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[车辆工程] 请教一个振动加速度的问题!

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发表于 2007-11-10 19:02 | 显示全部楼层 |阅读模式

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本帖最后由 wdhd 于 2016-4-8 11:18 编辑

  [size=178%]•  大家好,今天看了下振动加速度的书,发现上面有如下的描述:振动加速度传感器中,一般包含有预紧弹簧、质量块、压电元件等。书中提到当传感器的自振频率远超过被测物体的振动频率时,质量块与被测物体的运动状态相近,加速度相近,理论上说如果质量块与被测物体的运动状态完全相同时,此时质量块的运动状态最能反映测量点的运动状态,但此时质量块与测点之间没有相对运动,因此对压电元件是没有作用力的,即无法测量加速度。实际传感器工作时上,质量块同测点之间有相对运动,从而对压电元件产生拉、压作用,但此时质量块的运动状态同测点的运动状态已经不相同了,也就是说压电加速度传感器测量的本身就是存在一定的误差的,不知我是否是进了死胡同,还请高手指教。
  [ 本帖最后由 mofei 于 2007-11-10 19:04 编辑 ]
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发表于 2008-1-23 10:28 | 显示全部楼层
  呵呵,传感器用过一些,却不大深究其原理,我随便说说,仅供参考。
  振动加速度传感器分很多种,工作中常用的有应变式加速度计、压电式加速度传感器、ICP加速度传感器,加速度计和加速度传感器是一回事。你这里提到的应该是压电式加速度传感器了。
  1、正如你所提到的,压电元件受到作用力而产生了信号变化,那么只要质量块与压电元件之间有作用力就会产生信号变化,即使压电元件没受到作用力,信号也是存在的,只看上去是一条平稳的静态直线罢了。
  2、力和位移、速度没有直接关系,物体静止和匀速直线运动时都是外力为0的状态。根据牛二定律,力和加速度正比关系,所以传感器与测点之间没有相对运动(以测点为参考系),并不代表传感器没有加速度(注意此时的参考系是地球这一惯性系),只要传感器是在加速运动,传感器与测点之间就会有力的存在,因为传感器的加速度是测点给的作用力造成的,同样质量块也会给压电元件一个作用力,因为质量块的加速度和压电元件密切相关。
发表于 2008-1-23 19:58 | 显示全部楼层
噢,原来所谓icp传感器不是压电的哦。
发表于 2008-1-23 22:00 | 显示全部楼层
ICP传感器是压电传感器。
ICP(Integrated Circuits Piezoelectric)传感器就是指内置集成电路的压电传感器。ICP是美国PCB公司的注册商标,欧洲很多公司也称为IEPE。典型的ICP系统通常采用恒流源供电,供电电缆同时做为信号输出线,输出低阻抗信号。整个系统包括ICP传感器,普通的双芯电缆和一个不间断电源,所有的ICP系统都需要一个不间断电源为ICP传感器提供恒定的电流。  ICP传感器的高频响应通常受三个因素的限制:传感器的固有频率、内置放大器的类型以及传输电缆。ICP传感器的低频响主要考虑两个因素:一是传感器的放电时间常数;另外一个因素则是信号适调器的耦合电容。如果信号输出采用直流耦合方式,则低频响应只决定于传感器的放电时间常数,但直流耦合会带来零漂问题,因此大多数信号适调器都采用交流耦合。
加速度传感器一般分压阻式,电容式,压电式等。书上所描述的其实就是一个意思:压电式加速传感器无法测量频率为0的信号。大家注意一下自己买的压电式传感器的datasheet,没有一款的频响范围从0Hz开始的,压电式传感器测量的是动态信号,匀加速度它是无法测出的。压阻式和电容式的频响范围都是从0Hz开始的。

[ 本帖最后由 VIz_Jaqtaar 于 2008-1-23 22:15 编辑 ]
发表于 2008-1-24 21:58 | 显示全部楼层
本帖最后由 wdhd 于 2016-4-8 11:19 编辑
原帖由 VIz_Jaqtaar 于 2008-1-23 22:00 发表
ICP传感器是压电传感器。
ICP(Integrated Circuits Piezoelectric)传感器就是指内置集成电路的压电传感器。ICP是美国PCB公司的注册商标,欧洲很多公司也称为IEPE。典型的ICP系统通常采用恒流源供电,供电电缆同时做 ...

应该是国际上的标准叫法是IEPE,其他如ENDEVCO、B&K、kistler都是各有各的叫法,PCB的产品主要是ICP的,所以他才大力推广,但就产品来说,pcb在大厂里面算下等了。
发表于 2008-1-25 06:58 | 显示全部楼层
本帖最后由 wdhd 于 2016-5-18 09:36 编辑
原帖由 jojohup33 于 2008-1-24 21:58 发表

应该是国际上的标准叫法是IEPE,其他如ENDEVCO、B&K、kistler都是各有各的叫法,PCB的产品主要是ICP的,所以他才大力推广,但就产品来说,pcb在大厂里面算下等了。

ENDEVCO、B&K、kistler三家传感器各有专长,尤其ENDVCO的压阻式传感器,应该是最好的了,B&K也寻求与它合作.各有各的叫法麻烦您发出来让我们学习一下哪.就ICP(IEPE)式传感器来说个人觉得还是PCB的最好用,品质绝对不能说是下等,1967年开始PCB就做压电材料的传感器.这几家的几种主流传感器都用过.Kistler东西也不错,可惜价格稍高,但有些传感器就他家有,也不得不买啊.
发表于 2008-1-25 14:41 | 显示全部楼层
本帖最后由 wdhd 于 2016-4-8 11:19 编辑
原帖由 mofei 于 2007-11-10 19:02 发表
•  大家好,今天看了下振动加速度的书,发现上面有如下的描述:振动加速度传感器中,一般包含有预紧弹簧、质量块、压电元件等。书中提到当传感器的自振频率远超过被测物体的振动频率时,质量块与被测物体的运 ...

传感器的误差总是有的,不过在适用范围内的测试精度会好一些。
发表于 2008-1-25 17:27 | 显示全部楼层
本帖最后由 wdhd 于 2016-4-8 11:19 编辑
原帖由 VIz_Jaqtaar 于 2008-1-25 06:58 发表

ENDEVCO、B&K、kistler三家传感器各有专长,尤其ENDVCO的压阻式传感器,应该是最好的了,B&K也寻求与它合作.各有各的叫法麻烦您发出来让我们学习一下哪.就ICP(IEPE)式传感器来说个人觉得还是PCB的最好用,品质绝对不能 ...

加速度、振动、速度传感器是运动测量中的三种主要传感器,2000年该市场市值为7.9亿美元,预计其未来发展速度不会很快,。然而,其稳定而强劲的增长势头表明其市场规模将会攀上新的台阶,预计到2007年有可能达到11亿美元,增长率由1998年的3.5%将慢慢增长,到2007年达到5.3%。目前该市场的主力企业有三十几家,其中前五名公司即占据了31.3%的市场份额。而这种传感器的主要用户则来自汽车、工业、航空三大产业。这五家企业是Endevco占13.6%,WilcoxaResearch占9.1%,Motorola占4.2%,IMI占3.0%,AnalogDevices占1.4%。除了上述三个用户群以及一些经常性的用户外,无论是买方还是卖方都因为技术力量薄弱而无法获得进行设计和生产所需要的信息。。。。ENDEVCO公司是振动、冲击、惯性运动和动态压力测量领域中世界最大的动态仪表供应商,WilcoxonResearch第一个生产出压电式加速度计,使业界不再使用频?适配器,它在压电和压阻领域建立了不可动摇的地位。MOTOROLA公司则是内嵌式芯片生产商,并将之广泛用于汽车及工业传感器。IMI(PCB公司的一个分公司)重点在预防维护保养领域,AD公司则是全球最大的低成本加速度计供应商之一。
这是前两年的一篇市场分析报告的内容。
ENDEVCO成立与1947年,bk是40年代,kistler是1955年,pcb是1967。
内置电路国际上的标准叫法是IEPE(Integrated Electronics Piezo Electric ),ENDEVCO:Isotron,B&K:Deltatron,Kistler:Piezotron。还有一些别的公司的叫法。
这些公司的产品我都用过,bk和endevco的压电传感器差不多,但比pcb的要好,做比对时pcb的传感器会有细微的毛刺,kistler的介于中间。kistler的压力传感器最好,没有谁能比。压阻和电容的endevco的好,bk的声学传感器好,但台子现在不行了,是贴牌的,激光测震仪也是别家的。

[ 本帖最后由 jojohup33 于 2008-1-25 17:55 编辑 ]
发表于 2008-1-26 20:02 | 显示全部楼层
本帖最后由 wdhd 于 2016-4-8 11:20 编辑

  好,学习学习.不过我狂鄙视随便引用别人帖子的人,有墨水还好,没墨水就丢人了.
  关于ICP、IEPE我引用别人的文章,这个详细:
  ICP, IEPE, PIEZOTRON SENSORHISTORY, NEWS, & TECHNOLOGY
  Patent and Trademark Antics Generate Conflict
  The beginning of things is often vague, controversial, and confusing. The origin of the valuable, popular, ICP Piezotron (Integrated Circuit Piezoelectric) sensor concept in the mid 1960s is no exception. As usual, a number of gifted, diverse individuals, unaware of the work of others, were involved.
  The concept was first embodied in Piezotron® sensors in the year, 1965. When dramatically introduced by the original Kistler Instrument Corporation (KIC/USA) at the 1965 ISA Conference and Exhibit in New Orleans, a piezoelectric sensor operating over two ordinary wires amazed and dumbfounded the instrumentation community. Endevco called it the Confusatron on cards quickly printed and distributed to expose the suspected trick involved. Headlines of fake newspapers posted at the exhibit read “Lallygag Fails.”
  From this lively beginning, the two-wire ICP Piezotron idea was destined to become one of the real success stories of modern technology.
  The revolutionary ICP concept is now a de facto sensor-industry standard. Most modern recording and display instruments feature an ICP input. Over a dozen different manufacturers market ICP sensors under various aliases, including Isotron®, DeltaTron®, LIVM®, CCLD®, ACOtron®, Constant Current, CCM, and now, IEPE.
  Like computers, ICP Piezotron sensors are a marvel of modern technology. Electrostatically operating over two ordinary wires, they simply and naturally mate a charge-generating crystal with a charge-operated transistor. The low output impedance of the internal isolation amplifier practically eliminates interaction with external instruments from appreciably changing the signal. Newer, sophisticated versions include overload protection, integral active filters, integration, current-mode operation, and self-identifying memory.
  Rationalizing, some people now consider the ICP idea obvious, not really an invention. The record seems to support this view, although several patents were issued to different people for the same idea. Apparently the patent office also was confused by the new technology.
  The key patent, US 3,294,988 filed Sept. 24, 1964, was awarded to David Packard, an executive of Hewlett Packard fame, who claimed an intimate mechanical and electrical mating of a piezoelectric or pyroelectric crystal with an insulated-gate field-effect transistor. He apparently ssumed or knew that the basic idea and two-wire operation which he diagrammed were either obvious or already public domain. They were not claimed as inventions.
  Much later, KIAG, a Swiss offshoot of the original Kistler Company (KIC), acquired the remnants of original KIC Company from Sundstrand, and obtained rights to a KIC Piezotron® patent. Then in a French court that naturally favors European interests, KIAG charged that the ICP products of PCB infringed. They lost. The court ruled that explicit prior art contained in the Packard patent invalidated the KIC patent.
  About the same time as the Packard invention, the original US Kistler (KIC) Piezotron® creation started with a crude marketing idea to operate a piezoelectric sensor with a built-in transistor amplifier over two ordinary wires. When presented with the idea, the Kistler engineering manager almost immediately saw that one of a new family of insulated-gate transistors could do the job much more simply and elegantly. It did not need a bias voltage on the gate.
  A second transistor was added to lower the output impedance even further. Walter Kistler coined the name, Piezotron®.
  A special, ultra-high-value, tera-ohm resistor needed to slowly discharge the crystal capacitance and automatically zero the amplifier input was laboriously developed by a close associate, Fred Oettel, who started Eltec Instruments to manufacture it.
  About the same time, Phillips Electronics independently introduced an integrated-circuit version of the same two transistor amplifier. As a result, the Piezotron® quickly evolved into an I.C. Piezotron®, or more simply an ICP, which pCB later chose to further develop and promote.
  PCB Electronics operated for a year as a sole proprietorship promoting the ICP concept, before being incorporated as PCB Piezotronics late in the year 1967. But the increasingly popular ICP term was not registered as a trademark until 1990, and then deceptively as I.C.P. The first application was rightfully rejected as a descriptive, generic term. The claimed 1968 date and place of origin is still not correct, per a published 1967 ISA Paper.
  Incredibly, PCB then sued arch-rival KIC/KIAG for infringement of the I.C.P. trademark. The Swiss company countered claiming infringement of a mounting adapter patent. Kistler won on both counts. KIC and others now freely use the technical term ICP in ads and literature.
  IEPE (Integral Electronics Piezoelectric) is the IEST (Institute of Environmental Science and Technology) newly adopted term to identify ICP type piezoelectric sensors. According to a former president of Endevco, the term IEPE was in use at Endevco as early as 1980. It served primarily as an alternate way of describing ICP sensors. Although some systems people have adopted the awkward IEPE term, most sensor manufacturers continue to talk ICP, while publicly displaying their own alias terminology mentioned above.
  The awe-inspiring ICP Piezotron® development is one of the truly great accomplishments of the instrumentation community, although not one of its more noble ones. The effort involved many dedicated engineers and technicians,as well as a few unscrupulous, dishonest administrators.
  When now often applied to polarized condenser microphones, ICP technology ought to be more generally termed ICE (integral-circuit-electrostatic), or ICEM.
  Bob Lally, the author, can be reached at: lally@peopling.net. He helped start and build the original Kistler Instrument Corporation, founded PCB, conceived the two-wire ICP idea, and coined the term, ICP.
  最后哪个传感器好我也懒得说了,反正我也不是卖传感器的,大家自己用的好就OK啦!
  [ 本帖最后由 VIz_Jaqtaar 于 2008-1-26 20:13 编辑 ]
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