轮胎压力监测中英文资料外文翻译文献.doc

轮胎压力监测 中英文资料外文翻译文献参考文献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, GermanyAbstract：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 pressure, 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 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 years 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 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 capable 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 longer 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 some 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 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 signals 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 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 compressing,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 pressure.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 cover 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 can 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 for 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 experimental 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 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 antennaFoirmproved 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 distinguish 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 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 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 file. 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 pressure 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 different 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 hard 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 that 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 low 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 integrated 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 problems 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 thwemell 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.Experimental 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 surface 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.Seifert,R.Weigel,Quartz Pressure Sensor Based on SAW Reflective Delay Line,Proc.IEEE Ultrasonics Symposium 1996,pp.347-350.译文轮胎压力监测在汽车使用被动声表面波传感器 阿尔弗雷多波尔，塞弗特 1 ）应用电子实验室，大学27日， - 1040维也纳，奥地利 2 ）西门子公司中央研究实验室。 ，奥托哈恩环摘要：在我们的文件，我们目前的应用表面声波（声表面波）传感器不断的轮胎压力在道路车辆。有了这些，对轮胎压力可以读出的每一个阶段的驾驶。我们展示了实施原型装置测量轮胎压力，声表面波传感器的应用，改进版本和安装的审讯。这些问题在实际应用中进行了讨论。实验结果测量轮胎压力测试期间游乐设施介绍。 导言 经营公路车辆，失灵的运动轮胎，由于轮胎爆胎会导致严重的事故，并危及人的生命。此外，现在的汽车制造商尝试保存备用轮胎的车辆。它的成本通常只有重量和空间，因此，收益率更高的燃料消耗，但将需要不到一时间在10年以上汽车的生命。这不仅可以做到的，如果气压轮胎可以衡量即使在驾驶。目前使用的传感器含有活性成分，采用锂电池。大众这些传感器组件是造成约20克高动态负载。几年前，声表面波器件远远传感器应用的发明。使用的是一个港口的SAW延迟线连接到天线只，射频信号的审讯注入和传感器响应，携带资料重新转达了无线审讯。这些传感器能测量温度，机械负荷，力和位移等的好处是，声表面波传感器是完全无源器件，并包含没有电力供应，也没有半导体。它们的温度高达几百度，其寿命远远长于的电池供电，在车辆强烈的电磁污染是由点火系统传感器运作风险的损害，即使在粗糙的环境。首先，我们讨论压力测量采用声表面波传感器与无线目前某些类型的传感器组件和审讯我们讨论实施到本实验简要总结的内容文件。声表面波压力传感器电气行为被动声表面波压力传感器始终是一个端口延迟线多个反射或谐振器分别。在拖延，审讯传送突发信号，该传感器的响应一连串的扫射，每一个反射安排在基板的表面差别拖延两个或两个以上的反应信号测量一些物理价值，参数转化为改变传感器的表面长度或表面声波的速度，分别延迟里的反应一比长度李声表面波传播的基板表面和繁殖。侵害传感器1测量事业规模的传感器的反应应遵守个人拖延转变阿里响应信号源于硅反射镜可以收集载入传感器从拉伸和压缩，用于无线测量的扭矩等，声表面波传感器的基板可以会影响传感器弯曲膜，把边缘传感器固定在传感器装到弯曲由于转移的中心，膜加载的另一方面传感器可直接安装在膜或压电膜代表的SAW基板可以显示这些方法。图1 ： 一）膜转换转变弯曲的声表面波传感器（锯） 二）声表面波传感器安装在膜下一步是覆盖膜传感器组成的第一个间隔内和石英覆盖商会的传感器（图2 ） 。图2 ：集成压力室声表面波传感器保护生成氧化金属结构，表面由腔可以气体在参考腔是疏散，绝对压力值可以是简单的射频突发脉冲信号的反应进行评估在规模和膜由于压力的一个阶段转向例如度在汽车轮胎可帕斯卡尔。为了减少数据处理，为执行该决议的汽车。执行情况第一个原型，用于实验的压力商会与膜制成的传感器安装单位的枢纽第连接阀门的压力大会（图3 ） 。图3：压力腔第一个原型为轮胎气压的测量串行制造的传感器系统有别小得多，能够被纳入，我们实施了综合压力室（图2 ）进入传感器固定在轮辋，金属阀轴用作为传感器的天线（图4 ） 。图4 ：集成压力室固定在轮辋阀用作天线执行大会唯一