Recent advances and challenges in controlling quadrotors with suspended loads

Quadrotors have been utilized in a variety of applications where the payload needs to be transferred from one location to another, such as in mine detection, load delivery through hazardous environments, or locations that are inaccessible to ground vehicles. In these applications, the payload will be suspended underneath the vehicle and is subjected to large oscillations due to external disturbances or the acceleration of the vehicle itself. In this article, the most recent advancements in controlling the quadrotors vehicles with suspended loads are presented including control algorithms and techniques to implement these controllers. These techniques include the hardware and sensors besides the testing techniques for the developed control algorithms.