Research And Implementation Of High-precision Multi-point Synchronous Signal Acquisition System

In order to improve the power of the multi-explosive initiation system,it is necessary to make each bomb of the multi-explosive initiation system explode synchronously.However,this goal is impossible to achieve literally.To approach this goal,the only path is to minimize the time difference between the detonation of each explosive as much as possible.Therefore,a novel precisive time interval measurement system is needed to measure the time difference of each explosive initiation.However,at present,there is no such time interval measurement system specifically designed for multi-explosive initiation system,and most time interval measurement systems have too low measurement accuracy and too few measurement channels to meet the actual engineering requirements.Due to the above problems,a method based on signal processing and time interval measurement was studied in this paper.After the signal processing of explosive initiation signal and initiation trigger signal in multi-explosive initiation system,and the measurement of time interval between 16-way explosive initiation signals and detonation trigger signals,a set of precisive time interval measurement system for multi-explosive initiation system was established.The main research contents of this paper are as follows:1)Different signal shaping circuits were designed for different types of explosive initiation signals and initiation trigger signals to improve measurement accuracy.Explosive detonation signals can be divided into broken communication signals and on-off signals,and detonation trigger signals can be divided into pulse signals,broken communication signals and on-off signals.Therefore,shaping circuits designed for different signals to process explosive initiation signals and detonation trigger signals into interference-free pulse signals.2)In this paper,the time intervals between 16 explosive detonation signals were measured by ASIC-based chips TDC-GPX2.Six TDC-GPX2 chips were used to measure the time intervals,and the time intervals were calculated by measuring the time intervals between 16 explosive detonation signals and the same detonation trigger signals.Through the software programming of TDC-GPX2,the measurement accuracy is less than 1ns.Software programming of the TDC-GPX2 achieves measurement accuracy of better than 1ns from 10 ns to 160 ns.3)The lower computer and the upper computer part of the system were completed.The lower computer mainly uses STM32F103ZET6 as the main control of the system.The main control was connected to the serial port screen,AT24C512,multiple keys,RS232 communication module and RS485 communication module to realize the user’s manual selection of the signal types of the explosive detonation signals and the detonation trigger signals,and the time intervals of combinations of the 16 channels.The measurement results can also be stored locally,displayed,and uploaded to the host computer.The upper computer part was realized by QT,the main functions of the upper computer were database storage and data visualization display of the data uploaded by the lower computer,and can communicate with the lower computer through RS232 agreement.4)Various tests were carried out to test the performance of signal processing module,time interval measurement module,system lower computer and upper computer.After separate functional tests of the hardware equipment and the functions of each part of the system,the time interval measurement module,the system host computer and the lower computer were cascaded to perform the overall joint debugging of the hardware and software.The test results of the system show that 16-way explosive initiation signals can be measured synchronously,and the measurement accuracy is better than 1ns,which meets the actual project requirements and system design indicators.