Cooperative Shared-Load Carrying by Quadrotors
(6.8210 Final Project)
In our final project, we implement and test a set of control strategies for a multiple-quadrotor team to carry a slung load. Our goals are to stabilize the system to a set equilibrium point and to compute and stabilize to a dynamically-feasible trajectory specified by user-supplied waypoints. We derive a system model with hybrid dynamics, where the carrying cables are modeled as springs. To stabilize the system, we solve a nonlinear mathematical program to find an equilibrium point and compute a finite-horizon LQR controller. To construct trajectories through waypoints, we show that our system is differentially flat. We solve a quadratic program to find a piecewise-polynomial trajectory in the system’s output space and use a finite-horizon LQR controller to stabilize to the trajectory.