Model-based control of spatial 6-DOF hydraulic parallel robot manipulator

A novel model-based controller for spatial 6-DOF hydraulic parallel robot manipulator is presented, in order to improve the tracking performance and eliminate the dynamics coupling effects on the control performance of hydraulic parallel robot manipulator. The mathematical model involving mechanical system and hydraulic system of the spatial 6-DOF hydraulic parallel robot manipulator is established using Kane method and hydromechanics principle. The developed model-based control scheme utilizes the system dynamics and hydraulic system model to yield the current of servovalve, and only position and velocity of the hydraulic parallel robot manipulator are employed as its feedback. The pressure and acceleration information is not required in this approach. By using Hurwitz theorem, the stability of the developed approach for hydraulic robot manipulator is validated. The tracking performance of the proposed algorithm is analyzed via simulation. Simulation with typical trajectories is presented and an excellent control performance is obtained. Furthermore, this methodology can be extended to other hydraulic serial and parallel robot manipulator.