Algorithm for holding the UAV course by redistributing control signals

Nersisyan Nerses Grachevich

For multicopters that are UAVs with three or more rotors, the output control signal is a PWM (Pulse Width Modulation) signal, which determines the value of the angular velocity of a given motor. The purpose of the article is show that redistributing the output PWM signals with a certain function depending on the value of the yaw angle, the UAV will maintain its original direction, thus ignoring the rotation around its own axis. As a result of the given equations, the angular movements of the UAV can be observed with respect to a stationary coordinate system. The task is to bring a new algorithm for keeping the course of an unmanned aerial vehicle (UAV) when the yaw angle changes. The given functions are periodic; they transfer the PWM value of the given motor; therefore, the value of the angular velocity to the next motor. The transferred value of depends on the size of the yaw angle. The algorithm simplifies the control of UAVs, as the yaw angle is ignored, and it is sufficient to set only the desired pitch and roll angles or angular velocities. As a result, the algorithm can be integrated into the UAV control system as a separate block, with the control PWM signals at the input, and the new PWM values at the output, which are given to the motor speed controllers.

Keywords:unmanned aerial vehicle, quadcopter, algorithm, redistribution, direction, yaw, pwm