Abstract
Multi-rotor flying vehicles (MRFVs) are increasingly becoming the preferred means of transportation in various civilian and military applications, such as mine detection, reconnaissance missions, agriculture, and load transfer to areas inaccessible to ground vehicles. In these applications, the payload is suspended underneath the vehicle and subjected to large oscillations because of external disturbances or the vehicle's acceleration. This study proposes an anti-swing controller (ASC) based on time-delayed feedback of the load swing angles to be implemented in MRFVs with suspended load and operated by a PX4 autopilot. The PX4 autopilot is now widely used in commercial drones. The implementation of the proposed ASC does not require any modifications to the original PX4 firmware because it adds additional displacements to the original trajectories of MRFVs. The effectiveness of the ASC is evaluated by simulating a quadrotor as an example of MRFVs with different flight conditions.