A Partial Compliant Mechanism for Precise Remote-Center Motion

Remote-center motion (RCM) mechanisms employing compliant links provide friction-less and backlash-free motion of a part of mechanism about a remote-center of desired radius. Such precision mechanisms find use in many medical and engineering applications. A partial RCM mechanism employing an L-shaped cantilever beam is proposed, for the first time, to enable a mounted rigid-link to rotate precisely about one of its edges. The mechanism is conceived with multiple arrangements of the L-shaped cantilever beams to hold the rigid-link against another fixed link such that the “remote-center” of the mechanism coincides with one of the edges of the mounted rigid-link. The link and L-shaped cantilever are connected by means of a higher pair joint, thus a partially compliant mechanism. Remote-center coordinates are located by carrying out nonlinear “finite element analysis” of the cantilever beam. Further, the mechanism is fabricated and experiments are carried out to verify its working at high precision.