METHOD FOR CONTROLLING MULTIPLE FUEL INJECTORS FOR A VEHICLE

Abstract

Method for controlling multiple fuel injectors (36a, 36b) for a vehicle (12), the method comprising: Determining a total fuel mass for one combustion stage in a cylinder (22); Determining a first injection mass for a first fuel injector (36a) and a second injection mass for a second fuel injector (36b), wherein the sum of the first injection mass and the second injection mass equals the total fuel mass, the first fuel injector (36a) and the second fuel injector (36b) are configured to supply fuel to the cylinder (22), and a first minimum mass per pulse of the first fuel injector (36a) is greater than a second minimum mass per pulse of the second fuel injector (36b); and Control of the first fuel injector (36a) and the second fuel injector (36b) at least partially on the basis of the first injection mass and the second injection mass.

Description

INTRODUCTION

[0001] The present invention relates to a method for controlling a vehicle's engine and, in particular, to a method for controlling multiple fuel injectors for a vehicle.

[0002] For general background information, reference should be made in advance to the publications DE 10 2018 120 393 B4 and DE 10 2015 118 456 B4, which describe methods and systems for controlling fuel injection into the cylinders of an internal combustion engine.

[0003] To increase the power and efficiency of internal combustion engines, vehicles can be equipped with engines that employ various types of fuel injection systems. Direct injection (DI) systems use fuel injectors configured to inject fuel directly into the cylinder's combustion chamber. Port fuel injection (PFI) systems use fuel injectors configured to inject fuel into the intake port (i.e., upstream of the intake valve and combustion chamber). DI systems can allow for a higher compression ratio compared to PFI systems, resulting in increased engine efficiency. However, the increased efficiency provided by DI systems can come at the cost of increased small particulate emissions compared to PFI systems.Therefore, injection systems can utilize both direct injection (DI) and orifice fuel injection (PFI) injectors (sometimes referred to as "dual injection") to balance the advantages and disadvantages of DI and PFI systems. However, dual injection systems require control algorithms that account for design and implementation differences between DI and PFI systems to operate them within design parameters.

[0004] Thus, although engine control systems and procedures achieve their intended purpose, there is a need for a new and improved method for controlling fuel injectors for a vehicle.

[0005] The invention is therefore based on the objective of meeting this need. SUMMARY

[0006] This problem is solved by a method characterized by the features of claim 1.

[0007] Advantageous further developments of the invention result from the dependent claims.

[0008] According to a further aspect of the present invention, determining the first injection mass and the second injection mass can further include determining a first pulse count for a first set of pulses from the first fuel injector. Determining the first injection mass and the second injection mass can further include determining a second pulse count for a second set of pulses from the second fuel injector. Determining the first injection mass and the second injection mass can further include determining the first injection mass and the second injection mass at least partially based on the first pulse count and the second pulse count.

[0009] According to a further aspect of the present invention, determining the first pulse count and the second pulse count can further include determining the first pulse count at least partially based on a predetermined initial first injector pulse count. Determining the first pulse count and the second pulse count can further include determining the second pulse count at least partially based on a predetermined initial second injector pulse count.

[0010] According to a further aspect of the present invention, determining the first injection mass and the second injection mass can further include determining a first set of pulse masses, at least partially, based on the first number of pulses and the first injection mass. Each of the pulse masses in the first set corresponds to one pulse from the first set of pulses of the first fuel injector. Determining the first injection mass and the second injection mass can further include determining a second set of pulse masses, at least partially, based on the second number of pulses and the second injection mass. Each of the pulse masses in the second set corresponds to one pulse from the second set of pulses of the second fuel injector.Determining the first and second injection masses may further involve adjusting the first and / or second pulse count, at least partially, based on the first and second sets of pulse masses. Determining the first and second injection masses may also involve recalculating the first and second sets of pulse masses in response to this adjustment.

[0011] According to a further aspect of the present invention, determining the first injection mass and the second injection mass may further include adjusting the first injection mass and the second injection mass at least partially based on the first pulse count and the second pulse count in response to adjusting the first pulse count and / or the second pulse count.

[0012] According to a further aspect of the present invention, adjusting the first pulse count and / or the second pulse count can further include comparing each of the pulse masses of the first set with the first minimum mass per pulse. Adjusting the first pulse count and / or the second pulse count can further include comparing each of the pulse masses of the second set with the second minimum mass per pulse. Adjusting the first pulse count and / or the second pulse count can further include adjusting the first pulse count and / or the second pulse count in response to a determination that each of the pulse masses of the first set is less than or equal to the first minimum mass per pulse and that each of the pulse masses of the second set is less than or equal to the second minimum mass per pulse.

[0013] According to a further aspect of the present invention, adjusting the first pulse count and / or the second pulse count may further include reducing the first pulse count by one in response to a determination that the first pulse count is greater than one and that each of the first set of pulse masses is less than or equal to the first minimum mass per pulse and that each of the second set of pulse masses is less than or equal to the second minimum mass per pulse.

[0014] According to a further aspect of the present invention, adjusting the first pulse count and / or the second pulse count can further include reducing the second pulse count by one in response to a determination that the first pulse count is not greater than one, that the second pulse count is greater than one, and that each of the first set of pulse masses is less than or equal to the first minimum mass per pulse, and that each of the second set of pulse masses is less than or equal to the second minimum mass per pulse.

[0015] According to a further aspect of the present invention, adjusting the first pulse count and / or the second pulse count can further include deactivating the first fuel injector in response to a determination that the first pulse count is not greater than one, that the second pulse count is not greater than one, and that each of the first set of pulse masses is less than or equal to the first minimum mass per pulse, and that each of the second set of pulse masses is less than or equal to the second minimum mass per pulse.

[0016] According to a further aspect of the present invention, deactivating the first fuel injector can further include adjusting the first injection mass such that it is equal to zero. Deactivating the first fuel injector can further include adjusting the second injection mass such that it is equal to the total fuel mass.

[0017] Furthermore, a system for controlling multiple fuel injectors for a vehicle is described. The system may include a first fuel injector configured to deliver fuel to a cylinder. The first fuel injector has a first minimum mass per pulse. The system may also include a second fuel injector configured to deliver fuel to the cylinder. The second fuel injector has a second minimum mass per pulse. This second minimum mass per pulse is less than the first minimum mass per pulse. The system may also include a controller in electrical communication with both the first and second fuel injectors. The controller is programmed to determine a total fuel mass for a combustion stage in the cylinder.The controller is further programmed to determine a first injection mass for the first fuel injector and a second injection mass for the second fuel injector, at least partially, based on the total fuel mass. The controller is further programmed to control the first fuel injector and the second fuel injector, at least partially, based on the first and second injection masses.

[0018] According to a further aspect of the present invention, in order to determine the first injection mass and the second injection mass, the controller is further programmed to determine a first pulse count for a first set of pulses from the first fuel injector. In order to determine the first injection mass and the second injection mass, the controller is further programmed to determine a second pulse count for a second set of pulses from the second fuel injector. In order to determine the first injection mass and the second injection mass, the controller is further programmed to determine the first injection mass and the second injection mass at least partially based on the first pulse count and the second pulse count.

[0019] According to a further aspect of the present invention, in order to determine the first and second injection masses, the controller is further programmed to determine a first set of pulse masses, at least partially, based on the first number of pulses and the first injection mass. Each of the pulse masses in the first set corresponds to one from the first set of pulses of the first fuel injector. To determine the first and second injection masses, the controller is further programmed to determine a second set of pulse masses, at least partially, based on the second number of pulses and the second injection mass. Each of the pulse masses in the second set corresponds to one from the second set of pulses of the second fuel injector.To determine the first and second injection masses, the controller is further programmed to adjust the first and / or second pulse counts, at least partially, based on the first and second set of pulse masses. To determine the first and second injection masses, the controller is further programmed to recalculate the first and second set of pulse masses in response to adjustments to the first and / or second pulse counts.

[0020] According to a further aspect of the present invention, in order to adjust the first pulse count and / or the second pulse count, the controller is further programmed to compare each of the pulse masses of the first set with the first minimum mass per pulse. In order to adjust the first pulse count and / or the second pulse count, the controller is further programmed to compare each of the pulse masses of the second set with the second minimum mass per pulse. In order to adjust the first pulse count and / or the second pulse count, the controller is further programmed to adjust the first pulse count and / or the second pulse count in response to a determination that each of the pulse masses of the first set is less than or equal to the first minimum mass per pulse and that each of the pulse masses of the second set is less than or equal to the second minimum mass per pulse.

[0021] According to a further aspect of the present invention, in order to adjust the first pulse count and / or the second pulse count, the controller is further programmed to decrease the first pulse count by one in response to a determination that the first pulse count is greater than one and that each pulse mass of the first set is less than or equal to the first minimum mass per pulse, and that each pulse mass of the second set is less than or equal to the second minimum mass per pulse. In order to adjust the first pulse count and / or the second pulse count, the controller is further programmed to decrease the second pulse count by one in response to a determination that the first pulse count is not greater than one, that the second pulse count is greater than one and that each pulse mass of the first set is less than or equal to the first minimum mass per pulse, and that each pulse mass of the second set is less than or equal to the second minimum mass per pulse.

[0022] According to a further aspect of the present invention, in order to adjust the first pulse count and / or the second pulse count, the controller is further programmed to deactivate the first fuel injector in response to a determination that the first pulse count is not greater than one, that the second pulse count is not greater than one, and that each of the first set of pulse masses is less than or equal to the first minimum mass per pulse, and that each of the second set of pulse masses is less than or equal to the second minimum mass per pulse.

[0023] According to another aspect of the present invention, the first fuel injector is a pre-injection fuel injector (PFI) and the second fuel injector is a direct injection fuel injector (DI).

[0024] A method for controlling multiple fuel injectors for a vehicle is provided according to several aspects. The method may include determining a total fuel mass for a combustion stage in a cylinder. The method may further include determining an initial pulse count for a first set of pulses from a first fuel injector. The first fuel injector is a pre-injection fuel injector (PFI) configured to deliver fuel to the cylinder. The first fuel injector has a minimum initial mass per pulse. The method may further include determining a second pulse count for a second set of pulses from a second fuel injector. The second fuel injector is a direct injection fuel injector (DI) configured to deliver fuel to the cylinder.The second fuel injector has a second minimum mass per pulse. This second minimum mass per pulse is smaller than the first minimum mass per pulse. The method may further include determining a first injection mass for the first fuel injector and a second injection mass for the second fuel injector, at least partially based on the first and second pulse counts, respectively, wherein the sum of the first and second injection masses equals the total fuel mass. The method may further include controlling the first and second fuel injectors, at least partially based on the first and second injection masses.

[0025] According to a further aspect of the present invention, determining the first injection mass and the second injection mass can further include determining a first set of pulse masses, at least partially, based on the first number of pulses and the first injection mass. Each of the pulse masses in the first set corresponds to one pulse from the first set of pulses of the first fuel injector. Determining the first injection mass and the second injection mass can further include determining a second set of pulse masses, at least partially, based on the second number of pulses and the second injection mass. Each of the pulse masses in the second set corresponds to one pulse from the second set of pulses of the second fuel injector.Determining the first and second injection masses may further involve adjusting the first and / or second pulse count, at least partially, based on the first and second sets of pulse masses. Determining the first and second injection masses may also involve recalculating the first and second sets of pulse masses in response to this adjustment.

[0026] According to a further aspect of the present invention, adjusting the first pulse count and / or the second pulse count can further include comparing each of the pulse masses of the first set with the first minimum mass per pulse. Adjusting the first pulse count and / or the second pulse count can further include comparing each of the pulse masses of the second set with the second minimum mass per pulse. Adjusting the first pulse count and / or the second pulse count can further include decreasing the first pulse count by one in response to a finding that the first pulse count is greater than one and that each of the pulse masses of the first set is less than or equal to the first minimum mass per pulse, and that each of the pulse masses of the second set is less than or equal to the second minimum mass per pulse.Adjusting the first pulse count and / or the second pulse count may further include decreasing the second pulse count by one in response to a determination that the first pulse count is not greater than one, that the second pulse count is greater than one, and that each pulse mass of the first set is less than or equal to the first minimum mass per pulse, and that each pulse mass of the second set is less than or equal to the second minimum mass per pulse. Adjusting the first pulse count and / or the second pulse count may further include disabling the first fuel injector in response to a determination that the first pulse count is not greater than one, that the second pulse count is not greater than one, and that each pulse mass of the first set is less than or equal to the first minimum mass per pulse, and that each pulse mass of the second set is less than or equal to the second minimum mass per pulse.

[0027] Further areas of application will become apparent from the description provided here. It should be understood that the description and specific examples serve only as illustrations. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The drawings described here are for illustrative purposes only; they show: Fig. 1 a schematic diagram of a system for controlling multiple fuel injectors for a vehicle according to an exemplary embodiment; Fig. 2 a schematic diagram of a cylinder arrangement of an internal combustion engine of the vehicle according to an exemplary embodiment and Fig. 3 a flow chart of a method for controlling multiple fuel injectors according to an exemplary embodiment. DETAILED DESCRIPTION

[0029] The following description is merely exemplary and is not intended to limit the present invention, application or uses.

[0030] Vehicle fuel injection systems using both direct injection (DI) and pre-injection (PFI) fuel injectors (sometimes referred to as "dual injection") can be used to balance the advantages and disadvantages of DI and PFI systems. However, dual injection systems require control algorithms that account for design and implementation differences between DI and PFI systems in order to operate both systems within their designed parameters. Therefore, the present invention presents a new and improved system and method for controlling multiple fuel injectors (e.g.,DI and PFI fuel injectors) for a vehicle that ensures proper operation of the multiple fuel injectors even when fuel injector specifications (e.g., minimum mass per pulse) differ.

[0031] With reference to Fig. Figure 1 is a system for controlling multiple fuel injectors for a vehicle, illustrated and generally specified by reference numeral 10. The system 10 is shown with an exemplary vehicle 12. While a passenger car is illustrated, it should be noted that the vehicle 12 can be any type of vehicle. The system 10 generally includes a controller 14 and an internal combustion engine 16.

[0032] The controller 14 is used to implement a method 100 for controlling multiple fuel injectors for a vehicle, as described below. The controller 14 includes at least one processor 18 and a non-transient computer-readable memory device or non-transient computer-readable storage medium 20. The processor 18 can be a custom-made or commercially available processor, a central processing unit (CPU), a graphics processing unit (GPU), an auxiliary processor among several processors associated with the controller 14, a semiconductor-based microprocessor (in the form of a microchip or a chipset), a macroprocessor, a combination thereof, or generally an instruction-executing device.

[0033] The computer-readable storage device or computer-readable storage medium 20 may, for example, contain volatile and non-volatile memory in the form of read-only memory (ROM), read / write memory (RAM), and persistent memory (KAM). KAM is persistent or non-volatile working memory that can be used to store various operating variables while the processor 18 is switched off. The computer-readable storage device or computer-readable storage medium 20 may be implemented using a number of storage devices such as PROMs (programmable read-only memory), EPROMs (electrical PROMs), EEPROMs (electrically erasable PROMs), flash memory, or other electrical, magnetic, optical, or combined storage devices capable of storing data, some of which represents executable instructions used by the controller 14 to control various systems of the vehicle 12.

[0034] The controller 14 can also consist of multiple controllers that communicate electrically with each other. The controller 14 can be connected to additional systems and / or controllers of the vehicle 12 to allow the controller 14 to access data such as speed, acceleration, braking, and steering angle of the vehicle 12.

[0035] The controller 14 communicates electrically with the internal combustion engine 16. In one exemplary embodiment, the electrical communication is established using, for example, a CAN network, a FLEXRAY network, a local area network (e.g., Wi-Fi, Ethernet, and the like), a serial peripheral interface network (SPI network), or the like. It should be understood that various additional wired and wireless techniques and communication protocols are possible for communicating with the controller 14. Furthermore, it should be understood that electrical communication also includes power and / or energy transfer between electrical devices (e.g., using conductor wires and / or wireless power transmission techniques).

[0036] The internal combustion engine 16 is used to convert fuel into mechanical energy to power the vehicle 12. In an exemplary embodiment, the internal combustion engine 16 is an internal combustion engine (ICE). In a non-limiting example, the internal combustion engine 16 includes at least one cylinder assembly 22. The cylinder assembly 22 performs a combustion cycle to generate mechanical energy, as discussed below.

[0037] With reference to Fig. Figure 2 shows a schematic diagram of the cylinder arrangement 22. While a single cylinder arrangement 22 is shown, it should be understood that the internal combustion engine 16 can contain multiple cylinder arrangements. In an exemplary embodiment, the cylinder arrangement 22 includes a piston 24, which is movable in a combustion chamber 26 and is coupled to a crankshaft (not shown) by a connecting rod 28. The combustion chamber 26 takes in air and / or fuel through an inlet port 30a and expels exhaust gases through an outlet port 30b. The gas flow between the combustion chamber 26 and the inlet port 30a is controlled by an inlet valve 32a. The gas flow between the combustion chamber 26 and the outlet port 30b is controlled by an outlet valve 32b. In a non-restrictive example, the inlet valve 32a and the exhaust valve 32b are actuated by cams (not shown) on a camshaft (not shown).The cylinder arrangement 22 also includes a spark plug 34 to ignite a fuel / air mixture in the combustion chamber 26.

[0038] The cylinder arrangement 22 further includes a first fuel injector 36a and a second fuel injector 36b. The first fuel injector 36a and the second fuel injector 36b are used to deliver precise amounts of fuel (e.g., gasoline) into the combustion chamber 26. In an exemplary embodiment, the first fuel injector 36a and the second fuel injector 36b are electronically controlled fuel injectors. In a non-limiting example, the first fuel injector 36a and the second fuel injector 36b each include a solenoid valve (not shown) and a nozzle (not shown). The solenoid valve controls the flow of fuel (e.g., gasoline), and the nozzle atomizes the fuel (e.g., gasoline) into a fine mist. The solenoid valve is electronically controlled by the controller 14 to deliver fuel (e.g., gasoline) to the combustion chamber 26.to inject gasoline) into the combustion chamber 26 at the optimal time in the combustion cycle and in the optimal quantity for optimal combustion efficiency. In a non-limiting example, the solenoid valve is actuated by “pulses.” In the scope of the present invention, a pulse is an injection of fuel during the actuation of the solenoid valve. Each pulse has a pulse width that defines a time for which the solenoid valve is open per pulse and thus a quantity of fuel (typically measured in units of mass) injected per pulse. For example, the solenoid valve can be excited by a square wave signal to provide a set of pulses of fuel injection. A duty cycle of the square wave signal is controlled to adjust the quantity of fuel injected per pulse.It is understood that the solenoid valve can be energized by a non-periodic signal and / or signals that exhibit a variable frequency and / or a variable duty cycle over time. The first fuel injector 36a and the second fuel injector 36b are in electrical communication with the controller 14 to supply control signals to the solenoid valve of each of the first fuel injector 36a and the second fuel injector 36b.

[0039] Due to the electromechanical design of the first fuel injector 36a and the second fuel injector 36b and / or the electrical design of the control system (i.e., the controller 14), a minimum mass per pulse is defined for each of the first fuel injector 36a and the second fuel injector 36b. The minimum mass per pulse is the minimum mass of fuel that a fuel injector can inject per injection pulse. A first minimum mass per pulse is defined for the first fuel injector 36a, and a second minimum mass per pulse is defined for the second fuel injector 36b. In a non-restrictive example, the first minimum mass per pulse and the second minimum mass per pulse are specified using a simulation and / or a laboratory test and stored in the media 20 of the controller 14.Operating fuel injectors below the minimum mass per pulse can result in a non-deterministic fuel injection quantity per pulse. Therefore, it is advantageous to operate fuel injectors at or above a minimum mass per pulse to ensure precise combustion control.

[0040] In a non-restrictive example, the first fuel injector 36a is a pre-injection fuel injector (PFI) designed to inject fuel into the inlet port 30a so that it is carried into the combustion chamber 26 by a gas flow in the inlet port 30a. The second fuel injector 36b is a direct injection fuel injector (DI) designed to inject fuel directly into the combustion chamber 26. In a non-restrictive example, the first minimum mass per pulse of the first fuel injector 36a is greater than the second minimum mass per pulse of the second fuel injector 36b. For example, the first minimum mass per pulse may be in the range of 4–6 milligrams, and the second minimum mass per pulse may be in the range of 2–3 milligrams.It is to be understood that the types of fuel injectors and the mass per pulse values ​​provided above are merely exemplary and that the present invention is applicable to any fuel injection system having two or more fuel injectors per cylinder.

[0041] In one exemplary embodiment, the combustion cycle comprises four stages (also referred to as strokes). The intake stage begins when the piston 24 is at top dead center (TDC). As the piston moves downwards, the intake valve 32a opens and gases are drawn from the intake port 30a into the combustion chamber 26. Simultaneously, the first fuel injector 36a and / or the second fuel injector 36b are actuated to supply fuel to the fuel / air mixture.

[0042] In a non-restrictive example, the first fuel injector 36a is actuated by a first set of pulses, which contain a first pulse count. Each of the first pulses delivers one of the first set of pulse masses of fuel. The first pulse count can be any integer, including zero if the first fuel injector 36a is deactivated. Each of the first pulse masses is a fuel mass corresponding to one of the first pulses. Each of the first pulse masses can have the same or different values. To ensure proper operation of the first fuel injector 36a, each of the first pulse masses should be greater than or equal to the first minimum mass per pulse of the first fuel injector 36a.

[0043] In a non-restrictive example, the second fuel injector 36b is actuated by a second set of pulses, each containing a second pulse count. Each pulse of the second set delivers one of the second set's pulse masses of fuel. The second pulse count can be any integer, including zero if the second fuel injector 36b is deactivated. Each pulse mass of the second set is a fuel mass corresponding to one of the pulses in the second set. Each pulse mass of the second set can have the same or different values. To ensure proper operation of the second fuel injector 36b, each pulse mass of the second set should be greater than or equal to the second minimum mass per pulse of the second fuel injector 36b.

[0044] When piston 24 reaches bottom dead center (BDC), the intake valve 32a closes and the compression stage begins. As piston 24 moves upward, the fuel / air mixture in the combustion chamber 26 is compressed. When piston 24 reaches top dead center (TDC) again, the combustion stage begins and the compressed fuel / air mixture is ignited by the spark plug 34. During the combustion stage, the combustion of the fuel / air mixture drives piston 24 downward, providing mechanical energy to the crankshaft (not shown). When piston 24 reaches bottom dead center (BDC) again, the exhaust stage begins. During the exhaust stage, the exhaust valve 32b opens and piston 24 moves upward, expelling exhaust gases from the combustion stage into the exhaust port 30b.

[0045] After the exhaust gases are expelled, the exhaust valve 32b closes and the combustion cycle is completed and can be repeated to generate additional mechanical energy.

[0046] With reference to Fig.Figure 3 shows a flowchart of method 100 for controlling multiple fuel injectors. Method 100 begins in block 102 and proceeds to block 104. In block 104, the controller 14 determines a total fuel mass required for the combustion stage. In an exemplary embodiment, the controller 14 determines the total fuel mass based on several factors and / or measured values, including, for example, the intake air mass (measured, for example, using a mass airflow sensor (MAF sensor) or a manifold absolute pressure (MAP sensor)), the intake air temperature, the throttle position, the exhaust oxygen content, the engine speed, the engine load, the engine temperature, and / or the like.In a non-restrictive example, the controller uses 14 different algorithms and / or lookup tables to determine the total fuel mass based on any combination of the factors mentioned above. It should be understood that the discussion described above is merely exemplary and that various additional and / or alternative methods for determining the total fuel mass, including methods using additional and / or alternative sensors or algorithms, may be employed. After block 104, method 100 proceeds to block 106.

[0047] In block 106, the controller 14 divides the total fuel mass determined in block 104 between a first injection mass for the first fuel injector 36a and a second injection mass for the second fuel injector 36b such that the sum of the first injection mass and the second injection mass equals the total fuel mass determined in block 104. In an exemplary embodiment, the controller 14 uses a predetermined initial fuel mass ratio to divide the total fuel mass between the first fuel injector 36a and the second fuel injector 36b. In a non-restrictive example, the predetermined initial fuel mass ratio can be 50:50, meaning that the first injection mass equals the second injection mass.In another non-restrictive example, the specified initial fuel mass ratio can be 25:75, which means that the first injection mass is equal to twenty-five percent of the total fuel mass and the second injection mass is equal to seventy-five percent of the total fuel mass.

[0048] In another exemplary embodiment, the predetermined initial fuel mass ratio is determined by querying a lookup table stored in the media 20 of the controller 14, based on factors such as intake air mass, intake air temperature, throttle position, exhaust oxygen content, engine speed, engine load, engine temperature, and / or the like. In another exemplary embodiment, if the first fuel injector 36a is completely deactivated, the first injection mass is set to zero, and the second injection mass is set to the total fuel mass. In another exemplary embodiment, if the second fuel injector 36b is completely deactivated, the first injection mass is set to the total fuel mass, and the second injection mass is set to zero.The first and second injection masses are stored as variable variables in the media 20 of the controller 14, which can be modified during subsequent process steps, as discussed below. It should be understood that the discussion described above is merely exemplary and that various additional and / or alternative methods for dividing the total fuel mass between the first injection mass for the first fuel injector 36a and the second injection mass for the second fuel injector 36b, including methods using additional and / or alternative sensors or algorithms, may be employed. After block 106, process 100 proceeds to blocks 108 and 110.

[0049] In block 108, the controller 14 determines the initial pulse count for the first set of pulses of the first fuel injector 36a. In one exemplary embodiment, the initial pulse count is initially determined at least partially based on a predetermined initial first injector pulse count (e.g., one pulse) stored in the media 20. In another exemplary embodiment, the predetermined initial first injector pulse count is determined by querying a lookup table stored in the media 20 of the controller 14, based on factors such as intake air mass, intake air temperature, throttle position, exhaust oxygen content, engine speed, engine load, engine temperature, and / or the like. In yet another exemplary embodiment, if the first fuel injector 36a is completely deactivated, the initial pulse count is set to zero.The first pulse count is stored in the media 20 of the controller 14 as a variable that can be changed during subsequent process steps, as discussed below. It should be understood that the discussion described above is merely exemplary and that various additional and / or alternative methods for determining the first pulse count for the first set of pulses of the first fuel injector 36a, including methods using additional and / or alternative sensors or algorithms, may be employed. After block 108, the process 100 proceeds to block 112.

[0050] In block 112, the controller 14 determines the first set of pulse masses. In one exemplary embodiment, the first set of pulse masses is determined at least partially based on the first number of pulses determined in block 108 and the first injection mass determined in block 106. In a non-restrictive example, the first set of pulse masses is determined by distributing the first injection mass equally among the first set of pulses. In another exemplary embodiment, the first set of pulse masses is determined by querying a lookup table stored in the media 20 of the controller 14, based on factors such as intake air mass, intake air temperature, throttle position, exhaust oxygen content, engine speed, engine load, engine temperature, and / or the like.In another exemplary embodiment, if the first fuel injector 36a is completely deactivated, the pulse masses of the first set are all set to zero. The pulse masses of the first set are stored in the media 20 of the controller 14 as variable variables that can be changed during subsequent process steps. It should be understood that the discussion described above is merely exemplary and that various additional and / or alternative methods for determining the first set of pulse masses for the first set of pulses of the first fuel injector 36a, including methods using additional and / or alternative sensors or algorithms, may be employed. After block 112, the process 100 proceeds to block 114, as discussed in more detail below.

[0051] In block 110, the controller 14 determines the second pulse count for the second set of pulses of the second fuel injector 36b. In one exemplary embodiment, the second pulse count is initially determined at least partially based on a predetermined initial second injector pulse count (e.g., three pulses) stored in the media 20. In another exemplary embodiment, the predetermined initial second injector pulse count is determined by querying a lookup table stored in the media 20 of the controller 14, based on factors such as intake air mass, intake air temperature, throttle position, exhaust oxygen content, engine speed, engine load, engine temperature, and / or the like. In yet another exemplary embodiment, if the second fuel injector 36b is completely deactivated, the second pulse count is set to zero.The second pulse count is stored in the media 20 of the controller 14 as a variable that can be modified during subsequent process steps, as discussed below. It should be understood that the discussion described above is merely exemplary and that various additional and / or alternative methods for determining the second pulse count for the second set of pulses from the second fuel injector 36b, including methods using additional and / or alternative sensors or algorithms, may be employed. After block 110, the process 100 proceeds to block 116.

[0052] In block 116, the controller 14 determines the second set of pulse masses. In one exemplary embodiment, the pulse masses of the second set are determined at least partially based on the second pulse count determined in block 110 and the second injection mass determined in block 106. In a non-restrictive example, the pulse masses of the second set are determined such that they distribute the second injection mass equally among the second set of pulses. In another exemplary embodiment, the pulse masses of the second set are determined by querying a lookup table stored in the media 20 of the controller 14, based on factors such as intake air mass, intake air temperature, throttle position, exhaust oxygen content, engine speed, engine load, engine temperature, and / or the like.In another exemplary embodiment, if the second fuel injector 36b is completely deactivated, the pulse masses of the second set are all set to zero. The pulse masses of the second set are stored in the media 20 of the controller 14 as variable variables that can be changed during subsequent process steps. It should be understood that the discussion described above is merely exemplary and that various additional and / or alternative methods for determining the second set of pulse masses for the second set of pulses of the second fuel injector 36b, including methods using additional and / or alternative sensors or algorithms, may be employed. After block 116, the process 100 proceeds to block 114.

[0053] In block 114, controller 14 compares each pulse mass of the first set with a first minimum mass per pulse. Additionally, controller 14 compares each pulse mass of the second set with the second minimum mass per pulse. If all pulse masses of the first set are greater than the first minimum mass per pulse AND if all pulse masses of the second set are greater than the second minimum mass per pulse, procedure 100 proceeds to a ready state in block 118. If any pulse mass of the first set is less than or equal to the first minimum mass per pulse OR if any pulse mass of the second set is less than or equal to the second minimum mass per pulse, procedure 100 proceeds to block 120.

[0054] In block 120, controller 14 compares the first pulse count with one. If the first pulse count is less than or equal to one, procedure 100 proceeds to block 122, as discussed in more detail below. If the first pulse count is greater than one, procedure 100 proceeds to block 124.

[0055] In block 124, the controller 14 reduces the first pulse count by one. After block 124, the method 100 returns to block 112 to recalculate the first set of pulse masses based on the newly reduced first pulse count. In certain embodiments, after block 124, the method 100 returns to block 106 to adjust the first injection mass, at least partially, based on the newly reduced first pulse count.

[0056] In block 122, controller 14 compares the second pulse count with one. If the second pulse count is less than or equal to one, procedure 100 proceeds to block 126, as discussed in more detail below. If the second pulse count is greater than one, procedure 100 proceeds to block 128.

[0057] In block 128, the controller 14 reduces the second pulse count by one. After block 128, the method 100 returns to block 116 to recalculate the second set of pulse masses based on the newly reduced second pulse count. In certain embodiments, after block 128, the method 100 returns to block 106 to adjust the second injection mass, at least partially, based on the newly reduced second pulse count.

[0058] In block 126, the controller 14 deactivates the first fuel injector 36a. In the scope of the present invention, deactivating the first fuel injector 36a means that the first fuel injector 36a is not used for the combustion cycle and the entire fuel mass is injected through the second fuel injector 36b. After block 126, the method 100 returns to block 106 to adjust the first injection mass (i.e., setting the first injection mass to zero) and the second injection mass (i.e., setting the second injection mass such that it is equal to the total fuel mass).

[0059] In one exemplary embodiment, the controller 14 repeatedly exits the standby state 118 and restarts the procedure 100 in block 102. In a non-restrictive example, the controller 14 exits the standby state 118 and restarts the procedure 100 based on a timer, e.g., every three hundred milliseconds.

[0060] In an exemplary embodiment, the method 100 further comprises mechanisms for increasing the first pulse count and / or the second pulse count and / or reactivating the first fuel injector 36a. In a non-limiting example, the first pulse count and / or the second pulse count are increased and / or the first fuel injector 36a is reactivated in response to an increase in the intake air mass, the throttle position, the engine speed, the engine load, and / or the like.

[0061] System 10 and method 100 of the present invention offer several advantages. System 10 and method 100 enable efficient and effective operation of the internal combustion engine 16 with one or more cylinder arrangements, which have multiple fuel injectors with different minimum mass-per-pulse specifications. Using System 10 and method 100, the fuel distribution between injectors, the number of pulses per injector, and the fuel mass injected per pulse can be adjusted and optimized based on an engine load to operate all fuel injectors at or above their minimum mass-per-pulse specifications.

Claims

[1] Method for controlling multiple fuel injectors (36a, 36b) for a vehicle (12), the method comprising: Determining a total fuel mass for one combustion stage in a cylinder (22); Determining a first injection mass for a first fuel injector (36a) and a second injection mass for a second fuel injector (36b), wherein the sum of the first injection mass and the second injection mass equals the total fuel mass, the first fuel injector (36a) and the second fuel injector (36b) are configured to supply fuel to the cylinder (22), and a first minimum mass per pulse of the first fuel injector (36a) is greater than a second minimum mass per pulse of the second fuel injector (36b); and Control of the first fuel injector (36a) and the second fuel injector (36b) at least partially on the basis of the first injection mass and the second injection mass. [2] The method of claim 1, wherein determining the first injection mass and the second injection mass further comprises: Determining an initial number of pulses for a first set of pulses from the first fuel injector (36a); Determining a second pulse count for a second set of pulses from the second fuel injector (36b) and Determining the first injection mass and the second injection mass at least partially based on the first pulse count and the second pulse count. [3] The method of claim 2, wherein determining the first number of pulses and the second number of pulses further comprises: Determining the first pulse count at least partially based on a given initial first injector pulse count and Determining the second pulse count at least partially based on a given initial second injector pulse count. [4] The method of claim 2, wherein determining the first injection mass and the second injection mass further comprises: Determining a first set of pulse masses at least partially on the basis of the first number of pulses and the first injection mass, wherein each of the pulse masses of the first set corresponds to one of the pulses from the first set of the first fuel injector (36a); Determining a second set of pulse masses at least partially based on the second number of pulses and the second injection mass, wherein each of the second set of pulse masses corresponds to one of the second set of pulses of the second fuel injector (36b); Adjusting the first pulse count and / or the second pulse count at least partially based on the first set of pulse masses and the second set of pulse masses and Recalculating the first set of pulse masses and the second set of pulse masses in response to adjusting the first pulse count and / or the second pulse count. [5] The method of claim 4, wherein determining the first injection mass and the second injection mass further comprises: Adjusting the first injection mass and the second injection mass at least partially based on the first pulse count and the second pulse count in response to the adjustment of the first pulse count and / or the second pulse count. [6] The method of claim 4, wherein adjusting the first number of pulses and / or the second number of pulses further comprises: Compare each pulse mass of the first set with the first minimum mass per pulse; Compare each of the pulse masses from the second set with the second minimum mass per pulse and Adjusting the first pulse count and / or the second pulse count in response to a determination that each of the first set of pulse masses is less than or equal to the first minimum mass per pulse and that each of the second set of pulse masses is less than or equal to the second minimum mass per pulse. [7] The method of claim 6, wherein adjusting the first number of pulses and / or the second number of pulses further comprises: Decreasing the first pulse count by one in response to a finding that the first pulse count is greater than one and that each of the first set of pulse masses is less than or equal to the first minimum mass per pulse and that each of the second set of pulse masses is less than or equal to the second minimum mass per pulse. [8] The method of claim 6, wherein adjusting the first number of pulses and / or the second number of pulses further comprises: Decreasing the second pulse count by one in response to a determination that the first pulse count is not greater than one, that the second pulse count is greater than one, and that each of the first set of pulse masses is less than or equal to the first minimum mass per pulse, and that each of the second set of pulse masses is less than or equal to the second minimum mass per pulse. [9] The method of claim 6, wherein adjusting the first number of pulses and / or the second number of pulses further comprises: Deactivating the first fuel injector (36a) in response to a determination that the first pulse count is not greater than one, that the second pulse count is not greater than one, and that each of the first set of pulse masses is less than or equal to the first minimum mass per pulse, and that each of the second set of pulse masses is less than or equal to the second minimum mass per pulse. [10] Method according to claim 9, wherein deactivating the first fuel injector (36a) further comprises: Adjusting the first injection mass so that it is equal to zero; and Adjusting the second injection mass so that it equals the total fuel mass.

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