Design And Implementation Of Real-time High-speed Data Acquisition And Processing System For Radar In Mine

Underground mineral resources such as petroleum,natural gas and coal play a vital role in China's industrial development.At present,the mining area of mineral resources in China is gradually expanding and the mining efficiency and quality are gradually improved.As a very effective tool to detect the distribution of underground resources,the transient pulse well radar has been widely used.As a branch of transient pulse radar,inhole radar can go deep into underground mines,mainly solve the distribution problem of material around the well,and has the advantage of advanced detection.The traditional well radar adopts the system receiver,data acquisition board,and the data transmission adopts the separated structure.The signal received by the receiver is transmitted to the data acquisition unit through the cable for collection.This kind of system architecture has low integration degree,the signal attenuation in the transmission process is great and easy to be affected by electromagnetic interference.Because the underground radar moves slowly,the traditional sampling scheme is equivalent sampling,in which the target signal is equivalent to the exact same pulse signal,ignoring the random jitter of the actual signal.Therefore,it is necessary to design a radar data acquisition and processing system in the well to solve this problem.This design puts forward a kind of ultra-wideband receiver,high-speed data acquisition,data processing and transmission system integration design scheme,solves the system stability is weak,the integration degree is low,the anti-jamming ability is weak in the separate design.The design of traditional well radar receiver mainly includes low noise amplifier,RF switch and attenuator.Different from the previous design of adjusting the magnification by switching RF switches,this paper proposes a design scheme of well radar receiver which combines RF switches,low noise amplifier and programmable amplifier,and the stepper gain is accurate to 2d B.At the same time,the programmable amplifier can automatically adjust the gain of the system and solve the problem of signal gain saturation.In order to avoid the influence of signal random jitter in equivalent sampling,this paper proposes a logic system for real-time data acquisition and data processing of well radar based on FPGA,which realizes real-time acquisition of Gaussian pulse signal with center frequency of 50 MHz.The core device adopts highspeed analog-digital conversion device: double channel 500 Mbps,the accuracy is 12 bits,with very good linear integral deviation and linear differential deviation characteristics,to meet the requirements of real-time acquisition system.In order to overcome the attenuation in the long-distance transmission and improve the transmission speed of the signal,this paper adopts the optical fiber transmission mode for the real-time acquisition requirements.The optical fiber transmission rate of the system can reach up to 6.25Gbit/s,which can satisfy the long-distance low attenuation and high-speed transmission of data to the maximum extent.4G off-chip storage is added in the system,and the data interaction bandwidth reaches 25.6Gbit/s.And the traditional cable power supply is optimized for battery power supply,which improves the mobility of the system,realizes miniaturization,and can adapt to more complex working environment.The final test results show that the power supply system can provide stable power output,and the total power of the system reaches 5.8W.Both the digital system and the analog system work stably.The PLL chip and FPGA reference clock chip which provide sampling clock for ADC can stably output clock with low jitter and high phase noise.Receiver system,data acquisition system,storage system and optical transmission system can work normally and module design of target signal reception,collection,storage and data transmission,illustrates the receive and acquisition integration scheme is feasible and practical,for subsequent borehole radar system provides the design and implementation of a new project.