Power line inspection using segment measurement based on HT butterfly

This paper addresses the segment detection and measurement based on Hough Transform (HT) for unmanned aerial vehicle (UAV) power line inspection. We consider the fact that power lines usually turn their direction when they cross poles due to the gravity or designed corners, so straight line segment detection should be employed instead of simple straight line detection for these cases. Hough Transform (HT) butterflies are found suitable for image-based segments detection and measurement. The parameters of segments such as the position, the slope, the length are related to the features of the HT butterflies. Mathematical analysis is presented to demonstrate and build the relationship between the segment parameters measurement and the features of the HT butterflies. The application shows the proposed method is effective for power line inspection especially for corner detection when they cross poles.