JPH02296064A - Automatic transmission control device for vehicle - Google Patents

Abstract

PURPOSE:To adapt the speed change stage, applied at the time of a shift lever being selected back into the other range, to up slope running by providing a holding means for holding the judged result of the up slope running before being switched during changeover into the other mode by a switching means. CONSTITUTION:A sub-control device 20 functioning as a holding means calculates the average of the acceleration alpha of a vehicle according to various signals from a sensor group 1, as well as calculates the estimated value lambda of running resistance on the basis of this alpha and TVO (the moving average of throttle opening), and acts in such a way as to output overdrive inhibition ODINH in case the is larger than the specified reference value. The sub-control device 20 also acts in such a way as to hold alpha and the TVO value in case an operational information signal SF is inputted from a specific operating device 4 (for instance, a shift lever is selected from a drive range into the other range and the like).

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an automatic transmission control device for a vehicle, and more particularly, to an automatic transmission control device for a vehicle that determines whether the vehicle is running on an uphill road based on the magnitude of running resistance and changes the transmission characteristics. Concerning improvements to control devices.

(Prior art) Shift control of automatic transmissions used in vehicles, etc. refers to a shift pattern (so-called shift diagram) in accordance with the vehicle speed and throttle opening while the vehicle is running, and determines the gear ratio according to the driving condition. Generally, the gear ratio of an automatic transmission is changed by using the automatic transmission, but the above-mentioned shift pattern is predetermined assuming typical driving conditions. Therefore, if the driving condition is as expected, Although a very satisfactory speed change characteristic can be obtained, the determined speed change ratio may not be appropriate under unexpected driving conditions, such as when driving on an uphill road.

Therefore, the present applicant first proposed a "vehicle automatic transmission control device".
(Japanese Patent Application No. 1-79376) has been filed.

This device calculates an estimated value corresponding to the magnitude of running resistance based on trends in increase/decrease in physical quantities involved in engine combustion and vehicle acceleration, etc., and when the estimated value exceeds a reference value, it The system determines whether the vehicle is running on a road and changes the shift pattern to correspond to large running resistance.

(Problem to be Solved by the Invention) By the way, in the automatic transmission control device for a vehicle according to the prior application, for example, it is difficult to select the shift lever from the drive range to another range and then return to the drive range again. If such an operation is performed, the gear may not return to a gear suitable for driving uphill, so there is room for improvement.

That is, in the device according to the prior application, when the estimated value corresponding to the magnitude of running resistance exceeds the reference value while driving with the drive range selected, uphill running is determined. Driving is prohibited and 3rd gear is selected. In such a state, a larger driving force is desired, and the driver may select, for example, the 2nd range of the shift lever (selecting 2nd speed), and then return the shift lever to the drive range again. In this case, if the estimated value is reset to zero by operating the shift lever, the estimated value of running resistance will also be zero when the drive range is returned.

Therefore, if the drive range is in 3rd gear (uphill road detection), then when you select another range and then return to the drive range, 3rd gear suitable for uphill roads will not be selected and it will change to 4th gear. Then, the driving force becomes insufficient again, and it becomes necessary to select the 2nd range again. In the end 2
The sequence of gears - 4th gear - 2nd gear was repeated, and it was not possible to set the gear position (here, 3rd gear) suitable for running on an uphill road.

The present invention was made in view of these problems, and
For example, the purpose is to select a shift lever from a drive range to another range, and then change the gear position when returning to the drive range to be suitable for driving uphill.

(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 determines whether the vehicle is running on an uphill road based on an estimated value corresponding to the magnitude of running resistance acting on the own vehicle, An automatic transmission control device for a vehicle equipped with a switching means that can manually switch between a mode in which an automatic transmission is controlled so as to be in a transmission state suitable for driving uphill, and another mode other than the mode. A holding means is provided for holding the determination result of uphill running before the switching while the mode is switched to another mode by the switching means.

(Function) In the present invention, for example, when driving on an uphill road is detected and 3rd gear is selected, if the shift lever is selected from the drive range to another range and then returned to the drive range, the shift lever is not held. Third gear is selected again based on the previous estimate.

(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, ``■'' is a sensor group, and the sensor group 1 includes a throttle opening sensor 2 for detecting a throttle opening degree T■o, and a vehicle speed sensor 3 for detecting a vehicle speed V. Reference numeral 4 denotes a group of predetermined operating devices (switching means) that can affect the shifting characteristics of the automatic transmission. road, etc.) consists of a driving mode switch 7, etc. Each operation information of the predetermined device group 4 is represented by one signal S for convenience.

Therefore, this SF includes the select range information of the inhibitor switch 5 and the inhibition/inhibition information of the overdrive switch 6.
This information includes release information, driving mode selection information, and the like.

10 is an automatic transmission control unit (hereinafter referred to as ATCU),
ATCUIO is internally equipped with a mapped shift pattern. This shift pattern is based on the slot/7 torque opening T.
It is referenced by VO and vehicle speed ■, and this reference operation determines the gear ratio at that time and outputs the gear change signal S.
EL is output.

Reference numeral 11 denotes a valve controller of the automatic transmission, and the valve controller 11 combines valves according to SEL and operates the gear ratio of the automatic transmission. Here, the above-mentioned shift pattern is, for example, 1st to 4th gear overdrive (OD).
This is a shift diagram corresponding to a four-speed forward automatic transmission, in which the highest gear (OD) is selected at a predetermined high vehicle speed or higher.

However, when the OD inhibit signal ODINM is input, OD is not selected.

On the other hand, 20 is a sub-control device having a function as a holding means, and the sub-control device 20 calculates the acceleration τ of the vehicle according to various signals from the sensor group 1, and calculates this α and TVO (moving average of TVO). An estimated value λ of running resistance is calculated based on the value λ), and when this value λ exceeds a predetermined reference value, it operates to output 0 DINN. Further, this sub-control device 20 is configured to hold the values of τ and TVO described above when sir is input from the predetermined operating device 4 (for example, when the shift lever is selected from the drive range to another range). It also works.

In the sub-control device 20, there is a
``(X
, a function table, and a g(21 function table) shown in FIG. 2(b).The details of these tables will be described later.

Next, the effect will be explained.

FIG. 3 is a flowchart showing part of the processing that is repeatedly executed within the sub-control device 20 at every predetermined calculation cycle. In this flowchart, first, in step P1), the input of S is determined. For example, when the shift lever is in the drive range position, the vehicle speed V detected by the vehicle speed sensor 3 and the throttle detected by the throttle opening sensor 2 are Read the opening TVO (step PZ,
ps >, the moving average value TVO of TVO according to the following formula ■
is calculated (step P4).

・・・・・・■ The above formula ■ is used to smooth out some of the fluttering and fluctuation of the accelerator pedal while driving using a filter, and to improve the reliability of the data.The time constant of the above formula ■ is 20 seconds. It is preferable to keep it at a certain level.

Next, the first-order difference value ΔV (
Find Ll and use this as the acceleration of the vehicle. Note that if the above Δ■,,) are used as they are in actual calculation processing, there will be large variations, which will interfere with calculation processing, so this will be smoothed and set to α (step ps
).

Next, an estimated running resistance value λ is calculated based on TVO and i (step P6). The calculation of λ is performed as follows. That is, the function table f shown in FIG. 2(a)
(X) on TVO, and function table g, 2. shown in FIG. 2(b). is referenced by i, and both f (Xi, g (21) looked up from these tables are compared and the smaller value is determined as λ. (ゎ is, for example, a linear function straight line connecting two points (a) and (b), and TVO in (a) corresponds to the throttle opening normally used on a flat road, and (
The TVO in b) corresponds to the throttle opening normally used on steep slopes. In addition, g(2
, is, for example, a linear function straight line connecting two points (c) and (d), where ■ in (c) corresponds to the acceleration on an uphill road, and 1 in (d) corresponds to the acceleration on a flat road. do. Note that f (wa, g, 2) shown in FIGS. 2(a) and 2(b) is just an example, and the present invention is not limited thereto.

Here, the concept of calculating λ will be explained. now,
Assume that running resistance is zero (although this is not possible in reality). In this case, as long as even a small amount of output torque from the engine is generated and 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, the amount of running resistance (for example, let that value be A)
In this case, with driving force A' equal to A, the vehicle continues to travel at a constant speed without accelerating or decelerating. At this time, consider a case where the running resistance increases by ΔA. In this case, the driving force is A
If it remains as ', the vehicle will decelerate, and the acceleration acting on the vehicle at this time should become smaller. To explain this more specifically, in Figure 2 (a) and (b), i) the throttle is opened (TVO is large), and as a result, the acceleration (τ)
The larger the running resistance (λ) is, the smaller the running resistance (λ) is.

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

iii) 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 have reached the conclusion that there is a correlation between the engine's output torque, which 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. can do.

Therefore, the physical quantity that manipulates the engine's output torque (
Function table f (Xl
and a function table g whose parameters are vehicle acceleration (7), 2. By appropriately setting and referring to these two tables, it is possible to know the magnitude of the running resistance (more precisely, the estimated value λ).

The obtained λ is used as follows. That is,
λ is a predetermined reference value; 4. It is determined whether or not the limit has been exceeded (step p), and when the command is YES, ODINM for inhibiting OD is output (step Pe). Alternatively, when the NO instruction is given in step P, that is, when λ does not exceed LHi, this λ is set to a predetermined reference value Ltow.
It is determined whether or not the value has fallen below (Log>LLow) (step P9), and when the command is YES, the output of 0DINH is stopped (inhibition released) (step P+o). Above 2
Two reference values, i, L,. 8 is for determining the reference point for changing the shift pattern (in this case, OD prohibition) and returning (OD prohibition cancellation), and is set appropriately taking into account the vehicle's power characteristics and the automatic transmission's shift diagram. do it.

On the other hand, in the case of YES instruction in the previous step P1,
In other words, when the driver selects the shift lever from the drive range to another range, or when the overdrive switch is turned OFF (OD prohibited),
Alternatively, if a predetermined driving state mode is selected, steps P2 to P. Bypass the processing up to (running resistance calculation processing). Due to this bypass, the value of TVO1τ is held until the next running resistance calculation process.

Then, when the shift lever is returned to the drive range, the overdrive switch is turned on, and the vehicle is no longer in the predetermined driving state mode, steps P2 to
Running resistance calculation processing up to PIO is executed. Therefore, since the value of TVO1τ used at the time of restarting this process is the value that was being held, that is, a value sufficient to determine whether the vehicle is running on an uphill road, it is possible to immediately determine whether the vehicle is running on an uphill road. As a result, for example, when driving uphill, the drive range
When operated as 2nd range - drive range, the selected gear is 3rd gear (uphill road detected in drive range) - = 2nd gear (2nd gear).
Range) - 3rd speed (uphill road detected in drive range), and it is possible to select a gear position suitable for uphill road driving and improve the shift feeling.

In addition, even if you shift to flat road driving while driving in the 2nd range and operate the drive range in such a driving state, the vehicle will be in 3rd gear (uphill road detected when switching). As the vehicle continues to drive on a flat road thereafter, the estimated value λ falls below the predetermined reference value LLOW, the OD prohibition is canceled, and the gear is shifted to 4th gear, so no particular problem occurs.

(Effects) According to the present invention, for example, when the shift lever is selected from the drive range to another range and then returned to the drive range, the gear position can be made suitable for driving uphill. Feeling can be improved.

[Brief explanation of the drawing]

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.
FIG. 3 is a flowchart showing the processing. 4... Predetermined operating device group (switching means), 20.
...Sub control device (holding means).

Claims (1)

[Claims] There is a mode in which uphill road driving is determined based on an estimated value corresponding to the magnitude of the running resistance acting on the own vehicle, and the automatic transmission is controlled so that the automatic transmission is in a gear shifting state suitable for uphill road driving, and a mode other than the above mode. In an automatic transmission control device for a vehicle equipped with a switching means that can be manually switched to one of the other modes, while the switching means is switching to the other mode, the determination result of running uphill before switching to the other mode. An automatic transmission control device for a vehicle, characterized in that it is provided with a holding means for holding.