Research And Design For Elbow Flowmeter Measure System Based On CAN Field Bus

Field bus, make relationships between the process control devices andeven the high control management network, as a communication networkamong intelligent instruments in the field of process control automation,manufacturing automation. As CAN field bus is reliability, real time andagility in data communication, proposals a reliability solution at the presentfield control system to improve the communication among intelligentinstruments. After having analyzed elbow flowmeter technology development statusand trend, every part is designed in order to develop one intelligent flowmeasure instrument & system based on CAN bus with elbow flow sensor,conversion and calculate. Being based on elbow flowmeter measurement theory, the theory of freevortex and forced votex is introduced. After the excellence and shortcoming isanalyzed and compared, forced vortex and flow adjusting coefficient areselected in paper. And the elbow sensor with R/D=1.5 is designed. Using new MCU and computer hardware & software technology and fieldbus technology, put forward difference of presses, density of liquid anddiameter of pipe real time amending technology. At the same time calibrationtransform, auto- calibration, voltage monitoring and CAN communicationinterface are analyzed and designed. CAN bus basic technology is introduced. In allusion to CAN bustechnology characteristic, researched and analyzed technology criterion, framestructure and CAN bus interface electric connection mode. Hardware andsoftware of intelligent control system based on CAN bus controller, SJA1000are designed. Accordingly, precision of elbow flow measure instrument &system is improved, enhance system's opening, reliability and communicationfunction. The research roots in practice engineering. For practice system, Lots ofprojects are selected and Lots of integration and test are done. By experimentsand actual appliance, it is indicated that the system has some advantages, such IIas, reasonable structure, high reliability, simple operation and high ratio ofperformance to value.