Hi Everyone,I have a question for you. I'm designing auto landing system with ultrasonic sensor controlled elevator.It will take the control in last 3 meters for smooth touch to the ground.And another idea using this for low level flying with auto altitude.Did anyone try this before?
You need to be a member of diydrones to add comments!
I'll try to make UAV with autopilot landing using three sensors:
1) GPS - to proximitely (about 15 meters) find the land
2) Ultrasonic sensors - to precisely (1 inch) find the land from altitude about 6 meters
3) Pressure altimeter (about 15 cm) - to find the land second time
I'd find the land descending with ultrasonic sensor with normal UAV speed. Then I'll lift up and make second pass for landing with low speed knowing the height very precisely.
I think two passes for landing make it very carefull.
A few years back some guys in our lab tried to use an ultrasonic sensor with a micropilot to do auto-landings. The problem that they ran into was that the aircraft was traveling fast enough that by the time the signal returned to the aircraft the sensor had already moved too far away to receive it. At least, that was what they diagnosed the problem to be. There are some ultrasonic sensors with larger receivers that, supposedly, have been successfully used for auto landing on other aircrafts. The bigger problem I would worry about is that grass is going to give you a messy return signal at best.
Infrared sensors have a similar problem where the varying reflectivity of different surfaces can make things effectively invisible.
Other alternatives include laser altimeter (very expensive), gps, and barometric altimeter. The Piccolo autopilot is able to do autonomous landing using gps and barometric altitudes. And I expect that it could do it using just the gps altitude.
I am working on a similar feature on a Quad-Rotor heli with 4 ultrasonics, though I am still in the conceptual phase and need to start working on the control system equations for such a thing.
Replies
how do i integrate the ultrasonic sensors with the drone? apart from landing the drone I also want to navigate it indoors by avoiding objects.
step by step instructions will be helpful
1) GPS - to proximitely (about 15 meters) find the land
2) Ultrasonic sensors - to precisely (1 inch) find the land from altitude about 6 meters
3) Pressure altimeter (about 15 cm) - to find the land second time
I'd find the land descending with ultrasonic sensor with normal UAV speed. Then I'll lift up and make second pass for landing with low speed knowing the height very precisely.
I think two passes for landing make it very carefull.
Infrared sensors have a similar problem where the varying reflectivity of different surfaces can make things effectively invisible.
Other alternatives include laser altimeter (very expensive), gps, and barometric altimeter. The Piccolo autopilot is able to do autonomous landing using gps and barometric altitudes. And I expect that it could do it using just the gps altitude.