In the high voltage domain, the Corona discharge represents one of the most disturbing problems for the companies that transport electricity. Corona discharge is an electrical discharge brought on by the ionization of a fluid surrounding a conductor that is electrically energized. To combat this phenomenon it is necessary to keep high voltage power lines under surveillance and try to maintain losses at a reasonable value. The best manner to do this thing is by using a fixed-wing unmanned aircraft vehicle having on board the necessary sensors for detecting Corona discharge. In this paper we will focus on extracting and detecting high voltage lines from the images received from an UAV which will be analyzed using a number ofMATLAB functions. To detect lines into an image the Radon transformwill be used which is an integral transform that maps a function to its integrals over lines.

In this paper, an altitude control system is designed to increase the positioning accuracy of a mini-UAV on the z-axis of the inertial system and to improve conventional altitude control systems relying only on GPS, barometer or laser sensors which may have significant errors in certain flight conditions. The main objective of the mini-UAV is to monitor and detect a Corona Discharge that usually occurs on high voltage powerlines which implies a very good infrastructure in terms of on-board equipment because of the danger which occur when UAV flies quite close to the powerlines and into an intense electromagnetic field. To design the altitude controller for the longitudinal dynamics a control structure method, based on successively closed loops with different types of classic controllers was used. We concluded that the command structures with speed constraint was necessary to implement a speed device that automatically maintains a constant speed. Thus, the speed device is trying to maintain a constant speed using the throttle control. After modelling the longitudinal dynamics, numerical simulations were performed in MATLAB, Simulink and the obtained results confirmed a good performance of the proposed control strategy flight altitude control based on the automated speed device.