Abstract. Three degrees of freedom (3-DoF) parallel mechanism (PM) with
limbs of embedding structures is a kind of PM with a coupling relationship
between limbs. In order to obtain a more desirable motion, the analysis of
its actuated pairs shall be conducted. However, the fact that the existence
of limbs coupling results in non-unique limb group, this mechanism has
multiple limb groups. In this regard, the traditional input selection theory
is not suitable for direct application in the input rationality analysis.
Aiming to avoid this, a general extended input selection theory and limb
group selection rule are proposed. The former tackles the traditional input
selection theory which is not suitable for analyzing the input of PM with
limbs of embedding structures since it does not take the influence of group
into consideration, whereas the latter makes the calculation of the former
easier. Based on the extended input selection theory and the limb group
selection rule, the input and configuration of the 3-DoF PM with limbs of
embedding structures are improved.