM shield was carried out for various diameter ranges. Different TBM design or adaptation solutions are being considered to incorporate the robot and related devices e.g. worn/new cutter tools feed systems.
During the coming months, work will be focussing on the following:
• Detailed design and manufacturing of the deployer.
• Detailed design and manufacturing of disc cutter and drag bit prototypes for test purposes.
• Operational concept and mechanical design of the new/used tool feeding systems.
• Detailed design and manufacturing of a mock-up system to test the robot operation and the cutter tool
- Other topics of study include development of:
• An advanced multi-sensor ground prediction system for TBMs to enable fast, frequent and effective detection in
the ground ahead of the excavation face
• Cutter tools with a greatly increased lifetime
• A novel system for the modelling of global risks to be used for the definition of the best strategy both during
design and construction phases
• A suite of systems to model and control the impact of tunnelling on surrounding structures
• A decision support system for tunnel maintenance
• Development of master plans/concepts/technologies for inspection, maintenance and retrofitting efforts of
existing and new underground structures.
NFM 14m EPBM for Guadalquivir River Crossing in Spain
These studies are designed to meet five specific project directives; to:
• increase the productivity of underground
activities by at least 20%;
• enable underground operations with zero
impact on existing surroundings in urban and
• create inherently safe underground working
and operating environments;
• strengthen the global competitiveness of the
European construction industries; and
• increase the sustainable access to underground
resources in Europe, with the related decrease
of EU dependency on resource imports.
- NeTTUN plans to test and evaluate all of these in real operations on site at tunnels including Metro Line C construction under some of Rome's most ancient monuments, as well as with OHL where a pair of 14m diameter NFM machines are being used for the Guadalquivir River Crossing project in Spain, and Razel-Fayat on the Fréjus, and future projects.
EC awards ambitious R&D programme - TunnelTalk, October 2012
First of two NFM mega EPBMs ready for Spain - TunnelTalk, November 2011
Royal recognition for Donald Lamont - TunnelTalk, June 2011
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