Targeting at the problems that the navigation of existing underwater vehicles has large time delay and cannot meet the integra-tion of tracking and velocity measurement at the same time,an underwater positioning and velocity measurement method based on one-way acoustic path is proposed. Compared with the traditional long-baseline two-way sound path positioning and ranging,the proposed method is based on the synchronization system of the high-precision atomic clock,and realizes the one-way sound path target ranging and speed measurement. The underwater positioning and speed measurement integrated system is based on fast parallel computing capa-ble FPGA implementation,and the solution result can be completed in microseconds to reduce the delay effectively. Aiming at the inte-gration of target tracking and speed measurement,the underwater vehicle periodically transmits a chirp signal at the time of system syn-chronization,and the underwater beacon receiving array is designed to transform the signals in the time-frequency domain based on the short-time Fourier transform/inverse transform algorithm. Analysis can accurately extract the time of arrival and Doppler frequency offset of the signal,and the underwater beacon array can then calculate the relative relationship between each receiving beacon unit relative to the underwater vehicle within the system synchronization period. The radial velocity and radial distance can realize the tracking velocity measurement of the target. Simulation experiments show that the relative tracking error of this method is controlled at 0.2％,and the rel-ative error of velocity measurement is controlled at 0.8 m/s. The results of the lake test show that the relative tracking error of the pro-posed method is controlled at 5％,and the relative error of velocity measurement is controlled at 0.3 m/s.
关键词
水下通信/FPGA/单程声径/短时傅里叶变换/多普勒频偏/到达时刻
Key words
underwater communication/Field Programmable Gate Array( FPGA)/one-way sound track/Short-Time Fourier Transform ( STFT)/doppler frequency offset/Time Of Arrival( TOA)
维普
万方数据