Robust bearing angle estimator for low-cost 1-axis gimballed ultrasonic seeker

Abstract

This paper deals with the bearing angle estimation problem associated with a 1-axis gimballed ultrasonic seeker which can be used as a low-cost sensor for mobile robot applications. Under the assumptions that the target has a ultrasonic transmitter, and the gimbal control loops work properly, the moving target tracking reduces to the estimation problem of a piecewise constant bearing angle using real sinusoids measured by a receiver array mounted on the gimbal. To effectively cope with the real-time implementation issue, the bearing angle estimation problem is formulated in the setting of linear robust state estimation and resolved using the constrained robust weighted least squares (C-RWLS) method. Through simulation results, the proposed scheme provides more reliable and consistent estimation performance than the existing approaches.