Optic-flow based slope estimation for autonomous landing

Optic-flow based slope estimation for autonomous landing

De Croon, G.C.H.E.
Ho, H.W.
De Wagter, C.
Van Kampen, E.
Remes, B.
Chu, Q.P.

Aerospace Engineering

Control & Operations

2013-09-17

Micro Air Vehicles need to have a robust landing capability, especially when they operate outside line-of-sight. Autonomous landing requires the identification of a relatively flat landing surface that does not have too large an inclination. In this article, a vision algorithm is introduced that fits a second-order approximation to the optic flow field underlying the optic flow vectors in images from a bottom camera. The flow field provides information on the ventral flow (vx/h), the time-to-contact (h/ ? vz), the flatness of the landing surface, and the surface slope. The algorithm is computationally efficient and since it regards the flow field as a whole, it is suitable for use during relatively fast maneuvers. The algorithm is subsequently tested on artificial image sequences, hand-held videos, and on the images made by a Parrot AR drone. In a preliminary robotic experiment, the AR drone uses the vision algorithm to determine when to land in a scenario where it flies off a stairs onto the flat floor.

http://resolver.tudelft.nl/uuid:2470b744-ce1f-4cfc-b268-d8987cfb4bd4

IMAV 2013: Proceedings of the International Micro Air Vehicle Conference and Flight Competition, Toulouse, France, 17-20 September 2013

Institutional Repository

conference paper

(c) 2013 The Author(s)