Software Design Of Embedded System For UV-Visible Dual Spectral Camera

When the corona discharge of the high-voltage transmission accumulation to a certain situation,it will directly damage the transmission equipment,resulting in power supply accidents.Therefore,it is very important to find the location of the corona point as early as possible and as accurate as possible.At present,corona discharge detection methods are the following,respectively,direct observation method,ultrasonic detection method,pulse current method,image analysis method,infrared thermal imaging method and UV detection method.UV imaging method is an ultraviolet detection method,because of its low false alarm rate,small interference noise,high detection efficiency,it becomes a reliable and efficient corona detection method.An ultraviolet-visible dual-spectral camera based on the embedded system is designed to solve three questions of the existing camera of the UV imaging.The three questions are visible image trailing,the UV image and the visible image can not be fused accurately,high power consumption.This embedded system uses A20 ARM processor as a control unit,it can capture both ultraviolet and visible dual video equipment,and fuse the UV signal and visible signal,it can detect the corona point,but also to accurately find the location of the corona.In the design of the embedded system,the main work carried out as followings.(1)Design the system structure.The system allow the UV optical system and the visible optical system as the two inputs,three modes of video output.It's visible optical system can achieve zoom and focus function,and it's UV optical system achieve focus function.It has key-type human-computer interaction.It allows SD card or USB storage.(2)Design the system software.Using the embedded Linux system as the operating system,and Qt as a graphical user interface system,and in the system transplant a variety of image processing tools.(3)Design application software.The image interface is designed by using Qt.The V4L2 structure is used to acquire the two video signals simultaneously.The acquired video signal is divided into ultraviolet signal and visible signal.The acquired ultraviolet signal is filtered and compared with several filters Method.The UV signal and visible signal have been fused with weighted average fusion method.And there are three modes displaying theimage,only displaying UV signal,only displaying visible signal and displaying the fusion of UV signal and visible signal.(4)Correct UV image.In order to allow the UV image and the visible image to be precisely fused,the UV image is corrected using the visible image as a reference image.In the experiment,it is found that the transformation matrix of different detection distance has certain regularity,and the precise fusion of all detection distance can be realized according to the law of this transformation.