JPH0384255A - Speed change control device for automatic transmission - Google Patents

Abstract

PURPOSE:To prevent the occurrence of busy shift by a method wherein during down shift from second speed to a first speed, the degree of satisfaction of a fact that a current engine output demand amount is higher than that stored during up shift is determined from a membership function obtained through fuzzy inference. CONSTITUTION:A speed change control device 14 stores an engine output de mand amount, i.e., a throttle opening, available during up shift from the arbi trary first speed to the second speed of an automatic transmission 12. There after, even when a throttle opening is increased, while the degree of satisfaction of a membership function obtained through fuzzy inference regarding the increase thereof is low, namely, while the degree of the increase of a stored throttle opening is low, a computing result of a control rule reduces a possibility to effect down shift is reduced, and is difficult to permit down shift. This consti tution prevents the occurrence of down shift against the will of a driver, and prevents the occurrence of busy shift.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a shift control device for an automatic transmission, and in particular, prevents the occurrence of a busy shift in which the gear is changed against the driver's will. It is related to the technology to

BACKGROUND TECHNOLOGY Automatic transmissions for automobiles generally include a hydrodynamic transmission device, a transmission mechanism such as a planetary gear device, and a transmission control device, and each has a transmission ratio (rotational speed ratio of the input side to the output side). It has a plurality of different gears, and the gears are automatically switched in relation to the driving condition of the vehicle, including the engine output requirement. For example, in the shift control device described in Japanese Patent Application Laid-Open No. 58-30558, the gears are switched based on gear shift data using the engine output request amount and the vehicle speed as parameters. In addition, in Japanese Patent Application No. 121230/1987, which was previously filed by the applicant of the present application, the degree to which the actual driving condition satisfies a predetermined control rule is calculated for each gear stage by fuzzy reasoning.
Based on the calculation result, for example, the gear position is changed to the one with the highest degree of satisfaction, and even in this case, rules regarding the required amount of engine output are included.

Note that the engine output request amount corresponds to the engine load, and corresponds to the throttle opening, accelerator operation amount, fuel injection amount, etc. in the case of a diesel engine.

FIG. 7 is an example of gear change data for an automatic transmission having four forward gears. The change line is set in a step-like manner based on the throttle opening θ and the vehicle speed V, and the solid line in the figure is a switching line for an upshift where the gear ratio becomes smaller, and a broken line is a switching line for a downshift where the gear ratio becomes larger. Also, in the figure “1→2J, r
1.2 and 3.0/D such as "2→3" are respectively the 1st gear, 2nd gear, and 3rd gear of an automatic transmission, O/D (
(overdrive) gear, and the gear ratio gradually decreases from the first gear to the O/D gear.

Problems to be Solved by the Invention However, in such conventional gear shift control devices, even a slight increase in engine output demand may cause a downshift against the driver's will or shift between two gears. A busy shift, which involves repeating upshifts and downshifts, may occur.

Specifically, with reference to the gear change data shown in FIG.
/From point B1 to C1 after upshifting to D gear
Even if the throttle opening θ increases to point A, the gear position is not changed, but after an upshift is performed at point A2, B!
When the throttle opening θ increases from point C2 to point C2, even though the amount of increase in throttle opening θ is smaller than the amount of increase from point B to point C5, the shift from the O/D gear to the third gear changes. The downshift ends up increasing the torque more than necessary, against the will of the driver who was trying to increase the torque slightly. Furthermore, since there is an upshift and downshift switching line between the above 82 points and the C2 point, if the throttle opening θ slightly increases or decreases beyond the switching line, a busy shift will occur. .

The present invention has been made against the background of the above-mentioned circumstances, and its purpose is to prevent the occurrence of a gear shift or a busy shift against the driver's will.

Means for Solving the Problem In order to achieve this objective, even if the engine output demand increases after an upshift, it is sufficient to avoid downshifting unless the amount of increase is large. The present invention relates to a shift control device that automatically switches the gear stages in an automatic transmission having a plurality of gear stages in relation to the driving state of a vehicle including at least an engine output requirement, the invention comprising: a storage means for storing an engine output requirement upon upshifting from one gear to another second gear, and (middle) upon downshifting from the second gear to the first gear; The degree of satisfaction that the engine output request amount at that time is greater than the engine output request amount stored in the storage means is determined from a membership function based on predetermined fuzzy reasoning, and if the satisfaction degree is small, the downshift is performed. (C) a calculation means for calculating a predetermined control rule for fuzzy inference so as to reduce the possibility of performing the downshift; and (C) a determination means for determining whether or not to perform the downshift based on the calculation result of the calculation means. It is characterized by having the following.

Here, the control rule regarding the possibility of downshifting is such that, for example, the degree of satisfaction in the case of downshifting, upshifting, maintaining the status quo, etc. is determined by fuzzy reasoning depending on the driving state of the vehicle, etc. In the control device, control rules are defined for downshifting, and in this case, the determining means is determined to select, for example, the control rule with the highest degree of satisfaction.

In addition, for example, when changing gears based on gear switching data, if the switching line of the gear switching data is corrected by vague inference depending on the driving condition of the car, etc., this correction Since it is possible to reduce the possibility of downshifting, it can also be set as a control rule for correction using ambiguous reasoning. In that case, the determination means will determine whether or not to perform a downshift based on the corrected gear change data. Note that instead of correcting the gear change data, it is also possible to correct the driving parameters to be compared with the gear change data, such as the required engine output amount and the vehicle speed.

In addition, if there is a correction map that corrects the above-mentioned gear change data according to the vehicle type, vehicle weight, engine specifications, driver's preference, etc., the correction map is further corrected according to the driving condition of the car, etc. It can also be defined as a control rule for

In addition, only when it is determined that a downshift is to be performed based on the gear change data, a predetermined fuzzy inference control rule that includes a membership function related to an increase in engine output demand is used to downshift. The possibility (satisfaction level) of performing a shift may be determined, and it may be determined whether a downshift is possible based on the magnitude of the possibility.

Operation and Effects of the Invention In such a shift control device, the required engine output amount when a hairshift is made from an arbitrary first gear to a second gear is stored in the storage means, and then the required engine output is stored in the storage means. Even if the increase occurs, while the degree of satisfaction of the membership function regarding the increase is small, in other words, while the degree of increase relative to the engine output demand stored in the storage means is small, the calculation result of the control rule by the calculation means is down. Since this reduces the possibility of a shift, it becomes difficult for the determination means to permit a downshift, thereby preventing a downshift against the driver's will and, accordingly, preventing the occurrence of a busy shift. Ru.

Furthermore, in the present invention, the degree of increase in engine output demand is determined as the degree of satisfaction of the membership function by fuzzy inference, and the control rule is calculated in relation to the degree of satisfaction. Even if the number of driving parameters included in the system is large, there is an advantage that the amount of the program can be relatively small. In other words, when using fuzzy reasoning, the program amount only increases approximately in proportion to the number of driving parameters to be considered, whereas When storing the amount of increase, etc. in a data map, if the cases are divided according to the driving condition of the car, the amount of the map will increase approximately in proportion to the power of the number of driving parameters, and as the number of driving parameters increases. The amount becomes huge.

EXAMPLE Hereinafter, an example of the present invention will be described in detail based on the drawings.

Figure 1 shows the components of a vehicle automatic transmission to which the present invention is applied, including a torque converter 10 and a planetary gear type transmission mechanism 12.
and a speed change control device 14. An output shaft 16 of an engine (not shown) is connected to a pump impeller of the torque converter 10, while an input shaft 18 of a transmission mechanism 12 is connected to a turbine impeller on the driven side. Further, the input shaft 18 is selectively directly connected to the output shaft 16 via an L/U (lock-up) clutch CL.

The transmission mechanism 12 includes three single pinion type planetary gear devices 20, 22, and 24 coaxially arranged, the input shaft 18, and the output shaft 26, and the output shaft 26 is a differential gear (not shown). It is connected to the drive wheels of the vehicle via a device. Some of the components of the planetary gear train 20°22.24 are integrally connected to each other, and some are the three clutches C+, Cz.

Some are selectively connected to each other by C2, some are selectively connected to the housing 28 by four brakes B+, Bz, B2B4, and some are three one-way brakes. Latch F,,F2. F3
Depending on the direction of rotation, they can be engaged with each other or with the housing 28.

Above clutch C+, Cz, C:+, brake BI
.

B, ,B, ,B, are composed of, for example, a multi-disc clutch or a band brake with one or two bands with opposite winding directions, and each is actuated by a hydraulic actuator. By controlling the operation of each of these hydraulic actuators by the speed change control device 14, the speed change ratio (rotation speed of the input shaft 18/rotation of the output shaft 26) is determined as shown in FIG. There are four forward speeds and one reverse speed, each with different speeds. In such FIG. 2, "rlst".

'2ndJ, '3rdJ, and 'O/D J represent the forward-side first gear, second gear, third gear, and 0/D (overdrive) gear, respectively.
The above-mentioned gear ratio becomes smaller sequentially from the first gear to the O/D gear. Further, "rRev" represents a reverse gear stage.

Note that the torque converter 10 and the transmission mechanism 12 are constructed symmetrically with respect to the axis, so the lower side of the axis is omitted from illustration in FIG.

The speed change control device 14 is a hydraulic control device 3 equipped with a switching valve and the like.
0 and a microcomputer 32 that controls the operation of the hydraulic control device 30. The hydraulic control device 30 includes three solenoids Nα1, Nα2 . It is controlled by Nα3. Solenoid No. 1
and No. 92 relate to the transmission mechanism 12, and by selectively energizing these two solenoids No. 1 and No. 2, the four forward speeds are appropriately switched. Also, solenoid No. 3 is L/U
This relates to the clutch CL, whereby the input shaft 18 of the transmission mechanism 12 is selectively directly connected to the output shaft 16 of the engine.

The microcomputer 32 includes a vehicle speed sensor 34.
Throttle opening senna 36. Shift range sensor 38.
A vehicle speed signal Sv, a throttle distance signal Sθ, a shift range signal SS, and a brake signal SB are supplied from the brake sensor 40, respectively. These signals S
V, Sθ, SS, and SB are the vehicle speed V (km
/h).

It represents the throttle opening θ (%), shift range, and presence or absence of brake operation, and the above sensors 34, 36, 38, 4
0 are each constituted by a well-known appropriate detection means such as a rotation detector. The throttle opening degree θ represents the required engine output amount. Note that the shift range means the operating position of the shift lever, and in this example, the shift range is the operating position of the shift lever.
rD'', r2'', rL'', as shown in the figure.
"R".

A total of six ranges (rp, , rN) can be selected.

The microcomputer 32 also stores gear shift data for switching gears, L/U clutch switching data for switching engagement (ON) and release (OFF) of the L/U clutch CL, and the like. Timing data that determines the timing times Lr and Lzt for switching, an ambiguity rule that sets the degree of satisfaction to be selected for each gear based on the above-mentioned gear switching data, and a shift based on vague reasoning according to the driving state of the vehicle. Control rules and the like for selecting stages are stored. These data and programs are stored in advance in the ROM etc. of the microcomputer 32, and the microcomputer 32
Signal processing is performed according to a program preset in the ROM while utilizing the temporary storage function of the RAM, and the solenoid No. 1. By energizing No. 2° No. 3, respectively, the clutches C3, C2, Cx of the transmission mechanism 12
, and brakes B+, Bz, B:l, and B4 to control the switching of four forward gears, and control the switching of the L/U clutch CL. Said second
The figure shows the gears in each shift range and the operating states of the solenoids, clutches, brakes, and one-way clutches when establishing the gears. r*'' respectively represent an energized state, a non-energized state, and an energized state only when engaging the L/U clutch CL. Moreover, "○" in the column of clutches and brakes represents an engaged state, and no mark represents a non-engaged state. Further, "Δ" in the one-way clutch column indicates that the clutch is in an engaged state when the engine is driven, and no mark indicates a non-engaged state.

Next, an example of the operation of the speed change control device 14 will be explained with reference to the flowcharts shown in FIGS. 3 to 6. In addition,
Here, a case will be described in which the shift lever is operated to select the "D" or "2" range, which has a plurality of gears.

First, in step SSI, signals SV and Sθ are generated.

33. After the SB is read, in step SS2, the gear stage and L/U clutch switching data are respectively set according to the shift range represented by the signal SS. The gear change data is stored for shift ranges "D" and "2" each having a plurality of gears, using the vehicle speed ■ and the throttle opening θ as parameters.

Figure 7 shows an example of gear change data in the r[)J range, which is set in a step-like manner in the orthogonal coordinates of vehicle speed ■ and throttle opening θ, with the solid line being an upshift changeover line and the broken line being a downshift changeover line. This is the switching line.

In addition, the L/U clutch switching data is the vehicle speed V of the vehicle.
and throttle opening θ are stored as parameters for shift ranges “DJ” and “2” having a second gear, a third gear, or an O/D gear.

Figure 8 shows an example of L/U clutch switching data in the DJ range, which is set in a substantially step-like manner in the orthogonal coordinates of vehicle speed V and throttle opening θ, and the solid line indicates L/U clutch C4 at each gear. When engaging (OFF-
+ON) switching line, and the broken line is when the L/U clutch CL is released at each gear (ON→0FF)
This is the switching line.

Then, in the next step SS3, a gear selection routine, a gear is determined in accordance with the gear change data and a predetermined fuzzy inference control rule.

This gear selection routine is executed according to the flowchart shown in FIG. 4, and first, in step S1, the current gear (current gear) N is determined from the gear change data.

A reference gear position N1 is determined based on the throttle opening degree θ and the vehicle speed V. That is, a plurality of determination vehicle speeds Vt, Vt, V'l are set from the gear changeover data based on the current gear N and throttle opening θ, and these determination vehicle speeds are compared with the actual vehicle speed V. A reference gear N1 representing the gear to be selected is determined. Judgment vehicle speed V shown in FIG.

V, , V are when the current gear N is the third gear and the throttle opening θ is about 40%, and if V≦V, the first gear “1” is the reference gear N′″ and Vl <
If V2V5, the second gear "2" is determined as the reference gear N1, and if VZ<V≦V, the third gear "2" is determined as the reference gear N1.
3" is determined as the reference gear N1, and if Vl<V, the O/D gear "4" is determined as the reference gear N1. Note that the current gear position N is read based on the output signals to the solenoids N (Ll and Nα2).

In the subsequent step S2, the degree of satisfaction γ to be selected for each gear (J-1, 2, 3, 4) based on the predetermined ambiguity rule Q based on the reference gear N''. j) is set.Disambiguation rule Q
The satisfaction level γ, (j) is determined based on whether or not the gear position is close to the reference gear position N''.For example, for the reference gear position N1, the satisfaction level To(j)=1. Regarding the gear stage N8±1 adjacent to N1, the satisfaction level γo(
j) = 0.4, satisfaction level γ for gear N''±2
0(j)=0.1. Satisfaction level T for gear N1±3
It is set such that 0(j)=0. FIG. 9 shows the satisfaction level γ of each gear when the reference gear N1 is the third gear. It is a figure showing (j). Note that j=1. 2.
3. 4 correspond to the first gear, the second gear, the third gear, and the 0/D gear, respectively.

Next, after 'j=1' is set in step S3,
In step S4, the number of gears to change ΔN is calculated by subtracting the current gear N from j, and in step S5, the degree of satisfaction with which each gear should be selected according to the actual driving condition etc. is calculated using a control rule based on vague reasoning. γ(j) is calculated.

This control rule is determined according to the number of gear changes ΔN with respect to the current gear N, and three control rules R1 to R3 are set using the ambiguity rule Q and sub-rules related to various driving parameters, etc. . control rule R
1 defines the conditions to be met when maintaining the current gear position, that is, ΔN=0, and the control rule R2 is ΔN≧
+1, that is, the conditions that must be met when upshifting from the current gear, and the control rule R3 is ΔN
≦-1, that is, the condition that must be met when downshifting from the current gear position is defined. Among these, the control rule R3 regarding downshift is defined as follows using the above-mentioned ambiguity rule Q and sub-rules I and J.

R3=Q and (I or J) Sub-rule I>"The previous gear shift was a downshift" This rule is for determining whether the previous gear change was a downshift or not. The first example is the membership function fr(i) representing the degree
Shown in Figure 0. In this case, "i" represents whether the previous gear change was an upshift or a downshift, and the satisfaction level fI(i) for a downshift is 1 and the satisfaction level f+(i) for an upshift. is 0.

Sub-rule J〉 “The current throttle opening θ is greater than the specified amount compared to the throttle opening θU during the previous upshift.
” This rule is based on the increase amount Δθ (=θ−θ
It is used to determine whether U) is greater than or equal to a predetermined amount, and the membership function fa represents the degree of satisfaction of satisfying this rule.
An example of (Δθ) is shown in FIG. The values C, , C, in FIG.
It is set by an arithmetic expression that uses U and other driving conditions as parameters. The above membership function ft(Δθ) is
This is to determine the degree of satisfaction that the required engine output amount when performing a downshift (throttle opening θ in this embodiment) is larger than the required engine output amount when performing an upshift. Note that the throttle opening degree θU is stored in the RAM in step Q7 of FIG.

Furthermore, as is clear from the control rule R3, the sub-rule J is based on the satisfaction level f+(i) of the sub-rule I.
is O, in other words, when the previous gear shift was an upshift and the current gear N remains the upshifted gear, downshifting is regulated based on the size of the increase Δθ. It is for. That is, the control rule R3 corresponds to a control rule that is predetermined to reduce the possibility of downshifting when the satisfaction level of the membership function fi (Δθ) is small.

On the other hand, in ambiguous ## and reasoning, rand J is defined as algebraic product or minimum operation, etc., and ror is defined as logical sum or maximum operation, etc., but here, if they are defined as algebraic product and maximum operation, respectively, The satisfaction level T(j) of the control rule R3 is obtained according to the following equation (1).

γ(j) = ro (j) X max (f+ (i
), fa (Δθ))...(1) Here, if j=1 and the current gear N is "3",
Since the number of change gears ΔN is -2, in step S5, the degree of satisfaction γ (1) at which the first gear should be selected is determined by the above equation (1) in accordance with the control rule R3. Thereafter, it is determined in step s6 whether j is smaller than 4, and if it is smaller than 4, 1 is added to j in step S7, and then steps 34 and subsequent steps are repeated. As a result, the satisfaction levels r (1), γ (2), γ (3), which should be selected for each gear from j = 1 to j = 4, that is, from the 1st gear to the 0/D gear, are determined.
r(4) is calculated respectively. Specifically, when j=2, ΔN=-1, and in step S5, the satisfaction level T(2) at which the second gear should be selected is determined by the above equation (1) according to the control rule R3. is, j=3
In the case of j=4, ΔN-0 is obtained, and in step S5, the degree of satisfaction γ(3) at which the third gear should be selected is determined according to the control rule R1, and in the case of j=4, ΔN=+
1, and in step S5 the control rule R2
Satisfaction level γ(4) at which the O/D gear stage should be selected according to
is required.

FIG. 12 is a diagram showing an example of the degree of satisfaction γ (j) calculated in step S5. In this embodiment, among a series of signal processing logics by the microcomputer 32, control rule R3 is The part that calculates the satisfaction level r(j) according to the equation corresponds to the calculation means.

Note that when the shift range is "2", there is no switching to 0/D gear, so step S6 is performed when J is 3.
It will be determined whether or not it is smaller.

In this way, steps 34 to S7 are repeated, and j-
4 (in case of shift range "D"), step S6
The determination is No, and step S8 is then executed. In step S8, γ(k), which has the highest satisfaction level among the satisfaction levels r (j) of each gear stage calculated in step S5, is selected, for example, the satisfaction level r (j ) is obtained, γ(2) is selected, and in the next step S9, "k" of the above r(k), that is, the second gear on the upper side, is selected as the gear stage to be selected.
The gear position is determined. Of the series of signal processing logic by the microcomputer 32, the part that executes steps S8 and S9 corresponds to a determining means for determining whether or not to perform a downshift, and in this embodiment, it is not possible to determine whether or not to perform a downshift. This means that it has been done.

When the gear position is determined in this way, step SS4 in FIG. 3 is executed, and it is determined whether or not to change the gear position.
In other words, it is determined whether or not the determined gear position k is the same as the current gear position N. If the gear position k is different from the current gear position N, then the gear change routine of step SS5 is executed. Otherwise, if the current gear position is to be maintained, step SS5 is not executed and the gear change routine is executed. The L/U clutch switching routine of SS6 is executed.

In the gear changeover routine, as shown in FIG. 5, step Q1 is first executed to determine whether flag F1 is 1. If not, flag F1 is set to 1 in step Q2. At the same time, the timer TMI is reset and starts counting a new time. This flag F1
is set to 0 when the gear change is performed in step Q9 of the figure, so it is initially 0 when the new gear change is determined in step SS4, and timer TMI When the gear change is determined and step Q1 is executed, the time after that is measured.

Next, in step Q3, 54179 times t+, Lx, and Ls are set according to the timing data. The tie control data is used to temporarily release the L/U clutch CL at the time of gear change in order to smoothly change the gear. For example, as shown in FIG. 13, It is determined by the operating state of the L/U clutch Ct, the gear position to be changed, and whether the change is an upshift or a downshift. Further, as shown in FIG. 14, the timing time t1 is the time interval from the time T when it is determined that the gear is to be changed to the time T when the gear is actually changed. , 54
179 time t2 is the above time T.

54179 is the time interval from Tc to the time Tc at which the L/U clutch CL should be released, and the time t3 is the time Tb at which the L/U clutch CL should be released.
This is the time interval from T4 to time T4 at which it is safe to engage the L/U clutch CL. Note that the timing time tz is set to be thicker than the timing time 11 in the case of an upshift, and is set to be smaller than the timing time t (in this example, O) in the case of a downshift. There is.

Further, although FIG. 13 only shows the case of switching to an adjacent gear, the same settings are made even if the gear is changed by skipping one or two gears, although not shown.

After the timing times t+, tz, t, and x are set in this way, step Q4 is executed and the timer T
It is determined whether or not the MI counting time T1 is greater than the timing time t1, in other words, whether the time at which the gear stage should be changed has been reached. If it is greater than the time t, the next Step Q5 is executed in step QIO, but if not, timer TM2 is reset in step QIO, and the gear changeover routine ends.

In step Q5, it is determined whether or not the gear change is an upshift, and if it is an upshift, the gear is changed in step Q6, and
In step Q7, the throttle opening θU at this time is stored in the RAM based on the throttle opening signal Sθ. Furthermore, if the determination in step Q5 is No, that is, in the case of a downshift, the gear stage is changed in step Q8. When the gear position is changed in this manner, the flag F1 is set to O in step Q9, and then step QIO is executed and the gear position change routine ends. Note that the timer TM2 is reset each time this gear changeover routine is repeated, so it counts the time after the gear is changed. In this embodiment, of the series of signal processing logic by the microcomputer 32, the part that executes step Q7 corresponds to a storage means for storing the required engine output amount at the time of upshifting.

On the other hand, in the L/U clutch switching routine at step SS6, as shown in FIG.
In step 1, it is determined whether the counting time T1 of the timer TMI is greater than the timing time 11, in other words, whether the time at which the L/U clutch CL should be released after the gear change judgment has been made is determined. If it is determined that the time is greater than time 11, flag F3 is set to 1 in step L2,
If not, flag F3 is set to O in step L3. Subsequently, step L4 is executed, and the L
Based on the /U clutch switching data, it is determined whether the vehicle speed ■ and the throttle opening θ are within the range in which the L/U clutch CL should be engaged, and if they are within the range, the flag F4 is set in step L6. is set to 0, and if not, the flag F4 is set to 1 in step L5.

Further, in step L7, it is determined whether the brake is in an operating state (ON) based on the signal SB, and if the brake is in an operating state, a flag F5 is set in step L8.
is set to 1, and if not, the flag F5 is set to O in step L9. In step LIO, the signal S
Based on θ, it is determined whether the throttle opening degree θ is fully closed (θZO), and if it is fully closed, the timer TM3 is reset in step Lll, and then the timer TM3 is reset in step L12.
is executed, otherwise step L1 is executed immediately.
2 is executed. In step L12, timer T
Whether or not the counting time T of M3 is smaller than a predetermined time t4, in other words, whether only a short time has elapsed after the throttle opening θ is fully closed or released from the fully closed state. If the time is smaller than the time t4, the flag F6 is set to 1 in step L13; otherwise, the flag F6 is set to 0 in step L14. These steps L7 to L14 are performed because it is not preferable to engage the L/U clutch CL when the brake is in operation or when the throttle opening θ is fully closed. is a step provided to release the L/U clutch CL regardless of the L/U clutch switching data.

Subsequently, step L15 is executed, and it is determined whether the counting time T2 of the timer TM2 is greater than the timing time t, in other words, there is no problem even if the L/U clutch CL is engaged after the gear is changed. It is determined whether the time has reached or not, and if it is greater than the time t3, step L
At step 16, flag F3 is set to 0. Thereafter, in step L17, it is determined whether or not flags F3 to F6 are all 0. If all flags are O, L/U clutch CL is engaged in step L18, and if not, that is, flags F3 to If at least one F6 is 1, the L/υ clutch Ct is released in step L19.

With the above steps, the L/U clutch switching routine is completed, and steps 5SI-3S6 are repeatedly executed, so that the gear position and the L/U clutch CL are appropriately switched according to the driving state of the automobile.

Here, in the shift control device 14 of this embodiment, the throttle opening θU at the time of upshifting is stored, and the satisfaction level γ (j) when downshifting is performed by vague reasoning in the gear selection routine. As one sub-rule of the control rule R3 for determining the above-mentioned throttle opening θU, a sub-rule J is incorporated to determine whether the increase Δθ from the throttle opening θU is greater than or equal to a predetermined amount.
is small, that is, the membership number ra(Δθ
>, the satisfaction level r of control rule R3 is low.
(j) is also set low, which prevents downshifting against the driver's will due to slight changes in throttle opening θ, and thereby suppresses the occurrence of busy shifts. .

That is, for example, in the gear change data shown in FIG. 7, after an upshift is performed at point A2, the throttle opening θ increases from point B2 to point C2 beyond the downshift switching line (broken line). Also, if the increase amount Δθ of the throttle opening θ is small, the membership function f
The satisfaction level of □(Δθ) becomes low, and the satisfaction level r (j) of control rule R3 also becomes low, and the downshift is not performed.
This means that the downshift will not increase the torque more than necessary against the will of the driver who was trying to increase the torque slightly. Also, the above B! Dot and C! There is an upshift and downshift switching line between these points, but since no downshift is performed as described above, busy shifting is not performed even if the throttle opening θ increases or decreases beyond the switching line. There is no risk that this will occur, so it is 2.

In addition, since the above control rule R3 calculates the degree of satisfaction when downshifting is performed by fuzzy reasoning,
The parameter at that time is the amount of increase in throttle opening Δθ
Even if you add , the program amount does not increase that much, and the program amount (map amount) is smaller than, for example, when the increase amount Δθ is mapped as a judgment value for whether or not to permit downshifting. In other words, if the increase amount Δθ is set as a judgment value depending on the driving condition, the map amount increases approximately in proportion to the power of the number of driving parameters depending on the case of the driving condition. When using fuzzy inference like this, the amount of the program increases approximately in proportion to the number of parameters.

Furthermore, in this embodiment, the satisfaction level γ should be selected for each gear based on the gear changeover data. (j) is set, the final satisfaction level r (j) is determined according to the control rules R1 to R3, and the gear position with the highest satisfaction level r (j) is selected. For example, when correcting gear change data based on the calculation result using fuzzy reasoning, in order to obtain a specific correction amount from the calculation result, one point (de-ambiguation) is performed using a complicated calculation such as the center of gravity method. This is not necessary, however, it is also possible to determine the center of gravity or center of area of the satisfaction level T(j) using the center of gravity method, 9-area method, etc. when determining the gear position, and select the gear position closest to the center of gravity or area center.

Although one embodiment of the present invention has been described above in detail based on the drawings, the present invention can also be implemented in other embodiments.

For example, in the embodiment described above, the satisfaction level ro (j) is set based on the gear change data, and the satisfaction level r, (j)
Although the degree of satisfaction T(j) is determined by fuzzy inference including the degree of satisfaction γ.

It is also possible to provide a control rule that corrects the switching line of the gear shift data by vague inference according to the driving condition, etc., without setting (J). In that case, a rule regarding the increase amount Δθ will be incorporated into the control rule to be corrected.

Further, it is also possible to determine the gear position according to the driving state of the vehicle only by vague inference without using the gear changeover data.

In addition, although the switching line of the gear shift data in the above embodiment is set in a step-like manner in the orthogonal coordinates of the throttle opening θ and the vehicle speed V, the switching line may be a straight line, two curved lines, a curved line, etc. Instead, it is also possible to use gear change data based on other driving parameters. Note that it is also possible to correct this gear shift data using a correction map or the like according to engine specifications, driver preference, etc.

Furthermore, in the embodiment described above, the degree of satisfaction is calculated based on the driving state of the vehicle based on fuzzy reasoning not only when downshifting but also when maintaining the current gear or upshifting. When downshifting the gear by at least one gear, the amount of increase Δθ
It suffices if the possibility is determined by a control rule that includes a membership function for. If only the possibility of downshifting is determined, the possibility of downshifting is determined based on the magnitude of the possibility, and if the gear change data is corrected based on the possibility, the corrected shift data is determined based on the possibility. Whether downshifting is possible is determined based on the stage switching data.

Furthermore, the number of memberships f, (Δ
The values C+ and Ct of θ) are set experimentally or by calculation formulas, but it is possible to set the values C+ and Ct by setting different values for each current gear.
, Ct can be set as appropriate.

In addition, in the above embodiment, three control rules R1 to R3 are defined, but the number and content of the control rules, that is, sub-rules, can be set as appropriate, such as dividing upshifts and downshifts according to the number of change stages. can.

Furthermore, although the membership function fJ for fuzzy inference in the above embodiment is set with a slope, even if there is no slope and the satisfaction level is determined in two stages, ``1'' or ``O''. good.

Furthermore, in the above embodiment, "and" in ambiguous reasoning is
``, ror'' are defined as an algebraic product and a maximum operation, respectively, but these definitions and inference methods may be changed as appropriate.

Further, the automatic transmission of the embodiment described above has four forward speeds and one reverse speed, and the L/U clutch CL
However, the number of gears can be set as appropriate depending on the configuration of the transmission mechanism 12, and the L/U clutch CL
is not necessarily necessary to carry out the present invention.

Although other examples are not provided, the present invention can be implemented with various modifications and improvements based on the knowledge of those skilled in the art.

[Brief explanation of drawings]

FIG. 1 is a diagram illustrating the configuration of an automatic transmission equipped with a speed change control device according to an embodiment of the present invention. FIG. 2 is a diagram showing a gear position in the automatic transmission of FIG. 1, an energized state of a solenoid, and a locked state of an engagement element when establishing the gear position. FIG. 3 is a flowchart illustrating the operation of the automatic transmission of FIG. 1. FIG. 4 is a flowchart illustrating the gear selection routine of FIG. 3. FIG. 5 is a flowchart illustrating the gear changeover routine of FIG. 3. FIG. 6 is a flowchart illustrating the L/U clutch switching routine of FIG. 3. FIG. 7 is a diagram showing an example of gear change data in the automatic transmission shown in FIG. 1. FIG. 8 is a diagram showing an example of L/U clutch switching data in the automatic transmission shown in FIG. 1. FIG. 9 is a diagram showing an example of the satisfaction level of each gear stage set according to the ambiguity rule in step S2 of FIG. 4. FIGS. 10 and 11 are diagrams each showing an example of the membership function of the control rule used in step S5 of FIG. 4. FIG. 12 is an example of the inference result in step S5 of FIG. 4. FIG. 13 is an example of a data map regarding the timing time set in step Q3 of FIG. 1st
FIG. 4 is a time chart explaining the timing time shown in FIG. 13. 14: Shift control device 32: Microcomputer θ: Throttle opening (required amount of engine output) θU Throttle opening during near shift Δθ: Throttle opening increase amount f, (Δθ): Membership function regarding Δθ Step S5: Calculation Means step 3B, S9: Determination means step Q7: Storage means

Claims (1)

[Scope of Claims] A shift control device that automatically switches the gear position in relation to the driving state of the vehicle including at least the engine output requirement in an automatic transmission having a plurality of gear positions, the gear change control device comprising: an automatic transmission having a plurality of gear positions; storage means for storing an engine output requirement upon upshifting from one gear to another second gear; The degree of satisfaction that the required engine output amount is greater than the required amount of engine output stored in the storage means is determined from a membership function based on predetermined fuzzy reasoning, and if the degree of satisfaction is small, the downshift is performed. The method further includes a calculation means for calculating a control rule for fuzzy inference predetermined to reduce the possibility, and a determination means for determining whether or not to perform the downshift based on the calculation result of the calculation means. Characteristics of the automatic transmission shift control device.