COMPUTER-AIDED DESIGN OF FIXED WING UAV PATH TRACKING SYSTEM

Abstract

In this paper problem of smooth fixed-wing unmanned aerial vehicle path following is considered, when the reference path is the linear piecewise trajectory having points of discontinuity with abrupt changing of the heading angle. The ultimate goal is suppressing deflections of the state vector components, which are dangerous from the flight safety viewpoint, taking in consideration full mathematical model of the inner attitude control loop. The inner attitude control and outer guidance systems consist of the simplest commonly used elements like PD-controllers, washout filters and phase-lead compensators, which parameters have to be found by robust -optimization based on genetic algorithms. In order to avoid over-parameterization of optimization procedure, we propose to solve this problem using its decomposition by two consecutive stages: finding optimal parameters of inner loop at the first stage, and then finding optimal parameters of outer loop at the second stage. We propose to use low pass filter for reference roll signal conditioning, in order to obtain unmanned aerial vehicle smooth pseudo-Dubins flight path. Simulation of unmanned aerial vehicle flight in calm and moderate turbulent atmosphere proves the efficiency of proposed design method.