Design Of Underground Analog High-Definition IPC Coding Board Module

VideoLog oil and gas well visual detection technology is a front technology that directly obtains real-time video images from downhole.The IPC coding board module is mainly responsible for compressing and encoding the images collected by the camera,and then transmitting them to the cable transmission module,it is an important component of the Video Log downhole visual logging instruments.With the application of Video Log visual logging system in practical engineering,it is found that the existing array cameras use digital interface to connect the coding board,which leads to too many lines needed in the process of transmitting signals,and the coding board module cannot be put into the insulation equipment at the back end of the downhole instrument.and the coding board does not support dual-channel stream transmission function,does not support video storage function.to address these issues,this paper uses NVP6124 B as the analog camera receiving chip and Hi3516EV300 as the encoding chip to independently design a new generation of Video Log downhole TV-specific analog IPC encoding board module,which can receive video signals collected by AHD(high-definition analog)cameras and supports dual stream encoding and video storage functions.The main work of the paper is as follows:(1)The composition of VideoLog visual logging system is introduced,and the video coding technology and network transmission technology are described.the overall design scheme of downhole simulation high-definition IPC coding board module is proposed.According to the development requirements of Video Log visual logging system,the technical indicators of the analog IPC coding board module are made,and the chip of each module is selected according to the technical indicators.Combined with the overall design scheme,the design scheme of each module is completed.(2)The hardware design of the underground analog high-definition IPC coding board module is completed,and the reception,coding and transmission of AHD protocol video images are realized.Related interface circuit designs were completed based on the IPC encoding main chip Hi3516EV300.including the main chip minimum system design,NVP6124 B conversion circuit design,serial port module design,ethernet module design,NAND Flash module design,and storage module design.According to the power-on timing requirements of Hi3516EV300,the power supply module of the encoding board module was also designed.(3)The software design of underground simulation HD IPC coding board module is completed,firstly,the software development of the module is designed.then ported the Linux operating system to the encoding board,and according to the overall block diagram of software design,the video coding program,video transmission program and video parameter configuration program of IPC coding board module are designed in turn.The various parameters of the analog IPC encoding board module are tested in a laboratory environment,it is verified that the coding board module can receive high-definition images collected by the AHD camera,and can support real-time playback of color video with a resolution of 1280 × 960 and a frame rate of 30 Fps.and the results verified that the encoder board module can achieve dual-stream video transmission,serial communication,and video storage in a local area network.It can also transmit video images normally in high-temperature environments,and the hardware and software of the encoding board are functioning properly,The results of the tested show that the module meets all design specifications.