Design and implementation of a cable-driven parallel robot for additive manufacturing applications

This paper presents a new 6 degree-of-freedom cable-driven parallel robot fully constrained by 8 cables. This robot should perform medium size 3D part printing. Its distinguishing feature is a radial cable winding that is relevant due to the small cable diameter (0.54 mm) and the maximum cable length (1.732 m, 1 m cube diagonal). This winding solution has the advantage of being compact and easy to design. The robot trajectory planning uses a full geometric model of the pulley and winding system which is introduced in this paper. The cable elasticity is taken into account in the geometric model to increase the tool path following accuracy. Robot dynamic performances are analyzed for two different mobile platform geometries. From this analysis, we obtained an end-effector trajectory tracking error of less than 0.4 mm for a feedrate speed of 0.1 m/s.