An anthropomorphic robotic head for investigating gaze control

This paper presents the biomechatronic design and development of an anthropomorphic robotic head able to perform human eye movements as a tool for experimental investigation in neuroscience. This robotic head has been designed upon specifications derived from models of the human head and of human neck and eye movements, in terms of total mass, geometry, number of degrees of freedom (d.o.f.), joint velocities and accelerations. The robotic head has 7 d.o.f.: 4 d.o.f. specifically allowing the neck movements and 3 d.o.f. dedicated to the faster eye movements; it has a total mass of approximately 5.6 kg, and it is capable of reaching a maximum eye velocity and acceleration of 1000°/s and 10 000°/s2, respectively, compatible with human data. The coordination of neck and eye movements allows smooth pursuit; and the independent eye yaw movements allow vergence. As an example, the use of this robotic head for validating a novel neurophysiological model of gaze control is presented. The model has been implemented on the robot, which can transform the retina images into their mapping onto the relevant brain area (superior colliculus), calculate the coordinates of a visual stimulus appearing in the periphery, generate the velocity profiles for the eye motors and execute the eye movements. This implementation shows that the robotic head can perform human-like saccades and allows experimental comparison with human data, so as to validate and revise the model itself.