KR20020052540A - Method for controlling knock during restarting in hot temperature for a vehicle - Google Patents

Abstract

PURPOSE: A method for controlling knock at the restarting of a vehicle at high temperature is provided to prevent the excessive knock at the idling of the restarting of the vehicle at the high temperature, thereby improving the product value. CONSTITUTION: A method for controlling knock at the restarting of a vehicle at high temperature comprises the steps of: correcting an ignition period according to the feedback of engine rpms by confirming the high temperature restarting condition; applying the compensation air amount according to the variation of the engine load and increasing the engine rpms by adding the intake air amount to an engine when the ignition period is corrected according to the feedback of the engine rpms; determining whether the knock occurs by detected signals from a knock sensing sensor when the engine rpms increases according to the correction of the ignition period or the variation of the engine load; and terminating the correction of the ignition period by the feedback of the engine rpms, when the knock is detected from the knock sensing sensor and the number of the knock is more than the predetermined value.

Description

Knock control method for high temperature restart of car {METHOD FOR CONTROLLING KNOCK DURING RESTARTING IN HOT TEMPERATURE FOR A VEHICLE}

The present invention relates to a knock control method for restarting a car at a high temperature. More specifically, an ignition timing compensation method performed when the engine rotation speed does not follow the target rotation speed due to a decrease in charging efficiency of the intake machine due to an increase in intake temperature. The present invention relates to a knock control method at high temperature restart of the vehicle to improve the speed.

In general, engine control of a vehicle is performed by electronic control means such as an ECU (Electronic Control Unit). The ECU receives the detection signal of the in-vehicle sensing means to calculate the driving condition of the engine and perform driving condition control including air-fuel ratio control according to the calculated driving condition.

1 shows a signal processing flowchart of an ECU system for performing such engine control.

According to Figure 1, the input signal to the ECU is the engine speed detected and applied by the crank position sensor, the intake temperature detected and applied by the intake temperature sensor. Cooling water temperature sensed and applied by the water temperature sensor installed in the cooling system, and knock signal applied by the knock detection sensor installed in the cylinder.

Then, the ECU detects the driving condition of the engine according to the input signal sensed and applied by the plurality of sensing means as described above, and performs the engine control to be the optimal driving condition with the set map or the set logic.

Output signals of the ECU for performing such engine control include target rotational speed determination, ignition timing control, knock determination, and the like.

A flowchart of the knock control method at high temperature restart performed by the ECU is shown in FIG.

2, in the engine control of the ECU, when restarting at a high temperature of more than 40 ° C outside air temperature, the actual engine speed in the idle state is unable to follow the target speed due to a decrease in the charging efficiency of the intake machine according to the increase in intake temperature This is most often the case.

At this time, the actual engine speed is fed back to the rotational speed to follow the target rotational speed to advance the ignition timing.

Therefore, the ECU judges whether or not it corresponds to a high temperature restart, and if it is determined that the high temperature restart is performed, feedback control of the engine speed (ST11, ST12).

The ignition timing is corrected by the engine speed feedback control. Normally, when the high temperature is restarted, the ignition timing advance is made, and the ignition timing advance correction amount at this time is called θ1 (ST13).

As such, when the ignition timing is advanced at high temperature restart, the possibility of knocking increases because the intake air temperature and the cooling water temperature become very high. Thus, when knocking occurs, the ignition timing is perceived by a certain amount, and when knocking does not occur, the ignition timing is restored by a predetermined slope.

That is, when knock occurs due to the advance of the ignition timing, the ignition timing is perceived by the set correction value θ2 (ST14, ST15).

The total ignition timing then becomes a value θ1 + θ2 plus engine speed feedback correction and knock correction (ST16).

However, since the engine speed feedback correction and the knock correction are added to the total ignition timing, the total ignition timing is canceled with each other, so that the correction amount at the ignition timing is close to zero, and the probability of occurrence of knock is maintained without being reduced.

In particular, knocking with strong noise is generated at the shift range D stage or immediately after the load change of the air conditioner on. Such knocking is called `` Audible Knock, '' and when knocking occurs, the vehicle's marketability may deteriorate.

An example of the ignition timing according to the ignition timing compensation control at the time of high temperature restart is shown in FIG. 3.

As shown in Figure 3, there is a problem that knock occurs when the high-temperature restart idle idling, the deterioration of the merchandise.

And although the knock ignition timing compensation is performed, there is a problem that the compensation of the knock ignition timing is canceled due to the rotational speed feedback condition.

In addition, there is a problem that knock generation occurs continuously instead of a single occurrence.

The present invention has been created to solve the above-mentioned conventional problems, the object of the present invention is the ignition performed when the engine rotation speed does not follow the target rotation speed because the charging efficiency of the intake machine is lowered due to the increase in intake temperature In order to improve the timing compensation method, there is provided a knock control method at a high temperature restart of a vehicle.

1 is a signal processing flowchart of a general ECU system,

2 is a flowchart of a knock control method at high temperature restart of a vehicle according to the prior art;

Figure 3 is an illustration of the ignition timing compensation at high temperature restart according to the prior art,

4 is a signal processing flowchart of an ECU system to which the present invention is applied;

5 is a flowchart of a knock control method at high temperature restart of a vehicle according to an embodiment of the present invention;

6 is an exemplary view of ignition timing compensation at high temperature restart according to the present invention.

In the high temperature restarting knock control method of the vehicle of the present invention for achieving the above object, in the vehicle equipped with the electronic control means for engine control, the electronic control means to check the high temperature restart condition by the engine speed feedback ignition timing Performing a calibration; If the correction of the ignition timing by the engine speed feedback is performed, the electronic control means increases the engine speed by adding an intake air amount to the engine by applying a compensation air amount according to a change in the engine load; When the engine speed is increased due to the correction of the ignition timing by the engine speed feedback or the variation of the engine load, the electronic control unit is configured to determine whether knock occurs by receiving a detection signal from the knock detection sensor; When the knock is detected by the knock sensor and the number of knock occurrences exceeds a set value, the electronic control means includes stopping the ignition timing compensation by the engine speed feedback.

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

4 is a signal processing flowchart of an ECU system to which the present invention is applied, and FIG. 5 is a flowchart of a knock control method at high temperature restart of a vehicle according to an embodiment of the present invention, and FIG. 6 is an ignition timing at high temperature restart according to the present invention. An illustration of compensation.

According to Fig. 4, the input signal to the ECU includes the engine speed detected from the detection signal of the crank position sensor, the intake air temperature detected from the detection signal of the intake air temperature sensor, and the cooling water temperature detected from the detection signal of the cooling water temperature sensor. A shift range signal detected and applied by the beater switch, a knocking signal detected by the knock detection sensor provided in the cylinder, and an air conditioner load signal applied in accordance with the on / off operation of the air conditioner switch.

Then, the ECU receives each input signal as described above, detects the operating conditions of the engine, performs determination of target rotation speed determination, knocking determination, and the like, and performs ignition timing control and air volume control.

Thus, according to Fig. 5, the ECU has an air amount 1 (A1) for applying and maintaining a constant load change, and an air amount 2 (A2) for applying only at the initial load change. The air amount 1 and the air amount 2 may be set to an appropriate value calculated experimentally (ST21).

The ECU determines whether the high temperature restart condition is satisfied (ST22).

Preferably, the high temperature restart condition is a condition in which the intake air temperature detected by the intake air temperature sensor at startup exceeds 70 ° C, and the condition in which the coolant water temperature detected by the cooling water temperature sensor at startup exceeds 105 ° C. If it is established at the same time, it is set to be established.

When it is confirmed in step ST22 that the high temperature restart condition is established, the ECU performs engine speed feedback control according to the engine speed detected by the crank position sensor (ST23).

The ignition timing is corrected by the engine speed feedback control performed in step ST23. In general, when the high temperature is restarted, the advance of the ignition timing is made, and the ignition timing advance correction amount at this time is referred to as θ1 (ST24).

In addition, when the ignition timing correction θ1 according to the engine speed feedback is performed, the ECU determines whether a change in the engine load occurs (ST25).

At this time, the engine load fluctuation in the engine idling state occurs when the shift range is in the D or R range or when the air conditioner switch is turned on. The ECU generates the engine as described above through signals detected by the inhibitor switch and the air conditioner switch. The change in load can be recognized.

Upon detecting the change in the engine load in step ST25, the ECU adds the amount of air sucked into the engine. This addition of the intake air amount raises the target rotational speed when the load fluctuates, thereby supplying more mixers into the cylinder chamber, thereby causing a cooling effect and reducing the probability of knocking.

That is, when the variation of the engine load is confirmed in step ST25, the corrected air amount is applied to the air amount 1 (A1) and the air amount 2 (A2) together at the beginning of the engine load change. Expressed by the equation, it is equal to (air amount = A1 + A2) (ST26, ST27).

The state in which the air amount 1 (A1) and the air amount 2 (A2) are applied together is maintained until the elapsed time from the load fluctuation time reaches the set threshold time. That is, in the early stage of load fluctuations, a sudden change in load causes a decrease in engine speed, thereby increasing the possibility of knocking. To compensate for the possibility of knocks, more air is supplied at the beginning of load fluctuations.

When the threshold time has elapsed, the ECU stops adding the air amount 2 (A2) and performs air amount control so that only the air amount 1 is added (ST28).

The reason why only the air amount 1 (A1) is applied in step ST28 is that the load is kept constant when a certain time elapses from the load change, so that the air amount 2 (A2) applied in consideration of the sudden load at the beginning of the load change is unnecessary. .

At this time, the ECU maintains engine speed feedback control. That is, in order to reduce the difference between the actual rotational speed and the target rotational speed, the rotational speed feedback control is always performed to advance or perceive the ignition timing.

In addition, when the engine load variation does not occur in step ST25 or when step ST28 is performed, the ECU determines whether knocking is generated by receiving a detection signal of a knock detection sensor installed in the cylinder block (ST29).

In step ST29, it is determined that the detection signal of the knock detection sensor is a knock occurrence exceeding a set value.

Thus, when the occurrence of knocking is confirmed, the ECU corrects the ignition timing by the set knock correction value θ2. The correction value [theta] 2 according to the knock occurrence causes the ignition timing to be late (ST30).

When the ignition timing correction θ2 is performed according to the knock generation in step ST30, the ECU accumulates the number of knock occurrences and determines whether the accumulated knock generation count exceeds the set threshold knock count (ST31).

If the accumulated number of knock occurrences in step ST31 exceeds the threshold knock number, the ECU stops the ignition timing correction θ1 by the engine speed feedback. If this is expressed as an expression, it is equal to (θ1 = 0) (ST32).

On the other hand, after the corresponding determination condition is not satisfied in step ST31 or after step ST32 is performed, the ECU performs ignition timing control according to the ignition timing calculated by (ignition timing = θ1 + θ2) (ST33).

That is, according to Fig. 6, the total ignition timing is maintained at the ignition timing correction amount by the engine speed feedback before the occurrence of knock is detected, and the ignition timing correction by the engine speed feedback is prevented when the knock occurrence is confirmed. Only the ignition timing correction amount according to knock occurrence is maintained.

After the ignition timing control is performed according to the knock occurrence, when the engine load fluctuates, both the air volume 1 and the air volume 2 are applied to the air volume compensation line as in the a line on the air volume compensation line for the time corresponding to the compensation preparation stage, thereby increasing the engine speed. At the time point at which the compensation preparation step ends, the addition of the air amount 2, like the b line on the air amount compensation line, is stopped.

In addition, when knock generation is not detected in step ST29, the ECU returns the ignition timing corrected by the engine speed feedback according to the set slope and returns to the main routine.

In addition, when the high temperature restart condition is not established in step ST22, the ECU returns to the main routine.

According to the knock control method at the high temperature restart of the vehicle of the present invention described above, there is an effect of preventing excessive knock occurrence during high temperature hot restart idling to improve the merchandise of the vehicle.

In addition, since the ignition timing compensation according to the knock generation is not affected by the ignition timing compensation according to the engine speed feedback, the ignition timing correction for suppressing the generated knock may be efficiently performed.

In addition, there is an effect that it is possible to reduce the knock occurrence probability by the air amount control when the idle load changes.

Therefore, the knock generated at high temperature restart is only a one-time advantage and can be suppressed immediately.

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 (5)

(a) checking, by the electronic control means, a high temperature restart condition in a vehicle equipped with electronic control means for engine control, and performing ignition timing correction according to engine speed feedback; (b) when the ignition timing is corrected according to the engine speed feedback, the electronic control means increases the engine speed by adding an intake air amount to the engine by applying a compensation air amount according to a change in the engine load; ; (c) when the engine speed is increased due to the correction of the ignition timing by the engine speed feedback or the variation of the engine load, the electronic control means receives the detection signal of the knock detection sensor to determine whether the knock occurs; Wow; (d) when the knock is detected by the knock detection sensor and the number of knock occurrences exceeds a predetermined value, the electronic control means includes stopping the ignition timing compensation by the engine speed feedback. Knock control method at high temperature restart. The method of claim 1, wherein the high temperature restart conditions in the step (a), Characterized in that the condition is established when the condition that the intake temperature detected by the intake temperature sensor at the engine start exceeds the set value 1 and the condition that the coolant temperature detected by the coolant temperature sensor at the start exceeds the set value 2 at the same time are established. Knock control method at high temperature restart of automobile. The method of claim 1, wherein in step (a), The electronic control means stores the air quantity 1 for application and maintenance when the load changes, and the air amount 2 for application in addition to the air amount 1 at the beginning of the load variation in the storage medium. Way. The method of claim 1, wherein step (b) comprises: (B1) determining, by the electronic control means, whether an engine load is changed by receiving detection signals of an inhibitor switch and an air conditioner switch; (B2) if the engine load change is confirmed in the step (b1), the electronic control means determines whether the elapsed time after the load change reaches a set threshold time; When the elapsed time after the load change reaches the threshold time in the step (b2), the electronic control means increases the intake air amount by applying the air amount at the beginning of the load change and returns to the step (b2) (b3). Wow; When the threshold time of the elapsed time after the load change is reached in the step (b2), the electronic control means includes the step of controlling the intake air amount by applying the air amount during the load change duration (b4). Knock control method at high temperature restart of car. The method of claim 1, wherein step (c) comprises: The electronic control means is configured to determine whether knocking is generated by receiving a detection signal of a knock detection sensor installed in a cylinder block; Correcting the ignition timing by applying the ignition timing correction value according to the knock generation, when knock generation is confirmed from the signal of the knock detection sensor; When the correction of the ignition timing according to the knock occurrence is performed, the electronic control means accumulating the number of knock occurrences and determining whether the accumulated knock generation number exceeds a set threshold knock number; Stopping the ignition timing correction by engine speed feedback when the accumulated knock occurrence number exceeds the threshold knock number; After the knock generation is not confirmed from the signal of the knock sensor or the ignition timing correction by the engine speed feedback is stopped, the electronic control means includes maintaining the ignition timing control that is currently being performed. Knock control method at high temperature restart of car.