Fuel quantity monitoring based on fuel rail pressure

Abstract

A fuel delivery determination system includes an internal combustion engine having a plurality of cylinders, a plurality of fuel injectors configured to inject fuel for combustion in the cylinders, a fuel rail configured to provide fuel to the plurality of fuel injectors, and a fuel pump configured to pressurize fuel provided to the fuel rail. The system also includes a pressure sensor configured to detect fuel pressure within the fuel rail and a pressure signal configured to receive a pressure signal indicative of the fuel pressure detected by the pressure sensor, the pressure signal including pressure fluctuations caused by the fuel pump and determine fuel injected by one or more of the plurality of fuel injectors a quantity controller, wherein the determining includes removing or reducing at least some of the pressure fluctuations caused by the fuel pump.

Description

Technical Field

[0001] This disclosure relates generally to internal combustion engines, and more specifically, to a system for monitoring fuel injection in an internal combustion engine. Background Technology

[0002] Internal combustion engines are used in various types of machinery, including mobile and stationary machinery, to generate electricity, provide propulsion, and operate implements. Internal combustion engines, especially those used in industrial machinery, generate electricity at high output levels for extended periods by burning supplied fuel via a fuel system. Over time, components of the fuel system may wear out or even fail. In particular, the fuel pump and fuel injectors of the fuel system require periodic replacement.

[0003] Catastrophic failures of the fuel system are relatively rare and easily identifiable. However, anomalies, performance degradation, or relatively minor failures in the fuel system can be difficult to identify and diagnose. Consequently, engine systems may sometimes operate suboptimally for extended periods. In some cases, even when performance problems are obvious, it is difficult to identify the component causing the problem. Therefore, sometimes the wrong component is repaired or maintained, or repairs or maintenance involve unnecessary resources (e.g., time, parts, etc.). In some cases, minor problems may go undetected and persist, leading to more serious and / or costly failures, potentially resulting in mechanical downtime and increased repair costs.

[0004] Ishikawa describes an internal combustion engine controller in Japanese Patent Application Publication No. 2019-060279 ('279 Publication). The controller described in '279 Publication is configured to estimate the degree of wear and determine the timing of fuel injector replacement based on that degree of wear. The controller described in '279 Publication estimates the degree of wear by multiplying the number of fuel injections by the fuel rail pressure. The controller described in '279 Publication does not monitor fuel injection in a manner that takes into account fluctuations in fuel rail pressure.

[0005] The methods and systems disclosed herein can solve one or more of the problems described above and / or other problems in the art. However, the scope of protection provided by this disclosure is defined by the appended claims, and not by the ability to solve any particular problem. Summary of the Invention

[0006] In one aspect, a fuel delivery determination system may include an internal combustion engine having multiple cylinders, a plurality of fuel injectors configured to inject fuel for combustion in the cylinders, a fuel rail configured to supply fuel to the plurality of fuel injectors, and a fuel pump configured to pressurize the fuel supplied to the fuel rail. The system may also include a pressure sensor configured to detect fuel pressure within the fuel rail and a controller configured to receive a pressure signal indicating the fuel pressure detected by the pressure sensor (the pressure signal including pressure fluctuations caused by the fuel pump) and determine the amount of fuel injected by one or more of the plurality of fuel injectors, wherein the determination includes removing or reducing at least some of the pressure fluctuations caused by the fuel pump.

[0007] In another aspect, a fuel delivery determination system may include a fuel pressure sensor and a controller configured to output a pressure signal indicating fuel pressure within the fuel rail. The controller may be configured to determine the amount of fuel a first fuel injector is intended to inject, receive the pressure signal from the fuel pressure sensor, and identify pressure changes indicated in the pressure signal corresponding to the amount of fuel actually injected by the first fuel injector. The controller may also be configured to compare the amount of fuel actually injected by the first fuel injector with the amount of fuel intended to be injected by the first fuel injector, and identify the health condition of the first fuel injector based on the comparison.

[0008] In another aspect, a fuel delivery determination method may include receiving a pressure signal from a pressure sensor indicating fuel pressure within a fuel rail, determining a processed pressure signal that reduces or eliminates at least some pressure fluctuations (introduced by a fuel pump) in the processed signal, and identifying a pressure change indicated in the processed pressure signal corresponding to fuel injection. The method may also include determining the amount of fuel injected by one or more fuel injectors from a plurality of fuel injectors based on the identified pressure change. Attached Figure Description

[0009] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate various exemplary embodiments and, together with the specification, serve to explain the principles of the disclosed embodiments.

[0010] Figure 1 This is a schematic diagram of a fuel delivery system determined according to aspects of this disclosure.

[0011] Figure 2 yes Figure 1 A block diagram of the controller for the fuel delivery system.

[0012] Figure 3 It is a graph representing the pressure signal and the processed pressure signal corresponding to a series of crankshaft rotation angle positions.

[0013] Figure 4It is a chart that shows the estimated fuel injection quantity and the expected fuel injection quantity over a period of time.

[0014] Figure 5 It is a chart showing the health status of the pump delivering fuel.

[0015] Figure 6 This is a flowchart illustrating an exemplary method for determining fuel delivery. Detailed Implementation

[0016] The foregoing general description and the following detailed description are merely exemplary and illustrative and do not limit the claimed features. As used herein, the terms “comprises,” “comprising,” “having,” “including,” or other variations thereof are intended to cover non-exclusive inclusions, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but may also include other elements not expressly listed or inherent to such process, method, article, or apparatus. Furthermore, in this invention, relative terms (such as “about” and “approximately,” “generally,” etc.) are used to indicate possible variations of ±10% in the stated values. As used herein, the phrase “based on” includes the phrases “partially based on” and “entirely based on.”

[0017] Figure 1 This is a partial schematic diagram showing an internal combustion engine 12 (e.g., for industrial machinery) and a fuel delivery determination system 10. The fuel delivery determination system 10 may include components for determining the amount of fuel injected by the fuel injector 22. Specifically, the fuel delivery determination system 10 may include the internal combustion engine 12, a fuel system for delivering fuel to the internal combustion engine 12, and an electronic control module (ECM) 26, also referred to herein as a controller.

[0018] The internal combustion engine 12 may include multiple cylinders 14. Figure 1 The diagram shows six cylinders 14. The internal combustion engine 12 may have any suitable number of cylinders 14, such as two, three, four, six, eight, ten, twelve, twenty or more cylinders 14. The cylinders 14 may be arranged in an inline configuration, a V-configuration, or another configuration known in the art. The internal combustion engine 12 may be configured to burn a single fuel, such as diesel.

[0019] The fuel injector 22 for the fuel delivery system of the internal combustion engine 12 can be configured for direct fuel injection (as shown) or port fuel injection. The fuel injector 22 can be a common fuel rail injector, such as a hydraulically actuated electronically controlled injector. Each fuel injector 22 can communicate with an ECM 26, causing the injector 22 to inject fuel in response to a signal generated by the ECM 26. In at least some configurations, the fuel injector 22 can be configured to inject liquid fuels, such as diesel. The fuel injector 22 can be configured to inject gaseous fuels to replace or supplement the injection of liquid fuels.

[0020] The fuel delivery system for engine 12 supplies pressurized fuel to each injector 22. The fuel delivery system may include a fuel source 16 (e.g., fuel tank, oil pan, etc.), a fuel pump 18, and a common fuel rail 20. The fuel delivery system may also include known components such as fuel filters, pressure regulating valves, etc.

[0021] The sensor system provides feedback to the ECM 26, allowing the ECM 26 to control the fuel pump 18 and injector 22. Figure 1 In the example shown, the sensor system includes a common rail pressure sensor 24 and an engine speed sensor 28. The common rail pressure sensor 24 is configured to measure the fuel pressure within the common fuel rail 20, and the engine speed sensor 28 is configured to measure the engine speed of the engine 12 and output an engine speed signal. For example, the engine speed sensor 28 may be configured to detect the crankshaft position of the internal combustion engine 12. The common rail pressure sensor 24 may be configured to detect changes in fuel pressure within the common fuel rail 20.

[0022] Fuel pump 18 may be a positive displacement pump, such as a piston pump with multiple pumping elements. Fuel pump 18 may respond to commands from ECM 26. Specifically, ECM 26 may be configured to generate requests or commands (e.g., signals) to control pump output. This pump output may include, for example, pump displacement, pump inlet valve metering, and / or pump outlet valve metering. Control of the pump output provides control over the output pressure from fuel pump 18. In some aspects, the pumping frequency of fuel pump 18 may correspond to the rotational speed of internal combustion engine 12 as measured by engine speed sensor 28. Specifically, the pumping frequency of pump 18 may be associated with the crankshaft position of engine 12.

[0023] ECM 26 can be configured to receive signals from each sensor in the sensor system, including common rail pressure sensor 24 and engine speed sensor 28. In some configurations, ECM 26 is located on industrial machinery and is configured to monitor and control the machinery's fuel injection and monitor the health of one or more components of the fuel supply system. ECM 26 can communicate with one or more additional ECMs or other controllers on the industrial machinery.

[0024] Specifically, ECM 26 may include a single control module or controller. As used herein, "controller" includes a single controller or control module, or multiple controllers or control modules. ECM 26 may be embodied as a single processor or multiple processors that receive inputs, such as pressure change signals from common rail pressure sensor 24 and engine speed sensor 28. ECM 26 may include memory, auxiliary storage devices, processors (such as a central processing unit), or any other means for performing the tasks according to the invention, as described below. The memory or auxiliary storage devices associated with ECM 26 may store data and software to allow ECM 26 to perform its functions, including those described below with respect to method 600. Many commercially available microprocessors may be configured to perform the functions of ECM 26. Various other known circuits may be associated with ECM 26, including current monitoring circuits, signal conditioning circuits, communication circuits, and other suitable circuits.

[0025] Figure 2 This is a block diagram illustrating an exemplary configuration of the ECM 26. (As shown) Figure 2 As shown in Figure 2 and described above, ECM 26 may include one or more processors 30 and memory 32. The one or more processors 30 and memory 32 are operable to implement a phase offset analyzer 34, a fuel error estimator 36, and a pump and / or injector health analyzer 38. One or more modules of ECM 26, analyzer 34, estimator 36, and analyzer 38 may receive input 210 and generate output 220 to determine the health status of fuel pump 18 and fuel injector 22, and output a notification based on the determined health status.

[0026] Input 210 may include pressure change signals from common rail pressure sensor 24 and engine speed signals from engine speed sensor 28. Input 210 may also include other information related to the operation of internal combustion engine 12 and / or other components of fuel delivery determination system 10. Additional input 210 may include signals from, for example, temperature sensors, fuel flow sensors, airflow sensors, additional pressure sensors, etc. Input 210 may be received continuously or periodically while fuel delivery determination system 10 is in operation.

[0027] Phase offset analyzer 34 can be configured to receive pressure change signals from common rail pressure sensor 24, including pressure changes caused by fuel pump 18 and pressure changes caused by fuel injector 22, as described below. Analyzer 34 can be configured to process the signal from sensor 24, reducing or eliminating the portion of the signal generated by pump 18 to create a processed signal (also referred to herein as a phase offset signal), and output the phase offset signal to fuel error estimator 36. In some examples, the phase offset signal is a signal calculated by comparing pressure change values ​​at different times. By generating the phase offset signal, pressure fluctuations caused by pump 18 present in the pressure change signal can be removed or at least reduced.

[0028] Specifically, the phase offset analyzer 34 of the ECM 26 can be configured to process pressure signals from the common rail pressure sensor 24 and engine speed signals from the speed sensor 28. These signals can also be received and processed by the fuel error estimator 36 and the pump / injector health analyzer 38. The phase offset analyzer 34 can be configured to match a series of pressure measurements from the sensor 24 (e.g., pressure signals representing rail pressure changes over time) (such as the magnitude of the pressure changes) with corresponding crankshaft position measurements (also referred to herein as “crankshaft angles”) in the engine speed signals from the sensor 28. The process of matching pressure measurements with corresponding crankshaft positions generates a crankshaft angle indexed pressure signal (e.g., signal 302); Figure 3 The crankshaft angle index pressure signal can also be processed to generate a phase offset signal.

[0029] If needed, the phase offset analyzer 34 can also be configured to filter pressure change signals (e.g., by filtering the crankshaft angle index pressure signal). For example, the pressure signal (e.g., signal 302 representing pressure changes) can be filtered using a convolutional filter. The convolutional filter can apply a moving average to the raw data from the common rail pressure sensor 24 and the engine speed sensor 28. Other filtering techniques can be applied instead of or as a supplement to the convolutional filter. In some embodiments, the filtering technique does not significantly alter the phase of the filtered signal.

[0030] Phase offset analyzer 34 can generate a series of data points from the phase offset signal. To generate a data point from the phase offset signal, phase offset analyzer 34 can identify a reference data point in the crankshaft angle index pressure signal. This reference data point includes the pressure change amplitude (…). Figure 3 The y-axis value), the pressure change amplitude is related to a specific crankshaft angle ( Figure 3(x-axis value in the signal). This reference data point can be compared with a pair of data points also in the crankshaft angle index pressure signal. This pair of data points may include a first data point that leads the reference data point and a second data point that lags behind the reference data point. In some examples, the first and second data points may be separated from the reference data point by a predetermined distance (e.g., a predetermined phase), which is a specific crankshaft angle rotation degree. Based on the comparison of the reference data point with these first and second data points, the analyzer 34 can generate data points that constitute part of the phase offset signal. This process can be repeated for subsequent reference data points to generate the entire phase offset signal.

[0031] As described above, fuel pump 18 can pump at a set frequency (e.g., generating pump strokes). Each time a stroke occurs, fuel pump 18 can generate pulses in the pressure signal generated by common rail pressure sensor 24. Phase offset analyzer 34 can reduce or eliminate the content of these pulses in the pressure signal when generating a phase offset signal. For example, when fuel pump 18 performs a stroke at a rate equivalent to one stroke per 60 degrees of crankshaft rotation, phase offset analyzer 34 can be configured to generate a phase offset signal based on comparisons of data points offset by 60 degrees, 120 degrees, or other values ​​of crankshaft rotation, to reduce or eliminate the influence of pump 18 on the analyzed signal. The influence of pump 18 can be pressure fluctuations caused by pump 18. For example, a first data point can be advanced by 60 degrees of crankshaft rotation relative to a reference data point. A second data point can be delayed by 60 degrees of crankshaft rotation relative to the reference data point.

[0032] Fuel error estimator 36 can be configured to receive a phase offset signal generated by phase offset analyzer 34. Fuel error estimator 36 can evaluate this signal to identify the pressure change represented in the phase offset signal. In some aspects, fuel error estimator 36 can identify the maximum pressure value within the injection start window and the minimum pressure value within the injection end window, as described below. The pressure difference identifier algorithm of fuel error estimator 36 can identify the pressure difference between pairs of maximum and minimum pressure values.

[0033] The fuel error estimator 36 may also be configured with a fuel delivery estimator to assist in identifying fuel error values. The fuel delivery estimator can estimate the actual amount of fuel injected during one or more injection events. Specifically, the fuel delivery estimator can determine the actual amount of fuel injected based on the pressure difference identified by the pressure difference identifier. This actual injected fuel amount can be compared with the expected or anticipated fuel amount of the injection event. The difference between the expected fuel delivery and the actual fuel delivery represents the fuel error. This fuel error can be determined by the fuel error estimator 36 and output to the pump / injector health analyzer 38.

[0034] The pump / injector health analyzer 38 can be determined to analyze individual fuel error values ​​and, if necessary, track these fuel error values ​​over time. Fuel error values ​​can indicate when actual fuel delivery falls below the expected fuel delivery threshold by a predetermined minimum delivery threshold or more. In some cases, fuel error values ​​can indicate when actual fuel delivery exceeds the expected fuel delivery threshold by a predetermined maximum delivery threshold or more.

[0035] In some examples, the expected fuel delivery may correspond to the commanded pump delivery value ( Figure 5 The pump delivers fuel to fuel pump 18 to replace fuel in the common fuel rail 20 injected by fuel injector 22. The minimum and maximum delivery thresholds can be values ​​set based on the operating conditions of the internal combustion engine 12. For example, the maximum delivery threshold can increase with the commanded pump delivery value. The minimum delivery threshold can also increase when the commanded pump delivery value increases.

[0036] The pump / injector health analyzer 38 can be configured to identify poor health conditions (e.g., wear, component failure, etc.) of components in the fuel delivery system. The pump / injector health analyzer 38 can identify poor health conditions when the actual fuel delivery is determined to be below a minimum delivery threshold or above a maximum delivery threshold. When the actual fuel delivery is below the minimum delivery threshold, the pump / injector health analyzer 38 can determine that a first component is in poor health. For example, a fuel injector 22 may have a clogged nozzle, a malfunctioning injection valve, or other conditions that cause poor health of the fuel injector 22. When the actual fuel delivery is above the maximum delivery threshold, the pump / injector health analyzer 38 can determine that a different second component is in poor health. For example, a fuel injector 22 may have a leaking nozzle, a component of the fuel pump 18 (e.g., a piston) failure, etc.

[0037] In some respects, the pump / injector health analyzer 38 can be configured to distinguish between poor health of the fuel pump 18 and poor health of the injectors 22. For example, a high pressure drop measured during the injection window of a group of injectors 22 or all injectors 22 can be identified as poor health of the pump 18. Conversely, a high pressure drop occurring only for multiple injection events of a single injector 22 can be identified as poor health of that injector 22.

[0038] ECM 26 can be configured to generate pump command 40 as output 220. Pump command 40 causes fuel pump 18 to supply fuel to common fuel rail 20. Pump command 40 can also increase the fuel pressure in common fuel rail 20 to a desired pressure. The desired fuel pressure in common fuel rail 20 can be set by ECM 26 based on current operating conditions, such as the load on internal combustion engine 12, the desired output of internal combustion engine 12, and the speed of internal combustion engine 12 (e.g., detected by engine speed sensor 28). Specifically, pump command 40 can correspond to the aforementioned command pump delivery.

[0039] Injector command 42 causes each fuel injector 22 to inject a desired amount of fuel. Injector command 42 controls the injection start timing and injection end timing. Injector command 42 may include an injection start command generated during the injection start window and an injection end command generated during the injection end window. In an example where the fuel injector 22 is actuated by a solenoid valve, the solenoid valve can be energized by the injection start command and de-energized by the injection end command. The injection start window and injection end window may be determined individually by ECM 26 for each injector 22. The injection start window may be determined based on the current engine operating condition, requested output, etc. (e.g., retrieved from one or more mapping diagrams). The injection window may correspond to the range of crankshaft angle values ​​at which a particular injector 22 will start and end injection in response to injector command 42.

[0040] Pump notification 44 and injector notification 46 can be output by pump / injector health analyzer 38 based on the health status of fuel pump 18 and fuel injector 22. Pump notification 44 and injector notification 46 can be generated on a display, or as lighting in the machine cab, on a portable device (e.g., a mobile phone), and / or on one or more computing systems (e.g., a monitoring system for managing multiple industrial machines, a system for controlling a single industrial machine, etc.). For example, pump notification 44 can be issued when pump / injector health analyzer 38 identifies a component with poor health and determines that the component is fuel pump 18. Injector notification 46 can be issued when pump / injector health analyzer 38 determines that the component with poor health is fuel injector 22.

[0041] In some respects, in addition to identifying immediate or sudden health issues, the pump / injector health analyzer 38 can also record and monitor the health status of fuel system components over time. Specifically, the health analyzer 38 can monitor a gradual decline in health status over time, manifested as a gradual increase in the fuel error value generated by the fuel error estimator 36 over time. If necessary, the health analyzer 38 can determine the rate at which the health status of fuel system components declines over time, for example, based on the rate at which the fuel error value increases over time.

[0042] Pump notification 44 may include a display indicating the current health status of fuel pump 18. Notification 44 may not be issued when fuel pump 18 is operating normally, or pump notification 44 may indicate (e.g., on the display) that fuel pump 18 is operating normally. Pump notification 44 may indicate the rate at which the health status of fuel pump 18 declines (e.g., as the expected timeframe for responding to maintenance or repair of fuel pump 18). Additionally or alternatively, in response to determining that the health status of fuel pump 18 is poor (e.g., based on a single fuel error value deviating from a corresponding delivery threshold, or a minimum number of fuel error values ​​deviating from that delivery threshold), pump notification 44 may immediately indicate when the health status of fuel pump 18 is poor.

[0043] Injector notification 46 can be output in the same manner as pump notification 44 described above, by recording and monitoring the health status of injector 22 over time and / or by identifying immediate poor health conditions. Since the fuel system of fuel estimation system 10 includes multiple injectors 22, injector notification 46 can identify the specific injector 22 where a poor health condition occurs and / or the location of a specific fuel injector 22.

[0044] Industrial applicability

[0045] The systems and methods disclosed herein can be applied to any system that supplies pressurized fuel to one or more fuel injectors, such as industrial machines with internal combustion engines that allow the machines to perform work, move within the workplace, generate electricity, etc. Suitable industrial machines include, for example, power generation systems (e.g., generator sets), mining machinery, transportation machinery (e.g., mining trucks, off-highway trucks, etc.), earthmoving machinery, paving machinery, and others. Analysis of the pressure signals can be performed using an ECM 26 located on the machine, or by an ECM 26 located at a remote location (e.g., off-site), to monitor one or more machines, each including a fuel system.

[0046] Figure 3-5 This indicates that the signals and analyses performed by system 10 can be determined through fuel delivery. Specifically, Figure 3 The pressure signal 302 and the processed signal 304 are shown. The pressure signal 302 corresponds to a series of measurements taken by the common rail pressure sensor 24, forming data points. The processed signal 304 corresponds to a processed signal determined based on the pressure signal 302. The processed signal 304 may correspond to the aforementioned phase offset signal.

[0047] In some respects, pressure signal 302 corresponds to the crankshaft angle index pressure signal. According to Figure 3 On the y-axis, each measurement of pressure signal 302 represents the magnitude of pressure variation within the common fuel rail 20. The position of each measurement on the x-axis corresponds to the crankshaft angle measured by engine speed sensor 28. Pressure signal 302 can be filtered for downstream analysis if necessary. Figure 3 This represents the filtered signal 302. Specifically, the pressure signal 302 can be filtered in a manner that minimizes or eliminates phase distortion. As described above, the pressure signal 302 can be filtered using a convolutional filter that applies a moving average to the raw data from the common rail pressure sensor 24 and the engine speed sensor 28.

[0048] Processing signal 304 can be generated by phase offset analyzer 34 and analyzed by fuel error estimator 36. Processing signal 304 can be generated based on the analysis of data point pairs of pressure signal 302. In the example shown, pressure signal 302 includes a first data point 306, a second data point 308, and a third data point 310. The second data point 308 of signal 302 represents a reference point. The first data point 306 can rotate 60 degrees of crankshaft angle earlier than the second data point 308 and 120 degrees of crankshaft angle earlier than the third data point 310.

[0049] Each point of the processed signal 304 can be determined by evaluating two data points of signal 302 relative to a reference point also located in signal 302. These two data points can be 60 degrees earlier and 60 degrees later than the reference point, respectively. Each point of the processed signal 304 can be determined by: (i) determining the difference between the value (the value of the reference point of pressure signal 302) and the value of the data point 60 degrees earlier (“first difference”), (ii) determining the difference between the value of the reference point and the value of the data point 60 degrees later than the reference point (“second difference”), and (iii) combining the first and second differences (e.g., by addition). The combination of the two differences produces a pressure change value corresponding to the crankshaft angle position of the reference point. These three steps (i, ii, iii) can be repeated to determine each point of the processed signal 304.

[0050] exist Figure 3 In the example shown, when reference data point 308 is compared with data points 306 and 310, phase offset analyzer 34 determines that the corresponding point of processed signal 304 has approximately the same value as reference point 308. This is because the sum of the first difference between points 308 and 306 and the second difference between points 308 and 310 is zero. As another example, at another location of signal 302, second reference point 322 can be compared with first data point 320 and second data point 324. The result of this comparison is data point 326 of processed signal 304, because in this example, the sum of the first and second differences results in the negative value shown by point 322.

[0051] This process can remove the contents (e.g., pressure fluctuations) of the fuel pump 18 from the signal 304 based on the repetitive (e.g., periodic) manner in which the pressure changes caused by the fuel pump 18 occur (e.g., pressure pulses repeated twice per fuel injection). Once the processed signal 304 has been generated (e.g., as described above), the fuel error estimator 36 can identify the pressure difference present in the processed signal 304. Specifically, the pressure difference identifier of the fuel error estimator 36 can use predetermined injection start windows 312 and 316 and injection end windows 314 and 318. These windows 312, 314, 316, and 318 can correspond to known times (e.g., crankshaft angles) at the start and end of fuel injections in a series of regions within the processed signal 304.

[0052] The pressure differential identifier can identify the maximum pressure value within each injection start window 312, 316 and the corresponding minimum pressure value within each injection end window 314, 318. The difference between these values ​​represents the pressure differential ("dP") generated by the fuel injection event, where the dP value is identified when the pressure fluctuation of the fuel pump 18 is eliminated or reduced.

[0053] exist Figure 3 In this configuration, window 312 may correspond to the injection start window of the first fuel injector 22. Injection window 314 may correspond to the injection end window of the first fuel injector 22. Injection start window 316 and injection end window 318 may correspond to the second fuel injector. A subsequent injection window (not shown) is determined for each subsequent fuel injector 22 such that the dP value determined for each pair of injection windows is associated with a specific fuel injector 22.

[0054] Figure 4 Six actual fuel injection quantity waveforms 402 are shown. Each fuel injection waveform 402 is determined using the aforementioned dP value. Figure 4 The desired fuel injection quantity 404, corresponding to the commanded or expected fuel injection quantity, is also shown. Figure 4 In the meantime, the desired fuel injection quantity 404 is slightly offset below waveform 402 to facilitate the injection from... Figure 4 The desired fuel injection quantity 404 is visually distinguishable from the six actual fuel injection quantity waveforms 402 shown; these actual fuel injection quantity waveforms 402 are determined after eliminating pressure fluctuations from pump 18. When both fuel pump 18 and fuel injector 22 are in good working order, the desired fuel injection quantity 404 is typically aligned with the six actual fuel injection quantity waveforms 402.

[0055] exist Figure 4In the example shown, each fuel injector typically injects the expected amount of fuel. At the end of the graph shown, the three fuel injector waveforms indicate a first fault 406, a second fault 408, and a third fault 410. Faults 406, 408, and 410 indicate that the actual injection quantity drops below the expected fuel injection quantity 404. These decreases in actual injection quantity correspond to the processed signal 304 ( Figure 3 Flat areas, such as the areas immediately before and after the second data point 308.

[0056] Although the first fault 406, the second fault 408 and the third fault 410 each indicate that the amount of fuel injected is low or zero for a period of time, as mentioned above, a fault may also occur when the determined actual injection amount exceeds the expected fuel injection amount 404.

[0057] Figure 5 This is a diagram illustrating an example determination of the health status of fuel pump 18 and fuel injector 22. Health status region 502 represents acceptable operation of fuel pump 18 and fuel injector 22. In health region 502, the commanded delivery of fuel pump 18 typically corresponds to the actual amount of fuel injected. Health region 502 can be defined between a maximum delivery threshold 508 and a minimum delivery threshold 510. As mentioned above, the maximum delivery threshold 508 typically increases with increasing commanded pump delivery. The minimum delivery threshold 510 also typically increases with increasing commanded pump delivery.

[0058] When the actual injected fuel quantity drops below the minimum delivery threshold 510, the injector health analyzer 38 can determine that the fuel pump 18, fuel injector 22, or both are in poor health. As described above, the pump / injector health analyzer 38 can determine that the fuel pump 18 has malfunctioned or is experiencing a malfunction (e.g., the piston of the fuel pump 18 is unable to pump fuel). This malfunction in the fuel pump 18 can be indicated by the pump notification 44. Alternatively, the pump / injector health analyzer 38 can determine that a specific fuel injector 22 has malfunctioned or is experiencing a malfunction (e.g., the nozzle of the fuel injector 22 is clogged, the valve of the fuel injector 22 is stuck in the closed position, etc.). This malfunction in the injector 22 can be indicated by the injector notification 46.

[0059] When the actual injected fuel quantity rises above the maximum delivery threshold 508, the pump / injector health analyzer 38 can determine that the fuel injector 22 is in poor health. As described above, the health analyzer 38 can determine that the fuel injector 22 has malfunctioned or is experiencing a malfunction (e.g., fuel leakage from the injector nozzle, the valve of the injector 22 being stuck in the open position, etc.). This malfunction in the fuel injector 22 can be indicated by the injector notification 46.

[0060] Figure 6This is a flowchart illustrating a method 600 for determining fuel delivery according to an aspect of this disclosure. Step 602 of method 600 may include receiving a rail pressure signal. Specifically, step 602 may include receiving a signal from common rail pressure sensor 24 using ECM 26. The rail pressure signal received in step 602 may correspond to pressure signal 302 ( Figure 3 ).

[0061] Step 604 may include determining a phase offset signal. This signal may be determined based on the rail pressure signal received in step 602. Specifically, step 604 may include determining a processed signal 304 using a phase offset analyzer 34. In some aspects, step 604 may include generating a signal other than the phase offset signal. Specifically, step 604 may include generating a signal that reduces or eliminates the contents of the fuel pump 18 within the rail pressure signal received in step 602.

[0062] In step 606, the fuel error estimator 36 may identify one or more pressure differences from the phase offset signal or other signals determined in step 604. Step 606 may include identifying the pressure difference existing between injection start windows 312, 316 and injection end windows 314, 318, as described above. Figure 3 As stated above.

[0063] In step 608, the fuel error estimator 36 may determine the actual fuel delivery based on the pressure difference determined in step 606. Step 608 may include estimating fuel delivery using the fuel delivery estimator of the fuel error estimator 36. The fuel delivery estimate may be determined for each individual injector 22 and may be monitored over time.

[0064] Step 610 may include determining the health status of components of the fuel delivery system of engine 12, such as the health status of fuel pump 18 and / or fuel injector 22 as described above. Step 610 may include recording the health status of one or more components over time. Additionally or alternatively, step 610 may include generating one or more notifications, such as pump notification 44 and injector notification 46 as described above.

[0065] The disclosed system and method can be configured to monitor the health of fuel pump 18 and fuel injector 22 over time. Specifically, the system and method can be configured to identify poor health or component failure based on pressure changes detected using common rail pressure sensor 24. By separating pump strokes from injection events, contents of fuel pump 18, such as pressure fluctuations caused by pump strokes, can be reduced or eliminated. In some configurations, errors in fuel delivery can be obtained using a non-invasive monitoring system that can identify potential faults without requiring specialized testing equipment.

[0066] It will be apparent to those skilled in the art that various modifications and variations can be made to the disclosed methods and systems without departing from the scope of the invention. Other embodiments of the apparatus and systems will become apparent to those skilled in the art upon consideration of the description and practice of the devices and systems disclosed herein. This specification and examples are intended to be considered merely exemplary, and the true scope of the invention is indicated by the appended claims and their equivalents.

Claims

1. A fuel delivery determination system, the system comprising: An internal combustion engine having multiple cylinders; Multiple fuel injectors configured to inject fuel for combustion in the cylinder; A fuel rail configured to supply fuel to the plurality of fuel injectors; A fuel pump configured to pressurize the fuel supplied to the fuel rail; A pressure sensor configured to detect the pressure of the fuel in the fuel rail; as well as The controller is configured to: Receives a pressure signal indicating the fuel pressure detected by the pressure sensor, the pressure signal including pressure fluctuations caused by the fuel pump, and Determine the amount of fuel injected by one or more of the plurality of fuel injectors, wherein the determination includes removing or reducing at least some of the pressure fluctuations caused by the fuel pump.

2. The system of claim 1, wherein the controller is further configured to: Determine the processed pressure signal, wherein the processed pressure signal removes or reduces at least some of the pressure fluctuations caused by the fuel pump in the processed pressure signal, and Identify the pressure changes indicated in the processed pressure signal, the pressure changes corresponding to fuel injection.

3. The system according to any one of the preceding claims, wherein the pressure fluctuation caused by the fuel pump is the result of periodic fuel pressurization caused by the fuel pump.

4. The system according to any one of the preceding claims, wherein the controller is further configured to identify a poorly functioning fuel injector based on the determined amount of fuel injected by one or more of the plurality of fuel injectors.

5. The system according to any one of the preceding claims, wherein the controller is further configured to identify a fault in the fuel pump and a fault in the one or more fuel injectors.

6. The system according to any one of the preceding claims, wherein the controller is configured to identify a poorly functioning pump based on an increase in pressure change in a processed signal generated by removing or reducing at least some of the pressure fluctuations caused by the fuel pump from the pressure signal.

7. The system according to any one of the preceding claims, wherein the controller is configured to identify a faulty pump element based on a reduction in pressure changes in a processed signal generated by removing or reducing at least some of the pressure fluctuations caused by the fuel pump from the pressure signal.

8. A method for determining fuel delivery, the method comprising: Receive a pressure signal from the pressure sensor indicating the fuel pressure within the fuel rail; Determine a processed pressure signal, wherein the processed pressure signal reduces or eliminates at least some pressure fluctuations in the processed signal, the pressure fluctuations being introduced by the fuel pump; Identify the pressure changes indicated in the processed pressure signal, the pressure changes corresponding to fuel injection; as well as The amount of fuel injected by one or more fuel injectors among a plurality of fuel injectors is determined based on the identified pressure changes.

9. The method of claim 8, wherein the processed pressure signal is a phase offset signal generated by comparing points of different phases of the pressure signal with each other.

10. The method of claim 8 or 9, further comprising at least some of reducing the periodic fuel pressurization introduced by the fuel pump in the pressure signal.

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