GB2497294A - Operation of a Fuel Injection System for an Internal Combustion Engine - Google Patents
Operation of a Fuel Injection System for an Internal Combustion Engine Download PDFInfo
- Publication number
- GB2497294A GB2497294A GB1120855.0A GB201120855A GB2497294A GB 2497294 A GB2497294 A GB 2497294A GB 201120855 A GB201120855 A GB 201120855A GB 2497294 A GB2497294 A GB 2497294A
- Authority
- GB
- United Kingdom
- Prior art keywords
- fuel
- value
- engine
- injection
- cylinder
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 239000000446 fuel Substances 0.000 title claims abstract description 155
- 238000002347 injection Methods 0.000 title claims abstract description 144
- 239000007924 injection Substances 0.000 title claims abstract description 144
- 238000002485 combustion reaction Methods 0.000 title claims abstract description 33
- 230000003213 activating effect Effects 0.000 claims abstract description 5
- 238000000034 method Methods 0.000 claims description 27
- 238000004590 computer program Methods 0.000 claims description 14
- 230000004913 activation Effects 0.000 claims description 4
- 239000013256 coordination polymer Substances 0.000 claims 3
- 239000007789 gas Substances 0.000 description 12
- 230000008901 benefit Effects 0.000 description 7
- 238000004891 communication Methods 0.000 description 5
- 230000000694 effects Effects 0.000 description 5
- 230000006870 function Effects 0.000 description 5
- RDYMFSUJUZBWLH-UHFFFAOYSA-N endosulfan Chemical compound C12COS(=O)OCC2C2(Cl)C(Cl)=C(Cl)C1(Cl)C2(Cl)Cl RDYMFSUJUZBWLH-UHFFFAOYSA-N 0.000 description 3
- 239000000203 mixture Substances 0.000 description 3
- 230000032683 aging Effects 0.000 description 2
- 230000003466 anti-cipated effect Effects 0.000 description 2
- 239000003054 catalyst Substances 0.000 description 2
- 239000002826 coolant Substances 0.000 description 2
- 230000001419 dependent effect Effects 0.000 description 2
- 239000012530 fluid Substances 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 239000004215 Carbon black (E152) Substances 0.000 description 1
- 238000004364 calculation method Methods 0.000 description 1
- 230000003197 catalytic effect Effects 0.000 description 1
- 238000010531 catalytic reduction reaction Methods 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 239000006185 dispersion Substances 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 229930195733 hydrocarbon Natural products 0.000 description 1
- 150000002430 hydrocarbons Chemical class 0.000 description 1
- -1 lean NO traps Substances 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 238000006722 reduction reaction Methods 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 239000000243 solution Substances 0.000 description 1
- 239000002699 waste material Substances 0.000 description 1
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02D—CONTROLLING COMBUSTION ENGINES
- F02D41/00—Electrical control of supply of combustible mixture or its constituents
- F02D41/008—Controlling each cylinder individually
- F02D41/0085—Balancing of cylinder outputs, e.g. speed, torque or air-fuel ratio
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02D—CONTROLLING COMBUSTION ENGINES
- F02D41/00—Electrical control of supply of combustible mixture or its constituents
- F02D41/02—Circuit arrangements for generating control signals
- F02D41/14—Introducing closed-loop corrections
- F02D41/1497—With detection of the mechanical response of the engine
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02D—CONTROLLING COMBUSTION ENGINES
- F02D41/00—Electrical control of supply of combustible mixture or its constituents
- F02D41/30—Controlling fuel injection
- F02D41/38—Controlling fuel injection of the high pressure type
- F02D41/40—Controlling fuel injection of the high pressure type with means for controlling injection timing or duration
- F02D41/401—Controlling injection timing
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02D—CONTROLLING COMBUSTION ENGINES
- F02D41/00—Electrical control of supply of combustible mixture or its constituents
- F02D41/30—Controlling fuel injection
- F02D41/38—Controlling fuel injection of the high pressure type
- F02D41/40—Controlling fuel injection of the high pressure type with means for controlling injection timing or duration
- F02D41/402—Multiple injections
- F02D41/405—Multiple injections with post injections
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02D—CONTROLLING COMBUSTION ENGINES
- F02D2200/00—Input parameters for engine control
- F02D2200/02—Input parameters for engine control the parameters being related to the engine
- F02D2200/10—Parameters related to the engine output, e.g. engine torque or engine speed
- F02D2200/1002—Output torque
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
- Y02T10/00—Road transport of goods or passengers
- Y02T10/10—Internal combustion engine [ICE] based vehicles
- Y02T10/40—Engine management systems
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Electrical Control Of Air Or Fuel Supplied To Internal-Combustion Engine (AREA)
Abstract
Operation of an internal combustion engine (110,fig.1) comprising determining a target value of a torque generated by a fuel injection (preferably an after-injection) in a cylinder, and using the target value to determine a nominal value of fuel that is used to determine a nominal value of an energizing time (ETnom) and a nominal value of a start of injection timing (S0Inom). Applying a correction factor to the nominal value of fuel to obtain a fuel quantity corrected value that is used to determine a corrected value of the energizing time (ETadj), subtracting the difference between the corrected value of the ETadj and the nominal value of the ETnom from the nominal value of the SOInom to obtain a start of injection timing corrected value (SOIadj), and activating the fuel injector for the ETadj and at the SOIadj detecting an actual value of the engine torque, and adjusting the correction factor for a subsequent engine cycle using the difference between the actual value of engine torque and the target value thereof.
Description
GM Global Technology Operations LLC November 2gth, 2011
METHOD FOR OPERATING AN INTERNAL COMBUSTION ENGINE
TECHNICAL FIELD
The present disclosure relates to a method for operating an internal combustion engine, in particular for correcting cylinder unbalancing.
BACKGROUND
Internal combustion engines are provided with cylinders, each one accommodating a piston coupled to rotate a crankshaft. A fuel and air mixture is injected into a combustion chamber of each cylinder and ignited, resulting in hot expanding exhaust gasses causing reciprocal movement of the piston, the fuel being injected by injectors which in turn receive fuel at high pressure from a fuel common rail that is in fluid communication with a high pressure fuel pump.
Internal combustion engine are also generally equipped with an Electronic Control Unit (ECU) that manages the various functions of the engine among which the determination of the energizing time of the injectors is comprised.
In a conventional internal combustion engine, the quantity of fuel actually injected into each cylinder and at each injection may be different from the nominal fuel quantity requested by the electronic control unit (ECU) as a function of a torque request.
There are several factors which contribute to this difference, particularly the dispersion of the injectors characteristics, due to the production process spread, and the time-drift variations of the same characteristics, due to aging of the injection system. In fact, the current injector production processes are not accurate enough to produce injectors with tight tolerances; moreover, these tolerances become worse with aging during the injector life-time. As a result, for a given energization time and a given rail pressure, the quantity of fuel actually injected may be different from one injector to another.
This difference in fuel injected quantity results in a torque unbalancing cylinder-by-cylinder, causing some problems such as differences in pressure peak, differences in heat release and dynamic effects on a crankshaft wheel used in association with a sensor or pick up to detect the crankshaft rotation.
The engine torque request calculation is translated into fuel quantity request by means of an efficiency map and in turn the total fuel quantity is partitioned into a series of torque forming pulses due to respective fuel injections for each engine cycle.
The total fuel quantity requested by torque chain is generally divided into different multiple injections commanded by the Electronic Control Unit (ECU) of the vehicle, such as pilot-injections. pre-injections, used for example for reasons such as reduction of combustion noise1 one or more main injections and after and post-injections that both occur after the Top Dead Center (TDC) of the piston and that may be used for after-treatment reasons.
Usually calibration values of the engine that specify the after-injection is generally set in such a way that the target of the after-injection, for different combustion modes, is partially to produce torque and partially to warm up the catalyst.
However1 the correct calibration of the percentage of torque forming after-injection fuel quantity is quite difficult.
A cylinder balancing function is needed to equalize the torque produced in all the cylinders. The cylinder balancing function is generally done by means of a crank wheel study and acting on the cylinder dependent injection paths, in order to balance the torque produced during combustion phase Known control systems for correcting cylinder unbalancing comprise the steps of detecting the unbalancing magnitude cylinder-by-cylinder and modifying the cylinder-by-cylinder fuel injected quantity by means of a closed loop control.
This method may be applied to the after-injections and when the after-injection is calibrated with a certain percentage of torque forming value, the differential fuel introduced in each cylinder is added after the nominal End of Injection and at a crank angle where this differential quantity of fuel may not have much effect.
However, if the torque produced by the after-injection is over-estimated there is the risk to have an after-injection with a fuel quantity greater than needed, increasing the fuel consumption and the exhaust temperature. If the torque produced by the after-injection is underestimated, the after-injection authority would be too high and the main-injection would be reduced, causing a negative torque step. In other words, the after-injection will be partially burned due to the main-injection combustion. This may cause the main-injection to misfire, also likely bring the after-injection to misfire.
An object of an embodiment of the invention is to improve the efficiency of cylinder unbalancing correction.
Another object of an embodiment of the invention is to provide a method for correcting the unbalancing of a cylinder without using complex devices and by taking advantage from the computational capabilities of the Electronic Control Unit (ECU) of the vehicle.
Another object of the present disclosure is to meet these goals by means of a simple, rational and inexpensive solution.
These objects are achieved by a method, by an engine! by an apparatus, by an automotive system, by a computer program and a computer program product, and by an electromagnetic signal having the features recited in the independent claims.
The dependent claims delineate preferred and/or especially advantageous aspects.
SUMMARY
An embodiment of the invention provides a method for operating an internal combustion engine, the engine including a block defining at least one cylinder, each cylinder having a piston disposed therein and coupled to rotate a crankshaft and wherein a fuel injector is disposed to inject fuel into the cylinder, the method comprising the steps of: -determining a target value of a parameter indicative of a torque to be generated by a fuel injection in the cylinder during an engine cycle, -using the target value of the parameter indicative of a torque value to determine a nominal value of fuel to be injected during the fuel injection, -using the nominal value of fuel to determine a nominal value of an energizing time and a nominal value of a start of injection timing, -applying a correction factor to the nominal value of fuel, in order to obtain a fuel quantity corrected value, -using the fuel quantity corrected value to determine a corrected value of the energizing time, -subtracting the difference between the corrected value of the energizing time and the nominal value of the energizing time from the nominal value of the start of injection timing, in order to obtain a start of injection timing corrected value, -activating the fuel injector for the corrected energizing time and at the start of injection timing corrected value, to perform the fuel injection, -detecting an actual value of the engine torque parameter due to the fuel injection, -using the difference between the actual valOe of engine torque parameter and the target value of the parameter indicative of engine torque to adjust the correction factor to be used during a subsequent engine cycle.
An advantage of this embodiment is that it adds the quantity of fuel needed to perform a correction of the unbalancing of a cylinder at a crank angle at which there is a greater effect on torque.
According to a further embodiment of the invention, a minimum start of injection timing is defined.
An advantage of this embodiment is that it allows to avoid that, in case of an excessive correction, an injection is started at an inappropriate crank angle.
According to a further embodiment of the invention, if the activation of the fuel injector requires a start of injection timing that precedes the minimum start of injection timing, the fuel injector is activated at the minimum start of injection timing for the corrected energizing time.
An advantage of this embodiment is that it allows to avoid that the correction quantity injected raise the exhaust gas temperature too much.
According to a further embodiment of the invention, wherein the fuel injection is an after-injection.
An advantage of this embodiment is that the after-injection has an initial portion that contributes to engine torque and a portion that does not contribute to engine torque, therefore introducing the fuel correction quantity at the start of injection has a greater effect on torque.
According to still another embodiment of the invention, the step of detecting an actual value of the engine torque parameter due to the fuel injection in a cylinder in a given engine cycle is performed by means of a crank position sensor suitable to send crank position signals to an Electronic Control Unit of the engine.
An advantage of this embodiment is that it takes advantage from a sensor and from an electronic control device generally always present on modern vehicles.
An embodiment of the invention provides an apparatus for correcting cylinder unbalancing in an internal combustion engine, the engine including a block defining at least one cylinder, each cylinder having a piston disposed therein and coupled to rotate a crankshaft and wherein a fuel injector is disposed to inject fuel into the cylinder, the apparatus comprising: -means for determining a target value of a parameter indicative of a torque to be generated by a fuel injection in the cylinder during an engine cycle, -means for using the target value of the parameter indicative of a torque value to determine a nominal value of fuel to be injected during the fuel injection, -means for using the nominal value of fuel to determine a nominal value of an energizing time and a nominal value of a start of injection timing, -means for applying a correction factor to the nominal value of fuel, in order to obtain a fuel quantity corrected value, -means for using the fuel quantity corrected value to determine a corrected value of the energizing time, -means for subtracting the difference between the corrected value of the energizing time and the nominal value of the energizing time from the nominal value of the start of injection timing, in order to obtain a start of injection timing corrected value, -means for activating the fuel injector for the corrected energizing time and at the start of injection timing corrected value, to perform the fuel injection, -means for detecting an actual value of the engine torque parameter due to the fuel injection, -means for using the difference between the actual value of engine torque parameter and the target value of the parameter indicative of engine torque to adjust the correction factor to be used during a subsequent engine cycle.
Another embodiment of the invention provides for an apparatus in which the means for activating the fuel injector comprise an Electronic Control Unit.
Another embodiment of the invention provides for an apparatus in which the means for detecting an actual value of the engine torque parameter due to the fuel injection in a cylinder in a given engine cycle comprise a crank position sensor suitable to send crank position signals to an Electronic Control Unit of the engine.
Another embodiment of the invention provides for an automotive system comprising an internal combustion engine, the engine including a block defining at least one cylinder, each cylinder having a piston disposed therein and coupled to rotate a crankshaft and wherein a fuel injector is disposed to inject fuel into each cylinder, the fuel injectors being electronically controlled by an Electronic Control Unit of the engine, the crankshaft being provided with a crank position sensor suitable to send crank position signals to the ECU, wherein the Electronic Control Unit is configured to: -determine a target value of a parameter indicative of a torque to be generated by a fuel injection in the cylinder during an engine cycle, -. use the target value of the parameter indicative of a torque value to determine a nominal value of fuel to be injected during the fuel injection, -use the nominal value of fuel to determine a nominal value of an energizing time and a nominal value of a start of injection timing, -apply a correction factor to the nominal value of fuel, in order to obtain a fuel quantity corrected value, -use the fuel quantity corrected value to determine a corrected value of the energizing time, -subtract the difference between the corrected value of the energizing time and the nominal value of the energizing time from the nominal value of the start of injection timing, in order to obtain a start of injection timing corrected value, -activate the fuel injector for the corrected energizing time and at the start of injection timing corrected value, to perform the fuel injection, -detect an actual value of the engine torque parameter due to the fuel injection, -use the difference between the actual value of engine torque parameter and the target value of the parameter indicative of engine torque to adjust the correction factor to be used during a subsequent engine cycle.
S The method according to one of its aspects can be carried out with the help of a computer program comprising a program-code for carrying out all the steps of the method described above, and in the form of computer program product comprising the computer program.
The computer program product can be embodied as a control apparatus for an internal combustion engine, comprising an Electronic Control Unit (ECU), a data carrier associated to the ECU, and the computer program stored in a data carrier, so that the control apparatus defines the embodiments described in the same way as the method. In this case, when the control apparatus executes the computer program all the steps of the method described above are carried out.
The method according to a further aspect can be also embodied as an electromagnetic signal, said signal being modulated to carry a sequence of data bits which represents a computer program to carry out all steps of the method.
A still further aspect of the disclosure provides an internal combustion engine specially arranged for carrying out the method claimed.
BRIEF DESCRIPTION OF THE DRAWINGS
The various embodiments will now be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 shows an automotive system; Figure 2 is a cross-section of an internal combustion engine belonging to the automotive system of figure 1; Figure 3 is a schematic illustration of a correcting strategy for cylinder unbaláncing according to an embodiment of the invention; and Figure 4 is a schematic illustration of an after-injection profile according to an embodiment of the invention;
DETAILED DESCRIPTION
Preferred embodiments will now be described with reference to the enclosed drawings, where like reference numbers indicate like components.
Some embodiments may include an automotive system 100, as shown in Figures 1 and 2, that includes an internal combustion engine (ICE) 110 having an engine block 120 defining at least one cylinder 125 having a piston 140 coupled to rotate a crankshaft 145.
A cylinder head 130 cooperates with the piston 140 to define a combustion chamber 150.
A fuel and air mixture (not shown) is disposed in the combustion chamber 150 and ignited, resulting in hot expanding exhaust gasses causing reciprocal movement of the piston 140.
The fuel is provided by at least one fuel injector 160 and the air through at least one intake S port 210. The fuel is provided at high pressure to the fuel injector 160 from a fuel rail 170 in fluid communication with a high pressure fuel pump 180 that increase the pressure of the fuel received a fuel source 190. Each of the cylinders 125 has at least two valves 215, actuated by a camshaft 135 rotating in time with the crankshaft 145. The valves 215 selectively allow air into the combustion chamber 150 from the pod 210 and alternately allow exhaust gases to exit through a port 220. In some examples, a cam phaser 155 may selectively vary the timing between the camshaft 135 and the crankshaft 145.
The air may be distributed to the air intake port(s) 210 through an intake manifold 200. An air intake duct 205 may provide air from the ambient environment to the intake manifold 200. In other embodiments1 a throttle body 330 may be provided to regulate the flow of air into the manifold 200. In still other embodiments, a forced air system such as a turbocharger 230, having a compressor 240 rotationally coupled to a turbine 250, may be provided. Rotation of the compressor 240 increases the pressure and temperature of the air in the duct 205 and manifold 200. An intercooler 260 disposed in the duct 205 may reduce the temperature of the air. The turbine 250 rotates by receiving exhaust gases from an exhaust manifold 225 that directs exhaust gases from the exhaust ports 220 and through a series of vanes prior to expansion through the turbine 250. The exhaust gases exit the turbine 250 and are directed into an exhaust system 270. This example shows a variable geometry turbine (VGT) with a VGT actuator 290 arranged to move the vanes to alter the flow of the exhaust gases through the turbine 250. In other embodiments, the turbocharger 230 may be fixed geometry and/or include a waste gate.
The exhaust system 270 may include an exhaust pipe 275 having one or more exhaust aftertreatment devices 280. The aftertreatment devices may be any device configured to change the composition of the exhaust gases. Some examples of aftertreatment devices 280 include, but are not limited to, catalytic converters (two and three way), oxidation catalysts, lean NO traps, hydrocarbon adsorbers, selective catalytic reduction (SCR) systems, and particulate filters. Other embodiments may include an exhaust gas recirculation (EGR) system 300 coupled between the exhaust manifold 225 and the intake manifold 200. The EGR system 300 may include an EGR cooler 310 to reduce the temperature of the exhaust gases in the EGR system 300. An EGR valve 320 regu)ates a flow of exhaust gases in the EGR system 300.
The automotive system 100 may further include an electronic control unit (ECU) 450 in communication with one or more sensors and/or devices associated with the ICE 110.
The ECU 450 may receive input signals from various sensors configured to generate the signals in proportion to various physical parameters associated with the ICE 110. The sensors include, but are not limited to, a mass airflow and temperature sensor 340, a S manifold pressure and temperature sensor 350, a combustion pressure sensor 360, coolant and oil temperature and level sensors 380, a fuel rail pressure sensor 400, a cam position sensor 410, a crank position sensor 420, exhaust pressure and temperature sensors 430, an EGR temperature sensor 440, and an accelerator pedal position sensor 445. Furthermore, the ECU 450 may generate output signals to various control devices that are arranged to control the operation of the ICE 110, including, but not limited to, the fuel injectors 160, the throttle body 330, the EGR Valve 320, the VGT actuator 290, and the cam phaser 155. Dashed lines are used to indicate communication between the ECU 450 and the various sensors and devices, but some are omitted for clarity.
Turning now to the ECU 450, this apparatus may include a digital central processing unit (CPU) in communication with a memory system, or data carrier 460, and an interface bus.
The CPU is configured to execute instructions stored as a program in the memory system, and send and receive signals to/from the interface bus. The memory system may include various storage types including optical storage, magnetic storage, solid state storage, and other non-volatile memory. The interface bus may be configured to send, receive, and modulate analog and/or digital signals to/from the various sensors and control devices.
The program may embody the methods disclosed herein, allowing the CPU to carryout out the steps of such methods and control the ICE 110.
More specifically, Figure 3 shows a schematic illustration of a correcting strategy for cylinder unbalancing according to an embodiment of the invention.
A first step of the method is to determine a target value CPnom of a parameter indicative of a torque to be generated by a fuel injection in the cylinder 125 during an engine cycle.
Then, a nominal value of fuel Q00,, to be injected during the fuel injection is determined (block 10) using the target value CPflQm of the engine torque parameter value.
The engine torque parameter due to the fuel injection in a cylinder 125 may be a crank position or a velocity signal detectable by means of the crank position sensor 420 that is electronically connected to the Electronic Control Unit 450 of the engine 110.
In particular, a map correlating target torque values with corresponding nominal values of fuel Qnom to be injected during the fuel injection can be calibrated and memorized in the Electronic Control Unit 450 of the engine 110, for example in the form of a look up table.
Then the determined fuel quantity nominal value Q,,, determined from the map is used to calculate a nominal value of an energizing time ETnom and a nominal value of a start of
S
injection timing SO/non,.
If a multi-injection pattern in a single engine cycle is employed, such as the one represented in figure 3 where schematically some pre-injections 20,30, a main injection 40 and an after-injection 90 is represented, the nominal value of an energizing time ETnom and a nominal value of a start of injection timing SO/nomfor each of these injection may be determined.
In particular, the nominal energizing time ETn0m and the nominal value of a start of injection timing SOi,, are determined for the after-injection 90.
After-injections are fuel injections performed by the injectors 160 to inject fuel into the cylinders 125 of the engine 110 and that are activated after the Top Dead Center (TDC) of the piston Furthermore, a correction factor Q is applied to the determined fuel quantity nominal value Qnom, in order to obtain a fuel quantity corrected value Qadj* The correction factor Q0-. may have been calculated during the previous engine cycle in a closed loop fashion.
Then the fuel quantity corrected value Q8dJ is used to determine a corrected value of the energizing time ET6dJ.
A difference between the energizing time corrected value ET8dJ and the energizing time nominal value ET0n, is then calculated.
This difference is then subtracted from the nominal value of the start of injection timing SO/non,, in order to obtain a start of injection timing corrected value S°'adj* This timing value SO/ad! is anticipated with respect to the nominal value of the start of injection timing SO/non, (fig.4).
At this point the fuel injector 160 is activated for the corrected energizing time FTOdJ and at the start of injection timing 501adj corrected value, to perform the fuel injection.
Preferably, the activation of the fuel injector 160 for the corrected energizing time ET3ç and at the start of injection timing SO/adi corrected value is performed by means of an after-injection.
In figure 4 a schematic illustration of an after-injection profile for after-injection 90 is represented, the after-injection 90 having an initial portion 91, a central portion 92 and an end portion 94.
In Figure 4, initial portion 91 of the after-injection 90 is represented in order to express the fact that the corrected start of injection value SOf8 is anticipated with respect to the nominal value of the start of injection timing SOI,,, (fig.4).
In order to perform the cylinder balancing at the successive engine cycle, an actual value CPact of the engine torque parameter due to this fuel injection is detected and the difference between the engine torque parameter actual value CP2,1 and the engine torque parameter target value CPnom is used to adjust the correction factor Q, to be used during a subsequent engine cycle.
As stated above, the procedure described may be advantageously applied to the engine using fuel after-injections because after-injections have an initial portion that contributes to engine torque and a portion that does not contribute to engine torque, therefore introducing the fuel correction quantity at the start of injection has a greater effect on torque.
According to an embodiment of the invention, a minimum start of injection timing SOl,, is defined.
This is useful when the activation of the fuel injector 160 would require a start of injection timing SO/SdJ that precedes the minimum start of injection timing SO/mm. In this case the fuel injector 160 is activated at the minimum start of injection timing SO/M/, for the corrected energizing time ETadJ.
In other words, if the fuel quantity correction value to be injected by the injector 160 would require an anticipation of the start of injection that exceeds the minimum start of injection timing SO!,7,,,, the correction of the nominal fuel quantity to be injected in the cylinder 125 is performed in part by delaying the end of injection of the injector 160. In this case the total fuel quantity injected may extend to comprise also end portion 94 of the after-injection.
This procedure may be followed to avoid that the fuel correction quantity injected raises the exhaust gas temperature too much.
An important reason of anticipating the start of injection (SOl) in case of correction of cylinder unbalancing is that the portion 91 of the after-injection closer to the Top Dead Center (TDC) has a greater combustion efficiency, while the combustion efficiency decreases over time as the crank angle gets further from the Top Dead Center (TDC) reaching a minimum with end portion 94.
While at least one exemplary embodiment has been presented in the foregoing summary and detailed description, it should be appreciated that a vast number of variations exist. It should also be appreciated that the exemplary embodiment or exemplary embodiments are only examples, and are not intended to limit the scope, applicability, or configuration in any way. Rather, the foregoing summary and detailed description will provide those skilled in the art with a convenient road rap for implementing at least one exemplary embodiment, it being understood that various changes may be made in the function and arrangement of elements described in an exemplary embodiment without departing from the scope as set forth in the appended claims and their legal equivalents,
REFERENCE NUMBERS
crankshaft signal processing 20,30 pm-injections 40 main injection differential fuel quantities after-injection 91 initial portion of after-injection 92 central portion of after-injection 94 end portion of after-injection automotive system internal combustion engine (ICE) engine block cylinder 130 cylinder head camshaft piston crankshaft combustion chamber 155 cam phaser fuel injector fuel rail fuel pump fuel source 200 intake manifold 205 air intake duct 210 intake air port 215 valves of the cylinder 220 exhaust gas port 225 exhaust manifold 230 turbocharger 240 compressor 250 turbine 260 intercooler 270 exhaust system 275 exhaust pipe :ii 280 exhaust aftertreatment device 290 VGT actuator 300 EGR system 310 EGR cooler 320 EGR valve 330 throttle body 340 mass airflow and temperature sensor 350 manifold pressure and temperature sensor 360 combustion pressure sensor 380 coolant and oil temperature and level sensors 400 fuel rail pressure sensor 410 cam position sensor 420 crank position sensor 430 exhaust pressure and temperature sensor 445 accelerator pedal position sensor 450 electronic control unit (ECU) 460 data carrier
Claims (1)
- <claim-text>CLAIMS1. A method for operating an internal combustion engine (110), the engine (110) including a block (120) defining at least one cylinder (125), each cylinder (125) having a piston (140) disposed therein and coupled to rotate a crankshaft (145) and wherein a fuel injector (160) is disposed to inject fuel into the cylinder (125), the method comprising the steps of: -determining a target value (CP0n,) of a parameter indicative of a torque to be generated by a fuel injection in the cylinder (125) during an engine cycle, -using the target value (CPq0n,) of the parameter indicative of a torque value to determine a nominal value of fuel (Q) to be injected during the fuel injection, -using the nominal value of fuel (Qm) to determine a nominal value of an energizing time (ETnom) and a nominal value of a start of injection timing (SO/non,), -applying a correction factor (QCOrr) to the nominal value of fuel (Qn,). in order to obtain a fuel quantity corrected value (Qadj), -using the fuel quantity corrected value (Q81) to determine a corrected value of the energizing time (ETBdJ), -subtractFrig the difference between the corrected value of the energizing time (ET2dJ) and the nominal value of the energizing time (ETn0m) from the nominal value of the start of injection timing (SO/), in order to obtain a start of injection timing corrected value (SO/ad]), -activating the fuel injector (160) for the corrected energizing time (ETad)) and at the start of injection timing (SO/ad]) corrected value, to perform th! fuel injection1 -detecting an actual value (CPact) of the engine torque parameter due to the fuel injection, -using the difference between the actual value of engine torque parameter (CP3) and the target value of the parameter indicative of engine torque (CPnom) to adjust the correction factor (Qco) to be used during a subsequent engine cycle.</claim-text> <claim-text>2. A method according to claim 1, wherein a minimum start of injection timing (SOl,,,,) is defined.</claim-text> <claim-text>3. A method according to claim 2, wherein if the activation of the fuel injector (160) requires a start of injection timing (SOIa) that precedes the minimum start of injection timing (SO/,,,,,), the fuel injector (160) is activated at the minimum start of injection timing (SO/mm) for the corrected energizing time (ETadj).</claim-text> <claim-text>4. A method according to claim 1, wherein the fuel injection is an after-injection.</claim-text> <claim-text>5. A method according to claim 1, in which the step of detecting an actual value (CPacr) of the engine torque parameter due to the fuel injection in a cylinder (125) in a given engine cycle is performed by means of a crank position sensor (420) suitable to send crank position signals to an Electronic Control Unit (450) of the engine (110).</claim-text> <claim-text>6. An apparatus for correcting cylinder unbalancing in an internal combustion engine (110), the engine (110) including a block (120) defining at least one cylinder (125), each cylinder (125) having a piston (140) disposed therein and coupled to rotate a crankshaft (145) and wherein a fuel injector (160) is disposed to inject fuel into the cylinder (125), the apparatus comprising: -means for determining a target value (CP00,,,) of a parameter indicative of a torque to be generated by a fuel injection in the cylinder (125) during an engine cycle, -means for using the target value (CPnom) of the parameter indicative of a torque value to determine a nominal value of fuel (Qnom) to be injected during the fuel injection, -means for using the nominal value of fuel (Qnom) to determine a nominal value of an energizing time (ETnom) and a nominal value of a start of injection timing (SOlnom), -means for applying a correction factor (Q0) to the nominal value of fuel (Qnom), in order to obtain a fuel quantity corrected value (Q), -means for using the fuel quantity corrected value (Qadj) to determine a corrected value of the energizing time (ET8d)), -means for subtracting the difference between the corrected value of the energizing time (ET8) and the nominal value of the energizing time (ET,,0,,) from the nominal value of the start of injection timing (SO/), in order to obtain a start of injection timing corrected value (501gw)' -means for activating the fuel injector (160) for the corrected energizing time (ETadi) and at the start of injection timing (SO/) corrected value, to perform the fuel injection, -means for detecting an actual value (CP8j of the engine torque parameter due to the fuel injection, -means for using the difference between the actual value of engine torque parameter (CPaci) and the target value of the parameter indicative of engine torque (CP,,0,,,) to adjust the correction factor (Q0,) to be used during a subsequent engine cycle 7. An apparatus according to claim 6, in which the means for activating the fuel injector (160) comprise an Electronic Control Unit (450) 8. An apparatus according to claim 6, in which the means for detecting an actual value (CP8) of the engine torque parameter due to the fuel injection in a cylinder (125) in a given engine cycle comprise a crank position sensor (420) suitable to send crank position signals to an Electronic Control Unit (450) of the engine (110).9. An automotive system comprising an internal combustion engine (110), the engine (110) including a block (120) defining at least one cylinder (1 25), each cylinder (125) having a piston (140) disposed therein and coupled to rotate a crankshaft (145) and wherein a fuel injector (160) is disposed to inject fuel into each cylinder (125), the fuel injectors (160) being electronically controlled by an Electronic Control Unit (450) of the engine (110), the crankshaft (145) being provided with a crank position sensor (420) suitable to send crank position signals to the ECU (450), wherein the Electronic Control Unit (450) is configured to: -determine a target value (CP,,0) of a parameter indicative of a torque to be generated by a fuel injection in the cylinder (125) during an engine cycle, -use the target value (CP,,om) of the parameter indicative of a torque value to determine a nominal value of fuel (Q,,om) to be injected during the fuel injection, -use the nominal value of fuel (Qnom) to determine a nominal value of an energizing time (El,,0,,,) and a nominal value of a start of injection timing -apply a correction factor (Q) to the nominal value of fuel (Qnom). in order to obtain a fuel quantity corrected value (Q), -use the fuel quantity corrected value (Q0) to determine a corrected value of the energizing time (Elaqj), -subtract the difference between the corrected value of the energizing time (ET8dJ) and the nominal value of the energizing time (ET00m) from the nominal value of the start of injection timing (SO/no,,,), in order to obtain a start of injection timing corrected value (SO/n), -activate the fuel injector (160) for the corrected energizing time (ET33) and at the start of injection timing (SO/aq) corrected value, to perform the fuel injection, -detect an actual value (CP1) of the engine torque parameter due to the fuel injection, -use the difference between the actual value of engine torque parameter (CP3) and the target value of the parameter indicative of engine torque (CPnom) to adjust the correction factor (Qr,,ff) to be used during a subsequent engine cycle.10. An internal combustion engine (110), in particular Diesel engine, the engine (110) including a block (120) defining at least one cylinder (125)! each cylinder (125) having a piston (140) disposed therein, each cylinder (125) being equipped with a fuel injector (160) electronically controlled by an Electronic Control Unit (450) of the engine (110), the piston (140) being coupled to rotate a crankshaft (145) provided with a crank position sensor (420) suitable to send crank position signals to the Electronic Control Unit (450) that is configured for carrying out the method according to any any of the claims 1-5.11. A computer program comprising a computer-code suitable for performin the method according to any of the claims 1-5.12. Computer program product on which the computer program according to claim 11 is stored.13. Control apparatus for an internal combustion engine, comprising an Electronic Control Unit (450), a data carrier (460) associated to the Electronic Control Unit (450) and a computer program according to claim 11 stored in the data carrier.14. An electromagnetic signal modulated as a carrier for a sequence of data bits representing the computer program according to claim 11.</claim-text>
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB1120855.0A GB2497294B (en) | 2011-12-05 | 2011-12-05 | Method for operating an internal combustion engine |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB1120855.0A GB2497294B (en) | 2011-12-05 | 2011-12-05 | Method for operating an internal combustion engine |
Publications (3)
| Publication Number | Publication Date |
|---|---|
| GB201120855D0 GB201120855D0 (en) | 2012-01-18 |
| GB2497294A true GB2497294A (en) | 2013-06-12 |
| GB2497294B GB2497294B (en) | 2018-01-10 |
Family
ID=45541200
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB1120855.0A Expired - Fee Related GB2497294B (en) | 2011-12-05 | 2011-12-05 | Method for operating an internal combustion engine |
Country Status (1)
| Country | Link |
|---|---|
| GB (1) | GB2497294B (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111828191A (en) * | 2020-03-24 | 2020-10-27 | 同济大学 | Air-fuel ratio control system and method of hybrid power engine |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2002303188A (en) * | 2001-03-30 | 2002-10-18 | Mazda Motor Corp | Fuel injection method for diesel engine |
| US20020194837A1 (en) * | 2001-06-26 | 2002-12-26 | Caterpillar Inc. | Post injections during cold operation |
| US20030145581A1 (en) * | 2001-02-20 | 2003-08-07 | Yoshihisa Tashiro | Fuel injection control method for diesel engine and regenerative control method for exhaust gas after treatment device |
| US20040050360A1 (en) * | 2000-12-27 | 2004-03-18 | Werner Happenhofer | Method for controlling an internal combustion engine |
-
2011
- 2011-12-05 GB GB1120855.0A patent/GB2497294B/en not_active Expired - Fee Related
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20040050360A1 (en) * | 2000-12-27 | 2004-03-18 | Werner Happenhofer | Method for controlling an internal combustion engine |
| US20030145581A1 (en) * | 2001-02-20 | 2003-08-07 | Yoshihisa Tashiro | Fuel injection control method for diesel engine and regenerative control method for exhaust gas after treatment device |
| JP2002303188A (en) * | 2001-03-30 | 2002-10-18 | Mazda Motor Corp | Fuel injection method for diesel engine |
| US20020194837A1 (en) * | 2001-06-26 | 2002-12-26 | Caterpillar Inc. | Post injections during cold operation |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111828191A (en) * | 2020-03-24 | 2020-10-27 | 同济大学 | Air-fuel ratio control system and method of hybrid power engine |
| CN111828191B (en) * | 2020-03-24 | 2021-10-08 | 同济大学 | Air-fuel ratio control system and method of hybrid power engine |
Also Published As
| Publication number | Publication date |
|---|---|
| GB2497294B (en) | 2018-01-10 |
| GB201120855D0 (en) | 2012-01-18 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US9441525B2 (en) | Method and apparatus to control regeneration of a particulate filter | |
| CN104847516B (en) | The method for operating internal combustion engine | |
| US7895827B2 (en) | Method and apparatus for controlling engine operation during regeneration of an exhaust aftertreatment system | |
| US8463531B2 (en) | System and method for controlling exhaust gas recirculation systems | |
| US8280610B2 (en) | Control systems and methods for fuel and secondary air injection | |
| WO2012153418A1 (en) | Internal combustion engine control apparatus | |
| US20130003778A1 (en) | Method for evaluating an exhaust gas temperature in a exhaust pipe of an internal combustion engine | |
| US10138791B2 (en) | Method of cleaning up a particulate filter of an internal combustion engine | |
| US8316821B2 (en) | Method and system for enabling cylinder balancing at low idle speed using crankshaft speed sensor | |
| US8360030B2 (en) | Idle speed reduction systems and methods | |
| US8402748B2 (en) | Diesel fuel alternative detection and correction systems and methods | |
| US8868319B2 (en) | System and method for controlling intake valve timing in homogeneous charge compression ignition engines | |
| JP5146619B2 (en) | Control device for internal combustion engine | |
| GB2498783A (en) | A method of operating an internal combustion engine to provide correction of fuel injection times and indication of injector failure | |
| RU2704909C2 (en) | System and method for adjusting exhaust valve timing | |
| GB2498355A (en) | Controlling multiple fuel injections in an i.c. engine | |
| US20120296555A1 (en) | Method for operating an internal combustion engine | |
| GB2560758A (en) | A method of thermal protecting a particulate filter of an internal combustion engine | |
| US20110167803A1 (en) | System and method for controlling exhaust gas temperature during particulate matter filter regeneration | |
| US20120303240A1 (en) | Method for operating an internal combustion engine | |
| GB2497294A (en) | Operation of a Fuel Injection System for an Internal Combustion Engine | |
| GB2500890A (en) | Method of compensating an injection timing drift in a fuel injection system | |
| GB2491110A (en) | Method of operating an internal combustion engine having crankshaft position sensor correction means | |
| US8229651B2 (en) | Fuel correction systems and methods | |
| GB2500207A (en) | Fuel injection method comprising correction factors for fuel rail pressure and fuel temperature |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PCNP | Patent ceased through non-payment of renewal fee |
Effective date: 20180410 |