Flow Shadowing: A Method to Detect Multiple Flow Headings Using an Array of Densely Packed Whisker-Inspired Sensors

Understanding airow around a drone is critical for performing advanced maneuvers while maintaining ight stability. Recent research has worked to understand this ow by employing 2D and 3D ow sensors to measure ow from a single source like wind or the drone’s relative motion. Our current work advances ow detection by introducing a strategy to distinguish between two ow sources applied simultaneously from different directions. By densely packing an array of ow sensors (or whiskers), we alter the path of airow as it moves through the array. We have named this technique “ow shadowing” because we take advantage of the fact that a downstream whisker shadowed (or occluded) by an upstream whisker receives less incident ow. We show that this relationship is predictable for two whiskers based on the percent of occlusion. We then show that a 2x2 spatial array of whiskers responds asymmetrically when multiple ow sources from different headings are applied to the array. This asymmetry is direction-dependent, allowing us to predict the headings of ow from two different sources, like wind and a drone’s relative motion.