JP5179425B2 - Control device for automatic transmission - Google Patents

Description

  The present invention relates to a control device for an automatic transmission provided with a plurality of power transmission systems having a clutch for controlling disconnection / connection of power from a drive source and a transmission mechanism coupled to the clutch in a state where power can be transmitted.

  Conventionally, as an automatic transmission mounted on a vehicle, for example, an automatic transmission described in Patent Document 1 has been proposed. This automatic transmission is a so-called dual clutch type automatic transmission and includes two power transmission systems. The first power transmission system includes a first clutch and a gear train that is connected in a state capable of transmitting power to the first clutch and that has an odd number of gears (first gear, third gear, and fifth gear). And a first speed change mechanism. The second power transmission system is coupled to the second clutch and the second clutch in a state where power can be transmitted to the second clutch, and gears of even-numbered gear stages (second speed stage, fourth speed stage and sixth speed stage). And a second speed change mechanism having a row. For example, when the vehicle is driven with the first gear set, the power from the engine, which is the power source, is set by setting the first gear change mechanism to the first gear and engaging the first clutch. Is transmitted to the drive wheels via the first power transmission system, and the vehicle travels. When the gear stage is the first speed stage, the second clutch of the second power transmission system is in a released state, and power from the engine is not transmitted to the second power transmission system.

  Further, in the automatic transmission control device described in Patent Document 1, preshift control is executed in accordance with traveling information indicating the traveling state of the vehicle received from an external device such as a car navigation system. For example, when travel information indicating that the vehicle is turning in a corner is received from the car navigation system, the control device for the automatic transmission identifies the current gear position (for example, third gear) of the automatic transmission, The gear position in the second power transmission system to which no power is transmitted is a lower speed gear stage (in this case, the second speed stage) than the gear position (for example, the third speed stage) set in the first power transmission system. Pre-shift control is executed to prepare for That is, when the vehicle is turning, the preshift control is executed on the downshift side. As a result, when the shift stage of the automatic transmission is downshifted from the third speed to the second speed while the vehicle is turning, only the first clutch is released and the second clutch is engaged. Thus, the power from the engine is transmitted to the drive wheels via the second power transmission system. Therefore, it is possible to provide a quick downshift as compared with the case where the preshift control is not executed or the case where the preshift control is executed on the upshift side.

Japanese Patent Laid-Open No. 2007-232047

  By the way, the control apparatus for an automatic transmission described in Patent Document 1 executes pre-shift control according to vehicle travel information received from a car navigation system. However, in the car navigation system, there is information that makes it difficult to grasp the state of the vehicle on which the system is mounted. For example, in a car navigation system, it is difficult to grasp whether the vehicle is traveling with a very large load or whether the vehicle is traveling while towing. For this reason, the automatic transmission control device described in Patent Literature 1 may not be able to execute appropriate preshift control according to the state of the vehicle.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a control device for an automatic transmission that can execute appropriate preshift control in accordance with the state of a traveling vehicle.

In order to achieve the above object, the invention according to claim 1 relating to a control device for an automatic transmission is provided with a clutch for controlling the connection / disconnection of power from a driving source and a state in which power can be transmitted to the clutch. The power transmission system includes two power transmission systems each having a transmission mechanism that is configured to transmit power from the drive source to any one of the power transmission systems when the vehicle travels. Is a control device for an automatic transmission that performs control for bringing one clutch included in the engagement state into an engaged state and bringing the other clutch included in the other power transmission system into a disengaged state, and for calculating a target acceleration of the vehicle An acceleration calculating means; an actual acceleration calculating means for calculating an actual acceleration of the vehicle; a target acceleration calculated by the target acceleration calculating means; and an actual acceleration calculated by the actual acceleration calculating means; Calculates the difference, if the difference thus calculated is previously zero large value with the set difference threshold value or more than, the loading towing the vehicle travels at least one state of the state of the load a large amount of state and traction and stacking traction estimating means for estimating that the state, in the case where the power is transmitted vehicle from the driving source via a clutch to the one of the power transmission system is running, with the loading towing state by the loading traction estimating means When it is estimated that the vehicle body speed of the vehicle is faster than when the vehicle is estimated not to be in the loaded towed state by the loaded tow estimating means, the shift stage of the other power transmission system is set in the automatic transmission. And a pre-shift control means for performing pre-shift control so that the gear is prepared at a speed lower than the selected speed.

  According to the above configuration, since the driver is more likely to request more power in the loaded towing state, the power is transmitted with the vehicle body speed being higher than the case where it is estimated that the vehicle is not in the loaded towed state. The shift stage of the other power transmission system that has not been operated is a shift stage at a lower speed than the shift stage selected in the automatic transmission (that is, the shift stage selected by one of the power transmission systems to which power is transmitted). Be prepared. Therefore, even in a loaded towing state where there is a high possibility that a downshift will be executed, it is possible to execute an appropriate preshift control according to the state of the traveling vehicle.

Moreover, according to the said structure, it is estimated from the difference of a target acceleration and an actual acceleration whether it is in a loading traction state. That is, even if the vehicle is not equipped with an external device such as a car navigation system, appropriate pre-shift control is executed according to the state of the traveling vehicle.

According to a second aspect of the present invention, in the control device for an automatic transmission according to the first aspect , the load traction estimation means is a target calculated by the target acceleration calculation means during a preset estimation determination time. The gist of the present invention is to estimate the loaded towing state when a state where the difference between the acceleration and the actual acceleration calculated by the actual acceleration calculating means is not less than the difference threshold is continued.

  Generally, when a vehicle travels in a loaded towing state, a state where the difference between the target acceleration and the actual acceleration is equal to or greater than a difference threshold is continued. Therefore, in the present invention, when the state where the difference between the target acceleration and the actual acceleration is equal to or greater than the difference threshold is continued for a preset estimation determination time, it is estimated that the loaded towing state is present. Therefore, for example, when the vehicle travels on an uphill road, erroneous determination that the vehicle is in a loaded towing state is suppressed.

The block diagram of the vehicle carrying the automatic transmission in this embodiment. The skeleton figure which shows the automatic transmission of this embodiment. Map for starting timing of downshift, upshift and preshift control. A map for setting the offset amount according to the acceleration difference. The flowchart explaining a preshift determination processing routine.

An embodiment in which the present invention is embodied in a control device for an automatic transmission mounted on a vehicle will be described with reference to FIGS.
As shown in FIG. 1, the vehicle of this embodiment has a plurality of (four in this embodiment) wheels (right front wheel FR, left front wheel FL, right rear wheel RR, and left rear wheel RL) that are in contact with the road surface during traveling. Of these, the front wheels FR and FL function as drive wheels, and the rear wheels RR and RL function as driven wheels. Such a vehicle is provided with an engine 12 as a drive source that generates power (torque) according to the amount of depression of the accelerator pedal 11 by the driver. The power generated by the engine 12 is supplied to the automatic transmission 13 or the like. To the front wheels FR and FL. The vehicle of the present embodiment is provided with an electronic control unit (hereinafter referred to as “engine ECU”) 14 that controls the driving mode of the engine 12 in accordance with the operating mode of the accelerator pedal 11 by the driver, and the engine ECU 14. , An accelerator sensor SE1 for detecting the opening of the accelerator pedal 11 (also referred to as “accelerator opening”) is electrically connected. Then, the engine ECU 14 calculates the accelerator opening based on the detection signal from the accelerator sensor SE1, and transmits information related to the calculation result to the ECU 40 for the automatic transmission 13 described later.

Next, the automatic transmission 13 will be described with reference to FIG.
As shown in FIG. 2, the automatic transmission 13 according to the present embodiment is a so-called dual clutch type transmission having seven forward speeds and one reverse speed. Such an automatic transmission 13 includes a plurality (two in this embodiment) of clutches C1 and C2, a first input shaft 15 coupled to the first clutch C1, and a second clutch coupled to the second clutch C2. An input shaft 16, a first gear transmission mechanism 17 for odd-numbered stages (first speed, third speed, fifth speed and seventh speed), an even speed (second speed, fourth speed, sixth speed) and A second gear transmission mechanism 18 for the reverse gear and an output shaft 19 that can rotate coaxially with the input shafts 15 and 16 are provided. Power is transmitted from the output shaft 19 to the front wheels FR and FL via a differential (not shown).

  The first input shaft 15 is a rod-shaped member extending from the first clutch C1 in a predetermined direction (left-right direction in FIG. 2), and the first clutch C1 is engaged by driving the clutch actuator 20. When it becomes, it rotates centering on the rotating shaft line (not shown) extended along a predetermined direction. The second input shaft 16 is a cylindrical member extending along a predetermined direction from the second clutch C2, and the first input shaft 15 has a first clutch C1 in the second input shaft 16. The side part is accommodated. The second input shaft 16 rotates coaxially with the first input shaft 15 when the second clutch C <b> 2 is engaged by driving the clutch actuator 20. The engagement of the clutches C1 and C2 refers to the engagement between the input side and the output side of the clutches C1 and C2. The release of the clutches C1 and C2 refers to the input side and the output side of the clutches C1 and C2. Means that power transmission becomes impossible due to separation.

  The first gear transmission mechanism 17 is held in a state of being relatively rotatable with respect to the first input shaft 15, and is arranged in order along a predetermined direction, and a first gear transmission gear 211, a seventh gear transmission gear 217, 3 A speed change gear 213 and a fifth speed change gear 215 held in an integrally rotatable state with the output shaft 19 are provided. Further, the first gear transmission mechanism 17 is fixed to a counter shaft 22 arranged in parallel to the input shafts 15 and 16 and the output shaft 19 so as to be integrally rotatable, and each of the transmission gears 211, odd-numbered gears 211, A plurality of (four in this embodiment) counter gears 231, 233, 235, and 237 that individually mesh with 213, 215, and 217 are provided.

  The first gear transmission mechanism 17 includes a first gear selection mechanism 25 that selects the first-speed gear 211 or the seventh-speed gear 217, and the third-speed gear 213 or the fifth gear. A second gear selection mechanism 26 that selects the transmission gear 215 is provided. Each of the gear selection mechanisms 25 and 26 is provided with a cylindrical sleeve 24 that can rotate integrally with the first input shaft 15 on the outer peripheral side of the first input shaft 15. These sleeves 24 are arranged between a transmission gear (for example, a first-speed transmission gear 211) positioned on one side in a predetermined direction and a transmission gear (for example, a seventh-speed transmission gear 217) positioned on the other side in a predetermined direction. Each can be moved.

  Each of the gear selection mechanisms 25 and 26 is provided with a drive unit 27 for moving the sleeve 24 along a predetermined direction. The drive unit 27 receives a driving force from the selection actuators 28A and 28B. Are given respectively. Then, by driving the drive unit 27, the sleeve 24 is engaged with a transmission gear located on one side (left side in FIG. 2) in a predetermined direction or on the other side (right side in FIG. 2) in the predetermined direction. When arranged at the second engagement position where the transmission gear is positioned, the transmission gear engaged with the sleeve 24 can rotate integrally with the first input shaft 15. For example, when the sleeve 24 of the second gear selection mechanism 26 is disposed at the second engagement position, the power from the first input shaft 15 is transmitted to the fifth speed gear 215 via the sleeve 24. The On the other hand, when the sleeve 24 is disposed at a neutral position between the two transmission gears located on both sides in the predetermined direction, power is transmitted to the transmission gears 211, 213, 215, and 217 via the first input shaft 15. Not.

  The second gear transmission mechanism 18 is held in a state of being relatively rotatable with respect to the second input shaft 16, and each of the even-numbered transmission gears (second-speed transmission gear 212, fourth-speed transmission gear) arranged in order along a predetermined direction. A step-change gear 214, a sixth-speed gear 216), and a reverse gear 21R. The second gear transmission mechanism 18 is fixed to the counter shaft 22 so as to be integrally rotatable, and a plurality of (four in this embodiment) counters individually corresponding to the transmission gears 212, 214, 216, and 21R. Gears 232, 234, 236 and 23R are provided. The counter gears 232, 234, and 236 for the even-numbered forward gears mesh with the corresponding transmission gears 212, 214, and 216, respectively. Further, an idler gear 29 that meshes with the reverse gear 21R and the counter gear 23R is provided between the reverse gear 21R and the counter gear 23R. The idler gear 29 is connected to the reverse gear 21R from the reverse gear 21R. Power can be transmitted to the counter gear 23R.

  Further, the second gear transmission mechanism 18 includes a third gear selection mechanism 31 that selects the second gear transmission gear 212 or the fourth gear transmission gear 214, a sixth gear transmission gear 216, or the reverse gear transmission. A fourth shift speed selection mechanism 32 for selecting the gear 21R is provided. Each of these gear selection mechanisms 31 and 32 is similar to the first and second gear selection mechanisms 25 and 26 described above, and includes a sleeve 24 disposed on the outer peripheral side of the second input shaft 16 and selection actuators 28C and 28D. And a drive unit 27 to which the drive force is applied. That is, in the third and fourth shift speed selection mechanisms 31 and 32, the sleeves 24 are respectively disposed at any one of the first engagement position, the second engagement position, and the neutral position by the drive of the drive unit 27. The The transmission gear (for example, the second speed transmission gear 212) engaged with the sleeve 24 can rotate integrally with the second input shaft 16.

  In such an automatic transmission 13, when the vehicle is driven with the gear set to the first gear, the sleeve 24 of the first gear select mechanism 25 is moved to the first engagement position by driving the actuators 28A and 28B for selection. And the sleeve 24 of the second gear selection mechanism 26 is disposed at the neutral position. Subsequently, by driving the clutch actuator 20, the first clutch (one clutch) C1 is brought into an engaged state and the second clutch (the other clutch) C2 is brought into a released state. Then, the power from the engine 12 is transmitted from the first clutch C1, the first input shaft 15, the first speed transmission gear 211, the counter gear 231, the counter shaft 22, the counter gear 235, the fifth speed transmission gear 215, and the output. The vehicle travels to the front wheels FR and FL via the shaft 19 and the like. Therefore, in this embodiment, the first clutch C1, the first input shaft 15 and the first gear transmission mechanism 17 constitute a first power transmission system.

  Further, when the vehicle is driven with the gear position of the automatic transmission 13 set to the second gear, the sleeve 24 of the third gear selection mechanism 31 is engaged with the first engagement by driving the selection actuators 28C and 28D. The sleeve 24 of the fourth gear selection mechanism 32 is disposed at the neutral position while being disposed at the position and engaged with the transmission gear 212 for the second gear. Subsequently, by driving the clutch actuator 20, the second clutch (one clutch) C2 is brought into an engaged state, and the first clutch (the other clutch) C1 is brought into a released state. Then, the power from the engine 12 is transmitted from the second clutch C2, the second input shaft 16, the second speed transmission gear 212, the counter gear 232, the counter shaft 22, the counter gear 235, the fifth speed transmission gear 215, and the output. The vehicle travels to the front wheels FR and FL via the shaft 19 and the like. Therefore, in the present embodiment, the second clutch C2, the second input shaft 16, and the second gear transmission mechanism 18 constitute a second power transmission system provided in parallel with the first power transmission system.

Next, an electronic control unit (hereinafter referred to as “ECU”) 40 as a control unit that controls the driving of the automatic transmission 13 will be described below with reference to FIGS. 1 and 2.
As shown in FIGS. 1 and 2, the ECU 40 interface includes wheel speed sensors SE2 and SE3 for detecting the wheel speeds of the rear wheels RR and RL, and temperature sensors for detecting the temperatures of the clutches C1 and C2. SE4, SE5, a vehicle body speed sensor SE6 for detecting the vehicle body speed of the vehicle, and a brake switch SW1 for detecting whether a brake pedal (not shown) of the vehicle is operated are electrically connected. Further, the clutch actuator 20 and the selection actuators 28A to 28D are electrically connected to the interface of the ECU 40. Further, the ECU 40 receives various types of information related to the accelerator opening degree transmitted from the engine ECU 14.

  The ECU 40 has a digital computer constructed from a CPU 41, a ROM 42, a RAM 43, and the like. The ROM 42 has various control programs (such as preshift determination processing described later) for driving the actuators 20, 28A to 28D to control the automatic transmission 13, and various maps (such as the maps shown in FIGS. 3 and 4). And various threshold values (difference threshold value, estimation determination time, elimination estimation time, etc., which will be described later) and the like are stored. The RAM 43 also stores various information (actual acceleration, target acceleration, acceleration difference, offset amount, elapsed time, loading traction flag, etc., which will be described later) that can be appropriately rewritten while the ignition switch (not shown) of the vehicle is turned on. Each is remembered.

Next, various maps stored in the ROM 42 will be described with reference to FIGS.
A plurality of (seven in this embodiment) first maps shown in FIG. 3 are provided so as to individually correspond to the forward shift speeds. Therefore, in the following, the first map for the fourth speed stage will be described as an example, and the description of the first map for the other speed stages will be omitted.

  The first map is a map for determining the start timing of downshift, upshift, preshift control to the downshift side, and preshift control to the upshift side based on the vehicle body speed VS and the accelerator opening AR. That is, as shown in FIG. 3, the first map includes a downshift line indicating the downshift start timing, an upshift line indicating the upshift start timing, and a downshift indicating the start timing of the preshift control to the downshift side. A side pre-shift line and an up-side pre-shift line indicating the start timing of pre-shift control to the up-shift side are provided. Each of these lines is set so that the start timing is on the higher speed side as the accelerator opening AR is larger. The down-side preshift line is located on the higher speed side than the downshift line and on the lower speed side than the upside preshift line and the upshift line. Further, the up-side preshift line is located on the lower speed side than the upshift line.

  When the accelerator opening AR is the first opening AR1 and the vehicle body speed VS is the first speed VS1, downshift, upshift, preshift control to the downshift side, and preshift to the upshift side are performed. Control does not start. Further, when the accelerator opening AR is the second opening AR2 smaller than the first opening AR1, and the vehicle body speed VS becomes the second speed VS2 lower than the first speed VS1. The preshift control to the downshift side is executed. Further, when the accelerator opening degree AR is the third opening degree AR3 smaller than the second opening degree AR2 and the vehicle body speed VS becomes the third speed VS3 lower than the second speed VS2. Downshift is performed. On the other hand, when the accelerator opening degree AR is the fourth opening degree AR4 larger than the first opening degree AR1 and the vehicle body speed VS becomes the fourth speed VS4 higher than the first speed VS1. Pre-shift control to the upshift side is executed. Further, when the accelerator opening AR is the fifth opening AR5 larger than the fourth opening AR4 and the vehicle body speed VS becomes the fifth speed VS5 higher than the fourth speed VS4. Upshift is performed.

  Note that the preshift control to the downshift side means that the gear stage of the gear transmission mechanism on the side where no power is transmitted from the engine 12 is shifted by one stage from the gear stage selected at the present time in the automatic transmission 13. This refers to pre-shift control prepared in stages. Further, the preshift control to the upshift side means that the gear stage of the gear transmission mechanism on the side where no power is transmitted from the engine 12 is shifted by one stage from the gear stage selected at the present time in the automatic transmission 13. This refers to pre-shift control prepared in stages.

  The second map shown in FIG. 4 is a map for setting the offset amount Oft according to the acceleration difference DVSdiff, which is the difference between the actual acceleration of the vehicle (hereinafter referred to as “actual acceleration”) and the target acceleration. That is, the offset amount Oft is set to “0 (zero)” when the acceleration difference DVSdiff is less than the difference threshold value DVSdiffth, and is larger as the acceleration difference DVSdiff is larger when the acceleration difference DVSdiff is equal to or greater than the difference threshold value DVSdiffth. Set to a value. The offset amount Oft is a value for setting the position of the down-side preshift line in the first map. In the first map, when the offset amount Oft is “0 (zero)”, the down-side preshift line is arranged at the position indicated by the solid line in FIG. 3, while the offset amount Oft is “0 (zero)”. Otherwise, it is arranged at a position on the high speed side (for example, a position indicated by a broken line in FIG. 3).

Next, a preshift determination processing routine executed by the ECU 40 of the present embodiment will be described based on the flowchart shown in FIG.
When an ignition switch (not shown) of the vehicle is set to “ON”, the ECU 40 executes a preshift determination processing routine. In this pre-shift determination processing routine, the ECU 40 sets the loading / traction flag FLGsk to “OFF” (step S10). The loaded tow flag FLGsk is set to “ON” when the vehicle is in a loaded towed state in which at least one of a loaded state and a towed state is running, but is not in a loaded towed state. Is a flag set to “OFF”. Subsequently, the ECU 40 calculates the vehicle body speed VS based on the detection signal from the vehicle body speed sensor SE6, and derives the vehicle actual acceleration DVSr by differentiating the calculated vehicle body speed VS (step S11). Therefore, in this embodiment, ECU40 functions also as a real acceleration calculation means.

  Then, the ECU 40 calculates the target acceleration DVSt of the vehicle (step S12). Specifically, the ECU 40 acquires the accelerator opening AR from the information received from the engine ECU 14, acquires the gear stage currently selected in the automatic transmission 13, and obtains the accelerator opening AR and the gear stage from the acquired accelerator opening AR. The rotational speed of the output shaft 19 is estimated. Then, the ECU 40 calculates the target acceleration DVSt of the vehicle based on the estimated rotation speed of the output shaft 19. Therefore, in this embodiment, the ECU 40 also functions as target acceleration calculation means. The target acceleration DVSt is calculated as a speed close to the actual acceleration of the vehicle when traveling on a flat road surface when not in a loaded towing state.

  Subsequently, the ECU 40 calculates an acceleration difference DVSdiff by subtracting the actual acceleration DVSr calculated in step S12 from the target acceleration DVSt calculated in step S11 (step S13). Then, the ECU 40 determines whether or not the acceleration difference DVSdiff calculated in step S13 is greater than or equal to a preset difference threshold value DVSdiffth (step S14).

  Here, when the vehicle is in the loaded towed state, the load applied to the vehicle is larger than in the case of not being in the loaded towed state, so that a large amount of power is required to run the vehicle. Therefore, even when the same level of power is transmitted to the front wheels FR and FL, the acceleration is smaller in the loaded towed state than in the loaded towed state. In other words, the acceleration difference DVSdiff is larger in the loading towing state than in the loading towing state. Therefore, in the present embodiment, the difference threshold value DVSdiffth is set as a reference value for estimating whether or not the vehicle is in the loaded towing state based on the acceleration difference DVSdiff. Therefore, in the present embodiment, the ECU 40 also functions as a loading traction estimation unit.

  If the determination result in step S14 is affirmative (DVSdiff ≧ DVSdiffth), the ECU 40 determines whether or not the loading tow flag FLGsk is “OFF” (step S15). If this determination result is a negative determination (FLGsk = ON), the ECU 40 has already been estimated to be in the loaded towing state, and thus the process proceeds to step S11 described above. On the other hand, if the determination result in step S15 is affirmative (FLGsk = OFF), the ECU 40 determines that the determination result in step S14 is affirmative for the first time (that is, there is a possibility that the vehicle is in a loaded towing state). The first elapsed time T1, which is the elapsed time after the update, is updated (step S16). Subsequently, the ECU 40 determines whether or not the first elapsed time T1 updated in step S16 has exceeded a preset estimated determination time T1th (for example, 10 minutes) (step S17). The estimated determination time T1th is a value for determining that the loaded towed state has been reached when step S14 is continuously determined to be affirmative a plurality of times, and is set in advance by experiments or simulations.

  If the determination result in step S17 is negative (T1 ≦ T1th), the ECU 40 determines that there is a possibility that the loaded towing state is not present, and proceeds to step S11 described above. On the other hand, if the determination result in step S17 is affirmative (T1> T1th), the ECU 40 estimates that the loaded tow state has been reached, and sets the loaded tow flag FLGsk to “ON” (step S18). Subsequently, the ECU 40 substitutes the acceleration difference DVSdiff calculated in step S13 into the second map (see FIG. 4) to set the offset amount Oft according to the acceleration difference DVSdiff (step S19), and the process will be described later. Control goes to step S25.

  On the other hand, when the determination result of step S14 is negative (DVSdiff <DVSdiffth), the ECU 40 determines whether or not the loading tow flag FLGsk is “OFF” (step S20). If the determination result is affirmative (FLGsk = OFF), the ECU 40 has already been estimated not to be in the loaded towing state, and thus the process proceeds to step S11 described above. On the other hand, if the determination result in step S20 is a negative determination (FLGsk = ON), the ECU 40 may have determined that the determination results in steps S14 and S20 are both negative for the first time (that is, there is no longer a loaded traction state). The second elapsed time T2, which is the elapsed time since it was determined that there is, is updated (step S21). Subsequently, the ECU 40 determines whether or not the second elapsed time T2 updated in step S21 has exceeded a preset estimated cancellation time T2th (for example, 10 minutes) (step S22). The estimated cancellation time T2th is a value for determining that the load towing state is no longer present when both of steps S14 and S20 are negatively determined consecutively for a plurality of times, and is set in advance by experiments or simulations.

  If the determination result of step S22 is negative (T2 ≦ T2th), the ECU 40 determines that there is a possibility of being in a loaded towing state, and the process proceeds to step S11 described above. On the other hand, if the determination result in step S22 is affirmative (T2> T2th), the ECU 40 estimates that the loaded towing state is no longer present, and sets the loaded tow flag FLGsk to “OFF” (step S23). That is, the difference threshold value DVSdiffth is also a cancellation estimation threshold value that is a reference value for estimating whether or not the loaded towed state is lost. Therefore, in this embodiment, ECU40 functions also as a cancellation | release estimation means. Subsequently, the ECU 40 sets the offset amount Oft to “0 (zero)” (step S24), and the process proceeds to step S25 described later.

  In step S25, the ECU 40 resets each elapsed time T1, T2 to “0 (zero)”. Subsequently, the ECU 40 reads from the ROM 42 a first map for the speed stage (for example, the fourth speed stage) selected at the present time in the automatic transmission 13 and reduces it according to the offset amount Oft set in step S19 or step S24. The position of the side preshift line is set (step S26). Specifically, when the offset amount Oft is “0 (zero)”, the ECU 40 sets the down-side preshift line to the position indicated by the solid line in FIG. On the other hand, when the offset amount Oft is set to a value larger than “0 (zero)”, the ECU 40 sets the down-side preshift line at a higher speed side than the position indicated by the solid line in FIG. 3 according to the offset amount Oft. (The position on the right side in FIG. 3, for example, the position indicated by the broken line in FIG. 3) is set and this first map is stored in a predetermined area of the RAM 43.

  Thereafter, the ECU 40 estimates whether or not the ignition switch is “OFF” (step S27). If this determination result is a negative determination (switch = ON), the ECU 40 proceeds to step S11 described above. On the other hand, when the determination result of step S27 is affirmative (switch = OFF), the ECU 40 ends the preshift determination processing routine.

  That is, the ECU 40 reads out the first map corresponding to the current gear position of the automatic transmission 13 among the first maps stored in the predetermined area of the RAM 43 set in the preshift determination processing routine. When the ECU 40 estimates that the load is in the towing state, when the accelerator opening degree AR is the sixth opening degree AR6 and the vehicle body speed VS is the sixth speed VS6 (see FIG. 3), the ECU 40 proceeds to the downshift side. The pre-shift control is executed. On the other hand, when the ECU 40 estimates that the vehicle is not in the loaded towing state, when the accelerator opening degree AR is the sixth opening degree AR6 and the vehicle body speed VS is the sixth speed, the pre-shift control to the downshift side is executed. do not do. That is, the preshift control to the downshift side is executed in a state where the vehicle body speed VS is higher when it is estimated that the vehicle is in the traction loading state than in the case where it is estimated that the vehicle is not in the traction loading state. Therefore, in this embodiment, ECU40 which can adjust the start timing of the preshift control to a downshift side functions also as a preshift control means.

Therefore, in this embodiment, the following effects can be obtained.
(1) When the vehicle is estimated to be in a loaded towed state, the driver is more likely to request more power, so the vehicle body speed VS is higher than that in the case where it is estimated that the vehicle is not in a loaded towed state. The preshift control to the downshift side is executed. Therefore, even in a loaded towing state where there is a high possibility that a downshift will be executed, it is possible to execute an appropriate preshift control according to the state of the traveling vehicle.

  (2) When actually performing preshift control to the downshift side, a transmission gear (for example, a third-speed transmission gear 213) that can rotate integrally with the input shaft, and an input shaft (first input shaft) 15) and the sleeve 24 is engaged with the transmission gear. Therefore, when there is a high possibility that downshifting is required, preshift control to the downshift side needs to be started early. Therefore, in the present embodiment, when the vehicle travels in the loaded towed state, the preshift control to the downshift side is started at an earlier timing than in the case of not being in the loaded towed state. Therefore, when a downshift is actually requested, a quick downshift can be provided.

  (3) Further, the driver may request a downshift before the accelerator opening AR and the vehicle body speed VS are located on the left side of the downshift line in FIG. If the control configuration is such that the offset amount Oft is “0 (zero)” even if the vehicle is in the loaded towing state, pre-shift control to the downshift side is still executed when downshift is requested. It may not have been. In this case, after the downshift request is input to the ECU 40, the clutches C1 and C2 to be engaged are changed after the processing corresponding to the preshift control to the downshift side is executed. A large time difference occurs between when the ECU 40 is input to the ECU 40 and when the actual downshift is completed. In this regard, in the present embodiment, when it is estimated that the loaded towed state is established, the pre-shift control to the downshift side is executed in a state in which the vehicle body speed VS is faster than the case where it is estimated that the loaded towed state is not performed. Therefore, even if the driver requests a downshift before the accelerator opening AR and the vehicle body speed VS are located on the left side of the downshift line in FIG. 3, the preshift control to the downshift side is not performed at this time. It is more likely that it is running. Therefore, the time difference from when the downshift request is input to the ECU 40 until the downshift is actually completed can be reduced.

  (4) It is estimated from the acceleration difference DVSdiff whether the vehicle is in a loaded towed state. That is, even a vehicle not equipped with an external device such as a car navigation system can easily estimate whether the vehicle is in a loaded towed state, and as a result, appropriate preshift control according to the state of the traveling vehicle can be executed. .

  (5) Generally, when the vehicle travels in the loaded towing state, the state where the acceleration difference DVSdiff is equal to or greater than the difference threshold value DVSdiffth is continued. Therefore, in the present embodiment, when the state in which the acceleration difference DVSdiff is equal to or greater than the difference threshold value DVSdiffth is continued during the preset estimation determination time T1th, it is estimated that the loaded towing state is established. Therefore, for example, when the vehicle travels on an uphill road, it can be prevented that the vehicle is erroneously determined to be in a loaded towing state.

  (6) When a vehicle that is no longer in the loaded towing state travels, the state where the acceleration difference DVSdiff is less than the difference threshold value DVSdiffth should continue. Therefore, in the present embodiment, when the loading towing flag FLGsk is “ON” and the acceleration difference DVSdiff is less than the difference threshold value DVSdiffth for a preset estimated cancellation time T2th, It is estimated that the towing state has been eliminated. Therefore, when the loaded towing state is lost, the offset amount Oft can be reset to “0 (zero)”, and the preshift control to the downshift side can be returned to the normal state. In addition, for example, when the vehicle is temporarily stopped while waiting for a signal, it is possible to suppress erroneous estimation that the traction loading state has been eliminated.

In addition, you may change this embodiment into another embodiment as follows.
-In embodiment, you may abbreviate | omit each process of step S20-S24 of a preshift determination processing routine. In this case, once the loading towing flag FLGsk is turned “ON”, the offset amount Oft is set to a value larger than “0 (zero)” until the ignition switch is turned “OFF”. Even in this configuration, when the ignition switch is changed from “OFF” to “ON”, the loading towing flag FLGsk is set to “OFF”, and the offset amount Oft is an initial value “0 (zero)”. "Is set.

  Map information is stored in an external device such as a car navigation system. Therefore, when the car navigation system is mounted on a vehicle, the ECU 40 may receive information on the road surface on which the vehicle travels from the system. When the information received by the ECU 40 includes information indicating that the vehicle is traveling on a flat road surface that is not a slope, the processes in steps S16 and S17 may be omitted. Even if it comprises in this way, when a vehicle drive | works an uphill road, possibility that it will misdetermine that it is a loading traction state can be made small.

  In each seat of the vehicle, a sensor for detecting that a passenger is seated is provided. Therefore, based on the detection signal from each sensor, if it is possible to grasp the number of people on the vehicle, it is estimated that the loaded amount is large (that is, the towed state is loaded) when the number of passengers is equal to or greater than the predetermined number. May be.

In the embodiment, when the acceleration sensor is mounted on the vehicle, the actual acceleration DVSr may be calculated based on the detection signal from the acceleration sensor.
Next, the technical idea that can be grasped from the above embodiment and another embodiment will be added below.

(A) In the state estimated by the load traction estimation means to be in the load traction state, the target acceleration calculated by the target acceleration calculation means and the actual acceleration calculation means for a preset estimated estimation time When a state in which the difference from the calculated actual acceleration is less than a preset cancellation estimation threshold is continued, it further includes cancellation estimation means for estimating that the loading towing state has been canceled,
In the pre-shift control unit, when it is estimated that the load traction state is canceled by the cancellation estimation unit, the vehicle body speed of the vehicle is slower than the case where the load traction estimation unit estimates that the load traction state is established. In this state, pre-shift control is executed so that the gear position of the other power transmission system is prepared at a gear position that is lower than the gear speed selected by the gear mechanism of the one power transmission system. .

  DESCRIPTION OF SYMBOLS 12 ... Engine as drive source, 13 ... Automatic transmission, 15, 16 ... Input shaft which comprises power transmission system, 17, 18 ... Gear transmission mechanism which comprises power transmission system, 40 ... Control apparatus, Loading traction estimation means , Preshift control means, target acceleration calculation means, actual acceleration calculation means, ECU as cancellation estimation means, C1, C2 ... clutch constituting power transmission system, DVSdiff ... acceleration difference, DVSdiffth ... differential threshold corresponding to reset threshold, DVSr ... real acceleration, DVSt ... target acceleration, T1th ... estimation determination time, T2th ... elimination estimation time, VS ... body speed.

Claims (2)

There are two power transmission systems each having a clutch for controlling disconnection / connection of power from a drive source and a transmission mechanism connected in a state where power can be transmitted to the clutch. One clutch included in the one power transmission system is engaged and the other clutch included in the other power transmission system is released so that power from the drive source is transmitted to one of the power transmission systems. A control device for an automatic transmission that executes control for bringing the state into a state,
Target acceleration calculating means for calculating the target acceleration of the vehicle;
Actual acceleration calculating means for calculating the actual acceleration of the vehicle;
When the difference between the target acceleration calculated by the target acceleration calculation means and the actual acceleration calculated by the actual acceleration calculation means is calculated, and the calculated difference is equal to or greater than a difference threshold value set in advance to a value greater than zero In addition, a loading tow estimator that estimates that the vehicle is in a loaded towed state in which at least one of a loaded state and a towed state travels,
When the vehicle is traveling with power transmitted from the drive source via the clutch to the one power transmission system, the load traction estimation is performed when the load traction estimation means estimates that the load traction state is present. The speed of the other power transmission system is lower than the speed selected in the automatic transmission when the vehicle body speed is higher than the case where the vehicle is estimated not to be in the loaded towing state. And a pre-shift control means for performing pre-shift control so as to be prepared in the automatic transmission control device. The loading traction estimation unit has a difference between the target acceleration calculated by the target acceleration calculation unit and the actual acceleration calculated by the actual acceleration calculation unit equal to or greater than the difference threshold during a preset estimation determination time. 2. The control device for an automatic transmission according to claim 1 , wherein when the state is continued, it is estimated that the state is the loaded towing state.

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