Transmission Line Identification Methed Of UAV Aerial Image

Transmission lines are usually distributed in the complex environment. The aerial images of power lines are usually subject to interference of the straight edge in background,such as buildings, roads and other lines and so on, when inspect power line using UAV. In order to identify transmission line accurately, a set of power line detection method is proposed.A UAV aerial system of 650 mm wheelbase is build useing Open Source Flight Control PixHawk. The UAV can take aerial equipment, and it can achieve real-time image transmission and data transmission. The image of UAV is the object of study in line detection method. This method has 3 steps. Firstly, preprocess aerial images. Secondly, enhance lines and detect lines by using Hough Transform. At last, detect the sine by using Hough Transform and extract the power transmission lines.Pretreatment of aerial images is mainly to solve the problem of uneven illumination and distortion. Correct the nonlinear distortion of the image base on nonlinear distortion model, and reconstruct the image by gray interpolation. The aerial image is correct by histogram equalization to solve the problem of uneven illumination image. Ultimately, distortionless and uniform brightness images are obtained.Edge detection and line enhancement can be used to extract the pixel on line. Edge detection methods include:Robert algorithm, Prewitt algorithm, Sobel algorithm, Krisch algorithm, LoG Algorithm and Canny algorithm. Line enhancement method include:Radio algorithm and Hessian algorithm. Experiment results showed that Hessian algorithm can extract the linear pixels more efficiently. Detect the lines and get the parameters of the line in polar coordinates.A method of line extraction utilizing the correlation of parameters is proposed in this paper. Obtain relations of the parameters of the transmission line in image based on the relationship between the coordinate of transmission line and coordinate of image firstly. And then, extract transmission lines from the background with interference lines.Finally, the method was verified by experiments. Experiment results showed that the method can eliminate the interference of background line. Demonstrate that the proposed method can improve the robustness.