Obstacle avoidance in a terrestrial mobile robot provided with a scanning retina

This study describes the role of a novel visual sensor, called the “scanning local motion detector” (SLMD) for the visual navigation of a terrestrial mobile agent. Following a brief theoretical description of the principle of retinal scanning coupled with notion parallax, we show that a single retina of 24 pixels - when oriented in the mobile agent´s forward line of move - allows the latter to avoid the visually detected obstacles in a reflex manner by correcting its trajectory in real time. The results of the preliminary computer simulations yield credit to a zig-zag algorithm which allows the agent to avoid the oncoming obstacles while immediately “keeping an eye” on its lateral regions. In parallel with the simulation, we designed and built a hardware prototype of a scanning retina with coarse optical resolution (average angular sampling of 3°) mounted on top of a circular mobile platform. The preliminary results of the robot´s successful performances confirm the validity of the zig-zag algorithm