| The analysis and gathering of signal becomes the core of modern signal technique, which has very important effect on the development of science and society. As the foreside of the signal's analysis and gathering system, the sensor faces the object straightly. It is the advanced science and technology that attract the world attention and it is also the important sign of the science and technology which develop quickly. The piezoelectric accelerometer is an important sensor which uses for the gathering of the vibration and strike signal. It has advantages of small size,light weight,better ability of resist disturbance,convenient installation and so on. As an instrument which is used in broad fields, the piezoelectric accelerometer's signal gathering is very important.In the field of the signal gathering, National Instruments is not only the leader and the inaugurator of virtual technique, but also of the signal gathering production based on the PC. It provides the extensive choice of signal gathering production. However, equipping the system with NI's signal gathering hardware and software is expensive. At the same time, the signal of the piezoelectric accelerometer is low-frequency, so it is not the appropriate project with A/D card. It is necessary to choose the right hardware, write the right soft ware and found the economical and applied low-frequency signal gathering system.Based on the above characteristics, this paper analyses the signal, designs a low-frequency signal gathering system based on MCU. The system consists of hardware and software.The main function of the hardware is to amplify and filter the piezoelectricity acceleration sensor signal. In the system, TLC0831 of TI Company is used as the A/D converter, GMS97C2051 of LG Company is as microprocessor, and MAX232 is as the communication between the microprocessor and the computer. The system which consists of four modules: the conditioning circuit, the A/D conversion circuit, the MCU control circuit and the interface circuit are described in detail. It provides and analyses the schematic diagram of every modules.The software uses MCS-51 assembly language to compile the MCU program of data gathering. Graphical programming environment LabVIEW is a famous virtual development platform. It avoids the complexity of the traditional developing instrument, while providing the formidable function and guaranteeing the flexibility. This paper regards LabVIEW as the platform, designs the software of displaying in the real time for data gathering system.As it is a data gathering system based on computer, the system's function is flexibly defined and meets users' requirement easily. The system transmits the data to computer directly by serial interface, so it is easy to process and analyze the data. Finally the system has good man-machine interface, and is easily operated.Based on summarizing the characteristic of the piezoelectricity acceleration sensor's measurement, main achievements of the author include:(1) After the analysis of the signal, a design of a low-frequency data gathering system based on the A/D conversion circuit, the MCU control circuit and the interface circuit is put forward in this paper;(2)The MCU program has been compiled, based on the MCS-51 assembly language;(3) The panel has been compiled, based on LabVIEW for display;(4)The experiment has been carried out, and the experimental result has been obtained;(6) better suggestions for system's improvement and perfection has been put forward. |
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