针对无人机相对机场跑道的位姿估计问题,提出一种利用机场跑道图像和机载位姿测量传感器进行参数后验估计的方法.首先利用高度表、全球定位系统、惯性导航系统等机载传感器测量无人机的位姿参数.假设各参数的测量误差的先验分布已知且彼此独立,将某时刻的一组测量值看作是对真实值的一次采样.与此同时利用机载已标定相机拍摄跑道的图像,并假设两条跑道边缘直线可从图像中准确提取.受两平行直线透视成像的约束,真实参数必然位于参数空间中某个约束曲面上,进而计算得到位姿参数的后验均值估计.仿真结果验证了该方法的有效性.
To estimate UAV (unmanned aerial vehicle) pose relative to airfield runway, a posterior parameter estimation method using the runway image and onboard pose sensors is presented. Firstly, pose parameters of UAV are measured by onboard sensors such as altimeter, GPS (global positioning system) and INS (inertial navigation system). Supposing the prior probability distribution of each parameter's measurement error is given and all errors are independent, the measured values from sensors can be considered as a sample of real ones. At the same time of sampling, an image of the runway is acquired from onboard calibrated camera, and the two edge lines of the runway are assumed to be extracted exactly from the image. Subject to the constraint of the perspective view of two parallel lines, the real parameters must locate on a constraint surface in the parameter space, and thereby the posterior mean estimation of the parameters can be obtained. Simulation results show that the method is effective.