Design Of Front-End Of On-line Monitoring System For Air Compressor Based On FPGA

The condition monitoring is one of the important measures for controlling the operating conditions of the monitored equipment, judging the equipment's developmental trend in the future and reducing its fault rate. Thus, acquiring the accurate data of the operating equipment is the foundation of the condition monitoring. This paper, adapting the development of on-line monitoring system of rotating machinery and taking actual engineering issue as the background, designs the front-end of on-line monitoring system for air compressor, which efficiently carries out signal conditioning, data acquisition and data storage.At first, this paper analyses the air compressor's structure as well as its faults, which always happen, and puts forward the project of measuring point's arrangement and framework plan of on-line monitoring system. Then, combining with the requirement of the data acquisition system, and by contrast, the paper confirms the whole project of the data acquisition system. That is to say, it makes FPGA as the controlling core in order to implement the multi-channel synchronal data acquisition and data storage and adopts ARM processor to carry out network transmission of the data.After designing the whole project, this paper puts emphasis on the hardware design of front-end, which is divided into two parts: the signal conditioning module and the data acquisition module. The signal conditioning module includes the I/V transform circuit, the programmable amplifier, and the low-pass filter. The analog signal, which is exported from the sensor, is processed by the signal conditioning module and used by the data acquisition module. The data acquisition module includes interface circuit of AD converter, dual-port RAM and FPGA. FPGA, as the core chip, controls AD converters which do AD converting for the processed signals and saves the data in dual-port RAM according to time.After completing the hardware design of front-end, the paper plots out the whole logic function of FPGA into modules and designs software for every module. Meanwhile, by making use of ISE development platform and combining VHDL, the certain functions of every module are carried out respectively.In the end, the paper clarifies the reliability of the data acquisition system, puts forward the essential measures of assuring the reliability of the data acquisition system, and emphasizes that the anti-jamming design is main measure. Besides, by the aid of isolating, decoupling and grounding, the paper points out how to implement the anti-jamming design.