Best Sensors for Drones?

Hello all.

I’m looking to build a semi-autonomous drone that will avoid obstacles. I want to be able to accurately measure distance to an object, but also be able to determine whether or not a space in front of or to the side of the drone is too small for it to fit. Perhaps most important is price. I can’t spend more than $70 on this drone total, ideally under $50.

What would be the best sensors to use for this? Sonar? IR proximity? Image recognition and sonar combined?

Thanks in advance!

Your requirements are unrealistic and considering the cost restriction, very likely impossible to satisfy. The most useful sensor would be a fast laser range finder, like the Lidar lite, which costs about US $100.

Panning sonar (ping sensor). Maybe 2 mounted at the edge of your vehicle. If they can both see the opening is clear for a couple degrees to their outer edge and the middle is clear, you can infer there is room. Perhaps a feeler in front to avoid tumbles down stairs.

Distance ahead may be more limiting. Perhaps combine with another sensor for "farther out".

jremington: Your requirements are unrealistic and considering the cost restriction, very likely impossible to satisfy. The most useful sensor would be a fast laser range finder, like the Lidar lite, which costs about US $100.

Thanks for your input. However, I'm not willing to give up that easily. What does the laser range finder do that no other sensor cannot?

CrossRoads: Panning sonar (ping sensor). Maybe 2 mounted at the edge of your vehicle. If they can both see the opening is clear for a couple degrees to their outer edge and the middle is clear, you can infer there is room. Perhaps a feeler in front to avoid tumbles down stairs.

Distance ahead may be more limiting. Perhaps combine with another sensor for "farther out".

Thanks. If they are panning however, why would I need two? Or am I interpreting this wrong?

I was thinking that too when I started my reply, a single panning unit. With tilt too for height clearance determination. I guess try it and see how it works. We have two eyes, two ears, stereo seems to have benefits that work out okay.

What does the laser range finder do that no other sensor cannot?

Accuracy, long range and high speed.

Sonar is slow, has limited range, and because of rotor noise and vibrations, may not even work with a drone.

Something to keep in mind when working with drones these days- may places are making them illegal because of the problems they have caused (and risk to other people). We just went through Yellowstone and there were lots of places there where there were signs saying they were illegal. Just something to keep in mind for your project.

gpsmikey: Something to keep in mind when working with drones these days- may places are making them illegal because of the problems they have caused (and risk to other people). We just went through Yellowstone and there were lots of places there where there were signs saying they were illegal. Just something to keep in mind for your project.

Good advice. For now I plan to make it indoors only, but I'll keep it in mind.