Multiple quadrotors carrying a flexible hose: dynamics, differential flatness and control
This work addresses cooperative payload transportation for UAV systems, but it is incremental as it builds on existing cable-based transport methods.
The paper tackled the problem of modeling and controlling multiple quadrotors transporting a flexible hose by deriving a coordinate-free dynamics model and showing differential flatness for certain configurations, with validation through numerical simulations.
Using quadrotors UAVs for cooperative payload transportation using cables has been actively gaining interest in recent years. Understanding the dynamics of these complex multi-agent systems would help towards designing safe and reliable systems. In this work, we study one such multi-agent system comprising of multiple quadrotors transporting a flexible hose. We model the hose as a series of smaller discrete links and derive a generalized coordinate-free dynamics for the same. We show that certain configurations of this under-actuated system are differentially-flat. We linearize the dynamics using variation-based linearization and present a linear time-varying LQR to track desired trajectories. Finally, we present numerical simulations to validate the dynamics, flatness, and control.