JPH09126307A - Transmission controller for automatic transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suitably actuate an engine brake for the demand of speed reduction at continuous curve traveling or the like, while avoiding too much engine braking at coasting traveling. SOLUTION: At a usual speed reduction demand such as straight road traveling or the like, the second speed demand is generated at 3 or 4 speed depending on throttle operation speed ΔTVO (S58), but in the case of continuous curve traveling, the second speed demand is generated at 2 or 4 speed (S56). The lowest speed is selected among the third speed demand depending on acceleration ΔVSP (S57, S59), the first speed demand depending on throttle opening TVO and the car speed VSP (S62), and the second speed demand, and shifting is performed (S63).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shift control device for an automatic transmission, and more particularly to a shift control technique capable of responding to a driver's demand for deceleration.

[0002]

2. Description of the Related Art Generally, in an automatic transmission for a vehicle, a shift stage is selected based on a shift pattern preset according to a running state of the vehicle, and a shift is performed to the selected shift stage. Has become. That is, a shift pattern in which the shift speed is stored according to the engine load represented by the throttle opening and the vehicle speed is stored in advance in the storage means of the control unit, and the shift corresponding to the vehicle speed and the throttle opening at that time is stored. The gear is read from the shift pattern, and the shift is controlled based on the read gear.

Generally, the shift pattern is set so that the smaller the engine load (throttle opening) is, the more the vehicle tends to shift up if the vehicle speed is the same. Therefore, for example, when the driver suddenly returns the throttle (accelerator) to the fully closed state when entering a curve, the driver reversely shifts up according to the shift pattern, although the driver requests deceleration. Therefore, there is a problem that sufficient engine braking cannot be obtained in response to a driver's deceleration request.

In order to solve such a problem, the applicant of the present invention selects a gear according to the shift pattern, a gear according to the throttle operating speed, and a vehicle acceleration (rate of change of vehicle speed). A shift control device having a structure that shifts to the lowest speed among the shift speeds was previously proposed (see Japanese Patent Application No. 6-299251).

[0005]

However, when the lowest step selected by the throttle operation speed and the lowest step selected by the acceleration are the same, when entering a curved road, it is based on the throttle operation speed by releasing the foot. It is possible to shift to the gear that the driver intends by controlling to the gear, but when the vehicle is running straight, the accelerator is depressed for acceleration purposes, and after the vehicle speed rises, the operator releases the accelerator for coasting. At times, the gear was shifted to a lower gear than the gear intended by the driver, which sometimes caused excessive engine braking (see FIG. 13).

The present invention has been made in view of the above problems, and provides a shift control device capable of obtaining a sufficient engine brake in response to a driver's deceleration request and avoiding excessive effect of the engine brake. The purpose is to do.

[0007]

Therefore, a shift control device for an automatic transmission according to the invention of claim 1 is constructed as shown in FIG. In FIG. 1, the deceleration state determination means determines the deceleration state of the vehicle, and the deceleration speed setting means determines each parameter based on a plurality of operating state parameters when the deceleration state determination means makes a deceleration determination. The speed range is set for each of the different speed range selection ranges.

Then, the shift control means determines the lowest shift speed among the plurality of shift speeds set by the deceleration shift speed setting means as a shift speed and performs shift control. With such a configuration, in the deceleration state, the selection range of the shift speed is different for each different parameter.
While the third speed is selected as the lowest speed with another parameter, the chance that the second speed is finally selected is intentionally reduced, and engine braking is too effective. Can be avoided.

According to the second aspect of the invention, the plurality of operating state parameters are the rate of change between the accelerator operating speed and the vehicle speed. With such a configuration, it is possible to set the shift speed at the time of deceleration based on the accelerator return operation speed and the rate of decrease of the vehicle speed, and thus to set the shift speed corresponding to the driver's deceleration request. Is possible.

According to another aspect of the present invention, there is provided curve detecting means for detecting a traveling condition on a curved road, and gear fixing means for fixing a gear when the traveling condition on the curved road is detected by the curve detecting means. On the other hand, when a deceleration determination is made by the deceleration determination means while the curved road traveling state is detected by the curve detection means, the plurality of operating states are given priority over the deceleration shift speed setting means. The curve-time shift speed setting means for setting the shift speeds respectively from the same selection range of the shift speeds based on the parameters, and the predetermined period after the fixation of the shift speeds by the shift speed fixing means is released, A curve-exit shift control means for performing shift control by determining the lowest speed of the plurality of shift speeds set by the curve shift speed setting means as the shift speed. I was kicking configuration.

According to this structure, when traveling on a continuous curved road, it is possible to shift gears to a low-speed stage corresponding to the request, along with the deceleration operation prepared for the next curve. That is, for example, when acceleration and accelerator operation speed are used as a plurality of operating state parameters for setting the gear stage, up to the second speed is selected based on the acceleration, whereas up to the third speed is selected corresponding to the accelerator operation speed. If it is set to be selected only, when the vehicle enters the second curve where the vehicle speed has dropped sufficiently, the gear will not be shifted to the low speed side even if the throttle is closed rapidly. By switching so that 2nd speed is also selected,
It is possible to shift to the second speed in response to the deceleration request for the second curve entry.

The invention according to claim 4 is constructed as shown in FIG. In FIG. 2, a plurality of deceleration determination means make a vehicle deceleration determination based on mutually different parameters. The deceleration shift speed setting means sets each shift speed from a selection range of different shift speeds based on a plurality of deceleration determination results by the plurality of deceleration determination means.

Then, the shift control means determines the lowest speed stage among the plurality of shift stages set by the deceleration shift stage setting means as a shift stage and performs shift control. According to this configuration, the selection range of the shift speed differs for each different deceleration determination,
For example, in one deceleration determination, up to the second speed is selected, while in the other deceleration determination, the third speed is the lowest speed stage, so that the opportunity to finally select the second speed is intentionally reduced. Therefore, the excessive braking of the engine can be avoided.

According to a fifth aspect of the present invention, the plurality of deceleration determining means use the accelerator operating speed and the rate of change of the vehicle speed as the parameters, and determine the deceleration based on the rate of changing the accelerator operating speed and the vehicle speed. It is configured to perform. With this configuration, the deceleration determination is performed based on the accelerator return operation speed and the vehicle speed decrease rate, and the driver's deceleration request can be detected based on the throttle operation and the actual change in the vehicle speed.

According to a sixth aspect of the present invention, there is provided curve detecting means for detecting a traveling condition on a curved road, and gear fixing means for fixing a shift stage when the traveling condition on the curved road is detected by the curve detecting means. On the other hand, when deceleration determination is performed by the plurality of deceleration determination means while the curved road traveling state is detected by the curve detection means,
A curve-time shift stage that prioritizes the deceleration shift stage setting unit and sets each shift stage from a selection range of the same shift stage based on a plurality of deceleration determination results by the plurality of deceleration determination units. During the predetermined period after the fixing of the shift speed by the setting means and the shift speed fixing means, the lowest speed of the plurality of shift speeds set by the curve speed shift speed setting means is determined as the shift speed. And a shift control means at the time of escape from a curve for performing shift control.

According to this structure, when traveling on a continuous curved road, it is possible to shift gears to a low-speed gear corresponding to the request, along with the deceleration operation prepared for the next curve. That is, for example, when the deceleration determination is performed based on the acceleration (deceleration) and the accelerator operating speed, the second speed is selected based on the acceleration, whereas only the third speed is selected corresponding to the accelerator operating speed. If it is set to not be set, when the vehicle enters the second curve where the vehicle speed has dropped sufficiently, the gear will not be shifted to the low speed side even if the throttle is closed rapidly. If switching is performed so that the second speed is selected, it is possible to shift to the second speed in response to the deceleration request for the second curve entry.

In a seventh aspect of the invention, the deceleration determination in the curved road traveling state is performed only after the accelerator opening becomes a predetermined value or more in the curved road traveling state. According to such a configuration, when the shift speed is fixed in the deceleration state accompanying the entry of a single curve road, it is possible to avoid erroneously recognizing the deceleration during the fixed shift speed as the deceleration prepared for the next curve, Only on the continuous curved road, it is possible to set the shift speed with the same selection range from each of the plurality of deceleration determination results.

[0018]

Embodiments of the present invention will be described below. FIG. 3 is a system configuration diagram of an embodiment of a shift control device for an automatic transmission according to the present invention. In FIG. 3, an automatic transmission 2 is provided on the output side of an engine 1 mounted on a vehicle (not shown). This automatic transmission 2
Is a fluid type torque converter 3 interposed on the output side of the engine 1, a gear type transmission 4 connected to the engine 1 via the fluid type torque converter 3, and various transmission elements in the gear type transmission 4. And a hydraulic actuator 5 for performing the coupling / releasing operation.

The operating hydraulic pressure for the hydraulic actuator 5 is controlled via various electromagnetic valves (not shown), and an automatic transmission control unit (A / T-C / U) 6 is provided.
Shifts to a target shift speed by a combination of ON / OFF of the various electromagnetic valves. Signals from various sensors are input to the automatic transmission control unit 6. As the various sensors, there is provided a throttle sensor 8 for detecting an opening TVO of a throttle valve 7 which is interposed in an intake system of the engine 1 and opens and closes in conjunction with an accelerator pedal (not shown).

Further, the rotation speed N of the output shaft of the automatic transmission 2
A vehicle speed sensor 9 for detecting the vehicle speed VSP by detecting o is provided. Furthermore, the brake switch 10 indicating the operation / non-operation of the brake, the lateral acceleration of the vehicle (hereinafter,
Also called a horizontal G. ) Is provided as a lateral G sensor 11 as a curve detecting means.

The lateral G of the vehicle may be detected by the lateral G sensor 11 or may be calculated based on the rotational difference between the left and right driven wheels during cornering. Specifically, when the tread is Tr, the rotational speed of the right driven wheel is Nrr, and the rotational speed of the left driven wheel is Nrl, the turning radius R is R =
It is calculated as Tr (Nrr + Nrl) / {2 | Nrr−Nrl |}, and the lateral acceleration G is calculated as G = VSP ² / R.

Further, instead of detecting the traveling state on the curved road based on the lateral G of the vehicle, the traveling state on the curved road may be detected based on the steering angle of the steering wheel. Then, the automatic transmission control unit 6 determines a target shift speed based on signals from the various sensors, outputs a shift signal for turning on / off the electromagnetic valve in accordance with the target shift speed, and automatically shifts the speed. The shift operation in the machine 2 is controlled.

Next, a first embodiment of the automatic shift control according to the present invention will be described with reference to the flow charts of FIGS. It should be noted that the functions as the deceleration determination means, the plurality of deceleration determination means, the deceleration shift speed setting means, the shift control means, the shift speed fixing means, the curve shift speed setting means, and the curve escape shift control means are the same as those shown in FIG. As shown in the flowchart of FIG. 8, the control unit 6 is provided as software.

Prior to a detailed description of the processing contents shown in the flowcharts of FIGS. 4 to 8, the contents of the shift control shown in the flowcharts will be briefly described. In the control shown in the flowchart, when a deceleration request is made, the accelerator operation speed and the acceleration (changes in vehicle speed) are changed in order to positively shift to a lower speed than the gear set based on the engine load and the vehicle speed. The speed change control for deceleration is executed based on the rate. Here, if the deceleration request is for entering a curve, and if the vehicle travels on a curve following the deceleration operation, the gear position controlled for deceleration is held in the curve.

Further, when there is a deceleration request estimated to be prepared for the next curve while traveling on a curve, the holding state of the deceleration gear is continued for a predetermined time even after the end of the curve. On the other hand, if there is no deceleration request during the curve running, it is estimated that the curve is a single shot, and in this case, the normal shift control is resumed at the same time as the end of the curve running, and the driver's intention when the vehicle exits the curve. The gear shift is performed without significantly delaying the gear shift timing.

In this embodiment, the accelerator operating speed is represented by the throttle operating speed. Further, the deceleration determination may be performed based on the accelerator operation speed (throttle operation speed), and the deceleration determination may be performed based on the intake negative pressure or the change rate of the intake air amount that changes based on the accelerator operation. Hereinafter, the contents of the shift control outlined above will be described in detail with reference to the flowcharts of FIGS.

First, in step 1 (denoted as S1 in the drawing; the same applies hereinafter), input processing such as reading of detection signals from various sensors is performed. In steps 2 to 23, the throttle operation speed ΔTVO (throttle opening TV
O time change rate), vehicle acceleration ΔVSP (vehicle speed VSP
Change rate) and the vehicle speed VSP are set.

It is to be noted that the ΔTVO and ΔVSP are both shown to be positive in the increasing direction and negative in the decreasing direction. In step 2, as will be described later, the deceleration request flag F ₁ is set to 1 in the vehicle deceleration request state.
When the flag F ₁ is φ, the routine proceeds to step 3 to step 8, where the curve control throttle operation speed ΔTVO1, the continuous curve control throttle operation speed ΔTVO2, the curve control vehicle longitudinal acceleration ΔVSP.
1, vehicle body longitudinal acceleration ΔVSP for continuous curve control, vehicle speed VSP for curve control 1, vehicle speed VSP2 for continuous curve control
The latest throttle operation speed ΔTVO, acceleration ΔVSP, and vehicle speed VSP are set for each.

On the other hand, when the flag F ₁ is 1, the routine proceeds to step 9, where the curve traveling flag F ₂ which is set to 1 while the vehicle is traveling on a curve is discriminated as will be described later. When the deceleration request flag F ₁ is 1 and the curve running flag F ₂ is φ, the process proceeds to step 10 and the previous curve running flag F ₂ is determined.

When it is determined in step 10 that the flag F ₂ was 0 at the previous time as well, it means that the vehicle is not decelerating, but the vehicle is not in the curve running. In this case, the process proceeds to step 11 and thereafter. In step 11, the smaller of the previously set curve control throttle operation speed ΔTVO1 and the latest calculated operation speed ΔTVO is set as the current operation speed ΔTVO1.

[0031] The operating speed ΔTVO1 the operating speed of 1 is set to the deceleration request flag F ₁ to the present time Δ
Since the operation speed ΔTVO is set as the minimum value of TVO and the closing operation direction is shown as a negative value, for example, when the throttle is suddenly closed and then held fully closed, Operation speed ΔTVO when closed suddenly
However, it will be held continuously thereafter.

Therefore, even in the state of being fully closed after the sudden closing operation, the sudden closing operation in which the shift request to the lower speed stage is strong as the shift stage set based on the throttle operation speed ΔTVO1 is performed. The corresponding low speed can be held, and the engine braking effect by the downshift can be reliably obtained even when the throttle operation is instantaneously performed.

In step 12, the latest ΔTVO is set to the continuous curve control throttle operation speed ΔTVO2. In step 13, in the same manner as the curve control throttle operation speed ΔTVO1, a process for setting the minimum value of the acceleration ΔVSP from the time when the deceleration request flag F 1 is set to ₁ for the curve control vehicle longitudinal acceleration ΔVSP1. I do. Since the acceleration ΔVSP represents deceleration as a negative value, as described above, even if the deceleration becomes small immediately after the sudden deceleration, the required gear stage at the time of the sudden deceleration can be continuously maintained, and the engine braking by the downshift can be performed. The effect is surely obtained.

In step 14, the latest ΔVSP is set to the vehicle body longitudinal acceleration ΔVSP2 for continuous curve control. In step 15, the maximum value of the vehicle speed VSP from when the deceleration request flag F ₁ is set to 1 to the present time is set to the curve control vehicle speed VSP1. As a result, during deceleration from a high vehicle speed, the gear set for deceleration control is held at the relatively high speed side, and it is possible to prevent excessive engine braking.

In step 16, the latest vehicle speed VSP is set to the continuous curve control vehicle speed VSP2. On the other hand, when it is determined in step 10 that the flag F ₂ was 1 last time, it is when the vehicle exits the curve, and in that case, the curve control is performed in steps 17 to 19 in preparation for the entry into the subsequent curve. For the throttle operation speed ΔTVO1, vehicle longitudinal acceleration ΔVSP1, vehicle speed VSP1 set for continuous curve control ΔTVO2, ΔVSP2, VSP
Set 2 respectively.

When it is determined in step 9 that the flag F ₂ is 1, it means that the vehicle is traveling on a curve, and the routine proceeds to step 20 where the continuous curve flag F ₄ is 1.
It is determined whether or not the vehicle is traveling on a continuous curve. When the continuous curve flag F ₄ is 0, the routine proceeds to step 3 to step 8 and the throttle operation speeds ΔTVO1, ΔTVO.
2, vehicle body longitudinal acceleration ΔVSP1, ΔVSP2, vehicle speed VS
The latest values are set in P1 and VSP2, respectively.

When the continuous curve flag F ₄ is 1, at step 21, the smaller one of the previously set continuous curve control throttle operating speed ΔTVO2 and the latest calculated operating speed ΔTVO is set to the current one. A process for setting the operation speed ΔTVO2 is performed. In Step 22, the previously set vehicle body longitudinal acceleration ΔVSP2 for continuous curve control is set.
The smaller one of the calculated operation speed ΔVSP and the latest operation speed ΔVSP is set as the current acceleration ΔVSP2.

In step 23, the previously set vehicle speed VSP is set.
The larger one of 2 and the latest calculated vehicle speed VSP is set as the current vehicle speed VSP2. In step 24, it is determined whether or not the shift position by the select lever (not shown) is in the D range in which the automatic shift control is performed for all the shift speeds (for example, 1st speed to 4th speed).

If it is in the D range, the routine proceeds to step 25, where the road load (Road) set according to the vehicle speed VSP is set.
Load) Throttle opening TVO equivalent to the latest detected throttle opening TVO is compared. When the throttle opening TVO is less than the road load (Road Load), the routine proceeds to step 26, where it is judged whether or not the throttle operation speed ΔTVO1 is equal to or smaller than a predetermined value 1 (negative value) (deceleration judgment). ).

As described above, the throttle operation speed ΔTVO (time change rate of the throttle opening TVO) is calculated with the change in the opening direction of the throttle being positive and the change in the closing direction being negative. . The predetermined value compared with the throttle operation speed ΔTVO1 is the throttle operation speed ΔTVO1 and the vehicle speed VSP, as will be described later.
It is preferable that the characteristic is changed according to the vehicle speed VSP1 in accordance with the characteristic of the second required shift speed set on the basis of 1. For example, in the present embodiment, the second shift speed request 4 → 3
The shift line is set to a predetermined value, which makes it possible to accurately detect a deceleration state that requires downshifting according to the operating state of the vehicle.

The throttle opening TVO is the road load (Ro
ad Load) and the throttle operation speed ΔTVO1 is less than or equal to the predetermined value 1, it is determined that the deceleration request is being issued due to the closing operation of the throttle, and step 29
Then, the flow advances to and the flag F ₁ indicating whether or not the deceleration request state is set to 1 corresponding to the deceleration request state. On the other hand, if it is not determined that the deceleration is required by the determination in steps 25 and 26, the process proceeds to step 27, it is determined whether the brake switch 10 is ON or OFF, the brake switch 10 is ON, and the driver operates the brake. If so, go to step 28.

In step 28, the vehicle acceleration ΔVSP1
It is determined whether or not (time change rate of vehicle speed VSP) is equal to or less than a predetermined value 2 (negative value). The acceleration ΔVSP
As described above, is calculated by subtracting the detection value of the vehicle speed VSP from the latest detection value of a predetermined time before, and is calculated as a positive value when the vehicle is accelerated and a negative value when the vehicle is decelerated. Therefore, the determination in step 28 (determination of deceleration) is to determine whether or not the deceleration of the vehicle is equal to or higher than a predetermined value.

The predetermined value to be compared with the acceleration ΔVSP1 is the acceleration ΔVSP1 and the vehicle speed VSP, as will be described later.
It is preferable that the characteristic is changed according to the vehicle speed VSP1 in correspondence with the characteristic of the third required shift speed set on the basis of 1. For example, in the present embodiment, the third shift speed request 4 → 3
The shift line is set to a predetermined value, which makes it possible to accurately detect a deceleration state that requires downshifting according to the operating state of the vehicle.

When it is determined in step 28 that the acceleration ΔVSP1 is less than or equal to the predetermined value 2, the vehicle is decelerating due to the braking operation. At this time, the process proceeds to step 29, and the deceleration request flag F is set. It is set to 1 indicating a deceleration request state _1. That is, the deceleration request flag F
₁ indicates that the deceleration request is determined based on the throttle operation (the driver's intention to decelerate) and / or the deceleration request is determined based on at least one of the time when the vehicle is decelerated with the brake operation. Will be set.

In step 30, the deceleration request flag F ₁
When the deceleration request flag F ₁ is set to ₁ , the process proceeds to step 31, and the curve traveling flag F ₂ indicating whether or not the vehicle is traveling in a curve is determined. When the curve running flag F ₂ is set to φ indicating the non-curve running state, the routine proceeds to step 32, where it is determined whether the lateral G (lateral acceleration) detected by the lateral G sensor 11 is a predetermined value 4 or more. To determine.

Here, when the lateral G is equal to or larger than the predetermined value,
When it is determined that the vehicle is traveling on a curve, the curve traveling flag F ₂ is set to 1 in step 33, which indicates a traveling state on a curve. On the other hand, when φ indicating the non-curve traveling state is set in the curve traveling flag F ₂ and it is determined that the lateral G is less than the predetermined value, the process proceeds to step 34 and the timer T ₁ is set to the predetermined value 3 It is determined whether or not the value exceeds.

If the timer T ₁ is less than the predetermined value, the process proceeds to step 35 and the timer T ₁ is incremented by 1. If the timer T ₁ exceeds the specified value,
That is, when the deceleration request state is detected and the elapsed time after the deceleration request flag F ₁ is set to 1 exceeds the predetermined time, the process proceeds to step 38 and thereafter, whereby various flags F ₁ , F ₅ , F ₂ , F ₃ are reset to zero and the timer T ₁ is reset to zero.

Such timer T₁Reduced by
Shift control that responds to high speed demand is continued more than necessary and shift
Prevents delay in startup control. That is, the flag
F ₁When 1 is set to, as described later
Shift control to apply the engine brake to
However, such shift control is continued for a predetermined time or longer.
Then, based on the normal engine load and throttle opening,
Return to normal gear shift control, and shift up is possible after deceleration is complete.
It is possible to prevent the driver from feeling uncomfortable without doing so easily.
Stop.

On the other hand, when it is determined in step 31 that the flag F ₂ is set to 1, the step
Proceeding to 36, the end of the curve traveling is determined by determining whether the lateral G is smaller than the predetermined value 5.
It should be noted that the level of a predetermined value that is compared with the actual lateral G for discriminating the approach to the curve and the level of the predetermined value that is compared with the actual lateral G for the discrimination of the end of the curve may be different from each other.

Here, when it is determined that the lateral G is larger than the predetermined value and the curve traveling is continued, the routine proceeds to step 45, where the throttle opening TVO is set to the predetermined value (Road Load) during the curve traveling. ) Corresponding opening degree) It is determined whether or not the flag F ₃ indicating whether or not it has become greater than or equal to. When the flag F ₃ is φ, that is, when it is determined that the throttle opening TVO is not equal to or larger than the predetermined value during the current curve traveling, the routine proceeds to step 46, and the vehicle speed at that time is determined. Road Load
The corresponding opening R / LTVO is compared with the latest opening detection value TVO.

Here, the opening TVO is a predetermined value R / LTVO.
If it is above, the process proceeds to step 47, and the flag F is set.
Set 1 to ₃ . In this way, when the throttle is opened to the extent that the driver's willingness to accelerate is set while the vehicle is traveling on a curve and the flag F ₃ is set to 1, in the subsequent traveling on a curve, the routine proceeds from step 45 to step 48. move on.

In steps 48 to 51, the deceleration request state is determined in the same manner as in steps 25 to 28. If a deceleration request during curve running is determined, step 52 is executed.
Then, 1 is set to the continuous curve flag (hereinafter, also referred to as a curve deceleration request flag) F ₄ . That is, if a deceleration request is made after the throttle is opened while the vehicle is traveling on a curve, the flag F ₄ is set to 1.

When the end of the curve running is determined by the determination of the lateral G in step 36, the process proceeds to step 37, and the flag F ₄ is determined. When the flag F ₄ is 0, it means that the single-shot curve is escaped,
In this case, the process proceeds to steps 38, 39, 42 to 44 to reset the various flags F ₁ , F ₅ , F ₂ , F ₃ to zero and reset the timer T ₁ to zero.

When the flag F ₄ is set to 1, the throttle is opened and the vehicle is accelerated while the vehicle is traveling on a curve, but thereafter the vehicle is decelerated or the driver tries to decelerate the vehicle. You have shown your will. In such a case, since the curve is continuous, it is highly possible that the driver has attempted to decelerate the vehicle in preparation for the next curve. Then, when the vehicle is traveling on a continuous curve as described above, if the normal shift control is immediately returned to before the next curve, an unnecessary upshift is performed and the engine brake cannot be effectively operated. Such problems occur.

Therefore, when it is determined in step 37 that the flag F ₄ is set to 1, step
While resetting the flag F ₄ to zero at 40, the next step
In 41, after setting the second speed request permission flag F ₅ to 1,
Go to step 42 to step 44. Therefore, at this time, the flag F ₁ remains 1. The flag F ₅ is
This flag is a flag that permits shifting to the second speed based on the throttle operation speed ΔTVO when the vehicle exits the continuous curve. When 1 is set in step 41, the shifting to the second speed is permitted.

In step 53, the deceleration request flag F ₁
If the flag F ₁ is set to ₁ , the process proceeds to step 54 and the curve running flag F ₂ is determined. The deceleration request flag F ₁ is 1, and
If the curve traveling flag F ₂ is φ, that is, if the vehicle is not traveling on a curve due to a deceleration request, step 55.
Then, the process proceeds to step S5 and the flag F ₅ is determined.

When the flag F ₅ is 1, step
Proceed to 56, throttle operation speed ΔTVO1 and vehicle speed VSP
The second required shift speed is calculated based on 1. On the other hand, when the flag F ₅ is 0, the routine proceeds to step 58, where the second required shift speed is calculated based on the throttle operation speed ΔTVO1 and the vehicle speed VSP1 as well. Step 56,
The calculation of the required shift speed in 58 is performed with reference to maps as shown in FIGS. 9 and 10 in which the shift speed is stored in advance according to the throttle operation speed ΔTVO1 and the vehicle speed VSP1.

Here, the characteristic is such that the lower the speed of the throttle operation ΔTVO, the higher the speed of closing operation of the throttle (the higher the speed of closing operation of the throttle), the lower the speed is selected. The relatively high speed gear stage is selected. On the high vehicle speed side, a relatively high speed is selected to avoid excessive engine braking due to downshifting and overrev, and on the low vehicle speed side, engine braking due to downshifting is effective. A relatively high speed stage is selected in order to avoid overshooting and to allow a smooth stop.

However, in step 56, the selection range of the shift speed is the second speed, the third speed, and the fourth speed (see FIG. 9), but in step 58, it is limited to the third speed and the fourth speed, and the second speed is selected. Is not selected (see FIG. 10). According to such a configuration, for example, when the user releases his / her foot from the accelerator for the purpose of coasting on a straight road (when flag F ₅ = 0), even if the throttle is suddenly closed, the throttle operation speed ΔTVO indicates the third speed or higher. While the high speed is set, the deceleration is sufficiently small due to coasting, so it is possible to select the third or higher speed from the acceleration ΔVSP. Therefore, when the coasting is intended, shifting to the second speed is possible. This will prevent the engine braking from becoming too effective.

On the other hand, during traveling on a continuous curve, the flag F ₅ is set to 1, so that the throttle operation speed ΔT
Even if the selection of the second speed according to the VO is permitted and even if the rate of decrease of the vehicle speed is small, it is possible to shift to the second speed by releasing the foot from the accelerator. Step 56
Alternatively, when the second required shift speed is set in step 58, the routine proceeds to steps 57 and 59, where the third required shift speed is calculated based on the vehicle acceleration ΔVSP1 and the vehicle speed VSP1.

The calculation of the required shift speed in steps 57 and 59 is performed with reference to a map as shown in FIG. 11 in which the shift speed is stored in advance in accordance with the vehicle acceleration ΔVSP1 and the vehicle speed VSP1. Here, the characteristic is such that the lower the speed is, the higher the acceleration is toward the negative side (the greater the deceleration of the vehicle is), and the lower vehicle speed side and the higher vehicle speed side are the same as the characteristics in step 56. Then, the shift stage on the relatively high speed side is selected.

Third value according to the acceleration ΔVSP1 of the vehicle
The required shift speed has a selection range of 2nd to 4th. Therefore, normally, although the selection of the shift speed according to the throttle operation speed ΔTVO1 is the third speed or the fourth speed, the acceleration ΔVSP
The selection of the shift speed according to 1 is different for the second speed, the third speed, and the fourth speed. On the other hand, on the continuous curve road, both of them have a selection range of the second speed, the third speed, and the fourth speed. .

Further, in step 62, the first required shift speed corresponding to the normal shift speed is calculated based on the vehicle speed VSP and the throttle opening TVO (engine load). The calculation of the required shift speed in step 62 is performed in advance by calculating the vehicle speed VS.
This is performed with reference to a map as shown in FIG. 12 in which the shift speed is stored according to P and the throttle opening VSP. The shift map is set such that, as long as the vehicle speed VSP is the same, the smaller the throttle opening (engine load), the more likely it is to shift up.

Then, in step 63, the first, second and third required shift speeds are compared, and the shift speed which is the lowest speed among these is set as the final target shift speed,
The engine braking is activated by shifting to the target shift speed. In step 64, a shift signal is output to the electromagnetic valve to match the actual shift position with the set target shift speed.

On the other hand, when it is judged at step 53 that the deceleration request flag F ₁ is φ, the routine proceeds to step 60, where
The fourth required speed is set as the second required speed,
In the next step 61, the fourth highest speed, which is also the highest speed, is set as the third required speed. By setting the highest speed, it is possible to avoid setting the target speed at least on the lower speed side than the first required speed when the process proceeds to step 63, and substantially, the speed reduction request flag F is set. _{When 1} is φ, shift control is performed based on the first required shift speed.

In step 54, the curve running flag F ₂
When it is determined that 1 has been set to 1, the step 55 to the step 63 are jumped to the step 64 so that the target shift speed is not updated. That is, even if the deceleration request flag F ₁ is set to ₁ , if the curve running flag F ₂ is set to 1, the gear position up to that point is held and the gear shift is performed during the curve running. As a result, it is possible to prevent the driving force from changing, and it is possible to secure traveling stability when traveling on a curve. Therefore, when a vehicle enters a curve while being controlled to a speed lower than normal in response to a deceleration request for entering the curve, the vehicle travels while being held at the low speed.

However, in the case of a continuous curve, when a deceleration request is generated during the first curve running, 1 is set to the flag F ₄ and 1 is set to the flag F ₅ when the lateral G becomes small.
While the flag F ₂ is once reset, the routine proceeds to steps 56 and 57 to newly set the second shift speed for the curve. On the other hand, the fact that the curve is single shot (or the last curve of the continuous curve)
When it is determined that the flag F ₄ is φ, the flags F _{1 to} F ₅ are immediately reset to zero to return to the normal shift control, so that the shift timing is delayed with respect to the driver's intention. There is no.

[0068]

As described above, according to the first aspect of the present invention, the selection range of the shift speed is made different for each different operating condition parameter at the time of deceleration, so that, for example, one parameter is selected up to the second speed. On the other hand, with another parameter, by making the third speed the lowest speed, it is possible to intentionally reduce the chances that the second speed will be finally selected, and avoid excessive engine braking as appropriate. Has the effect of becoming.

According to the second aspect of the present invention, by setting the shift speed at the time of deceleration based on the accelerator return operation speed and the reduction rate of the vehicle speed, the shift speed that meets the driver's deceleration request can be set. The effect is that it can be set. According to the third aspect of the present invention, while preventing excessive braking of the engine when the throttle is closed for the purpose of coasting, the vehicle is traveling on a continuous curve along with the deceleration operation prepared for the next curve. There is an effect that it is possible to shift to a low speed stage corresponding to the request.

According to the invention as set forth in claim 4, since the selection range of the shift speed is made different for each different deceleration determination, for example, one deceleration determination selects up to the second speed, while another deceleration determination selects 3 speeds. The configuration in which the speed is set to the lowest speed has the effect of intentionally reducing the chances that the second speed will be finally selected and appropriately avoiding the excessive braking of the engine.

According to the fifth aspect of the present invention, the deceleration determination is performed based on the accelerator return operation speed and the vehicle speed reduction rate, and the driver's deceleration request is determined by the throttle operation and the actual vehicle speed change. There is an effect that it can be detected based on. According to the sixth aspect of the present invention, while preventing excessive braking of the engine when the throttle is closed for the purpose of coasting, the vehicle is traveling on a continuous curve along with the deceleration operation for the next curve. There is an effect that it is possible to shift to a low speed stage corresponding to the request.

According to the seventh aspect of the present invention, a single-shot curved road and a continuous curved road are surely discriminated, and only in the continuous curved road, the shift speed is set with the same selection range from each of a plurality of deceleration determination results. The effect is that it can be done.

[Brief description of the drawings]

FIG. 1 is a basic configuration block diagram of a shift control device for an automatic transmission according to a first aspect of the invention.

FIG. 2 is a basic configuration block diagram of a shift control device for an automatic transmission according to a fourth aspect of the invention.

FIG. 3 is a system configuration diagram of the automatic transmission according to the embodiment.

FIG. 4 is a flowchart showing an embodiment of shift control.

FIG. 5 is a flowchart showing an embodiment of shift control.

FIG. 6 is a flowchart showing an embodiment of shift control.

FIG. 7 is a flowchart showing an embodiment of shift control.

FIG. 8 is a flowchart showing an embodiment of shift control.

FIG. 9 is a diagram showing a setting characteristic of a shift speed depending on a throttle operation speed.

FIG. 10 is a diagram showing a setting characteristic of a shift speed depending on a throttle operation speed.

FIG. 11 is a diagram showing a setting characteristic of a shift speed according to acceleration.

FIG. 12 is a diagram showing a setting characteristic of a shift speed depending on a normal throttle opening and a vehicle speed.

FIG. 13 is a time chart for explaining problems of conventional control.

[Explanation of symbols]

 1 Engine 2 Automatic Transmission 3 Hydrodynamic Torque Converter 4 Gear Transmission 5 Hydraulic Actuator 6 Automatic Transmission Control Unit 7 Throttle Valve 8 Throttle Sensor 9 Vehicle Speed Sensor 10 Brake Switch 11 Lateral G Sensor

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical display F16H 59:66

Claims (7)

[Claims] 1. A deceleration state determination means for determining a deceleration state of a vehicle, and a deceleration state determination means for making a deceleration determination,
Based on a plurality of operating condition parameters, a deceleration gear stage setting means for setting a gear stage from a selection range of a gear stage different for each parameter, and a plurality of deceleration gear stage setting means. A shift control device for an automatic transmission, comprising: a shift control unit that determines a lowest shift stage among shift stages as a shift stage and performs shift control. 2. The shift control device for an automatic transmission according to claim 1, wherein the plurality of operating state parameters are change rates of an accelerator operating speed and a vehicle speed. 3. A curve detecting means for detecting a traveling condition on a curved road, and a gear stage fixing means for fixing a shift stage when the traveling condition on the curved road is detected by the curve detecting means, while the curve is provided. When the deceleration judgment is made by the deceleration judgment means while the detection means detects the traveling condition on a curved road, the deceleration speed setting means has priority over the deceleration speed setting means, and the same operation is performed based on the plurality of operating condition parameters. Curve shift speed setting means for setting the respective shift speeds within the selection range of the shift speed, and the curve shift speed setting means for a predetermined period after the fixation of the shift speed by the shift speed fixing means is released. A shift control means for exiting a curve for determining the lowest speed of the plurality of shift speeds set as a shift speed and controlling the shift. Shift control system for an automatic transmission according to claim 1 or 2. 4. A plurality of deceleration determining means for making a vehicle deceleration determination based on mutually different parameters, and a range of selection of different shift speeds based on a plurality of deceleration determination results by the plurality of deceleration determining means. From the above, the speed change speed setting means for setting each speed change speed, and the speed change control for performing the speed change control by determining the lowest speed speed of the plurality of speed speeds set by the speed reduction speed change speed setting means as the speed change speed And a shift control device for an automatic transmission, which includes: 5. The plurality of deceleration determining means use the accelerator operating speed and the rate of change of the vehicle speed as the parameters, and make deceleration determinations based on the accelerator operating speed and the rate of change of the vehicle speed, respectively. The shift control device for an automatic transmission according to claim 4. 6. A curve detecting means for detecting a traveling condition on a curved road, and a gear stage fixing means for fixing a shift speed when the traveling condition on the curved road is detected by the curve detecting means. When the plurality of deceleration determination means make a deceleration determination while the detection means detects a traveling condition on a curved road, the plurality of deceleration determination means are given priority over the deceleration shift speed setting means. Based on the result of the deceleration determination, a curve gear shift speed setting means for setting each shift speed from the same selection range of the shift speed, and a predetermined period after the shift speed is fixed by the shift speed fixing means. In the curve escape control means for determining the lowest speed of the plurality of shift speeds set by the curve shift speed setting means as a shift speed and performing shift control. Shift control system for an automatic transmission according to claim 4 or 5, characterized in that provided. 7. The deceleration determination in the curved road traveling state is performed only after the accelerator opening becomes equal to or larger than a predetermined value in the curved road traveling state.
Alternatively, a shift control device for an automatic transmission according to Item 6.