Dynamics and control of a novel 3-DoF spatial parallel robot

Dynamics modeling and trajectory tracking control of a new structure of spatial parallel robots from Delta robots family is elaborated. The proposed novel mechanism like ordinary Delta parallel mechanism has three degrees of pure translational freedom, but the position of robot's three active joints relative to each other is the main difference between this mechanism and Delta parallel mechanism, which has caused the change in geometry of platforms, and it shapes the asymmetrical structure in the robot mechanism and its workspace. The inverse dynamic modeling is performed based on the principle of virtual work. This paper extends our previous paper in which we compared implementation of computed torque (C-T) method using adaptive neuro-fuzzy controller and conventional PD controller. The PD and PID controllers of C-T method usually need manual retuning to make a successful industrial application, particularly in the presence of disturbance. In the present paper, we study feasibility of applying fuzzy PD and PID supervisory control for PD and PID used in C-T method for this parallel mechanism. The main motivation for this design was to cope with above problem for this complex nonlinear system. Numerous computer simulations demonstrate the effectiveness of the proposed control method in comparison with ordinary C-T method.