JP4649907B2 - Control device for continuously variable transmission - Google Patents

Description

  The present invention relates to a control device for a continuously variable transmission, and more particularly to a device that performs shift control of a continuously variable transmission.

  Conventional examples of continuously variable transmission control devices are disclosed in Patent Documents 1 to 3 listed below. In Patent Document 1, the engine and the continuously variable transmission are controlled by calculating an operation amount for making the vehicle acceleration estimated value coincide with the target acceleration by a model following control method using a state space method. The state feedback gain is switched based on the vehicle speed detection value and the input torque to the continuously variable transmission.

  In Patent Documents 2 and 3, feedback control is performed based on the deviation between the actual speed ratio and the target speed ratio so that the actual speed ratio matches the target speed ratio. And in patent document 2, when the start of a vehicle is detected, the feedback gain is increased. In Patent Document 3, the feedback gain is determined from the hydraulic pressure, the oil temperature, the gear ratio, and the output shaft rotation speed of the hydraulic control mechanism.

  In addition, the control devices for continuously variable transmissions of Patent Documents 4 to 8 listed below are disclosed.

JP 2002-36917 A JP 2000-39063 A JP-A-11-141670 Special Table 2002-523711 JP 2001-108084 A JP 2000-193074 A JP 2001-330113 A JP 2004-108482 A

  As will be described below, the continuously variable transmission has a non-linear characteristic regarding a gear ratio. For example, in a belt-type continuously variable transmission that can change the gear ratio by changing the belt diameter of the primary pulley and the secondary pulley, as shown in FIG. 3, the gear ratio γ and the oil of the primary pulley The characteristic between the pressure and the pressure difference ΔP between the oil pressures of the secondary pulley is nonlinear. In a toroidal continuously variable transmission that can change the gear ratio by changing the tilt angle of the rollers sandwiched between the input disk and the output disk, as shown in FIG. And the roller tilt angle θ become nonlinear. Due to this non-linear characteristic related to the gear ratio, the response of the speed change control is likely to change with respect to the change in the operating state of the continuously variable transmission.

  In Patent Documents 1 to 3, although the feedback gain is variable, an appropriate feedback gain is not set in consideration of the above-described nonlinear characteristic related to the gear ratio, so that the gear shift is performed in response to a change in the operating state of the continuously variable transmission. There is a problem that it is difficult to stabilize the responsiveness of the control.

  An object of the present invention is to provide a control device for a continuously variable transmission that can stabilize the responsiveness of shift control with respect to changes in the operating state of the continuously variable transmission.

A control device for a continuously variable transmission according to a reference example of the present invention transmits power from an input rotation element to an output rotation element via a power transmission element, and a contact diameter of the power transmission element to the input rotation element and the output rotation element. Is a device that performs shift control of a continuously variable transmission that can change a gear ratio by changing the speed ratio by an actuator, and performs a shift based on a deviation between a target value of the shift control and a detected value of the shift control, and a shift control gain. A shift control command value calculating unit that calculates a control command value and controls the actuator according to the shift control command value; and the shift control with respect to a decrease in a target value of the shift control or a decrease in a detected value of the shift control And a shift control gain setting unit that increases the gain.

In the control device for a continuously variable transmission according to the reference example of the present invention, the shift control gain setting unit substantially satisfies a relationship in which the shift control gain is inversely proportional to a target value of the shift control or a detection value of the shift control. In this manner, the shift control gain can be set.

In the continuously variable transmission control apparatus according to the reference example of the present invention , the target value of the shift control may be a target gear ratio, and the detected value of the shift control may be a detected gear ratio.

In the control device for a continuously variable transmission according to a reference example of the present invention , the target value of the shift control is a target rotation speed of the input rotation element, and the detection value of the shift control is a detection rotation speed of the input rotation element. It can also be.

  The control device for a continuously variable transmission according to the present invention transmits power from the input rotation element to the output rotation element via the power transmission element, and sets the contact diameter of the power transmission element to the input rotation element and the output rotation element. A logarithmic deviation for calculating the deviation between the logarithm of the target value of the shift control and the logarithm of the detected value of the shift control, which is a device for performing the shift control of the continuously variable transmission capable of changing the gear ratio by being changed by an actuator And a shift control command value calculation unit that calculates a shift control command value based on the deviation calculated by the logarithmic deviation calculation unit and controls the actuator based on the shift control command value. And

  In the control device for a continuously variable transmission according to the present invention, the logarithmic deviation calculation unit calculates a logarithm of a ratio between a target value of the shift control and a detection value of the shift control, thereby obtaining a target value of the shift control. It is also possible to calculate a deviation between the logarithm of the shift and the logarithm of the detection value of the shift control.

  In the control device for a continuously variable transmission according to the present invention, the logarithmic deviation calculating unit may calculate the logarithm of the target speed ratio and the detected speed ratio as a deviation between the logarithm of the target value of the speed change control and the logarithm of the detected value of the speed change control. Or the deviation between the logarithm of the target rotational speed of the input rotational element and the logarithm of the detected rotational speed of the input rotational element.

  In the control device for a continuously variable transmission according to the present invention, the input rotation element is a primary pulley, the output rotation element is a secondary pulley, and the power transmission element is a belt wound around the primary pulley and the secondary pulley. It can also be.

  In the control device for a continuously variable transmission according to the present invention, the input rotation element is an input disk, the output rotation element is an output disk, and the power transmission element is sandwiched between the input disk and the output disk. It can also be a roller.

In the continuously variable transmission control device according to the present invention, hydraulic pressure is applied to apply pulley thrust to the primary pulley and the secondary pulley, and the belt engagement diameters of the primary pulley and the secondary pulley are changed by the hydraulic actuator. Is a device that performs shift control of a belt-type continuously variable transmission that can change a gear ratio by controlling the shift control command based on a deviation between a target value of the shift control and a detected value of the shift control and a shift control gain. A shift control command value calculation unit that calculates the value and controls the actuator according to the shift control command value, and a pressure difference or a pressure ratio between the oil pressure supplied to the primary pulley and the oil pressure supplied to the secondary pulley. a shift control gain setting unit for changing the shift control gain, was closed to changes, the shift control gain setting unit, said gear The relationship control gain is proportional to an exponential function of the pressure difference or the pressure ratio to satisfy almost the gist to set the speed-change control gain.

  In the control device for a continuously variable transmission according to the present invention, the shift control gain setting unit may increase the shift control gain with respect to an increase in the pressure difference or the pressure ratio.

In the continuously variable transmission control device according to the present invention, hydraulic pressure is applied to apply pulley thrust to the primary pulley and the secondary pulley, and the belt engagement diameters of the primary pulley and the secondary pulley are changed by the hydraulic actuator. Is a device that performs shift control of a belt-type continuously variable transmission that can change a gear ratio by controlling the shift control command based on a deviation between a target value of the shift control and a detected value of the shift control and a shift control gain. A shift control command value calculation unit that calculates a value and controls the actuator according to the shift control command value, and changes the shift control gain with respect to a thrust difference or a thrust ratio change between the secondary pulley thrust and the primary pulley thrust have a, a shift control gain setting unit for, the shift control gain setting unit, the shift control gain is the thrust difference or The relationship that is inversely proportional to the exponential function of the serial thrust ratio to satisfy almost the gist to set the speed-change control gain.

  In the control device for a continuously variable transmission according to the present invention, the shift control gain setting unit may increase the shift control gain with respect to a decrease in the thrust difference or the thrust ratio.

  In the control device for a continuously variable transmission according to the present invention, the shift control command value calculation unit includes a deviation between a target gear ratio and a detected gear ratio as a deviation between the target value of the shift control and a detected value of the shift control, Alternatively, a deviation between the target rotational speed of the primary pulley and the detected rotational speed of the primary pulley can be used.

In the control device for continuously variable transmission according to the present invention, the roller is sandwiched between the input disk and the output disk, and the tilt angle of the roller is changed by the actuator so that the roller contacts the input disk and the output disk. A device for performing shift control of a toroidal continuously variable transmission capable of changing a gear ratio by changing a diameter, based on a deviation between a target value of shift control and a detected value of shift control, and a shift control gain A shift control command value calculation unit that calculates a shift control command value and controls the actuator according to the shift control command value; and the shift control command value with respect to an increase in a roller tilt angle that increases a contact diameter of the roller to the input disk. possess the shift control gain setting unit increases the control gain, and the shift control gain setting unit, Ho relationships that the shift control gain is proportional to an exponential function of the roller tilt angle As satisfied, and subject matter to set the speed-change control gain.

  In the control device for a continuously variable transmission according to the present invention, the shift control command value calculation unit includes a deviation between a target gear ratio and a detected gear ratio as a deviation between the target value of the shift control and a detected value of the shift control, Alternatively, the deviation between the target rotational speed of the input disk and the detected rotational speed of the input disk can be used.

  According to the present invention, the responsiveness of the shift control can be stabilized with respect to changes in the operating state of the continuously variable transmission, and the shift control can be performed with high accuracy.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention (hereinafter referred to as embodiments) will be described with reference to the drawings.

“Embodiment 1”
1 and 2 are diagrams showing an outline of the entire system configuration in which the control device for a continuously variable transmission according to Embodiment 1 of the present invention is used, and FIG. 1 is an overview of the configurations of the continuously variable transmission and the hydraulic control device. FIG. 2 schematically shows the configuration of the electronic control unit. The system of this embodiment is mainly configured by a belt-type continuously variable transmission 14, a hydraulic control device 40, and an electronic control device 42, and is mounted on a vehicle, for example.

  The belt-type continuously variable transmission 14 includes a primary pulley 30 connected to an input shaft 26, a secondary pulley 32 connected to an output shaft 36, and a substantially V-shaped cross section wound around the primary pulley 30 and the secondary pulley 32. The endless belt 34 is provided. Torque generated by the engine is transmitted to a primary pulley 30 (input shaft 26) as an input rotation element via a torque converter and a forward / reverse switching device (both not shown). The belt-type continuously variable transmission 14 transmits the torque transmitted to the primary pulley 30 to the secondary pulley 32 (output shaft 36) through an endless belt 34 as a power transmission element. The torque transmitted to the secondary pulley 32 as the output rotating element is transmitted to a driving load (for example, a driving wheel (not shown)).

The primary pulley 30 includes a primary movable sheave 30a that can move in the direction of the input shaft 26 and a primary fixed sheave 30b. Similarly, the secondary pulley 32 includes a secondary movable sheave 32a that can move in the direction of the output shaft 36 and a secondary fixed sheave 32b. A thrust in the direction of the input shaft 26 acts on the primary movable sheave 30a by the pressure Pp of the hydraulic oil supplied to the primary pulley oil chamber 30c. Similarly, the thrust in the direction of the output shaft 36 acts on the secondary movable sheave 32a by the pressure Ps of the hydraulic oil supplied to the secondary pulley oil chamber 32c. When the primary movable sheave 30a and the secondary movable sheave 32a move in the axial direction, the rotation radius (contact radius) of the portion where the endless belt 34 is wound around the primary pulley 30 and the secondary pulley 32 changes. As a result, the gear ratio γ (= the rotational speed N _in of the primary pulley 30 / the rotational speed N _out of the secondary pulley 32) of the belt-type continuously variable transmission 14 changes continuously.

  The hydraulic pressure supplied to the primary pulley oil chamber 30c and the secondary pulley oil chamber 32c of the belt type continuously variable transmission 14 is supplied by the hydraulic control device 40, and these hydraulic pressures are controlled by the electronic control device 42.

  Next, the main configuration of the hydraulic control device 40 will be described. The hydraulic control device 40 includes a hydraulic pressure supply pump 54, a regulator 56, a clamping pressure control valve 58, and a shift control valve 60.

  The hydraulic pressure supply pump 54 is driven to rotate by using torque generated by the engine, pumps up the hydraulic oil stored in the reservoir 52 and discharges it to the pressure line 68. The regulator 56 adjusts the hydraulic oil pressure PL in the pressure line 68 so as to become the set pressure. The hydraulic oil discharged from the hydraulic pressure supply pump 54 is supplied to the primary pulley oil chamber 30c and the secondary pulley oil chamber 32c, and is also used for lubrication of each part, supply hydraulic pressure to the clutch of the forward / reverse switching device, and the like.

  The transmission control valve 60 as a hydraulic actuator adjusts the transmission ratio of the belt-type continuously variable transmission 14 by adjusting the flow rate of hydraulic oil flowing in and out of the primary pulley oil chamber 30c. The speed change control valve 60 includes a speed increasing flow control valve 61, a speed reducing flow control valve 62, a speed increasing electromagnetic valve 63, and a speed reducing electromagnetic valve 64.

  The speed increasing electromagnetic valve 63 supplies the pressure (control pressure) controlled by the shift control command value from the electronic control device 42 to the speed increasing flow control valve 61. When the speed increasing flow control valve 61 is driven by the control pressure from the speed increasing electromagnetic valve 63 and the primary pulley oil chamber 30 c communicates with the pressure line 68 via the speed increasing flow control valve 61, the pressure increases from the pressure line 68. The working oil flows into the primary pulley oil chamber 30c through the speed flow control valve 61. As a result, a speed-up operation (upshift) can be performed. At this time, the flow rate of the hydraulic oil flowing into the primary pulley oil chamber 30c through the speed increasing flow control valve 61 is controlled by the control pressure from the speed increasing electromagnetic valve 63 (shift control command value from the electronic control unit 42). Be controlled.

  The deceleration solenoid valve 64 supplies the pressure (control pressure) controlled by the shift control command value from the electronic control device 42 to the deceleration flow control valve 62. When the deceleration flow control valve 62 is driven by the control pressure from the deceleration solenoid valve 64 and the primary pulley oil chamber 30c communicates with the reservoir 52 via the deceleration flow control valve 62, the deceleration flow rate from the primary pulley oil chamber 30c. The hydraulic oil flows out to the reservoir 52 through the control valve 62. As a result, a deceleration operation (downshift) can be performed. At this time, the flow rate of the hydraulic oil flowing out from the primary pulley oil chamber 30c through the deceleration flow rate control valve 62 is controlled by the control pressure from the deceleration solenoid valve 64 (the shift control command value from the electronic control unit 42). The

  The clamping pressure control valve 58 adjusts the pressure Ps of the hydraulic oil in the secondary pulley oil chamber 32c by adjusting the pressure PL of the hydraulic oil in the pressure line 68 and supplying it to the secondary pulley oil chamber 32c. The clamping pressure can be applied to the endless belt 34 by the pressure Ps of the hydraulic oil supplied to the secondary pulley oil chamber 32c, and slipping of the endless belt 34 can be suppressed. The clamping pressure control valve 58 here can be constituted by an electromagnetic valve that can be driven by a clamping pressure control command value from the electronic control unit 42, and the pressure Ps ( Belt clamping pressure) is controlled. The clamping pressure control command value is calculated by the electronic control unit 42 based on the input torque Tp to the primary pulley 30 and the gear ratio γ.

  Next, the main configuration of the electronic control unit 42 will be described. The electronic control unit 42 includes a shift control unit that performs shift control by controlling the drive state of the shift control valve 60 according to the shift control command value u. As shown in FIG. 2, the transmission control unit includes a target transmission ratio calculation unit 84, a transmission ratio calculation unit 88, a subtracter 85, a feedback control unit 86, and a feedback gain setting unit 87. ing.

The target gear ratio calculation unit 84 sets the target gear ratio γ _ref based on the throttle opening A, the engine speed Ne, and the vehicle speed V. The gear ratio calculation unit 88 calculates the gear ratio γ from the rotation speed N _in of the primary pulley 30 and the rotation speed N _out of the secondary pulley 32. The target transmission ratio γ _ref set by the target transmission ratio calculation unit 84 and the transmission ratio γ detected by the transmission ratio calculation unit 88 are input to the subtracter 85. The subtracter 85 calculates a control deviation e ₁ between the target speed ratio γ _ref and the detected speed ratio γ, and outputs it to the feedback control unit 86.

The feedback control unit 86 calculates and outputs a shift control command value u based on the control deviation e ₁ and the feedback gains K _P , K _P / T _I , and K _P × T _D. The drive control of the shift control valve 60 is performed by the shift control command value u from the feedback control unit 86, whereby the shift control for causing the speed ratio γ to follow the target speed ratio _γref is performed.

  Here, the shift control command value u (t) at time t can be calculated, for example, as a feedback control command value according to the following equation (1). The feedback control command value in the equation (1) includes a proportional term, an integral term, and a derivative term. For example, the integral term or the derivative term can be omitted, or the integral term and the derivative term can be omitted. it can.

In this embodiment, the feedback gain setting unit 87 sets the feedback gains K _P , K _P / T _I , and K _P × T _{D based} on the detected gear ratio γ. Thus, the feedback gain setting unit 87, the feedback gain K _P to changes in the speed ratio γ, K _P / T _I, changing the K _P × T _D.

Here, the characteristic of the difference ΔP (= Pp−Ps) between the pressure Pp of the primary pulley oil chamber 30c and the pressure Ps of the secondary pulley oil chamber 32c with respect to the speed ratio γ has a non-linear relationship as shown in FIG. More specifically, the absolute value of the slope of the pressure difference ΔP increases as the speed ratio γ decreases. This characteristic indicates that the amount of change in the pressure difference ΔP required to change the speed ratio γ by a predetermined amount increases as the speed ratio γ decreases. Therefore, the feedback gain K _P, by setting K _P / T _I, the K _P × T _D at a constant value, will be the response of the speed change control for changing of the gear ratio γ is changed, for example, the gear ratio γ is The smaller the value, the easier the response delay of the shift control occurs.

Therefore, the feedback gain setting unit 87, the feedback gain K _P relative reduction of the gear ratio γ, K _P / T _I, increasing K _P × T _D. By setting the feedback gains K _P , K _P / T _I , and K _P × T _D , the speed ratio γ decreases, and the amount of change in the pressure difference ΔP necessary to change the speed ratio γ by a predetermined amount increases. However, the shift control can be performed so as to increase the amount of time change of the pressure difference ΔP. Therefore, even if the speed ratio γ changes, the response of the speed change control can be stabilized.

Then, the feedback gain K _P in the feedback gain setting unit 87, K _P / T _I, for example the method of calculating the K _P × T _D will be described.

"Method by polynomial approximation"
The feedback gain setting unit 87 calculates K _P , T _I , and T _D using a polynomial relating to the gear ratio γ shown in Equation (2). In the equation (2), P _i , I _i , D _i (i = 0, 1, to m) are tuning parameters, and can be determined by analysis or experiment, for example. The polynomial order m can also be determined after adjustment by analysis or experiment, for example.

"Data Map and Interpolation Method"
Appropriate values of K _P , T _I and T _D are tuned in advance with respect to several speed ratios γ _i (i = 0, 1, to m) satisfying the minimum value γ _min ≦ γ _i ≦ the maximum value γ _max. deep. Then, a data table of K _P (γ _i ), T _I (γ _i ), and T _D (γ _i ) that can be expressed as a function of the gear ratio γ _i is created, and this data table is stored in the electronic control unit 42. The feedback gain setting unit 87 calculates K _P , T _I , and T _D using this data table. For example, the values of K _P , T _I , and T _D when the gear ratio is γ satisfying γ _j <γ <γ _{j + 1} and j <m are obtained by the equations (3) to (5) according to the primary interpolation equation. Each can be calculated.

  Further, as described above, the characteristic of the difference ΔP (= Pp−Ps) between the pressure Pp of the primary pulley oil chamber 30c and the pressure Ps of the secondary pulley oil chamber 32c with respect to the speed ratio γ has a non-linear relationship shown in FIG. is there. On the other hand, FIG. 4 shows characteristics when the shaft of the gear ratio γ having the characteristics shown in FIG. 3 is replaced with a logarithm log (γ) (logarithmic scale) of the gear ratio γ. As shown in FIG. 4, the characteristic of the pressure difference ΔP (= Pp−Ps) with respect to the logarithm log (γ) of the speed ratio γ is substantially linear. Therefore, the pressure difference ΔP can be approximated by the following equation (6) using the logarithm log (γ) of the speed ratio γ.

  ΔP = b−a × log (γ) (6)

  In the equation (6), a and b are coefficients. The base of the logarithm here is not particularly limited, but here, a case where a natural logarithm is used will be described as an example.

  The slope of the pressure difference ΔP with respect to the speed ratio γ, that is, the differential dΔP / dγ of the pressure difference ΔP with respect to the speed ratio γ can be approximated by the following equation (7). dΔP / dγ is substantially in an inversely proportional relationship.

  dΔP / dγ = −a / γ (7)

In order to stabilize the responsiveness of the shift control, it is preferable that the feedback gains K _P , K _P / T _I , and K _P × T _D are proportional to the absolute value of the slope dΔP / dγ of the pressure difference ΔP. Therefore, the feedback gain setting unit 87, the feedback gain _{K P, K P / T I} , K P × T D is to satisfy approximately the relationship in inverse proportion to the gear ratio gamma, the feedback gain K _P, K _P / T _I , K _P × T _D is preferably set.

As described above, in the present embodiment, the feedback gains K _P , K _P / T _I , and K _P × T _D are increased with respect to the reduction in the gear ratio γ, so that the nonlinear characteristic related to the gear ratio γ described above. Appropriate feedback gains K _P , K _P / T _I , and K _P × T _D can be set. Therefore, it is possible to stabilize the responsiveness of the shift control with respect to changes in the operating state of the belt type continuously variable transmission 14. Therefore, even if the driving state of the belt type continuously variable transmission 14 changes, the shift control can be performed with high accuracy.

  Next, another example of the present embodiment will be described.

In the present embodiment, the feedback gain setting unit 87 may feedback gain K _P using the target speed ratio gamma _ref instead of the gear ratio γ, K _P / T _I, also set K _P × T _D. That is, the feedback gain setting unit 87 can also be increased feedback gain K _P relative decrease of the target speed ratio _{γ ref, K P / T I} , the K _P × T _D. Even when the target gear ratio γ _ref is used, the values of K _P , T _I , and T _D can be calculated using the above-described polynomial approximation method and the data map and interpolation method. The feedback gain setting unit 87, the feedback gain _{K P, K P / T I} , K P × T D is a relationship that is inversely proportional to the target speed ratio gamma _ref to satisfy approximately the feedback gain K _P, K _P / T _I and K _P × T _D can also be set.

In the present embodiment, the feedback gain setting unit 87, the feedback gain K _P, based on the pressure difference ΔP (= Pp-Ps) in place of the gear ratio γ, K _P / T _I, the K _P × T _D By setting, the feedback gains K _P , K _P / T _I , and K _P × T _D can be changed with respect to the change of the pressure difference ΔP. As shown in FIG. 3, since the absolute value of the slope dΔP / dγ of the pressure difference ΔP increases as the pressure difference ΔP increases, the feedback gain setting unit 87 increases the feedback gain K _P , Increase K _P / T _I and K _P × T _D. Even when the pressure difference ΔP is used, the values of K _P , T _I , and T _D can be calculated using the above-described polynomial approximation method and the data map and interpolation method. The pressure Pp in the primary pulley oil chamber 30c and the pressure Ps in the secondary pulley oil chamber 32c can be detected by, for example, a pressure sensor (not shown).

  Further, the slope dΔP / dγ can be expressed by the equation (8) using the pressure difference ΔP, and can also be expressed using an exponential function of the pressure difference ΔP.

  dΔP / dγ = −a × exp ((ΔP−b) / a) (8)

Therefore, in order to stabilize the responsiveness of the shift control, the feedback gain setting unit 87 has a relationship in which the feedback gains K _P , K _P / T _I , and K _P × T _D are proportional to the exponential function of the pressure difference ΔP. It is preferable to set the feedback gains K _P , K _P / T _I , and K _P × T _D so that they are almost satisfied. The exponential function may be approximated by a polynomial using Taylor expansion, or may be calculated using a data map and interpolation method. In the above description, the ratio Pp / Ps between the pressure Pp of the primary pulley oil chamber 30c and the pressure Ps of the secondary pulley oil chamber 32c can be used instead of the pressure difference ΔP.

Further, the characteristics of the ratio W _out / W _in the thrust W _out and thrust W _in the primary pulley 30 of the secondary pulley 32c for the speed ratio γ is in the non-linear relationship as shown in FIG. Therefore, the feedback gain setting unit 87, by setting the feedback gain _{K P, K P / T I} , K P × T D based on the thrust ratio W _out / W _in, the change of the thrust ratio W _out / W _in feedback gain _{K P, K P / T I} , can also vary the K _P × T _D with respect. More specifically, since the absolute value of the thrust ratio W _out / W _in the more reduced thrust ratio W _out / W _in the slope _{d (W out / W in)} / dγ increases, the feedback gain setting unit 87 , the feedback gain K _P relative reduction in thrust ratio _{W out / W in, K P} / T I, increasing K _P × T _D. Note that the thrust ratio W _out / W _in, can be calculated based on the pressure Ps in the pressure Pp and the secondary pulley oil chamber 32c of the example primary pulley oil chamber 30c.

The characteristics of the thrust ratio W _out / W _in respect to the logarithm log (gamma) of the gear ratio gamma is approximately linear relationship as shown in FIG. Therefore, it is possible to represent the thrust ratio W _out / W _in approximated by the following equation (9), the thrust ratio W _out / W _in slope _{d (W out / W in)} / dγ following (10) It can be approximated by an expression.

W _out / W _in = d + c × log (γ) (9)
_{d (W out / W in)} / dγ = c / γ = c / exp ((W out / W in -d) / c) (10)

In the equations (9) and (10), c and d are coefficients. (10) from the equation, the inclination _{d (W out / W in)} / dγ can be represented using an exponential function of the thrust ratio W _out / W _in. Therefore, the feedback gain setting unit 87, the feedback gain _{K P, K P / T I} , K P × T D is to satisfy nearly inversely proportional to the exponential function of the thrust ratio W _out / W _in, the feedback gain K _P , K _P / T _I, it is preferable to set the K _P × T _D. In the above explanation, instead of the thrust ratio W _out / W _in, it can be used a difference W _out -W _in the thrust W _in thrust W _out and the primary pulley 30 of the secondary pulley 32.

In the above description of the present embodiment, the target speed ratio γ _ref is set as the target value of the speed change control, and feedback control is performed based on the target speed ratio γ _ref and the detected control deviation e ₁ of the speed ratio γ. Explained. However, in this embodiment, the control deviation of the rotational speed N _in of the primary pulley 30 to set the target rotation speed N _Inref of the primary pulley 30, the detected target rotational speed N _Inref of the primary pulley 30 as a target value of the speed change control it is also possible to perform the feedback control based on the e _N1. In that case, in the above description of the present embodiment, the case where the target speed ratio γ _ref is replaced with the target rotational speed N _inref of the primary pulley 30 and the speed ratio γ is replaced with the rotational speed N _in of the primary pulley 30 is considered. Good. That is, the feedback gain setting unit 87 provides feedback gains K _P , K _P / T _I , K _P × T _{D with} respect to a decrease _in the rotation speed N _in of the primary pulley 30 or a decrease _in the target rotation speed N _inref of the primary pulley 30. Increase. Then, the feedback gain setting unit 87, the feedback gain _{K P, K P / T I} , the relationship with K _P × T _D is in inverse proportion to the target rotation speed N _Inref rotational speed N _in or primary pulley 30 of the primary pulley 30 It is preferable to set the feedback gains K _P , K _P / T _I , and K _P × T _D so that they are almost satisfied.

  In the above description of the present embodiment, the case where the transmission control valve 60 is used as the actuator for changing the transmission gear ratio γ has been described. However, in the present embodiment, as an actuator for changing the speed ratio γ, a pump capable of reversibly moving the hydraulic oil between the primary pulley oil chamber 30c and the secondary pulley oil chamber 32c (for example, Patent Documents 4 to 7) can also be used.

  Moreover, in the above description, the case where the shift control of the belt-type continuously variable transmission 14 is performed by the control device according to the present embodiment has been described. However, shift control of the toroidal continuously variable transmission can be performed by the control device according to the present embodiment.

Although a specific configuration of the toroidal-type continuously variable transmission is not shown because it is well known, a roller is sandwiched between the input disk and the output disk, and the torque transmitted to the input disk is transmitted via the roller. Transmission is transmitted to the output disk. The gear ratio γ can be changed by changing the roller contact angle with the input disk and the output disk by changing the tilt angle θ of the roller by the actuator. Here, by performing drive control of the actuator based on the shift control command value u from the feedback control unit 86, shift control for causing the speed ratio γ to follow the target speed ratio γ _ref can be performed.

In the toroidal continuously variable transmission, the characteristic of the roller tilt angle θ with respect to the gear ratio γ has a non-linear relationship as shown in FIG. More specifically, the absolute value of the inclination of the roller inclination angle θ increases as the speed ratio γ decreases. Therefore, even when the shift control of the toroidal continuously variable transmission is performed, the feedback gain setting unit 87 reduces the speed ratio γ or the target speed ratio γ as in the case of performing the speed control of the belt type continuously variable transmission 14. _The feedback gains K _P , K _P / T _I and K _P × T _D are increased with respect to the decrease in _ref .

In the toroidal continuously variable transmission, the characteristic of the roller tilt angle θ with respect to the logarithm log (γ) of the speed ratio γ is substantially linear as shown in FIG. For this reason, the speed ratio γ and the differential dθ / dγ of the roller tilt angle θ are in an inversely proportional relationship. Therefore, even when performing shift control of the toroidal continuously variable transmission, the feedback gain setting unit 87, the feedback gain _{K P, K P / T I} , K P × T D is the gear ratio gamma, or target gear ratio gamma _ref It is preferable to set the feedback gains K _P , K _P / T _I , and K _P × T _D so as to substantially satisfy the inversely proportional relationship. In the characteristics of FIGS. 7 and 8, the direction in which the contact radius of the roller to the input disk increases is the direction in which the roller tilt angle θ increases.

Further, in the toroidal continuously variable transmission, as shown in FIG. 7, the absolute value of the inclination dθ / dγ of the roller inclination angle θ increases as the roller inclination angle θ increases. Therefore, the feedback gain setting unit 87, the feedback gain K _P, based on the roller tilt angle θ, K _P / T _I, set the K _P × T _D, increase in the roller tilting angle theta (the input disk roller Feedback gains K _P , K _P / T _I , and K _P × T _D can be increased. As shown in FIG. 8, since the characteristic of the roller tilt angle θ with respect to the logarithm log (γ) of the speed ratio γ is substantially linear, the roller tilt angle θ is calculated using a logarithmic function of the speed ratio γ. The inclination dθ / dγ can be expressed using an exponential function of the roller tilt angle θ. Therefore, the feedback gain setting unit 87, the feedback gain _{K P, K P / T I} , relationship to satisfy approximately the K _P × T _D is proportional to an exponential function of the roller tilt angle theta, the feedback gain K _P, K _P / T _I, it is preferable to set the K _P × T _D. The roller tilt angle θ can be detected by a sensor (not shown), for example.

In the above description of the shift control of the toroidal-type continuously variable transmission, the target rotational speed N _inref of the input disk is used instead of the target speed ratio γ _ref and the rotational speed N _in of the input disk is used instead of the speed ratio γ. May be detected and used.

“Embodiment 2”
FIG. 9 is a diagram showing a schematic configuration of a continuously variable transmission control device according to Embodiment 2 of the present invention, and shows a schematic configuration of the electronic control device 42. In the present embodiment, the speed change control unit that performs speed change control by controlling the drive state of the speed change control valve 60 according to the speed change control command value u, as shown in FIG. A calculation unit 88, a logarithmic deviation calculation unit 91, and a feedback control unit 86 are included. The logarithmic deviation calculation unit 91 includes logarithm calculation units 89 and 90 and a subtracter 85.

The logarithmic calculator 89 calculates the logarithm log (γ _ref ) of the target gear ratio γ _ref and outputs it to the subtracter 85. The logarithmic calculator 90 calculates the logarithm log (γ) of the detected gear ratio γ and outputs it to the subtracter 85. The subtracter 85 calculates a control deviation e ₂ between the logarithm log (γ _ref ) of the target speed ratio γ _{ref and} the logarithm log (γ) of the speed ratio γ, and outputs the control deviation e ₂ to the feedback control unit 86. The feedback control unit 86 calculates and outputs a shift control command value u based on the control deviation e ₂ and the feedback gains K _P , K _P / T _I , K _P × T _D. The drive control of the shift control valve 60 is performed by the shift control command value u from the feedback control unit 86, whereby the shift control for causing the speed ratio γ to follow the target speed ratio _γref is performed. As the logarithm here, for example, a natural logarithm can be used, but the base of the logarithm is not particularly limited.

  Here, the shift control command value u (t) at time t can be calculated as, for example, a feedback control command value according to the following equation (11). The feedback control command value of the equation (11) includes a proportional term, an integral term, and a derivative term. For example, the integral term or the derivative term can be omitted, or the integral term and the derivative term can be omitted. it can.

  Since other configurations are the same as those in the first embodiment, description thereof is omitted.

Here, assuming that the difference between the target speed ratio γ _ref and the speed ratio γ is Δγ, since Δ ₂ → 0 when Δγ → 0, the control deviation e ₂ between the logarithm log (γ _ref ) and the logarithm log (γ). Setting the value to 0 is equivalent to setting the difference Δγ between the target speed ratio γ _ref and the speed ratio γ to 0.

When the absolute value of the control deviation e ₂ between the logarithmic log (γ _ref ) and the logarithmic log (γ) is differentiated by the speed ratio γ, the following expression (12) is obtained.

Therefore, as shown in FIG. 10, when the speed ratio γ decreases, the absolute value of the control deviation e ₂ increases monotonously. FIG. 10 shows the control deviation e ₂ when Δγ = 0.1 as an example. Further, as described above, the characteristic of the pressure difference ΔP (= Pp−Ps) with respect to the logarithm log (γ) of the speed ratio γ is substantially linear as shown in FIG.

From the above, by calculating the shift control command value u based on the control deviation e ₂ between the logarithmic log (γ _ref ) and the logarithmic log (γ), the gear ratio γ decreases and the gear ratio γ is set to a predetermined amount. Since the control deviation e ₂ increases when the amount of change in the pressure difference ΔP required to change increases, the shift control can be performed so as to increase the amount of time change in the pressure difference ΔP. Therefore, setting the feedback gain _{K P, K P / T I} , the K _P × T _D at a constant value, the responsiveness of the speed change control can be stabilized against changes in the speed ratio gamma.

Here, the results of experiments conducted by the inventors of the present application are shown in FIGS. FIG. 11 shows an experiment in which the shift control is performed by the feedback control command value u calculated from the deviation between the target gear ratio γ _ref and the gear ratio γ and the constant feedback gains K _P , K _P / T _I , K _P × T _D. It is a result. On the other hand, FIG. 12 shows the feedback control command value calculated from the control deviation e ₂ between the logarithmic log (γ _ref ) and the logarithmic log (γ) and the constant feedback gains K _P , K _P / T _I , K _P × T _D. It is the experimental result which performed shift control by u. In the experimental results of FIG. 11, when the speed reduction ratio (gear ratio) γ is small, the speed reduction ratio (gear ratio) γ cannot follow the target speed reduction ratio (target speed ratio) γ _ref and a response delay occurs. On the other hand, in the experimental results of FIG. 12, even if the reduction ratio (transmission ratio) γ changes, the reduction ratio (transmission ratio) γ can substantially follow the target reduction ratio (target transmission ratio) γ _ref . Therefore, the effectiveness of the shift control of this embodiment is understood.

Next, an example of a method of calculating logarithms log (γ _ref ) and log (γ) by the logarithmic calculators 89 and 90 will be described. In the following description, an example of a logarithm log (γ) calculation method by the logarithm calculation unit 90 will be described, but the logarithm log (γ _ref ) calculation method by the logarithm calculation unit 89 can be calculated by the same method. is there.

"Method by Taylor deployment"
When the gear ratio γ takes a value from the minimum value γ _min to the maximum value γ _max, when the logarithmic function log (γ) is Taylor-expanded with the intermediate value γ _c = (γ _min + γ _max ) / 2, the following (13 ) Expression.

  The logarithm calculation unit 90 calculates the logarithm log (γ) by an expression obtained by approximating the expression (13) with a finite degree. The order is determined by analysis or experimentation.

"Data Map and Interpolation Method"
By calculating logarithmic function values with respect to several speed ratios γ _i (i = 0, 1, to m) satisfying the minimum value γ _min ≦ γ _i ≦ maximum value γ _max in advance, the logarithmic function log (γ _i ) Is created, and this data table is stored in the electronic control unit 42. Then, the logarithm calculation unit 90 calculates the logarithm log (γ) using this data table. For example, as shown in FIG. 13, the logarithm log (γ) when the gear ratio is γ satisfying γ _j <γ <γ _{j + 1} and j <m is expressed by the following (14) It can be calculated using an equation.

As described above, in the present embodiment, the shift control command value u is calculated based on the control deviation e ₂ between the logarithm log (γ _ref ) and the logarithm log (γ), thereby relating to the above-described speed ratio γ. Shift control based on an appropriate control deviation e ₂ for compensating the nonlinear characteristic can be performed. Therefore, the response of the shift control can be stabilized with respect to the change in the operating state of the belt type continuously variable transmission 14, and the shift control can be performed with high accuracy. Furthermore, in the present embodiment, the above-described nonlinear characteristic related to the speed ratio γ can be compensated without changing the feedback gains K _P , K _P / T _I , and K _P × T _D. The control logic for calculating can be simplified.

The control deviation e ₂ between the logarithm log (γ _ref ) and the logarithm log (γ) can also be expressed by the following equation (15).

e ₂ = log (γ _ref ) −log (γ) = log (γ _ref / γ) (15)

Therefore, the logarithmic deviation calculation unit 91 that outputs the control deviation e ₂ between the logarithm log (γ _ref ) of the target gear ratio γ _{ref and} the logarithm log (γ) of the gear ratio γ to the feedback control unit 86 is shown in FIG. As described above, the control deviation e ₂ can also be calculated by calculating the logarithm log (γ _ref / γ) of the ratio between the target speed ratio γ _ref and the detected speed ratio γ. According to the configuration shown in FIG. 14, since the logarithmic calculation process can be reduced by half when calculating the shift control command value u, the load for calculating the shift control command value u can be reduced.

In this embodiment, similarly to Embodiment 1, using the target rotational speed N _Inref of the primary pulley 30 instead of the target gear ratio gamma _ref, using the rotational speed N _in of the primary pulley 30 instead of the speed ratio gamma Also good. In that case, the logarithmic deviation calculation unit 91 calculates the control deviation e _N2 between the logarithm log (N _inref ) of the target rotational speed N _inref of the primary pulley 30 and the logarithm log (N _in ) of the rotational speed N _in of the primary pulley 30. Calculate and output to the feedback control unit 86. The logarithmic deviation calculation unit 91 may calculate the control deviation e _N2 by calculating log (N _inref / N _in ).

  Also in the present embodiment, as in the first embodiment, an actuator for changing the gear ratio γ is provided between the primary pulley oil chamber 30c and the secondary pulley oil chamber 32c instead of the shift control valve 60. A pump capable of reversibly moving the hydraulic oil (for example, see Patent Documents 4 to 7) can also be used.

Further, similarly to the first embodiment, the control device according to the present embodiment can perform the shift control of the toroidal continuously variable transmission. Even when performing shift control of the toroidal-type continuously variable transmission, the logarithmic deviation calculation unit 91 calculates the control deviation e ₂ between the logarithm log (γ _ref ) of the target gear ratio γ _{ref and} the logarithm log (γ) of the gear ratio γ. Calculate and output to the feedback control unit 86. Alternatively, the logarithmic deviation calculation unit 91 calculates the control deviation e _N2 between the logarithm log (N _inref ) of the target rotational speed N _inref of the input disk and the logarithm log (N _in ) of the rotational speed N _in of the input disk, and feeds back. Output to the controller 86. Then, the shift control is performed by controlling the actuator that can drive the roller by the shift control command value u from the feedback control unit 86.

  As mentioned above, although the form for implementing this invention was demonstrated, this invention is not limited to such embodiment at all, and it can implement with a various form in the range which does not deviate from the summary of this invention. Of course.

It is a figure which shows the outline of a structure of a continuously variable transmission and a hydraulic control apparatus. It is a block diagram which shows the outline of a structure of the control apparatus of the continuously variable transmission which concerns on Embodiment 1 of this invention. It is a figure which shows the characteristic of the difference of the pressure of the primary pulley oil chamber with respect to a gear ratio, and the pressure of a secondary pulley oil chamber. It is a figure which shows the characteristic of the difference of the pressure of the primary pulley oil chamber with respect to the logarithm of gear ratio, and the pressure of a secondary pulley oil chamber. It is a figure which shows the characteristic of ratio of the secondary pulley thrust with respect to a gear ratio, and a primary pulley thrust. It is a figure which shows the characteristic of ratio of the secondary pulley thrust with respect to the logarithm of gear ratio, and a primary pulley thrust. It is a figure which shows the characteristic of the roller tilt angle with respect to a gear ratio. It is a figure which shows the characteristic of the roller tilt angle with respect to the logarithm of gear ratio. It is a block diagram which shows the outline of a structure of the control apparatus of the continuously variable transmission which concerns on Embodiment 2 of this invention. It is a figure which shows the characteristic of the deviation of the logarithm of the target gear ratio with respect to the gear ratio, and the logarithm of the gear ratio. It is a figure which shows the experimental result which performed the conventional transmission control. It is a figure which shows the experimental result which performed the shift control by Embodiment 2 of this invention. It is a figure explaining the calculation method of the logarithm by a data map and interpolation. It is a block diagram which shows the outline of the other structure of the control apparatus of the continuously variable transmission which concerns on Embodiment 2 of this invention.

Explanation of symbols

  14 belt type continuously variable transmission, 30 primary pulley, 32 secondary pulley, 34 endless belt, 40 hydraulic control device, 42 electronic control device, 54 hydraulic supply pump, 56 regulator, 58 clamping pressure control valve, 60 transmission control valve, 61 Acceleration flow control valve, 62 Deceleration flow control valve, 63 Acceleration solenoid valve, 64 Deceleration solenoid valve, 84 Target gear ratio calculation unit, 85 Subtractor, 86 Feedback control unit, 87 Feedback gain setting unit, 88 gear ratio calculation unit, 89,90 logarithm calculation unit, 91 logarithm deviation calculation unit.

Claims (10)

Power is transmitted from the input rotating element to the output rotating element via the power transmitting element, and the gear ratio can be changed by changing the contact diameter of the power transmitting element to the input rotating element and the output rotating element with an actuator. An apparatus for performing a shift control of a transmission,
A logarithmic deviation calculator that calculates a deviation between the logarithm of the target value of the shift control and the logarithm of the detected value of the shift control;
A shift control command value calculating unit that calculates a shift control command value based on the deviation calculated by the logarithmic deviation calculating unit, and controls the actuator according to the shift control command value;
A control device for a continuously variable transmission. A control device for a continuously variable transmission according to claim 1,
The logarithmic deviation calculating unit calculates a logarithm of a ratio between the target value of the shift control and the detected value of the shift control, thereby calculating a deviation between the logarithm of the target value of the shift control and the logarithm of the detected value of the shift control. A control device for a continuously variable transmission. A control device for a continuously variable transmission according to claim 1 or 2,
The logarithmic deviation calculating unit is configured to calculate a deviation between a logarithm of the target speed ratio and a logarithm of the detected speed ratio, or a target rotation of the input rotation element A control device for a continuously variable transmission, which calculates a deviation between a logarithm of a speed and a logarithm of a detected rotation speed of an input rotation element. A control device for a continuously variable transmission according to any one of claims 1 to 3,
The control device for a continuously variable transmission, wherein the input rotation element is a primary pulley, the output rotation element is a secondary pulley, and the power transmission element is a belt wound around the primary pulley and the secondary pulley. . A control device for a continuously variable transmission according to any one of claims 1 to 3,
In the continuously variable transmission, the input rotation element is an input disk, the output rotation element is an output disk, and the power transmission element is a roller sandwiched between the input disk and the output disk. Control device. A belt-type continuously variable transmission that is supplied with hydraulic pressure to apply pulley thrust to the primary pulley and secondary pulley, and that allows the gear ratio to be changed by changing the engagement diameter of the belt to the primary pulley and secondary pulley with a hydraulic actuator. A device for controlling the speed change of the machine,
A shift control command value calculating unit that calculates a shift control command value based on a deviation between a shift control target value and a detected value of the shift control and a shift control gain, and controls the actuator based on the shift control command value;
A shift control gain setting unit that changes the shift control gain in response to a change in pressure difference or pressure ratio between the oil pressure supplied to the primary pulley and the oil pressure supplied to the secondary pulley;
Have
The transmission control gain setting unit sets the transmission control gain so that the transmission control gain substantially satisfies a relationship proportional to an exponential function of the pressure difference or the pressure ratio. Control device. A belt-type continuously variable transmission that is supplied with hydraulic pressure to apply pulley thrust to the primary pulley and secondary pulley, and that allows the gear ratio to be changed by changing the engagement diameter of the belt to the primary pulley and secondary pulley with a hydraulic actuator. A device for controlling the speed change of the machine,
A shift control command value calculating unit that calculates a shift control command value based on a deviation between a shift control target value and a detected value of the shift control and a shift control gain, and controls the actuator based on the shift control command value;
A shift control gain setting unit for changing the shift control gain with respect to a thrust difference or a thrust ratio change between the secondary pulley thrust and the primary pulley thrust;
Have
The transmission control gain setting unit sets the transmission control gain so that the transmission control gain substantially satisfies a relationship inversely proportional to the thrust difference or the exponential function of the thrust ratio. Control device. A control device for a continuously variable transmission according to claim 6 or 7,
The shift control command value calculation unit calculates a deviation between the target gear ratio and the detected gear ratio as a deviation between the target value of the shift control and the detected value of the shift control, or a target rotation speed of the primary pulley and a detected rotation of the primary pulley. A control device for a continuously variable transmission, characterized by using a deviation from speed. A toroidal type in which a roller is sandwiched between an input disk and an output disk, and the gear ratio can be changed by changing the roller contact angle to the input disk and output disk by changing the tilt angle of the roller by an actuator. A device for performing a shift control of a continuously variable transmission,
A shift control command value calculating unit that calculates a shift control command value based on a deviation between a shift control target value and a detected value of the shift control and a shift control gain, and controls the actuator based on the shift control command value;
A shift control gain setting unit that increases the shift control gain with respect to an increase in a roller tilt angle in which a contact diameter of the roller to the input disk increases;
I have a,
The continuously variable transmission control device, wherein the shift control gain setting unit sets the shift control gain so that the shift control gain substantially satisfies a relationship proportional to an exponential function of the roller tilt angle. . A control device for a continuously variable transmission according to claim 9,
The shift control command value calculation unit calculates a deviation between the target gear ratio and the detected gear ratio as a deviation between the target value of the shift control and the detected value of the shift control, or a target rotation speed of the input disk and a detected rotation of the input disk. A control device for a continuously variable transmission, characterized by using a deviation from speed .

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