一种改进的UAV高度无缝融合导航方法

A modified seamless height fusion navigation method of UAV

为了解决无人飞行器多机载高度传感器直接使用和切换导致的信号突变的问题,提出了一种基于微惯性器件、GPS、声纳、气压高度计的高度无缝融合方法。建立声纳和气压高度计误差模型,对其动态误差进行了分析和滤波预处理。采用基于增量的无缝融合方法获取高度变化估计值以修正气压高度。利用无迹卡尔曼滤波(UKF)方法将气压高度计、GPS和惯性导航系统信息进行有效融合获得精确的高度估计值。该方法考虑了各种高度传感器在动态环境下的误差特性,解决了模式切换带来的信号突变问题。飞行试验结果表明:采用该设计的方法系统具有较高的精度和可靠性。经过150 s飞行后,高度估计误差为0.470 7 m,能够满足无人飞行器飞行要求。

To solve problem of data jitter caused by direct usage and switch of various altitude sensors on unmanned aerial vehicle （UAV）, a seamless altitude fusion method is proposed based on micro inertial device/ GPS/sonar/barometric altimeter. Error models for sonar and barometric altimeter are established, and dynamic errors are analyzed and preproeessed. With seamless fusion method, altitude variation is obtained to calibrate barometric height. To get more accurate altitude, data of barometric altimeter, GPS and inertial navigation system are effectively fused by unscented Kalman filtering （UKF） method. This method takes error characteristics of various height sensors into consideration, can solve jitter problem when modes switching. Flight experimental result shows that designed system has high precision and reliability after fly for 150 s, error of altitude estimation obtained by this method reaches to 0. 470 7 m. It can meet flight requirement of UAV.