Relative Heading Estimation and Its Application in Target Handoff in GPS-Denied Environments

摘要

In this paper, we address the problem of target handoff between two fixed wing aircrafts that do not have access to Global Positioning Systems. The problem requires estimating the relative pose between the vehicles. We assume that onboard inertial measurement units can provide roll and pitch estimates of the aircraft attitude. We examine the observability of other relative states needed to do the handoff problem. In particular, we consider two different scenarios. In the first scenario, we assume that the relative position between the aircrafts is measured, as would be the case for a radar or a lidar sensor. We assume that the two aircrafts do not exchange their airspeed and turn rate information. Under mild assumptions, we show that the relative heading between the two aircrafts is observable. In the second scenario, we assume that only the bearing angle between the two aircrafts is measured, as would be the case for a vision sensor. We prove state observability for maneuvers that are relevant to target tracking and handoff. We also present an estimation algorithm that uses a bank of extended Kalman filters to estimate the relative states. Simulation results with full vehicle dynamics demonstrate the feasibility of the proposed approach.