Underwater Robots - Gianluca Antonelli.pdf

6.6 Fuzzy Inverse Kinematics 125
Fig. 6.12. Initial configuration of the UVMS for all the case studies. Desired endeffector
position: at the start time (A); after the first movement of12s (B); at the
final time (C)
Case Study n.1
The first simulation has been run bythe use of asimple pseudoinversion
of (2.68) with CLIK gain:
K E =blockdiag { 1 . 6 I 3 , I 3 } .
This solution is not satisfactory in presence of such alarge number of
degrees of freedom. The system, in fact, is not taking into accountthe different
nature of the degrees of freedom (vehicle and manipulator) leading to evident
drawbacks: large movement ofthe vehicle in position and orientation, final
configuration not suitable for sensor tuning, possible occurrence of kinematic
singularities or joint mechanical limits. As an example, Figure 6.13 reports
the sketch ofthe final configuration where the bottom sonar would not work
properly since the pitch is ≈ 18 deg.
B
A
C