On the Elastostatics of Spherical Parallel Machines with Curved Links

The paper presents the elastostatics analysis of a class of lower-mobility Parallel Kinematic Machines: the Spherical Parallel Machines. These robots usually recur to curved links in their structure to satisfy geometric constraints deriving from mobility reason. In fact, to make the mobile platform move with spherical motion all links or a part of these are constrained to have spherical motions too. This condition is generally obtained employing curved links with revolute pairs whose axes intersect at a common center of motion. Recurring to two-node Timoshenko’s beam element with constant strain fields to simulate curved beams in space we adapt a methodology proposed by the same authors to study the elastostatics of Spherical Parallel Machines. The method is finally applied to study the error positioning analysis of the Agile Eye. © Springer International Publishing Switzerland 2015.