JP2010203596A - Vehicular controller - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve fuel economy by reducing a speed of a car performing an up-shift operation. <P>SOLUTION: An automatic transmission is controlled so as to perform an up-shift operation when a car speed has increased to or beyond a car speed regulated by an up-shift line. An ECT-ECU runs a program containing a step of correcting the up-shift line so that if a car acceleration is not less than a predetermined one (YES at S108), the car speed regulated by the up-shift line decreases. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a vehicle control device, and more particularly, to a technique for performing control so as to reduce a vehicle speed at which an upshift of an automatic transmission mounted on a vehicle is executed.

  2. Description of the Related Art Conventionally, an automatic transmission that automatically shifts according to a vehicle speed is known. Generally, a torque converter is provided between an automatic transmission and a drive source such as an engine. The torque converter has a function of amplifying torque in accordance with the rotational speed difference between the pump impeller and the turbine runner. However, if there is a rotational speed difference between the pump impeller and the turbine runner, the energy transmission efficiency is deteriorated accordingly. Therefore, in order to improve the transmission efficiency of the torque converter, a lockup clutch capable of directly connecting the input shaft and the output shaft of the torque converter is provided.

  When the lockup clutch is engaged, the torque converter speed ratio (output shaft rotation speed / input shaft rotation speed) is “1”, and the output shaft of the drive source and the input shaft of the automatic transmission are directly connected.

  For example, when the vehicle speed increases until the vehicle speed exceeds a predetermined vehicle speed, the lockup clutch is engaged. Conversely, when the vehicle speed decreases until it becomes lower than the predetermined vehicle speed, the lockup clutch is released. In order to start hunting of the lockup clutch, a hysteresis is generally provided between the vehicle speed at which the lockup clutch is engaged and the vehicle speed at which the lockup clutch is released.

  As described above, in the state where the lock-up clutch is engaged, the transmission efficiency of the torque converter can be improved. Therefore, in order to improve the fuel efficiency of the vehicle, it is desirable to engage the lockup clutch as soon as possible.

  Japanese Patent Application Laid-Open No. 8-28678 (Patent Document 1) discloses that the rotational speed of the ON line that defines the turbine rotational speed when the torque converter is switched from the converter state to the lock-up state becomes lower as the acceleration of the vehicle increases. A control unit for changing to a rotational speed is disclosed.

  According to the control unit described in this publication, when the actual acceleration of the vehicle is suddenly greater than a predetermined acceleration, switching to the lock-up state is realized at an early stage, and as a result, fuel efficiency is improved. Can do.

JP-A-8-28678

  By the way, in order to further improve the fuel consumption, it is important to maintain the engine output shaft speed at a lower state. However, although the transmission efficiency of the torque converter can be improved by engaging the lock-up clutch, the degree of contribution to lowering the engine output shaft rotational speed is small.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a vehicle control device that can further improve the fuel consumption of the vehicle.

  A vehicle control apparatus according to a first aspect of the present invention is a vehicle control apparatus provided with a drive source and an automatic transmission coupled to the drive source. The control device includes means for detecting the vehicle speed, means for controlling the automatic transmission so as to upshift when the vehicle speed increases until the vehicle speed exceeds the first threshold value, and the first threshold value. Means for controlling the automatic transmission to downshift when the vehicle speed decreases until it becomes smaller than a small second threshold, means for detecting the acceleration of the vehicle, and the acceleration is equal to or greater than a predetermined acceleration In this case, a correction means for correcting the first threshold value to be small is provided.

  According to this configuration, the automatic transmission is controlled to upshift when the vehicle speed increases until the first threshold value is reached. The automatic transmission is controlled to shift down when the vehicle speed decreases until it becomes smaller than the second threshold value which is smaller than the first threshold value. In a vehicle equipped with an automatic transmission controlled in this way, in order to improve fuel efficiency, it is possible to upshift the automatic transmission at the lowest possible vehicle speed to lower the output shaft rotational speed of a drive source such as an engine. preferable. However, if the vehicle speed at which the automatic transmission is upshifted is reduced, the hysteresis between the vehicle speed at which the automatic transmission is upshifted and the vehicle speed at which the automatic transmission is downshifted is reduced, and the upshift and downshift are repeated in a short period of time. Is likely to occur. Therefore, when the acceleration is equal to or higher than a predetermined acceleration, the vehicle speed at which the automatic transmission is upshifted is lowered. As a result, the vehicle speed for upshifting can be reduced only when the vehicle is slowed down and the automatic transmission is unlikely to downshift. As a result, the output shaft speed of the drive source can be reduced without a busy shift. As a result, a vehicle control device that can further improve the fuel consumption of the vehicle can be provided.

  In the vehicle control apparatus according to the second aspect of the invention, in addition to the configuration of the first aspect of the invention, the correction means includes means for correcting the first threshold value so as to be reduced to the second threshold value. .

  According to this configuration, the vehicle speed at which the automatic transmission is upshifted is reduced until there is no hysteresis between the vehicle speed at which the automatic transmission is upshifted and the vehicle speed at which the automatic transmission is downshifted. Thereby, the vehicle speed at which the automatic transmission is upshifted can be made the lowest possible.

  In addition to the configuration of the first or second aspect of the invention, the vehicle control device according to the third aspect of the present invention is configured in advance after the automatic transmission is upshifted in a state where the first threshold value is corrected to be small. There is further provided means for returning the first threshold value to the original value for a predetermined time.

  According to this configuration, after the automatic transmission is upshifted at a lower vehicle speed than when the acceleration is small, the vehicle is decelerated for some reason and downshifted. Upshifting can be prevented until the vehicle speed increases beyond the threshold. As a result, a busy shift can be avoided.

  In the vehicle control apparatus according to the fourth aspect of the invention, a torque converter is provided between the drive source and the automatic transmission in addition to the configuration of any one of the first to third aspects of the invention. The torque converter is provided with a lock-up clutch that, when engaged, directly connects the output shaft of the drive source and the input shaft of the automatic transmission. The control device includes means for controlling the lock-up clutch so that the lock-up clutch is engaged when the vehicle speed increases until reaching the third threshold value or more, and a fourth threshold value smaller than the third threshold value. Means for controlling the lockup clutch to release when the vehicle speed decreases until the vehicle speed decreases, and if the acceleration is greater than or equal to a predetermined acceleration, the third threshold value decreases to the fourth threshold value Means for correcting so as to be corrected.

  According to this configuration, when the acceleration is equal to or higher than the predetermined acceleration, the lock-up clutch of the torque converter is engaged at a lower vehicle speed than when the acceleration is smaller than the predetermined acceleration. Thereby, the area | region which engages a lockup clutch can be expanded. Therefore, fuel consumption can be further improved.

  In addition to the configuration of the fourth invention, the vehicle control apparatus according to the fifth invention is predetermined after the lockup clutch is engaged in a state where the third threshold value is corrected to be small. Means for returning the third threshold value to the original value for a predetermined time.

  According to this configuration, after the lockup clutch is engaged at a lower vehicle speed than when acceleration is low, the vehicle decelerates for some reason and the lockup clutch is released. It is possible to prevent the lockup clutch from being engaged until the vehicle speed increases beyond the third threshold value. As a result, hunting of the lockup clutch can be avoided.

  A vehicle control device according to a sixth aspect of the invention is a vehicle control device provided with a drive source and an automatic transmission coupled to the drive source. The control device predicts from the vehicle acceleration the means for detecting the acceleration of the vehicle and the output shaft rotation speed of the drive source when the automatic transmission is upshifted before the automatic transmission is actually upshifted. And a means for predicting the timing at which the predicted output shaft rotational speed of the drive source becomes the target rotational speed, and the predicted output shaft rotational speed of the drive source becomes the target rotational speed. Means for outputting an upshift execution command to the automatic transmission at a timing preceding the timing by a time required for the upshift.

  According to this configuration, the output shaft rotational speed of the drive source in a state where the automatic transmission is assumed to be upshifted is predicted from the acceleration of the vehicle. Further, the timing at which the predicted output shaft rotational speed of the drive source becomes the target rotational speed is predicted. An upshift execution command is output to the automatic transmission at a timing that is earlier than the timing at which the predicted output shaft rotation speed of the drive source reaches the target rotation speed by the time required for the upshift. Thereby, the output shaft rotation speed of the drive source after the automatic transmission is actually upshifted can be brought close to the target rotation speed. For this reason, an upshift is performed at a vehicle speed as low as possible so that the output shaft rotational speed of the drive source does not become too high, for example, with respect to a target rotational speed preferable for fuel efficiency, and the output shaft rotational speed of the drive source is as much as possible. Can be lowered. As a result, a vehicle control device that can further improve the fuel consumption of the vehicle can be provided.

  According to a seventh aspect of the present invention, in addition to the configuration of the sixth aspect of the vehicle control device, according to the difference between the output shaft rotational speed of the drive source and the target rotational speed after the automatic transmission is actually upshifted, A means for correcting the time required for the upshift is further provided.

  According to this configuration, the time required for the upshift, that is, the timing at which the upshift execution command is output to the automatic transmission is determined based on the output shaft rotational speed of the drive source and the target rotation after the automatic transmission is actually upshifted. Feedback correction is performed according to the difference from the number. Thereby, the output shaft rotational speed of the drive source after the automatic transmission is actually upshifted can be made closer to the target rotational speed with higher accuracy.

  In the vehicle control apparatus according to the eighth invention, in addition to the configuration of the sixth or seventh invention, a torque converter is provided between the drive source and the automatic transmission. The rotational speed prediction means includes means for predicting the output shaft rotational speed of the automatic transmission from the acceleration of the vehicle, and the automatic transmission based on the predicted output shaft rotational speed of the automatic transmission and the gear ratio realized by the upshift. And a means for predicting the output shaft rotational speed of the drive source from the predicted input shaft rotational speed of the automatic transmission and the speed ratio of the torque converter.

  According to this configuration, the output shaft rotational speed of the drive source is accurately predicted under the assumption that the automatic transmission is upshifted in consideration of the acceleration of the vehicle, the gear ratio of the automatic transmission, and the characteristics of the torque converter. be able to.

It is a schematic block diagram which shows the power train of a vehicle. It is a skeleton figure which shows the planetary gear unit of an automatic transmission. It is a figure which shows the operation | movement table | surface of an automatic transmission. It is a figure which shows the hydraulic circuit of an automatic transmission. It is a functional block diagram of ECT-ECU in a 1st embodiment. It is a figure which shows a shift map. It is a figure which shows the corrected upshift line. It is a figure which shows a lockup on line and a lockup off line. It is a figure which shows the corrected lockup on line. It is a figure (the 1) which shows the control structure of the program which ECT-ECU performs in 1st Embodiment. The figure which shows the control structure of the program which ECT-ECU performs in 1st Embodiment (the 2) It is a functional block diagram of ECT-ECU in 2nd Embodiment. It is a figure which shows the output-shaft rotation speed NE of the estimated engine. FIG. 6 is a diagram (No. 1) showing a state where the output shaft speed NE of the engine after upshifting is higher than the target speed. It is a figure which shows the control structure of the program which ECT-ECU performs in 2nd Embodiment. It is a figure which shows the output-shaft rotation speed NE of an engine in case acceleration is small. FIG. 6 is a diagram (No. 2) showing a state where the output shaft speed NE of the engine after upshifting is higher than the target speed. It is a figure which shows the output-shaft rotation speed NE of an engine in case acceleration is large.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, the same parts are denoted by the same reference numerals. Their names and functions are also the same. Therefore, detailed description thereof will not be repeated.

<First Embodiment>
A vehicle equipped with a control device according to an embodiment of the present invention will be described with reference to FIG. This vehicle is an FR (Front engine Rear drive) vehicle. A vehicle other than FR may be used.

  The vehicle includes an engine 1000, an automatic transmission 2000, a torque converter 2100, a planetary gear unit 3000 that forms part of the automatic transmission 2000, a hydraulic circuit 4000 that forms part of the automatic transmission 2000, a propeller shaft 5000, A differential gear 6000, a rear wheel 7000, and an ECU (Electronic Control Unit) 8000 are included. The control device according to the present embodiment is realized by executing a program recorded in a ROM (Read Only Memory) 8002 of ECU 8000, for example.

  Engine 1000 is an internal combustion engine that burns a mixture of fuel and air injected from injector 1002 in a combustion chamber of a cylinder. The piston in the cylinder is pushed down by the combustion, and the crankshaft is rotated. The auxiliary power 1004 such as an alternator and an air conditioner is driven by the driving force of the engine 1000. A motor may be used as a power source instead of or in addition to engine 1000.

  Automatic transmission 2000 is connected to engine 1000 via torque converter 2100. Automatic transmission 2000 changes the rotational speed of the crankshaft to a desired rotational speed by forming a desired gear stage.

  The driving force output from automatic transmission 2000 is transmitted to left and right rear wheels 7000 via propeller shaft 5000 and differential gear 6000.

  The ECU 8000 includes a position switch 8006 for the shift lever 8004, an accelerator opening sensor 8010 for the accelerator pedal 8008, a pedaling force sensor 8014 for the brake pedal 8012, a throttle opening sensor 8018 for the electronic throttle valve 8016, and an engine speed sensor 8020. The input shaft rotational speed sensor 8022, the output shaft rotational speed sensor 8024, the oil temperature sensor 8026, and the water temperature sensor 8028 are connected via a harness or the like.

  The position (position) of shift lever 8004 is detected by position switch 8006, and a signal representing the detection result is transmitted to ECU 8000. Corresponding to the position of the shift lever 8004, the gear stage of the automatic transmission 2000 is automatically formed. Further, a manual shift mode in which the driver can select an arbitrary gear stage may be selected according to the driver's operation.

  Accelerator opening sensor 8010 detects the opening of accelerator pedal 8008 and transmits a signal representing the detection result to ECU 8000. The pedaling force sensor 8014 detects the pedaling force of the brake pedal 8012 (the force with which the driver steps on the brake pedal 8012), and transmits a signal representing the detection result to the ECU 8000.

  The throttle opening sensor 8018 detects the opening of the electronic throttle valve 8016 whose opening is adjusted by the actuator, and transmits a signal representing the detection result to the ECU 8000. Electronic throttle valve 8016 adjusts the amount of air taken into engine 1000 (output of engine 1000).

  Instead of or in addition to the electronic throttle valve 8016, the amount of air drawn into the engine 1000 can be reduced by changing the lift amount of the intake valve (not shown) or the exhaust valve (not shown) and the opening / closing phase. You may make it adjust.

  The engine speed sensor 8020 detects the speed NE of the output shaft (crankshaft) of the engine 1000 and transmits a signal representing the detection result to the ECU 8000. Input shaft rotational speed sensor 8022 detects input shaft rotational speed NI of automatic transmission 2000 (turbine rotational speed NT of torque converter 2100), and transmits a signal representing the detection result to ECU 8000. Output shaft rotational speed sensor 8024 detects output shaft rotational speed NO of automatic transmission 2000 and transmits a signal representing the detection result to ECU 8000.

  Oil temperature sensor 8026 detects the temperature (oil temperature) of oil (ATF: Automatic Transmission Fluid) used for the operation and lubrication of automatic transmission 2000, and transmits a signal indicating the detection result to ECU 8000.

  Water temperature sensor 8028 detects the temperature (water temperature) of cooling water for engine 1000 and transmits a signal representing the detection result to ECU 8000.

  The ECU 8000 includes a position switch 8006, an accelerator opening sensor 8010, a pedal effort sensor 8014, a throttle opening sensor 8018, an engine speed sensor 8020, an input shaft speed sensor 8022, an output shaft speed sensor 8024, an oil temperature sensor 8026, and a water temperature sensor. Based on a signal sent from 8028 or the like, a map stored in the ROM 8002, and a program, the devices are controlled so that the vehicle is in a desired running state.

  In the present embodiment, ECU 8000 has the forward 1st to 8th gears when the shift lever 8004 is in the D (drive) position and the D (drive) range is selected as the shift range of automatic transmission 2000. Automatic transmission 2000 is controlled so that one of these gears is formed. The automatic transmission 2000 can transmit a driving force to the rear wheel 7000 by forming any one of the first to eighth forward gears. In the D range, it may be possible to form a higher gear than the eighth gear. The gear stage to be formed is determined based on a shift diagram created in advance by experiments or the like using the vehicle speed and the accelerator opening as parameters.

  As shown in FIG. 1, ECU 8000 includes an engine ECU 8100 that controls engine 1000 and an ECT (Electronic Controlled Transmission) _ECU 8200 that controls automatic transmission 2000.

  Engine ECU 8100 and ECT-ECU 8200 are configured to be able to transmit and receive signals to and from each other.

  The planetary gear unit 3000 will be described with reference to FIG. Planetary gear unit 3000 is connected to a torque converter 2100 having an input shaft 2102 coupled to the crankshaft. Torque converter 2100 is provided with a lockup clutch 2106 that directly connects input shaft 2102 and output shaft 2104. When the lockup clutch 2106 is engaged, the input shaft 2102 and the output shaft 2104 are directly connected. That is, the output shaft of engine 1000 and the input shaft of automatic transmission 2000 are directly connected.

  The planetary gear unit 3000 includes a front planetary 3100, a rear planetary 3200, a C1 clutch 3301, a C2 clutch 3302, a C3 clutch 3303, a C4 clutch 3304, a B1 brake 3311, a B2 brake 3312, and a one-way clutch (F). 3320.

  The front planetary 3100 is a double pinion type planetary gear mechanism. Front planetary 3100 includes a first sun gear (S1) 3102, a pair of first pinion gears (P1) 3104, a carrier (CA) 3106, and a ring gear (R) 3108.

  The first pinion gear (P1) 3104 meshes with the first sun gear (S1) 3102 and the first ring gear (R) 3108. The first carrier (CA) 3106 supports the first pinion gear (P1) 3104 so that it can revolve and rotate.

  First sun gear (S1) 3102 is fixed to gear case 3400 so as not to rotate. First carrier (CA) 3106 is coupled to input shaft 3002 of planetary gear unit 3000.

  The rear planetary 3200 is a Ravigneaux type planetary gear mechanism. The rear planetary 3200 includes a second sun gear (S2) 3202, a second pinion gear (P2) 3204, a rear carrier (RCA) 3206, a rear ring gear (RR) 3208, a third sun gear (S3) 3210, a third Pinion gear (P3) 3212.

  Second pinion gear (P2) 3204 meshes with second sun gear (S2) 3202, rear ring gear (RR) 3208, and third pinion gear (P3) 3212. Third pinion gear (P3) 3212 meshes with third sun gear (S3) 3210 in addition to second pinion gear (P2) 3204.

  The rear carrier (RCA) 3206 supports the second pinion gear (P2) 3204 and the third pinion gear (P3) 3212 so that they can revolve and rotate. Rear carrier (RCA) 3206 is coupled to one-way clutch (F) 3320. The rear carrier (RCA) 3206 becomes non-rotatable when driving the first gear (when traveling using the driving force output from the engine 1000). Rear ring gear (RR) 3208 is coupled to output shaft 3004 of planetary gear unit 3000.

  The one-way clutch (F) 3320 is provided in parallel with the B2 brake 3312. That is, the outer race of the one-way clutch (F) 3320 is fixed to the gear case 3400, and the inner race is connected to the rear carrier (RCA) 3206.

  FIG. 3 shows an operation table showing the relationship between each gear position and the operation state of each clutch and each brake. By operating the brakes and the clutches in the combinations shown in the operation table, a forward 1st to 8th gear and a reverse 1st and 2nd gear are formed.

  The main part of the hydraulic circuit 4000 will be described with reference to FIG. The hydraulic circuit 4000 is not limited to the one described below.

  The hydraulic circuit 4000 includes an oil pump 4004, a primary regulator valve 4006, a manual valve 4100, a solenoid modulator valve 4200, an SL1 linear solenoid (hereinafter referred to as SL (1)) 4210, and an SL2 linear solenoid (hereinafter referred to as “the solenoid valve”). SL2 (described as SL (4)) 4220, SL3 linear solenoid (hereinafter referred to as SL (3)) 4230, SL4 linear solenoid (hereinafter referred to as SL (4)) 4240, and SL5 linear solenoid (hereinafter referred to as SL (3)). , SL (5)) 4250, SLT linear solenoid (hereinafter referred to as SLT) 4300, and B2 control valve 4500.

  Oil pump 4004 is connected to the crankshaft of engine 1000. As the crankshaft rotates, the oil pump 4004 is driven to generate hydraulic pressure. The hydraulic pressure generated by the oil pump 4004 is regulated by the primary regulator valve 4006 to generate a line pressure.

  Primary regulator valve 4006 operates using the throttle pressure regulated by SLT 4300 as a pilot pressure. The line pressure is supplied to the manual valve 4100 via the line pressure oil passage 4010.

  Manual valve 4100 includes a drain port 4105. From the drain port 4105, the oil pressure in the D range pressure oil passage 4102 and the R range pressure oil passage 4104 is discharged. When the spool of the manual valve 4100 is in the D position, the line pressure oil passage 4010 and the D range pressure oil passage 4102 are communicated, and hydraulic pressure is supplied to the D range pressure oil passage 4102. At this time, the R range pressure oil passage 4104 and the drain port 4105 are communicated, and the R range pressure of the R range pressure oil passage 4104 is discharged from the drain port 4105.

  When the spool of the manual valve 4100 is in the R position, the line pressure oil passage 4010 and the R range pressure oil passage 4104 are communicated, and the oil pressure is supplied to the R range pressure oil passage 4104. At this time, the D range pressure oil passage 4102 and the drain port 4105 are communicated, and the D range pressure in the D range pressure oil passage 4102 is discharged from the drain port 4105.

  When the spool of the manual valve 4100 is in the N position, both the D range pressure oil passage 4102 and the R range pressure oil passage 4104 are connected to the drain port 4105, and the D range pressure and R of the D range pressure oil passage 4102 are communicated. The R range pressure of the range pressure oil passage 4104 is discharged from the drain port 4105.

  The hydraulic pressure supplied to the D range pressure oil path 4102 is finally supplied to the C1 clutch 3301, the C2 clutch 3302, and the C3 clutch 3303. The hydraulic pressure supplied to the R range pressure oil passage 4104 is finally supplied to the B2 brake 3312.

  The solenoid modulator valve 4200 adjusts the hydraulic pressure (solenoid modulator pressure) supplied to the SLT 4300 to a constant pressure using the line pressure as the original pressure.

  SL (1) 4210 regulates the hydraulic pressure supplied to the C1 clutch 3301. SL (2) 4220 regulates the hydraulic pressure supplied to C2 clutch 3302. SL (3) 4230 regulates the hydraulic pressure supplied to the C3 clutch 3303. SL (4) 4240 regulates the hydraulic pressure supplied to C4 clutch 3304. SL (5) 4250 regulates the hydraulic pressure supplied to the B1 brake 3311.

  The SLT 4300 adjusts the solenoid modulator pressure in accordance with a control signal from the ECU 8000 based on the accelerator opening detected by the accelerator opening sensor 8010, and generates a throttle pressure. The throttle pressure is supplied to the primary regulator valve 4006 via the SLT oil passage 4302. The throttle pressure is used as a pilot pressure for the primary regulator valve 4006.

  SL (1) 4210, SL (2) 4220, SL (3) 4230, SL (4) 4240, SL (5) 4250, and SLT 4300 are controlled by a control signal transmitted from ECU 8000.

  The B2 control valve 4500 selectively supplies hydraulic pressure from one of the D range pressure oil passage 4102 and the R range pressure oil passage 4104 to the B2 brake 3312. A D range pressure oil passage 4102 and an R range pressure oil passage 4104 are connected to the B2 control valve 4500. The B2 control valve 4500 is controlled by the hydraulic pressure supplied from the SLU solenoid valve (not shown) and the biasing force of the spring.

  When the SLU solenoid valve is on, the B2 control valve 4500 is in the state on the left side in FIG. In this case, the B2 brake 3312 is supplied with the hydraulic pressure adjusted from the D range pressure using the hydraulic pressure supplied from the SLU solenoid valve as a pilot pressure.

  When the SLU solenoid valve is off, the B2 control valve 4500 is in the state on the right side in FIG. In this case, the R range pressure is supplied to the B2 brake 3312.

  The ECT-ECU 8200 will be further described with reference to FIG. Note that the function of the ECT-ECU 8200 described below may be realized by hardware or may be realized by software.

  The ECT-ECU 8200 of the ECU 8000 includes a vehicle speed detection unit 8202, an acceleration detection unit 8204, an upshift unit 8210, a downshift unit 8212, a first correction unit 8220, a first return unit 8230, and an engagement unit 8240. , A release unit 8242, a second correction unit 8250, and a second return unit 8260.

  The vehicle speed detection unit 8202 detects (calculates) the vehicle speed from the output shaft rotational speed NO of the automatic transmission 2000. Note that the output shaft rotational speed NO of the automatic transmission 2000 may be used instead of the vehicle speed.

  The acceleration detection unit 8204 detects (calculates) the acceleration of the vehicle by differentiating the vehicle speed. Note that the rate of change of the output shaft rotational speed NO of the automatic transmission 2000 may be used instead of the acceleration of the vehicle.

  Upshift unit 8210 controls automatic transmission 2000 to downshift according to a shift diagram with vehicle speed and accelerator opening as parameters. The downshift unit 8212 controls the automatic transmission 2000 to downshift according to the shift diagram.

  As shown in FIG. 6, in the shift diagram, an upshift line and a downshift line are set for each type of shift (a combination of a gear stage before the shift and a gear stage after the shift). Hysteresis is provided between the upshift line and the downshift line.

  Automatic transmission 2000 is controlled to upshift when the vehicle speed increases until the vehicle speed exceeds the vehicle speed defined by the upshift line. The automatic transmission 2000 is controlled so as to shift down when the vehicle speed decreases until it becomes lower than the vehicle speed defined by the downshift line.

  In addition, automatic transmission 2000 is controlled so as to shift up when the accelerator opening decreases until it becomes smaller than the accelerator opening defined by the upshift line. Automatic transmission 2000 is controlled so as to shift down when the accelerator opening increases until it reaches or exceeds the accelerator opening defined by the downshift line.

  Returning to FIG. 5, the first correction unit 8220 corrects the upshift line so that the vehicle speed defined by the upshift line becomes lower when the acceleration of the vehicle is equal to or higher than a predetermined acceleration. That is, the upshift line is corrected to be low.

  More specifically, as shown in FIG. 7, correction is performed so that the upshift line is lowered to the downshift line. This eliminates the hysteresis between the upshift line and the downshift line. Note that correction may be performed so that the upshift line is lowered in a range where the upshift line and the downshift line do not coincide with each other.

  Returning to FIG. 5, after the automatic transmission 2000 is upshifted in a state in which the upshift line is corrected to be lowered, the first return unit 8230 sets the upshift line to the original value for a predetermined time. Return to (vehicle speed). That is, the vehicle speed defined by the upshift line is returned to the initial value.

  The engaging portion 8240 controls the lockup clutch 2106 to engage according to a map using the vehicle speed and the accelerator opening as parameters. The release unit 8242 controls the lockup clutch 2106 to release (shut off) the vehicle according to a map using the vehicle speed and the accelerator opening as parameters.

  As shown in FIG. 8, in the map used for engagement and release of the lockup clutch 2106, a lock amplifier on line and a lockup off line are set. Hysteresis is provided between the lock amplifier on line and the lock amplifier off line.

  The lock-up clutch 2106 is controlled to engage when the vehicle speed increases until the vehicle speed exceeds the vehicle speed defined by the lock amplifier on line. The lockup clutch 2106 is controlled so as to be released when the vehicle speed decreases until it becomes lower than the vehicle speed defined by the lockup off line.

  Further, the lock-up clutch 2106 is controlled to be engaged when the accelerator opening decreases until it becomes smaller than the accelerator opening defined by the lock amplifier ON line. The lockup clutch 2106 is controlled so as to be released when the accelerator opening increases until the accelerator opening reaches or exceeds the accelerator opening defined by the lockup off line.

  Returning to FIG. 5, when the acceleration is equal to or higher than the predetermined acceleration, the second correction unit 8250 corrects the lock-up on line so that the vehicle speed defined by the lock-up on line becomes low. That is, the lockup on line is corrected to be low.

  More specifically, as shown in FIG. 9, correction is performed so that the lock-up on line is lowered to the lock-up off line. This eliminates the hysteresis between the lockup on line and the lockup off line. In addition, you may make it correct | amend so that a lockup on line may become low in the range where a lockup on line and a lockup off line do not correspond.

  Returning to FIG. 5, after the lockup clutch 2106 is engaged in a state in which the lockup on line is corrected so that the lockup on line is lowered, the second return unit 8260 performs the lockup on line only for a predetermined time. Return to the original value (vehicle speed). That is, the vehicle speed defined by the lock-up on line is returned to the initial value.

  With reference to FIG. 10, a control structure of a program executed by ECT-ECU 8200 for correcting the upshift line and the lockup on line will be described. Note that the program described below is repeatedly executed at a predetermined cycle.

  In step (hereinafter, step is abbreviated as S) 100, ECT-ECU 8200 detects the vehicle speed. In S102, ECT-ECU 8200 detects the acceleration of the vehicle.

  At S104, ECT-ECU 8200 detects the gradient of the road surface on which the vehicle is traveling. The gradient is detected according to a map created in advance by the developer so as to have, for example, the accelerator opening and acceleration as parameters. In addition, since it is sufficient to use a well-known technique for the method of detecting the gradient, detailed description thereof will not be repeated here.

  In S106, ECT-ECU 8200 determines whether or not the gradient is equal to or less than a predetermined gradient. If the gradient is equal to or smaller than a predetermined gradient (YES in S106), the process proceeds to S108. If not (NO in S106), this process ends.

  In S108, ECT-ECU 8200 determines whether or not the acceleration of the vehicle is equal to or greater than a predetermined acceleration. If the acceleration of the vehicle is equal to or greater than a predetermined acceleration (YES in S108), the process proceeds to S110. Otherwise (NO in S108), this process ends.

  In S110, ECT-ECU 8200 corrects the upshift line so that the vehicle speed defined by the upshift line becomes lower.

  In S112, ECT-ECU 8200 determines whether or not automatic transmission 2000 has been upshifted with the upshift line corrected so that the vehicle speed defined by the upshift line is reduced.

  If automatic transmission 2000 is upshifted with the upshift line corrected so that the vehicle speed defined by the upshift line is reduced (YES in S112), the process proceeds to S114. If not (NO in S112), the process proceeds to S120.

  In S114, ECT-ECU 8200 returns the vehicle speed defined by the upshift line to the original value (vehicle speed) for a predetermined time.

  At S120, ECT-ECU 8200 corrects the lock-up on-line so that the vehicle speed defined by the lock-up on-line is reduced.

  In S122, ECT-ECU 8200 determines whether or not lockup clutch 2106 is engaged in a state in which the lockup on line is corrected so that the vehicle speed defined by the lockup on line is reduced.

  If lock-up clutch 2106 is engaged with the lock-up on-line corrected so that the vehicle speed defined by the lock-up on-line is low (YES in S122), the process proceeds to S124. Otherwise (NO in S122), this process ends.

  In S124, ECT-ECU 8200 returns the vehicle speed defined by the lock-up on line to the original value (vehicle speed) for a predetermined time.

  Referring to FIG. 11, a control structure of a program executed by ECT-ECU 8200 for shifting and engaging (locking up) lockup clutch 2106 will be described. Note that the program described below is repeatedly executed at a predetermined cycle.

  In S130, ECU-ECU 8200 determines whether the vehicle speed has increased until it exceeds the vehicle speed defined by the upshift line, or whether the accelerator opening has decreased until it becomes smaller than the accelerator opening defined by the upshift line. to decide.

  If the vehicle speed increases until the vehicle speed exceeds the vehicle speed specified by the upshift line, or if the accelerator opening decreases until it becomes smaller than the accelerator opening specified by the upshift line (YES in S130), the process proceeds to S132. Moved to. If not (NO in S130), the process proceeds to S134.

  In S132, ECU-ECU 8200 controls automatic transmission 2000 to upshift.

  In S134, ECU-ECU 8200 determines whether the vehicle speed has decreased until it becomes lower than the vehicle speed defined by the downshift line, or whether the accelerator opening has increased until the accelerator opening defined by the downshift line is exceeded. to decide.

  If the vehicle speed decreases until it becomes lower than the vehicle speed defined by the downshift line, or if the accelerator opening increases until it reaches or exceeds the accelerator opening defined by the downshift line (YES in S134), the process is S136. Moved to. If not (NO in S134), the process proceeds to S140.

  In S136, ECU-ECU 8200 controls automatic transmission 2000 to downshift.

  In S140, ECU-ECU 8200 decreases the accelerator opening until the vehicle speed increases until the vehicle speed exceeds the vehicle speed defined by the lock amplifier on line or becomes smaller than the accelerator opening defined by the lock amplifier on line. Determine if you did.

  When the vehicle speed increases until the vehicle speed exceeds the vehicle speed specified by the lock amplifier on line, or when the accelerator opening decreases until it becomes smaller than the accelerator opening specified by the lock amplifier on line (YES in S140), The process proceeds to S142. If not (NO in S140), the process proceeds to S144.

  In S142, ECU-ECU 8200 controls lockup clutch 2106 to be engaged.

  In S144, ECU-ECU 8200 decreases the vehicle speed until it becomes lower than the vehicle speed defined by the lock-up off line, or increases the accelerator opening until the vehicle speed exceeds the accelerator opening defined by the lock-up off line. Determine whether.

  When the vehicle speed decreases until it becomes lower than the vehicle speed defined by the lock-up off line, or when the accelerator opening increases until it becomes equal to or greater than the accelerator opening defined by the lock-up off line (YES in S144). Is moved to S146. Otherwise (NO in S144), this process ends.

  In S146, ECU-ECU 8200 controls lockup clutch 2106 to be released.

  A speed change operation of automatic transmission 2000 based on the above-described structure and flowchart will be described.

  When the vehicle speed increases until the vehicle speed exceeds the vehicle speed specified by the upshift line, or the accelerator opening decreases until it becomes smaller than the accelerator opening specified by the upshift line (in S130) YES), automatic transmission 2000 is controlled to upshift (S132).

  If the vehicle speed decreases until it becomes lower than the vehicle speed defined by the downshift line, or if the accelerator opening increases until it exceeds the accelerator opening defined by the downshift line (YES in S134), the vehicle shifts down. Thus, automatic transmission 2000 is controlled (S136).

  When the vehicle speed increases until the vehicle speed exceeds the vehicle speed specified by the lock amplifier on line, or when the accelerator opening decreases until it becomes smaller than the accelerator opening specified by the lock amplifier on line (YES in S140), Lock-up clutch 2106 is controlled to engage (S142).

  When the vehicle speed decreases until it becomes lower than the vehicle speed defined by the lock-up off line, or when the accelerator opening increases until it exceeds the accelerator opening defined by the lock-up off line (YES in S144), release Thus, the lockup clutch 2106 is controlled (S146).

  In this manner, automatic transmission 2000 and lockup clutch 2106 are controlled according to the vehicle speed and the accelerator opening.

  By the way, in order to improve fuel efficiency, the automatic transmission 2000 is upshifted at the lowest possible vehicle speed to lower the output shaft rotational speed NE of the engine 1000, or the lockup clutch 2106 is engaged to transfer efficiency of the torque converter 2100. Is preferably increased.

  However, if the vehicle speed at which the automatic transmission 2000 is upshifted is reduced, the hysteresis between the vehicle speed at which the automatic transmission 2000 is upshifted and the vehicle speed at which the automatic transmission 2000 is downshifted is reduced, and the upshift and the downshift are repeated in a short period of time. Is likely to occur.

  Further, when the vehicle speed at which the lockup clutch 2106 is engaged is lowered, the hysteresis between the vehicle speed at which the lockup clutch 2106 is engaged and the vehicle speed at which the lockup clutch 2106 is released is reduced, and the lockup clutch 2106 is easily hunted.

  Therefore, the vehicle speed at which the automatic transmission 2000 is upshifted and the vehicle speed at which the lockup clutch 2106 is engaged are lowered only when the automatic transmission 2000 is busy and the lockup clutch 2106 is not easily hunted.

  More specifically, the vehicle speed is detected (S100). The vehicle acceleration is detected from the vehicle speed (S102). Further, the slope of the road surface on which the vehicle is traveling is detected (S104).

  If the road gradient is equal to or lower than a predetermined gradient (YES in S106), it is difficult to cause a problem that the driving force of the vehicle is insufficient due to the upshift. If the vehicle acceleration is equal to or higher than a predetermined acceleration (YES in S108), it can be said that there is a low possibility that the vehicle decelerates and automatic transmission 2000 is downshifted or lockup clutch 2106 is released.

  Therefore, only in this case, the upshift line is corrected so that the vehicle speed defined by the upshift line becomes low (S110). Similarly, the lock-up on-line is corrected so that the vehicle speed defined by the lock-up on-line becomes low (S120).

  As a result, the vehicle speed at which upshifting is performed can be reduced only when the vehicle is slowed down and the automatic transmission 2000 is unlikely to downshift. Therefore, the output shaft rotational speed NE of the engine 1000 can be lowered without the busy shift of the automatic transmission 2000. As a result, the fuel efficiency of the vehicle can be improved.

  In addition, the vehicle speed at which the lockup clutch 2106 is engaged can be reduced only when the vehicle is unlikely to decelerate and the lockup clutch 2106 is released. Therefore, transmission efficiency of torque converter 2100 can be improved while avoiding hunting of lockup clutch 2106. As a result, the fuel consumption of the vehicle can be further improved.

  Incidentally, after correcting the upshift line and the lockup on line, for example, when the brake pedal is operated by the driver, the vehicle may decelerate and the downshift or the lockup clutch 2106 may be released.

  If the vehicle is accelerated again in such a case, the automatic transmission 2000 may be upshifted again or the lockup clutch 2106 may be engaged.

  Therefore, when automatic transmission 2000 is upshifted with the upshift line corrected so that the vehicle speed defined by the upshift line is lowered (YES in S112), the upshift line is defined by a predetermined time. The vehicle speed is returned to the original value (vehicle speed) (S114).

  As a result, even if the vehicle decelerates and shifts down for some reason, and then re-accelerates, the upshift will continue until the vehicle speed increases beyond the vehicle speed defined by the normal (before correction) upshift line. You can prevent it from happening. As a result, a busy shift can be avoided.

  If lock-up clutch 2106 is engaged with the lock-up on-line corrected so that the vehicle speed defined by the lock-up on-line is lowered (YES in S122), the lock-up is performed only for a predetermined time. The vehicle speed defined by the ON line is returned to the original value (vehicle speed) (S124).

  As a result, for some reason, the vehicle decelerates, the lockup clutch 2106 is released, and even if reaccelerated, the vehicle speed increases beyond the vehicle speed defined by the normal (before correction) lockup on-line. Until then, the lock-up clutch can be prevented from being engaged. As a result, hunting of the lockup clutch 2106 can be avoided.

<Second Embodiment>
Hereinafter, a second embodiment of the present invention will be described. The present embodiment is different from the first embodiment described above in that an upshift timing is determined using an expected value of output shaft speed NE of engine 1000 instead of the vehicle speed. In the normal state, the present embodiment is the same as the first embodiment in that the shift is performed according to the upshift line and the downshift line in the shift diagram.

  With reference to FIG. 12, the function of ECT-ECU 8200 in the present embodiment will be described. Note that the function of the ECT-ECU 8200 described below may be realized by hardware or may be realized by software.

  The ECT-ECU 8200 includes a vehicle speed detection unit 8202, an acceleration detection unit 8204, a rotation speed prediction unit 8270, a timing prediction unit 8272, an upshift command unit 8274, and a feedback correction unit 8276.

  The vehicle speed detection unit 8202 and the acceleration detection unit 8204 are the same as the vehicle speed detection unit 8202 and the acceleration detection unit 8204 in the first embodiment described above. Therefore, detailed description thereof will not be repeated.

  The rotational speed prediction unit 8270 predicts the output shaft rotational speed NE of the engine 1000 in the state where the automatic transmission 2000 is upshifted from the acceleration of the vehicle before the automatic transmission 2000 is actually upshifted.

  That is, as indicated by the one-dot chain line in FIG. 13, the output shaft rotational speed NE of the engine 1000 under the assumption that the automatic transmission 2000 is upshifted is predicted from the acceleration of the vehicle. A future output shaft speed NE after the current time T1 is predicted from the acceleration of the vehicle.

  More specifically, output shaft rotational speed NO of automatic transmission 2000 is predicted from the acceleration of the vehicle. A future output shaft rotational speed NO after the current time T1 is predicted from the acceleration of the vehicle. The output shaft rotational speed NO of automatic transmission 2000 is predicted by adding the amount of change in output shaft rotational speed NO obtained from the product of acceleration and time to the current output shaft rotational speed NO.

  Further, the input shaft rotational speed NI (turbine rotational speed NT) of automatic transmission 2000 is predicted from the predicted output shaft rotational speed NO of automatic transmission 2000 and the gear ratio realized by the upshift. A future input shaft rotational speed NI after the current time T1 is predicted. The input shaft rotational speed NI is predicted by multiplying the predicted output shaft rotational speed NO by the gear ratio realized by the upshift.

  Further, output shaft speed NE of engine 1000 is predicted from predicted input shaft speed NI of automatic transmission 2000 and speed ratio of torque converter 2100 (turbine speed NT / output shaft speed NE of engine 1000). By dividing the predicted input shaft rotational speed NI of automatic transmission 2000 by the speed ratio of torque converter 2100, output shaft rotational speed NE of engine 1000 is predicted. The method for predicting the output shaft rotational speed NE of the engine 1000 is not limited to these.

  As shown in FIG. 13, the timing prediction unit 8272 predicts the timing (time T2 in FIG. 13) at which the predicted output shaft rotational speed NE of the engine 1000 becomes the target rotational speed. That is, a difference ΔT1 between the current time T1 and the time T2 at which the predicted output shaft rotational speed NE of the engine 1000 becomes the target rotational speed is calculated. The difference ΔT1 between time T1 and time T2 is calculated as the time required for the predicted output shaft speed NE of the engine 1000 to reach the target speed. For example, by dividing the difference between the expected value of the output shaft speed NE of the engine 1000 and the target speed at the current time T1 by the rate of change of the expected value of the output shaft speed NE of the engine 1000, the time T1 and A difference ΔT1 from the time T2 is calculated. Note that the method of predicting the timing at which the predicted output shaft rotational speed NE of the engine 1000 becomes the target rotational speed is not limited thereto.

  For the target rotation speed, for example, a lower limit value at which fuel cut can be executed is used. The target rotational speed is not limited to this.

  As shown in FIG. 13, the upshift command unit 8274 has a timing (time of FIG. 13) that is a time ΔT2 that is required for the upshift before the predicted output shaft rotational speed NE of the engine 1000 becomes the target rotational speed. At T3), an upshift execution command is output to automatic transmission 2000. That is, automatic transmission 2000 is controlled to start upshifting at time T3.

  Note that the time required for upshifting means the time required to start or complete the upshift.

  The time ΔT2 required for the upshift is determined according to a map having the vehicle acceleration as a parameter. The map is created in advance by the developer based on the results of experiments and simulations. The method for determining the time ΔT2 required for the upshift is not limited to this.

  Feedback correction unit 8276 corrects time ΔT2 required for the upshift according to the difference between output shaft speed NE of engine 1000 after automatic transmission 2000 is actually upshifted and the target speed.

  For example, as shown in FIG. 14, the time ΔT2 required for the upshift becomes longer as the output shaft speed NE of the engine 1000 after the automatic transmission 2000 is actually upshifted is higher than the target speed. Is done. That is, the timing for outputting an upshift execution command to automatic transmission 2000 is advanced.

  On the contrary, the time ΔT2 required for the upshift is corrected to be shorter as the output shaft speed NE of the engine 1000 after the automatic transmission 2000 is actually upshifted is lower than the target speed. That is, the timing for outputting an upshift execution command to automatic transmission 2000 is delayed. Note that the method of correcting the time ΔT2 required for the upshift is not limited to this.

  With reference to FIG. 15, a control structure of a program executed by ECT-ECU 8200 in the present embodiment will be described. Note that the program described below is repeatedly executed at a predetermined cycle. The same steps as those in the first embodiment described above are denoted by the same step numbers. Therefore, detailed description thereof will not be repeated here.

  In S200, ECT-ECU 8200 determines whether or not the acceleration of the vehicle is equal to or greater than a predetermined acceleration. If the acceleration of the vehicle is equal to or greater than a predetermined acceleration (YES in S200), the process proceeds to S210. Otherwise (NO in S200), this process ends.

  At S210, ECT-ECU 8200 predicts output shaft rotational speed NE of engine 1000 in the state where automatic transmission 2000 is upshifted from the acceleration of the vehicle before automatic transmission 2000 is actually upshifted.

  In S212, ECT-ECU 8200 predicts the timing at which predicted output shaft speed NE of engine 1000 becomes the target speed.

  In S214, ECT-ECU 8200 issues an upshift execution command to automatic transmission 2000 at a timing before time ΔT2 required for the upshift before the predicted output shaft speed NE of engine 1000 reaches the target speed. Is output.

  At S216, ECT-ECU 8200 corrects time ΔT2 required for the upshift according to the difference between output shaft speed NE of engine 1000 after automatic transmission 2000 is actually upshifted and the target speed.

  A speed change operation of automatic transmission 2000 based on the above-described structure and flowchart will be described.

  When the acceleration of the vehicle is small, by performing an upshift according to an appropriately set upshift line, as shown in FIG. 16, the output shaft rotational speed NE of the engine 1000 at the time T4 when the upshift is completed is obtained as a target rotational speed. Can be approached.

  On the other hand, when the acceleration of the vehicle is large, if the upshift is performed according to the upshift line, as shown in FIG. 17, output shaft speed NE of engine 1000 at time T5 when the upshift is completed becomes higher than the target speed. obtain. Therefore, in order to make the output shaft rotational speed NE of the engine 1000 as low as possible, it is desirable to perform the upshift at a lower vehicle speed.

  Therefore, when the vehicle acceleration is equal to or higher than the predetermined acceleration (YES in S200), the upshift is lower than when the vehicle acceleration is smaller than the predetermined acceleration (NO in S200). Automatic transmission 2000 is controlled to perform at the vehicle speed.

  More specifically, before the automatic transmission 2000 is actually upshifted, the output shaft rotational speed NE of the engine 1000 in the state where the automatic transmission 2000 is upshifted is predicted from the acceleration of the vehicle (S210).

  Further, the timing at which the predicted output shaft speed NE of the engine 1000 becomes the target speed is predicted (S212).

  Further, an upshift execution command for automatic transmission 2000 is output at a timing before the time ΔT2 required for the upshift before the predicted output shaft speed NE of engine 1000 reaches the target speed (S214). .

  Thereby, as indicated by a solid line in FIG. 18, the output shaft rotational speed NE of the engine 1000 after the automatic transmission 2000 is actually upshifted can be brought close to the target rotational speed. Therefore, the upshift is executed as soon as possible so that the output shaft speed NE of the engine 1000 does not become too high with respect to the target speed, and the output shaft speed NE of the engine 1000 can be made as low as possible. . As a result, the fuel consumption of the vehicle can be further improved.

  After automatic transmission 2000 is actually upshifted, time ΔT2 required for the upshift is corrected according to the difference between output shaft speed NE of engine 1000 and the target speed (S216).

  That is, the timing at which the upshift execution command is output to automatic transmission 2000 is feedback-corrected in accordance with the difference between output shaft speed NE of engine 1000 and the target speed. Thereby, output shaft speed NE of engine 1000 after automatic transmission 2000 is actually upshifted can be made closer to the target speed with higher accuracy.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  1000 engine, 2000 automatic transmission, 2100 torque converter, 2102 input shaft, 2104 output shaft, 2106 lock-up clutch, 3000 planetary gear unit, 4000 hydraulic circuit, 5000 propeller shaft, 6000 differential gear, 7000 rear wheel, 8000 ECU, 8002 ROM, 8004 Shift lever, 8006 Position switch, 8008 Accelerator pedal, 8010 Accelerator opening sensor, 8012 Brake pedal, 8014 Treading force sensor, 8016 Electronic throttle valve, 8018 Throttle opening sensor, 8020 Engine speed sensor, 8022 Input shaft speed sensor, 8024 Output shaft rotational speed sensor, 8026 Oil temperature sensor, 8028 Water temperature sensor, 8100 Engine ECU, 8200 ECT-ECU, 8202 Vehicle speed detection unit, 8204 Acceleration detection unit, 8210 Upshift unit, 8212 Downshift unit, 8220 First correction unit, 8230 First return unit, 8240 Engagement unit, 8242 Release unit, 8250 2nd correction | amendment part, 8260 2nd return part, 8270 Revolution estimation part, 8272 Timing prediction part, 8274 Upshift command part, 8276 Feedback correction | amendment part.

Claims (8)

A vehicle control device provided with a drive source and an automatic transmission coupled to the drive source,
Means for detecting the vehicle speed;
Means for controlling the automatic transmission to upshift when the vehicle speed increases until a first threshold value or greater;
Means for controlling the automatic transmission to downshift when the vehicle speed decreases until less than a second threshold value less than the first threshold value;
Means for detecting the acceleration of the vehicle;
A control device for a vehicle, comprising: correction means for correcting the first threshold value to be smaller when the acceleration is equal to or higher than a predetermined acceleration.   2. The vehicle control device according to claim 1, wherein the correction means includes means for correcting the first threshold value so as to decrease to the second threshold value.   After the automatic transmission is upshifted with the first threshold value corrected to be small, the first threshold value is returned to the original value for a predetermined time. The vehicle control device according to claim 1, further comprising means. A torque converter is provided between the drive source and the automatic transmission,
The torque converter is provided with a lockup clutch that directly connects the output shaft of the drive source and the input shaft of the automatic transmission by being engaged,
Means for controlling the lock-up clutch to engage when the vehicle speed increases until a third threshold or greater;
Means for controlling the lock-up clutch to release when the vehicle speed decreases until less than a fourth threshold that is less than the third threshold;
4. The apparatus according to claim 1, further comprising: a unit configured to correct the third threshold value so as to be reduced to the fourth threshold value when the acceleration is equal to or higher than a predetermined acceleration. The vehicle control device described in 1.   After the lock-up clutch is engaged with the third threshold value corrected to be small, the third threshold value is returned to the original value for a predetermined time. The vehicle control device according to claim 4, further comprising means. A vehicle control device provided with a drive source and an automatic transmission coupled to the drive source,
Means for detecting the acceleration of the vehicle;
A rotational speed prediction means for predicting the output shaft rotational speed of the drive source from the acceleration of the vehicle in a state where the automatic transmission is upshifted before the automatic transmission is actually upshifted;
Means for predicting the timing at which the predicted output shaft rotational speed of the drive source becomes the target rotational speed;
Means for outputting an upshift execution command to the automatic transmission at a timing preceding the timing at which the predicted output shaft rotational speed of the drive source becomes the target rotational speed by a time required for the upshift. A vehicle control device.   The apparatus further comprises means for correcting a time required for the upshift according to a difference between the output shaft rotation speed of the drive source and the target rotation speed after the automatic transmission is actually upshifted. The vehicle control device described in 1. A torque converter is provided between the drive source and the automatic transmission,
The rotation speed prediction means includes
Means for predicting the output shaft speed of the automatic transmission from the acceleration of the vehicle;
Means for predicting the input shaft speed of the automatic transmission from the predicted output shaft speed of the automatic transmission and the gear ratio realized by upshifting;
The vehicle control device according to claim 6, further comprising means for predicting the output shaft rotational speed of the drive source from the predicted input shaft rotational speed of the automatic transmission and the speed ratio of the torque converter. .

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