JP3085436B2 - Gear ratio control device for automatic transmission - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transmission ratio control device for an automatic transmission that determines a transmission gear ratio using vehicle speed information and predicted accelerator operation amount information.

[0002]

2. Description of the Related Art Conventionally, as a gear ratio control device for an automatic transmission, for example, one disclosed in Japanese Patent Application Laid-Open No. 4-125356 is known.

[0003] As shown in FIG. 8, the prior art reference discloses a transmission gear by comparing an accelerator opening detection value from an accelerator opening sensor and a vehicle speed detection value from a vehicle speed sensor with a predetermined shift pattern. An apparatus for determining a ratio (gear position) and performing automatic shifting is shown.

[0004]

However, in the above-described conventional gear ratio control device for an automatic transmission, the actual gear operation amount is determined because the gear ratio is determined by the accelerator operation amount of the driver. The shift is not performed unless the vehicle crosses the shift line of the shift pattern, and the shift is not always performed in accordance with the expectation of the shift that appears in the accelerator operation of the driver.

For example, even if the driver wants to accelerate and depresses the accelerator, it takes time to engage and release the inertia, clutches, bands, etc. of the rotating parts of the automatic transmission itself, and the transmission gear ratio is immediately increased. The fact is that does not change.

On the other hand, a plurality of shift patterns are prepared in recent automatic transmissions, and there is a system for arbitrarily selecting an optimal shift pattern for driving in an urban area or on a mountainous road. Also, on some models,
There is also a system that determines a driving method from an accelerator operation amount or the like and automatically switches to an optimal shift pattern accordingly (see Japanese Patent Application Laid-Open No. Sho 60-175858).

However, even if a plurality of shift patterns are present, the mechanical delay of the transmission itself is not avoided as described above, and the shift is selected to a certain extent so as to meet the expected shift. Satisfactory shifting is not always achieved with respect to shifting expectations.

Therefore, in order to solve these problems,
It is conceivable to predict the accelerator operation of the driver and to give an early instruction of the accelerator operation amount in order to compensate for the mechanical operation delay of the automatic transmission. However, the prediction of the accelerator operation amount is for predicting a change in the accelerator based on the driver's intention, and largely depends on the driver's intention. Therefore, the prediction of the accelerator opening is not easy.

That is, in general, on a mountain road, the accelerator operation becomes frequent at the ups and downs of a corner or a slope, and it becomes difficult to predict the accelerator operation. On the other hand, in the case of a running pattern in which the vehicle travels with a flat speed limit of about 50 km / h and repeated stop and start for each signal, as in an urban area, the accelerator operation is gentle and it is easy to predict the accelerator operation.

As described above, since it is difficult or easy to predict the accelerator operation depending on the road on which the vehicle is to be driven or how to drive, it is conceivable to change the method of predicting the accelerator operation in accordance with the actual driving situation. Can be

However, even in the case of this prediction method, it is not possible to grasp the driving situation unless the user travels for a while.
Immediately after riding, you cannot experience the crisp running predicted by the accelerator operation.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and has as its object to change the gear ratio of an automatic transmission that determines a gear ratio using vehicle speed information and predicted accelerator operation amount information. It is an object of the control device to achieve speed ratio control that can simultaneously secure a good driving performance that matches the way of driving in the selected shift pattern, simultaneously with the selection of the shift pattern.

[0013]

In order to achieve the above object, a speed ratio control apparatus for an automatic transmission according to the present invention comprises: a vehicle speed detecting means a for detecting a vehicle speed; Accelerator operation amount detection means b for detecting the operation amount; accelerator operation amount prediction value calculating means c for predicting a future accelerator operation amount based on the accelerator operation state; and a transmission gear ratio for vehicle speed information and accelerator operation amount information are preset. A plurality of speed change patterns d, speed change pattern selection means e for selecting one speed change pattern from the plurality of speed change patterns d according to driving conditions and a driver, vehicle speed information from the vehicle speed detection means a and the accelerator Speed change gear ratio determination for determining the speed change gear ratio by comparing the accelerator operation amount information from the operation amount predicted value calculation means c with the selected shift pattern d. In step f, the accelerator operation amount prediction value calculating means c changes the prediction range so as to calculate the accelerator operation amount prediction value as the selected gear change pattern is a power-oriented speed change pattern that is difficult to shift up. Accelerator operation amount prediction range changing means g.

[0014]

When the vehicle is running, the shift pattern selecting means e selects one shift pattern from a plurality of shift patterns d set in advance by the driving situation and the driver. Then, the accelerator operation amount prediction value calculation means c predicts the future accelerator operation amount based on the accelerator operation state obtained from the detection information from the accelerator operation amount detection means b, and the transmission gear ratio determination means f determines the vehicle speed detection means The transmission gear ratio is determined by comparing the vehicle speed information from a with the accelerator operation amount information from the accelerator operation amount prediction value calculation means c with the selected shift pattern d.

When the accelerator operation amount is predicted by this gear ratio control, the accelerator operation amount prediction range changing means g
The prediction calculation method is changed such that the prediction range is narrowed and the predicted value of the accelerator operation amount is calculated as the selected shift pattern is a power-oriented shift pattern that is difficult to shift up.

For example, when a normally-oriented shift pattern in which the vehicle travels while the accelerator operation is relatively monotonous is selected, the accelerator operation amount can be easily predicted and the prediction accuracy is high. , The accelerator operation amount prediction range in the accelerator operation amount prediction value calculation means c is widened, for example, the prediction time is changed to be longer.

On the other hand, when a power-oriented shift pattern in which the vehicle travels with relatively frequent accelerator operation is selected, the accelerator operation amount is difficult to predict and the prediction accuracy is low. At
The change is made so that the accelerator operation amount prediction range in the accelerator operation amount prediction value calculation means c is narrowed, for example, the prediction time is shortened.

Therefore, by utilizing the fact that the accuracy of predicting the accelerator operation amount can be estimated based on the type of the selected shift pattern, the predicted range of the accelerator operation amount is changed according to the selected shift pattern. At the same time, for example, when a normally-oriented shift pattern is selected, a gear ratio control that immediately responds to the driver's shift expectation is achieved. As described above, good driving performance that matches the way of driving in the selected shift pattern is immediately secured.

[0019]

Embodiments of the present invention will be described below with reference to the drawings.

First, the configuration will be described.

(First Embodiment) FIG. 2 is a diagram showing a speed ratio control system to which a speed ratio control device for an automatic transmission according to a first embodiment of the present invention is applied.

In FIG. 2, 1 is an automatic transmission, 2 is a control valve unit, 3 and 4 are shift solenoids,
5 is a vehicle speed sensor (corresponding to vehicle speed detecting means a), 6 is an accelerator opening sensor (corresponding to accelerator operation amount detecting means b), 7
Is an AT controller, and 8 is an AT mode switch (corresponding to a shift pattern selecting means e).

The shift control system of the AT controller 7 includes an accelerator opening predicted value calculating section 7a (corresponding to an accelerator operation amount predicted value calculating means c) and a shift pattern setting section 7b.
And a transmission gear ratio determination unit 7c (corresponding to transmission gear ratio determination means f) and an accelerator opening degree prediction time changing unit 7f (corresponding to accelerator operation amount prediction range changing means g).

The accelerator opening predicted value calculating section 7a calculates a current accelerator opening A (t) or a past accelerator opening A (t).
-Δ) and the like, and a future accelerator opening predicted value y (t + n) based on the accelerator operation state by a prediction method described later.
δ) is calculated. Where t is the current time, n is an integer,
δ is a control cycle or a sampling cycle.

The shift pattern setting section 7b stores in advance the economy pattern shown in FIG. 3 and the power pattern (corresponding to a plurality of shift patterns d) shown in FIG. Switch 8
, Any one of the shift patterns is selected.

The economy pattern is a shift pattern that is easy to shift up and is most suitable for economical driving as shown in FIG. 3, and the power pattern is a shift point compared to the economy pattern as shown in FIG. On the high-speed side where it is difficult to shift up, which is the optimal shift pattern for power-oriented operation.

The transmission gear ratio determination unit 7c compares the vehicle speed VSP from the vehicle speed sensor 5 and the predicted accelerator opening y (t + nδ) from the predicted accelerator opening calculation unit 7a with the selected transmission pattern. To determine the transmission gear position,
A control command for obtaining the determined transmission gear position is output to the shift solenoids 3, 4.

The accelerator opening predicted time changing unit 7d includes:
When the power pattern is selected by the AT mode switch 8, a change command for reducing the prediction coefficient n of the prediction time nδ is output to the accelerator opening predicted value calculation unit 7a,
When the economy pattern is selected by the AT mode switch 8, the prediction coefficient n of the prediction time nδ
Command to calculate the accelerator opening degree prediction value 7a
Output to

Next, the operation will be described.

[Prediction of accelerator opening] Regarding the prediction of the accelerator opening, Japanese Patent Application No. 4-26 filed earlier by the present applicant.
As described in No. 4674, it can be calculated by a method of auto-regressively predicting the accelerator opening, but here, a method of fitting past data to a predetermined curve and calculating a future value from the function is used. Will be described.

For example, as shown in FIG.
The past and present accelerator opening of δ, t−2δ is A
Assuming that (t), A (t−δ), and A (t−2δ), these three points are fitted by, for example, a quadratic function, and the function is f (t). It can be assumed that the opening also exists on the curve of this quadratic function, and the accelerator opening A (t + n
δ) is represented by f (t + nδ). In this manner, a future accelerator opening can be predicted.

That is, assuming that f (t) = at ² + bt + c, when this quadratic curve satisfies the following equation, a, b, and c are calculated by simultaneous equations, and future values are substituted into the function. To calculate a predicted accelerator opening.

F (t−2δ) = a (t−2δ) ² + b
(T−2δ) + c = A (t−2δ) f (t−δ) = a (t−δ) ² + b (t−δ) + c = A
(T−δ) f (t) = a (t) ² + b (t) + c = A (t) According to the above equation, a, b, c are obtained, f (t + nδ) is calculated, and the value is calculated as y ( t + nδ), which is used as a predicted value in the shift control.

[Predicted Time Changing Operation] FIG. 4 is a flowchart showing a flow of a predicted time changing operation process performed by the accelerator opening predicted time changing unit 7d of the AT controller 7.
Hereinafter, each step will be described.

In step 50, the AT mode switch 8
It is determined whether or not the shift pattern selected is a power pattern.

In step 51, a change command for reducing the prediction coefficient n of the prediction time nδ at the time of selecting the power pattern is output to the accelerator opening predicted value calculation section 7a.

In step 52, flag = 1 is set.

In step 53, when the economy pattern is selected, a change command for increasing the prediction coefficient n of the prediction time nδ is output to the accelerator opening degree predicted value calculation section 7a.

At step 54, the flag is set to "0".

In step 55, it is determined whether or not the current flag is different from the set old flag.

In step 56, when the flag ≠ old flag, the set flag is rewritten.

[Change in Predicted Time Based on Shift Pattern] Accelerator opening predicted value y predicted using the above-described prediction method and the like
If (t + nδ) becomes the same as the actual accelerator opening A (t + nδ), it means that the accelerator opening has been successfully predicted. However, in reality, there are traveling situations with high prediction accuracy and traveling situations with low prediction accuracy, and it is not always possible to always accurately predict the accelerator opening. Therefore, as described below, the prediction time is changed to suppress variations in prediction accuracy.

Here, if the shift pattern selected by the driver is a pattern in which the upshift shift point is set at a lower vehicle speed, as indicated by the name of the mountain road mode or power pattern, Empirically, the running pattern in the case of requesting such a shift pattern has a large accelerator movement, which may lead to a large error if the future is predicted too much. Therefore, the predicted future time is shortened. That is, in the flowchart of FIG. 5, the flow proceeds from step 50 to step 51,
In step 51, the prediction coefficient n is reduced. Specifically, it is assumed that n = nk (k is a constant, k <n).

In the case where the shift pattern selected by the driver is a pattern in which the vehicle speed of the upshift is relatively high and the engine speed is not significantly increased, as indicated by the names of economy mode and normal pattern. Empirically, the running pattern when such a shift pattern is requested is such that the change in the accelerator operation is small and there is no unexpected accelerator movement. Lengthen. That is, in the flowchart of FIG.
The flow proceeds from step 50 to step 53. In step 53, the prediction coefficient n is increased. Specifically, n = n + k (k is a constant).

[Reason why the prediction deviates greatly] The reason why the acceleration prediction deviates greatly from the actual accelerator operation amount will be described.

First, the prediction is such that even if a fairly good prediction function exists, human operations are non-ergodic,
In addition, prediction residuals always occur because they have non-linear characteristics with time-varying parameters and structural changes that cannot be observed from outside.

This tendency depends on the characteristics of the driver.
For a driver who suddenly accelerates or stops suddenly, the prediction residual becomes large, and for a driver who drives relatively calmly, the prediction may be quite accurate. Thus, there are drivers that are easy to predict and drivers that are difficult to predict.

Further, it is easy to predict in a driving situation where the driving operation is relatively monotonous, such as on an expressway, but it is difficult to predict in a driving situation in which the variety of driving operations is large, such as a curved mountain road.

As described above, the prediction situation greatly changes depending on the characteristics of the driver and the environment of the road on which the prediction is made, for example, the prediction deviates greatly or the prediction is quite accurate.

[Effectiveness of Predicted Time Change] As described above,
While the prediction accuracy changes depending on the characteristics of the driver and the environment of the road on which the vehicle is traveling, if the prediction time is fixed, when the vehicle is traveling with low prediction accuracy, the shift control based on incorrect prediction may give the driver a great sense of discomfort. This will impress the lack of drivability.

Therefore, while the prediction accuracy is checked by the selected shift pattern, the prediction time is lengthened in the driving situation in which the economy-oriented pattern with high prediction accuracy is selected, and the power-oriented pattern with low prediction accuracy is selected. By shortening the prediction time in the selected driving situation, the shift control is immediately performed in response to the driver's expectation of the shift when the economy pattern is selected by simultaneously selecting the shift pattern, and the power pattern is selected. In some cases, it is possible to immediately secure good driving performance that matches the way of driving in the selected shift pattern, such as preventing the driver from feeling uncomfortable or lacking in driving performance. As described above, in the shift control based on prediction, it is extremely effective to change the predicted time while watching the selected shift pattern.

Next, the effects will be described.

As described above, in the transmission ratio control device for the automatic transmission according to the first embodiment, the accelerator opening predicted time changing section 7d operates either the economy pattern or the power pattern by the driver. A to switch with
When the power pattern is selected by the T mode switch 8 and the AT mode switch 8, the prediction time nδ
Is output to the accelerator opening predicted value calculating section 7a, and when the economy pattern is selected by the AT mode switch 8, the predicted coefficient n of the predicted time nδ is increased. Since the apparatus is provided with the accelerator opening degree predicted time changing section 7d that outputs a change command to the accelerator opening predicted value calculating section 7a, it is possible to select a shift pattern at the same time as selecting a good shift pattern that matches the running style in the selected shift pattern. Gear ratio control that can immediately ensure drivability can be achieved.

(Second Embodiment) First, the configuration will be described.

FIG. 7 is a gear ratio control system to which a gear ratio control device for an automatic transmission according to a second embodiment of the present invention is applied.

In FIG. 7, reference numerals 1 to 7 are the same as those in the first embodiment.

The shift control system of the AT controller 7 is provided with a shift mode determining section 7e (corresponding to a shift pattern selecting means e) instead of the AT mode switch 8 of the first embodiment.

The shift mode judging section 7e judges the accelerator operation state based on the change speed and the change acceleration of the accelerator opening. For example, when the change in the accelerator operation amount is larger than the set change, the power change pattern is used as the shift pattern. A command for automatically selecting a pattern is output, and when the change in the accelerator operation amount is smaller than the set change, a command for automatically selecting an economy pattern as a shift pattern is output.

The accelerator opening predicted value calculating section 7d calculates
The prediction coefficient n of the prediction time nδ is changed according to a shift pattern selection command from the shift mode determination unit 7e.

Regarding the operation and effect of the second embodiment, there is a difference between the shift operation of the AT mode switch 8 performed by the driver to select the shift pattern or the automatic selection of the shift pattern by judging the accelerator operation condition. However, the same operation and effect as those of the device of the first embodiment can be obtained in the device of the second embodiment.

Although the embodiment has been described with reference to the drawings, the specific configuration is not limited to the embodiment, and even if there are changes and additions without departing from the gist of the invention, the invention is included in the invention. It is.

For example, in the embodiment, an example in which the present invention is applied to a stepped transmission is shown, but the present invention can also be applied to a continuously variable transmission.

In the embodiment, as the accelerator operation prediction range changing means, an example in which the prediction time of the accelerator opening is changed has been described. However, the prediction time is set to a fixed time, and the power change of the selected shift pattern is difficult to shift up. A means for changing the predicted value, which changes the predicted accelerator opening value in the accelerator opening predicted value calculation unit closer to the actual accelerator opening, may be adopted as the shift pattern.

[0064]

As described above, according to the present invention, in a transmission ratio control apparatus for an automatic transmission, which determines a transmission gear ratio by using vehicle speed information and predicted accelerator operation amount information, the operation condition is described. And a driver selects a shift pattern from among a plurality of shift patterns, and an accelerator operation amount prediction value calculating unit predicts that the selected shift pattern is a power-oriented shift pattern that is difficult to shift up. Since the apparatus is provided with an accelerator operation amount prediction range changing means for changing the range so as to calculate an accelerator operation amount prediction value, the speed change pattern is selected and, at the same time, the driving method in the selected gear change pattern is matched. The effect is obtained that the gear ratio control that can immediately ensure good driving performance can be achieved.

[Brief description of the drawings]

FIG. 1 is a diagram corresponding to claims showing a speed ratio control device for an automatic transmission according to the present invention.

FIG. 2 is a transmission ratio control system diagram to which the transmission ratio control device for the automatic transmission according to the first embodiment is applied;

FIG. 3 is a diagram illustrating an example of an economy pattern set in an AT controller of the device of the first embodiment.

FIG. 4 is a diagram illustrating an example of a power pattern set in an AT controller of the device of the first embodiment.

FIG. 5 is a flowchart showing a flow of an accelerator opening predicted time changing operation performed by an accelerator opening predicted time changing unit of the AT controller of the first embodiment device.

FIG. 6 is an accelerator opening characteristic diagram for predicting an accelerator opening using a quadratic function curve.

FIG. 7 is a diagram showing a gear ratio control system to which a gear ratio control device for an automatic transmission according to a second embodiment is applied.

FIG. 8 is a diagram showing a conventional gear ratio control device for an automatic transmission.

[Explanation of symbols]

 a vehicle speed detection means b accelerator operation amount detection means c accelerator operation amount prediction value calculation means d shift pattern e shift pattern selection means f transmission gear ratio determination means g accelerator operation amount prediction range changing means

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) F16H 61/00-61/28

Claims (1)

(57) [Claims] A vehicle speed detecting means for detecting a vehicle speed; an accelerator operation amount detecting means for detecting an accelerator operation amount; an accelerator operation amount prediction value calculating means for predicting a future accelerator operation amount based on an accelerator operation state; A plurality of shift patterns in which a transmission gear ratio with respect to the information and the accelerator operation amount information is set in advance; a shift pattern selecting means for selecting one of the plurality of shift patterns from the plurality of shift patterns according to a driving situation or a driver; Transmission gear ratio determination means for determining a transmission gear ratio by comparing the vehicle speed information from the detection means and the accelerator operation amount information from the accelerator operation amount prediction value calculation means with the selected shift pattern; The accelerator operation amount prediction value calculating means predicts that the shift pattern is a power-oriented shift pattern that is difficult to shift up. A gear ratio control device for an automatic transmission, comprising: accelerator operation amount prediction range changing means for changing the measurement range so as to calculate an accelerator operation amount prediction value.