FUEL PRESSURE MEASUREMENT AND ASSOCIATED PROCESSES, SYSTEMS AND CONTROLS

Abstract

A system and process for operating an internal combustion engine includes a fuel injector connected to a fuel rail, which injects fuel during an engine cycle. A high-pressure pump is connected to the fuel rail and includes pump elements that pressurize the fuel, as well as discrete-flow inlet metering valves that control the fuel flow from the pump elements. The fuel flow from the high-pressure pump's pump elements to the fuel rail is interrupted by the discrete-flow inlet metering valves during a portion of the engine cycle to obtain fuel pressure readings from the fuel rail during fuel injection.

Description

CROSS-REFERENCE TO RELATED REGISTRATION: The present application claims the priority and benefit of the filing date of the preliminary US application Ser. No. 63 / 736,081, filed on December 19, 2024, which is hereby incorporated by reference. TECHNICAL AREA The present application relates to fuel supply systems for internal combustion engines and associated processes, systems and control units for measuring fuel pressure and for carrying out fuel pressure measurements. STATE OF THE ART Fuel systems for internal combustion engines and the control systems for such systems use fuel system pressure measurements to determine the injection quantity, control the injectors, for diagnostics, and for other purposes. Existing techniques for obtaining fuel pressure measurements have a number of disadvantages, including speed, depth of intervention, complexity, precision, reliability, and robustness. There remains a significant need for the unique processes, systems, and controls disclosed here. DISCLOSURE OF EXEMPLARY EXECUTIONS In order to clearly, concisely, and precisely describe the exemplary embodiments of the present disclosure, the manner of their manufacture and use, as well as their practical application, manufacture, and use, reference will now be made to certain exemplary embodiments, which include those illustrated in the figures, and these will be described using specific terms. It is understood, however, that this does not create any limitation of the scope of the invention and that the invention, as set forth in the following claims of this disclosure, includes and protects such changes, modifications, and further applications of the exemplary embodiments that would occur to a person skilled in the art in the field, taking into account the present disclosure. SUMMARY Some embodiments include a unique method for quickly and non-contactly acquiring pressure measurements in the fuel system during the operation of an internal combustion engine. Some embodiments include unique systems for internal combustion engines that incorporate fuel injection systems and a control unit for quickly and non-contactly acquiring pressure measurements in the internal combustion engine's fuel system. Some embodiments include unique devices for obtaining quick and non-contact fuel pressure measurements for internal combustion engines. One aspect of the present disclosure relates to a novel control strategy for a high-pressure fuel pump. In one embodiment, micro-interruptions of the fuel pump operation by the fuel pump during each engine cycle are used to measure the fuel pressure, thereby creating a non-invasive system and method for controlling the fuel supply. By removing the pumping operation from a single injection event per engine cycle (with some throttling), this disclosed strategy enables precise fuel supply measurements without requiring intrusive requests to shut down the pump. Further embodiments, forms, objects, features, advantages, aspects, and benefits will become apparent from the following description and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic diagram illustrating certain aspects of a system comprising an internal combustion engine, an exemplary fuel system, and an exemplary electronic control system for determining fuel pressure measurements in the fuel system. Fig. 2 is a schematic diagram illustrating certain aspects of the exemplary fuel system from Fig. 1. Fig. 3 is a schematic diagram illustrating certain additional aspects of an example fuel system from Figs. 1 and 2. Fig. 4 is a flowchart of an exemplary process for determining pressure measurements in the fuel system using the system from Fig. 1 and the fuel systems from Figs. 2 and 3. Fig. 5 is a diagram showing exemplary rail pressures without pump shutdown and with pump shutdown during an engine cycle according to the process from Fig. 4.Figure 6A is a diagram illustrating, by way of example, the rail pressure and flow rate over the long term during fuel pressure measurement when discrete-flow inlet flow control valves (also known as active inlet flow control valves or AIM valves) are used to control the fuel flow to each pumping element according to the process of Figure 4. Figure 6B shows a comparison to Figure 6A with exemplary long-term rail pressures and flow rates for a process using a single variable-flow inlet flow control valve (also known as a single adjustable-orifice inlet flow control valve) to control the fuel flow to multiple pumping elements. Figure 7 is a flowchart of an example process for determining the fuel quantity using pressure measurements in the fuel system obtained according to the procedure of Figure 4. DETAILED DESCRIPTION OF EXAMPLES OF EXECUTION With reference to Figures 1 and 2, an exemplary engine system 100 (also referred to as System 100) is shown, comprising an engine 10 functionally connected to an intake system 6, an exhaust system 7, and a fuel system 9. The engine 10 can be an internal combustion engine, including, but not limited to, a compression-ignition engine using diesel or another suitable fuel, or a spark-ignition engine using gasoline, natural gas, hydrogen, or other suitable fuels. The engine 10 takes in intake air from the intake system 6 and fuel from the fuel system 9, combusts these inputs, and releases exhaust gases via the exhaust system 7. The engine 10 comprises several combustion cylinders 13 with corresponding reciprocating pistons (not shown) configured to generate mechanical energy from the combustion of a fuel during a combustion cycle. In the illustrated example, the engine 10 is configured as a six-cylinder engine comprising combustion cylinders 13a, 13b, 13c, 13d, 13e, and 13f. In other embodiments, the engine 10 can be configured and equipped with a different number of cylinders, for example, four cylinders, eight cylinders, twelve cylinders, sixteen cylinders, or any other number of cylinders as will be apparent to a person skilled in the art when considering the present disclosure. The engine 10 comprises a plurality of fuel injectors 12 configured to supply fuel to the respective combustion cylinders 13. In the illustrated example, the engine 10 comprises six injectors 12a, 12b, 12c, 12d, 12e, 12f, which are connected in a fluid circuit and configured and operable to inject fuel into the combustion cylinders 13a, 13b, 13c, 13d, 13e, 13f. It should be noted that the number of fuel injectors provided in other embodiments can vary according to the number of cylinders or can vary per cylinder, for example, with multiple fuel injectors per cylinder. Each cylinder 13a, 13b, 13c, 13d, 13e, 13f operates according to a combustion cycle in which fuel is injected for combustion. In a four-stroke engine, the combustion cycle comprises an intake stroke, a compression stroke, a power stroke, and an exhaust stroke for the piston in the corresponding cylinder 13a, 13b, 13c, 13d, 13e, 13f (hereinafter referred to individually and collectively as cylinder 13). The four piston strokes correspond to two complete revolutions of the crankshaft connected to the pistons, or 720 degrees, during which fuel may or may not be injected by fuel injectors 12a, 12b, 12c, 12d, 12e, 12f (hereinafter referred to individually and collectively as fuel injector 12). However, the present disclosure also provides for application with other combustion cycles, for example those in which two strokes of the piston are used for each combustion cycle.As used here, an engine cycle is the angle of rotation required by the engine crankshaft to complete the combustion cycle of one cylinder, for example 720 degrees for a four-stroke engine or 360 degrees for a two-stroke engine. In the illustrated embodiment, the fuel system 9 is configured and implemented as a high-pressure common-rail fuel injection system, which includes a fuel distributor 30 configured and operated to supply fuel at a relatively high pressure to the multiple fuel injectors 12. A fuel supply 32 is configured and operated to supply fuel to the fuel distributor 30 and may include a fuel reservoir 91, a low-pressure pump 92 functionally coupled to the fuel reservoir 91, and a high-pressure pump 93 functionally coupled to the low-pressure pump 92 and the fuel distributor 30. High-pressure fuel lines (not numbered) fluidically connect the high-pressure pump 93 to the fuel distributor 30 and the fuel distributor 30 to the multiple injectors 12. With further reference to Fig. 3, further aspects of an embodiment of the fuel system 9 are shown. The high-pressure pump 93 comprises a pump housing 110, which includes a pump camshaft 120 coupled to the engine's crankshaft to rotate with it at a known time interval. The pump housing 110 also includes a number of pump elements 112a, 112b, each having an inlet and an outlet. The pump elements 112a, 112b can, for example, each include a fluid chamber 114a, 114b and a piston 116a, 116b, which is housed in the respective fluid chamber 114a, 114b.The pistons 116a, 116b are connected to the camshaft 120, so that the rotation of the camshaft 120 by the crankshaft of the engine rotates the cams 122a, 122b, which act on the connected pistons 116a, 116b to set the connected pistons 116a, 116b into a reciprocating motion and supply the fuel distributor 30 with pressurized fuel via the corresponding outlet of the pump element 112a, 112b. Each of the outlets of the pump elements 112a, 112b can include a check valve 124a, 124b to prevent backflow into the liquid chambers 114a, 114b, which opens when the discrete flow rate inlet flow control valves 130a, 130b are controlled to supply fuel to the fuel distributor 30. The fuel flow to and from the pump elements 112a, 112b is controlled by a corresponding discrete-flow inlet metering valve 130a, 130b, which is mounted on or near the housing 110. Each discrete-flow inlet metering valve 130a, 130b includes an inlet that receives fuel from the low-pressure pump 92 and an outlet that is connected to the corresponding pump element 112a, 112b. Each discrete-flow inlet metering valve 130a, 130b includes a check valve provided by a valve seat 132a, 132b, a piston 134a, 134b, and an actuator 136a, 136b, for example, a solenoid valve. The piston 134a, 134b can be moved from a first position, in which it is released from the corresponding valve seat 132a, 132b, to a second position, in which it engages with the corresponding valve seat 132a, 132b, by an electric current supplied to the actuator 136a, 136b.It is provided here that the inlet flow control valves with discrete flow rate 130a, 130b in the embodiment shown can normally be set open to a first position, or that in other embodiments the inlet flow control valves with discrete flow rate are normally closed. In the first position of each inlet flow control valve with discrete delivery rate 130a, 130b, for example, when no current is supplied to the actuators 136a, 136b, the fuel flow from the connected pump element 112a, 112b is interrupted or stopped, so that the actuation of the pump element 112a, 112b pushes fuel from the liquid chambers 114a, 114b back to the low-pressure side and not to the fuel distributor 30. In the second position of the inlet flow control valves with discrete delivery rate 130a, 130b, the fuel in the connected liquid chamber 114a, 114b is pumped by the pump elements 112a, 112b to the fuel distributor 30. The discrete flow control inlet valves 130a, 130b also include vent lines to return air to fuel tank 91. The pump elements 112a, 112b can also be connected to the return line to return spilled or vented fuel to fuel tank 91.The system 100 further includes an electronic control system (ECS) 20 which is connected to the engine 10 and is configured to control one or more aspects of the engine 10, including the control of fuel injection into the engine 10 via fuel injectors 12 and of fuel flow into the pump elements 112a, 112b via discrete inlet metering valves 130a, 130b. Accordingly, the ECS 20 is connected to the discrete quantity intake metering valves 130a, 130b and is configured to switch each intake metering valve 130a, 130b on and off at predetermined times relative to an angular position of the camshaft 120 during each engine cycle in order to pump fuel into the fuel distributor 30 and to regulate the injection pressure as desired for the injection of fuel into the engine 10.The ECS 20 can also be connected to fuel injectors 12 and configured to switch each fuel injector 12 on and off at predetermined times to inject fuel into the engine 10 as desired. The ECS 20 includes at least one electronic control unit (ECU) 22 configured to perform the operations of the ECS 20 described herein, and in some embodiments may include additional ECUs configured to perform the operations of the ECS 20 described herein. The ECS 20 can further be structured to control other parameters of the engine 10, including aspects of the engine 10 that can be controlled by an actuator activated by the ECS 20. For example, the ECS 20 can communicate with actuators and sensors to receive and process sensor inputs and to transmit actuator output signals. Actuators can, but are not limited to, fuel injectors 12 and actuators 136a, 136b of the discrete-flow inlet metering valves 130a, 130b. The sensors can include any suitable devices for monitoring the operating parameters and functions of the system 100. For example, the sensors can include a pressure sensor 16 and a temperature sensor 18.The pressure sensor 16 is connected to the common fuel distributor 30 and is designed to transmit a pressure measurement within the common fuel distributor 30 to the ECS 20. The temperature sensor 18 is connected to the common fuel distributor 30 and is designed to transmit a temperature measurement within the common fuel distributor 30 to the ECS 20. As will be evident from the following description, the techniques described herein relating to fuel injectors or fuel injection parameters can be implemented in an ECS 20, which may include one or more control units for controlling various aspects of the system 100. In one embodiment, the ECS 20 comprises one or more electronic control units (ECUs) 22, such as an engine control unit or an engine control module. The ECS 20 may consist of digital circuits, analog circuits, or a hybrid combination of both types. Furthermore, the ECS 20 may be programmable, an integrated state machine, or a hybrid combination thereof. The ECS 20 may include one or more arithmetic logic units (ALUs), central processing units (CPUs), memory, limiters, conditioners, filters, format converters, or the like, which are not shown for clarity.In one embodiment, the ECS 20 is a programmable variant that executes algorithms and processes data according to an operating logic defined by programming instructions (such as software or firmware). Alternatively or additionally, the operating logic for the ECS 20 can be defined, at least partially, by hard-wired logic or other hardware. In addition to the sensor types described herein, the system and methods may encompass all other suitable sensors and their associated parameters. Accordingly, the sensors may include any suitable device used to acquire relevant physical parameters, including electrical, mechanical, and chemical parameters of the motor system 100. As used herein, the term "sensors" may include any suitable hardware and / or software used to directly or indirectly acquire or estimate motor system parameters and / or various combinations of such parameters. The motor system 100 can be provided and implemented in conjunction with equipment 101, which may include, for example, a vehicle such as a road vehicle, an off-road vehicle, a watercraft or another type of vehicle, a generator set, a pumping system or various other equipment as can be seen by a person skilled in the art taking into account the present disclosure. With reference to Fig. 4, a flowchart is shown illustrating certain aspects of an example process 400, which can be implemented and executed in one or more components of an electronic control system, such as ECS 20. In some embodiments, at least part of the process 400 can be implemented in one or more electronic control units of an electronic control system, such as ECU 22, or in additional or alternative electronic control units. Process 400 begins with the start operation 402, for example, in response to an ignition key event or engine start, and continues with operation 404, in which an engine system, for example, engine system 100 or another suitable engine system, is operated. In the illustrated example, engine system 100 is operated in operation during process 400, meaning that it operates according to the requirements of a specific mission or application without requiring a diagnostic or test mode (e.g., engine operation), a test cell, or any other disruption of normal mission operation. It should be noted that other embodiments may additionally or alternatively operate an engine system outside of mission operations, for example, in a test mode, a test cell, or other non-mission operation. From process 404, process 400 proceeds to process 406, in which fuel is directed via the corresponding inlet metering valves with discrete delivery rates 130a, 130b to the pumping elements 112a, 112b of the high-pressure pump 93. Process 400 continues with process 408 to pressurize the fuel distributor 30 with fuel. As explained above, the fuel distributor 30 is connected to fuel injectors 12, which serve to inject fuel into the corresponding cylinders 13 of the engine 10 during a combustion cycle of the corresponding cylinder 13. It is understood that processes 406, 408 can all occur simultaneously and / or in a different sequence than shown. Process 400 continues from process 408 into process 410 to control each of the multiple discrete-flow inlet metering valves 130a, 130b such that discrete flow rates from each of the corresponding pump elements 112a, 112b to the fuel distributor 30 are terminated or prevented during an engine cycle connected to the crankshaft of the engine 10. For example, a control signal from ECS 20 and / or ECU 22 can control the actuators 136a, 136b to enable or cause the pistons 134a, 134b to remain released from the corresponding valve seats 132a, 132b in order to terminate or interrupt the fuel flow to the fuel distributor 30 for a fuel injection event during the engine cycle. This pump shutdown (PCO) is time-coordinated to a predetermined angular position of the camshaft 120 depending on the measured injection time of the fuel injector 12.The fuel in the corresponding liquid chamber 114a, 114b is pumped out, while the inlet quantity control valve with discrete delivery rate 130a, 130b is controlled so that the fuel flow from the pump chambers 114a, 114b to the fuel distributor 30 is interrupted and the fuel in the pump chambers 114a, 114b is pumped back to the low-pressure side of the pump elements 112a, 112b. From process 410, process 400 continues into process 412 to measure the fuel distributor pressure in fuel distributor 30, while the discrete-flow inlet metering valves 130a, 130b are controlled to interrupt the fuel flow to fuel distributor 30 during the injection process. Since the discrete-flow inlet metering valves 130a, 130b are controlled to interrupt the fuel flow for the injection process for a period during the engine cycle defined by a pump shutdown window, the fuel flow from pump chambers 114a, 114b is interrupted during the pump shutdown window of the engine cycle. Process 412 takes place while one or more of the injectors 12 are injecting fuel from fuel distributor 30 into the corresponding combustion cylinder 13.Process 412 can, for example, process the output signals of a high-data-rate pressure sensor, such as pressure sensor 16 or any other pressure sensor configured to provide an output signal indicating the fuel pressure of fuel distributor 30. Such processing may include, for example, filtering, sampling, and / or other processing techniques, as will be apparent to a person skilled in the art when considering the present disclosure. Process 400 then continues in operation 414 to control the discrete-flow inlet metering valves 130a, 130b so that discrete quantities of fuel can flow from the pump elements 112a, 112b to the fuel distributor 30 in the same engine cycle in which the fuel distributor 30 pressure measurements were taken during pump shutdown. Operations 410, 412, and 414 can then be repeated, provided the activation conditions are met in subsequent engine cycles of engine 10, to perform additional pressure measurements at the same or a different crank angle starting position and / or for the same or a different crank angle duration. Process 400 terminates at operation 416, for example, in response to an ignition key off event, an engine stop event, or another process termination event. The pressure measurements of the fuel rail 30 obtained from process 400 can be used to control the operation of the engine 10 and / or the fuel system 9 and / or to diagnose the engine 10 and / or the fuel system 9. For example, the pressure measurements can be used to model the dynamic pressure of the fuel rail 30, which can then be used to determine the actual injection quantities and to control a fuel injection control parameter, such as an injection quantity (e.g., a total injection quantity for a set of multiple injection pulses, a distribution of a quantity over multiple injection pulses, or an injection quantity for a specific injection pulse), a rail pressure, an injection timing (e.g.,(an injection start for a series of multiple injection pulses, a distance or separation between multiple injection pulses, or the injection start of a specific injection pulse) and / or other injection control parameters, as will be apparent to a person skilled in the art taking into account the present disclosure. The pressure measurements can also be used in other control processes, for example, to determine fuel properties, the condition of the fuel system, system leaks, and / or to derive the speed of sound. It should be noted that multiple process iterations 400 and / or operations 410, 412, 414 can be performed in conjunction with a given set of rail pressure measurements. It should also be noted that operations 412 can be performed during multiple pulses of one or more injectors 12, for example, for multiple pulses of a fuel injector 12 per engine cycle or for multiple injections from multiple injectors 12 during multiple engine cycles. For example, Fig. 5 shows a diagram 500 of rail pressure with and without pump shutdown during an engine cycle 502, together with an exemplary pump shutdown window 504 during the engine cycle 502. The nominal fuel rail pressure 506 is the fuel pressure in the fuel rail 30 that occurs during fuel injection from the fuel injectors 12 over the engine cycle without pump shutdown. The nominal fuel pressure 506 is maintained within a nominal pressure drop band 508 throughout the entire engine cycle 502. A pump shut-off rail pressure 510 indicates the fuel pressure in the common fuel rail 30 that occurs during a pressure measurement procedure, for example, process 400, when a pump shut-off occurs during the engine cycle. When the fuel flow from the pump elements 112a, 112b to the fuel rail 30 is interrupted or stopped by the discrete-flow inlet metering valves 130a, 130b at start time 512, no more fuel is supplied to the fuel rail 30, causing the pressure in the fuel rail 30 to drop within window 504 until end time 514. The pressure measurements of the fuel rail 30 are performed within the pump shut-off window 504, while the discrete-flow inlet metering valves 130a, 130b are controlled to stop the fuel flow.At the end time 514, the discrete flow inlet quantity control valves 130a, 130b are controlled so that the fuel flow is restored, and the rail pressure begins to rise and can restore the nominal pressure conditions by the end of the engine cycle 502. The pump shut-off rail pressure 510 defines a larger pressure drop range 516 than the nominal pressure drop band 508, because the pressure in the fuel distributor 30 drops while the fuel flow is interrupted during the pump shut-off window 504. However, since each individual pumping operation of the high-pressure fuel pump 93 is controlled by the discrete-flow inlet metering valves 130a, 130b, the pump shut-off window 504 can be relatively small and fall within one engine cycle, allowing non-intrusive pressure measurements to be taken while fuel is being injected into the cylinders 13 through the injectors 12. Furthermore, a relatively small interval between successive pressure measurements from one engine cycle to the next is acceptable, as the need to obtain the pressure measurements has only a negligible effect on combustion and emissions. Referring to Fig. 6A, diagram 600 depicts the rail pressure and the electrical current over the long term during an exemplary engine cycle in which the discrete-flow inlet metering valves 130a, 130b are controlled by the electrical current to interrupt the fuel flow from the pump elements 112a, 112b to the fuel distributor 30. The current flow to the discrete-flow inlet metering valves 130a, 130b is interrupted at time t0, which corresponds to the start time 512 of the pump shut-off window 504, so that the discrete-flow inlet metering valves 130a, 130b interrupt the fuel flow from the pump elements 112a, 112b to the fuel distributor 30. Since there is no need to flush the pump elements 112a, 112b, the pressure measurements 602, 604 can be carried out immediately at time t0 without delay by flushing. In the illustrated example, two pressure measurements 602, 604 are performed within the pump failure window 504, and then the end 514 of the pump failure window 504 occurs, and the inlet flow control valves with discrete flow rates 130a, 130b are controlled so that fuel can flow to the fuel rail 30. There is a small delay 606 for the controls and the pump latency, after which the rail pressure reaches the nominal rail pressure conditions again at time t1. The penetration into the nominal operating pressures for the fuel rail pressure measurements using process 400 thus extends from time t0 to time t1. Fig. 6B shows a diagram 650 with the rail pressure and electrical current over the long term during an exemplary engine cycle in which a single adjustable inlet metering valve is used to control the fuel flow to all pumping elements of the high-pressure fuel pump. The current flow to the single inlet metering valve is terminated at time t0, similar to diagram 600. However, before the pressure measurements 652, 654 can be performed, a closing and purging time 658 is required because the single inlet metering valve must be energized long enough to completely interrupt the flow to the pump so that the pumping elements of the high-pressure pump can discharge the remaining fuel to allow pressure measurements. Once the pressure measurements are complete, a delay 660 is required for the inlet metering valve to open, in addition to the control latency 656. Thus, when an inlet metering valve controls the fuel flow to all pump elements, the impairment for the fuel rail pressure measurements extends from time t0 to time t2. This impairment is significantly greater than the impairment required when using process 400 of the present disclosure, as illustrated in Figure 600. In one example, the impairment of the earlier method illustrated by Figure 650 can be more than twice as long as the impairment of process 400 when performing pressure measurements. Furthermore, the rail pressure drop in the line when using process 400 in Figure 6A is less than the pressure drop that occurs in Figure 6B. The reduced interference enabled by process 400 of the present disclosure allows for faster convergence of adaptation algorithms that use pressure measurement data and enables the use of algorithms that leverage rapid pressure measurements to improve fuel delivery accuracy and potentially reduce fuel consumption through smaller injections. The reduced interference allows for more frequent measurements, which in turn facilitates faster convergence of the adaptation algorithms. With reference to Fig. 7, a flowchart is illustrated that demonstrates an example procedure 700 for determining fuel quantities, which uses, for example, procedure 400 to obtain pressure measurements of the fuel distributor 30. The procedure 700 begins at the rail pressure control block 702, which initiates the fuel quantity estimation process. The rail pressure control block 702 outputs a signal 752 to provide feedback on the status of the rail pressure tracking command to a subprocess 704. The subprocess 704 provides a routine to initiate a request to measure the fuel quantity at the injector. Subprocess 704 includes a Release Conditions Check Block 706, which checks the release conditions to determine if the conditions for executing Process 700 are met. All suitable release conditions for executing Process 700 are considered. Examples of release conditions include the engine temperature threshold, the stability of the operating point (fuel supply and pressure command), the fuel pressure control range, and the signal processing capacity. The Release Conditions Check Block 706 outputs an operating status signal 754 to a Run Measurement Discriminator Block 708 when the release conditions are met. Subprocess 704 also includes a Reset Measurement Discriminator Block 710, which resets the measurement discriminator when ECU 22 is first powered on or when the maintenance time reaches a calibrated threshold. The reset measurement discriminator block 710 outputs a discriminator reset signal 756, which forces the operational measurement discriminator block 708 to initialize the measurement discriminator's memory. The operational measurement discriminator block 708 outputs a combined signal 758 to request an injection measurement and a bitmask for accepted pulses to block 712 for synchronizing high-frequency pressure measurement events (synchronizer). The two outputs of the combined signal 758 from the operational measurement discriminator block 708 are the injector number for the requested fuel metering measurement and a bitmask. The bitmask identifies which pulses in the packet are sufficiently spaced to be used for the pressure measurement. If one or more pulses are accepted, the synchronizer is activated. Process 700 further includes synchronizer block 712 issuing a pump shutdown request signal (PCO) 760 to block 714, which determines the actuator commands for the discrete-flow inlet flow control valves 130a and 130b. Block 714 issues a PCO start information signal 762 to synchronizer block 712, indicating that pump shutdown is available in the current engine cycle. If the enable conditions are met, synchronizer block 712 repeatedly queries block 714 during the engine cycle until the pump shutdown window can be considered. Block 714 also issues a pump mass delivery margin status 764 to the block for verifying the activation conditions 704. The pump mass delivery margin is calculated here to ensure that the pressure control is reset to its nominal value within one engine cycle after pump shutdown. Process 700 also includes a block 716 for determining the injection duration and injection timing. The injection duration and injection timing block 716 outputs a signal for the injection duration and injection timing 766 to a buffer block for high-frequency rail pressure data 718. The buffer high-frequency rail pressure data block 718 also receives a high-frequency measurement request signal 768 from the synchronizer block 712 as soon as the synchronizer block 712 is informed whether the pump shutdown will occur in the current engine cycle or the next engine cycle. The high-frequency measurement request signal 768 informs the buffer high-frequency rail pressure data block 718 that a pressure measurement is imminent. The buffer high-frequency rail pressure data block 718 outputs a high-frequency measurement request and a high-frequency measurement buffer structure signal 770 to the synchronizer block 712.Signal 770 informs synchronizer block 712 of the status of the high-frequency measurement. When the status changes from "active" to "completed," the high-frequency measurement buffer structure, containing the coherent turn-on and timing information for the injectors, is sent to synchronizer block 712. Synchronizer block 712 also outputs a synchronizer status signal 772 to enable condition block 706 to indicate when the synchronizer is active and when the synchronizer update is complete. Synchronizer block 712 prepares a coherent injection measurement package for the process within a window established in a high-frequency pressure buffer processing block 722 via an initial signal 774 when a pump shutdown in block 714 can be considered in the current engine cycle. The coherent injection measurement packet signal 775 is then forwarded by the synchronizer block 712 to the buffer processing block 722 of the subprocess 720. The synchronizer block 712 appends the accepted pulse bit mask and the injector number to the high-frequency measurement buffer structure, which now contains the pressure buffer, the turn-on time, the time, the injector number, and the accepted pulse bit mask. When block 722 has finished processing the packet, it outputs a fuel estimate, which is related to the commanded power-on time and the measured rail pressure. This estimate is provided as the fuel supply measurement signal 776 to update the measurement queue block 724. The additional fuel supply measurement signal 776 sends the estimated fuel supply to the measurement queue. Additionally, block 722 provides a signal processing readiness signal so that state block 706 can indicate when block 722 is processing the data and when block 722 has finished processing the data and is ready for further processing. The measurement queue block 724 provides a measurement signal 778 for removing refueling to a block 726 for adjusting the injection fuel to the online model, so that the online model takes a measurement from queue block 724 to use for determining the fuel injection quantity. The measurement queue update block 724 also outputs a measurement queue space status signal 780 to the activation conditions block 706 when measurements are added to or removed from queue block 724. It should be noted that terms such as "non-volatile memory", "non-volatile storage medium" and "non-volatile storage device" refer to a range of 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 that such terms include a single or unitary device or medium that stores such information, multiple devices or media on or between which respective parts of such information are stored, and multiple devices or media on or between which multiple copies of such information are stored. It should be noted that terms such as "determine," "determined," "determination," and the like, when used in connection with a control procedure or process, an electronic control system or electronic control, electronic controls or components, or operations of the foregoing terms, refer comprehensively to a range of actions, configurations, devices, operations, and techniques that include, without limitation: the calculation or determination of a parameter or value; the retrieval of a parameter or value from a lookup table or by using a lookup operation; the receipt of parameters or values ​​from a data link or network communication; the receipt of an electronic signal (e.g.,a voltage, frequency, current or pulse width modulation (PWM) signal that specifies the parameter or value, receiving the output of a sensor that specifies the parameter or value, receiving other outputs or inputs that specify the parameter or value, reading the parameter or value from a memory location on a computer-readable medium, receiving the parameter or value as a runtime parameter and / or receiving a parameter or value from which the interpreted parameter can be calculated, and / or by referencing a default value that is interpreted as the parameter value. As detailed in this description, the present disclosure comprises a number of aspects and embodiments, including the following non-limiting examples. According to one aspect of the disclosure, a process for operating an internal combustion engine system is provided. The process involves supplying fuel to a plurality of pumping elements through a plurality of discrete-flow inlet metering valves connected to corresponding elements of the plurality of pumping elements;The vacuuming of a fuel distributor with fuel dispensed by a plurality of pumping elements, wherein the fuel distributor is connected to a plurality of fuel injectors that can be actuated to inject fuel into the corresponding cylinders of the plurality of cylinders of an internal combustion engine during an engine cycle; controlling each of the multiple discrete-flow inlet metering valves to terminate fuel flow from each of the multiple pumping elements to the fuel distributor during the engine cycle; measuring a pressure of the fuel distributor while the fuel flow from the plurality of pumping elements is interrupted during the engine cycle;and controlling the plurality of discrete-flow inlet metering valves to provide a fuel flow from at least one of the plurality of pumping elements to the fuel distributor during the engine cycle after measuring the fuel distributor pressure. In one embodiment, the method includes at least one of the following steps: controlling and diagnosing the internal combustion engine system in response to the measured pressure of the fuel distributor. In one embodiment, fuel is injected through at least one of the several fuel injectors during the engine cycle, while the pressure of the fuel distributor is measured. In one embodiment, fuel is injected through two or more of the multiple fuel injectors during the engine cycle, while the pressure of the fuel distributor is measured. In one embodiment, the plurality of pump elements comprises a first pump element and a second pump element. The plurality of inlet flow control valves with discrete flow rates comprises a first inlet flow control valve with discrete flow rate upstream of the first pump element and a second inlet flow control valve with discrete flow rate upstream of the second pump element. In one embodiment, both the first pumping element and the second pumping element include a chamber containing a piston that moves back and forth in the chamber to pump the fuel from the chamber into the fuel distributor. In one embodiment, controlling each of the multiple discrete-flow inlet metering valves to terminate the fuel flow involves controlling each of the multiple discrete-flow inlet metering valves at a predetermined angle of a camshaft that drives a pumping element of the corresponding discrete-flow inlet metering valve. In one embodiment, the pressure of the fuel distributor is measured immediately after the fuel flow has stopped, without purging the pump elements. In one embodiment, the method involves controlling each of the multiple discrete-flow inlet metering valves a second time to terminate the fuel flow from each of the pump elements to the fuel distributor during the engine cycle; measuring the fuel distributor pressure while the fuel flow to the fuel distributor from the plurality of pump elements is terminated the second time; and controlling the plurality of discrete-flow inlet metering valves to provide a fuel flow to the fuel distributor from at least one of the plurality of pump elements during the second time after measuring the fuel distributor pressure. In one embodiment, measuring the pressure of the fuel distributor during the engine cycle involves performing at least one pressure measurement of the fuel distributor. Another aspect of the present disclosure relates to a system comprising an internal combustion engine. The system includes a fuel injector in liquid communication with a fuel distributor, and the fuel injector is operable to supply fuel to one cylinder of the internal combustion engine during an engine cycle. The system includes a high-pressure pump in liquid communication with the fuel distributor, and the high-pressure pump includes a plurality of pumping elements and a plurality of inlet metering valves with discrete delivery rates, each assigned to a specific pumping element within the plurality of pumping elements.The system includes an electronic control system configured to control each of the multitude of discrete-flow inlet metering valves to stop the fuel flow from the multitude of pump elements to the fuel distributor during the engine cycle; to measure a fuel distributor pressure while the fuel flow from the multitude of pump elements is interrupted during the engine cycle; and to control the multitude of discrete-flow inlet metering valves to provide a fuel flow from at least one of the pump elements to pressurize the fuel distributor during the engine cycle after the fuel distributor pressure has been measured. In one embodiment, each of the multiple discrete-flow inlet flow control valves includes a valve seat, a piston that can be positioned to engage and disengage from the valve seat, and a solenoid valve that can be actuated to move the piston so that it disengages from or engages the valve seat in order to open or close the discrete-flow inlet flow control valve, allowing fuel to flow to the fuel distributor. In one embodiment, each of the multiple inlet flow control valves with discrete flow rate further includes a check valve downstream of the valve seat. In one embodiment, the plurality of pump elements comprises a first pump element and a second pump element. Both the first and second pump elements include a chamber and a piston housed within the chamber to pump fuel from the chamber into the fuel distributor. The plurality of discrete-flow inlet metering valves comprises a first discrete-flow inlet metering valve upstream of the first pump element and a second discrete-flow inlet metering valve upstream of the second pump element. In one embodiment, the electronic control system is configured to control each of the multiple discrete-flow inlet metering valves such that the fuel flow is terminated at a predetermined camshaft angle of a camshaft that drives a pumping element of the corresponding discrete-flow inlet metering valve during the engine cycle. In one embodiment, the electronic control system is configured to measure the pressure of the fuel distributor immediately after the fuel flow has ceased and without purging the pump elements. In one embodiment, the electronic control system is configured to control each of the multiple discrete-flow inlet metering valves a second time to terminate the fuel flow from the pump elements to the fuel distributor during the second period; to measure the pressure of the fuel distributor while the fuel flow to the fuel distributor from the plurality of pump elements is interrupted during the second period; and to control the plurality of inlet metering valves to provide a fuel flow to the fuel distributor from at least one of the plurality of pump elements during the second period after measuring the pressure of the fuel distributor. In one embodiment, the electronic control system is configured to inject fuel from the fuel injector during the engine cycle while the pressure of the fuel distributor is measured. In one embodiment, the fuel injectors include multiple fuel injectors that are in liquid communication with the fuel line, and the electronic control system is configured to inject fuel from at least two of the fuel injectors during the engine cycle while the pressure of the fuel line is measured. According to another aspect of the disclosure, a method involves switching off at least one fuel pump event associated with at least one injection event during each engine cycle of a plurality of engine cycles, and measuring a fuel pressure while the fuel pump event is switched off. Although exemplary embodiments of the disclosure have been shown and described in detail in the drawings and the preceding description, these are to be considered illustrative and not limiting, and it should be noted that only certain exemplary embodiments have been shown and described, and that all changes and modifications that are within the scope of the claimed inventions are to be protected. It is understood that the use of terms such as "preferably," "more preferred," "preferred," or "more preferred" in the above description indicates that the feature so described may be desirable, but is not absolutely necessary, and embodiments lacking this feature may be considered to be within the scope of the invention, the scope being defined by the following claims.When reading the claims, it should be noted that the use of terms such as "a," "an," "at least one," or "at least a part" does not intend to limit the claim to only one item, unless expressly stated otherwise in the claim. When the phrase "at least a part" and / or "a part" is used, the item may include a part and / or the entire item, unless expressly stated otherwise. QUOTES INCLUDED IN THE DESCRIPTION This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature US 63 / 736,081

[0001]

Claims

A process for operating an internal combustion engine system, comprising: supplying fuel to a plurality of pumping elements through a plurality of discrete-flow inlet metering valves assigned to the corresponding elements of the plurality of pumping elements; pressurizing a fuel distributor with fuel from the plurality of pumping elements, the fuel distributor being connected to a plurality of fuel injectors designed to inject fuel into the corresponding cylinder of the plurality of cylinders of an internal combustion engine during an engine cycle; controlling each of the discrete-flow inlet metering valves to terminate a fuel flow from each of the plurality of pumping elements to the fuel distributor during the engine cycle;Measuring a fuel distributor pressure while the fuel flow from the plurality of pumping elements is terminated during the engine cycle; and controlling the plurality of discrete-flow inlet metering valves to provide a fuel flow from at least one of the plurality of pumping elements to the fuel distributor during the engine cycle after measuring the fuel distributor pressure. The process according to claim 1, further comprising: at least one of the functions for controlling and diagnosing the internal combustion engine system in response to the measured pressure of the fuel line. The process according to claim 1, wherein fuel is injected through at least one of the plurality of fuel injectors during the engine cycle while the pressure of the fuel distributor is measured. The process according to claim 1, wherein fuel is injected through two or more of the plurality of fuel injectors during the engine cycle while the pressure of the fuel distributor is measured. Process according to claim 1, wherein: the plurality of pump elements comprises a first pump element and a second pump element; and the plurality of inlet flow control valves with discrete flow rate comprises an inlet flow control valve with discrete flow rate upstream of the first pump element and a second inlet flow control valve with discrete flow rate upstream of the second pump element. The process according to claim 5, wherein each of the first and second pump elements includes a chamber in which a piston is housed, which is moved back and forth in the chamber to pump the fuel from the chamber into the fuel distributor. The process according to claim 1, wherein controlling each of the multiple discrete-quantity inlet metering valves to terminate the fuel flow includes controlling each of the multiple discrete-quantity inlet metering valves at a predetermined angle of a camshaft driving a pumping element of the corresponding discrete-quantity inlet metering valve. Process according to claim 1, wherein the pressure of the fuel distributor is measured immediately after the fuel flow has ceased without purging the pump elements. The process according to claim 1, further comprising: controlling each of the multiple discrete-flow inlet metering valves a second time to terminate the fuel flow from each of the pump elements to the fuel distributor during the engine cycle; measuring the fuel distributor pressure while the fuel flow to the fuel distributor from the multiple pump elements is terminated a second time; and controlling the multiple discrete-flow inlet metering valves to provide a fuel flow to the fuel distributor from at least one of the multiple pump elements during the second time after measuring the fuel distributor pressure. The process according to claim 1, wherein measuring the pressure of the fuel distributor during the engine cycle includes performing at least one pressure measurement of the fuel distributor. A system with an internal combustion engine, the system comprising: a fuel injector in liquid contact with a fuel distributor, wherein the fuel injector can be actuated to supply fuel to a cylinder of the internal combustion engine during an engine cycle; a high-pressure pump in liquid contact with the fuel distributor, the high-pressure pump comprising multiple pump elements and multiple discrete-flow inlet metering valves assigned to the respective pump elements; and an electronic control system configured to: control each of the multiple discrete-flow inlet metering valves to terminate fuel flow from the multiple pump elements to the fuel distributor during the engine cycle; measure fuel distributor pressure while fuel flow from the multiple pump elements is terminated during the engine cycle;and controls the multitude of discrete-flow inlet metering valves to provide a fuel flow from at least one of the pumping elements to pressurize the fuel distributor during the engine cycle, after the fuel distributor pressure has been measured. System according to claim 11, wherein each of the multiple discrete flow rate inlet metering valves includes a valve seat, a piston that can be positioned to engage and disengage from the valve seat, and a solenoid valve that can be actuated to activate the piston so that it engages or disengages from the valve seat, allowing fuel to flow to the fuel distributor. System according to claim 12, wherein each of the multiple inlet flow control valves with discrete flow rate further includes a check valve downstream of the valve seat. System according to claim 11, wherein: the plurality of pumping elements comprises a first pumping element and a second pumping element, and each of the first pumping elements and the second pumping elements comprises a chamber and a piston housed in the chamber for pumping fuel from the chamber into the fuel distributor; and the plurality of discrete-quantity inlet metering valves comprises a first discrete-quantity inlet metering valve upstream of the first pumping element and a second discrete-quantity inlet metering valve upstream of the second pumping element. System according to claim 11, wherein the electronic control system is configured to: control each of the multiple discrete flow intake metering valves to terminate the fuel flow at a predetermined camshaft angle of a camshaft that drives a pump element of the corresponding discrete flow intake metering valve during the engine cycle. System according to claim 11, wherein the electronic control system is configured to: measure the pressure of the fuel distributor immediately after each of the multiple discrete flow rate inlet metering valves, which are controlled to terminate the fuel flow without purging the pump elements. System according to claim 11, wherein the electronic control system is configured to: control each of the multiple discrete-flow inlet metering valves a second time to terminate the fuel flow from the pump elements to the fuel distributor during the engine cycle; measure the fuel distributor pressure while the fuel flow to the fuel distributor from the plurality of pump elements is interrupted during the second time; and control the plurality of discrete-flow inlet metering valves to deliver fuel from at least one of the plurality of pump elements to the fuel distributor during the second time, after the fuel distributor pressure has been measured during the second time. System according to claim 11, wherein the electronic control system is configured to: inject fuel from the fuel injector during the engine cycle while the pressure in the fuel distributor is measured. System according to claim 11, wherein the fuel injector comprises a plurality of fuel injectors which are in fluid communication with the fuel distributor, and the electronic control system is configured to inject fuel from at least two of the fuel injectors during the engine cycles in which the pressure of the fuel distributor is measured. A method comprising: switching off at least one fuel pump operation associated with at least one injection operation during each engine cycle of a plurality of engine cycles; and measuring a fuel pressure while the fuel pump operation is switched off.

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