Estimation and Control of Gas Jet Quantity Using Fourier Transform Method

Abstract

A process for operating a gaseous fuel refueling system includes: operating a plurality of gaseous fuel injectors to inject gaseous fuel; measuring the pressure of gaseous fuel supplied to the plurality of gaseous fuel injectors during multiple gaseous fuel injections while operating the plurality of gaseous fuel injectors; determining a set of Fourier transform results in response to the measurement; determining an average injection quantity of the plurality of gaseous fuel injectors in response to a first subset of the Fourier transform results; determining a plurality of decomposed injection quantities of a plurality of subsets of the plurality of gaseous fuel injectors in response to a second subset of the Fourier transform results; and operating the gaseous fuel refueling system using the decomposed injection quantities.

Description

Technical Field

[0001] This application relates to control logic for gaseous fuel refueling systems and estimation and control of gaseous injection quantity using Fourier transform methods, as well as related devices, controls, diagnostics, processes, systems and technologies. Background Technology

[0002] Gaseous fuel filling systems for internal combustion engines and the control logic for such systems have many drawbacks, including those concerning accuracy, complexity, computational burden, dedicated hardware requirements, precision, reliability, and robustness, among others. There remains a significant demand for the unique devices, processes, systems, and techniques disclosed herein.

[0003] Disclosure of Example Implementations To clearly, concisely, and accurately describe the exemplary embodiments of this disclosure, the ways and processes of making and using these exemplary embodiments, and to enable the practice, making, and use of these exemplary embodiments, reference will now be made to certain exemplary embodiments, including those illustrated in the accompanying drawings, and these exemplary embodiments will be described using specific language. However, it should be understood that this does not limit the scope of the invention, and that the invention includes and protects such changes, modifications, and further applications of the exemplary embodiments that will occur to those skilled in the art. Summary of the Invention

[0004] Some embodiments include unique control logic for gaseous fuel refueling systems. Further embodiments include unique devices, systems, and processes that incorporate or embody such control logic. Further embodiments, forms, objects, features, advantages, aspects, and benefits will become apparent from the following description and drawings. Attached Figure Description

[0005] Figure 1 This is a schematic diagram illustrating certain aspects of an example engine system, including an example fuel filling system.

[0006] Figure 2 This is a schematic diagram illustrating some aspects of an example fuel refueling system.

[0007] Figure 3A and 3B This is a flowchart illustrating some aspects of the example process.

[0008] Figure 4A , 4B The graphs for 4C and 4C illustrate certain aspects of the example control logic.

[0009] Figure 5 This is a schematic diagram illustrating some aspects of an example fuel refueling system.

[0010] Figure 6A and 6B This is a flowchart illustrating some aspects of the example process.

[0011] Figure 7A and 7B It is a graph that shows some aspects of the example control logic.

[0012] Figure 8A and 8B It is a graph that shows some aspects of the example control logic.

[0013] Figure 9A , 9B 9C and 9D are graphs illustrating certain aspects of the example control logic.

[0014] Figure 10A-10F It is a graph that shows some aspects of the example control logic.

[0015] Figure 11 This is a flowchart illustrating some aspects of the example process.

[0016] Figure 12 This is a schematic diagram illustrating certain aspects of the example control logic. Detailed Implementation

[0017] refer to Figure 1 The diagram illustrates a system 11 comprising an engine 10 and a gaseous fuel refueling system 9. The gaseous fuel refueling system 9 is configured to supply gaseous fuels, such as natural gas, hydrogen, bio-derived gaseous fuels, hydrogen-mixed gas fuels, or other gaseous fuels, for combustion in the engine 10. The engine 10 includes a combustion chamber 13 (also referred to as a cylinder) of a reciprocating in-cylinder piston engine, configured to generate mechanical power from the combustion of gaseous fuel supplied by fuel injectors 12. Fuel injectors 12 are in fluid communication with a corresponding combustion chamber 13 of the engine 10 and are configured to inject gaseous fuel supplied to their respective combustion chamber 13.

[0018] In the illustrated embodiment, the fuel injectors 12 are configured and provided in a multi-port injection (MPI) arrangement, wherein each of the fuel injectors 12 is configured to inject fuel into a corresponding port of the intake manifold 37 leading to a specific corresponding combustion chamber 13 of the engine 10. It should be understood that in an MPI arrangement, each of the plurality of cylinders can be individually fueled via a dedicated injector (or a group of multiple dedicated injectors). Other embodiments may include other types and configurations of injectors.

[0019] Some embodiments include a single-point injection (SPI) arrangement, in which multiple fuel injectors are configured to inject fuel into a common intake system location leading to multiple combustion chambers up to all combustion chambers. It should be understood that an SPI arrangement may include multiple injectors configured to inject fuel at different locations within the common intake system location, but their locations are close enough that they can be considered to be injecting fuel at a single common point.

[0020] Some embodiments include a direct injection (DI) arrangement, in which multiple fuel injectors are configured to inject fuel directly into the respective combustion chambers of the engine. It should be understood that in a DI arrangement, each of the multiple cylinders can be individually supplied with fuel via a dedicated injector (or a group of multiple dedicated injectors).

[0021] In the illustrated embodiment, four fuel injectors 12 and four combustion chambers 13 are depicted. It should be understood that the engine 10 may include fewer or more fuel injectors 12 and combustion chambers 13. It should also be understood that the system 11 may be provided in a variety of forms, including as a prime mover system (or a component of a prime mover system) of a vehicle, a generator set, or other power load systems.

[0022] In the illustrated embodiment, the gaseous fuel refueling system 9 includes a gaseous fuel supply and injection system 17 and a gaseous fuel source system 32. The gaseous fuel supply and injection system 17 includes one or more rails 30 and one or more sets of injectors 12, each injector 12 being operatively coupled to and supplying gaseous fuel to a corresponding one of the one or more rails 30. The one or more rails 30 are further configured to receive pressurized fuel from the gaseous fuel source system 32.

[0023] The gaseous fuel source system 32 may include a high-pressure tank configured to store a supply of gaseous fuel under high pressure. In some embodiments, the gaseous fuel source system 32 may include additional components, such as a compressor configured to compress gaseous fuel received from a fuel tank and supply the compressed gaseous fuel to the one or more rails 30 and / or accumulator, and an electronically controllable valve configured to control the supply of gaseous fuel into and out of the accumulator and / or the one or more rails 30.

[0024] It should be understood that the illustrated form of the gaseous fuel refueling system 9 is merely one example of a fuel refueling system according to this disclosure. In other embodiments, the gaseous fuel refueling system 9 may be configured and provided as another type of gaseous fuel refueling system, such as a gaseous hydrogen fuel refueling system. In other embodiments, the gaseous fuel refueling system 9 may be configured and provided in other forms, such as a high-pressure common rail diesel fuel injection system or other types of fuel refueling systems.

[0025] System 11 also includes an electronic control system (ECS) 20 that communicates with engine 10 and is configured to control one or more aspects of engine 10, including controlling the injection of fuel into engine 10 via fuel injectors 12. Accordingly, ECS 20 may communicate with fuel injectors 12 and is configured to command each fuel injector 12 to open and close at predetermined times to inject fuel into engine 10 as needed. ECS 20 typically includes at least one electronic control unit (ECU) 22 configured to perform the operations of ECS 20, as further described herein, and in some embodiments, may include additional ECUs configured to perform the operations of ECS 20, as further described herein.

[0026] The ECS 20 can also be configured to control other parameters of the engine 10, which may include aspects of the engine 10 that can be controlled by actuators activated by the ECS 20. For example, the ECS 20 may communicate with actuators and sensors to receive and process sensor inputs and transmit actuator output signals. Actuators may include, but are not limited to, fuel injectors 12. Sensors may include any suitable devices for monitoring the operating parameters and functions of the system 11. For example, sensors may include one or more pressure sensors 16 and one or more temperature sensors 18. The one or more pressure sensors 16 communicate with one or more rails 30 and are configured to transmit measurements of the pressure of gaseous fuel (also referred to as fuel rail pressure or rail pressure) in the one or more rails 30 to the ECS 20. The one or more temperature sensors 18 communicate with one or more rails 30 and are configured to transmit measurements of the temperature of gaseous fuel (also referred to as fuel rail temperature or rail temperature) in the one or more rails 30 to the ECS 20. System 11 includes an intake manifold pressure (IMP) sensor 38 that communicates with and is configured to sense the pressure in the intake manifold 37.

[0027] As will be understood from the following description, the techniques described herein related to fuel injectors or fuel injection parameters can be implemented in ECS 20, which may include one or more controllers for different aspects of control system 11. In some embodiments, ECS 20 includes one or more electronic control units (ECUs), such as engine control units or engine control modules. ECS 20 may include digital circuitry, analog circuitry, or a hybrid combination of both. Furthermore, ECS 20 may be programmable, integrated state machines, or a hybrid combination thereof. ECS 20 may include one or more arithmetic logic units (ALUs), central processing units (CPUs), memories, limiters, regulators, filters, format converters, etc., which are not shown for clarity. In one form, ECS 20 is programmable, executing algorithms and processing data according to operating logic defined by programming instructions, such as software or firmware. Alternatively or additionally, the operating logic of ECS 20 may be defined at least in part by hardwired logic or other hardware.

[0028] In addition to the sensor types described herein, the system and method may encompass any other suitable sensor and its associated parameters. Accordingly, the sensor may include any suitable device for sensing any relevant physical parameters of engine system 11, including electrical, mechanical, and chemical parameters. As used herein, the term sensor may include any suitable hardware and / or software for directly or indirectly sensing or estimating any engine system parameters and / or various combinations of such parameters.

[0029] refer to Figure 2 Further details of an example embodiment of the gaseous fuel filling system 9 are shown. In the illustrated example of the gaseous fuel filling system 9, the gaseous fuel source system 32 is configured to supply pressurized gaseous fuel to the front rail 30f and the rear rail 30r. The front rail 30f and the rear rail 30r are configured to provide physically separate or separate gaseous fuel containment structures, which can be provided in various forms, including, for example, as physically separate or separate tubular fuel rails or pipes or physically separate orifices formed in engine components such as intake manifolds or cylinder heads. The front rail 30f and the rear rail 30r preferably supply pressurized gaseous fuel from the gaseous fuel source system 32 at separate and different locations to effectively provide a degree of isolation between their respective pressures.

[0030] The front rail 30f is configured and operable to supply pressurized gaseous fuel to a plurality of front injectors 12f, which are configured to inject gaseous fuel into specific front cylinder intakes among a plurality of front cylinder intakes 14f associated with a plurality of first cylinders 13f. In the illustrated example, the first plurality of cylinders 13f includes a first cylinder, a second cylinder, and a third cylinder formed in the block of an inline six-cylinder engine 10i. In the illustrated example, the plurality of front injectors 12f includes injectors 1A, 1B, 2A, 2B, 3A, and 3B. Injectors 1A and 1B are configured to supply gaseous fuel to a first intake port of the intake manifold 37 leading to a first combustion cylinder. Injectors 2A and 2B are configured to supply gaseous fuel to a second intake port of the intake manifold 37 leading to a second combustion cylinder. Injectors 3A and 3B are configured to supply gaseous fuel to the third intake port of the intake manifold 37 leading to the third combustion cylinder.

[0031] The rear rail 30r is configured and operable to supply pressurized gaseous fuel to a plurality of rear injectors 12r, which are configured to inject gaseous fuel into specific rear cylinder intakes among a plurality of rear cylinder intakes 14r associated with a plurality of second plurality of cylinders 13r. In the illustrated example, the second plurality of cylinders 13r includes a fourth, a fifth, and a sixth cylinder formed in the block of the inline six-cylinder engine 10i. In the illustrated example, the rear plurality of injectors 12r includes injectors 4A, 4B, 5A, 5B, 6A, and 6B. Injectors 4A and 4B are configured to supply gaseous fuel to a fourth intake port of the intake manifold 37 leading to a fourth combustion cylinder. Injectors 5A and 5B are configured to supply gaseous fuel to a fifth intake port of the intake manifold 37 leading to a fifth combustion cylinder. Injectors 6A and 6B are configured to supply gaseous fuel to the sixth intake port of the intake manifold 37 leading to the sixth combustion cylinder.

[0032] It should be understood that the front rail 30f and the rear rail 30r are a combination of these. Figure 1 One example shown and described is a first rail and a second rail separate or separate from the first rail. Other embodiments are also contemplated, wherein one or more rails 30 include a first rail and a second rail separate or separate from the first rail. Such embodiments include, for example, systems comprising, a relative arrangement and positioning of multiple fuel rails serving a group of inline cylinders in addition to front and rear; systems wherein one or more rails 30 include three or more rails; and / or systems wherein one or more rails 30 include two or more rails configured to supply gaseous fuel to the same group or category of cylinders. Similarly, while the illustrated example relates to an engine comprising six cylinders, other embodiments relate to other engines comprising more or fewer than six cylinders.

[0033] refer to Figure 3Aand 3B An example process 300 is shown for operating an electronic control system (e.g., ECS 20 or another electronic control system) that is operatively in communication with a fuel dispensing system (e.g., gaseous fuel dispensing system 9 or another fuel dispensing system). Process 300 may be implemented in and executed by one or more components of the electronic control system (e.g., one or more electronic control units (e.g., ECU 22 and / or other electronic control units)), and / or executed by other electronic control system components.

[0034] Process 300 is configured for the front cylinder bank and split-rail fuel system of a four-stroke six-cylinder engine. A similar process approach is used for the rear cylinder bank or alternative engine and fuel system configurations. For a six-cylinder engine with a non-split-rail system, the engine's half-fire frequency harmonic is equal to the injector's third-third frequency harmonic, and is incorporated into one of the options of the percentage difference between the individual injector's injection quantity and the average injection quantity value.

[0035] Process 300 begins with start operation 302 and proceeds to operation 304, which measures the pressure of gaseous fuel supplied to multiple injectors during the operation of multiple gaseous fuel injectors and performs multiple gaseous fuel injections. Operation 304 can measure and store rail pressure data for a complete engine cycle (e.g., 720 degrees @ 6 degrees sampling = 120 data points).

[0036] It should be understood that process 300 is configured to operate in conjunction with an MPI arrangement, where the injection cycle (a repeating cycle in which all injectors have been activated to perform injection, or where an injection event has occurred even if a zero-fuel charge is ordered) has the same fundamental frequency as the 720-degree engine cycle. Therefore, the cylinder ignition domain and the injector operating domain are mutually corresponding and can be considered interchangeably for some purposes.

[0037] Starting with operation 304, process 300 proceeds to operation 306, which responds to the pressure measurement results of operation 302 and determines a set of Fourier transform results. Operation 306 can calculate the average pressure. And the discrete Fourier transform results (real part) of the operating sequence frequencies of the 1 / 3, 2 / 3, 3 / 3, 6 / 3 and 9 / 3 injectors. , , , , imaginary part , , , , Amplitude , , , , Phase , , , , It should be understood that the operating sequence frequencies of the 3 / 3 injectors include the fundamental frequency, the operating sequence frequencies of the 1 / 3 and 2 / 3 injectors include the subharmonics of the fundamental frequency, and the operating sequence frequencies of the 6 / 3 and 9 / 3 injectors include the positive integer multiples of the fundamental frequency.

[0038] Starting with operation 306, process 300 proceeds to operation 308, which responds to the first subset of the Fourier transform results, such as the 3 / 3 injector sequence fundamental frequency, the 6 / 3 injector sequence frequency, and the 9 / 3 injector sequence frequency (or, in principle, additional positive integer harmonics of the fundamental frequency), to determine the average injection quantity of multiple gaseous fuel injectors. Operation 308 may utilize the average rail pressure based on fuel system configuration and engine and fuel operating conditions (engine speed and average rail pressure). The engine speed and the amplitude of the harmonics of the 1.0 (3 / 3), 1.0 (6 / 3), or 3.0 (9 / 3) injector operating sequence frequencies selected by the control structure. , or Calculate the average injection quantity of the cylinder in relation to the measured rail pressure. The estimated value. Operation 308 can be used. Figure 4A Graph 410 Figure 4B The curves 420 and Figure 4C One or more corresponding control logics in curve 430 determine the average injection quantity ( ).

[0039] Starting with operation 308, process 300 proceeds to operation 310, which determines adjustment parameters to compensate for differences in the system relationship between the pressure sensor and multiple injectors. For example, the distance between each injector and a given pressure sensor may differ, and the channel geometry along that distance may also differ. Operation 310 can use parameters based on engine speed, average rail pressure, etc. and average injection volume Equations or tables to calculate phase shift , Injection volume percentage multiplier , Injector percentage offset item , , ,as well as These parameters take into account the asymmetry of the fuel system flow channel geometry and the location of the pressure sensors.

[0040] Starting from operation 310, process 300 proceeds to operation 320, which determines the cylinder relative to the average injection quantity associated with the measured rail pressure. The difference in the percentage of injection volume For example, regarding the firing order of cylinders 1, 5, and 3, operation 320 can calculate the injection percentage difference as follows: ;as well as .

[0041] Starting with operation 320, process 300 proceeds to operation 322, which determines the fuel filling measurement results for each cylinder in relation to the measured rail pressure. Operation 322 can determine the fuel filling measurement results for cylinders 1, 5, and 3, for example, as follows: ); );as well as ).

[0042] Starting from operation 322, process 300 proceeds to operation 324, and can end or repeat. It should be understood that if process 300 ends, it can be repeated or restarted thereafter.

[0043] It should be understood that operations 320 and 322 are example operations that can be used to determine multiple decomposed injection quantities for multiple subsets of multiple gaseous fuel injectors in response to a second subset of the Fourier transform results. It should also be understood that in the example calculations described in conjunction with process 300, terms with the subscript "DFT" denote DFT values ​​determined at runtime, while other terms described are control characteristics predetermined at runtime, for example, which can be implemented as calibrable values.

[0044] refer to Figures 4A-4C Figures 410, 420, and 430 are shown, which depict certain aspects of example control logic that can be implemented in and executed by one or more components of an electronic control system, such as one or more electronic control units, and / or executed by other electronic control system components.

[0045] Figure 4AGraph 410 depicts a set of curves from which the fuel injection quantity can be determined as a function of the DFT amplitude for the 3 / 3 injector operating sequence frequency (corresponding to the fundamental frequency). Each set of curves in the graph corresponds to a different engine operating speed. Example control logic based on graph 410 may include a lookup table that receives input 411, including the determined DFT amplitude and engine speed, and determines and outputs the corresponding injection quantity 412 based on a calibrable predetermined value corresponding to the illustrated curve for the indicated engine speed.

[0046] Figure 4B Graph 420 depicts a set of curves from which the fuel injection quantity can be determined as a function of the DFT amplitude for the 6 / 3 injector operating sequence frequency (corresponding to the fundamental frequency). Each set of curves in the graph corresponds to a different engine operating speed. Example control logic based on graph 420 may include a lookup table that receives input 421, including the determined DFT amplitude and engine speed, and determines and outputs the corresponding injection quantity 422 based on a calibrable predetermined value corresponding to the graphed curve for the indicated engine speed.

[0047] Figure 4C Graph 430 depicts a set of curves from which the fuel injection quantity can be determined as a function of the DFT amplitude for the 9 / 3 injector operating sequence frequency (corresponding to the fundamental frequency). Each set of curves in the graph corresponds to a different engine operating speed. Example control logic based on graph 430 may include a lookup table that receives input 431, including the determined DFT amplitude and engine speed, and determines and outputs the corresponding injection quantity 432 based on a calibrable predetermined value corresponding to the graphed curve for the indicated engine speed.

[0048] It should be understood that the average value, weighted average value, or other statistical parameters can be determined based on two or more of the example control logic in graphs 410, 420, and 430, and the determined values ​​can be used as the output of the injection quantity. In some embodiments, control logic corresponding to another graph of graphs 410, 420, 430, or a positive integer multiple of the fundamental frequency can be utilized.

[0049] It should be understood that the control logic corresponding to and / or implementing the features shown and described in conjunction with Figures 410, 420, and 430 can be implemented using the aforementioned lookup tables (LUTs), runtime calculations, estimations, and / or statistical techniques, or by a combination of these methods with other computational techniques that would be conceived by those skilled in the art. It should also be understood that other control determinations disclosed herein can also be implemented using any of the methods described above.

[0050] The control logic based on curves 410, 420, and / or 430 is an example of control logic. This control logic is based on the fuel system configuration and engine and fuel operating conditions (engine speed and average rail pressure), utilizing the average rail pressure P_average, engine speed, and the amplitude of the frequency harmonics of the injector 3 / 3, 6 / 3, 9 / 3, or 12 / 3 operating sequence selected by the control structure. , , or The average injection quantity Q_average of the cylinder is calculated and estimated in relation to the measured rail pressure.

[0051] It should be understood that Figures 4A-4C An example is shown showing the relationship between the Discrete Fourier Transform (DFT) amplitude as a function of engine speed under average rail pressure P_average. An estimate of the injection quantity can be obtained at each ignition frequency harmonic. Alternatively, the ignition frequency harmonic with the most robust and accurate injection quantity estimate can be selected based on the amplitude of the local gain relationship between the DFT amplitude and the injection quantity. For example, for a representative system embodiment, the gain of the 6 / 3 injector operating sequence frequency harmonic is highest at a relatively low engine speed of 715 rpm; the gain of the 3 / 3 injector operating sequence frequency harmonic is highest at a higher engine speed of 1787.5 rpm; and the gain of the 9 / 3 injector operating sequence frequency harmonic is highest when the injection quantity is less than 60 mg and the engine speed is 1072.5 rpm.

[0052] refer to Figure 5 This illustration shows certain aspects of an example SPI gaseous fuel refueling system 509. In the illustrated example, a gaseous fuel supply 502 is configured to supply pressurized gaseous fuel to an inlet rail 510 via a filter 504 and a line 506. The inlet rail 510 is configured to supply fuel to a plurality of fuel injectors 512. A pressure sensor 511 is configured to measure the pressure of the gaseous fuel in the inlet rail 510. In the illustrated example, the plurality of fuel injectors 512 includes five fuel injectors: injector 512a, injector 512b, injector 512c, injector 512d, injector 512e, and injector 512f. In other embodiments, the plurality of fuel injectors 512 may include more or fewer injectors.

[0053] Multiple fuel injectors 512 are configured to inject gaseous fuel into an outlet rail 520, which is then supplied via line 522 to an intake manifold 530. The intake manifold 530 is configured to supply gaseous fuel to multiple cylinders 514 via multiple ports 513. In the illustrated example, the gaseous fuel filling system 509 is configured to supply fuel to six cylinders 514a, 514b, 514c, 514d, 514e, and 514f via six corresponding ports 513a, 513b, 513c, 513d, 513e, and 513f. In other embodiments, gaseous fuel may be supplied to a different number of cylinders and corresponding ports. The gaseous fuel filling system 509 is operatively coupled to an electronic control system (not shown), which may be similar to the ECS 20 described above.

[0054] refer to Figure 6A and 6B This illustrates the operation of the SPI fuel dispensing system ( For example Example process 600 of an electronic control system operatively communicating with an SPI gaseous fuel dispensing system 509 or another SPI fuel dispensing system. Process 600 may be implemented in and executed by one or more components of the electronic control system, such as one or more electronic control units, and / or executed by other electronic control system components.

[0055] Process 300 is configured for a single-point injection (SPI) system and fuel system for a four-stroke, six-cylinder engine. The fuel system consists of five injectors, with injection start command intervals of 120 crankshaft degrees allocated to the injectors. The injectors ignite sequentially based on their injector numbers. The engine ignition frequency harmonics are included in the percentage difference between the individual injector injection quantity and the average injection quantity value.

[0056] It should be understood that process 600 is configured to operate in conjunction with an SPI arrangement where the number of injectors is less than the number of cylinders; that is, five SPI injectors are configured to supply fuel to six cylinders. Accordingly, the base frequency of the injection cycle (a repeating cycle in which all injectors have been operated to perform injection, or an injection event has occurred even if a zero-fuel-load command is issued) is a 600-degree engine cycle, which differs from the base frequency of a 720-degree engine cycle. Therefore, the cylinder ignition domain and the injector operating domain may not correspond to each other. It should be understood that other SPI arrangements may have the same number of injectors as the number of cylinders; for example, six SPI injectors are configured to supply fuel to six cylinders. In such embodiments, the base frequency of the injection cycle will be the same as a 720-degree engine cycle, similar to process 300 of the MPI arrangement. It should also be understood that Process 600 provides an example of an injection quantity estimation method based on Discrete Fourier Transform (DFT) using a Single Point Injection (SPI) system consisting of a four-stroke, six-cylinder engine and a fuel system comprising five injectors. Injection start command intervals are distributed to the injectors at 120 crankshaft degrees, with the injectors ignited sequentially in the order of injectors 1, 5, 2, 4, and 3. It should also be understood that other SPI arrangements may have more injectors than cylinders. Furthermore, it should be understood that Process 600 can also be configured for other types of gaseous fuel systems, such as DI systems.

[0057] Process 600 begins with start operation 602 and proceeds to operation 604, which measures the pressure of the gaseous fuel supplied to multiple injectors during the operation of multiple gaseous fuel injectors and performs multiple gaseous fuel injections. Operation 604 can measure and store rail pressure data for a complete injector cycle (e.g., 600 degrees @ 6 degrees sampling = 100 data points).

[0058] Starting with operation 604, process 600 proceeds to operation 606, which responds to the pressure measurement results of operation 302 and determines a set of Fourier transform results. Operation 606 can calculate the average pressure. And the discrete Fourier transform results (real part) of the operating sequence frequencies of the 1 / 5, 2 / 5, 3 / 5, 4 / 5 and 5 / 5 injectors. , , , , imaginary part , , , , Amplitude , , , , Phase , , , , It should be understood that the operating sequence frequencies of the 5.5 injector include the fundamental frequency, while the operating sequence frequencies of the 1 / 5, 2 / 5, 3 / 5, and 4 / 5 injectors include the subharmonics of the fundamental frequency.

[0059] Starting with operation 606, process 600 proceeds to operation 608, which, in response to a first subset of the Fourier transform results, such as the fundamental frequency of the 5 / 5 injector operating sequence and / or its higher-order positive integer harmonics, determines the average injection quantity of multiple gaseous fuel injectors. Operation 608 may utilize the average rail pressure based on fuel system configuration and engine and fuel operating conditions (engine speed and average rail pressure). Engine speed and the amplitude selected by the control structure and / or its positive integer multiples (such as (or other higher-order injector operating sequence frequency harmonics), calculate the average injection quantity of the cylinder in relation to the measured rail pressure. The estimated value. Operation 608 can be used. Figure 8A The curves 810 and Figure 8B One or more corresponding control logics in the curve 820 determine the average injection quantity. .

[0060] Figure 7A Figure 710 shows the sinusoidal component of the fundamental frequency (5 / 5) output response DFT from the supply pressure signal associated with the average injection quantity of the injector. Figure 7B Figure 720 shows the sinusoidal component of the DFT output response from the supply pressure signal, which is associated with the average injection quantity of the injector and the harmonic frequency (10 / 5). Figure 7A and 7B In this process, the injector pulses are spaced out. It should be understood that process 600 can also be used in combination with partially overlapping injector pulses.

[0061] Starting with operation 608, process 600 proceeds to operation 610, which determines adjustment parameters to compensate for differences in the system relationship between the pressure sensor and multiple injectors. For example, the distance between each injector and a given pressure sensor may differ, and the channel geometry along that distance may also differ. Operation 610 can use parameters based on engine speed, average rail pressure, etc. and average injection volume Equations or tables to calculate phase shift , , , Injection volume percentage multiplier , , , Injector percentage offset item , , , and ,as well as These parameters take into account the asymmetry of the fuel system flow channel geometry and the location of the pressure sensors.

[0062] Starting from operation 610, process 600 proceeds to operation 620, which determines the cylinder relative to the average injection quantity associated with the measured rail pressure. The difference in the percentage of injection volume For example, Operation 620 can calculate the injection percentage difference as follows: .

[0063] Starting with operation 620, process 600 proceeds to operation 622, which determines the fuel filling measurement results for each cylinder in relation to the measured rail pressure. Operation 322 can determine the fuel filling measurement results for injectors 1 to 5, for example, as follows: ); ); ); );as well as ).

[0064] Starting from operation 622, process 600 proceeds to operation 624, and can end or repeat. It should be understood that if process 600 ends, it can be repeated or restarted thereafter.

[0065] It should be understood that operations 620 and 622 are example operations that can be used to determine multiple decomposed injection quantities for multiple subsets of multiple gaseous fuel injectors in response to a second subset of the Fourier transform results. It should also be understood that in the example calculations described in conjunction with process 600, terms with the subscript "DFT" denote DFT values ​​determined at runtime, while other terms described are control characteristics predetermined at runtime, which, for example, can be implemented as calibrable values.

[0066] refer to Figure 8A and 8BFigures 810 and 820 are shown, which depict certain aspects of example control logic that can be implemented in and executed by one or more components of an electronic control system, such as one or more electronic control units, and / or executed by other electronic control system components.

[0067] Figure 8A Graph 810 depicts a set of curves from which the fuel injection quantity can be determined as a function of the DFT amplitude for the 5 / 5 injector operating sequence frequency (corresponding to the fundamental frequency). Each set of curves in the graph corresponds to a different engine operating speed. Example control logic based on graph 810 may include a lookup table that receives input 811, including the determined DFT amplitude and engine speed, and determines and outputs the corresponding injection quantity 812 based on a calibrable predetermined value corresponding to the graphed curve for the indicated engine speed.

[0068] Figure 8B Graph 820 depicts a set of curves from which the fuel injection quantity can be determined as a function of the DFT amplitude for the 10 / 5 injector operating sequence frequency (corresponding to the fundamental frequency). Each set of curves in the graph corresponds to a different engine operating speed. Example control logic based on graph 820 may include a lookup table that receives input 821, including the determined DFT amplitude and engine speed, and determines and outputs the corresponding injection quantity 822 based on a calibrable predetermined value corresponding to the graphed curve for the indicated engine speed.

[0069] It should be understood that the example control logic based on graphs 810 and 820 can determine the average value, weighted average value, or other statistical parameters, and the determined value can be used as the output of the injection quantity. In some embodiments, control logic corresponding to another graph, such as graphs 810, 820, or positive integer multiples of the base frequency, can be utilized.

[0070] It should be understood that the control logic corresponding to and / or implementing the features shown and described in conjunction with Figures 810 and 820 can be implemented using the aforementioned lookup tables (LUTs), runtime calculations, estimations, and / or statistical techniques, or by a combination of these methods with other computational techniques that would be conceived by those skilled in the art. It should also be understood that other control determinations disclosed herein can also be implemented using any of the methods described above.

[0071] The control logic based on curves 810 and / or 820 is an example of control logic. This control logic is based on the fuel system configuration and engine and fuel operating conditions (engine speed and average rail pressure), utilizing the average rail pressure P_average, engine speed, and the amplitude of the 5 / 5 or 10 / 5 ignition sequence frequency harmonics selected by the control structure. or The average injection quantity Q_average of the cylinder is calculated and estimated in relation to the measured rail pressure.

[0072] It should be understood that Figure 8A and 8B An example is shown showing the relationship between the Discrete Fourier Transform (DFT) amplitude as a function of engine speed under average rail pressure P_average. An estimate of the injection quantity can be obtained at each ignition frequency harmonic. Alternatively, the ignition frequency harmonic with the most robust and accurate injection quantity estimate can be selected based on the amplitude of the local gain relationship between the DFT amplitude and the injection quantity.

[0073] refer to Figures 9A-9D Figures 910, 920, 930, and 940 illustrate examples of the relationship between the discrete Fourier transform amplitude and the average injection quantity of an example embodiment system associated with the example SPI gaseous fuel refueling system 509, which operates at an engine speed of 1400 rpm, with an average injection quantity of 122 mg per injector, and a gaseous fuel mixture at 35°C with a molecular weight of 18.07 g / mol. As with all exemplary embodiments and methods depicted, the output DFT sinusoidal characteristics depend on factors such as system layout and dimensional characteristics, engine speed, average rail pressure, injection quantity, and gaseous fuel composition.

[0074] Figure 910 shows the output DFT sine wave of the 1 / 5 harmonic term. Figure 920 shows the output DFT sine wave of the 2 / 5 harmonic term. Figure 930 shows the output DFT sine wave of the 3 / 5 harmonic term. Figure 940 shows the output DFT sine wave of the 4 / 5 harmonic term. Based on the fuel system configuration and engine and fuel operating conditions (engine speed and average rail pressure), the percentage difference between each individual injector in the cylinder and Q_average, associated with the measured rail pressure, can be estimated using the average rail pressure P_average, engine speed, and the amplitude and phase of all sub-harmonic terms selected by the control structure. For a representative example configuration with 5 injectors, the amplitude and phase used are: the 1 / 5, 2 / 5, 3 / 5, and 4 / 5 ignition sequence frequency harmonics. , , , , , , , .

[0075] refer to Figure 10A-10FThe diagrams 1010, 1020, 1030, 1040, 1050, and 1060 illustrate aspects of another embodiment of the control logic disclosed herein. The control logic based on diagrams 1010, 1020, 1030, 1040, 1050, and 1060 can utilize aggregated subharmonic values, which reduces the computational burden compared to calculating the individual injection quantity for each injector as described above. Through the example control logic, variations in the subharmonic DFT sum waveform can be used to identify over-limit and under-limit emissions of individual injectors.

[0076] Figure 10A Graph 1010 shows the curves corresponding to the DFT sums of the 1 / 5, 2 / 5, 3 / 5, and 4 / 5 harmonic terms, which combine the injector operation events of injector 1, injector 2, injector 3, injector 4, and injector 5. In the graph shown, the magnitude of each injection event is essentially equal, with some variation within the parameter range considered to reflect normal operation.

[0077] Figure 10B Graph 1020 shows the DFT sums corresponding to the 1 / 5, 2 / 5, 3 / 5, and 4 / 5 harmonic terms, which combine the injector operation events of injector 1, injector 2, injector 3, injector 4, and injector 5. In the graph shown, the amount of each injection event can still be considered almost equal, but the operation of injector 5 exhibits some excess, while the operation of injector 3 exhibits some underestimation, resulting in a reverse shift in the DFT sum waveform, as shown by the lowest negative value of the DFT sum waveform associated with the operation of injector 5 and the highest DFT sum waveform associated with the operation of injector 3.

[0078] Figure 10C Graph 1030 shows the DFT sums corresponding to the 1 / 5, 2 / 5, 3 / 5, and 4 / 5 harmonic terms, which combine the ejector operation events of ejector 1, ejector 2, ejector 3, ejector 4, and ejector 5. In the graph shown, the amount of each ejection event can still be considered almost equal, but the operation of ejector 5 exhibits some excess, while the operation of ejector 2 exhibits some underestimation, resulting in a reverse shift in the DFT sum waveform, as shown by the lowest negative value of the DFT sum waveform associated with the operation of ejector 2 and the highest DFT sum waveform associated with the operation of ejector 5.

[0079] Figure 10DGraph 1040 shows the curves corresponding to the DFT sums of the 1 / 5, 2 / 5, 3 / 5, and 4 / 5 harmonic terms, which combine the ejector operation events of ejector 1, ejector 2, ejector 3, ejector 4, and ejector 5. In the graph shown, the amount of each ejection event can still be considered almost equal, but the operation of ejector 1 exhibits some excess, while the operation of ejector 4 exhibits some underestimation, resulting in a reverse shift in the DFT sum waveform, as shown by the lowest negative value of the DFT sum waveform associated with the operation of ejector 1 and the highest DFT sum waveform associated with the operation of ejector 4.

[0080] Figure 10E Graph 1050 shows the DFT sums corresponding to the 1 / 5, 2 / 5, 3 / 5, and 4 / 5 harmonic terms, which combine the ejector operation events of ejector 1, ejector 2, ejector 3, ejector 4, and ejector 5. In the graph shown, the amount of each ejection event can still be considered almost equal, but the operation of ejector 4 exhibits some excess, while the operation of ejector 2 exhibits some underestimation, resulting in a reverse shift in the DFT sum waveform, as shown by the lowest negative value of the DFT sum waveform associated with the operation of ejector 4 and the highest DFT sum waveform associated with the operation of ejector 3.

[0081] Figure 10F Graph 1060 shows the curves corresponding to the DFT sums of the 1 / 5, 2 / 5, 3 / 5, and 4 / 5 harmonic terms, which combine the injector operation events of injector 1, injector 2, injector 3, injector 4, and injector 5. In the graph shown, the amount of each injection event can still be considered almost equal, but the operation of injector 1 exhibits some excess, while the operation of injector 3 exhibits some underestimation, resulting in a reverse shift in the DFT sum waveform, as shown by the lowest negative value of the DFT sum waveform associated with the operation of injector 5 and the highest DFT sum waveform associated with the operation of injector 1.

[0082] refer to Figure 11 An example process 700 for operating an electronic control system that is operatively in communication with a gaseous fuel refueling system is shown. Process 700 may be implemented in and executed by one or more components of the electronic control system, such as one or more electronic control units, and / or executed by other electronic control system components.

[0083] Process 700 is configured for the SPI system and fuel system of a four-stroke, six-cylinder engine. This fuel system consists of five injectors, with injection start command intervals distributed to the injectors at 120 crankshaft degrees. The injectors ignite sequentially based on their injector numbering order. The engine ignition frequency harmonics are included in the percentage difference between the individual injector injection quantity and the average injection quantity value. It should be understood that Process 700 can also be configured for other types of gaseous fuel systems, such as MPI or DI systems.

[0084] Process 700 begins with start operation 702 and proceeds to operation 704, which measures the pressure of the gaseous fuel supplied to multiple injectors during the operation of multiple gaseous fuel injectors and performs multiple gaseous fuel injections. Operation 704 can measure and store rail pressure data for a complete injector cycle (e.g., 600 degrees @ 6 degrees sampling = 100 data points).

[0085] Starting with operation 704, process 700 proceeds to operation 706, which responds to the pressure measurement results of operation 302 and determines a set of Fourier transform results. Operation 706 can calculate the average pressure. And the discrete Fourier transform results (real part) of the first harmonic frequencies for the operating sequence of the 1 / 5, 2 / 5, 3 / 5, and 4 / 5 injectors. , , , imaginary part , , , Amplitude , , , Phase , , , ).

[0086] Starting from operation 706, process 700 proceeds to operation 708, which uses the discrete Fourier transform amplitude and phase of the second harmonic frequencies for the operating sequence of the 1 / 5, 2 / 5, 3 / 5, and 4 / 5 injectors to calculate the sum of sinusoidal waveforms.

[0087] Starting from operation 708, process 700 proceeds to operation 717, which uses the relationship between the injection event location of the injector and the relative value of the corresponding local DFT subharmonic sum to estimate the relative injection quantity difference between each injector.

[0088] Starting from operation 708, process 700 also proceeds to operation 712, which (optionally) calculates the expected sum of sinusoidal waveforms based on the fuel system configuration and engine and fuel operating conditions (engine speed and average rail pressure), using discrete Fourier transform amplitudes and phases for the subharmonic frequencies of the 1 / 5, 2 / 5, 3 / 5, and 4 / 5 injector operating sequences. These subharmonic frequencies take into account the asymmetry of the fuel system flow channel geometry and pressure sensor locations. Parameters are used based on engine speed and average rail pressure. and average injection volume Calculate using equations or tables.

[0089] Starting from operation 712, process 700 proceeds to operation 714, which subtracts the measured DFT sum of the subharmonic terms from the expected DFT sum of the subharmonic terms.

[0090] Starting from operation 714, process 700 proceeds to operation 716, which uses the relationship between the injection event location of the injector and the relative value of the corresponding local DFT subharmonic sum to estimate the relative injection quantity difference between each injector.

[0091] Starting with operations 716 and 717, process 700 proceeds to operation 718, which balances the injection quantity by adjusting the on-time of the injector command. When the injector's injection quantity is less than the injector's average injection quantity (e.g.) Figure 10B Injector 3, Figure 10C Injector 5, Figure 10D Injector 4, Figure 10E Injector 2 or Figure 10F In the case of injector 1), the sum of the sinusoidal waveforms resulting from the discrete Fourier transform of the subharmonic frequencies will exhibit a local maximum positive value. This occurs when the injector's injection quantity exceeds its average injection quantity (e.g., [missing information]). Figure 10B Injector 5, Figure 10C Injector 2, Figure 10D Injector 1 in Figure 10E Injector 4 or Figure 10F In the injector 3), the sum of the sinusoidal waveforms resulting from the discrete Fourier transform of the subharmonic frequencies will exhibit a local maximum negative value. By utilizing the relationship between the injector's injection event location and the corresponding relative value of the local DFT subharmonic sum, the relative injection quantity difference between each injector can be estimated. By adjusting the injector's command activation time, the injection quantity can be balanced.

[0092] Starting from operation 718, process 700 proceeds to operation 719, and can be terminated or repeated. It should be understood that if process 700 is terminated, it can be repeated or restarted thereafter.

[0093] refer to Figure 12An example control logic 200 is illustrated, which may be implemented in and operated by one or more electronic control units or other components of an electronic control system. Control logic 200 includes injector control logic 210, which is configured to determine and output at least one injector control signal 219 in response to one or more inputs to control the operation of injector 12i. In the illustrated example, injector control logic 210 is configured to determine and output an injector command for a particular individual injector 12i. Control logic 200 may include additional examples of injector control logic that is the same as or similar to injector control logic 210, which is configured to determine and output injector commands for other particular individual injectors.

[0094] In the illustrated example, injector control logic 210 is configured to receive multiple inputs, including fuel filler command 202, engine speed 203, and intake manifold pressure (IMP) 204, rail pressure 206, and rail temperature 208. In other embodiments, injector control logic 210 may be configured to receive additional or alternative inputs.

[0095] The fuel filling command 202 may include fuel quantity (Q) and fuel filling pressure (P). The fuel filling command 202 may be determined and provided to the injector control logic 210 in response to operator input such as accelerator pedal position or to automated operation of electronic control systems such as adaptive cruise control systems. Engine speed 203 may be provided by an engine speed sensor. Engine speed 203 may be provided to the injector control logic 210 via a dedicated connection or via one or more communication networks.

[0096] IMP 204 may be provided by pressure sensor 38, which is operatively in communication with intake manifold 37 and configured to sense the pressure in the intake manifold. IMP 204 may be provided to injector control logic 210 via a dedicated connection or via one or more communication networks.

[0097] The rail pressure 206 can be provided by a pressure sensor 16, which is operatively in communication with the fuel rail 20 and configured to sense the pressure of the fuel rail, which is configured to supply fuel to the injector 12i and can also be configured to supply fuel to other injectors. The rail pressure 206 can be provided to the injector control logic 210 via a dedicated connection or via one or more communication networks.

[0098] The rail temperature 208 can be provided by a temperature sensor 18, which is operatively in communication with the fuel rail 20 and configured to sense the temperature of the fuel rail. The rail temperature 208 can be provided to the injector control logic 210 via a dedicated connection or via one or more communication networks.

[0099] Injector control logic 210 includes control circuitry configured to implement and execute control logic for processing inputs received by injector control logic 210, and configured to determine and output injector control signal 219. In the illustrated example, the circuitry of injector control logic 210 is configured to provide and execute pressure measurement processing logic 212, injection quantity estimation logic 214, injection control logic 216, and injection control modification logic 218. In other embodiments, the control logic provided by injector control logic 210 may be organized differently, wherein aspects of one or more logic blocks shown are combined in a single block or unit, divided into multiple blocks or units, and / or provided with additional or alternative blocks or units.

[0100] In the illustrated example, pressure measurement processing logic 212 and injection quantity estimation logic 214 are configured to implement and execute one or more operations of the process. Pressure measurement processing logic 212 is configured to perform multiple operations related to the reception and processing of rail pressure 206. Injection quantity estimation logic 214 is configured to perform multiple operations related to calculating fuel injection quantity estimates using the output of pressure measurement processing logic 212. In other embodiments, the above operations may be distributed differently among pressure measurement processing logic 212, injection quantity estimation logic 214, and / or additional logic injector control logic 210.

[0101] Injection control logic 216 is configured to determine an injector command to provide an output including injector control signal 219. Injector control logic 216 can be configured to determine an injector opening time command that effectively sets injector control signal 219 to an injector open state or value for a duration corresponding to the commanded injector opening time. Injector control logic 216 can determine the injector opening time command in response to fuel refueling command 202, engine speed 203, and intake manifold pressure (IMP) 204, rail pressure 206, and rail temperature 208, and can utilize various techniques to perform this determination.

[0102] In some embodiments, injector control logic 216 may be configured to provide as one or more lookup tables, maps, or response surfaces, which are configured and operable to provide injector start-up time commands in response to the aforementioned inputs.

[0103] In some embodiments, the injector control logic 216 may be configured and operable to solve one or more equations in response to the above inputs to determine the injector activation time command. Equation (1) provides an example of an equation that can be used in this way: (1) in The time for the injectors to open under command. The injection volume at a defined reference temperature. The gas pressure at the fuel rail. This refers to the intake manifold pressure, and The coefficients can be determined empirically or derived from a physics-based model and can be adjusted to change the effect of equation (1).

[0104] The injector-on state of injector control signal 219 effectively actuates switch 234. Switch 234 is operatively connected to a system voltage source (V_supply) and configured to selectively supply injector current (I_inj) to solenoid 124 of injector 12. Injector current (I_inj) effectively energizes solenoid 124 to cause a lifting movement of injector armature 122 (sometimes referred to as injector needle valve) in a direction generally indicated by arrow L. In the lifted position (shown in dashed form), injector armature 122 allows fuel supplied to injector passage 126 to exit from one or more orifices at the tip of injector 12 and enter as fuel injection (F_inj) into the port of intake manifold 27 leading to the associated combustion chamber of engine 10.

[0105] Injection control modification logic 218 is configured to modify the relationship between the injector opening time command and the injection quantity of the command utilized by injector control logic 216 as described above. In some embodiments, injection control modification logic 218 may be configured to modify one or more tables that define one or more relationships between the opening time of the command as a function of the injection quantity at a given gaseous fuel temperature and a given engine speed, as described above in conjunction with injector control logic 216. In some embodiments, injection control modification logic 218 may be configured to modify one or more coefficients of an equation that defines one or more relationships between the opening time of the command as a function of the injection quantity at a given gaseous fuel temperature and a given engine speed, as described above in conjunction with injector control logic 216. In some embodiments, injection control modification logic 218 may be configured to modify a value in an adaptive table that defines one or more relationships between the opening time of the command as a function of the injection quantity at a given gaseous fuel temperature and a given engine speed, as described above in conjunction with injector control logic 216.

[0106] Injection control modification logic 218 can modify one or more of the aforementioned relationships between the injector opening time command and the commanded injection quantity by comparing calculated fuel injection quantity estimates. Existing models of these relationships may include a set of lookup tables.

[0107] As shown in the specific implementation, this disclosure envisions several different embodiments, including but not limited to the following example embodiments.

[0108] A first example embodiment is a process for operating a gaseous fuel filling system, the system including a plurality of gaseous fuel injectors in fluid communication with a plurality of combustion cylinders, the process including: operating the plurality of gaseous fuel injectors to inject gaseous fuel; measuring the pressure of the gaseous fuel supplied to the plurality of gaseous fuel injectors during multiple gaseous fuel injections while operating the plurality of gaseous fuel injectors; determining a set of Fourier transform results in response to the measurement; determining an average injection quantity of the plurality of gaseous fuel injectors in response to a first subset of the Fourier transform results; determining a plurality of decomposed injection quantities of a plurality of subsets of the plurality of gaseous fuel injectors in response to a second subset of the Fourier transform results; and operating the gaseous fuel filling system using the decomposed injection quantities.

[0109] The second example embodiment includes features of the first example embodiment, wherein a first subset of the Fourier transform results includes one or more Fourier transform results obtained at corresponding positive integer harmonics of the operating fundamental frequency of the plurality of gaseous fuel injectors.

[0110] The third example embodiment includes the features of the second example embodiment, wherein a first subset of the Fourier transform results includes a first Fourier transform result obtained at a first positive integer harmonic of the fundamental frequency and a second Fourier transform result obtained at a second positive integer harmonic of the fundamental frequency.

[0111] The fourth example embodiment includes features of the first example embodiment, wherein a second subset of the Fourier transform results includes a set of subharmonics of the operating fundamental frequency of a plurality of gaseous fuel injectors.

[0112] The fifth example embodiment includes the features of the fourth example embodiment, wherein the set of subharmonics includes subharmonics for each fraction of the total number of injector ignition events relative to the fundamental frequency.

[0113] The sixth example embodiment includes the features of the first example embodiment, wherein the gaseous fuel filling system is configured as a single-point injection (SPI) system, wherein a plurality of gaseous fuel injectors are configured to inject gaseous fuel at corresponding locations to effectively supply fuel to any one of a plurality of combustion cylinders.

[0114] The seventh example embodiment includes the features of the sixth example embodiment, wherein the total number of the plurality of gaseous fuel injectors is less than or greater than the total number of the plurality of combustion cylinders, and the operating fundamental frequency of the plurality of gaseous fuel injectors is lower than the operating fundamental frequency of the combustion cylinders.

[0115] The eighth example embodiment includes the features of the first example embodiment, wherein the gaseous fuel filling system is configured as a multi-port injection (MPI) system, wherein multiple subsets of multiple gaseous fuel injectors are configured to inject gaseous fuel at corresponding locations to effectively supply fuel individually to one of a plurality of combustion cylinders.

[0116] The ninth example embodiment includes the features of the eighth example embodiment, wherein each of the plurality of subsets includes a plurality of injectors.

[0117] The tenth example embodiment includes the features of the eighth example embodiment, wherein the operating fundamental frequency of the plurality of gaseous fuel injectors is equal to the operating fundamental frequency of the combustion cylinder.

[0118] The eleventh example embodiment includes the features of the first example embodiment, wherein operating the gaseous fuel refueling system using the decomposed injection quantity includes modifying the injector control logic using the decomposed injection quantity, and controlling the gaseous fuel injector using the modified injector control logic.

[0119] The twelfth example embodiment includes features of the first example embodiment, wherein operating the gaseous fuel refueling system using the decomposed injection quantity includes diagnosing the gaseous fuel injector using the decomposed injection quantity.

[0120] The thirteenth example embodiment is a system comprising: an electronic control system operatively communicating with a gaseous fuel filling system including a plurality of gaseous fuel injectors in fluid communication with a plurality of combustion cylinders; the electronic control system being configured to: operate the plurality of gaseous fuel injectors to inject gaseous fuel; measure the pressure of gaseous fuel supplied to the plurality of gaseous fuel injectors during multiple gaseous fuel injections operated by the plurality of gaseous fuel injectors; determine a set of Fourier transform results in response to the pressure measurement results; determine an average injection quantity of the plurality of gaseous fuel injectors in response to a first subset of the Fourier transform results; determine a plurality of fractional injection quantities of a plurality of subsets of the plurality of gaseous fuel injectors in response to a second subset of the Fourier transform results; and operate the gaseous fuel filling system using the fractional injection quantities.

[0121] The fourteenth example embodiment includes the features of the thirteenth example embodiment, wherein a first subset of the Fourier transform results includes one or more Fourier transform results obtained at corresponding positive integer harmonics of the operating fundamental frequency of the plurality of gaseous fuel injectors.

[0122] The fifteenth example embodiment includes the features of the fourteenth example embodiment, wherein a first subset of the Fourier transform results includes a first Fourier transform result obtained at a first positive integer harmonic of the fundamental frequency and a second Fourier transform result obtained at a second positive integer harmonic of the fundamental frequency.

[0123] The sixteenth example embodiment includes the features of the thirteenth example embodiment, wherein a second subset of the Fourier transform results includes a set of subharmonics of the operating fundamental frequency of a plurality of gaseous fuel injectors.

[0124] The seventeenth example embodiment includes the features of the sixteenth example embodiment, wherein the set of subharmonics includes subharmonics for each fraction of the total number of injector ignition events relative to the fundamental frequency.

[0125] The eighteenth example embodiment includes the features of the thirteenth example embodiment, wherein the gaseous fuel filling system is configured as a single-point injection (SPI) system, wherein a plurality of gaseous fuel injectors are configured to inject gaseous fuel at corresponding locations to effectively supply fuel to any one of a plurality of combustion cylinders.

[0126] The nineteenth example embodiment includes the features of the eighteenth example embodiment, wherein the total number of the plurality of gaseous fuel injectors is less than the total number of the plurality of combustion cylinders, and the operating fundamental frequency of the plurality of gaseous fuel injectors is lower than the operating fundamental frequency of the combustion cylinders.

[0127] The twentieth example embodiment includes the features of the thirteenth example embodiment, wherein the gaseous fuel dispensing system is configured as a multi-port injection (MPI) system, wherein multiple subsets of multiple gaseous fuel injectors are configured to inject gaseous fuel at corresponding locations to effectively supply fuel individually to one of a plurality of combustion cylinders.

[0128] The twenty-first example embodiment includes the features of the twenty-tenth example embodiment, wherein each of the plurality of subsets includes a plurality of injectors.

[0129] The twenty-second example embodiment includes the features of the twenty-tenth example embodiment, wherein the operating fundamental frequency of the plurality of gaseous fuel injectors is equal to the operating fundamental frequency of the combustion cylinder.

[0130] The twenty-third example embodiment includes the features of the thirteenth example embodiment, wherein the electronic control system is configured to operate the gaseous fuel refueling system using a decomposed injection quantity, including modifying the injector control logic using the decomposed injection quantity and controlling the gaseous fuel injector using the modified injector control logic.

[0131] The twenty-fourth example embodiment includes the features of the thirteenth example embodiment, wherein the electronic control system is configured to operate the gaseous fuel refueling system using a decomposed injection quantity, including diagnosing the gaseous fuel injector using the decomposed injection quantity.

[0132] The twenty-fifth exemplary embodiment is a process for operating a gaseous fuel filling system, the system including a plurality of gaseous fuel injectors in fluid communication with a plurality of combustion cylinders, the process including: operating the plurality of gaseous fuel injectors to inject gaseous fuel; measuring the pressure of gaseous fuel supplied to the plurality of gaseous fuel injectors during multiple gaseous fuel injections by operating the plurality of gaseous fuel injectors; determining a set of Fourier transform results for a plurality of subharmonic frequencies in response to the measurement; determining a sum of sinusoidal waveforms in response to the set of Fourier transform results; determining a relative injection quantity difference between the plurality of gaseous fuel injectors in response to the sum of sinusoidal waveforms; and operating the gaseous fuel filling system in response to the relative injection quantity difference.

[0133] The twenty-sixth example embodiment includes the features of the twenty-fifth example embodiment, wherein determining a set of Fourier transform results includes determining the average gaseous fuel pressure of the operation, and determining the set of Fourier transform results in response to the average gaseous fuel pressure.

[0134] The twenty-seventh exemplary embodiment includes the features of the twenty-fifth exemplary embodiment, wherein the sum of the sinusoidal waveforms is determined in response to the amplitude and phase of a plurality of subharmonic frequencies.

[0135] The twenty-eighth exemplary embodiment includes the features of the twenty-fifth exemplary embodiment, wherein determining the relative injection quantity difference between the injectors also responds to the relationship between the injection event positions of the plurality of gaseous fuel injectors and the corresponding local values ​​of the sum of the sinusoidal waveforms.

[0136] The twenty-ninth example embodiment includes features of the twenty-fifth example embodiment, including: calculating the expected sum of sinusoidal waveforms considering the asymmetry of the flow channel geometry and pressure sensor positions of the gaseous fuel refueling system; determining the difference between the sum of sinusoidal waveforms and the expected sum of sinusoidal waveforms; and determining the relative injection quantity in response to the difference, the relationship between the injection event position of a single injector and the corresponding local value of the sum of sinusoidal waveforms, and the relationship between the injection event positions of multiple gaseous fuel injectors and the corresponding local values ​​of the sum of sinusoidal waveforms.

[0137] The thirtieth example embodiment includes the features of the twenty-fifth example embodiment, wherein operating the gaseous fuel refueling system in response to a relative injection quantity difference includes balancing the injection quantities among the plurality of gaseous fuel injectors by adjusting the opening time of a command for one or more of the plurality of gaseous fuel injectors.

[0138] The thirty-first example embodiment is a system comprising: an electronic control system operatively communicating with a gaseous fuel dispensing system including a plurality of gaseous fuel injectors in fluid communication with a plurality of combustion cylinders; the electronic control system being configured to: operate the plurality of gaseous fuel injectors to inject gaseous fuel; measure the pressure of gaseous fuel supplied to the plurality of gaseous fuel injectors during multiple gaseous fuel injections; determine a set of Fourier transform results for a plurality of subharmonic frequencies in response to the pressure measurement results; determine a sum of sinusoidal waveforms in response to the set of Fourier transform results; determine a relative injection quantity difference between the plurality of gaseous fuel injectors in response to the sum of sinusoidal waveforms; and operate the gaseous fuel dispensing system in response to the relative injection quantity difference.

[0139] The thirty-second example embodiment includes the features of the thirty-first example embodiment, wherein the electronic control system configured to determine a set of Fourier transform results includes an electronic control system configured to determine the average gaseous fuel pressure of operation and, in response to the average gaseous fuel pressure, determine the set of Fourier transform results.

[0140] The thirty-third example embodiment includes the features of the thirty-first example embodiment, wherein the sum of sinusoidal waveforms is determined in response to the amplitude and phase of a plurality of subharmonic frequencies.

[0141] The thirty-fourth example embodiment includes the features of the thirty-first example embodiment, wherein the electronic control system is configured to further determine the relative injection quantity difference between the injectors in response to the relationship between the injection event positions of the plurality of gaseous fuel injectors and the corresponding local values ​​of the sum of sinusoidal waveforms.

[0142] The thirty-fifth exemplary embodiment includes the features of the thirty-first exemplary embodiment, wherein the electronic control system is configured to: calculate a predicted sum of sinusoidal waveforms considering the asymmetry of the flow channel geometry and pressure sensor positions of the gaseous fuel refueling system; determine the difference between the sum of sinusoidal waveforms and the predicted sum of sinusoidal waveforms; and determine a relative injection quantity in response to the difference, the relationship between the injection event position of a single injector and a corresponding local value of the sum of sinusoidal waveforms, and the relationship between the injection event positions of multiple gaseous fuel injectors and corresponding local values ​​of the sum of sinusoidal waveforms.

[0143] The thirty-sixth exemplary embodiment includes the features of the thirty-first exemplary embodiment, wherein the electronic control system configured to operate the gaseous fuel refueling system includes an electronic control system configured to balance the injection volume among the plurality of gaseous fuel injectors by adjusting the onset time of commands for one or more of the plurality of gaseous fuel injectors.

[0144] It should be understood that terms such as “non-transitory memory,” “non-transitory memory medium,” and “non-transitory memory device” refer to various types of devices and storage media that can be configured to store information (such as data or instructions) that can be read or executed by a processor or other components of a computer system, and such terms include and cover a single or single device or medium storing such information, multiple devices or media in which corresponding portions of such information are stored, and multiple devices or media in which multiple copies of such information are stored.

[0145] It should be understood that when used in conjunction with control methods or processes, electronic control systems or controllers, electronic control, or the aforementioned components or operations, terms such as “determine,” “determined,” and “determining” inclusively refer, individually or in combination, to any of a number of actions, configurations, devices, operations, and techniques, including but not limited to the calculation or computation of parameters or values, obtaining parameters or values ​​from lookup tables or using lookup operations, receiving parameters or values ​​from data links or network communications, and receiving electronic signals indicating parameters or values. For example (Voltage, frequency, current or pulse width modulation (PWM) signal), the output of a sensor that receives an indication parameter or value, other outputs or inputs that receive an indication parameter or value, reading a parameter or value from a memory location on a computer-readable medium, receiving a parameter or value as a runtime parameter, and / or by receiving a parameter or value that can be calculated and interpreted as a parameter, and / or by referring to a default value that is interpreted as a parameter value.

[0146] While exemplary embodiments of the present disclosure have been shown and described in detail in the accompanying drawings and the foregoing description, they are intended to be illustrative rather than restrictive in character. It should be understood that only certain exemplary embodiments have been shown and described, and protection is intended for all changes and modifications falling within the spirit of the claimed invention. It should be understood that while the use of terms such as desirable, preferred, preferred, or more preferred in the foregoing description indicates that the features so described may be more desirable, this may not be necessary, and embodiments lacking these may be contemplated as being within the scope of the invention, defined by the appended claims. When reading the claims, the use of terms such as “a,” “an,” “at least one,” or “at least a portion” is not intended to limit the claims to only one object unless expressly stated to the contrary in the claims. When the language “at least a portion” and / or “a portion” is used, an item may include a portion and / or the entire item, unless expressly stated otherwise.

Claims

1. A process for operating a gaseous fuel injection system, the system comprising a plurality of gaseous fuel injectors in fluid communication with a plurality of combustion cylinders, the process comprising: Operate the plurality of gaseous fuel injectors to inject gaseous fuel; During multiple gaseous fuel injections performed by the plurality of gaseous fuel injectors, the pressure of the gaseous fuel supplied to the plurality of gaseous fuel injectors is measured; In response to the measurement, a set of Fourier transform results are determined; In response to a first subset of the Fourier transform results, the average injection quantity of the plurality of gaseous fuel injectors is determined; In response to a second subset of the Fourier transform results, multiple decomposed injection quantities of multiple subsets of the multiple gaseous fuel injectors are determined; as well as The gaseous fuel filling system is operated using the aforementioned decomposed injection quantity.

2. The process of claim 1, wherein the first subset of the Fourier transform results comprises one or more Fourier transform results obtained at corresponding positive integer harmonics of the operating fundamental frequency of the plurality of gaseous fuel injectors.

3. The process according to claim 2, wherein the first subset of the Fourier transform results includes a first Fourier transform result obtained at a first positive integer harmonic of the fundamental frequency and a second Fourier transform result obtained at a second positive integer harmonic of the fundamental frequency.

4. The process according to claim 1, wherein the second subset of the Fourier transform result includes a set of subharmonics of the operating fundamental frequency of the plurality of gaseous fuel injectors.

5. The process of claim 4, wherein the subharmonic group comprises each fraction of the total number of injector ignition events relative to the fundamental frequency.

6. The process of claim 1, wherein the gaseous fuel filling system is configured as a single-point injection (SPI) system, wherein the plurality of gaseous fuel injectors are configured to inject gaseous fuel at corresponding locations to effectively supply fuel to any one of the plurality of combustion cylinders.

7. The process according to claim 6, wherein the total number of the plurality of gaseous fuel injectors is less than or greater than the total number of the plurality of combustion cylinders, and the operating fundamental frequency of the plurality of gaseous fuel injectors is lower than the operating fundamental frequency of the combustion cylinders.

8. The process of claim 1, wherein the gaseous fuel filling system is configured as a multi-port injection (MPI) system, wherein a plurality of subsets of the plurality of gaseous fuel injectors are configured to inject gaseous fuel at corresponding locations to effectively supply fuel individually to a corresponding combustion cylinder among the plurality of combustion cylinders.

9. The process of claim 8, wherein each of the plurality of subsets comprises a plurality of injectors.

10. The process according to claim 8, wherein the operating fundamental frequency of the plurality of gaseous fuel injectors is equal to the operating fundamental frequency of the combustion cylinder.

11. The process of claim 1, wherein operating the gaseous fuel refueling system using the decomposed injection quantity includes modifying the injector control logic using the decomposed injection quantity, and controlling the gaseous fuel injector using the modified injector control logic.

12. The process of claim 1, wherein operating the gaseous fuel refueling system using the decomposed injection quantity includes diagnosing the gaseous fuel injector using the decomposed injection quantity.

13. A system comprising: An electronic control system, operatively communicating with a gaseous fuel dispensing system including multiple gaseous fuel injectors in fluid communication with multiple combustion cylinders, wherein the electronic control system is configured to: Operate the plurality of gaseous fuel injectors to inject gaseous fuel; During multiple gaseous fuel injections performed by the plurality of gaseous fuel injectors, the pressure of the gaseous fuel supplied to the plurality of gaseous fuel injectors is measured; In response to the pressure measurement results, a set of Fourier transform results are determined; In response to a first subset of the Fourier transform results, the average injection quantity of the plurality of gaseous fuel injectors is determined; In response to a second subset of the Fourier transform results, multiple decomposed injection quantities of multiple subsets of the multiple gaseous fuel injectors are determined; as well as The gaseous fuel filling system is operated using the aforementioned decomposed injection quantity.

14. The system of claim 13, wherein the first subset of the Fourier transform results comprises one or more Fourier transform results obtained at corresponding positive integer harmonics of the operating fundamental frequency of the plurality of gaseous fuel injectors.

15. The system of claim 14, wherein the first subset of the Fourier transform results includes a first Fourier transform result obtained at a first positive integer harmonic of the fundamental frequency and a second Fourier transform result obtained at a second positive integer harmonic of the fundamental frequency.

16. The system of claim 13, wherein the second subset of the Fourier transform results comprises a set of subharmonics of the fundamental operating frequency of the plurality of gaseous fuel injectors.

17. The system of claim 16, wherein the subharmonic group comprises each fraction of the total number of injector ignition events relative to the fundamental frequency.

18. The system of claim 13, wherein the gaseous fuel dispensing system is configured as a single-point injection (SPI) system, wherein the plurality of gaseous fuel injectors are configured to inject gaseous fuel at corresponding locations to effectively supply fuel to any one of the plurality of combustion cylinders.

19. The system of claim 18, wherein the total number of the plurality of gaseous fuel injectors is less than the total number of the plurality of combustion cylinders, and the operating fundamental frequency of the plurality of gaseous fuel injectors is lower than the operating fundamental frequency of the combustion cylinders.

20. The system of claim 13, wherein the gaseous fuel dispensing system is configured as a multi-port injection (MPI) system, wherein a plurality of subsets of the plurality of gaseous fuel injectors are configured to inject gaseous fuel at corresponding locations to effectively supply fuel individually to a corresponding combustion cylinder among the plurality of combustion cylinders.

21. The system of claim 20, wherein each of the plurality of subsets comprises a plurality of injectors.

22. The system of claim 20, wherein the fundamental operating frequency of the plurality of gaseous fuel injectors is equal to the fundamental operating frequency of the combustion cylinder.

23. The system of claim 13, wherein the electronic control system is configured to operate the gaseous fuel refueling system using the decomposed injection quantity, including modifying the injector control logic using the decomposed injection quantity, and controlling the gaseous fuel injector using the modified injector control logic.

24. The system of claim 13, wherein the electronic control system is configured to operate the gaseous fuel dispensing system using the decomposed injection quantity, including diagnosing the gaseous fuel injector using the decomposed injection quantity.

25. A process for operating a gaseous fuel injection system, the system comprising a plurality of gaseous fuel injectors in fluid communication with a plurality of combustion cylinders, the process comprising: Operate the plurality of gaseous fuel injectors to inject gaseous fuel; During multiple gaseous fuel injections performed by the plurality of gaseous fuel injectors, the pressure of the gaseous fuel supplied to the plurality of gaseous fuel injectors is measured; In response to the measurement, a set of Fourier transform results for multiple subharmonic frequencies is determined; In response to the Fourier transform result set, determine the sum of the sinusoidal waveforms; In response to the sum of the sinusoidal waveforms, the relative injection quantity difference between the plurality of gaseous fuel injectors is determined; as well as The gaseous fuel dispensing system is operated in response to the relative injection quantity difference.

26. The process of claim 25, wherein determining a set of Fourier transform results comprises determining the average gaseous fuel pressure of the operation, and determining the set of Fourier transform results in response to the average gaseous fuel pressure.

27. The process of claim 25, wherein the sum of the sinusoidal waveforms is determined in response to the amplitude and phase of the plurality of subharmonic frequencies.

28. The process of claim 25, wherein determining the relative injection quantity difference between each of the injectors further responds to the relationship between the injection event positions of the plurality of gaseous fuel injectors and corresponding local values ​​of the sum of the sinusoidal waveforms.

29. The process according to claim 25, comprising: Considering the asymmetry of the flow channel geometry and pressure sensor position of the gaseous fuel refueling system, calculate the expected sum of the sinusoidal waveform; Determine the difference between the sum of the sinusoidal waveforms and the expected sum of the sinusoidal waveforms; as well as The relative injection quantity is determined in response to the relationship between the difference, the injection event position of a single injector and the corresponding local value of the sum of the sinusoidal waveforms, and the relationship between the injection event positions of the plurality of gaseous fuel injectors and the corresponding local value of the sum of the sinusoidal waveforms.

30. The process of claim 25, wherein operating the gaseous fuel filling system in response to the relative injection quantity difference comprises balancing the injection quantities among the plurality of gaseous fuel injectors by adjusting the opening time of a command for one or more of the plurality of gaseous fuel injectors.

31. A system comprising: An electronic control system, operatively communicating with a gaseous fuel dispensing system including multiple gaseous fuel injectors in fluid communication with multiple combustion cylinders, wherein the electronic control system is configured to: Operate the plurality of gaseous fuel injectors to inject gaseous fuel; During multiple gaseous fuel injections performed by the plurality of gaseous fuel injectors, the pressure of the gaseous fuel supplied to the plurality of gaseous fuel injectors is measured; In response to the pressure measurement results, a set of Fourier transform results for multiple subharmonic frequencies is determined; In response to the Fourier transform result set, determine the sum of the sinusoidal waveforms; In response to the sum of the sinusoidal waveforms, the relative injection quantity difference between the plurality of gaseous fuel injectors is determined; as well as The gaseous fuel dispensing system is operated in response to the relative injection quantity difference.

32. The system of claim 31, wherein the electronic control system configured to determine a set of Fourier transform results comprises an electronic control system configured to determine the average gaseous fuel pressure of the operation and, in response to the average gaseous fuel pressure, determine the set of Fourier transform results.

33. The system of claim 31, wherein the sum of the sinusoidal waveforms is determined in response to the amplitude and phase of the plurality of subharmonic frequencies.

34. The system of claim 31, wherein the electronic control system is configured to further determine a relative injection quantity difference between each of the injectors in response to a relationship between the injection event position of the plurality of gaseous fuel injectors and a corresponding local value of the sum of the sinusoidal waveforms.

35. The system of claim 31, wherein the electronic control system is configured to: Considering the asymmetry of the flow channel geometry and pressure sensor position of the gaseous fuel refueling system, calculate the expected sum of the sinusoidal waveform; Determine the difference between the sum of the sinusoidal waveforms and the expected sum of the sinusoidal waveforms; and The relative injection quantity is determined in response to the relationship between the difference, the injection event position of a single injector and the corresponding local value of the sum of the sinusoidal waveforms, and the relationship between the injection event positions of the plurality of gaseous fuel injectors and the corresponding local value of the sum of the sinusoidal waveforms.

36. The system of claim 31, wherein the electronic control system configured to operate the gaseous fuel refueling system includes an electronic control system configured to balance the injection volume among the plurality of gaseous fuel injectors by adjusting the onset time of commands for one or more of the plurality of gaseous fuel injectors.

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