Two-Directional 1-g Visual Motion Sensor Inspired by the Fly's Eye

Abstract

Optic flow-based autopilots for Micro-Aerial Vehicles (MAVs) need lightweight, low-power sensors to be able to fly safely through unknown environments. The new tiny 6-pixel visual motion sensor presented here meets these demanding requirements in terms of its mass, size, and power consumption. This 1-gram, low-power, fly-inspired sensor accurately gauges the visual motion using only this 6-pixel array with two different panoramas and illuminance conditions. The new visual motion sensor's output results from a smart combination of the information collected by several 2-pixel Local Motion Sensors (LMSs), on the basis of the "time of travel" scheme originally inspired by the common housefly's Elementary Motion Detector (EMD) neurons. The proposed sensory fusion method enables the new visual sensor to measure the visual angular speed and determine the main direction of the visual motion without any prior knowledge. Through computing the median value of the output from several LMSs, we also end up with a more robust, more accurate, and more frequently refreshed measurement of the one-dimensional angular speed.

Bioinspired Visual Motion Estimation

“…Roubieu et al [89] presented a 23.3-mm  12.3-mm sensor weighing under 1 g (including optics). The sensor consists of five pairs of 1-D motion sensors which use tokens to measure the time for a feature to travel between neighboring locations, similar to the TI token method.…”

Event-based speed control on a sensor-less miniature thruster

“…It is based on a miniature direct current thruster GWS EDF-50 (see Fig. 1A, power: 24.41W, mass: 29g) which was previously embedded on the bio-inspired robot LORA III [9]. The maximum allowable current drawn is 3.4A under 7.2V.…”

“…In this paper, using miniature actuators which equipped the bio-inspired robot LORA III [9], an experimental setup was developed to test some event-based techniques for speed tracking and disturbance rejection. This work aims at comparing the performances of time-based and event-based control laws in terms of power consumption and control updates in particular an event-based state feedback approach that uses the instantaneous current information to limit the starting peak current and the power consumption.…”

Time-of-Travel Methods for Measuring Optical Flow on Board a Micro Flying Robot

“…Their OF-based strategies therefore provide inspiration for the development of smart autopilots for micro-air-vehicles (MAVs) [1,4,5] and smart artificial retinas [6,7,8,9,10,11,12]. …”

“…With a larger number of LMSs, output refresh rate increased (64 Hz with 5 LMSs) in an OF range from 25 to 350 °/s (i.e., 1.1-decade) at a constant natural lighting ∼1500 lux [8]. A similar OF range from 50 to 250 °/s (i.e., 0.7-decade) was measured with a semi-panoramic artificial eye, called CurvACE [9,28].…”