基于宇宙线缪子探测的水下定位方法研究

Research on underwater positioning method based on cosmic muons detection

水下航行器长时高精度导航定位是一个具有挑战性的问题。传统导航手段,如全球卫星导航、惯性导航、基于光学测量的天文导航等,在信号遮挡或长期运行等应用条件下存在局限性。针对上述问题,研究基于宇宙线缪子探测的水下定位方法,分别在水面和水下航行器上配置参考缪子探测器和载体缪子探测器,测量缪子信号到达参考缪子探测器和载体缪子探测器的时间之差(Time Difference of Arrival,TDOA),根据TDOA观测量和参考缪子探测器先验信息,估计得到载体缪子探测器的位置。设计了基于缪子探测器和惯性测量单元(Inertial Measurement Unit,IMU)的水下航行器全参数导航解算方法,建立了面向卡尔曼滤波器(Kalman Filter,KF)设计及系统性能分析的状态方程和观测方程,通过计算导航系统的克拉美劳下界(Cramer-Rao Lower Bound,CRLB)考察了缪子-惯性组合导航方法用于水下定位的潜在性能。数学仿真研究表明,面向水下航行器的缪子定位系统(Muon Positioning System,μPS)能够达到分米量级的精度水平。

Long-term and high-accuracy navigation for underwater vehicles is a challenging problem.In the case of signal occlusion or long-term operation,there are limitations for the traditional navigation approaches,such as global satellite navigation,inertial navigation and celestial navigation based on optical measurement.In order to cope with these problems,the underwater positioning method based on cosmic muons detection is studied.In the method,multiple reference muon detectors and a vehicle muon detector areconfigured on the surface and underwater vehicle respectively.The time difference of arrival(TDOA)of a muon between the reference and vehicle muon detectors is measured.Then the position of the vehicle muon detector is estimated according to the TDOA measurement and the prior information of the reference muon detectors.The state equation and the observation equation are established for the navigation filtering design and navigation performance analysis.The potential performance of the muon-inertial integrated navigation method for underwater vehicles is investigated by calculating the Cramer-Rao lower bound(CRLB)of the navigation system.In addition,an all-parameter navigation algorithm is designed based on the muon detectors,inertial measurement unit(IMU)and Kalman filter(KF).Through numerical simulations,it shows that the accuracy of the muon positioning system(μPS)is on the order of a few decimeters.