5线传感器的应用.doc

当使用一个5线（宽带）传感器，我们做出关于该传感器用于环境的某些假设，例如我们假设该传感器用于测量比较完善的排气燃烧的副产品。 When using a 5-wire (wideband) sensor we make certain assumptions about the environment the sensor is used in, for example we assume the sensor is used to measure the exhaust byproducts of fairly complete combustion. 燃烧可以是内部的，如在传统汽车或外部燃烧，如在炉或其他设备消耗燃料和氧气。 The combustion can be internal, as in a conventional vehicle or external combustion, as in a furnace or other device consuming fuel and oxygen. 如果这些条件改变后可能会导致不适当的读数。 If these conditions are altered then inappropriate readings may result. 例如，如果错过，火灾发生和未燃烧的燃料液滴穿过电机，然后传感器将读取瘦，因为它不会检测液体燃料。 For example, if a miss-fire occurs and unburnt droplets of fuel go through the motor, then the sensor will read lean as it will not detect the liquid fuel. 当调谐到一辆车，你不应该完全依赖于从一个传感器读数。 When tuning a vehicle, you should not rely solely on the reading from a sensor. 让你的常识，以及如何传感器工作，引导你所知甚少。 Let your common sense, and a little knowledge of how the sensor works, guide you. 宽带传感器需要一个控制器，因为它们比标准的窄带传感器复杂。 Wideband sensors require a controller because they are more complex than a standard narrowband sensor. 他们更准确的，因为这种复杂性，但这意味着他们需要一个技术复杂的控制器，他们在所有的工作。 They are more accurate because of this complexity, but this means they require a technically complex controller for them to work at all. 而传感器本身可以被认为是两个紧密相连的是一个沉闷的电加热到热读部分： The sensor itself can be thought of as two closely connected parts that are electrically heated to a dull read heat: 窄带传感器探测到一个小厅的氧气浓度。 A narrow-band sensor to detect the oxygen concentration within a small chamber. 甲泵输送氧离子电池，或从这个小室的表面。 A pump cell that transports oxygen ions to or from the surface of this small chamber. 正如我们将会看到，宽带传感器是由电流是流入或流出泵细胞泵浦的宽带电子控制器。 As we will see, the wideband sensor is operated by current that is pumped into or out of the pump cell by the wideband controller electronics. 这是根本不同的传感器，产生一个窄带的窄带电压，无需任何外部电子设备，当加热到工作温度。 This is fundamentally different to a narrowband sensor that produces its narrowband voltage, without any external electronics, when heated to operating temperature. 要了解宽带， 窄带 ，我们必须先了解传感器： To understand wideband, we must first understand narrowband sensors: 窄带传感器 Narrow Band Sensors 窄带传感器之间有一四线等。 Narrowband sensors have between one and four wires. 该线将永远是一个信号电压。 One of the wires will always be the signal voltage. 第二线可用于隔离结束的信号，以减少地面信号的噪声。 A second wire can be used to isolate the ground end of the signal to reduce signal noise. 三，四线传感器增加一个加热元件等传感器开始运行更快，更可靠。 Three and four wire sensors add a heating element so the sensor starts operating faster and more reliably. 在左边显示图像的一个4线制的代表 - 在实际窄带传感器往往是作为一个顶针形设计，以最大限度地面积暴露在废气。 The image at left shows a representation of a 4-wire version - in practical narrowband designs the sensor is often shaped as a thimble to maximise surface area exposed to the exhaust gas. 电加热器是用来提高温度的二氧化锆 （ZrO 2的 ）材料，该传感器是由元素。 The electrical heater is used to raise the temperature of the Zirconium Dioxide (ZrO 2 ) material that the sensor element is made from. 二氧化锆（通常掺杂氧化钇 ）是一种重要物质，机械刚度，同时保持红热状态的能力）进行的电流时，在熔融（。 Zirconium Dioxide (often doped with Yttrium oxide ) is an important substance that maintains mechanical rigidity while capable of conducting an electric current when in a molten (red hot) state. 该传感器电流是由氧离子，成为只有当传感器是够热。 The sensor current is carried by oxygen ions that become available only when the sensor is hot enough. 白金覆盖既导电和推动一个催化反应之间的氧离子和部分燃烧的燃料。 The Platinum covering is both conductive and promotes a catalytic reaction between oxygen ions and partially burned fuel. 在能斯特方程描述尾气催化剂的生产和电压的白金结果这一催化反应涉及氧离子。 The Nernst equation describes the voltage produced as a result of this catalytic reaction involving Oxygen ions, Platinum catalyst and exhaust gas. 十四 ，V s =（RT/4F）* 展览画册 ）宝2 =气体分压跨边界法律公告（蒲2 空气 /宝2 V s = (RT/4F)*ln(pO 2 air /pO 2 exh ) pO 2 = partial pressure across gas boundary 邮政署2 xxx是氧分压，氧传感器，是一种方便的代表性一侧的氧浓度对每个。 The pO 2 xxx is the partial pressure of oxygen, and is a convenient representation of the oxygen concentration on each side of the oxygen sensor. 该RT/4F项可以被看作是一个常数温度 T的乘积。 The RT/4F term can be thought of as a constant multiplied by temperature T . 这是什么公式说的是，具有丰富的混合物，那里几乎没有氧气，但大量的燃料，并免收电压 V 的传感器所产生的将是相当高的。 What this equation says is that with rich mixtures, where theres almost no oxygen, but lots of free fuel, the voltage V s produced by the sensor will be fairly high. 化学计量比周边一些免费的氧气变得可用，由传感器产生的电压迅速下降。 Around stoich some free oxygen becomes available and the voltage produced by the sensor rapidly drops. 图十四 ，V s迅速在左边显示了如何从一个伏特电压开关约0.9至0.1伏特左右在一个非常小的拉姆达（或空燃比）的范围。 The graph at left shows how V s rapidly switches from a voltage around 0.9 Volts to around 0.1 Volt over a very small Lambda (or AFR) range. 这种快速转换的原因之一是窄带传感器未在富裕地区，那里发生的最精确的功率调整。 This rapid switching is one reason narrowband sensors are not accurate in the rich region, where most power tuning takes place. 该方程也说，在更高的温度十四 ，V s也将更高。 The equation also says that at higher temperatures V s will also be higher. 这是显示在右边的图像。 This is shown in the image at right. 这是其他主要的原因窄带传感器距离不是很准确的化学计量比。 It is the other major reason why narrowband sensors are not very accurate away from stoich. 由于对电机负载变化时，传感器的温度会改变，而且会读不同的值，但实际拉姆达（或空燃比）并没有改变。 As the load on the motor varies, the temperature of the sensor will change, and it will read a different value, although the actual Lambda (or AFR) has not changed. 它可以通过测量温度补偿传感器的阻抗和计算其平均温度，而这正是最优质拉姆达米，使用窄带传感器（如与LSM - 11），这样做是为了提高自己准确性。 It is possible to temperature compensate by measuring the impedance of the sensor and calculating its average temperature, and this is what most better quality Lambda meters, that use a narrow band sensor (such as the LSM-11), do in order to improve their accuracy. 泵细胞 Pump Cell 窄带传感器，如上所述，检测电压 V 的Cell所产生的能斯特。 The narrowband sensor, described above, detects the voltage V s produced by the Nernst Cell. 它可以强制一个熔化的电流通过电解液与驱动化学反应，使氧气泵（在2形式的O -离子）从一个细胞一侧到另一端。 It is possible to force a current through the molten electrolyte and to drive the chemical reaction such that oxygen is pumped (in the form of o 2- ions) from one side of the cell to the other. 2 + 4E条- “ - 2的O 2 - O 2 + 4e - 2 O 2- 在一个富有的混合物的氧离子会结合起来，对泵细胞的催化表面燃料，产生水和二氧化碳。 In a rich mixture the oxygen ions will combine, on the pump cells catalytic surface, with fuel to produce water and carbon dioxide. 当所有的燃料消耗将不会有游离氧和由此产生的混合物将在化学计量。 When all the fuel is consumed there will be no free oxygen and the resulting mixture will be at stoich. 在稀混合（或空气甚至免费）泵电流反转，自由的氧气泵出直至不复存在，以及由此产生的混合物也将在化学计量。 In a lean mixture (or even in free air) the pump current is reversed and the free oxygen is pumped out until none remains, and the resulting mixture will also be at stoich. 右边的图像显示了在细胞和一个小泵室的废气可以进入。 The image at right shows a pump cell and a small chamber that exhaust gas can enter. 室内的丰富，或贫，气可减少或氧化，产生化学计量比的混合物。 The rich, or lean, gas inside the chamber can be reduced, or oxidised, to produce a stoich mixture. 一种泵的细胞的重要组成部分，是细胞的泵入孔和扩散腔宽度尺寸。 An important part of the pump cell is the size of the pump cells entry hole and width of the diffusion chamber. 由于这些都是为了制造变化问题，在运行参数利差预期，并计划使这种变化是必需的。 As these are all subject to manufacturing variations, spreads in operating parameters are expected, and a scheme to allow for this variation is required. 结合窄带和泵细胞“ - 5线传感器 Combining Narrow Band and Pump Cells 5-wire Sensor 结合窄带和泵细胞使传感器感应到窄带混合抽水进入或离开会议厅氧的扩散造成的。 Combining the narrow band and the pump cells allows the narrowband sensor to sense the mixture resulting from pumping oxygen into or out of the diffusion chamber. 由此产生的感应器会显示在左边。 The resulting sensor is shown at left. 为了节省电线， 和 （意义） 和 IP（泵）细胞连接在一起-他们都有一个共同的反应面，无论如何，所以这不是一个问题。 To save wires, the Vs (sense) and the Ip (pump) cells are connected together - they share a common reaction surface anyway, so this isnt a problem. 制造业的变化问题，这在不同的敏感性（不同的泵为同一拉姆达电流）传感器的结果，是通过增加一个校准解决的组成部分。 The manufacturing variation problem, which results in sensors of varying sensitivities (differing pump currents for the same Lambda), is solved by adding a calibration component. 一个电阻（Rcal）是修整后的传感器是建造及测试激光。 A resistor (Rcal) is laser trimmed after the sensor is constructed and tested. 激光材料和烧毁时增加值已知拉姆达的电阻值，直到产生一个标准的IP电流。 The laser burns away material and increases the value of the resistor until a standard Ip current is produced at a known Lambda value. 如果该电路转载于本身那么每个传感器将进一步校准的情况下自动校正控制器。 If this circuit is reproduced in the controller itself then each sensor will be automatically calibrated without further calibration. 很明显，因为每个传感器工厂校准，校准组件通常是在传感器连接器本身，如果有人删除该连接器，则传感器已成为无标定！ Obviously, as each sensor is factory calibrated, and the calibration component is usually in the sensor connector itself, if someone removes the connector, then the sensor has become uncalibrated! 许多控制器没有这条赛道，他们必须经过一个开放式空气标定阶段工作准确。 Many controllers do not have this circuit and they must go through a free-air calibration phase to work accurately. 还要注意，所有泵细胞宽带传感器将至少有5名来自传感器的电线。 Note also that all pump-cell wideband sensors will have at least 5 wires from the sensor. 六，七线将来自连接器（一些传感器使用的连接器的两端有免费的校准电阻）。 Six or 7 wires will come from the connector (some sensors use a calibration resistor in the connector that has both ends free). 有些事情需要注意的是，当传感器正在积极控制，内混合气的扩散是在化学计量和 VS电压接近450 mVolts。 Some things to note are that when the sensor is being actively controlled, the mixture in the diffusion chamber is at stoich and the Vs voltage is close to 450 mVolts. 有一个小自抽氧效应扩散到大气室由 VS传感器的一部分，但是这是远远小于行动泵细胞的。 There is a small self-pumping effect of atmospheric oxygen into the diffusion chamber by the Vs sensor part, but this is much smaller than the pump cells action. 由于大气中的氧气浓度（即自由空气）是用于必须保持作为传感器参考一边与当时的细胞，流通的空气背面-这通常是通过覆盖到电线护套/从传感器。 As atmospheric oxygen concentration (ie. free-air) is used as the reference on one side of the Vs cell, then the flow of air to the back of the sensor must be maintained - this is usually via the sheath covering the wires to/from the sensor. 电线护套不应该收缩！ The wire sheath should not be constricted! 宽带控制器是如何工作的？ How does a Wideband Controller Work? 该控制器的工作是维持的温度范围内密切扩散室和控制那里的混合物在化学计量泵或多或少叶电流，通过改变方向时，瘦叶和丰富的变化之间的混合物。 The job of the controller is to maintain the diffusion chambers temperature within close limits and to control the mixture there at stoich by pumping more or less Ip current, and by changing the direction of Ip when the mixture changes between lean and rich. 对知识产权作出精确测量计算查表的lambda使用的混合物。 A precise measurement of Ip is made to calculate the Lambda of the mixture by using a look-up table. 在右边的图像代表在操作中。 The image at right represents this in action. 运放 A代表电压产生差异，并与 450毫伏的参考电压为-的想法暂时维持在450毫伏比的化学计量值。 Op-Amp A produces a voltage representing the difference between Vs and a reference Voltage of 450 mV - the idea being to maintain Vs at the stoich value of 450 mV. 微控制器实现PID控制器采用传感器作为电流源所生成的叶当前所使用的配置与作为它的输入和输出驱动器乙的PID运算放大器。 A microcontroller implementing a PID controller uses Vs as its input and the PID output drives op-amp B configured as a current source which produces the Ip current used by the sensor. 运放 C直接测量泵电流，产生一个微控制器的电压是衡量。 Op-amp C directly measures the pump current and produces a voltage that is measured by the microcontroller. 微控制器等有效地转换成内部拉姆达澍表示，用来产生输出电压数据，存储 The microcontroller effectively converts Ip into an internal Lambda representation that is used to produce output voltages, stored as data etc. 对于控制器来上班了，传感器元素必须被加热到正确的操作温度下氧离子可以维持必要的催化反应。 For the controller to work at all, the sensor element must be heated to the correct operational temperature where oxygen ions can sustain the necessary catalytic reactions. 该传感器的温度保持在最佳工作温度的测量与意识或细胞阻抗（电阻）无论是泵单元。 The sensor temperature is maintained at the optimal operating temperature by measuring the impedance (electrical resistance) of either the pump cell or the Vs sense cell. 更准确的结果通常会导致细胞从 VS传感温度（单位是做技术的边缘 ），但是这可能是一个复杂的多一点比 IP测量电池阻抗。 More accurate results usually result from Vs cell temperature sensing (as is done in Tech Edge units) but this can be a little more complex than Ip cell impedance measurements. 大多数5线传感器加热器的设计生产能力在比汽车的电池电压低电压的最大加热功率。 The heater of most 5-wire sensors is designed to produce maximum heating power at a lower voltage than the vehicles battery voltage. 这是为控制电路中的电压损失和更迅速地热允许从冷，但它也意味着，传感器寿命长，控制器应注意不要在强调热身足够大的电流传感器时，破坏加热器可以流动。 This is to allow for voltage losses in the controller circuitry and for more rapid heat up from cold, but it also means that for a long sensor life, the controller should be careful not to stress the sensor during warmup when large enough currents to destroy the heater can flow. 在左边的图像显示，加热器控制电路的主要部分。 The i