Singularities of robot manipulators have been intensely studied in the last
decades by researchers of many fields. Serial singularities produce some local loss of
dexterity of the manipulator, therefore it might be desirable to search for singularityfree
trajectories in the jointspace. On the other hand, parallel singularities are very
dangerous for parallel manipulators, for they may provoke the local loss of platform
control, and jeopardize the structural integrity of links or actuators. It is therefore
utterly important to avoid parallel singularities, while operating a parallel machine.
Furthermore, there might be some configurations of a parallel manipulators that are
allowed by the constraints, but nevertheless are unreachable by any feasible path.
The present work proposes a numerical procedure based upon Morse theory,
an important branch of differential topology. Such procedure counts and identify the
singularity-free regions that are cut by the singularity locus out of the configuration
space, and the disjoint regions composing the configuration space of a parallel
manipulator. Moreover, given any two configurations of a manipulator, a feasible or
a singularity-free path connecting them can always be found, or it can be proved that
none exists.
Examples of applications to 3R and 6R serial manipulators, to 3UPS and
3UPU parallel wrists, to 3UPU parallel translational manipulators, and to 3RRR
planar manipulators are reported in the work.
| Identifer | oai:union.ndltd.org:unibo.it/oai:amsdottorato.cib.unibo.it:954 |
| Date | 17 April 2008 |
| Creators | Paganelli, Davide <1979> |
| Contributors | Innocenti, Carlo |
| Publisher | Alma Mater Studiorum - Università di Bologna |
| Source Sets | Università di Bologna |
| Language | English |
| Detected Language | English |
| Type | Doctoral Thesis, PeerReviewed |
| Format | application/pdf |
| Rights | info:eu-repo/semantics/openAccess |
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