Experimental verification of friction and dynamic models of a parallel kinematic machine

The Gantry-Tau is a parallel kinematic manipulator (PKM) that overcomes the workspace limitations of typical PKMs, while retaining PKM benefits such as small moving masses and high stiffness. An experimental verification of the dynamics of the Gantry-Tau is presented for the first time in this paper. A new friction model based on axial forces in the links of the 3-DOF Gantry-Tau combined with a recent inverse dynamics model for parallel kinematic machines is also presented and verified experimentally. The inverse dynamics model combining the friction model and the Jacobians shows a good match to the measured linear actuator forces from a full-scale prototype machine.