KR100456469B1 - brake negative pressure controlling method for engine in vehicle - Google Patents

Abstract

To reduce the idle speed actuator duty through the ignition timing advance and to reduce the required torque in order to solve the problem of the decrease of the negative pressure caused by the increase of the engine load;

Initializing all variables to be used when power is applied to the vehicle, and determining whether the first condition for improving the brake negative pressure during driving is satisfied; If it is determined in the step that the first condition for improving the brake negative pressure is satisfied, calculating the necessary correction negative pressure and determining whether the correction necessary negative pressure is equal to or greater than a predetermined reference value; Performing first-order correction by ignition timing correction if the correction required negative pressure is equal to or greater than a predetermined reference value and re-determining whether the correction necessary negative pressure is equal to or greater than a predetermined reference value; In this step, if the correction necessary negative pressure is equal to or more than a predetermined reference value, the second correction is performed by the air conditioner off control, normal ignition and idle control are performed, and when the engine is stopped, all the control ends. By increasing the brake negative pressure, it is possible to solve the problem of the brake pedal becoming hard at high ground and to improve the braking performance.

Description

Brake negative pressure controlling method for engine in vehicle}

The present invention relates to a vehicle engine, and more particularly, when the engine target rotational speed is the same in a vehicle equipped with an automatic transmission, the increase in the negative pressure can be controlled by reducing the idle actuator duty based on the proportional to the idle actuator duty. It relates to a brake negative pressure control method of a vehicle engine.

In general, a brake for braking a vehicle in a vehicle having an automatic transmission uses a negative pressure of an in-take manifold of the engine.

When the negative pressure of the engine is large, the brake boost operating pressure is relatively increased, so that the brake for braking the vehicle is also improved.

The in-tech manifold negative pressure at engine idle is a function of the engine speed and idle speed actuator opening, and the engine pressure increases, the lower the idle actuator opening (the lower the duty), the higher the negative pressure.

However, in the vehicle having the automatic transmission as described above, when the air conditioner is 'on' as shown in FIG. 5 or when the shift stage is driven at the forward driving 'D' stage, the engine load increases due to the increase in the idle actuator air volume. This implies that the negative pressure is reduced.

That is, in a small vehicle, the brake negative pressure tends to be low, and in the highlands, the brake pedal becomes stiff and the braking performance is deteriorated.

Accordingly, an object of the present invention is to solve the above problems, in order to solve the problem of the reduction of the negative pressure caused by the increase of the engine load, by reducing the idle speed actuator duty through the advance of the ignition timing, and by reducing the required torque, An object of the present invention is to provide a method for controlling brake negative pressure of a vehicle engine capable of increasing negative pressure.

The present invention for achieving the above object,

Initializing all variables to be used when power is applied to the vehicle, and determining whether the first condition for improving the brake negative pressure during driving is satisfied;

If it is determined in the step that the first condition for improving the brake negative pressure is satisfied, calculating the necessary correction negative pressure and determining whether the correction necessary negative pressure is equal to or greater than a predetermined reference value;

Performing first-order correction by ignition timing correction if the correction required negative pressure is equal to or greater than a predetermined reference value and re-determining whether the correction necessary negative pressure is equal to or greater than a predetermined reference value;

In this step, if the correction required negative pressure is equal to or greater than a predetermined reference value, the second correction is performed by the air conditioner off control, normal ignition and idle control are performed, and then all the control ends when the engine is stopped. It is done.

1 is a block diagram of a brake negative pressure control device of a vehicle engine according to the present invention;

2 is a flowchart illustrating a method for controlling a brake negative pressure of a vehicle engine applied to the present invention.

3 is a change chart of the idle actuator by the change in the ignition timing according to the present invention,

4 is a graph showing a torque change compared to an ignition timing according to the present invention;

5 is a graph of brake negative pressure change according to a conventional engine load.

<Description of Symbols for Main Parts of Drawings>

100: vehicle operation state detection device 110: throttle valve opening amount detection unit

120: engine speed detection unit 130: brake operation state detection unit

140: idle switch state detection unit 150: air conditioner operation state detection unit

160: vehicle speed detection unit 170: atmospheric pressure detection unit

180: in manifold pressure detection unit 190: shift lever position state detection unit

200: shift control device 300: engine control device

400: drive device

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

1 is a block diagram illustrating a brake negative pressure control device of a vehicle engine according to an exemplary embodiment of the present invention, and the vehicle operation state detection device 100 detects a signal that varies according to a change in an operation state of a vehicle.

The shift control apparatus 200 receives a shift lever position detected and applied by the vehicle operation state detection apparatus 200 and outputs a shift stage position.

The engine control apparatus 300 includes a throttle valve opening degree, an engine speed, a brake operating state, an idle switch state, an air conditioner operating state, a vehicle speed, an atmospheric pressure, an in-tech manifold detected and applied by the vehicle operating state detecting apparatus 100. When the pressure and the shift lever position output from the shift control device 200 are applied to satisfy the first condition for improving the brake negative pressure while driving the vehicle, the correction necessary negative pressure is calculated to be equal to or greater than a predetermined reference value. When performing the first correction by the ignition timing correction, re-determining whether the correction necessary negative pressure is equal to or greater than a predetermined reference value, performing the second correction by the air conditioner off control, and performing normal ignition and idle control. Next, when the engine stops, all control ends.

The driving device 400 adjusts an idle speed actuator state of the engine in synchronization with predetermined control signals output from the shift control apparatus 200 and the engine control apparatus 300.

The vehicle operation state detection device 100 includes a throttle valve opening amount detection unit 110 for detecting a change in the opening amount of a throttle valve to be interlocked according to an accelerator pedal operation state of a driver; An engine speed detector 120 which detects an engine speed that varies according to a change in an operation state of the vehicle; A brake operation state detection unit 130 for detecting an operation state of the brake according to a state of a switch that is changed according to a driver's brake pedal operation state; An idle switch state detection unit 140 for detecting a state of an idle switch that varies according to a change in an operation state of the vehicle; A vehicle speed detector 150 for detecting a vehicle speed that varies according to a driving state of the vehicle; An atmospheric pressure detector 170 for detecting an atmospheric pressure that varies according to driving conditions of the vehicle; An in manifold pressure detection unit 180 for detecting a pressure of the in-tech manifold which is changed according to a change in a vehicle operating state; The shift lever position detector 190 detects a position of the shift lever whose position is changed according to the shift lever operating state of the driver.

It will be described with reference to Figures 2, 3 and 4 attached to the brake negative pressure control method of the vehicle engine having the above configuration.

2 is a flowchart illustrating a method for controlling a brake negative pressure of a vehicle engine applied to the present invention, and FIG. 3 is a change chart of an idle actuator according to a change in an ignition timing according to the present invention, and FIG. 4 is a torque change versus an ignition timing according to the present invention. It is a graph shown.

When power is applied to the vehicle, the engine control apparatus 300 initializes all the variables used, and when the vehicle is driven, the vehicle operation state detecting apparatus 100 changes the opening degree of the throttle valve according to the change of the vehicle operation state. The engine speed, brake operation status, idle switch status, air conditioner operation status, vehicle speed, atmospheric pressure, in-manifold pressure and shift lever position status are detected.

Accordingly, when the shift control apparatus 200 outputs a predetermined control signal to the vehicle operating state detecting apparatus 100 to receive a shift lever position detected by the vehicle operating state detecting apparatus 100, the vehicle operating state. The detection apparatus 100 outputs a shift lever position in synchronization with an applied control signal.

The shift control apparatus 200 receives a shift lever position output from the vehicle operation state detecting apparatus 100 and performs the shift control by a preset program and simultaneously outputs the shift shift position by using can communication. .

In addition, the engine control device 300 includes a throttle valve opening degree, an engine speed, a brake operating state, an idle switch state, an air conditioner operating state, a vehicle speed, an atmospheric pressure, an in manifold pressure and a shift detected by the vehicle operating state detecting device 100. When a predetermined control signal is output to the vehicle operating state detecting device 100 and the shift control device 200 to receive the lever position state, the vehicle operating state detecting device 100 is detected in synchronization with the applied control signal. Opening degree, engine speed, brake operating state, idle switch state, air conditioner operating state, vehicle speed, atmospheric pressure, in-manifold pressure, etc., the shift control device 200 is a control signal applied from the engine control device 300 The shift lever position is outputted in CAN communication in synchronization with.

Accordingly, the engine control apparatus 300 includes a throttle valve opening degree, an engine speed, a brake operating state, an idle switch state, an air conditioner operating state, a vehicle speed, which is applied from the vehicle operating state detecting apparatus 100 and the shift control apparatus 200. In response to the atmospheric pressure, the in-manifold pressure, the shift lever position state, and the like, it is determined whether the first condition for improving the brake negative pressure is satisfied (S100 and S110).

The brake negative pressure improvement 1 condition is a brake braking condition in which the shift stage is the D range air conditioner on state, the shift stage is the D range, the air conditioner switch state is on, and the idle switch state is on (acceleration pedal switch off state). This is a condition that a predetermined time has elapsed since the brake operation state is on, and the vehicle speed is a predetermined set value (30 Kph) or more.

Therefore, when it is determined that the brake negative pressure improvement 1 condition is satisfied, the engine control apparatus 300 calculates and calculates the necessary correction negative pressure of the engine (S120).

The correction necessary negative pressure is calculated as brake negative pressure (BRAKE_PS) = atmospheric pressure (PU)-in manifold pressure (PS), sets the target negative pressure (TARGET) stored in the memory according to the engine operating state, and then sets the target negative pressure (TARGET). )-The correction necessary negative pressure (DELTA_PS) is calculated by the brake negative pressure (BRAKE_PS).

Subsequently, as the correction necessary negative pressure DELTA_PS is calculated, the engine control apparatus 300 determines whether the calculated correction necessary negative pressure DELTA_PS satisfies a condition greater than 0 (S130).

When it is determined that the correction necessary negative pressure DELTA_PS calculated above is greater than zero, the engine control apparatus 300 may reduce the idle speed actuator duty by the ignition timing advance correction as illustrated in FIG. 3. The first negative pressure correction is performed (S140).

The first negative pressure correction by the ignition timing correction is calculated by the correction required negative pressure DELTA_PS / negative pressure improvement effect per degree (DPS_DZW) calculated above.

In the above description, the negative pressure improvement effect (DPS_DZW) per 1 ° is set from a value stored in the memory according to the correction necessary negative pressure. That is, the negative pressure improvement effect value per 1 ° is determined as a matching value corresponding to the map data of the correction necessary negative pressure calculated in step S120.

As the first negative pressure correction by the ignition timing correction is performed, the engine control apparatus 300 calculates the correction required negative pressure DELTA_PS of the engine to set a value larger than 0 to the correction necessary negative pressure DELTA_PS. It is determined again to have (S150).

When the state of the engine satisfies the condition that the correction necessary negative pressure DELTA_PS is greater than 0, the engine control apparatus 300 reduces the idle speed actuator duty by the ignition timing advance correction as shown in FIG. 4. In operation S160, it is determined that there is a limit to the method, and a second correction for controlling off the air conditioner in operation.

That is, when the state of the engine satisfies the condition that the correction necessary negative pressure DELTA_PS is greater than 0, the air conditioner for controlling the engine negative pressure is determined to be forced to control off the air conditioner for a predetermined time (AIR CON_OFF_TIME). Outputs a control signal.

The predetermined time (AIR CON_OFF_TIME) of the air conditioner off control for adjusting the engine negative pressure is set to a data value stored in the memory according to the correction necessary negative pressure. That is, the air conditioner off control time is determined as a matching value corresponding to the map data of the correction necessary negative pressure calculated in step S120. As described above, the negative pressure improvement per degree in the first correction according to the present invention is improved. As described above, the effect value and the air conditioner off control time in the second correction are matched with a value corresponding to the data of the correction necessary negative pressure, that is, the correction necessary negative pressure calculated from the map type data. To apply a value.

In the above, by performing the first correction by the ignition timing correction and the second correction by forced air-conditioning off, the brake negative pressure can be prevented from being lowered, so that the engine control apparatus 300 is stored in the memory. After performing the normal ignition timing and idle control, and returns to the main routine when the engine is stopped (S170, S180).

However, if the brake negative pressure improvement first condition is not satisfied or it is determined that the correction necessary negative pressure is equal to 0, the engine control apparatus 300 performs normal ignition timing and idle control without performing engine idle speed actuator duty correction. Perform.

In addition, if it is determined in S180 that the engine continues to operate, the engine control apparatus 300 returns to step S110 of determining the first condition for improving the brake negative pressure.

Thereby, the problem that the brake underpressure is low and the brake pedal becomes hard at high ground, the problem of the braking performance deterioration, etc. can be prevented.

As described above, the present invention reduces the idle speed actuator duty through the advance of the ignition timing and reduces the required torque to solve the problem of the decrease in the negative pressure caused by the increase in the engine load, thereby increasing the brake negative pressure to brake the high ground. It can solve the problem of the pedal hardening and also improve the braking performance.

Claims (7)

Initializing all variables to be used when power is applied to the vehicle, and determining whether the first condition for improving the brake negative pressure during driving is satisfied; If it is determined in the step that the first condition for improving the brake negative pressure is satisfied, calculating the necessary correction negative pressure and determining whether the correction necessary negative pressure is equal to or greater than a predetermined reference value; Performing first-order correction by ignition timing correction if the correction required negative pressure is equal to or greater than a predetermined reference value and re-determining whether the correction necessary negative pressure is equal to or greater than a predetermined reference value; In this step, if the correction required negative pressure is equal to or greater than a predetermined reference value, the second correction is performed by the air conditioner off control, normal ignition and idle control are performed, and then all the control ends when the engine is stopped. A brake negative pressure control method for a vehicle engine. 2. The brake negative pressure improving first condition is a brake braking condition in which the shift stage is a D range air conditioner on state, the shift stage is a D range, the air conditioner switch state is on, and the idle switch state is on (acceleration). Pedal switch off state), a state in which a certain time has passed since the brake operation state is turned on, and the vehicle negative pressure control method for a vehicle engine comprising a condition that the vehicle speed is more than a predetermined set value. The method according to claim 1, wherein the correction necessary negative pressure is calculated by applying the brake negative pressure to atmospheric pressure-in manifold pressure, setting the target negative pressure stored in the memory according to the engine operating state, and then calculating the correction necessary negative pressure by the target negative pressure-brake negative pressure. Brake negative pressure control method of a vehicle engine comprising a The method of claim 1, wherein the ignition timing correction includes performing an ignition timing advance correction to reduce an idle speed actuator duty, and calculating and correcting the correction required negative pressure by a negative pressure improvement effect per 1 °. . 5. The method of claim 4, wherein the negative pressure improvement effect per 1 ° is set at a value stored in a memory according to the correction necessary negative pressure. The method of claim 1, wherein the air conditioner off control includes determining the air conditioner off for adjusting the engine negative pressure to forcibly turn off the air conditioner for a predetermined time. The method of claim 1, wherein the predetermined time of the air conditioner off control for adjusting the engine negative pressure is set to a data value stored in a memory according to the required correction negative pressure.