Gradient-Based Online Trajectory Planning for Quadrotor Transportation Systems

Trajectory planning has been an important research area for quadrotor transportation systems for a long time. However, generating feasible trajectories in real-time that allow quadrotor transportation systems to navigate safely in complex environments remains a challenging issue. This article proposes an efficient gradient-based safety constraint that helps keep the system away from obstacles. Furthermore, this paper combines safety constraint with a novel B-spline-based optimization method that utilizes an improved hybrid-state A* algorithm for path searching to generate desired trajectory. Strategies to speed up path searching and unconstrained optimization problem constructed in B-spline optimization guarantee the computational efficiency. The feasibility of the resulting trajectory has been verified through simulation.