• 专利附录
  • 专利说明
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    • 专利摘要:
    Summary The present invention relates to a method for diagnosing a condition by a means of transport having a first additive for treating an exhaust stream resulting from combustion in an internal combustion engine (101), said first additive being fed to said exhaust stream, and the said means being used at least one first hazardous substance (NO 2) in said exhaust gas strain, wherein at least one nature has said additive is diagnosed by using a first sensor (302; 312). The method comprises, when signals emitted from said first sensor (302; 312) indicate a deviation with respect to said At least one nature of said additive in a first diagnosis: determining whether said signals emitted from said first sensor (302; 312) are affected by a gas hazard occurrence, and if the signal emitted by said first sensor is affected by a gas occurrence, perform a second diagnosis of said At least one condition when the influence of said gas occurrence has diminished.
    公开号:SE1450377A1
    申请号:SE1450377
    申请日:2014-03-31
    公开日:2015-10-01
    发明作者:Ola Stenlåås；John Hult；Emma Lindström
    申请人:Scania Cv Ab；
    IPC主号:
    专利说明:

    BACKGROUND OF THE INVENTION Field of the Invention exhaust gas according to the preamble of claim 1. The invention also relates to a system, a means of transport and a vehicle, as well as a computer program and a computer program product, which implement the method according to the invention.
    Background of the invention Due to e.g. Increased government interests regarding hazardous pollutants and air quality in e.g. urban areas, emission standards and rules have been developed in many jurisdictions.
    Such emission standards often constitute sets of requirements which define acceptable limits for exhaust emissions in vehicles equipped with internal combustion engines. For example, levels of emissions of nitrogen oxides (NO), hydrocarbons (HC), carbon monoxide (CO) and particulate matter are often regulated for most types of vehicles in these standards.
    Unwanted releases of substances such as e.g. chemical compounds can e.g. reduced by reducing fuel consumption and / or by after-treatment (purification) of the exhaust gases caused by the combustion engine combustion.
    Exhaust gases from an internal combustion engine can e.g. finished by using a so-called catalytic purification process. There are different types of catalysts, where different types may be required for different industries and / or for the purification of different types of compounds present in the exhaust stream, and concerning at least nitrogen oxides NO (such as nitrogen oxide NO and nitrogen dioxide NO2) include heavy vehicles often a process in which an additive is supplied to the exhaust gas stream resulting from the combustion of the internal combustion engine in order, usually by utilizing a catalyst, to reduce the hazardous cost of nitrogen oxides NO to less harmful compounds (mainly nitrogen gas and water vapor).
    A common type of catalyst for use in NOx reduction, where additives are supplied, is SCR (Selective Catalyst Reduction) catalysts. SCR catalysts use ammonia (NH3), or a compound from which ammonia can be generated / formed, as an additive to reduce the danger of nitrogen oxides NO in the exhaust gas stream.
    The additive is injected into the exhaust gas stream resulting from the internal combustion engine, the catalyst is fed up, the additive supplied to the catalyst is absorbed (stored) in the catalyst, and the nitrogen oxides NOx the exhaust gases then react with the ammonia stored in the catalyst to form clams. above).
    When adding additives, it is important that the amount of added additive does not become too thick or too small. It is suedes' responsibility that the supplied amount of additives corresponds to a expected amount of additives. Furthermore, it is important for the reduction that the added additive also consists of an additive of the related type. SUMMARY OF THE INVENTION It is an object of the present invention to provide a method for diagnosing a condition in a means of transport when an additive is supplied to an exhaust stream. This object is achieved by a process according to claim 1.
    The present invention relates to a method for diagnosing a condition in a means of transport, having a first additive treated with an exhaust gas resulting from combustion in an internal combustion engine, said first additive being supplied with said exhaust gas, and said first additive being used for at least one additional additive. the first dangerous substance in said exhaust gas, wherein at least one nature of said additive is diagnosed by using a first sensor. The method comprises that, when signals emitted from said first sensor indicate a deviation with respect to said at least one nature, said additives in an initial diagnosis: - determining whether said signals emitted from said first sensor are affected by a gas hazard, and - signals emitted by the first sensor are affected by a gas deposit, perform a second diagnosis of said at least one condition when the influence of said gas deposit has decreased. The means of transport can e.g. consists of a vehicle.
    As mentioned above, the presence of at least some substances in an exhaust gas resulting from combustion can be reduced by adding additives to the exhaust stream, the additive reacting with one or more substances present in the exhaust stream to form less hazardous substances. 4 Eg. Supply of additives can be used to reduce the concentration of nitrogen oxides NO in the exhaust gases of the combustion engine. However, it is important that the additive is supplied in proportion to the substance (s) to be reduced in order for the desired effect to occur.
    Likewise, it is important that steering wheel-type additives are supplied to the exhaust pipe. If the wrong type, or an excessively small amount of additive, is added in relation to the presence of the substance to be reduced, there is a great risk that an undesirable excess of the substance will still line up after the reduction, and thus to be released into the environment of the means of transport with risk father to allow the spruce guard is exceeded.
    Conversely, if an excessive amount of additive is added, surpluses of other undesirable substances may instead accumulate.
    For example. With regard to NO reduction, an excess of ammonia may be released into the vehicle's environment. Although ammonia is a harmful substance that is often regulated by law with regard to emissions, excess ammonia does not matter either.
    With regard to the additive, the amount required for reduction to be obtained to the desired extent may be disproportionately large, provided that the cost of the additive in the process of e.g. A commercial vehicle can have a significant impact on vehicle economy.
    This can lead to the use of additives of a less suitable type, with a dangerous reduction of unwanted substances as a result.
    In order to ensure that additives of the desired quality and quantity are supplied to the exhaust stream, and also in order to avoid situations where the desired additive has been replaced with other less suitable, but economically more dangerous, additives with a common function, there are also ever stricter requirements. ex. vehicles through the use of self-diagnosis, so-called OBD (Onboard diagnostics) must be able to detect errors with regard to the additive and its supply.
    Among other things, there are, or will be, requirements on the vehicle's vehicle to diagnose a condition of the additive directly, e.g. in terms of quality or consumption. This can be achieved by using a sensor arranged in the additive medium tank, such as a quality sensor, where a nature, such as e.g. chemical composition or consumption, of the additive can be assessed by using such a quality sensor.
    Furthermore, in cases where errors are detected, the vehicle's control system will, for a certain period of time, take limitation measures with regard to e.g. performance, turns, in order to avoid such limiting measures with risky vehicle downtime as failed, the vehicle in case of detected defects will be forced to workshop in order to avoid unwanted downtime. If this is done when faults are detected, but without any actual fault, this can result in unnecessary workshop costs, and unwanted costs for vehicle downtime. The present invention provides a method of reducing the risk of inadvertent workshop visits by determining whether a detected fault is likely to actually constitute a fault. If this is not the case, a new diagnosis is made when the risk exposures are good so that a correct diagnosis can be made.
    This is accomplished by, when signals emitted from said first sensor indicate a deviation with respect to said at least one nature of said additive, 6 determining whether said signals emitted from said first sensor are affected by a gas deposit. This can e.g. performed by analyzing the emitted sensor signals, where it e.g. It can be determined whether the sensor signals start going towards the extreme value, or exceed an upper spruce value or below a lower spruce value, where the spruce values can be set so that the value exceeding the upper spruce value or below the lower spruce value does not normally occur during operation.
    The presence of gas can also e.g. determined by performing a verification feed by means of another type of sensor. If the verification feed indicates correct function, such as e.g. that a conversion (reduction) of said first substance, which is related by utilization of the additive, actually takes place, this indicates that a gas mixture in the additive additive tank is present and causes incorrect signals. According to one embodiment, it is required that the sensor signals indicate gas presence and that a verification feed indicates normal operation.
    According to one embodiment, it is required that sensor signals both indicate an incorrect substance and an incorrect tank level in order for a gas mixture to be considered to be present.
    If the signals emitted from said first sensor are affected by a gas hazard occurrence, a new diagnosis of said at least one condition is performed when the impact from said gas occurrence has decreased. The gas hazard occurrence can e.g. is assumed to have decreased when the vehicle / means of transport has been stationary for a certain period of time, or when the conditions when the vehicle / means of transport are in such a way that the gas occurrence decreases, as when traveling along a horizontal road at a substantially constant speed for some time. If the new diagnosis since 7 no longer indicates any deviation, the suedes system can be assumed to function correctly, whereby unnecessary workshop visits may have been avoided.
    Additional features of the present invention and parts thereof will be apparent from the following detailed description of exemplary embodiments and the accompanying drawings.
    Brief Description of the Drawings Fig. 1A shows a driveline in a vehicle in which the present invention with a vehicle part can be used.
    Fig. 1B shows a control unit in a vehicle control system.
    Fig. 2 shows an example of an after-treatment system with the supply of additives in which the present invention with a vehicle part can be used.
    Figs. 3A-B show examples of applicable sensors for use with the present invention.
    Fig. 4 schematically shows an exemplary method according to an embodiment of the present invention.
    Figs. 5A-B schematically show interpretations of sensor signals emitted by a sensor arranged in an additive tank.
    DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS The present invention will hereinafter be exemplified for a vehicle. However, the invention is also applicable to other types of means of transport, such as to aircraft and watercraft, respectively, as long as an additive is supplied to an exhaust stream resulting from combustion.
    Furthermore, in the present description and appended claims, the term "substance" is used, which at least in the present description and appended claims includes chemical compounds as well as mixtures.
    Fig. 1A schematically shows a driveline in a vehicle 100 according to an embodiment of the present invention. The vehicle 100 schematically shown in Fig. 1A comprises a driveline with an internal combustion engine 101, which in a conventional manner, via a shaft outgoing on the internal combustion engine 101, usually via a flywheel 102, is connected to a gearbox 103 via a clutch 106. The internal combustion engine 101 is controlled by the control system of the vehicle 100 via an engine control unit 115. Likewise, dangerous examples, clutch 106 and gearbox are controlled by a control unit 116, respectively.
    Furthermore, a shaft 107 emanating from the gearbox 103 drives drive wheels 113, 114 via an end shaft 108, such as e.g. a conventional differential, and drive shafts 104, 105 are connected to said end shaft 108. Fig. 1A thus shows a drive line of a certain type, but the invention is applicable to all types of drive lines, and also to e.g. hybrid vehicles. The vehicle shown also includes a post-treatment system 130 for post-treatment (purification) of the exhaust gases resulting from combustion in the combustion engine 101. The functions of the finishing system 130 are controlled by a control unit 131.
    The after-treatment system 130 may be of different types, and according to the embodiment shown, the supply of additives is carried out in a catalytic exhaust gas purification process. An example of a finishing system 130 to which the present invention can be applied is shown in more detail in Fig. 2, and in the exemplary embodiment shown, the finishing system includes a SCR (Selective Catalytic Reduction) catalyst 201.
    The finishing system may also include additional components (not shown), such as e.g. additional catalysts and / or particulate filters, which may be arranged upstream and / or downstream of the SCR catalyst 201.
    Supply of additives can, as above, e.g. is used in reducing the concentration of nitrogen oxides NO in the exhaust gases from the combustion engine by using an SCR catalyst.
    This additive can, as according to the embodiment shown, e.g. be urea-based, and e.g. consists of AdBlue, which is a frequently used additive, and which consists of a mixture of about 32.5% urea mixed with water. Urea forms ammonia on heating which then reacts with nitrogen oxides in the exhaust stream. The present invention is applicable to the use of AdBlue, as well as to the use of other urea-based additives, and as to other types of additives, where these other additives may be provided for the reduction of nitrogen oxides NO or other substances present in the exhaust stream.
    Fig. 2 thus shows, in addition to said catalyst 201, a urea dosing system (UDS), which comprises a urea tank 202, which is connected to an injection nozzle 205 by utilizing which additive is injected into the exhaust stream 119 of the combustion engine 101 upstream of the combustion engine 101. the catalyst 201.
    The urea dosing is controlled by a UDS control unit 204, which generates control signals for controlling the supply of additives so that the desired amount is injected into the exhaust stream 119 from the tank 202 by means of the injection nozzle 205. Furthermore, a luminaire is arranged in the tank 202, there are two example fittings; are exemplified below in connection with Figs. 3A-3B, which had a respective sensor for diagnosing the supply of the additive.
    In general, there are dosage systems for dosing additives of choice described in the prior art, and exactly how injection of additives is dosed / performed is not described further, but the present invention relates to a method for diagnosing a condition with respect to the additive, where the diagnosis e.g. . can be performed with respect to the chemical composition, tank level or color usage of the additive.
    In particular, the present invention provides a method which, when sensor signals received from one or more sensors 302: 312 arranged in the additive tank (see Figs. 3A and 3B, respectively) indicate a deviation with respect to a nature of the additive, determines whether a detected deviation is actually constitutes an error, or if the error is due to the sensor performing a non-representative feed due to the influence of a gas deposit.
    As mentioned above, in order to ensure that the vehicle complies with established emission regulations, there is a stricter requirement that the vehicle, by using its own diagnosis, OBD must be able to detect when faults occur with regard to the supply of additives during operation. This can e.g. This is achieved by, for example for nitrogen oxides NOR, estimating a degree of conversion, as by comparing an occurrence of NO, the supply of additives is increased with the danger of NO, the catalyst 201 is reduced, thus it can be determined whether the desired conversion, ie. reduction, takes place, and thus whether the supply of additives can be assumed to be carried out in the desired manner. The presence of NO upstream of the supply of additives or downstream of the catalyst 201 can e.g. determined by the use of NOx sensors 207, 208. 11 At least in some jurisdictions, however, requirements will also be placed on the vehicle's ability to assess the supply of additives through a direct assessment of the additive and not indirectly through the use of e.g. a degree of conversion.
    This can be achieved by using a sensor arranged in the additive medium tank, where e.g. the chemical composition of the additive, the degree of filling in the tank and / or the use can be assessed by using such a quality sensor.
    An exemplary method 400 according to the present invention is shown in Fig. 4 and is described below, where the method according to the invention may be arranged to be performed by any applicable control unit, such as e.g. UDS control unit 204. Generally, control systems in vehicles consist of a communication bus system consisting of one or more communication buses for interconnecting a number of electronic control units (ECUs), or controllers, and various components arranged on the vehicle 100. Such a control system can thus comprise a large number of control units, and the responsibility for a specific function can be divided into more than one control unit.
    For the sake of simplicity, in addition to the control unit 204 shown in Fig. 2, in Fig. 1A only three further electronic control units 115, 116, 131 are shown. The method according to the present invention can thus be arranged to be performed by any control unit present in the control system of the vehicle 100. sasom e.g. The UDS control unit 204 or the control unit 131 which is generally responsible for the operation of the finishing system 130, or alternatively be divided into several control units which are dangerous to the vehicle 100. The present invention can thus be implemented in any control unit in the vehicle control system.
    Control units of the type shown are normally arranged to receive sensor signals from different parts of the vehicle, e.g. from 12 gearboxes, engine, clutch and / or other control units or components on the vehicle. The control unit generated control signals are normally dependent on both signals from other control units and signals from components. For example. If the control unit 204 controls the supply of additives to the exhaust stream 119, e.g. depend on information such as received from one or more additional controllers. For example. the control can be at least partly based on information from the control unit 115 which is responsible for the operation of the combustion engine 101. Similarly, the UDS controller 204 of the present invention will receive signals from one or more sensors disposed in the additive tank 202.
    The control units can furthermore be arranged to emit control signals to different parts and components of the vehicle, such as e.g. means for controlling the injection nozzle 205.
    Furthermore, the control units' control of various functions is often controlled by programmed instructions. These programmed instructions typically consist of a computer program, which when executed in the control unit causes the control unit to perform the desired control, as well as to control the various hazardous functions in the vehicle, and also to perform process steps according to the present invention.
    The computer program is usually part of a computer program product, where the computer program product comprises a suitable storage medium 121 (see Fig. 1E) with the computer program stored on said storage medium 121. The computer program may be non-volatile stored on said storage medium. Said digital storage medium 121 may e.g. consists of someone from the group: ROM (Read-Only Memory), PROM (Programmable Read-Only Memory), EPROM (Erasable PROM), Flash memory, EEPROM (Electrically Erasable PROM), a hard disk drive, etc., and be arranged in or in connection with the control unit, 13 wherein the computer program is executed by the control unit. By following the instructions of the other computer program, the behavior of the vehicle in a specific situation can thus be adapted.
    An exemplary control unit (UDS control unit 204) is shown schematically in Fig. 1B, the control unit in turn may comprise a calculating unit 120, which may be constituted by e.g. any suitable type of processor or microcomputer, e.g. a Digital Signal Processor (DSP), or an Application Specific Integrated Circuit (ASIC). The calculating unit 120 is connected to a memory unit 121, which provides the calculating unit 120 e.g. the stored program code and / or the stored data calculation unit 120 need to be able to perform calculations, e.g. to determine whether an error code should be activated. The calculation unit 120 is also arranged to store partial or final results of calculations in the memory unit 121.
    Furthermore, the control unit is provided with devices 122, 123, 124, 125 for receiving and transmitting input and output signals, respectively. These input and output signals may contain waveforms, pulses, or other attributes, which of the devices 122, 125 for receiving input signals may be detected as information for processing the calculation unit 120. The devices 123, 124 for transmitting output signals are arranged to convert calculation results from the calculation unit. 120 to output signals for transmission to other parts of the vehicle control system and / or the component (s) for which the signals are intended. Each of the connections to the devices for receiving and transmitting input and output signals, respectively, may consist of one or more of: a cable; a data bus, such as a CAN bus (Controller Area Network bus), a MOST bus (Media Oriented Systems 14 Transport), or any other bus configuration; or a wireless connection.
    Referring to Fig. 4, there is shown an exemplary method 400 in accordance with the present invention. The process begins in step 401, where it is determined whether a deviation in the nature of the additive has been detected. This deviation may refer to any applicable parameter with respect to the additive, such as e.g. with respect to tank level, consumption or chemical composition. Other types of conditions may also be provided for inspection in accordance with the present invention.
    Concerning additives containing urea can e.g. a urea quality sensor is used in this respect. There are different types of urea quality sensors, and a very schematic example of a urea quality sensor is shown in Fig. 3A.
    Fig. 3A shows the additive tank 202. Furthermore, a fitting 300 is arranged in the tank 202, which comprises a raft 301 which in a conventional manner indicates the degree of filling (additive level) 304 in the tank 202. Furthermore, Fig. 3A shows a urea quality sensor 302, which is arranged in the luminaire 300, but which may alternatively be arranged separately from the luminaire 300. The sensor 302 shown is formed by an ultrasonic sensor, which by sending signals to a reflecting surface 303, which is at an edge distance Li from the sensor 302, can determine the speed of sound in the liquid by using the distance L1 and the time it takes for an emitted signal to return to the sensor 302 after being reflected to the surface 303.
    It is generally the case that the speed of sound in liquids varies with the composition of the liquid, and by determining the speed of sound, e.g. the urea content in the liquid is determined, as different urea levels will have different sound velocities in the liquid. The control system can e.g. include stored values for different water shoes, and different levels of active substances, such as e.g. urea. Thus, by using the urease sensor 302, e.g. determine whether the additive contains the desired urea level by determining whether the actual speed of sound in the liquid corresponds to the expected rate of sound, or whether the additive tank is likely to contain incorrect liquid, such as e.g. water or other liquid. If the contents are considered to be incorrect liquid, an error signal can be generated. Thus, the chemical composition of the additive can be analyzed using ultrasound diagnosis as above.
    Furthermore, Fig. 3B shows another example of a urea quality sensor 312, which also consists of an ultrasonic sensor arranged in a luminaire 310. Instead, as in Fig. 3A, the degree of filling / additive level in the tank 202 is determined by using a fleet, the urea quality sensor 312 is also used in this respect. This is achieved by, on the one hand, performing feeds for a can stretch L2, whereby the speed of sound for an unknown liquid can be determined as above, and whereby the liquid can thereby be analyzed. By then also feeding the time for reflections towards the water surface 313, the distance LX to the water surface can be determined after the speed of sound in the water has been determined, whereby thus the water level in the tank 202, and thus the remaining volume can be determined. Thus, by determining the change in tank level over time, consumption can be analyzed using the urea quality sensor 312.
    As will be appreciated, the sensors shown in Figures 3A-B are merely examples, and there are also other types of sensors, such as other types of urea quality sensors, where the present invention is applicable. For example. the sensor does not need to be 16 of an ultrasonic sensor. By utilizing sensors of e.g. the types shown in Figs. 3A-B, the additive can be analyzed, e.g. with respect to a concentration of active substance. It is also possible to determine whether it is probable that the additive refueled in the vehicle is in fact a related additive. Based on the outcome of such an analysis, Atgarder can then be taken if necessary, e.g. cm it is established that the additive does not consist of a colored additive.
    In at least some jurisdictions, there are or are also provisions that meant that the vehicle's control system must be arranged to take action if necessary, and the supply of additives works incorrectly. For example. such provisions may mean that the vehicle automatically reduces the maximum available torque from the combustion engine by e.g. 20% or other established level when a first time has elapsed after the deviation has been detected, as after a first number of hours. If it has been sailing for a further time, such as a further number of hours, without the fault being remedied, the vehicle can be arranged to automatically limit speed to e.g. 20 km / h. Such speed limitation often meant in practice that the vehicle was forced to stop in order to be towed to a workshop. Normally, the time limits are set so that the vehicle can be safely driven to a workshop for the application of applicable procedures.
    Vehicles are thus to a greater extent equipped with functions for automatic limitation of the vehicle's performance based on self-diagnosis, OBD.
    In cases where such an analysis shows errors with workshop visits as follows, but where it turns out that there is no error, e.g. due to incorrect sensor signals, this results in costly downtime. The present invention 17 therefore provides a method for determining whether sensor signals may be affected by a gas occurrence when deviations are indicated in order to avoid workshop visits unnecessarily.
    Thus, if in step 401 it is determined that a deviation in a nature of the additive exists, the procedure proceeds to step 402. In step 402 it is determined whether it can be suspected that the deviation is due to the criterion being affected by gas being mixed in the additive and / or other sat affects the sensor. This can e.g. be arranged to be suspected that the signal emitted by the sensor is approaching a maximum or minimum value. An example of this is shown in Fig. 5A, where a graph is shown of estimated consumption with time t. Until time TA, the emitted sensor signals indicate a consumption according to a gradient 501. At / after time TA, however, the sensor suddenly emits signals indicating the value as exceeds or falls below a spruce value LIMmAx and LIM -r respectively and e.g. consists of the maximum value 502 or the minimum value 503.
    The inventors of the present invention have realized that sensor signals going towards e.g. the extreme value as the maximum / minimum value may be due to gas being mixed into the additive and thereby affecting the measurement signal. Whether the sensor signals go towards the maximum value or the minimum value can be controlled by the design of the sensor. Thus, if the quality sensor suddenly emits unexpected signals, or if the signals begin to move towards extreme values, it may be suspected that the signals are affected by a gas deposit. Regarding the above signals, it can e.g. these are required to be emitted for a certain time, such as during the time interval TA-TB in Fig. 5A, in order for errors to be considered to exist at all. Thus, if it is suspected that the deviation may be due to a gas deposit in the additive, the procedure 18 continues from step 402 to step 403. If, on the other hand, it is not suspected that the measurement value is affected by a gas deposit, which e.g. may be the case if the measure indicates a lower risk of e.g. urea in the additive, where possible water refueling may be the cause, the procedure continues to a step 410 where usual measures are taken with e.g. activation of applicable error codes. transition to step 410 can e.g. The deviation occurs in such a way that the sensor signals emitted are within the interval below LIMNS and Exceeding LIMIN, in which case the error can be considered to be due to another cause than gas occurrence.
    As mentioned above, Fig. 5A shows an example of tank volume determination. Fig. 5B shows a corresponding example of chemical composition, where in Fig. 5B the y-axis represents urea content, and where at time TA the content suddenly deviates from the extreme value 505 or 506 in the corresponding way as above. Thus, even in such cases, the procedure may be arranged to proceed to step 403.
    According to one embodiment, it is required that both signals regarding chemical composition and signals regarding the degree of filling of the tank, which may be the case, but not necessarily the case, when using a sensor of the type shown in Fig. 3B, deviate from the colored value.
    In step 403, according to the embodiment shown, a verification procedure is performed to assess a probability that an error has actually occurred. This can e.g. This can be achieved by determining, in a customary manner, a degree of conversion before the reduction in which the additive is arranged, such as reduction of nitrogen oxides NOR. This can e.g. is carried out by utilizing the sensor 207 arranged upstream of the additive supply and the sensor 208 arranged downstream of the supply of 19 additives, whereby a degree of conversion can be calculated and compared with the expected degree of conversion based on e.g. assumed supply of additives. The occurrence upstream of the supply of additives can also e.g. berdknas based on any applicable model of the internal combustion engine and e.g. the amount of fuel supplied to the combustion engine. Thus, according to this embodiment, the NOx sensor 207 shown in Fig. 2 is not required.
    If the calculated conversion rate to a sufficient extent corresponds to the expected conversion rate, this is an indication that the system is nevertheless functioning correctly, and that the signals emitted by the quality sensor may be affected by a gas deposit. In this case, the procedure proceeds to step 405 as below. Conversely, if the estimated degree of conversion gives a further indication that the additive supply is incorrect, the procedure proceeds from step 404 to step 410 before taking the usual steps. Verification feed such as e.g. as above can alternatively be used as a criterion for transition from step 402 to step 405, whereby steps 403-404 are omitted.
    If the suedes verification feed indicates that errors are not dangerous, the error code or codes associated with the detected deviation are activated in step 405, whereby also one or more times may begin to be counted from this activation before statutory measures are taken when deadlines expire, such as torque reduction / speed reduction as above, unless the error code (s) are deactivated as below.
    The process then proceeds to step 406 to determine whether one or more conditions are met with a new diagnosis of said nature of said additives. as long as this is not the case, the procedure remains in step 406 while otherwise proceeding to step 407. During the time the procedure is in step 406 and diagnosis is thus not performed, the "usual" diagnosis of additives issued may be arranged to be barred by belt. and the hall, e.g. in cases where the sensors emit the value in the case of gas mixing that goes towards the minimum value. The same can be arranged to be performed with sensors that emit the high value when mixing with gas, alternatively e.g. Upper alarm limits may be provided to be turned off when the method is in step 406 in order to avoid further error reporting.
    Furthermore, the method may be arranged to be in step 406 for a certain time, such as e.g. a number of hours may, if a certain number of hours have elapsed, proceed to step 410 may thereby alert the driver to the need for service so that appropriate measures have time to be taken before e.g. speed reduction takes place and the vehicle clamed risks being left standing next to the road. According to the present invention, when it is suspected that quality assumptions are affected by the presence of gas in the additive, a new diagnosis is made when the conditions are such that the effect of the occurrence of the gas danger has completely disappeared or been reduced to some extent. The diagnostic conditions in step 406 may be based on one or more applicable conditions, and may e.g. consists of any of the examples below. transition to step 407 can e.g. occurs when the vehicle 100 has been stationary for some time, such as e.g. If the vehicle 100 has been stationary for a break or a daily rest period for some time, such as an appropriate number of hours or minutes. When the vehicle 100 is stationary, the gas mixed in the additive, e.g. due to splashing caused by low tank volume in combination with uneven flow, 21 are separated from the liquid, the liquid being sueded again becoming increasingly homogeneous as time passes at standstill. According to one embodiment, therefore, step 406 determines whether the vehicle has been stationary for the applicable time, whereby, if so, the procedure proceeds to step 407 for re-diagnosis as below.
    The idle time required in step 406 can e.g. be set to a fixed value, alternatively e.g. be set to a value that depends on the corresponding tank volume and / or degree of filling, where a longer time may be required at lower filling degrees with a varyingly larger gas content due to the more favorable occurrence of sludge. Suitable time can e.g. also be set based on empirical feeds. The time can also be arranged to depend on e.g. the temperature of the additive, ie the gas solubility of the additive usually depends on the temperature. Likewise, the release of gas from the liquid can take place at different speeds at different temperatures. transition to step 407 may also be arranged to take place based on the rate of change of the sensor signal, e.g. after the vehicle has stopped. For example. the quality sensor signal can be arranged to be monitored continuously even after the vehicle has stopped, whereby a change in the emitted sensor signal which arises over time can largely be assumed to be due to a change in the gas content of the liquid, and when the sensor signal change rate has subsided or below the rate of change. a new diagnosis according to step 407 may be arranged to be performed. transition to step 407 may also be arranged to take place when the vehicle is in motion, but where e.g. certain criteria may be required to be met in order for a diagnosis to be made. For example. it may be required that the vehicle 100 22 be driven at a substantially constant speed along a substantially flat surface for some appropriate time so that the gas content of the additive can thus be considered to have been reduced to an appropriate extent and a diagnosis can be made. Furthermore, it can e.g. it is required that the inclination of the vehicle during any applicable time is within the applicable limits. The vehicle movements can e.g. determined by using a gyro and / or an accelerometer.
    The diagnosis can also be arranged to be performed continuously, but where the drill guard for e.g. Sensor signals may be arranged to be due to advanced gas admixture, and are suede to be relatively different from the boron values normally used. These wells can in turn be arranged to e.g. depending on the time of the vehicle in the stationary state, the configuration of the additive tank and the sensor, as with respect to tank geometry, sensor type, etc., the degree of additive level in the additive tank, the additive temperature, the additive temperature change. Such drill guards and bar guard changes can be applied to all of the exemplified diagnostic criteria above.
    Thus, when it is determined that the applicable conditions for making a new diagnosis are met in step 406, the procedure then proceeds to step 407, where a new diagnosis with respect to a nature of the additive can be made, and where the diagnosis can now be made in cases which most likely involved that the impact of the gas involved is small. If at the diagnosis in step 407 it is determined that deviations still exist, step 408, the procedure proceeds to step 410 following the usual procedures as above. If, on the other hand, the challenging diagnosis determines that deviation is no longer dangerous, the deviation thus most likely being due to gas mixing, the procedure continues to step 23 409, whereby activated error codes are deactivated and timing for limiting vehicle performance is also stopped. The procedure can then Aterga e.g. to step 401 to re-determine whether new deviations exist.
    The present invention thus provides a process which can avoid costly workshop visits in situations where in practice no tel is dangerous, but where the cause of the fault has been caused by gas being mixed into the additive. By utilizing the present invention, unnecessary workshop visits can often be avoided. The procedure shown can e.g. applied when diagnosing the chemical composition of the additive or the use / additive level in the additive tank. The diagnosis can also, at e.g. utilization of a sensor of the type shown in Fig. 3B, is carried out when simultaneously diagnosing the composition of the liquid and the tank volume / consumption, respectively. Furthermore, the invention can be arranged to be active only at e.g. situations when the additive level in the additive tank is less than the appropriate level of flange as any applicable proportion of full tank as lower tank levels usually result in larger water flows in the tank and thus gas mixing.
    Furthermore, the invention has the advantage that since the time intervals generally applied before actions such as torque limitation / speed limitation are taken are relatively long (a relatively initial number of hours), the present invention can be allowed to take a relatively initial number of hours to ensure that tel is not available in practice. in situations when said is indicated by emitted sensor signals. According to the embodiment shown above, errors have been detected with the sensor arranged in the additive tank, while it is determined whether signals emitted from the sensor emitted in the additive tank are affected by a gas hazard occurrence by using a sensor to determine a conversion rate for conversion means by said additive.
    According to one embodiment, the diagnosis is performed in reverse order. According to this embodiment, it is determined whether signals regarding the degree of conversion, such as e.g. signals from the sensor 208, indicate a deviation, e.g. by the degree of conversion being undesirably low or the content measured by the sensor 208 being undesirably high. It can then be determined whether these sensor signals are affected by a gas hazard occurrence, where this determination is performed by analyzing sensor signals emitted from the sensor arranged in the additive tank, where this analysis can be performed exactly as above.
    The present invention has been exemplified above in connection with vehicles. However, the invention is also applicable to any means of transport such as aircraft or watercraft.
    Further embodiments of the method and system according to the invention are found in the appended claims. It should also be noted that the system can be modified according to various embodiments of the method according to the invention (and vice versa) and that the present invention is not in any way limited to the above-described embodiments of the method according to the invention, but relates to and includes all embodiments of the appended independent the scope of protection of the requirements.
    For example. The present invention is applicable to the diagnosis of all known additives and oxen future additives supplied to the exhaust stream for the reduction of the substance present in the exhaust stream. Likewise, the invention as above is equally applicable regardless of which substance in the exhaust stream is reduced. The invention is thus in no way limited to the reduction of nitrogen oxides, or additives from which ammonia is formed. 26
    权利要求:
    Claims (31)
    [1]
    1. determining whether said signals emitted from said first sensor (302; 312) are affected by a gas occurrence, and 2. if said signals emitted from said first sensor are affected by a gas occurrence, perform a second diagnosis of said At least one condition affecting said gas. gas content has decreased.
    [2]
    A method according to claim 1, wherein said nature of said additive is constituted by a chemical composition of said additive or a consumption of said additive.
    [3]
    A method according to claim 1 or 2, wherein said first sensor is arranged in an additive tank.
    [4]
    A method according to claim 3, wherein said nature of said additive is constituted by an additive level A in said additive tank. 27
    [5]
    The method of any of claims 1-4, further comprising determining whether said signals emitted from said first sensor (302; 312) are affected by a gas deposit by analyzing sensor signals emitted from said first sensor (302; 312).
    [6]
    The method of claim 5, further comprising determining that said signals emitted from said first sensor (302; 312) are affected by a gas hazard occurrence when said sensor signals exceed a near spruce value or fall below a lower spruce value.
    [7]
    The method of claim 5, further comprising determining that said signals emitted from said first sensor (302; 312) are affected by a gas hazard occurrence when said sensor signals represent an extreme value of said first sensor (302; 312).
    [8]
    The method of any of claims 1-7, further comprising determining whether said signals emitted from said first sensor (302; 312) are affected by a gas deposit by using at least a second sensor (207, 208).
    [9]
    The method of claim 8, further comprising: - determining by means of said second sensor (207, 208) a degree of conversion of the reduction of said first substance in said exhaust stream (119), and - determining whether said from said first sensor (302; 312) ) emitted signals are affected by a gas deposit based on said degree of conversion.
    [10]
    A method according to any one of the preceding claims, further comprising, provided that it has been determined that said signals emitted from said first sensor (302; 312) are affected by a gas deposit: - performing said second diagnosis when at least one first condition for performing said other diagnosis is met.
    [11]
    The method of claim 10, further comprising interrupting said procedure if said first condition has not been met a second time.
    [12]
    A method according to claim 10 or 11, wherein said first condition is one or more from the group: 1. the means of transport has been stationary for a first time, such as a first number of hours and / or minutes; signals emitted from said first sensor have ceased to travel, as after said means of transport has stopped; 2. the rate of change receives signals emitted from said first sensor less than a first value; said means of transport is driven at a substantially constant speed along a substantially flat surface for a third time; 3. The lateral and / or longitudinal inclination of the means of transport is less than one initial inclination.
    [13]
    A method according to claim 12, wherein said first time consists of one or more of the group: 1. a time dependent on additive tank volume and / or radiating degree of filling in said additive tank; 2. an empirically determined time; one time dependent on the temperature of the additive.
    [14]
    The method of claim 8, wherein by means of said first sensor a degree of conversion is determined for the reduction of said first substance in said exhaust gas stream (119), further comprising: - determining whether said signals emitted from said first sensor are affected by a gas hazard occurrence by analysis 29 of sensor signals emitted from a second sensor arranged in an additive tank.
    [15]
    The method of claim 14, further comprising determining that said signals emitted from said first sensor are affected by a gas deposit when said sensor signals from said second sensor exceed a byer spruce value or fall below a lower spruce value.
    [16]
    The method of claim 14, further comprising determining that said signals emitted from said first sensor are affected by a gas deposit when said sensor signals from said second sensor represent an extreme value of said second sensor.
    [17]
    A method according to any one of the preceding claims, further comprising performing said second diagnosis when said means of transport (101) has been stationary for a first time.
    [18]
    The method of claim 17, wherein said first time is arranged to depend on an additive level in an additive tank.
    [19]
    A method according to claim 17 or 18, wherein said first time is arranged to depend on a temperature for said additive.
    [20]
    A method according to any one of the preceding claims, further comprising determining that said signals emitted from said first sensor (302; 312) are affected by a gas occurrence when said emitted signals both indicate incorrect substance and an incorrect additive level in an additive tank.
    [21]
    The method of any of the preceding claims, further comprising: - activating at least one error code when signals emitted from said first sensor (302; 312) indicate a deviation, and 1. deactivating said At least one error code if said second diagnosis indicates that deviation does not ldngre fOreligger.
    [22]
    A method according to any one of the preceding claims, further comprising: 1. determining a travel rate for said signals emitted by said first sensor (302; 312), and - performing said second diagnosis when said rate of change is less than an initial rate.
    [23]
    The method of any of the preceding claims, further comprising determining whether said signals emitted from said first sensor (302; 312) are affected by a gas presence when the additive level in an additive tank is less than a first level.
    [24]
    A method according to any one of the preceding claims, wherein said gas deposit constitutes a gas deposit in an additive tank.
    [25]
    A process according to any one of the preceding claims, wherein said first additive is arranged to supply said exhaust gas stream with a first catalyst (201).
    [26]
    The process of claim 25, wherein said first catalyst is an SCR catalyst (201).
    [27]
    A computer program comprising program code, which if said program code is executed in a computer, causes said computer to perform the procedure according to any of claims 1-26.
    [28]
    A computer program product comprising a computer-curable medium and a computer program according to claim 27, wherein said computer program is included in said computer-curable medium. 31
    [29]
    A system for diagnosing a condition in a means of transport has a first additive for treating an Iranian combustion in an exhaust gas stream resulting from an internal combustion engine (101), said first additive being supplied with said exhaust stream (119), and said first additive being used for redox At least one first of the said exhaust gas hazardous substance (NO.), Wherein at least one nature has said additive is diagnosed by using a first sensor (302; 312), characterized in that the system comprises means adapted to, other signals emitted from said sensor (NO.). 302; 312) indicates a deviation with respect to the said At least one condition has said additives at an initial diagnosis: 1. determine whether the said signals emitted from said first sensor (302; 312) are affected by a gas occurrence, and 2. at the first occurrence. signals emitted by the first sensor are affected by a gas deposit, perform a second diagnosis of ndmnda Atminsta a condition ndr impact from ndmnda gas danger occur has decreased.
    [30]
    Transport means (100), characterized in that it comprises a system according to claim 29.
    [31]
    Vehicle (100), characterized in that it comprises a system according to claim 29. FIG. 'IA 13 116) 103 j1 ------ 104 ------ 108 106 j131107 101 1, ------ f ---- 1 14 2/6
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    同族专利:
    公开号 | 公开日
    SE538597C2|2016-09-27|
    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    法律状态:
    优先权:
    申请号 | 申请日 | 专利标题
    SE1450377A|SE538597C2|2014-03-31|2014-03-31|Method and system for diagnosing, in a transport medium, the nature of an additive for supply to an exhaust stream|SE1450377A| SE538597C2|2014-03-31|2014-03-31|Method and system for diagnosing, in a transport medium, the nature of an additive for supply to an exhaust stream|
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