RU2584083C2 - Ice control procedure for allowance for fuel properties - Google Patents

Abstract

FIELD: engines and pumps.

SUBSTANCE: claimed invention consists in introduction of a definite measure (for example, fuel feed limitation) in case the definite ICE mode is revealed (for example, knocking). The check is performed to make sure that the fuel tank communicated with the ICE is filled. After introduction of said measure checked is whether the fuel from the fuel tank reaches the ICE after its filling and if the ICE operation in a definite mode terminates to cancel said definite measure at execution of aforesaid terms. This invention discloses the computer program products with the program code meant for execution of the claimed process at the existing ICEs with no extra hardware components.

EFFECT: higher accuracy of control.

4 cl, 1 dwg

Description

The invention relates to a method for controlling an internal combustion engine (ICE) to account for fuel properties. The present invention further relates to a computer program product that contains program code stored on a computer-readable medium, and which is intended to implement the method of the invention, as well as to an internal combustion engine equipped with a control unit in which a computer program is implemented that implements all the stages of the proposed in the invention of the method.

State of the art

Fuel for internal combustion engines consists of a mixture of hydrocarbon compounds and may contain additives of oxygen-containing organic components, as well as additives to improve its properties. Depending on the relative content of various hydrocarbons in the fuel, various effects on the internal combustion engine’s performance are manifested, especially on its power, fuel consumption, acoustic characteristics (for example, detonation), starting qualities and emissions of harmful substances with exhaust gases. Modern ICEs should be able to operate on fuels of different quality without a noticeable deterioration in their performance.

When controlling the operation of the internal combustion engine, measures are usually taken in response to a specific nature or mode of operation of the internal combustion engine, such as, for example, detonation, the occurrence of which is due to the low quality of the fuel. Serious measures that a driver of a car equipped with an appropriate ICE feels are activated only if necessary. Such measures include, for example, measures for detonation control, when the magnitude of the change in the ignition timing to the late takes too large values. In this case, the filling of the internal combustion engine cylinders is further limited in order to protect it or to protect certain of its parts from negative consequences, especially in the exhaust tract. The function to limit the filling of the internal combustion engine cylinders may, depending on the actual conditions, be activated many times in one trip and then canceled again. In the event that the cause of the detonation is the fuel that the vehicle has been refueled, a similar process of activating-deactivating the function to limit the filling of ICE cylinders is repeated until such fuel is completely consumed and refueling with better fuel. This approach affects the driving quality, respectively, the dynamic properties of the car and is clearly palpable for the driver, since the internal combustion engine for a long time does not always develop the same power, respectively, the same torque in full load mode.

Various methods for responding to changes in fuel quality after refueling a fuel tank are known in the art.

DE 10063677 A1 describes a method for controlling the operation of an internal combustion engine, namely, depending on the operating parameters of the internal combustion engine, the basic duration of fuel injection is determined; stop the engine and the time of its restart, and the correction factor assign a weight coefficient, which is selected depending on the level of fuel in the fuel m tank before stopping the internal combustion engine and the fuel level in the fuel tank when restarting the engine. In this case, the operation of the internal combustion engine is controlled, thus, depending on the fact of fueling detected. However, the provided adaptation leads to a periodic change in the power of the internal combustion engine.

DE 4027947 A1 describes a method that ensures the operation of an internal combustion engine in a cold state, when its composition changes significantly when refueling, for example, as a result of refueling a fuel tank after almost completely emptying it mainly with methanol containing fuel. Based on the information about the fuel levels in the tank before and after refueling and on the basis of the data on the fuel available for sale, it is estimated what composition the fuel in the tank can have. Then, for the operation of internal combustion engines on fuels of a possible composition, control actions are changed during pre-emptive control and they are examined on which fuel the internal combustion engine works best. These effects are then used to further regulate the operation of the internal combustion engine. In such a system, therefore, measures that change the mode of operation of the internal combustion engine are taken depending on the fuel levels in the tank. However, this method is not designed to recognize differences in the quality of fuel of the same type.

DE 4117440 A1 describes a method for adaptively controlling an air-fuel mixture to take into account the properties of the fuel supplied to the internal combustion engine. To take such properties of the fuel into account, adaptation is performed at high speed if, after refueling, it is established that when applying the previously existing adaptation coefficient, poor control results are achieved. As soon as good control results are again achieved, the usual adaptation starts at the usual low speed. For this purpose, fill levels of the vehicle’s fuel tank with lambda control of the internal combustion engine installed on it before and after refueling are determined, based on information about these fill levels of the fuel tank and known information on the fuel composition at the gas station, values for possible fuel compositions in the tank and the coefficient the excess air in the combustible mixture is controlled using adaptation values alternating through a specific number of injection cycles that relate to different possible compositions Fuel tank. Then they investigate at which values the best results characterizing the operation of the engine are achieved, and this value, at which the best operation of the engine is ensured, is used as the actual adaptation value. In accordance with this, accurate information about the fuel levels in the fuel tank is used to adapt the parameters controlling the operation of the internal combustion engine. However, such constant adaptation leads to a periodic change in engine power.

DE 102007019281 A1 describes a method for controlling the properties of the fuel supplied to the internal combustion engine, and on the basis of data on the volume and volumetric flow rate of fuel in at least one part of the fuel system, determined by the geometry of this part and the known values of the fuel flow through it, conclude possible duration of fuel stay in this part of the fuel system. Based on information about such a duration of fuel in this part of the fuel system at the prevailing temperature, the residual stability of the fuel until it is irreversibly decomposed is determined. However, this only takes into account the aging of the fuel in the fuel tank and the replacement of old fuel with a new one. The method described in this publication is not suitable for purposefully coordinating appropriate measures with fuel, which is already of poor quality when refueling.

US 2009/00331987 A1 describes a device for recognizing a fuel that is not suitable in composition for operating an internal combustion engine. In this case, it is first checked whether detonation occurs in the internal combustion engine and whether it is caused by the composition of the fuel. If detonation due to the fuel composition is detected in the internal combustion engine, it is regulated to prevent further detonation.

DE 102007034189 A1 describes a method for determining the composition of a mixture of two fuels based on the output of a knock sensor. The determination of the composition of the mixture begins after the fact of refueling the car with fuel is detected and the identified composition is used as an input value for the detonation control of the internal combustion engine of the car.

DE 102007042718 A1 describes a method for determining the composition of the fuel supplied to an internal combustion engine based on its ignition timing at which detonation does not yet occur.

From DE 102007020959 A1, a method for determining the alcohol content in a fuel supplied to an internal combustion engine is known. Changes in the alcohol content in the fuel are determined based on the characteristics of the signal from the oxygen sensor (lambda probe) installed in the exhaust path of the internal combustion engine. The signal characteristic of the oxygen sensor is analyzed after the newly refilled fuel reaches the fuel nozzle of the first cylinder of the internal combustion engine. The moment at which this newly charged fuel will enter the cylinder is determined on the basis of the volume of the fuel distributor, including the section up to the fuel nozzle of the first cylinder, and the volume of the fuel pipe, and also taking into account the actual operating modes of the engine as a function of the speed of its shaft and relative load, respectively filling his cylinders.

DE 19901006 A1 describes a method involving the use of a fuel composition sensor to adjust the desired ratio between air and fuel in the combustible mixture formed by them supplied to the engine, in order to allow a continuous change in the composition of the (mixed) fuel. At the same time, regulation is carried out in which the advancement of a small amount of fuel and the corresponding stoichiometric ratio between air and fuel are monitored using the stack memory, so that the engine control unit can respond to changes in fuel consumption.

The basis of the present invention was the task of developing a method for controlling an internal combustion engine, which method would provide the possibility of ICE operation even for a longer time with the constant dependence of the power delivered by it / the torque developed by it on the speed of rotation. Such a method should first of all provide the possibility of recognizing low-quality fuel by the loss of power and thereby provide the driver of a car equipped with an appropriate ICE with the opportunity to avoid in the future certain gas stations where refueling with such low-quality fuel is possible.

Summary of the invention

Advantages of the Invention

This problem is solved according to the invention using a method of controlling an internal combustion engine (ICE) to take into account the properties of the fuel, which consists in the fact that:

- introduce a restriction on the filling of the internal combustion engine cylinders when detonation is detected in it,

- check whether the fuel tank connected to the internal combustion engine was refueled after the restriction of filling its cylinders was introduced,

- check:

a) whether the fuel has reached the internal combustion engine from the fuel tank after refueling and

b) whether the detonation in the internal combustion engine stopped, and

- cancel the restriction on the filling of the internal combustion engine cylinders when conditions a) and b) are fulfilled.

Checking whether the fueling has been carried out is preferably carried out using the corresponding fueling recognition function. A similar fueling recognition function is usually already implemented in engine management systems.

The recognition of low quality fuel according to the invention is carried out primarily by means of the corresponding knock recognition function. For fuel, which is allowed to operate on this ICE, the dependence of the maximum value of the change in the ignition timing in the late direction on the rotation frequency is known. A change in the ignition timing to the late by large values can be caused only by unacceptably low quality fuel. Such changes in the ignition timing are detected by an appropriate threshold survey. In order to exclude the possibility of activating the function to limit the filling of the internal combustion engine cylinders due to only temporary significant changes in the ignition timing in the late direction, such an excess of the threshold value should preferably also be maintained for an acceptable period of time.

After that, activate the function to limit the filling of the internal combustion engine cylinders. It then remains activated until a new fueling of the ICE fuel tank has occurred and until after that the following criteria have been met:

a) the new fuel reached the internal combustion engine through the fuel system (power system);

b) the recognition criterion, in this case, the change in the ignition timing in the direction of the late detonation control system, again lies in the normal range.

In order to identify the fulfillment of criterion a), the fuel consumption from the moment of refueling is determined.

It is necessary to take into account that the fuel reaching the engine does not change from the old to the new instantly, but instead the new fuel forms a mixture with the old fuel, in which the proportion of new fuel gradually increases as the fuel supplied to the engine is consumed. Therefore, up to the moment when the proportion of new fuel in all the fuel supplied to the internal combustion engine reaches a sufficiently large value, the fuel consumption from the moment of the last refueling it should usually exceed the volume of the fuel system in its area between the fuel tank and the internal combustion engine. For this reason, to check whether the fuel from the fuel tank has reached the internal combustion engine after refueling, the fuel consumption is determined from the moment of the last refueling, while the moment at which the fuel reaches the internal combustion engine is taken to be the moment at which the fuel consumption becomes no less values V × F, where V denotes the volume of the fuel system in its area from the fuel tank to the internal combustion engine, a F is a coefficient greater than 1.

The object of the invention is further a computer program, which when it is executed by a computing device or control unit implements all the stages of the method proposed in the invention and described above. Such a computer program is presented in the form of a computer program product that contains program code stored on a computer-readable medium, and which is intended to implement the method of the invention when this program is executed by a computing device or control unit, for example, an engine control unit. With the help of such a computer program, a particularly effective control of the internal combustion engine is possible. A particular advantage of a computer program is the possibility of a hassle-free implementation of the method of the invention in relation to existing ICEs without the need for equipping them with additional components. In this case, only appropriate coordination of the control software is necessary by installing a computer program stored in the form of a computer program product on a machine-readable medium, for example, in a control unit of an internal combustion engine.

The object of the present invention is also an internal combustion engine equipped with a control unit in which a computer program is executed that implements all the stages of the method proposed in the invention.

Other advantages and distinguishing features of the invention are discussed below on the example of one of the variants of its implementation with reference to the single drawing attached to the description, which option, however, is not limited to the method proposed in the invention. Certain distinctive features of the invention can in each case be implemented individually or in combination with each other.

Drawing

In the accompanying description, a single drawing shows a diagram illustrating the inventive method for controlling an internal combustion engine to account for fuel properties.

Description of an embodiment of the invention

The accompanying description of the drawing shows a diagram illustrating the proposed invention. First, according to the invention, it is checked whether the engine is operating in detonation mode (1). When recognizing a similar mode of operation of the internal combustion engine, a restriction is placed on the filling of its cylinders (2). After the introduction of such a restriction, it is checked whether fueling has occurred (3). When the fact of fueling is recognized, it is checked whether the internal combustion engine has reached the fuel in the fuel tank after refueling and if detonation has stopped (4). When these conditions are met, the restriction on the filling of the internal combustion engine cylinders (5) is canceled. In the event that the restriction on the filling of the internal combustion engine cylinders was canceled (5) or was not introduced at all, the driver of the vehicle driven by this internal combustion engine does not feel any influence on the dynamic properties of the vehicle (6). In the same case, if the restriction of the filling of the internal combustion engine cylinders was introduced (2) and the fact of fueling was not recognized (3) or if the conditions are not met according to which the fuel from the fuel tank reached the internal combustion engine and it does not work anymore in the detonation mode ( 4), then the function for restricting the filling of ICE cylinders remains and is further activated, and for the driver, the influence of such a restriction on the filling of ICE cylinders on the dynamic properties of a car is noticeable (7)

The method proposed in the invention prevents the occurrence of a situation in which, after refueling with low-quality fuel, the function to limit the filling of ICE cylinders during its operation is repeatedly activated and then deactivated. Moreover, the restriction on the filling of the internal combustion engine cylinders is canceled only after the best quality fueling has occurred and such fuel, after refueling, has also actually reached the internal combustion engine through the fuel system. For the driver of a car driven by these ICEs, such an approach means that the ICE will even work for a longer time with the constant dependence of the power it gives / the torque it develops on the speed. Proposed in the invention method can be implemented in relation to ICE without the need to make changes to its design. Moreover, this requires only the appropriate coordination of the software that controls the internal combustion engine by installing the appropriate computer program, for example, in the engine control system.

Claims (4)

1. The method of controlling an internal combustion engine (ICE) to account for the properties of the fuel, namely, that
- introduce a restriction on the filling of the internal combustion engine cylinders when detonation is detected in it (1, 2),
- check whether the fuel tank connected to the internal combustion engine was refueled after the restriction of filling its cylinders was imposed (3),
- check (4):
a) whether the fuel has reached the internal combustion engine from the fuel tank after refueling and
b) whether the detonation in the internal combustion engine stopped, and
- cancel the restriction on the filling of the internal combustion engine cylinders under the conditions a) and b) (5),
moreover, to check whether the fuel from the fuel tank reached the internal combustion engine after refueling, the fuel consumption is determined from the moment of the last refueling, while the moment at which the fuel reaches the internal combustion engine is taken to be the moment at which the fuel consumption becomes not less than V × F, where V denotes the volume of the fuel system in its area from the fuel tank to the internal combustion engine, and F represents a coefficient greater than 1. 2. The method according to p. 1, characterized in that the check whether the fueling was carried out (3) is carried out using the corresponding function for the recognition of fueling. 3. A computer program product that contains program code stored on a computer-readable medium, and which is intended to implement the method according to claim 1 or 2, when the program is executed by a computing device or control unit. 4. An internal combustion engine equipped with a control unit on which a computer program is executed that implements all the stages of the method according to claim 1 or 2.