|RESEARCH - Robot Upgrade|
The University of Girona has at the moment two available autonomous underwater vehicles: GarbiAUV and Ictineu. Garbi is a robot designed to be operated in the sea coast for observation purposes. It is controlled by 5 DC propellers reaching a maximum horizontal velocity of 2 knots. It has basic high density foam that allows a maximum depth of 30 meters. Garbi has several basic underwater sensors: a Doppler Velocity Logger (DVL), an Imaging Sonar, two low- quality video cameras (color and black and white) and a GPS. It can operate autonomously following a predefined mission for a maximum endurance of 6 hours. The second robot, Ictineu, has very similar features, concerning actuators and sensors, but it is smaller and was designed for working in a pool environment. Ictineu was built for participating in the SAUC-E competition which was held in London in 2006. Ictineu won the European competition doubling the points of the second team. Garbi and Ictineu share the sensors and software architecture (Ridao et al. 2002, Carreras et al. 2006) since the high cost of these equipments does not allow the replication of them.
|Underwater vehicles developed by our group at the University of Girona (Left) GarbiAUV at the pool of the Underwater Robotics Centre. (Right) Ictineu Autonomous robot, winner on August 2006 of the SAUC-E European Autonomous Underwater Competition.|
The kind of mission proposed in this project cannot be fulfilled by any of these two prototypes due to the required space to install new sensors, the limited maximum depth and the slow velocity. In fact, the group of the University of Girona has already two sensors that cannot be installed in Garbi: the USBL global positioning system and the trinocular camera; and five new propellers (which were already bought to support this new vehicle). Moreover, this project requires the inboard installation of the photographic camera and the acoustic camera.
Therefore the project proposes the development of a new Autonomous Underwater Vehicle able to carry all sensors, able to work at 200 meters depth and able to reach velocities of 5 knots. The main work will consist on defining the new shape and structure, and integrating the already mentioned sensors (as was made in the development of Ictineu).
After the building of the robot, several systems will have to be developed. First of all, the vehicle controller, which now is tuned for Garbi and Ictineu, will be retuned for the new AUV . The new surface sensors, the DGPS and the INS, will be integrated with the USBL to obtain a high quality estimation of the robot georeferenced position . Also, since the USBL unit contains an acoustic modem, a communication protocol will be defined to send the georeferenced position and mission control commands to the robot. This task will include the implementation of a human-machine interface that will allow scientists, at surface, the supervision and control of the mission. The next task will concentrate on integrating the two new cameras, the photographic camera and the acoustic camera. In this case, new software drivers and testing will be required.
Finally, once all systems related with the new AUV have been built, integrated or programmed, a final task will be dedicated to set-up the mission controller and its components. The mission control software has already been implemented and tested (Carreras et al. 2006) only the definition of the mission will be required. This mission will be defined using a small set of parameters. These parameters, for example, will be the four corners of the surface to mosaic and the methodology to generate the intermediate trajectories. The mission controller will require an obstacle avoidance skill which will be analyzed and implemented according to the features of the underwater environment. Finally, the software architecture will be modified to allow the online modification of the mission parameters from the human-machine interface at surface and from the online mosaic engine.