JP2882608B2 - Automatic transmission control system for vehicles - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an automatic transmission control apparatus for a vehicle, and more particularly, to an automatic transmission control apparatus for a vehicle that determines a traveling on an uphill road from the magnitude of traveling resistance and changes the transmission characteristic. It relates to improvement of a control device.

2. Description of the Related Art Shift control of an automatic transmission used for a vehicle or the like determines a gear ratio according to a running state by referring to a shift pattern (a so-called shift diagram) according to a vehicle speed and a throttle opening during running. In general, the speed change ratio of the automatic transmission is switched, but the speed change pattern is determined in advance by assuming a typical driving state, and therefore, if the driving state is as expected, While almost satisfactory shift characteristics can be obtained, the determined gear ratio may not be appropriate in a traveling state different from the assumption, for example, when traveling on an uphill road.

Therefore, the present applicant first described "automatic vehicle speed change control device".
(Patent application filed on March 29, 2001).

This device calculates an estimated value corresponding to the magnitude of the running resistance based on the increase / decrease tendency of the physical quantity involved in engine combustion and the acceleration of the vehicle, and if the estimated value is larger than the reference value, The shift pattern is changed to correspond to a large running resistance. That is,
Since the magnitude of the traveling resistance corresponds to a change in overall traveling conditions such as, for example, the gradient of a road surface, the weight of a load, or air resistance, it is possible to optimally change a shift pattern according to any traveling state. it can.

(Problems to be Solved by the Invention) Incidentally, such an automatic transmission control apparatus for a vehicle according to the prior application is excellent in that the shift characteristic is changed in accordance with the running state. However, there is room for improvement in that the driver may be mistaken for a failure in the automatic transmission for the reasons described in (1).

That is, when a vehicle traveling at high speed shifts from a flat road to an uphill road, the shift speed of the vehicle is, for example, an overdrive stage on a flat road, and the overdrive stage is prohibited by the determination of the uphill road. The gear position (however, in the case of a 4-speed automatic transmission with overdrive) is entered. Such a downshift operation itself is not a particular problem because it compensates for the insufficient driving force during traveling on an uphill road.However, the overdrive selection when traveling on a flat road suddenly and immediately The change to the third gear without a risk of being erroneously recognized as a failure of the automatic transmission.

Therefore, the present invention, the driver who has recognized the failure, usually,
Focusing on trying some operation, for example, tilting the shift lever from the drive range to another range or operating the overdrive switch, and when these operations are performed, traveling on the uphill road The purpose is to restore the change characteristic to the state before the determination.

(Means for Solving the Problems) In order to achieve the above-mentioned object, the present invention provides a method for measuring the relationship between a first state quantity representing a time-series variation pattern of an engine load and a second state quantity representing an acceleration of a vehicle. An automatic transmission control device for a vehicle, which calculates an estimated value corresponding to the magnitude of the running resistance acting on the own vehicle and performs control to change the shift characteristics of the automatic transmission based on the estimated value. When a predetermined operating device that can affect the characteristics is operated,
The apparatus further comprises a canceling means for resetting the first state quantity and the second state quantity to initial values.

(Operation) The first state quantity is an analysis parameter for exploratoryly capturing a pattern of a rough change of a series of numerical values (ie, a time series) observed over time, and is a calculation time constant (pattern search). The longer the time until the result appears, the higher the analysis accuracy can be obtained, but when applied to vehicles, a time constant as short as possible is required in terms of responsiveness, but it is still several tens of seconds (for example, about 20 seconds) ) Is necessary, and once the first state quantity obtained by such a time constant is reset to the initial value, the cancellation of the shift-up prohibition is maintained as long as several tens of seconds do not elapse even if the running resistance does not change. it can. That is, if the reset operation is performed in response to the operation of the driver who has mistakenly recognized as a failure, the estimated amount corresponding to the magnitude of the running resistance acting on the own vehicle will be obtained unless a certain time determined by the time constant has elapsed. Since the original value is not restored, the return to the driving range (drive range) can cancel the shift-up prohibition that was automatically performed before the reset, thereby achieving the above object.

Hereinafter, the present invention will be described with reference to 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 described. In FIG. 1, reference numeral 1 denotes a sensor group including a throttle opening sensor 2 for detecting a throttle opening TVO and a vehicle speed sensor 3 for detecting a vehicle speed V. Reference numeral 4 denotes a predetermined operating device capable of affecting a shift characteristic of an automatic transmission. so,
The predetermined operating device 4 corresponds to, for example, a shift lever 5, an overdrive switch 6, a low μ road (eg, a snowy road) traveling mode switch 7, and another shift characteristic selecting device 8. Note that the shift lever 5 is exactly an inhibitor switch and outputs select range information of the shift lever 5. Each operation information of a predetermined operating device 4 is representative of one signal S _F convenience. Therefore, this _SF includes select range information of the shift lever 5, prohibition / release information of the overdrive switch 6, traveling mode selection information, and the like.

Reference numeral 10 denotes an automatic transmission control device (hereinafter referred to as ATCU).
Reference numeral 10 has a mapped shift pattern therein. The speed change pattern is referred to by the throttle opening TVO and the vehicle speed V. The speed change ratio at that time is determined by this reference operation, and the speed change signal SEL is output. 11 is a valve controller of the automatic transmission, the valve controller 11 combines valves according to SEL,
Operate the gear ratio of the automatic transmission. Here, the shift pattern is a shift diagram corresponding to, for example, a four-speed automatic transmission with an overdrive (OD) of 1st to 4th speed, and the uppermost gear (OD) is selected above a predetermined high vehicle speed. It is supposed to be. However, when the OD inhibit signal OD _INH is input, OD is not selected.

On the other hand, reference numeral 20 denotes a sub-control device having a function as a canceling unit. The sub-control device 20 is configured to control the vehicle acceleration (corresponding to the “second state quantity” described in the gist of the invention) in accordance with various signals from the sensor group 1. ), And based on this and ▲ ▼ (moving average value of TVO; equivalent to “first state quantity representing time-series variation pattern of engine load” described in the gist of the invention), The estimator λ is calculated, and when λ is larger than a predetermined reference value, OD _INH
It operates to output. Also, this sub-control device 20
Operates so as to cancel the above value of ▲ ▼ when _SF is input from the predetermined operation device 4. In the sub-controller 20, there are two function tables used when calculating λ, that is, f _(x) shown in FIG.
It has a function table and a g _(z) function table shown in FIG. 2 (b). The details of these tables will be described later.

 Next, the operation will be described.

FIG. 3 is a flowchart showing a part of a process repeatedly executed in the sub-control device 20 at a predetermined calculation cycle. In this flowchart, 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 P ₁ and P ₂ ), and the moving average value of TVO is calculated according to the following equation.
Calculate ▼ (step P ₃ ).

The above equation is used to smooth the flapping of the accelerator pedal while driving, and the firagi with a primary filter to improve the reliability of the data.The time constant of the above equation is
Preferably, the time is about 20 seconds.

Next, the first-order difference value ΔV _(t) of V at a predetermined time Δt
And use this as the vehicle acceleration. When the above ΔV _(t) is used as it is in the actual calculation processing,
Variation is large, so hindering the operation process, which is referred to as by smoothing (step P _4).

Next, determine the S _F input from a predetermined operation unit 4 (Step P _5), for example, when the operation of the predetermined operation device 4 by the driver is not performed, ▲ ▼ and running based on The estimated value λ of the resistance is calculated (step P ₆ ).
The calculation of λ is performed as follows. That is, the function table f _(x) shown in FIG.
Further, referring to the function table g _(z) shown in FIG. 2 (b), f _(x) ,
By comparing both g _(z) , the smaller value is determined as λ. F _(x) shown in FIG. 2 (a) is, for example, a linear function line connecting two points (a) and (b).ロ in (b) corresponds to a normally used throttle opening with a steep gradient. G _(z) shown in FIG. 2 (b) is, for example, 1 connecting two points (c) and (d).
(C) corresponds to acceleration on an uphill road, and (d) corresponds to acceleration on a flat road. Note that f _(x) shown in FIGS. 2 (a) and 2 (b ₎ ,
g _(z) is only an example, and is not limited to this.

Here, the concept of the calculation of λ will be described. It is now assumed that the running resistance is zero (although it is not possible). In this case, the vehicle accelerates as long as the output torque of the engine is generated even if it is small and the output torque of the engine is transmitted to the wheels. This is because a driving force exceeding the running resistance (zero) is given. On the other hand, when the traveling resistance has a certain magnitude (for example, the value is A), the vehicle continues to travel at a constant speed without acceleration or deceleration at a driving force A 'equivalent to A. At this time, the running resistance becomes Δ
Let us consider a case where only A increases. In this case, if the driving force remains at A ', the vehicle decelerates, and the acceleration acting on the vehicle at this time should be small. This will be described in more detail with reference to FIGS. 2 (a) and 2 (b). In FIG. 2 (a) and FIG. It is.

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

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

From these typical facts, we came to the conclusion that there is a correlation between the output torque of the engine that determines the driving force and the acceleration of the vehicle to which the driving force is applied, corresponding to the magnitude of the running resistance. can do.

Therefore, a function table f in which the physical quantity (▲ ▼) for controlling the engine output torque is used as a parameter
_(x) and a function table g _{(z )} having the vehicle acceleration () as a parameter are appropriately set, and by referring to these two tables, the magnitude of the running resistance (strictly speaking, the estimated amount λ ).

The obtained λ is used as follows. That is, it is determined whether or not λ has exceeded a predetermined reference value L _Hi (step P ₇ ), and if YES, an OD _INH for inhibiting OD is output (step P ₈ ). Alternatively, if NO instruction in step P _7, i.e., lambda is when not exceeding L _Hi, this lambda is determined whether below a predetermined reference value _{L LOW (L Hi> L LOW} ) ( step P ₉ ), stop (prohibition release the output of the OD _INH when the YES command) (step P _10). The two reference values L _Hi and L _LOW correspond to changes in the shift pattern (here, O
This is for determining reference points for D prohibition) and return (OD prohibition release), and may be appropriately set in consideration of the power characteristics of the vehicle, the shift diagram of the automatic transmission, and the like.

On the other hand, in step P _5, the case of YES instruction, i.e., the result of the determination of the uphill road, automatically OD prohibited (4th speed →
(3rd speed), when the predetermined operating device 4 is operated by the driver who mistakenly recognizes the shift operation from the 4th speed to the 3rd speed as a failure of the automatic transmission, the vehicle is already traveling on an uphill road. The value of ▲, which has become large enough for the determination, is reset to the initial value (for example, 0) at the start of the determination (steps P ₁₁ and P ₁₂ ). As a result, at the next execution of the program, λ is
The value becomes smaller than L _Hi or L _LOW , and at that time, if the operation of the predetermined operation device 4 is restored, the OD prohibition can be released and the overdrive can be selected. That is, in response to a series of operations such as a coping operation by the driver who has recognized the failure, for example, disabling the overdrive switch to the prohibition state and then releasing the prohibition state, the overdrive is once prohibited in the uphill traveling determination. The shift characteristic can be returned to a state where overdrive is selected again.

As described above, according to the present embodiment, when the vehicle is judged to be traveling uphill and the overdrive is automatically prohibited (4th to 3rd speed), the driver who mistakenly recognizes this shift operation as a failure of the automatic transmission. When the predetermined operation device 4 is operated,
Since ▼ and RESET are reset, the value of λ is changed to L _Hi
Or L _LOW . As a result, it is possible to return to the overdrive selection state again the shift characteristic in which the overdrive is once prohibited in the uphill traveling determination.
The shift characteristic can be returned to the state before the uphill traveling determination.

(Effects) According to the present invention, when a predetermined operation device is operated by a driver, the shift characteristics can be returned to a state before it was determined that the vehicle was traveling on an uphill road.

[Brief description of the drawings]

1 to 3 are diagrams showing an embodiment of an automatic transmission control device for a vehicle according to the present invention. FIG. 1 is a configuration diagram thereof, and FIGS. 2 (a) and 2 (b) are function tables f _(x ) thereof. ₎ , G _(z), and FIG. 3 is a flowchart showing the processing. 4... Predetermined operating device, 20... Sub-control device (cancel means).

Continuation of front page (72) Inventor Makoto Kimura 2 Takara-cho, Kanagawa-ku, Yokohama-shi, Kanagawa Nissan Motor Co., Ltd. (56) References JP-A-61-220939 (JP, A) JP-A-55-132451 (JP , A) JP-A-61-103045 (JP, A)

Claims (1)

(57) [Claims] An estimated value corresponding to the magnitude of a running resistance acting on a host vehicle from a correlation between a first state variable representing a time-series variation pattern of an engine load and a second state variable representing a vehicle acceleration. In an automatic transmission control device for a vehicle that performs control to change the transmission characteristics of the automatic transmission based on the estimated value, a predetermined operation device that can affect the transmission characteristics of the automatic transmission is operated. And a canceling means for resetting the first state quantity and the second state quantity to initial values.