JPH0953716A - Gear change control device for continuously variable transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate a feeling of inharmoniousness of generating an abrupt gear change due to switching from feedforward gear change control to feedback gear change control although a target change gear ratio is not changed. SOLUTION: A motor 88 is operated in answer to the number U of command steps to open a gear change control valve 83 to move power rollers 44c, 44d up and down in opposite directions, and to cause a tilt-rolling of the power rollers, and allow the power rollers to perform gear change which corresponds to the number U. An arithmetic unit 130a determines the number SFHB of feedback steps based on the deviation of a target tilt-rolling angle ϕ* from an actual tilt-rolling angle ϕ, an arithmetic unit 120 retrieves the number SFF of feedforward steps corresponding to the target tilt-rolling angle ϕ* from a map 120a. A switching device 140 switches SFF or SFB to U in response to the judged results of a judgement unit 100c. A correction unit 120b corrects the map 120a by an amount of the deviation of U before and after the switching from SFF to SFB, which is determined by the arithmetic unit 130b.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a continuously variable transmission such as a V-belt type continuously variable transmission and a toroidal type continuously variable transmission, and more particularly to a shift control device thereof.

[0002]

2. Description of the Related Art In a continuously variable transmission, a gear shift actuator such as a step motor is operated by a command operation amount corresponding to a target gear ratio, and a gear shift control valve is operated in response to the command manipulated variable so that the target gear ratio is not changed. A gear shift is caused. Then, the speed change progress state is fed back to the speed change control valve by a mechanical feedback system, and when the speed change to the target speed change ratio is completed, the speed change control valve self-returns to the neutral state, and It is conventional to configure so that the achievement state of can be maintained.

When determining the operation amount of the shift actuator, the transmission input / output rotation speed is detected to obtain the actual gear ratio represented by the ratio of the two, and this has any deviation from the target gear ratio. The so-called feedback control, which determines the actuator operation amount so as to eliminate the gear ratio deviation depending on whether the gear ratio is present, is preferable in the sense that the influence of disturbance on the gear shift control can be eliminated and the gear shift control can be performed with high accuracy.

However, on the other hand, a sensor for detecting the input / output speed of the transmission is indispensable for this feedback control. The sensor for detecting the rotational speed of the transmission passes through the teeth on the pulse gear which rotates together with the rotary member for the input / output of the transmission. The one that photoelectrically detects the number is often used. For this reason, the number of passing teeth on the pulse gear decreases in the low rotation range,
The detection accuracy of the input / output rotation speed deteriorates, and the reliability of the feedback control itself becomes insufficient.

Therefore, conventionally, for example, Japanese Patent Laid-Open No. 14636/1990 is used.
As seen in the V-belt type continuously variable transmission described in Japanese Patent Publication No. 6, in the low rotation range where the detection accuracy of the input / output rotation speed deteriorates,
The so-called feedforward control, which uniquely gives the planned actuator operation amount to the target gear ratio by map search etc., is adopted, and the detected input / output is performed in the high rotation range where the detection accuracy of the input / output speed does not matter. It has been proposed to perform feedback control based on rotation speed.

[0006]

However, in the speed change control device for the continuously variable transmission, the speed change progress state is fed back to the speed change control valve by a mechanical feedback system as described above. The mechanical feedback amount of the gear shift progressing state may become inaccurate due to the deformation of the component itself that constitutes the mechanical feedback system or the relative displacement between the components, which occurs according to the transmission torque. This inaccuracy becomes a disturbance and increases the deviation of the actual speed ratio from the target speed ratio, and if the feedback speed change control can eliminate the deviation from the target speed ratio due to the disturbance to some extent, the feedforward speed control In that case, the deviation from the target gear ratio due to the disturbance cannot be eliminated, and the following problems occur.

That is, regarding the toroidal type continuously variable transmission, the inaccuracy of the mechanical feedback amount is called torque shift, and tends to be significantly larger than that in the V-belt type continuously variable transmission. The greater the transmission transmission torque, the more remarkable it becomes. Figure 7
Under the condition that the target gear ratio does not change as shown by the alternate long and short dash line, the deviation state of the actual gear ratio with respect to the target gear ratio is changed during the period in which the toroidal continuously variable transmission is feedforward gearshift controlled, It is shown separately for the period during the feedback shift control.

As is clear from the time-dependent change of the actual speed ratio shown by the solid line in this figure, during the feedforward control in the low vehicle speed range before the instant t ₁ , the actual speed ratio changes due to the large torque shift. Large deviation from the ratio (deviation between the two is shown as power roller tilt angle deviation Δφ _t )
However, this is not eliminated, and the gear ratio deviation due to the torque shift tends to be eliminated after the feedforward control is switched to the feedback control at the instant t _{1 as the} vehicle speed increases.

For this reason, the actual gear ratio changes before and after the instant t ₁ at which the feedforward control is switched to the feedback control, regardless of the running condition in which the target gear ratio is not changed. The occupant feels an unexpected shift shock, which makes him feel uncomfortable.

In the V-belt type continuously variable transmission described in the above document, when the target gear ratio is changed by switching the operation mode, the sudden change of the primary pulley pressure involved in the gear shift control is alleviated, and The pressure hunting is prevented by this, and therefore shock countermeasures are taken, but by switching from feedforward control to feedback control, it is possible to eliminate the feeling of strangeness caused by a change in the actual gear ratio even though the target gear ratio does not change. There has been no countermeasure.

Here, it is conceivable that the actuator operation amount to be given in the feedforward control is corrected and determined in advance by the torque shift amount. However, the magnitude of the torque shift depends on the cause of occurrence and Since there are many variations due to individual differences and changes over time, and it is almost impossible to predict accurately in advance, it is difficult to deal with this with common sense measures.

According to the present invention, from the viewpoint that the magnitude of the torque shift appears as the amount of change in the actual gear ratio after switching from the feedforward control to the feedback control, the actuator operation to be given during the feedforward control. The amount is corrected according to the actual gear ratio change amount, and therefore, when switching from the feedforward control to the feedback control, a gear shift with an uncomfortable feeling occurs even though the target gear ratio does not change. An object of the present invention is to propose a shift control device that does not cause

[0013]

To this end, a shift control device for a continuously variable transmission according to a first aspect of the present invention causes a continuously variable shift by operating an actuator, and the operation amount of the actuator corresponds to a target gear ratio. In a continuously variable transmission adapted to switch between the feedforward control for determining the predetermined operation amount and the feedback control for determining the operation amount of the actuator according to the gear ratio deviation between the target gear ratio and the actual gear ratio. An actuator operation amount deviation calculating means for calculating an actuator operation amount deviation between the actuator operation amount at the time of switching from the feedforward control to the feedback control and the actuator operation amount at the time when a set time elapses from the switching; Actuator operation amount to be used in forward control Only the actuator manipulated variable deviation and the arithmetic, is provided with a feedforward control plan operation quantity correction means for correcting so that the deviation is reduced.

In such a configuration, the actuator corresponds to the predetermined operation amount corresponding to the target gear ratio determined by the feedforward control, or the gear ratio deviation between the target gear ratio and the actual gear ratio determined by the feedback control. The continuously variable transmission performs a continuously variable gear shift toward the target gear ratio by operating the actuator in response to the operation amount command.

Here, the actuator operation amount deviation calculating means calculates an actuator operation amount deviation between the actuator operation amount at the time of switching from the feedforward control to the feedback control and the actuator operation amount at the time when a set time has elapsed from the switching. Calculate
Also, the means for correcting the planned operation amount for feedforward control is
The actuator operation amount to be used in the feedforward control is corrected so that the deviation is reduced by the calculated actuator operation amount deviation.

Therefore, the planned actuator operation amount corresponding to the target gear ratio obtained by the feedforward control is
It is possible to reduce the deviation between the actual gear ratio and the target gear ratio during the feedforward control by taking into consideration the disturbance that changes one by one. For this reason, the actual gear ratio does not change due to the switching from the feedforward control to the feedback control regardless of the traveling condition in which the target gear ratio does not change, and the vehicle occupant does not change when the control mode is switched. It is possible to eliminate the uncomfortable feeling of sudden shift shock.

In the continuously variable transmission shift control device according to the second aspect of the present invention, when the actuator operation amount to be used in the feedforward control is determined for each throttle opening degree of the engine in the preceding stage of the transmission, the feed operation is performed. The forward control planned operation amount correcting means is configured to correct a predetermined actuator operation amount corresponding to the engine throttle opening at the time of switching from the feedforward control to the feedback control.

In the structure of the second aspect of the invention, the predetermined actuator operation amount is appropriately corrected for each engine throttle opening in response to the disturbance such as the torque shift changing according to the engine throttle opening. As a result, the function and effect of the first invention can be achieved more reliably.

A shift control device for a continuously variable transmission according to a third aspect of the invention is configured to set the set time in accordance with the calculated actuator operation amount deviation.

According to the structure of the third aspect of the invention, the calculated actuator operation amount deviation more accurately represents the degree of disturbance such as torque shift, and thus the effects of the first and second aspects of the invention are obtained. It can be achieved more reliably.

In the shift control device for a continuously variable transmission according to the fourth aspect of the present invention, the feedforward control planned manipulated variable correcting means switches from feedforward control to feedback control in which the actuator manipulated variable deviation is equal to or greater than a set deviation. When a predetermined number of times continues, the planned actuator operation amount is corrected.

According to the configuration of the fourth aspect of the invention, it is possible to prevent the planned correction of the actuator operation amount from being made erroneously or unnecessarily, and the correction can be accurately performed to make the first to third aspects of the invention. The action and effect of can be achieved more reliably.

In the shift control device for a continuously variable transmission according to the fifth aspect of the invention, the feedforward control planned operation amount correcting means corrects the correction amount when the predetermined actuator operation amount is corrected by the predetermined number of feedforwards. The determination is made based on all the deviations of the actuator operation amounts during the switching from the control to the feedback control.

According to the structure of the fifth invention, the predetermined amount of actuator operation is corrected exactly, and the correction can be made more accurately than in the fourth invention. It can be achieved reliably.

[0025]

Embodiments of the present invention will be described below in detail with reference to the drawings. 1 and 2 exemplify a toroidal-type continuously variable transmission equipped with a shift control device according to an embodiment of the present invention. FIG. 1 is a diagrammatic vertical sectional side view of the toroidal-type continuously variable transmission. 2 is a diagrammatic vertical sectional front view thereof, and FIG. 2 also shows a shift control device according to an embodiment of the present invention.

In FIG. 1, 20 is a torque converter,
Reference numeral 30 is a forward / reverse switching mechanism, and 40 is a toroidal type continuously variable transmission. The torque converter 20 includes a pump impeller 20a to which engine rotation is input and a turbine runner 2
0b, the stator 20c, and the lockup clutch 20.
It is assumed that the pump impeller 20a fluidly drives the turbine runner 20b through the internal working fluid to transmit the engine rotation to the torque converter output shaft 21. The torque converter 20 includes the pump impeller 20 by engaging the lockup clutch 20d.
By directly connecting a and the turbine runner 20b, the fluid drive state (converter state) is switched to the lockup state, and engine rotation can be mechanically transmitted to the torque converter output shaft 21.

The forward / reverse switching mechanism 30 is interposed between the torque converter output shaft 21 and the input shaft 41 of the toroidal type continuously variable transmission 40, and has a double pinion type planetary gear set 31, a forward clutch 32, and a reverse drive. It is composed of a brake 33. Here, the double pinion type planetary gear set 31 is a pinion set 31p including a pair of pinions meshing with each other.
The carrier 31c that rotatably supports the transmission is attached to the transmission input shaft 4
1 and can be coupled to the torque converter output shaft 21 by the forward clutch 32. Then, the sun gear 31s that meshes with the pinion on the inner side of the pinion set 31p is bound to the torque converter output shaft 21, and the ring gear 31r that meshes with the pinion on the outer side of the pinion set 31p can be fixed to the transmission case 42 by the reverse brake 33. To do.

The forward / reverse switching mechanism 30 is in a neutral state in which the rotation of the torque converter output shaft 21 is not transmitted to the transmission input shaft 41 when both the forward clutch 32 and the reverse brake 33 are in the released state, and the forward clutch 32 is operated. Torque converter output shaft 2 when fastening only
1 rotation is transmitted to the transmission input shaft 41 as it is (the input shaft 41 is normally rotated), and the reverse brake 3
When only 3 is engaged, the reverse rotation state in which the rotation of the torque converter output shaft 21 is reversely reduced and transmitted to the transmission input shaft 41 (the input shaft 41 is reversely rotated) can be achieved.

The toroidal type continuously variable transmission 40 has two toroidal transmission units 44 and 45, and these toroidal transmission units 44 and 45 have the same structure as follows. That is, the input cone disks 44a and 46a,
The output cone disks 44b and 46b are coaxially arranged so that the toroidal curved surfaces face each other, and the rotation axis O ₁ of the input / output cone disk is sandwiched between the toroidal curved surfaces of the input / output cone disks on both sides thereof. The pair of arranged power rollers 44c, 44d and 46c, 46d are interposed.

Two toroidal transmission units 44, 46
Are coaxially arranged so that the output cone disks 44b and 46b are back to back,
a and 46a are supported on the disk support shaft 48 via ball splines 50 and 52 so as to rotate therewith,
The output cone disks 44b and 46b are connected to an output shaft 54 which is rotatably supported on a disk support shaft 48.

Toroidal transmission unit 44 in the previous stage
A loading cam 56 is interposed between the input cone disc 44a and the transmission input shaft 41a, and the rotation of the transmission input shaft 41 is transmitted to the input cone disc 44a via the loading cam. The rotation of the input cone disc 44a is controlled by the rotation of the input cone disc 46 of the toroidal transmission unit 46 in the subsequent stage via the shaft 48.
It is also transmitted to a. These input cone discs 44a, 4
The rotation of 6a is caused by frictional contact with the power rollers 44c, 4c.
4d and 46c, 46d are transmitted to the output cone discs 44b, 46b, but the power rollers 44c, 44d and 46c, 46d are connected to the corresponding input cone discs 44 to enable the initiation of such power transmission.
A disc spring 58 for preloading is provided between a and 46a and the output cone disks 44b and 46b. On the other hand, the loading cam 56 generates thrust according to the torque transmitted to the input cone disc 44a, and the power rollers 44c, 44d
And 46c and 46d are input cone disks 44a and 4
6a and the output cone discs 44b and 46b are clamped so that the above power transmission can be continued.

An output gear 60 is arranged between the output cone disks 44b and 46b, and the output gear 60 is connected to the output shaft 54. Then, a counter gear 62 is meshed with the output gear 60, and this gear 62 is connected to a counter shaft 64 extending outside the transmission case 42 so that the shifting power to the output cone disks 44b and 46b can be taken out. To

Each power roller 44c, 44d and 46
As shown in FIG. 2, c and 46d are rotatably supported by a trunnion 71 via a pivot pin 70, and the trunnion has a spherical joint 7 at its upper end for each toroidal transmission unit.
2 rotatably and swingably at both ends of the upper link 73, and a lower link 75 at the lower end by a spherical joint 74.
Both ends of are rotatably and swingably connected. And
The upper link 73 and the lower link 75 have their centers supported by the spherical joints 76 and 77 so as to be swingable in the vertical direction on the transmission case 42, and both trunnions 71 in each toroidal transmission unit can be vertically moved in synchronization with each other in opposite directions. To do so. However, it goes without saying that even between the toroidal transmission units, the vertical movement directions of the trunnions are made opposite to each other in consideration of the rotation direction.

A gear shift control device for shifting gears by vertically moving both trunnions 71 in each toroidal transmission unit in synchronism with each other in opposite directions will be described below with reference to FIG. Each trunnion 71 is provided with a piston 78 for individually stroking the trunnion 71, and upper chambers 79 and 80 and lower chambers 81 and 82 are defined on both sides of each piston 78, respectively. And the piston 78 which makes a pair
In order to control the strokes in opposite directions to each other, a shift control valve 83 is installed. Here, the shift control valve 83 allows a spool type inner valve body 83a and a sleeve type outer valve body 83b to slide relative to each other. The outer valve body 83b is slidably fitted to the outer valve housing 83c.

The transmission control valve 83 is an input port 83d.
Oil pump 84 and pressure regulator
A line from the pressure source connected to the pressure source consisting of the valve 85
Pressure P _LSupply. Also, one communication port of the shift control valve 83
Port 83e to piston chambers 79 and 82 and to the other
Connect the port 83f to the piston chambers 80 and 81 respectively.
You. The inner valve body 83a is placed under the one trunnion 71.
On the cam surface of the precess cam 86 fixed to the end,
The outer valve body 83 b
To the step motor 88 as a speed change actuator.
Drive-engaged with a lock and pinion model.

The operation command for the shift control valve 83 is given by the step motor 88 which responds to the shift command value (actuator operation amount = motor drive step number) U as a stroke to the outer valve body 83b via the rack and pinion. With this operation command, the outer valve body 83b of the shift control valve 83 is displaced relative to the inner valve body 83a from the neutral position to, for example, the position shown in FIG.
The line pressure P _L to 3d is supplied to the chambers 80 and 81, while the other chambers 79 and 82 are drained, and the outer valve body 83b of the shift control valve 83 is in a neutral position relative to the inner valve body 83a. When the shift control valve 83 is opened by being displaced in the opposite direction from
The line pressure P _L to the input port 83d is supplied to the chambers 79 and 82, while the other chambers 80 and 81 are drained, and the two trunnions 71 are fluid-pressured through the piston 78 in the corresponding vertical direction in the figure. It shall be displaced in the opposite direction.
This allows the power rollers 44c, 44d and 46c,
46d are vertically moved in mutually opposite directions (in the same phase) and at the same time.

Here, the power rollers 44c, 44d and
46c and 46d are the rotation axis O ₂Is the input / output cone
Disk rotation axis O₁Off from the position shown in Figure 2 which intersects with
Will be set and the offset will cause power loss.
Is a swing component from the input / output cone disk,
Axis of rotation O₂Swing axis line O_ThreeTilt around
Thus, continuously variable transmission can be performed.

During such a speed change, the recess cam 86 connected to the lower end of one trunnion 71 is connected via the speed change link 87 to the trunnion 71 and the power rollers 44c, 44.
The vertical movements and tilt angles of d, 46c and 46d described above are mechanically fed back to the inner valve body 83a of the shift control valve 83. The step motor 88 is operated by the above continuously variable transmission.
When the gear shift command value U to is achieved, the mechanical feedback via the recess cam 86 causes the inner valve body 83a of the gear shift control valve 83 to move to the initial neutral position relative to the outer valve body 83b. At the same time, the power roller 44c,
44d, 46c, 46d, by the rotation axis O ₂ returns to the illustrated position that intersects the rotational axis O ₁ of the input and output cone discs 1 and 2, it is possible to maintain the achieved state of the shift command value.

Since the purpose of control is to set the power roller tilt angle to a value corresponding to the target speed change ratio, the precess cam 86 basically needs to feed back only the power roller tilt angle. The reason why the power roller offset amount is also fed back here is that a damping effect is given to prevent the shift control from becoming oscillating,
This is for avoiding the hunting phenomenon of the shift control.

The actuator operation amount U to the step motor 88 is determined by the controller 100, which detects the signal from the throttle opening sensor 101 for detecting the engine throttle opening TVO and the vehicle speed VSP. In addition to inputting a signal from the vehicle speed sensor 102, the specific installation location is shown in FIG.
Transmission input rotational speed N _i (engine rotational speed N _e may be used)
The signal from the input rotation sensor 103 for detecting the speed and the signal from the output rotation sensor 104 for detecting the transmission output speed N _o are input.

The controller 100 uses the various inputs described above.
Based on the information,
The actuator operation amount U shall be determined. I mean
The controller 100 is shown in FIG. 2 as a functional block diagram.
With the configuration as shown, the target tilt angle calculation unit 100a
Throttle opening based on the shift map stored in memory.
Degree TVO and vehicle speed VSP, target transmission input
After determining the power rpm, this transmission target input rpm and the vehicle
Transmission output speed N calculated based on the speed VSP_oIn ratio with
Power roller target tilt angle corresponding to the target gear ratio
φ ^*Is calculated.

On the other hand, in the controller 100, the actual tilt angle calculation unit 100b uses the actual transmission ratio N _i based on the transmission input rotation speed N _i from the sensor 103 and the transmission output rotation speed N _o from the sensor 104. / after obtaining the N _o, calculates the power rollers actual target tilting angle φ corresponding to the actual speed ratio. Then, the controller 100 includes the actuator operation amount calculation unit 1
In the feedforward control unit 120 which forms 10, the feedforward step number S _FF of the step motor 88 corresponding to the power roller target tilt angle φ ^* is set to the throttle opening TVO based on the feedforward step number map 120a. Ask for each.

The controller 100 further includes a feedback control unit 13 which constitutes an actuator operation amount calculation unit 110.
The feedback step number calculation unit 130a within 0 calculates the proportional gain K _p and the integral gain K based on the tilt angle deviation Δφ between the actual tilt angle φ of the power roller and the target tilt angle φ ^*.
By using K _p + (K _i / S) determined by _i (S is a differential operator), the feedback step number S _FB according to the tilt angle deviation Δφ is obtained.

Further, the controller 100 determines in the control mode switching determination section 100c whether or not the vehicle speed VSP is in a high vehicle speed range in which the rotation detection accuracy of the rotation sensors 103 and 104 is sufficiently high for practical use. Since the feedback control is better than the feedforward control as described above, the control mode switcher 140 forming the actuator operation amount calculation unit 110 is used to set the feedback step number S _FB to the actuator operation to the step motor 88. The feedback control becomes inaccurate as described above unless the vehicle is switched to the position where the quantity U is set, and conversely, if it is not in the high vehicle speed range, the control mode switch 140 is used to set the feedforward step number S _FF to the step motor 88. The actuator operation amount U is set to a position.

On the other hand, the step number deviation calculation unit 130b in the feedback control unit 130 includes a timer 130c.
Along with this, the actuator operation amount deviation calculating means in the present invention is configured. As described below, the deviation of the actuator operation amount U before and after the switching from the feedforward control to the feedback control (the tilt angle deviation indicated by Δφ _S in FIG. The corresponding step number deviation ΔU) is obtained. In other words, the timer 130c is based on a signal from the control mode switching determination unit 100c, measures the elapsed time after switching instant to the feedback control from the feedforward control (instant t ₁ in FIG. 7). Step number deviation calculator 13
0b is the actuator operation amount U at the time of switching.
= S _FF and the actuator operation amount U = S _{FB at} the moment when the timer 130c measures the set time indicated by Δt in FIG.
The step number deviation ΔU between and is calculated. Here, the set time Δt is set to a predetermined long time within a range in which the target tilt angle φ ^* (target gear ratio) does not change.

The map correction unit 120b in the feedforward control unit 120 corresponds to the feedforward control planned operation amount correction means in the present invention, and the step corresponding to the current throttle opening TVO in the feedforward step number map 120a. The number is corrected so that this deviation is reduced by the step number deviation ΔU.

In the control mode switch 140, the number of feedback steps S _FB or the number of feed forward steps S _FF
2 receives the actuator operation amount U determined by the stepping drive in accordance with the control command value U, the stepping motor 88 changes the outer valve element 83b of the shift control valve 83 from the inner valve element 83b.
It is displaced from the neutral position relative to a. As a result, the hydraulic servo constituted by the speed change control valve 83 and the piston 78 is connected to the power rollers 44c, 44d, 46c and 4.
6d is offset in the direction of the tilt axis O ₃ , and the power roller tilts about the axis O ₃ by this offset. This tilting changes the arc diameter of the contact locus of the power roller with respect to the input / output cone disk so that the input rotation speed approaches the target input rotation speed (target gear ratio), that is, the gear ratio is continuously changed to a predetermined value. Gear shifting can be performed.

As described above, the precess cam 86 during the gear shift feeds back the power roller offset amount and the power roller tilt angle to the inner valve body 83a of the gear shift control valve 83 and follows this displacement of the outer valve body 83b. To reduce the relative displacement between the inner and outer valve bodies of the shift control valve 83. This relative displacement becomes smaller as the shift progresses, and finally becomes 0 when the shift command value U is achieved. At this time, the inner valve body 83a and the outer valve body 83b of the shift control valve 83
Can relatively return to the initial neutral position, and can maintain the achievement state of the shift command value U (actual tilt angle φ = target tilt angle φ ^* ).

By the way, the map 120a used for determining the feedforward step number S _FF is corrected by the map correcting section 120b as described above, that is, from the feedforward control to the feedback control obtained by the step number deviation calculating section 130b. Actuator operation amount (feed-forward step number S _FF ) at the time of switching and the set time Δt from the switching (see FIG. 7)
The map value of the feedforward step number S _FF corresponding to the throttle opening TVO is calculated by the map correction unit 120b by the actuator operation amount deviation ΔU between the actuator operation amount (feedback step number S _FB ) and the deviation. As shown in FIG. 7, the actual gear ratio (actual tilt angle φ) during feedforward control is changed from that shown by the solid line to that shown by the chain double-dashed line by the above map correction, as shown in FIG. It is changed and approaches the target gear ratio (target power roller tilt angle φ ^* ), and the deviation between them (tilt angle deviation Δφ _t ) becomes small.

Therefore, the actuator operation amount (feed-forward step number S _FF ) obtained by the feed-forward control takes into consideration disturbances such as torque shifts which are changing one by one, and the actual gear ratio and the target gear change during the feed-forward control are performed. The deviation from the ratio can be reduced. For this reason, the actual gear ratio does not change due to the switching from the feedforward control to the feedback control regardless of the traveling condition in which the target gear ratio does not change, and the vehicle occupant does not change when the control mode is switched. It is possible to eliminate the uncomfortable feeling of sudden shift shock.

Further, since the map value of the feedforward step number S _FF corresponding to the engine throttle opening TVO is corrected in the above map correction, the feedforward step number S S for each engine throttle opening TVO.
_{Since the FF} will be corrected, disturbances such as torque shift will change according to the engine throttle opening, and the feedforward step number S _FF will be corrected appropriately without excess or deficiency, thus ensuring the above-mentioned effects. Can be achieved.

When the controller 100 is composed of a microcomputer, by executing the control programs shown in FIGS. 3 and 4, the same operation as that of the above embodiment can be obtained. In FIG. 3, first, in steps 211 to 214, the throttle opening TVO, the input rotation speed N _i , the output rotation speed N _o , and the vehicle speed VSP are respectively set.
The calculation is performed based on the signal from the corresponding sensor.

Next, in step 215, a memo is written in advance.
Throttle opening TV based on the shift map
Target transmission input rotation from O and vehicle speed VSP
Number N _i ^*And then in step 216,
Speed target input speed N_i ^*And the transmission output speed N_oWhen
Power roller target corresponding to the target gear ratio represented by the ratio
Tilt angle φ^*Is calculated.

[0054] At step 217, it is determined whether or not the vehicle speed VSP is the set vehicle speed VSP _S above, the set vehicle speed VSP _S, the
The lower limit value of the vehicle speed range is set so that the rotation detection accuracy of the rotation sensors 103 and 104 is sufficiently high to be practical. VSP ≧ V
In the high vehicle speed range of SP _S, the feedback control is better than the feedforward control as described above. Therefore, in step 218, the subroutine explicitly shown in FIG. 4 is executed to obtain the actuator operation amount by the feedback control. The feedback step number S _FB is set to the actuator operation amount U to the step motor 88, and at the same time, the feedforward step number map used in the feedforward control is corrected by the subroutine shown in FIG.

However, if the vehicle speed is not in the high vehicle speed range of VSP ≧ VSP _S , the feedback control becomes inaccurate as described above. Therefore, in step 219, the actuator operation amount is obtained by the feedforward control. That is, based on the feedforward step number map 120a (the same as in FIG. 2), the feedforward step number S _FF of the step motor 88 corresponding to the power roller target tilt angle φ ^* is set to the throttle opening TVO. The feedforward step number S _FF is determined as the actuator operation amount U to the step motor 88.

In step 220, step 21
The actuator operation amount U determined in 8 or 219 is output to the step motor 88 to cause the toroidal continuously variable transmission to shift to the target gear ratio.

The feedback control process and the feed-forward control map correction process of FIG. 4 will be described below. In step 231, the transmission input rotational speed N _i calculated in step 212 and the transmission calculated in step 213. after determining the actual gear ratio N _i / N _o on the basis of the output speed N _o, it calculates the power rollers actual target tilting angle φ from the actual speed ratio. In the next step 232, the tilt angle deviation Δφ between the actual tilt angle φ of the power roller and the target tilt angle φ ^*.
In step 233, based on the tilt angle deviation Δφ, K _p + (K _i / S) + K _d S determined by the proportional gain K _{p, the} integral gain K _i , and the differential gain K _d is used (S Is a differential operator), and the feedback step number S _FB according to the tilt angle deviation Δφ is obtained.

In step 234, step 21 in FIG.
After performing the switching determination from the feedforward control to the feedback control in 7, it is determined whether the set time Δt shown in FIG. 7 has elapsed. If the set time Δt is not reached, the control is terminated and the feedforward control step number map is not corrected. When the set time Δt has elapsed, the control is performed in step 23 corresponding to the actuator operation amount deviation calculating means in the present invention.
5, the actuator operation amount U = S _{FF at} the instant of switching from the feedforward control to the feedback control (instant t _{1 in} FIG. 7) and the actuator operation amount at the instant when the set time Δt has elapsed from the instant of switching. The step number deviation ΔU between U = S _FB is calculated. Here, the set time Δt is set to a predetermined long time within a range in which the target tilt angle φ ^* (target gear ratio) does not change.

In step 236, it is judged whether or not the step number deviation ΔU before and after the switching of the control mode is equal to or more than the set value ΔU _{S, and} if ΔU ≧ ΔU _S , it is possible to switch from the feedforward control to the feedback control. Since the shift shock does not occur, the control is ended as it is and the feedforward control step number map is not corrected. When it is determined in step 236 that ΔU ≧ ΔU _s , in step 237 corresponding to the feedforward control planned operation amount correcting means in the present invention, the current value in the feedforward step number map 120a (the same as that shown in FIG. 2) is calculated. The number of steps corresponding to the throttle opening TVO is corrected so that the deviation is reduced by the step number deviation ΔU.

Also in this example, the map used for determining the feedforward step number S _FF is modified in the same manner as in the above-mentioned embodiment, and the actual gear ratio (actual tilt rotation) at the time of switching from the feedforward control to the feedback control is changed. The time series change of the angle φ) can be changed from that shown by the solid line in FIG. 7 to that shown by the two-dot chain line.
Therefore, the actuator operation amount calculated by the feedforward control (the number of feedforward steps S _FF )
However, it is possible to reduce the deviation between the actual gear ratio and the target gear ratio during the feedforward control by taking into consideration disturbances such as torque shift that changes with each other, which changes the target gear ratio. The actual gear ratio does not change due to switching from feedforward control to feedback control regardless of driving conditions, and eliminates the discomfort that the occupant of the vehicle suddenly feels a shift shock when switching the control mode. be able to.

In each of the above embodiments, the set time Δt in FIG. 7 is a constant value.
It is more practical to make t variable by the processing shown in the subroutine of FIG. Therefore, the subroutine of FIG. 5 is basically the same as the subroutine of FIG.
It is assumed that steps 241 and 242 are added between steps 232 and 233 of the subroutine. Step 2
In step 41, reference is made to a planned map which defines a suitable relationship between the step number deviation ΔU before and after the control mode switching obtained by the previous calculation and the set time Δt, and step 242
Then, the set time Δt corresponding to the step number deviation ΔU is obtained from the map by searching. Here, the set time Δt is
It goes without saying that it is increased as the step number deviation ΔU increases.

Therefore, in step 234, after the switching from the feedforward control to the feedback control, the set time Δt at the time of determining whether the set time Δt has elapsed is the step number deviation ΔU obtained by the previous calculation. As a result, the step number deviation ΔU obtained in step 235 this time more accurately represents the degree of disturbance such as torque shift, and the map correction described above is accurately performed without excess or deficiency. The convergence to the value can be accelerated.

FIG. 6 shows still another example of the subroutine shown in FIG. 4. The subroutine of this example is step 2 shown in FIG.
51 and 252 are added. In step 251, it is determined whether or not the determination result of ΔU ≧ ΔU _S has occurred a predetermined number of times in succession in step 236. Only when the determination result of ΔU ≧ ΔU _S has been issued a predetermined number of times in succession, step 237 is performed. The map will be modified in. When modifying the map in step 237, refer to step 2
At 52, the average value ΔU _ave of the step number deviation ΔU during the predetermined number of times is obtained, and the feedforward control step number map is corrected by this average value ΔU _ave .

In the configuration of this example, the step number deviation ΔU before and after the switching of the control mode is the set value ΔU _S
The feed forward control step number map is corrected only when the above determination results occur a predetermined number of times in succession, so that the map correction is prevented from being made erroneously or unnecessary. Therefore, the accuracy of the correction can be ensured.

Further, in this example, when the map is corrected, the correction amount is set to the average value ΔU _{ave of} all the step number deviations ΔU during the switching from the feedforward control to the feedback control for the predetermined number of times. Can be made correct and accurate, and the correction can be made more accurate.

In each of the above-described embodiments, when it is determined that the feedforward control should be switched to the feedback control, the vehicle speed VSP is used to make the determination. It is also possible to use the above determination criteria as the time of engagement or the time of engagement of the starting friction element. Especially in continuously variable transmissions, the fluid transmission device such as the torque converter in the preceding stage is brought into the lockup state in which the input and output elements are directly connected to each other at an early stage. It is more likely that this will occur after the vehicle is up, and the effect of reducing the shift shock due to the above map modification becomes more pronounced.

[Brief description of drawings]

FIG. 1 is a schematic vertical cross-sectional side view illustrating a toroidal type continuously variable transmission to be subjected to gear shift control by a device of the present invention.

FIG. 2 is a diagrammatic vertical sectional front view showing the toroidal-type continuously variable transmission together with its shift control system.

FIG. 3 is a flowchart showing a main routine of a shift control program executed by a controller of the toroidal type continuously variable transmission.

FIG. 4 is a flowchart of a subroutine showing a feedback control program and a feedforward control actuator operation amount map correction program in the shift control program.

FIG. 5 is a flowchart showing another example of the same subroutine.

FIG. 6 is a flowchart showing still another example of the same subroutine.

FIG. 7 shows the state of deviation between the target gear ratio and the actual gear ratio when the feedforward control is switched to the feedback control, before and after the correction of the feedforward control step number map. It is an operation time chart shown in comparison.

[Explanation of symbols]

20 Torque converter 30 Forward / reverse switching mechanism 40 Toroidal type continuously variable transmission 44 Toroidal transmission unit 44 _a Input cone disc 44 _b Output cone disc 44 _C Power roller 44 _d Power roller 46 Toroidal transmission unit 46 _a Input cone disc 46 _b Output cone Disc 46 _C Power roller 46 _d Power roller 56 Loading cam 60 Output gear 62 Counter gear 64 Counter shaft 70 Pivot pin 71 Trunnion 73 Upper link 75 Lower link 78 Piston 83 Shift control valve 86 Precess cam 87 Shift link 88 Step motor (shift actuator) 100 Controller 100a Target tilt angle calculation unit 100b Actual tilt angle calculation unit 100c Control mode switching determination unit 101 Throttle opening sensor 102 Vehicle speed sensor 103 Input rotation sensor 104 Output rotation sensor 110 Actuator operation amount calculation unit 120 Feed forward control Part 120a feedforward step number map 120b map correction part (planned operation amount correction means for feedforward control) 130 feedback control part 130a feedback step calculation part 130b step number deviation calculation part (actuator operation amount deviation calculation part) 130c timer 140 control mode Switch

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Claims (5)

[Claims] 1. A feed-forward control in which a continuously variable shift is generated by operating an actuator, and an operation amount of the actuator is set to a predetermined operation amount corresponding to a target gear ratio, and an operation amount of the actuator is set to a target gear ratio and In a continuously variable transmission adapted to switch and use feedback control that is determined according to a gear ratio deviation between actual gear ratios, an actuator operation amount at the time of switching from the feedforward control to the feedback control and a set time from the switching. An actuator operation amount deviation calculation means for calculating an actuator operation amount deviation between the actuator operation amount at the time of elapse and an actuator operation amount to be used in the feedforward control are calculated by the calculated actuator operation amount deviation. Modify to decrease The shift control device for a continuously variable transmission, characterized by comprising a feed-forward control for scheduled operation quantity correction means. 2. The feed forward control planned manipulated variable correction according to claim 1, wherein the actuator manipulated variable to be used in the feed forward control is determined for each throttle opening of the engine in the preceding stage of the transmission. A shift control device for a continuously variable transmission, wherein the means is configured to correct the predetermined actuator operation amount corresponding to an engine throttle opening when switching from feedforward control to feedback control. 3. The shift control device for a continuously variable transmission according to claim 1, wherein the set time is set according to the calculated actuator operation amount deviation. 4. The feedforward control planned manipulated variable correcting means according to claim 1, wherein the actuator manipulated variable deviation is equal to or larger than a set deviation, and the feedforward control is switched to the feedback control. A shift control device for a continuously variable transmission, characterized in that when a predetermined number of times continues, a predetermined actuator operation amount is corrected. 5. The scheduled operation amount correcting means for feedforward control according to claim 4, when the scheduled operation amount of the actuator is corrected, the correction amount is switched from the feedforward control of the predetermined number of times to the feedback control. A shift control device for a continuously variable transmission, wherein the shift control device is configured to make a determination based on all of the deviations in the actuator operation amount.