KR100643992B1 - shift control method for automatic transmission - Google Patents

Abstract

The present invention performs a learning control for correcting the deviation between the engine and the automatic transmission when a power off up shift occurs while driving, and stores it, so that it can be applied during the next power off up shift, thereby obtaining a stable shift quality. The purpose is to make it.

In order to achieve the above object, the present invention includes the steps of performing a shift control so that the duty value is increased by a constant rate of change from the set initial duty value when the shift request signal to the power-off up shift while driving; After the input of the shift request signal in the above step, continuously detecting a change in turbine rotation speed after a predetermined time elapses, and calculating a shift completion time point based on the detected change in turbine rotation speed; After the step, when the turbine speed reaches the turbine speed at the completion of the speed change, performing shift control such that the duty value is increased at a constant first rate of change while the duty value is increased to a set duty value; After the step, executing shift control so that the duty value is increased to a constant second rate of change from the time when the turbine speed becomes lower than the turbine speed at the first synchronizing time; After the above step, if the turbine speed is equal to the target turbine speed at the synchronous time, outputting the duty value at 100% and ending the shift control; During the shift control process from the output of the initial duty value to the completion of the shift, the occurrence of the tie up is detected by comparing the change rate of the turbine speed and the average change rate of the calculated turbine speed, and the duty value is generated when the tie up occurs. After the correction learning, it is memorized and implemented the learning control reflecting this in the next shift control; During the shift control process after the initial synchronization time point, the difference between the target turbine speed and the set turbine speed and the current turbine speed are compared with each other to detect the occurrence of the run up, and to correct the duty value when the run up occurs. Next, it is memorized and it is characterized in that the learning control reflecting this in the next shift control.

Description

Shift control method for automatic transmission

1 is a block diagram showing the configuration of a shift control apparatus in a vehicle equipped with an automatic transmission to which the present invention is applied.

2 is a control pattern diagram of an automatic transmission during a 2-3 speed power-off up shift according to an embodiment of the present invention.

3 is a flowchart illustrating a control method during power-off upshift of the automatic transmission according to the embodiment of the present invention.

4 is a flowchart illustrating a control method when a tie up occurs in FIG. 3.

FIG. 5 is a graph illustrating a correction map in which a duty correction amount applied when a tie up occurs in FIG. 4 is variably set according to a change rate of turbine rotational speed.

6 is a flowchart illustrating a control method when a run up occurs in FIG. 3.

FIG. 7 is a graph illustrating a correction map in which a duty correction amount applied when a run up occurs in FIG. 6 is variably set according to a decrease in turbine rotation speed.

8 is a control pattern diagram showing a change in duty value when no run up occurs.

    <Description of Symbols for Main Parts of Drawings>

10-driving state detection unit 20-shift control unit

30-drive actuator

The present invention relates to a shift control method of an automatic transmission, and more particularly, to a shift control method of an automatic transmission to improve the quality of the shift through the learning control when the power off up shift occurs during driving.

In general, when a lift foot up phenomenon occurs in which the driver releases an accelerator pedal while driving, the driving state of the vehicle is a state in which the engine is driven while the engine is driven. Is switched to the so-called power-off state, and the shift stage is shifted to at least one step higher speed than the current traveling shift stage.

At this time, the turbine rotation speed is lowered, in this case, the shift control involved is commonly referred to as a power off up shift (POWER OFF UP SHIFT).

However, such power-off upshifts have many problems in various types of shift control, which are caused by the following causes.

In other words, when a power-off shift occurs while driving, a decrease in engine speed is accompanied, and the decrease in engine speed is caused by a characteristic depending on the engine, and the clearance for the components of the automatic transmission side is also reduced. It is also accompanied by the difference, and especially when fuel cut control to cut off the fuel from the engine during shift control or a situation such as on / off switching of the air conditioner is involved at the same time, the requirement from the completion of the shift to the end of the shift As the time varies variably, it becomes impossible to secure a certain level of shift quality, which is a cause that can cause the occurrence of a shank during shift control.

Therefore, in the shift control to the power-off up shift, learning control is required so that shift control can be performed irrespective of an engine and a transmission side deviation.

Accordingly, the present invention has been made in view of the above, and it is possible to perform the learning control for correcting the deviation between the engine and the automatic transmission when a power off upshift occurs during driving, and store the same. By doing so, the purpose is to obtain a stable shift quality.

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According to the present invention for achieving the above object, in the shift control method of the automatic transmission, when the shift request signal to the power-off shift during driving is input, shift control so that the duty value is increased at a constant rate of change from the set initial duty value Implementing the step;
After the input of the shift request signal in the step of executing the shift control, when the time required for the stable detection of the turbine speed has elapsed, the change in the turbine speed is continuously detected, and the shift is completed based on the detected change in the turbine speed. Calculating a viewpoint;
After the calculating step at the completion of the shift time, if the turbine speed reaches the turbine speed at the shift completion time, shift control is performed such that the duty value is increased at a constant first rate of change while the duty value is increased to the set duty value. Doing;
After the shift control is performed such that the duty value is increased at the first rate of change, the duty value is changed to a constant second rate of change that is greater than the first rate of change from the time when the turbine speed is lower than the turbine speed at the first synchronization time. Implementing shift control to be increased;
After the shift control is performed such that the duty value is increased at the second rate of change, if the turbine speed is equal to the target turbine speed at the synchronous time, the duty value is output at 100% and the shift control is terminated. Undertake;
During the shift control process from the output of the initial duty value to the completion of the shift, the occurrence of the tie up is detected by comparing the change rate of the turbine speed and the average change rate of the calculated turbine speed, and the duty value is generated when the tie up occurs. After the correction learning, the learning control reflecting this in the next shift control is executed;
During the shift control process after the initial synchronization time point, the difference between the target turbine speed and the set turbine speed and the current turbine speed are compared with each other to detect the occurrence of the run up, and to correct the duty value when the run up occurs. Next, it is memorized and it is characterized in that the learning control reflecting this in the next shift control.
According to the present invention, when the tie-up occurs, the learning control corrects the maximum duty value by subtracting the correction amount to the maximum duty value when the tie-up occurs while the current duty value reaches the set maximum duty value. ;
When the tie-up occurs while the current duty value does not reach the set maximum duty value, the initial duty value is corrected by subtracting the correction amount from the initial duty value.
In addition, in the present invention, the learning control at the time of determining the occurrence of the run-up, when the run-up occurs while the current duty value reaches the set maximum duty value, corrects the maximum duty value by adding the correction amount to the maximum duty value. ;
When the run-up occurs when the current duty value does not reach the set maximum duty value, the correction is performed by adding the correction amount to the incremented duty value to increment the original incremented duty value again.
Further, the present invention is characterized in that the correction applied to each of the learning control performed at the time of the tie-up and the run-up is performed in consideration of the oil temperature of the operating oil, by adding a value selected from the preset map according to the oil temperature It is done.
Further, in the present invention, the learning control performed at the time of occurrence of the tie-up and the run-up is the generation of the power off-up shift signal during driving and the opening amount of the throttle opening amount in the on state of the idle switch, It is characterized in that it is enforced only when all cases are satisfied.
In addition, the learning control performed at each occurrence of the tie-up and the run-up is characterized in that it is configured to prohibit each time the idle throttle opening amount is less than the set value, or when the oil temperature of the hydraulic oil is less than the set value.
Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

In the shift control method of the automatic transmission according to the present embodiment, as shown in FIG. 1, a vehicle equipped with a normal automatic transmission basically including a driving state detection unit 10, a shift control unit 20, and a driving actuator 30. In this case, it is applied to shift control accompanying a specific process (power off-up shift) during shifting while driving.

First, in a vehicle equipped with an automatic transmission, the traveling state detection unit 10 includes a throttle position sensor 11 for detecting an opening amount of a throttle valve during driving and an idle switch 12 for detecting an idle state of a throttle valve. , The rotation speed detection sensor 13 for detecting the rotation speed of the turbine and the output shaft, the inhibitor switch 14 for detecting the position of the shift lever, the oil temperature sensor 15 for detecting the oil temperature of the hydraulic oil (ATF), and the like. It is configured to include.

In addition, the shift control unit 20 transmits an optimum duty control signal to the drive actuator 30 so as to control the appropriate fastening and release of the friction element during shifting according to various signals input from the driving state detection unit 10. It consists of a shift control unit (TCU) to output.

In addition, the drive actuator 30 is operated in accordance with a control signal output from the shift control unit 20 to operate a component to be accompanied by the actual shift, the component is a friction element of the clutch and brakes And various valves for performing pressure control on the operating pressure supplied to and released from the friction element, solenoid valves for driving the valves, and the like.

On the other hand, in the automatic transmission equipped with the above-described basic basic components, the control shown in Figure 2 during the power-off up shift from the second to the third speed in the process of a series of shift control accompanying the power off-up shift during driving The pattern diagram and the flow chart of the control method shown in FIG. 3 will be described in detail as follows.

First, when the lift foot-up is performed by the driver while driving at 2 speeds, the shift control unit 20 receives a change in the opening amount of the throttle valve through the throttle position sensor of the driving state detection unit 10 and inputs the input. Based on the received signal, it is determined whether the current driving situation corresponds to a power off up shift. (S10), (S12).

In this case, when the current shift state does not correspond to the power off up shift, shifting is performed by normal main control (S13). When the shift state is corresponding to the power off up shift, the shift control unit 20 includes a fill time FILL TIME; The control duty value is output as 100% in order to improve the response of the shift until the time required for the hydraulic oil to be completely supplied into the pressure chamber of the friction element.

In this process, when the fill time elapses, the shift control unit 20 starts the shift control at the third speed such that the duty value is gradually increased at a constant initial change rate while the duty value is lowered to the set initial value D1. (S14)

In this case, the initial duty value D1 output from the shift controller 20 is an experimental value calculated through a plurality of tests.

Then, after the predetermined time T1 (approximately 150 ms) has elapsed after the shift request signal to the power-off shift is input, the change in the turbine speed is continuously detected until the end of the shift control. )

In this case, the predetermined set time T1 is also an experimental value calculated through a plurality of tests, for calculating the shift completion point after the shift request to the power off-up shift, that is, the change in the turbine speed. Is the minimum elapsed time required to reliably detect.

In the process S16, if the set time T1 has not elapsed, the normal shift control is performed without calculating the shift completion time point (S17).

Subsequently, when the time T1 set in the process S16 elapses, the shift completion time point for determining the timing of the shift completion time is calculated based on the detected change in the turbine rotation speed. The calculation is made through the following relationship (S18).

[Relationship]

Turbine rotational speed at the time of completion of shift = target turbine rotational speed + turbine rotational speed change rate (Nt ') * predetermined time T2

At this time, the target turbine rotation speed is calculated as a product between the rotation speed of the output shaft and the gear ratio of the target speed change stage.

Here, the change rate (Nt ') of the turbine speed is the degree of change with respect to the time of the turbine speed (Nt) detected in real time during the shifting process, the predetermined time T2 (approximately 250ms) is the shift synchronization point It is the set value calculated through a number of tests considering the responsiveness of hydraulic pressure at the previous time.

On the other hand, after the step (S18), the current shift control duty value and the maximum duty value set through a plurality of tests are compared with each other. If the current duty value is larger than the set maximum duty value, the current duty value is The shift controller 20 outputs a set maximum duty value, that is, outputs a control signal for limiting the upper limit value of the current duty value increased at a constant initial change rate to the set maximum duty value (S20). S21)

In other words, the control duty rises to a constant slope until the shift completion time is reached after the output of the initial duty value, but it is necessary to limit the duty value so that the corresponding friction element cannot actually be operated. After outputting the value, the predetermined maximum duty value is set until the shift completion time is reached, so that the control duty is not greater than the set maximum duty value, that is, the rise of the control duty is limited to the maximum duty value, thereby allowing tip-in during shifting. It is possible to reduce the shank caused by and to ensure the reliability of the control.

On the contrary, when the current duty value is smaller than the set maximum duty value, the change rate of the turbine rotational speed continuously detected during the shift control process from the output time point of the initial duty value D1 to the shift completion time point, and the The occurrence of a tie up is detected by comparing the average rate of change of the turbine rotational speed, which is continuously detected and calculated during the process (S22).

In this process, when the rate of change of the detected turbine speed is greater than the average rate of change of the turbine speed which is continuously detected and calculated during the previous process of the shift control, it is determined that the tie up occurs (S23), and the duty value at the time of the tie up occurs. After the correction training, it is memorized and the learning control reflecting the next shift control is executed.

That is, the learning control at the time of determining the occurrence of the tie-up in the step (S23) is made through the process as shown in FIG.

First, when a tie up occurs while the current duty value reaches the set maximum duty value, correction is performed by subtracting the correction amount to the maximum duty value, that is, lowering the maximum duty value.

In other words, if a tie-up occurs while the current duty value reaches the set maximum duty value, the friction element is fastened too fast because the preset maximum duty value is too large, and the turbine speed is lost during the shifting process. Since it did not fall to the set level, in this case, the maximum duty value is set smaller to lower the turbine speed to the set level.

If a tie-up occurs in a state where the current duty value does not reach the set maximum duty value, correction is performed by subtracting the correction amount to the initial duty value D1, that is, lowering the initial duty value.

In other words, if a tie up occurs when the current duty value does not reach the set maximum duty value, since the initial duty value is too large, the corresponding friction element is fastened so fast that the turbine speed is not set during the shifting process. In this case, the initial duty value is set smaller so that the turbine speed is lowered to the set level.

In addition, the duty correction amount applied in each case is selected and applied from a map in which the correction duty value is set according to the change rate Nt 'of the turbine rotational speed as shown in FIG. 5. Data is also stored as a map in the shift controller 20 as a set value calculated through a plurality of experiments.

Further, the correction applied above is made in consideration of the oil temperature of the working oil, that is, the correction amount in the learning control is determined by adding a value selected from a map in which a correction duty value is preset according to the oil temperature of the working oil. The correction amount according to the oil temperature of the hydraulic oil is stored as a map in the shift controller 20 as experimental values calculated through a plurality of tests.

On the other hand, in the above step (S22), if the change rate of the detected turbine rotation speed is smaller than the average change rate of the calculated turbine rotation speed, since it is a normal case that no tie-up occurs, the shift control proceeds to the subsequent process. Done. That is, the current turbine rotation speed and the turbine rotation speed calculated at the shift completion time point are compared with each other. (S24) In this case, the subsequent process after performing the correction learning as in the above-mentioned step (a) is also performed in the above process ( Of course, the same as S24).

If the turbine rotation speed detected in the process S24 is greater than the turbine rotation speed at the shift completion time, the process returns to the step S20 to repeat the above-described process.

Subsequently, when the current turbine speed reaches the turbine speed at the completion of the shift in the process S24, the duty value is constant at the first predetermined rate of change while the current duty value is incremented to the set duty value D2. Shift control is performed to increase the speed. (S26)

After the above step S24, the current turbine speed and the target turbine speed at the synchronous time point are compared with each other.

In this case, if the current turbine speed is greater than the target turbine speed at the synchronous time in step S28, the process returns to step S26 to repeat the above-described process.

On the contrary, when the current turbine speed is smaller than the target turbine speed at the first synchronization time point in the above step S28, the shift control is performed such that the duty value is constantly increased from this time point at a predetermined second change rate. Will be implemented. (S30)

Here, the second rate of change is set to a larger value than the first rate of change, which is 100% of the duty value to be output at the end of the shift control in the course of shift control after the synchronization point, so that the shift completion point is determined. In the previous shift control process, the duty cycle is increased to a smaller first change rate to observe the run-up trend. In the latter shift control process, the shift control process is performed at the end of the shift control. It is intended to improve the response of the shift by increasing the duty value at a second rate of change larger.

On the other hand, after the above-described step (S30), during the shift control process after the initial synchronization time point, the difference value ΔNt between the current turbine speed and the target turbine speed and the set turbine speed (for example, 50 RPM) is determined. The occurrence of the run up is detected by comparing with each other (S32).

Here, the set turbine speed serves as a kind of spare area for reducing the sensitivity of the judgment when the run-up is judged when the turbine speed drops below the target turbine speed of the synchronous point. Of course, it was produced through a number of tests.

In the above step S32, if the current turbine speed is smaller than the difference value ΔNt between the target turbine speed and the set turbine speed, the current turbine speed is excessively dropped relative to the target turbine speed, that is, turbine rotation. If the drop amount is greater than or equal to the set value, the occurrence of the run-up is determined (S33), the duty value is corrected and learned in the run-up generation, and the memory is memorized and the learning control reflecting the change is performed during the next shift control.

That is, the learning control when determining the occurrence of the run-up in the step (S33) is made through the process as shown in FIG.

First, when a run-up occurs in a state where the current duty value reaches the set maximum duty value, the maximum duty value is corrected by adding the correction amount to the maximum duty value.

In other words, if the run-up occurs when the current duty value reaches the set maximum duty value, the friction element is set too late because the preset maximum duty value is too small, and the turbine speed is set during the shifting process. Since it falls below the target turbine speed, which is a level, in this case, the maximum duty value is set larger to prevent the turbine speed from falling below the set level.

If a run-up occurs while the current duty value does not reach the set maximum duty value, a correction is performed to add the correction amount to the incremented duty value D2 to increment the first incremented duty value D2 again. Perform.

In other words, if the run-up occurs when the current duty value does not reach the set maximum duty value, the friction element is tightened too late because the incremented duty value D2 is too small, and the turbine is in the process of shifting. Since the rotation speed falls below the target turbine speed, which is a predetermined level, in this case, the incremented duty value D2 is set larger to prevent the turbine speed from falling below the set level.

As shown in FIG. 7, the correction amount applied in each case is a map in which the correction duty value is set according to the difference between the target turbine speed and the actual turbine speed, that is, the amount of decrease in the turbine speed. In this case, the set map data is stored as a map in the shift control unit 20 as a set value calculated through a plurality of experiments.

Further, the correction applied above is made in consideration of the oil temperature of the working oil, that is, the correction amount in the learning control is determined by adding a value selected from a map in which a correction duty value is preset according to the oil temperature of the working oil. The correction amount according to the oil temperature of the hydraulic fluid is an experimental value calculated through a plurality of tests and stored in the shift control unit 20 as a map.

After the above step S32, when the current turbine speed is equal to the target turbine speed at the synchronous time, the duty value is output at 100%, and the shift control is terminated. Of course, the subsequent process after performing the correction learning as in the same as the above process (S34), of course.

In addition, in the process S32, if the turbine speed is not smaller than the difference value ΔNt between the target turbine speed and the set speed, that is, no run-up occurs, as shown in the control pattern diagram shown in FIG. When the current turbine speed reaches the target turbine speed again after the synchronization point, the duty value is immediately output to 100% to quickly terminate the shift control process, thereby improving the response of the shift.

On the other hand, the learning control performed when the tie-up and run-up occurs according to an embodiment of the present invention is made only when all three conditions are satisfied.

First, the power-off up shift signal should be generated while driving, and secondly, the opening amount of the throttle valve should be <0.7V and the idle switch ON, and third, the oil temperature (ATF)> 0 ° C. If any one of the conditions is not satisfied, the shift control unit 20 prohibits learning control for the corrected duty.

That is, the condition for prohibiting the learning control is when "throttle valve opening amount> 0.65V" or "idle switch off (OFF)" or "oil temperature (ATF) ≤ 0 ° C".

This is not a normal driving state when the opening amount of the throttle valve is small, and also a normal driving state when the oil temperature is 0 ° C. or lower, and thus prohibits the learning control, and when shifting during the next normal driving due to unnecessary learning. This is to prevent shifting to learning data that is not suitable for the situation.

In addition, as described above, the duty value is increased to a predetermined set value D2 at the time when the shift completion time has elapsed during the shift control during power-off up-driving, and at different first and second change rates. Each increase detects that the current turbine speed falls below the target turbine speed due to various factors or other external causes in the transmission after the point where the current turbine speed coincides with the target turbine speed at the synchronous point. This is to make the corresponding control.

In addition, another reason is that when the shift is completed, shifting the shift value to 100% as in the normal shift control is completed. This is to solve the quality deterioration problem of the shift caused when the situation that cannot be terminated.

As described above, according to the shift control method of the automatic transmission according to the present invention, the occurrence of tie-up is detected from the change in the turbine speed from the beginning of the shift to the completion of the shift at the time of power-off shift during driving. Through the learning of correction, the learning control based on this is carried out at the next shift, and the detection and detection of the occurrence of the run-up in which the turbine speed drops below the target turbine speed at the synchronizing point until the shift is completed at the completion of the shift are detected. When the next shift is carried out through the time-correction learning, the learning control is performed as a medium. Therefore, depending on the characteristics of the engine and the transmission, the shift is carried out from the completion of the shift to the shifting synchronous point according to the degree of deterioration of the engine speed when the power-off is shifted. The time required until the end of can be properly adjusted to the degree of decrease in turbine speed, It is possible to reduce the quality spread of the shift.

In addition, by increasing the control duty value to another rate of rise two times after the shift completion point during the shift to the power-off shift, and detecting the occurrence of the run-up, the response of shifting as well as more stable shifting is performed. Since even the castle can be shortened, the quality of the shift can be improved.

Claims (7)

In the shift control method of the automatic transmission, When the shift request signal to the power-off shift during driving is input, performing shift control so that the duty value is increased from the set initial duty value at a constant rate of change; After the input of the shift request signal in the step of executing the shift control, when the time required for the stable detection of the turbine speed has elapsed, the change in the turbine speed is continuously detected, and the shift is completed based on the detected change in the turbine speed. Calculating a viewpoint; After the calculating step at the completion of the shift time, if the turbine speed reaches the turbine speed at the shift completion time, shift control is performed such that the duty value is increased at a constant first rate of change while the duty value is increased to the set duty value. Doing; After the shift control is performed such that the duty value is increased at the first rate of change, the duty value is changed to a constant second rate of change that is greater than the first rate of change from the time when the turbine speed is lower than the turbine speed at the first synchronization time. Implementing shift control to be increased; After the shift control is performed such that the duty value is increased at the second rate of change, if the turbine speed is equal to the target turbine speed at the synchronous time, the duty value is output at 100% and the shift control is terminated. Undertake; During the shift control process from the output of the initial duty value to the completion of the shift, the occurrence of the tie up is detected by comparing the change rate of the turbine speed and the average change rate of the calculated turbine speed, and the duty value is generated when the tie up occurs. After the correction learning, the learning control reflecting this in the next shift control is executed; During the shift control process after the initial synchronization time point, the difference between the target turbine speed and the set turbine speed and the current turbine speed are compared with each other to detect the occurrence of the run up, and to correct the duty value when the run up occurs. Next, the shift control method of the automatic transmission, characterized in that for performing the learning control reflecting this in the next shift control by remembering this. delete The method of claim 1, The learning control at the time of determining the occurrence of the tie-up, when the tie-up occurs while the current duty value reaches the set maximum duty value, corrects the maximum duty value by subtracting the correction amount to the maximum duty value; If the tie-up occurs when the current duty value does not reach the set maximum duty value, the shift control method for an automatic transmission, characterized in that for correcting the initial duty value by subtracting the correction amount to the initial duty value. The method of claim 3, wherein The learning control at the time of determining the occurrence of the run-up, when the run-up occurs while the current duty value reaches the set maximum duty value, corrects the maximum duty value by adding the correction amount to the maximum duty value; In the case where the run-up occurs when the current duty value does not reach the set maximum duty value, the correction is performed by adding the correction amount to the incremented duty value to increment the original incremented duty value again. Shift control method. The method of claim 4, wherein The correction applied to the learning control performed at the time of the tie-up and the run-up is performed in consideration of the oil temperature of the hydraulic oil, and is performed by adding a value selected from a preset map according to the oil temperature. Shift control method. The method of claim 5, The learning control performed at the time of occurrence of the tie-up and the run-up satisfies both the generation of the power off-up shift signal during driving and the opening amount of the throttle opening amount in the on state of the idle switch, and the case where the oil temperature of the hydraulic oil is 0 ° C. A shift control method of an automatic transmission, characterized in that it is limited to the case. The method of claim 6, The learning control performed at the time of occurrence of the tie up and the run up is configured to prohibit each time the idle throttle opening amount is less than or equal to the set value or when the oil temperature of the hydraulic oil is less than or equal to the set value.

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