The invention relates to a robotic device for the positioning and orientation of a platform that is connected thereto by means of articulated support structures forming parallel mechanical links, each in the form of a serial kinematic chain of articulations that are interconnected by support segments. The inventive device (1) is characterized in that it comprises three articulated parallel mechanical links comprising: (i) two opposing, symmetrical and co-planar support structures (4 and 5), and (ii) a third support structure (6) which is located in a plane that is perpendicular to the plane containing the support structures (4 and 5). According to the invention, the articulated links formed by the three supports structures (4, 5 and 6) enable the controlled movement of points belonging to the platform (2) on a surface corresponding to a spherical or ellipsoidal cap and, preferably, essentially to a half-sphere, thereby providing at least five degrees of freedom.