Abstract

PEDDLE, I.K.  and  MILNE, G.W.. Development of a Low Cost Waypoint Navigation Autopilot for an unmanned Aerial Vehicle. R&D j. (Matieland, Online) [online]. 2007, vol.23, pp.18-24. ISSN 2309-8988.

This paper elicited special praise from the reviewers. Sadly, Professor Garth Milne, who played a principal role in South Africa's satellite program, was taken from us too early on 25 May 2007 (ed.) This paper describes the development of a waypoint navigation autopilot for a small Unmanned Aerial Vehicle. The aircraft's nonlinear dynamic model is developed from first principles using only empirical and geometric data. A computationally inexpensive flight control system, based upon output feedback alone, is developed to operate with low cost commercial-off-the-shelf sensors. A novel multiple root loci design method is used to design the longitudinal multiple-input-multiple-output output feedback controller. A computationally inexpensive waypoint navigation algorithm is described. The practical implementation of the autopilot on a microprocessor based avionics package with a total cost of less than R5000 is discussed. Results from three days of flight tests verify the autopilot's practical success. The immediate success can be largely attributed to the controller architecture and the extensive simulation of the entire autopilot in the two nonlinear simulators that were developed.