Ejector flow rate calculation for gas component sensor compensation

Abstract

Method for a power machine (10) comprising the following: Adjusting exhaust gas recirculation (EGR) based on a flow rate at an ejector intake port, wherein the flow rate is based on a flow characteristic of the ejector (36) and a flow characteristic of a power engine system and not on sensor measurements, wherein an outlet of the The power engine system is coupled to the ejector intake channel; and further comprising compensating a measurement of a gas component sensor arranged in a power engine inlet downstream of an outlet of the ejector (36) on the basis of the flow rate at the ejector intake channel.

Description

[0001] The present application relates to the calculation of the flow rate of a gas from a vehicle system entering a suction channel of an ejector, and the compensation of gas component sensor dilution concentration measurements based on the calculated flow rate of the gas.

[0002] DE 10 2011 078 993 A1 discloses a method for extracting fuel vapors. DE 10 2010 029 150 A1 discloses a variable venturi nozzle system and method for an engine. US 2005 / 0 235 969 A1 discloses an internal combustion engine system and a method for controlling it.

[0003] In some vehicle systems, exhaust gases and gases from other engine components can enter the engine intake stream under certain conditions. Because these gases contain various combinations of reducing agents, oxidizing agents, and diluents, it may be desirable to determine their composition and flow rate, as well as how they might affect combustion, and to implement appropriate combustion control actions. For this purpose, one or more gas component sensors may be placed in the intake passage of a vehicle engine to measure the presence of reducing agents (e.g., hydrocarbons), oxidizing agents, and diluents (e.g., carbon monoxide and water) in the intake stream. However, in some vehicle systems, gases entering the intake passage upstream of the gas component sensor can cause the sensor to misread diluents.Conventional solutions for accounting for the presence of gases that affect gas component sensor readings involve determining the flow rate of the gases into the intake passage and using this flow rate, in conjunction with the gas concentration as measured by the gas component sensor, to determine how to correct the sensor's readings. Determining the flow rate of gases entering the intake passage can often be achieved using only existing sensors, such as those commonly found in vehicle systems, like atmospheric pressure (BP), compressor inlet pressure (CIP), and manifold absolute pressure (MAP) sensors.In the case of fuel vapors being purged from a fuel vapor purge system into the engine inlet via a canister purge valve (CPV), the flow rate may, for example, be a function of the vacuum level where the vapors enter the inlet passage and the opening extent (e.g., duty cycle) of the CPV.

[0004] However, the inventors here have recognized that determining the flow rate of gases entering an engine intake passage in the manner described above may not be achievable in vehicle systems that incorporate ejectors to create a vacuum (e.g., a vacuum used to purge the fuel vapor storage canister, to draw leakage gases from the crankcase into the intake passage, or to recirculate exhaust gases into the intake passage). For example, an ejector's intake port may be coupled to a fuel vapor purge system, a crankcase ventilation system, or an exhaust gas recirculation system, instead of, or in addition to, the system being directly coupled to the intake passage. A drive outlet of the ejector may be coupled to the intake passage, so that the gases entering the ejector's intake port are directed to the intake passage via the ejector's drive outlet.In these examples, it may not be possible to calculate the gas flow rate into the inlet port, as it may not be possible to calculate the gas flow rate into the ejector suction port using measurements from existing pressure sensors alone. In some systems, an additional pressure sensor may be added to the ejector suction port to allow the calculation of the gas flow rate into the ejector suction port, which may represent all or part of the gas flow rate into the inlet port (and consequently, the gas flow rate at the gas component sensor). However, this method may be undesirable due to the cost of adding a pressure sensor to the ejector suction port (or to each ejector suction port in examples where more than one system incorporates an ejector to draw gases into the inlet port).

[0005] The inventors alone recognized that the flow rate of gases entering an ejector intake duct from a vehicle system can be determined without a dedicated pressure sensor at the ejector intake duct by superimposing ejector flow rate characteristics with flow rate characteristics of the vehicle system. In cases where, for example, the vehicle system outlet is in series with the ejector intake duct, the intersection of the vehicle system flow rate characteristic and the ejector flow rate characteristic can provide the gas flow rate at the ejector intake duct as well as the pressure at the ejector intake duct. In examples where the vehicle system outlet is not in series with the ejector intake duct, the gas flow rate in paths other than the path to the intake duct can be determined using conventional methods (e.g., based on data from existing pressure sensors and other known parameter values ​​such as...).The CPV duty cycle for fuel vapor purge gases can be determined, and the vehicle system flow rate characteristic can be shifted based on the gas flow rates in paths other than the path to the intake manifold. The shifted characteristic of the ejector flow rate characteristic can then be superimposed, and the intersection of the characteristics can provide the gas flow rate at the ejector intake manifold as well as the pressure at the ejector intake manifold. In these examples, the flow rate at the ejector intake manifold can then be summed with the gas flow rate in any other paths leading to the inlet passage upstream of the gas component sensor to determine the gas flow rate as seen by the gas component sensor.The control unit can then determine, based on the gas flow rate from the vehicle system, as seen by the gas component sensor, and the gas concentration, as derived by the gas component sensor, how to compensate for the measurements taken by the gas component sensor.

[0006] In one example, the flow rate of a gas from a vehicle system entering an ejector intake port can be determined by a procedure for a power engine. This procedure involves superimposing an ejector intake port flow rate characteristic as a function of vacuum with a flow rate characteristic as a function of vacuum of a power engine system connected to the port, and determining a flow rate of gases from the power engine system based on the intersection of these characteristics. The control system can then calculate a reducing agent concentration (e.g., fuel vapor concentration) of the gases from the power engine system using this flow rate and a reducing agent concentration measurement of the total flow at a gas component sensor (e.g., an inlet UEGO sensor) located downstream of the ejector outlet in a power engine intake passage.In some examples, the calculated reducing agent concentration can then be used to determine the effect of the reducing agent on the diluent concentration measurements of the gas component sensor, in order to determine a suitable compensation for the measurements. If diluent concentration measurements can be used as a basis for exhaust gas recirculation (EGR) settings in some systems, compensating for the diluent concentration measurements can, among other advantages, improve the EGR settings.

[0007] Naturally, the above summary is intended to introduce, in simplified form, a selection of concepts that are further described in the detailed description. It is not intended to identify any key or essential features of the claimed subject matter, the scope of which is defined solely by the claims that follow the detailed description. Furthermore, the claimed subject matter is not limited to implementations that overcome any disadvantages specified above or in any part of this disclosure.

[0008] Fig. Figure 1 shows a schematic diagram of a vehicle system.

[0009] Fig. Figure 2 shows a graph representing the relationship between the flow rate and the vacuum at an ejector intake port, a graph representing the relationship between the flow rate and the vacuum at the outlet of a fuel vapor scavenging system, and a graph superimposing the ejector intake port and fuel vapor scavenging system flow rate / vacuum characteristics.

[0010] Fig. Figure 3 shows a flow chart representing a procedure for compensating the measurements of a gas component sensor located in a power engine inlet passage, based on the flow rate and concentration of gases from a fuel vapor purge system.

[0011] Fig. Figure 4 shows a flowchart illustrating a method for determining the flow rate of gases from a fuel vapor purge system, as seen by a gas component sensor in an engine intake passage, in conjunction with the methods of Fig. 3 and Fig. 5 can be used.

[0012] Fig. Figure 5 shows a flowchart representing a method for calculating the concentration of fuel vapor in fuel vapor purge gases, which, in conjunction with the methods of Fig. 3 and Fig. 4 can be used.

[0013] The following description relates to systems and methods for a power unit in a vehicle system that includes an ejector intake port coupled to an outlet of a power unit system (e.g., a fuel vapor scavenging system), wherein an outlet of the ejector is connected to an inlet passage of the power unit upstream of a gas component sensor such as an inlet UEGO sensor. As described in Fig. As shown in Figure 1, an EGR system can also be connected to the inlet passage upstream of the gas component sensor. In some embodiments, such as the embodiment of Fig. 1. In which a fuel vapor purge system outlet is connected to an ejector intake port, the flow characteristics of the fuel vapor purge system and the ejector can be used as a basis for obtaining the flow rate of gases from the fuel vapor purge system at the ejector intake port independently of sensor measurements, as in Fig. 2 shown. While some systems may include, for example, pressure or flow rate sensors on the ejector suction channel, those shown in Fig. The flow characteristics shown in Figure 2 can instead be used as a basis for obtaining the flow rate (and pressure) at this point in the system. Based in part on this flow rate, it may be possible to compensate for readings from a gas component sensor downstream of the ejector outlet, as described in the methods of Fig. 3-5 described. The compensated measured values ​​can improve the adjustment of the engine operation, e.g. the EGR setting.

[0014] Fig. Figure 1 shows a schematic diagram of a vehicle system 100. The vehicle system 100 comprises a power unit 10, which may be included in the propulsion system of a motor vehicle. Atmospheric air entering an inlet passage 22 of the power unit 10 is directed to an inlet manifold 44. The inlet manifold 44 is configured to supply the intake air from the inlet 22 or an air / fuel mixture to one or more combustion chambers 30 of the power unit 10. The vehicle system 100 further comprises an exhaust manifold 48 and an exhaust passage 148, which ultimately leads to an exhaust pipe (not shown) that finally discharges exhaust gas into the atmosphere. The power unit 10 can be controlled, at least partially, by a control system 14 with a control unit 12 and by input from a vehicle driver via an input device (not shown).

[0015] An ambient air temperature sensor (AAT sensor) 120 can be arranged at the inlet of the inlet passage 22 to measure the ambient air temperature. Furthermore, an air pressure sensor (BP sensor) 26 can be arranged at the inlet of the inlet passage 22 to measure the ambient air pressure.

[0016] Downstream of the AAT and BP sensors, the ambient air entering the inlet passage 22 can be filtered by an air filter 32. An air intake system throttle (AIS throttle) 34 can be located in the inlet passage 22 downstream of the air filter 32. The AIS throttle 34 can be controlled by the control system 14 to throttle the air flowing in the inlet passage 22. The pressure downstream of the AIS throttle can be adjusted by setting a throttle plate of the AIS throttle. In some examples, if the throttle plate of the AIS throttle is controlled such that the AIS throttle is in an open position, the pressure downstream of the AIS can increase to such an extent that gases from the fuel vapor scavenging system do not flow in flow path C, as described below.Furthermore, the position of the AIS throttle valve 34 can determine whether exhaust gas recirculates back into the inlet passage 22, as described below.

[0017] Downstream of the AIS throttle valve 34, the engine 10 may further comprise a compression device such as a turbocharger or supercharger with at least one compressor 52. For a turbocharger, the compressor 52 may be driven at least partially by a turbine 54 via a shaft (not shown) arranged along the exhaust passage. A boost pressure limiter 55 is provided to redirect exhaust gases, for example, to regulate the speed of the turbine 54. For a supercharger, the compressor 52 may be driven at least partially by the engine and / or an electric machine and may not include a turbine. Consequently, the amount of compression provided to one or more cylinders of the engine via a turbocharger or supercharger can be varied by the control unit 12.

[0018] An exhaust gas cleaning device 71 is shown arranged along the exhaust passage downstream of the turbine 54. Exhaust gas cleaning devices 71 can be a selective catalytic reduction (SCR) system, a three-way catalyst (TWC), a NOₓ filter, or a catalytic converter. x -trap, various other exhaust gas purification devices, or combinations thereof. Device 71, for example, could be a TWC, and device 72 (in Fig. (1 not shown) can be a particulate filter (PF). In some embodiments, the exhaust gas purification device 71 can also be periodically reset during operation of the engine 10 by operating at least one cylinder of the engine within a specific air / fuel ratio.

[0019] The vehicle system 100 further includes a compressor bypass valve (CBV) 53 to relieve pressure in the intake system when the engine is supercharged. The CBV 53 can allow compressed air to be recirculated into the intake passage 22 upstream of the compressor 52. For example, the CBV 53 can open to recirculate compressed air upstream of the compressor 52 to relieve pressure in the intake system during selected conditions to reduce the effects of compressor surge loading. In a particular example, the CBV 53 is actuated by vacuum.

[0020] The vehicle system 100 further comprises a charge air cooler (CAC) 60, which is arranged along the inlet passage 22 downstream of the compressor 52. The CAC 60 can cool inlet air that has been heated due to compression by the compressor 52 in order to increase the density of the air charge supplied to the engine 10. By increasing the air charge density, the combustion efficiency of the engine 10 can be increased.

[0021] Downstream of the CAC 60 and upstream of the intake manifold 44, the intake passage 22 may include a throttle valve 20. The position of the throttle valve 20 can be set by the control unit 12 via a signal supplied to an electric motor or actuator included with the throttle valve 20, a configuration commonly referred to as electronic throttle control (ETC). In this way, the throttle valve 20 can be actuated to modify the intake air supplied to the combustion chambers 30 of the engine 10. It can be seen that in configurations with a supercharger rather than a turbocharger, the throttle valve 20 may be omitted.

[0022] The vehicle system 100 further comprises a fuel vapor purge system 102. The fuel vapor purge system 102 includes a fuel tank 80 capable of holding multiple fuel mixtures, including fuels with a range of alcohol concentrations, such as various gasoline-ethanol blends, including E10, E85, gasoline, etc., and combinations thereof. A fuel tank pressure converter 86 may be included between the fuel tank 80 and the fuel vapor canister 82 to provide an estimation of fuel tank pressure and, for example, for leak detection when the engine is off. The fuel vapor canister 82 may be filled with an adsorbent to temporarily capture fuel vapors (including vaporized hydrocarbons) during fuel tank refueling operations and "running loss" (i.e., fuel vaporized during vehicle operation).In one example, the adsorbent used is activated carbon. During refueling, expelled air from tank 80 escapes to the atmosphere via a canister vent valve (CVV) 95. When air is passed over the fuel vapor storage media, this air can also be drawn from the atmosphere through the CVV 95. The flow of air and vapors between the fuel vapor canister 82 and the atmosphere can be controlled via the CVV 95. For example, the CVV 95 can discharge gases (e.g., air) from the fuel vapor purge system 102 to the atmosphere when fuel vapors are stored or captured from the fuel tank 80. The CVV 95 can also allow fresh air to be drawn into the fuel vapor purge system 102 when stored fuel vapors are purged to the inlet passage 22.

[0023] Fuel vapors released from the fuel vapor canister 82, for example during a purge process, can be directed into the inlet passage 22 and ultimately into the inlet manifold 44. The vapor flow can be regulated by a canister purge valve (CPV) 83, which is coupled between the fuel vapor canister and the inlet passage 22. The control unit 12 can, for example, control the position of the CPV 83 to change its duty cycle, where a duty cycle of 0% corresponds to a fully closed position and a duty cycle of 100% corresponds to a fully open position. The control unit 12 can store a current position of the CPV 83 in memory (e.g., as a "commanded valve position"), and this information can be used as a basis for purge flow rate calculations, as described in detail below.

[0024] After passing through the CPV 83, the steam flow can be directed into one or more flow paths. As described in Fig. As shown in Figure 1, flow path A couples the CPV 83 to the inlet passage 22 immediately upstream of the inlet manifold 44 via a line 74, whereas flow paths B and C couple the CPV 83 to a suction port and an outlet of an ejector 36 arranged parallel to the compressor 52 (via lines 76 and 78, respectively). A driving flow of compressed inlet air through the ejector 36 (e.g., a driving flow from an inlet of the ejector 36 downstream of the compressor 52 to the outlet of the ejector 36 upstream of the compressor 52) can generate a vacuum that can be used to purge fuel vapors from the fuel vapor canister 82 into the inlet passage 22 upstream of the compressor 52 via flow path B. Flow path B can always be open regardless of pressure differences within the inlet system. A check valve 64 can be arranged in line 76 to prevent backflow in this line (e.g.,to prevent a flow from the ejector 36 towards the CPV 83), a check valve 62 can be arranged in the line 74 to prevent a backflow in this line (e.g. a flow from the inlet manifold towards the CPV 83), and a check valve 66 can be arranged in the line 78 to prevent a backflow in the line (e.g. a flow from the inlet passage 22 upstream of the compressor 52 towards the CPV 83).

[0025] In addition to flow path B, the vapor flow from the fuel vapor scavenging system 102 can flow in flow path A if the intake manifold pressure is lower than atmospheric pressure. For example, the flow of vapors exiting the CPV 83 can diverge into a first and a second flow, with the first flow entering the intake passage 22 via flow path A and the second flow entering the ejector 36 intake port via flow path B. The respective quantities of vapors flowing in paths A and B in this scenario can depend on the pressures at the intake port and the intake manifold. For example, if the intake port pressure is lower relative to the intake manifold pressure (and consequently the vacuum is higher), the second flow can be greater than the first.

[0026] In addition to the flow in path B, or in addition to the flow in paths A and B, vapor can flow in flow path C if the compressor inlet pressure is lower than atmospheric pressure. The respective amounts of vapor flowing in paths B and C (or paths A, B, and C) can again depend on the pressures where the paths terminate (e.g., the ejector intake duct for flow path B, the intake manifold for flow path A, and the compressor inlet / outlet of ejector 36 for flow path C). For example, if the AIS throttle plate is controlled such that the AIS throttle is in an open position, the pressure downstream of the AIS can increase to such an extent that gases from the fuel vapor scavenging system do not flow in flow path C.

[0027] It can be seen that during conditions under which steam flows only in path B and not in paths A or C, the CPV 83 and the suction channel of the ejector 36 are arranged in series, and the flow rate through the CPV 83 is equal to the flow rate into the suction channel.

[0028] A closed crankcase ventilation (PCV) system 104 may also be included in the vehicle system 100. The combustion chambers 30 may be arranged above a lubricant-filled crankcase 106, in which pistons of the combustion chambers rotate a crankshaft. The pistons may be substantially isolated from the crankcase by one or more piston rings, which suppress the flow of the air / fuel mixture and combustion gases into the crankcase. Nevertheless, a significant amount of fuel vapor may bypass the piston rings and enter the crankcase over time. To reduce the deteriorating effects of the fuel vapor on the viscosity of the engine lubricant and to decrease the escape of vapor into the atmosphere, the crankcase may be continuously or periodically vented via the PCV system 104. In the Fig. In the configuration shown in Figure 1, the PCV system 104 comprises a PCV valve 108 located in the line 116, which couples the intake manifold 44 and the crankcase 106 via an intake oil separator 110. The PCV valve can be any fixed or adjustable allocation valve. In one embodiment, the direction of the crankcase ventilation airflow depends on the relative values ​​of the manifold manifold pressure (MAP) and the ambient pressure (BP). Under uncharged or minimally charged conditions (e.g., when BP > MAP) and when the PCV valve 108 is open, air enters the crankcase via a crankcase ventilation pipe 114 and is discharged from the crankcase into the intake manifold 44 via the line 116. In some embodiments, a second oil separator 112 may be present between the crankcase 106 and the crankcase ventilation pipe 114, as shown.

[0029] Furthermore, an exhaust gas recirculation (EGR) system can route a desired portion of the exhaust gas from the exhaust port 148 to the intake port 22 via an EGR port 140. The amount of EGR supplied to the intake port 22 can be varied by the control unit 12 via an EGR valve 142. Additionally or alternatively, EGR can be drawn from the exhaust system to the intake air system when the AIS throttle valve 34 is partially closed. Furthermore, an EGR sensor 144 can be located within the EGR port and can provide a reading of one or more parameters relating to the pressure, temperature, and concentration of the exhaust gas. Under certain conditions, the EGR system can be used to regulate the temperature of the air-fuel mixture within the combustion chamber, thus providing a method for controlling the ignition timing during certain combustion modes.Furthermore, under certain conditions, some of the combustion gases can be retained or captured in the combustion chamber by controlling the exhaust valve timing, such as by controlling a variable valve timing mechanism.

[0030] A throttle valve intake pressure sensor (TIP sensor) 35 can be arranged downstream of the CAC 60 and upstream of the throttle valve 20. Furthermore, a gas component sensor, such as a universal intake / exhaust gas oxygen sensor (intake UEGO sensor) 50, can be arranged downstream of the CAC 60 and upstream of the throttle valve 20. The main function of the intake UEGO sensor 50 can be the measurement of the diluent concentration, particularly with regard to the diluents N2, CO2, and H2O. The intake UEGO sensor 50 can, for example, be arranged downstream of the connection points of the EGR passage 140 and the crankcase ventilation pipe 114, as shown in Fig. As shown in Figure 1, the sensor can therefore measure the concentration of the diluents N2, CO2, and H2O from the EGR system, N2, CO2, and H2O from crankcase gases, and H2O in the intake air (due to humidity). As shown in Figure 1. Fig. As shown in Figure 1, the inlet UEGO sensor 50 can also be located downstream of line 78. Consequently, a mixture of fuel vapor and air from the fuel vapor purge system 102, entering the inlet passage 22 upstream of the inlet UEGO sensor 50, can affect the measurements of the inlet UEGO sensor. Fuel vapor (e.g., HC) can, for example, act as a reducing agent at the inlet UEGO sensor, thereby reducing the partial pressure of oxygen measured by the sensor and causing an incorrect reading of diluents by the sensor.

[0031] To compensate for the influence of the fuel vapor / air mixture on the inlet UEGO sensor measurements, it may be necessary to determine the concentration of fuel vapor entering inlet passage 22 from line 78, as well as the total flow rate of fuel vapor purge gases entering inlet passage 22 from line 78. As with respect to Fig. As described in 3-5, the purge gas flow rate at the intake UEGO sensor can be determined by superimposing an ejector intake port flow rate / vacuum characteristic with a fuel vapor purge system flow rate / vacuum characteristic. The fuel vapor concentration of the purge gases can then be determined based on the fuel vapor concentration measured by the intake UEGO sensor and the purge gas flow rate at the intake UEGO sensor. Finally, the fuel vapor concentration of the purge gases can be used to determine how to compensate for the diluent concentration measured by the intake UEGO sensor to provide a more accurate diluent concentration, for example, for use in determining how to adjust the EGR.

[0032] It can be seen that additional measures can be taken to compensate for other factors that affect the measurements of the inlet UEGO sensor 50. For example, increased (charged) pressure can increase the partial pressure of air measured by the sensor 50. Since the sensor 50 can be located downstream of the compressor 52, as shown in Fig. As shown in Figure 1, a pressure sensor can therefore be located at the site of the inlet UEGO sensor (in the example of Fig. 1 the TIP sensor 35) can be used to compensate for the effect of compressor charging on the partial pressure of oxygen measured by sensor 50.

[0033] As described above, the vehicle system 100 comprises a control system 14. The control system 14 is shown receiving information from several sensors 16 (various examples of which are described here) and sending control signals to several actuators 75 (various examples of which are described here). As an example, the sensors 16 may include the air pressure sensor (BP sensor) 26, located in the intake passage 22 upstream of the air filter 32; the compressor inlet pressure sensor (CIP sensor) 28, located in the intake passage 22 upstream of the compressor 52; the throttle valve inlet pressure sensor (TIP sensor) 35; the intake UEGO sensor 50, located upstream of the throttle valve 20; and the manifold MAP sensor 24, located in the intake manifold 44. Furthermore, other sensors, such as...Fuel tank pressure, intake manifold UEGO, temperature, air / fuel ratio, and composition sensors may be coupled to various locations in the vehicle system 100. As another example, the actuators may include fuel injector actuators (not shown), the AIS throttle valve 34, the throttle valve 20, the canister purge valve (CPV) 83, the canister vent valve (CVV) 95, the compressor bypass valve (CBV) 53, the boost pressure limiter 55, and other control valves located in . Fig. 1. Not shown, include.

[0034] The control system 14 includes a control unit 12. The control unit 12 can be a microcomputer with the following, although in Fig. 1 Not shown: a microprocessor unit, input / output ports, an electronic storage medium for executable programs and calibration values ​​(e.g., a read-only memory chip), a random-access memory, a hold memory, and a data bus. The storage medium read-only memory can be programmed with computer-readable data representing instructions that can be executed by the microprocessor to perform the procedures described below, as well as other variations that are expected but not specifically listed. For example, the control unit can receive communication (e.g., input data) from the various sensors, process the input data, and trigger the actuators in response to the processed input data based on an instruction or code programmed therein, according to one or more routines. Example control routines are discussed here with regard to Fig. 3-5 described.

[0035] Fig. Figure 2 shows a graph 200, which represents the relationship between the flow rate and the vacuum at an ejector intake port; a graph 202, which represents the relationship between the flow rate through the CPV of a fuel vapor purge system and the vacuum downstream of the CPV; and a graph 204, in which the ejector intake port and CPV flow rate / vacuum characteristics are superimposed. Fig. 1 is Fig. Figure 2 shows an embodiment in which an ejector generates a vacuum that draws gases from a fuel vapor scavenging system into the engine intake passage. However, it can be seen that in other embodiments, graphs 202 and 204 can be replaced by a graph representing the flow rate / vacuum characteristic for another vehicle system that directs gases into an ejector intake channel, and a graph in which the ejector intake channel characteristic and the characteristic of that vehicle system are superimposed. In an alternative embodiment, for example, graph 202 can represent the flow rate through an EGR passage and the vacuum at the outlet of the EGR system. In another exemplary embodiment, graph 202 can represent the flow rate of crankcase gases through a PCV system and the vacuum at the outlet of the PCV system.Graphs 200, 202 and 204 can represent data stored in one or more lookup tables in the memory of a control system, e.g., control system 14 of . Fig. 1. Alternatively, the graphs can each represent the outputs of function expressions stored in the memory of a control system. As used here, the "overlay" or "blending" of graphs 200 and 202 to obtain graph 204 can, in an example, refer to setting a function expression for one of the characteristics shown in graph 200 equal to a function expression for one of the characteristics shown in graph 202 in order to find the intersection point. Alternatively, another suitable procedure can be used to find the intersection point of the characteristics of graphs 200 and 202.

[0036] Graph 200 of Fig. Figure 2 illustrates the relationship between the flow rate and the vacuum (e.g., negative pressure) at the intake port of an ejector. The y-axis of graph 200 represents the flow rate at the intake port of an ejector in grams per second, and the x-axis of graph 200 represents the vacuum at the intake port of the ejector with respect to kPa below atmospheric pressure. As shown in graph 200, the flow rate at the intake port of an ejector can decrease when the vacuum at the intake port of the ejector increases. In the context of an ejector coupled to a fuel vapor purge system with a CPV, for example, when the CPV is fully open, the flow rate of purge gases into the intake port of the ejector can be relatively high. Furthermore, because the CPV is fully open during these conditions, the pressure differential between the ejector intake port and the compressor inlet (where the purge gases terminate) can be relatively low.In principle, a relatively high flow rate of purge gases into the ejector's suction port can correspond to a relatively low level of ejector vacuum (e.g., less than kPa below atmospheric pressure). Conversely, when the CPV is completely closed, the pressure differential between the ejector suction port and the compressor inlet can be relatively high due to the relatively large vacuum created at the ejector suction port as it vents the gases remaining downstream of the closed CPV. In the example of... Fig. 2. The relationship between the flow rate and the vacuum differs for various TIP values. For the purposes of this discussion, TIP is a gauge pressure. However, it can be seen that within the powertrain control module (e.g., within control system 14), TIP is usually both measured and displayed as absolute pressure. Although the characteristics for TIP values ​​of 30, 40, and 50 kPa are shown, it can be seen that the control system can store characteristics for other possible TIP values ​​in a lookup table. Alternatively, the control system can determine the characteristic corresponding to a given TIP value using a function expression, so that the characteristic for a currently detected TIP value can be determined without requiring the storage of an extensive lookup table.While the slope of the characteristic curve is essentially the same for TIP values ​​of 30, 40, and 50 kPa, the X and Y intersection points of the characteristics are larger for larger TIP values ​​and smaller for smaller TIP values. Consequently, under conditions where the TIP is relatively high, the maximum ejector flow rate and maximum ejector vacuum can be greater than under conditions where the TIP is relatively low. The in . Fig. The ejector characteristics shown are essentially exemplary; it can be seen that different ejectors may have different characteristics that can be used without deviating from the scope of the invention.

[0037] Graph 202 of Fig. Figure 2 represents the relationship between the flow rate through a CPV of a fuel vapor purge system (e.g., CPV 83 of fuel vapor purge system 102) and the vacuum downstream of the CPV. The y-axis of graph 202 represents the flow rate through the CPV in grams per second, and the x-axis of graph 200 represents the vacuum downstream of the CPV with respect to kPa below atmospheric pressure. As shown, the flow rate through the CPV can be directly proportional to the vacuum downstream of the CPV, so the characteristics of graph 202 are lines with a positive slope. The positive slope can represent the effect of the flow resistance of the fuel vapor storage canister (e.g., the pressure of the atmospheric air flowing through the fuel vapor storage canister can decrease due to the flow resistance presented by the canister, thus creating a vacuum downstream of the canister).Each characteristic of graph 202 corresponds to a different duty cycle of the CPV. For example, the characteristic labeled "100% duty cycle" represents the relationship between the flow rate through the CPV and the vacuum downstream of the CPV when the CPV is fully open; the characteristic labeled "50% duty cycle" represents the relationship between the flow rate through the CPV and the vacuum downstream of the CPV when the CPV is either 50% open or open for 50% of the time; and the characteristic labeled "25% duty cycle" represents the relationship between the flow rate through the CPV and the vacuum downstream of the CPV when the CPV is either 25% open or open for 25% of the time.As shown, when the CPV duty cycle is larger, a higher flow rate is required to achieve a given vacuum level relative to the CPV duty cycle. Conversely, at smaller CPV duty cycles, the CPV's flow resistance can increase the flow resistance of the fuel vapor storage canister, thereby increasing the pressure differential between the pressure point (BP) upstream of the fuel vapor storage canister and the area downstream of the CPV. The CPV flow rate and vacuum characteristics are described in [reference missing]. Fig. Figure 2 is merely an example; it can be seen that different fuel vapor purging systems and different CPVs can exhibit different characteristics that can be used without deviating from the scope of the invention. For example, the flow rate curve as a function of the CPV's vacuum depends on the valve technology used. A laminar flow element, a sharp-edged orifice, and a sound-absorbing throttle all produce characteristically different pressure curves as a function of the flow rate.

[0038] In graph 204 of Fig. 2. Characteristics from each of graphs 200 and 202 are superimposed to achieve an intersection point. Specifically, the characteristic of graph 200 corresponding to a TIP value of 40 kPa and the characteristic of graph 202 corresponding to a duty cycle of 100% are superimposed. Graph 204 is only an example; while conditions where the TIP has a value other than 40 kPa and / or conditions where the CPV duty cycle is not 100%, it can be seen that other characteristics corresponding to the actual TIP value and CPV duty cycle can be superimposed in a similar manner. As shown, the X-axis of graph 204 represents the negative pressure at the ejector suction channel and downstream of the CPV, whereas the Y-axis of graph 204 represents the flow rate through the ejector suction channel and the flow rate through the CPV.Under conditions where the CPV and the ejector intake manifold are in series, the vacuum at the ejector intake manifold can be equal to the vacuum downstream of the CPV, and the flow rate through the ejector intake manifold can be equal to the flow rate through the CPV. In some systems, for example, the CPV can couple the fuel vapor storage system to the ejector intake manifold alone, in which case the CPV is always in series with the ejector intake manifold. In such systems, the vacuum downstream of the CPV is equal to the vacuum at the ejector intake manifold, and the flow rate through the CPV is equal to the flow rate at the ejector intake manifold. Since the X and Y axes of graphs 200 and 202 represent the same parameter in such a system, the graphs can consequently be superimposed.Although the flow rate at the ejector intake port (which is equal to the flow rate through the CPV) and the vacuum level at the ejector intake port (which is equal to the vacuum level downstream of the CPV) are unknown for a given CPV duty cycle and TIP value, they can be determined in this way by superimposing graphs 200 and 202. Specifically, the x-coordinate at the intersection of the characteristics can be the vacuum level at the ejector intake port (and downstream of the CPV), and the y-coordinate at the intersection of the characteristics can be the flow rate through the ejector intake port (and through the CPV). Consequently, the flow rate and vacuum at the ejector intake port can be determined without adding an additional pressure sensor to the system at the ejector intake port.

[0039] In other systems, such as the vehicle system 100 from Fig. However, the passage in which the CPV is located can couple the fuel vapor scavenging system with the ejector intake manifold as well as other engine components. As in Fig. As shown in Figure 1, for example, the flow downstream of CPV 83 can diverge into flow paths A, B, and C. Purge gases can flow in flow path B during substantially all engine operating conditions because the pressure at the ejector intake port can be lower than the BP during substantially all engine operating conditions. Purge gases can flow in flow path A in addition to flow path B when the MAP is lower than the BP. Furthermore, purge gases can flow in flow path C in addition to flow path B, or in addition to flow paths A and B, when the CIP is lower than the BP. During conditions where purge gases flow in flow path A and / or C in addition to flow path B (e.g., conditions where less than all the flow exiting the engine system outlet enters the ejector intake port), the fuel vapor purge system 102 cannot be arranged in series with the ejector intake port.During such conditions, it may therefore be necessary to adjust the CPV flow characteristic based on the flow rate in each flow path leaving the fuel vapor purge system outlet and bypassing the ejector suction channel (e.g., flow path A and / or C) before adjusting the ejector and CPV characteristics (e.g., those shown in graphs 200 and 202 of ). Fig. 2 shown) are superimposed. For example, it may be necessary to shift the CPV characteristic corresponding to the current CPV duty cycle to account for the flow of purge gases in flow path A and / or C, as shown in reference to Fig. 4 is described. In this way, it may be possible to determine the flow rate and vacuum level at the ejector intake port without adding an additional pressure sensor to the system, even if the CPV and the ejector intake port are not arranged in series. Alternatively, instead of shifting the CPV flow characteristic, in some embodiments the flow rate and vacuum level at the ejector intake port can be determined only during conditions in which all the flow exiting the fuel vapor scavenging system outlet enters the ejector intake port, for example, when the AIS throttle valve is open and the intake manifold pressure is greater than or equal to atmospheric pressure.

[0040] In contrast, during conditions where the entire flow exiting the fuel vapor purge system outlet enters the ejector suction channel, it may not be necessary to shift the CPV flow characteristics or otherwise take into account the flow in the other flow paths besides flow path B.

[0041] Fig. Figure 3 shows a flow chart describing a procedure 300 for compensating the diluent concentration measured by a gas component sensor located in a power engine inlet passage (e.g., an inlet UEGO sensor such as sensor 50 from Fig. 1) is based on the flow rate and fuel vapor concentration of purge gases from a fuel vapor purge system. The influence of the presence of fuel vapor on the readings of the gas component sensor (e.g., fuel vapor in purge gases entering the intake passage upstream of the gas component sensor) can be compensated for, so that the gas component sensor readings more accurately reflect the amount of diluents (such as CO2 and H2O from EGR) present in the intake system. The compensated gas component sensor readings can then be used as a basis for EGR adjustment, e.g., adjusting the EGR to achieve a desired diluent concentration level in the intake system.

[0042] In 310, the procedure 300 includes determining the flow rate of purge gases at the inlet UEGO sensor (e.g., inlet UEGO sensor 50 of Fig. 1) In one example, the flow rate of purge gases at the inlet UEGO sensor can be measured via the [unclear text]. Fig. The procedures shown in section 4 and described below are used to determine the gases. As used here, “purge gases” refers to gases from a fuel vapor purge system, such as System 102 of [Company Name]. Fig. 1.

[0043] Following 310, procedure 300 continues to 312. In 312, procedure 300 includes determining the fuel vapor concentration of the purge gases (e.g., the fuel vapor concentration of the purge gases as opposed to the fuel vapor concentration of the total flow seen by the inlet UEGO sensor). In a non-limiting example, this determination can be carried out by performing the procedure described in Fig. The procedures shown in section 5 can be carried out. In some examples, the concentration can be stored by the control system as the ratio of moles of fuel vapor (e.g., HC) to liters of oxygen or as a percentage composition.

[0044] Following 312, the procedure continues from 300 to 314. In 314, procedure 300 comprises measuring the diluent concentration at the inlet UEGO sensor (e.g., the diluent concentration of the total flow seen by the inlet UEGO sensor). In one example, the sensor can output a voltage proportional to the concentration of a diluent (e.g., N2, H2O, CO2) in the total flow at the sensor, and this voltage can be sent to the control system (e.g., to control system 14 of Fig. 1) be sent. The control system can then perform calculations based on this voltage to determine the diluent concentration (e.g., the N2 concentration) of the total flow observed at the sensor. Measuring the diluent concentration can involve measuring the concentration of one diluent of interest or measuring the concentration of more than one diluent. Furthermore, the control unit can control the inlet UEGO sensor to measure the concentration of a first group of one or more diluents during a first operating condition and to measure the concentration of a second, different group of one or more diluents during a second operating condition.

[0045] Following step 314, procedure 300 continues to step 316. In step 316, procedure 300 involves compensating the diluent concentration measurement (e.g., from step 314) based on the fuel vapor concentration of the purge gases (e.g., as determined in step 312). In one example, the control system can store a lookup table in memory containing compensation amounts corresponding to different fuel vapor concentrations and perform a calculation that includes the compensation amount needed to achieve a compensated diluent concentration. In another example, the control system can perform the compensation by solving an equation with the fuel vapor concentration and the measured diluent concentration as inputs and the compensated diluent concentration as output.

[0046] Following 316, procedure 300 continues to 318. In 318, procedure 300 includes adjusting the EGR based on the compensated diluent concentration. An example is an EGR valve such as valve 142 from Fig. 1 can be set, which can regulate the amount of exhaust gas that is recirculated to the engine intake passage. Although the EGR in the example of Method 300 is set based on the compensated diluent concentration measurement, in other embodiments other operations or parameter values ​​can be set based on the compensated diluent concentration (e.g., PCV system operation, AIS throttle opening, main throttle opening, etc.) without departing from the scope of this disclosure.

[0047] Fig. Figure 4 shows a flow diagram illustrating Method 400 for determining the flow rate of gases from a fuel vapor purge system, as seen by a gas component sensor in an engine intake passage (e.g., an intake UEGO sensor), in conjunction with the Method of Fig. 3 can be used. In particular, procedure 400 can be performed in step 310 of procedure 300 in some examples.

[0048] In 410, procedure 400 includes determining the duty cycle of a CPV (e.g., the CPV 83 of Fig. 1) The current duty cycle of the CPV can, for example, be stored in the memory of the control system, in which case determining the duty cycle of the CPV may involve accessing this stored value. A duty cycle of 100% may correspond to a fully open CPV valve, a duty cycle of 50% may correspond to a CPV valve that is open 50% of the time or half-open all the time, and a duty cycle of 0% may correspond to a fully closed CPV valve.

[0049] In procedure 400, part 412 involves measuring the values ​​of AAT, BP, CIP, TIP, and MAP. For example, this step might involve the control system receiving acquired values ​​from AAT, BP, CIP, TIP, and MAP sensors (e.g., sensors 120, 26, 28, 35, and 24).

[0050] Following step 412, procedure 400 continues to step 414. In step 414, procedure 400 involves determining the purge gas flow rate in flow path A based on the BP, MAP, and CPV duty cycle. In a non-limiting example, the purge gas flow rate in flow path A can be a function of the BP, MAP, and CPV duty cycle. The control unit can calculate this flow rate by substituting the values ​​of the BP and MAP measured in step 412 and the CPV duty cycle determined in step 410 into a function expression.

[0051] Following step 414, procedure 400 continues to step 416. In step 416, procedure 400 involves determining the purge gas flow rate in flow path C based on the BP, CIP, and CPV duty cycle. The purge gas flow rate in flow path C can, for example, be a function of the BP, CIP, and CPV duty cycle. The control unit can calculate this flow rate by substituting the values ​​of the BP and CIP measured in step 412 and the CPV duty cycle determined in step 410 into a function expression.

[0052] Following 416, procedure 400 continues to 418. In 418, procedure 400 involves shifting the CPV flow rate / vacuum characteristic for the current CPV duty cycle by subtracting the purge gas flow rates in flow paths A and C. As with reference to Fig. As described in section 2, during conditions where purge gases flow in one or both of the flow paths A and C in addition to flow path B, the fuel vapor purge system outlet may not be in series with the ejector suction port. To determine the flow rate and vacuum at the ejector suction port by superimposing the characteristics and finding their intersection point (e.g., as in graph 204 of [reference missing]), the following applies: Fig. As shown in Figure 2), the characteristic representing the flow through the CPV and the negative pressure downstream of the CPV may need to be adjusted to account for the flow of purge gases in flow paths other than flow path B during these conditions. For example, if purge gases flow through paths A and / or C, the sum of the purge gas flow rates in the paths may need to be subtracted from the CPV characteristic (e.g., the characteristic shown in Figure 202, corresponding to the current duty cycle) before being superimposed on the ejector suction duct characteristic (e.g., the characteristic shown in Figure 200, corresponding to the current TIP) to find the intersection point, as shown in Figure 204.In a non-limiting example where both the CIP and MAP are less than the BP, the purge gas flow rate in flow path A can be determined to be 0.1 g / s in step 414, and the purge gas flow rate in flow path C can be determined to be 0.2 g / s in step 416. If the current CPV duty cycle is 100%, the characteristic shown in graph 202 for this CPV duty cycle can be shifted by -0.3 g / s at step 418. Before the shift, the slope of this characteristic can be 1 / 100, as shown, and the Y-intercept can be 0, as shown in graph 202, in which case the equation for the characteristic is Y = (1 / 100)X, where Y is the flow rate through the CPV and X is the vacuum downstream of the CPV. After the shift, the equation for the characteristic can change to Y = (1 / 100)X - 0.3.It can be seen that for non-linear characteristics, the shifting can involve various computational methods. Furthermore, other methods can be used to account for the flow of purge gases in flow paths A and / or C without deviating from the scope of this disclosure. In examples where purge gases do not flow in either flow path A or C, step 418 can be omitted. Depending on the system, in practice a pressure differential may close the check valve in either flow path A or flow path C, so that flow paths A and C are not open simultaneously.

[0053] Following 418, procedure 400 continues to 420. In 420, procedure 400 involves superimposing the shifted CPV flow rate / vacuum characteristic and the ejector suction channel flow rate / vacuum characteristic for the current value of the TIP (e.g., as measured in 412) to determine the intersection point of the characteristics. The shifted CPV flow rate / vacuum characteristic can represent the flow rate of purge gases in flow path B with respect to the vacuum level of the purge gases in flow path B. Since flow path B is in series with the ejector suction channel, the shifted characteristic can be superimposed on the ejector suction flow characteristic, and the intersection point of the two characteristics can represent the flow rate through the ejector suction channel and the vacuum at the ejector suction channel. As above with respect to Fig. As described in section 2, the "superimposition" of the shifted CPV flow rate / vacuum characteristic and the ejector suction channel flow rate / vacuum characteristic in a non-limiting example can refer to setting a function expression for the shifted CPV flow rate / vacuum characteristic equal to a function expression for the ejector suction channel flow rate / vacuum characteristic in order to find the intersection point. In other examples, the superimposition can refer to a different procedure for finding an intersection point of the two characteristics. It can be seen that the superimposition of the characteristics can take place either literally or symbolically, depending on how the control system stores the shifted relationship between the CPV flow rate and the vacuum in memory, and depending on how the control system stores the relationship between the ejector suction channel flow rate and the vacuum in memory.

[0054] After step 420, the procedure continues from step 400 to step 422. In step 422, step 400 involves summing the fuel vapor purge gas flow rates in flow paths B and C to obtain the fuel vapor purge gas flow rate at the inlet UEGO sensor. For example, the flow rate in flow path B, determined in step 420, can be stored in memory, the flow rate in flow path C, determined in step 416, can also be stored in memory, and the control unit can add these two flow rates together to obtain the purge gas flow rate at the inlet UEGO sensor.Although the fuel vapor purge gas flow rate in flow path A is determined in step 414, in the example vehicle system described here, flow path A terminates downstream of the inlet UEGO sensor. Therefore, the purge gas flow rate in flow path A is only used when determining the purge gas flow rate and vacuum level in flow path B and is not used in step 422. However, in other example vehicle systems, flow path A may terminate upstream of the inlet UEGO sensor, or the inlet UEGO sensor may be located downstream of flow path A. In such systems, the purge gas flow rate in flow path A may also be a summand in step 422.

[0055] The flow rate of fuel vapor purge gases at the inlet UEGO sensor, obtained in step 422, can be used to determine the fuel vapor concentration of the purge gases (e.g., via the method of Fig. 5) Then, the diluent concentration measured by the inlet UEGO sensor (or calculated based on its measurements) can be compensated for based on the fuel vapor concentration of the fuel vapor purge gases. Finally, the EGR can be adjusted based on the compensated diluent concentration. By determining the flow rate of fuel vapor purge gases, as seen by the inlet UEGO sensor, using Method 400, the diluent concentration measured by the inlet UEGO sensor can therefore be compensated to improve the EGR adjustment without the need for an additional pressure or flow rate sensor on the ejector intake manifold.It can be seen that similar procedures can be carried out for other vehicle systems associated with an ejector intake manifold, depending on whether their flow rates / vacuum characteristics intersect with ejector intake manifold flow rates / vacuum characteristics when the characteristics are superimposed. Furthermore, it can be seen that the compensated diluent concentration can be used for purposes other than, or in addition to, EGR adjustment.

[0056] Fig. Figure 5 shows a flowchart representing a procedure 500 for calculating the concentration of fuel vapor in fuel vapor purge gases, which, in conjunction with the procedure of Fig. 3 and Fig. 4. In particular, procedure 500 can be performed in some examples in step 312 of procedure 300. The fuel vapor concentration calculated via procedure 500 is the concentration of fuel vapor in the purge gases leaving the fuel vapor purge system, e.g., in one or more of the flow paths A, B, and C.

[0057] In procedure 500, part 510 involves determining the total flow rate at the inlet UEGO sensor. In one example, the control system can determine the total flow rate at the inlet UEGO sensor as a function of the TIP (e.g., as determined by the TIP sensor 35 in the system of Fig. 1 measured) and the diameter of the inlet passage (e.g., the inlet passage 22 of Fig. 1) Calculate. Alternatively, another method can be used to determine the total flow rate at the inlet UEGO sensor. In the Fig. In the example vehicle system shown in Figure 1, the flow rate at the inlet UEGO sensor can be a function of the flow rates of purge gases entering the inlet passage via one or more of the flow paths A, B and C, as well as the flow rate of the charged inlet flow, which may include the EGR flow and / or crankcase ventilation flow.

[0058] Following step 510, procedure 500 continues to step 512. In step 512, procedure 500 involves determining the percentage of purge gases in the total flow. This determination may involve dividing the purge gas flow rate at the intake UEGO sensor (e.g., as determined via procedure 400) by the total flow rate at the intake UEGO sensor (e.g., as determined in step 510) and multiplying the quotient by 100. In an illustrative example, step 512 may determine that the purge gases constitute 10% of the total flow at the intake UEGO sensor. The remaining 90% may include intake air, recirculated exhaust gas from the EGR system, crankcase leakage gases, etc., depending on the vehicle system configuration and engine operating conditions.

[0059] Following 512, procedure 500 continues to 514. In 514, procedure 500 includes measuring the fuel vapor concentration at the inlet UEGO sensor. In one example, the sensor can output a voltage proportional to a concentration of fuel vapor (e.g., HC) in the overall flow at the sensor, and this voltage can be sent to the control system (e.g., to control system 14 of Fig.1) be sent. The control system can then perform calculations based on this voltage to determine the fuel vapor concentration at the sensor. It can be seen that even in embodiments where the fuel vapor scavenging system is the only source of fuel vapor upstream of the intake UEGO sensor, the fuel vapor concentration at the intake UEGO sensor cannot be equal to the fuel vapor concentration in scavenging gases, since other components (e.g., intake air, diluent from the EGR, etc.) may be present in the overall flow at the intake UEGO sensor in addition to the scavenging gases.

[0060] Following step 514, procedure 500 continues to step 516. In step 516, procedure 500 comprises determining the fuel vapor concentration of purge gases based on the fuel vapor concentration at the inlet UEGO sensor (e.g., as determined in step 514) and the percentage of purge gases in the total flow (e.g., as determined in step 512). The determination may involve multiplying the percentage of purge gases in the total flow by the fuel vapor concentration at the inlet UEGO sensor, where the fuel vapor concentration at the inlet UEGO sensor is converted into a percentage composition by the control system. In such an example, 10% of the total flow at the inlet UEGO may consist of purge gases, and the percentage composition of fuel vapor in the total flow at the inlet UEGO sensor may be 5%.By multiplying these two quantities, it can be determined that the fuel vapor concentration of the purge gases (in the form of a percentage composition) is 50% fuel vapor, 50% air. This information can then be used in conjunction with the purge gas flow rate at the intake UEGO sensor (e.g., as determined via Procedure 400) to determine how to compensate for the diluent concentration measured by the intake UEGO sensor. The compensated diluent concentration can then be used as the basis for the EGR setting. For example, while EGR is off, the intake UEGO sensor can function as an intake HC sensor, measuring the fuel vapor concentration. Conversely, while fuel vapor purge is off, the intake UEGO sensor can function as a diluent concentration sensor.However, during conditions where both EGR and fuel vapor purge are enabled, the fuel vapor concentration can change slowly, and consequently, the dilution can be easily separated from the purge vapor effects on the intake UEGO sensor reading.

[0061] It should be noted that the example control and estimation routines contained herein can be used with various power machine and / or vehicle system configurations. The specific routines described here can represent one or more of any number of processing strategies, such as event-driven, interrupt-driven, multitasking, multithreading, and the like. In principle, various actions, operations, or functions shown in the sequence can be performed in parallel or, in some cases, omitted. Likewise, the order of processing is not necessarily required to achieve the features and benefits of the example implementations described here, but is included for ease of explanation and description.One or more of the depicted actions or functions can be performed repeatedly, depending on the specific strategy used. Furthermore, the described actions can graphically represent code to be programmed into the computer-readable storage medium in the powertrain control system.

[0062] It is evident that the configurations and routines disclosed herein are essentially exemplary and that these specific embodiments should not be considered limiting, as numerous variations are possible. For example, the above technology can be applied to V-6, I-4, I-6, V-12, 4-boxer, and other types of power engines. The subject matter of this disclosure includes all new and non-obvious combinations and sub-combinations of the various systems and configurations and other features, functions, and / or properties disclosed herein.

[0063] The following claims specifically indicate certain combinations and subcombinations that are considered novel and not obvious. These claims may refer to "one" element, "a first" element, or the equivalent thereof. Such claims should be understood as encompassing the integration of one or more such elements, neither requiring nor excluding two or more such elements. Other combinations and subcombinations of the disclosed features, functions, elements, and / or properties may be claimed by amending the present claims or by filing new claims in this or a related application.

[0064] Such claims, whether broader, narrower, the same or different in scope compared to the original claims, are also considered to be included in the subject matter of the present disclosure.

Claims

[1] Method for a power machine (10) comprising the following: Adjusting exhaust gas recirculation (EGR) based on a flow rate at an ejector intake port, wherein the flow rate is based on a flow characteristic of the ejector (36) and a flow characteristic of a power engine system and not on sensor measurements, wherein an outlet of the The power engine system is coupled to the ejector intake channel; and further comprising compensating a measurement of a gas component sensor arranged in a power engine inlet downstream of an outlet of the ejector (36) on the basis of the flow rate at the ejector intake channel. [2] Method according to claim 1, further comprising determining a concentration of a reducing agent in gases from the power engine system, wherein the compensation of the measurement of the gas component sensor is further based on the concentration of the reducing agent. [3] The method of claim 2, further comprising: During a first condition, under which the entire flow leaving the engine system outlet enters the ejector intake port, adjusting the EGR based on the flow rate at the ejector intake port; and during a second condition, under which less than the entire flow leaving the engine system outlet enters the ejector intake channel, adjusting the flow characteristics of the engine system based on a flow rate in each flow path leaving the engine system outlet and bypassing the ejector intake channel, and adjusting the EGR based on a set flow rate at the ejector intake channel, wherein the set flow rate at the ejector intake channel is based on the flow characteristics of the ejector (36) and the set flow characteristics of the engine system. [4] Method according to claim 3, wherein the flow rate in each flow path leaving the power machine system outlet and bypassing the ejector suction channel is based on detected values ​​of temperature and pressure. [5] Method according to claim 4, wherein the engine system is a fuel vapor purging system (102) and wherein the outlet of the fuel vapor purging system (102) is located downstream of a canister purging valve (83) (CPV) of the fuel vapor purging system (102). [6] Method according to claim 5, wherein the flow rate in each flow path leaving the outlet of the fuel vapor purge system (102) and bypassing the ejector suction channel is further based on a duty cycle of the CPV (83). [7] Power engine system comprising the following: an ejector (36) that bypasses an inlet compressor, wherein a suction channel of the ejector (36) is coupled downstream of a fuel vapor purging system (102), wherein no sensors are arranged between the channel and the fuel vapor purge system (102); an exhaust gas recirculation system (EGR system) coupled to the intake passage (22); and a gas component sensor located in the inlet passage (22) downstream of the EGR system and an outlet of the ejector (36); and a control system (14) with computer-readable commands for: Adjusting the exhaust gas recirculation (EGR) based on a flow rate at the ejector intake port, wherein the flow rate is based on a flow characteristic of the ejector (36) and a flow characteristic of the CPV (83) and is not based on sensor measurements, wherein the control system (14) further comprises computer-readable commands to compensate for a measurement of the gas component sensor based on the flow rate at the ejector intake port. [8] Power engine system according to claim 7, further comprising: an air intake system throttle valve (34) (AIS throttle valve) located in the inlet passage (22) upstream of the compressor; and a main throttle valve located in the intake passage (22) downstream of the gas component sensor and upstream of the intake manifold. [9] Power engine system according to claim 8, further comprising: a first flow path that couples the canister purge valve (83) (CPV) of the fuel vapor purge system (102) with the inlet passage (22) downstream of the gas component sensor when the inlet manifold pressure is lower than the atmospheric pressure; a second flow path that couples the CPV (83) to the ejector suction channel; and a third flow path that couples the CPV (83) with the inlet passage (22) downstream of the AIS throttle valve (34) when the compressor inlet pressure is lower than the atmospheric pressure. [10] Power engine system according to claim 9, wherein the control system (14) further comprises computer-readable commands for determining a concentration of fuel vapor in gases leaving the fuel vapor purge system (102) and wherein the compensation of the measurement of the gas component sensor is further based on the concentration of the fuel vapor. [11] Power machine system according to claim 10, wherein the control system (14) further comprises computer-readable commands for adjusting the EGR based on the compensated measurement. [12] Method for a power machine comprising the following: When the entire flow exiting an outlet of a fuel vapor purge system (102) enters an ejector intake channel, a flow rate at the ejector intake channel is determined independently of sensor measurements based on a flow characteristic of the ejector intake channel and a flow characteristic of the fuel vapor purge system (102), wherein the flow characteristic of the fuel vapor purge system (102) is based on a duty cycle of a canister purge valve (83) (CPV) of the fuel vapor purge system (102) and wherein the outlet of the fuel vapor purge system (102) is located downstream of the CPV (83). [13] Method according to claim 12, wherein the entire flow exiting the outlet of the fuel vapor purge system (102) enters the ejector intake duct when an air intake system throttle valve (34) (AIS throttle valve) arranged upstream of an outlet of the ejector (36) is open and the intake manifold pressure is greater than or equal to the atmospheric pressure. [14] Method according to claim 13, further comprising compensating a measurement of a gas component sensor arranged in a power engine inlet passage (22) downstream of the outlet of the ejector (36) on the basis of the flow rate at the ejector suction channel. [15] Method according to claim 14, further comprising determining a concentration of fuel vapor in the flow leaving the outlet of the fuel vapor purge system (102), wherein the compensation of the measurement of the gas component sensor is further based on the concentration of the fuel vapor. [16] Method according to claim 15, further comprising adjusting the exhaust gas recirculation based on the compensated measurement.

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