KR100387874B1 - Method for 4 →3 adjustable shift control of automatic transmission in vehicle - Google Patents

Abstract

In order to fundamentally improve the cross shock between the engine speed Ne and the turbine speed Nt, which are a problem when shifting 4 → 3 before stoppage, the shift timing is set to the engine speed Ne and the turbine speed Nt. In order to solve the cross-shock at the time of shifting by increasing the engine speed Ne by the data communication with the engine control apparatus when it determines according to the state of and controls below the limit vehicle speed;

Determining whether a shift request signal input from a vehicle driving at four speeds satisfies a 4 → 3 variable shift control condition before stopping; Determining whether the vehicle speed reaches a predetermined first preset reference value when it is determined that the 4? 3 variable shift control condition before stopping is satisfied in the above step; After determining that the vehicle speed reaches a predetermined first set reference value in the step, and outputting the corresponding 4 → 3 shift control signal before the stop according to the change of the engine speed and the actual turbine speed, stop It is possible to prevent the cross shocks occurring during all 4 → 3 shifts, to increase the degree of freedom during development related to the cost down of the engine control unit, and to increase the accuracy of shifts by inducing accurate shifts even in durability and abnormalities. have.

Description

4 → 3 ADJUSTABLE SHIFT CONTROL OF AUTOMATIC TRANSMISSION IN VEHICLE}

The present invention relates to an automatic transmission for a vehicle, and more particularly, to a four-to-three variable shift control method of an automatic transmission for a vehicle in which a four-to-three variable shift control is performed before stopping during four-speed driving.

In general, an automatic transmission for a vehicle is provided with a shift control device that automatically adjusts a transmission ratio according to a traveling speed and a load of the vehicle.

The shift control device performs a shift by controlling a plurality of clutches and brakes installed in the gear train in an activated or inoperative state to adjust the output rotation speed of the planetary gear device.

According to the shift pattern stored in the memory according to a preset program in the automatic transmission vehicle which performs the shift as described above, that is, upshift or 4 to 1 to 4 speed sequentially according to the output shaft rotation speed and the throttle valve opening degree corresponding to the vehicle speed. Shift down to 1 speed in the middle.

In the automatic transmission vehicle in which the shift is made as described above, in the case of a transmission in which a one-way clutch (O.W.C: One Way Clutch) is not coupled at the third shift stage, the shift of 4 → 3 before stopping is shifted in a clutch-to-clutch manner.

In the above case, the control method at the time of shifting includes a power on / off method and the like, and its characteristics vary according to the control method.

However, in the conventional method described above, the power on / off control method is determined by the engine speed Ne and the turbine speed Nt at the time of shifting. Since Ne) has to start shifting when the turbine speed (Nt) is higher than the turbine rotation speed (Nt), the shift time point generally occurs in the low speed range, and thus is likely to be four speeds when re-acceleration in the low speed range, which is a negative factor in the vehicle acceleration performance. This involves a problem.

Since the power-off control should start shifting at a time when the engine speed Ne is lower than the turbine speed Nt, a shift time point generally occurs in the high speed range, and thus the engine brake feeling and the speed change in the high speed range. As the engine speed Ne needs to be lowered when manufacturing costs are reduced, if the engine side is abnormal or if the durability is severe, it may cause a cross shock between the turbine speed Nt and the engine speed Ne. have.

Accordingly, an object of the present invention is to solve the above problems, and in order to fundamentally improve the cross shock between the engine speed Ne and the turbine speed Nt, which is a problem at the time of 4 → 3 shifting before stoppage. The shift timing is determined according to the state of the engine speed Ne and the turbine speed Nt, and when the control speed is lower than the limit vehicle speed, the engine speed Ne is increased through data communication with the engine control device. The purpose of the present invention is to provide a variable shift control method of 4 → 3 before stoppage of an automatic transmission for a vehicle that can fundamentally solve the occurrence of time cross shock.

The present invention for achieving the above object,

Determining whether a shift request signal input from a vehicle driving at four speeds satisfies a 4 → 3 variable shift control condition before stopping;

Determining whether the vehicle speed reaches a predetermined first preset reference value when it is determined that the 4? 3 variable shift control condition before stopping is satisfied in the above step;

And after determining that the vehicle speed reaches a first predetermined reference value in the above step, outputting a corresponding 4 → 3 shift control signal before stopping according to a change in engine speed and turbine speed. .

1 is a block diagram showing the configuration of the 4 → 3 variable shift control device before stop of the automatic transmission for a vehicle according to the present invention.

Figure 2 is a flow chart of the operation 4 → 3 variable shift control method before the stop of the automatic transmission for a vehicle applied to the present invention.

Figure 3 is a flow chart of the operation 4 → 3 variable shift control subroutine before stop of the automatic transmission for a vehicle according to the present invention.

4 is a graph showing the relationship between the engine speed and the turbine speed when the 4 → 3 variable speed control before the stop of the automatic transmission for a vehicle according to the present invention.

<Description of Symbols for Main Parts of Drawings>

100: vehicle driving state detection means 110: throttle valve opening degree detection unit

120: turbine rotation speed detection unit 130: output shaft rotation speed detection unit

140: engine speed detection unit 150: shift lever position detection unit

160: oil temperature detection unit 200: shift control means

300: driving means

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

1 is a block diagram of a shift control apparatus of an automatic transmission for a vehicle according to the present invention. The vehicle driving state detecting apparatus 100 detects a vehicle driving state that is variably output according to the driving state of a vehicle, and the shift control apparatus 200 To output a predetermined control signal to the vehicle operation state detection device 100 to receive the signal detected by the vehicle driving state detection device 100, the throttle valve opening degree of the vehicle to be output in synchronization with the control signal, The turbine speed, output shaft speed, engine speed, shift lever position and oil temperature are input to determine whether the shift request signal input from the vehicle driving at four speeds satisfies the condition 4 to 3 variable shift control before stopping. When it is determined that the variable speed control condition is satisfied before 4 → 3, the vehicle speed reaches the predetermined reference value. 3 outputs a shift control signal, and when the vehicle speed does not reach a predetermined set reference value, compares and determines a difference between the engine speed and the target turbine speed and outputs a corresponding shift control signal, and the driving apparatus 300 In synchronism with the shift control signal output from the shift control apparatus 200, the shift shifter is completed without shift shock when shifting 4 → 3 before stoppage.

The apparatus 100 for detecting a vehicle operation state includes: a throttle valve opening amount detection unit 110 which is applied when a shift stage is determined by detecting an opening amount of a throttle valve that interlocks according to an accelerator pedal operation state of a driver; A turbine rotation speed detection unit (120) which is applied at the time of determining the shift stage by detecting the turbine rotation speed of the automatic transmission vehicle in operation; An output shaft rotation speed detection unit (130) which is applied to determine a speed change stage by detecting the rotation speed of the output shaft of the automatic transmission as a signal corresponding to the vehicle speed of the vehicle being driven; An engine speed detection unit 140 which is applied when the speed of the engine is determined by determining the speed of the engine of the running vehicle; A shift lever position detector 150 for detecting a position of a shift lever whose position is changed according to a shift lever operating state of the driver; The oil temperature detector 160 detects a change in oil temperature that varies according to an operation state of the vehicle.

With reference to Figures 2, 3 and 4 attached to the shift control operation of the automatic transmission for a vehicle having the above configuration will be described in detail.

The vehicle driving state detecting apparatus 100 detects a throttle valve opening degree, a turbine rotational speed, an output shaft rotational speed, an engine rotational speed, a shift lever position, an oil temperature, and the like, which vary according to the vehicle driving state.

Accordingly, the shift control apparatus 200 outputs a predetermined control signal to the vehicle driving state detecting apparatus 100, and the vehicle driving state detecting apparatus 100 is applied to the predetermined control signal output from the shift control apparatus 200. Throttle valve opening degree, turbine rotation speed, output shaft rotation speed, engine rotation speed, shift lever position, oil temperature, and the like detected in synchronization with each other.

The shift control apparatus 200 receives the throttle valve opening, the turbine rotational speed, the output shaft rotational speed, the engine rotational speed, the shift lever position, and the oil temperature input from the vehicle driving state detection device 100. It is determined whether the 4? 3 variable shift control condition is satisfied before stopping (S100 and S110).

In the variable shift control condition of 4 to 3 before stopping, the current shift stage is not shifting to another shift stage, the current shift stage is not a sport mode and a hold mode, and the shift positions are N, P, and R ranges. Should not be detected.

As described above, when it is determined that the 4 to 3 variable shift control condition is satisfied before stopping in the vehicle driving at the 4 speed, the shift control apparatus 200 reaches the predetermined first set reference value (about 1620 rpm). It is determined whether the comparison (S120).

In the case where it is determined that the vehicle speed No of the traveling vehicle reaches a predetermined first setting reference value (about 1620 rpm), the shift control apparatus 200 as shown in FIG. 4 shows the engine speed Ne as shown in FIG. 4. It is determined whether is smaller than the turbine speed (Nt) (S130).

Ne <Nt

As shown in ① of FIG. 4, when it is determined that the engine speed Ne is smaller than the turbine speed Nt, the shift control apparatus 200 even after the speed change, the engine speed Ne and the turbine speed Nt. Since there is no possibility of crossover, the shift control signal 4? 3 before the power off stop is outputted to start the shift of 4 to 3 before the normal power off stop previously set in the memory (S140).

However, when it is determined that the engine speed Ne is greater than or equal to the turbine speed Nt, the shift control apparatus 200 has a predetermined second vehicle speed No as shown in 2 in FIG. 4. It is determined whether the detected engine speed Ne at the time of the set value (about 1620 rpm) has a value larger than the vehicle speed No x 3 speed gear ratio i3 (S150).

In the above, the vehicle speed No x 3 speed gear ratio i3 is the turbine speed Nt after the shift, and thus maintains a condition where the engine speed Ne is larger than the turbine speed Nt even after the shift.

The three-speed target turbine speed (No x) calculated by the arithmetic expression in which the detected engine speed Ne at the time when the vehicle speed No is the predetermined first set value (about 1620 rpm) is set in the memory. If it is determined that the value is larger than i3), the shift control apparatus 200 outputs the shift control signal 4 → 3 before power-on stop previously set in the memory, as shown in ② of FIG. 4 (S160). .

However, the detected engine speed Ne at a time when the vehicle speed No is a predetermined first set value (about 1620 rpm) in S150 is smaller than the vehicle speed No x 3 speed gear ratio i3. If it is determined to have, the shift control apparatus 200 performs a three-speed shift prohibition control subroutine (S170).

That is, the three speed shift prohibition control entry does not satisfy the condition where the engine speed Ne is greater than the turbine speed Nt and the engine speed Ne is greater than the vehicle speed No x 3 speed gear ratio i3. Otherwise, three-speed shifts are prohibited as the turbine speed Nt and engine speed Ne cross when the gearshift speed is shifted 4 → 3 before stopping.

Therefore, under the above conditions, the speed of the shift is first lowered to the low speed region (the vehicle speed No is lowered, so the turbine speed Nt at the third speed is also lowered. You will find a condition that remains greater than (Nt).

Therefore, when the 3-speed prohibition control subroutine starts, the shift control apparatus 200 compares and determines whether the vehicle speed No has reached a predetermined second set value (about 1400 rpm) as shown in FIG. (S200, S210).

The reason for selecting the vehicle speed as the threshold speed which is the second set value (about 1400 rpm) in the above three speed shift prohibition control can be controlled so as not to generate a cross shock by lowering the shift time to a low speed range, but prohibiting the shift to a very low vehicle speed. In this case, the marginal speed is selected because it affects the subordinate shift (in this case, 3 → 2 before stopping).

Therefore, when it is determined that the vehicle speed No reaches a predetermined second set value (about 1400 rpm) which is the limit vehicle speed, the shift control apparatus 200 determines whether the predetermined condition A is satisfied (S220).

The predetermined condition A is the engine speed Ne> (turbine speed Nt)-output shaft speed change rate (dNo) x gear ratio before shifting (i4) x predetermined third set time (about 0.3 sec)) x Gear ratio i3 after shifting.

The condition A is a condition for determining whether the engine speed Ne is maintained in the turbine speed Nt even after the shift in consideration of the predetermined third set time (about 0.3 sec), which is the shift time. If satisfied, perform the 4 → 3 shift control subroutine before the power on stop before the power on stop, and return the main routine to perform the 4 → 3 shift control before the power on stop, as shown in ③ of FIG. 4. (S230).

In this way, the shift time can be lowered in the low speed range so as to prevent cross shock from occurring.

However, in the case where the vehicle speed No satisfies the 3-speed shift prohibition control up to the limit vehicle speed at which the vehicle speed No is the second predetermined reference value (about 1400 rpm), the shift control apparatus 200 is not shown in the drawing. The engine speed Ne request is output to the engine controller ECU, and the shift is started by outputting the shift control signal 4 → 3 before power-on stop stored in the memory as shown in ④ of FIG. 4. do.

In this case, the engine control unit (ECU) is typically about 100 to 200 msec from the time when the engine speed rise is requested until the actual rise occurs, and a time of 200 to 300 msec from the output of the 4 to 3 shift control signal before the stop is started. Since it is necessary, it is good to proceed simultaneously with the request time of engine speed increase.

In the above shift control device 200, the engine speed increase demand amount is 200 to 300 rpm and the engine lift request end point at the engine control unit (ECU) side, which is not shown in the drawing, is 4?

As a result, it is possible to prevent the cross shock that may occur when shifting 4 → 3 before stopping.

As described above, the variable speed control method before the stop of the automatic transmission for a vehicle according to the present invention is a crossover between the engine speed Ne and the turbine speed Nt, which are a problem at the time of the shift 4 to 3 before stop. In order to fundamentally improve the shock, the shift timing is determined according to the state of the engine speed Ne and the turbine speed Nt, and when the control speed is controlled below the limit vehicle speed, the engine speed is determined by data communication with the engine control device ( It is possible to solve the crossover shock during shifting by increasing Ne).

Claims (11)

Determining whether a shift request signal input from a vehicle driving at four speeds satisfies a 4 → 3 variable shift control condition before stopping; Determining whether the vehicle speed reaches a predetermined first preset reference value when it is determined that the 4? 3 variable shift control condition before stopping is satisfied in the above step; After it is determined that the vehicle speed reaches a predetermined first set reference value in the above step, outputting a corresponding 4 → 3 shift control signal before stopping according to a change in the engine speed and the actual turbine speed. 4 → 3 variable shift control method before the automatic transmission of a vehicle. The variable shift control condition according to claim 1, wherein the current shift stage is not shifted to another shift stage, the shift mode is not a sport mode or a hold mode, and the shift positions are N, P, and R ranges. 4 → 3 variable shift control method before the stop of the automatic transmission for a vehicle is not detected. The method of claim 1, wherein the predetermined first set value is about 1620 rpm. The variable shift control method according to claim 1, wherein when the engine speed is lower than the actual turbine speed, the power off stop before 4 to 3 shift control signal is output. The method of claim 1, further comprising: determining a difference between the engine speed and the third-speed target turbine speed when the engine speed is determined to be higher than the actual turbine speed; If it is determined in the step that the engine speed is higher than the three-speed target turbine rotation speed, 4 → 3 variable speed control method before the stop of the automatic transmission for a vehicle, characterized in that for outputting the power-stop 4 → 3 shift control signal. The automatic transmission for a vehicle according to claim 5, further comprising: outputting a three speed shift prohibition control signal when it is determined that the engine speed is higher than the actual turbine speed and the engine speed is lower than the three speed target turbine speed. 4 → 3 variable shift control method before stop. The method of claim 6, wherein the three-speed shift prohibition control signal comprises: determining whether the vehicle speed is lower than a predetermined second predetermined reference value; And if it is determined that the vehicle speed is lower than the predetermined second predetermined reference value in the above step, determining whether the predetermined condition A is satisfied. The predetermined second set reference value is about 1400 rpm, and condition A is an engine speed Ne> (turbine speed Nt)-output shaft speed change rate dNo x gear ratio i4 before shifting. 4 to 3 variable shift control method before the stop of the automatic transmission for a vehicle, including the predetermined third set time (about 0.3 sec) x after the shift. The method of claim 7, wherein when the vehicle speed reaches a predetermined second set reference value, the vehicle speed change control signal is output before the power-on stop. 3 Variable Shift Control Method. The engine speed increase request signal is output when the vehicle speed reaches the predetermined second set reference value, and the engine speed increase request signal is output. 4 → 3 variable shift control method before the stop of the vehicle automatic transmission, characterized in that for outputting. The variable speed control method according to claim 10, wherein the end point of the engine speed increase request is a completion point of a shift of 4 to 3 before the power-off stop is completed.