【作者】 吕召鹏；

【导师】 吴美平；

【作者基本信息】 国防科学技术大学 ， 控制科学与工程， 2011， 硕士

【摘要】 SINS/DVL组合导航系统利用DVL提供的高精度速度信息抑制捷联惯导系统的误差积累,是目前广泛应用的水下组合导航技术。然而,在工程实践中有两大因素制约着SINS/DVL组合导航定位精度:一是DVL与IMU之间的安装标校误差;另一个是DVL自身测速误差。针对以上两大问题,本文从以下几个方面对SINS/DVL组合导航技术进行了研究:1、推导并建立了基于安装误差角和刻度因子误差在线估计的SINS/DVL组合导航系统误差模型。在建立组合导航系统误差模型的过程中,首先推导了捷联惯导系统误差模型;然后建立了基于安装误差角和刻度因子误差的DVL误差模型;最后在捷联惯导系统误差模型和DVL误差模型的基础上,建立了基于安装误差角和刻度因子误差在线估计的组合导航系统误差模型。2、利用非线性全局可观性理论,分析了组合导航系统的可观性。通过可观性分析,可以得到组合导航系统模型状态量的可估计性,在理论上说明组合导航系统误差模型的合理性。利用全局可观性分析得出了如下主要结论:若载体运动满足姿态不变,比力变化,则刻度因子可观;载体做匀速直线运动,并且只考虑偏航方向安装角以及天向速度为零,则航向安装角可观;载体运动满足姿态不变,比力变化,且不同时刻比力导数线性无关,则安装角可观。文中还利用仿真实验验证了可观性分析的结论。3、通过船载试验对SINS/DVL组合导航系统模型进行了验证。在常规的船体行驶速度条件下,刻度因子误差导致的测速误差通常很小,所以在船载试验中忽略了刻度因子误差的影响。在船载试验结果分析中,首先利用迭代递推的方法得出如下结论:基于安装误差角和刻度因子误差补偿的组合导航系统模型可以有效提高SINS/DVL组合导航的定位精度。然后分析了基于安装误差角在线估计的SINS/DVL组合导航系统的导航结果,结果表明,安装误差角在线估计方法可以有效估计出安装误差角,在线解决IMU与DVL的安装标校问题,提高SINS/DVL组合导航定位精度,在工程实践中具有一定的实用性。更多还原

【Abstract】 SINS/DVL integrated navigation system using the high accurate velocity offered by DVL to restrain the error accumulation of SINS is a widely-used under-water integrated navigation technology. However, there are still two main factors restricting the positioning accuracy of it. One is the misalignment between IMU and DVL. The other one is velocity error of DVL itself. For the two factors, researches on SINS/DVL integrated navigation technology have been done as the following aspects:1. The error model of SINS/DVL based on online estimation of misalignment angles and scale factor error is deduced. In the process of deducing,firstly, the error model of the SINS is deduced. Then, the error model of DVL based on misalignment angles and scale factor error is designed. Finally, the error model of SINS/DVL based on online estimation of misalignment angles and scale factor error is composed of the error model of SINS and the error model of DVL.2. The nonlinear global observability analysis approach is used to analyze the observability of SINS/DVL integrated navigation system. Though observability analysis, the estimatility of state variables in the integrated model is proved,and the rationalioty of the model is shown. The main conclusions are presented as following: the scale factor is observable when the carrier takes a movement with constant attitude and time-varying special force.And if the yaw-direction misalignment angle is only considered and the upward velocity is zero, the yaw-direction misalignment angle is observable when the carrier takes an linear movement with constant velocity. And the misalignment angles are observable when the carrier takes a movement with constant attitude and time-varying special force and linearly independent derivatives of special force for different time. The above conclusions are supported by simulations results.3. The error model of SINS/DVL is validated by vessel tests. The scale factor error is neglected in vessel tests because its influnce is very small when the vessel moves in normal speed. In the analysis of vessel tests, firstly,using calibration method, we attain the conclusion that the positioning accuracy is improved greatly after compensating by the integrated model based on misalignment angle and scale factor. Then, the navigation result of SINS/DVL based on online estimation of misalignment angle is analyzed, which shows that the online estimation method could effectively estimate the misalignment angle to slove the misalignment between IMU and DVL online, and improve the positioning accuracy of SINS/DVL, which could be usefull in the project.更多还原