Intelligent Measurement And Control System Of Flow And Its Realization With VHDL

With the development of science and technology, flow measurement technique isattracting more and more attention, playing a great role especially in energyconservation. To help people be more aware of the importance of water saving andreduce the burden of management in water supply due to manual meter transcription,remote meter transcription system and intelligent IC card flow meter have beendeveloping in a rapid pace.Based on traditional IC card flow meter, a novel intelligent flow measurementsystem is researched and developed in this thesis. In the system, a new transient flowmeasuring method called three-point differential pressure method is applied, whichcan avoid the influence on the fluidal characters in the measuring process effectivelyand reflect the dynamic characteristic of the fluid factually, and then improve theperformance of the flow measurement availably. In this method, the measurementparameter has a simple evolution relationship with the sensor parameter, which makesthe data processing simple and convenient. A very simple structure of the sensordevice leads to a very low cost, and it can be used in the flow measurement systemwith different pipeline size through model correction and data compensation, whichwould achieve it with a broad application scope. The pressure sensor can be made bysilicon processing technics, which make the integration of the research production inthis thesis possible, and the whole system will become more subminiature, precise andintelligent. Field Programmable Gate Array (FPGA) is used to design the whole flowmeasurement and control system and meanwhile Very-High-Speed HardwareDescription Language (VHDL) is applied for system programming. The content ofthis thesis mainly includes the following three points. Firstly, based on the theory ofmulti-point differential pressure method for flow measurement, a complete IC cardflow measurement and control system is designed and its workflow is achieved.Secondly, the system is divided into several modules and VHDL is used to describeeach interface and control module. Finally, analog simulation is performed for eachmodule and the whole system with the EDA software Foundation 3.li produced byXinlinx. The simulation result indicates that the function of each module has satisfiedpreset requirement of the whole system. In contrast to traditional design method,VHDL holds several outstanding advantages such as short design period, excellentintegrated density and stability, convenient for modification and update of systemfunctions and etc. As FPGA chip has stable performance and low power consumption,it will gradually become the main stream of digital instrument system chipdevelopment in the future.This thesis is the foundation for the realization of flow measuring system on chip.Through further design improvement and function extension, a novel subminiatureintegrated intelligent flow instrument would occur, which can also be transferred intovarious flow measuring system, and be widely applied in the fields of people life,industry production and flow measurement of other kinds of liquid and gas.