A Research On Multi-Channel Synchronous Overpressure Measurement System

Shockwave is an important index in weapon damage assessment.Presently,two methods are commonly used for shockwave measurement: lead wire measurement and wireless storage measurement.Due to the long lead cable which can be over a hundred meters,the lead wire measurement has narrow frequency range and low signal-to-noise ratio,meanwhile,wireless storage method does not perform well in synchronicity and data reading.Besides,neither of these two methods can be monitored and controlled remotely.To solve this problem,this thesis introduces a wireless multi-channel synchronous overpressure measurement system which enables high-precision multi-point synchronous remote monitoring of shockwave measurement.This paper first analyzed the status quo of shockwave overpressure measurement,and assessed three common methods of multi-channel synchronous acquisition,then chose synchronous sampling ADC for multi-channel synchronous acquisition and designed an overall measuring scheme consisting multi-channel recorder,wireless relay terminal and long-distance control terminal,and realized long-distance control through the bridge communication of wireless relay terminal.This paper elaborated the hardware design for the acquisition recorder,including the power management,the analog signal filter,synchronous sampling ADC,the eMMC memorizer and the USB3.0 reading.It analyzed the eMMC5.0 protocol,ADC reading and USB3.0 data transmission in detail,and designed the FPGA control logic.Meanwhile,the online sequence of these key parts was verified through SignalTap II,and the design of wireless relay terminal and LabVIEW upper computer software programing was also introduced in this paper.Then the synchronous acquisition of the recorder and the noise reduction of the synchronous power supply were tested.The results show that the synchronization accuracy among channels is more than 1μs,and synchronous power supply can reduce 33.3% of the ripple noise,while the USB3.0 reading speed can reach 125MB/s.Finally,through practical test at range and data analysis,a number of feature of this measurement system were verified,such as good synchronization,less noise,convenient data recovery,and long-distance control etc.