Path Planning for Cooperative Aerial Load Transportation in Complex Environments

In this article, a planning algorithm is presented, which is capable to design an overall path in the first stage and determine the formation shape of a cooperative load transportation system forced to move in a spatial hypothetical tunnel (an authorized tunnel), in the second stage. The planning algorithm works in multipassages environment containing obstacles with different shapes and dimensions. The shape of the formation is determined optimally to handle nonconvex constraints like obstacle avoidance, intercollision avoidance between agents and allowable range of cable forces for minimal swing motion. The optimization algorithm also considers the response of the system dynamics and ability of controllers in tracking the optimal path and formation shape. Three types of optimization-based path planning methods are presented called simultaneously all waypoints, waypoint by waypoint (WBW), and waypoints in risk. It is shown that the WBW method presents the best performance in terms of adjustment of the formation shape for passing through narrow passages in complex environment without external or internal collision.