JPH07224924A - Speed change ratio controller of automatic transmission - Google Patents

Abstract

PURPOSE:To achieve a speed change ratio control capable of rapidly securing good operability matching the way of running in a selected speed change pat tern, symultaneously with the selection of the speed change pattern, in a speed change ratio controller of an automatic transmission in which a speed change gear ratio is determined by utilizing vehicle speed information and predicted acceleration operational quantity information. CONSTITUTION:A speed change ratio controller of automatic transmission is provided with a speed change pattern selection means (e) for selecting one speed change pattern according to an operational condition and a driver out of plural speed change patterns (d), and an acceleration operational quantity prediction range change means (g) for making a prediction range small by an acceleration operational quantity prediction value calculation means (c) as the selected speed change pattern is more closer to power orientated speed change pattern hard to be shifted up, so as to calculate and vary the acceleration operational quantity prediction value.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gear ratio control device for an automatic transmission that determines a 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.

According to the above-mentioned conventional source, as shown in FIG. 8, a transmission gear is obtained 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 preset shift pattern. A device for determining a ratio (gear position) and performing automatic shifting is shown.

[0004]

However, in the above-mentioned conventional gear ratio control device for an automatic transmission, the gear ratio is determined by the accelerator operation amount of the driver, and therefore the actual accelerator operation amount is required. However, there is a problem that the gear shift is not performed unless the vehicle crosses the shift line of the gear shift pattern, and the gear shift is not always performed in accordance with the gear shift expectation 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 disengage the inertia, clutch, band, etc. of the rotating portion of the automatic transmission itself, and the gear ratio is immediately changed. The fact is that does not change.

On the other hand, recent automatic transmissions are provided with a plurality of shift patterns, and there is a system for arbitrarily selecting an optimal shift pattern for driving in urban areas or mountain roads. Also, in some models,
There is also a system that judges the driving method from the accelerator operation amount and the like and automatically switches to the optimum shift pattern (see Japanese Patent Laid-Open No. 175858/60).

However, even if there are a plurality of shift patterns, the mechanical delay of the transmission itself as described above is not avoided, and the shift can be performed in accordance with the shift expectation to some extent by selecting the shift pattern. It is not always possible to achieve a satisfactory shift with respect to the shift expectation.

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

That is, generally, on a mountain road, the accelerator operation becomes frequent at the corners and ups and downs of the slope, and it becomes difficult to predict the accelerator operation. On the other hand, in the case of a driving pattern such as an urban area where the speed is limited to about 50 km / h and the vehicle starts and stops repeatedly at each signal, 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 to be traveled and the way of traveling, it is conceivable to change the accelerator operation prediction method according to the actual driving situation. To be

However, even in the case of this prediction method, the traveling situation cannot be grasped unless the vehicle travels for a while.
Immediately after getting on, you cannot experience the crisp driving due to the accelerator operation prediction.

The present invention has been made in view of the above problems, and an object thereof is to provide a gear ratio of an automatic transmission that determines a gear ratio using vehicle speed information and predicted accelerator operation amount information. In the control device, at the same time as selecting the shift pattern, it is possible to achieve the gear ratio control that can immediately secure good drivability that matches the running style in the selected shift pattern.

[0013]

In order to achieve the above object, in a gear ratio control device for an automatic transmission according to the present invention, as shown in the claim correspondence diagram of FIG. 1, a vehicle speed detecting means a for detecting a vehicle speed and an accelerator. An accelerator operation amount detecting means b for detecting an operation amount, an accelerator operation amount predicted value calculating means c for predicting a future accelerator operation amount based on an accelerator operation situation, and a gear ratio for vehicle speed information and accelerator operation amount information are preset. The plurality of shift patterns d, a shift pattern selecting means e for selecting one shift pattern from the plurality of shift patterns d depending on the driving situation and the driver, vehicle speed information from the vehicle speed detecting means a, and the accelerator. Transmission gear ratio determination for determining the transmission gear ratio by comparing the accelerator operation amount information from the operation amount predicted value calculation means c with the selected transmission pattern d The gear f and the power-oriented gear shift pattern in which the selected gear shift pattern is less likely to be shifted up are changed so that the accelerator manipulated variable predicted value calculation means c narrows the prediction range and calculates the accelerator manipulated variable predicted value. Accelerator operation amount prediction range changing means g.

[0014]

When the vehicle is traveling, the shift pattern selecting means e selects one shift pattern from a plurality of shift patterns d preset by the driving situation and the driver. Then, the accelerator operation amount predicted value calculating means c predicts a future accelerator operation amount based on the accelerator operation situation obtained from the detection information from the accelerator operation amount detecting means b, and the transmission gear ratio determining means f estimates the vehicle speed detecting means. The transmission gear ratio is determined by comparing the vehicle speed information from a and the accelerator operation amount information from the accelerator operation amount predicted value calculating means c with the selected shift pattern d.

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

For example, when a normal-oriented shift pattern is selected in which the vehicle is traveling while the accelerator operation is relatively monotonous, it is easy to predict the accelerator operation amount and the prediction accuracy is high. In the above, the accelerator operation amount prediction range in the accelerator operation amount prediction value calculation means c is changed to be wider, for example, to increase the prediction time.

On the other hand, when a power-oriented shift pattern is selected in which the vehicle is traveling with relatively frequent accelerator operation, it is difficult to predict the accelerator operation amount and the prediction accuracy is low. At
The accelerator operation amount prediction range in the accelerator operation amount prediction value calculating means c is changed to be narrow, for example, to shorten the prediction time.

Therefore, by utilizing the fact that the prediction accuracy of the accelerator operation amount can be estimated by 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 as selecting, for example, achieving a gear ratio control that immediately responds to the driver's expectation of shifting when selecting a normal-oriented shift pattern, and preventing discomfort to the driver and preventing drivability when selecting a power-oriented shift pattern. As described above, the good drivability that matches the running manner in the selected shift pattern is immediately ensured.

[0019]

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

First, the structure will be described.

(First Embodiment) FIG. 2 is a gear ratio control system diagram to which a gear 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 shift pattern selecting means e).

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

The accelerator opening predictive value calculation unit 7a uses the present accelerator opening A (t) and the past accelerator opening A (t).
-[Delta]) and the like, and a future accelerator opening degree predicted value y (t + n) based on the accelerator operation state by a prediction method described later.
Calculate δ). Where t is the current time, n is an integer,
δ is a control period or a sampling period.

The shift pattern setting section 7b stores the economy pattern shown in FIG. 3 and the power pattern shown in FIG. 4 (corresponding to a plurality of shift patterns d) in the storage circuit of the AT controller 7 in advance, and the AT mode is set. Switch 8
One of the shift patterns is selected by the switch operation by.

As shown in FIG. 3, the economy pattern is a shift pattern that is easy to shift up and is most suitable for economical driving, and the power pattern is, as shown in FIG. 4, a shift point as compared with the economy pattern. Is a high-speed side that makes it difficult to shift up, and is a shift pattern that is optimal for power-oriented driving.

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

The accelerator opening predicted time changing unit 7d is
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,
Further, when the economy pattern is selected by the AT mode switch 8, the prediction coefficient n of the prediction time nδ
A change command for increasing the accelerator opening predicted value calculation unit 7a
Output to.

Next, the operation will be described.

[Prediction of Accelerator Opening] Regarding the prediction of accelerator opening, Japanese Patent Application No. 4-26 filed previously by the applicant of the present application.
Although it can be calculated by a method of predicting the accelerator opening recursively as described in No. 4674, here, a method of fitting past data to a predetermined curve and calculating a future value from the function. Will be described.

For example, as shown in FIG. 6, time t, t-
The past and present accelerator opening degrees of δ and t-2δ are A
Let (t), A (t−δ), and A (t−2δ) be the fitting of these three points by, for example, a quadratic function, and let that function be f (t). It can be assumed that the opening degree also exists on the curve of this quadratic function, and the accelerator opening degree A (t + n
δ) is represented by f (t + nδ). In this way, the future accelerator opening can be predicted.

That is, when f (t) = at ² + bt + c, and this quadratic curve satisfies the following equation, a, b, c are calculated by simultaneous equations, and future values are substituted into the function. Calculate the 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) From the above equation, a, b, c are obtained, f (t + nδ) is calculated, and the value is y ( t + nδ), which is used as a predicted value for shift control.

[Predicted time changing operation] FIG. 4 is a flow chart showing the flow of the predicted time changing operation process performed by the accelerator opening predicted time changing section 7d of the AT controller 7.
Each step will be described below.

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

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

In step 52, flag = 1 is set.

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

In step 54, flag = 0 is set.

In step 55, it is judged whether the present flag and the set old flag are different.

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

[Change of Prediction Time According to Gearshift Pattern] Predicted accelerator opening value y using the above prediction method or the like
If (t + nδ) becomes the same as the actual accelerator opening A (t + nδ), it means that the favorable accelerator opening can be predicted. However, in reality, there are driving situations with high prediction accuracy and driving situations with low prediction accuracy, and it is not always possible to predict a good accelerator opening. Therefore, as described below, the prediction time is changed to suppress the variation in the prediction accuracy.

Here, when the shift pattern selected by the driver is the mountain road mode or the pattern in which the upshift shift point is set at a low vehicle speed as indicated by the name of the power pattern, Empirically, the traveling pattern when requesting such a shift pattern has a large accelerator movement and may lead to a large error if the future is predicted too much, so 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, n = n−k (k is a constant, k <n).

In the case where the shift pattern selected by the driver is a relatively high upshift vehicle speed as shown by the names of economy mode and normal pattern, and a pattern in which the engine speed is not increased so much is selected. Empirically, the traveling pattern when requesting such a shift pattern is that the change in accelerator operation is small and there is no unexpected accelerator movement, so predicting the future may lead to a large error, so the predicted future time Lengthen. That is, in the flowchart of FIG.
The flow proceeds from step 50 to step 53, and in step 53, the prediction coefficient n is increased. Specifically, n = n + k (k is a constant).

[Reason for Large Deviation of Prediction] The reason why the prediction of accelerator deviates greatly from the actual accelerator operation amount will be described.

First, the prediction is that the human operation is non-ergodic, even if a fairly good prediction function exists.
In addition, the prediction residual always occurs because it has a non-linear characteristic with a time-varying parameter and has a structural problem that the parameter change cannot be observed from the outside.

This tendency depends on the characteristics of the driver.
For drivers who perform sudden acceleration or sudden stop, this prediction residual becomes large, and for drivers who drive relatively gently, the prediction may be quite accurate. Thus, there are drivers that are easy to predict and drivers that are difficult to predict.

Further, although it is easy to predict in a traveling situation where the driving operation is relatively monotonous such as an expressway, it is difficult to predict in a traveling situation where there is a great variety of driving operations such as a curved mountain road.

As described above, the prediction situation greatly changes such that the prediction is greatly deviated or the prediction is considerably accurate depending on the characteristics of the driver and the environment of the road on which the vehicle travels.

[Effectiveness of changing predicted time] 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 running, if the prediction time is fixed, the driver may feel a lot of discomfort due to incorrect shift prediction control when driving with low prediction accuracy. , It will impress the lack of drivability.

Therefore, while watching the prediction accuracy according to the selected shift pattern, the prediction time is lengthened in a 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. In the selected driving situation, by shortening the prediction time, at the same time as selecting the shift pattern, the shift control that immediately responds to the driver's expectation of shifting when the economy pattern is selected is achieved, and the selection of the power pattern is also achieved. In some cases, it is possible to instantly secure good drivability that matches the driving style in the selected shift pattern, such that the driver is prevented from feeling uncomfortable or lack of drivability. As described above, in the shift control based on the prediction, it is extremely effective to change the predicted time while observing the selected shift pattern.

Next, the effect will be described.

As described above, in the gear ratio control system for the automatic transmission according to the first embodiment, the accelerator opening predicted time changing section 7d operates the economy pattern or the power pattern by the driver. Switch with A
When the power pattern is selected by the T mode switch 8 and the AT mode switch 8, the predicted time nδ
The prediction command n for decreasing the prediction coefficient n is output to the accelerator opening prediction value calculation unit 7a, and when the AT mode switch 8 selects the economy pattern, the prediction coefficient n for the prediction time nδ is increased. Since the device is provided with the accelerator opening predicted time changing unit 7d that outputs the change command to the accelerator opening predicted value calculation unit 7a, it is possible to select the shift pattern and simultaneously match the running manner in the selected shift pattern. It is possible to achieve a gear ratio control that can ensure drivability immediately.

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

FIG. 7 is a gear ratio control system diagram 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, 1 to 7 have the same structure as the first embodiment device.

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

The shift mode determination unit 7e determines the accelerator operation status based on the changing speed and the changing acceleration of the accelerator opening. For example, when the change in the accelerator operation amount is larger than the set change, the power 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 the economy pattern as the shift pattern is output.

In addition, in the accelerator opening predicted value calculation unit 7d,
The prediction coefficient n of the predicted time nδ is changed by the shift pattern selection command from the shift mode determination unit 7e.

Regarding the function and effect of the second embodiment, the difference is that the shift pattern is selected by the switching operation of the AT mode switch 8 by the driver, or the shift pattern is automatically selected by judging the accelerator operation status. However, since the same effects as those of the first embodiment device can be obtained in the second embodiment device, the description thereof will be omitted.

Although the embodiments have been described above with reference to the drawings, the specific configuration is not limited to the embodiments, and modifications and additions within the scope of the present invention are included in the present invention. Be done.

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

In the embodiment, as the accelerator operation prediction range changing means, an example in which the predicted time of the accelerator opening is changed is shown, but the predicted time is set to a fixed time and the selected gear shift pattern is hard to shift up. A means for changing the predicted value for changing the predicted accelerator opening value in the predicted accelerator opening value calculation unit to be closer to the actual accelerator opening as the shift pattern is changed may be adopted.

[0064]

As described above, according to the present invention, in the gear ratio control device of the automatic transmission for determining the gear ratio using the vehicle speed information and the predicted accelerator operation amount information, the operating condition Or a driver selects a shift pattern from a plurality of shift patterns, and the selected shift pattern is a power-oriented shift pattern that is difficult to shift up. Since the device is provided with the accelerator operation amount prediction range changing means for changing the range to be narrowed so as to calculate the accelerator operation amount prediction value, at the same time as selecting the shift pattern, it matches the running manner in the selected shift pattern. It is possible to obtain the effect that it is possible to achieve the gear ratio control that can immediately secure good drivability.

[Brief description of drawings]

FIG. 1 is a claim correspondence diagram showing a gear ratio control device for an automatic transmission according to the present invention.

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

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

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

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 gear ratio control system diagram 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 detecting means b accelerator operation amount detecting means c accelerator operation amount predicted value calculating means d shift pattern e shift pattern selecting means f shift gear ratio determining means g accelerator operation amount predicting range changing means

Claims (1)

[Claims] 1. 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 predicted value calculating means for predicting a future accelerator operation amount based on an accelerator operation situation, and a vehicle speed. A plurality of speed change patterns in which a speed change gear ratio for the information and the accelerator operation amount information is set in advance, a speed change pattern selecting means for selecting one speed change pattern from the plurality of speed change patterns according to a driving situation and a driver, and the vehicle speed. A transmission gear ratio determining unit that determines a transmission gear ratio by comparing the vehicle speed information from the detection unit and the accelerator operation amount information from the accelerator operation amount predicted value calculation unit with the selected transmission pattern, and the selected transmission gear ratio determining unit. As the shift pattern is a power-oriented shift pattern that is hard to shift up, the accelerator operation amount predicted value calculation means predicts the shift amount. A gear ratio control device for an automatic transmission, comprising: an accelerator operation amount prediction range changing means for changing a measurement range so as to calculate an accelerator operation amount prediction value.