Real-Time Optimal Trajectory Generation for a Quadrotor with a Cable-Suspended Payload

The quadrotor system with a suspended payload expands the range of applications for quadrotors, playing a significant role in scenarios such as cargo transportation and rescue missions. However, trajectory planning for suspendedload unmanned aerial vehicles in complex environments remains a challenging task. In this paper, we propose a framework for rapidly generating optimal trajectories that minimize payload swing and maximize stability. The trajectory planning problem is decomposed into two main parts: front-end path search and backend nonlinear trajectory optimization. The front-end generates an initial collision-free path without considering the payload swing. The back-end employs a gradient-based optimization algorithm to enhance the trajectory's smoothness while taking into account the feasibility of the trajectory and the swing dynamics of the suspended payload. This method ensures that the quadrotor maintains stability while tracking the trajectory, optimizing the overall system performance. The proposed approach is validated in complex simulation environments, verifying its feasibility and real-time response in the quadrotor system.