JPH08210480A - Speed change operation start timing detecting device for automatic transmission - Google Patents

Abstract

PURPOSE: To high accurately detect the speed change operation start timing by providing a speed ratio force setting means of setting speed ratio forcedly to 1, so as to suppress an error of calculating the speed ratio of a torque converter to a minimum limit, in the case that the speed ratio calculated by a speed ratio calculating means is larger than 1 at speed change time during acceleration. CONSTITUTION: During vehicle operation, in a CPU 6, here are calculated an engine speed Ne from an output of a crank angle sensor 9, output shaft rotational speed No and a car speed based on an output of an output shaft rotational speed sensor 11. The present speed ratio eS (=No×IL/Ne) of a torque converter 3 is calculated. In the case of deciding speed change time during acceleration from a car speed or the like, the speed ratio eS of the torque converter 3 is compared with 1, to forcedly set the speed ratio eS to 1, in the case of a relation where eS>1. Next by using the set speed ratio and a correction coefficient, a deciding rotational speed for judging a speed change operation start point is calculated and compared with the present engine speed, to judge the speed change operation start point.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for detecting a start timing (hereinafter also referred to as a start point) of a gear shifting operation for performing line hydraulic pressure, torque down control, etc. during gear shifting of an automatic transmission.

[0002]

2. Description of the Related Art Conventionally, when shifting an automatic transmission for an automobile, the fuel supply amount is reduced or stopped, the ignition timing is retarded,
The engine torque is reduced by decreasing the intake air flow rate or a combination thereof to suppress a sudden change in the output shaft torque of the transmission during a gear shift to mitigate the shift shock. The period for performing the gear shift should be the period during which the gear shift operation is actually performed after the torque change is transmitted (after the torque phase elapses) after the gear shift operation is started.
Here, when the gear shifting operation is being performed, the gear ratio is interrupted by the gear shifting so that the speed ratio between the output shaft of the automatic transmission and the turbine shaft of the torque converter, which is the input shaft, is the gear ratio before the gear shifting. It can be considered as a period from the time when the gear ratio starts to change to the time when the gear ratio reaches a new gear ratio after the shift is completed. This shift operation period is called an inertia phase, and the shift operation period is conventionally detected by various methods.

For example, the applicant of the present application, for example, determines the rotational speed for determination obtained by correcting one of the engine rotational speed and the pseudo rotational speed with the speed ratio of the torque converter without providing a turbine rotational speed sensor or the like. Japanese Patent Application No. 6-217594 proposes a shift operation period detection device for an automatic transmission, which is capable of detecting the start point and the end point of a shift operation with high precision by comparing one with the other. .

This is, for example, the rotation of the transmission output shaft.
Speed N_OAnd the gear ratio I before shifting_LAnd depending on the shifting conditions
While multiplying by the set correction coefficient K, the torque converter
Speed ratio e at the start of gear shifting_S(= N_O× I_L/ Engine times
Gear ratio I before shifting, divided by rolling speed Ne)_LFixed to
Engine speed (= N_O× I_L× K / e_S)
Is the rotational speed Ne for determining the shift operation start point._SEstimated as
However, the actual engine rotation speed Ne is equal to the determination rotation speed N.
e_SThe point where the speed falls below the
Put out. The end point of the shifting operation is detected by the transmission
Power shaft rotation speed N _OAnd the gear ratio I after shifting_HAnd shift line
While multiplying by the correction coefficient K'set according to the situation,
Speed ratio e at the start of shifting the torque converter_SDivided by,
Gear ratio I before shifting_HEngine speed when fixed to
Degree (= N_O× I_H× K '/ e_S) To determine the end point of gear shifting operation
Regular rotation speed Ne_eEstimated as the actual engine speed
Ne is the rotation speed Ne for the determination._eWhere you reached
It is detected as the end point of the shift operation.

[0005]

However, even the device proposed in Japanese Patent Application No. 6-217594 has the following problems. That is, the engine rotation speed Ne is detected by utilizing the pulse signal generation cycle or generation frequency from the crank sensor provided on the engine side, while the output shaft rotation speed No of the transmission is the output shaft rotation speed. The detection is performed by using the pulse signal generation period or generation frequency from the sensor. This is because the engine control uses the signal from the crank sensor generated in a relatively short cycle in order to improve the detection response in order to adapt to the engine control in which acceleration and deceleration are frequent and rapid. In transmission control, in order to prioritize the stability of transmission control (prevention of repeated upshifting and downshifting), detection response is lower than in engine control and occurs in a relatively long cycle. This is because it is preferable to use a signal from the output shaft rotation sensor, or because of restrictions such as a mounting location.

Therefore, for example, when both the engine rotational speed Ne and the transmission output shaft rotational speed No are obtained by cycle measurement, the number of pulse signals generated per revolution differs between the crank sensor and the output shaft rotational sensor. In addition, since there is a difference in the rotation speed itself between the engine rotation speed Ne and the transmission output shaft rotation speed No, the cycle measurement timing is deviated or extended between the crank angle sensor and the output shaft rotation sensor. There will be a difference in the update timing of the detected value between the engine rotation speed Ne and the transmission output shaft rotation speed No.

Therefore, the torque converter is locked up.
Speed ratio e_S(= N _O× I_L/ Ne)
It may not be 1.0, and the start point of the gear shifting operation is detected.
There may be an error in. The engine speed Ne
And the method of measuring the transmission output shaft rotation speed No.
If so, the same problem occurs. The present invention provides such
It was made in view of the conventional problems.
Torque controller generated due to detection error of machine output shaft rotation speed
Accurately minimizes the error in detection of the speed ratio of the barter.
Of automatic transmission that can detect the start timing of gear shifting operation
An object of the present invention is to provide a shift operation start timing detection device.
It

[0008]

Therefore, the shift operation start timing detecting device for an automatic transmission according to the invention of claim 1 is connected to an output shaft of an engine through a torque converter as shown in FIG. In a shift control device for an automatic transmission to which engine torque is transmitted, an engine rotation speed detecting means for detecting an engine rotation speed, an output shaft rotation speed detecting means for detecting a rotation speed of an output shaft of the automatic transmission, and the engine. Speed ratio calculating means for calculating the speed ratio of the torque converter based on the rotation speed and the output shaft rotation speed; pre-shift gear ratio detecting means for detecting the gear ratio of the automatic transmission before shifting; Pseudo turbine rotation speed estimation means for estimating the pseudo turbine rotation speed based on the output shaft rotation speed and the gear ratio,
Shift operation start timing detection means for detecting one of the engine rotation speed and the pseudo turbine rotation speed with the speed ratio, and detecting the start timing of the shift operation by comparing the corrected one and the other. And a speed ratio compulsory setting means during acceleration during shift for forcibly setting the speed ratio to 1 when the speed ratio calculated by the speed ratio calculation means during acceleration during shift is greater than 1. Composed of.

Further, as in the invention described in claims 2 and 3, when the speed ratio calculated by the speed ratio calculating means during deceleration shift is less than 1, the speed ratio is forcibly set to 1. The decelerating gear shifting speed ratio forced setting means may be provided alone instead of the accelerating gear shifting time ratio forced setting means, or may be provided together with the accelerating gear shifting time ratio ratio forced setting means. Good.

As described in claim 4, the shift during acceleration or the shift during deceleration may be determined based on the load / load characteristic line.

[0011]

In the device according to the first aspect of the present invention, although the speed ratio of the torque converter should not actually become greater than 1 via the speed ratio forcing during speed change during acceleration, the engine rotation speed and the output shaft If the calculated value is greater than 1 due to the difference in the rotation speed calculation cycle, the calculation method, etc.,
Forcedly set the speed ratio to 1. Therefore, the calculation error of the speed ratio of the torque converter due to the detection error in the engine rotation speed or the output shaft rotation speed can be suppressed to the minimum, so that the shift operation start timing can be detected with high accuracy. Therefore, the lockup release, the engine torque correction, the line hydraulic pressure switching control, etc. can be executed at appropriate timings, and the shift shock mitigation performance and the durability of each shift element can be improved.

In the device according to the second aspect of the present invention, although the speed ratio of the torque converter should not actually become smaller than 1 via the speed ratio forced setting means during deceleration, the engine speed or When the output shaft rotation speed is calculated to be smaller than 1 due to a different calculation cycle or calculation method, the speed ratio is forcibly set to 1.
Therefore, the calculation error of the speed ratio of the torque converter due to the detection error in the engine rotation speed or the output shaft rotation speed can be suppressed to the minimum, so that the shift operation start timing can be detected with high accuracy. Therefore, the lockup release, the engine torque correction, the line hydraulic pressure switching control, etc. can be executed at appropriate timings, and the shift shock mitigation performance and the durability of each shift element can be improved.

In the device according to the third aspect of the invention, the speed ratio of the torque converter is actually set to 1 via the speed ratio forcibly setting speed ratio during acceleration and the speed ratio forcibly setting speed ratio during deceleration. However, due to the difference in the calculation cycle and calculation method of the engine rotation speed and output shaft rotation speed,
If the calculated value is not 1, the speed ratio is forcibly set to 1. Therefore, it is possible to simultaneously obtain the above-described effects of the inventions of claims 1 and 2.

Further, in the device according to the fourth aspect of the present invention, it is determined whether the shift during acceleration or the shift during deceleration is based on the load / load characteristic line. Thus, it is possible to determine with the simple configuration, during the shift during acceleration (hereinafter, also referred to as power-on shift) or during the shift during deceleration (hereinafter, also referred to as power-off shift).

[0015]

An embodiment of the present invention will be described below with reference to the drawings. In FIG. 2 showing the configuration of this embodiment, an automatic transmission 2 is connected to the output side of the engine 1. Automatic transmission 2
Is a torque converter 3 interposed on the output side of the engine 1,
The gear type transmission 4 connected through the torque converter 3 and the various transmission elements in the gear type transmission 4 are connected and
And a hydraulic actuator 5 for performing a releasing operation. The operating hydraulic pressure for the hydraulic actuator 5 is ON / OFF controlled via various electromagnetic valves (not shown).

Signals from various sensors are input to the control unit 6. As the various sensors, a throttle sensor 8 for detecting the opening TVO of the throttle valve 7 of the intake system of the engine 1 is provided. A crank angle sensor 9 is provided on the crankshaft of the engine 1 or a shaft that rotates in synchronization with the crankshaft. The signal from the crank angle sensor 9 is a pulse signal for each predetermined crank angle generated through a disk having an outer peripheral groove (or hole) provided for each predetermined crank angle in conjunction with the rotation of the crankshaft, and is generated. The engine rotation speed Ne is calculated from the cycle.

Further, the output shaft rotational speed sensor 11 for detecting the rotational speed N _O of the output shaft 10 of the automatic transmission 2 is provided. The signal from the output shaft rotation speed sensor 11 is, for example, a pulse signal for each predetermined rotation angle generated by using a tooth profile, a groove, or the like carved in the rotating body that interlocks with the output shaft 10. The rotation speed N _O is calculated. The output shaft rotation speed sensor 11 also serves to detect the vehicle speed.

The control unit 6 controls the throttle valve opening TV when the select lever is in the D range based on the operation position signal of the select lever operated by the driver.
The gear shift positions of the first to fourth gears are automatically set according to O and the vehicle speed VSP, and the gear type transmission 4 is set via the hydraulic actuator 5.
Is controlled to the gear shift position, and at the same time, the start point of the gear shift operation (inertia phase) is detected, and the engine torque is adjusted to fuel supply amount, ignition timing, intake air in order to mitigate the shift shock caused by the gear shift operation. It can be corrected by the flow rate. Similarly, the line hydraulic pressure during the shift operation period is controlled to be switched, and the lockup clutch of the torque converter 3 can be released when the shift operation start point is detected.

Here, the speed ratio calculating means, the pseudo turbine rotation speed estimating means, the speed change operation start timing detecting means, the speed ratio changing speed compulsory setting means during acceleration, and the speed ratio compulsory setting time during deceleration shifting in this embodiment are used. A shift operation start point detection routine performed by the control unit 6 having software functions will be described with reference to the flowchart of FIG.

Step (denoted as S in the figure. The same applies hereinafter) 1
Then, the engine rotation speed Ne is calculated based on the pulse signal from the crank angle sensor 9. Further, the output shaft rotation speed No and the vehicle speed VSP are calculated based on the pulse signal from the output shaft rotation speed sensor 11. In step 2, the current speed ratio e _s (= No × I _L / Ne) of the torque converter is calculated. Note that N _O × I _L is the input shaft 10 of the automatic transmission 2.
That is, it is the rotation speed of the turbine shaft of the torque converter 3.

In step 3, the speed ratio setting flag Flag is set.
Is 1 (Flag = 1 indicates that the speed ratio e _s has already been set). If NO, the process proceeds to step 4, and if YES, the process proceeds to step 12. In step 4, it is determined whether or not there is a shift request. Yes
If NO, the process proceeds to step 5, and if NO, the process proceeds to step 15. This determination is based on whether or not the driver has operated the shift selector and the normal shift map (throttle valve opening TV
Map for selecting a gear based on O and vehicle speed VSP)
It is judged based on the above.

In step 5, the current throttle valve opening TVO and the so-called load / load as shown in FIG.
Compare with the load characteristic line. The R / L characteristic line is a throttle valve opening TVO line that is determined for each gear ratio and obtains the vehicle speed VSP (that is, the current vehicle speed V
It means the throttle valve opening TVO that can maintain the acceleration at 0 with respect to SP).

If TVO ≧ R / LTVO (power-on shift), the process proceeds to step 6. TVO <R /
If it is LTVO (power off shift), proceed to step 10. Here, the step 5 constitutes a means for discriminating between the speed change during acceleration (power-on shift) and the speed change during deceleration (power-off shift). In step 6, the speed ratio e _s of the torque converter calculated in step 2 is compared with 1. If the speed ratio e _s > 1, then go to step 7. If the speed ratio e _s ≦ 1, the process directly proceeds to step 8.

In step 7, the speed ratio e _s is forcibly set to 1 irrespective of the calculation result in step 2.
That is, the speed ratio e _s of the torque converter may be greater than 1 in the calculation due to the difference in the calculation cycle and the calculation method of the engine rotation speed Ne and the output shaft rotation speed No. Since the speed ratio e _s of the torque converter does not become larger than 1 at the time of power-on shift, using the result of the speed ratio e _s > 1 may cause an error in detection of a shift operation starting point described later. Because. As a result, it is possible to eliminate the calculation error of the speed ratio e _s and maintain the accuracy of detection of the shift operation starting point, which will be described later.

In step 5, TVO <R /
In case of LTVO (power off shift), go to step 10.
Proceed, but in step 10, the speed calculated in step 2
Ratio e _sCompare with 1. Speed ratio e_sIf ≧ 1, then
Then proceed to step 8. Speed ratio e_sIf <1, then
Proceed to Step 11.

In step 11, during power off shift,
Since the speed ratio e _s never becomes smaller than 1, the speed ratio e _s is forcibly set to 1 regardless of the calculation result in step 2, and the process proceeds to step 8. That is, the calculation error of the speed ratio e _s due to the difference in the calculation cycle, the calculation method, etc. of the engine rotation speed Ne and the output shaft rotation speed No is minimized to improve the detection accuracy of the shift operation starting point described later. This is to maintain.

In step 8, the calculated or forcibly set speed ratio e _s is set as the speed ratio e _o used in the shift operation period detection routine described later. Step 9
Then, the speed ratio setting flag Flag is set to 1, and the process proceeds to step 12. In step 12, the speed ratio e _O of the torque converter has been set in step 8, the correction coefficient using the K, the engine speed N _e as compared to determination rotational speed N _es for determining the shift operation starting point (= N _O × I _L × K /
e _s ) is calculated, and the current engine rotation speed N _e is compared with the determination rotation speed N _es . The value of the correction coefficient K may be a fixed value, but it is preferably set variably according to various conditions at the time of shifting. That is, since the speed ratio changes from the time when the shift is judged to the moment when the inertia phase actually starts, the correction coefficient K is provided to correct this, so the inertia phase actually starts when the shift is judged. The larger K is, the larger the change in the speed ratio is. Regarding the engine load, the larger the load, the smaller the change in speed ratio (because the speed ratio at the time of gear shift determination is close to 1), so the correction coefficient K is also set to a small value. Since the change in the speed ratio is small (because the speed ratio at the time of shifting judgment is close to 1), the correction coefficient K is also set to a small value, and the shift pattern is the same as that of the vehicle speed. In the (shifted pattern), the change in the speed ratio is smaller than that in the normal pattern, so the correction coefficient K is also set to a small value, and the lockup clutch is turned on and off.
As for F, when ON, the change in speed ratio is large, so O
The correction coefficient K is set to a larger value than in the case of FF. These may be determined only by the respective conditions, but more preferable values can be obtained by setting the values in consideration of some or all of the conditions. For example, it is obtained by normalizing the value obtained by multiplying each value. That is, the correction coefficient K may be the same as that disclosed in Japanese Patent Application No. 6-217594.

If the comparison result between the current engine rotation speed N _e and the determination rotation speed N _es is N _e ≧ N _es , it is determined that it is not the shift start time, and the process returns to step 1. . On the other hand, if it is determined that N _e <N _es , the routine proceeds to step 13, where it is determined that the shift operation start point is reached, and the routine proceeds to step 14, where the speed ratio setting flag Flag is set to 0, and this flow To finish.

Thus, according to this embodiment, in practice
Torque converter speed ratio e_sShould be 1, but
Calculation cycle and calculation of engine speed Ne and output shaft speed No
Due to different output methods etc., it will not be 1 in calculation
In some cases, force ratio e _sSet to 1
Therefore, the engine rotation speed Ne and the transmission output shaft rotation speed No
Even if there is a detection error of_s
It is possible to minimize the detection error of
It is possible to detect the operation start point with high accuracy.
Lockup release, engine torque correction, line oil pressure switching
Control can be executed at appropriate timing,
Improving shock absorbing performance and durability of each shifting element
Can be.

In this embodiment, the pseudo turbine rotation speed is corrected (divided) by the speed ratio of the torque converter, and a value corresponding to the engine rotation speed is compared with the actual engine rotation speed. However, the actual engine rotation speed may be corrected (multiplied) by the speed ratio, and the value corresponding to the turbine rotation speed may be compared with the pseudo turbine rotation speed.
It goes without saying that the two are completely equivalent.

[0031]

As described above, according to the present invention, although the speed ratio of the torque converter should actually be 1, the calculation cycle and calculation method of the engine speed and the output shaft speed are different. Due to this, if the speed ratio does not become 1 in the calculation, the speed ratio is forcibly set to 1. Therefore, the speed ratio of the torque converter due to the detection error in the engine speed or the output shaft speed is detected. Since the calculation error can be suppressed to the minimum, the shift operation start timing can be detected with high accuracy, and thus the lockup release, the engine torque correction, the line hydraulic pressure switching control, etc. can be performed at appropriate timing. It is possible to improve the shock-absorbing performance of gear shifting and the durability of each gear shifting element.

Further, as in the invention of claim 4, when the gear change during acceleration or the gear change during deceleration is judged on the basis of the load / load characteristic line, it is possible to realize a simple structure.
It is possible to determine whether the shift is being performed during acceleration or during deceleration.

[Brief description of drawings]

FIG. 1 is a block diagram illustrating a configuration of the present invention.

FIG. 2 is an overall system configuration diagram of an embodiment of the present invention.

FIG. 3 is a flowchart illustrating a shift operation start timing detection routine of the above embodiment.

FIG. 4 is a diagram showing an example of a load / load characteristic line.

[Explanation of symbols]

 1 engine 2 automatic transmission 3 torque converter 6 control unit 8 throttle sensor 9 crank angle sensor 10 transmission output shaft 11 output shaft rotation speed sensor

Claims (4)

[Claims] 1. A shift control device for an automatic transmission, which is connected to an output shaft of an engine and which transmits engine torque via a torque converter, in an engine speed detecting means for detecting an engine speed, and an output of the automatic transmission. Output shaft rotation speed detection means for detecting the rotation speed of the shaft; speed ratio calculation means for calculating the speed ratio of the torque converter based on the engine rotation speed and the output shaft rotation speed; and a gear of the automatic transmission before shifting. Pre-shift gear ratio detection means for detecting a ratio, pseudo turbine rotation speed estimation means for estimating a pseudo turbine rotation speed based on the output shaft rotation speed of the automatic transmission and the gear ratio, the engine rotation speed and the One of the pseudo turbine rotation speeds is corrected by the speed ratio, and the start timing of the shift operation is detected by comparing the corrected one with the other. And a means for forcibly setting the speed ratio during the shift during acceleration when the speed ratio calculated by the speed ratio calculating means during the shift during acceleration is greater than 1 A shift operation start timing detection device for an automatic transmission, comprising: 2. A shift control device for an automatic transmission, which is connected to an output shaft of an engine and which transmits engine torque via a torque converter, and engine rotation speed detecting means for detecting engine rotation speed, and output of the automatic transmission. Output shaft rotation speed detection means for detecting the rotation speed of the shaft; speed ratio calculation means for calculating the speed ratio of the torque converter based on the engine rotation speed and the output shaft rotation speed; and a gear of the automatic transmission before shifting. Pre-shift gear ratio detection means for detecting a ratio, pseudo turbine rotation speed estimation means for estimating a pseudo turbine rotation speed based on the output shaft rotation speed of the automatic transmission and the gear ratio, the engine rotation speed and the One of the pseudo turbine rotation speeds is corrected by the speed ratio, and the start timing of the shift operation is detected by comparing the corrected one with the other. And a means for forcibly setting the speed ratio during deceleration during forced deceleration when the speed ratio calculated by the speed ratio calculation means during deceleration is less than 1. A shift operation start timing detection device for an automatic transmission, comprising: 3. A shift control device for an automatic transmission, which is connected to an output shaft of an engine and which transmits engine torque via a torque converter, and engine rotation speed detecting means for detecting engine rotation speed, and output of the automatic transmission. Output shaft rotation speed detection means for detecting the rotation speed of the shaft; speed ratio calculation means for calculating the speed ratio of the torque converter based on the engine rotation speed and the output shaft rotation speed; and a gear of the automatic transmission before shifting. Pre-shift gear ratio detection means for detecting a ratio, pseudo turbine rotation speed estimation means for estimating a pseudo turbine rotation speed based on the output shaft rotation speed of the automatic transmission and the gear ratio, the engine rotation speed and the One of the pseudo turbine rotation speeds is corrected by the speed ratio, and the start timing of the shift operation is detected by comparing the corrected one with the other. And a means for forcibly setting the speed ratio during the shift during acceleration when the speed ratio calculated by the speed ratio calculating means during the shift during acceleration is greater than 1 And a speed ratio compulsory setting means during deceleration shifting forcibly setting the speed ratio to 1 when the speed ratio calculated by the speed ratio calculating means during deceleration is less than 1. A shift operation start timing detection device for an automatic transmission characterized by being configured. 4. The automatic system according to claim 1, wherein the shift during acceleration or the shift during deceleration is determined based on a load / load characteristic line. A device for detecting the start timing of gear shifting operation of a transmission.