A biologically inspired model of binocular control on a free head

A single layer, symmetrical bilateral controller with dual modalities has been developed for a robotic head, based on symmetries in brainstem circuits for the oculomotor control system (OCS). This robotic head controller is unique in the biological approach during its development, and its structural elegance afforded by the single layer organization. Extensions to this controller are based on connections between brainstem and cerebellar structures, and the OCS circuit. To make the robotic head better reflect biology: 1. velocity feedback is added to account for floccular projections to the brainstem OCS, and 2. integral feedback is added to represent findings of vector averaging mechanisms in superior colliculus. The resulting OCS controller has a structure better matched with what has been reported in brainstem premotor-circuit topology. The new bilateral OCS not only retains the structural and analytical simplicity of its precursor, but it now has an improved bandwidth for its pursuit mode, and can track faster objects with smaller errors, while requiring fewer saccades.