Vehicle control method, engine control method (versions)

<b>TECHNICAL FIELD OF THE INVENTION</b>

The present invention relates generally to methods and systems for the protection of motor vehicle from the early ignition components overheat.

<b>BACKGROUND</b>

In certain operating conditions, the engines that have a high degree of compression or force to increase the specific power output, can be prone to combustion phenomena with early ignition at low engine speeds. Premature combustion due to early ignition, can cause high pressure inside the cylinder and may lead to combustion pressure wave such detonation during combustion, but with greater intensity.

<b>SUMMARY OF THE iNVENTION</b>

The authors recognized that in certain operating conditions, the steps taken to suppress misfire in a cylinder may also lead to an increased probability of pre-ignition. More specifically, in response to the event of misfire in the cylinder, the engine controller may overlap with the fuel in the cylinder misfire, to prevent the exhaust gas catalytic converter from overheating. Additionally, the remaining cylinders can be actuated leaner than stoichiometry to reduce the amount of unburned fuel. However, lean operation cylinder may increase predisposition early ignition of the engine, especially at higher engine speed, and accelerate the deterioration of engine performance.

The above problem at least in part, may be entrusting a method for controlling a vehicle, comprising, during driving of the vehicle engine, the actuating cylinder for pumping air without fuel injection, while the other cylinder burns a lean fuel mixture, and air restriction into the cylinders, so that it was smaller than the threshold value. Thus, by limiting the engine load when some cylinders undergo fuel overlap, and the other cylinders are operating on a lean mixture, the propensity for early call ignition engine can be reduced.

In one example, in response to the event of misfire in the first cylinder of the engine, fuel injection from in-cylinder misfire can be overlapped, along with the fact that air continues to be pumped therethrough. Other cylinders, in this case, can be operated with the air-fuel ratio, which is poorer than stoichiometry to reduce the amount of unburned fuel remaining in the cylinders. In this case, to reduce the likelihood of early ignition in a cylinder, which may be caused by depleted operating conditions, particularly at mid to high engine speed, engine load may be restricted. Load limit may be based on the lean fuel-air ratio of poverty and the number of cylinders running on a lean mixture (or the number of cylinders operating with fuel overlap). Load limit can also be based on the history of early ignition of the engine (the engine characteristic indicating predisposition to early ignition), and engine speed. Essentially, the magnitude and duration of the load limiting can be adjusted to give a temperature regulated exhaust possibility and probability of pre-ignition possibility to decrease. After a certain amount of time has elapsed, the load limit can be gradually reduced to zero.

Thus, by limiting the load of the engine during conditions when multiple cylinders are operating on a lean mixture, and subjected to other fuel cylinders overlap, overheating of the catalytic converter of exhaust gas components and associated performance deterioration can be reduced. in the cylinder by reducing engine temperatures, predisposition to early ignition event may also decrease. By limiting the engine load while suppressing misfire probability events early ignition misfire induced suppression may also decrease. In general, it can decrease the deterioration of engine performance.

Thus, in one aspect there is provided a method of controlling a vehicle, comprising, during driving of the vehicle engine, the actuating cylinder for pumping air without fuel injection, while the other cylinder burns a lean mixture of fuel and air restriction cylinders that it was smaller than the threshold value.

The restriction is preferably based on the degree of poverty lean air-fuel mixture, the limit increases with the degree of poverty.

The restriction is preferably based on the engine speed, and the limit is increased when the engine speed is higher than the threshold speed.

The restriction is preferably based on the temperature of exhaust gas at the restriction increases as the exhaust gas temperature above the threshold temperature.

Restricting air preferably includes one or more of the intake throttle opening decrease, increasing the opening wastegate turbocharger, the adjustment of the phase distribution cylinder valve to reduce the inlet air charge, increasing the amount of exhaust gas recirculation.

The engine is preferably a supercharged engine attached to the turbocharger, while the threshold value based on the temperature at the turbine inlet.

Actuation preferably occurs in response to the event of misfire in the cylinder.

Limitation preferably terminated after the expiry of the duration threshold.

The restriction is preferably performed before the occurrence of pre-ignition events in the engine.

The threshold value is preferably a first threshold value, and the method further comprises, in response to an early event in the engine ignition, the additional air into the cylinders limitation as to be smaller than the second threshold value, lower than the first threshold.

An additional constraint is preferably terminated after the event or the ignition is switched off the ignition.

According to another aspect, a method for controlling an engine, comprising, in response to the event of misfire, the overlap of fuel into the first cylinder, the actuation of the second cylinder with the air-fuel ratio, the poorer than stoichiometry, and the restriction of the engine load.

Limitation is preferably based on the degree of poverty lean fuel-air ratio.

Limitation preferably further based on the early history of the engine ignition, when the restriction increases with the number of early ignition of the engine.

Limitation preferably terminated after the expiry of the duration threshold.

According to another aspect, a method of engine control, including operation of the engine in the first mode with all cylinders performing combustion and a first limit of the load, and engine operation in the second mode with a first number of cylinders, pumping air without fuel injection, with the second number of cylinders works with the air-fuel ratio, the poorer than stoichiometry, and the second load limit, wherein the first and second load limits based on at least engine speed.

During the first mode, all the cylinders is preferably carried out combustion at stoichiometry, and the method further includes the engine operation in the third mode all cylinders performing combustion, and at least one cylinder operating with the air-fuel ratio richer than stoichiometry, and the third limit load, and based on at least the engine speed.

The second load limit is preferably more restrictive than the first limit of the load at higher engine speed, the third load limit is more restrictive than the second load limit at lower engine speed.

During the third mode of the third load limit is preferably re-established in response to the switching cycle / engine shutdown, and during the first mode of operation, the first load limit is reset after a first threshold duration, wherein during the second mode of operation of the second load limit is reset by after the second threshold duration.

The first duration threshold is preferably based on the number of engine ignitions earlier, and the duration of the second threshold based on the number of engine ignitions early and exhaust gas temperature.

It should be understood that the disclosure given above, provided with reference to the simplified form of lists of concepts that are further described in the detailed description. It is not intended to identify key or essential features of the claimed subject matter, the scope of which is defined uniquely by the claims that accompany the detailed description. Furthermore, the claimed subject matter is not limited to implementations that solve any disadvantages noted above or in any part of this disclosure.

<b>BRIEF DESCRIPTION OF DRAWINGS</b>

FIG. 1 is an exemplary combustor.

FIG. 2 is a high-level block diagram of a method for setting the cylinder to ensure fuel and engine load limit during selected engine operating conditions.

FIG. 3 is a schematic view of the load limiting procedure.

FIG. 4 is a high-level block diagram of a method for selecting the limit load to be applied during selected engine operating conditions according to FIG. 2.

FIG. 5 is an exemplary configuration of load limitations.

<b>DETAILED DESCRIPTION OF THE INVENTION</b>

The methods and systems for taking measures on the pre-ignition events in the cylinder, and the anomalous combustion event (for example, a misfire), which can act as a precursor of early ignition events in the cylinder. In particular, the restriction of the engine load such as the engine system of FIG. 1, may be performed in response to an existing or imminent early ignition. The motor controller may be configured to perform a control procedure such as the exemplary procedure of FIG. 2-4, to adjust the fuel injection into the cylinder (Fig. 2), and the engine load in response to an anomalous combustion event such as the event of misfire in the cylinder and / or pre-ignition events in the cylinder. limiting the load can be controlled (FIGS. 3-4), in order to reduce the likelihood of (further) pre-ignition events in the cylinder. load limiting exemplary configuration described herein with reference to FIG. 5. By limiting the engine load while suppressing the misfire probability of the event early ignition caused by the suppression of a misfire can be reduced.

FIG. 1 depicts an exemplary embodiment of the combustion chamber or cylinder 10 of the engine combustion. The engine 10 may receive the control parameters of a control system including a controller 12, and the input data 130 from the driver of the vehicle through the input device 132. In this example, the input device 132 includes an accelerator pedal and a pedal position sensor 134 for generating a pedal position PP proportional signal. Cylinder 14 (herein also "combustion chamber") of the engine 10 may include a wall 136 of the combustion chamber with the piston 138 disposed therein. Piston 138 may be attached to the crankshaft 140 so that reciprocation of the piston was converted into rotary motion of the crankshaft. Crankshaft 140 may be connected to at least one drive wheel of the passenger vehicle through the transmission system. Furthermore, the starter electric motor may be attached to the crankshaft 140 through the flywheel to allow the motor 10 to start the operation.

Cylinder 14 may receive intake air through a series of air inlet pipes 142, 144 and 146. The air inlet pipe 146 can communicate with other motor cylinder 10 in addition to the cylinder 14. In some embodiments, one or more inlets may include supercharging device such as a turbocharger or supercharger. For example, FIG. 1 shows an engine 10 configured turbocharger comprising a compressor 174 that is configured between the inlet pipes 142 and 144, and an exhaust turbine 176, arranged along the outlet 148. The compressor 174 may be at least partially actuated exhaust turbine 176 via the shaft 180, where supercharging device is configured as a turbocharger. However, in other instances, such as where the engine 10 is provided with a turbocharger, a turbocharger exhaust turbine 176 optionally may be omitted, where the compressor may be driven by mechanical power input motor or engine. Throttle 20, which includes a throttle valve 164 may be installed along the intake pipe of the engine to change the flow rate and / or pressure of intake air supplied to the engine cylinders. For example, a choke 20 may be located downstream of the compressor 174, as shown in FIG. 1, or, alternatively, it may be provided upstream of compressor 174.

Exhaust pipe 148 may receive the exhaust gases from the other cylinders of the engine 10 in addition to the cylinder 14. The exhaust gas sensor 128 is shown attached to the outlet 148 upstream of the device 178 emission control. Sensor 128 may be selected from a variety of suitable sensors for dispensing readings air / fuel ratio in the exhaust gases, such as a linear oxygen probe or UEGO (universal or wide-range oxygen quantity sensor in the exhaust gas), a dual-mode oxygen sensor or EGO sensor (which shows), HEGO (heated EGO), NO_x, HC, and CO. The device 178 emission control can be a three-way catalytic converter (TWC), catcher NO_xAnd various other devices reduce exhaust gases toxicity or combinations thereof.

The temperature of the exhaust gases can be assessed by one or more temperature sensors (not shown) located at the outlet port 48. Alternatively, the exhaust gas temperature can be derived based on the engine operating conditions such as speed, load ratio of the air-fuel ratio ( AFR), the spark delay, etc. Furthermore, the exhaust gas temperature can be calculated by one or more sensors 128 exhaust gases. It may be appreciated that the exhaust gas temperature, alternatively, can be measured by any combination of temperature estimation methods listed in herein.

Each cylinder of the engine 10 may include one or more inlet valves and one or more outlet valves. For example, the cylinder 14 is shown comprising at least one intake poppet valve 150, and at least one exhaust poppet valve 156 located in the upper region of the cylinder 14. In some embodiments, each cylinder of the engine 10, including the cylinder 14, may include at least two intake poppet valve and at least two exhaust poppet valves located in the upper region of the cylinder.

Inlet valve 150 may be controlled by controller 12 by driving the cam 151 via the cam drive system. Similarly, the exhaust valve 156 can be controlled by the system controller 12 through the drive cam 153. Each of the systems 151 and 153 of the cam actuator may include one or more cams and may use one or more of the switching systems cam profile (CPS), adjustable cam timing (VCT), adjustable valve timing (VVT) and / or controlled valve lift (VVL), which can be controlled by the controller 12 to change the operation of the valves. Intake valve 150 and exhaust valve 156 may be determined by sensors 155 and 157 of valve position, respectively. In alternative embodiments, the inlet and / or outlet valve can be controlled by the distributor valve with electromagnetic control. For example, cylinder 14, alternatively, may include an inlet valve controlled by an electromagnetic valve actuator and an outlet valve controlled by a cam drive comprising a CPS system and / or VCT. In still other further embodiments, the inlet and outlet valves can be controlled by the spool or valve drive system or drive system or valve with variable valve timing phases.

The cylinder 14 may have a compression ratio which is a ratio of volumes when piston 138 is at bottom dead center, to when the top dead center. Typically, the compression ratio is in the range from 9: 1 to 10: 1. However, in some instances, where other fuel is used, the compression ratio can be increased. For example, this can occur when using a high-octane fuel or fuel with a high latent enthalpy of vaporization. The compression ratio may also be improved if direct injection is used, because of its effect on engine operation with knocking.

In some embodiments, each cylinder of the engine 10 may include a spark plug 192 to initiate the combustion. System 190 can output ignition spark in the combustion chamber 14 via spark plug 192 in response to spark advance signal SA from controller 12, under the chosen operating conditions. However, in some embodiments, the spark plug 192 can be omitted, such as where the engine 10 can initiate self-ignition combustion or the fuel injection as it may occur in some diesel engines. In some other circumstances, the characteristics deterioration spark plugs 162 may cause misfire in the combustion chamber 14. Essentially, if left unattended, the characteristics deterioration subjected spark plug can also lead to an increased occurrence of pre-ignition events in the cylinder. Degradation of the spark plug, for example, may include a degradation in performance spark plug wire (eg, broken wire, short-circuited wire), derating of the electrode (eg, worn electrode), contamination or corruption of the spark plug, etc.

In one example, in response to the threshold amount and / or frequency of pre-ignition events in the cylinder after the event in a misfire during selected engine operating conditions, the motor controller can be concluded that the spark plug is subjected to degradation, and restrict combustion in located under the influence of the cylinder at high engine loads. The controller may also limit the engine load.

In some embodiments, each cylinder of the engine 10 can be configured with one or more fuel nozzles for supplying fuel to it. As a non-limiting example, the cylinder 14 is shown comprising a fuel injector 166. Fuel injector 166 is shown attached directly to the cylinder 14 for injecting fuel directly therein in proportion to pulse width of signal FPW received from controller 12 via electronic driver 168. Thus, fuel injector 166 provides what is known as direct injection (hereinafter also referred to as «DI») of fuel in the combustion cylinder 14. Despite the fact that Fig. 1 shows a nozzle 166 as a side injector, it may also be located above the piston, such as near the position of spark plug 192. This situation may improve mixing and combustion when the engine is working with an alcohol fuel due to the low volatility of some alcohol-containing fuel. Alternatively, the nozzle may be positioned above and near the intake valve to improve mixing. Fuel can be supplied to the fuel injector 166 of the fuel supply system 8, a high pressure, comprising a fuel tank, fuel pumps, and a guide-way valve for fuel. Alternatively, fuel can be delivered to single-stage fuel pump at lower pressure, in which case, timing direct fuel injection may be restricted to a greater degree during the compression stroke than if a high pressure fuel system. Furthermore, although not shown, fuel tanks may have a pressure transducer issuing a signal to the controller 12. It will be appreciated that in an alternative embodiment, nozzle 166 may be a nozzle channel issuing fuel into the intake passage upstream flow from the cylinder 14.

Furthermore, it should be understood that, despite the fact that the illustrated embodiment illustrates a motor driven by a single injection through the fuel injection nozzle directly; in alternative embodiments, the engine can be operated through the use of two nozzles (for example, direct injection injector and the injector into the intake port) and adjusting the relative volume of each injection nozzle.

The fuel injector may be supplied to the cylinder during a cylinder cycle. Moreover, the distribution and / or the relative volume of fuel supplied from the nozzle may vary depending on operating conditions. Furthermore, for a single combustion event, multiple injection of fuel delivered per cycle can be performed. Multiple injections may be performed during the compression stroke, the intake stroke or any combination thereof. Fuel may be injected during the cycle to adjust the ratio of air quantity to the quantity of fuel injected (AFR) combustion. For example, fuel can be injected to provide a stoichiometric AFR. AFR sensor may be incorporated into the dispensing cylinder AFR estimation. In one example, AFR sensor may be a sensor exhaust gas composition, such as the sensor 128 by measuring the amount of residual oxygen (poor mixtures) and unburned hydrocarbons (rich mixtures) in the exhaust gases, the sensor can determine the AFR. Essentially, AFR may be issued as a value of lambda (λ), that is, as a ratio to stoichiometric AFR applicable to this mixture. Thus lambda 1.0 indicates stoichiometric mixture richer than the stoichiometric mixture may have a lambda value of less than 1.0, and poorer than the stoichiometric mixture may have a lambda greater than 1.

As described above, FIG. 1 shows only one cylinder of a multi-cylinder engine. Essentially, each cylinder likewise can include its own set of intake / exhaust valves, fuel injector (s), spark plugs, etc.

Fuel tanks in the fuel system can store 8 fuel with different fuel qualities, such as different fuel compositions. These differences may include various alcohol content, different octane different heat of vaporization, different fuel mixtures and / or combinations thereof, etc.

Engine 10 may further include one or more knock sensors (not shown) for reading and anomalous combustion event of anomalous combustion event differences caused detonation from those indicative of pre-ignition. For example, the input signal from the knock sensor in the cylinder and / or the crankshaft acceleration sensor may be used to indicate an anomalous combustion event in the cylinder. The knock sensor may be a sensor for vibrations of the engine block or ionization sensor configured spark plug in each cylinder. On the basis of the knock sensor signal characteristics, such as timing, amplitude, intensity, frequency, etc. signal, and / or on the basis of the acceleration of the crankshaft sensor signal, the controller can identify early ignition. For example, the pre-ignition event in the cylinder can be determined based on the knock signal in a cylinder, measured in the first, earlier window being larger than the first upper threshold value, along with the fact that the detonation event in the cylinder can be determined based on the knock signal cylinder, measured in a second later the window is greater than the second, lower threshold. Windows, in which the signals are estimated knocking can be windows crank angle. Additionally, pre-ignition detonation may vary based on the engine operating conditions during detection of abnormal combustion. For example, the abnormal combustion detected at higher engine speeds and loads, can be attributed to knocking in addition to the fact that it is in the lower engine speeds and loads may be indicative of early ignition. In fact, the actions of suppression taken to take action in response to the detonation may differ from those taken by the controller to take action in response to the pre-ignition. For example, the detonation can be subjected as to respond using the ignition delay and the EGR along with the fact that pre-ignition may be subjected as to respond by enrichment or depletion of a cylinder and a limit value of the engine load.

The controller 12 shown in FIG. 1 as a microcomputer including a microprocessor unit 106, the ports 108 of I / O, an electronic storage medium for executable programs and calibration values, shown as circuit 110 only memory in this particular example, random access memory 112, nonvolatile memory 114, and data bus. Controller 12 may receive signals from various sensors attached to the engine 10, in addition to those signals as discussed previously, including the measurement of mass flow of air introduced (MAF) sensor 122 from the mass air flow; The engine coolant temperature (ECT) sensor temperature 116 attached to the nozzle 118 of cooling; a profile ignition readout signal (PIP) of the Hall sensor 120 (or other type) connected to the crankshaft 140; throttle position (TP) from throttle position sensor; absolute manifold pressure signal (MAP) sensor 124, AFR in the cylinder 128 with EGO sensor and abnormal combustion from detonation sensor and the acceleration sensor of the crankshaft. engine speed signal, RPM, controller 12 may be formed from the PIP signal. manifold pressure signal, MAP, a manifold pressure sensor can be used to provide an indication of pressure or vacuum in the intake manifold.

A ROM storage medium 110 may be programmed with machine-readable data representing the command executed by the processor 106 to perform the methods described below, as well as options that are anticipated, but not specifically listed.

As configured, the components of the engine system of FIG. 1 enable control method of a vehicle, comprising, during actuation of the vehicle by a motor, the actuation of the cylinder for pumping air without fuel injection, while the other cylinder burns a lean mixture of fuel and air restriction into the cylinders to was less than the threshold value. Thus, by limiting the engine load during selected conditions, for example, in response to the event of misfire in the cylinder, operating and / or imminent pre-ignition can be suppressed, and it can be protected from degradation.

Next, with reference to FIG. 2 discloses an exemplary procedure 200 for setting the engine operating conditions (in particular, fuel injection and engine load) in response to the event of abnormal combustion such as misfire in the cylinder to reduce the frequency of occurrence of combustion events with inevitable early ignition.

At 202, may be determined by the engine operating conditions. Such, for example, may include engine speed, torque demand, engine load, engine temperature, exhaust gas temperature, catalyst temperature, the air pressure in the reservoir, the air temperature in the reservoir, the background early ignition of the engine (including score early ignitions of the engine and / or cylinder), the turbine inlet temperature (where the engine includes a turbocharger), etc.

At 204, it may be determined whether the detected event in a misfire in the engine cylinder. In one example, the event of misfire in the cylinder is determined based on the acceleration of the crankshaft. In another example, a misfire in the cylinder based on an air-fuel ratio in the exhaust gas, for example, based on the input signal the amount of oxygen in the exhaust gas sensor (e.g., UEGO sensor). In yet another example, the misfiring cylinder based on the ionization of the spark plug (e.g., ionization current) which is determined by the ionization sensor attached to the spark plug.

If the event of misfire in the cylinder is not determined, the process can move to 205 to determine whether the detected event is pre-ignition in the cylinder. As previously concretized, early ignition event in the cylinder can be identified, and differ from the detonation in the cylinder on the basis of the knock sensor output signal. For example, in response to the knock signal output from the knock sensor, which is larger than the upper threshold value in the earlier crank angle, pre-ignition can be detected.

If the pre-ignition is detected, then, at 206, the motor controller can drive the motor in the first mode (as particularized 208) all cylinders engaged in the combustion. More precisely, all the cylinders can be engaged in incineration stoichiometry. Optionally, the engine may also be operated with a load limit value, for example, the first limit load applied to the engine. In particular, the first load limit may be used, if necessary, in anticipation of pre-ignition events (ie, before there is any real whatsoever early ignition event). As concretized in FIG. 3-4, the first load limit can be selected based on engine operating conditions such as engine speed, engine through early ignitions, the charge collector temperature, implied octane fuel, fuel air ratio, etc. For example, if the engine (or a particular cylinder) has an account early ignitions, which is higher than the threshold score, the motor may be predisposed to early ignition events in the cylinder, especially at the selected engine operating conditions (e.g., low speed conditions). Therefore, to reduce the probability of an event early ignition, increasing restriction of the engine load can be applied. Load limit, in particular, can be applied at the time of low engine speeds, when more than likely early ignition. In comparison, if the engine ignition through early is lower than the threshold score, the early ignition of the engine can not be expected, and may not apply any load restrictions.

As used herein, the restriction of the engine load may include one or more of the intake throttle opening decrease, increasing the opening wastegate turbocharger, setting the installation phase distribution cylinder valve to reduce the inlet air charge, increasing the amount of exhaust gas recirculation. For example, the value of the intake air charge, directed into the engine may be reduced by a first amount, for example, as long as the engine load is reduced below the first threshold.

Essentially, the load limit may be kept as long as not expired (first) threshold duration or distance. For example, waiting for the low frequency early ignition, the load limit can be filtered with the distance over which the vehicle is conducted. In comparison, a particularized herein, in response to a high incidence of early ignition limit load can be performed, which loop is exited with the ignition key. For example, a timer may be started when the limit load is driven at 206. Then, at 210, it may be determined whether the threshold duration has expired. If not, it may continue to apply a first load limit. In comparison, at 214, during the first mode of operation, the load limit can be reset (i.e., load limitation is discontinued) at the expiration of the duration threshold. The threshold duration, for example, may be based on the number of engine ignitions early or early ignitions amount divided by the number of miles traveled.

Returning to 204, if the event of misfire is confirmed, the procedure can be extended to 216, wherein the engine controller may control the motor in a second mode (as particularized 218) with a first number of cylinders, pumping air without fuel injection, the second number of cylinders, working on the air-fuel ratio, poorer than the stoichiometry, and with the magnitude of load limiting, for example, with a second limit of the load applied to the engine. On the basis of the engine operating conditions, the second load limit may be more restrictive than the first limit load. Specifically, the second load limit can be used to reduce the likelihood of pre-ignition events caused by suppressive misfiring cylinder configuration.

In particular, during the second mode, the controller may override the ignition fuel-permeable cylinder (s) to suppress misfire and reduce the likelihood of further developments of misfire in the cylinder. However, the controller can continue to pump air through the permeable ignition cylinder (s) for overriding the fuel. To compensate for the overlap of the fuel in the cylinder misfires (s), the other cylinders of the engine can be operated with a fuel mixture which is leaner than stoichiometry. For example, the controller may apply without feedback regulation to control the engine air-fuel ratio which is leaner than stoichiometry. The controller may apply without feedback regulation in the absence of feedback control in order to better ensure that excess fuel does not remain in the exhaust gas catalytic converter. In essence, if the other cylinders of the engine operated on a lean mixture than stoichiometry, pre-ignition in the cylinder can not be caused, but may be formed exotherm in the exhaust gas due to the fresh air reaction pumped from output from engine operation (i.e., transmissive cylinder ignition with fuel overlapped) with excess fuel remaining in the catalyst. Exotherm can cause overheating and deterioration of the characteristics of the catalytic converter.

In comparison, scrolling through the remaining cylinders of the engine can be kept colder exhaust temperatures, and may decrease the performance degradation of the catalyst. However, the operation of the engine at a lean mixture used to suppress misfire event itself can cause pre-ignition in the cylinder, in particular at high engine speed. Thus, to reduce the likelihood of early ignition, which occurs in response to overwhelming misfiring engine at lean mixture, the engine load may be limited or even earlier detection of early occurrence of engine ignition event.

As stated previously, the limitation of the engine load may include one or more of the intake throttle opening decrease, increasing the opening wastegate turbocharger, setting the installation phase distribution valve cylinder to reduce the intake air charge and increasing the amount of exhaust gas recirculation. Thus, during the second mode of operation, the value of the intake air charge, directed into the engine may be decreased by a second amount (which may be greater or lesser than the first value of the first limit load applied during the first mode of operation). For example, the value of the second load limit can reduce the load limit of the motor below the second threshold value, which is lower than the first threshold. In one example, where the engine is a supercharged engine, the second threshold may be based on the temperature at the turbine inlet. In further still other examples, the threshold may be based on the temperature of the exhaust manifold or exhaust valve.

Restriction of air into the cylinders, for example, may be based on the degree of poverty lean air-fuel mixture, wherein, the restriction increases as the degree of poverty is increased.

In another example, the restriction may be based on the temperature of the exhaust gas, wherein, the restriction increases as the exhaust temperature rises above a threshold temperature (e.g., a temperature above which the deterioration of characteristics of the components may occur). In yet another example, the restriction may be based on engine speed, wherein the restriction is increased when the engine speed is higher than the threshold speed. In particular, the limit may be increased to a higher engine speed, because the stages suppress misfire may have a higher probability of causing early ignition at higher engine speed.

As concretized in FIG. 3-4, the applicable load limit can be based on various engine operating conditions, including engine speed, engine ignition early history (or the number of early ignition of the engine), the first number of cylinders, which were derived from the work (ie, the number of cylinders in which the fuel has been blocked, and only air is pumped through them), and the degree of poverty lean fuel-air ratio. In one example, setting limits on the basis of the history of early ignition of the engine may include an increase in the load limit (ie, becoming more restrictive limit load) to the extent that it increases the expense of earlier engine ignitions. In addition, a timer may be started when the second driven load limit value. At 220, it may be determined whether the elapsed (second) threshold length. If not, the limit load can be maintained at 224. In contrast, at 222, during the second mode, the second load limit can be reset (i.e., load limitation is discontinued) at the expiration of the duration threshold. The threshold time may be based on the number of early ignition and engine exhaust temperature. In another example, the load limit may be terminated after the engine is operated below the threshold for a load threshold duration, and may be renewed injection of fuel into all cylinders. In one example, (second) threshold duration, after which the second load limit can be reset, it may be longer than the (first) threshold duration, after which resets the first load limit (used during the first mode of operation).

In some embodiments, the restriction to be performed during each of the first and second modes of engine operation, may be performed prior to the actual occurrence of pre-ignition events in the engine. In response to an early event in the engine ignition occurring even after the applied load limit, the controller may be configured to further limit the air to the engine cylinders from the current threshold to a lower threshold. That is, the more restrictive the load limit can be used to suppress the actual early ignition of the engine.

Returning to 205, if the early ignition event in the cylinder is confirmed, the procedure may proceed to 226, wherein the engine controller may control the motor in the third mode (as particularized 228) with all cylinders performing combustion, and at least one cylinder operating on the air-fuel ratio richer than stoichiometry. More precisely, influenced early ignition cylinder (or cylinders) may be enriched by a certain amount along with the fact that the supply of fuel remaining cylinders is adjusted so that the exhaust gases are maintained at or near stoichiometry. In an alternative embodiment, instead of enrichment, being influenced by the cylinder (s) may be subjected to depletion along a certain amount so that the supply of fuel remaining cylinders is adjusted so that the exhaust gases are maintained at or near stoichiometry. Through enrichment (or depletion) under the influence of the early ignition cylinder in response to an event pre-ignition may be suppressed by subsequent events early ignition. The duration and degree of enrichment (or depletion) may for example be based on the number of ignitions earlier under the influence of the cylinder and / or the number of ignitions of the engine earlier. In addition, the value can be applied load limiting. For example, a third load limit can be applied to the motor when the third limit load is more restrictive than at least the first limit of the load. As concretized with reference to FIG. 3-4, the third load limit may be based on various engine operating conditions including at least engine speed. In one example, the second load limit may be more restrictive than the third load limit at higher engine speeds (as more likely caused by misfire early ignition) along with the fact that the third load limit may be more restrictive than the second load limit at lower engine speed (when pre-ignition more likely). In essence, the third load limit can be used to suppress the effects of pre-ignition events. For example, the third value can reduce the load limiting load limit of the engine below the third threshold value, which is lower than the first threshold value, and, optionally, lower than the second threshold value.

During the third operating mode, the third load limit can be reset in response to the switching cycle / engine off. Accordingly, at 230, it may be determined whether the switching cycle / engine-off occurred. In one example, power cycle / engine-off may be determined in response to the event of ignition on / off. At 232, in response to the switching cycle / engine shutdown, the third load limit can be reset. That is, the value of the third load restrictions can be lifted. If switching cycle / engine shutdown is not confirmed, at 234, the third load limit can continue to be used.

The speed with which different load limits gradually enter and / or exit of the various modes may also differ. For example, limiting the load in response to the occurrence of pre-ignition (ie, the third load limit) can be implemented immediately, and with some temporary worsening of driving opportunities, while limiting the load in response to an event of a misfire (ie, the second load limit) can It takes a period of time based on the temperature of the component constant growth time to "facilitate" the load limit on the spot so as to not cause a feeling of insufficient driving capability.

It should be understood that, in some embodiments, the restriction to be performed during each of the first and second modes of engine operation, may be performed prior to the actual occurrence of pre-ignition events in the engine. In response to an early event in the engine ignition occurring even after the applied load limit, the controller may be configured to further limit the air in the cylinder chamber on the prevailing threshold to a lower threshold. That is, the more restrictive the load limit can be used to suppress the early ignition of the engine. In one example, in response to an event pre-ignition occurring while the engine is operating in the first or second mode, the controller can immediately switch the engine in the third mode and applying a third load limit, if the third load limit is the most restrictive load limit .

It is understood that, despite the fact that the image of the procedure suggests that the third load limit is more restrictive than the second load limit during selected operating conditions, the second load limit can be (already is) is more restrictive than the third limit load. For example, at low to medium engine speed (e.g., 1000-2800 rpm), where the nascent more likely early ignition, the third load limit may be lower than the second limit load. However, at medium to high engine speed (e.g. 3000-3500 rpm) caused by pre-ignition may be more likely due to the operation of the cylinder on at lean without misfiring cylinders. During such conditions, the second load limit may be lower than the third limit load. As concretized in FIG. 3, the motor controller may be configured to estimate the load limits based on various factors in the containment predetermined operating conditions, and then to apply the lowest limit of the load, which moderates the early ignition.

Substantially more restrictive limit the load applied to the engine, particularly during the second and third modes of operation may reduce the engine output. Thus, when using more restrictive limits load associated warning may be issued to the driver of the vehicle to warn him of an upcoming reduced power state (such as an associated diagnostic lights indicating faulty operation can be set or displayed). In addition, a timer, a leading countdown until terminated until more restrictive limit load, may also be displayed to indicate to the driver can be resumed when the engine power.

Next, with reference to FIG. 3 shows a schematic view of the load limiting procedure 300. The procedure may start with a feedforward load limiting portion, wherein the load limitation is performed in anticipation of pre-ignition and taking into account various other limiting load conditions and load requirements, 304. More specifically, the first controller may determine K1 load limits based on the engine operating conditions, e.g. based on the speed status - engine load 302, and also define load limits corresponding to one or more restrictive conditions load (or "attributes") and load requirements. Those, for example, may include load limits to ensure proper traction control (eg, load limits, responsible for wheel slip), the load limits in anticipation of the likelihood of early ignition or misfire, etc. The controller may select the lowest of all the limits of the load, the estimated nominal yield load, or Tqe_load_limit, 306, at the same time, the lowest load limit applies pending the pre-ignition.

Tensile loads can be truncated after truncation load 308. Truncation load may be based on various factors. In one example, the controller may begin with a nominal load truncation, which is based on the nominal conditions. This truncation nominal load may be issued (for example, read from a two-dimensional (2D) regulating characteristics) as a function of engine speed and manifold charge temperature. Truncation then the load can be adjusted by the multiplication factor which ranges from -1 to 1. The ratio may be based on measurements of the feedforward such as fuel octane value, or ethyl alcohol content of alcohol in the fuel, fuel air ratio, the score early engine ignitions and the expense of engine misfire. Thus, the lean fuel air ratio or nizkooktanovooe fuel, which will be forced to climb higher probability of early ignition, are the result of truncation of the load at which the interpolation load truncation moves the load limit to a lower value (such as the value of pre-ignition suppression with low impact). In another example, a rich fuel air ratio or high octane value fuel may be a consequence of a higher load limit (such as pre-ignition suppression value with high impact).

Truncation load also includes a part of the feedback load limiting pre-ignition, in which the load limit is further adjusted based on the frequency or taught by the account early ignitions to counter counted 314 early ignition. Frequency of flashes early increases as an increasing number of pre-ignition events for miles of vehicle travel, and decreases as the number of miles traveled increases. As such, a sufficient number of miles, the frequency of early ignitions can be returned to zero and have no effect on the load limit, if not observed early ignition. However, the operating conditions can affect the expectation of early ignition, and hence, the nominal load limit. The limit load torque is then allowed to load a second truncation K2 controller to determine the allowable load limit torque, 326.

At the same time, the counter early ignitions can count the number of pre-ignition events. Once the threshold amount of pre-ignition events is reached, the counter 314 early ignitions can be operated and can begin to determine the frequency of 316 early ignitions. If the frequency of early ignitions high limit can be calculated PI_load_limit early ignition load 318. This limit early ignition load can be more aggressive "rate of assimilation", depending on the miles and can be activated only when a large number of pre-ignition events occurred in a short amount of time .

In addition, parallel misfire counter can count the number of events of an engine misfire. Once the threshold number of events misfire is reached, the counter 320 misfire can be activated and can begin to determine the frequency of 322 misfire. If there is a misfire, can be calculated from the load limit of misfire misfire_load_limit, 324. This limit load misfire may be based on at least the engine speed.

K2 controller may then select the desired load limit 326, the lowest of these load limits. Thus, the required load limit can be the lowest of the permitted load limit load limit early ignition and limit load misfire. As particularized herein, load limits early ignition and misfire can be more restrictive than the permitted limit load torque, but may vary relative to each other on the basis of the engine speed. For example, at low engine speed, which probably should be "inherent" pre-ignition limit early ignition load can be the most restrictive. In comparison, at higher engine speed, such as when it is probable should occur due to early ignition misfire, the load limit of misfire may be the most restrictive. By selecting the lowest possible limit load, pre-ignition can be reduced, along with measures for other influencing factors on the load containment. Next, with reference to FIG. 4 shows an exemplary procedure 400 for setting limit values ​​of load that must be used in the procedure of FIG. 2, on the basis of various engine operating conditions. Essentially, various loading limits may be determined based on various engine operating factors containment. The controller of the engine, in this case, can choose the lowest load limit (ie, a higher amount of load limits) in order to satisfy the most limited operating parameter of the engine needs.

At 402, engine operating modes can be assessed and / or measured. Such, for example, may include engine speed, driver requested torque, engine ignitions account earlier, catalytic converter temperature, engine coolant temperature, turbine inlet temperature, etc. At 404, based on estimated operating conditions of the engine, based on a plurality of feature extraction load limits can be determined for a variety of demanding load limit operating conditions (eg, load_limit1, load_limit2, until load_limitn for n different features). For example, the limit load can be determined based on the torque demand by the driver along with the fact that another load limit can be determined based on the desired value traction control. Also, other loading limits may be determined based on various factors containment components of the engine temperature. Such, for example, may include a load limits to maintain the temperature of the engine, the temperature of the catalytic converter, the turbine inlet temperature, the temperature of the charge in the reservoir, etc. Likewise, the load ranges may be determined based on the account (or frequency) of the early or ignitions in the engine cylinder and account (or frequency) of misfire in the cylinder.

In one example, for each parameter, the initial feedforward load limiting value may be determined based on the engine speed, the manifold charge temperature, fuel octane implied, fuel-air ratio, etc. Size feedforward load limit may be lower, less restrictive limit load, which limits the amount of air in the cylinders to make it smaller than the threshold value. In addition, the initial yield stress can produce temperatures of exhaust gases opportunity maintained at or below the threshold temperature. Essentially, the initial value of feedforward load limiting can be used in anticipation of pre-ignition events. Then, the feedback adjustment may be effected for load limiting which is based on the number of ignitions earlier. For example, the limit load can be adjusted by counting early ignitions coefficient which is a function of vehicle travel in miles. Thus, each event is pre-ignition may increase the rate of early ignitions account along with the fact that the accumulated mileage can decrease by a factor earlier ignition. In alternate embodiments, account ignitions early factor may also be a function of the combustion cycle.

Then, at 406, various load limits can be compared, and the controller can select the lowest load limit (as herein referred to as the selected limit load torque «Tqe_load_limit»). That is, the controller may select a minimum value of from 1 to load_limit load_limit n. In one example, the different load limits can be stored and subjected to access from the memory controller in which load limits are stored as table loads. Load tables may be implemented as a function of engine speed. By comparison, the limits of the load (or load requests) from a variety of loads of tables and select the lowest load limit can be given engine load at which the probability of (further) pre-ignition is reduced, in addition, together with the adoption of measures in response to the problem of excess temperature of the components .

At 408, the truncation of the load can be determined based on the estimated engine operating conditions for the selection or authorization of the selected limit load torque. For example, truncation of the load outputted by the controller can be a number between -1 and 1, and can be used as a multiplier for the selected torque. Truncation load may be based on the number of early ignitions octane fuel ethanol content of the fuel, the amount of early ignitions, the number of misfiring, the air-fuel ratio, etc. At 410, truncating the load factor can be used to resolve a certain load limit. In an alternative embodiment, the load indicator truncation between -1 and 1 can be used as a factor interpolation between the calculated high and low load limits, determined at 404.

At 412, it may be determined whether the rate of early ignitions higher than the threshold value. For example, it may be determined whether there was a threshold quantity of engine pre-ignition events in a given mileage traveled by the vehicle. In an alternative embodiment, it may be determined whether the number of engine firing events early in the driving cycle higher than the threshold value. If the frequency (or expense) of early ignitions is higher than the threshold, then, at 416, can be determined by the limit load pre-ignition (PI_load_limit). More precisely, once reached a threshold number of pre-ignition events, the controller may consider additional events early ignition is based on the passed-mile vehicle and ruled by integrating (ie, reduce) by a factor earlier ignitions with a more intense rate to determine a more restrictive load limit motor. A more restrictive limit early ignition load can be more intensely to take action in response to the pre-ignition.

If a high frequency pre-ignition is not confirmed at 412, or after determining the pre-ignition limit load at 416, the routine proceeds to 414 where it is determined whether the frequency (or account) misfire higher than the threshold value. Threshold misfire can be calibrated with respect to the excess temperature of the components and / or emission threshold values. For example, it may be determined whether there was a threshold number of events of an engine misfire for a given mileage traveled by the vehicle. In an alternative embodiment, it may be determined whether the number of events of an engine misfire in the driving cycle higher than the threshold value. If the frequency (or account) misfire is higher than the threshold, then at 418, limit load can be determined misfire (misfire_load_limit). For example, a certain torque limit can be adjusted depending on the coefficient counting a misfire based on the frequency of misfire, to determine the limit load misfire. A more restrictive limit load misfire can more intensely to take action in response to the misfire and misfire caused by pre-ignition.

At 420 the controller can select and apply the lowest limit of the load, as applicable. For example, if there is pre-ignition, but not at a sufficiently high frequency, the controller may adjust the rate of early ignitions accounts based on the invoice ignitions early truncation and accordingly adjust the load. After that, the controller can use a truncated and the permitted load limit torque, Tqe_load-limit. If even after the application of a truncated load limit, the frequency of early ignitions increases too quickly determined limit load early ignition, and can be used from the lower Tqe_load-limit and pre-ignition_load-limit. In one example, pre-ignition_load-limit is more restrictive than Tqe_load-limit. In another example, when, after the application of the truncated load limit frequency misfiring increases too quickly determined load limit of misfire, and can be used in smaller and misfire_load-limit Tqe_load-limit. In one example, misfire_load-limit is more restrictive than Tqe_load-limit.

In another example, if, even after applying the load limit truncated, increased frequency of early ignitions too fast and the frequency of misfire increases, can be used in smaller Tqe_load-limit, pre-ignition_load-limit and misfire_load_limit. In fact, pre-ignition limit load may be lower at lower engine speed, while misfire_load-limit may be lower at higher engine speed. Thus, based on the engine operating conditions, the lowest limit of the load may vary.

If the pre-ignition limit load at 420 is chosen, the limit load limiting can be activated or "fixed" until the cycle is not certified until the on / off or the engine ignition on / off. In comparison, if the load limit of misfire is selected at 420, limit load limiting can be activated or "fixed" as long as no confirmed that the engine load remains below the threshold load for a certain period of time. After a threshold amount of time the combustion in the cylinder may be renewed. If the combustion in the cylinder without further successful events misfire, the load limit of misfire can be removed and, if required, can be taken any other load limits.

Essentially, when a pre-ignition limit limiting load applied to the engine, the engine power can be reduced. Thus, when applying a load restraining limit associated warning may be issued to the driver of the vehicle to warn him of an upcoming reduced power state (such as an associated diagnostic lamp malfunction indication mode can be set or displayed). In addition, a timer, a leading countdown until terminated until more restrictive limit load, may also be displayed to indicate to the driver when the engine power can be restored.

It will be appreciated that certain loads or truncation load limit can be changed slowly in order to reduce the disturbance torque. More precisely, truncation of the load may be filtered (e.g., using a moving average filter) over time (for example, using a filter constant) slowly to linearly modify certain load truncation. The controller may optionally coordinate gradual change in load of the engine via a fuel injection operation to reduce torque perturbations.

The procedures of FIG. 3-4 further explained exemplary load limit settings of FIG. 5. More specifically, the multi-dimensional control characteristic 500 of FIG. 5 shows changes in the engine load on the curve 504 at various engine speeds shown in the curve 502.

Before t1, the engine may be running with no load limit. At t1, based on the early history of the engine ignition, under the given conditions of the engine operation, pre-ignition can be prevented. In particular, for a given engine load, and in the range of lower engine speeds, it may be probable early ignition event in the cylinder. Accordingly, t1, the engine controller to limit engine load may first small value to reduce the engine load to the load 510. In essence, this is the first load limit can be carried out before the emergence of any event was pre-ignition in the cylinder.

At t2, the event may be detected misfire in the cylinder. In response to the event of misfire in the cylinder, the controller can pump air through the cylinder without fuel injection in it. Simultaneously, the controller may burn a lean fuel mixture in the remaining cylinders for combustion of any excess amount of unburned fuel in the exhaust gas catalytic converter. However, lean-burn operation itself may cause pre-ignition in the engine, particularly at mid to high engine speed. Therefore, to reduce the likelihood of pre-ignition, which is caused by overwhelming misfiring cylinder to work lean, the engine load can be further limited to reduce the engine load to the load 512. This is the second load limit can also be performed before the emergence of any event was pre-ignition in the cylinder.

At t3, the ignition can be detected early event in the cylinder. In response to early ignition event in the cylinder, at least for being influenced early ignition cylinder can undergo enrichment temporarily along with the fact that the other cylinders are supplied with fuel in order to sustain the release at or near stoichiometry. To reduce the likelihood of pre-ignition events in the cylinder, which, otherwise, could lead to a deterioration in engine performance, the engine load is further limited to reduce engine load to the load 514.

At t4, before the load limitation may be discharged may be determined by engine misfire event. Here, in response to this cylinder, as in t2, the controller may pump the air through the cylinder without fuel injection in it along with the burning lean fuel-air mixture in the other cylinders. However, since the engine load is already limited engine load 514, which is lower than the engine load 512, otherwise required to take action in response to misfire due to early ignition, no additional load limit can not be performed. At t5, in response to an event on / off the ignition, limiting the load can be stopped, and the engine load can be reduced.

Thus, the load limiting pre-ignition warning comes along with some minor load restrictions caused by an event is detected early ignition, and then suddenly switched load limiting misfire, it will limit the engine load in order to protect the exhaust components, besides, with additional decrease in the propensity to early ignition, through the lower load limit. However, if events continue to occur early ignition, the load limit will be running as long as there are not satisfied with the correct entry conditions. Thus, by reducing the engine load while suppressing misfire lean combustion conditions of the engine components heat overload can be reduced to the same, along with a reduced likelihood of pre-ignition caused by the lean combustion conditions. By selecting and applying the load limit, which reacts to the temperature of the components as well as deterring factors early ignition, deterioration of motor characteristics of pre-ignition may be reduced.

It should be noted that the exemplary control and evaluation procedures included in the materials herein can be used with various engine configurations, systems and / or vehicle. Specific procedures described herein can represent one or more of any number of processing strategies such as event-driven, interrupt-driven, multi-tasking, multi-threading, and the like. As such, various acts illustrated, the operations or functions may be performed in the sequence illustrated, in parallel, or in some cases omitted. Similarly, the order of processing is not necessarily required to achieve the features and advantages of the exemplary embodiments described herein, but is shown for ease of illustration and description. One or more of the actions or functions illustrated may be performed repeatedly, depending on the strategy used. Furthermore, the described steps may graphically represent code to be programmed in a computer-readable storage medium in the engine control system.

It should be understood that the configurations and processes disclosed herein are exemplary in fact, and that these specific embodiments are not to be considered in a limiting sense, because numerous variations are possible. For example, the above technology can be applied to a V6 engine types, I-4, I-6, V-12, opposed 4-cylinder set, and other engine types. Subject of the present invention includes all the new and nonobvious combinations and subcombinations of the various systems and configurations, and other features, functions and / or properties disclosed herein.

Subsequent claims in detail specifies some combinations and sub-combinations are considered to be new and non-obvious. These claims may refer to a singular element or "a first" element or the equivalent. It should be understood that such claims include the association of one or more such elements without requiring nor excluding two or more such elements. Other combinations and subcombinations of the disclosed features, functions, elements and / or properties may be claimed by the claims of this change in the claims or presentation of new claims in this or a related application. Such claims, broader, narrower, equal, or different in volume relative to the original claims, are also regarded as included in the scope of the present invention.