Trends of instrument of a favourable turn coming back measures the development of experimental stage
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source:KAIHER CNC Machining
Summary: The trends of instrument of new-style a favourable turn coming back that developed a kind to be able to measure many dynamic machinery to measure parameter at the same time measures experimental stage, introduced experimental stage form, experimental content, measure principle and hardware implementation method. The too big vibration that when instrument of 1 foreword a favourable turn coming back moves, produces is one of main reasons that cause machinery to destroy, because this turns to coming back,mechanical locomotive condition undertakes real time is monitored, the dynamic character that analyses a system is mechanical to assuring to rotate the reliability that run is very fundamental. 20 centuries 80 time are prime, industrial developed country begins to develop condition of instrument of a favourable turn coming back to monitor diagnose a system with breakdown, throw industrial application very quickly. Handle the development of technical development and relevant computer software as signal, at present instrument of a favourable turn coming back is monitored with diagnostic system to online detect develop with the direction of assayer system. We developed trends of instrument of a kind of new-style a favourable turn coming back to measure experimental stage. This experiment stage is compositive a variety of contemporary detect technology, can detect at the same time the oscillatory noise of transmission system and transmission error, can undertake online analysis, accurate and affirmatory breakdown produces the position. In addition, this experiment stage still can be used at universities and colleges " oscillatory theory " , " vibration and noise control " , " rotor is kinetic " , " test technology " the experiment of the task studies the education experiment that waits for special training course and the scientific research such as concerned transmission error, oscillatory, noise, rotor. Of 2 experiments stage form experimental stage to reach software of form a complete set to wait by circuit of timing electric machinery, mechanical gearing, sensor, hardware, computer form. Among them, mechanical gearing by gear, worm wheel deputy, rotor, shaft coupling, bearing wait for a spare parts to form; Sensor is aged by inductance type bar (2) , sensor of vortex flow of bar of photoelectricity type tine, cable (2) , amplifier of acceleration sensor, charge, sound level plan form. Measure experiment of experiment, sound measurement of a confusion of voices, rotor to measure an experiment to wait to finish transmission error to measure experiment, vibration, use modular the relevant hardware circuit that designed a method to design experimental station (include transmission error to measure circuit, rotor to measure the) such as circuit of circuit, sound measurement of oscillatory a confusion of voices, every module can fulfil a kind of specific function independently. Principle of job of 3 experiments station and hardware implementation (the system of FMT(Full Microcomputerized Transmission Error System) that the measurement of transmission error develops by this laboratory development can realize 1) transmission error and the nicety with characteristic motion are measured, mirror gear truely, intuitionisticly through error curve deputy the transmission error that waits for transmission catenary. The transmission error of this experimental stage surveys a test is designed according to principle of FMT system work, it can differ to having the gear that transmission compares deputy undertake the error is measured. The measurement of transmission error is to pass the high speed end in runner shaft and low speed end to install tine bar to collect respectively signal, right signal undertakes synchronous displacement is compared, processing and the analysis such as clock interpolation will come true. Transmission error is measured used airspace to measure a way, undertake dimensional sampling to signal namely, use airspace to analyse a law to undertake data processing. This method suits the function analysis of positive drive system particularly, clarity and affirmatory corresponding concern are had between its analysis result and breakdown mode, be helpful for the exact location of breakdown. The computation of each airspace frequency and rotate speed, time has nothing to do, count a decision by transmission construction of system and tine only, axis (or bearing, gear) the positional serial number of dimensional position, dynamic feature and airspace chart has affirmatory corresponding concern. Graph if the graph is shown 1 times,signal of transmission error of block diagram of principle of processing of signal of 1 transmission error handles a principle. Choose 2 AT89C51 chip to process low speed end and two signal that high speed carries at the same time, compose works in coordination into double CPU system. Do not need any times frequency and scale down processing to two signal, direct input personal computer has count. With K second sampling is exemple, reach through computation above all the P1 of integral part Σ of pulse signal P1, try to seek the decimal part that gives tally to cannot numerate next, criterion the transmission error expression that disperse of earning of this second sampling changes is fraction of Ek= Σ P1+ - in P0N1 type: Ek -- the transmission error of K second sampling is worth N1 -- the pulse equivalent P0 of pulse signal P1 -- the correspondence when having transmission error the P1 pulse at P2 of each sampling signal the decimal part that counts nominal value to give pulse signal P1 to beg, can all the way Pt of time pulse signal is auxiliary time staff guage, through begging a sampling to order from beginning to end each nod the time Tj of P1j correspondence, establish spatio-temporal and coherent disperse function relationship, criterion the dimensional position of correspondence of sampling hour T3 can be passed inside insert or analytic type begs extrapolate piece. Alternate through undertaking to collection airspace discrete data as similar as time domain FFT airspace pays a family name (SFFT) , attainable token is measured the airspace curve that dynamic parameter follows case of angular displacement change, its pay a family name commutation result token the distributinging case that this parameter follows dimensional frequency. (Because major a favourable turn coming back fetterses to all can simplify,2) rotor character checks for rotor model, because this checks an analysis,the correlated characteristics of rotor has important sense. Use this experimental station the test of achievable rotor major attribute, make dynamic curve in draw of the real time on the computer. Rotate speed measures rotor rotate speed to change along with the change of electric machinery rotate speed. Rotor rotate speed is higher, oscillatory amplitude is bigger, but lift when rotate speed when be worth to some, amplitude begins to drop, value of this rotate speed is namely " critical rotate speed " . To measure rotate speed, need to open a deepness to be the keyway of a few millimeter beforehand on runner shaft. Use electromagnetism switch to regard rotate speed as sensor, when runner shaft is rotational, electromagnetism switch outputs pulse signal. As perpendicular as axes on rotor plane direction installs two mutual and perpendicular cable vortex flow sensor is used at measuring displacement. As direct as the object that be measured contact does not require when sensor of electric vortex flow is measured, have wider frequency noisy range, suit the measurement of rotor vibration very much. Sensor of electric vortex flow will be voltage to change with the displacement change changeover between the object that be measured, send MAX197 chip to undertake A/D is changed voltage value next, MAX197 is chip of 12 collateral ADC, power supply voltage + 5V, change time 6µs, sampling rate 100ksps, imitate of 8 passageways input is measured (can choose all passageway or partial passageway) through process designing. Graph if principle of rotate speed of block diagram of principle of processing of signal of 2 rotate speed, displacement and processing of synchronous displacement signal pursues show 2 times. After plastics of enlarge of classics of signal of rotate speed pulse, classics is odd of a machine exterior interrupt a mouth to send AT89C51 chip, outside opening, the ministry interrupts INT0, timer chooses way 2, time time is 65536µs, drop when pulse when the edge comes, enter interrupt, open timer to begin to time at the same time and change into travel A/D, changeover ends cause interrupt, data puts memery block. Calculate in all 8 pulse, drop when the 8th pulse when the edge comes, stop to time, calculate rotate speed value; Show on LED rotate speed displacement is worth finally, upload PC screen to show through serial mouth at the same time. Indication chip chooses Max7219, it is output of kind of new-style and serial input in all cathode LED demonstrates drive, the line is thirdly serial receive Rikeli connection arrives on all sorts of general UP. Show use piece inside dynamic scanning mode, can control brightness through process designing, show out of control to prevent LED, shunt-wound beside end of Max7219 power source carry capacitance (47µF) . Show with what form by CD4094 or 74LS164 circuit photograph is compared, this indication circuit structure simple, power inferior, flexibility is good. Phasic (offset) measure phasic be character of instrument of a favourable turn coming back is important measure one of parameter. When undertaking dynamic balancing to runner shaft, can decide according to phasic value aggravating or those who go weighing is azimuthal; In the system that monitor, phasic value can help diagnostic machine error. The photo corner value that a favourable turn coming back fetterses is the phasic difference that the some on the signal of oscillatory fundamental frequency that points to rotor some instant and runner shaft secures a mark, if be fundamental frequency signal and scale of fiducial pulse signal on same time axis, what can decide fundamental frequency signal according to fiducial pulse signal is phasic. This experimental stage chooses rotate speed signal to regard fiducial pulse as signal, what measure oscillatory signal Px accordingly is phasic. X Xiang Zhen moves changeover of comparator of signal classics voltage to be pulse signal, send RS trigger together with fiducial pulse signal next, get Pn of phasic poor pulse, undertake with clock pulse Pt interpolation evacuation has count into 16 tally, computation ends cause interrupt, odd a machine read in computation to be worth, computation at the same time the value sends into serial shift register, show on LED computation is worth. Design numerical value is N, cycle of base mark signal is Tb, clock frequency is Ft, formula of computation of phasic value is × of Ø=n/Pft360 ° =nTb the axes contrail that contrail of axes of 360 ° Tbft measures rotor is to point to axes to go up opposite at bearing athletic contrail, it reflected the oscillatory condition of runner shaft directly. Through monitoring axes contrail, can judge a machine movement is smooth. As perpendicular as axes on rotor plane direction installs sensor of two mutual and perpendicular electric vortex flow, collect X, Y to Xiang Zhen uses signal and be changed into travel A/D, send sheet changeover value piece undertake handling in machine. ADC chip uses MAX197, its standard microprocessor interface but conveniently with sheet piece machine connection. Use AT89C51 chip to undertake data is collected with processing, upload curve of contrail of PC scale axes. (Stage of experiment of sound measurement of 3) oscillatory a confusion of voices chooses sensor of the acceleration that suppress report to get oscillatory signal. This sensor changes element with pressing electric data to be, can output the charge that becomes direct ratio with acceleration or voltage, have a structure simple, job reliable, span big, frequency band is broad, interference rejection sex is good wait for an advantage. The buy before choosing what charge amplifier regards acceleration as sensor puts much. Use sound level plan to collect noise signal. Use 12 data to collect calorie of PCI-9118, it has 32 PCI bus line, plug and Play, 12 resolution, frequency of highest A/D sampling amounts to 333kHz, 16 Chan Duan or quantity of 8 differential imitate input a passageway, odd polarity or bipolar input, sudden means scans, but choice of process designing gain, quantity of imitate of 2 12 high speed outputs a passageway, 4 numbers measure I/O passageway, contain the driver with LabVIEW interface. Signal of classics of oscillatory noise signal recuperates module to send PCI-9118 to collect card directly. Use LabVIEW to be able to undertake the graph changes process designing, weave fictitious instrument measures an order (include the) such as analysis of time domain weaveform, spectrum analysis, relevant analysis, raised a program to develop efficiency greatly. Measure through undertaking to oscillatory noise signal from many angle with the analysis, can regard breakdown as diagnostic basis. The place on 4 epilogue put together is narrated, the trends of instrument of a favourable turn coming back of development measured experimental stage to apply advanced mechanical quantity integratedly to test a technology, can realize the measurement of many dynamic parameter and analysis at the same time, wide applied perspective is had in scientific research, education and manufacturing practice. CNC Milling