Virtual intersecting location based UAV circumnavigation and bearings-only target-tracking techniques

摘要

The use of agents to circle a moving target and estimate its states with bearing measurements only is a kind of passive tracking technique, and has received wide attention in recent years. However, the performance of the existing estimation and control laws for moving agent are still not so satisfactory when the target position is not known beforehand. In this paper, an unbiased estimator to locate the position of the target and a controller to circumnavigate around the target at a prescribed circular distance are investigated for an unmanned aircraft vehicle (UAV). First, a rough target-state estimator and a rough two-stage saturation UAV circumnavigation strategy are introduced, and their convergence performance is analyzed. Second, a virtual intersecting localization algorithm (VILA) is proposed based on a rough estimation strategy, and then the accurate target-state estimation is obtained with a Kalman filter. Third, the UAV rough circumnavigating strategy is modified with the accurate target-state estimation. By numerical simulation, it is verified that the steady estimation error with VILA is asymptotically unbiased, and the estimation accuracy is much higher than that of the existing estimation methods. It is also proven that the control error by the proposed UAV circumnavigating strategy can asymptotically converge to zero by the modified controller, which is also superior to that for the existing circumnavigating controller. (C) 2019 Elsevier Inc. All rights reserved.