Autoland Controller Design Procedure based on Total System Error Concept for a Small UAV Aircraft

In this article a design procedure for an automatic landing UAV controller is presented under the precept to achieve a given total system error position accuracy level. An output feedback design procedure is used to determine a set of controller gains for the vertical and lateral motion. In order to adapt the controller accuracy performance as a function of the achieved navigation uncertainty level, the selected set of controller gains is investigated in the framework of a nonlinear autoland simulation incorporating the modeling of specific atmospheric disturbances and sensor error models. The results of these simulations are used to allocate each controller gain set a specific position accuracy level. By governing the selection of the controller gains by the achieved navigation performance, the total system error can be maintained within the prescribed limits and a higher system availability and continuity can be achieved for the autoland manoeuver.