In a previous work, this author showed that ten topologies for under-actuated parallel wrists can be generated from the fully-parallel wrist. Three of them are obtained by simply replacing a spherical pair (S) with a nonholonomic spherical pair (nS). The S-(nS)PU-SPU, and S-(nS)PU-2SPU wrists are two of these three. The position analysis of these two wrists is studied in this paper. In particular, all the four position-analysis problems, which are necessary for implementing their path planning, are addressed and solved in closed-form. Despite their different topology, the position-analysis of these two wrists can be practically solved by using the same formulas and algorithms. Based on the deduced formulas, a path-planning algorithm is proposed. The obtained results make the studied wrist topologies able to replace “ordinary” wrists in the manipulation tasks which do not require tracking.
ON THE S-(nS)PU-SPU AND S-(nS)PU-2SPU UNDER-ACTUATED WRISTS
DI GREGORIO, Raffaele
2011
Abstract
In a previous work, this author showed that ten topologies for under-actuated parallel wrists can be generated from the fully-parallel wrist. Three of them are obtained by simply replacing a spherical pair (S) with a nonholonomic spherical pair (nS). The S-(nS)PU-SPU, and S-(nS)PU-2SPU wrists are two of these three. The position analysis of these two wrists is studied in this paper. In particular, all the four position-analysis problems, which are necessary for implementing their path planning, are addressed and solved in closed-form. Despite their different topology, the position-analysis of these two wrists can be practically solved by using the same formulas and algorithms. Based on the deduced formulas, a path-planning algorithm is proposed. The obtained results make the studied wrist topologies able to replace “ordinary” wrists in the manipulation tasks which do not require tracking.I documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
