Inverse jerk analysis of symmetric zero-torsion parallel manipulators

In this work the inverse velocity, acceleration and jerk analyses of a class of three-degrees-of-freedom parallel manipulators are approached by means of the theory of screws. The concept of reciprocal screws allows to obtain simple and decoupled expressions to compute the joint rates, up to the third time derivative, of the class of manipulators under study given the instantaneous kinematic properties of the center of the moving platform. The interdependency between the angular and linear kinematic properties of the moving platform is also derived. A case study is included.

► Zero-torsion robots are intended to be used in biomechanical applications.
► Human motions are performed by controlling the jerk.
► The jerk analysis is approached by resorting to reciprocal screw theory.
► A correlation between the kinematic properties of the robot is established.
► Case study is verified with the aid of commercially available software.