Research On Methods For Recognition And Status Detection Of Power Line Based On Aerial Images

Through power lines electric power goes where it is needed, it is laden with responsibility. Power line inspection at stated intervals is is an effective means of realizing status detection, and it is is of significance for the safe operation of power grid. In this paper, the aerial surveying technique is introduced to power line inspection, and a method for recognition and status detection of power line based on aerial images is proposed to impove the timeliness on the inspection information processing of power line. The preprocessing method of aerial image and the methods for recognition and status detection of transmission line and insulator are studied in this paper. The main work is done as follows.1. According to the actual situation of aerial image, the preprocessing method is studied. By using optical correction, it can be improved the brightness unbanlanced and contrast descending of aerial images because of the light conditions changing. Due to the serious noise jamming and motion blurring in aerial image, an improved Weiner filtering algorithm with wavelet de-noising is proposed based on the image quality evaluation function, and it can produce the better filtering effect and enhance the quality of image restoration.2. The background of aerial image is very complex, and the background objects will change their appearance under the different conditions. An algorithm is put forward to extract and recognize power lines from natural complex background: a developed Canny operator is used to realize preparatory image segmentation, and an adaptive Hough transform combined with mathematical morphology method is studied to extract and recognize the power lines by setting proper threshold values of length and width.3. On the basis of power lines extraction and recognition in aerial image, a novel method for transmission line sag measurement based on active vision is proposed. Considering the process of aerial image acquisition is an active vision process, by the application of 3D reconstruction and GPS technology, the space curve model of power line has been constructed, and then the sag of power line can be calculated with this model. After the influences on the measuring accuracy of all parts of measurement system being analyzed in detail, the methods to eliminate the influences are proposed and identified. The experimental results have demonstrated accuracy and effectiveness of this method.4. Analyzing of the essential features of insulator, the description methods of insulator are presented by using color feature, shape feature, invariant moment feature and wavelet coefficients feature. A new approach of insulator recognition and status detection from aerial image is put forward based on multiple features information fusion, and the information fusion system based on RBF neural network is accomplished. On the basis of information fusion system, the recognition and status detection of insulator has been implemented. By the corresponding algorithms, the common faults of insulator have been diagnosed, such as string breakage, pollution, crack, icing and snow covering. The experiment results show that the method has the advantages of high correct detecting probability, strong antinoise ability and a good application prospects.