JP2011208697A - Vehicle control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vehicle control device capable of reliably creating lock-up clutch learning opportunities.SOLUTION: The vehicle control device includes a torque converter, an engine, a lock-up clutch engaging means, a torque adjusting means, and a learning means. The torque converter has a lock-up clutch. The lock-up clutch engaging means performs engagement of the lock-up clutch depending on a reduction of an accelerator opening. The torque adjusting means adjusts torque to moderate the degradation gradient of an engine revolving speed during the engagement of the lock-up clutch. The learning means performs learning of the engaging force of the lock-up clutch during engagement and prohibits the learning in accordance with the adjustment amount of the torque adjustment. When the learning means prohibits the learning, the torque adjusting means restricts the adjustment amount of the torque adjustment during executing the next or later engagement to restart the learning by the learning means.

Description

  The present invention relates to control of a vehicle including a lockup clutch.

  Conventionally, a vehicle that engages a lock-up clutch during deceleration operation is known. For example, Patent Document 1 discloses a technique for storing a learning correction value for feedback control of a slip amount according to a driving state of an engine or an alternator in deceleration slip control. Patent Document 1 discloses a technique for prohibiting learning when the operating state of an air conditioner or an alternator changes during learning of a learning correction value. In addition, Patent Document 2 discloses a technique of stopping learning when learning the hydraulic pressure at the time of engagement when the ignition timing retardation amount is equal to or greater than a predetermined determination reference value.

Japanese Patent Laid-Open No. 2003-065433 JP 09-144866 A

  For the purpose of improving fuel efficiency and suppressing the occurrence of shock at the time of engagement, etc., the loss of engine torque is reduced during the engagement operation, or torque is applied to the engine by an electric motor to adjust the gradient of decrease in engine speed Control (hereinafter referred to as “torque adjustment control”) may be executed. On the other hand, the appropriate engagement force to be applied to the lockup clutch differs depending on whether or not the torque adjustment control is executed during engagement. Therefore, there is a possibility that the accuracy of learning may be reduced by mixing the case where torque adjustment control is executed and the case where torque adjustment control is not executed. On the other hand, if learning is prohibited during torque adjustment control in order to maintain learning accuracy, there is a problem in that learning opportunities decrease.

  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 capable of reliably providing a learning opportunity for a lock-up clutch.

  In one aspect of the present invention, a torque converter having a lock-up clutch, an engine connected to an input shaft of the torque converter, and a lock-up clutch that engages the lock-up clutch in response to a decrease in accelerator opening While learning the engagement force, the torque adjustment means for gradual decrease in the engine speed by adjusting the torque during the engagement, and the engagement force of the lock-up clutch during the engagement, Learning means for prohibiting learning based on the adjustment amount of the torque adjustment, and when the learning means prohibits the learning, the torque adjusting means, when performing the engagement after the next, The adjustment is limited and the learning is resumed.

  The vehicle control apparatus includes a torque converter, an engine, lockup clutch engagement means, torque adjustment means, and learning means. The torque converter has a lockup clutch. The lockup clutch engagement means is, for example, an ECU (Electronic Control Unit), and engages the lockup clutch in response to a decrease in the accelerator opening. Here, “engagement of the lock-up clutch” refers to a process of changing the state of the lock-up clutch. Specifically, from the released state to the engaged state, from the released state to the slip state, from the slip state to the engaged state, slip This corresponds to the process of shifting from the state to the slip state. The torque adjusting means is, for example, an ECU, and makes the gradient of decrease in the engine speed gentle by adjusting the torque while the lockup clutch is engaged. Here, the “decreasing gradient” refers to the degree of decrease in the engine speed accompanying a change with time. “Torque adjustment” refers to adjustment of torque generated in the vehicle, and specifically corresponds to adjustment of engine loss torque. The learning means is, for example, an ECU, which learns the engagement force of the lockup clutch at the time of engagement, and prohibits learning based on the adjustment amount of torque adjustment. In addition, when the learning unit prohibits learning, the torque adjusting unit restricts the adjustment amount of torque adjustment when the subsequent engagement is performed, and resumes learning by the learning unit. Here, “limitation of adjustment amount” includes both the case where the adjustment amount is 0, that is, the case where torque adjustment is prohibited, and the case where the adjustment amount is limited within a predetermined value. In this way, even when learning is prohibited due to torque adjustment, the vehicle control device ensures that learning is prioritized over torque adjustment and the learning opportunity is provided at the next engagement. be able to.

  In one aspect of the above vehicle control apparatus, when the torque adjustment is being performed, the vehicle control device further includes a fuel injection control unit that performs fuel cut from the start of the engagement to the completion of the engagement. In this aspect, the vehicle control device executes the torque adjustment to moderate the engine speed decrease gradient regardless of the fuel supply, execute the engagement of the lockup clutch, and generate a shock related to the engagement. It is determined that it can be suppressed. Therefore, in this aspect, the vehicle control device can improve fuel efficiency by executing fuel cut.

  In another aspect of the above vehicle control apparatus, the torque adjusting means releases the restriction when the engagement is stable after the restriction. Here, the torque adjusting means determines that the engagement is stable, for example, when the engagement succeeds once or a predetermined number of times. Thus, the vehicle control apparatus determines whether learning has been sufficiently performed based on whether or not the engagement is stable. And the control apparatus of a vehicle can restart torque adjustment in the state which fully performed learning by restarting torque adjustment after engagement is stabilized. In addition, the vehicle control device can improve the fuel consumption and reduce the shock associated with the engagement by resuming the torque adjustment.

  In another aspect of the vehicle control apparatus, the learning means prohibits the learning when the adjustment amount is equal to or greater than a predetermined value. Here, the predetermined value is, for example, a lower limit value of torque adjustment that may reduce learning accuracy. By doing in this way, the control apparatus of a vehicle can exclude that an outlier is excluded, and can suppress that the precision of the commanded engagement force falls by learning.

  In another aspect of the vehicle control apparatus, the torque adjusting means adjusts the torque by changing engine characteristics to reduce engine torque loss. Thereby, the control apparatus of a vehicle can make moderate the fall gradient of the engine speed during engagement suitably.

  In another aspect of the vehicle control apparatus, the torque adjustment unit performs the torque adjustment by reducing a loss of the engine torque by reducing a compression ratio of the engine.

  In another aspect of the vehicle control device described above, an electric motor that operates as a driving source of the vehicle is further provided, and the torque adjustment unit performs the torque adjustment by applying torque to the engine by the electric motor. Also by this, the vehicle control apparatus can preferably moderate the decreasing gradient of the engine speed being engaged.

  In another aspect of the above vehicle control apparatus, the torque adjustment means adjusts the torque by reducing a load on auxiliary equipment. Auxiliary equipment includes, for example, a power steering pump, an alternator, an air conditioner, and other peripheral devices necessary for the vehicle other than the engine body. According to this aspect as well, the vehicle control device can preferably reduce the loss of engine torque and make the gradient of decrease in engine speed during engagement gentle.

1 shows an example of a system to which a vehicle control device according to each embodiment of the present invention is applied. It is a schematic diagram which shows the structure of a torque converter. It is a schematic block diagram of an engine. It is an example of the flowchart which shows the process sequence of this embodiment.

  Preferred embodiments of the present invention will be described below with reference to the drawings.

[Schematic configuration]
(System configuration)
FIG. 1 is a schematic configuration showing an example of a system to which a vehicle control apparatus according to this embodiment is applied. Note that broken line arrows in the figure indicate signal input / output. The system is mounted on a vehicle and includes an engine 1, a motor generator MG, a torque converter 2, and an automatic transmission mechanism 3.

  The engine 1 and the motor generator MG correspond to a drive source of a hybrid vehicle (hereinafter also simply referred to as “mounted vehicle”) on which the system is mounted, and are connected in series. The torque converter 2 and the automatic transmission mechanism 3 are connected to these drive sources. Specifically, the output shafts of engine 1 and motor generator MG are connected to the input shaft of torque converter 2. The output shaft of the torque converter 2 is connected to the input shaft of the automatic transmission mechanism 3. The output shaft 5 of the automatic transmission mechanism 3 is connected to drive wheels (not shown). Therefore, the driving force from the engine 1 and the motor generator MG is alternatively or jointly changed through the torque converter 2 and the automatic transmission mechanism 3 and transmitted to the driving wheels, and the mounted vehicle is driven to travel.

  Further, when the accelerator pedal (not shown) is released during traveling and the vehicle decelerates, the driving force from the driving wheels is transmitted to the driving source via the automatic transmission mechanism 3 and the torque converter 2. At this time, a braking action by the friction torque of the engine 1 occurs, and power generation is performed by driving the motor generator MG. Since the motor generator MG is connected to the input shafts of the engine 1 and the torque converter 2, when the motor generator MG generates power, the motor generator MG is placed on the output shaft 1a of the engine 1 and the input shaft of the torque converter 2. More regenerative braking torque acts. Therefore, the ECU 10 can change the rotational speed of the engine 1 by controlling the motor generator MG.

  The engine 1 is a heat engine that generates power by burning fuel, and examples thereof include a gasoline engine and a diesel engine. The engine 1 is controlled by a control signal S1 supplied from the ECU 10. The engine 1 is a variable compression ratio engine capable of changing the compression ratio indicating the degree of compression of the air-fuel mixture. The configuration of the engine 1 will be described in more detail with reference to FIG.

  The torque converter 2 is a kind of fluid type power transmission device having a function of transmitting power through oil. The torque converter 2 is configured to be able to fasten and release between the input shaft and the output shaft of the torque converter 2 by a lock-up clutch. When the lockup clutch is released, the driving force is transmitted between the engine 1 and the motor generator MG, which are driving sources, and the automatic transmission mechanism 3 via oil. In a state where the lockup clutch is engaged, the drive source and the automatic transmission mechanism 3 are directly connected, and the driving force from the drive source is directly transmitted to the automatic transmission mechanism 3. The hydraulic control device 4 has a function of adjusting the hydraulic pressure of oil supplied to the torque converter 2.

  An ECU (Electronic Control Unit) 10 includes a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), an A / D (Analog to Digital) converter, and an input / output converter. Based on detection signals from various sensors, the engine 1, the motor generator MG, and the hydraulic control device 4 are controlled. In FIG. 1, an arrow indicated by a broken line indicates a flow of a control signal supplied from the ECU 10. For example, ECU 10 detects the rotational speeds of engine 1 and motor generator MG based on detection signals from rotational speed sensors (not shown) provided in each of engine 1 and motor generator MG. The ECU 10 controls the motor generator MG and the hydraulic control device 4 by supplying control signals S2 and S3 based on these rotational speeds. The ECU 10 functions as a lockup clutch engagement means, torque adjustment means, learning means, and fuel injection control means in the present invention.

(Configuration of torque converter)
The configuration of the torque converter 2 will be described in detail with reference to FIG. FIG. 2 is a schematic diagram showing the configuration of the torque converter. In FIG. 2, a solid line arrow and a broken line arrow without reference numerals indicate the flow of oil.

  The torque converter 2 mainly includes a lock-up clutch 21, a pump impeller 22, a turbine liner 23, and a stator 24. The lockup clutch 21 includes a lockup piston 21a provided with a facing 21b, and a converter cover 26.

  Output shafts 1 a and Ma of engine 1 and motor generator MG are connected to input shaft 27 of torque converter 2. Therefore, the rotational speed of the input shaft 27 of the torque converter 2 matches the rotational speed of the motor generator MG (motor rotational speed) and the rotational speed of the engine 1 (engine rotational speed). The input shaft 27 of the torque converter 2 is connected to the pump impeller 22 via the converter cover 26. The output shaft 28 of the torque converter 2 is connected to the lockup piston 21 a and the turbine liner 23. The rotational speed of the output shaft 28 of the torque converter 2 matches the turbine rotational speed. The stator 24 has a one-way clutch 25 and has a torque amplification function.

  The release-side oil chamber 31 and the fastening-side oil chamber 32 are connected to the hydraulic control device 4 via a passage 33, and the oil goes back and forth in the passage 33. Based on the control signal S3 from the ECU 10, the hydraulic control device 4 supplies the oil pressure to the release side oil chamber 31 between the converter cover 26 and the lockup piston 21a, and the engagement side on the pump impeller 22 side. The oil pressure is switched between the oil chamber 32 and the oil pressure of the oil. Note that the passage 33 actually passes through the output shaft 28 of the torque converter 2, but in FIG. 2, the passage 33 is illustrated independently of the output shaft 28 for convenience of explanation.

  When the hydraulic control device 4 supplies the hydraulic pressure to the fastening side oil chamber 32, the hydraulic pressure is drained from the release side oil chamber 31. Therefore, the oil flows in the direction from the fastening side oil chamber 32 toward the release side oil chamber 31 as indicated by the broken arrow. In this case, since the hydraulic pressure in the fastening side oil chamber 32 is larger than the hydraulic pressure in the release side oil chamber 31, the force in the direction indicated by the arrow AW1, that is, the force in the direction in which the lockup piston 21a is pressed against the converter cover 26. Act. That is, a force that increases the fastening force (hereinafter also referred to as “engagement force”) of the lockup clutch 21 acts. This engagement force is proportional to the magnitude of the hydraulic pressure supplied to the fastening side oil chamber 32.

  Further, when the hydraulic control device 4 supplies the hydraulic pressure to the release side oil chamber 31, the hydraulic pressure is drained from the fastening side oil chamber 32. Therefore, the oil flows in a direction from the release side oil chamber 31 toward the fastening side oil chamber 32 as indicated by a solid line arrow. In this case, the hydraulic pressure in the release-side oil chamber 31 is greater than the hydraulic pressure in the engagement-side oil chamber 32. Therefore, the force in the direction indicated by the arrow AW2, that is, the force in the direction in which the lockup piston 21a is pulled away from the converter cover 26. Act. That is, a force that weakens the engagement force of the lockup clutch 21 is applied.

  Therefore, the ECU 10 can adjust the engagement force of the lockup clutch 21 by controlling the hydraulic control device 4 and adjusting the hydraulic pressure supplied to the release side oil chamber 31 or the engagement side oil chamber 32. Specifically, the ECU 10 controls the hydraulic pressure control device 4 to adjust the hydraulic pressure supplied to the release-side oil chamber 31 or the engagement-side oil chamber 32, whereby the oil pressure of the release-side oil chamber 31 and the engagement-side oil chamber are adjusted. 32 can change the magnitude relationship between the hydraulic pressures 32 and realize an engaged state in which the lock-up clutch 21 is engaged and a converter state in which the lock-up clutch 21 is released. it can.

  Further, the ECU 10 supplies a control signal S3 to the hydraulic control device 4 in an intermediate region between the engaged state and the converter state of the lock-up clutch 21, and the hydraulic pressure of the release side oil chamber 31 or the engagement side oil chamber 32 is supplied. By adjusting the hydraulic pressure, slip control is performed to bring the facing 21b of the lockup piston 21a and the converter cover 26 into a sliding state (hereinafter referred to as “slip state”). For example, the lockup clutch 21 is controlled to be in a slip state when the vehicle decelerated from the accelerator pedal is decelerated.

  Hereinafter, the control for changing the state of the lockup clutch 21 when the vehicle decelerating the accelerator pedal is called “deceleration lockup control”, and the process for changing the state of the lockup clutch 21 is “engaged”. " Accordingly, the deceleration lockup control includes not only the case where the lockup clutch 21 is controlled from the released state to the converter state, but also the case where the lockup clutch 21 is controlled from the slip state to the converter state and from the slip state to the slip state.

(Engine configuration)
FIG. 3 shows a schematic configuration diagram of the engine 1 shown in FIG. A solid line arrow in the figure shows an example of a gas flow.

  The engine 1 mainly includes an intake passage 11, a throttle valve 12, a fuel injection valve 14a, an intake valve 14b, a spark plug 14c, an exhaust valve 14d, electromagnetic drive mechanisms (so-called electromagnetic cams) 14e, 14f. And a cylinder 15a, a combustion chamber 15b, a piston 15c, a connecting rod 15d, and an exhaust passage 16. In FIG. 3, only one cylinder 15a is shown for convenience of explanation, but the engine 1 actually has a plurality of cylinders 15a.

  Intake air (air) introduced from outside passes through the intake passage 11, and the throttle valve 12 adjusts the flow rate of intake air passing through the intake passage 11. The throttle valve 12 is an electronic throttle valve whose opening degree is controlled by a control signal S12 supplied from the ECU 10. The intake air that has passed through the intake passage 11 is supplied to the combustion chamber 15b. The fuel injected by the fuel injection valve (injector) 14a is supplied to the combustion chamber 15b.

  Further, the combustion chamber 15b is provided with an intake valve 14b and an exhaust valve 14d. The intake valve 14b controls communication / blocking between the intake passage 11 and the combustion chamber 15b by opening and closing. The exhaust valve 14d controls communication / blocking between the exhaust passage 16 and the combustion chamber 15b by opening and closing. The intake valve 14b and the exhaust valve 14d are called valve opening timing and valve closing timing (hereinafter referred to as “valve timing”) and lift amount (hereinafter referred to as “valve lift amount”) by electromagnetic drive mechanisms 14e and 14f, respectively. ) Etc. are controlled. In this case, the electromagnetic drive mechanisms 14e and 14f are controlled by control signals S14e and S14f supplied from the ECU 10.

  In the combustion chamber 15b, the air-fuel mixture of intake air and fuel supplied as described above is burned by being ignited by the spark plug 14c. In this case, the piston 15c reciprocates by combustion, the reciprocating motion is transmitted to the crankshaft (not shown) via the connecting rod 15d, and the crankshaft rotates. Exhaust gas generated by combustion in the combustion chamber 15 b is exhausted from the exhaust passage 16.

  The accelerator opening sensor 40 is a sensor configured to be able to detect an accelerator opening corresponding to an operation of an accelerator pedal (not shown) by a driver. The accelerator opening sensor 40 supplies the ECU 10 with a detection signal S40 corresponding to the detected accelerator opening. The engine speed sensor 41 supplies an output pulse of the engine speed to the ECU 10 by a detection signal S41. Further, the turbine rotation speed sensor 43 supplies a detection signal S43 of the turbine rotation speed to the ECU 10.

  The alternator 42 generates power using the power transmitted from the engine 50 when the mounted vehicle is decelerated based on the control signal S42 of the ECU 10, and supplies the generated power to a battery (not shown). The alternator 42 also functions as an electric motor that temporarily generates driving torque for the mounted vehicle based on the control signal S42 of the ECU 10.

[Control method]
Hereinafter, the process which ECU10 performs is demonstrated. Hereinafter, “electric motor” is a generic term for the alternator 42 and the motor generator MG.

(Example of torque adjustment control)
First, torque adjustment control for adjusting the decrease gradient of the engine speed during deceleration lockup control will be specifically described. The ECU 10 executes the torque adjustment control described below to moderate the engine speed decrease gradient during the deceleration lockup control regardless of the fuel supply. Therefore, the ECU 10 can perform fuel cut during the deceleration lockup control, and can suppress the execution of robust engagement and the occurrence of shock during engagement. The torque adjustment control described below may be arbitrarily combined.

1. Changing engine characteristics First, control for changing engine torque characteristics to adjust engine torque loss will be described. The ECU 10 changes the characteristics of the engine 1 so as to moderate the decrease gradient of the engine speed during the deceleration lockup control and enable fuel cut. Here, the control for changing the characteristics of the engine 1 by changing at least one of the compression ratio, the valve timing or / and the valve lift amount, and the throttle opening will be described.

  First, an example in which the compression ratio is changed will be described. In general, as the compression ratio is lower, engine torque loss such as pump loss in the exhaust stroke and friction loss in the compression stroke and expansion stroke is reduced. Therefore, when starting the deceleration lockup control, the ECU 10 reduces the compression ratio by a predetermined ratio based on, for example, the gear ratio. Specifically, the ECU 10 decreases the compression ratio as the gear ratio at the start of the deceleration lockup control is larger. The above-mentioned predetermined ratio is determined with reference to a predetermined map or expression based on the gear ratio and the like. Further, the map or the like is created in advance based on, for example, an experiment and held in the memory of the ECU 10. Thereby, ECU10 can reduce the loss of an engine torque and can adjust the fall gradient of the engine speed at the time of deceleration lockup control.

  Next, an example in which the valve timing or / and the valve lift amount is changed will be described. When the ECU 10 starts the deceleration lockup control instead of or in addition to the compression ratio control, the valve timing of the intake valve 14b and the exhaust valve 14d and / or the valve lift amount for all or some of the cylinders 15a. To control. Specifically, when executing the deceleration lockup control, the ECU 10 increases the valve lift amount and / or lengthens the overlap between the valve opening timing of the intake valve 14b and the valve opening timing of the exhaust valve 14d. Execute. Alternatively, the ECU 10 fully closes the intake valve 14b and the exhaust valve 14d. In particular, as with the compression ratio control, the ECU 10 changes the control method and the control amount of the intake valve 14b and the exhaust valve 14d so that the loss of engine torque is further reduced as the gear ratio is larger. By executing the above control, the ECU 10 can reduce the pump loss in the intake / exhaust stroke.

  Next, an example of changing the throttle opening will be described. The ECU 10 changes the throttle opening when starting the deceleration lockup control. Specifically, the ECU 10 controls the throttle valve 12 so as to increase the throttle opening during the deceleration lockup control instead of or in addition to the engine negative torque control described above, whereby the intake passage 11 is controlled. Reduce pump loss at In particular, the ECU 10 increases the throttle opening so that the loss of engine torque is further reduced as the gear ratio is increased. By executing the above control, the ECU 10 can reduce the pump loss in the intake stroke.

2. Next, a description will be given of a method for controlling the decrease in the engine speed during the deceleration lockup control to a suitable gradient by changing the load of the auxiliary machinery of the engine 1. The above-mentioned auxiliary machines correspond to, for example, a power steering pump, an alternator 42, and an air conditioner.

  For example, the ECU 10 temporarily stops the operation of the auxiliary equipment when the engine speed is decreasing when the speed reduction ratio is large, such as when the gear ratio is large. Let Thereby, ECU10 can reduce the load concerning the engine 1, and can suppress the rapid fall of an engine speed irrespective of fuel supply.

3. Generation of Drive Torque by Electric Motor The ECU 10 causes the electric motor to generate drive torque from the start of deceleration lockup control to the completion of engagement. As a result, the ECU 10 adjusts the gradient of decrease in the engine speed regardless of fuel supply to ensure engagement, and suppresses the occurrence of shock during engagement.

  This will be specifically described. The ECU 10 drives the alternator 42, the motor generator MG, or both together with the start of the deceleration lockup control in order to suppress a rapid decrease in the engine speed due to the decrease in the accelerator opening. In particular, the ECU 10 increases the amount of drive torque (also referred to as “output torque”) generated by these electric motors as the gear ratio at the start of the deceleration lockup control increases. That is, when the gear ratio is large, the ECU 10 predicts that the shock due to the engagement is large, adjusts the torque transmitted to the input shaft of the automatic transmission mechanism 3 by the electric motor, assists the drive of the engine 1 and rotates the engine. Decrease the slope of the number. On the other hand, when the gear ratio is small, the ECU 10 determines that the shock caused by the inertia of the engine 1 at the time of engagement is small, and compared with the case where the gear ratio is large, the input shaft of the automatic transmission mechanism 3 by the electric motor. The amount of adjustment of the torque may be reduced.

  By doing so, the ECU 10 can make the gradient of decrease in the engine speed gradual regardless of the fuel supply during the deceleration lock-up control, reduce the shock generated at the time of engagement, and execute the engagement robustly. .

(Learning control)
Next, a method for learning the engagement force during the deceleration lockup control executed by the ECU 10 will be described. The ECU 10 calculates, by learning, a set value (hereinafter referred to as “lock-up set value”) of the engagement force instructed to the hydraulic control device 4 by the control signal S3 during the deceleration lock-up control. Hereinafter, the correction value to the lockup set value obtained by learning is referred to as “learning correction value La”. When the learning correction value La is a positive value, the lockup setting value is changed in a direction to increase the engagement force, and when the learning correction value La is a negative value, the lockup setting value is changed in a direction to weaken the engagement force. And

  Specifically, the ECU 10 calculates the learning correction value La when the predetermined condition is satisfied, for example, when it is determined that the engagement has failed in the deceleration lockup control. For example, the ECU 10 determines that the differential rotation between the engine rotational speed detected after the deceleration lockup control and the turbine rotational speed (hereinafter simply referred to as “detected differential rotational speed”) is the differential rotational speed of the control target (hereinafter “target difference”). It is determined that the engagement has failed if it is more than the predetermined number of revolutions than the “number of revolutions”. In this case, for example, the ECU 10 sets the learning correction value La to a predetermined value and adds it to the lockup setting value. The aforementioned predetermined value is stored in advance in the memory of the ECU 10, for example. In another example, the ECU 10 determines the learning correction value La with reference to a predetermined map or the like based on the relative value between the detected differential rotational speed and the target differential rotational speed. The above map is created in advance based on experiments or the like and stored in the memory of the ECU 10.

  Further, the ECU 10 executes the following first control to fifth control in consideration of a case where torque adjustment control is executed in addition to or instead of the above-described processing. This will be specifically described. The ECU 10 may execute a combination of two or more of the first control to the fifth control at the same time.

1. First Control In the first control, the ECU 10 learns when the torque adjustment amount (hereinafter referred to as “torque adjustment amount Tf”) by the torque adjustment control during the deceleration lockup control exceeds a predetermined threshold. Ban. Thereby, ECU10 improves the precision of learning. This will be specifically described below.

  First, the ECU 10 monitors the torque adjustment amount Tf by the torque adjustment control during the deceleration lockup control. More specifically, the torque adjustment amount Tf corresponds to a decrease in engine torque loss that accompanies this when torque adjustment control for changing the characteristics of the engine 1 or the load on the auxiliary machinery is executed. When torque adjustment control using an electric motor as a drive source is executed, the torque adjustment amount Tf corresponds to an adjustment amount by torque adjustment control of torque transmitted to the input shaft of the automatic transmission mechanism 3.

  Specifically, the ECU 10 may specify the torque adjustment amount Tf with reference to a predetermined map or the like based on the control amount of the control target operated by the torque adjustment control, and based on the detection values of various sensors, You may specify with reference to a predetermined map. The above-described map is created in advance based on, for example, experiments, and is stored in the memory of the ECU 10. A specific example of this will be described. For example, when the torque adjustment control for increasing the throttle opening degree of the throttle valve 12 by a predetermined opening degree is executed, the ECU 10 refers to a map of a change amount of the throttle opening amount and the torque adjustment amount Tf by the torque adjustment control. The torque adjustment amount Tf is estimated from the above-mentioned predetermined opening. In addition, in the case of the above-described example, the ECU 10 refers to a map of the change amount of the intake air intake amount and the torque adjustment amount Tf, so that the torque adjustment amount Tf is based on the change of the intake air amount detected from an air flow meter (not shown). Is identified.

  Next, the ECU 10 prohibits learning control when the torque adjustment amount Tf is greater than or equal to a predetermined threshold (hereinafter referred to as “threshold Tfth”) during deceleration lockup control. Specifically, in this case, the ECU 10 does not calculate the learning correction value La by the deceleration lockup control. The threshold value Tfth is set to the lower limit of the torque adjustment amount Tf that may decrease the learning accuracy based on, for example, experiments.

  This will be supplementarily described. In general, when the torque adjustment control is executed during engagement, when the torque adjustment control is not executed, the gradient of decrease in the engine speed is different, so that an appropriate engagement force to be set for the lockup clutch 21 is different. In particular, this tendency becomes significant when the torque adjustment amount Tf is large. Even when the torque adjustment amount Tf is controlled to be constant, the actual torque adjustment amount Tf varies with respect to the target torque adjustment amount Tf due to external factors such as a change in outside air temperature. there is a possibility. Then, when learning is performed when the torque adjustment amount Tf increases due to an external factor or the like, the ECU 10 may reduce the accuracy of the lockup set value.

  Considering the above, when the torque adjustment amount Tf is equal to or greater than the threshold value Tfth, the ECU 10 prohibits learning in the deceleration lockup control. Thereby, ECU10 can suppress the fall of the learning precision resulting from torque adjustment control.

2. Second Control In the second control, the ECU 10 varies the learning correction value La depending on whether or not the torque adjustment control is executed during the deceleration lockup control. Thus, the ECU 10 appropriately learns the engagement force in consideration of the difference in the decrease gradient of the engine speed based on whether or not the torque adjustment control is executed during the deceleration lockup control.

  Specifically, the ECU 10 executes deceleration lockup control with torque adjustment control (hereinafter referred to as “lockup control with torque control”), and deceleration lockup control without torque adjustment control (hereinafter referred to as “lockup control with torque control”). , Called “lockup control without torque control”), the lockup set value is separately learned. That is, the ECU 10 applies a lock-up setting value (hereinafter referred to as “setting value with torque control”) applied in the former case and a lock-up setting value (hereinafter referred to as “setting value without torque control”) applied in the latter case. ").) Is held. When the ECU 10 executes the lockup control with torque control and calculates the learning correction value La, the ECU 10 reflects the learning correction value La in the setting value with torque control. Similarly, when the ECU 10 executes the lockup control without torque control and calculates the learning correction value La, the ECU 10 reflects the learning correction value La in the setting value without torque control.

  At this time, the ECU 10 makes the learning correction value La reflected in the setting value with torque control different from the learning correction value La reflected in the setting value without torque. Specifically, the ECU 10 indicates that the lockup control without torque control requires a stronger engagement force due to the difference in the engine speed decrease gradient than the lockup control with torque control. to decide. Then, the ECU 10 makes the learning correction value La reflected in the setting value without torque larger than the learning correction value La reflected in the setting value with torque control. By doing in this way, ECU10 can correct | amend a lockup setting value appropriately in consideration of the difference in the fall gradient of an engine speed resulting from the presence or absence of torque adjustment control at the time of deceleration lockup control.

  In addition to this processing, the ECU 10 may reflect the setting value without torque control by changing the learning correction value La calculated at the time of lockup control with torque control. That is, the ECU 10 determines that a lower gradient of the engine speed is higher in the lockup control without torque control than in the lockup control with torque control, and a stronger engagement force is required, and increases the learning correction value La. Let For example, in this case, the ECU 10 increases the learning correction value La by a predetermined value or by multiplying by a predetermined ratio. Note that the above-described predetermined value or the like may be stored in advance in the memory of the ECU 10, for example, or learning correction is performed in a direction in which the engagement force is increased as the torque adjustment amount Tf by torque adjustment control at the time of learning correction value La calculation increases. The value La may be set to a value to be changed. In the latter case, the ECU 10 determines a specific predetermined value or the like with reference to a map or the like stored in advance in a memory, for example. Thus, the ECU 10 can appropriately learn the setting value without torque control while ensuring the opportunity for learning the setting value without torque control.

  Similarly, the ECU 10 may reflect the setting value with torque control by changing the learning correction value La calculated during deceleration lockup control without torque control. That is, the ECU 10 determines that the lowering of the engine speed is slower in the lockup control with torque control than in the lockup control without torque control, and the engagement force may be relatively weak. Reduce La. For example, in this case, the ECU 10 may decrease the learning correction value La by a predetermined value or may decrease it by multiplying by a predetermined ratio. The above-mentioned predetermined value etc. are memorize | stored in the memory of ECU10 previously, for example. Thus, the ECU 10 can appropriately learn the setting value with torque control while ensuring the opportunity for learning the setting value with torque control.

  A supplementary explanation will be given of the effect of the second control. When the learning correction value La learned at the time of lockup control with torque control is applied to the lockup setting value without torque control, the ECU 10 corrects the lockup setting value without torque control at the next lockup control without torque control. There is a possibility that the amount cannot be engaged due to insufficient amount. Similarly, when the learning correction value La learned at the time of lockup control without torque control is applied to the lockup setting value with torque control, the ECU 10 lockup setting with torque control is performed at the next lockup control with torque control. The value is excessively increased, which causes a shock at the time of engagement. Considering the above, by executing the second control, the ECU 10 can appropriately learn the lockup set value in consideration of the presence or absence of torque adjustment control during the deceleration lockup control.

3. Third Control In the third control, when the ECU 10 determines that the learning control should be prohibited based on the first control, the ECU 10 restarts the learning control by prohibiting the torque adjustment control in the next deceleration lockup control. Thereby, ECU10 ensures the opportunity of learning.

  Specifically, based on the first control, when the torque adjustment amount Tf is equal to or greater than the threshold value Tfth, the ECU 10 prohibits learning in order to suppress a decrease in learning accuracy. On the other hand, in order to suppress a decrease in learning opportunities due to this, the ECU 10 prohibits the torque adjustment control in the deceleration lockup control after the next time. Thus, the ECU 10 can secure a learning opportunity and correct the lockup set value to an appropriate value by learning.

  If the ECU 10 determines that the engagement is stable after prohibiting the torque adjustment control, the ECU 10 resumes the torque adjustment control from the next deceleration lockup control. For example, the ECU 10 determines that the engagement is stable when the detected differential rotational speed is within a predetermined rotational speed difference from the target differential rotational speed. The aforementioned predetermined rotational speed difference is stored in advance in the memory of the ECU 10. Thereby, ECU10 can provide the opportunity of learning reliably and can correct | amend a lockup setting value appropriately.

  Even if the learning is prohibited based on the first control, the ECU 10 does not prohibit the torque adjustment control when the engagement is successful or when it is determined that the other learning is sufficiently performed. Also good. That is, the ECU 10 prohibits the torque adjustment control and continues the learning only when it is determined that the other learning needs to be executed when the engagement fails. Thus, the ECU 10 can prioritize learning over torque adjustment control only when it is determined that learning is necessary, and can increase opportunities for torque adjustment control and improve fuel economy and the like.

4). Fourth Control In the fourth control, instead of the third control, when the ECU 10 determines that learning should be prohibited based on the first control, the torque adjustment control is limited so that the torque adjustment amount Tf is less than the threshold value Tfth. To do. Thereby, ECU10 enables the fuel cut at the time of deceleration lockup control, continuing learning.

  This will be specifically described. Based on the first control, when the torque adjustment amount Tf is equal to or greater than the threshold value Tfth, the ECU 10 prohibits learning in order to suppress a decrease in learning accuracy. Then, the ECU 10 limits the torque adjustment control so that the torque adjustment amount Tf is less than the threshold value Tfth in the deceleration lockup control after the next time. As described above, the ECU 10 restricts the torque adjustment control to suppress a decrease in learning accuracy, and secures the learning opportunity by suppressing the torque adjustment amount Tf to be less than the threshold value Tfth. Moreover, ECU10 adjusts the fall gradient of an engine speed irrespective of fuel supply by continuing torque adjustment control. Thereby, ECU10 can enable the fuel cut at the time of deceleration lockup control.

  Further, when the ECU 10 determines that the engagement is stable after limiting the torque adjustment control, the ECU 10 restarts the torque adjustment control from the next deceleration lockup control. For example, the ECU 10 determines that the engagement is stable when the detected differential rotational speed is within a predetermined rotational speed difference from the target differential rotational speed. The aforementioned predetermined rotational speed difference is stored in advance in the memory of the ECU 10.

  Further, the ECU 10 may execute the above-described control only when it is determined that it is necessary to execute other learning when the engagement fails when learning is prohibited. That is, for example, even when learning is prohibited, if the ECU 10 determines that the engagement is successful, or if other learning is sufficiently performed, the ECU 10 performs torque adjustment control at the next deceleration lockup control. It does not have to be restricted. Thus, the ECU 10 can prioritize learning over torque adjustment control only when it is determined that learning is necessary, and can increase opportunities for torque adjustment control and improve fuel economy and the like.

5. Fifth Control When the ECU 10 calculates the learning correction value La while prohibiting the torque adjustment control, the ECU 10 prohibits the torque adjustment control in order to prioritize learning, and prohibits the torque adjustment control due to other factors. The learning correction value La is varied. Thereby, ECU10 performs the learning according to the condition.

  This will be specifically described. First, when the torque adjustment amount Tf is equal to or greater than the threshold value Tfth, the ECU 10 prohibits the torque adjustment control at the time of the next deceleration lockup engagement as in the third control. Hereinafter, this case is referred to as a “first case”. On the other hand, when a failure occurs in the auxiliary machinery, various valves, etc., which are controlled by the variable torque control, the ECU 10 cannot perform torque adjustment control by the motor because the charge amount is less than a predetermined amount. When the torque adjustment control cannot be executed due to the limitation, the torque adjustment control is prohibited. Hereinafter, this case is referred to as a “second case”.

  Then, the ECU 10 uses different lockup setting values for the first case and the second case. That is, the ECU 10 sets a lockup setting value applied to the first case (hereinafter referred to as “first case setting value”) and a lockup setting value applied to the second case (hereinafter referred to as “second case setting value”). ").) Is held. When the ECU 10 executes the deceleration lockup control in the first case and calculates the learning correction value La, the ECU 10 reflects the learning correction value La in the first case setting value. Similarly, when the ECU 10 executes the deceleration lockup control in the second case and calculates the learning correction value La, the ECU 10 reflects the learning correction value La in the second case setting value. Thereby, ECU10 considers the difference in the fall gradient of the engine speed in a 1st case and a 2nd case, and sets the lockup setting value according to each case.

  Further, the ECU 10 makes the learning correction value La reflected in the first case set value different from the learning correction value La reflected in the second case set value. For example, in the second case, the ECU 10 estimates that there is an uncontrollable element for some reason and there is an unpredictable part in the system behavior, and the absolute value of the learning correction value La is larger than that in the first case. The value (hereinafter also referred to as “learning amount”) is decreased. Thereby, the ECU 10 can suppress an unnecessary increase in engagement force or the like in the second case.

  In addition to this processing, the ECU 10 may apply a predetermined calculation to the learning correction value La learned in the first case and then apply it to the second case setting value. Similarly, the ECU 10 may perform a predetermined calculation on the learning correction value La learned in the second case and then apply it to the first case set value. For example, after subtracting a predetermined value from the learning correction value La learned in the first case, or after multiplying the learning correction value La by a number less than 1, the ECU 10 reflects it in the second case setting value. Similarly, the ECU 10 adds the learning correction value La learned in the second case to a predetermined value, or after multiplying the learning correction value La by a number larger than 1, reflects the learning correction value La in the first case setting value. The predetermined value and the like described above are set in advance based on experiments and the like, and are stored in the memory of the ECU 10. Thereby, ECU10 can ensure the opportunity of learning with respect to any value of a 1st case setting value and a 2nd case setting value.

(Processing flow)
Next, an example of the processing procedure of this embodiment will be described. FIG. 4 is an example of a flowchart showing a processing procedure executed by the ECU 10 in the present embodiment. In the flowchart of FIG. 4, as an example, the ECU 10 executes the first control and the third control in combination. ECU10 repeatedly performs the process of the flowchart shown in FIG. 4, for example according to a predetermined period.

  First, the ECU 10 determines whether to perform deceleration lockup control (step S101). And ECU10 advances a process to step S102, when it is judged that deceleration lockup control is performed (step S101; Yes). On the other hand, when determining that the deceleration lockup control is not performed (step S101; No), the ECU 10 monitors whether or not the deceleration lockup control is continuously executed.

  Next, the ECU 10 determines whether or not the flag F is 0 (step S102). Here, the “flag F” is a flag for the ECU 10 to determine whether or not the torque adjustment control should be prohibited in order to prioritize learning based on the third control. Specifically, when the flag F is 1, it indicates that the torque adjustment control should be prohibited at the next deceleration lockup control. When the flag F is 0, the torque adjustment control at the next deceleration lockup control is prohibited. Indicates not to. Here, it is assumed that the initial value of the flag F is set to 0. If the flag F is 0 (step S102; Yes), the ECU 10 advances the process to step S103. On the other hand, when the flag F is not 0 (step S102; No), the ECU 10 advances the process to step S111. This will be described later.

  Next, the ECU 10 determines whether or not torque adjustment control should be executed (step S103). That is, in this case, the ECU 10 has a possibility that a shock at the time of engagement is generated due to a large gear ratio or the like, and whether or not it is necessary to moderate a decrease gradient of the engine speed by torque adjustment control. judge. And ECU10 advances a process to step 104, when it is judged that torque adjustment control should be performed (step S103; Yes). On the other hand, when the ECU 10 determines that it is not necessary to execute torque adjustment control (step S103; No), the ECU 10 proceeds to step S109.

  Next, the ECU 10 determines whether or not the engagement is successful (step S104). For example, the ECU 10 determines whether the engagement is successful based on the detected rotational speed difference and the target rotational speed difference. When the ECU 10 determines that the engagement is successful (step S104; Yes), the ECU 10 sets the learning correction value La to 0 and sets the flag F to 0 (step S108). That is, in this case, the ECU 10 determines that there is no need to correct the lockup set value because the engagement has been successful. Further, the ECU 10 determines that it is not necessary to prioritize learning over torque adjustment control.

  On the other hand, when the ECU 10 determines that the engagement has not been successful (step S104; No), the ECU 10 determines whether or not the torque adjustment amount Tf is equal to or greater than the threshold value Tfth (step S105). When the torque adjustment amount Tf is equal to or greater than the threshold value Tfth (step S105; Yes), the ECU 10 prohibits learning and sets the flag F to 1 based on the first control (step S106). That is, in this case, the ECU 10 determines that the learning accuracy is low, prohibits the engagement learning, and sets the flag F to 1 in order to execute the learning reliably in the next deceleration lockup control. Thereby, ECU10 can ensure the opportunity of learning.

  On the other hand, when the torque adjustment amount Tf is less than the threshold value Tfth (step S105; No), the ECU 10 sets the learning correction value La to the predetermined value “L1” and sets the flag F to 0 (step S107). That is, in this case, the ECU 10 determines that there is no possibility that the learning accuracy will be lowered, obtains the learning correction value La, and reflects it in the lockup set value.

  Next, the process of step S109 will be described. The ECU 10 determines whether the engagement has succeeded after executing the deceleration lockup control without torque control (step S109). If the engagement is successful (step S109; Yes), the ECU 10 sets the learning correction value La to 0 and sets the flag F to 0 (step S108). On the other hand, when the engagement is not successful (step S109; No), the ECU 10 sets the learning correction value La to the predetermined value “L2” and sets the flag F to 1 (step S110). That is, the ECU 10 corrects the lockup set value by the predetermined value L2 because the engagement has failed, determines that it is necessary to provide a learning opportunity even during the next deceleration lockup control, and sets the flag F. Set to 1.

  Next, step S111 and subsequent processing will be described. When the ECU 10 determines that the flag F is not 0 (step S102; No), the ECU 10 prohibits the torque adjustment control (step S111). Thereby, ECU10 can provide the opportunity of learning a lockup setting value reliably.

  Next, the ECU 10 determines whether or not the engagement is successful (step S112). When the ECU 10 determines that the engagement is successful (step S112; Yes), the ECU 10 sets the learning correction value La to the predetermined value “L3” and sets the flag F to 0 (step S113). That is, in this case, the ECU 10 changes the lockup set value by a predetermined value L3 in consideration of prohibiting the torque adjustment control, determines that the engagement is stable, sets the flag F to 0, and sets the torque Cancel the prohibition of adjustment control. On the other hand, when the ECU 10 determines that the engagement has not been successful (step S112; No), the ECU 10 sets the learning correction value La to the predetermined value L2 and sets the flag F to 1 (step S110). That is, the ECU 10 corrects the lockup set value by the predetermined value L2 because the engagement has failed, determines that it is necessary to provide a learning opportunity even during the next deceleration lockup control, and sets the flag F. Set to 1.

[Modification]
Next, a modification of this embodiment will be described. The following modifications can be combined and applied to the above-described embodiment.

(Modification 1)
In the description of the torque adjustment control, the ECU 10 starts the fuel cut by performing the torque adjustment control together with the start of the deceleration lockup control. However, the control method to which the present invention is applicable is not limited to this. Instead of this, the ECU 10 may execute the torque adjustment control even when the fuel injection is executed during the deceleration lockup control. Also in this way, the ECU 10 reduces the fuel injection amount necessary for making the gradient of decrease in the engine speed gentle by torque adjustment control.

(Modification 2)
In the description of FIGS. 1 and 2, the mounted vehicle is a hybrid vehicle. However, the configuration to which the present invention is applicable is not limited to this. Alternatively, the mounted vehicle may be a vehicle that does not include the motor generator MG and uses the engine 1 as a drive source. In this case, ECU10 performs torque adjustment control by changing the characteristic of the engine 1, or changing the load of auxiliary machinery, for example.

1 engine (internal combustion engine)
2 Torque converter 3 Automatic transmission mechanism 4 Hydraulic control device 5 Output shaft 10 ECU
DESCRIPTION OF SYMBOLS 11 Intake passage 12 Throttle valve 14b Intake valve 14d Exhaust valve 14e, f Electromagnetic drive mechanism 15a Cylinder 16 Exhaust passage 40 Accelerator opening sensor 41 Rotation speed sensor 42 Alternator MG Motor generator

Claims (8)

A torque converter having a lock-up clutch;
An engine connected to the input shaft of the torque converter;
Lockup clutch engagement means for engaging the lockup clutch in response to a decrease in the accelerator opening;
Torque adjusting means for gradual decrease in the engine speed by adjusting torque during the engagement;
Learning means for performing the learning of the engagement force of the lock-up clutch at the time of the engagement, and prohibiting learning based on the adjustment amount of the torque adjustment,
When the learning means prohibits the learning, the torque adjusting means restricts the adjustment amount and restarts the learning at the time of execution of the subsequent and subsequent engagements. Control device.   The vehicle control device according to claim 1, further comprising fuel injection control means for performing fuel cut from the start of the engagement to the completion of the engagement when the torque adjustment is performed.   3. The vehicle control device according to claim 1, wherein the torque adjusting unit releases the restriction when the engagement is stabilized after the restriction. 4.   4. The vehicle control device according to claim 1, wherein the learning unit prohibits the learning when the adjustment amount is a predetermined value or more. 5.   5. The vehicle control device according to claim 1, wherein the torque adjustment unit performs the torque adjustment by changing a characteristic of the engine to reduce a loss of engine torque. 6.   The vehicle control device according to claim 5, wherein the torque adjustment unit performs the torque adjustment by reducing a loss of the engine torque by lowering a compression ratio of the engine. An electric motor that operates as a driving source of the vehicle;
The vehicle control device according to any one of claims 1 to 6, wherein the torque adjustment unit performs the torque adjustment by applying torque to the engine by the electric motor.   The vehicle control device according to any one of claims 1 to 7, wherein the torque adjustment unit performs the torque adjustment by reducing a load of auxiliary machinery.

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