JP3818600B2 - Braking control device for vehicle with automatic transmission - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to a braking control device for a vehicle with an automatic transmission.
[0002]
[Prior art]
A shift shock at the time of shifting (for example, upshifting) of the automatic transmission is caused by engagement of frictional engagement elements (clutch or brake) in the automatic transmission, so that the rotational speeds on the input side and the output side of the automatic transmission This occurs when the ratio (gear ratio) is switched instantaneously and the output shaft torque fluctuates.
[0003]
The output shaft torque at the time of shifting changes depending on the transmission torque (time change thereof) when the friction engagement element is engaged. The transmission torque of the friction engagement element is determined mainly depending on the hydraulic pressure when the friction engagement element is engaged. Accordingly, if the engagement hydraulic pressure is adjusted to a low value, the absolute value of the transmission torque at the friction engagement element or its change can be reduced, so that the shift shock can be reduced. That is, since the shift time is long (sliding time is long), the durability of the friction engagement element is lowered.
[0004]
Conversely, if the engagement hydraulic pressure is set to a high value, the transmission torque at the friction engagement element also increases, so the shift shock increases, but the engagement is completed in a short time, so the durability is improves.
[0005]
In view of such a point, as one method for reducing the shift shock at the time of shifting, conventionally, the engagement hydraulic pressure that directly defines the change mode of the output shaft torque is changed according to the degree of progress of shifting. For example, a method has been proposed in which, for example, a peak or a dip that causes a sensation in the fluctuation of the output shaft torque is avoided as much as possible (while the shift time itself does not become long).
[0006]
Although this method is a relatively effective method, a linear solenoid valve and its drive circuit for controlling the engagement hydraulic pressure with high responsiveness in accordance with the progress of the shift, a sensor for checking the progress of the shift (in the timer) A sufficient accuracy cannot be expected), and the system becomes expensive.
[0007]
By the way, in general, when the accelerator is depressed and the generated torque of the engine is high, if the engagement hydraulic pressure remains the same, the shift time becomes longer and the durability of the friction engagement element is reduced. When the opening degree is large and the generated torque of the engine is high, the pressure is adjusted to a high level.
[0008]
Therefore, as another method for reducing the shift shock focusing on this point, for example, Japanese Patent Application Laid-Open No. 59-97350 has proposed that the generated torque of the engine itself is lowered during the shift. . As is clear from the above description, if the hydraulic control device (engagement hydraulic pressure generated in the same) is the same, even if the engine torque is reduced, only the shift time is shortened (only the durability is improved). ) Shift shock cannot be reduced.
[0009]
However, in anticipation of the engine torque being reduced, if the design is changed so that the hydraulic control device (engagement hydraulic pressure generated in) is adjusted in advance to a low pressure, this can reduce the shift shock. It becomes possible. Even if the hydraulic pressure is adjusted to a low level, the torque generated by the engine is reduced, so that the shift time can be shortened and the durability of the friction engagement element is ensured.
[0010]
However, this method of reducing the engine torque at the time of shifting requires the development and design change of a hydraulic control device corresponding to the reduction of the engine torque, and the reduction of the engine torque is not always possible. It was. For example, if the engine torque is reduced when it is cold, there is a risk of misfire. In addition, when the engine torque is reduced by retarding control, the exhaust system temperature tends to rise due to increased afterburning. Therefore, if the exhaust system temperature becomes too high, the catalyst is protected. As a result, it may become impossible to further retard the ignition.
[0011]
As described above, if the reduction of the engine torque at the time of shifting is simply stopped when the reduction of the engine torque cannot be executed for some reason, the hydraulic control device can reduce the engine torque as described above. Since it is designed to be engaged at a low hydraulic pressure in advance, the engagement time (shifting time) becomes very long and the durability is significantly impaired.
[0012]
Therefore, under the present circumstances, it is a fact that a unique method for reducing the shift shock has not yet been determined, including costs and durability of the frictional engagement elements.
[0013]
In JP-A-2-2005540, when the engine torque cannot be reduced during a shift for some reason, the shift shock cannot be reduced. Therefore, the braking device is operated to brake the driving wheel instead. Techniques for doing so have been proposed.
[0014]
[Problems to be solved by the invention]
However, the technique disclosed in the above Japanese Patent Application Laid-Open No. 2-2005540 is as follows: “When reducing the engine torque (there is no fear of a shift shock), the hydraulic pressure is adjusted to“ high ”. When it is impossible to reduce the hydraulic pressure, it is said that “the brake is activated while the hydraulic pressure is stopped (ie, the hydraulic pressure is adjusted to a low pressure)”, and the basic technology There were some doubtful contents in the explanation of the thought, and there was no disclosure of how to apply braking force, etc., so there was no content that could be said to have provided effective technology when adopted in actual vehicles It was.
[0015]
The present invention has been made in view of the above-described situation regarding the technology for reducing the shift shock, and ensures the shock during the shift at a relatively low cost (regardless of the torque reduction of the engine). An object of the present invention is to provide a braking control device for a vehicle with an automatic transmission that can be reduced.
[0016]
[Means for Solving the Problems]
  As shown in FIG. 1, the invention described in claim 1 is an automatic transmission comprising an automatic transmission and means capable of applying a braking force to drive wheels independently of a driver's brake operation. Shifting of an automatic transmission in a braking control device for a vehicle equipped with a machineInertia phase startedPredetermined related toseasonMeans for detecting, means for detecting the type of shift, means for detecting the engine demand output,Means for detecting the actual acceleration of the vehicle, means for detecting the degree of progress of the shift, means for setting the target acceleration in accordance with the degree of progress of the shift, the type of shift, and the engine required output;Means for setting a braking force at the time of shifting capable of controlling a change mode of acceleration of the vehicle at the time of shifting to a desired mode;Means for correcting the shifting braking force in real time by the difference between the actual acceleration and the target acceleration;The above-mentioned problem is solved by applying the braking force at the time of shifting to the drive wheel from the predetermined time.
[0017]
  The invention described in claim 2In the invention of claim 1,The detection of the shift type includes at least detection of whether or not the shift is an upshift.In addition, there is a high means for detecting the progress of the shift.Detecting the hydraulic pressure value of the fast friction engagement elementSteppedWhen upshifting,Target accelerationIn addition to the shift type and engine demand output,in frontHydraulic pressure value of high-speed stage friction engagement elementAccording toSimilarly, the above-described problem is solved.
[0018]
  The invention according to claim 33. The invention according to claim 1, wherein the target acceleration is set depending on an actual acceleration before the start of shifting.This also solves the above-mentioned problem.
[0019]
  The invention according to claim 4In a braking control device for a vehicle with an automatic transmission that includes an automatic transmission and means capable of applying a braking force to the drive wheels independently of the driver's brake operation, the inertia phase of the automatic transmission shift is started. A means for detecting a related predetermined time, a means for detecting a shift type, a means for detecting an engine request output, and a change mode of the acceleration of the vehicle at the time of the shift according to the shift type and the engine request output. At least one of a means for setting a braking force during shifting that can be controlled to a desired mode, a means for detecting the actual acceleration of the vehicle, a means for detecting the degree of progress of shifting, and a means for detecting the hydraulic value of the high-speed friction engagement element The detection of the shift type includes at least detection of whether or not the shift is an upshift. In the case of an upshift, the shift braking force is determined in addition to the shift type and the engine request output. Set according to at least one of the degree of progress of the shift and the hydraulic value of the high-speed friction engagement element, and when the shift type is a power-off upshift and the actual acceleration is negative, The shifting braking force is applied from the predetermined timing, but the shifting braking force is not applied when the shift type is a power-off upshift and the actual acceleration is positive.This also solves the above-mentioned problem.
[0020]
  The invention described in claim 5The invention according to claim 4 further includes means for detecting the actual output shaft torque of the automatic transmission, means for setting the target output shaft torque in accordance with the type of the shift and the required output of the engine, and the actual output shaft. The above problem is also solved by providing means for correcting the braking force during shifting depending on the difference between the torque and the target output shaft torque.
The invention according to claim 6 is the invention according to claim 4, further comprising means for setting a target acceleration in accordance with the type of the shift and the engine required output, and the shift timing according to the difference between the actual acceleration and the target acceleration. The above-mentioned problem is solved by providing the means for correcting the power.
The invention according to claim 7 solves the above-mentioned problem in the invention according to claim 6 by setting the target acceleration in accordance with the actual acceleration before the start of shifting.
[0021]
[Action]
In the present invention, the shift shock is reduced by applying a braking force to the drive wheels when the automatic transmission is in the shifting process. In this case, the engine torque reduction control does not necessarily have to be associated, and the braking force is set according to the type of shift and the engine request output so that the vehicle acceleration change mode becomes a desired mode. The
[0022]
Here, the type of shift is a distinction between an upshift or a downshift, a shift between when the accelerator is depressed or a shift when the accelerator is released, or from what speed stage to what speed stage. This refers to the distinction between shifting and the like.
[0023]
The engine demand output indicates the generated torque required by the driver for the engine. Specifically, the accelerator pedal opening, throttle opening, engine intake air amount, intake pipe negative pressure, fuel injection amount Alternatively, it can be obtained from the relationship between these and the engine speed.
[0024]
“Making the acceleration of the vehicle in a desired mode” may be considered synonymous with “making the rotational acceleration of a specific member of the automatic transmission in a desired mode”. In addition, in this case, it may be considered synonymous to “make the output shaft torque have a desired mode” of the automatic transmission. This is because the acceleration of the vehicle, the rotational acceleration of a specific member of the automatic transmission, and the output shaft torque of the automatic transmission all show similar change characteristics.
[0025]
In the case of the present invention, the engagement hydraulic pressure itself generated in the hydraulic control device is basically not changed at all. That is, the present invention is basically intended to reduce the shift shock without changing the hydraulic control device in the automatic transmission at all.
[0026]
However, the present invention prevents the combined use of the known technology for reducing engine torque at the time of shifting (although it can be applied to a vehicle that does not have a control mechanism for reducing engine torque at all). is not. However, in this case, when the engine torque is reduced, the engagement hydraulic pressure of the friction engagement element is adjusted to “low”, and when the engine torque is not reduced for some reason, the control to adjust to this “low” is performed. Is stopped and the pressure is adjusted to the normal engagement hydraulic pressure. This tendency is in the opposite direction to the technique disclosed in Japanese Patent Laid-Open No. 2-2005540.
[0027]
During upshifting, if the braking force during shifting is set depending on the type of shifting, the required engine output, the degree of progress of shifting, or the hydraulic pressure value of the high-speed friction engagement element, An increase in vehicle driving force (output shaft torque) in the vicinity of the engagement of the high-speed stage frictional engagement element can be reliably prevented, and a smoother shift can be achieved.
[0028]
When the actual output shaft torque of the automatic transmission is detected, the target output shaft torque is set according to the type of shift and the required output of the engine, and the braking force is corrected according to this difference, the engine torque The shift shock can be reliably reduced regardless of the product variation such as the efficiency of the automatic transmission, the friction coefficient between the brake pad and the brake disc, and the like.
[0029]
Instead of correcting the braking force during shifting depending on the difference between the actual output shaft torque and the target output torque, the actual acceleration of the vehicle is detected and the target acceleration is set according to the type of shift and the required output of the engine. The same effect can be obtained even if the braking force at the time of shifting is corrected based on the difference between the actual acceleration and the target acceleration.
[0030]
In this case, if the target acceleration is set depending on the actual acceleration before the start of the shift in addition to the shift type and the engine request output, the influence of the road surface gradient can be effectively removed.
[0031]
【Example】
Embodiments of the present invention will be described below in detail with reference to the drawings.
[0032]
In FIG. 2, 10 is a brake pedal, 12 is a booster, 14 is a master cylinder, 16 is a reservoir, 18 is a pump for traction control (TRC pump), 20 is a master cylinder cut solenoid valve, 22 is a reservoir cut solenoid valve, 24 and 26 are pumps for the anti-lock brake system (ABS pump), 28, 30, 32 and 34 are three-position solenoid valves, 36 is a front wheel cylinder, and 38 is a rear wheel cylinder.
[0033]
Since this vehicle is a rear wheel drive vehicle, the application of the braking force during shifting according to the present invention is realized by a route using the traction control pump (TRC pump) 18 acting only on the rear wheels. The TRC pump 18 is driven by an electric pump (not shown) driven by a command from a traction control computer (TRC ECU) 80. Normally, it is turned off, and when it is turned on, the oil is pumped from the reservoir 16 and discharged to the oil passage 72 side on the rear wheel cylinder 38 side.
[0034]
The master cylinder cut solenoid valve 20 selectively connects the rear wheel cylinder oil passage 71 to either the TRC pump discharge oil passage 72 or the master cylinder oil passage 73 that generates hydraulic pressure in accordance with the depression force of the brake pedal. This is a (switching) valve. The rear wheel cylinder oil passage 71 and the master cylinder oil passage 73 communicate with each other when the switch is off (position in FIG. 2), and the rear wheel cylinder oil passage 71 and the TRC pump discharge fluid passage 72 communicate with each other when the switch is on. ing.
[0035]
The reservoir cut solenoid valve 22 is a valve that switches between communication and non-communication between the oil passage 74 on the rear wheel cylinder 38 side and the reservoir 16, and is a non-communication when OFF (position in FIG. 2) and a valve that communicates when ON. It is.
[0036]
Of the three-position solenoid valves 28, 30, 32 and 34, the three-position solenoid valves indicated by reference numerals 32 and 34 correspond to the three-position solenoid valves for rear wheel braking according to the embodiment of the present invention.
[0037]
That is, the three-position solenoid valves 32 and 34 are: (1) increase in brake hydraulic pressure by communicating the oil passages 75 and 76 on the rear wheel cylinder 38 side with the oil passage 71 on the master cylinder cut solenoid valve 20 side, (2) Decrease in brake hydraulic pressure by connecting the oil passages 75, 76 on the rear wheel cylinder 38 side with the oil passage 74 on the reservoir cut solenoid valve 22 side, (3) Brake hydraulic pressure by disconnecting both This is a valve that switches between the three positions of holding. The three-position solenoid valves 32 and 34 are driven by a pattern output (pressure increase t1 (ms), pressure decrease t2 (ms)) corresponding to a braking force to be applied, which will be described later. As a result, the rear wheel cylinder 38 The brake hydraulic pressure is determined by the history (integration) of the pattern output. Note that the pressure increasing position is set when OFF.
[0038]
Since the basic hardware configuration of the braking control circuit S that can apply this arbitrary braking force is already known, only this level of explanation will be given here. 2 is a proportional valve, 42, 44, 46, 48, 50, 52, 54, 56, 58, 60, 62 are check valves, and 64, 66 are reservoirs.
[0039]
As shown in FIG. 3, an automatic transmission control computer (ECT ECU) 82 has an engine speed signal from an engine speed sensor 90, a range position signal from an operation position sensor 91 of a driver's shift lever, a foot A foot brake signal from the brake switch 92, a throttle opening signal from the throttle sensor 93, an output shaft speed (vehicle speed) signal from the output shaft speed sensor 94, and the like are input, and a traction control computer (TRC ECU) ) 80 is input with a signal from the wheel speed sensor 97 of the driving wheel.
[0040]
Since the automatic transmission control computer (ECT ECU) 82 determines an appropriate shift stage depending on the throttle opening and the vehicle speed, it can naturally determine the type of shift. The automatic transmission control computer 82 calculates the vehicle acceleration from the output shaft rotation speed information by a method described later.
[0041]
Next, the operation of this embodiment will be described based on the control flow shown in FIG.
[0042]
First, the meaning of the flags F1 to F4 used in this control flow will be described.
[0043]
The flag F1 is a flag that is set to 1 when a solenoid output (shift command) to another gear is detected. That is, it is a flag that is set to 1 when entering the control for applying the braking force during shifting according to the present invention, and set to 0 when leaving.
[0044]
The flag F2 is a flag that is set to 1 when the shift is an upshift and is set to 0 when the shift is a downshift.
[0045]
The flag F3 is 1 when the gear shift is a gear shift that is executed when the power is on (the accelerator is depressed), and is 0 when the gear shift is a gear that is executed when the power is off (the accelerator is released). Flag.
[0046]
The flag F4 is a flag that is set to 1 when the timer for applying the braking force is counting and 0 otherwise when the power-on downshift is executed.
[0047]
The control flow will be specifically described below.
[0048]
In step 102, it is determined whether or not the flag F1 is 1, that is, whether or not the actual braking control is already being executed. In many cases, since the engine is not being executed, the routine proceeds to step 104 where it is determined whether or not a solenoid output to another gear, that is, a new gear shift command has been issued. When the shift command is not detected, the routine proceeds to step 106, where the flag F1 is set to 0, and further, after the flag F4 is set to 0 at step 122, a brake off (non-braking) request is issued to step 124 and returned.
[0049]
Eventually, if any shift command is issued in the automatic transmission, a determination of YES is made in step 104, and the routine proceeds to step 108 where the flag F1 is set to 1. Next, at step 110, it is determined whether or not the shift is an upshift. If it is an upshift, a flag F2 is set to 1 at step 112. If it is a downshift, the routine proceeds to step 114 where the flag F2 is set to zero.
[0050]
In step 116, it is determined whether or not the shift is a shift performed in a power-on state. When the speed change is executed in the power-on state, the flag F3 is set to 1 in step 118. When the speed change is executed in the power-off state, the flag F3 is set to 0 in step 120.
[0051]
In the first flow in which the shift command is detected, after confirming what kind of shift the shift is in this way, the flag F4 is set to 0 in step 122, and then the brake is turned off in step 124. A request is made and returned for the time being.
[0052]
However, the next time this flow is started, the flag F1 is set to 1, so a YES determination is made at step 102 and the routine proceeds to step 130. In steps 130, 132, and 134, flow distribution according to the type of shift is executed.
[0053]
As a result, when the shift is a power-on upshift, the routine proceeds to step 136 where the engine rotational speed Ne is changed to the output shaft rotational speed No of the automatic transmission at the low gear (speed before shifting) side gear ratio i L. It is determined whether or not a substantial shift has started (whether or not an inertia phase has started) by determining whether or not the value is smaller than a value obtained by subtracting the predetermined value N1 from the value multiplied by. Until the inertia phase is started, the routine proceeds to step 152, where the actual acceleration at that time is defined as the actual acceleration G1 before shifting, and is returned through steps 122 and 124.
[0054]
  When it is determined that the inertia phase has been started, the routine proceeds to step 138, where the engine speed Ne is obtained by multiplying the output shaft rotational speed No by the gear ratio iH on the high speed (speed stage after shifting) side to determine the constant N2. TheaddedThan valuesmallIt is determined whether or not Initially stillsmallSince it is not determined that the engine has been lost, a map search is performed for the initial value Tbo of the required brake torque based on the throttle opening TA, the actual acceleration G1 before the shift, and the target acceleration G2 based on the shift progress degree. Brake torque correction based on the difference between the target acceleration G2 and the actual acceleration G3 is performed in real time based on the equation Tb = K (target acceleration G2−actual acceleration G3) + Tbo. A request for braking force is issued.
[0055]
In this case, the target acceleration is determined in real time so as to have the characteristics shown by the broken line in FIG.
[0056]
In this embodiment, the actual acceleration G of the vehicle is detected by calculation from the signal of the output shaft rotational speed sensor (vehicle speed sensor) 94. There are two methods for calculating the acceleration: a constant distance calculation method and a constant time calculation method, both of which are publicly known calculation methods, so only a brief description of the constant distance calculation method will be given here. I will.
[0057]
As shown in FIG. 6, first, a total TGSP2SN for the latest n pulses of the input pulse period (time) TGSP2D of the output shaft rotation speed sensor 94 and a total TGSP2SP for n pulses before n pulses are obtained. Next, the vehicle speeds SPDN and SPDP are respectively obtained from the sum TGSP2SN for the latest n pulses and the sum TGSP2SP for the n pulses before n pulses based on the formula (1).
[0058]
SPDN (P) = (n / TGSP2SN (P) · np) × (2πr / i diff) (1)
[0059]
Here, np is the number of pulses detected by the sensor 94 per rotation of the output shaft, i diff is the differential gear ratio, and r is the tire dynamic load radius.
[0060]
The acceleration G of the vehicle can be obtained by approximation as a change in the vehicle speed during the time TGSP2D. That is, G = (SPDN−SPDP) / TGSP2SN.
[0061]
On the other hand, when the shift type is a power-off upshift, the routine proceeds from step 134 to step 150. Here, first, it is determined whether or not the engine rotational speed Ne is smaller than a value obtained by subtracting a predetermined value N1 from a value obtained by multiplying the output shaft rotational speed No by the gear ratio iL on the low speed stage (speed stage before shifting). By determining, the substantial start of shifting (start of inertia phase) is determined. As long as the inertia phase has not yet started, the routine proceeds to step 152, where the actual acceleration at that time is defined as the actual acceleration G1 before shifting, and is returned through steps 122 and 124. When it is determined that the inertia phase has started, the routine proceeds to step 154, where it is determined whether or not the actual acceleration G1 before the shift is negative. If it is zero or positive, the power is off and the actual acceleration is positive, so it can be determined that the vehicle is traveling on a downhill road. The braking force control is not particularly executed. This is because, when the accelerator is fully closed and the vehicle is accelerating on a downhill road, even if a power-off upshift is executed, almost no shift shock occurs.
[0062]
  On the other hand, when it is determined that the actual acceleration G1 before the shift is negative, the routine proceeds to step 156, where the engine rotational speed Ne becomes the output shaft rotational speed No and the gear ratio on the high speed stage (the speed stage after the shift). The constant N2 from i HaddedThan valuesmallBy determining whether or not the shift has occurred, the vicinity of the end of the shift is detected. If it is determined that the vicinity of the end of the shift has not yet been reached, the routine proceeds to step 158, where a map of the target acceleration G4 based on the initial value Tb 'of the required brake torque and the actual acceleration G1 before the shift is searched. In step 160, the correction of the brake torque due to the difference between the target acceleration G4 and the actual acceleration G3 is performed in real time based on the equation Tb = K (target acceleration G4-actual acceleration G3) + Tb '. A request to brake on (apply braking force) based on the result is issued.
[0063]
When the type of shift is a power-on downshift, the routine proceeds from step 132 to step 170. In step 170, it is determined whether or not the flag F4 is 1. Since it is initially set to 0, the routine proceeds to step 172, where the engine speed Ne is a constant N3 from the value obtained by multiplying the output shaft speed No by the gear ratio iL on the low speed (shifted speed) side. By determining whether or not the value is larger than the value obtained by subtracting, the vicinity of the substantial shift end of the power-on downshift is detected.
[0064]
Initially, since this determination is NO, the process is returned as it is through steps 122 and 124. However, when it is determined that the end of the shift has been reached, the routine proceeds to step 174 where the flag F4 is set to 1. In step 176, the timer T2 is reset and the count-up is started. In step 178, it is determined whether or not the timer T2 is smaller than the predetermined value t3. As long as it is determined that the timer T2 is smaller, the routine proceeds to step 180, where a calculation processing routine for the required brake torque based on the throttle opening TA is executed. Based on the result, a request to brake on (apply braking force) is issued in step 144.
[0065]
Once the flag F4 is set to 1 in step 174, the determination in step 170 is YES in the subsequent flow, so the process proceeds directly to step 178, where it is determined whether the timer T2 is smaller than the predetermined value t3. To be judged. Eventually, when it is determined that the timer T2 has become larger than the predetermined value t3, the process returns via steps 106, 122, and 124, and the braking force control during the power-on downshift is terminated.
[0066]
When the shift type is a power-off downshift, the routine proceeds from step 132 to step 190, where the flag F1 is reset to 0, and the routine returns directly through step 124. That is, when the shift type is a power-off downshift, no braking force control is executed. This is because a shift shock hardly becomes a problem during a power-off downshift.
[0067]
In the above-described embodiment, the braking force is feedback-corrected in real time based on the actual acceleration G3 of the vehicle or the difference between G4 and the target acceleration G1, but this is applied to the actual output shaft torque and the target output shaft. It is good also as a structure which performs feedback correction | amendment based on the difference with a torque.
[0068]
Note that FIG. 7 shows a shift command of the automatic transmission and the on / off time chart of each device of the braking control device when this control flow is executed.
[0069]
Although the present invention can basically be executed independently (independently) of engine torque control at the time of shifting, as described above, the present invention and engine torque control at the time of shifting are used together. Is possible. In this case, specifically, in the case of a power-on upshift, when NO is determined in step 138 of FIG. 4, in the case of a power-off downshift, in the case where NO is determined in step 156, step 140 is performed. , 142, or steps 158 and 160, respectively, and the engine torque may be reduced. In the case of a power-on downshift, the engine torque may be reduced in parallel with the processing of step 180 when YES is determined in step 178.
[0070]
When engine torque reduction is executed, the hydraulic control device of the automatic transmission is adjusted to a lower pressure. As a result, it is possible to achieve further reduction in shift shock without lengthening the shift time (without reducing the durability of the friction engagement element).
[0071]
In the present invention, it goes without saying that real-time engagement pressure control at the time of shifting using a linear solenoid may be used in combination.
[0072]
【The invention's effect】
As described above, according to the present invention, it is possible to always reduce the shift shock without changing the hydraulic control system of the automatic transmission, and without being restricted such that it cannot be executed when it is cold, for example. The effect of being able to do is obtained.
[Brief description of the drawings]
FIG. 1 is a block diagram showing the gist of the present invention.
FIG. 2 is a schematic diagram showing the configuration of a vehicle braking control apparatus to which the present invention is applied.
FIG. 3 is a block diagram showing input states of various sensors.
FIG. 4 is a flowchart showing a control flow executed in the embodiment.
FIG. 5 is a diagram showing characteristics of a target acceleration (output shaft torque) of a vehicle
FIG. 6 is a diagram for explaining a method of calculating actual acceleration from a vehicle speed sensor.
FIG. 7 is a time chart showing a shift command of the automatic transmission and on / off of each device of the braking control device.
[Explanation of symbols]
10 ... Brake pedal
14 ... Master cylinder
16 ... Reservoir
18 ... TRC pump
20 ... Master cylinder cut solenoid valve
22 ... Reservoir cut solenoid valve
24, 26 ... ABS pump
28, 30, 32, 34 ... 3-position solenoid valve
36 ... Front wheel cylinder
38 ... Rear wheel cylinder (wheel cylinder of drive wheel)

Claims (7)

In a braking control device for a vehicle with an automatic transmission, including an automatic transmission and means capable of applying a braking force to the drive wheels independently of a driver's brake operation,
Means for detecting a predetermined time related to the start of the inertia phase of the shift of the automatic transmission;
Means for detecting the type of shift;
Means for detecting the engine demand output;
Means for detecting the actual acceleration of the vehicle;
Means for detecting the degree of progress of the shift;
Means for setting a target acceleration according to the degree of progress of the shift, the type of shift, and the engine demand output;
Means for setting a braking force at the time of shifting capable of controlling a change mode of acceleration of the vehicle at the time of shifting to a desired mode;
Means for correcting the braking force during shifting in real time based on the difference between the actual acceleration and the target acceleration ,
A braking control device for a vehicle with an automatic transmission, wherein the braking force is applied to the driving wheel from the predetermined time. In claim 1,
The detection of the shift type includes at least detection of whether the shift is an upshift, and further
Means for detecting the degree of progress of the gear shift is a hydraulic value of the detection means of the high-speed stage friction engaging elements,
In an upshift, the target acceleration is set according to the type of shift, the engine demand output, and the hydraulic pressure value of the high-speed stage friction engagement element . In claim 1 or 2 ,
A braking control apparatus for a vehicle with an automatic transmission , wherein the target acceleration is set depending on an actual acceleration before the start of shifting. In a braking control device for a vehicle with an automatic transmission, including an automatic transmission and means capable of applying a braking force to the drive wheels independently of a driver's brake operation,
Means for detecting a predetermined time related to the start of the inertia phase of the shift of the automatic transmission;
Means for detecting the type of shift;
Means for detecting the engine demand output;
Means for setting a braking force at the time of shifting that can control a change mode of the acceleration of the vehicle at the time of shifting to a desired mode according to the type of the shift and the engine request output;
Means for detecting the actual acceleration of the vehicle;
Comprising at least one of means for detecting the degree of progress of the shift and means for detecting the hydraulic value of the high-speed friction engagement element;
The detection of the type of shift includes at least detection of whether the shift is an upshift,
At the time of upshift, the braking force at the time of shifting is set according to at least one of the type of shifting, the engine request output, the degree of progress of shifting and the hydraulic value of the high-speed friction engagement element,
When the shift type is a power-off upshift and the actual acceleration is negative, the driving wheel is applied with the braking force during the shift from the predetermined time, but the shift type is a power-off upshift. And when the actual acceleration is positive, the braking force during shifting is not applied.
A braking control device for a vehicle with an automatic transmission. In claim 4, further:
Means for detecting the actual output shaft torque of the automatic transmission;
Means for setting a target output shaft torque according to the type of shift and the required output of the engine;
Means for correcting the shifting braking force depending on the difference between the actual output shaft torque and the target output shaft torque;
A braking control device for a vehicle with an automatic transmission, comprising: In claim 4, further:
Means for setting a target acceleration in accordance with the type of shift and the required engine output;
Means for correcting the shifting braking force by the difference between the actual acceleration and the target acceleration;
A braking control device for a vehicle with an automatic transmission, comprising: In claim 6,
A braking control apparatus for a vehicle with an automatic transmission, wherein the target acceleration is set in accordance with an actual acceleration before the start of shifting.

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