Low-cost relative navigation sensors for miniature spacecraft and drones

Proximity relative navigation systems for autonomous small spacecraft and Micro Aerial Vehicles are under continuous investigation, aiming to obtain low-cost and low-resources miniaturized sensors. In this paper, after a review on the state of the art of relative navigation systems for cooperative and non-cooperative miniature space and aerial vehicles, two simple, low cost devices for proximity navigation are presented. The first one is conceived for operation between cooperative vehicles, and exploits a dual system comprising a small camera imaging an array of LEDs and a LED-photodiode couple for precise range estimation based on intensity measurements. The second sensor is designed to perform proximity ranging and attitude determination with respect to non-cooperative objects in space, air or ground. It is based on a miniature camera that detects the light spots on the target surface generated by three lasers mounted on the chaser vehicle. Theoretical models have been developed for both sensors, and were used to perform a preliminary assessment of performance through numerical simulations.