KR100877778B1 - Controlling method for decreasing a tip-in shock under lift foot up shift for automatic transmission - Google Patents

Abstract

The present invention relates to a shift control method for reducing a tip-in impact on a lift foot-up shift of an automatic transmission. The present invention relates to determining whether a shift of a power-off shift is detected in a power-on state and determining turbine rotation speed ( Nt) ≤ turbine speed reference value (No × Cij), engine speed (Vrpm) ≥ engine speed reference value, throttle opening rate ≥ throttle opening rate reference value, cooling water temperature> cooling water temperature reference value, and whether it is not shift control section A first step (S10) and; If the first step S10 is satisfied, after maintaining the torque reduction demand amount during the setting time T1, after outputting the torque reduction demand amount to the constant slope ramp1 during the setting time T2, the torque reduction demand amount is fixed to the ramp2 A second step (S20) for outputting the " SB "point; When the "SB" point is satisfied in the second step (S20), it is composed of a third step (S30) for outputting a torque reduction demand at a predetermined slope (ramp3) during the set time (T3) time, the tip during the lift foot-up shift (tip-in) It is an invention that can reduce the impact, it is possible to prevent the acceleration degradation occurs during the shift.

Automatic transmission, shift control, LFU, shift shock, total control.

Description

Controlling method for decreasing a tip-in shock under lift foot up shift for automatic transmission

1 is a block diagram of a system for implementing a method according to the invention,

2 is a flow chart showing the flow of the method according to the invention,

3 shows an example of a torque reduction request pattern in the method according to the invention.

       Showing drawings.

<Explanation of symbols for 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

The present invention relates to a shift control method for reducing tip-in impact on a lift foot-up shift of an automatic transmission.

In general, the automatic transmission applied to a vehicle is controlled by the shift control device controlling a plurality of solenoid valves to control the hydraulic pressure according to the driving speed of the vehicle, the opening ratio of the throttle valve, and various other conditions. The shift is made.

In other words, when the driver changes the range by operating the shift lever, the manual valve port is changed, and the hydraulic pressure supplied from the oil pump is selectively operated according to the duty control of the solenoid valve to selectively operate various operating elements of the transmission gear mechanism. Is done.

The automatic transmission operated as described above is shifted by the interaction of the friction element that is deactivated in the operating state with the friction element that is deactivated in the operating state when the gear shift is made to the target shift stage. The shifting performance of the automatic transmission depends heavily on the timing of the actuation and deactivation of the elements.

Various shift control methods for allowing a flexible shift of the automatic transmission are shown.

As one of such shift control methods, when the accelerator pedal is set for deceleration while driving a vehicle in an automatic transmission vehicle, the vehicle speed fluctuation is caused by a sudden drop in the engine speed while shifting from the shift stage to the next shift stage. Lift foot up (LFU) shifting is made to prevent the impact of the vehicle body.

In this lift foot-up shift, the hydraulic pressure is temporarily reduced to neutral, and then momentarily pressurized near the sync point to achieve optimum control of the perfect sync point.

However, since the conventional lift foot-up shift uses engine torque reduction control until after the shift is completed, there is a problem in that the acceleration deterioration during shifting is large.

The present invention is to solve the above drawbacks, the present invention is to provide a shift control method for reducing the tip-in impact on the lift foot-up shift of the automatic transmission.

The impact reduction control method, which is a tip when shifting the lift foot-up of the automatic transmission of the present invention, determines whether a shift of the power-off upshift is detected in the power-on state, and turbine rotation speed (Nt) ≤ turbine rotation speed reference value (No × Cij). A first step of determining whether the engine speed Vrpm ≥ engine speed reference value, throttle opening rate ≥ throttle opening rate reference value, cooling water temperature> cooling water temperature reference value, and the shift control section; If the first step is satisfied, after the torque reduction demand is maintained for the set time T1, the torque reduction demand is output at a constant slope ramp1 during the set time T2, and then the torque reduction demand is output at the constant ramp2. And a second step of determining an "SB" point; If the "SB" point is satisfied in the second step, it is achieved as the third step of outputting the torque reduction demand amount at a constant ramp3 during the set time T3 time.

1 is a block diagram of a system for implementing a method according to the invention, FIG. 2 is a flow chart showing the flow of the method according to the invention, and FIG. 3 is an example of a torque reduction request pattern in the method according to the invention. Figure showing.

An embodiment of the present invention will be described in detail with reference to the accompanying drawings.

Referring to FIG. 1, when the driving state of the vehicle is transmitted to the ECU 20 from the engine control detection unit 10 including various sensors, the ECU 20 compares the input information with preset data and determines the engine control driver. Control 30 to ensure that the engine is operating in optimum condition.

On the other hand, the engine control detection unit 10 is mounted on the vehicle to detect information necessary for engine control, such as vehicle speed sensor, engine speed sensor, coolant temperature sensor, turbine speed sensor, throttle position sensor (TPS), etc. Well-known sensors.

In addition, the engine control driver 30 means a driver for engine control.

In the ECU 20, if there is information necessary for shift control, the controller 20 transmits the information to the TCU 40 for controlling the shift so that the shift control can be made. In this case, the TCU 40 may compare the information transmitted from the ECU 20 and the information input from the shift control detecting unit 50 with preset data to control the shift control driver 60 to achieve an optimum shift. Make sure

The shift control detecting unit 50 is mounted on a vehicle to detect information necessary for shift control, and is a known sensor such as an input / output speed sensor, an oil temperature sensor, an inhibitor switch, and a brake switch.

In addition, the shift control driver 60 means a solenoid valve applied to the hydraulic control of the automatic transmission.

The control method of the present invention by the system configured as described above is controlled by the flow as shown in FIG.

First, the first step (S10) is a process of determining the conditions of the total control by the lift put-up in the state of driving in the power-on state.

That is, it is determined whether the following conditions are satisfied as the turbine rotation speed determination point for executing the total control indicated by " A "

1) It is determined whether the shift of the power-off up shift is detected in the power-on state. At this time, it may be determined that the power-off after two operation cycles at the shift time. 2) Turbine Speed Nt ≤ Turbine Speed Reference Value No x Cij, Turbine Speed Reference Value can be determined by multiplying engine speed No and coefficient Cij determined by the gear stage. For example, the coefficient C12 determines how much the 1-> 2-speed shift has progressed to determine whether to apply the torque reduction control. 3) Engine RPM (Vrpm) ≥ The engine speed reference value is determined. At this time, the engine speed reference value is determined at about 850 RPM. 4) Throttle opening rate ≥ The throttle opening rate reference value is determined, and the throttle opening rate reference value is determined at about 5%. 5) Cooling water temperature> Cooling water temperature reference value is determined, the cooling water temperature reference value is determined at about 30 ℃. 6) Next, the condition on whether or not the shift control section is determined.

On the other hand, when the following conditions are satisfied, the conditions are released and immediately return to normal control. That is, 1) the throttle opening rate is 5% or more of the reference value, 2) the total control time exceeds the set time of about 1.5 seconds, or 3) the total control execution signal is received from the ECU within 80 ms of the set time from the total control start point. This is the case without.

When the conditions of the first step S10 are satisfied, the second step S20 maintains the torque reduction demand amount (S21), and this time T is maintained for the set time T1. Next, the torque reduction required amount is output at a constant slope (ramp1) (S23), and this time (T) is maintained for a predetermined set time (T2) (S24). Next, while outputting the torque reduction request amount at a constant slope (ramp2) (S25), the "SB" point is determined (S26).

Next, in the third step S30, when the "SB" point is satisfied in the second step S20, the torque reduction demand amount is output at a predetermined slope ramp3 during the set time T3 (S31). At this time, the ignition timing retard is not used but only slow is used.

The impact reduction control method, which is a tip when shifting the lift foot-up of the automatic transmission of the present invention as described above, has been performed for a predetermined time until the end of the shift, unlike the engine torque reduction control for a predetermined time from the lift foot-up shift to the end of the shift. By controlling the torque reduction demand in multiple stages during the lift foot-up shift, it is an invention having the effect of preventing acceleration lowering and reducing tip-in impact during rapid torque reduction demand change.

Claims (1)

It is judged whether the shift of the power-off shift is detected in the power-on state, and turbine speed (Nt) ≤ turbine speed reference value (No x Cij), engine speed (Vrpm) ≥ engine speed reference value, throttle opening rate ≥ A first step of determining whether or not the throttle opening ratio reference value, the cooling water temperature> cooling water temperature reference value, and the shift control section are not; If the first step is satisfied, after the torque reduction demand is maintained for the set time T1, the torque reduction demand is output at a certain slope ramp1 during the set time T2, and then the torque reduction demand is output at a different ramp2. And a second step of determining an "SB" point; When the "SB" point is satisfied in the second step, a third step of outputting the torque reduction demand at a different slope (ramp3) during the set time (T3) time, which is a tip when shifting up the shift of the automatic transmission Impact reduction control method.

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