KR100354002B1 - Method for controlling a air flow quantity of vehicle - Google Patents

Abstract

The present invention relates to a method of controlling the air volume of a vehicle to control the air amount by the throttle opening degree and the engine speed when the intake air amount sensor abnormality,

The present invention includes the steps of detecting the throttle angle and the engine speed when an abnormality occurs in the intake air amount sensor; Calculating the throttle threshold and determining the air volume in the step; Determining whether the throttle angle is less than or equal to the calculated throttle limit in a state where the air amount is determined in the step; Subtracting any amount of crystal air from the throttle angle if the throttle angle is less than the calculated throttle limit in the step; In this step, if the throttle angle is not less than the calculated throttle limit, it is characterized in that the step of subtracting any amount of the determined air from the throttle limit.

Description

METHOD FOR CONTROLLING A AIR FLOW QUANTITY OF VEHICLE}

The present invention relates to a method for controlling the air volume of a vehicle, and more particularly, to a method for controlling the air volume of a vehicle so that the amount of air can be controlled by the throttle opening degree and the engine speed when the intake air amount sensor is abnormal.

Generally, the air volume control of the vehicle includes a signal input from an intake air amount sensor 1, an engine speed sensor 2, a throttle valve switch 3, and an intake air temperature sensor 4, as shown in FIG. It is determined by the electronic control device 5 which controls the signals to be set by a predetermined program, wherein the intake air amount sensor is determined as an important factor in determining the injection amount of gasoline.

Therefore, if the air-fuel ratio of the engine is determined and the amount of air is unknown, the required amount of gasoline is not determined.

Therefore, the intake air amount sensor calculates the amount of air introduced into the cylinder during normal operation.

However, when the intake air amount sensor abnormality, the air amount is predicted through a predetermined air amount prediction map MAP, ie, a throttle angle and an engine speed function, and the air amount is finally determined after correcting the intake temperature.

However, it is necessary to measure and map the air volume in all areas of the throttle angle and the engine speed in preparation for the malfunction of the intake air quantity sensor, and the correction by the throttle angle, the engine speed and the intake temperature is required in all areas. There is a problem that an error occurs because it is impossible to predict the perfect air volume.

Accordingly, an object of the present invention is to set the intake air amount sensor to calculate the air amount based on the throttle angle and the engine speed during malfunction, so that the air amount can be predicted without error in the entire area.

1 is a control block diagram of an apparatus for controlling air volume of a typical vehicle.

Figure 2 is a flow chart for the air amount control method of the vehicle of the present invention.

Figure 3 is a graph of air volume for the throttle angle applied to the present invention.

4 is a graph of engine speed against a throttle limit applied to the present invention.

5 is a graph of the air volume when the throttle angle applied to the present invention is below the throttle limit.

Figure 6 is a graph of the engine speed and the determined air amount applied to the present invention.

In order to realize the above object, the present invention includes the steps of calculating the throttle limit value, determining the air amount when an intake air amount sensor abnormality occurs, and determining whether the throttle angle is less than the calculated throttle limit value in the state where the air amount is determined; Subtracting any amount of crystal air from the throttle angle if the throttle angle is less than the calculated throttle limit in the step; In this step, if the throttle angle is not less than the calculated throttle limit, it is characterized in that the step of subtracting any amount of the determined air from the throttle limit.

Therefore, according to the present invention, by determining the air amount by the throttle angle and the engine speed when the intake air amount sensor abnormality, it is possible to accurately predict the air amount without error over the entire region without mapping the determined air amount by the throttle angle and the engine speed area It will be possible.

Hereinafter, described in detail with reference to the accompanying drawings, preferred embodiments of the present invention.

2 is a flowchart of a method for controlling an air volume of a vehicle according to the present invention, the method comprising: detecting an throttle angle and an engine speed when an error occurs in an intake air amount sensor (20); Calculating (21) a throttle limit and determining the amount of air in said step (20); Determining (22) whether the throttle angle is less than or equal to the calculated throttle limit in a state where the air amount is determined in the step (21); Subtracting any amount of crystal air from the throttle angle if the throttle angle in the step 22 is below the calculated throttle limit; If in step 22 the throttle angle is not below the calculated throttle limit, then step 24 is made to subtract any amount of determined air from the throttle limit.

According to the present invention made as described above, when an abnormality occurs in the intake air amount sensor, the electronic controller detects the throttle angle and the engine speed from the throttle valve switch and the engine speed sensor (step 20).

Subsequently, the electronic control apparatus calculates the detected throttle limit value by a predetermined program and determines the engine speed (step 21), that is, as shown in FIG. 3, the air amount according to the throttle angle is determined by the throttle angle. As the air volume increases, the air volume no longer increases when the limit throttle angle is reached. This corresponds to the point indicated by the "0" mark. These values, in which the air volume no longer increases with each engine speed, are called "throttle thresholds" and can be expressed as a function of engine speed.

Therefore, as shown in FIG. 4, the throttle limit value can be displayed as a curve to represent the throttle limit value for each engine speed, and the curve is expressed as throttle limit value = T ₁ ln (RPM) − T ₂ . Where T _{1 and} T ₂ are constants.

Subsequently, when the throttle angle is less than or equal to the throttle limit, the air amount corresponding to the throttle angle and the throttle limit value is shown as shown in FIG. 5. Here, the amount of air according to the throttle angle for each engine speed may be set (modeled) as follows.

Air volume = A ln (throttle angle)-B

Where A and B vary depending on the engine speed, and become constant at constant speeds.

Air _flow at 1500 rpm = A _{1500 rpm} ln (throttle angle)-B _{1500 rpm}

Air at 1600 rpm = _1600rpm A ln (throttle angle) - B _1600rpm

Represented by

When A and B are set (modeled) with respect to engine speed, as shown in FIG. 6, it can be represented by the following formula.

A = a ₁ ln (number of revolutions) - a ₂

B = b ₁ ln (speed)-b ₂ a _1, a _2, b _{1 and} b ₂ are constants respectively.

Therefore, the relational expression for finally setting (modeling) the air volume according to the throttle angle is as follows.

1) Air volume = A ln (throttle angle)-B

= {a ₁ ln (speed)-a ₂ } ln (throttle angle)-{b ₁ ln (speed)-b ₂ }

........ For throttle angle ≤ {T ₁ ln (speed)-T ₂ }

2) air volume

= {a ₁ ln-a ₂ } {T ₁ ln-t ₂ }-{b ₁ ln-b ₂ }

Throttle angle>> {T ₁ ln (speed)-T ₂ }

In the above relation, T _1, T _2, a _1, a _2, b _{1, and} b ₂ are all constants and determined according to engine characteristics. Therefore, this setting (modeling) is applied to the control logic of the actual engine, and only the ideal number values are mapped, so that the air volume matching for each engine speed and throttle region is unnecessary.

When the throttle limit value and the air amount are determined as described above, the electronic controller determines whether the currently detected throttle angle is less than or equal to the calculated throttle limit value (step 22).

At this time, if the throttle angle is less than the calculated throttle limit, the electronic controller determines the air volume = A ln (throttle angle)-B (step 23).

However, if the throttle angle is not equal to or less than the calculated throttle limit value, the electronic controller determines the air volume = A ln (throttle limit value)-B and finally outputs it (step 24).

As described above, the present invention calculates the throttle limit value, determines the air amount when the intake air amount sensor abnormality occurs, and determines whether the throttle angle is less than or equal to the calculated throttle limit value and determines the air amount based on the throttle angle and the limit. By doing so, when the intake air amount sensor abnormality, the air amount determined by the throttle angle and the engine speed can be accurately predicted without any error over the entire region without mapping the throttle angle and the engine speed by region.

Claims (1)

In the air volume control method of the vehicle, Detecting a throttle angle and an engine speed from a throttle valve switch and an engine speed sensor when an intake air amount sensor abnormality of the vehicle occurs; Calculating a throttle threshold at which the air amount no longer increases for each of the detected engine speeds according to a program preset in the electronic controller, and determining the air amount; Determining whether the sensed throttle angle is less than or equal to the calculated throttle limit; Subtracting any determined air quantity from the sensed throttle angle if the sensed throttle angle is below the calculated throttle limit; And subtracting a predetermined amount of determined air from the calculated throttle limit if the sensed throttle angle is not equal to or less than the calculated throttle limit.