KR101284326B1 - A shift control system of automatic transmission on vehicle and method thereof - Google Patents

Abstract

If the brake is detected during the engine speed increase control in the area of deceleration direct control after the power-off up shift due to the lift put-up in the automatic transmission, the control hydraulic pressure applied to the engine speed condition is determined to execute the down-shift before stopping. This is to avoid shock.

According to the present invention, when a power off up shift occurs due to a lift foot-up in a driving state, a process of determining a control hydraulic pressure according to a deceleration change rate of a vehicle speed and executing a power off-up shift, and deceleration-directed control when a shift completion of a target shift stage is detected. A process of determining whether it is an area, or a deceleration direct control area, in which a lock-up clutch is coupled to execute deceleration direct control; When the comparison value of the engine speed and turbine speed exceeds the reference value, the engine speed control is executed to assist the deceleration direct control, the deceleration direct control is maintained, and the brake operation is performed while the engine speed control is executed. If downshift is detected, the control hydraulic pressure applied by the relationship between engine speed and turbine speed is determined. It comprises the step of executing the prompt.

Automatic transmission, direct deceleration control, LFU, control hydraulic pressure, downshift before stop

Description

SHIFT CONTROL SYSTEM OF AUTOMATIC TRANSMISSION ON VEHICLE AND METHOD THEREOF}

The present invention relates to an automatic transmission, and more particularly, engine rotation when a down shift occurs during engine lift control after a power off up shift according to a lift foot up. The present invention relates to a shift control apparatus and a method of an automatic transmission in which a shock is generated by controlling a downshift before stopping with a control hydraulic pressure to which a number condition is applied.

In the automatic transmission, the shift control means operates a plurality of actuators to control the hydraulic pressure according to the traveling speed and the opening amount [TPS (%)] of the throttle valve so that the automatic shift is made to the target shift stage.

The automatic transmission has a release side element that is released from the operating state when the shift is performed to the target shift position and an engagement side element that is changed from the released state to the operating state and release and operation of the release side and engagement side element Is performed by the hydraulic pressure supplied to the element.

In order to improve fuel efficiency, the automatic transmission uses deceleration direct control that combines a lock up clutch in a certain operating area, thereby expanding the fuel cutoff area of the engine.

The automatic transmission performs a power-off up shift in accordance with the lift foot-up, and enters the deceleration direct control region by the inertia driving.

If it is determined that the speed reduction direct connection control area is supplied, the control hydraulic pressure is supplied to the lock up clutch to engage the lock up clutch, thereby executing the speed reduction direct control.

Conventional automatic transmissions have the following problems.

When brake operation is detected during deceleration direct control and normal lockup clutch control, the shift control means releases the lockup clutch for engine stall prevention and noise prevention (NVH), and the engine control means releases the fuel supply cutoff control. Worse fuel economy.

In addition, when the downshift before stop occurs due to the brake operation in the deceleration direct control region, the engine speed Ne becomes higher than the turbine speed Nt, thereby causing a shift shock and engine noise.

The present invention has been invented to solve the above problems, and its object is that if downshift is detected before stopping by brake operation during execution of engine speed increase control in the deceleration direct control region after power-off shift, By controlling the downshift by applying a control hydraulic pressure determined according to the difference between the engine speed and the turbine speed, the shock is not generated.

A shift control apparatus of an automatic transmission according to a feature of the present invention for realizing the above object,

An engine control detection unit comprising one or more sensors and detecting and providing general information necessary for engine control to the ECU;

An ECU which compares the information detected by the engine control detection unit with the set control data and executes the engine speed increase control in the deceleration direct control region through the engine control driver;

The control hydraulic pressure is determined according to the information transmitted from the ECU and the information detected by the shift control detecting unit, and the control of the power-off up shift and the deceleration direct control are executed. A TCU that determines the control hydraulic pressure and executes a downshift before stop if the operation is detected;

In accordance with the control of the TCU includes a shift control drive unit for operating the clutch and the brake which is a friction element to synchronize the target gear stage.

In addition, the shift control method of the automatic transmission according to the present invention, the process of determining whether the power-up up shift due to the lift put-up in the driving state;

Calculating a deceleration change rate of the vehicle speed if the power off up shift is performed, and determining a control hydraulic pressure according to the deceleration change rate to perform a power off up shift;

Determining whether the speed change direct control region is detected when the shift completion of the target speed change stage is detected;

In the deceleration direct control region, engaging the lock-up clutch to execute deceleration direct control, and determining whether a comparison value of the engine speed and the turbine speed exceeds a set reference value in the state of the deceleration direct control;

Assisting deceleration direct control by executing engine speed increase control when a comparison value of the engine speed and the turbine speed exceeds a reference value;

If the deceleration direct control is maintained and the downshift due to brake operation is detected while the engine speed increase control is being executed, the process of executing the downshift before stopping by determining the control hydraulic pressure applied by the engine speed and the turbine speed relationship is performed. Include.

According to the above-described configuration, the present invention prevents shock generation by adjusting the slope of the control hydraulic pressure when the downshift before stopping according to the brake operation is executed in the state in which the control of the engine speed increases after the power-off upshift is performed. This improving effect is expected.

DETAILED DESCRIPTION Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention.

As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention.

1 is a view showing a configuration of a shift control apparatus of an automatic transmission according to an embodiment of the present invention.

As shown in the drawing, the present invention includes an engine control detector 10, an ECU 20, an engine control driver 30, a TCU 40, a shift control detector 50, and a shift control driver 60.

The engine control detection unit 10 includes an accelerator pedal sensor, a throttle valve sensor, a vehicle speed sensor, a crank angle sensor, an engine speed sensor, a coolant temperature sensor, a brake sensor, and the like, and detects general information necessary for engine control. Information is provided to the ECU 20.

The ECU 20 controls the engine in an optimal state by comparing the general information applied by the engine control detection unit 10 with the preset control data to control the engine control driver 30.

In addition, the ECU 20 executes engine lift control to prevent instability and stall of the engine speed in the deceleration direct control region after the shift of the power off up shift, and information on the engine speed and whether the brake is operated or not. To the TCU 40.

The TCU 40 analyzes the information transmitted from the ECU 20 and the information input from the shift control detecting unit 50 to determine the lift foot up in which the throttle opening degree TH is detected as 0%. When the current shift stage is determined, the target shift stage for the power-off up shift is determined, and a control value for executing the shift to the target shift stage is determined and applied to the shift control driver 60.

The shift control detecting unit 50 provides the TCU 40 with information necessary for shift control, including a speed sensor, an oil temperature sensor, an inhibitor switch, a turbine speed sensor, and the like.

The shift control driving unit 60 is an actuator for operating the supply and discharge of hydraulic pressure, and is operated by a control signal applied from the TCU 40 to operate a coupling side operating element and a release side operating element to shift the target shift stage. Executes synchronous and deceleration direct control.

The ECU 20 and the TCU 40 are connected through either CAN communication or serial communication to perform communication with each other.

When the TCU 40 detects the operation of the brake while the engine rotation speed is controlled in the deceleration direct control region after completing the power-off up shift according to the lift put-up, the TCU 40 performs the correction hydraulic pressure for the downshift before stopping. Calculation is performed as follows, and the downshift before stop is performed through the shift control driver 60.

Pr2 = P (Base) + P (Gradient) + P (dNo) + P (dNe)

Where Pr2: final output oil pressure, P (Base): normal base oil pressure, P (Gradient): hydraulic slope, P (dNo): vehicle speed change correction hydraulic pressure, P (dNe): control of engine speed Corrected hydraulic pressure when in use.

The correction hydraulic pressure during the increase control of the engine speed is applied to a map value applied to Table 1 below according to a value obtained by subtracting the turbine speed from the engine speed for each shift stage.

Gearshift Down shift (3 → 2, 4 → 3, 5 → 4) Ne-Nt (RPM) -30 0 30 100 200 Calibration duty -One% -1.5% -2% -2.5% -3%

For example, assuming that the power-off 3 → 4 speed up shift occurs due to the lift foot-up while driving, the turbine speed Nt is changed to the fuel cut control after the 3 → 4 speed shift is completed. ) If it is larger than the number of revolutions, deceleration direct control is started because it meets deceleration direct control.

At this time, when the absolute value of the difference between the engine speed Ne and the turbine speed Nt exceeds 250 RPM, the engine lift control is started for smooth deceleration direct control.

In this process, if the downshift before stop occurs due to the operation of the brake, the hydraulic correction value is calculated according to the difference between the engine speed and the turbine speed, and then the downshift before the stop is executed through the shift control driver 60. Prevents shift shocks.

The shift control operation of the automatic transmission according to the present invention including the above-described function will be described in more detail.

The ECU 20 and the TCU 40 detect and analyze general driving control information through the engine control detection unit 10 and the shift control detection unit 50 while driving in a state of synchronizing arbitrary shift stages. The exchanged information is exchanged (S101).

That is, the ECU 20 detects and analyzes information such as whether the accelerator pedal is operated, the opening ratio of the throttle valve, the engine speed, the vehicle speed, the coolant temperature, and the like through the engine control detection unit 10, and the TCU 40 shifts the speed. The control detection unit 50 detects and analyzes information of the vehicle speed, oil temperature, and turbine revolutions, and exchanges the result analyzed by serial communication or CAN communication.

In operation S101, it is determined whether a power-off up shift due to a lift put-up occurs (S102).

When the power off up shift occurs in the determination of S102, the vehicle speed change is detected over time to calculate the deceleration change rate dNo (S103), and the control hydraulic pressure Pr1 according to the deceleration change rate dNo is calculated as follows. Determine (S104).

Pr1 = P (Base) + P (Gradient) + P (dNo)

Subsequently, a signal for controlling the control hydraulic pressure Pr1 determined as described above is output to the shift control driver 60 to allow the power-off shift to proceed stably through the operation of the clutch and the brake (S105).

It is determined whether the shift of the power-off up shift is completed by the output of the control hydraulic pressure Pr1 (S106). If it is determined that the shift is completed, it is determined whether the area of deceleration direct control (S107).

If it is determined that the area of the deceleration direct connection control has been entered, the TCU 40 executes deceleration direct control that couples the lock-up clutch through the shift control driver 60 (S108).

The engine speed Ne and the turbine speed Nt are detected in the process of performing the deceleration direct control as described above (S109), and the result of the difference between the turbine speed Nt and the engine speed Ne is calculated. It is determined whether the absolute value is a set reference rotation speed, preferably greater than 250 RPM (S110).

If the absolute value of the result of calculating the turbine speed Nt at the engine speed Ne in the determination of S110 exceeds the set reference speed, the ECU 20 controls the engine speed through the engine control driver 30. The smooth deceleration direct control is executed by executing the rising control of (S111).

As described above, it is determined whether the downshift before stopping by the operation of the brake occurs in the state in which the deceleration direct control proceeds and the increase of the engine speed is in progress (S112).

When the downshift before the stop occurs in the determination of S112, the control hydraulic pressure Pr2 for the downshift before the stop during the engine speed increase control is determined as follows (S113).

Pr2 = P (Base) + P (Gradient) + P (dNo) + P (dNe)

Thereafter, the shift control driving unit 60 operates the clutch and the brake which are the friction elements with the control hydraulic pressure Pr2 of the down-shift downshift determined as described above to perform the downshift (S114).

When it is determined that the downshift before stop is completed (S115), when the completion of the downshift is determined, the shift control operation is terminated.

The above operation will be described with reference to FIG. 3.

For example, when the throttle opening degree TH is detected as 0% by the lift foot-up while driving at the third speed, an upshift from the third speed to the fourth speed is started (SS1).

At this time, the driving of the inertia is started by the power-off, the engine speed Ne and the turbine speed Nt are lowered, and the vehicle speed is decelerated, so that the deceleration change rate dNo of the vehicle speed is calculated to control according to the deceleration change rate dNo. The oil pressure Pr1 is determined as follows and output as a control oil pressure for 4 speed synchronization.

Pr1 = P (Base) + P (Gradient) + P (dNo)

When the turbine rotation speed Nt reaches the synchronous point of the four speed shift by the output of the control hydraulic pressure Pr1, the shift completion SF is determined and it is determined whether the control area is directly connected to the deceleration.

If it is determined that the speed reduction direct connection control area is provided, the control hydraulic pressure is supplied to the lock up clutch to engage the lock up clutch, thereby executing the speed reduction direct control.

If the absolute value of the result of subtracting the turbine speed (Nt) from the engine speed (Ne) while the deceleration direct control is in progress exceeds 250 RPM (the reference speed), increase the engine speed control to smoothly execute the deceleration direct control. Run

As described above, if deceleration direct control is executed and sudden deceleration occurs due to the operation of the brake pedal while the engine speed Ne control is in progress, the deceleration direct control is canceled and at the same time, the downshift before stopping from 4 to 3 speeds. Execute (SS2).

At this time, the control hydraulic pressure Pr2 to which the conditions of the engine speed and the turbine speed are applied for the third speed engagement at the fourth speed is determined as follows, and is output as shown in "A" of FIG. 3.

Pr2 = P (Base) + P (Gradient) + P (dNo) + P (dNe)

Therefore, when downshifting before stop is outputted, the control hydraulic pressure Pr2 determined as described above is output and the hydraulic drive of the stable slope is executed to change the engine speed Ne and the turbine speed Nt as shown in "B". Remains stable and shift shocks do not occur.

Although the embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements of those skilled in the art using the basic concepts of the present invention defined in the following claims are also provided. Include in the scope of rights.

1 is a view showing a configuration of a shift control apparatus of an automatic transmission according to an embodiment of the present invention.

2 is a flowchart illustrating a shift control procedure in an automatic transmission according to an embodiment of the present invention.

3 is a view illustrating a shift control pattern in an automatic transmission according to an embodiment of the present invention.

4 is a diagram illustrating a shift control pattern applied to a conventional automatic transmission.

<Explanation of symbols for the main parts of the drawings>

10: engine control detection unit 20: ECU

30: engine control drive unit 40: TCU

50: shift control detecting unit 60: shift control driving unit

Claims (6)

An engine control detection unit comprising one or more sensors and detecting and providing general information necessary for engine control to the ECU; An ECU which compares the information detected by the engine control detection unit with the set control data and executes the engine speed increase control in the deceleration direct control region through the engine control driver; The control hydraulic pressure is determined according to the information transmitted from the ECU and the information detected by the shift control detecting unit, and the control of the power-off up shift and the deceleration direct control are executed. A TCU that determines the control hydraulic pressure and executes a downshift before stop if the operation is detected; A shift control apparatus of an automatic transmission comprising a shift control driver for synchronizing a target shift stage by operating a clutch and a brake, which are friction elements, under the control of a TCU. The method of claim 1, After completion of the power-off shift, the ECU executes engine speed increase control for deceleration direct control in which a shock is not generated when the absolute value is greater than the set reference speed as a result of the comparison between the engine speed and the turbine speed in the deceleration direct area. Shifting control of automatic transmission. The method of claim 1, The ECU and the TCU is connected via any one of the CAN communication or serial communication and the transmission control device of the automatic transmission for performing mutual communication. Calculating a rate of change of deceleration of the vehicle speed when a power-off up shift due to the lift put-up is detected; Determining a control hydraulic pressure according to a deceleration change rate of the vehicle speed to perform a power off up shift; Determining whether the speed change direct control region is detected when the shift completion of the target speed change stage is detected; In the deceleration direct control region, engaging the lock-up clutch to execute deceleration direct control, and determining whether a comparison value of the engine speed and the turbine speed exceeds a set reference value in the state of the deceleration direct control; Assisting deceleration direct control by executing engine speed increase control when a comparison value of the engine speed and the turbine speed exceeds a reference value; If downshift is detected due to brake operation while deceleration direct control and engine speed increase control are being executed, the automatic control includes determining the control hydraulic pressure applied by the engine speed and turbine speed relationship and executing the downshift before stopping. Transmission control method of the transmission. 5. The method of claim 4, The engine speed increase control assisting the deceleration direct control is performed when the absolute value of the result of calculating the turbine speed at the engine speed exceeds 250 RPM. 5. The method of claim 4, And a control hydraulic pressure of the downshift before stop determined by brake operation during the engine speed increase control in the deceleration direct control region is determined as follows. Pr2 = P (Base) + P (Gradient) + P (dNo) + P (dNe) here, Pr2: final output hydraulic pressure, P (Base): normal hydraulic pressure level, P (Gradient): Hydraulic slope, P (dNo): Vehicle speed change correction hydraulic pressure, P (dNe): Corrected hydraulic pressure during engine speed increase control.

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