Experimental study on the influence of controller firmware on multirotor actuator dynamics

In this paper the dynamic response of a propeller actuator commonly used in hobby unmanned aerial vehicles is studied experimentally. It is shown that the choice of electronic speed controller firmware has a significant effect on the overall actuator dynamics. Six different scenarios are tested: 1+2) Rising/falling step response with the standard firmware of the Hobbyking F30a, 3+4) Rising/falling step response with firmware from Simon Kirby/GitHub and 5+6) Rising/falling step response with firmware from Simon Kirby/GitHub including complementary Pulse-Width-Modulation (PWM) switching. Experimental results show a significant difference in actuator dynamics depending on the chosen firmware. By using firmware with complementary PWM switching, the rising and falling step responses are very similar. Such model symmetry is an advantage for control systems development, both in terms of robustness and performance.