Smooth Path Planning for Unmanned Aerial Vehicles with Airspace Restrictions

The problem of generating smooth paths in a bounded airspace having arbitrarily shaped flight-restricted zones and obstacles is considered. Paths derived from four-parameter logistic curves are investigated as a prospective solution. Flight-restricted areas and obstacles are represented by convex polygons, and simple analytic conditions are derived for avoiding them. A design parameter space approach is used to generate multiple feasible paths between a given set of waypoints with zero end curvature. The proposed methodology offers continuous upper curvature bounded paths, which are desirable for the bank angle limitation of unmanned aerial vehicles. A comparison with existing path-planning methods highlights the advantages in terms of inherent curvature continuity as well as analytic conditions for obstacle avoidance and confinement. Scenarios with multiple obstacles and waypoints are considered, and the solutions are validated on a realistic six-degree-of-freedom model of the Aerosonde unmanned aerial vehicle. The methodology offers a simple and analytic path-planning methodology for generating easily computable multiple feasible paths satisfying the noted constraints.