KR100394638B1 - Method for controlling fuel injection during acceleration of engine for a vehicle - Google Patents

Abstract

In the method of controlling the fuel amount during acceleration of the vehicle engine of the present invention, when the acceleration condition set by the air amount change rate or the throttle opening amount change rate detected in the vehicle equipped with the electronic control means is established, the electronic control means is connected to the mapped basic fuel amount. Calculating a fuel injection amount according to a compensation fuel amount for each region and a compensation fuel amount for each water temperature, and performing fuel amount control using the calculated fuel injection amount; If the fuel amount control is performed with the estimated fuel injection amount, the electronic control means detects a fuel enrichment and performs fuel amount learning to vary the fuel amount if the detected fuel enrichment is not within a predetermined threshold region. Through the fuel quantity learning, it is possible to secure the acceleration performance appropriate to each condition by actively compensating for the various variations that may occur due to the variation between the vehicles, the variation between the engines, the vehicle endurance driving state and the characteristics of the fuel used. Can be reduced.

Description

TECHNICAL FOR CONTROLLING FUEL INJECTION DURING ACCELERATION OF ENGINE FOR A VEHICLE}

The present invention relates to a fuel amount control method for accelerating an engine of a vehicle, and more particularly, in order to secure acceleration performance by performing electronic fuel compensation compensation learning when the engine is accelerated in a vehicle equipped with the electronic control means. The present invention relates to a fuel amount control method for accelerating an automobile engine.

In general, the electronic control means such as ECU (Electronic Control Unit) mounted on the vehicle is the operating state of each component in the vehicle and the engine control that adapts to the driver's intention based on the driving conditions detected by various sensors including the vehicle speed sensor. Generates diagnostic code indicating.

A schematic diagram of such an ECU system is shown in FIG.

According to FIG. 1, the ECU system calculates a driving condition based on the sensing means 10 for detecting various kinds of information about the driving condition of the vehicle, and the information detected by the sensing means 10, according to the driving condition. ECU 20 for generating a diagnostic code or performing fuel injection amount control.

The sensing means 10 includes a throttle valve opening amount sensor 11 for detecting an throttle opening amount according to an accelerator pedal operation of a driver, a water temperature sensor 12 for detecting a cooling water temperature, and an intake air flow rate for detecting an intake flow rate. A sensor 13, an oxygen sensor 14 for detecting the oxygen concentration in the exhaust gas, and an engine speed sensor 15 for detecting the engine speed.

Such ECU system is to control the fuel injection amount according to the engine operating conditions detected by the sensing means (10). Usually, the fuel injection amount is increased when the vehicle is accelerated or when the engine load or the electric load increases.

When the driver accelerates, the amount of air rapidly increases, and thus, when the fuel amount is injected, a situation in which the amount of air is momentarily excessive (or momentary fuel shortage) occurs.

As such, if the amount of air is excessively instantaneous, the phenomenon of lack of acceleration and excessive generation of nitrogen oxide (NOx) components in the emission gas may occur.

Therefore, the engine control system (EMS) applies a control method that injects an additional fuel amount other than the basic fuel amount when determining the acceleration condition and compensates it, and performs appropriate fuel compensation for the transition section during operation.

2 is a flowchart illustrating a fuel amount control method for accelerating an engine of a vehicle according to the prior art.

According to FIG. 2, the ECU 20 calculates the throttle opening amount detected by the throttle opening amount sensor 11 and the intake air amount detected by the intake air flow rate sensor 13, respectively.

The ECU 20 determines whether the calculated change rate of the air amount or change rate of the throttle opening amount satisfies the set acceleration condition (ST10).

Thus, when the set acceleration condition is established in step ST10, the ECU 20 calculates the mapped basic fuel amount and applies the compensation amount for each region (ST11, ST12).

Subsequently, the ECU 20 applies a compensation amount for each temperature according to the cooling water temperature detected by the water temperature sensor 12 (ST13).

When the compensation amount for each temperature is applied, the fuel injection amount controlled by the ECU 20 is equal to ((basic injection amount) * (area compensation amount for each region) * (compensation amount for each water temperature)) (ST14).

On the other hand, if it is confirmed in step ST10 that the acceleration condition is not satisfied, the fuel injection amount by the ECU 20 is controlled according to the mapped basic fuel amount (ST15).

However, the fuel compensation method at the time of acceleration described above sets the basic injection amount according to the rate of change of the air volume or the amount of change in the throttle opening, and in addition to this, only the additional compensation is made due to the increased frictional force when the coolant temperature is low. There is a problem in that compensation for vehicle deterioration is impossible.

In addition, there is a problem in that compensation for a problem caused by a difference in fuel conditions in a special region is not made.

On the other hand, although there is a fuel learning correction in a normal driving state, the response to the transition section such as acceleration is inevitably lacking.

The present invention was created to solve the above-mentioned conventional problems, and an object of the present invention is to secure the acceleration performance by performing the fuel amount compensation learning by the electronic control means when the engine is accelerated in the vehicle equipped with the electronic control means. To provide a fuel amount control method during the acceleration of the engine for automobiles to.

1 is a schematic configuration diagram of an ECU system,

2 is a flowchart of a fuel amount control method for accelerating an engine of a vehicle according to the prior art;

3 is a flowchart of a fuel amount control method for accelerating an engine for a vehicle according to an exemplary embodiment of the present invention.

Explanation of symbols on the main parts of the drawings

10: detection means 11: throttle valve opening amount sensor

12 water temperature sensor 13 intake air flow sensor

14 oxygen sensor 15 engine speed sensor

20: ECU

The method for controlling fuel amount during acceleration of an automobile engine of the present invention for achieving the above object is the electronic control means when the acceleration condition set by the air amount change rate or the throttle opening amount change rate detected in the vehicle equipped with the electronic control means is established. Calculating a fuel injection amount according to the mapped basic fuel amount, the region-specific compensation fuel amount, and the water temperature-compensated fuel amount, and performing fuel amount control with the calculated fuel injection amount; If the fuel amount control is performed with the estimated fuel injection amount, the electronic control means detects a fuel enrichment and performs fuel amount learning to vary the fuel amount if the detected fuel enrichment is not within a predetermined threshold region. It is characterized by that.

Hereinafter, exemplary embodiments of the present invention will be described with reference to the accompanying drawings.

3 is a flowchart of a fuel amount control method for accelerating an engine for a vehicle according to an exemplary embodiment of the present invention.

The electronic control means of the present invention is preferably implemented by ECU 20 (see Fig. 1).

According to Fig. 3, the in-vehicle ECU 20 calculates the throttle opening amount detected by the throttle opening amount sensor 11 (see Fig. 1) and the intake air amount detected by the intake air flow sensor 13 (see Fig. 1), respectively. do.

The ECU 20 determines whether the calculated change rate of the air amount or change rate of the throttle opening amount satisfies the set acceleration condition (ST21).

Variables for setting the acceleration condition are the engine speed, the filling efficiency, the amount of change in the opening of the throttle body, the cooling water temperature and the like.

Thus, when the acceleration condition is established in step ST21, the ECU 20 calculates the mapped basic fuel amount and applies the compensation amount for each region (ST22 and ST23).

Subsequently, the ECU 20 applies a compensation amount for each temperature according to the cooling water temperature detected by the water temperature sensor 12 (see FIG. 1) (ST24).

When the compensation amount according to the water temperature is applied, the fuel injection amount controlled by the ECU 20 is equal to ((basic injection amount) * (area compensation amount) * (compensation amount by water temperature)) (ST25).

On the other hand, since the problem of acceleration / deceleration is determined by the adequacy of the correction fuel amount, it is currently used to control the mixing ratio of fuel and air to the theoretical air-fuel ratio (A / F = 14.7) when the correction fuel amount is not appropriate. Fuel Back Gain Control is used.

The fuel feedback control performs the fuel amount control by the signal from the oxygen sensor 14 (refer to FIG. 1) used in the vehicle. Therefore, when the oxygen sensor signals that the fuel is excessive, the gain value is reduced and multiplied by the basic fuel amount, thereby reducing the total fuel amount and keeping the air-fuel ratio constant. On the contrary, when the oxygen sensor sends a fuel shortage signal, the gain is increased to multiply the basic fuel amount to increase the total fuel amount.

The theoretical air-fuel ratio is maintained while repeating this feedback gain control.

Thus, the feedback gain control can be used to measure the fuel shortage condition during acceleration. That is, when the feedback gain value during acceleration increases, it is determined that the acceleration fuel amount is insufficient, and when the gain value decreases, it can be determined that the acceleration fuel amount is excessive. The determination is made to increase or decrease the amount of accelerated fuel so that a proper amount of accelerated fuel is maintained in the same region.

Normally, the proper air-fuel ratio at the time of acceleration is determined to be within the range of +1 and -2, that is, within 12.7 to 15.7 of the theoretical air-fuel ratio.

Therefore, when fuel amount control is performed with the fuel injection amount calculated in step ST25, the ECU 20 detects the oxygen concentration in the exhaust gas from the signal detected by the oxygen sensor 14 (see Fig. 1). When the oxygen concentration is applied to the mapped data, the air-fuel ratio or the fuel richness may be calculated.

When the fuel richness is calculated as described above, the ECU 20 determines that the fuel amount control is properly performed when the calculated fuel richness is within the set critical region, but the fuel richness is not within the critical region. If not, it is determined that the fuel amount control is not properly performed.

Thus, if it is determined that the fuel amount control is not appropriate, the ECU 20 performs the fuel amount increase learning or the fuel amount reduction learning by varying the fuel amount according to the fuel richness. At this time, if the fuel richness is low, it is called lean combustion. If the fuel richness is high, it is determined as rich combustion.

Preferably, the lean burn determination condition is set to be established when the lambda value detected by the oxygen sensor is larger than 1.1, and the rich combustion determination condition is set to be established when the lambda value is smaller than 0.8.

The ECU 20 then determines whether a lean burn condition is established based on the calculated fuel richness. The lambda value for establishing the lean combustion condition indicates the upper limit of the critical region (ST26).

If it is confirmed in step ST26 that the lean burn condition is established, the ECU 20 performs fuel amount increase learning (ST27).

In this case, the fuel quantity increase learning means to control the fuel amount by increasing the injected fuel amount, storing the increased fuel amount in a memory, and then applying the same in subsequent fuel amount control.

And in step ST26, when the fuel richness does not hold a lean combustion condition, the ECU 20 determines whether the fuel richness holds a rich combustion condition. The lambda value for establishing the rich combustion condition indicates the lower limit of the critical region (ST28).

If it is confirmed in step ST28 that the fuel richness does not hold the rich combustion condition, the ECU 20 performs fuel quantity reduction learning (ST29).

The fuel amount reduction learning is performed in the same manner as the fuel amount increase learning. The fuel amount reduction learning is performed by reducing the fuel amount to increase the air-fuel ratio, and then storing the reduced fuel amount data in a memory and applying it in subsequent fuel amount control.

On the other hand, when it is confirmed in step ST28 that the fuel richness does not satisfy the rich combustion condition, it corresponds to that the appropriate fuel amount compensation is made by the fuel injection amount calculated in step ST25.

Therefore, if it is confirmed in step ST28 that the rich combustion condition is not established, the ECU 20 returns to the main routine without performing fuel amount increase learning and fuel amount loss learning.

In addition, if it is confirmed in step ST21 that the acceleration condition is not satisfied, the fuel injection amount by the ECU 20 is controlled according to the mapped basic fuel amount (ST30).

In addition, when step ST27, step ST29, or step ST30 is performed, the ECU 20 returns to the main routine.

According to the fuel amount control method for accelerating the engine of a vehicle of the present invention described above, the fuel amount learning to actively compensate for the various variations that can occur due to the variation between the vehicle, the variation between the engine or the vehicle endurance running state and the characteristics of the fuel used, etc. By doing so, it is possible to secure the acceleration performance suitable for each condition and to reduce the emission gas.

Although the preferred embodiment of the present invention has been described above, the present invention may use various changes, modifications, and equivalents. It is clear that the present invention can be applied in the same manner by appropriately modifying the above embodiments. Therefore, the above description does not limit the scope of the following claims.

Claims (3)

(a) When the acceleration condition set by the air amount change rate or the throttle opening amount change rate detected in the vehicle equipped with the electronic control means is established, the electronic control means may be configured according to the mapped base fuel amount, the compensation fuel amount for each region, and the compensation fuel amount for each water temperature. Calculating a fuel injection amount and performing fuel amount control with the calculated fuel injection amount; (b) When fuel amount control is performed with the estimated fuel injection amount, the electronic control means detects fuel concentration and performs fuel amount learning to vary the fuel amount when the detected fuel concentration is not within a predetermined threshold region. A fuel amount control method for accelerating the engine of a vehicle, characterized in that it comprises a step. The method of claim 1, wherein in step (b), And the critical region is set to a region in which the richness of the fuel detected by the oxygen sensor is smaller than the set lean burn determination value and larger than the set rich combustion determination value. The method of claim 1, wherein step (b) comprises: If fuel amount control is performed with the calculated fuel injection amount, the electronic control means calculates an oxygen concentration in the exhaust gas from a signal detected by an oxygen sensor and calculates a lambda value indicating fuel density; When the fuel richness is calculated, the electronic control means determining whether a lean combustion condition is established based on the fuel richness; If it is confirmed that the lean combustion condition is established, the electronic control means increases fuel amount and stores the increased fuel amount data in a storage medium to perform fuel amount increase learning; If the fuel richness does not establish a lean combustion condition, the electronic control means determines whether the fuel richness establishes a rich combustion condition; If it is determined that the fuel richness does not satisfy the rich combustion condition, the electronic control means reduces fuel amount and stores the reduced fuel amount data in a storage medium to perform fuel amount reduction learning; If it is confirmed that the lean combustion condition and the rich combustion condition are not established at the same time, the electronic control means includes the step of returning to the main routine without performing fuel amount increase learning and fuel amount reduction learning. How to control the amount of fuel during acceleration.