【作者】 吕冰；

【导师】 乔钢；

【作者基本信息】 哈尔滨工程大学 ， 水声工程， 2011， 硕士

【摘要】 多普勒计程仪是舰船导航设备之一。随着海洋技术的发展,越来越多的国家和机构开始对它进行研究,尤其是适用于深海环境的大深度计程仪。声速补偿曾经是多普勒计程仪精度提高的一个瓶颈,相控阵的应用则从根本上消除了这一问题,使其性能得到很大提高。本文围绕此类多普勒计程仪,从系统角度进行进一步研究。算法上,本文研究了FFT测频、过零法测频和复协方差测频三种方法,通过matlab仿真软件对它们的测频性能进行了对比。软件开发方面,在CCS环境下编写了回波信号模拟器软件,通过采用查表法缩小了DSP计算正弦函数所用的时间,实现了模拟器造数的实时性；研究了整个系统的工作流程,包括系统自检流程、不同水深情况下的回波信号搜索和跟踪算法,在CCS环境下对它们进行编程实现。在VC++6.0环境下,开发了整个系统的显控软件,实现用户与系统交互,实时显示系统工作时的波形和测频结果。数据的后续处理方面,重点研究了数据的平滑处理算法,对于野点剔除和平滑速度问题进行了深入研究。本文末尾,对湖试情况进行了介绍,根据联调和试验情况对各个算法的测频性能和适用情况进行了分析和预测。更多还原

【Abstract】 DVL (Doppler Velocity Log) is one of the navigation equipments on ship. With the development of marine technology, more and more countries and institutions began to study it, especially the one for deep sea environment.Velocity compensation was once a bottleneck to improve the accuracy. The application of phased-array technique on sonar solved this problem in theory, which made the performance of Doppler log greatly improved. In this thesis, we made further study on this kind of Doppler log.In this thesis, three frequency estimation algorithms have been researched:FFT algorithm, Zero-cross algorithm and Complex-covariance algorithm. Their performances in frequency estimation have been compared in matlab simulation environment. In the part of software development, the software of signal simulator was developed on CCS platform. To make sure the simulator’s real-time performance, look-up table algorithm was used which reduced the calculation time of sine function in DSP greatly. The system flow and interfaces between different parts were designed in the DSP control software, including the self-test process, search and follow algorithm in different water depths. And the display and control software which would display the waves and frequency measurement in real-time was developed on Visual C++ platform; it implements user interaction with the system as well. In the part of data process, a lot of work was done on the data smoothing algorithm in this thesis, especially the relation of outliers’elimination and smoothing speed. And last, the situation of the lake test was introduced, and the performances and application conditions of the algorithms were analyzed based on the experimentation condition.更多还原