KR20040097483A - a control method for vibration improvement of engine in automobile - Google Patents

Abstract

PURPOSE: A vibration control method of an engine for a vehicle is provided to avoid engine rpm within the resonant frequency band, and to prevent vibration on each load by setting the avoidance engine rpm corresponding to resonant frequency and lowering the desired engine rpm in applying load. CONSTITUTION: An engine control unit decides the engine vibration generating condition by receiving engine coolant temperature, engine rpm, vehicle speed and change of switches from a vehicle state detecting unit(S100-S130), and detects load applied by a driver(S140). Resonant frequency and avoidance engine rpm are predetermined corresponding to each load(S150,S160), and estimated increase engine rpm is set corresponding to each load(S170). Values corresponding to each load are compared with the avoidance engine rpm(S180,S190). The engine control unit calculates and modifies the desired engine rpm according to each load(S200). The idle actuator control signal is output after calculating the actual inflow amount of air(S210).

Description

{A control method for vibration improvement of engine in automobile}

The present invention relates to a vibration control method of a vehicle engine, and more particularly, to a vibration control method of a vehicle engine for preventing the shaking of the engine when various loads are applied after the engine warm-up.

In general, after the engine warm-up, when the various air loads such as air conditioner, headlamp, and power steering are applied, the engine speed increases by 100 rpm or more before reaching the target engine speed, and then enters the target engine speed before reaching the target engine speed. In this case, when the frequency is higher than 100rpm, when it coincides with the resonant frequency band of the vehicle body vibration, there is a problem of severe shaking of the vehicle body.

If there is an element that impedes the user's comfort, such as shaking the vehicle body, there is a problem that damages the image of the vehicle manufacturer as well as user complaints. Therefore, in order to prevent the above-mentioned vibration of the vehicle body, the conventional technology has continued to improve the quality of the engine mounting insulator or the like, but it does not solve the problem of the vehicle body vibration.

Accordingly, an object of the present invention is to solve the above problems, avoiding the body resonance frequency, power steering wheel resonance frequency, air compressor resonance frequency by the engine speed control to improve the body vibration and vibration By setting the engine speed range, if the engine speed is higher than the expected engine speed when the load is applied, the target engine speed can be lowered to cope with the load, and the control to avoid the engine speed in the resonant frequency band region. It is to provide a vibration control method of a vehicle engine.

1 is a block diagram of a vibration control device of a vehicle engine according to an embodiment of the present invention;

2 is a flowchart illustrating a method of controlling vibration of a vehicle engine according to an embodiment of the present invention;

3 is a resonant frequency setting map chart for each load according to an embodiment of the present invention;

FIG. 4 is a diagram illustrating an expected engine speed setting map compared to a target engine speed when load is applied according to an embodiment of the present invention.

<Description of Symbols for Main Parts of Drawings>

100: vehicle operation state detection device 110: cooling water temperature detection unit

120: engine speed detection unit 130: vehicle speed detection unit

140: idle switch detection unit

150: various load switch detection unit

200: engine control device 300: drive device

The present invention for achieving the above object,

Determining an engine vibration generation condition when the engine of the vehicle is started;

Determining whether load is applied to the vehicle engine when the engine vibration generation condition is satisfied at the step;

If it is determined that the load to the vehicle engine is applied at the step, setting the vibration avoidance engine speed according to the vehicle load application;

Comparing the engine vibration avoidance engine speed set in the step with the engine speed when a load is applied;

If it is determined that the actual engine speed is greater when the load is applied than the vehicle vibration avoidance engine speed in the above step, the actual engine speed is characterized in that the step consisting of resetting the engine vibration avoidance engine speed or less.

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

1 is a block diagram illustrating a configuration of a vibration control apparatus for a vehicle engine according to an exemplary embodiment of the present invention, FIG. 2 is a flowchart illustrating a method for controlling vibration of a vehicle engine according to an exemplary embodiment of the present invention, and FIG. FIG. 4 is a diagram illustrating a resonant frequency setting map for each load, and FIG. 4 is a diagram illustrating an estimated engine speed setting map compared to a target engine speed when load is applied according to an embodiment of the present invention.

1 is a configuration diagram of a vibration control apparatus for a vehicle engine according to an exemplary embodiment of the present invention, which detects a change in a coolant temperature, an engine speed, a vehicle speed, an idle switch, and various load switches that vary according to a change in an operation state of a vehicle. An operation state detection device 100; When the engine engine of the vehicle is started by receiving a change in the coolant temperature, engine speed, vehicle speed, idle switch, and various load switches detected and applied by the vehicle operation state detection device 100, When it is determined whether the load is applied to the vehicle engine, and it is determined that the load is applied, the vibration avoidance engine rotation speed according to the vehicle load application is set, and when the load is applied, the engine rotation avoidance engine rotation speed is set. If it is determined that the actual engine speed is greater when the load is applied, the engine control device 200 for outputting a control signal for adjusting the engine intake air amount by resetting the actual engine speed to the vehicle vibration avoidance engine speed or less; Synchronizing with the control signal output from the engine control device 200, the driving device 300 for changing the amount of air sucked into the engine.

The apparatus 100 for detecting a vehicle operation state includes a coolant temperature detector 110 for detecting a change in engine coolant temperature after the vehicle is started;

An engine speed detector 120 which detects a change in engine speed that is changed according to a change in an operation state of the vehicle;

A vehicle speed detection unit 130 for detecting a vehicle speed change that varies according to a change in an operation state of the vehicle;

An idle switch detection unit 140 detecting an on / off state of an idle switch that is variable in association with a change in an accelerator pedal operation state of a driver;

It consists of a load switch detection unit 150 for detecting a variety of load switch changes that vary depending on the operation of the air conditioner switch, headlights, power steering wheel and other load switch operation.

With reference to the accompanying drawings, a vibration control method for a vehicle engine having the above configuration will be described by way of example.

When the driver starts the engine to drive the vehicle, the engine control apparatus 200 changes the engine coolant temperature, engine speed, vehicle speed, idle switch, and various load switches that are detected and applied by the vehicle operation state detection apparatus 100. Determine the engine vibration generation condition by receiving the input (S100 ~ S130).

In the above, the engine vibration generating condition is that after the engine is started, the coolant temperature of the actual engine must be equal to or greater than the first preset temperature (eg, 80 ° C) preset in the memory, and the actual running vehicle speed of the vehicle is preset in the memory. It should be less than or equal to the second set vehicle speed (e.g., 15 Kph), the engine idle state with the engine idle switch in the 'on' state, and the engine speeds y1, y2, y3, If the condition is equal to or less than one of y4 and y5, the engine control apparatus 200 determines that vibration may be generated in the started engine.

In the above, when it is determined that the condition that the vibration can be generated in the engine started vehicle, the engine control apparatus 200 determines whether the load according to the driver's operation is applied (S140).

Here, the load refers to an air conditioner, a power steering, a headlight, a power train, a shift stage, and the like, which are driven according to a driver's switch operation to increase the engine speed.

Therefore, when it is determined that the load is applied to the engine started according to the driver's switch operation, the engine control apparatus 200 is preset in the memory as shown in FIG. 3 to prevent vibration due to the load application. The resonant frequencies x1 to x5 and the avoided engine speeds y1 to y5 for each load are set (S150 and S160).

The resonance frequency of each load is a frequency band obtained through a plurality of tests, and the vibration avoidance engine speed of each load is an engine calculated by multiplying an operation constant (eg, 30) by the resonance frequency obtained through a plurality of tests. Is the rotation speed. The resonance frequency and vibration avoidance engine speed of each load are stored in a memory.

That is, the avoidance engine speed = resonance frequency f operation constant 30.

For example, in setting the resonant frequency for each load, the air conditioner (x1) 28Hz, power steering (x2) 27Hz, headlight (x3) 15Hz, power train (x4) 16Hz, D lazy (x5) 16Hz can be set.

Here, the resonance frequency is an example, and has a different value for each vehicle.

Accordingly, the avoided engine speed y according to the resonance frequency x is

Air conditioner (y1): 28 × 30 = 840 rpm

Power steering (y2): 29 × 30 = 870 rpm

Headlight (y3): 15 × 30 = 450 (900) rpm

Power train (y4): 16 × 30 = 480 (960) rpm

D range (y5): 16 × 30 = 480 (960) rpm

Is set.

Subsequently, the engine control device 200 sets the expected engine speed z1 to z5 for each load applied as shown in FIG. 4 (S170).

The estimated engine speeds z1 to z5 for each load are preset values in a memory obtained through a plurality of tests.

For example, air conditioner (z1): 120 rpm,

Power steering (z2): 150rpm,

Headlight (z3): 100 rpm,

Power train (z4): 100 rpm,

D range (z5): 100rpm

Is set in memory.

Subsequently, the engine control apparatus 200 calculates the target engine speed A to E for each load to be developed below, and the expected engine at the time of applying each load to the base engine speed base rpm according to the air-fuel ratio. The sum of the rotational speeds z1 to z5 is added to calculate the calculated K, and the respective calculated value K for each load and the avoidance engine speeds y1 to y5 for each load applied above are respectively calculated. Comparison is made (S180, S190).

That is, when it is determined that the value K for each load load calculated above is greater than the avoided engine speeds y1 to y5 for each load to be applied, the engine control apparatus 200 may avoid the engine torque for each load applied. After calculating the target engine speeds A to E for each load by subtracting the corresponding operation constants for the numbers y1 to y5, the target engine speeds are changed (S200).

For example, the change of the target engine speed A according to the air conditioner driving is performed as follows.

If the basic target engine speed + (z1 + z2 + z3 + z4 + z5) <y1 is satisfied, the target engine speed A is calculated as y1 a (subtraction constant: 50). Therefore, the change target engine speed B of the power steering is

When the basic target engine speed + (z1 + z2 + z3 + z4 + z5) <y2 is satisfied, the target engine speed B is calculated as y2 b (subtraction operation constant: 80).

The change target engine speed (C) when the headlight is driven

When the basic target engine speed + (z1 + z2 + z3 + z4 + z5) <y3 is satisfied, the target engine speed C is calculated as y3 c (subtraction constant: 100).

The change target engine speed (D) when driving the power train

When the basic target engine speed + (z1 + z2 + z3 + z4 + z5) <y4 is satisfied, the target engine speed D is calculated as y4 d (subtraction constant: 90).

Finally, the change target engine speed (E) at the shift stage D range

When the basic target engine speed + (z1 + z2 + z3 + z4 + z5) <y5 is satisfied, the target engine speed E is calculated as y5 e (subtraction constant: 70).

As described above, the engine control apparatus 200 that has calculated the change target engine speed outputs an idle actuator control signal for controlling the amount of air sucked in so as to follow the change target engine speed (S210). ).

In outputting a control signal to the idle actuator, the engine control apparatus 200 first calculates the amount of air when the load is applied per unit engine speed according to the expected engine speed of rising (the amount of air when the load is applied / z1 or z2 or z3 or z4 or z5), by subtracting the amount of air calculated by multiplying the subtracted engine speed, the idle actuator is controlled to reach the changed target engine speed.

Thus, after the engine is started, the avoided engine speed is set for the resonant frequency according to the respective loads. If the expected engine speed value is higher than the set value when the load is applied, the target engine speed is lowered to apply the load. By avoiding the engine rotational speed in the resonant frequency band region so as to correspond to, it is possible to prevent the generation of vibration for each applied load.

As described above, the vibration control method of the vehicle engine according to the present invention sets the avoidance engine speeds for the resonant frequencies according to the respective loads by controlling the engine speed in order to improve the body vibration and vibration. When the expected engine speed value is higher than or equal to the set value, the target engine speed is lowered to correspond to the applied load, thereby avoiding the engine speed in the resonant frequency band region, thereby preventing occurrence of vibration for each applied load. can do.

Claims (4)

Determining an engine vibration generation condition when the engine of the vehicle is started; Determining whether load is applied to the vehicle engine when the engine vibration generation condition is satisfied at the step; If it is determined in this step that the load to the vehicle engine is applied, setting the vibration avoidance engine speed in response to the vehicle load application in the memory; Comparing the engine vibration avoidance engine speed set in the step with the engine speed when a load is applied; Resetting the target engine speed to be less than or equal to the vehicle vibration avoidance engine speed when it is determined that the actual engine speed is greater than the vehicle vibration avoidance engine speed in the step; And outputting a control signal for controlling the intake air amount so as to follow the target engine speed reset in the step. The vibration control method of claim 1, wherein the vibration avoidance engine rotation speed includes setting a vibration avoidance engine rotation speed corresponding to a resonant frequency band for each load stored in a memory through a test. The method of claim 1, wherein the method for resetting the target engine speed to be less than or equal to the vehicle vibration avoidance engine speed is performed by adding and calculating a value obtained by adding the estimated engine speed at the time of applying each load to the basic engine speed according to the air-fuel ratio. Calculating and comparing the calculated value with the avoided engine revolutions for each load applied thereto; If it is determined that the value for each load calculated in the above step is greater than the avoided engine speed for each load applied, the corresponding engine constant for each avoided engine speed for each load applied is subtracted to calculate the target engine speed for each load. And then changing the target engine speed to control the vibration of the vehicle engine. The method of claim 1, wherein the method of controlling the intake air amount to follow the reset target engine speed is calculated by multiplying the subtracted engine speed by calculating the amount of air when the load is applied per unit engine speed according to the expected expected engine speed. And subtracting the calculated amount of air to control the amount of intake air to reach the changed target engine speed.