Research On Key Technologies Of Long-distance Image And Audio Sensor Online Monitoring System

The Internet of Things is a highly integrated and comprehensive application of a new generation of information technology,which is of great significance to a new round of industrial transformation and the green,intelligent and sustainable development of the economy and society.In this context,the concept of "Ubiquitous Power Internet of Things" has been proposed,and overhead line status perception has become an important part of it.The hazard of icing to overhead lines has been verified in the 2008 severe snowstorm.At present,sound and image monitoring is an important method for ice monitoring,but the traditional energy supply method has the disadvantage of instability.In addition,the collected images are too redundant and the amount of data is too large,resulting in unstable transmission.Therefore,this thesis adopts the method of optical fiber energy transmission to supply energy for the audio and image sensor.Optical fiber transmission has the characteristics of greener,safer,more stable and longer distance transmission.In addition,this thesis also utilizes discrete cosine Fourier transform(DCT)to compress the collected images.Compared with other compression methods,the DCT transform occupies less memory and is more in line with the requirements of the current commonly used hardware systems.Therefore,it is of great significance to study a set of long-distance image and audio sensor online monitoring system based on optical fiber energy transmission.The main research contents of this thesis are as follows:(1)A system scheme for co-transmission of long-distance energy and communication based on optical fiber energy transmission is designed.The system uses wavelength division multiplexing technology to transmit energy and information in the same fiber,and provides long-distance stable energy supply for the load.The system has the ability to output 57mW of electrical power and transmit information at a rate of 1Gbps when the incident optical power is 500mW and the optical fiber transmission distance is 10km.(2)Developed a low-power video and audio node.Aiming at the limitation that the output power of the energy transfer system is low and the ordinary nodes cannot work stably,this thesis adopts the power management and intermittent working mode to ensure the stable operation of the nodes in the system.(3)A DCT algorithm suitable for this system is designed to compress images.Since the information collected by the image sensor occupies a large amount of memory,the problem of long time for sensor energy supply and charging often occurs during the transmission process.In this thesis,the DCT algorithm is used to transform the scheme.After the block,quantization,and encoding,on the basis of the basic restoration of the image,the compression ratio of the image is increased to 8,so that the real-time performance of the system acquisition is guaranteed.