【作者】 黄卫权； 王振旭； 孙硕；

【Author】 Huang Weiquan;Wang Zhenxu;Sun Shuo;School of Intelligent Science and Engineering,Harbin Engineering University;

【机构】 哈尔滨工程大学智能科学与工程学院；

【摘要】 在水下捷联惯性导航系统(SINS)与声学多普勒计程仪(DVL)组合导航系统中,导航精度很大程度上取决于DVL的测速性能。目前国内顶尖水平的DVL测速精度约为±0.2%±0.2cm/s,这一精度限制已成为提升水下潜器导航精度的瓶颈。同时,DVL工作时需要主动发射声波信号,影响了水下潜器的隐蔽性。为解决上述问题,提高水下潜器的测速精度与隐蔽性,借鉴了车载激光多普勒测速仪(LDV)的参考光结构光路,提出了基于光纤组建的水下LDV方案。光学上采用基于532nm波长单纵模激光的参考光结构,通过高灵敏度光电二极管和高速AD转换芯片实现微弱信号采集;在信号处理方面,基于FPGA硬件平台,运用数字锁相环技术实现多普勒信号的高精度解调,从而依据多普勒频移原理精确解算载体运动速度。实验验证表明,所提出的水下光纤LDV方案的测速精度优于DVL。更多还原

【Abstract】 In the integrated navigation system combining Strapdown Inertial Navigation System(SINS) a nd Acoustic Doppler Current Profiler(DVL) for underwater applications,navigation accuracy largely dep ends on the velocity measurement performance of the DVL.Currently,the top-tier DVLs in China offer a velocity measurement accuracy of approximately ±0.2% ±0.2 cm/s,which has become a bottleneck for improving the navigation precision of underwater vehicles.Additionally,the DVL’s operation requires activ e acoustic signal emission,compromising the stealth of underwater vehicles.To address these issues and e nhance both the velocity measurement accuracy and stealth of underwater vehicles,an underwater Laser Doppler Velocimeter(LDV) scheme based on optical fiber configuration was proposed,drawing inspiratio n from the reference-beam optical path of vehicular LDVs.Optically,the design employs a reference-beam structure using a 532 nm single-longitudinal-mode laser,with weak signal acquisition achieved through h igh-sensitivity photodiodes and high-speed analog-to-digital(AD) conversion chips.For signal processing,t he system utilizes a Field-Programmable Gate Array(FPGA) hardware platform and applies digital phase-locked loop(PLL) technology to achieve high-precision demodulation of Doppler signals,thereby accurat ely calculating the vehicle’s velocity based on the Doppler shift principle.Experimental validation demons trates that the proposed underwater fiber-optic LDV scheme achieves superior velocity measurement accur acy compared to DVLs.更多还原