JP5164616B2 - Vehicle start control device - Google Patents

Description

  The present invention relates to a start control device for a vehicle equipped with an automatic transmission, for example, a start control device suitable for start control performed when returning to forward travel from idle neutral control.

  In a vehicle equipped with an automatic transmission, a state in which the shift command by the shift lever is set at the forward travel position and the vehicle is in a stopped state satisfying a predetermined condition (for example, a brake pedal is depressed to When the accelerator is operated and the accelerator is idling and the vehicle is stopped), a predetermined clutch (clutch for engaging the first gear = friction engagement element) in the automatic transmission is released to neutral. Setting to a state close to is conventionally performed as idle neutral control. When predetermined conditions such as release of the brake pedal and depression of the accelerator pedal are satisfied, control for releasing the idle neutral control and engaging the predetermined clutch to return to forward travel is performed. In that case, if the clutch operating oil pressure is not appropriate, smooth clutch engagement is not performed, and a problem such as occurrence of a shock occurs.

In Japanese Patent Laid-Open No. 2005-42742 (Patent Document 1), when returning from idle neutral control, if the engine speed fluctuates, the clutch operating oil pressure (steady standby pressure) becomes excessive and insufficient, resulting in smooth clutch engagement. In view of the fact that a problem such as occurrence of a shock occurs without being performed, an invention for solving this problem has been disclosed. In this Patent Document 1, as one solution to this, the deviation between the engine speed at the start of the return from the idle neutral control and the current engine speed during the return control is sequentially calculated, and the calculated deviation is set to the magnitude / positive / negative. Accordingly, it is shown that the correction amount of the clutch operating oil pressure is sequentially determined, and this correction amount is added to the base oil pressure to sequentially correct the steady standby pressure. However, in such a clutch hydraulic pressure correction technique based on the engine rotational speed, the influence of engine fluctuations and the like are included, so that it is not possible to accurately detect that slippage has occurred in the clutch being engaged. There is a problem that it is difficult to perform start control that accurately copes with clutch slippage. That is, when slipping occurs at the time of clutch engagement due to insufficient torque in the crack due to deterioration of the clutch mechanism or deterioration of hydraulic oil, it has not been possible to cope with this appropriately. In addition, since the steady standby pressure is immediately corrected according to the determined correction amount, depending on the hydraulic response, the clutch may be abruptly engaged, which may lead to a deterioration in merchantability.
JP 2005-42742 A

In Japanese Patent Publication No. 3-16545 (Patent Document 2), although not directly related to idle neutral control, clutch operation when shifting from one speed ratio to another speed ratio in automatic shift control of a vehicle is performed. There is shown an invention in which the hydraulic pressure is corrected by learning to prevent a reduction in transmission characteristics. Specifically, the time required for the speed ratio during the shift to change from the first predetermined value to the second predetermined value is measured, and this measured time is compared with a reference time that satisfies a predetermined shift characteristic. The clutch operating oil pressure is supplied at the pressure value that corrects the previous error at the next shift shift by updating the stored clutch operating oil pressure value to decrease or increase according to the length. Thus, the shift is intended to be performed in a time close to a reference time that satisfies a predetermined shift characteristic. However, this method cannot accurately detect clutch slip due to a decrease in clutch torque capacity, and cannot be applied to a device that performs accurate clutch engagement control upon return from idle neutral control. For example, when clutch slip occurs due to a decrease in the torque capacity of the clutch, the speed ratio moves from the convergence direction to the divergence direction, but after the speed ratio moves in the divergence direction, it finally moves in the convergence direction. Depending on how it is determined, since it eventually reaches the second predetermined value across the first predetermined value when moving in the convergence direction, it takes a time to change from the first predetermined value to the second predetermined value. The measured value becomes shorter, and there is a possibility that the correction to increase the hydraulic pressure is necessary, but the correction to decrease works. In addition, in the hydraulic control based on the measurement of the time when the first predetermined value changes to the second predetermined value, when the clutch slip occurs after the speed ratio reaches the second predetermined value, There is also a problem that the hydraulic pressure cannot be corrected considering the above.
Japanese Examined Patent Publication No. 3-16545

  If the friction coefficient μ of the clutch decreases due to deterioration of the clutch mechanism or hydraulic fluid, etc., when returning from idle neutral control, the torque of the clutch when the accelerator is depressed before the clutch is fully engaged in the in-gear process of the clutch. The capacity is insufficient and slipping occurs in the clutch, and judder (vibration due to slipping of the clutch) due to the slip occurs. This impairs the merchantability of the automatic transmission and reduces drivability. A similar problem occurs when gearing in from the normal neutral state to the first forward speed.

  The present invention provides a vehicle start control device that prevents the occurrence of the above-described judder and improves the merchantability and drivability when returning from idle neutral control or when gearing in from the neutral state to the first forward speed. It is something to be offered.

A vehicle start control device according to the present invention is a vehicle start control device equipped with an automatic transmission having an engagement element that is engaged based on hydraulic control at the time of start. Differential rotation detection means for detecting differential rotation of output rotation, slip determination means for determining that slippage has occurred in the engagement element according to the increase degree of the differential rotation, and slippage in the engagement element by the determination means Correction means for setting a correction amount for correcting the hydraulic pressure of the engagement element at the next start when it is determined that the difference has occurred, and the differential rotation detection means is configured to detect the difference every predetermined cycle. Rotation is detected, the determination means, if the differential rotation is increased by a predetermined number of times, and the difference between the differential rotation at the beginning of the increase and the maximum differential rotation is not less than a predetermined reference value, Sliding on the engaging element Wherein the determining and has occurred. As a result, it is possible to eliminate (cancel or filter) noise-like transient differential rotation fluctuations, and to perform the slip determination of the engaging element with high accuracy.

  As an example, in the vehicle, an idle neutral control that releases the engagement element when the shift instruction by the shift lever is set to the forward travel position and the vehicle state is stopped satisfying a predetermined condition. And the start control device performs start control when the engagement element is engaged to return from the idle neutral control to forward travel.

  When returning from the idle neutral control, a hydraulic device for moving the engagement element to engage an engagement element corresponding to a predetermined gear (for example, a clutch for realizing a gear ratio of the first forward speed) is provided. Hydraulic oil is supplied. The same applies to the case where the vehicle is shifted from the normal neutral state to the first forward speed. In such an in-gear process, slipping occurs when the torque capacity of the engagement element is insufficient. According to the present invention, the differential rotation detection means detects the differential rotation between the input rotation and the output rotation of the engagement element, and the determination means determines whether or not the engagement element has slipped according to the increase degree of the differential rotation. To do. When slippage occurs in the engaging element, even if the accelerator is depressed and the input rotation is increased, the output rotation does not follow the input rotation, the differential rotation is increased, and the engine is blown up. Therefore, it can be determined whether or not slippage has occurred in the engagement element based on the degree of increase in the differential rotation. If it is determined that slip has occurred in the engagement element, the hydraulic pressure of the engagement element is corrected at the next start (when returning from idle neutral control or in-gearing from the neutral state to the first forward speed). Set the correction amount to do. In this way, by reflecting the correction amount learned last time in the next gear-in process, the pressure of the hydraulic oil can be appropriately controlled so that judder does not occur.

  As an example, the determination means determines the slip amount of the engagement element when it is determined that slip has occurred in the engagement element, and the correction means determines the correction amount of the operating hydraulic pressure of the engagement element. It is set according to the slip amount of the joint element. Thereby, the correction | amendment of the working hydraulic pressure of this engagement element can be performed appropriately according to the slip amount of an engagement element.

  As an example, the correction means sets the correction amount of the hydraulic pressure of the engagement element in association with the accelerator pedal opening of the vehicle when the slip occurs. Accordingly, the hydraulic pressure of the engagement element can be corrected appropriately in correlation with the accelerator pedal opening (engine throttle opening).

  As an example, the correction means sets the correction amount of the hydraulic pressure of the engagement element in association with the hydraulic oil temperature of the engagement element when the slip occurs. Thereby, it is possible to appropriately correct the hydraulic pressure of the engagement element in correlation with the hydraulic oil temperature.

  As an example, the determination means includes an increase counter that is incremented when the differential rotation has increased from the previous time, and a decrease counter that is incremented when the differential rotation has decreased from the previous time or has not changed. The counter is reset when the up counter is incremented, and the up counter is reset when the value of the down counter reaches a predetermined down reference value. If the up counter value is equal to or greater than the predetermined up reference value, the counter is reset. It is determined that the differential rotation has increased more than the predetermined number of times. In this case, if the predetermined rotation reference value is not reached even if the rotational speed is temporarily decreased when the differential rotation is increasing, the increase counter is not reset, and a noise-like transient difference is not achieved. The rotation descent can be eliminated (cancelled or filtered), and even if the differential rotation rises temporarily when it is in a descent trend, when the descent counter value reaches a predetermined descent reference value, Since the reset is performed, it is possible to eliminate (cancel or filter) the transient increase in differential rotation that is noisy, and in this way, it is possible to determine the slippage of the engaging element with higher accuracy.

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

  FIG. 1 is a block diagram showing an outline of a power transmission system and a control system of a vehicle provided with a start control device according to an embodiment of the present invention. The power transmission system of the vehicle is set by inputting the engine 1 as a power source, the torque converter 2 as a fluid coupling for transmitting the rotational output of the engine 1 to the transmission gear mechanism 3, and the rotational output of the torque converter 2. And a differential gear mechanism 4 that distributes the output rotation of the transmission gear mechanism 3 to left and right wheels (for example, rear wheels) 5. A hydraulic control device 6 is provided with the torque converter 2 and the transmission gear mechanism 3, and the hydraulic control device 6 is a hydraulic control type engagement element (inside the torque converter 2 and the transmission gear mechanism 3). By engaging or releasing a clutch or the like in a predetermined combination, the torque converter 2 is locked up and the input / output speed ratio in the transmission gear mechanism 3 is set to a required gear stage. The automatic transmission of the vehicle includes the torque converter 2, the transmission gear mechanism 3, the hydraulic control device 6, and the like.

  A control system for controlling the power transmission system of the vehicle is controlled by a sensor provided in each part of the vehicle, an electronic control unit (ECU) 10 to which an output of each sensor is input, and the electronic control unit 10. The hydraulic control device 6 and the like. The rotation sensor 11 detects the rotation speed Ne of the input shaft of the torque converter 2 (engine rotation speed) Ne, the rotation sensor 12 detects the rotation speed Ni of the input shaft of the transmission gear mechanism 3, and the rotation sensor 13 detects the transmission gear mechanism 3. The rotation speed No of the output shaft is detected, and the vehicle speed sensor 14 detects the vehicle speed Nv. The vehicle speed Nv may be calculated from the input shaft rotational speed Ni or the output shaft rotational speed No without providing the vehicle speed sensor 14 that exclusively detects the vehicle speed Nv. For example, the vehicle speed Nv can be detected based on a relational expression such as “Nv = Ni × speed ratio × tire diameter” or “Nv = No × tire diameter”. The shift lever position sensor 15 detects the position of the shift lever operated by the driver. As is well known, shift lever positions include, for example, P (parking), R (reverse travel), N (neutral), D (advance travel in automatic transmission mode), etc. There is a position for manually designating a specific gear stage such as speed or 1st speed. The brake sensor 16 detects that the brake pedal is depressed by a predetermined amount or more and the brake is applied. The throttle sensor 17 detects the throttle opening of the engine 1 for which the opening is set according to depression of the accelerator pedal. The ATF temperature sensor 18 detects the temperature of hydraulic oil (ATF oil temperature) TATF in the hydraulic control device 6. The coolant temperature sensor 19 detects the temperature of the engine coolant. The accelerator pedal sensor 20 detects an accelerator pedal opening APAT corresponding to depression of the accelerator pedal.

  The specific configuration of the vehicle power transmission system and the control system shown in FIG. The vehicle start control device according to the present invention is included in the electronic control unit 10 and is implemented as one of various control functions that can be realized by the electronic control unit 10. In the embodiments described below, the vehicle start control device according to the present invention is executed by a computer program included in the electronic control unit 10, and is used when returning to forward travel from the aforementioned "idle neutral control". This relates to start control or start control when shifting to the first forward speed from the neutral state. However, the vehicle start control device according to the present invention is not limited to a computer program, and can of course be configured with dedicated electronic circuit hardware.

  FIG. 2 is a flowchart schematically showing a routine of AT (automatic shift) control processing that is repeatedly executed by the computer included in the electronic control unit 10 at a cycle of 10 milliseconds. In parameter calculation S1, detection signals of the sensors including the sensors 11 to 19 are read, parameters indicating various states of the vehicle are calculated based on the signals, and the calculated parameters are temporarily stored in a register. Each temporarily stored parameter is appropriately referred to and used when executing other processing in the routine of FIG. If the detection signal read from the sensor can be used as a parameter as it is, the read detection signal is calculated as a parameter as it is, but the required parameter is calculated by obtaining a predetermined calculation based on the detection signal read from the sensor. There is also a case.

For example, the differential rotation DNMEG between the input rotation and the output rotation of a specific clutch (LOW clutch for realizing the first forward speed) that is currently being engaged and controlled in the transmission gear mechanism 3 is the input shaft rotation speed read from the rotation sensor 12. Based on Ni, the output shaft rotational speed No read from the rotation sensor 13, and a predetermined speed ratio R _LOW realized by the transmission gear mechanism 3 by engaging the clutch, the following calculation is performed. It is assumed that Ni / No = R _LOW when the clutch engagement is completed and there is no difference between the input rotation and the output rotation of the clutch.
DNMEG = Ni-No × R _LOW
That is, the function of “differential rotation detection means for detecting the differential rotation between the input rotation and the output rotation of a specific clutch (engagement element)” is realized by calculating the parameter of the differential rotation DNMEG in accordance with the above formula in the parameter calculation S1. Has been.

  In the shift control S2, the optimum shift speed is determined by referring to the automatic shift pattern based on each parameter, and the shift speed currently set in the transmission gear mechanism 3 needs to be changed (shifted). The shift control electromagnetic solenoid (not shown) for selecting the hydraulic pressure supply operation in the hydraulic control device 6 is turned on (attached) so as to engage or disengage a predetermined engagement element (clutch) in order to realize the new gear position. Control) to turn off (turn off) or turn off (turn off).

  Further, in the shift control S2, when a predetermined condition for the idle neutral control is satisfied, the shift control electromagnetic solenoid is turned on (energized) so as to release the predetermined engagement element (clutch) for the idle neutral control. ) Or off (turn off). As described above, in the idle neutral control, the shift pedal is set to the forward travel position, the accelerator pedal is released and the engine is idling, the brake pedal is depressed more than a predetermined amount, and the vehicle speed Nv is substantially zero. When a predetermined condition such that the vehicle is substantially stopped is satisfied, a predetermined engagement element is engaged, typically at the first forward speed (and also at other forward speeds). This is a control for releasing the LOW clutch to be set to the neutral state.

  Further, in the shift control S2, when a predetermined return condition (for example, release of the brake pedal is released while the accelerator pedal is depressed) is satisfied during the idle neutral control, the shift control S2 is released for the idle neutral control. The shift control electromagnetic solenoid is turned on (energized) or off (deenergized) so as to engage a predetermined engagement element (the LOW clutch).

  In the lockup clutch control S3, when a predetermined condition is satisfied, the lockup electromagnetic solenoid is turned on (energized) or turned off (deactivated) so that the lockup clutch of the torque converter 2 is engaged / released. ) Is set.

  In the linear solenoid control S4, in order to supply hydraulic oil to a predetermined engagement element (clutch) selected to be engaged in the shift control S2 and move the selected engagement element (clutch) in the engagement direction, Control is performed to turn on (energize) a linear electromagnetic solenoid (not shown). The linear solenoid control S4 includes a subroutine S41 for calculating the hydraulic oil pressure command value. The hydraulic pressure command value calculation subroutine S41 includes a subroutine S42 for calculating a hydraulic pressure command value during forward in-gear processing. This subroutine S42 includes a subroutine S43 for calculating a hydraulic pressure command value for in-gear processing from idle neutral control (in-gear processing for returning from idle neutral control to forward travel).

  In this subroutine S43, in order to determine that slip has occurred in the LOW clutch for in-gear during in-gear processing from idle neutral control or in-gear processing from the normal neutral state, according to one embodiment of the present invention. Subroutine S44. This subroutine S44 realizes a function corresponding to a determination means for determining that slip has occurred in the LOW clutch based on the degree of increase in the differential rotation between the input rotation and the output rotation of the LOW clutch for in-gear. Subroutine S43 includes a current in-gear hydraulic pressure command routine S45 for calculating a pressure command value of hydraulic fluid to be supplied in response to turning on (biasing) of the linear electromagnetic solenoid in the current in-gear processing.

  Further, in the hydraulic pressure command value calculation subroutine S41, when it is determined in the clutch slip determination subroutine S44 that slip has occurred in the in-gear LOW clutch, the hydraulic pressure of the clutch at the next start is corrected. A correction value backup subroutine S46 for setting the correction value is included. This correction value backup subroutine S46 realizes a function corresponding to a correction means for setting a correction amount for correcting the hydraulic pressure of the clutch at the next start when it is determined that the clutch has slipped. .

  After the linear solenoid control S4, a failure detection process S5 is executed, and one cycle job is completed.

  FIG. 3 is a flowchart showing an example of the clutch slip determination subroutine S44. In step S51, the difference between the previous value and the current value of the “Differential rotation between the input rotation and output rotation of the LOW clutch” (hereinafter referred to as “clutch differential rotation”) calculated in the parameter calculation S1 is compared, and the clutch differential rotation is detected. It is determined whether DNMEG is increasing (that is, increasing) or decreasing (that is, decreasing). This previous value is the previous value in the job of FIG. 2 executed in a cycle of 10 milliseconds. That is, the clutch differential rotation DNMEG calculated this time is the current value, and the clutch differential rotation DNMEG calculated in the job 10 milliseconds before is the previous value. When the clutch is not slipped, the clutch differential rotation DNMEG is lowered (decreased) in time and converges to 0. However, when the clutch is slipped, the input rotation is increased by depressing the accelerator pedal. On the other hand, the output rotation does not increase accordingly, and the clutch differential rotation DNMEG increases (increases) in time.

  The upward or downward tendency of the clutch differential rotation DNMEG according to the presence or absence of clutch slipping is not a simple increase or a simple decrease, but includes a noise-like fluctuation component. Therefore, such a noise-like fluctuation component is removed (filtered) by the following processing so as to grasp an accurate upward tendency or downward tendency.

  If the current value of the clutch differential rotation DNEG is greater than the previous value, the value of the “rising counter” is incremented by 1 in step S52. When the value of “rise counter” is incremented in step S52, the value of “decrease counter” is reset to 0 in the next step S53.

  On the other hand, if the current value of the clutch differential rotation DNEG is not greater than the previous value (decreases or does not change), the value of the “decrease counter” is incremented by 1 in step S54. As described above, since the “decrease counter” is reset when the clutch differential rotation DNMEG increases, the value of the “decrease counter” increases when the clutch differential rotation DNMEG does not increase continuously.

  In step S55, it is checked whether or not the value of the “rising counter” is 1. When the value of the “rising counter” is 1, it means that the clutch differential rotation DNMEG has started to rise. If the value of the “rising counter” is 1, each parameter at the start of raising of the clutch differential rotation DNMG is stored as a slip related parameter in step S56. Specifically, the current clutch differential rotation DNMEG is latched in the register as “clutch differential rotation minimum value” DNMEGmin, and the current clutch differential rotation DNMEG is also latched in the register as “clutch differential rotation maximum value” DNMEGmax. Pedal opening “APAT” is latched in the register as “accelerator pedal opening at start of slip” APATigl, and the current “ATF oil temperature” TATF is latched in the register as “slip start oil temperature” TATFingl. When the value of the “rising counter” is other than 1, this step S56 is jumped.

In step S57, it is checked whether the value of the “decrease counter” is equal to or greater than a predetermined decrease reference value CALIB ₁ . This lowering reference value CALIB ₁ is a value that can confirm that the lowering (decrease) of the clutch differential rotation DNMEG is not temporary, and is appropriately determined in the design. Take a large value. If YES, that is, if the value of the “decrease counter” reaches the predetermined decrease reference value CALIB ₁ , the values of the “increase counter” and the “decrease counter” are reset to 0 in step S58. Since the downward trend, that is, the convergence of the clutch differential rotation DNMG was once confirmed, it was found that the value held in the “rising counter” was transient noise-like. In order to cancel (filter) the fluctuation, the “rising counter” is reset. The reason for resetting the “down counter” at this time is to return the clutch slip determination condition to the initial state. If the value of the “decrease counter” has not reached the predetermined decrease reference value CALIB ₁ , step S58 is jumped.

At step S59, the value of the "rising counter" checks whether a predetermined elevated reference value CALIB ₂ or more. This increase reference value CALIB ₂ is a value that can be used to confirm that the increase (increase) in the clutch differential rotation DNMEG is not temporary, and is appropriately determined in the design. Take a large value. If YES, that is, if the value of the “rising counter” reaches a predetermined rising reference value CALIB ₂ , the slip determination primary flag F_JUDFL1 is set to 1 in step S60. The slip determination primary flag F_JUDFL1 of 1 indicates that the clutch differential rotation DNMEG has increased more than a predetermined number of times (the number of jobs of the AT control process in FIG. 2), that is, is increasing, in other words, clutch slippage has occurred. This indicates that the possibility is high. If the value of the “rise counter” has not reached the predetermined rise reference value CALIB ₂ , step S60 is jumped.

  In step S61, it is checked whether or not the current clutch differential rotation DNMEG is larger than the stored “clutch differential rotation maximum value” DNMEGmax. If it is larger, the “clutch differential rotation maximum value” DNMEGmax is updated by the current clutch differential rotation DNMEG ( S62). Thus, the maximum clutch differential rotation DNMEG after the “increase counter” is reset to 0 is stored as “clutch differential rotation maximum value” DNMEGmax.

  In step S63, the difference between the "clutch differential rotation maximum value" DNMEGmax and the "clutch differential rotation minimum value" DNMEGmin is calculated, and this difference is calculated as the clutch slip amount DNMEG.

In step S64, the calculated clutch slip DDNMEG checks whether greater than a predetermined judgment reference value CALIB _3, a DDNMEG> CALIB _3, and the slippage determining primary flag F_JUDFL1 is 1, then the clutch It is determined that slip has occurred. Thus, when both conditions of DDNMEG> CALIB ₃ and F_JUDFL1 = 1 are satisfied, the slip determination flag F_DNMEGFL is set to 1 in step S65 to indicate that it has been definitely determined that the clutch has slipped. .

  FIG. 4 is a flowchart showing an example of the correction value backup subroutine S46. In step S70, it is checked whether or not the slippage determination flag F_DNMEGL is 1. If YES, in step S71, a correction value Ccur for correcting the operating hydraulic pressure of the clutch is determined according to the clutch slip amount DNMEG and added to the value of the correction amount counter FC (FC = FC + Ccur). . The correction amount counter FC cumulatively counts and holds a correction value for correcting the operating hydraulic pressure of the clutch. The correction amount counter FC holds correction amount data as a function of the accelerator pedal opening and the ATF oil temperature (that is, in association with the accelerator pedal opening and the ATF oil temperature). Therefore, referring to the “accelerator opening at the start of slip” APATingl and the “oil temperature at the start of slip” TATFingl latched in step S56 in FIG. 3, respective values (accelerator opening at the start of slip and the start of the slip) The correction amount counter FC corresponding to the oil temperature) is called, and the correction value Ccur determined in the current in-gear process is added to the value of the correction amount counter FC (the correction amount up to the previous in-gear process). The correction amount data held by the correction amount counter FC is the hydraulic oil pressure so that the clutch does not slip under the same conditions of the accelerator pedal opening and the ATF oil temperature in the next in-gear processing by the LOW clutch. It is used as control data for increasing.

  The correction amount counter FC does not have to be provided corresponding to the fine values of the accelerator pedal opening and the ATF oil temperature, and there are a plurality of ranges of values that the accelerator pedal opening and the ATF oil temperature can take. Dividing into stages, the correction amount counter FC may be provided in a matrix corresponding to each stage. Further, the correction amount counter FC may be provided corresponding to one of the accelerator pedal opening and the ATF oil temperature without being provided corresponding to both.

  Note that the correction value backup subroutine S46 may be executed at least once at the end of the current in-gear process, for example.

  FIG. 5 is a flowchart showing an example of the current in-gear oil pressure command routine S45. In step S81, the correction amount data of the correction amount counter FC is read in accordance with the accelerator pedal opening APAT and the ATF oil temperature TATF obtained in the parameter calculation S1 of FIG. In step S82, a base hydraulic pressure command value corresponding to the linear electromagnetic solenoid is calculated. In step S83, it is checked whether the accelerator pedal is ON. If the accelerator pedal is ON, start control according to the present invention is performed in steps S84 and S85.

  In step S84, a hydraulic pressure correction amount is calculated by multiplying the read correction amount data of the correction amount counter FC by a predetermined correction hydraulic pressure coefficient. In step S85, the calculated hydraulic pressure correction amount is added to the calculated base hydraulic pressure command value to calculate the current in-gear hydraulic pressure command value. By setting the clutch operating oil pressure corresponding to the energization of the linear electromagnetic solenoid according to the current in-gear oil pressure command value calculated in this way, the clutch slip that occurred during the previous in-gear process does not occur in the current in-gear process. Thus, the clutch operating oil pressure is controlled. Thereby, it is possible to prevent judder from occurring due to insufficient torque of the clutch. Note that the slip determination primary flag F_JUDFL1 and the slip determination flag F_DNMEGFL are set at an appropriate timing determined by design, for example, when the idle neutral control is canceled or when shifting from the neutral state to the first forward speed. It is reset when in-gear processing starts.

  FIG. 6 is a graph showing an example of actual measurement of each data when judder occurs due to insufficient torque of the clutch, with the horizontal axis representing time and the vertical axis representing the actual measurement value of each data. FIG. 6A shows an “idle N flag” indicating the on / off state of the idle neutral control, which is turned off at time t1, and that the idle neutral control has been released at time t1. Show. Further, FIG. 6A shows actual measurement data of the speed ratio of the input / output shaft of the transmission gear mechanism 3, the clutch differential rotation DNMEG, and the accelerator pedal opening, and further, a measured value of the acceleration G applied to the vehicle. Also shown for reference. FIG. 6B shows the on / off state of the slippage determination primary flag F_JUDFL1 and the slippage determination flag F_DNMEGFL corresponding to the data state shown in FIG. 6A, and the command value of the clutch operating oil pressure. . In FIG. 6A, a portion where clutch slip occurs is schematically surrounded by a dotted line. Referring to FIG. 6 (a), it can be understood that when clutch slip occurs, the acceleration G vibrates greatly and judder occurs after an appropriate time delay.

  The processing operation in the flow of FIGS. 2 to 5 executed corresponding to the actual measurement example of FIG. 6 will be described. In FIG. 6, the clutch differential rotation DNMEG is decreasing (decreasing) from time t1 to time t2. At time t2, the clutch differential rotation DNMEG switches from lowering to rising. When the AT control processing job shown in FIG. 2 is executed at time t2, if the current value of the clutch differential rotation DNMEG is larger than the previous value in step S51 (FIG. 3) in the clutch slippage determination subroutine S44 in the linear solenoid control S4. The increase counter is incremented to “1” (S52). Thus, the process proceeds from YES in step S55 to step S56, and the clutch differential rotation minimum value DNMEGmin, the clutch differential rotation maximum value DNMEGmax, the slip start accelerator pedal opening APATingl, and the slip start oil temperature TATFingl are latched.

  Thereafter, as the clutch differential rotation DNMEG continues to increase (increase), the value of the increase counter is sequentially increased (increased) (S52 in FIG. 3). Further, the clutch differential rotation maximum value DNMEGmax is also updated sequentially (S61, S62 in FIG. 3).

When the value of the increase counter reaches a predetermined increase reference value CALIB ₂ (eg, “3”) at time t3, YES is determined in step S59 (FIG. 3) during execution of the AT control processing job at time t3. In S60, the slip determination primary flag F_JUDFL1 is set to 1. The current clutch differential rotation DNMEG is updated as DNMEGmax (S62), and a clutch slip amount DNMEG, which is the difference between this new DNMEGmax and DNMEGmin latched at time t1, is obtained (S63). If this clutch slip amount DNNMEG is larger than a predetermined determination reference value CALIB ₃ , the determination condition in step S64 is satisfied, and the slip determination flag F_DNMEGFL is set to 1 (S65).

  If the clutch slip continues thereafter, the clutch differential rotation maximum value DNMEGmax is sequentially updated (S61, S62 in FIG. 3). In the measurement example of FIG. 6, the clutch differential rotation DNMEG at the time t4 becomes the final maximum value DNMEGmax. Therefore, in this in-gear process, finally, the difference between the true clutch differential rotation maximum value DNMEGmax (value at the time t4) and the clutch differential rotation minimum value DNMEGmin is calculated and stored as the clutch slip amount DNMEG. (S63).

  In the correction value backup subroutine S46 (FIG. 4), the correction value Ccur is determined according to the clutch slip amount DNMEG in the current in-gear process calculated as described above, and the accelerator pedal opening APATingl and the slip start at the start of the slip. The correction value Ccur is added to the value of the correction amount counter FC called in correspondence with the oil temperature TATFingl (S71). The value of the correction amount counter FC is “0” if no clutch slip has occurred in the past by a combination of the corresponding accelerator pedal opening value and ATF oil temperature value. When a clutch slip occurs this time with a combination of the corresponding accelerator pedal opening value and the ATF oil temperature value, a correction value Ccur having a value that compensates for this slip is determined according to the detected clutch slip amount DNMEG. This is added to the value of the correction amount counter FC corresponding to the combination of the corresponding accelerator pedal opening value and ATF oil temperature value.

  In the in-gear process of the actual measurement example shown in FIG. 6, the hydraulic pressure compensation according to the correction value Ccur determined as described above has not been made yet. That is, the correction amount data of the correction amount counter FC read in step S81 of the current in-gear oil pressure command subroutine S45 shown in FIG. 5 is data that does not predict the occurrence of clutch slip that will occur this time (for example, 0). Therefore, as shown in FIG. 6, clutch slip occurs and judder occurs.

  FIG. 7 is a graph showing an example of actual measurement of each data at the time of the LOW clutch in-gear process at the next release of the idle neutral control as a result of learning the hydraulic pressure correction amount according to the present invention in the actual measurement example shown in FIG. Yes, the horizontal axis is time, and the vertical axis is the measured value of each data. As shown in FIG. 7, the previously learned hydraulic pressure correction amount is added to the command value of the clutch operating hydraulic pressure, so that the clutch torque deficiency is eliminated, clutch slippage does not occur, and judder occurs. Will not do.

  The processing operation in the flow of FIGS. 2 to 5 executed corresponding to the actual measurement example of FIG. 7 will be described. When the idle neutral control is released at time t11 in FIG. 7, the corresponding shift control electromagnetic solenoid and linear electromagnetic solenoid are energized, and the in-gear processing of the LOW clutch is started (S2, S4, S42, S43 etc.). For a while from time t11, the accelerator pedal is not depressed or the accelerator pedal opening is small. Therefore, when the accelerator pedal is not depressed, the processing is performed in the NO route of step S83 in FIG. 5 so that the operating hydraulic pressure is not increased. When the accelerator pedal opening is small, the small accelerator pedal opening Accordingly, the correction amount data of the correction counter FC read in step S81 in FIG. 5 is 0 (not learned by the in-gear process in FIG. 6), so that the hydraulic pressure is not increased. Eventually, when the accelerator pedal opening and the current value of the ATF oil temperature correspond to the state learned in the process of FIG. 6 at time t12, the correction amount of the correction counter FC read in step S81 of FIG. The data is learned by the in-gear process of FIG. 6 so as to eliminate the clutch torque shortage. Accordingly, the current in-gear hydraulic pressure command value is calculated by adding the previously learned hydraulic pressure correction amount to the base hydraulic pressure command value (S85). As a result, the hydraulic pressure is increased so as to eliminate the clutch torque shortage in response to changes in the accelerator pedal opening and the ATF oil temperature, so that clutch slip does not occur and judder does not occur. . Of course, if the previously learned hydraulic pressure correction amount is not sufficient and clutch slipping still occurs, learning is further performed to increase the hydraulic pressure correction amount.

The block diagram which shows the outline of the power transmission system and control system of a vehicle provided with the start control apparatus which concerns on one Embodiment of this invention. FIG. 2 is a flowchart schematically showing an AT (automatic shift) control routine repeatedly executed at a cycle of 10 milliseconds by a computer included in the electronic shift control unit (ECU) in FIG. 1. The flowchart which shows an example of clutch slip determination subroutine S44. The flowchart which shows an example of correction value backup subroutine S46. The flowchart which shows an example of this in-gear oil pressure command routine S45. The graph which shows the actual measurement example of each data when judder generate | occur | produces by the torque shortage of a clutch. The graph which shows the example of actual measurement of each data in the time of the LOW clutch in-gear process at the time of the next idle neutral control cancellation | release as a result of having learned the hydraulic pressure correction amount according to this invention.

Explanation of symbols

1 Engine 2 Torque converter 3 Transmission gear mechanism 4 Differential gear mechanism 5 Wheel (for example, rear wheel)
6 Hydraulic control device 10 Electronic control unit (ECU)

Claims (6)

A vehicle start control device equipped with an automatic transmission having an engagement element that is engaged based on hydraulic control at the start,
Differential rotation detection means for detecting a differential rotation between an input rotation and an output rotation of the engagement element;
Slip determining means for determining that slip has occurred in the engagement element according to the degree of increase in the differential rotation;
Correction means for setting a correction amount for correcting the hydraulic pressure of the engagement element at the next start when the determination means determines that slippage has occurred in the engagement element ;
The differential rotation detection means detects the differential rotation every predetermined cycle,
The determination means determines that the engagement element is applied to the engagement element when the difference rotation is increased a predetermined number of times or more and a difference between the difference rotation that starts to increase and the maximum difference rotation is not less than a predetermined reference value. A start control device for a vehicle, characterized in that it is determined that a slip has occurred . In the vehicle, idle neutral control is performed to release the engagement element when the shift instruction by the shift lever is set to the forward travel position and the vehicle state is stopped while satisfying a predetermined condition. ,
2. The vehicle start control device according to claim 1, wherein the start control device performs start control when the engagement element is engaged to return to forward travel from the idle neutral control. 3. The determination means determines a slip amount of the engagement element when it is determined that slip has occurred in the engagement element;
The vehicle start control device according to claim 1, wherein the correction unit sets a correction amount of the hydraulic pressure of the engagement element according to a slip amount of the engagement element.   The correction means sets the correction amount of the hydraulic pressure of the engagement element in association with the accelerator pedal opening of the vehicle when the slip occurs. The vehicle start control device according to claim 1.   5. The correction unit according to claim 1, wherein the correction means sets a correction amount of the hydraulic pressure of the engagement element in association with a hydraulic oil temperature of the engagement element when the slip occurs. A vehicle start control device according to claim 1. The determination means includes an increase counter that is incremented when the differential rotation has increased from the previous time, and a decrease counter that is incremented when the differential rotation has decreased from the previous time or has not changed. When the counter is incremented, the counter is reset. When the value of the descending counter reaches a predetermined descending reference value, the counter is reset. The vehicle start control device according to any one of claims 1 to 4, wherein it is determined that the vehicle has risen more than the predetermined number of times.

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