Mobile robot localization by a distributed sensor network in nuclear fusion scenarios of ITER
- Supervisor: Doutor Alberto Vale
- Co-Supervisor: Prof. Rodrigo Ventura
Framework
ITER-International Thermonuclear Experimental reactor is a joint international research and development project that aims to demonstrate the scientific and technical feasibility of fusion power (a safety source of energy with abundant fuel resources, to meet the needs of a growing world population). The ITER reactor is installed on a building (the Tokamak building) with dimensions equivalent to a football field and where the human beings are not allowed as soon as the operation starts. A Transfer Cask System (TCS) for the transportation of components during maintenance operations is required.
The TCS consists of an unshielded (with respect to gamma radiation) mobile vehicle with dimensions similar to an autobus with a maximum load of 100T and moved by air-cushion, provided with autonomous guidance and docking. This TCS must be able to travel between different pre-defined start/goals locations in different levels of the Tokamak building.
Objectives
A localization system for the TCS vehicle, given the constraints of the problem. This includes a methodology for planning the location of the sensor network for the vehicle localization, and the localization algorithm itself.
Description
The guidance of the TCS vehicle is primarily based on following electrical wires grounded on the floor. These wires carry an electrical current, whose magnetic field is measured by electromagnetic sensors onboard the vehicle. The vehicle is guided by the measured deviation from these wires, thus following the path defined by them. However, it is necessary to localize the vehicle continuously, not only for redundancy, but also in the event of the vehicle getting off-track. The TCS transports radioactive contents shielded by protective covering. Therefore, it is not feasible to install electronic devices on the TCS, given the radioactive constraints and thus the short time duration of components.
This thesis addresses the problem of localizing the TCS using a network of sensors mounted on the walls of the plant. Two issues have to be addressed: (1) the methodology for planning the installation of sensors on the environment, such that a precise localization of the vehicle is always possible, taking into account the environment geometry and the tightness of the plant free space, and (2) the localization algorithm for the TCS using this network of sensors.
Related links
- Further information on RH in ITER: http://www.ipfn.ist.utl.pt/rh
- ITER - http://www.iter.org