JP3557934B2 - Control device for automatic transmission for vehicles - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a control apparatus for an automatic transmission for a vehicle that automatically switches the gear position of the automatic transmission for a vehicle, and particularly to a technique for determining a degree of tie-up during a clutch-to-clutch shift control period.
[0002]
[Prior art]
In a control device for an automatic transmission for a vehicle, the opening of one hydraulic friction engagement device and the engagement of the other hydraulic friction engagement device of the two friction engagement devices involved in shifting are overlapped. There is a case where a so-called clutch-to-clutch shift in which the shift is performed by the shift is performed. In such a clutch-to-clutch shift, if the timing of opening of one hydraulic friction engagement device and engagement of the other hydraulic friction engagement device are not precisely performed, the automatic transmission will The output shaft torque of the engine temporarily drops, or a so-called tie-up occurs, or an overshoot in which the input shaft rotation speed of the automatic transmission temporarily exceeds the rotation speed after shifting, that is, an engine in which the engine rotation speed temporarily rises Or blowing.
[0003]
For this reason, according to the conventional control device, the tie-up or overshoot is detected, and the hydraulic tie-up or overshoot is reduced during the next shift period so that the tie-up or overshoot becomes smaller than a predetermined reference value. The engagement pressure of the friction engagement device is controlled by learning.
[0004]
[Problems to be solved by the invention]
By the way, in the above-described conventional control device, the occurrence of the tie-up is determined based on the output shaft rotational acceleration of the automatic transmission having decreased by a predetermined value or more. For example, a control device for an automatic transmission for a vehicle described in Japanese Patent Application Laid-Open No. 5-296323 is the one. However, in such a control device, the tie-up amount or the degree of the tie-up is not detected at all. For this reason, since the engagement pressure of the hydraulic friction engagement device must be gradually learned to the blow side, it takes time to converge the tie-up when a tie-up occurs. There was a disadvantage that a ring could not be obtained.
[0005]
On the other hand, the degree of tie-up, that is, the degree of tie-up is determined from the decrease amount of the output shaft rotational acceleration of the automatic transmission, and the learning correction amount is determined in accordance with the tie-up degree, thereby quickly tying up. However, the output shaft rotation of the automatic transmission may be mixed with disturbances that are difficult to remove sufficiently in practice, such as irregular noise due to irregularities on the road surface. In some cases, the detection accuracy of the degree of tie-up is not sufficiently obtained, and the learning control for converging the tie-up may not function sufficiently.
[0006]
The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a control device for an automatic transmission for a vehicle, in which a degree of tie-up occurring during a clutch-to-clutch shift period can be suitably obtained. Is to do.
[0007]
[Means for Solving the Problems]
The gist of the present invention for achieving the above object is to provide an automatic transmission for a vehicle in which one of a plurality of gears is selected according to a combination of operations of a hydraulic friction engagement device. At the time of shifting, the opening of the release-side hydraulic friction engagement device and the engagement of the engagement-side hydraulic friction engagement device of the pair of hydraulic friction engagement devices involved in the shift are performed in an overlapping manner. (A) an input shaft rotation speed detecting device for detecting an input shaft rotation speed of the automatic transmission; and (b) an input shaft rotation speed detecting device for the clutch-to-clutch shift period. A primary differential value calculating means for sequentially calculating a primary differential value of the detected input shaft rotational speed; and (c) integrating a primary differential value of the input shaft rotational speed sequentially calculated by the primary differential value calculating means. Calculating the integrated value of the primary differential value of the power shaft rotation speed, and outputting the output of the automatic transmission caused by the overlapping of the engagement states of the pair of hydraulic friction engagement devices during the clutch-to-clutch shift period. Tie-up, a temporary decrease in shaft torqueTie-up that gets bigger asAs a quantity indicating the degree of, And the integrated value of the first derivativeOutput means and, (d) The engagement of the hydraulic friction engagement device during the clutch-to-clutch shift period is determined based on an amount indicating the degree of the tie-up represented by the integrated value of the primary differential value of the input shaft rotation speed output from the integrating means. Shifting transient control means for controlling the combined pressure;Is to include.
[0008]
【The invention's effect】
With this configuration, during the clutch-to-clutch shift period, when the primary differential value calculating means sequentially calculates the primary differential value of the input shaft rotation speed, for example, the difference for each sampling period, the integrating means calculates the primary differential value. Are sequentially integrated to calculate an integrated value, and the integrated value is tied up.Tie-up that gets bigger asIs output as the amount indicating the degree of the tie-up, the degree of the tie-up occurring during the clutch-to-clutch shift period can be suitably obtained.Therefore, the shift transition control means controls the engagement pressure of the hydraulic friction engagement device during the clutch-to-clutch shift period based on the amount indicating the degree of the tie-up,Converge tie-ups quicklyButIt becomes possible.
[0009]
Other aspects of the invention
Preferably, the primary differential value for sequentially determining whether the magnitude of the primary differential value of the input shaft rotation speed sequentially calculated by the primary differential value calculation means is equal to or less than a predetermined reference value. When the determining means and the primary differential value determining means determine that the primary differential value of the input shaft rotation speed is equal to or less than a predetermined reference value, a clear operation for clearing the integrated value of the integrating means to zero. Means are further provided. With this configuration, since only the first derivative of the input shaft rotational speed at the time of occurrence of tie-up is integrated, integration in the case of non-tie-up is prevented, and the reliability of the obtained tie-up degree is further enhanced. .
[0010]
Preferably, an overshoot determining means for determining the occurrence of an overshoot in which the input shaft rotational speed temporarily exceeds the rotational speed after the shift within the clutch-to-clutch shift period, and an overshoot occurrence time Overshoot occurrence time determining means for determining whether or not the time is equal to or less than a predetermined reference value, and the overshoot occurrence time determining means determines that the overshoot time is equal to or less than the predetermined reference value. In this case, there is further provided overshoot-related control prohibiting means for prohibiting overshoot-related control executed in connection with the occurrence of overshoot determined by the overshoot determining means. When a strong tie-up occurs, the tie-up is caused by the early engagement of the engagement-side hydraulic friction engagement device, which causes the input rotational speed to overshoot at the same time. However, with the above configuration, even if the occurrence of overshoot is determined, the overshoot-related control executed by the overshoot-related control prohibiting means in connection with the determination of the occurrence of overshoot is performed. Is prohibited, so that overshoot-related control is not performed when tie-up should be dealt with.
[0011]
Preferably, the tie-up of the engagement pressure of the hydraulic friction engagement device during the clutch-to-clutch shift period is performed based on the integrated value output from the integrating means and indicating the degree of the tie-up. Tie-up learning control means for correcting so as to be canceled is provided. In this way, even if a tie-up occurs, the tie-up learning control means immediately eliminates the tie-up, so that a suitable shift feeling can be obtained.
[0012]
Preferably, the overshoot occurrence time determination means determines a determination reference value in advance based on the magnitude (amplitude or height) of the overshoot, and the overshoot occurrence time is shorter than the determination reference value. It is to determine whether or not. Normal overshoot has a fixed relation between its size and width (occurrence time), but in contrast, overshoot generated due to strong tie-up is There is a phenomenon that the width is small. According to the above, there is an advantage that the overshoot generated due to the strong tie-up is more reliably determined.
[0013]
Preferably, when the overshoot occurrence time determining means determines that the overshoot occurrence time is greater than the determination reference value, the hydraulic pressure during the clutch-to-clutch shift period is determined based on the magnitude of the overshoot. An overshoot learning control means for correcting the engagement pressure of the frictional engagement device so that the overshoot is eliminated is provided. With this configuration, even if an overshoot occurs, the overshoot is quickly eliminated by the overshoot learning control means, so that a suitable shift feeling can be obtained.
[0014]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.
[0015]
FIG. 1 shows a torque converter 12 connected to an engine 10 of a vehicle, an automatic transmission 14, a differential gear device 16, a hydraulic control device for controlling a shift speed of the automatic transmission 14, that is, a hydraulic control circuit 18, A shift electronic control device 20 for controlling the control circuit 18 and the like are shown. Power output from the engine 10 is transmitted to drive wheels (not shown) via the torque converter 12, the automatic transmission 14, the differential gear device 16, the left and right axles 22 and 24, and the like.
[0016]
The torque converter 12 is connected to a pump impeller 28 connected to the crankshaft 26 of the engine 10 and an input shaft 30 of the automatic transmission 14 and receives power from the pump impeller 28 via fluid. A lock-up clutch 40 for directly connecting the turbine wheel 32, a fixed wheel 38 fixed to a position-fixed housing 36 via a one-way clutch 34, and a pump wheel 28 and the turbine wheel 32 via a damper (not shown). And
[0017]
The automatic transmission 14 is a multi-stage transmission that achieves four forward gears and one reverse gear, and includes the input shaft 30, a set of Ravigneaux-type planetary gear devices 44, and a Ravigneaux-type planetary gear device. A ring gear 48 that rotates together with a ring gear 46 of 44 and functions as an output shaft that outputs driving force from the engine 10 to the differential gear device 16 or transmits power between the ring gear 48 and the differential gear device 16. And a counter shaft 50.
[0018]
In the Ravigneaux type planetary gear set 44, a single pinion planetary gear set 52 and a double pinion planetary gear set 54 share a carrier 56 and the ring gear 46. The single pinion planetary gear device 52 includes a sun gear 58, a planetary gear 60 attached to the carrier 56, and the ring gear 46. The double pinion planetary gear 54 includes a sun gear 62, a first pinion gear 64 and a second pinion gear 66 that are integrally connected to each other and rotatably attached to the carrier 56.
[0019]
Some of the components of the single pinion planetary gear set 52 and the double pinion planetary gear set 54 are not only integrally connected to each other but also selectively connected to each other by three clutches C1, C2, and C3. It has become. Some of the components of the single pinion planetary gear set 52 and the double pinion planetary gear set 54 are selectively connected to the housing 36 by three brakes B1, B2, and B3. Is engaged with the housing 36 by two one-way clutches F1 and F2 in the rotation direction. In addition, since parts other than the counter shaft 50 of the torque converter 12 and the automatic transmission 14 are configured symmetrically with respect to the axis of the input shaft 30 and the like, in FIG. The lower side is omitted.
[0020]
The clutches C1, C2, C3 and the brakes B1, B2, B3, which are hydraulic friction engagement devices, are, for example, multi-plate clutches or band brakes having one or two bands with opposite winding directions. The frictional engagement and the disengagement thereof are respectively controlled by the hydraulic control circuit 18 which operates according to a command from the electronic control unit 20 for shifting, so that the gear ratio γ as shown in FIG. (= The number of rotations of the input shaft 30 / the number of rotations of the counter shaft 50) can be obtained with four forward speeds and one reverse speed. “1ST”, “2ND”, “3RD”, and “4TH” in FIG. 2 respectively represent a first gear, a second gear, a third gear, and a fourth gear on the forward side. The gear ratio γ gradually decreases from the first gear to the fourth gear. In FIG. 2, “P”, “R”, “N”, “D”, “2”, and “L” are parking (P) ranges that are selectively selected by manual operation of the shift lever 84. , Reverse (R) range, neutral (N) range, drive (D) range, second (2) range, and low (L) range, respectively. The P range and the N range are non-travel ranges selected when the vehicle is not driven, and the R range, the D range, the 2 range, and the L range are travel ranges for moving the vehicle backward or forward. The two ranges and the L range are also engine brake ranges because they not only increase the driving force of the vehicle but also generate engine brakes.
[0021]
In FIG. 2, a mark “○” indicates an engaged or operating state, and a mark “X” indicates a released or non-operating state. The shift between the fourth gear and the third gear in the D range is realized by the opening operation of one of the two hydraulic friction engagement devices involved in the shift and the engagement operation of the other. In a so-called clutch-to-clutch shift, for example, in a 4 → 3 downshift from the fourth gear to the third gear, the engagement operation of the clutch C1 and the release operation of the brake B1 are in an overlapped state or This is performed by being executed in the underlap state.
[0022]
The hydraulic control circuit 18 has three solenoid valves SV1 to SV3 used for controlling the gear position of the automatic transmission 14 and the like, and a size corresponding to a throttle opening TA detected by a throttle opening sensor 76 described later. Control hydraulic pressure P_S, A linear solenoid valve SLU for generating a hydraulic pressure for controlling the frictional engagement of the lock-up clutch 40, the disengagement of the frictional engagement, the control of the slip amount, and the like, and a hydraulic control circuit 18. Hydraulic oil temperature T_OILAnd an oil temperature sensor 88 functioning as a hydraulic oil temperature detecting device for detecting the oil temperature.
[0023]
The shift electronic control device 20 is a so-called microcomputer including a CPU 70, a RAM 72, a ROM 74, an input / output interface (not shown), and the like. The microcomputer includes an opening of a throttle valve provided in an intake pipe (not shown) of the engine 10. The throttle opening sensor 76 for detecting TA, the rotation speed N of the engine 10_E, An engine speed sensor 78 for detecting the rotational speed N of the turbine wheel 32_TThat is, the rotation speed N of the input shaft 30_INInput shaft speed sensor 80 for detecting the rotation speed of the counter shaft 50_CThat is, the vehicle speed sensor 82 for detecting the vehicle speed V, the operation position of the shift lever 84, that is, the operation position sensor 86 for detecting any of the L, S, D, N, R, and P ranges, and the hydraulic oil in the hydraulic control circuit 18. From the oil temperature sensor 88 for detecting the temperature, a signal indicating the throttle opening TA, the engine speed N_E(Rpm), input shaft speed N_IN(Rpm), output shaft speed N_C(Rpm), that is, a signal representing the vehicle speed V, the operating position P of the shift lever 84_ST, The hydraulic oil temperature T in the hydraulic control circuit 18_OILAre respectively supplied. The CPU 70 of the shift electronic control device 20 processes the input signal using the RAM 72 according to a program stored in the ROM 74 in advance, and based on the processing result, for example, detects the traveling state of the vehicle, The control of SV1 to SV3, the linear solenoid valves SLT and SLU, and the like are executed.
[0024]
FIG. 3 is a diagram schematically illustrating a configuration of a main part of the hydraulic control circuit 18. In FIG. 3, source pressure generating device 90 has a line oil pressure P obtained by adjusting the pressure of hydraulic oil pumped from hydraulic pump 92 driven to rotate by engine 10 to a value corresponding to the engine load._LIs output to the shift valve device 94 and the like as the original pressure of each of the hydraulic friction engagement devices C1, C2, C3, B1, B2, B3. The manual valve 96 is mechanically connected to the shift lever 84, and responds to the operation of selecting the travel range of the shift lever 84 so that the line oil pressure P_L, The hydraulic pressure corresponding to the selected travel range, for example, the R range pressure, the D range pressure, the 2 range pressure, and the L range pressure are output to the shift valve device 94. Also, the solenoid on-off valves SV1 and SV2 are operated by the electronic shift control device 20 exclusively for selecting a gear position, and thereby output a signal pressure to the shift valve device 94.
[0025]
The shift valve device 94 is switched at the time of shifting based on the hydraulic pressure corresponding to the travel range from the manual valve 96 and the hydraulic pressure signals from the two first and second solenoid on-off valves SV1 and SV2. It is provided with a 2-shift valve, a 2-3 shift valve, a 3-4 shift valve, etc., and applies hydraulic pressure to each hydraulic friction engagement device C1, C2, C3, B1, B2, B3 according to the operation shown in FIG. Is selectively supplied. Of the hydraulic friction engagement devices C1, C2, C3, B1, B2, B3, the clutches C1, C2, C3 and the brakes B1, B2 are used to alleviate an increase in the engagement hydraulic pressure, that is, the engagement torque. C1 accumulator A_C1, C2 accumulator A_C2, C3 accumulator A_C3, B1 accumulator A_B1, B2 accumulator A_B2Are connected respectively. The above C1 accumulator A_C1And B1 accumulator A_B1And the above C2 accumulator A_C2, C3 accumulator A_C3, And B2 accumulator A_B2Includes a line hydraulic pressure P that can be changed by a command from the shift electronic control device 20._LAre supplied as the accumulating back pressure, and shift transition control for adjusting the engagement hydraulic pressure of each hydraulic friction engagement device during the shift transition period is performed.
[0026]
The shift valve device 94 and the clutches C1 and C1 accumulator A_C1Between the hydraulic pressure signal from the third solenoid on-off valve SV3 and the engagement pressure P of the brake B1._B1A plurality of oil passages having orifices and an oil for switching between the plurality of oil passages for adjusting the engagement timing or the release timing of the clutch C1 according to the vehicle state by switching the flow resistance therebetween. An orifice switching valve device 98 having a path switching valve is provided.
[0027]
FIG. 4 shows a line hydraulic pressure P which is a source pressure of the hydraulic oil supplied to the clutch C1 and the brake B1 in the hydraulic control circuit 18._LFIG. 3 is a diagram for explaining a source pressure generating device 90 for generating the pressure in detail. In FIG. 4, the hydraulic pump 92 is rotationally driven by the engine 10 and sucks the recirculated hydraulic oil through the strainer 100 to pump it to the line pressure regulating valve 102.
[0028]
The line pressure regulating valve 102 is provided with a plunger 110, a spool valve element 112 provided to be movable in the axial direction in a state in which the plunger 110 is in contact with the plunger 110, and opening and closing between an input port b and an output port d. A spring 116 for urging the valve element 112 in the valve closing direction via a spring receiving plate 114. The hydraulic pressure of the hydraulic oil from the hydraulic pump 92 supplied to the input port b of the valve 116 is supplied to the linear solenoid valve SLT. Hydraulic pressure P supplied to the input port a from_SOf the line pressure P corresponding to the load of the engine 10, that is, the input torque of the automatic transmission 14,_LAdjust the pressure. The input port c of the line pressure regulating valve 102 is supplied with the hydraulic pressure of the input port b as a feedback hydraulic pressure. The urging force of the spring 116 is W_REGThe area of the annular pressure receiving surface of the land 118 of the spool_REG1The area of the pressure receiving surface of the plunger 110 for urging the spool valve element 112 in the valve closing direction of the output port d is A_REG2Then, the line hydraulic pressure P_LIs represented by the following equation (1). Here, the equation (1) represents the line hydraulic pressure P_LIs the control oil pressure P_SIs generated in proportion to. Control oil pressure P_SIs the engine load or the input torque T of the automatic transmission 14._INIn the normal case representing the magnitude of_LIs the engine load or the input torque T of the automatic transmission 14 that is a necessary and sufficient value within a range in which slippage of the hydraulic friction engagement device does not occur._INIs adjusted to a normal pressure adjustment value having a size corresponding to the pressure adjustment value.
[0029]
(Equation 1)
P_L= (A_REG2/ A_REG1) ・ P_S+ W_REG/ A_REG1  ... (1)
[0030]
The linear solenoid valve SLT includes a spool valve element 120 that opens and closes between an input port a and an output port b, and a spring 122 that urges the spool valve element 120 in a valve opening direction. The input port a has a constant pressure P_SOLAnd its constant pressure P_SOLFrom the electronic control unit for shifting 20 to the linear solenoid S_SLTControl hydraulic pressure P as a hydraulic pressure adjusted in accordance with the exciting current output to_SIs generated at output port b. The above linear solenoid S_SLTThe urging force for urging the spool valve element 120 in the valve closing direction of the output port b in accordance with the exciting current of F_I, The urging force of the spring 122 is W_SLT, The area of the annular pressure receiving surface of the land 124 of the spool valve 120_SLTThen, the oil chamber 128 between the land 124 and the land 126 and the output port b are communicated by the oil passage 130, and the oil pressure acting on the annular pressure receiving surface of the land 124 is the control oil pressure P_S, The control hydraulic pressure P_SIs represented by equation (2).
[0031]
(Equation 2)
P_S= W_SLT/ A_SLT-F_I/ A_SLT        ... (2)
[0032]
In FIG. 4, the pressure reducing valve 132 includes a spool valve 136 that opens and closes between an input port a and an output port b, and a spring 138 that urges the spool valve 136 in a valve opening direction. The line hydraulic pressure P supplied to a_LWith the above constant pressure P_SOLAnd the pressure is generated at the output port b and supplied to the linear solenoid valve SLT, the linear solenoid valve SLU, and the like. The input port c of the pressure reducing valve 132 is supplied with the hydraulic pressure of the output port b as a feedback hydraulic pressure. The above constant pressure P_SOLRepresents the pressure receiving area communicating with the input port c of the spool valve element 136 as A_MOD, The urging force of the spring 138 is W_MODThen, the pressure becomes a constant pressure represented by Expression (3).
[0033]
(Equation 3)
P_SOL= W_MOD/ A_MOD  ... (3)
[0034]
FIG. 5 is a functional block diagram illustrating a main control function of the electronic control unit 20 for shifting. In FIG. 5, the shift control point means 142 calculates the actual vehicle speed V, throttle opening TA, fuel injection amount F, intake air amount from a shift diagram previously selected in response to the travel range selection operation of the shift lever 84. The shift of the automatic transmission 14 is determined based on the engine load represented by any one of Q, an accelerator pedal operation amount, and the like, and a shift output for realizing the determined gear is performed. That is, in the shift point control means 142, the point representing the actual vehicle speed V and the engine load is, for example, 3-4 points in the two-dimensional coordinates composed of the vehicle speed axis representing the actual vehicle speed V and the engine load axis representing the engine load. When the vehicle crosses the shift line and enters the third speed region from the fourth speed region divided by the shift line, a 4 → 3 down shift line is determined.
[0035]
The shift transition control means 144 controls the engagement pressure of the hydraulic friction engagement device during the shift process in response to the shift output from the shift point control means 142 in order to enhance the shift feeling. That is, in the shift transient control means 144, when the shift point control means 142 determines that the 4 → 3 downshift is performed, as shown in the time chart of FIG. The engagement pressure P of the brake B1 according to the degree of progress of the shift so that the release of B1 and the engagement of the clutch C1 are performed at appropriate timing._B1And the engagement pressure P of the clutch C1_C1Is controlled. Brake B₁After the engagement of the clutch C1 is started at the same time when the clutch C1 is released, the engagement timing of the clutch C1 is adjusted by the orifice switching valve device 98, and the tie-up learning control means 146 performs learning so that tie-up is suppressed. Back pressure (= P_L) Is accumulator A_B1And A_C1Or the back pressure corrected by learning so that the overshoot is suppressed by the overshoot control means 148 (= P_L) Is accumulator A_B1And A_C1Is supplied to the engagement pressure P during the 4 → 3 downshift period._B1And P_C1Is controlled.
[0036]
The tie-up degree calculating means 150 determines the input shaft rotation speed N during the clutch-to-clutch shift period such as the 4 → 3 downshift._INFirst derivative DN_IN, And the integrated value DDN_INThe output shaft torque T of the automatic transmission 14 generated due to the overlapping of the engagement states of the pair of hydraulic friction engagement devices involved in the clutch-to-clutch shift._OIs output as an amount indicating the degree of tie-up, which is a temporary decrease in FIG. 7 shows the input shaft rotation speed N_INFirst derivative DN_INAnd the integrated value DDN_INAre shown.
[0037]
That is, the tie-up degree calculating means 150 determines the input shaft rotation speed N detected by the input shaft rotation speed sensor 80 during the clutch-to-clutch shift period._INFirst derivative N_INThat is, the difference DN for each sampling cycle_IN(= N_{IN (i)}-N_{IN (i-1)}), And the primary differential value DN of the input shaft rotation speed sequentially calculated by the primary differential value calculating unit 154._INIs integrated to obtain a first derivative value DN_INIntegrated value DDN_INIs sequentially calculated and output as an amount indicating the degree of tie-up of the automatic transmission 14 caused by the overlapping of the engagement states of the pair of hydraulic friction engagement devices during the clutch-to-clutch shift period. And an integrating means 160.
[0038]
The tie-up degree calculating means 150 includes the input shaft rotation speed N sequentially calculated by the primary differential value calculating means 154._INFirst derivative DN_INIs a predetermined criterion value A₁Primary differential value determining means 156 for sequentially determining whether or not the input shaft rotation speed N_INFirst derivative DN_INIs a predetermined criterion value A₁A clearing unit 158 for clearing the integrated value of the integrating unit 160 to zero when it is determined to be below is further provided. The input shaft rotation speed N_INMay contain noise, so that the above criterion value A₁Is a primary differential value DN when a tie-up occurs during a clutch-to-touch touchdown shift._INSo that only the first derivative value DN when the tie-up occurs_INIt is set to a value slightly smaller than.
[0039]
The tie-up learning control means 146 determines whether the input shaft rotation speed N_INIs a value immediately before the synchronous rotation speed, for example, in a 4 → 3 downshift, the rotation speed G in the third speed is established.₃× N_OIs determined to have reached a value lower by a predetermined value (for example, about 50 rpm), and the integrated value DDN integrated by the integrating means 160 is determined by the tie-up determining means 153._INIs a preset tie-up determination reference value B.₁That is, when the occurrence of a tie-up is determined based on exceeding the control target, the integrated value DDN output from the integrating means 160 as an amount indicating the degree of the tie-up._INBased on the back pressure (= line hydraulic pressure P) that controls the engagement pressure of the hydraulic friction engagement device during the clutch-to-clutch shift period._L) Is corrected so that the tie-up is eliminated. For example, line hydraulic pressure P_LCurrent D during the shift period of the linear solenoid valve SLT for controlling the_SLTTo the correction value k (DDN_IN-DDN_IN1), And the back pressure (= P) corrected by learning in the next clutch-to-clutch shift._L) Is accumulator A_B1And A_C1To suppress tie-up. The above DDN_IN1Is the target tie-up amount (degree), that is, the maximum value of the allowable tie-up amount. Therefore, for example, in a 4 → 3 downshift, an integrated value DDN indicating the tie-up degree_INIs the target tie-up amount DDN_IN1If the driving current D is larger than_SLTCorrection value k (DDN_IN-DDN_IN1) To increase the engagement pressure P of the clutch C1._C1And the input shaft rotation speed N due to the engagement of the clutch C1 is reduced._INTie-up degree DDN_INThe larger is the slower.
[0040]
The overshoot determining means 162 determines the input shaft rotational speed N during the clutch-to-clutch shift period._INIs N in a rotational speed after a shift, for example, a 4 → 3 downshift._O× G₃(However, G₃Indicates the occurrence of an overshoot S (see FIG. 8) that temporarily exceeds the speed ratio of the automatic transmission 14 in the third gear, and determines the magnitude (amplitude) A of the overshoot S._OIs a predetermined criterion value A₁Judgment is made based on exceeding. The overshoot occurrence time determination means 164 calculates the overshoot S occurrence time (width) T_OIs a predetermined criterion value T₁It is determined whether or not: The overshoot-related control inhibiting means 166 determines the overshoot S occurrence time T_OIs a predetermined criterion value T₁If it is determined to be less than the above, the overshoot-related control executed in connection with the occurrence of the overshoot S determined by the overshoot determination means 162, for example, the execution of the overshoot learning control 148 is prohibited. I do. When a strong tie-up occurs, in the engagement-side hydraulic frictional engagement device which causes the tie-up, for example, in a 4 → 3 downshift, the clutch C1 is pulled up by early engagement so that the input rotational speed N_INOvershoot S also occurs at the same time._OTakes advantage of the fact that the overshoot S is shorter than the normal overshoot S, and even if the overshoot S is determined by the overshoot determining means 162, the time width T_OIs the criterion value T₁In the following cases, it is determined that it is not normal overshoot, and the overshoot-related control is prohibited.
[0041]
The overshoot occurrence time determination means 164 determines the actual size (amplitude or height) A of the overshoot S from the relationship stored in advance._OCriterion value T based on₁Is determined in advance, and the overshoot occurrence time T_OIs the criterion value T₁It is to determine whether or not: Since a normal overshoot has a certain relationship between its size and width (occurrence time), the previously stored relationship is obtained by experiment.
[0042]
The overshoot learning control means 148 determines the overshoot S occurrence time T by the overshoot occurrence time determination means 164._OIs the criterion value T₁If it is determined that the overshoot S is larger than_O, The next engagement pressure is corrected so that the overshoot of the engagement pressure of the hydraulic friction engagement device during the clutch-to-clutch shift period is eliminated. For example, for example, in a 4 → 3 downshift, the magnitude A indicating the overshoot amount_OIs the target overshoot amount A₁If the driving current D is larger than_SLTCorrection value k (A_O-A₁) To reduce the engagement pressure P of the clutch C1._C1And the input shaft rotation speed N due to the engagement of the clutch C1 is increased._INOvershoot amount A_OThe larger is the faster.
[0043]
Hereinafter, a main part of the control operation of the shift electronic control device 20 will be described with reference to FIG. FIG. 9 shows a 4 → 3 downshift learning correction routine executed during a power-on 4 → 3 downshift.
[0044]
In FIG. 9, SA1 corresponding to the input shaft rotational speed synchronization immediately before determining means 152, the input shaft rotational speed N at the time of 4 → 3 downshift._INIs the synchronous rotation speed, ie, G₃× N_OA predetermined value (for example, a value of about 50 rpm) α₃× N_O-Α) is determined. The predetermined value corresponds to a lower limit value of a region where tie-up is expected to occur. Initially, the determination of SA1 is denied, so that in SA2 corresponding to the first derivative value calculation means 154, the input shaft rotation speed N_INFirst derivative DN_INAre sequentially calculated. Next, at SA3 corresponding to the primary differential value determination means 156, the primary differential value DN calculated at SA2 is obtained._INIs a predetermined criterion value A₁Is determined.
[0045]
Initially, the determination at SA3 is denied, so the integrated value DDN is determined at SA4 corresponding to the clearing means 158._INIs cleared to zero. Therefore, the input shaft rotation speed N_INEven if the first derivative DN_INIs the criterion value A₁Is exceeded, it does not exceed continuously, so the determination of SA3 is denied and the integrated value DDN is again_INIs cleared to zero. However, a 4 → 3 downshift, which is a clutch-to-clutch shift, proceeds, and the input shaft rotation speed N_INIs raised to the first derivative DN_INIs larger, the determination in SA3 is affirmative, so that in SA5 corresponding to the integrating means 160, the primary differential value DN calculated in SA2 is obtained._INIs started. T in FIG.₂The time point indicates this state. The broken line in FIG. 6 indicates the input shaft rotation speed N when no tie-up occurs._INIs shown.
[0046]
Next, in SA8 corresponding to the overshoot determination means 162, the occurrence of overshoot S_OIs a predetermined criterion value A₁The determination is made based on whether or not the above has been achieved. When a normal tie-up occurs, the judgment in SA8 is denied, so that the overshoot learning control of SA11 is prohibited in SA9 corresponding to the overshoot-related control prohibiting means 166, and then this routine is repeated. As a result, as shown in FIG._INAre sequentially integrated, and the integrated value DDN_INAre sequentially increased. The input shaft rotation speed N shown in FIG._INThe points on the line indicating are sampling points.
[0047]
While the above steps are repeatedly executed, the input shaft rotation speed N_INIs the synchronous rotation speed (G₃× N_O-Α), when the determination of SA1 is affirmative, the integrated value DDN indicating the degree of tie-up is obtained in SA6 corresponding to the tie-up determination means 153._INIs a preset tie-up determination reference value B.₁Is determined. If the determination in SA6 is denied, since learning control for suppressing tie-up is not required, SA8 is not executed and SA8 and subsequent steps are executed.
[0048]
However, if the determination in SA6 is affirmative, in SA7 corresponding to the tie-up learning control means 146, the transient pressure of the clutch C1 during the 4 → 3 shift, that is, the engagement pressure P_C1A that controls the_C1Pressure P acting as back pressure_LSignal D for controlling the linear solenoid valve SLT for controlling the_SLTIs the integrated value DDN indicating the tie-up degree for the next 4 → 3 shift._INIs corrected based on That is, D_SLT= D_SLT+ K (DDN_IN-DDN_IN1) Is calculated.
[0049]
If the determination of SA8 is affirmative due to the occurrence of a normal overshoot S instead of the tie-up or the occurrence of an overshoot S related to the occurrence of a strong tie-up, the overshoot occurrence time determination means 164 , The width of the overshoot S, that is, the occurrence time T_OIs a predetermined criterion value T₁Is determined. This criterion value T₁Is a value for judging whether the overshoot S is the normal overshoot S or the overshoot S related to the occurrence of a strong tie-up. Amplitude or height) A_OIs determined based on
[0050]
If the determination in SA10 is denied, it is considered that the overshoot S is related to the occurrence of a strong tie-up, and thus the overshoot learning control is prohibited in SA9. Since it is considered to be the chute S, in SA11 corresponding to the overshoot learning control means 148, the transient pressure, ie, the engagement pressure P, of the clutch C1 at the time of 4 → 3 shift._C1A that controls the_C1Pressure P acting as back pressure_LSignal D for controlling the linear solenoid valve SLT for controlling the_SLTIs the magnitude A indicating the degree of the overshoot for the next 4 → 3 shift._OIs corrected based on That is, D_SLT= D_SLT−k (A_O-A_O1) Is calculated.
[0051]
As described above, according to the present embodiment, during the 4 → 3 downshift period, which is the clutch-to-clutch shift, the input shaft rotation speed N is determined by the primary differential value calculation means 154 (SA2)._INFirst derivative DN_INWhen sequentially calculated, the integration unit 160 (SA5) uses the first derivative DN_INAre successively integrated to obtain an integrated value DDN_INIs calculated, and the integrated value DDN is calculated._INIs output as an amount indicating the degree of tie-up, the degree of tie-up occurring during the clutch-to-clutch shift period can be suitably obtained. Therefore, in the learning control for eliminating the tie-up by the tie-up learning control means 146 and improving the shift feeling, the learning correction amount k (DDN) corresponding to the degree of the tie-up is set._IN-DDN_IN1) Can be determined, so that the tie-up can be quickly converged.
[0052]
Further, according to the present embodiment, the input shaft rotation speed N sequentially calculated by the primary differential value calculation means 154 (SA2)._INFirst derivative DN_INIs a predetermined criterion value A₁The primary differential value determining means 156 (SA3) which sequentially determines whether or not the input shaft rotation speed is equal to or less than the input shaft rotational speed N is determined by the primary differential value determining means 156._INFirst derivative DN_INIs a predetermined criterion value A₁If it is determined that the value is below, a clearing unit 158 (SA4) for clearing the integrated value of the integrating unit 160 to zero is further provided. By doing so, the input shaft rotation speed N when a tie-up occurs_INFirst derivative DN_INIs integrated, so that integration in the case of non-tie-up is prevented, and the reliability of the obtained degree of tie-up is further enhanced.
[0053]
Further, according to the present embodiment, the input shaft rotation speed N during the 4 → 3 downshift period which is the clutch-to-clutch shift._INIs the rotational speed G after shifting₃× N_OOvershoot determination means 162 (SA8) for determining the occurrence of overshoot S that temporarily exceeds_OIs a predetermined criterion value T₁The overshoot occurrence time determining means 164 (SA10) for determining whether or not the following conditions are satisfied, and the overshoot occurrence time T_OIs a predetermined criterion value T₁If it is determined to be less than the above, the overshoot related control prohibiting means 166 (SA9) for prohibiting the overshoot related control executed in connection with the overshoot determining means 162 determining that the overshoot has occurred. Are further provided. When a strong tie-up occurs, the clutch is pulled up by the early engagement of the clutch C1, which is the cause of the tie-up, so that the input rotational speed N_INOvershoot occurs simultaneously. However, with the above configuration, even if the occurrence of overshoot is determined, overshoot-related control executed by the overshoot-related control prohibiting means 166 in connection with the determination of occurrence of overshoot is performed. Since the control, that is, the execution of the overshoot learning control means 148 is prohibited, the overshoot-related control is not performed when tie-up should be dealt with.
[0054]
Further, according to the present embodiment, the integrated value DDN output from the integrating means 160 and indicating the degree of tie-up is provided._INBased on the engagement pressure P of the clutch C1 during the 4 → 3 downshift period._C1Is provided by the tie-up learning control means 146 (SA7) for correcting the tie-up so that the tie-up is eliminated. Therefore, a suitable shift feeling can be obtained.
[0055]
Further, according to the present embodiment, the overshoot occurrence time determination means 164 (SA10) determines the magnitude (amplitude or height) A of the overshoot S._OCriterion value T based on₁Is determined in advance, and the occurrence time T of the overshoot S is determined._OIs the criterion value T₁It is to determine whether or not: The normal overshoot S has the magnitude A_OAnd width (occurrence time) T_OThere is a certain relation between the overshoot S and the overshoot S caused by the strong tie-up._OWidth T for_OIs small. According to the above, there is an advantage that the overshoot S generated due to a strong tie-up is more reliably determined.
[0056]
Further, according to the present embodiment, the overshoot occurrence time T_OIs the criterion value T₁If it is determined that the overshoot S is larger than_OBased on the engagement pressure P of the clutch C1 during the 4 → 3 downshift period._C1Is provided, the overshoot learning control means 148 (SA11) is provided to correct the overshoot S so that the overshoot S is eliminated. Therefore, a suitable shift feeling can be obtained.
[0057]
As described above, one embodiment of the present invention has been described with reference to the drawings. However, the present invention can be applied to other aspects.
[0058]
For example, in the above-described embodiment, a 4-to-3 downshift that is a clutch-to-clutch shift has been described, but a 3-to-4 upshift may be used.
[0059]
Further, in the automatic transmission 14 of the above-described embodiment, the clutch-to-clutch shift is provided between the third speed gear and the fourth speed gear door. A clutch-to-clutch speed change between them may be used.
[0060]
Although the automatic transmission 14 of the above-described embodiment is configured as the fourth forward speed, the automatic transmission 14 may be configured as the third forward speed or the fifth forward speed.
[0061]
Further, the tie-up learning control means 153 and the overshoot learning control means 148 of the above-described embodiment are provided with an engagement pressure P of the clutch C1, which is an engagement-side hydraulic friction engagement device in a 4 → 3 downshift._C1Learning correction, but the engagement pressure P of the brake B1 which is the hydraulic friction engagement device on the release side in the 4 → 3 downshift._B1May be learned and corrected.
[0062]
The above is merely an example of the present invention, and the present invention can be variously modified without departing from the gist of the present invention.
[Brief description of the drawings]
FIG. 1 is a diagram illustrating a configuration of a vehicle power transmission device including a control device according to an embodiment of the present invention.
FIG. 2 is a diagram illustrating a shift speed achieved by a combination of operations of a friction engagement device provided in the automatic transmission of FIG. 1;
FIG. 3 is a block diagram schematically illustrating a main configuration of a hydraulic control device that controls the automatic transmission of FIG. 1;
FIG. 4 is a hydraulic circuit diagram specifically illustrating a hydraulic circuit configuration of the source pressure generating device of FIG.
5 is a functional block diagram for explaining a main part of a control function of the electronic control unit for shifting shown in FIG. 1;
FIG. 6 is a time chart for explaining an operation of a 4 → 3 downshift in the shift electronic control device of FIG. 1;
7 is a time chart illustrating a line corresponding to the tie-up, which is a line indicating the input shaft rotation speed in FIG. 6, and an integrated value obtained by integrating the primary differential values of the portion.
FIG. 8 is a time chart for explaining an overlap occurring at the time when the input shaft rotation speed reaches the synchronous rotation in FIG. 6;
9 is a flowchart illustrating a control operation of the shift electronic control device of FIG. 1, and is a diagram illustrating a 4 → 3 downshift learning correction routine.
[Explanation of symbols]
14: Automatic transmission
80: Input shaft rotation speed sensor (input shaft rotation speed detection device)
154: primary differential value calculating means
156: primary differential value determination means
158: Clearing means
160: integration means
162: overshoot determination means
164: Overshoot occurrence time determination means
166: Overshoot-related control prohibition means
C1: clutch, B1: brake (hydraulic friction engagement device)

Claims (3)

In a vehicular automatic transmission in which one gear is selected from a plurality of gears according to a combination of operations of a hydraulic friction engagement device, a pair of hydraulic friction engagement devices involved in clutch-to-clutch shifting are provided. A control device of a type that performs the opening of the release-side hydraulic friction engagement device and the engagement of the engagement-side hydraulic friction engagement device in an overlapping manner,
An input shaft rotation speed detection device that detects an input shaft rotation speed of the automatic transmission,
In the clutch-to-clutch shift period, a primary differential value calculating means for sequentially calculating a primary differential value of the input shaft rotational speed detected by the input shaft rotational speed detection device,
The integrated value of the primary differential value of the input shaft rotational speed is calculated by integrating the primary differential value of the input shaft rotational speed sequentially calculated by the primary differential value calculating means, and the first differential value is calculated during the clutch-to-clutch shift period. as a quantity indicating the degree of temporary lowering a tie-up which tie up increases as increases the output shaft torque of the automatic transmission caused by the overlap of the engaged state of the hydraulic friction engagement device pair, the Integrating means for outputting an integrated value of the first derivative ,
The engagement of the hydraulic friction engagement device during the clutch-to-clutch shift period is determined based on the amount indicating the degree of tie-up represented by the integrated value of the primary differential value of the input shaft rotation speed output from the integrating means. A control device for an automatic transmission for a vehicle, comprising: shift transient control means for controlling a combined pressure . Primary differential value determining means for sequentially determining whether the magnitude of the primary differential value of the input shaft rotation speed sequentially calculated by the primary differential value calculating means is equal to or less than a predetermined reference value,
Clearing means for clearing the integrated value of the integrating means to zero when the primary differential value determining means determines that the primary differential value of the input shaft rotation speed is equal to or less than a predetermined reference value. The control device for an automatic transmission for a vehicle according to claim 1, further comprising: Overshoot determining means for determining occurrence of overshoot in which the input shaft rotational speed temporarily exceeds the rotational speed after the shift during the clutch-to-clutch shift period;
Overshoot occurrence time determining means for determining whether or not the overshoot occurrence time is equal to or less than a predetermined reference value;
If the overshoot occurrence time determining means determines that the overshoot time is equal to or less than a predetermined reference value, the overshoot determining means determines that overshoot has occurred. The control device for an automatic transmission for a vehicle according to claim 1 or 2, further comprising an overshoot-related control prohibiting unit that prohibits the executed overshoot-related control.

Images