JPH0972414A - Speed change controller for vehicular automatic transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To decide a shifting position corresponding to traveling resistance and the speed changing intention of a driver. SOLUTION: Traveling resistance RESIALL (RESIALL=F1-RESIa -RESIr1 + TGTRA) is calculated based on a current driving force F1(S7), acceleration resistance RESIa (S8), rolling resistance + air resistance RESTIr1 (S9) and an addition correcting value TGTRA (S11) set as a larger value when the average value TVOave (S10) of throttle opening is larger. Then, a driving force after up shifting is compared with the traveling resistance RESIALL and if the driving force after up shifting is smaller than the traveling resistance RESIALL, up shifting is prohibited.

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 for a vehicle, and more particularly to a device for determining a shift speed based on a comparison between a driving force of a vehicle and a running resistance.

[0002]

2. Description of the Related Art In a shift control of an automatic transmission for a vehicle, a method is generally used in which a shift speed is determined by referring to a shift map in which a shift speed is set in advance according to a throttle opening and a vehicle speed. However, in the configuration in which the gear position is determined as described above, since the running resistance change is not considered, for example, when traveling on an uphill road, an unnecessary upshift is performed by releasing the foot from the accelerator when entering a corner, Sometimes, the highest speed is selected, so that the engine brake cannot be actuated and the load on the foot brake increases, which causes a problem.

Therefore, for example, the device disclosed in Japanese Examined Patent Publication No. 1-55346 has a structure in which the gear is determined based on the comparison between the driving force and the running resistance at each gear. Specifically, when the driving force at the shift speed after the shift is equal to or lower than the running resistance, the shift is prohibited to prevent unnecessary upshifting. The running resistance W compared with is: running resistance W = current running resistance Wist + running resistance threshold Δ
Set as W.

The threshold value ΔW of the running resistance is a value for securing a surplus driving force after shifting, and is set depending on the engine speed and the actual acceleration value.

[0005]

However, as described above, in the configuration in which the threshold value ΔW of the running resistance is set depending on the engine speed and the actual acceleration value, it is difficult to reflect the driver's intention. The throttle operation that is not linked to the vehicle acceleration is ignored in the control, and there is a problem that it is difficult to perform a shift corresponding to the driver's shift request.

The present invention has been made in view of the above problems, and in a configuration for determining a shift speed based on a comparison between running resistance and driving force, the intention of the driver is reflected in the control to determine the shift speed. Is intended to be done.

[0007]

Therefore, a shift control device for an automatic transmission for a vehicle according to the invention of claim 1 is constructed as shown in FIG. In FIG. 1, the driving force calculation means calculates the driving force of the vehicle, and the running resistance calculation means calculates the actual running resistance of the vehicle.

On the other hand, the threshold setting means sets the threshold of the running resistance according to the history of the engine load. Then, the shift speed determining means determines the shift speed based on the actual running resistance, the threshold value of the running resistance, and the driving force. With this configuration, when the driver's acceleration request is strong, the engine load is high on average, so by setting the threshold of the running resistance according to the history of the engine load, the driver's acceleration request is strong. It is possible to avoid unnecessary upshifting.

According to the second aspect of the invention, the threshold value setting means is configured to represent the engine load by the throttle opening. According to such a configuration, the driver's intention is detected from the throttle opening history operated by the driver,
The shift speed is determined in accordance with this, and the shift speed that faithfully reflects the driver's intention can be determined.

According to the third aspect of the present invention, the history of the engine load in the threshold setting means is the average value of the throttle opening, and the larger the throttle opening is, the more the threshold value of the running resistance is selected to the lower speed side. The configuration is set in the direction. According to this configuration, when the throttle opening is large on average, it is estimated that the driver has a strong tendency to accelerate, so the threshold value is set so that the lower speed side is selected.

According to another aspect of the present invention, the history of the engine load in the threshold value setting means is an average value of the changing speed of the throttle opening, and the larger the changing speed of the throttle opening is, the higher the threshold value of the running resistance is set. The configuration is such that the low speed side is set in the selected direction. According to this configuration, when the rate of change of the throttle opening is large on average, it is estimated that the driver tends to intend rapid acceleration and rapid deceleration, so that the lower speed side is selected. Set the threshold.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below. In FIG. 2 showing the system configuration of the embodiment, an automatic transmission 2 is provided on the output side of the engine 1. The automatic transmission 2 includes a torque converter 3 interposed on the output side of the engine 1, a gear type transmission 4 connected through the torque converter 3, and a combination of various transmission elements in the gear type transmission 4. And a hydraulic actuator 5 for performing a releasing operation. The operating hydraulic pressure for the hydraulic actuator 5 is ON / OFF controlled through various electromagnetic valves. Here, the electromagnetic solenoids 6A and 6B for shifting are used for automatic shifting.
Only is shown.

Signals are input to the control unit 7 from various sensors. As the various sensors, a vehicle speed sensor 9 that obtains a rotation signal from an output shaft 8 of the automatic transmission 2 and detects a vehicle speed (output shaft rotation speed) VSP is provided. Further, a potentiometer-type throttle sensor 11 for detecting an opening TVO of a throttle valve 10 which is interposed in an intake system of the engine 1 and opens and closes in conjunction with an accelerator operation of a driver is provided.

A crank angle sensor 12 is provided on the crankshaft of the engine 1 or a shaft that rotates in synchronization with the crankshaft. The signal from the crank angle sensor 12 is, for example, a pulse signal for each reference crank angle, and the engine speed Ne is calculated from the cycle thereof. The control unit 7 has a built-in microcomputer and performs a shift control based on signals from the various sensors.

In the shift control by the control unit 7, the first to fourth speeds are automatically set according to a shift control routine which will be described later, and the combination of ON / OFF of the shift electromagnetic valves 6A and 6B is controlled. The gear type transmission 4 is controlled to the gear position via the hydraulic actuator 5.
Next, the shift control routine shown in the flowcharts of FIGS. 3 and 4 will be described. This routine is executed every predetermined time. Incidentally, the driving force calculation means, the running resistance calculation means,
The control unit 7 has the functions of the threshold value setting means and the shift speed determining means by software as shown in the flow charts of FIGS.

In step 1 (denoted as S1 in the drawing; the same applies hereinafter), the vehicle speed VSP is detected based on the signal from the vehicle speed sensor 9. In step 2, the throttle sensor
The throttle opening TVO (accelerator opening) is detected based on the signal from 11. In step 3, as shown in FIG. 5, the shift speed is selected with reference to a shift map (shift pattern diagram) in which the shift speed is determined in advance according to the vehicle speed VSP and the throttle opening TVO. In the shift pattern diagram of FIG. 5, a solid line shows an upshift line showing an upshift characteristic, and a broken line shows a downshift line showing a downshift characteristic.

In step 4, it is determined whether the upshift request, the downshift request, or no shift is requested based on the comparison between the selected shift speed and the current shift speed. If it is determined in step 4 that there is neither an upshift request nor a downshift request, this routine is ended. If it is determined that there is a downshift request, the process proceeds to step 5 to downshift to the next gear. Then, this routine is finished.

If there is an upshift request (for example, 3rd speed → 4th speed), the process proceeds to step 6 and subsequent steps in order to determine the suitability of the upshift. In addition, for example, when the present speed is the third speed and the shift speed selected from the shift map is the fourth speed, naturally the fourth speed is the next shift speed, which will be described later.
Whether to actually execute the shift to the high speed is determined based on the correlation between the running resistance and the driving force. If the present speed is the second speed and the gear selected from the shift map is the fourth speed, ,
For the time being, it is determined whether or not upshifting is possible by setting the third gear as the next gear, and if upshifting to the third gear is possible, the next gear is set as the fourth gear and the fourth gear is set. It should be determined whether or not the shift to is possible.

In step 6, referring to the map shown in FIG. 6, the current throttle opening TVO and turbine rotational speed Nt.
Based on and, the turbine torque Tt _CGP is calculated.
The turbine speed Nt may be directly detected by the turbine sensor, but may be calculated from the engine speed Ne and the torque converter characteristic. In step 7, based on the calculated turbine torque Tt _CGP , the driving force (current driving force) F1 at the current gear stage (for example, 3rd speed) is calculated by the following equation.
Is calculated.

F1 = Tt _CGP × CG _RATIO × k Note that CG _RATIO is a gear ratio of the current gear (third speed), and k is a constant determined by the tire radius and the like. In step 8, the acceleration resistance RESI _a is calculated according to the following equation. RESI _a = ΔVSP × W × K where ΔVSP is the vehicle speed change amount, W is the vehicle weight, and K is a constant.

In step 9, referring to the map shown in FIG. 7, from the vehicle speed VSP, the rolling resistance + air resistance RE
Calculate SI _rl . In step 10, the average value TVOave of the throttle valve opening TVO is calculated. The average value TV
Oave may be a simple average value of the opening TVO within a predetermined period, or may be a value obtained by sequentially weighting the opening TVO. Here, the throttle valve opening T
VO is a parameter representative of the engine load, and when the driver's intention to accelerate is strong, the accelerator is deeply depressed on average, and the average value TVOave that indicates the history of the engine load is larger. Become.

In step 11, the addition correction value TGT _RA (threshold of running resistance) is calculated from the average value TVOave with reference to the map shown in FIG. The addition correction value TGT
_RA is larger when the average value TVOave is larger, that is,
The larger the driver's tendency to accelerate, the larger the value is set.

In step 12, the addition correction value TGT _{RA is} added to the actual running resistance obtained by subtracting the acceleration resistance RESI _a and the rolling resistance + air resistance RESI _rl from the current driving force F1 as in the following equation. (Travel resistance threshold value) is added and corrected, and the travel resistance RE finally used for determining the shift speed is used.
Ask for SI _ALL . _{RESI ALL = (F1-RESI a} -RESI rl) + T
GT _{RA As} will be described later, since the upshift to a gear having a driving force lower than the traveling resistance RESI _ALL is prohibited, the addition correction value TGT _RA (threshold of the traveling resistance) is a margin. The value is equivalent to the driving force.

Here, since the addition correction value TGT _RA is set as a larger value as the average value TVOave is larger, it is larger when the average value TVOave is large and the driver tends to accelerate. The upshift is performed only when the surplus driving force can be secured, which means that the lower the lower speed side is selected as the average value TVOave is larger.

In step 13, the throttle opening TVO corresponding to the current vehicle speed VSP on the downshift line from the next shift speed (4th speed) to the current shift speed (3rd speed) in the shift pattern diagram is obtained, This is TVO _DWN (downshift throttle opening at the next gear). That is, as shown in FIG. 8, for example, when the current shift speed is the third speed, the fourth speed → the third speed at the same vehicle speed VSP _{1 as the} point C when the upshift request of the third speed → the fourth speed is generated. The throttle opening TVO _DWN at the point D on the downshift line is _calculated .

In step 14, referring to the map shown in FIG. 6, the turbine torque Tt _NGP is calculated based on the downshift throttle opening TVO _DWN and the current turbine speed Nt at the next shift stage (4th speed). calculate. In step 15, based on the calculated turbine torque Tt _NGP , the driving force (maximum driving force after shifting) F2 at the next shift stage (4th speed) is calculated by the following equation.

F2 = Tt _NGP × NG _RATIO × k Incidentally, NG _RATIO is a gear ratio of the next shift stage (4th speed), k is a constant determined by the tire radius and the like, and the driving force F2 is
Is the estimated driving force value after shifting when the vehicle speed is constant and an upshift is performed according to the shift map. Steps
At 16, the maximum driving force F2 at the next gear (4th speed) is compared with the running resistance RESI _ALL .

As a result of the comparison, when F2 ≧ RESI _ALL , it is determined that the surplus drive force set according to the average value TVOave is ensured after the gear shift, so the routine proceeds to step 17, where the upshift is performed. Allow the next gear (4
Speed up). On the other hand, F2 <
In the case of RESI _ALL , it is determined that the surplus drive force set according to the average value TVOave is not secured after the gear shift, so the routine proceeds to step 18, where the upshift is prohibited and the current gear (3rd gear) is set. ) Hold.

When the upshift is prohibited, the upshift line from the current shift stage to the next shift stage in the shift pattern diagram is moved to the high vehicle speed side instead of holding the current shift stage. You may According to this configuration, it is possible to prevent the upshift from being performed after the gear shift due to the inability to secure the surplus driving force in response to the change in the running resistance, and it is possible to prevent the deterioration of the drivability due to the unnecessary upshift.

Further, a value TGT _RA (a threshold value of the running resistance) to be added to the running resistance as a value corresponding to the surplus driving force is set according to the average value TVOave of the throttle opening, and the average value TVOave is set. since a structure to further increase the TGT _RA when large, when the average value TVOave request for acceleration of increase driver is large,
It is possible to avoid unnecessary upshifting.

By the way, in the routine for determining the shift stage shown in the flow charts of FIGS. 3 and 4, the value TGT _RA corresponding to the margin driving force is set based on the throttle opening average value TVOave. As in the routines shown in the flowcharts of FIGS. 10 and 11, the average value Δ of the changing speed of the throttle opening (throttle operation speed)
The TGT _RA may be set based on TVOave.

In the flow charts of FIGS. 10 and 11,
Regarding steps 1 to 9, the same processing as the above-mentioned processing is performed. In step 10a, the changing speed ΔTVO of the throttle opening TVO is calculated. Step 10b
Then, the average value ΔTVOave of the change speed ΔTVO is
It is calculated as a parameter indicating the history of engine load.

The average value ΔTVOave may be a simple average value of the changing speed ΔTVO within a predetermined period, or may be a value obtained by sequentially weighting the changing speed ΔTVO. Here, when the driver's intention of sudden acceleration or deceleration is strong, the accelerator operation speed increases, so the average value ΔTVOave becomes larger. In step 11a, the addition correction value TG is calculated based on the average value ΔTVOave.
T _RA (threshold of running resistance) is determined. As shown in FIG. 12, the larger the average value ΔTVOave is, the larger the added correction value TGT _RA is set.
When the driver has a strong intention to suddenly accelerate or decelerate, a lower speed stage side is selected to ensure a larger surplus driving force.

After step 12, as in the case of determining the addition correction value TGT _RA based on the average value TVOave,
The running resistance RESI _ALL is calculated by using the addition correction value TGT _RA.
Is set, and by comparison with the driving force after upshifting,
It is determined whether or not the upshift is performed.

[0035]

As described above, according to the shift control device for an automatic transmission for a vehicle according to the invention of claim 1, the shift stage is determined in consideration of the driver's intention indicated in the history of the engine load. The effect is that it can be done. According to the invention of claim 2, the driver's intention is detected from the history of the opening degree of the throttle operated by the driver to determine the shift speed. Therefore, the shift speed that faithfully reflects the driver's intention is determined. There is an effect that can be done.

According to the third aspect of the present invention, when the throttle opening is large on average, it is estimated that the driver has a strong tendency to accelerate, and control can be performed so that the lower speed side is selected. There is. According to the fourth aspect of the invention, when the speed of change of the throttle opening is large on average, it is estimated that the driver tends to suddenly accelerate or decelerate, and the lower speed side is selected. There is an effect that can be controlled to.

[Brief description of drawings]

FIG. 1 is a functional block diagram showing a basic configuration of a shift control device according to a first aspect of the invention.

FIG. 2 is a system configuration diagram of the embodiment.

FIG. 3 is a flowchart showing a first half portion of a shift control routine of the first embodiment.

FIG. 4 is a flowchart showing the latter half of the shift control routine of the first embodiment.

FIG. 5 is a diagram showing a shift pattern diagram.

FIG. 6 is a diagram showing a map for calculating turbine torque.

FIG. 7 is a diagram showing a map for calculating rolling resistance + air resistance.

FIG. 8 is a diagram showing a method of calculating a downshift throttle opening.

FIG. 9 is a diagram showing characteristics of a running resistance threshold value in the first embodiment.

FIG. 10 is a flowchart showing a first half portion of a shift control routine of the second embodiment.

FIG. 11 is a flowchart showing the latter half of the shift control routine of the second embodiment.

FIG. 12 is a diagram showing characteristics of a running resistance threshold value in the second embodiment.

[Explanation of symbols]

 Reference Signs List 1 engine 2 automatic transmission 6A, 6B electromagnetic valve for shift 7 control unit 9 vehicle speed sensor 11 throttle sensor 12 crank angle sensor

Claims (4)

[Claims] 1. A driving force calculating means for calculating a driving force of a vehicle, a running resistance calculating means for calculating an actual vehicle running resistance, and a threshold setting means for setting a running resistance threshold value according to a history of an engine load. A shift control device for an automatic transmission for a vehicle, comprising: a shift speed determining unit that determines a shift speed based on the actual running resistance, a threshold value of the running resistance, and a driving force. 2. The shift control device for an automatic transmission for a vehicle according to claim 1, wherein the threshold setting means causes the engine load to be represented by a throttle opening. 3. The history of engine load in the threshold setting means is an average value of throttle opening, and the running resistance threshold is set to a direction in which a lower speed side is selected as the throttle opening is larger. The shift control device for an automatic transmission for a vehicle according to claim 2, characterized in that. 4. The history of the engine load in the threshold setting means is an average value of the changing speed of the throttle opening, and the larger the changing speed of the throttle opening, the lower the threshold of the running resistance is selected. 3. The shift control device for an automatic transmission for a vehicle according to claim 2, wherein the shift control device is set to a direction.