• 专利附录
  • 专利说明
  • 权利要求
  • 类似技术
  • 同族专利
  • 引用文献
  • 法律状态
  • 优先权
    • 专利摘要:
    METHOD AND DEVICE TO CONTROL A CATALYTIC SCR CONVERTER OF A VEHICLE. The present invention provides a method and an apparatus for controlling an SCR catalytic converter (2). The invention describes a control method based on a model that includes a physical model of the SCR catalyst (2) with more than one NH3 storage cell and a physical model of a NOx sensor (4). The observer's feedback gain forces the sensor outputs estimated from the model to converge to the measurements, therefore, there is no ambiguity in determining the operational point.
    公开号:BR112012015671B1
    申请号:R112012015671-3
    申请日:2010-12-22
    公开日:2020-08-25
    发明作者:Theophil Auckenthaler
    申请人:Fpt Motorenforschung Ag；
    IPC主号:
    专利说明:

    [0001] [0001] The present invention relates to a method and device for controlling a vehicle's SCR catalytic converter, in particular in the field of vehicle combustion engines. Description of the state of the art
    [0002] [0002] Many combustion engines, which have to comply with current and future emission legislation, make use of a selective catalytic reduction (SCR) system in order to reduce nitrogen oxides (NOx).
    [0003] [0003] In current operating systems, a urea solution is injected into the exhaust gases upstream of the SCR catalyst. Urea is transformed into ammonia (NH3), which in turn reduces NOx to harmless nitrogen (N2) and water (H20) in the SCR catalyst. The relevant chemical reactions occur after ammonia has been absorbed on the catalyst surface.
    [0004] [0004] Generally, the NOx conversion efficiency of the SCR catalyst is dependent on the amount of ammonia stored (ie, absorbed), the temperature, the speed in space, that is, the volume of gas in the catalyst per unit time, the NO2 / NO ratio of NOx, and other conditions. Temperature and spatial speed are generally dependent on the operation of the motor and cannot be directly influenced by the SCR controller. The amount of ammonia stored is usually adjusted by a dedicated controller, which controls the estimated ammonia level. The NO2 / NO ratio is dependent on the performance of a diesel oxidation catalyst (DOC) and a diesel particulate filter (DPF), mounted upstream of the SCR catalyst. In current concepts, the NO2 / NO ratio cannot be adjusted directly, since it depends mainly on the DOC / DPF temperatures, the space speed, and the DPF soot load.
    [0005] [0005] Current SCR control systems make use of a model, in which the SCR catalyst is modeled as an NH3 storage tank. The amount of NH3 stored is calculated from the injected urea, and the amount of NH3 consumed by SCR reactions. The amount of stored ammonia is then adjusted in such a way that the desired NOx conversion efficiency is achieved. An external control circuit through a NOx measuring device is then used to adjust the amount of urea injected so that the estimated by a model and the measurement of the NOx conversion efficiency converge.
    [0006] [0006] Known schemes for an SCR controller are described in for example Schar: "Control of a Selective Catalytic Reduction Process" (PhD thesis No. 15,221, ETH Zurich.) Or in Chi, Da Costa: "Modeling and Control of a SCR Urea after-treatment system, SAE 2005-01-0966, or in Herman, Wu, Cabush, Shost: "Control Based on SCR Dosage Model and OBD Strategies with NH3 Sensor Return", SAE 2009- 01-0911.
    [0007] [0007] The known scheme of a prior art SCR controller includes a closed loop controller based on a NOx sensor downstream of the SCR catalyst.
    [0008] [0008] The known control approach lacks precision, especially when the NH3 slip must be accounted for, too.
    [0009] [0009] The prior art control systems aim to control the storage level of the entire SCR or to control an overall NOx conversion efficiency. Some concepts even include the calculation and limitation of NH3 slippage, that is, dispersion of NH3 in the exhaust gases, without reacting with NOx. However, this usually implies a parallel controller, which is then combined with the NOx controller by minimum selection, for example, of the amount of urea to be injected. Generally, the criteria for enabling or disabling controllers in the event of sensor failure or turning off / on are difficult from an implementation point of view. Currently available NOx sensors exhibit significant cross-sensitivity with NH3.
    [0010] [00010] Figure 2 of the state of the art shows a typical sensor output characteristic depending on the injected urea.
    [0011] [00011] Such a characteristic is an even function, therefore, it is not a dual function.
    [0012] [00012] Under normal conditions, the output of the NOx sensor decreases with the increase in urea injection. However, when the NH3 slip begins to increase, the NOx sensor's output characteristic transforms and the sensor's output increases with increased urea injection.
    [0013] [00013] The ambiguous characteristic of the NOx sensor leads to the problem that the NH3 slip potential can be interpreted as NOx and vice versa. This can lead to a destabilization of the controller. For example, when NH3 is interpreted as NOx, the control algorithm increases the injection of urea in order to reduce NOx emissions. This will lead to an additional increase in NH3 slip, which in turn leads to to an additional increase in urea injection, since NH3 is interpreted as NOx.
    [0014] [00014] Thus, the signal from the sensor is ambiguous, and its ambiguity can destabilize the control system. In order to differentiate between NOx and NH3, the urea injection has to be excited, for example, by switching between two levels. The known systems depend on a rapid response, which is not given with large volumes of catalyst in the future, and / or in operating conditions almost in a steady state, which hardly occurs during normal operation. Summary of the invention
    [0015] [00015] Therefore, it is the main objective of the present invention to provide a method and device for controlling a vehicle SCR catalytic converter, which overcomes the above problems / disadvantages.
    [0016] [00016] An observer device requires the estimation of NOx or NH3 to converge to measured values, that is, the observer regulates gains / parameters of that estimate using as a feedback ("feedback") the difference / error between the above estimated values and said measured values.
    [0017] [00017] By this means, the main advantage of the invention is that the observer knows at all times the polarity of the sensor model, that is, the observer inherently distinguishes at all times which side of the characteristic is in reality, if the NOx signal increases or decreases with increasing amounts of stored ammonia. Thus, the ambiguity of the sensor output is overcome.
    [0018] [00018] Therefore, the controller only controls the estimated / modeled sensor output level. If no real sensor is available, the corresponding observer return gain is switched to zero, which significantly simplifies implementation, and makes the same ECU (Vehicle Electronic Control Unit) suitable for various engine configurations or applications in various working conditions, for example, when starting the engines.
    [0019] [00019] In accordance with another aspect of the present invention, the SCR catalyst is considered to be divided into a plurality of cascading cells, and only the storage level of the first cell is controlled, despite the fact that the Adjustment is calculated from a demand for global NOx conversion efficiency or NH3 slip limitation restriction.
    [0020] [00020] Since the calculation of ECU and memory resources are limited, an advantageous implementation of the method of the present invention provides the step of considering the SCR catalyst as comprising only a few storage cells and controlling the NH3 stored only in the first of said cells.
    [0021] - Controle de NOx: Quantidade de NH3 armazenada na primeira célula, a fim de alcançar a eficiência de conversão de NOx alvo desejada do catalisador de SCR inteiro, ou seja, levando em conta a contribuição em termos de eficiência de conversão de NOx, das outras células de armazenamento a partir da segunda para o n-éssima. - Controle de NH3: Quantidade de NH3 armazenada na primeira célula, a fim de atingir o nível exigido de NH3 na saída do catalisador de SCR, levando também em conta a contribuição em termos de níveis de armazenamento de NH3, das outras células de armazenamento a partir da segunda para a n-éssima. [00021] According to a preferred embodiment, the controller calculates one of the points defined below: - NOx control: Amount of NH3 stored in the first cell, in order to achieve the desired target NOx conversion efficiency of the entire SCR catalyst, ie, taking into account the contribution in terms of NOx conversion efficiency, of the others storage cells from the second to the nth. - NH3 Control: Amount of NH3 stored in the first cell, in order to reach the required level of NH3 at the outlet of the SCR catalyst, also taking into account the contribution in terms of NH3 storage levels, from the other storage cells to from the second to the nth.
    [0022] [00022] According to another embodiment, the controller calculates both set points, so the actual set point is obtained from a minimum selection.
    [0023] [00023] Therefore, a multiple cell approach is advantageous, since the accuracy can be significantly improved, if the axial distributions of the gas components and the stored ammonia are taken into account.
    [0024] [00024] According to another aspect of the invention, the controller that performs the method described here is capable of detecting and preventing NH3 slippage, if an NH3 sensitive NOx sensor is used alone, without any specific NH3 measurement device. The SCR catalyst method incorporates the NOx sensor model including cross-sensitivity of NH3.
    [0025] [00025] If the divergence of the controller is detected, because a missing NH3 slip is detected, or because a NH3 slip is not detected, the controller reverses the polarity of the stored NH3 and NOx sensor for the calculation of the operating point present in the sensor characteristic.
    [0026] [00026] Advantageously, no external NH3 slip detection system is necessary, since the method and the method application controller can be used directly.
    [0027] [00027] These and other objectives are achieved by means of a method and a device, as described in the attached claims, which form an integral part of the present description. Brief description of the drawings
    [0028] - A Fig. 1 mostra uma conhecida característica de saída do sensor de NOx ambígua, - A Fig. 2 mostra um esquema de controle de SCR de acordo de com a presente invenção, - A Fig. 3 mostra um esquema de controle baseado em modelo de SCR de acordo com o desenho da figura 2, com base em um alvo eficiência de NOx, - A Fig. 4 mostra um esquema de controle baseado em modelo de SCR de acordo com o desenho da figura 2, com base em um ponto de ajuste de nível de deslizamento de NH3, - A Fig. 5 mostra uma recuperação de erro operada de acordo com a presente invenção, quando NOx é detectado como NH3, - A Fig. 6 mostra uma recuperação de erro operada de acordo com a presente invenção, quando NOx é detectado como NH3. [00028] The invention will become completely clear from the detailed description below, given by means of a simple and exemplary non-limiting example, to be read with reference to the figures in the accompanying drawings, in which: - Fig. 1 shows a known output characteristic of the ambiguous NOx sensor, - Fig. 2 shows an SCR control scheme according to the present invention, - Fig. 3 shows a control scheme based on the SCR model according to the drawing in figure 2, based on a NOx efficiency target, - Fig. 4 shows a control scheme based on SCR model according to the drawing in figure 2, based on an NH3 slip level setpoint, - Fig. 5 shows an error recovery operated according to the present invention, when NOx is detected as NH3, - Fig. 6 shows an error recovery operated in accordance with the present invention, when NOx is detected as NH3.
    [0029] [00029] The same reference numbers and letters in the drawings designate the same or functionally equivalent parts. Detailed description of preferred embodiments
    [0030] [00030] The method and device for controlling the SCR catalyst comprises the fact of considering a model of SCR catalyst as divided into multiple storage cells. In each cell, the amount of ammonia stored and the exhaust gas components of the relevant gas (NOx, NH3, etc.) are calculated. In addition, the method may be responsible for the temperature, where the temperature of each cell is calculated. Therefore, the method estimates, by means of a sensor model, the behavior of the sensors actually assembled, being able to distinguish the point of operation on the sensor characteristic and being able to invert the polarity of the curve.
    [0031] [00031] As a very important feature, the NH3 sensitivity of the NOx sensor is reflected by the model.
    [0032] [00032] With reference to fig. 2, the physical exhaust line 1 comprises a true SCR catalyst 2, optionally including an oxidation catalyst to reduce NH3 slip, a urea dosing module 3, a NOx sensor 4, an NH3 sensor 5 , upstream and downstream temperature sensors 6, 7.
    [0033] [00033] An NH3 8 storage model is fed with the physically relevant inlet and outlet quantities, such as the inlet that releases mass flow 9, upstream of the NOx catalyst (NO and NO2), concentration and temperature, the amount of injected urea, and the exhaust mass flow downstream.
    [0034] [00034] The estimated sensor outputs 10, respectively, of NOx and NH3, are compared with the measured results of sensors 4 and 5. The errors are then used in an observer cycle, with a given gain 11, to correct the state variables of the estimation models, which are the amounts of ammonia stored in each cell, so that the calculated sensor outputs converge for the measurements.
    [0035] [00035] One of the most innovative aspects of the present invention is the concept of controlling only the level of ammonia storage of the first cell (in the gases that cross the direction) of the various cells into which the SCR catalyst is considered to be divided.
    [0036] [00036] The controller is the same for NOx and NH3 slider. Only the set points for the two control objectives are calculated separately. The actual setpoint is obtained from a minimal selection, since the NH3 slider is actually only a limitation of the NH3 displacement.
    [0037] [00037] The proposed control concept has two purposes. On the one hand, an NOx conversion efficiency target for the SCR catalyst has to be achieved. On the other hand, an NH3 slip limit should not be exceeded. Thus, the limitation of NH3 slip is dominant.
    [0038] [00038] Since the dynamics of the storage cells from the 2nd to the nth is slow compared to the dynamics of the first cell, only the last is directly controlled.
    [0039] - controle de NOx: A Figura 3 mostra um esquema do conceito de controle de NOx. A partir do objetivo global da eficiência da conversão de NOx 31 e da eficiência conseguida de células 32 a partir da segunda para a n-éssima célula calculada a partir dos níveis de armazenamento correntes, um objetivo da eficiência para a primeira célula 37 é calculado no bloco 33. Este objetivo de eficiência é convertido em um ponto de ajuste para o nível de armazenamento de NH3 da primeira célula, no bloco 34, em que o estado atual do sistema 35 (temperatura, velocidade espacial, razão NO2/NO, etc) é levado em consideração. [00039] Therefore, a NOx control scheme can be of the type of control based and / or type of limitation of slip of NH3. - NOx control: Figure 3 shows a schematic of the NOx control concept. From the overall objective of the efficiency of NOx conversion 31 and the efficiency achieved from cells 32 from the second to the nth cell calculated from of current storage levels, an efficiency target for the first cell 37 is calculated in block 33. This efficiency target is converted into a setpoint for the NH3 storage level of the first cell in block 34, where the Current state of system 35 (temperature, space speed, NO2 / NO ratio, etc.) is taken into account.
    [0040] - limitação de escorregamento de NH3: um esquema do conceito de limitação de NH3 está representado na Figura 4. A partir do limite de NH3 na cauda do catalisador de SCR 41, um nível de armazenamento da última célula é calculado no bloco 42 com a temperatura e outras condições de operação, como a velocidade espacial e proporção NO2/NO no bloco 43. Começando a partir do último elemento, um nível de armazenamento de NH3 é calculado para cada célula 44, o qual é necessário para atingir o nível desejado de armazenamento de NH3 da última célula em estado estacionário sob condições de operação atuais (temperatura, velocidade espacial, relação NO2/NO, etc). Finalmente, o nível de armazenamento desejado da primeira célula 45 é obtido, o qual é alimentado para a seleção mínima 46 para o ponto de ajuste de nível de NH3. O mínimo do ponto de ajuste de controle NH3 45 e do ponto de ajuste de controle de NOx 46 (ver acima) é selecionado e comparado com o valor real do nível de NH3 na primeira célula 47. O deslocamento é, então, transmitido a um controlador 48, o qual ajusta a quantidade de ureia ou de NH3 49. Uma vez que o cálculo de ECU e recursos de memória são limitados, uma implementação vantajosa do método poderia modelar o SCR como uma 2 ÷ 3 células de armazenamento. [00040] The minimum of the NOx control setpoint 34 and the NH3 control setpoint 36 (see below) is selected and compared to the actual value of the NH3 level in the first cell 37. The offset is then , transmitted to a controller 38, which adjusts the amount of urea or NH3 39. - NH3 slip limitation: a scheme of the NH3 limitation concept is shown in Figure 4. From the NH3 limit on the tail of the SCR 41 catalyst, a storage level of the last cell is calculated in block 42 with the temperature and other operating conditions, such as spatial speed and NO2 / NO ratio in block 43. Starting from the last element, an NH3 storage level is calculated for each cell 44, which is necessary to achieve the desired storage level of NH3 from the last cell in steady state under current operating conditions (temperature, space speed, NO2 / NO ratio, etc.). Finally, the desired storage level of the first cell 45 is obtained, which is fed to the minimum selection 46 for the NH3 level setpoint. The minimum of the NH3 control setpoint 45 and the NOx control setpoint 46 (see above) is selected and compared to the actual value of the NH3 level in the first cell 47. The offset is then transmitted to a controller 48, which adjusts the amount of urea or NH3 49. Since the calculation of ECU and memory resources are limited, an advantageous implementation of the method could model the SCR as a 2 ÷ 3 storage cells.
    [0041] - Ganhos de retroalimentação variável. Os ganhos de retroalimentação, isto é, o ajuste das variáveis de estado (quantidade de NH3 armazenada ou outras) impostas pelos desvios entre as saídas do sensor medidos e calculados, pode ser variado sobre o ponto de operação e / ou em condições especiais de operação, tais como temperatura, velocidade espacial, amônia armazenada ou outros. Sob condições normais de operação, um erro do sensor de NOx positivo conduz a uma diminuição da amônia armazenada, a fim de aumentar a saída do sensor de NOx calculada para o nível de medida. No entanto, se a ureia em excesso é injetada e o sensor de NOx, principalmente, mede NH3, o nível de amônia modelado armazenado é aumentado de modo a eliminar o desvio do sensor. Este comportamento é automaticamente capturado quando se utiliza um método observador não linear, como um filtro de Kalman estendido, e os similares, por favor, ver, por exemplo Welch, Bispo: "Uma Introdução ao Filtro de Kalman", URL http: / / www. cs. unc. edu / ~ welch / media / pdf / kalman_intro. pdf. Outras condições podem fazer uma mudança de ganho de retroalimentação necessário: Em primeiro lugar, se se sabe que uma saída do sensor é imprecisa sob condições bem definidas, por exemplo, durante os transientes, a retroalimentação pode ser temporariamente enfraquecida, isto é, a correção é reduzida. Em segundo lugar, os ganhos de retroalimentação podem ser temporariamente aumentados, se necessário. Se, por exemplo, o escorregamento de NH3 é detectado pelo sensor de NH3, a retroalimentação do sensor de NOx é enfraquecida e o sensor de retroalimentação de NH3 aumentado a fim de priorizar o sensor de NH3 e assegurar uma estimativa correta de deslizamento de NH3 pelo controlador. Isto é necessário para permitir que o controlador tome as medidas apropriadas (por exemplo, reduzir a injeção de ureia). - A extensão do método de controle, através da introdução de um sistema de identificação, por exemplo, um filtro de Kalman estendido. Assim, as variáveis de estado adicionais são introduzidas, que representam constante para parâmetros lentamente à deriva, como capacidade de armazenamento do catalisador ou compensações de injeção de uréia ou sensores, a qualidade da ureia. O circuito fechado de retroalimentação do observador também corrige estes parâmetros e, portanto, permite a adaptação do modelo para alterações a longo prazo, tais como o envelhecimento do sistema ou deriva de concentração da solução de ureia. - Disponibilidade de informações do sensor: sensores de gás normalmente não podem ser operados sob todas as condições. Especialmente durante a operação de arranque a frio, quando as gotas de água estão presentes nos gases de escape, alguns sensores devem ser desligados. Sob estas condições, o circuito fechado de retroalimentação é simplesmente desligado, isto é, o sistema de controle funciona em circuito aberto e não é corrigido com os dados do sensor. - O método de controle pode ser estendido a qualquer sensor de gás nitrogenado, do qual a saída pode ser calculada por meio de um modelo. Os sensores de temperatura ou espécies de gás não discutidso aqui (por exemplo, N2O) podem ser uma opção. [00041] The method can be applied to NOx and NH3, or other nitrogenous species, such as NO2, NO, N2O. Advantageously, by implementing the method of the present invention, the following elements, variations and modifications can be achieved: - Variable feedback gains. The feedback gains, that is, the adjustment of the state variables (amount of stored NH3 or others) imposed by the deviations between the measured and calculated sensor outputs, can be varied on the operating point and / or under special operating conditions , such as temperature, space speed, stored ammonia or others. Under normal operating conditions, a positive NOx sensor error leads to a decrease in the stored ammonia in order to increase the calculated NOx sensor output to the measurement level. However, if excess urea is injected and the NOx sensor mainly measures NH3, the stored modeled ammonia level is increased in order to eliminate sensor drift. This behavior is automatically captured when using a nonlinear observer method, such as an extended Kalman filter, and the like, please see, for example, Welch, Bishop: "An Introduction to the Kalman Filter", URL http: / / www. cs. unc. edu / ~ welch / media / pdf / kalman_intro. pdf. Other conditions can make a necessary feedback gain change: First, if it is known that a sensor output is inaccurate under well-defined conditions, for example, during transients, the feedback can be temporarily weakened, that is, the correction is reduced. Second, feedback gains can be temporarily increased, if necessary. If, for example, the NH3 slip is detected by the NH3 sensor, the NOx sensor's feedback is weakened and the NH3 feedback sensor is increased in order to prioritize the NH3 sensor and ensure a correct NH3 slip estimate by controller. This is necessary to allow the controller to take the appropriate measures (for example, to reduce urea injection). - The extension of the control method, through the introduction of an identification system, for example, an extended Kalman filter. Thus, additional state variables are introduced, which represent a constant for slowly drifting parameters, such as catalyst storage capacity or compensation for urea injection or sensors, the quality of urea. The observer's feedback loop also corrects these parameters and therefore allows the model to be adapted for long-term changes, such as system aging or drift of the urea solution. - Availability of sensor information: gas sensors cannot normally be operated under all conditions. Especially during the cold start operation, when water droplets are present in the exhaust gases, some sensors must be turned off. Under these conditions, the feedback loop is simply switched off, that is, the control system operates in an open circuit and is not corrected with the sensor data. - The control method can be extended to any nitrogen gas sensor, from which the output can be calculated using a model. Temperature sensors or gas species not discussed here (for example, N2O) may be an option.
    [0042] [00042] The control concept shown inherently uses the storage and controller model to detect whether the NOx (or NH3) sensor signal is interpreted correctly. Hereby, the main advantage of the invention is that the controller "knows", at all times, the polarity of the estimation sensor model, that is, whether the NOx signal increases or decreases with increasing amounts of stored ammonia. Thus, the model inherently "knows" at all times that side of the feature in Figures 5 and 6, it really is. The detection of a wrong exit and its recovery method can be formulated as follows: Case 1: "The divergence towards the NOx side", that is, NH3 is detected as NOx:
    [0043] - ponto de ajuste para NH3 armazenado é persistentemente crescente - nenhum deslizamento de NH3 é estimado - Retroalimentação do controlador é negativa, isto é, o sinal de sensor de NOx aumenta com o nível de armazenamento de NH3 descrescente. Para a recuperação do erro de polarização: a quantidade de NH3 armazenada é aumentada por uma rampa, até que o sinal do sensor de NOx calculado é igual a uma medida no lado direito (ver a seta na Figura 6). Caso 2: "Divergência para lado de NH3", ou seja, NOx é detectado como NH3:[00043] The detection of wrong polarity (wrong operating point) is dependent on the following conditions, which must be fulfilled over a period of time (dependent on temperature). - set point for stored NH3 is persistently increasing - no slip of NH3 is estimated - Controller feedback is negative, that is, the NOx sensor signal increases with the decreasing NH3 storage level. For the recovery of the polarization error: the amount of NH3 stored is increased by a ramp, until the signal from the calculated NOx sensor is equal to a measurement on the right side (see the arrow in Figure 6). Case 2: "Divergence towards NH3 side", that is, NOx is detected as NH3:
    [0044] [00044] The detection of the polarization error is dependent on the following conditions, which must be satisfied for a period of time (temperature dependent):
    [0045] - deslizamento de NH3 significativo ocorre no modelo - Retroalimentação do controlador é positivo, ou seja, sinal de NOx diminui com o nível de armazenamento de NH3 crescente. [00045] Setpoint for stored NH3 is persistently decreasing - significant NH3 slip occurs in the model - Feedback from the controller is positive, that is, the NOx signal decreases with the increasing NH3 storage level.
    [0046] [00046] For recovery, the amount of NH3 stored is reduced by a ramp, until the calculated NOx sensor signal is equal to a measurement on the left hand side (see the arrow in Figure 5).
    [0047] [00047] Once recovery has become effective, the NOx controller or NH3 slip limitation described above takes the system to the desired NOx conversion efficiency or limits NH3 emissions to the maximum level.
    [0048] [00048] This invention can be advantageously implemented in a computer program which comprises means of program code to perform one or more steps of such method, when such program is executed on a computer. For this reason, the patent also covers the computer program, and the computer-readable medium that comprises a recorded message, computer-readable medium such that it comprises the program code means for performing one or more steps of such a method, when such a program is run on a computer.
    [0049] [00049] Many changes, modifications, variations and other uses and applications of the present invention will be evident to those skilled in the art after consideration of the description and the accompanying drawings that describe preferred embodiments thereof. All these changes, modifications, variations and other uses and applications that do not depart from the spirit and scope of the invention are considered to be covered by the present invention.
    [0050] [00050] Other details of implementation will not be described, as the one skilled in the art is capable of carrying out the invention from the teachings of the description above.
    权利要求:
    Claims (13)
    [0001]
    A method for controlling a vehicle's SCR catalytic converter comprising the step of using an estimated nitrogen gas sensor output as a reference value, forcing the estimated sensor output to converge to a measured value characterized by the fact that, in an observer, convergence is forced by means of adjusting the amount of stored ammonia or other state variables using variable feedback gains, which depend on operational conditions, such as temperature, space speed, stored ammonia or others, where the amount or signal of the observer's feedback gains are used to detect divergence and to initiate a recovery step from said divergence, said divergence being due to a misinterpretation of the NOx sensor signal, caused by the NH3 ambiguity / NOx of the sensor characteristic.
    [0002]
    Method, according to claim 1, characterized by the fact that convergence is forced by means of additional constant adjustment to slowly derive parameters, such as catalyst storage capacity or displacement of urea injection or sensors, or the urea quality.
    [0003]
    Method according to claim 1, characterized by the fact that said recovery step provides to adjust the amount of ammonia or other amounts stored in the observer, such as to converge to the correct side of the NOx sensor characteristic.
    [0004]
    Method according to any one of the preceding claims, characterized by the fact that if a divergence is detected, because a missing NH3 slip is detected or because a present NH3 slide is not detected, the controller reverses the polarity of the sensor. NH3 and NOX stored for the calculation of the operating point present in the sensor characteristic.
    [0005]
    Method, according to claim 1, characterized by the fact that said nitrogenous gases are NOX and / or NH3, and / or NO2, and / or NO, and / or N2O.
    [0006]
    Method, according to any of the preceding claims, characterized by the fact that it further comprises the step of considering the SCR catalytic converter as divided into a succession of two or more storage cells, and the step of controlling NH3 stored only in one of said cells, preferably in the first.
    [0007]
    Method according to any of the preceding claims, characterized by the fact that it further comprises the step of controlling an amount of injected urea or the amount of NH3 or any other reducing agent that is converted to NH3, by calculating a catalyst conversion efficiency.
    [0008]
    Method according to any of claims 1 to 6, characterized in that it further comprises the step of controlling an amount of injected urea or amount of NH3 or any other reducing agent that is converted to NH3, an injection of urea, by through a calculation of a sliding level of NH3 in the SCR catalytic converter.
    [0009]
    Method according to either of claims 7 or 8, characterized in that the amount of injected urea, or amount of NH3 or any other reducing agent that is converted to NH3, is controlled by means of both calculated set points by targeting, a level of NH3 storage and a catalyst conversion efficiency.
    [0010]
    Method, according to claim 9, characterized by the fact that said defined points are calculated separately and in which the actual defined control point is obtained from a minimum selection of said defined points.
    [0011]
    Method according to any of the preceding claims, characterized by the fact that if no sensor is available or the NOx or NH3 sensor output is not or is partially reliable, the corresponding feedback gain is adjusted or switched to zero.
    [0012]
    Device for controlling a vehicle SCR catalytic converter characterized by the fact that it comprises means for implementing the method as defined in any of the preceding claims.
    [0013]
    Computer-readable medium comprising instructions thereon, characterized by the fact that when executed by a computer, it performs the method as defined in any one of claims 1 to 11.
    类似技术:
    公开号 | 公开日 | 专利标题
    BR112012015671B1|2020-08-25|method and device for controlling a scr catalytic converter in a vehicle
    EP2551480B1|2020-11-04|Engine exhaust purification device
    US7736595B2|2010-06-15|Dosing agent injection control for selective catalytic reduction catalysts
    BRPI1000840B1|2020-03-17|METHOD FOR DOSING AN AMMONIUM RELEASING REDUCTION AGENT IN AN EXHAUST GAS FLOW
    KR100592414B1|2006-06-22|Method of Estimating NOX Storage
    BR112012022796B1|2021-02-09|control system for dosing compensation in a scr system
    US20050252197A1|2005-11-17|Diesel aftertreatment systems
    US20050103099A1|2005-05-19|Diesel aftertreatment systems
    JP6080954B2|2017-02-15|Control device, exhaust purification device for internal combustion engine, and control method for exhaust purification device
    BRPI1000809B1|2020-01-21|method for dosing an ammonia releasing reducing agent in an exhaust gas stream
    BR112012014614B1|2020-12-08|method for controlling a fill level of a reducer buffer level
    US9261002B2|2016-02-16|Feed-back for closed-loop selective catalytic reduction control
    US8898032B2|2014-11-25|Method for estimating an exhaust gas temperature
    US10502114B2|2019-12-10|Concentration calculation apparatus, concentration calculation system, and concentration calculation method
    US20220049637A1|2022-02-17|Method and device for controlling at least one scr catalytic converter of a vehicle
    CN111911269A|2020-11-10|Method for monitoring an SCR catalytic converter
    EP3084162B1|2017-11-01|Method and control assembly for operating an exhaust gas system
    KR100992816B1|2010-11-08|System for correction a stored ammonia quantity of emission reduce line on diesel vehicle and method thereof
    US20210189935A1|2021-06-24|Method for controlling an scr catalytic converter
    US11280241B2|2022-03-22|Method of adjusting the dosage of reductant in an SCR catalyst
    JP2018178734A|2018-11-15|Exhaust emission control system for internal combustion engine
    US20210123367A1|2021-04-29|Method of adjusting the dosage of reductant in an scr catalyst
    JP2020076361A|2020-05-21|Humidity estimation device
    US10808590B2|2020-10-20|Selective catalytic reduction adaptation for accuracy and minimized tailpipe impact
    同族专利:
    公开号 | 公开日
    BR112012015671A2|2017-12-12|
    CN102686842B|2014-12-24|
    RU2012131306A|2014-01-27|
    RU2560120C2|2015-08-20|
    US20120310507A1|2012-12-06|
    JP2013515897A|2013-05-09|
    JP5805103B2|2015-11-04|
    AU2010334855A1|2012-08-09|
    CN102686842A|2012-09-19|
    ES2434741T3|2013-12-17|
    EP2339136A1|2011-06-29|
    WO2011076839A1|2011-06-30|
    EP2339136B1|2013-08-21|
    AU2010334855B2|2014-05-22|
    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    DE59601433D1|1995-09-29|1999-04-15|Siemens Ag|METHOD AND DEVICE FOR IMPLEMENTING A POLLUTANT IN AN EXHAUST GAS ON A CATALYST|
    US5771685A|1996-10-16|1998-06-30|Ford Global Technologies, Inc.|Method for monitoring the performance of a NOx trap|
    US6295809B1|1999-07-12|2001-10-02|Ford Global Technologies, Inc.|Emission control system with a catalyst|
    JP4088412B2|2000-12-26|2008-05-21|トヨタ自動車株式会社|Air-fuel ratio control device for internal combustion engine|
    US6882929B2|2002-05-15|2005-04-19|Caterpillar Inc|NOx emission-control system using a virtual sensor|
    US7093427B2|2002-11-21|2006-08-22|Ford Global Technologies, Llc|Exhaust gas aftertreatment systems|
    DE10301606A1|2003-01-17|2004-07-29|Robert Bosch Gmbh|Process for operating a catalyst of an I.C. engine of a vehicle, comprises controlling the amount of re-agent depending on the observed parameter of an adapted observation system|
    SE526404C2|2004-01-20|2005-09-06|Scania Cv Abp|Method and apparatus for controlling the injection of reducing agents|
    JP4455159B2|2004-05-24|2010-04-21|財団法人日本自動車研究所|Urea SCR system|
    DE102004046640B4|2004-09-25|2013-07-11|Robert Bosch Gmbh|Method for operating an internal combustion engine and device for carrying out the method|
    US7155334B1|2005-09-29|2006-12-26|Honeywell International Inc.|Use of sensors in a state observer for a diesel engine|
    DE102006027357B4|2006-06-13|2015-12-03|Volkswagen Ag|Method for operating an SCR catalytic converter and exhaust system|
    GB0614445D0|2006-07-20|2006-08-30|Ricardo Uk Ltd|Control of selective catalytic reduction|
    US20080098725A1|2006-10-31|2008-05-01|Caterpillar Inc.|Exhaust system having mid-reducer NOx sensor|
    JP2008157136A|2006-12-25|2008-07-10|Mitsubishi Fuso Truck & Bus Corp|Exhaust emission control device for internal combustion engine|
    JP2008196340A|2007-02-09|2008-08-28|Mitsubishi Fuso Truck & Bus Corp|Exhaust emission control device and exhaust emission control method for internal combustion engine|
    US7810313B2|2007-03-19|2010-10-12|Honeywell International Inc.|Method and system for the simultaneous measurement of a plurality of properties associated with an exhaust gas mixture|
    JP4767218B2|2007-06-08|2011-09-07|本田技研工業株式会社|Exhaust gas purification device for internal combustion engine|
    DE602007005125D1|2007-07-31|2010-04-15|Delphi Tech Inc|r catalytic reduction|
    US7992380B2|2007-08-23|2011-08-09|Caterpillar Inc.|Emission control system implementing reduction agent injection|
    US8230677B2|2007-11-26|2012-07-31|Michigan Technological University|NOx control systems and methods for controlling NOx emissions|
    JP2009180150A|2008-01-30|2009-08-13|Toyota Motor Corp|Abnormality determination device of nox sensor used for exhaust emission control system|
    US20110036078A1|2009-08-14|2011-02-17|International Engine Intellectual Property Company , Llc|Method for urea injection control|DE102011077246B3|2011-06-09|2012-06-06|Ford Global Technologies, Llc|Filtering method for nitrous oxide sensor of exhaust system, involves setting data of nitrous oxide sensor as ammonia measured values when ratio of nitrous oxide modeling error to ammonia modeling error is greater than upper threshold|
    DE102011122127A1|2011-12-22|2013-06-27|Deutz Aktiengesellschaft|Method and device for tank level detection in a motor vehicle|
    FR2988305B1|2012-03-22|2014-02-28|Renault Sa|METHOD FOR DETERMINING THE AMOUNT OF AMMONIA STOCKEY IN A CATALYST, AND CORRESPONDING SYSTEM|
    US8943798B2|2012-10-12|2015-02-03|Ford Global Technologies, Llc|Methods and systems for ammonia slip detection|
    US9046025B2|2013-06-07|2015-06-02|GM Global Technology Operations LLC|Selective catalytic reduction device monitoring system|
    CN104179555B|2013-08-01|2016-12-28|吉林师范大学|A kind of supercharged diesel engine SCR system transient state NH3leakage control system and method|
    US9309797B2|2014-03-05|2016-04-12|GM Global Technology Operations LLC|System and method for controlling dosing in selective catalytic reduction catalyst|
    TWI533921B|2014-03-26|2016-05-21|財團法人車輛研究測試中心|Analysis system of gas cross-sensitivity phenomenon and method thereof|
    US9453449B2|2015-01-06|2016-09-27|Robert Bosch Gmbh|Diesel exhaust system and method for controlling exhaust fluid dosing|
    CN104975923B|2015-06-09|2017-12-19|上海海事大学|A kind of observation procedure and observation system of SCR system of diesel engine input state|
    US9506390B1|2015-06-18|2016-11-29|Ford Global Technologies, Llc|Distributed control of selective catalytic reduction systems|
    US9695727B2|2015-09-02|2017-07-04|Deere & Company|System and method for adaptive aftertreatment control of NOx|
    DE102016204323B4|2016-03-16|2018-03-08|Continental Automotive Gmbh|Method for determining a corrected nitrogen oxide value and ammonia value in an internal combustion engine|
    JP6638549B2|2016-05-02|2020-01-29|いすゞ自動車株式会社|Exhaust gas purification system for internal combustion engine and exhaust gas purification method for internal combustion engine|
    JP6769861B2|2016-12-20|2020-10-14|日野自動車株式会社|Control device and control method for urea SCR system|
    EP3339591B1|2016-12-21|2019-08-14|Perkins Engines Company Limited|Control method and apparatus for a selective catalytic reduction system|
    US20190093540A1|2017-09-27|2019-03-28|General Electric Company|Systems and methods adjusting for aftertreatment system condition|
    US20190093535A1|2017-09-27|2019-03-28|General Electric Company|Systems and methods for adjusting for aftertreatment system condition|
    IT201800003831A1|2018-03-21|2019-09-21|Fpt Motorenforschung Ag|METHOD OF ANALYSIS OF A SIGNAL GENERATED BY A NOX SENSOR OF AN ACTIVE SCR CATALYST AND RELATIVE METHOD AND SYSTEM OF CONTROL OF THE ACTIVE SCR|
    IT201800020851A1|2018-12-21|2020-06-21|Fpt Motorenforschung Ag|METHOD AND DEVICE FOR CONTROL OF AT LEAST ONE SCR CATALYTIC CONVERTER OF A VEHICLE|
    CN110645077B|2019-10-15|2021-11-02|黄冈师范学院|Ammonia injection rate and state synchronous estimation method for Urea-SCR system of diesel engine|
    CN111075544A|2019-12-20|2020-04-28|一汽解放汽车有限公司|Urea consumption deviation diagnosis method based on urea liquid level sensor|
    USD917374S1|2020-03-19|2021-04-27|Richard Blake Tamagni|Catalytic converter cover|
    USD917373S1|2020-03-19|2021-04-27|Richard Blake Tamagni|Catalytic converter cover|
    法律状态:
    2017-12-26| B25D| Requested change of name of applicant approved|Owner name: FPT MOTORENFORSCHUNG AG (CH) |
    2019-01-08| B06F| Objections, documents and/or translations needed after an examination request according art. 34 industrial property law|
    2019-10-01| B06U| Preliminary requirement: requests with searches performed by other patent offices: suspension of the patent application procedure|
    2020-07-07| B09A| Decision: intention to grant|
    2020-08-25| B16A| Patent or certificate of addition of invention granted|Free format text: PRAZO DE VALIDADE: 20 (VINTE) ANOS CONTADOS A PARTIR DE 22/12/2010, OBSERVADAS AS CONDICOES LEGAIS. |
    优先权:
    申请号 | 申请日 | 专利标题
    EP09180647.1|2009-12-23|
    EP09180647.1A|EP2339136B1|2009-12-23|2009-12-23|Method and device for controlling an scr catalytic converter of a vehicle|
    PCT/EP2010/070475|WO2011076839A1|2009-12-23|2010-12-22|Method and device for controlling an scr catalytic converter of a vehicle|
    [返回顶部]