From a design point
of view, it is crucial to predict singular configurations of
a manipulator in terms of inputs in order to improve
the dexterity and workspace of a manipulator. In this paper,
we present a simple, yet a systematic appoach to obtain
singularity contours for a class of five-bar planar parallel manipulators
which are based on five rigid links and five single
degree of freedom joints – revolute and prismatic joints. The
determinants of the manipulator Jacobian matrices are evaluated in terms
of joint inputs for a specified set of geometric parameters,
and the contours of the determinants at 0.0 plane which
are the singularity contours in joint space are generated for
the three types of singularities reported in the literature. The
proposed approach/algorithm is simple and systematic, and the resulting equations
are easy to solve on a computer. The singularity contours
for all the class are presented in order to demonstrate
the method. It is concluded that the proposed method is
useful in trajectory planning and design of five-bar planar parallel
manipulators in order to improve their dexterity and workspace.