Design And Implementation Of Real-time Signal Acquisition And Processing System

With the continuous progress of science and technology,the structure of various types of electronic systems and automation equipment is becoming more and more complex,and more and more functions need to be realized.The common signal measuring equipment in railway field has some problems,such as low sampling rate,limited storage depth,weak scalability and lack of intelligence.In this paper,a real-time signal acquisition and processing system is designed and developed based on the engineering background of automatic test,which uses digital oscilloscope as the lower computer and PC as the upper computer.Through the duplex communication between the computer and the digital oscilloscope,the system realizes the real-time acquisition of the signal,the high sampling rate,the long storage depth and the adaptive measurement of the occasional transient pulse on the railway site,which improves the shortcomings of the existing measurement equipment.The main work of this paper is as follows:First of all,based on the practical application requirements of the real-time signal acquisition and processing system,this paper designs the composition and overall framework of the system,and realizes the communication module,acquisition module,memory module,adaptive measurement module and signal analysis and processing module of the system by using the modular design concept.The system improves the problem that the existing measuring equipment can not carry out adaptive measurement according to the magnitude of the signal.Secondly,with the help of the communication module and acquisition module of the system,the initialization configuration and self-adaptive adjustment of the oscilloscope parameters are completed.At the same time,the generation mechanism of the oscilloscope dead time is deeply analyzed.The method of controlling multiple oscilloscopes to measure signal alternately is adopted to reduce the dead time of the oscilloscope.The self-adaptive measurement module of the system can meet the requirements of the high amplitude transient pulse and other sudden change signals.In the aspect of data storage module,on the basis of controlling the digital oscilloscope to collect the signals in real time,it can synchronously transmit the signals collected by the oscilloscope to the memory of the PC,which makes up for the defect of insufficient storage depth of the digital oscilloscope.The signal analysis and processing platform is used to realize the time-domain analysis and frequency-domain analysis of signals.Thirdly,the method of signal adaptive measurement is studied.Through the comparative analysis of various adaptive measurement methods,the adaptive measurement method for unknown signals is designed and implemented.Fourth,through experiments,the system indexes such as storage depth,storage speed,adaptive measurement and optimization of oscilloscope dead time are verified one by one.The system has been applied to the on-site measurement of electromagnetic interference in track circuit equipment in Yangquan North Station,and has basically realized the predetermined function.The paper includes 34 pictures,13 tables and 44 references.