KR20150047829A - Method for controlling shifting considering status of piston during static shifting - Google Patents

Abstract

The present invention relates to a shift control method in consideration of a piston state during a static shift, comprising the steps of: when a shift control is started during a shift, updating a time and a pressure to a predetermined control cycle after starting a shift control; Determining a current piston state flow rate by using a control time (drain time) when a previous shift has been completed before the fill operation, according to a result of the determination; Determining a current piston state flow rate by using a control time and a pressure when the previous shift has been completed after the peak, adding a drain amount compensation value according to an external state to the drain amount by the piston state, And when the drain compensation is completed, shifting to a corresponding shift control process to shift And a step of completing the control.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a shift control method for controlling a shift state of a piston,

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a shift control method in consideration of a piston state during a static shift, and more particularly, to a shift control method that estimates a state of a hydraulic pressure level in a piston when a target gear is changed to a one- The present invention relates to a shift control method that takes into consideration a piston state during a static shift in which control is completed by moving to a control section corresponding to a corresponding pressure when the engine is rotated.

Generally, during shift control, the target gear is changed at any time, and the state of the member that applies the hydraulic pressure also varies.

In most cases, there is no pressure in the piston of the member to which the hydraulic pressure is to be applied. However, in some cases, there is a hydraulic pressure in the piston to which the hydraulic pressure should be applied according to the previous control state.

A typical case of the latter case (when hydraulic pressure in a piston to which hydraulic pressure is applied) is a return shift (for example, a shift from B to A after A to B shift) (see FIG. 1). Particularly, in the case of a static transmission having frequent shifting, it sometimes occurs that hydraulic pressure can not be drained.

At this time (that is, when the hydraulic pressure is not drained), a shift shock due to the hydraulic pressure occurs when a new control is started.

Therefore, the position of the turbine RPM (Revolution Per Minute) and the accelerator position sensor (APS) is determined to determine whether or not the delay time is applied, and the automatic transmission fluid (ATF) And the delay time corresponding to the temperature of the battery.

Here, the accelerator pedal position sensor (APS) refers to a sensor or a sensor that converts a voltage in proportion to an amount of depression of an accelerator pedal, and then inputs it to a transmission controller (e.g., TCU) to adjust the speed.

However, it is difficult to accurately grasp the state of the controlled members (that is, the internal oil pressure state) only by a few conditions for determining whether or not the delay time is applied, and the determination of the delay time is performed only by the temperature of the automatic transmission oil (ATF) There is a problem that the accuracy is poor to judge. Accordingly, when shifting is performed according to the above conditions, a shift shock can be caused. Also, since the concept of the delay time itself excludes quick response, there is a problem in that the speed of shifting is low.

In other words, conventionally, in order to perform the other speed change control after performing the speed change control, it is required to include a predetermined delay time (delay time set in consideration of the turbine RPM, APS, etc.) therebetween, , And in some cases, there is a problem of causing a shift shock.

BACKGROUND ART [0002] The background art of the present invention is disclosed in Korean Patent Laid-Open Publication No. 10-2008-0053150 (published on Jun. 12, 2008, a shift control method and system thereof).

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above problems, and it is an object of the present invention to provide a hydraulic pressure control apparatus and a hydraulic control method thereof, which is capable of predicting a hydraulic level state in a piston when a target gear is changed from a gear shift state to a one- And a shift control method in which a control state is shifted to a corresponding control period and a piston state during static shift is considered.

A shift control method in consideration of a piston state during a static shift according to an aspect of the present invention includes: updating a time and a pressure to a predetermined control cycle after starting shift control when shifting control is started during shifting; Determining whether a previous shift has ended before a fill; Confirming a current piston state flow rate by using a control time (drain time) when the previous shift has been completed before the fill, according to the determination result; Checking the current piston state flow rate using the control time and the pressure when the previous shift has been completed after the completion of the determination according to the determination result; Performing drain compensation by adding the drain amount due to the piston state to the drain amount compensation value according to the external state; And shifting to the corresponding shift control process to complete the shift control when the drain compensation is completed.

In the present invention, the fill is characterized in that the operating oil pressure is filled in the clutch.

In the present invention, the step of checking the current piston state flow rate using the control time is characterized by predicting the current piston state by the natural drain by calculating the flow rate applied during the fill control .

In the present invention, the step of checking the current piston state flow rate using the control time and the pressure is characterized by adding the amount of drain due to the natural drain and the amount of drain due to the release pressure.

In the present invention, the drain amount according to the external condition is a drain amount generated from at least one of turbine RPM, APS, and ATF temperature.

The present invention estimates the current piston state and eliminates or reduces the delay time that waits for the hydraulic pressure to be drained when shifting during shifting, thereby ensuring quick response of shifting.

FIG. 1 is a flowchart showing a conventional reverse shift process with time delay. FIG.
BACKGROUND OF THE INVENTION Field of the Invention [0001] The present invention relates to a shift control method,

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of a shift control method considering a piston state during a static shift according to the present invention will be described with reference to the accompanying drawings.

In this process, the thicknesses of the lines and the sizes of the components shown in the drawings may be exaggerated for clarity and convenience of explanation. In addition, the terms described below are defined in consideration of the functions of the present invention, which may vary depending on the intention or custom of the user, the operator. Therefore, definitions of these terms should be made based on the contents throughout this specification.

2 is a flowchart illustrating a shift control method in consideration of a piston state during static shift according to an embodiment of the present invention.

As shown in FIG. 2, a transmission control unit (TCU) (not shown) for shifting control in consideration of a piston state during a static shift according to an embodiment of the present invention includes a gear- In the case of a return shift, the hydraulic pressure level in the piston is predicted and the control is completed by moving to the control period corresponding to the pressure when restoring the original speed change stage.

That is, the transmission control unit TCU updates and stores the control time (drain time) and pressure (duty) at a predetermined control cycle after starting the shift control when the shift control is started during the shift (S101).

It is determined whether the previous shift has been completed before the fill (S102).

Here, the fill means that the operating oil pressure is filled in the clutch. Therefore, the fill time means the time that the working oil pressure is filled.

In the case where the previous shift has been completed before the fill (Yes in S102), the control terminated before the fill (i.e., shift control) calculates the flow rate applied during the fill control according to the determination result To predict a current piston state by a natural drain (S103). In other words, the current piston state flow rate is checked using the drain time.

However, when the previous shift has been completed after the fill, the amount of drain due to the natural drain and the amount of drain due to the release pressure are both calculated (S104).

That is, "natural drain amount + drain amount due to pressure" is calculated.

In other words, the current piston state flow rate is checked using the control time (drain time) and the pressure.

At this time, there are two cases in which the control is finished after the fill (i.e., the shift control). That is, the case where the previous shift is completed and the case where the previous shift is not completed exist.

For reference, the automatic transmission shifts the automatic transmission to the target shift stage by controlling the hydraulic pressure by operating the plurality of actuators by the transmission control unit (TCU) according to the running speed of the vehicle and the opening amount of the throttle valve. Side element that is released from the operating state and the engagement-side element that is converted from the released state to the operating state when the shift is performed to the target speed change stage, and release and operation of the release side and engagement side element And is executed by the hydraulic pressure supplied to each element.

After the amount of drain is calculated for each case (when control has been completed before the fill and after the fill has been completed) as described above, the calculated amount of drain and the amount of drain generated by the other drain element are compensated S105).

Here, the other drain element means a drain generating element according to the turbine RPM, APS, and ATF temperature.

That is, the amount of drain due to the piston state, as well as the compensation of the drain amount according to the external state (i.e., current turbine RPM, ATF temperature, APS, etc.).

When the drain compensation is completed by adding the drain compensation value as described above, the shift control is shifted to the corresponding shift control phase to complete the shift control (S106).

For reference, it is possible to use the following equations (1) and (2) to predict the piston control state by calculating the flow rate introduced into the piston.

Equation 1 below is an ISO 5167 flow rate equation.

here,

: Effluent coefficient (

):

Wow

Determined by

E: Proximity velocity coefficient

,

: Available (d / D)

: Flow meter number (

, E)

: Expansion coefficient of compressible fluid (water = 1)

: Differential pressure across the orifice (Pascals, 1 Pascal =

bar)

: Fluid density (kg / m3)

The following equation (2) is a simplified equation (unit: metric, error ± 5%).

As described above, the present invention estimates the current piston state and eliminates or reduces the delay time for waiting for the hydraulic pressure to be drained during the shifting during shifting, thereby ensuring quick response of the shifting.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, I will understand the point. Accordingly, the technical scope of the present invention should be defined by the following claims.

Claims (5)

Updating the time and pressure to a predetermined control cycle after starting the shift control when the shift control is started during the shift;
Determining whether a previous shift has ended before a fill;
Confirming a current piston state flow rate by using a control time (drain time) when the previous shift has been completed before the fill, according to the determination result;
Checking the current piston state flow rate using the control time and the pressure when the previous shift has been completed after the completion of the determination according to the determination result;
Performing drain compensation by adding the drain amount due to the piston state to the drain amount compensation value according to the external state; And
And shifting to the corresponding shift control process to complete the shift control when the drain compensation is completed.
The method of claim 1,
And the operating oil pressure is filled in the clutch.
The method according to claim 1,
Wherein the step of verifying the current piston state flow rate using the control time comprises:
Wherein the current piston state is predicted by a natural drain by calculating a flow rate applied during the fill control, wherein the current piston state is predicted by a natural drain.
The method according to claim 1,
Wherein the step of checking the current piston state flow rate using the control time and the pressure includes summing the amount of drain due to the natural drain and the amount of drain due to the release pressure. The shift control method considered.
2. The method according to claim 1, wherein the amount of drain,
Turbine RPM, APS, ATF temperature, and the like.

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