JPH0571623A - Controller of automatic transmission for vehicle - Google Patents

Abstract

PURPOSE:To prevent any miscontrol due to false detection from occurring by suspending a sloping control itself at time of a sudden change in engine load. CONSTITUTION:An ascending difference calculated this time is compared with the so-far accumulative means value, thereby judging whether it is in an increment direction or decrement direction in relation to the value of up to the last time. When so judged that it is in the decrement direction, a moderating factor KPNO is set down to a value YKPNODN and then a weighting mean value is sought in this way. In addition, when so judged that it is in the increment direction, whether throttle opening is suddenly changed or not is judged, and when so judged that it is not suddenly changed, the moderating factor is set down to a value YKPNOUP, after checking a fact that braking operation is not yet done, a weighting mean value is calculated. In succession, when so judged that the throttle opening is suddenly changed, such a motion as seeking the weighting mean value is jumped, determining a map by the mean value calculated at the last time. With this constitution, any miscontrol is preventable at a time when the throttle opening is suddenly changed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for an automatic transmission for a vehicle, and more particularly to a control device for improving a shift control characteristic when traveling on an uphill road.

[0002]

2. Description of the Related Art Generally, a control device for an automatic transmission for a vehicle prepares a gear shift scheduling map in advance and retrieves it from an operating parameter indicating an engine load such as a throttle opening during running and an operating parameter indicating a vehicle speed. The gear ratio is determined. However, since the gear shift map is created based on a general traveling state, it does not always give good gear shifting characteristics when traveling on an uphill / downhill road. Therefore, Japanese Patent Publication Sho 59-8
As disclosed in Japanese Patent No. 698, a gear shift map is separately provided according to the condition of a traveling road such as traveling on a flat road and traveling on an uphill road, and a vehicle on a flat road is prepared from operating parameters such as throttle opening and vehicle speed. A technique has been proposed in which an index indicating the running resistance of the vehicle, specifically, an expected value of the running acceleration is obtained, compared with the actual vehicle acceleration calculated from the vehicle speed, and a gear shift map is selected according to the comparison result. ing.

[0003]

By the way, in this type of control, it is necessary to accurately determine the running acceleration of the vehicle, or more generally, the index indicating the running resistance, from operating parameters such as engine load. There is a time lag due to a delay in the intake system, fuel supply system, drive train, etc. until the load fluctuation appears in the driving force fluctuation, and this becomes remarkable especially when the engine load suddenly changes. Therefore, when such an engine load suddenly changes, it is not possible to accurately detect the index indicating the running resistance, and the shift control itself may be erroneous.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to solve the above-mentioned drawbacks and to provide a control device for an automatic transmission for a vehicle which prevents erroneous control due to erroneous detection when the engine load suddenly changes.

Further, in the above-mentioned prior art, it is necessary to set the predicted acceleration separately for all shift positions, and the structure is complicated, and the shift characteristic is switched according to the difference between the predicted acceleration and the actual acceleration. Therefore, there is a possibility that the control value is frequently switched, such as when the operating state suddenly changes, and the control stability is deteriorated.

Therefore, a second object of the present invention is to provide a control device for an automatic transmission for a vehicle which solves the above-mentioned drawbacks of the prior art.

[0007]

In order to solve the above-mentioned object, the present invention, for example, as set forth in claim 1, obtains a value indicating running resistance of a vehicle from operating parameters including engine load, and uses it as a reference. It is determined whether or not the vehicle is traveling on an uphill / downhill road by comparing with the value, and when it is determined that the vehicle is traveling on an uphill / downhill road, uphill / downhill control is performed to determine the gear ratio so that the gear stage is suitable for traveling on the uphill / downhill road. In a control device for an automatic transmission for a vehicle, the uphill / downhill control is stopped when the engine load suddenly changes.

[0008]

Since the uphill / downhill control itself is stopped when the engine load suddenly changes, the control value is not erroneously determined.

[0009]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is an overall schematic view of a control device for an automatic transmission for a vehicle according to the present invention. In the figure, reference numeral 10 indicates an internal combustion engine. The engine output generated by the internal combustion engine 10 is sent to the transmission 14 via the shaft 12 and is transmitted to the main shaft 18 via the pump impeller 16a of the torque converter 16 and the turbine runner 16b.
A gear mechanism 22 having four forward stages and one reverse stage is provided between the main shaft 18 and the counter shaft 20, and a secondary shaft 24 is arranged parallel to the counter shaft 20. Hydraulic clutches C1 to C4 are arranged at each gear. In addition, what is indicated by the symbol CH is a hydraulic clutch for bypassing the one-way clutch 26. Here, the transmission output is final gear 2
8 to the differential device 30 and drive the drive wheels 34 through the drive shaft 32. still,
The hydraulic clutch C4 is used for forward and reverse movements, and when the selector 36 is located to the left in the figure, the fourth forward speed is established, and when the selector 36 is located to the right, the reverse gear RVS is established via an idle gear (not shown).

A throttle opening sensor 40 for detecting the opening of a throttle valve (not shown) arranged in the intake passage (not shown) of the internal combustion engine 10 is provided. A vehicle speed sensor 42 that detects the vehicle speed from the rotational speed of the shaft 20 is provided near the counter shaft 20 of the transmission 14. Further, a brake switch 44 for detecting the presence or absence of a brake operation is provided near a brake pedal (not shown).
Is provided, and P, R, N, D4, D are provided near a range selector (not shown) mounted on the floor of the driver's seat of the vehicle.
A range selector switch 46 for detecting the range position selected by the driver out of seven ranges of 3, 2, and 1 is provided. The output of the throttle opening sensor 40, etc.
(Electronic control unit) 50.

The ECU 50 includes a CPU 50a and a ROM 50.
b, RAM 50c, input circuit 50d and output circuit 50e
The sensor (switch) output is input to the microcomputer via the input circuit 50d. In the microcomputer, the CPU 50a selects a gear shift map according to the traveling path to determine a shift position (gear stage), and energizes the solenoid valves 54 and 56 of the hydraulic control circuit through the output circuit 50e, as described later in detail. By de-exciting, a shift valve (not shown) is switched, and the hydraulic clutch at a predetermined gear stage is released / engaged. The solenoid valves 58 and 60 are for on / off control of the lockup mechanism 16c of the torque converter 16.

Next, the operation of the control device will be described with reference to the flow chart of FIG. 2. Before that, the features of the control device will be briefly described with reference to FIG. The expected acceleration (only for the third speed) expected for the vehicle when traveling on a flat road is preset according to the throttle opening and the vehicle speed. On the other hand, the actual acceleration actually generated by the vehicle is obtained from the vehicle speed, multiplied by a coefficient, and corrected to a value corresponding to the third speed. The values are then compared and the difference PNO,
The PKU is calculated and averaged, and then the corresponding gear shift map is selected (switched). Expected acceleration is E
In the CU 50, the map stored in the ROM 50b is retrieved from the throttle opening and the vehicle speed.
The characteristics of the map are shown in FIG. Here, the expected acceleration is calculated from the throttle opening and the vehicle speed by the vehicle speed, the gear stage,
This is because the driving force, that is, the acceleration obtained by the engine load is different in a traveling state where the road surface gradient is the same, and the traveling resistance, particularly the air resistance, is a value proportional to the vehicle speed. Five types of gear shift maps are prepared for heavy climbing, light climbing, flat road, light descent, and heavy descent. Figure 5
6 shows characteristics of a map for a flat road, and FIG. 6 shows characteristics of a map for a light uphill road (third speed region is enlarged as compared with that for a flat road). Although omitted for simplification, as shown in FIG. 7, each map has hysteresis in the up-shift direction and the down-shift direction.

Returning to the flow chart of FIG.
A parameter required for the calculation is obtained with 0. For the throttle opening etc. as a parameter, the sensor output value is obtained as it is,
Further, the vehicle speed is calculated by counting the output pulse of the sensor 42 for a predetermined time, and the change state of the throttle opening is also detected in this step. Therefore, it will be described below with reference to the flow chart of FIG. .. The program shown in the flow chart of FIG. 2 is started by a timer interrupt every 20 ms.

In the flow chart of FIG. 8, first, S1
At 00, the throttle opening THPT detected a predetermined time before is read, and at S102, the difference (absolute value) from the throttle opening THUS detected this time is calculated to obtain a predetermined throttle opening YDTTH (for example, 0.5 / 8 × WOT [degrees]). ])). When it is determined in S102 that the difference exceeds the predetermined value, that is, when the amount of change in the throttle opening is large, the process proceeds to S104, the predetermined value YTMETN is set to the throttle sudden change timer (down counter) TMETN, and time measurement is started. To do. When it is determined in S102 that the difference is less than the predetermined value, the program is immediately terminated.

Returning to the flow chart of FIG.
Proceed to step 12 to obtain the above-mentioned predicted acceleration (referred to as "GGH").

FIG. 9 is a subroutine flow chart showing the work. The description will be made with reference to FIG.
200, throttle opening (throttle opening used for map search is called "GMAPTH") and current vehicle speed V
From this, the map search value GGBASE of the expected acceleration is obtained by referring to the map whose characteristics are shown in FIG. As described above, this value is the traveling acceleration that is expected to be output when the vehicle travels on the flat road using the third gear at the throttle opening and the vehicle speed, and Is represented by [m / s ² ]. The values shown in FIG. 4 are exemplarily described for the convenience of understanding.

Next, in S202, the down counter GG
After confirming that the value of CNT1 (described later) is zero, S20
At 4, the counter is set to a predetermined value YGGCNT and started. As will be described subsequently, this counter determines changes in the anti-acceleration processing interval, where the changes between the previous value of the predicted acceleration and the value retrieved this time are gradually increased (decreased) when the change is large. That is, first, in S206, the value obtained by adding and subtracting the minute value YDG1L, H to the value GGBASE searched this time is compared with the previous value GGH, and whether the change between the previous value and the current value is within the predetermined range. Determine whether or not. When it is determined in S206 that it is within the predetermined range, the change amount is small, so
In step S208, the map search value (current value) GGBASE is set as the current predicted acceleration GGH.

When it is determined in S206 that the change exceeds the predetermined range, the process proceeds to S210, in which the previous predicted acceleration GGH is compared with the current map search value GGBASE, and it is determined that the change is increasing. If so, the process proceeds to S212, and the value obtained by adding the predetermined unit amount YDG2 to the previous value GGH is set as the current expected acceleration GGH, and the program is temporarily terminated. Then, the counter value is decremented in S214 until it is determined in S202 that the counter value has reached zero at the next program startup, and when it is determined that it has reached zero, S20 is executed.
While starting a new counter at 4, S206, S2
After 10 steps, the process reaches S212, where the predetermined unit amount YDG2
Is added to correct the increase. That is, as shown by the alternate long and short dash line in FIG. 10, when there is a large change from the previous value, a predetermined amount (YDG2) is determined every predetermined time (GGCNT1) until it is determined in S206 that the current map search value has been reached. Gradually increase.
This makes it possible to avoid sudden changes in expected acceleration,
Control hunting due to momentary depression of the accelerator pedal can be prevented.

This situation is the same when it is determined that the predicted acceleration retrieved in S210 has decreased with respect to the previous value. In that case, the routine proceeds to S216, where the throttle opening is the opening CTH near full closure, Specifically, (0.5 / 8) x WOT
[Degree], it is determined whether or not it is below, and the reduction unit amounts YDG3US, YDG3 are made different in S218 and 220 according to the comparison result, and the map search value is gradually reduced and corrected.
The unit amount is changed here because the torque variation follows the throttle opening change faster when the throttle opening is near the fully closed position or less than in other cases. Therefore, the unit quantity should be YDG3 <YDG3US. 11
Shows the stepwise correction in the decreasing direction.

Returning to the flow chart of FIG. 2 again, the program proceeds to S14 to calculate the actual acceleration HDELV. Figure 1
2 is a subroutine flow chart showing the work. As described above, since the predicted acceleration is the value when traveling in the third gear, it is necessary to correspond to the actual acceleration as well. Therefore, in the flowchart of FIG. Is determined to be the second speed or lower, the third speed, or the fourth speed, and S30 is determined according to the determination result.
4, the procedure proceeds to S306 and S308 to determine the correction coefficient.
The correction coefficient is similar to the expected acceleration map shown in FIG.
There are three types of maps that pre-map the ratio values according to the throttle opening and vehicle speed. There are three types for 1st, 2nd, 3rd, and 4th. The value of the ratio is searched and obtained from the degree GMAPTH and the vehicle speed V (the correction coefficient obtained by the map search is referred to as "GGFBASE"). The reason why the first speed and the second speed are not distinguished here is that the purpose of this control is originally to improve the shift characteristics on the uphill and downhill roads. Specifically, when it is determined that the road is an uphill road or a downhill road, it is for a flat road. The map is switched to an uphill or downhill map, but the one for uphill is downshifted to increase driving force, and the one for downhill is downshifted to obtain engine braking effect. Since the first speed is the lowest speed and there is no possibility of downshifting, the same data as the second speed is used for convenience of this control. Further, the map of the ratio for the third speed is "1.0" on the data because the predicted acceleration compared with the actual acceleration corrected using this ratio is the one at the third speed.

Next, in S310, after confirming that the value of the second down counter GGCNT2 is zero, S310 is executed.
In step 312, the counter is set to a predetermined value YGGCNT and started, and the correction coefficient retrieved in S314 is compared with the previous value to determine whether or not it exceeds a predetermined range. The same processing as the one with the expected acceleration is performed. That is, first, S31
In 4, the current value ± YDF1L, H is compared with the previous value, and if it is within that range, the process proceeds to S316 and the map search correction coefficient GGFBASE
Is used as the correction coefficient GGF as it is, and the actual acceleration HDELV is calculated by multiplying the first-level difference ΔV of the detected vehicle speed value, that is, the vehicle speed change at every predetermined time, in S318. If it is determined in S314 that the value exceeds the range, the process proceeds to S320 and the previous value GG
If F is compared with the current value GGFBASE and it is determined that it is in the increasing direction, the process proceeds to S322 and the unit value is increased to the previous value GGF.
The value obtained by adding YDF2 is used as the correction coefficient for this time, and when it is determined that there is a decreasing direction, the process proceeds to S324 and the decreasing unit amount YDF3
The value obtained by subtracting is the correction coefficient for this time. Then, each time the program is started next time or later, this increment (decrease) correction is repeated every time it is determined that the counter value decremented in S326 has reached zero in S310, and is repeated until it is determined in S314 that the value has approached the previous value. The reason for this configuration is to prevent a sudden change in the control value in the same manner as described in the explanation of the expected acceleration in the flow chart of FIG. Although the actual acceleration is calculated from the vehicle speed difference value here, the differential value may be obtained, and in any case, these are expressed in units [m / s ² ] equivalent to the predicted acceleration.

Next, returning to the flow chart of FIG.
Proceeding to step 6, the difference between the predicted acceleration GGH and the actual acceleration HDELV, PNO, PKU, is calculated. FIG. 13 is a subroutine flow chart showing the calculation work. Where P
KU means the difference in the downhill direction obtained by subtracting the expected acceleration GGH from the actual acceleration HDELV, and PNO means the difference in the uphill direction obtained by subtracting the actual acceleration HDELV from the expected acceleration GGH.

In the flow chart of FIG. 13, first S4
00, the difference PKU in the downhill direction is calculated from the above-described calculation formula. The subtraction order of the difference is changed because the actual acceleration is higher than the expected acceleration (on a flat road) on the downhill, and the opposite is true on the uphill. The difference between uphill and downhill is calculated here regardless of whether the vehicle is actually uphill or downhill.It is simply the difference between the actual acceleration and the expected acceleration in the downhill direction. Then, the opposite is only taken as the difference in the climbing direction. That is, as will be described later, since the map is selected from the average value of these values, if the vehicle is actually going downhill, only the difference PKU in the downhill direction should be a positive value. Since the value in the uphill direction should be zero or less, by selecting the map using only positive values, the speed ratio can be optimized immediately by responding to changes in slope without installing a tilt sensor, etc. You can decide.

Next, the routine proceeds to S402, where it is judged whether or not the throttle opening is below the fully closed opening CTH, and when it is judged to be below fully closed, the routine proceeds to S404 where the value of the timer (down counter) TMPAVB is set. Determine if it has reached zero. As will be described later with reference to FIG. 2, this timer is set when the brake operation is performed and is started when the brake is released. Therefore, the determination in this step is made based on whether or not the brake operation is being performed, or more accurately, whether or not a predetermined time has elapsed since the brake was released after the brake was once depressed. That is, even if the brake is once depressed, the braking force does not immediately become zero due to the response delay of the braking system even if the brake is released, so that it is determined that the brake is being operated for the predetermined time (timer value). When it is determined in S404 that the brake timer value is not zero (during brake operation), the process proceeds to S406, in which a predetermined amount YDADO5 is added and the difference PKU is calculated.
To increase. This is to compensate for the decrease in the actual acceleration due to the braking force. Next, in S408, the actual acceleration HDELV is subtracted from the predicted acceleration GGH to calculate the difference PNO in the uphill direction.

Returning to the flow chart of FIG.
If the brake switch is turned on in step 18, it is determined whether the brake switch is turned on. If it is determined that the brake switch is turned on, the process proceeds to step S20, in which the brake timer TMPAVB is set to a predetermined value YTMPAVB and started (as described above, Once the brake on is detected, the timer value continues to be reset each time this step is looped, the brake pedal is released and the brake on judgment is denied, and the down count continues without being reset. Therefore, this timer value will eventually indicate the time elapsed since the brake was turned off). Next, in S22, it is determined whether or not the "D4, D3, 2" range is selected from the range selector switch signal. When the result is affirmative, the process proceeds to S24, in which range switching is being performed among the three ranges. Judge whether
When the result is negative, the routine proceeds to S26, and the timer TMPAHN2 is started (when the result in S24 is affirmative, S26 is jumped, so this timer value indicates the elapsed time for range switching as in S20). Next, in S28, it is confirmed from the bit of the BROK2 flag whether or not the brake signal is normal. Whether or not the brake signal is normal is checked by another routine (not shown). For example, after the ignition switch is turned on, when the brake on signal and the brake off signal continue for a predetermined time respectively, the brake signal is normal. If not, it is determined that the brake signal is abnormal, and the result is shown in this flag.

If it is determined in S28 that the brake signal is normal, it is determined in S30 whether the range is being changed again. If it is determined that the range is not being changed, the process proceeds to S32, in which it is determined whether the timer TMPAHN has reached zero. To determine. This starts at the time when the excitation patterns of the solenoid valves 54 and 56 described above are switched in another subroutine (not shown), and indicates whether or not gear shifting is in progress. Therefore, when this timer value reaches zero, it means that gear shifting is not in progress, so the routine proceeds to S34, where it is judged whether or not the current gear is the first speed, and when it is denied, the routine proceeds to S36. Average PNOAV of the differences PNO, PKU in the direction of uphill and downhill obtained in advance
E, PKUAVE, more specifically, a weighted average value is calculated. FIG. 14 is a subroutine flow chart showing the work.

Explaining with reference to the figure, the uphill direction difference PNO calculated this time in S500 is compared with the cumulative average value (weighting coefficient) PNOAVE up to that time, and the value is increasing or decreasing with respect to the previous value. Determine if there is. If it is determined that the value is in the decreasing direction, the process proceeds to S502 and the coping coefficient KP
After setting NO to YKPNODN, the process proceeds to S504, and the weighted average value is calculated from the illustrated formula. If it is judged that the throttle opening is in the increasing direction, the routine proceeds to S506, where it is judged whether or not the value of the throttle sudden change timer TMETN shown in FIG. 8 is zero, that is, whether or not the throttle opening is suddenly changed, and the sudden change is made. If it is determined that the value has not been set, the process proceeds to S508, and the coefficient is set to YKPN.
After setting OUP, and after confirming that the brake operation is not performed in S510, the process proceeds to S504, and the weighted average value is calculated. If it is determined in S506 that there is a sudden change in the throttle opening, the process jumps to S504. Therefore, in this case, the map is determined (held) by the previously calculated average value PNOAVEn-1. This can prevent the control value (map selection) from being erroneous when the throttle opening suddenly changes. The same is true when it is determined in S510 that the brake is ON, and the engine output torque apparently decreases by the amount of the braking force that is generated in proportion to the force with which the driver steps on the brake pedal, and the map search throttle opening is changed. Since the corresponding engine output has not occurred, S504 is jumped to and the previously calculated average value is used. Next, in S512, the calculated value is compared with the upper limit value YPNOCUT, and if it exceeds that, S5
Rewrite to the upper limit value at 14. That is, as shown in FIG.
When the vehicle finishes climbing and returns to a flat road, the map needs to be promptly corrected for the flat road, so an upper limit value is set here.

Then, the average value of the downhill direction difference values is calculated. That is, in S516, the current calculated value PKU is compared with the average value PKUAVE up to the previous time, and when it is determined that there is an increasing direction, it means that the downhill is still downhill, so the vehicle speed V is changed in S518. After comparing with the predetermined vehicle speed YVOAD1, and then confirming that the throttle opening has not suddenly changed in S520 and S522, S524 and S5 are determined according to the comparison result.
Proceed to step 26 and select the idle coefficient (weighting coefficient) KPKU, and
Proceeding to 528, the weighted average value PKUAVE of this time is calculated. The reason for changing the coefficient according to the vehicle speed here is that the value of the running resistance does not increase so much during the downhill,
This is to create an opportunity to shift down early from the vehicle speed. Therefore, the coefficient value is set to YKPKUUPH> YKPKUUPL, and the coefficient value is increased as the vehicle speed becomes higher, and thus the current value is greatly reflected in the average value. When it is determined in S520 and S522 that the throttle is suddenly changing for the same reason as described above for PNO, S528 is jumped and the average value up to the previous time is used.

When it is determined in S516 that the current value is in the decreasing direction with respect to the cumulative average value up to the previous time, it is determined that the downhill is being completed, so in S530, the throttle is below the fully closed opening degree. After confirming that there is, go to S532,
After confirming that the brakes are not being operated, the process proceeds to S534, and similarly, any one of the coping coefficients is selected according to the vehicle speed to obtain the average value (S536, S538, S52).
8). Again, the coefficient is set higher on the high vehicle speed side for the same reason as the increasing direction. Next, in S540 and subsequent steps, it is determined whether the calculated value exceeds the upper limit value.
2 limit to the upper limit. This is to correct the detection delay when returning to a flat road as in the case of climbing as shown in FIG. When it is determined in S532 that the brake is being operated, it is difficult to obtain an accurate value as described in S510. Therefore, the process immediately goes to S540 and S542, and the average value up to the previous time is used.

Returning to FIG. 2, when the conditions from S18 to S34 are satisfied, the process proceeds to S36 to calculate the difference average value as just described. Here, the condition is satisfied in FIG. The case of not performing will be described. First, S22
No, that is, when it is determined that the vehicle is in the P, R, N, 1 range, it is not necessary to perform the uphill / downhill control, so the process proceeds to S38, and the timer started in S26 for determining the range switching elapsed time is When it is no longer needed and is reset, the process proceeds to S42 to set the difference average value to "0". As a result, a map for a flat road is selected as described later. This is the same when it is determined in S28 that the brake signal is abnormal. If it is determined that the range is being switched in S30 and the timer value has reached zero in S40, it takes a long time to switch the range, which is not considered to be a normal state. Since it is understood that it has occurred, the process similarly jumps to S42. In order to maintain the continuity of this control until it is determined in S40 that the timer value has reached zero, the process proceeds to S44, in which the difference is the same as described above in S506 of the flow chart of FIG. The previous value is used as the average value. This also applies to the case where it is determined in S32 that the gear is being changed. If the gear is being changed, the gear position cannot be determined and the acceleration is not stable. Therefore, the process proceeds to S44 and the previous average value is used. Further, even when it is determined in S34 that the vehicle is currently in the first speed, no further downshift is possible, so the same applies in the sense of simplifying the calculation.

In the flow chart of FIG.
Proceed to 46 to perform the work of discriminating between uphill and downhill MAPS1,2. Explaining "MAPS1,2 discriminating work", 0, 1, 2, and 5 types of shift maps prepared according to the gradient are explained.
This is a work in which five numbers 3 and 4 are given, and the maximum value and the minimum value that can be taken from the difference average value just obtained are respectively set as the values of MAPS1,2. This will be described with reference to the flow chart of the subroutine shown in FIG.
In 600 to S606, the average value PNOAVE in the uphill direction is compared with the map reference value PNOmn, and then S608 to S6.
At 14, the average value PKUAVE in the downhill direction is compared with the map reference value PKUmn. As a result, S6
One of 16 to S632 is selected and the minimum value (“MAPS1”) and the maximum value (“MAPS2”) that can be taken are determined. FIG. 17 shows the map reference value set corresponding to the difference average value.

That is, in this control, as described above,
Five types of maps are prepared and specified by numbering them as follows. 0: Map for heavy climbing 1: Map for light climbing 2: Map for flat roads 3: Map for light descending slopes 4: Map for heavy descending slopes As shown in FIG. 17, there is a hysteresis area between each map. Therefore, any of the adjacent maps can be taken when the difference average value is located there. Therefore, in this work, the maximum value and the minimum value (for the map number) that can be taken are decided for the time being. The selection results of the flow chart of FIG. 16 are summarized as shown in FIG. It should be noted that, starting from FIG. 17, S in the flow chart of FIG.
It will be appreciated that the flat road map is selected by zeroing the difference mean at 42.

Therefore, returning to the flow chart of FIG. 2, one of the two types of maps determined in the next S48 is finally determined.

Explaining this with reference to the subroutine flow chart of FIG. 19, first, the map currently selected in S700 (referred to as "MAPS") and MAPS2 (maximum map).
To compare. That is, it is logically possible to determine a map to be selected so that maximum map ≧ selection map ≧ minimum map. Therefore, it is first judged whether or not the current map exceeds the maximum map. Change the selection map so that it is less than the maximum map value.

Therefore, when it is determined in S700 that the current map exceeds the maximum map, assuming that the current map number is the minimum value 0, the map numbers "1, 2, 3,
Since it is either 4 "(map number 0 is impossible because it exceeds" 0 "), it is determined in S702 whether or not the current map is number 2 (flat road map). When it is done, the map number will be called "3, 4", which means that it is a downhill road map.
In S704, the map is determined by subtracting "1" from the current map number. For example, when the heavy downhill road map is currently used, it is switched to the light downhill map. When it is determined in S702 that the current map is equal to or lower than the flat road map, the map is either "2, 1", and the road is switched from the flat road to the light grade or from the light grade to the heavy grade. Incidentally, as shown in FIGS. 5 and 6, the maps used in this control are as follows:
Also, for heavy uphill roads, it is set to be larger than for light uphill roads. This also applies to the downhill side, and the third speed region expands from a flat road to a light downhill to a heavy downhill.
This is set to increase the driving force when climbing uphill and to utilize the engine brake when descending downhill. As a result, when the vehicle is currently in 4th speed, the map is switched to 3rd speed immediately. There is a risk of being downshifted, which is an undesired downshift that the driver does not expect. In order to avoid this, in S706, it is determined whether or not the current gear is the third gear, and only when it is determined that the third gear or less, the map is changed from the flat road to the light uphill or from the light uphill to the heavy uphill. I switched to. Therefore, when the vehicle is in the 4th speed, the map switching is stopped.

When it is determined in S700 that the current map is less than or equal to the maximum map, the condition on the upper limit side is satisfied, and therefore the lower limit side is subsequently determined. That is, in S708, the current map (number) is MAPS1 (minimum map (number)).
If it is determined that the above is the case, and if it is determined that the map is the minimum map or more, the above logical expression is satisfied, so the map is not switched.

If it is determined in S708 that the current map (number) is less than the minimum map, the value needs to be corrected to a value greater than the minimum map. Then, subsequently, in S710, the current map and the flat road map are compared. If the current map is judged to be smaller than for flat roads, the map to take is
Since it is said to be either 1, 2 ", it proceeds to S712 and adds 1 to the current map to correct the increase. Therefore, if the map for light climbing is currently used, the map for flat road is If the uphill map is used, the map is switched to the light uphill map.When it is determined in S710 that the current map is equal to or higher than the flat road map, the current map number is "2" or "3" ( Since it is determined in S708 that it is smaller than the minimum map, even if the minimum map is assumed to be the maximum value of 4, "4" cannot occur. "And" 2 "or" 3 "
Since there is a problem of expansion of the third speed range in the case of addition from, the process proceeds to S714, it is determined whether or not the present speed is lower than the third speed, and if the speed is lower than the current third speed, an unexpected downshift does not occur. In S712, the map is switched immediately, and when it is determined that the vehicle is in the fourth speed, the current map (number) and the flat road map (number) are compared in S716. If it is determined in S716 that the current map (number) is a flat road map, the process proceeds to S718, the vehicle speed is compared with a predetermined value YKUV1, and the current map (number) is not a flat road map, that is, If it is determined that the map is for a light descent, the process proceeds to S720 and the vehicle speed is set to another predetermined value YKUV.
If the vehicle speed is determined to be equal to or higher than the predetermined value in those steps as compared with 3, the map is switched by jumping to S712. This will be described with reference to FIG. 20. As described above, in the uphill / downhill map, the third speed region is expanded as compared with the flat road map. The boundary speed line from the third speed to the fourth speed for the slope is set as shown by the vehicle speed YKUV1 in FIG. Therefore, when the vehicle speed is above this boundary vehicle speed, there is no fear of downshifting.
Proceed to 12 to switch the map. On the other hand, when it is judged that the vehicle speed is lower than the boundary vehicle speed, there is a risk of downshifting,
The following steps determine whether a downshift will occur. FIG. 20 shows switching from the flat road map (No. 2) to the light downhill map (No. 3), but from the light downhill map (No. 3) to the heavy downhill map (No. 4).
The same applies when switching to.

If it is determined in S718 and S720 that the current vehicle speed is less than the boundary vehicle speed, the process proceeds to S722, in which it is determined whether the throttle opening is less than or equal to the fully closed position. When denied, it means that the accelerator pedal is being depressed, and moreover, it means that the accelerator pedal is being depressed at the 4th speed, so downshifting may cause a shock, and a special driving condition may result. In any case, the driver does not intend to decelerate the vehicle by downshifting and using the engine brake. Therefore, S712 is skipped and map switching is not performed.

When it is determined in S722 that the throttle opening is less than or equal to the fully closed position, the accelerator pedal is not depressed and the driver's intention to decelerate is inferred. Therefore, the process proceeds to S724 and the current map is for a flat road again. If it is a flat road map, the map is switched by jumping to S712, and if it is denied, the current map is called a light descending road map, so proceed to S726. It is determined whether or not the brake operation is performed, and it is determined whether or not the driver really has a deceleration intention. When the brake operation is not performed, it is considered that the driver does not have the intention of decelerating, so S712 jumps and the map is not switched. If it is determined that the brake is being operated, S7
28 to S730, the current vehicle speed V is set to the predetermined value YVOAD1,2
Compared to S732, S734, S736
The deceleration data (to be described later) is selected in step S73, the deceleration data selected in step S738 is compared with the actual deceleration DTV, and the amount of decrease in vehicle speed per unit time during braking operation, and the actual deceleration DTV is large. In this case, it is determined that there is a sudden deceleration, and the process proceeds to S712 to switch the map. This is because the deceleration at the time of downshift is higher as the vehicle speed is higher even when the brake operation is performed and the driver intends to decelerate, so to prevent sudden engine braking (due to downshift), Maps are not switched unless the deceleration due to the brake becomes higher as the vehicle speed increases. Therefore, only when it is determined from the comparison result that the sudden deceleration is intended, the map is switched to downshift. FIG. 21 shows the relationship of the deceleration data.

Next, in S740, it is determined whether or not the determined map (number) is "4" (for heavy descending slope). If the result is affirmative, the process proceeds to S742, where the throttle opening TH is a predetermined value.
THREF, concretely it is judged whether it is (2/8) × WOT [degrees] or more, and when affirmative, it proceeds to S744 and forcibly rewrites the map (number) to 3 (for light descent) I chose
This is because the driver wants to accelerate and does not want to brake the engine even when it is determined to be a heavy downhill slope, and thus the driver's intention is met.

Returning to the flow chart of FIG. 2 again, the shift position (gear stage) is determined from the vehicle speed and the throttle opening based on the map that has been finally determined (switched or held) in S50. .. It should be noted that this work is publicly known and the gist of the present invention is not there, so further description will be omitted.

In this embodiment, as described above, the expected acceleration indicating the running resistance of the vehicle is obtained from the throttle opening, the road surface gradient is estimated by comparing with the actual acceleration, and the map is switched to the uphill / downhill map. When the throttle opening suddenly changes in the calculation of the difference average value used for the calculation, the calculation is stopped and the previous value is used, so that the map selection is not mistaken. Since the predicted acceleration is set only for the third speed, the configuration is simplified and the map switching is determined by obtaining the weighted average value of the difference between the predicted acceleration and the actual acceleration. Stable control can be performed even when the state changes suddenly.

FIG. 22 is a flow chart of the main part of the second embodiment of the present invention, which is the same as the flow chart of FIG. 14 shown in the first embodiment.
It is similar to a flow chart. In the second embodiment, when it is determined in S506 that the throttle opening is suddenly changing from the value of the timer TMETN, the process proceeds to S5060, and the coping coefficient KPNO is set to YKPNOLST. Then S50
In step 4, the calculated average value is calculated from the formula shown. Here, the coefficient YKPNOLST has a minimum value such as "0.01". As a result, since the current value is hardly reflected in the average value in the calculation of S504, it is possible to obtain the same effect as holding the previous value itself without performing the calculation in the first embodiment. The same applies when it is determined in S510 that the brake is being operated. Although not shown,
Similarly, when it is determined in S520 and 522 in the flow chart of FIG. 14 that the throttle opening suddenly changes in the downhill direction, the minimum value is used.

Although five types of maps are used in the above embodiment, the number of maps may be reduced by using the same type for light climbs and light descents. Furthermore, only one map may be used, and the characteristic thereof may be modified according to the average difference value between the predicted acceleration and the actual acceleration.

Although the acceleration is used as the parameter indicating the running resistance, it is not limited to this, and any parameter may be used as long as it shows an index corresponding to the running resistance, particularly the gradient resistance. Although the actual acceleration is calculated from the vehicle speed, it may be directly detected by using an acceleration sensor.

Although the throttle opening is used as the parameter indicating the engine load, the accelerator pedal depression amount may be used.

[0048]

According to the first aspect of the present invention, the value indicating the running resistance of the vehicle is obtained from the operating parameters including the engine load, and it is compared with the reference value to judge whether or not the vehicle is running on an uphill / downhill road. In a control device for an automatic transmission for a vehicle, which performs uphill / downhill control to obtain a gear ratio suitable for traveling on the uphill / downhill road when it is determined that the vehicle is traveling on the uphill / downhill road, the uphill / downhill road is controlled when the engine load suddenly changes. Since the control is stopped, there is no risk of erroneous control even when the engine load changes suddenly.

In the control device for the automatic transmission for a vehicle according to the second aspect of the invention, when the engine load suddenly changes, the determination as to whether or not the vehicle is traveling on an uphill / downhill road is stopped. Even when the load changes abruptly, it is possible to realize stable control without making a mistake in the determination, for example, by continuing the control before the sudden change.

According to a third aspect of the present invention, a vehicle speed sensor for outputting a vehicle speed signal corresponding to the vehicle speed, an engine load sensor for outputting an engine load signal corresponding to the engine load, and a vehicle speed signal and an engine load signal are provided. Means for storing the expected acceleration to be obtained in advance, means for obtaining the actual acceleration of the vehicle, comparison means for comparing the actual acceleration with the expected acceleration, and predetermined according to the vehicle speed signal and the engine load signal. In a control device for an automatic transmission for a vehicle, which includes means for switching a gear ratio according to the selected gear shift characteristic and means for changing the gear shift characteristic in accordance with a comparison result of the comparison means, the gear shift characteristic is provided when an engine load signal suddenly changes. Since the change of the engine load is canceled, when the engine load changes suddenly, for example, by continuing the control before the sudden change, as described in claim 2, despite the change of the engine load. It is possible to realize a stable control on.

In the control device for the automatic transmission for a vehicle according to the present invention, since the comparison result is held when the engine load signal suddenly changes, the comparison result can be maintained even when the engine load suddenly changes. By keeping the above, it is possible to realize stable control at all times regardless of changes in the engine load, without suddenly changing the transmission characteristics.

In the vehicle automatic transmission control device according to the present invention, the comparison means obtains the difference between the actual acceleration and the expected acceleration, and adds the difference to the previous value to obtain the weighted average value. Therefore, when the engine load signal suddenly changes, the weighting coefficient of the average value is changed.
The same effect as described in claim 4 can be obtained.

According to another aspect of the present invention, there is provided a vehicle speed control device for outputting a vehicle speed signal corresponding to a vehicle speed, and an engine load sensor outputting an engine load signal corresponding to an engine load. Means for pre-storing an expected acceleration that should be obtained for a predetermined gear ratio corresponding to the vehicle speed signal and the engine load signal, means for obtaining the actual acceleration of the vehicle for the predetermined gear ratio, and the difference between the actual acceleration and the expected acceleration Seeking
Means for calculating the average value by adding to the previous value, means for switching the gear ratio according to any one of a plurality of types of gear shift characteristics that are predetermined in accordance with the vehicle speed signal and the engine load signal, and the average value It is configured so as to include means for comparing with a value and changing the shift characteristic in accordance with the comparison result, so that the configuration is simplified and the shift characteristic is changed by comparing the average value with a predetermined value. Even when the state changes suddenly, the characteristics are not frequently changed, and stable control can be realized.

[Brief description of drawings]

FIG. 1 is an explanatory diagram generally showing a control device for an automatic transmission for a vehicle according to the present invention.

FIG. 2 is a main flow chart showing the operation of an ECU (electronic control unit) in FIG.

FIG. 3 is an explanatory block diagram functionally showing the characteristics of the present control device.

FIG. 4 is an explanatory diagram showing characteristics of expected acceleration used in the flow chart of FIG.

FIG. 5 is an explanatory diagram showing characteristics of a flat road map used in the flow chart of FIG. 2;

FIG. 6 is an explanatory diagram showing characteristics of a light climbing map used in the flow chart of FIG. 2;

FIG. 7 is an explanatory diagram showing hysteresis characteristics such as a flat road map used in the flow chart of FIG. 2;

FIG. 8 is a subroutine flow chart showing a throttle opening change amount detection operation in the flow chart of FIG.

FIG. 9 is a subroutine flow chart showing expected acceleration calculation work in the flow chart of FIG.

FIG. 10 is an explanatory diagram showing a sleep process when the change in expected acceleration in the flow chart of FIG. 9 is large in the increasing direction.

FIG. 11 is an explanatory diagram showing a sleep process when the change in the predicted acceleration in the flow chart of FIG. 9 is large in the decreasing direction.

12 is a subroutine flow chart showing the actual acceleration calculation work in the flow chart of FIG.

FIG. 13 is a subroutine flow chart showing the difference calculation work between the predicted acceleration and the actual acceleration in the flow chart of FIG.
It is a chart.

14 is a subroutine flow chart showing the difference average value calculation operation in the flow chart of FIG.

FIG. 15 is an explanatory diagram showing characteristics of an upper limit value used in the flow chart of FIG.

FIG. 16 is a subroutine flow chart showing the map discrimination work in the flow chart of FIG. 2;

FIG. 17 is an explanatory diagram showing a discriminating operation of the flow chart of FIG. 16;

FIG. 18 is an explanatory diagram showing a determination result of the flow chart of FIG. 16;

FIG. 19 is a subroutine flow chart showing the map determination work of the flow chart of FIG. 2;

FIG. 20 is an explanatory diagram showing the characteristic of the boundary vehicle speed from the flat road map to the light uphill road map used in the flow chart of FIG. 19;

FIG. 21 is an explanatory diagram showing a relationship of deceleration data used in the flow chart of FIG.

FIG. 22 is a flow chart of FIG. 14 showing the second embodiment of the present invention.
It is a main part subroutine flow chart which shows the difference average value calculation work similar to a chart.

[Explanation of symbols]

 10 Internal Combustion Engine 14 Transmission 40 Throttle Opening Sensor 42 Vehicle Speed Sensor 44 Brake Switch 46 Range Selector Switch 50 ECU (Electronic Control Unit)

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Satoru Sunada 1-4-1, Chuo, Wako-shi, Saitama Inside the Honda R & D Co., Ltd. (72) Inventor Hideo Furukawa 1-4-1, Chuo, Wako-shi, Saitama Stock Company Honda Technical Research Institute

Claims (6)

[Claims] 1. A value indicating running resistance of a vehicle is obtained from operating parameters including engine load, and it is compared with a reference value to determine whether or not the vehicle is traveling on an uphill / downhill road. When making a determination, in a control device for an automatic transmission for a vehicle that performs uphill / downhill control as much as possible to obtain a gear ratio suitable for running on the uphill / downhill road, when the engine load suddenly changes, the uphill / downhill control is stopped. A control device for a characteristic automatic transmission for a vehicle. 2. A value indicating the running resistance of the vehicle is obtained from operating parameters including engine load, and it is compared with a reference value to judge whether or not the vehicle is traveling on an uphill / downhill road. When making a determination, in a control device for an automatic transmission for a vehicle that performs ascent and descent control as much as possible to achieve a shift stage suitable for traveling on the ascent and descent roads, when the engine load suddenly changes, it is determined whether or not the vehicle is traveling on an ascent and descent road. A control device for an automatic transmission for a vehicle, which is characterized by being discontinued. 3. A vehicle speed sensor that outputs a vehicle speed signal corresponding to a vehicle speed, an engine load sensor that outputs an engine load signal corresponding to an engine load, and an expected acceleration that should be obtained in response to the vehicle speed signal and the engine load signal. In advance, a means for obtaining the actual acceleration of the vehicle, a comparing means for comparing the actual acceleration with the predicted acceleration, and a gear ratio based on a speed change characteristic predetermined according to the vehicle speed signal and the engine load signal. In a control device for an automatic transmission for a vehicle, which includes means for switching the gear shift ratio and means for changing the gear shift characteristic according to the comparison result of the comparison means, the change of the gear shift characteristic is stopped when the engine load signal suddenly changes. A control device for an automatic transmission for a vehicle characterized by the above. 4. A vehicle speed sensor that outputs a vehicle speed signal corresponding to a vehicle speed, an engine load sensor that outputs an engine load signal corresponding to an engine load, and an expected acceleration that should be obtained in response to the vehicle speed signal and the engine load signal. In advance, a means for obtaining the actual acceleration of the vehicle, a comparing means for comparing the actual acceleration with the predicted acceleration, and a gear ratio based on a speed change characteristic predetermined according to the vehicle speed signal and the engine load signal. In a control device for an automatic transmission for a vehicle, the control device including a switching means for changing the engine speed and a changing means for changing the shift characteristic in accordance with a comparison result of the comparing means, wherein the comparison result is held when the engine load signal suddenly changes. A control device for an automatic transmission for a vehicle. 5. A vehicle speed sensor that outputs a vehicle speed signal corresponding to a vehicle speed, an engine load sensor that outputs an engine load signal corresponding to an engine load, and an expected acceleration that should be obtained corresponding to the vehicle speed signal and the engine load signal. In advance, a means for obtaining the actual acceleration of the vehicle, a comparing means for comparing the actual acceleration with the predicted acceleration, and a gear ratio based on a speed change characteristic predetermined according to the vehicle speed signal and the engine load signal. In the control device for the automatic transmission for a vehicle, which comprises a switching means for changing the speed change characteristic and a changing means for changing the shift characteristic according to the comparison result of the comparing means, the comparing means obtains the difference between the actual acceleration and the expected acceleration, The weighted average value is added to the previous value and compared with a predetermined value, and the weighting coefficient of the average value is changed when the engine load signal suddenly changes. Control device. 6. A vehicle speed sensor for outputting a vehicle speed signal corresponding to a vehicle speed, an engine load sensor for outputting an engine load signal corresponding to an engine load, and a predetermined gear ratio corresponding to the vehicle speed signal and the engine load signal. Means for storing the expected acceleration to be obtained in advance, means for obtaining the actual acceleration of the vehicle for the predetermined gear ratio, comparing the actual acceleration and the expected acceleration to obtain a difference, and adding the result to the previous value Means for calculating the average value, means for switching the gear ratio according to any one of a plurality of predetermined speed change characteristics in accordance with the vehicle speed signal and the engine load signal, and comparing the average value with a predetermined value, the comparison result And a means for changing the shift characteristic according to the above.