Résumé
A four-degree-of-freedom parallel robot capable of displacing a traveling plate with four degrees of freedom at a high speed and a high acceleration and positioning the traveling plate with high rigidity and high precision. The four-degree-of-freedom parallel robot has four actuators fixed to a base, four parallel linkages each of which is coupled at its upper end to a tip end of an arm of each of the actuators through a kinematic element such as a universal joint, and a traveling plate whose four corners are coupled to lower ends of the parallel linkages through kinematic elements. By controlling the actuators, a main member of the traveling plate is displaced with four degrees of freedom, i.e., translated in all directions and rotated around a predetermined axis. Only axial forces are applied to rods constituting the parallel linkages. Thus, the traveling plate can be positioned at a high speed and with high rigidity as well as high precision.