JPH02266154A - Automatic shift controller for vehicle - Google Patents

Abstract

PURPOSE:To avoid any wrong ascent traveling by correcting an estimate value to the decrement side when judging a drop in engine power on the basis of each temperature of an engine and an automatic transmission, with an automatic transmission controller which estimates running resistance on the basis of engine load and car speed information and varies a shift characteristic. CONSTITUTION:Car speed V by a car speed sensor 3 and opening TVO by a throttle opening sensor 2 are read in, and a running average valve TVO is operated by a subcontroller 20. Acceleration alpha of a vehicle is found out of one step different value of V at specified time. Engine water temperature TF is compared with reference temperature TREF, discriminating 'cold' or 'hot' of an engine. Next, an estimate value lambda of running resistance is operated on the basis of TVO and alpha. lambda at time of the determined engine cold comes to a smaller value than lambda at time of engine warmup, the estimate value lambdaof running resistance at time of engine cold, namely, in a specified engine driving state can be corrected to the decrement side. Therefore a wrong ascent judgement is avoidable in this way.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to an automatic transmission control device for a vehicle.

(Prior Art) Generally, electronically controlled automatic transmissions (hereinafter sometimes abbreviated as A/T) refer to a shift pattern and change the gear ratio according to the vehicle speed and throttle opening. However, in this type of gear, for example, when driving uphill at a relatively high speed, there is a frequent shift between the upper gear (for example, 4th gear or overdrive: OD) and the next gear (for example, 3rd gear). A so-called busy shift, in which the gear shifting operation is repeated, may occur, which is unpleasant. Therefore,
``Method for determining when a vehicle equipped with an automatic transmission is running on an uphill road'' (Japanese Unexamined Patent Application Publication No. 62-1) which detects uphill driving and avoids busy shifting by selecting a lower gear when going uphill.
80153) is known.

(Problem to be Solved by the Invention) However, in such conventional devices, the uphill road driving is detected based on the engine load and vehicle speed, so for example, when the engine is cold, , erroneous uphill road driving detection was sometimes performed.

In other words, in the conventional system described above, the main cause of the decrease in vehicle speed while driving is an increase in running resistance (for example, an increase in road surface slope).
Utilizing this fact, when the vehicle speed decreases, it is determined that the vehicle is running on an uphill road, and the shift characteristics are changed to be suitable for driving on an uphill road (for example, one that prohibits the highest gear or one that makes it difficult to reach the highest gear). However, this reduction in vehicle speed is a phenomenon that can also be seen in certain engine operating conditions where the engine output decreases, such as when the engine is cold or overheating. Even though the vehicle was running or running on a gentle slope, a decreasing trend in vehicle speed was observed, and it was sometimes incorrectly determined that the vehicle was running on a slope.

In this way, if it is mistakenly determined that the vehicle is traveling on a flat road, the highest gear will not be selected even if the vehicle speed reaches a high state, making the driver feel that some kind of abnormality has occurred in the transmission control device. This caused the inconvenience of concerns. (Objective of the Invention) Therefore, an object of the present invention is to correctly detect whether the vehicle is traveling on an uphill road during a specific engine operating state.

(Means for Solving the Problems) In order to achieve the above object, the automatic transmission control device for a vehicle according to the present invention calculates an estimated value of running resistance of the vehicle based on engine load information and vehicle speed information, and calculates the estimated value of the running resistance of the vehicle based on engine load information and vehicle speed information. An automatic transmission control device for a vehicle that determines that the vehicle is in a running state with high running resistance when the resistance exceeds a predetermined value, and changes the shift characteristics of the automatic transmission to one corresponding to the running state,
temperature detection means for detecting the temperature of a power unit including an engine and an automatic transmission; a determination means for determining a specific engine operating state in which the output of the engine is reduced based on an output signal of the temperature detection means; , correction operation means for correcting the estimated value to the decreasing side when the engine driving state is determined.

(Operation) In the present invention, the estimated value of the running resistance of the vehicle is corrected to decrease during a specific engine operating state, such as when the engine is cold. Therefore, for example, when a vehicle has just started its engine and the vehicle speed does not increase that much even though the throttles are depressed, as if the vehicle was running on a hill, the estimated value of the running resistance at that time can be calculated using a small estimate. Therefore, the above phenomenon will not be mistaken as running on the uphill road.

(Example) Hereinafter, the present invention will be explained based on the drawings.

1 to 3 are diagrams showing an embodiment of an automatic transmission control device for a vehicle according to the present invention.

First, the configuration will be explained. In FIG. 1, 1 is a sensor group, and sensor group 1 includes a throttle opening sensor 2 that detects the throttle opening TVO, and a vehicle speed that detects the vehicle speed from the rotational speed of the output shaft of the automatic transmission, the drive wheels, etc. A sensor 3, a type detection sensor 4 that detects the gasoline type F (type such as regular gasoline or high-octane gasoline), an engine water temperature sensor 5 that detects the engine water temperature T, and an oil temperature T of the automatic transmission. It has various sensors such as an ATF oil temperature sensor 6 that detects the load W on the vehicle body, and a vehicle body load sensor that detects the load W on the vehicle body.

The engine water temperature sensor 5 functions as a temperature detection means. Note that the temperature detection means detects the temperature of the power unit including the engine and automatic transmission (engine water temperature T, ,
The ATF oil temperature sensor 6 may be used instead of the engine water temperature sensor 5, or both of these may be used.

Reference numeral 10 denotes an automatic transmission control unit (hereinafter referred to as ATCU), and the inside of this ATCUIO is provided with a manual shift pattern. This shift pattern is referred to by the throttle opening TVO and the vehicle speed V, and the current gear ratio is determined by this reference operation and the shift signal SEL is output.

Reference numeral 11 denotes a valve controller for the automatic transmission, and the valve controller 11 combines valves according to SEL to operate the gear ratio of the automatic transmission.

” The above-mentioned shift pattern is a shift diagram corresponding to, for example, a 4-speed forward automatic transmission with an overdrive (OD) of 1st to 4th speeds, and the highest gear (OD) is selected at a predetermined high vehicle speed or higher. It looks like this.

However, when the ○D inhibition signal 0DINH is input, OD is not selected. In other words, it is possible to change the speed change characteristics.

On the other hand, reference numeral 20 denotes a driver control device having functions as a determination means and a correction operation means.
, and also calculates the estimated running resistance value λ (this λ becomes a large value when driving uphill, for example) based on this α and TVO (moving average value of TVO). However, when this λ is larger than a predetermined reference value, it operates to output ○DINM.

Further, based on T from the sensor group 1, for example, it is determined whether the engine is running in a cold state, and during the operation, the estimated value λ is corrected to the decreasing side. In the sub-control device 20,
There are two function tables used when calculating λ, namely the f(Xi function table and the second
g, 2. Not shown in figure (b). A function table is provided. By the way, it is desirable to use these function tables as Menharsisop functions. Function table f (Xi
and g, 2. has two straight lines shown as a solid line and a broken line, respectively, and f is representative. , is f for warming up the engine. , A and '(X)B for when the engine is cold. In other words, these two straight lines are linear function lines connecting the two points (a), (b), (a') and (mouth'), and the TVO at (a) is on a flat road or "after engine warm-up". On the other hand, TVO in (a') corresponds to the throttle opening normally used on a flat road and when the engine is cold. In addition, TVO in (b) is steep and corresponds to the throttle opening normally used "after the engine warms up",
On the other hand, the TVO at (mouth') is steep and corresponds to the throttle opening normally used when the engine is cold. Also, to explain points (c), (d), (c') and (2') of g +z〉A% g +21 B, α in (c) is the acceleration on an uphill road and "after the engine warms up." Correspondingly, i in (d) corresponds to the acceleration on a flat road "after the engine warms up", while α in (c') corresponds to the acceleration on an uphill road "when the engine is cold", and ( i in 2') corresponds to the acceleration on a flat road and when the engine is cold.

Next, the effect will be explained.

FIG. 3 is a flowchart of a running resistance calculation processing program executed inside the sub control device 20. In FIG. 3, first, the vehicle speed V detected by the vehicle speed sensor 3 and the throttle opening TVO detected by the throttle opening sensor 2 are read (steps PI, P2), and the moving average value TV of TVO is calculated according to the following formula (2). Step P3) to calculate ○.

・・・・・・■ The above formula ■ is used to smooth out the fluctuations and fluctuations caused by pressing the accelerator while driving, and improve the reliability of the data.The time constant of the above formula ■ is 2.
It is preferable to set the time to about 0 seconds.

Next, although the processing steps are omitted, the first-order difference value ΔV (t) of V at a predetermined time Δt is obtained, smoothed, and used as the acceleration α of the vehicle.

Next, read the engine water temperature T (step P5)
, this T, and the base f$ temperature TREF are compared. T R
EF is an appropriate temperature (for example, TREF - 70°C) for determining whether the engine is cold or warmed up, and TF is TR
If TF is smaller than TREF, it is determined that the engine is cold (NO command), and if TF is larger than TREF, it is determined that the engine is warmed up (YES command). In the case of YES command, the second (
Function tables f (+n , g (21) for engine warm-up, f, ゎ A, , g (Z
) A is selected in steps P7 and P8), whereas in the case of NO command, f (X) 8% for engine cold time is selected.
g + Z) Select B (steps P7, P,.

).

Next, an estimated value λ of the running resistance is calculated based on the TVO and 1 obtained previously (step Pz).

The calculation of λ is performed as follows. That is, Fig. 2 (a
) is the selection side (f(X)
A or f++nB) with TVO, and the second
Function table g shown in Figure (b), 2. The selection side (g+z
) A or gtz+B) is referenced by 1, and both f (Xl, g, 2.) looked up from these two tables are compared and the smaller value is determined as λ.

Now, when the size of TVO is θ and the size of α is ν, the selection side is f, ゎ A, g (21A, that is, considering the case when the engine is warmed up, in this case f (Xl, g, 2
．． The values of are f fXl-(e) and g12゜-(
) is obtained. Then, the smaller of (E) and (E) is determined as λ at this time. Then f (XI
A% g tz, select A. Consider the case when the engine is cold. When the engine is cold, even if TVO is set to θ, 7 does not become ν. In this case, positive should be a value smaller than ν. The difference in α corresponds to the difference Q in engine output characteristics between warm-up and cold times. Therefore, f (X) A is the same both when the engine is warmed up and when it is cold.
, g (If ZI A is used, a value of λ that is inappropriate as an estimate of the actual running resistance will be obtained,
This causes incorrect uphill road determination in the steps described below. In this example, f 011 A, g (
Z) In addition to A, f for engine cold time, ゎ B,
Since g (z) B is set, it is possible to obtain λ that is suitable as an estimated value of the actual running resistance even when the engine is cold, and it is possible to avoid incorrect uphill road determination in the step described below.

That is, f, ゎB is the right side (T
VO increasing side), and g+z)B is set to g(
2) It is set to the left side of A (positive decreasing side).

Now, if TVO is θ and α is ν, then this f (X)
When selecting B, gtz+B (when the engine is cold),
f (X) and g +2+ are each f (X) =
(E′), g(Z) ” (E′) is obtained. This means that if f (Xl Δ, g+z+A is selected) (
(when the engine warms up) compared to (ho)(he)
Since both values of ′) are small, therefore, (
λ when the engine is cold, determined by whichever is smaller, is smaller than λ when the engine is warmed up. The estimated value λ of running resistance can be corrected to the decreasing side.

Here, the concept of the relationship between λ and running resistance will be explained. Now, assume that the running resistance is zero (although this is actually impossible). In this case, as long as even a small amount of engine output is generated and that engine output is transmitted to the wheels, the vehicle will accelerate. This is because a driving force that exceeds running resistance (zero) is provided. On the other hand, when the running resistance is of a certain magnitude (for example, its value is written as A), with a driving force A' equal to A, the vehicle continues to run at a constant speed without accelerating or decelerating. At this time, there is a case where the running resistance increases by ΔA. In this case, if the driving force remains A', the vehicle will decelerate and the acceleration acting on the vehicle should become smaller. To explain this more specifically, in Figure 2 (a) and (b), the throttle is opened (TVO is large) and as a result, the acceleration <
cx> becomes large, the running resistance (λ) becomes small.

11) If the acceleration decreases when the throttle opening is constant, the running resistance is large.

111) If the acceleration remains the same, does not increase much, or decreases even though the throttle is opened, the running resistance is large.

From these representative facts, we come to the conclusion that there is a correlation between the output of the engine that determines the driving force and the acceleration of the vehicle to which that driving force is applied, which corresponds to the magnitude of the running resistance. be able to.

Therefore, the physical quantity (TVO
) is a function table f (X), and a function table g, 2 is a function table whose parameters are vehicle acceleration (1).
．． By appropriately setting and referring to these two tables, it is possible to know the magnitude of the running resistance (more specifically, the estimated value λ).

λ obtained at each time when the engine is warmed up and when it is cold.
is used in the following way. In other words, it is determined whether λ exceeds a predetermined reference value (a value corresponding to a typical uphill road) L++t (step P+z), and when the YES command is issued, that is, when uphill road running is determined, the uphill road running is determined. ○D and N are output for prohibiting OD so as to achieve a suitable speed change (step P13).

Alternatively, in this step, the normal speed change pattern may be replaced with a speed change pattern for running on an uphill road.

On the other hand, when λ does not exceed LH4, it is determined whether this λ is less than a predetermined reference value Lol,l (however, L++t>Ltow) (Step P14). If YES, the output of OD, □ to stop (remove OD prohibition) (
Step P15). Alternatively, the speed change pattern for driving on the uphill road is returned to the normal speed change pattern.

In this way, in this embodiment, f (
It is equipped with a function table (for example, a membership function) in which XI A, g + z + A and f (Xi 8% g tz, B) are set for engine cold time, and the above table is selected according to the engine water temperature TF. Therefore, for example, the estimated value λ of running resistance when the engine is cold can be corrected to be smaller than λ when the engine is warmed up, and it is possible to obtain λ suitable for cold operation. Therefore, it is possible to avoid incorrect uphill running judgments that occur during cold driving.

In the above embodiment, the specific engine operating state is the engine cold time, and during this cold time, f, ゎB, g(z)B
However, it is not limited to this. For example, f (XIB, g+zlB) may be selected even when the engine water temperature TF is at a predetermined high temperature (so-called overheating state or a water temperature close to it). This means that the engine output under the predetermined high temperature is also cool. This is because there is a tendency for the time to decrease in the same way as the time difference, and therefore, there is a risk that an incorrect uphill road running determination may be made in this case as well.

In addition, as in the above embodiment, two function tables f (X
), g (XI) to determine the uphill road and switch the shift pattern, thereby preventing the frequent switching of the shift pattern due to repeated release of the accelerator when driving on a curved road on a hill, which was the case with conventional devices. In addition, since it is possible to determine the uphill road even on a uphill road where the throttle opening does not reach a large opening for a long time, the accuracy of the determination can be improved.

(Effects) In the present invention, the estimated value of running resistance is corrected to the decreasing side in certain operating conditions where the engine output decreases, such as when the engine is cold, overheating, or close to overheating. , it is possible to avoid driving on the wrong road.

[Brief explanation of drawings]

1 to 3 are diagrams showing an embodiment of the automatic transmission control device for a vehicle according to the present invention, FIG. 1 is a configuration diagram thereof, and FIG.
a) (b) is its function table f+x+, g +Z)
FIG. 3 is a flowchart 1 of the running resistance calculation processing program. 5...Engine water temperature sensor (temperature detection means), 2
0-...Zub control device (judgment means, 1 stage of correction operation).

Claims (1)

[Claims] An estimated value of running resistance of the vehicle is calculated based on engine load information and vehicle speed information, and when the estimated value exceeds a predetermined value, it is determined that the vehicle is in a running state with high running resistance, and the automatic transmission is activated. In an automatic transmission control device for a vehicle that changes the transmission characteristics of a vehicle according to the driving condition, a temperature detection means for detecting the temperature of a power unit including an engine and an automatic transmission, and a temperature detection means for detecting the temperature of a power unit including an engine and an automatic transmission; A determination means for determining a specific engine operating state in which the engine output decreases, and a correcting operation means for correcting the estimated value to a decreasing side when the specific engine operating state is determined. Features: Automatic transmission control device for vehicles.