英文翻譯及文獻(xiàn) 單片機-傳感器 壓力檢測

1、參考文獻(xiàn)Monitoring the Tire Pressure at Cars Using Passive SAW SensorsAlfred Pohl 1, G. Ostermayer , L. Reindl 2, F. Seifert1) Applied Electronics Laboratory, University oETechnology, Gusshausstrasse 27, A-1040 Vienna, Austria2) Siemens Central Research Lab., Otto Hahn Ring 6, D-$1739 Munich, GermanyAbs

2、tract：In our paper we present the application of surface acoustic wave (SAW) sensors to the continuous manitaring of the tire pressure in road vehicles. With these, the tire pressure can be read out in every phase of driving. We show the implemented prototype setup for measurement of the tire pressu

3、re, the applied SAW sensors, improved versions and the interrogation setup. The problems in practical application are discussed. Experimental results measuring the tire pressure during test rides are presented. INTRODUCTIONOperating a road vehicle, a malfunction of the tires in motion due to a tire

4、puncture can cause serious accidents and endanger human life. Furthermore, nowadays manufacturers of cars try to save the spare wheel in vehicles. Usually it only costs weight and space, therefore it yields a higher fuel consumption,although it will be required less than one time in more than ten ye

5、ars of a cars life. This only can be done, if the air pressure in the tires can be measured even during driving. Currently used sensors contain active components, powered by a Lithium battery. The mass of these sensor assemblies is about 20 grams causing high dynamic load. A few years ago,wirelessIy

6、 interrogable SAW devices far sensor applications were invented. 1，2, 3. Using an one port SAW delay line connected to an antenna only,an RF interrogation signal is fed into and the sensor response,carrying thesensor information is retransmitted wirelessly to the interrogator. These sensors are capa

7、ble for measurement of temperature, mechanical load, force and displacement, etc. The advantage is, that SAW sensors are totally passive devices and contain neither power supply nor semiconductors. They withstand temperatures up to several hundreds of degree centigrades, their lifetime is much longe

8、r than that of battery powered systems.Further,in vehicles strong electromagnetic pollution is generated by ignition systems etc.SAW sensors operate without risk of damage even in rough environments. First we discuss pressure measurement employing SAW sensors with wireless interrogation.We present s

9、ome types of sensor assemblies and the interrogation system.Next we discuss the implementation into thecar and thenwe present experimentally results.Finally a brief summary concludes the content of the paper.SAW PRESSURE SENSORSThe electrical behaviour of a passive SAW pressure sensor always is that

10、 of a one port delay line with multiple reflectors or a resonator,respectively. In the delay linecase,the interrogator transmits a burst signal,the sensor responds with a chain of bursts,one for every reflector arranged at the substrates surface.The differential delay between two or more response si

11、gnals is evaluated.To measure some physical value,the parameter has to be converted into a change of sensors surface length or surface acoustic waves velocity,respectively.The delay ri of the response of areflector i is the ratio of SAW propagation length Li on the substrates surface and propagation

12、 velocityv,.Affecting the sensor with a measurand causes a scaling of the sensors response to be observed as individual delay shifts Ari of the response signals si originating frotmhe reflectors i.Mechanical measurands can be collected by loading the sensor mechanically.Apart from stretching and com

13、pressing,utilized for wireless measurement of torque,etc.the SAW sensors substrate can be bent.Pressure can affect the sensor by bending a membrane,shifting the edge of a sensor fixed on theother side.Here the sensor is loaded to be bent due to a shift of the center of a membrane loaded by the press

14、ure.On the other hand the sensor can directly be fitted to the membrane or a piezoelectricmembrane representing the SAW substrate can be used.Figure 1 shows these methods. Fig.1:a)Membrane converting pressureto shift bendingthe SAW sensor(SAWS)b)SAW sensor fitted to the membraneThe next step is to c

15、over the sensor membrane by a cap consisting of a spacer frame and a quartz cover plate.This yieldsanintegratedpressure chamber SAW sensor4(fig.2).Fig.2:Integrated pressure chamber SAW sensorThecover protects theSAW generating metallic structure from oxidation and the surface from dust.The cavity ca

16、n befiIledwith a gas at reference pressure.If the cavity is evacuated,absolute pressure values can bemeasured.Measurement is made byinterrogationusing simple RF burst signals.The response impulses are evaluated in magnitude and phase.Bending the membrane due to pressure loadyields a phase shift of f

17、or instance 100 degree for lo4 Pascal.With this theairpressure in car tires can be measuredwith a resolutioonf approx.IOPascal(0.01 Bar).To reduce the amount of data to process,for the implementation in cars the resolution was reduced to 50 mBar.IMPLEMENTATIONThe first prototype used for the experim

18、ental measuremenwtsas a pressure chamber with a membrane made of brass.The sensor unit was fitted to a hub cap andwas connected to the valve by a pressure assembly(fig.3). Fig.3:First prototype of pressure chamber formeasurement of tire pressureFor serial manufacture the sensor systemhave tobe much

19、smaller and able to be integrated in the tire.Therefore we implemented the integrated pressure chamber(fig.2)into the tire.The sensor was fixed to the rim,the metallic valve shaft was used as the sensors antenna(fig.4).Fig.4:Integrated pressure chamber fixed to the rim,valve used as antennaFoirmprov

20、ed implementation a sensor assembly only fitted to the valve was developed(fig.5). The total mass of the unit is only a few grams,the dynamic load is small even driving at high speed.Fig.5:Pressure sensor forfitting into the valve shaftThcear based interrogation system uses space diversity to distin

21、guish the sensors in the tires.Therefore below every car wing an antenna has to be employed.We used coaxial cables,hut it is difficult and expensive to use them in cars.Our investigationsshow the applicability of twisted pair wires too.Fig.6:Interrogation antenna on carFor measurement we developed a

22、 small sized interrogation system transmitting bursts and looking for the phase shift between the response signal bursts.The system was controlled by a one chip microcontroller and abisle to display the measurement result on aLCD display.In fig.7 a photograph of the system is shown.Fig.7:System for

23、wireless interrogation of passiveSAW sensors(50 x 100 x 160 mm)MEASUREMENTRESULTSTo test our sensors and our system we made a lot of test rides within the area and around the city of Vienna.The interrogation system was coupled to alaptop computer.The pressure values were measured and recorded to a f

24、ile. The figures 8 and 9 show characteristic behaviour of tire pressure for different driving conditions. Due to the shocks from a rugged lane,in the left part of fig.8 the absolute pressure value swings around the mean value by the least significant bit,0.05 Bar.The narrow higher peaks of tire pres

25、sure belong to braking maneuvers(the sensor was mounted toa front wheel).The longer increase of tire pressure and the following period of decay is due to riding over a curbstone.The system showed high reliability even when driving in a heavy snow storm. tire pressureBarFig.8:Tire pressure for differ

26、ent driving conditionsIn figure 9 the pressure in the right front wheel can be observed zoomed in time while passing a two track grade crossing with an adjacent water channel across the lane.Due to the dilapidated arrangement of the grade crossing,hard shocks are transmitted to thecar body causing h

27、ard pressure shocks in the tires.Fig.9:Tire pressure crossing a grade crossing withtwo tracks and a water channel across the laneDISCUSSIONSAW sensors with wirelessly interrogation are free of maintenance and withstand high thermal and mechanical load.The measurement performance is comparable to tha

28、t of competitors.The effort in car based system is higher for SAW sensors,since theactive sensor units transmit preconditioned digital information containing pressure valueand sensor The major advantage of SAW devices in identification. applications,where high revolutions per time occur, is their lo

29、w mass.The centrifugal force is m.v*/r,with the mass m,the velocity v and the radius r.To minimize dynamic mechanical load,the mass of a system applied to rotating parts should be as low as possible.Whereas conventional sensor units for tire pressure measurements have a mass of approx.20 grams,the i

30、ntegrated pressure sensor itself(fig.5) has a mass of less than one gram.The complete SAW sensor units mass in worst case is only a few grams.Conventional systems are powered by a Lithium battery.In case of a worn tire,since the battery cannot be checked,the sensor should be replaced too,yielding pr

31、oblems of waste disposal.For a system integrated in the car electronic,it is needless to display the pressure of each tire continuously.Here,only a malfunction should trigger an alert.The systems display can be canceled,reducing systems cost.CONCLUSIONTheadvantagews of passive SAW sensors make thwem

32、ell suited for vehicular applications.Especially for measurement of tire pressure low mass and the fact thatthey are free of maintenance makethem to be superior over the competitors.The SAW sensors for pressure measurement,the implementation in tires and the system forinterrogation were discussed.Ex

33、perimental results out of a lot of measurement rides were presented.REFERENCESlReindl,F.Muller,C.Ruppel,WE.Bulst and F.Seifert,Passive surface wave sensors which can be.wirelessly interrogated,International Patent Appl WO 93/13495(1992).2Seifert F.,Bulst W.E.,Ruppel C.,Mechanical sensors based on su

34、rface acoustic waves,Sensors andActuators,A44(1994)231-2393G.Scholl,T.Ostertag,L.Reindl,H.Scherr,0.Sczesny,U.Wolff,Wireless SAW Sensors for Remote Measurement of Physical Parameters,Proc.IEEE Intern.Workshopon Commercial Radio Sensors and Communication Techniques,1997,pp.51-58.4H.Scherr,G.Scholl,F.S

35、eifert,R.Weigel,Quartz Pressure Sensor Based on SAW Reflective Delay Line,Proc.IEEE Ultrasonics Symposium 1996,pp.347-350.譯文輪胎壓力監(jiān)測在汽車使用被動聲外表波傳感器 阿爾弗雷多波爾，塞弗特 1 應(yīng)用電子實驗室，大學(xué)27日， - 1040維也納，奧地利 2 西門子公司中央研究實驗室。 ，奧托哈恩環(huán)摘要：在我們的文件，我們目前的應(yīng)用外表聲波聲外表波傳感器不斷的輪胎壓力在道路車輛。有了這些，對輪胎壓力可以讀出的每一個階段的駕駛。我們展示了實施原型裝置測量輪胎壓力，聲外表波傳感器

36、的應(yīng)用，改良版本和安裝的審訊。這些問題在實際應(yīng)用中進(jìn)行了討論。實驗結(jié)果測量輪胎壓力測試期間游樂設(shè)施介紹。 導(dǎo)言 經(jīng)營公路車輛，失靈的運動輪胎，由于輪胎爆胎會導(dǎo)致嚴(yán)重的事故，并危及人的生命。此外，現(xiàn)在的汽車制造商嘗試保存?zhèn)溆幂喬サ能囕v。它的本錢通常只有重量和空間，因此，收益率更高的燃料消耗，但將需要不到一時間在10年以上汽車的生命。這不僅可以做到的，如果氣壓輪胎可以衡量即使在駕駛。目前使用的傳感器含有活性成分，采用鋰電池。群眾這些傳感器組件是造成約20克高動態(tài)負(fù)載。幾年前，聲外表波器件遠(yuǎn)遠(yuǎn)傳感器應(yīng)用的創(chuàng)造。使用的是一個港口的SAW延遲線連接到天線只，射頻信號的審訊注入和傳感器響應(yīng)，攜帶資料重新轉(zhuǎn)

37、達(dá)了無線審訊。這些傳感器能測量溫度，機械負(fù)荷，力和位移等的好處是，聲外表波傳感器是完全無源器件，并包含沒有電力供給，也沒有半導(dǎo)體。它們的溫度高達(dá)幾百度，其壽命遠(yuǎn)遠(yuǎn)長于的電池供電，在車輛強烈的電磁污染是由點火系統(tǒng)傳感器運作風(fēng)險的損害，即使在粗糙的環(huán)境。首先，我們討論壓力測量采用聲外表波傳感器與無線目前某些類型的傳感器組件和審訊我們討論實施到本實驗簡要總結(jié)的內(nèi)容文件。聲外表波壓力傳感器電氣行為被動聲外表波壓力傳感器始終是一個端口延遲線多個反射或諧振器分別。在拖延，審訊傳送突發(fā)信號，該傳感器的響應(yīng)一連串的掃射，每一個反射安排在基板的外表差異拖延兩個或兩個以上的反響信號測量一些物理價值，參數(shù)轉(zhuǎn)化為改變

38、傳感器的外表長度或外表聲波的速度，分別延遲里的反響一比長度李聲外表波傳播的基板外表和繁殖。侵害傳感器1測量事業(yè)規(guī)模的傳感器的反響應(yīng)遵守個人拖延轉(zhuǎn)變阿里響應(yīng)信號源于硅反射鏡可以收集載入傳感器從拉伸和壓縮，用于無線測量的扭矩等，聲外表波傳感器的基板可以會影響傳感器彎曲膜，把邊緣傳感器固定在傳感器裝到彎曲由于轉(zhuǎn)移的中心，膜加載的另一方面?zhèn)鞲衅骺芍苯影惭b在膜或壓電膜代表的SAW基板可以顯示這些方法。圖1 ： 一膜轉(zhuǎn)換轉(zhuǎn)變彎曲的聲外表波傳感器鋸 二聲外表波傳感器安裝在膜下一步是覆蓋膜傳感器組成的第一個間隔內(nèi)和石英覆蓋商會的傳感器圖2 。圖2 ：集成壓力室聲外表波傳感器保護(hù)生成氧化金屬結(jié)構(gòu)，外表由腔可以氣體在參考腔是疏散，絕對壓力值可以是簡單的射頻突發(fā)脈沖信號的反響進(jìn)行評估在規(guī)模和膜由于壓力的一個階段轉(zhuǎn)向例如度在汽車輪胎可帕斯卡爾。為了減少數(shù)據(jù)處理，為執(zhí)行該決議的汽車。執(zhí)行情況第一個原型，用于實驗的壓力商會與膜制成的傳感器安裝單位的樞紐第連接閥門的壓力大會圖3 。圖3：壓力腔第一個原型為輪胎氣壓的測量串行制造的傳感器系統(tǒng)有別小得多，能夠被納入，我們實施了綜合壓力室圖2 進(jìn)入傳感器固定在輪輞，金屬閥軸用作為傳感器的天線圖4 。圖4 ：集成壓力室固定在輪輞閥用