基于惯导及声学浮标辅助的水下航行器导航定位系统

针对纯惯导系统误差发散和无线电信号在水下衰减快从而无法精确定位的问题,设计了一种基于声学浮标辅助惯导的水下定位系统,该系统由惯导系统和声学定位系统组成,其中声学定位系统由若干个浮标构成水听器阵,浮标的经纬度坐标由GPS提供,浮标完成对接收到的声源信号的处理,利用互相关测时延差的方法来进行定位。由于水下噪声、混响等因素会造成接收到的多路声信号出现模糊互相关峰,因此对接收信号应进行频域加权处理。最后利用声学系统的定位信息来校正惯导的误差。仿真结果表明:与基本互相关方法相比,加权处理能有效提高时延差的精度,所提出的惯导和声学浮标辅助设备导航系统能够使定位误差小于2 m,保证了水下航行器能够长时间在水下航行。

Underwater positioning system based on INS and acoustic buoy system for underwater vehicle

In view of the divergence of INS (inertial navigation system) errors and the attenuation of radio signals in underwater,an underwater positioning system is designed based on the INS aided by acoustic buoy system.The acoustic positioning system consists of several buoys whose locations are provided by GPS.The buoys receive acoustic signal from the signal source and provide the position of AUV by using the cross-correlation method to measure the time delay difference.Owing to the fuzzy correlation peaks caused by propagation noise,reverberation and other factors,the received signals are filtered by a frequency domain weighted algorithm.The position estimated by the acoustic positioning system can be used to correct the error of the inertial navigation system.Simulation results show that,compared to the basic cross-correlation method,the frequency domain weighted algorithm can effectively improve the accuracy of time delay difference,and the positioning precision is superior to 2m by using the proposed navigation system,which can guarantee the vehicle's long time underwater navigation.