FUEL VOLUME MONITORING USING RAIL PRESSURE

Abstract

A fuel supply control system (10) comprises a multi-cylinder internal combustion engine (12) (14), multiple fuel injectors (22) configured to inject fuel into the cylinders (14) for combustion, a fuel rail (20) configured to supply fuel to the multiple fuel injectors (22), and a fuel pump (18) configured to pressurize the fuel supplied to the fuel rail (20). The system (10) also includes a pressure sensor (24) configured to detect the fuel pressure in the fuel rail (20) and a control unit (26) configured to receive a pressure signal (302) indicating the fuel pressure detected by the pressure sensor (24).The pressure signal (302) encompasses the pressure fluctuations caused by the fuel pump (18) and determines the amount of fuel injected by one or more of the multiple injectors (22). This determination involves removing or reducing at least some of the pressure fluctuations caused by the fuel pump (18).

Description

Technical field

[0001] The present disclosure relates generally to internal combustion engines and in particular to a system for monitoring fuel injection in an internal combustion engine. State of the art

[0002] Internal combustion engines are used in various types of machinery, including mobile and stationary equipment, to generate electrical energy, provide propulsion power, and operate working tools. In particular, internal combustion engines for industrial machinery generate high-performance energy over extended periods by burning fuel through a fuel system. Over time, components of a fuel system can wear out or even fail. Fuel pumps and injectors, in particular, are regularly replaced.

[0003] Catastrophic fuel system failures are rare and relatively easy to detect. However, irregularities, reduced performance, or relatively minor failures in fuel systems can be difficult to identify and diagnose. As a result, engine systems sometimes operate suboptimally for extended periods. In some situations, even when a performance problem is obvious, it is difficult to identify the component causing the performance issue. Consequently, repairs or maintenance are sometimes performed on the wrong component or require unnecessary resources (e.g., time, parts, etc.). In some situations, minor problems can go undetected and lead to more serious and / or costly failures, resulting in downtime and increased repair costs.

[0004] A control unit for an internal combustion engine is described in Japanese patent application no. 2019-060279 (the “279 Publication”) by Ishikawa. The control unit described in the 279 Publication is configured to estimate the degree of wear and, based on this wear, determine the time for replacing a fuel injector. The control unit described in the 279 Publication estimates the degree of wear by multiplying the number of fuel injections by the rail pressure. The control unit described in the 279 Publication does not monitor fuel injection in a way that takes into account fluctuations in the rail pressure.

[0005] The methods and systems of this disclosure can solve one or more of the problems mentioned above and / or other problems in this field. However, the scope of the protection afforded by this disclosure is defined by the accompanying claims and not by the ability to solve a specific problem. Summary

[0006] In one embodiment, a fuel supply detection system may include a multi-cylinder internal combustion engine, multiple fuel injectors configured to inject fuel into the cylinders for combustion, a fuel rail configured to supply fuel to the multiple 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 control unit configured to receive a pressure signal indicating the fuel pressure detected by the pressure sensor, wherein the pressure signal includes pressure fluctuations caused by the fuel pump, and determine the amount of fuel injected by one or more of the multiple 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 supply detection system can include a fuel pressure sensor configured to output a pressure signal indicating the fuel pressure within a fuel rail, and a control unit. The control unit can be configured to determine the desired amount of fuel to be injected by a first fuel injector, receive the pressure signal from the fuel pressure sensor, and identify any pressure change indicated in the signal, where the pressure change corresponds to the actual amount of fuel injected by the first fuel injector.The control unit can also be configured to compare the actual amount of fuel injected by the first fuel injector with the desired amount of fuel to be injected by the first fuel injector, and to determine the condition of the first fuel injector based on the comparison.

[0008] In another aspect, a method for detecting fuel supply may involve receiving a pressure signal from a pressure sensor indicating the fuel pressure within a fuel rail, determining a processed pressure signal that reduces or eliminates at least some pressure fluctuations in the processed signal, wherein the pressure fluctuations are caused by a fuel pump, and detecting a pressure change indicated in the processed pressure signal, wherein the pressure change corresponds to a fuel injection. The method may further involve determining the quantity of fuel injected by one or more fuel injectors of a plurality of fuel injectors based on the identified pressure change. Brief description of the drawings

[0009] The accompanying drawings, which are included in and form part of this description, illustrate various exemplary embodiments and, together with the description, serve to explain the principles of the disclosed embodiments. Fig. Figure 1 is a schematic diagram of a fuel supply detection system according to aspects of the disclosure. Fig. 2 is a block diagram of a control unit of the fuel supply detection system. Fig. 1. Fig. Figure 3 is a diagram representing a pressure signal and a processed pressure signal corresponding to a series of crank angle positions. Fig. Figure 4 is a diagram showing the estimated fuel injection quantity and the desired fuel injection quantity over a period of time. Fig. Figure 5 is a diagram that shows the state of the pump delivery according to the fuel supply. Fig. Figure 6 is a flowchart illustrating an exemplary procedure for determining the fuel supply. Detailed description

[0010] Both the preceding general description and the following detailed description are merely exemplary and explanatory and do not limit the features as claimed. As used herein, the terms "comprises," "comprising," "having," "incorporating," or other variations thereof are intended to cover a non-exclusive inclusion such that a process, method, article, or device comprising a list of elements may contain not only those elements but may also contain other elements not expressly listed or belonging to such process, method, article, or device. Furthermore, relative terms such as "about," "essentially," "generally," and "approximately" are used in this disclosure to indicate a possible deviation of ±10% of the stated value.As used here, the expression “based on” includes the expressions “partially based on” and “fully based on”.

[0011] Fig. Figure 1 is a partially schematic diagram depicting an internal combustion engine 12 (e.g., for an industrial machine) and a fuel delivery detection system 10. The fuel delivery detection system 10 may include components for detecting the amount of fuel injected by a fuel injector 22. In particular, the fuel delivery detection system 10 may include an internal combustion engine 12, a fuel system for supplying fuel to the internal combustion engine 12, and an electronic control module (ECM) 26, also referred to here as the control unit.

[0012] The internal combustion engine 12 can contain several cylinders 14, wherein in Fig. Figure 1 shows six cylinders 14. The internal combustion engine 12 can have any suitable number of cylinders 14, for example, two, three, four, six, eight, ten, twelve, twenty, or more cylinders 14. The cylinders 14 can be arranged in a straight configuration, a V configuration, or any other configuration known in the art. The internal combustion engine 12 can be configured for the combustion of a single fuel, for example, diesel fuel.

[0013] The fuel injectors 22 of the fuel supply system for the internal combustion engine 12 can be configured for direct injection (as shown) or port injection. The fuel injectors 22 can be common-rail injectors, for example, hydraulically actuated, electronically controlled injectors. Each fuel injector 22 can be connected to the ECM 26, so that the injectors 22 inject fuel in response to signals generated by the ECM 26. In at least some configurations, the fuel injectors 22 can be configured to inject a liquid fuel, for example, diesel fuel. The fuel injectors 22 can be configured to inject a gaseous fuel instead of, or in addition to, injecting a liquid fuel.

[0014] The fuel supply system for engine 12 can supply each injector 22 with pressurized fuel. The fuel supply system can include a fuel source 16 (e.g., a fuel tank, a sump, etc.), a fuel pump 18, and a common distribution pipe 20. The fuel supply system can also include familiar components such as fuel filters, pressure regulating valves, etc.

[0015] A sensor system can provide feedback to the ECM 26 so that the ECM 26 can control the fuel pump 18 and the injectors 22. In the Fig. In the example shown, the sensor system includes a common rail pressure sensor 24, configured to measure the fuel pressure in the common rail 20, and an engine speed sensor 28, configured to measure the engine speed 12 and output an engine speed signal. The engine speed sensor 28 can, for example, be configured to detect the position of a crankshaft of the internal combustion engine 12. The common rail pressure sensor 24 can be configured to detect changes in fuel pressure within the common fuel line 20.

[0016] The fuel pump 18 can be a positive displacement pump, for example, a piston pump with multiple pumping elements. The fuel pump 18 can respond to instructions from the ECM 26. In particular, the ECM 26 can be configured to generate requests or commands (e.g., signals) to control the pump output. This pump output can include, for example, the pump displacement, the metering of the pump inlet valve, and / or the metering of the pump outlet valve. Controlling the pump output can allow control of the fuel pump 18's outlet pressure. In some aspects, the pumping frequency of the fuel pump 18 can correspond to the rotational speed of the internal combustion engine 12, which is measured by the engine speed sensor 28. In particular, the pumping frequency of the pump 18 can be linked to the position of a crankshaft of the engine 12.

[0017] The ECM 26 can be configured to receive signals from any of the sensors in the sensor system, including the common rail pressure sensor 24 and the engine speed sensor 28. In some configurations, the ECM 26 is located on an industrial machine and is configured to monitor and control the fuel injection of that machine, as well as to monitor the condition of one or more components of the fuel supply system. The ECM 26 can communicate with one or more additional ECMs or other control units for the industrial machine.

[0018] In particular, the ECM 26 can comprise a single control module or control unit. As used herein, a “control unit” includes both single control units or control modules and a plurality of control units or control modules. The ECM 26 can include a single processor or multiple processors that receive inputs such as pressure change signals from the common-rail pressure sensor 24 and the engine speed sensor 28. The ECM 26 can include a memory, a secondary storage device, a processor such as a central processing unit, or any other means for performing a task consistent with the present disclosure, as described below. The memory or secondary storage associated with the ECM 26 can store data and software to enable the ECM 26 to perform its functions, which are described below in relation to Method 600.Numerous commercially available microprocessors can be configured to perform the functions of the ECM 26. Various other well-known circuits can be connected to the ECM 26, including power monitoring circuits, signal conditioning circuits, communication circuits, and other suitable circuits.

[0019] Fig. Figure 2 is a block diagram illustrating an example configuration of the ECM 26. As shown in Fig. As shown in Figure 2 and described above, the ECM 26 can include one or more processors 30 and a memory 32. The one or more processors 30 and the memory 32 can be operated to implement a phase shift analyzer 34, a fuel fault estimator 36, and a pump and / or injector condition analyzer 38. One or more of the modules of the ECM 26, analyzer 34, estimator 36, and analyzer 38 can receive input 210 and produce outputs 220 to determine the condition of the fuel pump 18 and the fuel injectors 22 and to issue notifications based on the determined condition.

[0020] The inputs 210 can include pressure change signals from the common rail pressure sensor 24 and engine speed signals from the engine speed sensor 28. The inputs 210 can also include other information relating to the operation of the internal combustion engine 12 and / or other components for the fuel supply determination system 10. Additional inputs 210 can include, for example, signals from temperature sensors, fuel flow sensors, airflow sensors, additional pressure sensors, and others. The inputs 210 can be received continuously or periodically while the fuel supply determination system 10 is operating.

[0021] The phase shift analyzer 34 can be configured to receive pressure change signals from the common rail pressure sensor 24, as described below, which include pressure changes caused by both the fuel pump 18 and the fuel injectors 22. The analyzer 34 can be configured to process the signals from the sensor 24, reduce or eliminate the pump 18-generated content of this signal to produce a processed signal (here also referred to as the phase shift signal), and output the phase shift signal to the fuel fault estimator 36. In some examples, the phase shift signal is a signal calculated by comparing pressure change values ​​at different times. Generating the phase shift signal allows for the removal or at least reduction of pressure fluctuations present in the pressure change signal caused by the pump 18.

[0022] In particular, the phase shift analyzer 34 of the ECM 26 can be configured to process pressure signals from the common rail pressure sensor 24 and the engine speed signal from the engine speed sensor 28. These signals can also be acquired and processed by the fuel fault estimator 36 and the injection pump / injector condition analyzer 38. The phase shift analyzer 34 can be configured to compare a series of pressure measurements (e.g., the pressure signal representing changes in rail pressure over time) from sensor 24, such as orders of magnitude of a pressure change, with corresponding crankshaft position measurements, also referred to here as "crankshaft angle," in the engine speed signal from sensor 28. The process of comparing pressure measurements with the respective crankshaft positions can generate a crankshaft angle-indexed pressure signal (e.g., signal 302). Fig. 3) generate. The crank angle indexed pressure signal can be further processed to generate the phase shift signal.

[0023] If desired, the phase shift analyzer 34 can be further configured to filter pressure change signals (e.g., by filtering the crank angle-indexed pressure signal). For example, the pressure signal (e.g., signal 302, representing pressure changes) can be filtered using a convolution filter. The convolution filter can apply a moving average to the raw data from the common rail pressure sensor 24 and the engine speed sensor 28.

[0024] Instead of or in addition to a convolution filter, other filtering techniques can also be used. In some embodiments, the filtering technique does not significantly change the phase of the filtered signal.

[0025] The phase shift analyzer 34 can generate the phase shift signal as a series of data points. To generate a data point in the phase shift signal, the phase shift analyzer 34 can identify a reference data point in the crank angle-indexed pressure signal. This reference data point includes a pressure change quantity (y-axis value in Fig. 3), which corresponds to a specific crank angle (x-axis value in Fig. 3) is connected. This reference data point can be compared to a pair of data points that are also located in the crank angle-indexed pressure signal. This pair of points can include a first data point that is advanced relative to the reference data point and a second data point that is delayed relative to the reference data point. In some examples, the first and second data points can be separated from the reference data point by a predetermined distance (e.g., a predetermined phase), where the distance is a specific number of degrees of crank angle rotation. Based on the comparison of the reference data point with these first and second data points, the analyzer 34 can generate a data point that is part of the phase shift signal. This process can be repeated for subsequent reference data points to generate the entire phase shift signal.

[0026] As described above, the fuel pump 18 can pump at a defined frequency (e.g., generate pump strokes). With each stroke, the fuel pump 18 can generate a pulse in the pressure signal produced by the common rail pressure sensor 24. The phase shift analyzer 34 can reduce or eliminate the content of these pulses in the pressure signal when generating the phase shift signal. For example, if the fuel pump 18 pumps at a frequency corresponding to a 60-degree crankshaft rotation, the phase shift analyzer 34 can be configured to generate a phase shift signal based on a comparison of data points offset by 60 degrees of crankshaft rotation, 120 degrees of crankshaft rotation, or another value, in order to reduce or eliminate the influence of the pump 18 on the analyzed signals. The influence of the pump 18 can consist of pressure fluctuations caused by the pump 18.For example, the first data point can be advanced by 60 degrees of crank angle rotation relative to the reference data point. The second data point can be delayed by 60 degrees of crank angle rotation relative to the reference data point.

[0027] The fuel fault estimator 36 can be configured to receive the phase shift signal generated by the phase shift analyzer 34. The fuel fault estimator 36 can evaluate the signal to identify changes in pressure represented in the phase shift signal. In some aspects, the fuel fault estimator 36 can identify maximum and minimum pressure values ​​within the injection windows, as described below. A dP identification algorithm of the fuel fault estimator 36 can identify the difference between maximum and minimum pressure values.

[0028] The fuel fault estimator 36 can further be configured with a fuel supply estimator to assist in the identification of fuel fault values. The fuel supply estimator can estimate the actual amount of fuel injected during one or more injection events. In particular, the fuel supply estimator can determine the actual amount of fuel injected based on the pressure differential identified by the dP identifier. This actual amount of injected fuel can be compared to a desired or expected amount of fuel for the injection event. The difference between the desired fuel supply and the actual fuel supply represents a fuel fault. This fuel fault can be detected by the fuel fault estimator 36 and output to the injector condition analyzer 38.

[0029] The pump / injector condition analyzer 38 can be configured to analyze individual fuel fault values ​​and, if desired, track fuel fault values ​​over time. The fuel fault value can indicate when the actual fuel supply was below the desired fuel supply by a predetermined minimum threshold or more. Under certain circumstances, the fuel fault value can also indicate when the actual fuel supply was above the desired fuel supply by a predetermined maximum threshold or more.

[0030] In some examples, the desired fuel supply can correspond to a command value for pump delivery ( Fig. 5), wherein the pump supply is issued to the fuel pump 18 to replace the fuel in the common distribution pipe 20 that was injected by the fuel injector 22. The minimum supply threshold and the maximum supply threshold can be values ​​that are set based on the conditions of the internal combustion engine 12. For example, the maximum supply threshold can increase with an increasing setpoint for the pump supply. The minimum supply threshold can also increase if the setpoint for the pump delivery rate increases.

[0031] The pump / injector condition analyzer 38 can be configured to detect a poor condition (e.g., wear, element failure, etc.) of a fuel supply system component. The condition analyzer 38 can detect a poor condition when the measured actual fuel delivery is below the minimum delivery threshold or above the maximum deployment threshold. If the actual fuel delivery is below the minimum delivery threshold, the pump / injector condition analyzer 38 can determine that the condition of a first component is poor. For example, a fuel injector 22 may have a clogged nozzle, a defective injector, or some other condition that causes the fuel injector 22 to be in a poor condition.If the actual fuel supply exceeds the maximum supply threshold, the injector condition analyzer 38 can detect that the condition of a differential component is poor. For example, a fuel injector 22 may have a leaking nozzle, a component (e.g., a piston) of the fuel pump 18 may be defective, etc.

[0032] In some aspects, the condition analyzer 38 can be configured to differentiate between a poor condition of the fuel pump 18 and a poor condition of the injectors 22. For example, a high pressure drop measured during the injection windows for a group of injectors 22 or for all injectors 22 can be identified as a poor condition of the pump 18. Conversely, a high pressure drop occurring over several injection cycles for only one injector 22 can be identified as a poor condition of that injector 22.

[0033] The ECM 26 can be configured to generate 220 pump commands 40 as outputs. These pump commands 40 can cause the fuel pump 18 to supply fuel to the common rail 20. Furthermore, the pump commands 40 can cause the fuel pressure in the common rail 20 to increase to a desired pressure. The desired fuel pressure in the common rail 20 can be set by the ECM 26 based on current conditions, such as the load of the internal combustion engine 12, the desired power output of the internal combustion engine 12, the rotational speed of the internal combustion engine 12 (e.g., detected by the engine speed sensor 28), etc. In particular, the pump commands 40 can correspond to the pump delivery command described above.

[0034] The injection commands 42 can cause each fuel injector 22 to inject the desired amount of fuel. The injection commands 42 can control the start and end of the injection timing. The injection commands 42 can include a start command for injection, generated during a start window for injection, and a stop command for injection, generated during an end window for injection. In examples where the fuel injector 22 is actuated by a solenoid valve, the solenoid valve can be activated with the start command for injection and deactivated with the stop command for injection. The start and end of the injection windows can be determined individually for each injector 22 by the ECM 26. The start of the injection window can be set based on the current engine conditions, the requested power, etc. (e.g.,(can be retrieved from one or more cards). The injection windows can correspond to a range of crank angle values ​​at which a specific injector 22 begins or ends injection in response to injection commands 42.

[0035] Pump message 44 and injection message 46 can be output by the injector condition analyzer 38 based on the condition of the fuel pump 18 and the fuel injectors 22. Pump message 44 and injection message 46 can be displayed on a screen or as lighting in the cab of a machine, on a portable device (e.g., a mobile phone), and / or on one or more computer systems (e.g., a monitoring system for managing multiple industrial machines, a system for controlling a single industrial machine, etc.). For example, pump message 44 can be output if the pump / injector condition analyzer 38 detects a poor condition of a component and determines that this component is the fuel pump 18.The injection message 46 can be issued by the pump / injector condition analyzer 38 if the condition analyzer 38 determines that the component in poor condition is the fuel injector 22.

[0036] In some aspects, the pump / injector condition analyzer 38 can log and monitor the condition of the fuel system components over time, in addition to identifying immediate or sudden deteriorations in condition. Specifically, the condition analyzer 38 can monitor a gradual deterioration of condition over time, represented by a gradual increase in fuel fault values ​​generated by the fuel fault estimator 36. If desired, the condition analyzer 38 can determine the rate at which the condition of one or more fuel system components deteriorates over time, for example, based on the rate at which the fuel fault values ​​increase over time.

[0037] Pump message 44 may include a display indicating the current status of fuel pump 18. If fuel pump 18 is operating normally, message 44 may not be issued, or it may indicate (e.g., on a display) that fuel pump 18 is operating normally. Pump message 44 may indicate the rate at which the condition of fuel pump 18 is deteriorating (e.g., as the expected time when maintenance or repair should be performed on fuel pump 18). Additionally or alternatively, pump message 44 may indicate when the condition of fuel pump 18 is poor, immediately after a poor condition of fuel pump 18 is detected (e.g., based on a single fuel fault value that deviates from the relevant delivery limit, or a minimum number of fuel fault values ​​that deviate from this delivery limit).

[0038] The injection message 46 can be issued in the same manner as described above with respect to the pump message 44, by logging and monitoring the condition of the injectors 22 over time and / or by identifying immediate bad conditions. Since the fuel system of the fuel estimation system 10 includes a multitude of injectors 22, the injection message 46 can identify the specific injector 22 and / or the position of the specific fuel injector 22 where the bad condition exists. Industrial applicability

[0039] The systems and methods disclosed herein can be applied to any system that supplies one or more fuel injectors with pressurized fuel, such as an industrial machine with an internal combustion engine that enables the machine to perform work, move around a construction site, generate electrical power, etc. Suitable industrial machines include, for example, power generation systems (e.g., generators), mining machines, transportation machines (e.g., mining dump trucks, all-terrain trucks, etc.), earthmoving machines, road pavers, and others. The pressure signal analysis can be performed using an ECM 26 located on the machine or by an ECM 26 at a remote location (e.g., off-site) to monitor one or more machines, each incorporating a fuel system.

[0040] The Fig. Figures 3-5 represent signals and analyses that can be performed with the fuel supply detection system 10. In particular, they show Fig. 3. A pressure signal 302 and a processed signal 304. The pressure signal 302 corresponds to a series of measurements that form data points and are measured with a common-rail pressure sensor 24. The processed signal 304 corresponds to a processed signal that was determined based on the pressure signal 302. The processed signal 304 can correspond to the phase shift signal described above.

[0041] In some aspects, the pressure signal 302 corresponds to a crank angle-indexed pressure signal. Each measurement of the pressure signal 302 represents the magnitude of the pressure changes within the common manifold 20 along the y-axis. Fig. 3. The position of each measurement on the x-axis corresponds to the angle measured by the motor speed sensor 28. If desired, the pressure signal 302 can be filtered to facilitate downstream analysis, whereby Fig. Figure 3 represents a filtered signal 302. In particular, the pressure signal 302 can be filtered to minimize or eliminate phase distortions. As described above, the pressure signal 302 can be filtered using a convolution filter that applies a moving average to the raw data from the common pressure sensor 24 and the motor speed sensor 28.

[0042] The processed signal 304 can be generated using a phase shift analyzer 34 and analyzed using a fuel error estimator 36. The processed signal 304 can be generated based on an analysis of pairs of data points from the pressure signal 302. In the example shown, the 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 the signal 302 represents a reference point. The first data point 306 can be located 60 degrees of crankshaft rotation before the second data point 308 and 120 degrees of crankshaft rotation before the third data point 310.

[0043] Each point of the processed signal 304 can be determined by evaluating two data points of signal 302 with respect to a reference point, which is also located in signal 302. The two data points can each be located 60 degrees of crank angle rotation before and 60 degrees of crank angle rotation after the reference point. Each point of the processed signal 304 can be determined by: (i) determining the difference (“a first difference”) between this value (the value of the reference point of pressure signal 302) and the value of the data point located 60 degrees earlier, (ii) determining the difference (“a second difference”) between the value of the reference point and the value of the data point located 60 degrees later from the reference point, and (iii) combining the first difference and the second difference (e.g., by addition). The combination of the two difference values ​​yields a pressure change value, which corresponds to the crank angle position of the reference point.These three steps (i, ii, iii) can be repeated to determine each point of the processed signal 304.

[0044] In the Fig. In the example shown, the phase shift analyzer 34 determines, when comparing the reference data point 308 with data points 306 and 310, that the corresponding point of the processed signal 304 has approximately the same value as the reference point 308. This is determined because the first difference between points 308 and 306 and the second difference between points 308 and 310 add up to zero. As another example, a second reference point 322 can be compared with a first data point 320 and a second data point 324 at a different point in the signal 302. The result of this comparison is a data point 326 of the processed signal 304, since the first and second differences, when added together, result in the negative value shown for point 322.

[0045] This process can remove the content (e.g., pressure fluctuations) or the influence of pump 18 from signal 304 according to the repetitive (e.g., cyclical) way in which pump 18 causes pressure changes (e.g., a pressure pulse that repeats twice with each fuel injection). Once the processed signal 304 has been generated, for example, as described above, the fuel fault estimator 36 can identify pressure differentials present in the processed signal 304. In particular, the dP identifier of the fuel fault 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., crank angle) at which fuel injection begins and ends in a series of regions in the processed signal 304.

[0046] The dP identifier can identify the maximum pressure value within the beginning of each injection window 312, 316 and the corresponding minimum pressure value within the end of each injection window 314, 318. The difference between these values ​​indicates the pressure differential (“dP”) resulting from a fuel injection operation, with the dP value being identified with the pressure fluctuations of the fuel pump 18 that are removed or reduced.

[0047] In Fig. 3. Window 312 can correspond to the beginning of the injection window for a first fuel injector 22. Injection window 314 can correspond to the end of the injection window for the first fuel injector 22. The beginning and end of injection windows 316 and 318 can correspond to a second injector. Subsequent injection windows (not shown) are determined for each subsequent injector 22 such that the dP values ​​determined for each pair of injection windows for a specific fuel injector 22 are linked.

[0048] Fig. Figure 4 shows six actual fuel injection quantity waveforms 402. Each fuel injection waveform 402 is determined using the dP values ​​described above. Fig. Figure 4 also shows a desired fuel injection quantity 404, which corresponds to the specified or desired fuel injection quantity. Fig. In Figure 4, the desired fuel injection quantity 404 is slightly offset below the waveforms 402 to facilitate visual differentiation of the desired fuel injection quantity 404 from the six actual fuel injection quantity waveforms 402, as shown in Figure 4. Fig. Figure 4 shows that these actual fuel injection quantity waveforms 402 are determined after removing the pressure fluctuations from the pump 18. The desired fuel injection quantity 404 generally agrees with the six actual fuel injection quantity waveforms 402 when both the fuel pump 18 and the fuel injector 22 are in good working order.

[0049] In the Fig. In the example shown, each of the fuel injectors generally injects the expected amount of fuel. Towards the end of the diagram shown, three fuel injector waveforms indicate a first fault 406, a second fault 408, and a third fault 410. Faults 406, 408, and 410 indicate actual injection quantities that fall below the desired fuel injection quantity 404. These drops in actual injection quantities correspond to ranges of the processed signal 304 ( Fig. 3), which are flat, such as the areas immediately before and immediately after the second data point 308.

[0050] While the first error 406, the second error 408 and the third error 410 each represent a low or no fuel injection quantity for a certain period, errors can also occur if the detected actual injection quantity exceeds the desired fuel injection quantity 404, as described above.

[0051] Fig. Figure 5 is a diagram illustrating example determinations for the condition of the fuel pump 18 and the fuel injectors 22. A "good condition" range 502 represents acceptable operation of the fuel pump 18 and the fuel injector 22. Within the "good condition" range 502, the specified delivery rate of the pump 18 generally corresponds to the actual amount of fuel injected. The "good condition" range 502 can be defined between a maximum delivery threshold 508 and a minimum delivery threshold 510. As described above, the maximum delivery threshold 508 can generally increase with an increasing specified pump delivery rate. The minimum delivery threshold 510 can also generally increase with an increase in the delivery rate specified by the command pump.

[0052] If the actual amount of fuel injected falls below the minimum supply threshold of 510, the injector condition analyzer 38 can detect that the condition of the fuel pump 18, the fuel injector 22, or both is poor. As described above, the pump / injector condition analyzer 38 can detect that the fuel pump 18 has failed or is malfunctioning (e.g., that a piston in the fuel pump 18 is no longer pumping fuel). This fault in the fuel pump 18 can be indicated by a pump message 44. Additionally or alternatively, the pump / injector condition analyzer 38 can detect that a specific fuel injector 22 has failed or is malfunctioning (e.g., the nozzle of the fuel injector 22 is clogged, a valve of the fuel injector 22 is stuck in the closed position, etc.). This fault in injector 22 can be indicated by the injection message 46.

[0053] If the actual amount of fuel injected exceeds the maximum delivery threshold 508, the injector condition analyzer 38 can detect that the condition of fuel injector 22 is poor. As described above, the injector condition analyzer 38 can detect that fuel injector 22 has failed or has a fault (e.g., a nozzle of fuel injector 22 is leaking, a valve of fuel injector 22 is stuck in an open position, etc.). This fault in fuel injector 22 can be indicated by an injection fault message 46.

[0054] Fig. Figure 6 is a flowchart illustrating a method 600 for determining the fuel supply according to aspects of the disclosure. Step 602 of the method 600 may involve retaining a rail pressure signal. In particular, step 602 may involve retaining signals from the common rail pressure sensor 24 with ECM 26. The rail pressure signal retained in step 602 may be related to pressure signal 302 ( Fig. 3) correspond.

[0055] Step 604 may involve detecting a phase shift signal. This signal may be detected based on the rail pressure signal acquired in step 602. In particular, step 604 may involve detecting a processed signal 304 using a phase shift analyzer 34. In some aspects, step 604 may involve generating signals other than a phase shift signal. In particular, step 604 may involve generating a signal that reduces or eliminates the contribution of the fuel pump 18 within the rail pressure signal acquired in step 602.

[0056] In step 606, the fuel fault estimator 36 can identify one or more pressure differentials in the phase shift signal or another signal detected in step 604. Step 606 may involve identifying pressure differentials present between the beginning of injection windows 312, 316 and the end of injection windows 314, 318, as described above. Fig. 3 described.

[0057] In step 608, the fuel error estimator 36 can determine an actual fuel supply quantity based on the pressure difference(s) determined in step 606. Step 608 can involve estimating the fuel using the fuel supply estimator of the fuel error estimator 36. The fuel supply estimate can be determined for each individual injector 22 and monitored over a specific period of time.

[0058] Step 610 may involve determining the status of a component of the fuel supply system for engine 12, for example, the status of the fuel pump 18 and / or the fuel injector 22, as described above. Step 610 may involve logging the status of one or more components over time. Additionally or alternatively, step 610 may involve generating one or more notifications, such as a pump message 44 and an injector message 46, as described above.

[0059] The disclosed system and method can be configured to monitor the condition of the fuel pump 18 and the fuel injector 22 over a specified period. Specifically, the system and method can be configured to identify poor condition or component failures based on pressure changes detected by the common rail pressure sensor 24. Issues within the fuel pump 18, such as pressure fluctuations due to pump strokes, can be reduced or eliminated by separating the pump strokes from the injection processes. In some configurations, fuel delivery errors are detected with a discreet monitoring system that identifies potential failures without the need for specialized test equipment.

[0060] Those skilled in the art will recognize that various modifications and variations can be made to the disclosed method and system without departing from the scope of the disclosure. Other embodiments of the method and system are apparent to those skilled in the art from a review of the patent specification and from the practical application of the device and system disclosed herein. It is intended that the patent specification and the examples given are to be considered merely illustrative, with the true scope of the disclosure being defined by the following claims and their equivalents. QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] JP 2019-060279

[0004]

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