Aerospace Guidance, Navigation and Control

Description :
        A decoupled approach to trajectory generation based on a cubic spline geometry formulation is introduced. The distinct consideration of boundary conditions yields a continuously differentiable trajectory definition such that path tracking errors are minimized during flight. A curvature-based, dimensionless space-filling curve allows to determine a suitable velocity profile along the path for hover-capable vehicles. Tracking of the trajectory is enabled by a conversion between the spline parameters and the arc length of the spline. In the past years, this approach in combination with a suitable trajectory tracking control has been successfully flight tested with an unmanned helicopter.

Autonomous flight in densely populated environment like urban terrain generally requires excellent maneuverability. Hence, helicopter-based UAV platforms are preferred. Especially for dynamic high speed flight, changes like moving obstacles or mission updates can require such complex control platforms to be equipped with an on board motion planning system. However, the integrated optimization of a motion planning task can comprise a whole set of hard realtime computations when aspects like task sequence ordering, route planning, reactive obstacle avoidance, and vehicle control are considered.