The project aim is to build a quadrotor helicopter flies with 4 spinning propellers on a + shaped frame. It uses four brushless motors. Each motor will be controlled by an ESC (Electronic Speed Controller). The ESCs will be controlled by the microcontroller. This microcontroller will also take input from a RC radio receiver, so you can control the helicopter from the ground using a RC radio transmitter. A lithium polymer battery is used to power the project.
When one rotor spins faster than the rotor on the opposing side, the faster side will have more lift, and thus the helicopter will tilt. When the helicopter is tilted, the air is being blown slightly sideways instead of directly down, and the helicopter will move.
The propellers also need to be in counter-rotating pairs, two spin clockwise and two spin counter-clockwise. This way, the helicopter does not spin on the vertical axis since the rotational inertia is cancelled out. But when the pair that’s spinning in one direction is faster than the other pair, the helicopter will spin on the vertical axis. This is how the helicopter controls its direction.
The flight controller circuit contains an accelerometer and gyroscope sensor so that an ATmega644PA microcontroller can detect undesired changes in the helicopter’s angle, and adjust each rotor’s speed accordingly to counter the variation. This microcontroller will do this hundreds of times per second, keeping the helicopter stable in the air.
The flight controller is a completely open source circuit. The circuit schematic and PCB files are provided here. The flight controller is completely Arduino compatible. The source code is a modified version of AeroQuad (open source Arduino based quadrocopter control code). The flight characteristics can be adjusted using AeroQuad’s configurator utility. This quadrocopter project is designed by Frank26080115.
Project Detail and Documentation