Large-capacity quadcopter’s designing on the controllers of the pixhawk cube family

Abstract

The quadrocopter’s design and configuration that capable to carry a payload of up to 30 kg based on the Pixhawk 2 Cube flight controller using Arducopter ver.4.1.5 firmware for FMUv3 devices was completed in the paper. For ensuring a flight range of 10-12 km, the using of 44000 mAh battery and payload of 10-15 kg is recommended. It has been established that when building large-sized copters, before setting up the PID controller, it’s necessary to pre-configure the parameters that are used by the PID controller. The failure to do so will often cause the aircraft to crash on its first flight. These are motor thrust linearization parameters, acceleration values for different axes and filters that go to the input of the PID controller. Experimentally tested the stability of the quadrocopter’s flight in windy weather in navigation modes for firmware Arducopter ver.4.1.5. At wind speeds up to 10 m/s with gusts up to 14-15 m/s, the flight stability was noted in automatic mode and in automatic return to the starting point mode. The high accuracy of the operation of the Ardupilot firmware navigation system was established when the cargo drop point was reached in automatic mode. The error was no more than 1.0-1.5 m at wind speed of 6-7 m/s. The effectiveness of mechanical vibration isolation for flight controllers of the Pixhawk Cube family has been experimentally established. When installing them on the frame of the copter, there is no need to use mechanical vibration decoupling. However, taking into account the low frequency of the frame oscillations from the operation of the propeller group (about 30 Hz), it’s necessary to design the frame with the frequency of natural oscillations outside this range. The using of software dynamic notch filters to reduce the impact of vibrations from running motors on the readings of the accelerometer and gyroscope is considered. On the frame of 2000 mm quadrocopter, it’s shown that such filters significantly reduce the amplitude of not only the detected fundamental frequency, but also their harmonics. The various ways of setting up actuators controlled by servos and relays for dropping loads, switching operating modes by video systems, switching on and off spraying mechanisms when using such drones in agriculture are considered.