0000000000680784
AUTHOR
Oyvind Magnussen
Experimental validation of a quaternion-based attitude estimation with direct input to a quadcopter control system
This paper presents a method to calculate the attitude quaternion of a quadcopter with few calculations. The quaternion calculation is based on accelerometers and gyroscopes from an Inertial Measurement Unit (IMU). The quaternion from the accelerometer is calculated as the shortest rotation arc from the gravity vector in the navigation frame. The quaternion from the gyroscope is calculated based on equations of the quaternion derivative. A complementary filter is combining the two quaternions with a componentwise comparison. The attitude estimation is calculated without any trigonometric functions. The quaternion is directly used as an input to the attitude controller. The attitude controll…
Multicopter UAV design optimization
Designing and selecting hardware for a multirotor can be challenging in order to get the best flight performance out of the system. In addition to selecting the hardware, the number of actuators can also be altered. For a 4 actuator (quadrotor) setup, one set of hardware can give the optimal design, while for a 6 actuator setup (hexarotor) the same hardware may not necessarily give the same response. In this paper we present a design optimization process of a multirotor, where the hardware is selected from a set of low-cost off-the-shelf standard RC hobby parts. Constraining the problem to a given hardware ensures existence of the selected hardware, and the design can be implemented. Also t…
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. …