弱纹理条件下无人机姿态参数估计

基于视觉定位的无人机在弱纹理环境下,位置容易产生漂移,针对该问题,提出一种基于改进Snake算法与ORB(oriented FAST and rotated BRIEF)特征光流相结合的方法,对无人机运行参数进行估计,从而改善漂移.首先,采用高斯滤波对采集视频帧进行去噪处理;然后,计算视频帧灰度共生矩阵,判断是否均处于...

Attitude Parameter Estimation of UAV under Weak Texture Condition

Unmanned aerial vehicle (UAV) based on visual positioning is prone to drift in a weak texture environment. To solve the problem, this study proposes a method integrating the improved Snake algorithm and ORB (oriented FAST and rotated BRIEF) feature optical flow to estimate the operating parameters of UAV. Firstly, Gaussian filtering is used to denoise the collected video frames. Then, the gray level co-occurrence matrix of video frames is calculated, and whether they are all in the weak texture area is judged. If they are all weak texture parts, ORB optical flow algorithm is used to estimate the parameters. If there is a non-weak texture area, the center of gravity of the area is calculated by the improved Snake model, by which the drift is estimated. With the homography matrix, the rotation component is obtained by decomposition. Laboratory experiments verify that the accuracy of parameter estimation is higher than 95% and the average processing time is as short as 0.025 s in both weak and non-weak texture areas.