Underwater Robots - Gianluca Antonelli.pdf

1.5.1 Fault Detection/Tolerance for UUVs
1.7 Future Perspectives 11
ROVS and AUVs are complex systems engaged in missions in un-structured,
unsafe environments for which the degree of autonomy becomes acrucial
issue. In this sense, the capability todetect and tolerate faults is akey to
successfully terminate the mission or recuperate the vehicle. Anoverview of
fault detection and fault tolerance algorithms, specifically designed for UUVs
is presented in Chapter 4.
In Figure 1.8, the vehicle Romeo operating over thermal vents inthe
Milos Island, Aegean Sea, Greece, is shown; this vehicle has been built
at the RobotLab, National Research Council (CNR-ISSIA), Genova, Italy
( http://www.robotlab.ian.ge.cnr.it/). This vehicle has been object of
several experimental studies on fault detection/tolerance algorithms.
1.6 UVMS’ Coordinated Control
The use of Autonomous Underwater Vehicles (AUVs) equipped with amanipulator
(UVMS) to perform complex underwater tasks give rise to challenging
control problems involving nonlinear, coupled, and high-dimensional
systems. Currently, the state of the art is represented by tele-operated master/slave
architectures; few research centers are equipped with autonomous
systems [180, 321].
The core of this monograph isdedicated to this topic, in Chapter 6the
kinematic control will be discussed, Chapter 7presents dynamic control laws
for UVMSs and Chapter 8shows some interaction control schemes.
1.7 Future Perspectives
Underwater robotics research isaninteresting topic. Current technology allows
to safely run long duration missions that involve one single AUV, e.g., as
in the case of the Naval Postgraduate School or the Ura laboratory vehicles,
or to execute manned-in-the-loop manipulation tasks. There are, however,
research topics that need to be further investigated.
The UVMSs need to be studied in the field; from the theoretical aspect,
in fact, many ofthe associated problems have been studied and, possibly,
solved: kinematic and dynamic control laws, as well as interaction control
laws have been designed and successfully simulated. Fewexperimental set-up
have also been used; these, however, reproduced only oversimplified environments.
Interesting results might beachieved by means of afully actuated
autonomous underwater vehicle carrying a6-DOF manipulator.
The actuating system might beimproved inaneffort to reduce the limit
cycles caused by the thrusters’ dynamics at very low velocities; new blade