Nature is class. Birds are also class. If you have ever seen a bird gliding in the wind, that is exactly what this project is trying to emulate. The world record flight time for a two-seat glider is over 70 hours set in 1961 in Hawaii. This record has not been beaten because it is seen as being a pointless and dangerous challenge. Alpine swifts can fly for 6 months at a time without landing in fact.
So it is not too crazy to imagine building an autonomous glider that can remain airborne for large periods of time. To do this, a stable control system and suite of algorithms is required.
I bought a hand thrown glider for €5 in Lidl. The first thing to do was to put a motor and servos on it. Initially it would be controlled using my stock RC controller and receiver.
Motor control and sensors
There are two roll servos, one pitch servo, one yaw servo and a propeller BLDC. There will also be a 9DOF IMU, altitude barometer, windspeed sensor, GPS, and RC receiver.
The final board for testing will place an ESP32 inbetween the RC receiver and the motors so that PID control and more complex controllers can be implemented.
Web interface / datalogging
PID controllers will be implemented for each of the axes for simpler intial controls and some level of automation.Related Posts:
One of the goals of this project is to create a robust control system that can withstand imbalance in the plane, gusts of wind, stalling and the ability to take tight turns. PID controllers are the first initial starting point, but many changes will be necessary.
Waypoints can be added to form a path which the plane will follow. GPS, altitude and a good control system are all necessary for this part of the project.
Much like how birds glide in the wind, this stage will do the same. Wind direction needs to be determined. Then an algorithm needs to be developed to maintain this direction and glide efficiently.
Thermals provide a good source of lift on a sunny day. Thermal identification and following could help increase flight time.
I bought a BMS for the battery that I have a while ago. However, the BMS was faulty. I have a new one that I have been meaning to install for a while. It's finally installed now 😊
The goal is to maximise the flight time of the glider, using thermals, solar and wind.
Flight test report Tuesday 1.9.2020 11:26 Positives: New access point web interface worked very well All parameters worked It wasn’t wet :D Airspeed works and appears to be altitude agnostic (shortlived flights don’t give good data) Negatives: The plane kept leaning left Integral barely helped any leaning Integrated while in my hand Plane seems to be balanced (at least very roughly) The plane either nose-dived or stalled Oscillation occured during flights Gusts of wind caused plane to go out of control Summary The actual web interface for the plane is working very very well.…