Robust Bearing Angle Error Estimation for Mobile Robots With a Gimballed Ultrasonic Seeker

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