基于航拍序列图像的输电线弧垂测量方法

Method of Transmission Line Sag Measurement Based on Aerial Image Sequence

弧垂是输电线路运行的一个重要参数,直接关系到电网运行的安全性和可靠性。提出了一种基于直升机巡检时采集的航拍序列图像进行弧垂测量的新方法。选取输电线路上的隔离棒作为识别目标,采用归一化互相关图像匹配算法,结合基于小波的金字塔分层搜索策略,测量出隔离棒中心在序列图像上的像素坐标;然后基于立体视觉技术对隔离棒中心的三维空间坐标进行测量;最后通过最小二乘非线性回归算法,计算出输电线的实际弧垂。实验结果表明该方法可以提高弧垂测量的效率,并且适合在复杂地理条件下应用。

Sag is one of the most important parameters of power transmission line operation; and it will directly affect the security and the reliability of the electric network. A novel method of sag measurement based on aerial image sequence acquired from the helicopter used for the power line inspection was presented in this paper. Firstly, the space-dampers on the transmission line were used as feature points; and the normalized correlation method of image matching combined with the pyramidal layered searching method based on wavelet translation was used to measure the coordinates of the feature points in the sequence images. Secondly, with the stereo vision technology, the three dimensional coordinates of the feature points in the coordinated system were measured. Finally, via the method of least square curve fitting, the actual sag of the transmission line was calculated. The experimental results prove the validity and the feasibility of the proposed method both theoretically and practically; and results also demonstrated that this method can promote the efficiency of sag measurement and can be particularly suitable for complex geographical conditions.