Optimization Method of UUV Maneuvering Target Bearing-Only Tracking for Best Observation With a Flank Array

In response to the problems encountered during underwater bearing-only target tracking (BOTT), namely, the increase in the actual measurement error of the flank array as the target's relative azimuth deviates from the unmanned underwater vehicle (UUV) abeam direction and the poor tracking performance due to the endfire saturation region of the flank array, a path optimization method for UUV tracking of maneuvering targets that is specifically oriented toward achieving the best observation by the flank array is designed. A system model is established, and the variation in measurement accuracy with respect to the relative azimuth of the target is analyzed and modeled. The maneuvering target is detected when the sonar accuracy changes in real time. According to the bearing-only information measured, the target state is estimated by matching the measurement noise variance with the sonar measurement error in real time. On the basis of the estimated state, the best observation method is used to generate the maneuvering trajectory of the UUV online to reduce measurement noise during target detection. Constraints related to the endfire saturation region are also considered to avoid situations where the target becomes unobservable. The simulation results show that the proposed method can achieve persistent target tracking while considering the actual characteristics of the flank array.