Systems and methods for measuring fuel injection during pump operation

Abstract

The present invention relates to a system and method for measuring fuel injection during pump operation. A method for controlling the operation of a fuel injector during operation of a fuel pump delivering fuel to a fuel accumulator in response to measuring the amount of fuel injected by a fuel injector from the fuel accumulator into an engine cylinder is disclosed, the method comprising: determining an average pressure of the fuel accumulator over a first time period prior to a fuel injection event; predicting an average pressure at a pumping event (Q pump ) during the period; determining an average pressure of the fuel accumulator during a second time period after the fuel injection event; estimating fuel leakage; and estimating a fuel leak by adding the average pressure during the first time period to Q pump , and subtracting the leakage and the average pressure during the second time period to calculate an injected fuel amount; and using the calculated injected fuel amount to control the operation of the fuel injector.

Description

[0001] This application is a divisional application of the Chinese patent application with application number 201880092127.7, application date April 10, 2018, and invention name “System and method for measuring fuel injection during pump operation” (international application number PCT / US2018 / 026874). Technical Field

[0002] The present invention relates generally to fuel injection systems and, more particularly, to methods and systems for measuring fuel injection quantities during normal operation of a fuel pumping system. Background Art

[0003] In an internal combustion engine, one or more fuel pumps deliver fuel to a fuel accumulator. Fuel is then delivered from the accumulator to the engine's cylinders by fuel injectors for combustion, thereby powering the engine-driven systems. Accurately characterizing the amount of fuel delivered to the cylinders by the fuel injectors is desirable for a variety of reasons. In conventional fuel delivery systems, the amount of injected fuel is periodically characterized by shutting down the fuel pump and measuring various fuel delivery system variables. This approach can disrupt engine operation and provide inaccurate results, in part due to unintended pumping. Therefore, there is a need for an improved method for measuring the amount of injected fuel during pump operation. Summary of the Invention

[0004] According to one embodiment, the present disclosure provides a method for controlling operation of a fuel injector during operation of a fuel pump delivering fuel to a fuel accumulator in response to measuring an amount of fuel injected by a fuel injector from the fuel accumulator into an engine cylinder, the method comprising: determining an average pressure of the fuel accumulator over a first time period prior to a fuel injection event at which the fuel injector injects fuel from the fuel accumulator into the engine cylinder; predicting an average pressure of the fuel accumulator at a pumping event (Q pump ) during the period; determining an average pressure of the fuel accumulator during a second time period after the fuel injection event; estimating fuel leakage; and estimating the average pressure during the first time period by adding the average pressure during the first time period to Q pump , and subtracting the leakage and the average pressure during the second time period to calculate the amount of fuel injected by the fuel injector; and during a subsequent fuel injection event, using the calculated amount of fuel injected by the fuel injector to control the operation of the fuel injector. In one aspect of this embodiment, the pumping event occurs after the first time period and before the fuel injection event. In another aspect, Q pump In another aspect, the prediction Q pumpThe method comprises: generating an adaptive model of the operation of the fuel pump, comprising: estimating a start of pumping ("SOP") position of a plunger of the fuel pump; estimating Q using the estimated SOP position; pump ; Determine the convergence value of the estimated SOP position; and determine the estimated Q pump and using the adaptive model to predict Q by inputting the convergence value of the estimated SOP position, the measured fuel pressure in the fuel accumulator, and the measured fuel temperature in the fuel accumulator into the adaptive model pump . In a variation of the present aspect, estimating the SOP position includes: receiving a raw measurement of the fuel pressure in the fuel accumulator; identifying a quiet segment in the raw measurement; fitting a model to the identified quiet segment; using the fitted model to determine an output representing the propagation of the fuel pressure in the fuel accumulator without interference from pumping events; and identifying a difference between the output of the fitted model and the raw measurement of the fuel pressure in the fuel accumulator. In another variation, identifying the quiet segment includes filtering the raw measurement using a median filter, the length of the median filter corresponding to the oscillation frequency of the fuel pressure in the fuel accumulator. In yet another variation, identifying the quiet segment also includes evaluating a derivative of the filtered raw measurement to identify a segment of the derivative having an approximately zero slope. In another aspect of this embodiment, the adaptive model uses the following relationship: Qpump = fcam(EOP-SOP)*δA*δ(P,T)-t*δL(P,T), where fcam is a table of the relationship between the position of the plunger and the crank angle of the engine, EOP is the end pumping position of the plunger, A is the area of the plunger, δ(P,T) is the density of the fuel in the fuel accumulator, t is the duration of the pumping event, and L(P,T) is the fuel leakage of the fuel pump. In a variation of this aspect, at least one of δ(P,T) and L(P,T) is modeled by a first-order polynomial in the fuel temperature dimension or at least a second-order polynomial in the fuel pressure dimension. In another aspect, using the calculated amount of fuel injected by the fuel injector to control the operation of the fuel injector includes adjusting an opening time equation corresponding to the fuel injector.

[0005] In another embodiment, the present disclosure provides a system for controlling operation of a fuel injector during operation of a fuel pump that delivers fuel to a fuel accumulator in response to measuring an amount of fuel injected by a fuel injector from the fuel accumulator into an engine cylinder, the system comprising: a pressure sensor positioned to measure a pressure of the fuel in the fuel accumulator; a temperature sensor positioned to measure a temperature of the fuel in the fuel accumulator; and a processor in communication with the pressure sensor to receive a pressure value representative of the measured pressure of the fuel in the fuel accumulator and in communication with the temperature sensor to receive a temperature value representative of the measured temperature of the fuel in the fuel accumulator; wherein the processor is configured to: determine an average pressure of the fuel accumulator over a first time period prior to a fuel injection event at which the fuel injector injects fuel from the fuel accumulator into the engine cylinder; and predict an average pressure of the fuel accumulator during a first time period prior to a fuel injection event at which the fuel injector injects fuel from the fuel accumulator into the engine cylinder. pump ) during the period; determining an average pressure of the fuel accumulator during a second time period after the fuel injection event; estimating fuel leakage; and estimating the average pressure during the first time period by adding the average pressure during the first time period to Q pump , and subtracting the leakage and the average pressure during the second time period to calculate the amount of fuel injected by the fuel injector; and during a subsequent fuel injection event, using the calculated amount of fuel injected by the fuel injector to control the operation of the fuel injector. In one aspect of this embodiment, the pumping event occurs after the first time period and before the fuel injection event. In another aspect, Q pump In another aspect, the processor is further configured to predict Q by performing the following operations: pump : Generate an adaptive model of the operation of the fuel pump, generating the adaptive model of the operation of the fuel pump by: estimating the start of pumping ("SOP") position of the plunger of the fuel pump; estimating Q using the estimated SOP position pump , determine the convergence value of the estimated SOP position; and determine the estimated Q pump and using the adaptive model to predict Q by inputting the convergence value of the estimated SOP position, the measured fuel pressure in the fuel accumulator, and the measured fuel temperature in the fuel accumulator into the adaptive model pump. In a variation of this aspect, the processor is configured to estimate the SOP position by: receiving a raw measurement of the fuel pressure in the fuel accumulator; identifying a quiet segment in the raw measurement; fitting a model to the identified quiet segment; using the fitted model to determine an output representing the propagation of the fuel pressure in the fuel accumulator without interference from pumping events; and identifying a difference between the output of the fitted model and the raw measurement of the fuel pressure in the fuel accumulator. In another variation, the processor is configured to identify the quiet segment by filtering the raw measurement using a median filter, the length of the median filter corresponding to the oscillation frequency of the fuel pressure in the fuel accumulator. In another variation, the processor is configured to identify a segment of the derivative having an approximately zero slope by evaluating the derivative of the filtered raw measurement to identify the quiet segment. In another aspect of the present disclosure, the adaptive model uses the following relationship: Qpump = fcam(EOP-SOP)*A*δ(P,T)-t*L(P,T), where fcam is a table of the relationship between the position of the plunger and the crank angle of the engine, EOP is the pumping end position of the plunger, A is the area of the plunger, δ(P,T) is the density of the fuel in the fuel accumulator, t is the duration of the pumping event, and L(P,T) is the fuel leakage of the fuel pump. In a variation of this aspect, at least one of δ(P,T) and L(P,T) is modeled by a first-order polynomial in the fuel temperature dimension or at least a second-order polynomial in the fuel pressure dimension. In another aspect, the processor is configured to control the operation of the fuel injector by adjusting an opening time equation corresponding to the fuel injector to use the calculated amount of fuel injected by the fuel injector.

[0006] Although multiple embodiments are disclosed, other embodiments of the present invention will become apparent to those skilled in the art from the following detailed description, which shows and describes illustrative embodiments of the present invention. Accordingly, the drawings and detailed description are to be regarded as illustrative in nature and not restrictive. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] The above and other features of the present disclosure and the manner in which these features are obtained will become more apparent, and the present disclosure itself may be better understood, by referring to the following description of embodiments of the present disclosure taken in conjunction with the accompanying drawings, in which:

[0008] Figure 1 is a schematic diagram of the fuel supply system; and

[0009] Figure 2 is a graph showing the measured rail pressure and the average rail pressure of the common rail accumulator.

[0010] Although the present disclosure is susceptible to various modifications and alternatives, specific embodiments are shown by way of example in the drawings and are described in detail below. However, the present disclosure is not limited to the specific embodiments described. On the contrary, the present disclosure is intended to cover all modifications, equivalents, and alternatives falling within the scope of the appended claims. DETAILED DESCRIPTION

[0011] Those skilled in the art will recognize that the provided implementations may be implemented in hardware, software, firmware, and / or a combination thereof. For example, the controller disclosed herein may form part of a processing subsystem comprising one or more computing devices having memory, processing, and communication hardware. The controller may be a single device or a distributed device, and the functions of the controller may be performed by means of hardware and / or as computer instructions on a non-transitory computer-readable storage medium. For example, the computer instructions or programming code in a controller (e.g., an electronic control module ("ECM")) may be implemented in any feasible programming language (e.g., C, C++, HTML, XTML, JAVA), or any other feasible high-level programming language, or a combination of a high-level programming language and a low-level programming language.

[0012] As used herein, the modifier "about" used in conjunction with a quantity is inclusive of the stated value and has the meaning dictated by the context (e.g., it includes at least the degree of error associated with measurement of the particular quantity). When used in the context of a range, the modifier "about" should also be considered to disclose the range defined by the absolute values of the two endpoints. For example, a range of "from about 2 to about 4" also discloses a range of "from 2 to 4."

[0013] Now refer to Figure 1 , shows a schematic diagram of a portion of a fuel supply system for an engine. The fuel supply system 10 generally includes: a high-pressure pump 12; a fuel reservoir such as a common rail accumulator (hereinafter referred to as "rail 14"); and a plurality of fuel injectors 16. As is known in the art, the pump 12 includes a plunger 18 that reciprocates within a cylinder 20. Typically, fuel is supplied to a chamber 22 within the cylinder 20 via an inlet 24, is compressed by the upward movement of the plunger 18, thereby increasing the pressure of the fuel, and is supplied to an outlet check valve (OCV) 28 via an outlet 26, and from there to the rail 14. The fuel from the rail 14 is periodically delivered by the fuel injectors 16 to a corresponding plurality of cylinders (not shown) of an internal combustion engine (not shown). A small circumferential gap 30 exists between an outer surface 32 of the plunger 18 and an inner surface 34 of the cylinder 20 to allow the plunger 18 to reciprocate within the cylinder 20.

[0014] Fuel is provided from a fuel source 36 into a supply line 38. The fuel source 36 may include a low-pressure fuel transfer pump (not shown). A hydromechanical actuator (hereinafter referred to as an inlet metering valve or "IMV" 40) is configured to control the amount of fuel distributed to the high-pressure fuel pump 12. Although only one high-pressure fuel pump 12 is shown, it should be understood that any number of high-pressure pressure fuel pumps 12 may be used in various applications. Embodiments of the fuel pump 12 design may include a floating plunger pump, a positive displacement pump, or a retracting plunger pump design or other suitable designs for pumping pressurized fuel in a high-pressure fuel pump system.

[0015] IMV 40 may include a variable area orifice, such as one operated by a solenoid, to control the amount of fuel pumped. Processor 41 may command IMV 40 to fully close to prevent fuel from passing from supply line 38 to fuel pump 12. However, due to the nature of the valve, there may be a natural rate of leakage through clearances between the valve components and into inlet check valve passage 42 upstream of inlet check valve 44. When the fuel is sufficiently pressurized within inlet check valve passage 42, the tolerance of check valve 44 may be reached, and the leaked fuel flow may enter fuel pump 12 via inlet 24. This may result in an overpressure of the leaked fuel flow.

[0016] The present disclosure may also include a venturi device 50 disposed within the continuous fuel flow circuit. The fuel flow circuit includes a supply line 52, one end of which is fluidly connected to the venturi device 50. The other end of the supply line 52 is disposed upstream of the IMV 40 and is fluidly connected to the supply line 38. The supply line 52 connected to the venturi device 50 serves as an air bleed orifice to disperse air from the supply line 38 upstream of the IMV 40. The fuel flow circuit also includes an inlet venturi passage 54, one end of which is fluidly connected to the venturi device 50 at an inlet 56. The other end of the inlet venturi passage 54 is disposed downstream of the IMV 40 and is in fluid communication with the inlet check valve passage 42. Figure 1 As shown, ends of the supply line 52 and the inlet venturi passage 54 are fluidly connected to the supply line 38 and the inlet check valve passage 42 , respectively, and are disposed upstream of the pump 12 .

[0017] A fuel pump drain circuit 58 is provided that, in one embodiment, connects a fuel pump drain 60 to a fuel drain supply line 62. The fuel drain supply line 62 can be fluidly connected to a fuel drain 64 of a fuel tank (not shown). In a preferred embodiment, the fuel flow circuit includes an output 66 of the venturi device 50 that is fluidly connected to the fuel drain supply line 62. As further described below, the disclosed venturi device 50 enables fuel within the fuel drain supply line 62 to flow away from the pump 12 to the fuel drain 64.

[0018] The venturi device 50 utilizes a continuous fuel flow circuit, including a portion upstream of the IMV 40. In one embodiment, this includes the portion of the continuous fuel flow circuit immediately upstream of the IMV 40 to create a low-pressure region within the throttle region of the venturi device 50. The continuous fuel flow circuit connects the low-pressure zone of the venturi device 50 to the inlet metering circuit of the pump 12. The venturi device 50 directs fuel flow leakage from the IMV 40 away from the pump 12 back toward the fuel drain 64 so that the leakage fuel flow is not pressurized by the pump 12. By design, the disclosed venturi device 50 combines the functions of bypassing vapor flow upstream of the IMV 40 and removing fuel flow leakage from the IMV 40 downstream of the fully closed IMV 40.

[0019] When the plunger 18 moves in the pumping cycle, the plunger 18 moves between a start of pumping (SOP) position and an end of pumping (EOP) position. The SOP position is after the plunger 18 moves past its bottom dead center (BDC) position, while the EOP position is before the top dead center (TDC) position of the plunger 18.

[0020] During the compression stroke of plunger 18 (i.e., as it moves from the BDC position to the TDC position), the fuel in chamber 22 is compressed, causing the pressure in chamber 22 to increase to the point where the force on the chamber side of OCV 28 equals the force on the rail side of OCV 28. As a result, OCV 28 opens, and fuel begins to flow through outlet 26 and OCV 28 to rail 14. As plunger 18 continues to travel toward the TDC position, fuel continues to flow to rail 14 in this manner. Consequently, the pressure of the fuel in rail 14 increases. Conversely, as fuel injectors 16 deliver fuel from rail 14 to cylinders for combustion under the control of processor 41, the pressure of the fuel in rail 14 decreases. The present disclosure provides a method for estimating the amount of fuel injected by each fuel injector 16 while fuel pump 12 is operating.

[0021] A disadvantage of the fuel pump assemblies known from the prior art is that at certain operating points, and in particular at so-called zero pumping, when the pump 12 does not require a quantity of fuel and the IMV 40 is closed, some unintended pumping may still occur. Depending on the way the IMV 40 functions, unintended pumping, for example caused by leaks or measurement errors on the part of the IMV 40, is difficult to avoid despite great technical efforts to counteract it. If unintended pumping occurs too frequently, it may prevent the collection of sufficient measurements to evaluate the performance of the injectors 16. Such an evaluation of the injectors 16 is often necessary to comply with applicable emissions regulations. Thus, in some prior art systems where sufficient injector measurements are not possible, the pump 12 is marked as defective and a fault indication is provided to the user. However, the system and method of the present disclosure are not sensitive to the above-mentioned self-pumping and should eliminate such fault indications.

[0022] In accordance with the present disclosure, the amount of fuel injected by injector 16 may be measured by calculating the pressure drop due to injection and converting the pressure drop to mass using the following equation:

[0023]

[0024] Where V is the pressurized volume, c 2 is the speed of sound, ΔP is the pressure drop, and Q is the injection quantity. ΔP can be determined by processor 41 by comparing measurements from pressure sensor 43 before and after fuel injection by one of injectors 16. Pressure sensor 43 is positioned downstream of OCV 28 and is configured to sense the fuel pressure in rail 14. In the simplest case, the system's mass balance is determined solely by the injection quantity. However, as described below, there are two other components that may affect the pressure drop.

[0025] First, system leakage affects pressure drop. System leakage is the continuous leakage from the high-pressure system to the low-pressure side through the imperfect seal, as described above. Leakage is measured in bar / s (bars per second), expressed as L. As described below, the variable t (time) multiplied by L gives the pressure drop due to leakage over the considered period.

[0026] The amount of fuel pumped to rail 14 also affects the pressure drop in rail 14. The mass removed from rail 14 due to injection from fuel injectors 16 and leakage needs to be replaced to maintain the desired rail pressure. Pump 12 provides this mass. The pumped mass is expressed in units of bar or mass, depending on whether the consideration is in the pressure or mass domain. Conversion from one domain to the other is accomplished using the relationship outlined in equation (1) above.

[0027] Using the above assumptions, the observed rail pressure is represented by the sum of the injection quantity, the pumping mass of the pump 12, and system leakage. If two of these variables are known, the third can be estimated by subtracting the known values from the rail pressure signal. Assuming that system leakage and pumping mass are predictable values that can be predicted using real-time available inputs, the injection quantity can be estimated. The following model also assumes that the average pressure of the available static rail pressure segments, where no injection or pumping occurs, can be determined given sufficient data length.

[0028] Now refer to Figure 2 , trace 70 is the fuel pressure in rail 14 as measured by pressure sensor 43 and read by processor 41. The rail pressure of trace 70 increases during pumping events (e.g., as shown by arrow 78) and decreases during injection events (e.g., as shown by arrow 74). System leaks are typically too small to be detected in a system similar to Figure 2 However, if it is not taken into account, it is large enough in many cases to affect the accuracy of injection quantity estimation.

[0029] As discussed further below, trace 70 depicts two different scenarios of timing between pumping events and injection events. Specifically, in the first scenario, the first pumping event, shown by arrow 78, is adjacent in time to the first injection event, shown by arrow 74. The two events are not separated by the average rail pressure calculation. In the second scenario, the second pumping event, shown by arrow 72, is isolated from the second injection event, shown by arrow 75. The average rail pressure calculation separates the two events. Figure 2 In the example, the two injections (ΔP1) indicated by arrows 74 and 75 are inj and ΔP2 inj ) occurs over the entire time period of 400 data samples.

[0030] As described above, regarding the first injection event ΔP1 inj 74. Pumping Event ΔP pump 78 is close to ΔP1 in time inj This makes it difficult to determine the average pressure before the first injection. It should be noted that in some cases, the pumping event may even occur substantially simultaneously with the injection event, thereby completely masking the pressure drop.

[0031] Reference again Figure 2 , determine the average pressure before the pumping event 78 (ie, P1 mean 76) and the predicted pumping ΔP pump78. These quantities are determined using an adaptive algorithm for estimating the mass pumped by pump 12, as described in co-pending patent application filed on April 10, 2018, entitled "ADAPTIVE HIGH PRESSURE FUELPUMP SYSTEM AND METHOD FOR PREDICTING PUMPED MASS," attorney docket number CI-17-0699-01-WO (hereinafter referred to as the "Adaptive Application"), the entire disclosure of which is expressly incorporated herein by reference. Using the principles described in the adaptive algorithm, the mass of fuel pumped is measured. Then, at the start of pumping ("SOP") (i.e., the start of arrow 74), the pressure and temperature of the fuel in rail 14 are identified to predict the pumping mass for pumping event 78. The SOP is determined as explained in the Adaptive Application by adaptively adjusting a model of the pump and finding the convergence of the model, which is indicative of the SOP. The pressure of the rail 14 is measured by a pressure sensor 43, and the temperature of the fuel in the rail 14 is measured by a temperature sensor 45 arranged operatively close to the rail 14. More specifically, the equation Qpump = fcam(EOP-SOP)*A*δ(P,T)-t*L(P,T) from the adaptive application is used to determine δ, L, and EOP. Knowing these values, we can determine the SOP and, from this, the magnitude of the pumping event 78. It should be understood that while the pumping predictions of the adaptive application are of quality, Figure 2 The pressure values depicted in can be easily derived using standard relationships well known in the art. Using these terms and the estimated mean pressure P2 after injection mean 80, the pressure drop due to injection can be calculated using the following formula:

[0032] ΔP1 inj = P1 mean – P2 mean + ΔP pump – tL (2)

[0033] For the second injection ΔP2 inj , the average pressure before injection P3 mean 82 and the average pressure after injection P4 mean 84 is available and no pumping event prediction is required because in ΔP2 inj No pumping event occurred before or during (i.e., ΔP in Equation (2) pump =0). Therefore, the pressure drop due to the second injection event is calculated using the following equation:

[0034] ΔP2 inj = P3mean – P4 mean – tL (3)

[0035] Using the above-described method, the amount of fuel injected can be accurately determined without shutting down the pump 12. Using previous methods, the pump 12 is commanded to pump zero mass and then a measurement of the fuel injected is taken. However, due to imperfections in the pumping system, small pumping events can occur during these measurements, resulting in deviations that affect the accuracy of the measurements. Using the method of the present disclosure, fuel injection measurements are obtained during the expected operation of the pump 12, without inaccuracies caused by unexpected pumping. This also allows more data to be collected about the fuel injectors 16 because there is no need to wait for the pump 12 to reach zero mass pumping. While historically fuel injection measurements may have been taken once per minute (or other time period suitable for the application requirements), using the method of the present disclosure without disabling the pump 12, only the processing power of the processor 41 limits the amount of data that can be acquired for making fuel injection measurements.

[0036] The fuel injection measurement / estimation provided by the present disclosure is used by processor 41, among other things, to adjust the on-time equation for fuel injector 16. Specifically, the injector on-time equation describes the relationship between on-time, rail pressure, and fuel injection quantity, and, as is known in the art, is used to improve fuel delivery accuracy. Because the disclosed method accounts for hardware anomalies such as injector orifice blockage and manufacturing tolerances, it can also provide improved fuel economy and improved emissions performance.

[0037] It should be understood that the connecting lines shown in the various figures included herein are intended to represent exemplary functional relationships and / or physical connections between the various elements. It should be noted that many alternative or additional functional relationships or physical connections may exist in actual systems. However, benefits, advantages, solutions to problems, and any elements that may make any benefit, advantage, or solution appear or become more apparent should not be construed as key, required, or essential features or elements. Therefore, the scope is limited only by the appended claims, in which, unless expressly stated otherwise, elements in the singular are not intended to mean "one and only one," but rather "one or more." Furthermore, when a phrase similar to "at least one of A, B, or C" is used in a claim, the phrase should be interpreted to mean that in one embodiment, A can exist alone; in one embodiment, B can exist alone; in one embodiment, C can exist alone; or in a single embodiment, any combination of elements A, B, or C can exist, such as A and B, A and C, B and C, or A, B, and C.

[0038] In the detailed description herein, references to "one embodiment," "an embodiment," "an exemplary embodiment," etc. indicate that the described embodiment may include certain features, structures, or characteristics, but each embodiment may not necessarily include certain features, structures, or characteristics. Moreover, such phrases do not necessarily refer to the same embodiment. In addition, where a particular feature, structure, or characteristic is described in conjunction with an embodiment, it is considered to be within the knowledge of those skilled in the art who would benefit from this disclosure and would affect that feature, structure, or characteristic in conjunction with other embodiments, whether or not explicitly described. After reading the specification, it will be apparent to those skilled in the relevant art how to implement the disclosure in alternative embodiments.

[0039] Furthermore, no element, component, or method step in this disclosure is intended to be dedicated to the public regardless of whether the element, component, or method step is expressly recited in a claim. No claim element herein shall be construed under 35 U.S.C. § 112(f) unless the element is expressly recited using the phrase "means for..." As used herein, the term "comprise" or any other variation thereof is intended to encompass a non-exclusive inclusion such that a process, method, article, or apparatus that includes a list of elements does not include only those elements but may include other elements not expressly listed or inherent to the process, method, article, or apparatus.

[0040] Various modifications and additions may be made to the exemplary embodiments discussed without departing from the scope of the present disclosure. For example, while the embodiments described above refer to specific features, the scope of the present disclosure also includes embodiments having different combinations of features and embodiments that do not include all of the described features. Therefore, the scope of the present disclosure is intended to encompass all such alternatives, modifications, and variations that fall within the scope of the claims, as well as all equivalents thereof.

Claims

1. A method of controlling operation of a fuel injector in response to measuring an amount of fuel injected from a fuel accumulator by a fuel injector during operation of a fuel pump delivering fuel to the fuel accumulator, the method comprising: determining an average pressure of the fuel accumulator during a first time period prior to a fuel injection event and an average pressure of the fuel accumulator during a second time period after the fuel injection event; The mass of fuel delivered by the fuel pump to the fuel accumulator during a pumping event, Q pump and estimate fuel spills; By adding the average pressure during the first time period to Q pump , and subtracting the leakage and the average pressure during the second time period to calculate the amount of fuel injected by the fuel injector; as well as The calculated amount of fuel injected by the fuel injector is used to control operation of the fuel injector during a subsequent fuel injection event.

2. The method according to claim 1, wherein The pumping event occurs after the first period and before the fuel injection event.

3. The method according to claim 1, wherein Q pump is zero.

4. The method according to claim 1, wherein Prediction Q pump The method comprises generating an adaptive model of the operation of the fuel pump, wherein generating the adaptive model of the operation of the fuel pump comprises: estimating a pumping start position, i.e., a SOP position, of a plunger of the fuel pump; Use the estimated SOP position to estimate Q pump ; determining a convergence value of the estimated SOP position; and Determine the estimated Q pump The convergence value of ; and Q is predicted using the adaptive model by inputting the convergence value of the estimated SOP position, the measured fuel pressure in the fuel accumulator, and the measured fuel temperature in the fuel accumulator into the adaptive model. pump .

5. The method according to claim 4, wherein Estimated SOP positions include: receiving a raw measurement of fuel pressure in the fuel accumulator; identifying quiet segments in the raw measurements; Fitting the model to the identified quiet segments; using the fitted model to determine an output representing the propagation of fuel pressure in the fuel accumulator without being disturbed by a pumping event; and A difference between an output of the fitted model and the raw measurement of fuel pressure in the fuel accumulator is identified.

6. The method according to claim 5, wherein: Identifying quiet sections includes filtering the raw measurements using a median filter having a length corresponding to an oscillation frequency of the fuel pressure in the fuel accumulator.

7. The method according to claim 5, wherein: Identifying quiet segments further includes evaluating derivatives of the filtered raw measurements to identify segments of the derivative having approximately zero slope.

8. The method according to claim 4, wherein The adaptive model uses the following relationship: Qpump=fcam(EOP-SOP)*A*δ(P,T)-t*L(P,T), where fcam is the relationship between the position of the plunger and the crank angle of the engine, EOP is the pumping end position of the plunger, A is the area of the plunger, δ(P,T) is the density of the fuel in the fuel accumulator, t is the duration of the pumping event, and L(P,T) is the fuel leakage of the fuel pump.

9. The method according to claim 8, wherein At least one of δ(P, T) and L(P, T) is modeled by a first order polynomial in the fuel temperature dimension or at least a second order polynomial in the fuel pressure dimension.

10. The method according to claim 1, wherein Using the calculated amount of fuel injected by the fuel injector to control operation of the fuel injector includes adjusting an opening time equation corresponding to the fuel injector.

11. A processor for controlling operation of a fuel injector in response to measuring an amount of fuel injected by the fuel injector during operation of a fuel pump delivering fuel to a fuel accumulator, the processor being configured to: determining an average pressure of the fuel accumulator during a first time period prior to a fuel injection event and an average pressure of the fuel accumulator during a second time period after the fuel injection event; The mass of fuel delivered by the fuel pump to the fuel accumulator during a pumping event, Q pump and estimate fuel spills; By adding the average pressure during the first time period to Q pump , and subtracting the leakage and the average pressure during the second time period to calculate the amount of fuel injected by the fuel injector; as well as The calculated amount of fuel injected by the fuel injector is used to control operation of the fuel injector during a subsequent fuel injection event.

12. The processor according to claim 11, wherein: The pumping event occurs after the first period and before the fuel injection event.

13. The processor according to claim 11, wherein: Q pump is zero.

14. The processor of claim 11 , further configured to: estimating a pumping start position, i.e., a SOP position, of a plunger of the fuel pump; Use the estimated SOP position to estimate Q pump ; determining a convergence value of the estimated SOP position; Determine the estimated Q pump The convergence value of as well as generating an adaptive model of the operation of the fuel pump, wherein Q is predicted using the adaptive model by inputting the convergence value of the estimated SOP position, the measured fuel pressure in the fuel accumulator, and the measured fuel temperature in the fuel accumulator into the adaptive model. pump .

15. The processor of claim 14 , further configured to estimate the SOP position by: receiving a raw measurement of fuel pressure in the fuel accumulator; identifying quiet segments in the raw measurements; Fitting the model to the identified quiet segments; determining an output using the fitted model, the output representing the propagation of fuel pressure in the fuel accumulator without being disturbed by a pumping event; and A difference between an output of the fitted model and the raw measurement of fuel pressure in the fuel accumulator is identified.

16. The processor of claim 15, further configured to identify quiet segments by filtering the raw measurements using a median filter, the median filter having a length corresponding to an oscillation frequency of the fuel pressure in the fuel accumulator.

17. The processor of claim 15, further configured to identify quiet segments by evaluating derivatives of the filtered raw measurements to identify segments of the derivative having approximately zero slope.

18. The processor of claim 14, wherein: The adaptive model uses the following relationship: Qpump=fcam(EOP-SOP)*A*δ(P,T)-t*L(P,T), where fcam is the relationship between the position of the plunger and the crank angle of the engine, EOP is the pumping end position of the plunger, A is the area of the plunger, δ(P,T) is the density of the fuel in the fuel accumulator, t is the duration of the pumping event, and L(P,T) is the fuel leakage of the fuel pump.

19. The processor of claim 18, wherein: At least one of δ(P, T) and L(P, T) is modeled by a first order polynomial in the fuel temperature dimension or at least a second order polynomial in the fuel pressure dimension.

20. The processor of claim 11, further configured to use the calculated amount of fuel injected by the fuel injector to control operation of the fuel injector by adjusting an opening time equation corresponding to the fuel injector.

21. A system for controlling operation of a fuel injector in response to measuring an amount of fuel injected by a fuel injector from a fuel accumulator during operation of a fuel pump delivering fuel to the fuel accumulator, the system comprising: a pressure sensor positioned to measure fuel pressure in the fuel accumulator; as well as a processor in communication with the pressure sensor and configured to: determining an average pressure of the fuel accumulator during a first time period before a fuel injection event and an average pressure of the fuel accumulator during a second time period after the fuel injection event based on information received from the pressure sensor; The mass of fuel delivered by the fuel pump to the fuel accumulator during a pumping event, Q pump and estimate fuel spills; calculating the amount of fuel injected by the fuel injector by adding the average pressure during the first time period to Qpump and subtracting the leakage and the average pressure during the second time period; as well as The calculated amount of fuel injected by the fuel injector is used to control operation of the fuel injector during a subsequent fuel injection event.

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