In this paper, a nonlinear proportional derivative control (NPD) is proposed to solve the trajectory tracking problem of a parallel Delta robot. In order to handle the strong coupling effect and external disturbances as well as to realise high-precision trajectory tracking, the proportional and derivative gains are adapted through time using the tracking error and its time derivative respectively. Experiments are carried out on the parallel Delta-4 robot, and it is shown the effectiveness and the superiority of the NPD controller over the fixed gains PD controller.
Nicolas Henri Bernard Flammarion, Oguz Kaan Yüksel, Etienne Patrice Boursier
Laurent Villard, Emmanuel Lanti, Alberto Bottino, Mohsen Sadr
Xavier Fernandez-Real Girona, Riccardo Tione