JP6696763B2 - Automatic transmission control device - Google Patents

Description

  The present invention relates to a control device for an automatic transmission.

  In recent years, so-called idling stop control has been widely adopted for vehicles using an engine as a drive source for the purpose of improving fuel efficiency. In the idling stop control, for example, when the brake pedal is depressed by the driver's foot to operate the brake and the vehicle speed drops below a predetermined idling stop execution vehicle speed, the engine is automatically stopped (idling stop). After the engine is automatically stopped, for example, when the foot is released from the brake pedal and the brake is released, the engine is automatically restarted (restored from idling stop).

  Some vehicles that employ idling stop control are equipped with a stepped automatic transmission (AT) as a transmission. The automatic transmission is provided with a P range (parking range), an R range (reverse range), an N range (neutral range), and a D range (forward range). These ranges are selected by operating a shift lever provided in the vehicle compartment, and a clutch (brake) provided in the automatic transmission is engaged / released according to the selected range. Specifically, all clutches are released in the P range and the N range. In the R range, a specific clutch is engaged. In the D range, the clutch engaged in the R range is released, and a combination of engagement and release of the other clutches selectively configures a plurality of shift speeds. The clutch is hydraulically engaged / disengaged.

  FIG. 6 is a diagram showing an example of a temporal change of the turbine speed, the instruction current value, and the oil pressure of the clutch at the time of returning from the idling stop.

  Since the mechanical oil pump driven by the power of the engine is stopped during idling stop, the hydraulic pressure is released from each clutch of the automatic transmission and each clutch is released. Therefore, when returning from the idling stop, the control device that controls the automatic transmission engages the clutch (for example, when the shift lever is located at the D position corresponding to the D range, the clutch forming the first speed). Engagement control is performed.

  To restart the engine, the engine spark plug is sparked while the engine is cranking. When the engine is completely detonated, the engine speed increases, and the turbine speed that is the speed of the turbine runner of the torque converter increases as the engine speed increases. The control device determines that the engine has completely exploded when the engine speed increases to a predetermined engine speed (for example, 400 rpm).

  On the other hand, in an example of engagement control, for example, when the solenoid valve for controlling the hydraulic pressure supplied to the clutch is a normally open type, from the start of engine cranking to the determination of complete explosion (time T101-T102), the instruction current value of the solenoid valve (the target value of the current supplied to the solenoid valve) is held at zero. By holding the indicated current value at 0, the solenoid valve is held fully open, and the solenoid valve supplies the clutch with the increase of the hydraulic pressure (the hydraulic pressure generated by the mechanical oil pump) supplied to the solenoid valve. Oil pressure rises.

  When the complete explosion of the engine is determined, the instruction current value of the solenoid valve is increased from 0 to the initial current value (time T102). After that, the instruction current value of the solenoid valve is held at the initial current value. Meanwhile, the filling of the clutch with oil is completed (time T103). When the filling of the clutch with oil is completed and the piston for bringing the clutch plate and the clutch disc into pressure contact with each other to generate a frictional force comes into contact with the clutch plate, the clutch begins to engage while sliding. Along with this, the torque transmission capacity of the clutch increases and the turbine speed decreases.

  When the turbine speed drops by a predetermined amount (time T104), the command current value of the solenoid valve is gradually reduced from the initial current value by sweeping at a constant time change rate.

  When the clutch engagement is completed and the clutch slippage disappears, the turbine rotation speed stops decreasing, and the turbine rotation speed becomes the 1st speed synchronous rotation speed (the output of the automatic transmission when the 1st speed is configured). The number of revolutions synchronized with the number of revolutions) matches. If the instruction current value of the solenoid valve is not 0 at the time when the synchronization of the turbine speeds is detected (time T105), the instruction current value is reduced to 0 and the engagement control is ended.

JP, 2005-117738, A

  The hydraulic characteristics of the automatic transmission vary from unit to unit, and the time lag from the start of engagement control of the clutch to the start of engagement (from the start of engine cranking to the start of movement of the vehicle) varies.

  Specifically, the hydraulic characteristic of the automatic transmission varies between the lower limit characteristic indicated by the two-dot chain line and the upper limit characteristic indicated by the broken line. As for the lower limit characteristic, the rise of the hydraulic pressure is slower and the hydraulic pressure value is lower than the central characteristic shown by the solid line. Therefore, in a unit (automatic transmission) having a hydraulic characteristic closer to the lower limit characteristic, when the clutch starts to have a transmission torque capacity (when the clutch piston comes into contact with the clutch plate), compared to a unit having a central characteristic. Although the generated shock is small, there is a concern that the time lag from the start to the end (engagement completion) of the clutch engagement control is long. In the upper limit characteristic, the hydraulic pressure rises faster and the hydraulic pressure value is higher than the central characteristic. Therefore, in a unit having a hydraulic characteristic closer to the upper limit characteristic, the time lag from the start to the end of the clutch engagement control is shorter than that in an automatic transmission having a central characteristic, but when the clutch starts to have a transmission torque capacity. There is concern that the shock that will occur will be great.

  FIG. 7: is a figure showing the result of the sensory evaluation (sensory test) of the conventional automatic transmission.

  The instruction current value in the engagement control (corresponding to the hydraulic pressure instruction value that is the target value of the hydraulic pressure supplied to the clutch) is sensory-evaluated so that the time lag in the unit with the lower limit characteristic does not exceed the limit line and The shock generated when the clutch starts to have the transmission torque capacity in the unit is set so as not to exceed the limit line.

  Therefore, as shown by the broken line in FIG. 7, if the instruction current value is changed so that the performance of the unit with the central characteristic is improved, the shock generated when the clutch starts to have the transmission torque capacity in the unit with the upper characteristic is the limit line. Will exceed. Therefore, the indicated current value cannot be changed, and even the unit having the central characteristic cannot improve the performance related to the shock or the time lag.

  It is an object of the present invention to provide a control device for an automatic transmission that allows tuning to improve performance with respect to shock or time lag.

  In order to achieve the above object, a control device for an automatic transmission according to the present invention is a control device for an automatic transmission that includes a hydraulic circuit and an engagement element that is engaged by hydraulic pressure supplied from the hydraulic circuit. The hydraulic circuit is controlled until the rotational speed input to the automatic transmission rises from 0 to a predetermined judgment value in the engagement control. In order to limit the hydraulic pressure supplied to the engagement element after the filling process for setting the instruction value for controlling the specified value to the predetermined filling value and after the filling process, the instruction value is set to the predetermined value from the filling value. Initial processing to change to the initial value of, and the time from the start of the initial processing until the engaging element begins to have torque transmission capacity, depending on the deviation between the measured actual time and the preset target time , And a learning process for learning and correcting the determination value.

  According to this structure, in the engagement control for engaging the engagement element of the automatic transmission, the filling process sets the instruction value for controlling the hydraulic circuit to the filling value. By this filling process, the engagement element can be quickly filled with oil, and the responsiveness of the engagement element can be improved. When the number of revolutions input to the automatic transmission rises from 0 and reaches a predetermined judgment value, the filling process is ended, the initial process is started, and the instruction value is changed from the filling value to the initial value. The hydraulic pressure supplied to the coupling element is more limited than during the filling process.

  In parallel with the initial processing, the elapsed time from the start of the initial processing is measured. When the hydraulic pressure is supplied to the engagement element and the engagement element starts to have the torque transmission capacity, the elapsed time up to that point is acquired as the real time. Then, the deviation between the real time and the preset target time is obtained, and the determination value is learned and corrected according to the deviation.

  When the real time is longer than the target time, the determination value is increased and corrected according to the deviation between the real time and the target time. When the determination value is increased and corrected, the time until the number of rotations input to the automatic transmission reaches the determination value becomes longer, and the execution time of the filling process becomes longer. As a result, the hydraulic pressure supplied to the engagement element rises faster, and the time lag from the start to the end of the engagement control is shortened.

  Conversely, when the actual time is shorter than the target time, the determination value is reduced and corrected according to the deviation between the actual time and the target time. By reducing and correcting the determination value, the time until the number of revolutions input to the automatic transmission reaches the determination value is shortened, and the execution time of the filling process is shortened. As a result, the rising of the hydraulic pressure supplied to the engagement element becomes gentle, and the shock that occurs when the engagement element starts to have the torque transmission capacity is reduced.

  Therefore, it is possible to converge the shock and the time lag variation due to the variation of the hydraulic characteristics. Since the variations in the shock and the time lag are converged, it is possible to perform tuning (for example, changing the filling value and / or the initial value) with respect to the unit having the central characteristic (automatic transmission) to improve the performance related to the shock or the time lag.

  It is also possible to suppress variations in hydraulic characteristics by hardware design, but for that purpose, it is necessary to close the tolerances of parts and select parts that meet the tight tolerances, which leads to an increase in unit cost. .. On the other hand, the control can suppress the shock and the time lag variation due to the variation of the hydraulic characteristics, and thus the increase of the unit cost can be suppressed.

  The instruction value for controlling the hydraulic circuit may be a target value of the hydraulic pressure supplied to the engagement element (instruction hydraulic pressure). In this case, the initial value is smaller than the filling value.

  In addition, in the configuration in which the valve for controlling the hydraulic pressure supplied to the engagement element is included in the hydraulic circuit and the valve is a valve capable of controlling the output hydraulic pressure by the current value, the instruction value for controlling the hydraulic circuit is set. May be a target value (instruction current value) of the current supplied to the valve. In this case, the initial value is a value larger than the filling value.

  According to the present invention, it is possible to converge the shock and the variation in the time lag due to the variation in the hydraulic characteristics. Since the variations in the shock and the time lag converge, it becomes possible to perform tuning for improving the performance related to the shock or the time lag with reference to the unit (automatic transmission) having the central characteristic.

It is a figure which shows the structure of the principal part of the vehicle in which the control apparatus which concerns on one Embodiment of this invention is mounted. It is a skeleton diagram showing a configuration of a drive system of a vehicle. It is a figure which shows the state of each engagement element in P range, R range, N range, and D range. 6 is a timing chart for explaining clutch engagement control at the time of returning from idling stop, showing an example of temporal changes in turbine rotation speed and a command current value of a solenoid valve. It is a figure showing the result of the sensory evaluation of an automatic transmission. It is a figure which shows an example of the time change of the turbine rotation speed, the instruction | indication electric current value, and the hydraulic pressure of a clutch in the conventional engagement control. It is a figure showing the result of the sensory evaluation of the conventional automatic transmission.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

<Structure of essential parts of vehicle>
FIG. 1 is a diagram showing a configuration of a main part of a vehicle 1 equipped with a control device according to an embodiment of the present invention.

  The vehicle 1 is an automobile that uses the engine 2 as a drive source.

  The output of the engine 2 is transmitted to driving wheels (for example, left and right front wheels) of the vehicle 1 via a torque converter 3 and a stepped automatic transmission (AT) 4. The engine 2 includes an electronic throttle valve 71 for adjusting the amount of intake air into the combustion chamber of the engine 2, an injector (fuel injection device) 72 for injecting fuel into intake air, and a spark plug 73 for causing electric discharge in the combustion chamber. Etc. are provided. Further, the engine 2 is provided with a starter (not shown) for starting the engine.

  The vehicle 1 is equipped with a plurality of ECUs (Electronic Control Units) having a configuration including a CPU, a ROM, a RAM, and the like. The ECU includes an engine ECU 11, an AT ECU 12, a brake ECU 13, and an IDS (idling stop) ECU 14. The plurality of ECUs are connected to each other so as to be capable of bidirectional communication according to a CAN (Controller Area Network) communication protocol.

  An accelerator sensor 21, an engine speed sensor 22, a throttle opening sensor 23, etc. are connected to the engine ECU 11.

  The accelerator sensor 21 outputs a detection signal corresponding to the operation amount of an accelerator pedal (not shown) operated by the driver. Based on the signal input from the accelerator sensor 21, the engine ECU 11 sets the ratio of the operation amount of the accelerator pedal to the maximum operation amount of the accelerator pedal, that is, 0% when the accelerator pedal is not pressed, and the accelerator pedal is pressed to the maximum. The accelerator opening degree, which is a percentage with time as 100%, is calculated.

  The engine speed sensor 22 outputs a pulse signal in synchronization with the rotation of the engine 2 (rotation of the crankshaft) as a detection signal. The engine ECU 11 converts the frequency of the pulse signal input from the engine rotation speed sensor 22 into the rotation speed of the engine 2 (engine rotation speed).

  The throttle opening sensor 23 outputs a detection signal corresponding to the opening of the electronic throttle valve 71 (throttle opening).

  The engine ECU 11 is an electronic device provided in the engine 2 for starting, stopping and adjusting the output of the engine 2 based on information obtained from detection signals of various sensors and / or various information input from other ECUs. The throttle valve 71, the injector 72, the spark plug 73, etc. are controlled.

  A shift position sensor 24, a turbine speed sensor 25, and the like are connected to the AT ECU 12.

  The shift position sensor 24 outputs a detection signal according to the position of the shift lever (select lever). As positions of the shift lever, for example, a P position (parking position), an R position (reverse position), an N position (neutral position) and a D position (drive position) are provided. The P position, R position, N position and D position correspond to the P range, R range, N range and D range, respectively. The shift lever can be operated to shift between the P position, the R position, the N position and the D position, and the range operation can be instructed by the shift operation.

  The turbine rotation speed sensor 25 outputs a pulse signal in synchronization with the rotation of the turbine runner 32 (see FIG. 2) of the torque converter 3 as a detection signal. The AT ECU 12 converts the frequency of the pulse signal input from the turbine rotation speed sensor 25 into the turbine rotation speed that is the rotation speed of the turbine runner 32.

  The AT ECU 12 changes the range or the shift stage of the automatic transmission 4 based on the information acquired from the detection signals of the various sensors and / or the various information input from other ECUs. A valve included in the hydraulic circuit 74 for supplying hydraulic pressure to the valve is controlled.

  The valves include a C2 solenoid valve 75 and the like for controlling the hydraulic pressure supplied to the clutch C2 (see FIG. 2). As the C2 solenoid valve 75, a valve whose output hydraulic pressure can be controlled by a current value, for example, a normally open type linear solenoid valve is used.

  A brake sensor 26, a vehicle speed sensor 27, etc. are connected to the brake ECU 13.

  The brake sensor 26 outputs a detection signal according to the operation amount of a brake pedal arranged in the vehicle compartment.

  The vehicle speed sensor 27 includes, for example, a rotor made of a magnetic material that rotates as the vehicle 1 travels, and an electromagnetic pickup provided in a non-contact manner with the rotor. Each time the rotor rotates by a certain angle, a pulse signal is output as a detection signal from the electromagnetic pickup. Since the frequency of the pulse signal corresponds to the vehicle speed, the brake ECU 13 converts the frequency of the pulse signal input from the vehicle speed sensor 27 into the vehicle speed.

  The brake ECU 13 controls the brake actuator 76 and the like based on the information (the operation amount of the brake pedal, the vehicle speed of the vehicle 1) acquired from the detection signals of various sensors and / or various information input from other ECUs. The braking force applied from each brake to the wheels is controlled so that the vehicle 1 is braked while the posture of the vehicle 1 is kept stable.

  The vehicle 1 is equipped with an idling stop function. The IDSECU 14 executes idling stop control, which is control for the idling stop function. As information necessary for this idling stop control, information such as the vehicle speed and the operation amount of the brake pedal is input from the brake ECU 13 to the IDSECU 14.

  In the idling stop control, when the brake pedal is operated (depressed) while the vehicle 1 is traveling, the IDSECU 14 repeatedly determines whether or not a predetermined idling stop condition is satisfied. The idling stop condition is, for example, a condition that the vehicle speed is equal to or lower than a predetermined idling stop execution vehicle speed (for example, 10 km / h), and that the brake pedal is operated for a certain time or longer. When the idling stop condition is satisfied, the IDSECU 14 outputs an IDS request to the engine ECU 11, and the engine ECU 11 automatically stops the engine 2 (idling stop).

  During idling stop, it is repeatedly determined whether or not a predetermined restart condition is satisfied. The restart condition is, for example, a condition that the operation of the brake pedal is released (the driver's foot is released from the brake pedal) while the engine 2 is automatically stopped. When the restart condition is satisfied, the IDSECU 14 outputs a restart request to the engine ECU 11. In response to this restart request, the engine ECU 11 restarts the engine 2 (returns from idling stop).

<Drive system configuration>
FIG. 2 is a skeleton diagram showing the configuration of the drive system of the vehicle 1.

  The torque converter 3 includes a pump impeller 31, a turbine runner 32, and a lockup clutch 33. The output shaft (E / G output shaft) of the engine 2 is connected to the pump impeller 31, and the pump impeller 31 is integrally rotatably provided around the same rotation axis as the E / G output shaft. ing. The turbine runner 32 is provided so as to be rotatable about the same rotation axis as the pump impeller 31. The lockup clutch 33 is provided to directly connect / separate the pump impeller 31 and the turbine runner 32. When the lockup clutch 33 is engaged, the pump impeller 31 and the turbine runner 32 are directly connected, and when the lockup clutch 33 is released, the pump impeller 31 and the turbine runner 32 are separated.

  When the E / G output shaft is rotated while the lockup clutch 33 is released, the pump impeller 31 rotates. When the pump impeller 31 rotates, a flow of oil from the pump impeller 31 toward the turbine runner 32 occurs. This oil flow is received by the turbine runner 32, and the turbine runner 32 rotates. At this time, the amplifying action of the torque converter 3 occurs, and the turbine runner 32 generates power larger than the power (torque) of the E / G output shaft.

  When the E / G output shaft is rotated while the lockup clutch 33 is engaged, the E / G output shaft, the pump impeller 31, and the turbine runner 32 rotate integrally.

  An oil pump 5 is provided between the torque converter 3 and the automatic transmission 4. The pump shaft of the oil pump 5 is rotatably provided integrally with the pump impeller 31. As a result, when the pump impeller 31 is rotated by the power of the engine 2, the pump shaft of the oil pump 5 rotates and the oil pump 5 generates hydraulic pressure. The hydraulic pressure generated by the oil pump 5 is supplied to the hydraulic circuit 74.

  The automatic transmission 4 is a 4-speed AT having four shift stages of forward movement and one reverse movement. The automatic transmission 4 includes an input shaft 41, an output shaft 42, a center shaft 43, and a Ravigneaux type planetary gear mechanism 44.

  The input shaft 41 is connected to the turbine runner 32 of the torque converter 3 and is provided so as to be integrally rotatable about the same rotation axis as the turbine runner 32.

  The output shaft 42 is provided in parallel with the input shaft 41.

  The center shaft 43 is provided on the same rotation axis line as the input shaft 41, separated from the input shaft 41 on the side opposite to the engine 2 side.

  The planetary gear mechanism 44 includes a front sun gear 51, a rear sun gear 52, a carrier 53, a ring gear 54, a long pinion gear 55 and a short pinion gear 56. The front sun gear 51 is fitted onto the center shaft 43 so as to be relatively rotatable. The rear sun gear 52 is provided on the side opposite to the engine 2 side with respect to the front sun gear 51, and is fitted onto the center shaft 43 so as to be relatively rotatable. A center shaft 43 is connected to the carrier 53, and the carrier 53 is rotatably provided integrally with the center shaft 43. The carrier 53 rotatably supports a long pinion gear 55 and a short pinion gear 56. The ring gear 54 has an annular shape surrounding the periphery of the carrier 53 outside the rear sun gear 52 in the radial direction of rotation, and meshes with the long pinion gear 55. The long pinion gear 55 has an axial length longer than that of the short pinion gear 56, and meshes with the front sun gear 51. The short pinion gear 56 meshes with the rear sun gear 52 and the long pinion gear 55.

  The ring gear 54 holds the first output gear 61 so as to have a common rotation axis. The first output gear 61 is meshed with the second output gear 62 which is supported by the output shaft 42 so as not to rotate relative to it. A third output gear 63 is supported by the output shaft 42 so as not to rotate relative to it, and the third output gear 63 meshes with a ring gear 64 provided in the differential gear 6. Accordingly, the rotation of the ring gear 54 is transmitted to the differential gear 6 via the first output gear 61, the second output gear 62, the output shaft 42, and the third output gear 63.

  Further, the automatic transmission 4 includes three clutches C1 to C3, two brakes B1 and B2, and a one-way clutch F.

  The clutch C1 is switched between an engaged state (on) for connecting the input shaft 41 and the front sun gear 51 and a released state (off) for releasing the connection.

  The clutch C2 is switched between an engaged state (on) for connecting the input shaft 41 and the rear sun gear 52 and a released state (off) for releasing the connection.

  The clutch C3 is switched between an engaged state (on) for connecting the input shaft 41 and the center shaft 43 (carrier 53) and a released state (off) for releasing the connection.

  The brake B1 is switched between an engaged state (ON) for braking the front sun gear 51 and a released state (OFF) for allowing the rotation of the front sun gear 51.

  The brake B2 is switched between an engaged state (on) for braking the carrier 53 and a released state (off) for allowing the rotation of the carrier 53.

  The one-way clutch F allows only the forward rotation of the carrier 53 (rotation in the same direction as the output shaft of the engine 2).

<Engagement table>
FIG. 3 is a diagram showing states of the clutches C1 to C3, the brakes B1 and B2, and the one-way clutch F in the P range, the R range, the N range, and the D range.

  In FIG. 3, “◯” indicates that the clutches C1 to C3 and the brakes B1 and B2 are in the engaged state. Further, it shows that the one-way clutch F is in an engaged state in which the reverse rotation of the carrier 53 is prevented.

  In the P range and the N range, the clutches C1 to C3 and the brakes B1 and B2 are released.

  In the R range, the clutch C1 and the brake B2 are engaged, and the clutches C2, C3 and the brake B1 are released.

  At the first speed in the D range, the clutch C2 is engaged and the clutches C1 and C3 and the brakes B1 and B2 are released.

  At the second speed in the D range, the clutch C2 and the brake B1 are engaged, and the clutches C1, C3 and the brake B2 are released.

  At the third speed in the D range, the clutches C2 and C3 are engaged and the clutch C1 and the brakes B1 and B2 are released.

  At the fourth speed in the D range, the clutch C3 and the brake B1 are engaged, and the clutches C1, C2 and the brake B2 are released.

<Engagement control>
FIG. 4 is a timing chart for explaining the engagement control of the clutch C2 at the time of returning from the idling stop, and shows an example of a temporal change of the turbine rotation speed and the instruction current value of the C2 solenoid valve 75.

  When the engine restart condition is satisfied after the engine 2 is automatically stopped by the idling stop control, cranking of the engine 2 is started to restart the engine 2 (time T1). Then, the spark plug 73 of the engine 2 is sparked while the engine 2 is cranked.

  On the other hand, when the shift lever is located at the D position in response to the start of the cranking of the engine 2, the AT ECU 12 starts the engagement control for engaging the clutch C2 forming the first gear. (Time T1). In the engagement control, the AT ECU 12 executes each process described below.

  In the engagement control, first, the filling process is executed. In the filling process, the instruction current value, which is the target value of the current supplied to the C2 solenoid valve 75, is held at 0. When the engine 2 completely explodes, the engine speed increases, and the turbine speed that is the speed of the turbine runner 32 of the torque converter 3 increases as the engine speed increases. The filling process is continued until the turbine speed increases to the turbine determination value or the engine speed increases to the engine determination value (time T1-T2).

The turbine determination value is set by adding the learning value _n to a fixed basic value. The learning value _n is a value set by the learning process. The learning process will be described later.

  The engine determination value is a constant value, and in a state where the engine 2 and the torque converter 3 operate normally, the engine rotation speed reaches a value that the engine rotation speed reaches the engine determination value after the turbine rotation speed reaches the turbine determination value. It is set. Therefore, the reason that the termination condition of the filling process includes the condition that the engine speed has increased to the engine determination value is to prevent the engine speed from rising due to a slow rise of the turbine speed for some reason. Is.

  When the turbine speed increases to the turbine determination value or the engine speed increases to the engine determination value, the filling process ends, and then the first initial process is executed. In the first initial process, the instructed current value of the C2 solenoid valve 75 is increased from 0 to the first initial current value (time T2). Then, the instruction current value of the C2 solenoid valve 75 is held at the first initial current value. By holding the instruction current value of the C2 solenoid valve 75 at the first initial current value, the hydraulic pressure supplied to the clutch C2 is limited in the first initial process as compared with the filling process.

  While the first initial process is being executed, that is, while the command current value of the C2 solenoid valve 75 is being maintained at the first initial current value, the oil filling of the clutch C2 is completed. When the filling of the oil into the clutch C2 is completed and the piston comes into contact with the clutch plate, the clutch C2 starts to engage while sliding, so that the clutch C2 starts to have a torque transmission capacity. As the torque transmission capacity of the clutch C2 increases, the turbine speed decreases from the peak.

  When the turbine speed drops by a first predetermined amount (for example, 30 rpm), the first initial process ends, and then the second initial process is executed. In the second initial process, the instruction current value of the C2 solenoid valve 75 is increased from the first initial current value to the second initial current value (time T3). After that, the instruction current value of the C2 solenoid valve 75 is held at the second initial current value.

  When the turbine rotation speed decreases and the turbine rotation speed decreases by a second predetermined amount (for example, 50 rpm) larger than the first predetermined amount (time T4), the second initial process ends and the sweep process is executed. In the sweep process, the instruction current value of the C2 solenoid valve 75 is gradually reduced from the second initial current value by the sweep at a constant time change rate (time gradient). As a result, the engagement of the clutch C2 progresses, and the turbine rotation speed decreases.

  After the start of the sweep process, it is determined whether or not the turbine speed matches the first speed synchronous speed. The 1st speed synchronous rotation speed is the rotation speed of the input shaft 41 (see FIG. 2) that is synchronized with the rotation speed of the output shaft 42 (see FIG. 2) when the shift stage of the automatic transmission 4 constitutes the 1st speed stage. Is. When the engagement of the clutch C2 progresses and the slippage of the clutch C2 disappears, the decrease of the turbine rotation speed stops and the turbine rotation speed matches the first speed synchronous rotation speed. If the instruction current value of the C2 solenoid valve 75 is not 0 at the time when the turbine rotation speed matches the first speed synchronous rotation speed (time T5), the instruction current value is reduced to 0 and the engagement control is ended. It

<Learning process>
For example, if the learning condition is satisfied at the start of the first initial process, the AT ECU 12 executes the learning process. The learning conditions include, for example, a condition that the accelerator pedal is not depressed, a condition that the vehicle speed is equal to or lower than a predetermined vehicle speed, and a condition that the duration of the idle stop performed before the engagement control is performed is equal to or less than a certain time. There is a condition that there is such a condition, and the learning condition may include one or a plurality of those conditions (AND condition), or may include other conditions.

  In the learning process, the elapsed time from the start of the first initial process is measured. When the turbine rotation speed drops from the peak by the first predetermined amount and the first initial process ends, the measurement of the elapsed time is stopped. Then, the elapsed time from the start to the end of the first initial process is acquired as the real time.

The rewritable non-volatile memory (flash memory, EEPROM, or the like) built in the ATECU 12 updates and stores the learning value _n after the learning process each time the learning process is executed. When the real time is acquired, a preset target time is subtracted from the real time, and the subtracted value is acquired as a deviation. The learning value _n is set to a value obtained by multiplying the deviation by a predetermined gain and adding the multiplication value to the learning value _n-1 after the previous learning process. That is, the learning value _n after the current learning process is set according to the following equation.

Learning value _n (rpm) = learning value _n-1 + deviation (msec) x gain (rpm / msec)

The learning value _n is added to the basic value to set the turbine determination value at the next engagement control. Therefore, the turbine determination value is learned and corrected according to the deviation between the target time and the actual time from the start to the end of the first initial process.

<Effect>
As described above, in the engagement control for engaging the clutch C2 of the automatic transmission 4, the charging process causes the instruction current value, which is the target value of the current supplied to the C2 solenoid valve 75, to become the charging current value 0. Is set. By this filling process, the clutch C2 can be quickly filled with oil, and the responsiveness of the clutch C2 can be improved. When the turbine speed that is the rotation speed input to the automatic transmission 4 increases from 0 and reaches the turbine determination value, the filling process is ended, the first initial process is started, and the instruction current value is the filling current value. Is changed from 0 to the first initial current value, and the hydraulic pressure supplied to the clutch C2 is restricted more than in the filling process.

  In parallel with the first initial process, the elapsed time from the start of the first initial process is measured. When the supply of the hydraulic pressure to the clutch C2 progresses and the clutch C2 starts to have the torque transmission capacity, the elapsed time up to that point, that is, the elapsed time until the first initial process is ended is acquired as the real time. Then, the deviation between the actual time and the preset target time is obtained, and the turbine determination value is learned and corrected according to the deviation.

  When the real time is longer than the target time, the turbine determination value is increased and corrected according to the deviation between the real time and the target time. By increasing and correcting the turbine determination value, it takes a longer time for the turbine speed to reach the turbine determination value, and the filling processing execution time becomes longer. As a result, the hydraulic pressure supplied to the clutch C2 rises faster, and the time lag from the start to the end of the engagement control is shortened.

  On the contrary, when the actual time is shorter than the target time, the turbine determination value is reduced and corrected according to the deviation between the actual time and the target time. By reducing and correcting the turbine determination value, the time until the turbine rotation speed reaches the turbine determination value is shortened, and the execution time of the filling process is shortened. As a result, the rising of the hydraulic pressure supplied to the clutch C2 becomes gradual, and the shock generated when the clutch C2 starts to have the torque transmission capacity is reduced.

  Therefore, as shown by the broken line in FIG. 5, it is possible to converge the variation in the shock and the time lag due to the variation in the hydraulic characteristics. Since the variation in shock and time lag converges, tuning that improves performance related to shock or time lag based on the unit having the central characteristic (automatic transmission 4) (for example, changing the charging current value and / or the initial current value) is possible. Becomes

  It is also possible to suppress variations in hydraulic characteristics by hardware design, but for that purpose, it is necessary to close the tolerances of parts and select parts that meet the tight tolerances, which leads to an increase in unit cost. .. On the other hand, the control can suppress the shock and the time lag variation due to the variation of the hydraulic characteristics, and thus the increase of the unit cost can be suppressed.

  Further, since the turbine determination value is learned and corrected, even if the hydraulic characteristic of the automatic transmission 4 changes due to deterioration over time, the change in the hydraulic characteristic can be compensated. Therefore, it is possible to suppress the occurrence of variations in hydraulic characteristics due to the aged deterioration of the automatic transmission 4.

  In addition, in the engagement control, after the instruction current value of the C2 solenoid valve 75 is held at the filling current value, a period in which the instruction current value is held at the first initial current value is passed and then the second initial current value is set to two levels. Can be raised at. Until the clutch C2 starts to have the torque transmission capacity, in other words, the command current value is held at the relatively low first initial current value until the piston of the clutch C2 comes into contact with the clutch plate. It is possible to shorten the time lag from the start until the clutch C2 starts to have the torque transmission capacity. Then, after the clutch C2 starts to have the torque transmission capacity, the turbine rotation speed starts to decrease, the turbine rotation speed sufficiently decreases, and the instruction current value is relatively decreased until the decrease amount reaches the second predetermined amount. The second initial current value which is relatively high is maintained. As a result, it is possible to suppress the synchronous shock that occurs at the time of synchronization when the turbine speed matches the first speed synchronous speed.

<Modification>
Although one embodiment of the present invention has been described above, the present invention can be implemented in other forms.

  For example, the command current value, which is the target value of the current supplied to the C2 solenoid valve 75, corresponds to the command oil pressure, which is the target value of the oil pressure supplied to the clutch C2. Therefore, in the engagement control, the command current value is set. Similarly, the command hydraulic pressure may be set as a command value in the engagement control.

  In the engagement control described above, the shift lever is shifted from the P position or the N position to the D position immediately after the engine 2 is started, not only when the engine is returned from the idling stop (when the engine 2 is restarted by the idling stop control). May be executed if

  Further, although the configuration in which the vehicle 1 is equipped with the stepped automatic transmission 4 has been taken up, the present invention is directed to a continuously variable transmission or a power split type continuously variable transmission including a clutch that is engaged when the vehicle 1 starts. It can also be applied to vehicles equipped with a transmission. A power split type continuously variable transmission includes a belt type continuously variable transmission mechanism that continuously changes power by changing a gear ratio and a constant transmission mechanism that changes power at a constant gear ratio. Is a transmission that can be divided into two systems for transmission.

  Each sensor described above is merely an example of a sensor related to the present invention, and other sensors may be connected to the engine ECU 11, the AT ECU 12, the brake ECU 13, and the IDSECU 14.

  Further, some or all of the functions of engine ECU 11, AT ECU 12, brake ECU 13, and IDSECU 14 may be integrated into one ECU.

  In addition, various design changes can be made to the above-described configuration within the scope of the matters described in the claims.

4 Automatic transmission 12 AT ECU (vehicle control unit)
74 Hydraulic circuit C2 Clutch (engagement element)

Claims (1)

Comprises an engagement element for engaging by the oil pressure supplied from the hydraulic circuit and the hydraulic circuit, a control apparatus for an automatic transmission power of the engine are entered via a torque converter,
Controlling the hydraulic circuit to execute engagement control for engaging the engagement element,
In the engagement control,
The initiated in response to the start of cranking of the engine, until the rotational speed input to the automatic transmission is increased to a Jo Tokoro determination value, the hydraulic circuit for controlling an instruction value given Filling process to set the filling value,
After the filling process, an initial process of changing the indicated value from the filling value to a predetermined initial value so that the hydraulic pressure supplied to the engagement element is restricted more than that during the filling process,
The time from the start of the initial process until the engagement element starts to have a torque transmission capacity is measured, and the determination value is learned and corrected according to the deviation between the measured real time and a preset target time. A control device that performs learning processing.

Images