JP2010112397A - Speed-change controller for continuously variable transmission - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a speed-change controller for a continuously variable transmission wherein a hysteresis between an actual accelerator opening and an accelerator opening for speed-change control becomes an optimum value responding to the intention of a driver or an operating state such as a load condition of a vehicle. <P>SOLUTION: In the speed-change controller for a continuously variable transmission, the accelerator opening for speed-change control APO<SB>(c)</SB>is set in response to the actual accelerator opening APO<SB>(a)</SB>, and speed-change control is carried out based upon the accelerator opening APO<SB>(c)</SB>. The hysteresis h between the actual opening APO<SB>(a)</SB>and the control opening APO<SB>(c)</SB>is changed in response to a vehicle speed VSP, and operating states of fuel consumption performance and power performance. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention provides a shift control device for a continuously variable transmission that sets a shift control accelerator opening according to an actual accelerator opening and performs a shift control based on the shift control accelerator opening. It relates to the technology to be optimized.

  A continuously variable transmission has a characteristic of downshifting steplessly in response to depression of an accelerator pedal (hereinafter referred to as “accelerator”), and is always accompanied by a minute shift according to changes in the accelerator opening. If a minute fluctuation occurs after the operation, the direct feeling (responsiveness) to the accelerator operation actually intended by the driver is impaired.

On the other hand, the conventional shift control device switches the shift control (shift map) according to the driving state such as the driver's intention and the load condition of the vehicle, and the actual accelerator opening (hereinafter referred to as “actual accelerator opening”). Acceleration operation frequency (accelerator resolution) by setting the accelerator opening for shift control according to the degree of acceleration) and providing a dead zone (hysteresis) between the actual accelerator opening and the accelerator opening for shift control. There is an apparatus that eliminates excessive shift control that is executed in response to an accelerator operation when the value is equal to or greater than a predetermined value (see, for example, Patent Document 1).
JP 2004-324842 A

  However, the conventional shift control device is set regardless of the driving state such as the driver's intention and the load state of the vehicle without considering any specific setting of the hysteresis. For this reason, in the conventional shift control device, even if the shift control is switched according to the driving state with an emphasis on fuel consumption performance, power performance, etc., a dead zone for shift is uniformly generated.

  That is, in the conventional shift control device, the hysteresis is optimized in a certain driving region (driving state), but in other driving regions, there is a problem that the shift response and fuel consumption are deteriorated.

  An object of the present invention is to set the hysteresis between the actual accelerator opening and the accelerator opening for shift control to an optimum value according to the driving state such as the driver's intention and the load condition of the vehicle. is there.

The transmission control device for a continuously variable transmission according to the present invention sets the accelerator opening for shift control according to the actual accelerator opening, and when performing shift control based on the accelerator opening for shift control,
The hysteresis between the actual accelerator opening and the shift control accelerator opening is changed according to the operating state.

  According to the present invention, the hysteresis between the actual accelerator opening and the shift control accelerator opening is determined by the driving style (driving mode), the driver's intention represented by the accelerator resolution, the vehicle speed, the road gradient, and the curve. It becomes an optimum value according to the driving state such as the load state of the vehicle represented by the curvature radius of the surface and the frictional resistance of the road surface.

  Therefore, according to the present invention, even if the shift control is switched according to the driver's intention and the driving state such as the load state of the vehicle, the hysteresis is also optimized according to the switching. Optimum shift control according to the driving state can be realized without impairing the direct feeling of operation.

  Hereinafter, a transmission control device for a continuously variable transmission according to the present invention will be described with reference to the drawings.

  FIG. 1 is a system diagram schematically showing a power train equipped with a shift control device for a belt type continuously variable transmission, which is an embodiment of the present invention, and FIG. 2 shows a basic concept of the present invention. It is a block diagram. FIG. 3 is a block diagram including a hysteresis map according to the present invention used for setting hysteresis.

  In FIG. 1, reference numeral 1 denotes an engine that is a drive source, and a torsional damper D / P is connected to the rear of the engine 1. An oil pump O / P is connected to the rear of the torsional damper D / P, and an input rotation transmission mechanism 2 is disposed. The input rotation transmission mechanism 2 includes a forward clutch 2a connected to the torsional damper D / P and a reverse clutch 2b connected to the output of the forward clutch 2a via a planetary gear mechanism.

  Reference numeral 3 is a belt-type continuously variable transmission (hereinafter referred to as “continuously variable transmission”) disposed behind the input rotation transmission mechanism 2, and reference numeral 4 is a primary pulley. The primary pulley 4 is a variable pulley having a fixed flange 4a connected to the input rotation transmission mechanism 2 and a movable flange 4b controlled by hydraulic pressure.

  Reference numeral 5 denotes a secondary pulley that is connected via a V-belt 6 that spans the primary pulley 4. Similar to the primary pulley 4, the secondary pulley 5 is a variable pulley having a fixed flange 5 a and a movable flange 5 b controlled by hydraulic pressure. Wheels 9L and 9R are connected to the fixed flange 5a from the final drive gear set 7 through the differential gear device 8.

Reference numeral 10 denotes a controller equipped with a CPU and the like. The controller 10 includes, for example, a signal from the accelerator opening sensor 11 that detects the actual accelerator opening APO _(c) , a signal from the throttle opening sensor 12, a signal from the vehicle speed sensor 13, and a signal from the engine speed sensor 14. A signal, a signal from the transmission input speed (primary speed) sensor 15, a signal from the transmission output speed (secondary speed) sensor 16, and driving style information I reflecting the driving style of the driver are input. The

  The driving style information I includes, for example, a signal from an economy mode switch 17 that selects a driving state that emphasizes fuel efficiency and a signal from a sports mode mode switch 18 that selects a driving state that emphasizes power performance.

Reference numeral 19 denotes a forward travel range pressure P _D that controls the engagement and release of the forward clutch 2 a and the reverse clutch 2 b, a primary pulley pressure P _PRI that controls the primary pulley 4, and a secondary pulley pressure P _SEC that controls the secondary pulley 5. It is a control valve unit provided with a plurality of hydraulic control valves for supplying.

In the present embodiment, the controller 10 determines the target transmission input rotational speed Ni _(o) based on the throttle opening TVO and the vehicle speed VSP, as in the conventional shift control, in order to realize the optimum shift control, and this target shift control. Each hydraulic control valve built in the control valve unit 19 is controlled so as to achieve the transmission input rotational speed Ni _(o) .

That is, in the present embodiment, the controller 10 follows the flow as shown in the block diagram of FIG. 2 according to the actual accelerator opening APO _(a) from the accelerator opening sensor 11 and shift control accelerator opening APO _(c). And the target transmission input rotational speed Ni _(o) is determined based on the shift control accelerator opening APO _(c) .

In the controller 10, as shown in the figure, when the actual accelerator opening APO _(a) is input from the accelerator opening sensor 11, first, the hysteresis setting means 101 determines the actual accelerator opening APO _(a) and the shift control. Hysteresis h with respect to the accelerator opening APO _(c) is set according to the operation state described later.

Hysteresis setting unit 101 sets the hysteresis h in accordance with the operating state based on the hysteresis map shown in FIG. 3 as a code M _1. The hysteresis map M ₁ includes a plurality of hysteresis lines L (in this embodiment, preset in accordance with the vehicle speed VSP and the driving style of whether the driver emphasizes fuel efficiency or power performance. Illustratively, there are four hysteresis lines L _{a to} L _d (showing L _a <L _b <L _c <L _d ).

As shown in the hysteresis map M ₁ , the hysteresis lines L _{a to} L _d of the present embodiment each maintain a constant large value when the vehicle speed VSP is low, and then gradually decrease as the vehicle speed VSP increases. Indicates.

That is, in this embodiment, the individual hysteresis line L _a ~L _d, as the vehicle speed VSP is high, the value of the hysteresis h is set to be smaller with the increase. This setting has a large margin driving force at low vehicle speeds, so there is almost no need for downshifting and there is no problem even if the hysteresis h is set large. On the other hand, the margin driving force is small at high vehicle speeds, This is because it is conceivable that the driving force must be ensured by downshifting.

Further, according to the hysteresis map M ₁ , the value of each hysteresis line L gradually decreases as the driver's intention goes toward increasing the weighting of the power performance (in this embodiment, the power performance is most important). when the relative hysteresis line L _a is selected) of, in accordance with increasing the weighting of the fuel efficiency, the individual values of the hysteresis line L is gradually increased (the present embodiment, when the most emphasis on fuel efficiency , Hysteresis line L _d is selected).

That is, in this embodiment, when importance is attached to fuel consumption performance, by selecting a hysteresis line having a large value (hysteresis line L on the hysteresis line L _d side), the value of hysteresis h is set so as to increase the power performance. When importance is attached, the hysteresis h is set to be small by selecting a hysteresis line having _a small value (hysteresis line L on the hysteresis line La side). In this setting, when importance is attached to the fuel efficiency, it is necessary to suppress the minute shift to improve the fuel efficiency. Therefore, it is preferable to set the hysteresis h to a large value. This is because it is preferable to improve the hysteresis h because it is necessary to improve it.

In this embodiment, upon optimizing the hysteresis h, and inputs the signal and driving style information I from the vehicle speed sensor 13, in either emphasized or power performance emphasizing fuel efficiency, four hysteresis line L _a ~L After selecting the most suitable hysteresis line L from _d, the hysteresis line L is determined by obtaining a hysteresis h corresponding to the vehicle speed VSP based on the hysteresis line L.

For example, when traveling at a vehicle speed V ₁ while placing the highest priority on fuel efficiency, the hysteresis line L _d having the smallest value is selected from the four hysteresis lines L _{a to} L _d as shown in the hysteresis map M _1. The hysteresis h ₁ corresponding to the hysteresis line L _d is selected. Thereby, the hysteresis h (= h ₁ ) corresponding to the vehicle speed VSP and the driving style is determined.

After determining the hysteresis h, the controller 10 optimizes the shift control accelerator opening APO _{(c) by} the shift control accelerator opening optimization means 102 shown in FIG. Optimization of the shift control accelerator opening APO _(c) is performed as shown in FIG. 4 based on the optimized hysteresis h determined by the hysteresis setting means 101.

In setting the shift control accelerator opening APO _(c) according to the actual accelerator opening APO _(a) , when the hysteresis h does not exist, the shift control accelerator opening APO _(c) is based on the solid line L ₀ . Determined. For example, when the actual accelerator opening APO _(a) is in the state of APO _(a) = a ₀ indicated by point A, the shift control accelerator opening APO _(c) is APO _(c) = A ₁ .

On the other hand, when the present embodiment is not applied and the hysteresis h (= h ₁ ) is uniformly given to the actual accelerator opening APO _(a) , even if the accelerator is depressed from the point A, the shift control accelerator is opened. The degree APO _(c) is the speed change accelerator opening until the actual accelerator opening APO _(a) is increased by the hysteresis h ₁ as shown by the point B regardless of the driving state such as the vehicle speed VSP and the driving style. APO _(c) remains APO _(c) = A ₁ and is determined based on the solid line L ₁ only after reaching the state of point B where the actual accelerator opening APO _(a) becomes a ₁ .

That is, when this embodiment is not applied, regardless of the driving state such as the vehicle speed VSP or the driving style, even if the actual accelerator opening APO _(a) increases from a ₀ to a ₁ due to depression of the accelerator, The accelerator opening APO _(c) for shift control remains at APO _(c) = A ₁ , but when the actual accelerator opening APO _(a) becomes a ₁ or more by further depression, the vehicle state changes to the point B Shift in the direction of the arrow d ₁ along the solid line L ₁ , the shift control accelerator opening APO _(c) is the shift control accelerator opening corresponding to the actual accelerator opening APO _(a) on the solid line L _1. Degree APO _(c) .

On the other hand, when the hysteresis h is set according to the vehicle speed VSP and the driving style as in the present embodiment, when the hysteresis h is optimized in the increasing direction, the actual accelerator opening APO _(a) is The shift control accelerator opening APO _(c) remains APO _(c) = A ₁ until it increases from a ₀ to a ₂ (> a ₁ ) due to depression, but the actual accelerator opening APO _(a) Is further increased to a ₂ or more by further depression, the vehicle state shifts from the point C in the direction of the arrow d ₂ along the two-dot chain line L ₂ , so that the shift control accelerator opening APO _(c) is The shift control accelerator opening APO _(c) corresponding to the actual accelerator opening APO _(a) on the dotted line L ₂ is optimized.

Further, in this embodiment, when the hysteresis h is optimized in the direction in which the hysteresis h decreases according to the vehicle speed VSP and the driving style, the actual accelerator opening APO _(a) is reduced from a ₀ to a ₃ (<a ₁ ) by the depression of the accelerator. The accelerator opening APO _(c) for shift control remains at APO _(c) = A ₁ until it increases until the actual accelerator opening APO _(a) becomes a ₃ or more by further depression. Shifts from the point D in the direction of the arrow d ₃ along the alternate long and short dash line L ₃ , so that the shift control accelerator opening APO _(c) is equal to the actual accelerator opening APO _(a) on the alternate long and short dash line L _3. Is optimized to the shift control accelerator opening APO _(c) .

Incidentally, when the driver reduces the amount of depression of the accelerator, is up to the solid line L _0, to maintain the current state of the shift control accelerator opening APO _(c), after reaching the solid line L _0, of the vehicle Since the state shifts in the direction of the arrow d ₀ along the solid line L ₀ , the shift control accelerator opening APO _(c) corresponds to the actual accelerator opening APO _(a) on the solid line L ₀ . The accelerator opening APO _(c) is determined.

After optimizing the shift control accelerator opening APO _(c) , the controller 10 causes the shift control execution means 103 of FIG. 2 to execute the target transmission input rotation speed based on the shift control accelerator opening APO _(c). Determine Ni _(o) .

In this embodiment, the shift map M ₂ shown in FIG. 2 is stored in the controller 10, and the target transmission input rotational speed Ni _(o) is determined using the shift map M ₂ . Shift map M ₂ is an existing shift map of the throttle opening TVO and vehicle speed VSP as parameters.

Therefore, in this embodiment, the throttle opening corresponding to the shift control accelerator opening APO _{(c) is determined} from the shift control accelerator opening APO _(c) optimized by the shift control accelerator opening optimization means 102. calculating a degree TVO, calculated with the throttle opening TVO, based on the vehicle speed VSP detected by the vehicle speed sensor 13, the above-mentioned transmission map M ₂ from the target transmission input speed N _I and _(o), achieve this Thus, each hydraulic control valve in the control valve unit 19 is controlled.

Incidentally, according to the present invention, as the shift map M _2, by utilizing the one that the accelerator opening APO and vehicle speed VSP as a parameter, it is also possible to calculate the target transmission input rotation speed N _{I (o)} direct . Further, the structure of the shift map M ₂ is not limited as long as it can calculate the target transmission input rotational speed NI _(o) based on the accelerator opening APO.

  If the vehicle speed VSP is set as a parameter for the hysteresis h as in the present embodiment and the hysteresis h is set to be smaller as the vehicle speed VSP is higher, the direct operation to the accelerator operation intended by the driver is performed at a low vehicle speed with a large margin driving force. While priority can be given to shift control that provides a sense of sensation, priority can be given to optimal shift control according to driving conditions at high vehicle speeds with a small marginal driving force.

  In addition, as in this embodiment, paying attention to the driving style as the driving state and using the mutually contradictory performances of the power performance and the fuel efficiency as the evaluation criteria for the hysteresis h, the hysteresis h is set large when the fuel efficiency is important. When the power performance is regarded as important, if the hysteresis h is set small, an optimum value according to the driving style can be obtained.

FIG. 5 is an analysis diagram in which the distribution of the fuel consumption rate is simulated from the relationship between the engine speed V _E and the engine torque T _E. In this analysis diagram, regions where the fuel consumption rate is low and fuel consumption is good are represented by dense regions, and conversely, regions where the fuel consumption rate is high and fuel consumption is not good are represented by rough regions.

  Since the continuously variable transmission can perform a stepless speed change, it is possible to perform a gear shift aiming at an engine operating point (for example, a point P in FIG. 5) at which the fuel efficiency is optimal in a certain driving situation.

  However, in the case where the hysteresis h is not provided, even if the shift control is performed aiming at the engine operating point P at which the fuel consumption is optimal, as shown by the arrows in FIG. As a result, the engine operating point P is deviated.

  Further, as described above, when the hysteresis h is uniformly set without considering any specific setting of the hysteresis h as in the case where the present embodiment is not applied, a certain operation region (operation state) ) Is optimal, but in other driving regions, fuel consumption will deteriorate.

  For this reason, as in the present embodiment, when importance is attached to the fuel efficiency, by setting the hysteresis h to be large, if the minute shift is suppressed, the deviation from the target engine operating point P is also suppressed. Even when compared with the case where the present embodiment is not applied, it is clear that the fuel consumption is improved.

FIG. 6 is a time chart showing the operation of this embodiment when power performance is important. This time chart shows, in time series, the operation when the accelerator is depressed and accelerated after the actual accelerator opening APO _(a) is made constant while traveling at a certain vehicle speed.

As described above, when the present embodiment is not applied and no particular consideration is given to the specific setting of the hysteresis h, when the actual accelerator opening APO _(a) = a _{0 is} stepped on at time T ₀ , As shown by the broken line, the downshift is started from the time T ₁ when the actual accelerator opening APO _(a) = a _1, which is delayed by the hysteresis h _1, is reached.

On the other hand, in this embodiment, when the accelerator pedal is depressed from the actual accelerator opening APO _(a) = a _{0 at} time T ₀ , for example, the optimum feeling corresponding to the driving state is also obtained by the direct feeling for the accelerator operation intended by the driver. When the hysteresis h is set with emphasis on the shift control, the actual accelerator opening APO _(a) = a ₃ (a ₃ <a _{3 )} before the optimized hysteresis h = h ₂ as shown by the solid line in FIG. It made it downshift is started from the time T ₃ reached _1).

For this reason, as in this embodiment, when emphasizing the power performance, by setting the hysteresis h to be small, the engine speed is set to achieve the target shift (target transmission output rotational speed N _{I (o)} ). If Hayamere the shift start earlier the increase start number N _E, since the shift response is improved, as compared with the case of not applying the present embodiment, it is clear that the improved power performance.

Moreover, according to this invention, it is also possible to include a road surface gradient as a driving | running state. In this case, the road surface gradient is detected from a gradient angle sensor or the like, and the hysteresis h (hysteresis line L) is set to increase as the road surface gradient θ increases. According to such a configuration, it is possible to set the optimal shift control accelerator opening APO _(c) according to the gradient road. For this reason, as the road surface gradient on which power performance is important becomes steeper, the power performance can be more weighted, so that comfortable driving can be realized.

Furthermore, according to the present invention, it is possible to include the frequency of accelerator operation (accelerator resolution) as the driving state. In this case, the resolution of the accelerator is detected from the signal from the accelerator opening sensor 11, and when the resolution is appropriate (when the frequency of the accelerator operation is low), the hysteresis h (hysteresis line L) is set small. When the resolution is small (when the frequency of accelerator operation is high), the hysteresis h (hysteresis line L) is set large. According to such a configuration, it is possible to set the optimal shift control accelerator opening APO _(c) according to the frequency of the driver's accelerator operation. For this reason, the comfortable driving | operation which emphasized the direct feeling with respect to the accelerator operation which the driver | operator intended can be implement | achieved.

In addition, according to the present invention, it is also possible to include the radius of curvature R of the curved road (curve) as the operating state. In this case, the curvature radius R of the curved road is detected based on a signal from the lateral acceleration sensor, and when the curvature radius R is large, the hysteresis h is set large. When the curvature radius R is small, the hysteresis h is small. Set as follows. This is because a so-called R curve with a small radius of curvature R tends to cause slip (side slip), and it is safer to have lower sensitivity to driving force (sensitivity to accelerator operation). According to such a configuration, it is possible to set the optimum shift control accelerator opening APO _(c) according to the curvature radius R of the curved road. For this reason, the more sharp the curved surface on which power performance is important, the more weight can be put on the power performance, so that comfortable driving can be realized.

Furthermore, according to the present invention, it is possible to include the frictional resistance (friction coefficient μ) of the road surface as the driving state. In this case, the friction coefficient μ of the road surface is detected on the basis of a signal from the wheel rotation speed sensor and the hysteresis h is set to be large when the friction coefficient μ is small, and the hysteresis h is set when the friction coefficient μ is large. Set to be smaller. This is because, on a road surface having a small frictional resistance, a slip of wheel rotation is likely to occur, and it is safer that sensitivity to driving force (sensitivity to accelerator operation) is smaller. According to such a configuration, it is possible to set the optimum shift control accelerator opening APO _(c) according to the curvature radius R of the curved road. For this reason, the more sharp the curved surface on which power performance is important, the more weight can be put on the power performance, so that comfortable driving can be realized.

As described above, according to the present invention, the hysteresis h between the actual accelerator opening APO _(a) and the shift control accelerator opening APO _(c) is representative of driving style (driving style) and accelerator resolution. Optimum value according to the driver's intention, the vehicle speed VSP, the road surface gradient θ, the radius of curvature R of the curved surface, the road surface friction resistance (friction coefficient μ), etc. It becomes.

  Therefore, according to the present invention, even if the shift control is switched according to the driver's intention and the driving state such as the load condition of the vehicle, the hysteresis h is also optimized according to the switching. Optimal shift control according to the driving state can be realized without impairing the direct feeling with respect to the accelerator operation.

  The above is a preferred embodiment of the present invention, but various modifications can be made within the scope of the claims. For example, at least one of the operation states described above may be adopted. Furthermore, each structure employ | adopted for each form can mutually be combined suitably.

1 is a system diagram schematically showing a power train equipped with a shift control device for a belt-type continuously variable transmission, which is an embodiment of the present invention. It is a block diagram which shows the basic concept of this invention. FIG. 4 is a block diagram including a hysteresis map according to the present invention used for setting hysteresis. It is a setting map for optimizing the accelerator opening for shift control using hysteresis from the actual accelerator opening. It is the analysis figure which simulated the distribution of the fuel consumption rate from the relationship between the vehicle speed and the engine torque. It is a time chart which shows operation | movement of this form when attaching importance to power performance.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Engine 2 Input rotation transmission mechanism 2a Forward clutch 2b Reverse clutch 3 Belt type continuously variable transmission 4 Primary pulley 4a Primary side fixed pulley 4b Primary side movable pulley 5 Secondary pulley 5a Secondary side fixed pulley 5b Secondary side movable pulley 6 V belt 7 Final drive gear set 8 Differential gear unit 9L, 9R Wheel
10 Controller
11 Accelerator position sensor
12 Throttle opening sensor
13 Vehicle speed sensor
14 Engine rotation sensor
15 Transmission input speed (primary speed) sensor
16 Transmission output speed (secondary speed) sensor
17 Economy mode switch
18 Sport mode switch
19 Control valve unit

Claims (7)

In a transmission control device for a continuously variable transmission that sets an accelerator opening for shift control according to an actual accelerator opening and performs shift control based on the accelerator opening for shift control,
A shift control apparatus for a continuously variable transmission, comprising hysteresis setting means for setting a hysteresis between an actual accelerator opening and a shift control accelerator opening in accordance with an operating state.   2. The transmission control apparatus for a continuously variable transmission according to claim 1, wherein the hysteresis setting means detects a vehicle speed as a driving state and sets the hysteresis to be smaller as the vehicle speed increases.   3. The hysteresis setting means according to claim 1, wherein the hysteresis setting means detects a driving style as a driving state, and sets the hysteresis large when the driving style emphasizes fuel efficiency, and sets the hysteresis small when importance is placed on power performance. A transmission control device for a continuously variable transmission.   The continuously variable transmission according to any one of claims 1 to 3, wherein the hysteresis setting means detects a road surface gradient as an operation state, and sets a larger hysteresis as the road surface gradient increases. Gear shift control device.   5. The hysteresis setting means according to claim 1, wherein the hysteresis setting means detects an accelerator resolution as an operating state, sets the hysteresis small when the resolution is appropriate, and sets the hysteresis large when the resolution is small. A speed change control device for a continuously variable transmission.   6. The hysteresis setting means according to claim 1, wherein the hysteresis setting means detects a radius of curvature of the curved road as an operating state, sets the hysteresis large when the radius of curvature is large, and sets the hysteresis when the radius of curvature is small. A transmission control device for a continuously variable transmission, characterized by being set to a small value.   The hysteresis setting means according to any one of claims 1 to 6, wherein the hysteresis setting means detects a frictional resistance of the road surface as an operating state, sets the hysteresis large when the frictional resistance is small, and sets the hysteresis when the frictional resistance is large. A variable speed control device for a continuously variable transmission, characterized in that

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