Self-reconfigurable planar parallel robot

This paper proposes a novel self-reconfigurable parallel robot which is capable of self-reconfiguring to other various types of planar parallel robots on a horizontal plane. The limbs (legs) of the proposed parallel robot are 2R (two-revolute-joint) open kinematic chains whose second joints are unactuated. Reconfiguration is done by the coupling and decoupling of the platform(s) and limbs, which enables the proposed parallel robot to change workspaces and exchange tools. Uncertainty singularities enable such a robot to self-reconfigure without additional actuators at its coupling mechanism. This paper proposes appropriate uncertainty singular configurations for coupling and decoupling. In addition, it is shown that there exist a geometrically stable uncertainty singular configurations, which are useful especially for decoupling. Experiments are carried out to verify the self-reconfiguration.