Robotic Glider Set To Break Autonomous Flight Records 33
SoaringIsAwesome writes "Dan Edwards, a student at NC State University, is attempting to break two records by creating an autonomous glider. The project goal is a 142-mile cross country flight and a 25-mile flight (with return) without human intervention. The glider finds thermal updrafts and automatically circles them to gain altitude, much like birds and insects do. Recently, the glider flew in the desert for 4.5 hours, covering 70.5 miles by itself using only air currents to stay aloft. Since the NC State demonstration vehicle does not have a motor, this shows real promise for unmanned aerial vehicles (UAVs) that actually have a motor, with possibilities of extending flight duration considerably. Combine daytime soaring with a solar energy system to charge batteries for the night, such as the 84-hour flight by QinetiQ's Zephyr, and you might just get an answer to flying for months on end. With this kind of endurance, the eye in the sky that the city of Lancaster is considering might be even more practical."
Re:NC is North Carolina, right? (Score:4, Informative)
Re:NC is North Carolina, right? (Score:3, Informative)
Cross country in Gliding generally refers to flying outside glide range of the airfield, most often onn a triangular course of a set distance.
Re:Autonomous Soaring (Score:3, Informative)
The problem basically breaks down into two parts:
1) find a thermal
Standard theory says that thermals are spaced at intervals of about 1.5 times their vertical extension (ground to cloud base or top of blue thermal with no Cu cloud on top) and using all his senses a glider pilot has a fair chance of getting from one to the next without hitting the ground first. If the only available option to find the next thermal is to fly in a straight line and wait until you hit it, it's still working most of the time (that's when thermals are not marked by clouds and i suppose this guy's gizmo can't see them anyway). Taking into consideration the much smaller L/D (distance that it can glide from a given height) of a model i don't know if it still works, but the results in TFA seem to confirm this. I can't see that he uses another way of finding the thermal
2) use the thermal = climb
I'd think that given the small turning radius of a model glider and the large radius of a thermal not too near the ground there is no need to center the thermal nearer to the core in order to get some altitude. This might not apply to microthermals near the ground and is not very effective of course. The development (read the papers on the website) tries to deal with this problem by modeling the thermal from measurements of vertical speed and maneuvering the glider nearer to it's core in order to climb faster / at all. BTW that's what >50% of soaring a glider is all about and it's something that involves lots of senses, hence my first comment.