Research Of Engineering Blasting Vibration Signal Acquisition And Processing Based On FPGA

Blasting fields construction environment are usually very harsh, it is essential tomeasurement the blasting vibration conveniently and accurately. This paper introducesthe current situation of blasting vibration measurement system either home or abroad,because of these complicated operations, unitary function, high price and so on, wewere researched and developed a high precision, multi-function, low price, highspeed and portable blasting vibration measurement instrument. This instrument isbased on FPGA, it is detection, store, analysis, display and transport the velocity dataof soil due to blasting vibration, composition of power supply, parameters setting,signal adjusting, A/D converting, data storage and analysis, result display and datatransport.Vibration detection system power supply by lithium battery, the low voltagewarning current will light red indicator when the voltage below a certain value so thatusers can charging battery in time and guarantee system operate normally. Parameterslike sample frequency, single detect time, trigger mode and level, coupling mode canstore in the system before vibration detection, change the value of above parametersalso be allowed in the blasting field, which can satisfied different detect environment.This system works in ground coupling mode, DC coupling mode and AC couplingmode, change these three modes in turn can regulate zero point automatically.AGC(Auto Gain Control) be used in this vibration detect system, it means that largeramplitude signal own a smaller amplification and smaller amplitude own a largeramplification, and by this way weak signal can be displayed more details. Thresholdjudgment and valid data convert are complete by two different A/D convert, comparewhit the systems take MCU as a core the former system could fast more than five times,and the sampling rate reached250Ksps. SDRAM and FLASH can guaranteehigh-speed storage and data could not lose when power off.32M FLASH can storage8129segments detect data; however, a bigger storage capacity FLASH could insteadthe smaller one for more data storage. This vibration detect system also has thecapacity of data analysis; compute vibration last time and the highest vibration speed,finally display the results on the LCD screen. The vibration detect system andcomputer can link by a serial port line.Finally, experiments on this instrument at vibrating field proved that date acquaint by blasting vibration detect system is reliable, and it is very practical for blastingvibration detect, assessment blasting safety, and guiding blasting construction.