JPH0581792B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a control device for an automatic transmission, and more specifically to a control device for an automatic transmission, and more specifically, by applying fuzzy control theory, The present invention relates to an automatic transmission control device that enables control similar to the judgment and operation of an expert driver.

(Prior Art) Traditionally, manual transmissions have been used for vehicle transmissions, in which the driver considers the surrounding circumstances and decides when to shift depending on the driving condition, and then operates the clutch pedal and shift lever. I was shifting gears. However, since such manual transmission is cumbersome, automatic transmissions have been developed and are now installed in the majority of passenger cars sold. In the case of a control device for such an automatic transmission, a shift valve is provided in the hydraulic circuit, and a throttle pressure proportional to the throttle opening is applied to one end of the valve, and a governor pressure proportional to the vehicle speed is applied to the other end. The system automatically switches gears by supplying/cutting off hydraulic pressure to the gear clutch depending on the pressure ratio between the two. In addition, with the subsequent introduction of electronic control, a control device was configured with a microcomputer, which searched the shift map stored in its memory based on the throttle opening and vehicle speed, detected the shift point, and energized/deactivated the solenoid valve. The gear is switched by energizing and driving the shift valve.

Therefore, in conventional automatic control devices, the timing of the shift, which would have been determined and operated by the driver himself in the case of manual transmissions, is determined uniquely from the throttle opening and vehicle speed, resulting in an unnatural shift. It was undeniable that a significant shift would occur. For example, when climbing a hill, if the driver returns the throttle opening to the cruise opening as when driving on flat ground, depending on the speed of the vehicle, the driver may shift up, resulting in insufficient driving force and having to step on the accelerator pedal again. This caused an inconvenience in that the driver had to downshift and shift up repeatedly, giving the driver a feeling of being busy. Such inconveniences also occur when towing a camping car or the like, when the weight of the vehicle increases due to loading, or when driving at high altitudes where engine charging efficiency deteriorates.

If we consider why the driver depresses the accelerator pedal to open the throttle valve, it is because he expects the vehicle to follow the driver's request for acceleration by opening the throttle valve. None other than that. In other words, the above-mentioned inconvenience occurs because the control device issues a shift command even though the margin driving force is reduced and the controllability of the vehicle is not sufficiently ensured. Therefore, in order to do so, it is necessary to accurately grasp the driving force and running resistance in the control device, and to confirm that the driving force exceeds the running resistance and that there is a margin of driving force before shifting up. This is due to the fact that it is not done that way.

From this point of view, a technique described in Japanese Patent Application Laid-Open No. 60-143133 has recently been proposed, in which the torque required by the driver is determined from the amount of accelerator pedal depression, and the separately calculated hill-climbing resistance is subtracted. The required acceleration is calculated using Furthermore, a shift diagram corresponding to the detected hill climbing resistance is selected from among a plurality of best fuel economy shift diagrams, and the throttle opening is adjusted to achieve the required acceleration based on the constant acceleration traveling locus data on the shift diagram. The system is configured to control the throttle opening and then search a shift diagram based on the changed throttle opening and vehicle speed to make a shift decision and maintain the acceleration before the change.

(Problem to be Solved by the Invention) However, in the above-mentioned conventional technology, although the gear shift decision is made taking into consideration the torque requested by the driver, the shift decision is made only based on the shift diagram set in advance. This technology is different from the previous technology in that it can only respond to certain set situations, and in any case, the timing of the shift is uniquely determined from the throttle opening and vehicle speed. It was difficult to escape the same criticism.

If this is a manual transmission vehicle, when the driver performs a gear shifting operation, he or she should recognize that the vehicle is climbing a slope and avoid inadvertent upshifting. In other words, in a vehicle with a manual transmission, the driver grasps the driving condition of the vehicle including the surrounding conditions, recognizes the driving force that the vehicle is outputting, and also foresees and masters the increase or decrease in the driving force when shifting. The timing of the shift should have been determined by selecting various empirical rules. That is,
The above-mentioned disadvantages are due to the fact that in conventional control, human judgment and actions are ignored and are not reflected in control. In other words, in conventional automatic shift control technology, the timing of shifting is basically determined mechanically from the throttle opening and vehicle speed, and the timing of shifting is not determined based on multiple variables of the vehicle driving condition. Therefore, the occurrence of the above-mentioned inconvenience was unavoidable.
Further, the above-mentioned circumstances are similar not only to stepped transmissions but also to continuously variable transmissions. That is, the continuously variable transmission is no different from the case of a stepped transmission in that the speed ratio is changed depending on the running state of the vehicle. Therefore, in this specification, the term "shifting" is used to mean both a change in the shift position in a stepped transmission and a change in the gear ratio (speed ratio) in a continuously variable transmission.

Therefore, an object of the present invention is to eliminate the above-mentioned drawbacks of the prior art, and to apply fuzzy control theory to automatic gear shift control, which was previously judged and operated by an expert driver in manual transmission vehicles. It is an object of the present invention to provide a control device for an automatic transmission that enables judgments and operations similar to human decision-making.

A further object of the present invention is to provide an automatic transmission control device configured to realize the control of the automatic transmission described above not only for a stepped transmission but also for a continuously variable transmission.

(Means for Solving the Problems) In order to achieve the above object, the automatic transmission control device according to the present invention is an automatic transmission in which the gear ratio is adjusted stepwise or continuously, as shown in FIG. A control device for detecting the operating state of the engine or vehicle, including at least the engine speed, throttle opening, amount of change in throttle opening, vehicle speed, amount of change in vehicle speed, road slope angle, and current gear ratio. Condition detection means 1 detects, for all the gear ratios that can be changed from the current gear ratio, changes in the margin driving force that would occur if the gears were shifted to that gear ratio, through the running resistance calculated based on the road surface inclination angle. The driving state change prediction means 2 predicts a fuzzy production rule by quantifying the driving state to be detected and the driving state change to be predicted by a membership function, and a setting means 3 that presets a plurality of values based on operations and judgments, and a gear ratio determining means that determines a gear ratio by performing fuzzy inference from the detected operating state, predicted operating state change, and fuzzy production rule. 4, and a drive means 5 for driving the transmission mechanism according to the output of the speed ratio determining means.

Note that in the above, the term "shift" is used to include both a change in the shift position in a stepped transmission and a change in the gear ratio (speed ratio) in a continuously variable transmission.

(Function) It is possible to incorporate the gear shifting operations that are judged and operated by an experienced driver in a vehicle with a manual transmission into the gear shifting control through fuzzy reasoning, making it possible to make gear shifting judgments similar to human decision-making, and to reduce the slope of the road surface. Since the change in the margin driving force is predicted based on the running resistance calculated through each corner, frequent changes in the gear ratio can be reliably prevented.

(Embodiments) Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

FIG. 2 is a schematic diagram showing the entire automatic transmission control device according to the present invention. Referring to the figure, reference numeral 10 indicates the main body of the internal combustion engine. An intake passage 12 is connected to the engine body 10, and an air cleaner 14 is attached to the tip side of the intake passage 12. Therefore, the intake air introduced from the air cleaner 14 is
The flow rate is regulated through a throttle valve 16 that operates in conjunction with an accelerator pedal (not shown) on the floor of the driver's seat of the vehicle and reaches the engine body. A fuel injection valve (not shown) is provided at an appropriate position near the combustion chamber (not shown) of the intake passage 12 to supply fuel,
Intake air is mixed with fuel, enters a combustion chamber, is compressed by a piston (not shown), and is then ignited via a spark plug (not shown) to explode and drive the piston. The piston driving force is converted into rotational motion and extracted from the engine output shaft 18.

Transmission 2 is located after the engine body 10.
0 is connected, and the engine output shaft 18 is connected there to a torque converter 22 and its pump impeller 22a. Torque converter 22
The turbine runner 22b is connected to a main shaft (mission input shaft) 24. A countershaft (mission output shaft) 26 is juxtaposed to the main shaft 24, and one shaft is placed between the two shafts.
Speed gear G1, 2nd speed gear G2, 3rd speed gear G3 and 4
A speed gear G4 and a reverse gear GR are provided, and multi-plate hydraulic clutches CC1, CC2, CL3, and CL4 are provided correspondingly to each gear (the reverse gear clutch is omitted for simplicity of illustration). . Further, a one-way clutch 28 is attached to the first gear G1. An oil passage 30 connecting a hydraulic power source (not shown) and a tank (not shown) is connected to these hydraulic clutches, and two shift valves 32 and 34, A and B, are inserted in the middle of the oil passage 30. The shift valve changes its position depending on the energized/de-energized state of the two electromagnetic solenoids 39 and 38, and controls the supply/discharge of pressure oil to the clutch group. The torque converter 22 is equipped with a lock-up mechanism 40, which directly connects the turbine runner 22b and the engine output shaft 18 in response to a command from a control unit, which will be described later. The countershaft 26 is connected to a rear axle 44 via a differential device 42, and rear wheels 46 are attached to both ends of the countershaft 26. Furthermore, such engine body 1
0, transmission 20, and differential device 42 are mounted on a chassis (not shown), and a frame (not shown) is also mounted on the chassis to form a vehicle.

A throttle sensor 50 consisting of a potentiometer or the like is provided near the throttle valve 16 in the intake passage 12 to detect its opening, and a distributor (not shown) near the engine body 10 is provided. A crank angle sensor 52 made of an electromagnetic pickup or the like is provided on the rotating portion of the piston, detects the crank angle position of the piston, and outputs a signal at every predetermined crank angle. Furthermore, a tilt angle sensor 4 for detecting the tilt angle of the vehicle, that is, the tilt angle of the road surface on which the vehicle is traveling, is provided at an appropriate position on the vehicle body frame (not shown).
A vehicle speed sensor 56 consisting of a reed switch or the like is provided at an appropriate position of 0 to detect the running speed of the vehicle. The outputs of these sensors 50, 52, 54, and 56 are sent to a speed change control unit 60. Furthermore,
The outputs of a range selector switch 62 for detecting the selected position of the range selector and a shift position switch 64 for detecting the shift position (gear stage) are also sent to the control unit.

FIG. 3 is a block diagram showing details of the speed change control unit 60. As shown in the figure, the outputs of the throttle sensor 50 and inclination angle sensor 54 are input to the control unit, and then are first input to the level conversion circuit 68.
is input into the micro-channel, amplified to an appropriate level,
The information is input to the computer 70. The microcomputer 70 includes an input port 70a, an A/D conversion circuit 70b, a CPU 70c, a ROM 70d, and
It includes a RAM 70e, an output port 70f, and a group of registers and counters (both not shown), and the output of the level conversion circuit 68 is
The signal is input to the D conversion circuit 70b, converted into a digital value, and temporarily stored in the RAM 70e. Similarly, the outputs of the crank angle sensor 52 and the like are waveform-shaped by a waveform shaping circuit 72 within the speed change control unit, and then input into the microcomputer via the input port 70a and temporarily stored in the RAM 70e. The CPU 70c determines a shift command value as described later based on these measured values and the calculated values calculated from them, and sends it from the output port 70f to the first output circuit 74 and/or the second output circuit 76, and outputs it to the electromagnetic solenoid 36. , 38 are energized/de-energized to switch or hold the shift position. Incidentally, the gear stage is switched such that, for example, when both solenoids are de-energized (off), the fourth gear is engaged, but such a gear shift operation itself via an electromagnetic solenoid is not known. However, since this is not a feature of the present application, detailed explanation will be omitted.

Next, the operation of the present control device will be explained with reference to the flow chart shown in FIG. 4 and subsequent figures.

Here, before going into specific explanation, the characteristics of the present control device will be briefly explained.The characteristics of the control device according to the present invention are as follows: By applying fuzzy control theory, the control device according to the present invention is able to make decisions at the time of shifting in a manner similar to human decision-making. The point is that it is configured in such a way that it determines. That is, the feature of the present invention lies not in the configuration of the control device itself, but in the operation of the control device, that is, the control method. Furthermore, since the fuzzy control theory itself is being applied in various fields recently,
A detailed explanation will be omitted, but to put it simply, it is a control regulation that vaguely grasps the state recognition of the controlled object and determines the control value based on that state recognition (referred to as "pull duction rule"). itself is expressed verbally in the form of "if...then...",
In the pull-down rules, the criteria for determining the situation or the contents of the operation are treated as fuzzy quantities (expressed as fuzzy labels or variables), which are quantified using membership functions. In other words, although it uses ambiguous information that humans perform, flexible and highly adaptable control operations are modeled using fuzzy theory, and control values are calculated using fuzzy inference. Since it is easy to express the knowledge possessed by humans, it is easy to adapt to so-called expert systems that incorporate the knowledge and judgment of experts into a computer system. This control device is based on such a theory.

Therefore, in the case of this control device, work such as creation of production rules necessary for introducing fuzzy control theory is done when designing the control system of automatic transmission, and control values are calculated based on the control algorithm during actual driving. Specifically, it is determined as follows.

(1) Creation of pull-action rules As will be described later, create an appropriate number of rules expressed in language such as ``If you are aiming for cruise at a reasonable rotation speed, do not shift''. When creating these rules, we analyze the judgments and operations of expert drivers in manual transmission vehicles, and then select the rules of thumb that are derived from the analysis.

(2) Determination of parameters and membership functions At the same time, determine the parameters from which the state of the controlled object will be recognized, select the parameters (variables) to be used for each of the above-mentioned pull-down rules, and further determine the parameters. The evaluation criteria are determined by determining the membership function of (the state expressed by such a membership function is called a fuzzy label). As this parameter, this control device uses an actual measured value, which is a physical quantity detected through a sensor, and a calculated value obtained by differentiating the measured value. Specifically, the engine speed, throttle opening, vehicle speed, throttle variation, acceleration, etc. are used as parameters, as shown in Fig. 10.
In the coordinates, the horizontal axis (hereinafter referred to as the "domain") is given a parameter and an appropriate waveform (the membership function), and the vertical axis is given a value from "0" to "1.0" (hereinafter referred to as the "membership value (grade)"). ) is attached. The control device according to the present invention is characterized in that when determining the membership function of a parameter, the function value of a specific rule is set high, and this point will be described later.

The above is the preparatory work during vehicle design. In addition, in the preparation stage, selection of a sensor for detecting the determined parameters, storage of control rules or instructions for calculation procedures in the memory of the microcomputer of the control unit, etc. are also performed.

(3) Control during actual running During running, the CPU 70c in the microcomputer detects (calculates) parameters.
Then, after referring to the control rules and performing fuzzy reasoning to select one of the control rules and determining the control result, for example, 1st gear up, based on the control rules, predetermined electromagnetic solenoids 36 and 38 are energized/de-energized. This will engage the first gear. In addition, in this fuzzy inference, the membership value is calculated for the parameters related to each control rule, the minimum value is taken as the evaluation value of that control rule, and the control rule with the highest evaluation value among all control rules is selected. do. Such mini-max operations themselves are often used in fuzzy inference. In addition, Fig. 4 and Fig. 5 to be described later, or Fig. 16 and Fig. 1
The configuration in FIG. 7 corresponds to claim 1.

Next, the operation of this control device will be explained with reference to FIG. 4 and subsequent figures. FIG. 4 is a main routine flow chart schematically showing the operation of the present control device. In addition, this program is, for example, 10ms to
It is activated at an appropriate cycle of 40ms.

First, in S10, the actual measured value detected by the above-mentioned sensor when the program is started this time is read and stored. This actual measured value is the engine speed Ne
(rpm) (calculated by integrating the output of the crank angle sensor 52 mentioned above for a predetermined time), vehicle speed V (Km/h),
Throttle opening θTH (degrees), slope angle of running road surface
tanθ, current shift position (gear stage) signal S
FTO (calculated from the ratio of transmission input shaft rotation speed to output shaft rotation speed, or engine speed, throttle opening, vehicle speed, etc.), elapsed time after shift tSFT (s)
(This is determined by measuring time with a microcomputer timer counter, not the sensor output.
That is, when a shift command is issued in the microcomputer, a bit in an appropriate flag register is turned on, and the elapsed time from when the bit is turned on is measured to obtain the range position signal P.
RANGE is used.

Subsequently, in S12, it is confirmed that the range selector is in the D range, and then in S14, it is determined whether or not a gear shift operation is currently being performed. This judgment work is performed with reference to the shift command flag mentioned above.
If it is recognized in S14 that the gear is not being shifted, the process proceeds to S16 and a gear shift command value is determined. This will be discussed later. Incidentally, if the result in S12 or S14 is negative or affirmative, this program is immediately terminated.

Figure 5 shows the subroutine for determining the shift command value.
This is a flow chart. To explain according to the same figure, first, in S100, the vehicle speed V (Km/h) is determined from the sensor output values detected when the program was started last time.
Read out the throttle opening θTH (degrees) and calculate the acceleration α (Km/h/s) (vehicle speed deviation), the throttle change amount ΔθTH (degrees/S), and the acceleration change amount Δα
(Km/h/s/s) is calculated. In other words, as shown in Fig. 6, the acceleration and throttle change amounts are determined by the deviation (unit time) between the value at the time of program startup this time (time n) and the value at the previous program startup (time n-1). This is done by finding the first-order differential value divided by n-(n-1). Further, the amount of change in acceleration is obtained by further differentiating the acceleration with respect to time. In the actual calculation, the acceleration is "Km/h/0.1s", the throttle variation is "degrees/0.1s", and the acceleration variation is "Km/h/0.1s".
Calculated as "h/0.1s/0.1s".

Next, in S102, the rotation speed after shifting Ne−SFT
Calculate. Since this is a gear other than the current gear, in this example 4 forward gears, it is estimated how the engine speed will change if it is assumed that a gear is shifted from a certain gear to the other 3 gears. and
More specifically, this will be explained according to the subroutine flow chart in FIG.

To explain according to Fig. 7, first, the vehicle speed V is read out in S200, and then the current shift position is read out in S202.
Read SFT0, initialize the counter value SFT1 that counts the shift position after shifting in S204, and
=1 (SFT1=1 means first speed).
Next, in S206, the difference between the first gear and the current shift position SFT0 is determined to calculate the maximum number of gears that can be shifted down. As shown in FIG. 8, if the vehicle is currently in third gear, this corresponds to -2 gear. continue,
In S208, the gear ratio G/R of the first gear is read from the data previously stored in the ROM 70d of the microcomputer, and after confirming in S210 that the first gear is not the current shift position, S212
The post-shift rotational speed Ne-SFTR is calculated as follows.

Ne−SFT=(V×1000×G/R)/(60×
6.28×r) [rpm] Where, V: Vehicle speed, 1000, 60, 6.28: Constant for calculating vehicle speed from gear ratio, G/R: Gear ratio (of the relevant gear), r: Tire effective radius ( m) Next, in S214, the gear stage (1st speed)
The number of gears is calculated from the difference between the current gear and the current gear, and this process is repeated until the fourth gear is reached (S216, 218).
After reaching the top gear, the number of gears that can be increased is calculated in S220 and the process ends. FIG. 8 shows an example of these calculations. The configurations shown in FIG. 7 to FIG. 18, which will be described later, correspond to claim 2.

Returning to FIG. 5 again, a search for fuzzy production rules is then performed in S104. FIG. 9 is a subroutine flowchart of the subroutine, but before going into the explanation of the subroutine, the rules used in this embodiment will be briefly explained with reference to FIG. 10. still,
As described above, the rules, parameters used, membership functions, etc. are determined in advance when designing the control system of the vehicle.

FIG. 10 is an explanatory diagram showing the fuzzy production rules in detail, and in the case of this embodiment, 44 rules are used. This will be explained below.

Rule 1 Fuzzy label used Conclusion Throttle change amount ΔθTH [degrees without shift/
0.1s. Specifically WOT/8/0.1s. same as below. Furthermore, WOT=84 degrees] Acceleration α [Km/h/0.1s. Same hereafter] Engine speed Ne [rpm. The same applies hereafter] Rule implication: ``If you are aiming for cruise at a reasonable rotation speed, do not shift.'' In other words, if you are aiming for cruise at a reasonable rotation speed, there will be no change in the throttle opening.
The acceleration should also be constant, and the engine speed should also be
It is expected that 2000rpm or less is appropriate for cruising (in terms of engine speed, 2000 to 4000rpm is appropriate for cruising depending on the degree, and 4000rpm or more is not considered appropriate for cruising), so it is considered to be appropriate for cruising. The satisfaction level of the rule is evaluated, and if the satisfaction level is higher than that of all other rules, this rule will be adopted.

The evaluation method for such a rule will be described later with reference to FIG. 9, but to briefly describe it, we search for a position where the value of the parameter detected (or calculated) in rule 1 matches on the domain and extend the perpendicular line. ,
The membership value (more specifically referred to as "grade") on the vertical axis intersecting the waveform is read. For example, if the actual value is ΔθTH=0
(degrees/0.1s), α=0 (Km/h/0.1s), Ne=
Set to 3000rpm. When this is applied to the fuzzy label in FIG. 10, the grade of ΔθTH is 0.95, the grade of α is 0.95, and the grade of Ne is 0.5, as shown by the broken line. In such a case, the grade of the minimum value becomes an evaluation that indicates the entire related fuzzy label in the sense that at least its range is also satisfied with all other fuzzy labels, and as a result, the evaluation of rule 1 is 0.5. . Subsequently, all the rules are evaluated in the same way, and the rule with the highest evaluation value is adopted as having the highest degree of satisfaction, and the shift position is determined according to the conclusion indicated by that rule. Therefore, if Rule 1 is adopted, there will be no shift.

Here, what is distinctive about this embodiment is that only the parameter of rule 2 is given a membership function of maximum 1.0, and the maximum value of the remaining 43 rules remains at 0.95. As a result, the evaluation value of rule 2 becomes relatively high in the mini-max calculation described above, and the possibility that rule 2 is selected increases. The reason for this configuration is that the rule group shown in FIG. 10 can be roughly divided into the following two types.

a. Rules for protecting the engine (Rule 2) b. Other rules (Rules 1, 3 to 44) In this case, Rule 2 is more important than the other rules because it relates to damage to the engine. I can do it. In other words, if a group of rules is examined in detail, a hierarchical structure based on importance can be seen.In other words, it is desirable to ensure that rules with a high degree of importance are selected in the operating state for which they are intended. It turns out. As a result of this configuration, in operating conditions where the engine is running at high speeds, there is a high probability that Rule 2 will be selected and the first gear will be increased, regardless of other conditions such as throttle opening. control can be achieved.
In the case of this embodiment, only rule 2 is given top priority, and the maximum membership function values are also 1.0 and 0.95.
Although only two types were used, it goes without saying that more detailed grading may be used.

Next, rule 2 and subsequent rules will be explained.

Rule 2 Fuzzy Label Conclusion Engine speed Ne only Implications of 1st gear up rule ``At high speeds, 1st gear up is applied to protect the engine.'' This is a rule for engine protection, and when the engine speed is
When entering the red zone exceeding 6000 rpm, the engine is shifted up to 1st gear to protect the engine.
Note that the expression "1st gear up" means shifting up by 1st gear, for example, moving from 2nd gear to 3rd gear, but does not mean shifting to 1st gear. This also applies to other rules.

Rule 3 Fuzzy Label Conclusion Elapsed time after shift tSFT [s] Do not shift Throttle change amount ΔθTH Implications of the rule "Do not change immediately after shifting" The driver should not press the throttle valve hard immediately after shifting. It is assumed that the driver does not intend to change gears, and a dead zone of a predetermined time, for example, about 1.6 to 2.5 seconds is provided.

Rule 4 (Rule 5, 6) Fuzzy Label Conclusion Current shift position SFT0 3rd gear down Vehicle speed V [Km/h. same as below〕
(2nd gear, 1st gear down) Throttle opening θTH [degrees. same as below. still,
WOT = 84 degrees] Rule implication "If the throttle is fully closed and the vehicle speed is extremely low, shift to 1st gear" Rules 4 to 6 are rules for downshifting to 1st gear when the throttle is fully closed and the vehicle speed is extremely low. Yes, when this rule is the current shift position is 4th gear, and the next rule 5 is 3rd gear,
Rule 6 is when the vehicle is in second gear. These rules are the initial actions of the shift.

Rule 7 (Rule 8) Fuzzy label Conclusion Current shift position SFT0 2nd gear down Vehicle speed V (1st gear down) Throttle opening θTH Implications of the rule "If the vehicle is fully closed and the vehicle is at low speed, go to 2nd gear" This rule and the following rules are This rule is similar to Rules 4 to 6, and shows an example in which even if the vehicle speed has not returned to that extent, if the vehicle speed is still low, the vehicle is shifted to second speed.

Rule 9 Fuzzy Label Conclusion Throttle opening θTH Do not shift Throttle change amount ΔθTH Implications of the rule: ``If the throttle returns suddenly, there is no intention to shift, so do not shift.'' This is to prevent the control from becoming lax. This is mainly a matter of control technology.

Rule 10 Fuzzy Label Conclusion Current shift position SFT0
Acceleration change from 1st to 2nd speed ΔαKm/h/0.1s/0.1s. The same applies below] Control toughness CT (2nd gear) Rotation speed after shifting Ne-SFT [rpm. Same hereafter] (2nd gear) Acceleration α Throttle change ΔθTH Implications of the rule: ``Shift up from 1st gear to 2nd gear during acceleration if the acceleration saturates and the controllability after shifting is good.'' Acceleration increases If the throttle is reaching saturation and the throttle has not been returned (while still being depressed), it will shift to second gear. In this case, since the speed increases, the control toughness at the second speed, which is the destination stage, is searched, and the post-shift rotational speed is also evaluated with reference to the calculated value at the second speed.

Note that this rule also uses the concept of control toughness as a parameter and makes decisions after predicting the situation in the case of upshifting. Control toughness is a term coined by the inventors, and is used to mean "a coefficient representing the appropriateness of the vehicle's response to changes in throttle opening θTH." This concept was devised from the viewpoint of one of the purposes of the present invention, as described above, to eliminate the busy feeling caused by frequently repeated shifts when climbing a slope or towing a camper car.
In other words, the above-mentioned inconvenience arises from not securing sufficient margin driving force, which is obtained by subtracting running resistance, which is an extrinsic load of the vehicle, from the driving force. This becomes noticeable during upshifts when the amount decreases.

To explain this point with reference to the driving force diagram in Figure 11, assuming that the engine is currently running at Ne0, the difference from the full-throttle driving force, equivalent to the surplus horsepower, is shown as shown in the figure. . In this case, running resistance increases when running uphill compared to when running on a flat road because gradient resistance is added. When the throttle opening is returned to the cruise opening in this state, the shift point is uniquely determined from the vehicle speed and the throttle opening in the conventional control device, so the shift up is automatically performed, and the engine is therefore shifted up. The number of rotations is
Ne1, and the full-throttle driving force also decreases, so the equivalent amount of spare horsepower also decreases, and as a result, downshifting is performed again. Just like that, Atsup.
As mentioned above, the repeated down and up cycles gave the driver a troublesome feeling.

In other words, in this case, the running resistance is large relative to the equivalent horsepower, and the vehicle is in a state where it is unable to respond appropriately to the driver's requests, and such a state cannot be taken into consideration when making a shift decision. If possible, it should be possible to avoid meaningless shift-ups. Therefore, in this control system, the appropriateness of the vehicle's response is expressed in terms of the margin driving force using a concept called control toughness, and the decision to shift up is made in consideration of this concept. Any parameter may be used to determine the control toughness as long as it can detect the amount equivalent to the surplus horsepower, but in the present invention, the running resistance, particularly the gradient resistance, is used to determine the control toughness. That is, as shown in FIG. 12, the slope of the running path is usually expressed as tanθ (=height h/length l).
Based on this gradient tamθ, the membership function μ is determined for each speed stage as shown in FIGS.
defined. In each figure, the domain (horizontal axis) has a slope (+
The side indicates uphill, the - side indicates downhill), and
The membership value is set on the vertical axis. To give an overview, when the slope is zero (flat ground), the reduction in surplus driving force is small, so the membership value is set to the maximum value, and since the driving force in 1st gear is relatively large, the slope range that continues to the maximum value is set. The shape is approximately trapezoidal, and the decrease in membership value is small despite the increase in slope. Furthermore, the membership function is defined so as to become narrower in a triangular shape as the speed stage increases, and especially in the case of the highest stage, the triangle becomes sharper. The control toughness fuzzy label is stored in the ROM 70d for each speed stage, and in actual calculation, it is calculated for the speed stage to which the shift destination is to be shifted. For example, in the case of Rule 10, an increase from 1st gear to 2nd gear is planned, so calculations are made for 2nd gear. Note that this configuration corresponds to claim 3.

Rule 11 Fuzzy Label Conclusion Current shift position SFT0 Do not shift Acceleration change Δα Acceleration α Throttle change ΔθTH Implications of the rule: "Do not apply rule 10 when it is not considered that acceleration is in progress." This rule is a supplement to rule 10. There are rules in place if it is not considered to be accelerating.
This was established to prohibit the adoption of 10. In other words, in fuzzy inference, the pull reduction rule with the highest evaluation value is automatically selected, so even if the evaluation value of rule 10 is not very high even if it is not being accelerated and therefore the evaluation value of rule 10 is not that high, other rules If the evaluation value is even lower, Rule 10 will be adopted, and as a result, an inappropriate control value will be determined. In order to avoid this, in this rule, one of the fuzzy labels in Rule 10, specifically the membership function of acceleration α, forms a complement of what is called a fuzzy set. In other words, in Rule 10, acceleration α is set so that the grade becomes high when it is increasing (meaning that it is accelerating), whereas in this rule, the grade is set when it is decreasing. It is determined that it will grow bigger. As a result, when the driving condition is similar to Rule 10 but differs significantly in that it is not accelerating, the grade of acceleration α becomes higher in Rule 11,
Therefore, it can prevent the adoption of Rule 10. In this sense, it can be said that it has a function similar to that of giving priority to the function values described above. In addition, since shifting is not planned in this rule, the rotation speed after shifting and control toughness are not referred to.

Rule 12 Fuzzy label Conclusion Current shift position SFT0 Do not shift Acceleration change Δα Acceleration α Throttle change ΔθTH Implications of the rule: ``If the acceleration does not saturate, shift will not be performed.'' This rule is also a counterpart to Rule 10.
If it is determined from the acceleration change amount Δα that the acceleration α is not saturated, it is determined that the speed will not be changed since it is still possible to accelerate. Therefore, also in this rule, the acceleration change amount Δα is a complementary set to that of Rule 10, which prevents the adoption of Rule 10 in a driving state that meets this condition.

Rule 13 Fuzzy Label Conclusion Current shift position SFT0 Do not shift Vehicle speed V Implication of the rule ``At extremely low speeds, there is no need to shift up to 2nd gear, so do not shift.'' This is a rule similar to Rules 4 to 8.

Rule 14 Fuzzy label Conclusion Current shift position SFT0 1st gear up Throttle change ΔθTH Vehicle speed V Acceleration α Control toughness (2nd gear) Implications of the rule: ``When acceleration force is weak, shift up according to vehicle speed.'' This is during slow acceleration. This is a rule in which the engine speed is increased by one gear to improve fuel efficiency in driving conditions where there is no throttle operation, the vehicle speed is stable, and the driver does not have much intention of accelerating, i.e., in driving conditions where the driver is accelerating slowly. be. As mentioned above, when there is sudden acceleration, the acceleration becomes saturated, so it is possible to use this as an indicator to determine shift-up, but when there is slow acceleration, such a phenomenon is not observed, so the shift-up is determined using vehicle speed as an indicator. . Since we plan to move up to 2nd gear, we will also evaluate the control toughness of 2nd gear.

Rule 15 Fuzzy label Conclusion Current shift position SFT0 1st gear up Acceleration change Δα (from 2nd gear to 3rd gear) Control toughness CT (3rd gear) Rotational speed after shifting Ne-SFT (3rd gear) Acceleration α Throttle change Quantity ΔθTH ``Shift up from 2nd gear to 3rd gear during acceleration if the acceleration saturates and the control toughness of the vehicle after the shift is good.'' This is similar to Rule 10 above, but different. The only difference is that Rule 10 stipulates the increase from 1st gear to 2nd gear, but only the increase from 2nd gear to 3rd gear. Therefore, detailed explanation will be omitted. In addition, rules 16 and 17
is similar to rules 11 and 12 and is complementary to rule 15.

Rule 18 Fuzzy Label Conclusion Current shift position SFT0 Do not shift Engine speed Ne Throttle change amount ΔθTH Implications of the rule ``Even if the throttle operation is performed with the intention of accelerating, if the rotation speed is high enough, the engine will accelerate, so it will not shift. ” When the driver intends to accelerate by stepping on the accelerator pedal, this control device recognizes that intention. In this case, it is determined from the rotational speed whether to shift down and increase the driving force to accelerate, or to accelerate without downshifting. That is, when the rotational speed is high, the driving force is large, so acceleration can be achieved without changing the shift.

Rule 19 Fuzzy Label Conclusion Current shift position SFT0 1st gear up Throttle change ΔθTH Vehicle speed V Acceleration α Control toughness CT (3rd gear) Implications of the rule "If acceleration force is weak, shift up according to vehicle speed" Similar to rule 14 This is the standard, and the difference is that the current shift position is 2nd gear, and as a result, the vehicle speed V is 30 km/h and the membership value has increased to 1.0, and the rest are the same.

Rule 20 Fuzzy label Conclusion Current shift position SFT0 No gear shift Throttle change ΔθTH Vehicle speed V Acceleration α Implications of the rule ``Even in the same case as above, if the vehicle speed is not satisfied, do not shift up'' Rule 14 does not provide such supplementary provisions. The reason why Rule 19 was provided is that Rule 14 is scheduled to be in 1st gear, whereas Rule 19 is scheduled to be in 2nd gear.
This is because the vehicle speed is required to be satisfied because the driving force is reduced when the vehicle speed is higher. Therefore, the vehicle speed V of Rule 20 is set to be the complement of that of Rule 19 (only on the low speed side).

Rules 21-26 These are similar to Rules 15-20, the only difference being that they are intended to shift up from 3rd gear to 4th gear.

Rule 27 Fuzzy Label Conclusion Current shift position SFT0 No gear change Engine speed Ne Throttle change amount ΔθTH Implications of the rule: “Even if you operate the throttle with the intention of accelerating, if the engine speed is high enough, it will accelerate, so it will not go down.” Rule 24 It is similar to

Rule 28 Fuzzy Label Conclusion Throttle opening θTH 3rd gear up Throttle change ΔθTH Acceleration α Control toughness CT (4th gear) Rotation speed after shifting Ne-SFT (4th gear) Implications of the rule ``Intention to shift from acceleration to cruise If it is clear and the controllability after shifting up is good (3rd gear) up.'' This indicates that the acceleration is being accelerated from the acceleration α, the throttle opening θTH has been returned to the cruise opening, and the 4th gear is Rotation speed after shifting at speed
Ne-SFT also shifts to 3rd gear and the highest gear if the control toughness in 4th gear is good in driving conditions where the speed is expected to reach around 2000 rpm. Therefore, this rule assumes that the current shift position is in the first gear.

Rule 29 Fuzzy Label Conclusion Throttle opening θTH No gear change Throttle change ΔθTH Acceleration α Implications of the rule "Do not increase when the precondition is not acceleration" This is a supplement to Rule 28, and under driving conditions similar to Rule 28. This is to avoid acceleration if acceleration is not detected from the vehicle speed V. Therefore, the acceleration α of rule 29 is a complement set of rule 28. Such a configuration makes it possible to avoid the disadvantages seen in the prior art.

Rules 30 to 33 These rules have the same meaning as rules 28 and 29 described above, and are different only in that the planned current shift position is different.

Rule 34 Fuzzy Label Conclusion Current shift position SFT0 3rd gear down Throttle opening θTH Post-shift speed Ne-SFT (1st gear) Vehicle speed V Implications of the rule: (If the throttle is fully open, the post-shift speed must be extremely high. ) Kickdown'' From this rule to the last rule 48 are the rules for kickdown. In this rule, the current shift position SFT0 is 4th gear, the throttle is depressed greatly, and the rotational speed Ne− after shifting in 1st gear.
It is expected that the SFT will not become extremely high, and if the vehicle speed V is low, the vehicle will be shifted down by three gears and dropped to the lowest gear. Furthermore, the rules
Similarly, 35 to 37 are kickdowns when the vehicle is in 4th gear, and the rules are divided depending on the state of each vehicle speed, and the degree of downturn can be set to 2nd gear or 1st gear depending on the difference in throttle opening, etc. It stops quickly. Incidentally, the above configuration etc. are claimed in claim 4.
corresponds to the term.

Also, rules 38 to 42 define the kickdown when the current shift position is in 3rd gear.
Rules 43-44 plan for kickdown when the vehicle is in second gear, and are similar to rules 35-37.

With the above as the premise, the fuzzy production rule search subroutine flow chart of FIG. 9 will be explained. First, in S300, the total number of rules N is read. In this embodiment, the total number of rules is 44.

Next, in S302, the counter that counts the rule number is initialized and the initial value is set to "n=1".
(meaning rule 1). Next, S304
Initializes the calculation field (not shown) for the membership value μ in the RAM 70e of the microcomputer, and sets the membership value μ0 to 1.0.

Next, in S306, the conclusion part (number of gears) of the n-th rule is read. Therefore, when the program is started for the first time, "0" (no shift), which is the conclusion of rule 1, is read.

Next, the number of gears read in S308 is
It is determined whether the maximum number of gears that can be down is exceeded as calculated in the flow chart in Figure 7, and if the number of gears scheduled for the rule exceeds the maximum number of gears, even if the rule is selected. Since it is meaningless, the process moves to S310 and the membership value μ0 of the rule is set to 0.0. If it is determined in S308 that the maximum number of gears that can be lowered is exceeded, then in S312 it is determined whether the conclusion of the rule is within the maximum number of gears that can be lowered.
If it exceeds that, move to S310 for the same reason.

If S312 is also affirmed, then S316
Read the total number L of fuzzy labels at
In S316, the value 1 of a counter for counting the number of fuzzy labels is set to the initial value "1". For example, in the case of rule 1, the number of fuzzy labels is read as four.

Subsequently, in S318, the membership value μn1 of the first label of the nth rule is read. As mentioned above, this applies the values actually detected or calculated from them to the domain,
This refers to the work of reading the membership value at the point where the waveform intersects with the perpendicular line raised upward from there.
Since it is the first time the program is started, ΔθTH of rule 1 =
0 (degrees/0.1s), α=0 (Km/h/0.1s), Ne=3000
The first value in (rpm), μ11= for ΔθTH
It means to read as 0.95. Next, in S320, compare μ0 initialized in S304 with μn1 read in all steps, and if μn1 is smaller than μ0,
In S322, rewrite the value of μ0 to μn1, and in the next S324
Increment the label number in step S318, read the membership values of all fuzzy labels in the same rule sequentially, and perform step S326.
After it is confirmed that the rules have been read, the minimum membership value μ0 is set as the membership value μ0n of the rule n in S328. In addition, if the S320 determines that μ0 is smaller than μn1, the
Along with jumping to S324, the above-mentioned S308, 312
If the rule is denied, the membership value of 0.0 is set as the minimum value for that rule (S310). More than S300
.about.328, the minimum membership value for one rule is selected.

Next, the number of rules n is incremented in S330, and repeated until it is determined that the total number of rules has been reached in the next S332. After reaching the total number of rules, the process proceeds to S334, selects the rule with the maximum membership value, and executes that rule. Adopt (S336). In this case, as described above, since the function value is relatively large in the operating state planned by Rule 2, there is a high possibility that Rule 2 will be selected.
Claim 5 is the structure of FIG. 9 to FIG. 21, which will be described later.
Corresponds to items 9 to 9.

Thereafter, returning to FIG. 4 again, the output process is performed according to the conclusion of the rule selected in S18, and the speed is changed. That is, the solenoids 36 and 38 are energized/deenergized via the output circuits 74 and 76 to engage or hold the desired gear stage.

As described above, in this embodiment, not only actual measured values such as throttle opening or vehicle speed, but also the degree of adaptation of the vehicle's response to the driver's expectations are quantitatively measured from the gradient resistance and used as parameters. The system analyzes the judgments and operations observed in manual transmission vehicles by expert drivers based on the parameters of , sets multiple control laws that are derived, and evaluates the control laws through fuzzy reasoning to select optimal control values. With this structure, the driving state of the vehicle, including surrounding conditions, can be grasped in multiple variables and processed instantly, making it possible to perform automatic gear change control similar to the judgment and operation of a skilled driver in a manual transmission vehicle. It is something. That is, control using the fuzzy method enables more appropriate control similar to human manual gear shifting operations, and is not limited to setting data as seen in the prior art, or is based on throttle opening and vehicle speed. There are no inconveniences such as the timing of shifting being determined mechanically. In addition, by further increasing the number of disclosed rules, it is possible to realize shift control that is compatible with emission countermeasures.
Furthermore, it is possible to respond more flexibly to the shift control characteristics desired by the user. In this sense, the present invention is completely different from the prior art in purpose, structure, and effect.

FIG. 14 and subsequent figures show a second embodiment of the present invention, and show an example in which the shift control using the above-mentioned fuzzy inference is applied to a continuously variable transmission (CVT).

To explain the following, FIG. 14 is an overall schematic diagram illustrating the continuously variable transmission with a focus on the hydraulic circuit. In the same figure, a continuously variable transmission 100 includes a constant displacement hydraulic pump 102 having a transmission input shaft 24 driven by an engine main body 10 via an engine output shaft 18.
and a variable displacement hydraulic motor 106 having a drive shaft 104 and disposed on the same axis as the hydraulic pump.
are connected to each other to form a hydraulic closed circuit 108. In the closed circuit, the hydraulic pump 10
The discharge port of the hydraulic motor 106 and the inlet of the hydraulic motor 106 are connected to each other by a high pressure oil passage 108h.
02 are mutually connected to each other by a low pressure oil passage 108l. In the hydraulic closed circuit, a short-circuit path 110 is provided between the discharge port and the suction port of the hydraulic pump 102, that is, between the high-pressure and low-pressure oil paths 108h and 108l, and a short-circuit path 110 is provided in the middle of the short-circuit path 110. provided. Moreover, the hydraulic pump 10
In addition to 2, a replenishment pump 114 is provided,
The replenishment pump is driven by a mission input shaft 24, and its discharge port is connected to check valves 116, 118, 12.
0 through the high pressure and low pressure oil passages 108h, 10
8l, and supplies hydraulic oil pumped up from the oil tank 122 to the hydraulic closed circuit. In addition, code 12
4 indicates a relief valve.

The transmission output shaft 26 connected to the rear wheel 46 is arranged parallel to the drive shaft 104 of the hydraulic motor 106, and a forward/reverse switching device 130 is provided therebetween. This forward/reverse switching device includes a first
and second drive gears 132, 134, and output shaft 26
a first driven gear 136 that is rotatably supported by and meshes with the first drive gear; and an intermediate gear 13.
A second driven gear 1 is connected to the second driving gear via 8 and is rotatably supported by the output shaft 26.
40 and a driven clutch gear 1 fixed to the output shaft 26 between the first and second driven gears 134 and 140.
42, and a clutch member 144 selectively connecting the driven clutch gear and both driven gears 136, 140. First and second driven gears 13
Driving clutch gears 136a and 140a are provided at the ends of the driven clutch gears 142 of No. 6 and 140, and the clutch member 144 is located at a position where the driving clutch gears 136a and the driven clutch gears 142 are connected. , and a position connecting the driven clutch gear 142 and the drive clutch gear 140a. In such a forward/reverse switching device 130, as shown in FIG.
When the output shaft 26 is connected to the driven clutch gear 142, the output shaft 26 is rotated in a direction opposite to the rotational direction of the drive shaft 104, and the rear wheel 46 can rotate in the forward direction. Conversely, when the driven clutch gear 142 and the drive clutch gear 140a are connected, the output shaft 2
6 is rotated in the same direction as the drive shaft 104, and the rear wheel 4
6 is rotatable in the backward direction.

The clutch valve 112 is driven by a servo cylinder 150, the forward/reverse switching device 130 is controlled by a range drive mechanism 152 consisting of a hydraulic cylinder, etc., and the displacement of the hydraulic motor 106 is controlled by a hydraulic cylinder 154. It is carried out at the same time. To explain them individually below, the servo cylinder 150 includes a cylinder 156, a piston 162 that defines the inside of the cylinder into a head chamber 158 and a rod chamber 160, and a piston rod 164 integrated with the piston.
It consists of a spring 166 that urges the piston 162 toward the head chamber in the rod chamber. The tip of the piston rod 164 is connected to the clutch valve 112 via a link 168, and the piston 16
2 is moved to the maximum right by the spring 166, the clutch valve 112 becomes fully open, and in this state, the hydraulic fluid discharged from the hydraulic pump 102 flows through the short-circuit path 110.
The hydraulic motor 106 is not driven, and therefore no power is transmitted to the rear wheels 46 via the output shaft 26. On the other hand, the piston 162
When the clutch valve 11 moves to the left against the spring force of 6, the clutch valve 11
2 becomes small, the continuously variable transmission 100 becomes a half-clutch state, and when the piston 162 is further driven to move as much as possible to the left, the clutch valve 112 closes and the power is completely transferred to the rear wheel 46. communicated.

Here, referring to FIG. 15, the hydraulic motor 106
To explain this, the motor is, for example, a variable displacement axial piston motor, and as shown in the figure, a cylinder lock 172 connected to the drive shaft 104 has a plurality of cylinders arranged annularly around the axis of rotation of the shaft. Two pistons 174 are slid together, and a swash plate 176 that defines the reciprocating stroke of the pistons is disposed at a position facing these pistons with a variable inclination angle θTRU. In the piston group, a cylinder chamber 17 corresponding to a piston in an expansion stroke
8 is communicated with the high pressure oil passage 108h, and the cylinder chamber 180 corresponding to the piston in the contraction stroke is communicated with the low pressure side oil passage 108l. Therefore, the high-pressure oil discharged from the hydraulic pump 102 is sucked into the cylinder chamber 178, and the low-pressure oil discharged from the cylinder chamber 180 is returned to the hydraulic pump 102. During this period, the piston 174 in the expansion stroke receives air from the swash plate 176. Cylinder block 17 due to reaction torque
2 and the drive shaft 104 are rotationally driven.

Since the capacity of the hydraulic motor is determined by the stroke of the piston 174, by moving the inclination angle θTRU of the swash plate 176 to the left from the maximum position shown by the solid line to the minimum position shown by the chain line, the speed ratio The ratio (G/R) can be changed steplessly from the minimum to the maximum. Here, the speed ratio e is expressed by the following equation.

Speed ratio e=Output rotation speed/Input rotation speed=Pump capacity/Motor capacity Therefore, at one end of the swash plate 176, there is a swing link 18.
One end of 2 is connected via a pin 184,
The other end of this link 182 is connected to the aforementioned hydraulic cylinder 154 via a second pin 186.

The hydraulic cylinder 154 is slidably connected to the cylinder 190 and is connected to the head chamber 1 inside the cylinder.
92 and a piston 196 defined in a rod chamber 194.
and a piston rod 1 integrated into the piston.
It consists of 98. One end of the swing link 182 is connected to the tip of the piston rod 198 via the pin 186, and when the piston 196 moves to the maximum right, the tilt angle θTRU of the swash plate 104 becomes maximum, and the capacity of the hydraulic motor 106 becomes maximum. Therefore, the speed ratio e becomes the minimum. Conversely, when the piston 196 moves to the left as much as possible, the inclination angle of the swash plate becomes the minimum as shown by the chain line, the motor capacity becomes the minimum, and the speed ratio e becomes the maximum.

Now, returning to Figure 14 again, we will explain the pilot valves that control these hydraulic cylinders.
The aforementioned servo cylinder 150 is provided with an electromagnetic pilot valve 200. The pilot valve 20
0 indicates oil passages 202 and 20 communicating with the head chamber 158 and rod chamber 160 of the servo cylinder 150, respectively.
4 and a supply oil passage 206 that communicates with the discharge port of the replenishment pump 114 and a return oil passage 208 that communicates with the oil tank 122, and includes a sleeve 210 and a spool 212 that is relatively movable within the sleeve. . Further, a piston rod 164 of a servo cylinder 150 is connected to the sleeve 210 via a link 214, and the action of the servo cylinder 150 is fed back to the pilot valve 200.

Thus, the spool 212 is movable between three positions on the left and right including the neutral position, and when it moves to the left and reaches the right position, the head chamber 158 of the servo cylinder 150 is moved.
The discharge oil pressure of the replenishment pump 114 is introduced to the valve 114, and the rod chamber 160 is opened to the oil tank 122, thereby the piston 162 moves to the left and the clutch valve 112 closes as described above. Furthermore, when the spool 212 moves to the right, the discharge hydraulic pressure is guided to the rod chamber 160 of the servo cylinder 150, and the head chamber 158 is released to the oil tank, so the piston 162 moves to the right and the clutch valve 112
opens the valve. Since the cylinder 150 is a servo cylinder, as the piston rod 164 moves due to the movement of the piston 162, the sleeve 210 also moves and stops at an appropriate position. Through such a mechanism, by moving the piston 162 according to the amount of movement of the spool 212, the opening degree of the clutch valve 112, that is, the opening degree of the short circuit path 110 can be adjusted as desired.

Next, the second pilot valve 220 that controls the hydraulic cylinder 154 will be explained. This pilot valve 220 is connected to the head chamber 1 of the hydraulic cylinder.
Oil passage 222 and rod chamber 194 that can communicate with 92
an oil passage 224 that communicates with
4 inserted between the return oil passage 226 connected to 2
Consists of a port restriction switching valve (solenoid valve). This pilot valve 220 includes a sleeve 228 and a spool 230 that is movable within the sleeve. be. That is, when the spool 230 moves to the left, high pressure hydraulic oil is introduced into the head chamber 192 of the hydraulic cylinder 154 and discharged from the rod chamber 194.
The piston 196 and the piston rod 198 move to the left, and as described above, the angle of inclination of the swash plate 176 becomes smaller, the hydraulic motor capacity becomes smaller, and the speed ratio e becomes larger. Conversely, when the spool 230 moves to the right,
The hydraulic oil is discharged from the head chamber 192 and guided to the rod chamber 194, causing the piston 196 and piston rod 198 to similarly move to the right, the swash plate inclination angle increases, the hydraulic motor capacity increases, and the speed ratio e
becomes smaller. The pressure distribution between the head chamber 192 and rod chamber 194 in the hydraulic cylinder 154 is determined by the degree of restriction of the pilot valve 220 (i.e., the position of the spool), and the piston 196 and piston rod 198 are The hydraulic motor 10 operates at a speed proportional to the difference.
6 changes, the speed ratio e, that is, the gear ratio G/
R can be changed.

The pilot valves 200, 220 are connected to the speed change control unit 60, and the speed change control unit energizes/deenergizes the solenoids of the pilot valves to move the spools 212, 230 to arbitrary positions. That is, the speed change control unit includes a throttle sensor 50, a crank angle sensor 52, an inclination angle sensor 54, and a vehicle speed sensor 5 as in the first embodiment.
From these input values, control values are calculated as described later, and the transmission/cutoff of power is controlled via the pilot valve 200, and the gear ratio is arbitrarily controlled via the pilot valve 220.
Furthermore, the speed change control unit also controls the operation of a range drive mechanism 152 equipped with a hydraulic cylinder, and changes F (forward) and N ( neutral),
Based on the R (reverse) signal, a forward or reverse gear train is established in the forward/reverse switching device 130 described above. It goes without saying that such range position information is also input to the speed change control unit via the range selector switch 62. Although the main focus of the present invention is on continuously variable transmission control applying fuzzy reasoning and not on the continuously variable transmission mechanism itself, the spools 212 and 230 in the pilot valves 200 and 220 are connected to oil (not shown). Through pressure or spring force or through duty control of a solenoid valve, it is moved by a predetermined amount in either the left or right direction, and for example, in the case of the pilot valve 220, a desired throttle is applied to adjust the speed ratio of the continuously variable transmission mechanism to a desired value. Needless to say, the configuration is such that the value can be controlled.

Next, the operation of the speed change control unit in the second embodiment will be explained with reference to FIG. 16 and subsequent figures. still,
The description of the second embodiment will focus on the points that are essentially different from the first embodiment. For example, the details of the speed change control unit and the like are similar to those shown in FIG. 3 of the first embodiment, and therefore will be omitted. It goes without saying that the same applies to preparatory work such as creating rules before the actual race.

FIG. 16 is a main flow chart schematically showing the speed change control of the second embodiment. To explain according to the diagram, first, in S500, measured parameter values are read and stored. The current speed change ratio (gear ratio) G/R is calculated from the input/output rotation speed ratio of the transmission, etc., as in the first embodiment. Next, in S502, the forward range (the F
range), and if it is affirmative,
Proceeding to S504, a shift command value is determined, and output processing is performed in S506, and if it is determined in S502 that it is not in the forward range, this program is immediately terminated.

Figure 17 is S504 of the flow chart in Figure 16.
2 is a flow chart showing a routine for determining a shift command value. In the figure, after calculating the acceleration α etc. in S600 in the same manner as in the first embodiment, the process proceeds to S602 to calculate the post-shift rotation speed.

Figure 18 is a flow chart showing the calculation method. First, in S700, the gear ratio change coefficient γ
Initialize, specifically, initialize the counter value that counts it.

To summarize the control of this embodiment, since this embodiment uses a continuously variable transmission, the concept of gear ratio is used instead of the shift position in the first embodiment, and the target gear ratio is This is done by inferring sequentially. Therefore, the object of inference is not the gear ratio itself, but a coefficient that changes the gear ratio (the gear ratio change coefficient γ described above). That is, target gear ratio (G/R) = current gear ratio (G/R)
Calculate by ×γ. Therefore, the gear ratio (G/R) is expressed as a total reduction ratio as shown in Figure 19, and the defined area is
The closed interval from 3.0 (highest side) to 11.0 (lowest side) was assumed to be covered by a fuzzy set as shown in the figure. In the diagram, the fujii label HI "largely moves the gear ratio to the High side", and MH "changes the gear ratio to the medium side".
"to the High side", ML "to the gear ratio a little to the Low side",
LO indicates "increase the gear ratio to the Low side".

Furthermore, as shown in FIG. 20, the gear ratio change coefficient γ is defined by seven fuzzy sets ranging from 0.27 to 3.74. In addition, in the fuzzy label shown in the figure, BU is "largely on the High side", MU is "moderately on the High side", SU is "slightly on the High side",
HD "holds the current gear ratio", SD "holds the current gear ratio", and SD "holds the current gear ratio"
"on the low side", MD means "moderately on the low side", and BD means "largely on the low side".

Therefore, when initializing S700, the value of the counter indicating the gear ratio change coefficient γ is set to the highest value “0.27”.
means to set it to .

Subsequently, in S702, the post-shift rotation speed is calculated. The rotation speed after shifting is calculated at several points, specifically at the second point.
In Figure 0, the values of the gear ratio change coefficient γ when the grade value is 1.0, that is, 0.27, 0.42, 0.65, 1.0, 1.56,
Multiply the current gear ratio by 7 types, 2.42 and 3.74, and calculate each value obtained.

Next, the post-shift rotation speed calculated in S704 is stored in the corresponding address, CFLNE (here, FL means HI, MH, ML, and LO described above). In addition, here, seven gear ratio change coefficients γ are given, but only four FLs indicating the gear ratio are given, which is why, for example, when the vehicle is currently on the lowest side, it cannot go any lower than that. This is because there are various restrictions. The same is true when you are on the highest side.

Next, in S706, the gear ratio change coefficient counter value γ is updated by multiplying by 1.55, and in S708, the value of the lowest side
Calculate individually until it is confirmed that 3.74 has been reached.

Returning to Figure 17 again, the final step
In S604, a target change ratio is determined through fuzzy reasoning.

Figure 21 is a flow chart showing the subroutine.
In S800, the grade values of membership functions are calculated for all rules, and the values of the conclusion part are waveform-synthesized and summed. Next, in S802, the center of gravity is calculated, and in S804, the gear ratio change coefficient γ is determined from the values on the domain that intersects with the center of gravity.
In S806, a target gear ratio (G/R) is calculated.

FIG. 22 shows 43 rules used in the second embodiment. The difference in the first embodiment from the rule shown in FIG. 10 is that the shift position is indicated by the gear ratio (G/R) instead of the shift position, and the conclusion is indicated by the gear ratio change coefficient γ described above. This is true, and the implications of the rules differ accordingly, but the rest of the structure is the same. Regarding the control toughness, for the 7 values of the gear ratio change coefficient γ, we discretely calculate the 4 actually possible values of the determined post-shift Ne, and from among them, we calculate the control toughness according to the rule. The satisfaction level of the rule is evaluated by searching for a value corresponding to the shift amount shown in the conclusion part.
Therefore, this embodiment is not different from the first embodiment in this respect.

Therefore, in the fuzzy inference of the first embodiment, a mini-max operation was used to select the rule that obtained the maximum grade value, and the shift command value was determined according to the conclusion determined by that rule. In the example, after finding the mini value, synthesize the obtained waveform,
Find the center of gravity and determine the shift command value. To explain this point with reference to Fig. 23, the engine speed Ne is now 3000 rpm, the amount of throttle change is 0,
The acceleration is also set to zero. When the grade value of Rule 1 is calculated, the grade value of the engine speed is 0.5, so when the waveform of the conclusion part is cut at that value, it becomes trapezoidal as shown. Further, regarding rule 2, since the waveform does not intersect with the waveform, no waveform remains in the conclusion part. As shown at the end of the figure, when the above results are mapped onto the same domain, a hatched trapezoid is obtained. By finding the center of gravity G and then extending the perpendicular line downward, we can obtain the value at the intersection, in this case γ=1.0. still,
Although only the cases of rules 1 to 2 are shown as examples, the procedure is repeated up to rule 43, and the obtained waveforms are synthesized to find the center of gravity. Note that the rules are created assuming different driving conditions, so even if fuzzy inference is performed on all the rules, only about two or three will remain.

Based on the results obtained, the 16th
Output processing is performed in S506 of the main flow chart, and the electromagnetic pilot valve 220 described above is
to change the capacity of the hydraulic motor 106,
Control the gear ratio to a desired value.

Since the present embodiment is configured as described above, when controlling the speed change of the continuously variable transmission, the speed change judgment and operation performed by an expert driver in a manual transmission vehicle can be performed by controlling the speed ratio through fuzzy reasoning. This can also be incorporated into continuously variable speed control, providing smooth speed change characteristics that do not give a busy feeling, and also accurately responding to emission countermeasures and individual user requirements.

In this example, the speed ratio was calculated through fuzzy reasoning, but it is also possible to calculate the speed of change of the speed ratio. Although described above, it goes without saying that a pulley type mechanism may also be used.

Incidentally, although the present invention has been explained in connection with stepped and non-stroke transmissions in the above first and second embodiments,
The present invention is also applicable to traction control.

(Effects of the Invention) According to claim 1, the gear shifting operation that was judged and operated by a skilled driver in a vehicle with a manual transmission can be incorporated into the gear shifting control through fuzzy reasoning, which is similar to human decision-making. This enables accurate gear shifting decisions. In other words, by understanding the driving state of the vehicle including surrounding conditions in multiple variables and processing it through fuzzy reasoning, it is possible to make judgments and actions similar to those made by expert drivers in manual transmission vehicles. This can be achieved during control. Furthermore, since changes in the reserve driving force are predicted based on the running resistance calculated based on the road surface inclination angle, frequent changes in the gear ratio can be reliably avoided, and it is possible to avoid presetting as seen in conventional technology. Since the shift point is not mechanically determined from the throttle opening degree and the vehicle speed based on the determined shift diagram, it is possible to realize shift control that responds immediately to constantly changing driving conditions. Furthermore, by appropriately determining the shift rules, it is possible to individually respond to shift control corresponding to emission countermeasures or shift characteristics desired by each user.

According to the second aspect of the present invention, by predicting changes in the engine speed, the gear ratio can be determined more appropriately.

According to the third aspect of the present invention, since this is used for determining a shift-up, the gear ratio at the time of a shift-up can be more appropriately determined.

According to the fourth aspect, since this is used for determining downshifting, it is possible to more appropriately determine the gear ratio at the time of downshifting.

According to claims 5 and 6, since the speed ratio is determined by selecting one of the fuzzy production rules, the speed ratio can be easily determined.

According to claims 7 to 9, inappropriate determination of the gear ratio can be avoided.

[Brief explanation of drawings]

Fig. 1 is a diagram corresponding to the claims of the present invention, Fig. 2 is a schematic diagram showing the overall configuration of a control device for an automatic transmission according to the present invention, Fig. 3 is a block diagram showing details of the control unit, and Fig. 4 5 is a flow chart showing the main shift routine that is the operation of the unit.
The figure is a flow chart showing the shift command value determination subroutine, FIG. 6 is an explanatory diagram explaining the parameter calculation therein, and FIG.
A flow chart showing a subroutine for calculating the rotation speed after shifting of the chart, FIG. 8 is an explanatory diagram showing an example of the calculation, and FIG. 9 is a flow chart showing a fuzzy production rule search subroutine of the flow chart in FIG. , FIG. 10 is an explanatory diagram showing the rule, FIG. 11 is a driving force diagram showing the premise of control toughness used in the rule, FIG. 12 is an explanatory diagram of gradient resistance expressed by control toughness, and FIG. Figures a to d are explanatory diagrams showing control toughness in which membership functions are given to each shift position, and Figure 14 shows an overall control system for a continuously variable transmission, which is a second embodiment of the present invention, centering on the hydraulic circuit. 15 is an enlarged explanatory sectional view showing the structure of the hydraulic motor therein, FIG. 16 is a flow chart showing the main routine of the speed change control unit, and FIG. 17 is the speed change command value therein. A flow chart showing the determination routine, FIG. 18 is a flow chart showing the post-shift rotation speed calculation subroutine in the flow chart of FIG.
9 is an explanatory diagram showing the membership function of the gear ratio used in the second embodiment, FIG. 20 is an explanatory diagram similarly showing the membership function of the gear ratio change coefficient, and FIG. 21 is an explanatory diagram showing the membership function of the gear ratio change coefficient. FIG. 22 is an explanatory diagram showing a group of rules used in the second embodiment, and FIG. 23 is an explanatory diagram showing a fuzzy inference method. 10... Internal combustion engine body, 16... Throttle valve, 18... Engine output shaft, 20... Transmission, 22... Torque converter, 24... Main shaft, 26... Counter shaft, 30
... Oil passage, 32, 34 ... Shift valve, 36,
38... Electromagnetic solenoid, 42... Differential device, 46... Rear wheel, 50... Throttle sensor, 52... Crank angle sensor, 54... Tilt angle sensor, 56... Vehicle speed sensor, 60... ...Shift control unit, 62...Range selector switch, 64...Shift position switch, 80...
...Micro computer, 100...Continuously variable transmission, 102...Quantitative discharge type hydraulic pump, 104...
...Drive shaft, 106...Variable displacement hydraulic motor, 1
08...Hydraulic closed circuit, 110...Short circuit, 112
...Clutch valve, 114...Replenishment pump, 11
6,118,120... Check valve, 122... Oil tank, 124... Relief valve, 130... Forward/forward switching device, 132... First drive gear, 134...
Second driving gear, 136...First driven gear, 138
...Intermediate gear, 140...Second driven gear, 142
... Driven clutch gear, 144 ... Clutch member, 150 ... Servo cylinder, 152 ... Range drive mechanism, 154 ... Hydraulic cylinder, 156 ...
...Cylinder, 158...Head chamber, 160...Rod chamber, 162...Piston, 164...Piston rod, 166...Spring, 168...Link,
170... Connection member, 172... Cylinder block, 174... Piston, 176... Oblique plate, 17
8,180...Cylinder chamber, 182...Swing link, 184,186...Pin, 190...Cylinder, 192...Head chamber, 194...Rod chamber,
196... Piston, 198... Piston rod, 200... Pilot valve, 202, 204...
...oil path, 206...supply path, 208...return oil path, 210...sleeve, 212...spool,
214...link, 220...pilot valve, 2
22, 224... Oil path, 226... Return oil path, 2
28...sleeve, 230...spool.

Claims (1)

[Scope of Claims] 1. A control device for an automatic transmission in which the gear ratio is adjusted stepwise or continuously, comprising: (a) engine speed, throttle opening, amount of change in throttle opening, vehicle speed, amount of change in vehicle speed; Driving state detection means for detecting the driving state of the engine or vehicle including at least the road surface inclination angle and the current speed ratio, b. a driving state change prediction means for predicting a change in the margin driving force that will be expected to occur based on the running resistance calculated based on the road surface inclination angle; c. membership of the driving state to be detected and the driving state change to be predicted; a setting means for presetting a plurality of fuzzy production rules quantified by functions based on operations and judgments of a driver in a vehicle with a manual transmission; d) the detected driving state and the predicted driving; a gear ratio determining means for determining a gear ratio by performing fuzzy inference consisting of state changes and fuzzy production rules; and (e) a driving means for driving a transmission mechanism in accordance with an output of the gear ratio determining means. Characteristic automatic transmission control device. 2. Claim 1, wherein the operating state change prediction means further predicts a change in engine speed that will occur if the gear ratio is changed from the current gear ratio to the gear ratio that can be changed. A control device for the automatic transmission described above. 3. The automatic transmission control device according to claim 2, wherein the predicted value is used for a shift-up determination. 4. The automatic transmission control device according to claim 2, wherein the predicted value is used for determining downshift. 5. The control device for an automatic transmission according to claim 1, wherein the speed ratio is determined by selecting one of the plurality of fuzzy production rules. . 6. The control device for an automatic transmission according to claim 5, wherein the selection of the plurality of rules is performed by calculating the suitability of a rule consequent with respect to the detected value and/or predicted value. 7. The automatic transmission control device according to claim 6, wherein the plurality of rules have different maximum values of membership functions forming the rules. 8. The automatic transmission control device according to claim 6, wherein the membership function of the rule with a high degree of importance is set relatively large compared to other rules. 9. The automatic transmission control device according to claim 8, wherein the highly important rule is a rule for engine protection.