Fusing neuromorphic motion detector outputs for robust optic flow measurement

This paper presents a method for generating robust measurements by fusing the outputs of multiple elementary motion detector (EMD) circuits. The competitive feature tracker (CFT) algorithm is used to implement the EMD circuits. CFT measures motion by timing the movement of a feature across the visual field. Fusion is performed with leaky integrators. Each leaky integrator corresponds to a range of velocities and is stimulated whenever an EMD detects motion in the leaky integrator's velocity range. Thus the leaky integrator corresponding to the correct velocity receives the most stimulus. The other leaky integrators receive stimulus only from incorrect measurements. These incorrect stimuli are hence "voted out" and ignored. A proof-of-principle was obtained by implementing the algorithm in an optic flow sensor and exposing the sensor to moving texture stimulus. This sensor was then mounted onto a glider and placed in a control loop to cause the glider to steer away from a wall before collision.