UAV control on the basis of bearing-only observations

This work considers the control of the UAV (unmanned aviation vehicle) on the basis of bearing-only observations including azimuth and elevation angles. During the autonomous mission UAV needs the navigation with the aid of optoelectronic camera or/and with passive radar systems which are able to capture the angular position of objects with known coordinates and to measure the angles of the sight line. Since these measurements involve the real position of UAV in implicit form some of nonlinear filters such as Extended Kalman filter (EKF) or others must be used in order to implement these measurements for UAV control. Meanwhile all these approaches to filtering give the UAV position estimation with unknown and uncontrollable bias [3], [18], which make the precise navigation rather difficult. At the same time there is well-known method of pseudomeasurements which reduces the estimation problem to the linear settings, though these methods have a bias also [7]. In this article we suggest the application of V. S. Pugachev filter [16] to the modified pseudomeasurements method without bias. On its basis the estimation and control algorithms for tracking of given reference path under external perturbation and noised angular measurements have been developed. Another problem of tracking for randomly moving object is also considered and the proposed estimation algorithm shows the good results as well.