Research Of Multiparameter Drilling Instrument Based On The Single Chip Computer System

Drilling instrument should continuously measure and analyze theparameters during drilling process in order to make drilling more safe andrational.With the AT89C52 as the control center, an intelligent instrument hasbeen developed in modular design approach. Signal regulator circuits, dataacquisition module, Flash large capacity memories, keyboard and displaymodule, serial communication module and software module are expandedaround the AT89C52 to finish the design of system, whose function is toacquire ,convert, store ,display and transport analog and digital quantities.Andsomemethodsofmeasurementareimproved.All of the parameters are converted to anolog signals and pulse signalsby each sensor. All of the signals are converted into ADC or counter one byone controlled by CD74HC4051.In the measurement of analog signal, thevoltage and current signals are converted to voltage of ?5 ~+5V by signalregulator circuits, which is the measurement area of analog to digitalconverter(ADC).Asoftwarefilterissetuptosievedisturbs.In the measurement of pulse signal, the weak pulse signals out of table speed and pump stroke rate sensor are amplified and filtered. And pulsedither eliminating circuit is applied to the forward and backward pulsesignals out of hook sensor to avoid miscount. Both timing and countingmethodaretakentoattainthehigheraccuracy.Theresultscanbedealwithbycomputerautomatically.Furthermore,the watch dog chip X5045 is applied. And warning circuit is set up. Data istransported from this instrument to host computer through serial port.Formulas of the mian parameters and scale transformations of sensors arefiguredout.Experiments show that the intelligent instrument has the advantage ofhighprecision,workstabilityandsoon.