水下载体的声学定位系统测距误差分析

Ranging error analysis of acoustic positioning system for underwater vehicle

基于单信标测距的定位方法,是水下载体声学定位技术的进一步发展,但是国内外的研究都是基于定位解算方法本身,研究过程中都是给定一个声学定位系统测距误差.本文针对其中的声学测距进行了研究,首次从水声学原理方面着手分析了影响声学测距的误差源以及各误差源对测距误差和定位精度的影响程度.首先分析了声信号传播速度的影响,无论是声速测量误差还是声线弯曲影响,测距误差都表现为一种随水平距离增加而增大的固定误差,水平定位误差在几十厘米的水平;然后分析了声信号传播介质的影响,环境噪声、信号混响和多途会造成信号检测与时延估计误差,测距误差的大小与时延估计误差成正比,水平定位误差与测时误差引起的测距误差大小相当;最后分析了声信号发射接收异步的影响,测距误差的大小既与载体航行速度成正比,也与发射点距信标与航迹垂线的距离成正比,水平定位误差的大小与载体航行速度成正比,载体航行速度1m·s-1的情况下水平定位误差就达到了几米的水平,必须针对发射接收异步的情况进行补偿.

Positioning method based on single beacon ranging is the further development of positioning technology . But most of the researches at home and abroad are based on the positioning algorithm itself ,the research process is given an acoustic ranging error .The acoustic ranging is studied in this paper .The error source of acoustic ranging is analyzed from the aspect of the principle of acoustic for the first time .And the influence degree of each error source on the ranging error and positioning accuracy is analyzed .Firstly ,the influence of acoustic signal propagation speed is analyzed ,the range error is shown as a fixed error which increases with the increase of the horizontal distance ,no matter caused by sound velocity measurement error or sound line inversion .Horizontal positioning error is at the level of tens of centimeters .And then analyze the effect of acoustic signal propagation medium .Environmental noise ,＆amp;nbsp;reverberation and multi‐path signal will cause the signal detection and time delay estimation error .The size of time delay estimation error is proportional to the distance error .The horizontal positioning error is about the same as the ranging error .Finally ,the influence of acoustic signal transmitting and receiving asynchronous is analyzed .The size of the ranging error is proportional to the speed of the carrier .Horizontal positioning error is relatively large at the level of a few meters .