JP2910384B2 - Transmission control device for automatic transmission - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shift control device for an automatic transmission.

[0002]

2. Description of the Related Art An automatic transmission selects a corresponding shift speed by selectively engaging various friction elements, and shifts to another shift speed by switching engagement / release of a friction element. By the way, if the engagement of the friction element and the release of the other friction elements are not performed in a timely manner during this shift, the engine may run idle,
This causes the pull-in of the torque, causing a large shift shock or deteriorating the shift feeling.

[0003]

Therefore, the present applicant has
Previously, Japanese Patent Application No. 3-23903 has proposed a shift control device which enables the engagement and release of a friction element to be performed with good timing. According to this, it is possible to realize a smooth shift so that the engine does not run idle and a deep torque is not drawn in as compared with the related art. Then
Considering the following points, the above technology has room for improvement in driving performance. That is, at the time of gear shifting, the release-side friction element is controlled so that the amount of idling of the transmission input rotation becomes an appropriate value, and the engagement-side friction element is engaged while controlling the release progression. In the control of the engagement side, if the engagement side ramp is set to one step or a step input, in order to reduce the pull-in of the torque, for example, in the case of the ramp control, it is difficult to increase the ramp speed so much. Therefore, the shift lug (driver from shifting command is time to feel the shift start, corresponds to the time from the shift command at t ₁ in FIG. 7 from A) becomes more acute. In view of the relationship with the throttle opening, when the throttle opening is small, it is better to make the ramp in the inertia phase small and fasten it smoothly.However, the ramp is uniform throughout the torque phase and the inertia phase. If the ramp is extended and the torque phase ramp is determined to be the same (ie, smaller), the shift lag becomes longer by that amount,
Conversely, when the throttle opening is large, it is desired to increase the ramp in the inertia phase to prevent air blowing. However, by extending this ramp, the ramp in the torque phase is made the same (ie,
If it is determined to be large, the pulling torque becomes large.

[0004] An object of the present invention is to further improve from such a point, and it is possible to alleviate the above-mentioned restrictions on the pull-in of the torque and the shift lag, and to achieve both of them. An object of the present invention is to provide a shift control device for a transmission.

[0005]

According to the present invention, there is provided the following shift control device for an automatic transmission. When shifting is performed by engaging and releasing the plurality of friction elements by supplying and discharging the working fluid pressure to and from the plurality of friction elements, the first control is performed until engagement of the engaged friction element is started. A coupling element control unit that supplies the working fluid pressure to the friction element to be coupled based on the second control amount during a period from immediately after the start to the time when the friction element is coupled to the friction element to be coupled; Release element control means for discharging the working fluid pressure from the released friction element so that the rotational idling becomes a predetermined amount until the engagement is started. The second control amount is set by a ramp whose inclination increases as the throttle opening increases.

[0006]

According to the present invention, the plurality of friction elements are fastened by supplying / discharging the working fluid pressure to / from the plurality of friction elements.
When shifting is performed by releasing the clutch, the engagement element control means is based on the first control amount until the engagement of the friction element to be engaged is started. Based on the second control amount, the working fluid pressure is supplied to the friction element to be fastened, and the release element control means controls the rotation of the friction element until the engagement of the friction element to be fastened is started. The working fluid pressure is discharged from the released friction element so that the amount of air blowing becomes a predetermined amount. However, the fastening element control means adjusts the second control amount such that the larger the throttle opening is, the more the second control amount is inclined. Is also set by the lamp that increases.
Thus, during the torque phase, the first rotation is maintained in a state where the idling of rotation is maintained at a predetermined amount by controlling the release-side friction element.
By controlling the engagement-side frictional element based on the control amount, the shift lag is reduced while the pull-in torque is reduced, and during the inertia phase, the ramp is determined by a ramp whose inclination increases as the throttle opening increases. By controlling the engagement-side friction element by the control amount of the above, it is possible to reduce the pull-in torque while preventing the idling. As described above, by providing different control amounts for the torque phase and the inertia phase and performing the two-stage engagement control, the control amount is reduced in order to reduce the pull-in of the torque, and the shift lag is reduced. In order to achieve this, it is necessary to increase the amount of control in order to achieve the conflicting issues, and to adjust the hydraulic waveform freely from the beginning of the inertia phase transition, enabling control according to operating conditions. Therefore, when trying to reduce the torque pull-in, it is possible to alleviate the restriction that the shift lag is increased, and it is also possible to reduce the torque pull-in while reducing the shift lag, thereby further improving drivability. Make improvements possible.

[0007]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 shows the configuration of an embodiment of a gear train of an automatic transmission to be controlled by the apparatus of the present invention. In the drawing, 1 is an input shaft, 2 is an output shaft, and a first planetary gear set 3 and a second planetary gear set 4 are interposed coaxially between these input and output shafts. The first planetary gear set 3 is a simple planetary gear set including a first sun gear 3S, a first ring gear 3R, a first pinion 3P, and a first carrier 3C, and the second planetary gear set 4 is also a second sun gear 4S.
Second ring gear 4R, second pinion 4P, and second carrier 4C
A simple planetary gear set consisting of

An input shaft 1 receives rotation from an engine (not shown) via a torque converter T / C, and connects the input shaft to a second sun gear 4S. The input shaft 1 can be further coupled to the first carrier 3C by a high clutch H / C,
The first clutch can be connected to the first sun gear 3S by the reverse clutch R / C. The first sun gear 3S can be further fixed by a band brake B / B, and the first carrier 3C can be further fixed by a low reverse brake LR / B, and can be connected to the second ring gear 4R by an overrun clutch OR / C. .
Further, the first ring gear 3R and the second carrier 4C are drivingly connected to each other, and these are connected to the output shaft 2. In such a gear train, friction elements H / C, R / C, B / B, LR / B and OR / C
The following table shows the relationship between the engagement (indicated by a circle), release (no mark), and the selected gear.

[0010]

[Table 1]

[0011] For the shift control of the automatic transmission, the engine speed sensor 5 for detecting an engine rotation N _e, the turbine rotation (transmission input rotation) the turbine rotation Sanse 6 for detecting the N _t, the output shaft rotation (transmission output an output shaft rotation sensor 7 for detecting the rotation) N _o, the throttle opening sensor 8 detects the throttle opening TVO, and the automatic transmission oil temperature (AT oil temperature)
Each signal from the oil temperature sensor 9 for detecting T _at is input to a shift control control unit (ATCU) 10 and the ATCU
10 performs the speed change control by executing the control programs shown in FIGS.

1 → 2 based on the gear train shift control at the time of auto-up (upshift during D range selection)
In the case of shifting, this shifting releases the low reverse brake LR / B and the band brake B /
Achieved by concluding B. In the case of 1 → 2 auto-up, the engaged side realizes 2nd speed by B / B engagement, but at the same time, if the single engagement clutch LR / B is not released, an interlock occurs, and if the release is too early, Air blow occurs, which is suppressed by the following control,
In this control, switching of the control amount on the engagement side is also taken into consideration.

FIG. 2 shows a process of measuring a signal to be measured during the shift control, and is performed for a predetermined time Δt (for example, 10 ms).
c) Executed by a periodic interrupt. First engine shown respectively in step 21 FIG 1 N _e, the turbine rotation N _t
(Transmission input rotation), as well as measuring the transmission output rotation N _o, measures the throttle opening TVO and the AT oil temperature T _at the engine. The gear ratio of the next step 22, 23 in each transmission _{g r = N t / N o} , and the torque converter speed ratio e = N
calculates the _t / N _e, applied further step 24, for use as a preceding value (calculated value before one) g _r (OLD) in the next processing currently calculated value g _r of the gear ratio, and in this process In the next processing, the previously stored calculated value is further stored two times before (2
To be used as the previous calculation value) g _r (OLD2), respectively stored, and in a subsequent step 25, the torque ratio t (e) and the torque capacity coefficient τ (e) corresponding to the rotation ratio e based on the torque converter performance data. ) And multiplying them by turbine torque (transmission input torque) T _t = t
(e) × τ (e) is calculated.

[0014] Figure 3 shows a control signal output program for outputting the oil pressure P _L and hydraulic P _H of the fastening element B / B of the disengagement element LR / B computed as described below in step 31, scheduled interruption every predetermined time interval Δt Execute by

FIG. 4 shows a shift control program for determining the hydraulic pressures P _L and P _H , which is also processed by a periodic interruption at regular time intervals Δt. In step 41, the throttle opening TVO
From the transmission output rotation N _o (vehicle speed), a suitable shift speed is determined based on a shift pattern stored in advance, and the preferred shift speed is compared with the currently selected shift speed to determine whether or not to shift. If a shift is to be performed, the type of shift is determined. In the next step 42, the oil pressure of the friction element (low reverse brake LR / B in the above example) to be released is reduced according to the type of shift, and the friction element (band plate B / B in the above example) to be engaged is reduced. The shift (1 → 2 shift in the above example) is advanced by increasing the oil pressure. At this time, both oil pressures are successively increased by the control programs shown in FIGS.
(Shift clutch control).

In the speed change clutch control in step 42, the ATCU
10 controls the engagement force (constant value or ramp control) of the engagement-side friction element depending on the state of the gear ratio when controlling the release-side friction element so that the amount of rotation of the automatic transmission becomes a proper value at the time of shifting of the automatic transmission. Switch. Preferably, in this case, the switching control of the engagement force (constant value or ramp control) of the engagement-side friction element is performed based on operating conditions such as the throttle opening TVO, the AT oil temperature T _at , and the transmission input shaft torque T _t . The switching is controlled by any one or more, more preferably, in accordance with each controlled friction element. When switching the lamp control, the ATCU 10 can perform the engagement control based on the first ramp in the torque phase and the engagement control based on the second ramp different from the first ramp in the inertia phase. Then, at the end of the torque phase feedback (F / B) control (point A in FIG. 7), the engagement side ramp speed is changed according to the operating conditions. In this case, the second ramp can be controlled to increase as the throttle opening TVO increases.

When it is determined at step 51 in FIG. 5 that this is the first time,
In other words, only once at the shift command instant t ₁ in FIG.
The middle step 52 is executed, and the following processing is performed. That is, calculates the hydraulic pressure conversion required engagement capacity P _OP of the release element LR / B. In the calculation of P _OP , when the friction coefficient of the release element LR / B is μ, the number of friction plates is N, the friction area is A, and the average effective diameter of the friction plates is R, μ × 2 × N × A × First, a coefficient k represented by R is obtained.
And which calculates a torque sharing rate T _b of the release element LR / B, the required engagement capacity value P _OP of the release element LR / B and a turbine torque T _t by _{P OP = T t × T b} / k. Furthermore, this value P
_A margin oil pressure value P (α) is added to _OP so that the oil pressure of the disengagement side friction element does not slip out, and P _OP + P
(Α), which is referred to as a release-side hydraulic pressure P _L. Also, the fastening element B / B side commands the pre-shelf pressure P _pr , but since this pre-shelf pressure is for reducing the loss stroke of the element, a pressure equivalent to the return spring force is applied to the pre-shelf pressure. Pressure _Ppr . Then, P _OP + P obtained as described above
(Alpha) is set to the hydraulic P _L of the release element LR / B, and sets the P _pr to the hydraulic P _H of the fastening element B / B.

In step 52, the throttle opening TV stored in the map in advance for ramp control of the release hydraulic pressure is set.
The release ramp time T _MRrel (TVO) corresponding to O is read, and the ratio P _OP / T _MRrel between the above-mentioned P _OP value and this T _MRrel value is _represented by P
Calculated as _{rmp (rel)} value. This value _{Prmp (rel)} is a step amount at the time of ramp which is used when performing control to reduce the hydraulic pressure of the release-side element in step 55 described later. Further, the throttle opening TVO, and wherein the fastening ramp time for ramp control of the engagement side element which has been previously mapped to the memory as a function of both the AT oil temperature T _at the (first 1) T _MRap1 (TVO, T
_at) with the read-free, reads the necessary engagement is a function of the throttle opening TVO shelf pressure P _C (TVO) from the map. And
TVO value of the point, obtains a read filled-in these values from the ratio _{P C (TVO) / T MRap1} = P rmp (ap1) in response to T _at value, this will be described later in the hydraulic control of the engagement elements B / B Steps
In step 59, the engagement hydraulic pressure step amount (control amount) when the ramp control (first ramp control) is performed during the torque phase is set.

[0019] Furthermore, the release element LR gear ratio feedback in step 60 to be described later in the hydraulic control / B (/ F B) feedback gain proportional part K _p used to control, the integrated amount K _i, the differential component K _d, the target gear ratio is applied in the F / B control g _RTRG (predetermined racing amount equivalent), and a feedback termination gear ratio g _rmin each reading of the F / B control end value in step 52 Execute. Note that step 52
Is basically provided for each shift type.

The second after, in step 53, 54, when the gear ratio g _r is smaller than the target gear ratio g _RTRG illustrated in FIG. 7 (instant t ₂ before), the step 55 is selected, the release element pressure P _L was decreased by the step amount P _{rmp (rel),} the processing returns respectively in this step 55 executes each rETURN at the next time tasks to step 51, gradually decreases the hydraulic pressure P _L in as shown. In this way increase the turbine rotation due to the release of the release element, it is higher than the gear ratio g _r is pre-shift (1-speed) corresponding gear ratio. Until the gear ratio g _r initially reaches the target gear ratio g _RTRG, the loop of steps 51-53-54-55 are repeated Kaee,
When it is determined in step 54 that the target gear ratio g _rtrg has been reached (instantaneous t ₂ ), step 56 is executed once and FLAG =
With a 1, the P _OP value stack to P _STCK, using this as an open value in the subsequent feedback control (see step 60).

[0021] The instant t ₂ thereafter, skip from step 53 to step 57 with the passage of FLAG = 1, step 57-60
As a result, the gear ratio feedback control is performed on the release element side, and the ramp control is performed on the engagement element side. Steps
57, steps of the gear ratio g _r is determined whether the feedback termination gear ratio g _rmin smaller, also step 58 determines whether the engagement element pressure P _H command requires fastening shelf pressure P _C (TVO) or In step 57, when the determination result is NO, step 58 and subsequent steps are selected. Steps
During determination result when even the NO at 58, thus, less than concluded when the gear ratio g _r is greater than the feedback termination gear ratio g _rmin elements hydraulic pressure command P _H (lamp oil) the value P _C (TVO), step 58 advances the process by selecting the step 59 to step 60 to apply the first engagement hydraulic pressure step amount P _{rmp (ap1)} in step 58, the hydraulic pressure command P _H by the P _{rmp (ap1)} Perform ramp control for increasing control. Such first lamp control, as shown in FIG. 7, but are basically performed in the gear ratio feedback control period (between instant t ₂ ~t _3), the hydraulic pressure command value P _H is P _C (TVO) On the way upon reaching the increasing control value P _H is aborted at that point, step 59 is skipped.

The gear ratio g _r is the gear ratio feedback control of the instantaneous t ₂ after the release element side initiated When a target gear ratio g _RTRG is performed by execution of step 60, the release element is a gear ratio g _r The progress of the decrease in the release element oil pressure is feedback-controlled so as to achieve the prescribed airflow. Here, PID (proportional, integral, derivative) does this by controlling, for each executing this step, proportional part, respectively the integrated amount and the differential component _{s, g rerr = g r -g r} (OLD), g rint = g r −
g _rtrg , g _rdeg = g _r + g _r (OLD2) -2 × g _r (OLD)
And the feedback hydraulic pressure P is calculated using these values.
Let _fb be P _fb = g _rerr × K _p + g _rint × K _i + g _rdeg × K _d
And the PID control is performed by _{obtaining the} release element hydraulic pressure from the _equation P _L = P _stck + P _fb by _{using this} value and the P _stck value set in step 56. Thus, during the torque phase,
The release element, whose release is controlled as described above, provides control to keep a slight air blow. Accordingly, the release of the release element is controlled to progress so that the amount of idle rotation at the time of gear shifting becomes an appropriate value. On the other hand, in this process, the fastening element side is gradually increased by the first ramp control at a ramp speed corresponding to the set engagement hydraulic pressure step amount _{Prmp (ap1),} and the actual oil pressure of the fastening element increases. Step 57
Is, during this time, the gear ratio g _r a feedback end gear ratio g
_rmin monitors with a, instant t the gear ratio g _r is determined to become smaller than the feedback end gear ratio g _rmin
In step ₃ , the release hydraulic pressure command is set to the O command in step 61, and the control is shifted to the routine of FIG. That is, here, the gear ratio feedback control during the torque phase is released, the release element LR / B is released, and the engagement element B / B side is also terminated at the end of the torque phase feedback control (instantaneous t ₃ , ie, FIG. At (A point 7), the first lamp control up to that point is released, and the control is switched to the second ramp control in the inertia phase.

The control of the fastening element in the inertia phase is as follows.
As shown in FIG. 6, first, when it is determined in step 71 that this routine is the first time, step 72 is executed only once. Here, since the ramp control on the fastening element side has two stages,
The second, depending on both the throttle opening TVO and the AT oil temperature
Ramp time (second) T _MRap2 for ramp control
(TVO, T _at) with reading free from the map, necessary fastening shelf pressure P _C (TVO) reads from the map corresponding to the throttle opening TVO, the ratio P _C of these P _C (TVO) values and T _MRap2 ( TVO)
/ _TMRap2 is newly set as the engagement ramp step amount _{Prmp (ap2)} (control amount) when ramp control is newly performed in step 75. Here, the step amount _{Prmp (ap2)} can be set to increase with the throttle opening TVO. When the throttle opening TVO is small, P
Setting small _{rmp (ap2)} value, in FIG. 7, in the inertia phase early, the fastening element changes in oil pressure P _H and the output shaft torque becomes that of shown in each two-dot chain line change, conversely, the throttle opening If the value of _{Prmp (ap2) is} set to a large value when TVO is large, the respective transitions show changes as indicated by the chain line. Further steps
At 72, it is assumed that a shift end gear ratio g _rend (for example, a value of about 1.02 times the post-shift gear ratio) applied to the determination at step 73 described later is read.

From the second time onward, steps 73 and below are selected. Step 73, the gear ratio g _r is the shift end gear ratio g _rend
Step 74 of determining whether or not the value is smaller than
Wherein a similar determination steps as 58, these determination results, among the gear ratio g _r is greater than g _rend value, yet while not reaching the required fastening shelf pressure P _C (TVO) (instant t ₃ ~ e.g. during instant t ₄₎ performs a second ramp control in step 75, the step 75 for each run, by applying the fastening ramp step pressure P _{rmp (ap2),} as shown in FIG. 7, the torque phase P with different ramp amounts
by _{rmp (ap2)} raising the fastening element pressure P _H. Thus, the instant t ₄ subsequent to P _H ≧ P _C (TVO) is satisfied, the process returns while skipping step 75 to step 71 to continue the control shelf pressure. During this time, in step 73, monitors the gear ratio g _r for decreasing with the shelf pressure control continues, the gear ratio g _r
Once but it falls below the value g _{re nd} (instant t _5), Step 76
By the execution, the fastening element pressure P _H is completely engaged the commands the highest value P _max engagement element B / B so as to raise up to the line pressure, and ends the shift control.

With the above-described control, the release / engagement switching can be always performed with good timing, and it is possible to realize a smooth gear shift with a small torque pull-in while reliably preventing the engine from idling, The drivability can be further improved by switching the side lamp control. Compared to the system in which the fastening side ramp is one-stage, in this case, when trying to reduce the torque pull-in, the ramp speed cannot be increased, resulting in a large shift lag. In the embodiment, since the ramp speed during the torque phase feedback control can be increased in two stages, the shift lag can be reduced, and both the shift lag and the pull-in torque can be achieved. Can also be alleviated. If one wants to shorten the precharge time (between t _{2 and} t ₃ ) in FIG. 7, this can be done by increasing the slope of the first ramp control (or by applying a shelf pressure as described below). In addition, it is possible to realize the above with a smaller torque pull-in state than in the case of a single-stage ramp.

The fact that the fastening ramp can be made in two stages is as follows.
Since the pull-in torque waveform from the start of the inertia phase can be freely controlled by the second ramp control, 1
As compared with the step type, the feeling of pulling in at the beginning of the inertia phase can be freely controlled.

Furthermore, when the lamp speed is changed in accordance with the operating conditions in switching the lamp control, more fine-grained control can be realized. In particular, when the second ramp speed is set so as to increase with the throttle opening, when the throttle opening is small, the shift lag is reduced while aiming for a smooth engagement by reducing the ramp speed in the inertia phase. While avoiding the lengthening and avoiding the increase in the pull-in torque when the throttle opening is large, it is also easy to respond to the demand to increase the ramp in the inertia phase to prevent air blowing,
More appropriate control can be achieved.

The present invention is not limited to the above embodiment. For example, although described in the embodiments according to the switching of the lamp control, to provide a shelf pressure instead to increase the inclination of the first ramp in order to shorten the time between the instant t ₂ ~t ₃ in the example of FIG. 7 The switching control may be performed in any suitable manner, and is not limited to the switching of the lamp control. The release-side element is gear ratio feedback control, and switching control is performed according to the state of the gear ratio. However, the present invention is not limited to the gear ratio, and may be, for example, turbine rotation or the like.

[0029]

According to the present invention, during the torque phase,
In a state in which the idling of rotation is maintained at a predetermined amount by the control of the release-side friction element, the control of the engagement-side friction element based on the first control amount reduces the pull-in torque and reduces the shift lag, thereby reducing the inertia. During the phase, the engagement-side frictional element is controlled by the second control amount determined by the ramp, the inclination of which increases as the throttle opening increases, so that the pull-in torque can be reduced while preventing the idling. By providing different control amounts for each of the torque phase and the inertia phase and performing two-stage engagement control, the control amount is reduced in order to reduce the pull-in of the torque, and the shift lag is increased. The control amount must be increased in order to achieve the objectives, and freely adjust the hydraulic pressure waveform from the beginning of the inertia phase transition. It can be adjusted, to enable control in accordance with the operating conditions. Therefore, while trying to reduce the pull-in of the torque and reduce the shift lag,
Drivability can be further improved.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of an embodiment of a gear train of an automatic transmission to be subjected to shift control by the device of the present invention.

FIG. 2 is a flowchart of a signal measurement processing program as a control program in the example.

FIG. 3 is a program flowchart for a control signal output process.

FIG. 4 is a program flowchart for shifting determination and shifting control.

FIG. 5 is a flowchart of an example of a control program showing contents in a torque phase of the shift control process of FIG. 4;

FIG. 6 is a flowchart of an example of a program showing contents in an inertia phase in the shift control.

FIG. 7 is a shift operation time chart of the same example.

[Explanation of symbols]

 Reference Signs List 1 input shaft 2 output shaft 3 first planetary gear set 4 second planetary gear set 5 engine rotation sensor 6 turbine rotation sensor 7 output shaft rotation sensor 8 throttle opening sensor 9 transmission oil temperature sensor 10 control unit (ATCU) T / C Torque converter LR / B Low reverse brake B / B Band brake H / C High clutch OR / C Overrun clutch R / C Reverse clutch

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-62-246653 (JP, A) JP-A-63-19455 (JP, A) JP-A-2-120562 (JP, A) JP-A-5-205 141516 (JP, A) JP-A-3-292458 (JP, A) JP-A-4-210158 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) F16H 59/00-61 / 12 F16H 61/16-61/24 F16H 63/40-63/48 B60K 41/00-41/28

Claims (1)

(57) [Claims] 1. The provision of a working fluid pressure to a plurality of friction elements .
Connecting and releasing the plurality of friction elements by supply / discharge
Therefore, when shifting, the first frictional element is engaged until the engagement of the friction element to be engaged is started.
Between the time immediately after the start and the conclusion
Based on the second control amount, the friction element to be engaged
Between the fastening element control means for supplying dynamic fluid pressure and the engagement of the friction element to be fastened,
A friction element that is released so that the amount of rotation
Release element control means for discharging the working fluid pressure from
In the shift control device for an automatic transmission, the second control amount is inclined as the throttle opening increases.
A speed change control device for an automatic transmission, wherein the speed change control device is set by a ramp that also increases .