JP2005163940A - Shift control device for continuously variable transmission - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve the accuracy in controlling gear shift by inhibiting the undershoot of an actual change gear ratio caused by the delay in response in feedback control and the compensation of torque shift by feed forward. <P>SOLUTION: A compensator 53e for compensating torque shift in a toroidal type continuously variable transmission prevents the enlargement of deviation of change gear ratio by temporarily inhibiting the compensation of torque shift when the variation of accelerator stepping amount becomes more than a predetermined value in a case when the deviation between a target change gear ratio and the actual change gear ratio becomes more than a predetermined value E1. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an improvement in a transmission control device for a continuously variable transmission used in a vehicle or the like.

  In a toroidal-type continuously variable transmission, the gear speed is controlled while the torque reaction force is supported by the servo oil pressure, so the servo oil pressure also fluctuates as the input torque fluctuates. A phenomenon called torque shift occurs.

In order to compensate for this torque shift, conventionally, a torque shift compensator is added to perform feedforward compensation (Patent Document 1). The configuration of this torque shift compensator is shown in FIG. The controller including the torque shift compensator detects the input torque to the toroidal continuously variable transmission transmitted from the engine controller, or estimates it from a predetermined map using the throttle opening, and according to the input torque and the gear ratio. The torque shift compensation (estimated) map output value is obtained from the torque shift compensation map shown in FIG. Next, a value obtained by smoothly changing the torque shift compensation map output value by a time constant according to the driving state (value obtained by applying a low-pass filter) was determined as a torque shift compensation value, and offset correction was performed from the target gear ratio. .
JP 2001-99298 A

  However, in the above conventional example, if the accelerator is stepped on suddenly with the actual gear ratio being far behind the target gear ratio, the delay amount and the torque shift compensation amount overlap each other, as shown in FIGS. As described above, there is a problem that undershoot (X portion in the figure) occurs.

  For example, as shown in FIGS. 15 and 16, consider a case where the actual gear ratio follows the target gear ratio with a delay with respect to the target gear ratio by feedback control during sudden deceleration or the like. Note that this gear ratio deviation generally occurs during the transition of feedback control.

  In this state, when the accelerator is depressed at time A and suddenly accelerates, a large engine torque is generated, so that the torque shift compensator is activated, and correction is performed so that the gear ratio becomes Hi as the input torque increases. However, in this case, since the actual speed ratio is originally located on the Hi side with respect to the target speed ratio, if the torque shift compensation corresponding to the increase in the input torque is performed, the Hi side is further corrected, so feedback Since the deviation on the Hi side due to the control delay and the correction to the Hi side overlap with the torque shift compensation, the deviation is further opened. For this reason, there is a problem that undershoot occurs in the actual gear ratio as shown by X in the figure, which gives the driver a sense of discomfort.

  Accordingly, the present invention has been made in view of the above-described problems, and suppresses an undershoot of the actual gear ratio caused by a response delay in feedback control and torque shift compensation by feedforward, thereby improving the accuracy of the shift control. With the goal.

  The present invention provides a toroidal-type continuously variable transmission that performs feedback control of a gear ratio, when torque shift compensation is performed, if the deviation amount between the target gear ratio and the actual gear ratio is equal to or greater than a predetermined value E1. When the amount of change in the accelerator operation amount exceeds a predetermined value due to depression, torque shift compensation is temporarily prohibited to prevent the gear ratio deviation from being enlarged.

  Therefore, according to the present invention, when the accelerator is stepped on in a state where the actual gear ratio is greatly delayed from the target gear ratio by feedback control, such as during sudden deceleration, torque shift compensation is performed. The gear ratio is further corrected to the Hi side, but since the torque shift compensation is temporarily prohibited at this time, the actual gear ratio that has become the Hi side is brought close to the target gear ratio by the torque shift, and Prevents undershoot as in the example, and makes it possible to obtain good tracking performance by matching the target gear ratio with the actual gear ratio, improving the drivability of a vehicle equipped with a toroidal-type continuously variable transmission. It becomes.

  Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.

  FIG. 1 shows an example in which the present invention is applied to a single cavity toroidal continuously variable transmission in which a plurality of power rollers 21 are sandwiched between a pair of an input disk 20a and an output disk 20b. An engine 1 is connected to the type continuously variable transmission 10 via a torque converter 11 having a lock-up clutch L / U, and a step motor 3 as an actuator that responds to a command value of the speed change controller 2 is provided with a speed change control valve. The gear ratio is continuously controlled via a hydraulic control device such as the above.

  The speed change control controller 2 converts the range signal POS from the inhibitor switch 9 and the throttle opening TVO (or accelerator depression amount APS) corresponding to the driver's accelerator pedal (not shown) operation from the accelerator operation amount sensor 5 toroidal type. The input shaft rotation speed Ni detected by the input shaft rotation sensor 6 of the continuously variable transmission 10, the output shaft rotation speed No detected by the output shaft rotation sensor 4, the oil temperature from the oil temperature sensor (not shown), and the vehicle speed sensor 7 The vehicle speed VSP detected by is read. The inhibitor switch 9 includes a manual mode and generates an upshift or downshift command signal in accordance with a driver's operation.

  The shift controller 2 communicates with the engine controller 12 to read the engine rotational speed Ne and the engine output torque detected by the crank angle sensor 8.

Then, the speed change controller 2 corrects the ultimate speed ratio i _PT and the command speed ratio i _PC corresponding to these operating states with the torque shift compensation amount corresponding to the input torque Tin (≈Teng) and the actual speed ratio i _PR. Thus, the command speed ratio i _PC and the actual speed ratio i _PR are smoothly changed. The command speed ratio i _PC is a target value for each control cycle toward the ultimate speed ratio i _PT .

  In the toroidal type continuously variable transmission, as shown in FIG. 2, a pivot shaft 22 that pivotally supports a power roller 21 is provided on a trunnion 23 that is rotatable about an axis and that is displaceable in an axial direction. The pivot shaft 22 is supported by a trunnion 23 on the base end side so as to be swingable. A hydraulic cylinder 50 is connected to the proximal end side rod 23 a of the trunnion 23 to drive the trunnion 23 in the axial direction in accordance with the hydraulic pressure from the transmission control valve 60.

  For this reason, the shift control valve 60 is driven by a step motor 3 (actuator) controlled by the shift controller 2 and controls the intake and discharge of the pressure oil to and from the hydraulic cylinder 50.

  Further, the toroidal continuously variable transmission is provided with a mechanical feedback mechanism, and a recess cam 45 is fixed to the lower end of the rod 23a of the trunnion 23. The rotation (= tilting) of 23 and the axial displacement are fed back to the transmission control valve 60, and the transmission control valve 60 corrects the pressure oil supplied to the hydraulic cylinder 50 in accordance with the mechanical feedback amount. The shift control valve 60 is configured by a valve in which a spool driven by the step motor 3 and a sleeve driven by a feedback link are combined on the same axis. The inclined surface 45a of the precess cam 45 is provided with a steeply inclined portion for increasing the gain of mechanical feedback on the lowest and highest Hi sides, so that the tilt angle of the trunnion 23 exceeds the lowest or highest Hi. A collision with a stopper (not shown) is prevented.

  Next, a torque shift that occurs in the toroidal type continuously variable transmission as described above will be described with reference to FIG.

  When the input torque transmitted from the input disk 20a to the power roller 21 increases, the clamping force of the power roller 21 increases between the input disk 20a and the output disk 20b due to the action of a loading cam mechanism (not shown). The thrust force Th generated on the roller 21 increases. As the thrust force Th increases, the trunnion 23 connected by the upper and lower links 41 and 42 is elastically deformed and bent as shown by a broken line in the figure, and as a result, the recess cam 45 provided at the lower end of the rod 23a is inclined.

  Due to the inclination of the recess cam 45, the cam surface 45a is also displaced as indicated by the wavy line in the figure, and the feedback link 44 that is in sliding contact with the displaced cam surface is displaced as indicated by the broken line in the figure. 60 spools shift. Since the differential pressure of the hydraulic cylinder 50 changes in accordance with this “spool deviation”, the tilt angle (transmission ratio) of the power roller 21 deviates from the target value, which becomes a torque shift.

  The second factor is that the pivot shaft 22 that pivotally supports the power roller 21 is supported at its base end by a trunnion 23 so as to be swingable. However, when input torque is applied to the power roller 21, the pivot shaft 22 and the trunnion 23 are supported. The axis of the power roller 21 deviates from the axis of the input disk 20a as shown by a two-dot chain line in the figure (hereinafter referred to as the power line). (Shift of the roller) causes a shift to the larger side of the gear ratio, which becomes a torque shift.

  For example, when torque is input to the continuously variable transmission, the trunnion 23 is deformed, and a “spool displacement” occurs, there is almost no delay in the movement of the step motor (actuator) relative to the “spool displacement”. It is possible to follow (the step motor only needs to move at a speed corresponding to the deviation).

  FIG. 3 is a block diagram of a main part of the shift control system. The transmission control system is roughly divided into a dynamic characteristic compensation unit 53a, a response compensation unit 53b, a transmission ratio command value conversion unit (transmission ratio step number conversion map in the figure) 54, and a continuously variable transmission (step) to be controlled. Motor, hydraulic control unit (transmission control valve 60 and the like), and transmission mechanism unit).

A reaching speed ratio i _PT from an unillustrated reaching speed ratio calculating section is input to the dynamic characteristic compensating section 53a and the responsiveness compensating section 53b.

Note that, in the reaching gear ratio calculation unit, as in the conventional example, the operating range (D range, L range, M range, etc.) set by the inhibitor switch 9, the throttle opening TVO, the detected oil temperature, and the vehicle speed VSP are used. The ultimate transmission ratio i _PT is obtained from a preset map or the like.

The dynamic characteristic compensation unit 53a outputs a dynamic characteristic compensation output i _PFF by feedforward, and the responsiveness compensation unit 53b outputs a dynamic characteristic compensation output correction value i _PFB by feedback (for example, PI control).

Further, the torque shift compensator 53e, the real speed ratio i _PR from a real speed ratio calculation section (not shown), the engine output torque Teng of the engine controller 12 is input by the feed-forward, the torque shift compensation amount TSRTO Output.

The actual speed ratio i _PR is calculated from the detected input shaft rotational speed Ni and output shaft rotational speed No.

より求める。

Ask more.

  Here, the dynamic characteristics of the toroidal-type continuously variable transmission 10 (hereinafter simply referred to as a continuously variable transmission) can be expressed by the third order / fourth order as shown in the following equation.

ただし、Ｋｐ：無段変速機１０のゲイン。

Kp: gain of continuously variable transmission 10

n3, n2, n1, n0, d4, d3, d2, d1, d0: parameters representing the dynamic characteristics of the continuously variable transmission.

Since the speed ratio of the speed change mechanism portion with respect to the angular position of the step motor 3 is not proportional as shown in FIG. 4, the gain Kp of the continuously variable transmission is calculated according to the actual speed ratio i _PR of the speed change mechanism portion. . Further, each coefficient in the above equation (2) representing the dynamic characteristics of the continuously variable transmission changes according to the output shaft rotational speed No. Therefore, the coefficient is created from the output shaft rotational speed No based on an identification experiment or the like, and a predetermined map. Is calculated with reference to FIG.

  Since the gain of the continuously variable transmission is represented by Kp, each coefficient is determined so that the steady gain of the term indicating the transfer characteristic is 1. Based on the above, each element of the shift control system shown in FIG. 3 will be described.

  First, the dynamic characteristic compensator 53a is a so-called feedforward compensator, and a gear ratio response desired by the designer is given by the following equation.

但し、ζ、ω：設計者が希望する変速比応答を得るためのパラメータである。

Here, ζ, ω are parameters for obtaining the speed ratio response desired by the designer.

The dynamic characteristic compensation output i _PFF is calculated based on the following equation (4) so that the actual speed ratio i _PR follows the dynamic characteristic G _T (s).

つまり、動特性補償部５３ａは４次／５次フィルタで構成される。

That is, the dynamic characteristic compensator 53a is configured with a fourth-order / fifth-order filter.

  Next, the responsiveness compensation unit 53b includes a target gear ratio calculation unit 53c and a dynamic characteristic compensation output correction unit 53d (feedback compensator).

The target speed ratio calculating unit 53c, the designer inputs the attained gear ratio i _PT is calculated based the target speed ratio i _PM is a lever ratio desired response in the following equation (5). The target speed ratio i _PM is a transient target speed ratio until the actual speed ratio i _PR reaches the final speed ratio i _PT .

動特性補償出力補正部５３ｄでは、積分特性を有し、制御対象のパラメータの変化に対し安定性が補償されているフィルタを用いて動特性補償出力補正値ｉ_PFBを、次の（６）式の偏差量ｉ_ERRから算出する。

In the dynamic characteristic compensation output correction unit 53d, the dynamic characteristic compensation output correction value i _PFB is expressed by the following equation (6) using a filter having an integral characteristic and whose stability is compensated for a change in the parameter to be controlled. The deviation amount i is calculated from _ERR .

次にトルクシフト補償部５３ｅについて説明する。

Next, the torque shift compensation unit 53e will be described.

  First, as the engine torque Teng, an estimated value of the engine torque received from the engine controller 12 or an estimated value converted from the throttle opening TVO (or the accelerator operation amount APS) by a predetermined map is used. The engine torque Teng only needs to indicate the input torque of the toroidal continuously variable transmission 10.

  As shown in FIG. 5, the torque shift compensation unit 53e is divided into a map calculation unit C10 and an output determination unit C11. An example of the control performed by the torque shift compensator 53e is shown in the flowchart of FIG.

First, step S1 shown in FIG. 6 shows a map calculation unit C10, which receives a gear ratio (actual gear ratio i _PR or target gear ratio i _PM ) and engine torque Teng as input, and a torque shift compensation map ( A torque shift compensation map value is obtained from FIG. 14) of the conventional example, and a torque shift compensation map output TRQSFT_M is calculated by multiplying the torque shift compensation map value by -1.

  Next, the output determination unit C11 determines whether to output or stop the torque shift compensation map output TRQSFT_M (S2 to Sll in FIG. 6), and determines the torque shift compensation amount TSRTO (S12 and S13 in FIG. 6). .

  Here, when outputting the torque shift compensation amount, TSRTO = TRQSFT_M, and when stopping the output, TSRTO = 0. However, when torque shift compensation is stopped or when restarting from a stopped state, the output is smoothly changed.

  In order to realize this, it can be realized by, for example, a first-order lag low-pass filter. That is, the state variable K indicating whether the torque shift compensation amount is output or stopped is determined, the stopped state is set to K = 0, the output state is set to K = 1, and the change in K is smoothly performed. Assuming that the value is A, the relationship between K and A can be expressed by the following equation (7) by the processing of S12 in FIG. Using A obtained from the equation (7), the torque shift compensation amount TSRTO can be expressed by the following equation (8) from S13 in FIG.

ただし、Ｔはローパスフィルタの時定数であり、最適な所定値に設定する。

However, T is a time constant of the low-pass filter, and is set to an optimum predetermined value.

  Here, the determination of whether to stop or output (selection method of the state variable K) is as shown in S2 to S11 of FIG. 6 and is performed as follows.

First, in the case of K = 1, the S2-S4 determination process of FIG. 6 is a predetermined value E1 or more with a deviation amount i _ERR between the target gear ratio and the actual gear ratio, such as when sudden deceleration (deceleration is a predetermined value or more). In this case, when the accelerator is depressed and the change amount ΔTVO of the throttle opening (or the accelerator operation amount) exceeds a predetermined value, the torque shift compensation is stopped (from S5 in FIG. 6, K = 0). . Note that the change amount ΔTVO of the throttle opening may be obtained, for example, from the difference between the current throttle opening TVO and the throttle opening during the previous control.

Next, because the torque shift compensation is stopped (K = 0), the process proceeds from the determination in S2 of FIG. 6 to S6. Due to the determination process in S6, a torque shift occurs and the actual speed ratio i _PR becomes the target speed ratio i. _{When PM} is exceeded, that is, when the deviation amount i _ERR exceeds the negative predetermined value E2, torque shift compensation is restarted (from Sll, K = 1). Further, if the deviation i _ERR has settled below a predetermined value E3 by the determination process of S7, or if the deviation i _ERR has settled below the predetermined value E3 even once, torque shift compensation is performed after the processes of S8 and S9. Is resumed (K = 1).

Here, when the torque shift compensation is being resumed, if the deviation amount i _ERR (or its absolute value), which is the determination process shown in S8 of FIG. 6, is greater than or equal to a predetermined value E4, it is smoothly changed by the process of S9. As shown in FIG. 7, the time constant T is increased in accordance with the deviation amount i _ERR (or its absolute value).

When the torque shift compensation is restarted, the processes in S7 to S9 are performed in order to suppress the deviation i _{ERR from} being opened because the feedback compensator cannot respond to the change because the torque shift compensation is suddenly resumed. When the amount i _ERR once settles below a predetermined value, the processes of S8 and S9 are performed.

  In the above case, the operation is performed when the accelerator is depressed. However, when the accelerator is released, that is, when the throttle opening TVO becomes 0 (S10 in FIG. 6), torque shift compensation is resumed ( K = 1).

In this way, the gear ratio command value i _pc is calculated from the equation (9) using the dynamic characteristic compensation unit output i _PFF , the dynamic characteristic compensation output correction value i _PFB, and the torque shift compensation unit output TSRTO.

この（９）式から算出される最終的な変速比指令値ｉ_pcを用いることにより、パラメータ変動や外乱の影響を受けにくく、かつ設計者が希望する変速比応答が得られる。

By using the final gear ratio command value i _pc calculated from the equation (9), it is difficult to be affected by parameter fluctuations and disturbances, and a gear ratio response desired by the designer can be obtained.

However, since the gear ratio of the transmission mechanism and the angular position of the step motor 3 are not in a proportional relationship, the gear ratio command value conversion unit 54 refers to the gear ratio-step number conversion map shown in FIG. The value i _pc is converted into a step motor angular position command value θc, which is output to the step motor 3.

  A response when the accelerator is depressed from sudden deceleration using the torque shift compensator 53e as described above will be described below.

First, in the control of the conventional example, as shown in FIG. 15 (an example near the lowest level) and FIG. 16 (an example other than the lowest level), the actual speed ratio i _PR is delayed with respect to the target speed ratio i _PM due to rapid deceleration. When following, the actual gear ratio (solid line in the figure) is lower than the target gear ratio (dashed line in the figure) toward the Hi side (small side), and the deviation i _ERR has a positive value. Become. At this time, when the accelerator is depressed, the engine torque Teng rises with the rise of the throttle opening TVO, and a torque shift occurs.

Torque shift due to depression of the accelerator raises the gear ratio to the Low side, but in order to compensate for the torque shift as the torque rises, it tries to correct the gear ratio to the Hi side. Here, in the conventional example shown in FIGS. 15 and 16, since the actual speed ratio i _PR is located on the Hi side with respect to the target speed ratio i _PM during the rapid deceleration, the torque shift compensation is performed and further on the Hi side. In order to apply the correction, the deviation amount i _ERR was increased more (X portion in the figure). In addition, hunting may occur depending on operating conditions.

In order to avoid this, in the present invention, as shown in FIG. 8 (an example near the lowest level) and FIG. 9 (an example other than the lowest level), the above condition, that is, the deviation amount i _ERR is equal to or greater than a predetermined value E1. In this case, when the throttle opening TVO becomes a predetermined value or more, the state variable K is set to K = 0, and torque shift compensation is stopped.

As a result, since the torque shift compensation is temporarily prohibited, the actual speed ratio i _PR is increased to the Low side due to the influence of the torque shift, and approaches the target speed ratio i _PM to obtain the deviation amount i _ERR . Can be small.

  As a result, it is possible to improve the target followability and to suppress unnecessary undershoot and hunting as shown in the conventional example, thereby improving the accuracy of the shift control.

  Next, a case where torque shift compensation is resumed after torque shift compensation is stopped (prohibited) as described above will be described below.

As shown in FIG. 8 and FIG. 9, when the deviation amount i _ERR settles below a predetermined amount E3 near 0 by the action of the feedback compensator (53d), it is determined that the state is stable, and the state variable K is set to K = 1. To resume torque shift compensation. At this time, by resuming the torque shift compensation, it is possible to perform appropriate torque shift compensation that can cope with each operation state.

Here, when resuming torque shift compensation according to the above equation (8), the amount of change in torque shift compensation is integrated by the feedback compensator (53d) so that the follow-up performance is maintained while the deviation i _ERR is kept small. Can do. However, when the change in torque shift compensation is fast, the feedback compensator cannot follow, and the deviation _iERR may increase. In this case, by increasing the time constant T as shown in FIG. 7, the change in torque shift compensation can be moderated, and the deviation amount i _ERR can be reduced as time D shown in FIG.

Further, when the change amount of the torque shift is larger than the deviation amount i _ERR , the actual speed ratio i _PR exceeds the target speed ratio i _PM and causes an overshoot as shown in FIG. In this case, since it takes time until the deviation amount i _ERR becomes small in the action by feedback compensation, the state variable K is set to K = 1, and torque shift compensation is resumed. As a result, by resuming the torque shift compensation, as shown by time CD in FIG. 11, the deviation can be quickly suppressed, and good followability can be obtained.

  Although the above-described operation and effect are operations when the accelerator is depressed, a case where the accelerator is released will be described below.

When the torque shift compensation is stopped as described above, if the accelerator is released, if the torque shift compensation is stopped, the influence of the torque shift after time C as shown by the dotted line in FIG. As a result, the actual speed ratio i _PR is shifted to the Hi side, resulting in a deviation.

  For this reason, when the accelerator is released, that is, when the throttle opening TVO becomes 0, the state variable K is set to K = 1, and the torque shift compensation is immediately restarted as shown in FIG. Therefore, it is possible to obtain a good follow-up performance by suppressing the influence of the torque shift at.

As described above, according to the present invention, when the deviation amount i _ERR between the target gear ratio and the actual gear ratio is equal to or greater than the predetermined value E1, the change amount ΔTVO of the throttle opening due to depression of the accelerator becomes equal to or greater than the predetermined value. When the torque shift compensation amount acts in the direction of increasing the gear ratio deviation, the torque shift compensation is temporarily prohibited.

As a result, torque shift compensation is performed when the accelerator is depressed in a state where the actual gear ratio is below the Hi side and the deviation is large with respect to the target gear ratio, such as during sudden deceleration. The gear ratio is further corrected to the Hi side, which increases the amount of deviation. In such a case, the torque shift works in a direction to increase the gear ratio to the low side and reduce the deviation i _ERR. Therefore, by stopping the torque shift compensator or setting the torque shift compensation amount = 0, By suppressing undershoot and hunting of the actual gear ratio, the target gear ratio and the actual gear ratio can be matched to obtain good followability, and the drivability of a vehicle equipped with a toroidal type continuously variable transmission Can be improved.

Then, when the deviation i _ERR between the target gear ratio and the actual gear ratio settles below the predetermined value E3 (near 0) due to temporary prohibition of torque shift compensation (when the change amount of the torque shift is small), the torque shift is resumed. To do.

When the torque shift change amount due to depression of the accelerator is small, the deviation amount caused by the torque shift is reduced, and the deviation is further reduced by the action of the feedback compensator (53d). At this time, a state in which the deviation amount i _ERR is equal to or less than a predetermined value (near 0) is determined as a stable state, and the torque shift compensation amount is gradually returned to a normal value. As a result, the feedback compensator is integrated, but appropriate torque shift compensation can be performed, and it becomes possible to cope with the subsequent driving situation.

Further, when the actual speed ratio becomes larger than the target speed ratio due to torque shift, that is, when the deviation amount i _ERR becomes equal to or less than the negative predetermined value E2, torque shift compensation is resumed.

  Under conditions where the amount of change in torque shift due to accelerator depression is large, the actual gear ratio may exceed the target gear ratio due to torque shift by temporarily prohibiting torque shift compensation. Under such conditions, by quickly restarting the torque shift compensation, the deviation amount can be minimized, and the follow-up performance of the shift control can be improved.

  Further, when the accelerator is released after the accelerator is depressed to temporarily disable the torque shift compensation, that is, when the throttle opening becomes zero, the torque shift compensation is resumed.

When the accelerator is released, if the torque shift compensation is stopped, a torque shift to the Hi side occurs due to the transmission torque on the engine break side, so that the gear ratio deviation i _ERR is further increased. For this reason, it is possible to suppress the torque shift by quickly restarting the torque shift compensation, and to ensure the accuracy of the shift control after preventing the undershoot of the actual gear ratio when the accelerator is depressed.

Furthermore, when the torque shift compensation is resumed, if the deviation i _ERR has settled below a predetermined value even once, the torque shift compensation amount will be exceeded if the deviation i _ERR (or its absolute value) exceeds a predetermined value E4. Since the time constant T for smoothly changing the torque is increased according to the deviation amount (or its absolute value), the feedback compensator can follow this change in the process of restarting the torque shift compensation. If the deviation amount (or its absolute value) exceeds a predetermined value, the time constant T for smooth change is increased according to the deviation amount i _ERR (or its absolute value) to provide feedback compensation. Thus, it is possible to effectively act the device, improve followability with respect to the target gear ratio, and improve the accuracy of the shift control.

  In the above embodiment, the determination of the rapid deceleration may be performed by detecting the deceleration (or acceleration) of the vehicle and determining that the deceleration is abrupt when the deceleration is equal to or greater than a predetermined deceleration.

  As described above, in the continuously variable transmission control device according to the present invention, the torque shift of the toroidal continuously variable transmission can be accurately compensated and the follow-up performance of the feedback control can be ensured. The present invention can be applied to a shift control device for a continuously variable transmission for a vehicle.

The system block diagram of the continuously variable transmission which shows embodiment of this invention. Similarly, the principal part sectional drawing of a trunnion is shown. The block diagram which shows the principal part of a transmission control controller similarly. The map which shows the relationship between the position of a step motor and a gear ratio. The block diagram which shows the content of the torque shift compensation part. The flowchart which shows an example of control of a torque shift compensation part. A map showing the relationship between the gear ratio deviation and the time constant T. The graph showing the operation shows the relationship between the throttle opening, the gear ratio, the torque shift compensation amount, the feedback compensation amount, the engine torque, and the time when the accelerator is depressed and is near the lowest. The graph showing the action shows the relationship between the throttle opening, the gear ratio, the torque shift compensation amount, the feedback compensation amount, the engine torque, and the time when the accelerator is depressed and the vicinity is not near the lowest. The graph showing the operation shows the relationship between the throttle opening, the gear ratio, the torque shift compensation amount, the feedback compensation amount, the engine torque and the time when the change in the torque shift compensation amount is large when resuming the torque shift compensation. The graph showing the action shows the relationship between the throttle opening, the gear ratio, the torque shift compensation amount, the feedback compensation amount, the engine torque, and the time when the actual gear ratio is overshooted when the accelerator is depressed. The graph showing the operation shows the relationship between throttle opening, gear ratio, torque shift compensation amount, feedback compensation amount, engine torque and time when the accelerator is released after the accelerator is depressed. The block diagram which shows the principal part of the conventional transmission control controller. The map which shows the relationship between the input torque which used the gear ratio as a parameter, and a torque shift compensation amount. A conventional example is shown, and shows the relationship between the throttle opening, the gear ratio, the torque shift compensation amount, the feedback compensation amount, the engine torque, and the time when the accelerator is depressed and is near the lowest. Similarly, the conventional example is shown, and the relationship between the throttle opening, the gear ratio, the torque shift compensation amount, the feedback compensation amount, the engine torque, and the time when the accelerator is depressed and other than near the lowest is shown.

Explanation of symbols

2 Shift control controller 3 Step motor 10 Toroidal type continuously variable transmission 12 Engine control controller 20a Input disk 20b Output disk 21 Power roller 23 Trunnion 45 Precess cam 50 Hydraulic cylinder 53a Dynamic characteristic compensation part 53b Responsiveness compensation part 53d Dynamic characteristic compensation output correction 53e Torque shift compensation unit 60 Shift control valve

Claims (10)

A trunnion that rotatably supports a power roller that transmits driving force between the input and output disks;
A shift control valve that supplies hydraulic pressure to a hydraulic actuator that drives the trunnion;
A speed change actuator for driving the speed change control valve;
A feedback compensation means for calculating a target speed ratio according to the driving state and calculating a drive amount of the speed change actuator such that an actual speed ratio matches the target speed ratio;
Input torque detection means for detecting input torque;
Torque shift compensation amount calculating means for calculating a torque shift compensation amount based on the input torque;
A shift actuator control means for calculating a command value to the shift actuator based on a drive amount of the shift actuator and a torque shift compensation amount, and controlling the shift actuator;
A shift control device for a continuously variable transmission, comprising: a mechanical feedback mechanism coupled to the trunnion and the shift control valve, and feeding back a displacement amount of the trunnion to the shift control valve;
The torque shift compensation amount calculating means includes:
A speed change control device for a continuously variable transmission, comprising: a compensation prohibiting means for prohibiting torque shift compensation when the input torque increases with the actual speed ratio being delayed with respect to the target speed ratio.   The shift control apparatus for a continuously variable transmission according to claim 1, wherein the compensation prohibiting means smoothly changes the torque shift compensation amount toward zero.   The compensation prohibiting means includes gear ratio deviation calculating means for calculating a deviation between the actual gear ratio and the target gear ratio, and when the deviation is equal to or greater than a predetermined value, the actual gear ratio is delayed with respect to the target gear ratio. The shift control device for a continuously variable transmission according to claim 1 or 2, wherein it is determined that the state is accompanied. A deceleration detecting means for detecting deceleration of the vehicle, and a rapid deceleration detecting means for detecting sudden deceleration when the deceleration is equal to or greater than a predetermined deceleration,
3. The compensation prohibiting means determines that the actual gear ratio is in a state with a delay with respect to a target gear ratio when the sudden deceleration is determined. A transmission control device for a continuously variable transmission. Accelerator operation amount detection means for detecting the operation amount of the accelerator pedal is provided,
The shift control device for a continuously variable transmission according to claim 1 or 2, wherein the compensation prohibiting means determines an increase in input torque when a change amount of an accelerator operation amount is a predetermined amount or more.   6. The compensation prohibiting means restarts the torque shift compensation when the deviation between the actual gear ratio and the target gear ratio is eliminated or becomes equal to or less than a predetermined deviation. Shift control device for continuously variable transmission.   6. The continuously variable transmission according to claim 1, wherein the compensation prohibiting unit restarts torque shift compensation when an actual speed ratio becomes larger than a target speed ratio. Shift control device. Accelerator operation amount detection means for detecting the operation amount of the accelerator pedal is provided,
The shift control device for a continuously variable transmission according to any one of claims 1 to 5, wherein the compensation prohibiting means restarts torque shift compensation when the accelerator pedal is released.   9. The compensation prohibiting means smoothly changes a torque shift compensation amount from 0 to a value based on the input torque when resuming torque shift compensation. Shift control device for continuously variable transmission.   If the deviation between the actual gear ratio and the target gear ratio exceeds a predetermined value when resuming torque shift compensation, the compensation prohibiting means sets the torque shift compensation amount from 0 based on the input torque according to a time constant. The speed change control device for a continuously variable transmission according to claim 10, wherein the time constant is increased as the deviation increases, and the time constant is increased.

Images