Study On Intelligent Execution Mechanism Based On HART Protocol

(1) Item's background and according as taskIn eighties of 20 century, Chinese actuator-manufacturers widely imported advanced foreign technique to promote their production. Then in the early nineties of 20 century, in order to possess their own manufacturing property right of actuator they united one another to develop new intellective actuators. But limited by temporal behindhand computer technique, the developing achievement did not get real practical use. At the end of nineties of 20 century, the international field-bus standard was established; the entirely dispersed and entirely open field-bus system is produced; the requirement of the instrument-intellectualization and field-bus had become more urgent. Meantime, the computer industry had established a solid base for the development of intelligent instrument.HART protocol intelligent electric-actuator is formed according to technical requirement of the product development. The item is a Chongqing's key project in scientific and technological research of 2000 year.(2) Main content of studyThe article discusses the field-bus (HART protocol) intelligent electric-actuator, that is a fundamental mode product of terminal-actuator of a new type of open automatic system. The product is made of four main part, include electric-controller, driver motor, gear-boxing and position transformation etc.We have designed and manufactured of the two-gear-tooth is same driving system in item. Thus it is added that we study machining technique, calculate, demonstrability and design for driveling system, and go along compare of experiment. Based on testing, we have achieved many checking computations and improving, the testing answer for expectation finally.Electric-controller is nubbin in developping. We are based on designing to structure of circuit, we are dead against in time and stabilization for controlling and communications, precision and rapidity for transformation etc. we have completed to select on microprocessor, clock-frequency and A/D transfer. It carry out transformation for valve position signal, and select on solid-switch AC. and display.We had study and applied for field-bus technique (HART protocol) up to the minute international, that achieve long-distance communication for electric-actuator.In the product of industrialisation is made perfectly. Reliability analysis for intelligent actuator. We had applied for technique of reliability, that analyzes reliability of the product theoretically, and result answer for expectation whether or not. The calculation indicates that the Mean Time Between Failures (MTBF) is 90640h that can satisfy practical requirement.The project had be making sure in Jan. 2000 year, untill had be checkuped in Jan. 2002 year, it take two years. The sample of actuator had be tested by The Measure Center of Machine Industry. The performance is achieve requirement in plan-tast.(3) Meaning and purpose of studyThrough item's research, we have traced the newest development of the instrument in the world and have fetched up the technical gap between china and advanced foreign country. The following aims is reached.(1) The technique of automatic instrument is changed from analog to digital. The automation is changed from closing system to open system.(2)The actuator and control devices in the control room are digitalized. The serial dual-directional multistation-communication is completed.(3) The distance between china-made actuator and foreign-made actuator is shortened. We have got our own advanced actuator-manufacturing intellectual asset in the form of copyright and patent.(4) The wide range of departments of national economy (such as electricity, metallurgy, petrochemical industry, construction-material industry, light industry, paper-making industry) will equipped with China-developed advanced automatic equipment. The production efficiency will be increased greatly.(5 ) The success of this item will cause vigorous development of the instrument industry of China. C...