There are only three 6-SPS parallel manipulators with triangular base and platform: the octahedral, the flagged, and the partially-flagged studied in this paper. The forward kinematics of the octahedral manipulator is algebraically intricate, while those of the other two can be solved by three trilaterations. As an additional nice feature, the flagged manipulator is the only parallel platform for which a cell decomposition of its singularity locus has been derived. Here we prove that the partially-flagged manipulator admits also a well-behaved decomposition, technically called a stratification, some of whose strata are not topological cells, though. Remarkably, the adjacency diagram of the 5 and 6 dimensional strata (which shows what 5 dimensional strata are contained in the closure of a 6 dimensional one) is the same as for the flagged manipulator. The availability of such a decomposition permits devising a redundant 7-SPS manipulator, combining two partially-flagged ones, which admits a control strategy that completely avoids singularities. Simulation results support these claims. ; This work was supported by the project 'Grup de recerca consolidat - Grup de Robòtica' (4810). This work was supported in part by the Catalan Research Commission. The work of M. Alberich-Carramiñana was supported by DGICYT under Project MTM2006-14234-C02-02. ; Peer Reviewed


    Access

    Download


    Export, share and cite



    Title :

    Partially-flagged parallel manipulators: singularity charting and avoidance



    Publication date :

    2009-01-01


    Remarks:

    doi:10.1109/TRO.2009.2018970



    Type of media :

    Article (Journal)


    Type of material :

    Electronic Resource


    Language :

    English



    Classification :

    DDC:    629



    Flagged parallel manipulators

    Alberich-Carramiñana, Maria / Thomas, Federico / Torras, Carme | BASE | 2007

    Free access

    Architecture singularities in flagged parallel manipulators

    Borràs, Julia / Thomas, Federico / Torras, Carme | BASE | 2008

    Free access

    On redundant flagged manipulators

    Alberich-Carramiñana, Maria / Thomas, Federico / Torras, Carme | BASE | 2006

    Free access