Performance Comparisons on Fully-Actuated Multirotors with Different Actuation Modes

Caleb Probine, Karl A. Stol

Abstract:

For the interaction of Unmanned Aerial Vehicles (UAVs) with the environment, their ability to station-keep is critical. In conventional
station keeping, a UAV will change attitude to
translate, and reject disturbances. Meanwhile, a
fully-actuated UAV can exert these forces without rolling or pitching: this is also known as
vectored thrust. These two methods of position
control represent two actuation modes, with very
different dynamics. The work presented in this
paper investigates how Proportional-IntegralDerivative (PID) controllers can be tuned to
compare the two actuation modes discussed in
wind disturbance rejection tasks. The comparison is made fair by ensuring that actuator usage is the same between the two cases. Overall, when tuned for moderate control precision,
it is found that the actuator usage is significantly higher when vectored thrust is used, making it less favourable for general station keeping tasks. However, linear model studies indicate
that higher precision may necessitate the use of
vectored thrust, rather than conventional methods.