Steering by Gazing: An Efficient Biomimetic Control Strategy for Visually-guided Micro-Air Vehicles

• Kerhuel Lubin
• Viollet Stéphane
• Franceschini Nicolas

• Gaze stabilization
• Smooth pursuit
• Oculomotor Reflexes ORs
• Visual Fixation Reflex VFR
• Vestibulo-ocular Reflex VOR
• Micro-Air Vehicle MAV
• Steering strategy
• Sen- sorimotor control
• Biorobotics
• Autonomous robots

OSCAR 2 is a twin-engine aerial demonstrator equipped with a monocular visual system, which manages to keep its gaze and its heading steadily fixed on a target (a dark edge or a bar) in spite of the severe random perturbations applied to its body via a ducted fan. The tethered robot stabilizes its gaze on the basis of two Oculomotor Reflexes (ORs) inspired by studies on animals: - a Visual Fixation Reflex (VFR) - a Vestibulo-ocular Reflex (VOR) One of the key features of this robot is the fact that the eye is decoupled mechanically from the body about the vertical (yaw) axis. To meet the conflicting requirements of high accuracy and fast ocular responses, a miniature (2.4-gram) Voice Coil Motor (VCM) was used, which enables the eye to make a change of orientation within an unusually short rise time (19ms). The robot, which was equipped with a high bandwidth (7Hz) "Vestibulo-Ocular Reflex (VOR)" based on an inertial micro-rate gyro, is capable of accurate visual fixation as long as there is light. The robot is also able to pursue a moving target in the presence of erratic gusts of wind. Here we present the two interdependent control schemes driving the eye in the robot and the robot in space without any knowledge of the robot's angular position. This "steering by gazing" control strategy implemented on this lightweight (100-gram) miniature aerial robot demonstrates the effectiveness of this biomimetic visual/inertial heading control strategy.