Underwater Robots - Gianluca Antonelli.pdf

126 6. Kinematic Control of UVMSs
Fig. 6.13. Final configuration of the UVMS for the first case study. The redundancy
is not exploited and the possible occurrence of undesired configurations is
not avoided
Case Study n.2
In the second case study aweighted pseudoinverse is added in order to redistribute
the motion between vehicle and manipulator including acost factor
that can be considered, e.g., proportional to the ratio of their inertias. The
following matrix of gain has been used:
W − 1 =blockdiag { 0 . 01I 6 , I 6 } .
Despite the much different costs of the two movements, the vehicle is still
required tomove in order to contribute to the end effector motion. However
it would be preferable to move the vehicle only when absolutely necessary,
leading to sole movement ofthe manipulator in ordinary working conditions.
As an example, the vehicle attitude, in terms of Euler angles, for the last simulation
isshown in Figure 6.14. The vehicle still has apitch ofabout 20 deg.
Case Study n.3
The drawback shown by the algorithm as presented in the Case Study n. 2can
be easily avoided by resorting to asingularity-robust task priorityredundancy
B
A
C