JPH04131559A - Line pressure learning control device for automatic transmission - Google Patents

Abstract

PURPOSE:To ease shock in a phase change point during speed change so as to improve speed change shock performance by performing the partial control of line pressure at the time of phase change during speed change action in addition to controlling the line pressure in the whole speed change period in order to bring the speed change time in line with the target value. CONSTITUTION:The speed change time is clocked by a speed change time clocking means, the torque waveform, during speed change, of the output shaft torque of an automatic transmission is detected by a torque waveform detecting means, a phase change point during speed change is detected by a phase change point detecting means, and the overshoot or undershoot of the output shaft torque during phase change is computed by a computing means from the torque waveform during speed change. In a total correction quantity updating means, the speed change time is compared with the target value, and the total correction quantity is set increasingly or decreasingly in the direction of coinciding with the target value so as to rewrite the total correction quantity data of a storage means. A partial correction quantity updating means sets the partial correction quantity increasingly or decreasingly in the suppressing direction at the time of the overshoot or undershoot more than the preset specified value, and rewrites the being correction quantity data of the storage means.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a line pressure learning control device that learns and controls line pressure during gear shifting of an automatic transmission for an automobile.

<Conventional technology> In automatic transmissions for automobiles, the discharge pressure of an oil pump is regulated to obtain line pressure, which is then supplied to a hydraulic circuit to control the operating hydraulic pressure of a torque converter and various speed change elements in a gear type transmission. This line pressure is controlled to an appropriate oil pressure according to the engine output.

Namely, a torque converter in an automatic transmission.

The line pressure, which is the source of the working oil pressure for various transmission elements, must be adjusted to the appropriate oil pressure according to the engine pressure. If the oil pressure is higher than the appropriate oil pressure during gear shifting, the torque transmission efficiency will increase.
Engine vibration and gear change shock are transmitted to the output shaft, increasing noise and vibration. Furthermore, if the oil pressure is lower than the appropriate oil pressure during gear shifting, slipping occurs, reducing transmission efficiency, causing a feeling of prolonged gear shifting, deteriorating the durability of the automatic transmission, and further deteriorating fuel efficiency.

Therefore, in the past, the line pressure was controlled by having a map that predetermined the optimal line pressure according to the throttle valve opening, etc., and driving the line pressure actuator based on this map. (Refer to Publication No.-9054, etc.).

Furthermore, during gear shifting, learning control is performed to keep the gear shifting time constant.

That is, when shifting, the basic line pressure is set based on the throttle valve opening etc. with reference to the basic line pressure map on the ROM, and the basic line pressure is set based on the throttle valve opening etc. with reference to the correction amount map on the RAM. The correction amount is set by adding the correction amount to the basic line pressure to set the line pressure, and control is performed based on this.
The shift time is detected based on the time during which the rotation speed is decreasing, etc., and if the shift time is longer than the target value, the correction amount is set to the increasing side in order to increase the line pressure, and the correction amount map on the RAM is rewritten. , if the gear shift time is shorter than the target value, set the correction amount to the decreasing side to lower the line pressure and press R.
The correction amount maps on A and M are rewritten.

<Problems to be Solved by the Invention> However, in the conventional line pressure learning control during shifting, the line pressure during shifting is uniformly changed in an overall correction manner so that the shifting time becomes a target value. That is, as shown in FIG. 9, for example, the actual shift time T is set to the target value (target T).
When the time was longer, the correction amount was set to the increasing side to uniformly increase the line pressure during gear shifting as shown by the dashed line. In this case, this increase correction causes a spike-like shock (amount of overshoot and amount of undershoot) in the output shaft torque at the time of a phase change in which the turbine shaft rotational speed changes during gear shifting, as shown by the dashed line in the figure. ) becomes large, and there is a problem in that the shift shock performance in this area is not improved. Furthermore, the 9th
In the figure, the line pressure during gear shifting is shown as constant, but some models control the operating oil pressure to change it to the optimum value for each phase.

The present invention has been made in view of the above circumstances, and an object of the present invention is to further improve shift shock performance by alleviating shock at a phase change point during shift.

<Means for Solving the Problems> Therefore, as shown in FIG. 1, the present invention provides a line pressure learning planning device for an automatic transmission that learns and controls line pressure during gear shifting. A basic line pressure setting means for setting the basic line pressure; a rewritable storage means for storing the total correction amount and the partial correction amount for each area of the engine operating state; and a total correction amount based on the engine operating state from the storage means. and a search means for searching for the partial correction amount; a line pressure calculation means for calculating the line pressure from the basic line pressure, the total correction amount and the partial correction amount; and a line pressure calculation means for driving the line pressure actuator based on the calculated line pressure. A line pressure control means for controlling line pressure, a shifting time measuring means for measuring the shifting time during shifting, and a torque waveform during shifting by sampling signals from a torque sensor that detects the output shaft torque of the automatic transmission. A torque waveform detection means for detecting a phase change point, a phase change point detection means for detecting a phase change point during a shift, and an overshoot amount or undershoot of the output shaft torque at the time of a phase change as an integral value of the torque fluctuation amount from the torque waveform during a shift. a calculation means for calculating the shot amount; and an overall correction amount for comparing the shifting time with the target value, increasing or decreasing the overall correction amount in a direction that matches the target value, and rewriting the data of the overall correction amount in the storage means. an updating means; a partial correction amount update for increasing/decreasing the partial correction amount in a direction to suppress the overshoot amount or undershoot amount when it is equal to or greater than a predetermined value, and rewriting the data of the partial correction amount in the storage means; It was constructed with means.

<Operation> In this configuration, the basic line pressure setting means sets the basic line pressure, the retrieval means retrieves the total correction amount and the partial correction amount based on the engine operating state, and the line pressure calculation means retrieves the total correction amount and the partial correction amount. The line pressure is calculated from the basic line pressure, the total correction amount, and the partial correction amount, and the line pressure actuator is driven by the line pressure control means to divide the line pressure.

On the other hand, the shift time measuring means measures the shift time, the torque waveform detection means samples the output shaft torque of the automatic transmission and detects the torque waveform during the shift, and the phase change point detection means detects the phase change during the shift. The point is detected, and the calculating means calculates the overshoot amount or undershoot amount of the output shaft torque at the time of phase change from the torque waveform during the gear shift as an integral value of the torque fluctuation amount. Then, the overall correction amount updating means compares the shifting time with the target value, increases or decreases the overall correction amount in a direction that matches the target value, rewrites the data of the overall correction amount in the storage means, and rewrites the data of the overall correction amount in the storage means. The updating means increases or decreases the partial correction amount in a direction to suppress the overshoot amount or the undershoot amount when it is equal to or greater than a predetermined value, and rewrites the data of the partial correction amount in the storage means.

In this way, by controlling the line pressure during the entire shifting period to make the shifting time match the target value, and also partially controlling the line pressure at the time of phase change during shifting, It reduces shock and further improves shift shock performance.

<Example> Hereinafter, one embodiment of the present invention will be described based on the drawings.

In FIG. 2 showing the configuration of this embodiment, an automatic transmission 2 is provided on the output side of the engine 1. The automatic transmission 2 includes a torque converter 3 that includes a pump 3a and a turbine runner 3b interposed on the output side of an engine 1, a gear type transmission 4 connected via this torque converter 3, and this gear type transmission 4. It is equipped with a hydraulic actuator 5 that connects and releases various speed change elements therein. Hydraulic actuator 5
The hydraulic pressure is turned on and off via various electromagnetic valves.
Although FF control is performed, only shift electromagnetic valves 6A and 6B for automatic gear shifting are shown here. Note that 7 is the a car of the automatic transmission 2.

Here, the torque converter 3 and the hydraulic actuator 5
An oil pump 8 driven by the input shaft (turbine shaft) 3c of the gear type transmission 4 is used to obtain the line pressure which is the working oil pressure for the orifice 9. Solenoid valve 10. A pressure modifier valve 11 and a pressure regulator valve 12 are also provided.

The electromagnetic valve 10 obtains pilot pressure based on the discharge pressure of the oil pump 8 guided through the orifice 9 (duty controlled as described later). The pressure modifier valve 11 amplifies the pilot pressure. The regulator valve 12 regulates the discharge pressure from the oil pump 8 to a line pressure proportional to the pilot pressure from the pressure modifier valve 11, and then adjusts the discharge pressure from the oil pump 8 to a line pressure proportional to the pilot pressure from the pressure modifier valve 11.
and the hydraulic circuit such as the hydraulic actuator 5.

Signals from various sensors are input to the control unit 13.

As the various sensors described above, a potentiometer-type throttle sensor 15 is provided that detects the opening degree TVO of the throttle valve 14 in the intake system of the engine 1.

Further, a crank angle sensor 16 is provided on the crankshaft of the engine l or a shaft that rotates in synchronization with the crankshaft. The signal from the crank angle sensor 16 is, for example, a pulse signal for each reference crank angle, and the engine rotational speed N is calculated from the period thereof.

Further, a hot wire type air flow meter 17 for detecting the intake air flow rate Q is provided in the intake system of the engine 1. From this intake air flow rate Q and engine rotational speed N, the basic fuel injection amount Tp = KXQ/N (K
is a constant) is calculated.

Further, a vehicle speed sensor 18 is provided which obtains a rotation signal from the output shaft 7 of the automatic transmission 2 and detects the vehicle speed vSP.

Further, a magnetostrictive torque sensor 19 is provided which is attached to the output shaft 7 of the automatic transmission 2 and detects the output shaft torque Tr.

Further, an input shaft rotation sensor 20 is provided that detects the input shaft rotation speed (turbine shaft rotation speed) NA of the gear type transmission 4.

The control unit 13 is, for example, an integrated type that incorporates a CPU for engine control (fuel injection and ignition timing control) and a CPU for automatic transmission control, and uses dual port RAM that can be accessed from both CPUs. , With such a configuration, the engine rotation speed N is calculated by the engine control CPU.

Data such as basic fuel injection amount Tp is transferred to automatic transmission control CP
Available in U.

The automatic transmission control CPU of the control unit 13 mainly performs gear change control and line control.

Shift control is performed in accordance with the operation position of the select lever. In particular, when the select lever is in the D range, the shift position from 1st to 4th gear is automatically set according to the throttle valve opening TVO and vehicle speed VSP, and the shift control is performed in accordance with the operating position of the select lever. Turn on solenoid valves 6A and 6B
- Control the OFF combination to control the gear type transmission 4 to its shift position via the hydraulic actuator 5.

Line pressure control is performed by duty-controlling the electromagnetic valve IO as a line pressure actuator according to the line pressure control routine shown in Fig. 6 using the learning correction amount learned by the learning routine shown in Figs. 3 to 5. . here,
By increasing the duty (valve opening time ratio),
Line pressure can be increased.

Next, each learning routine shown in FIGS. 3 to 5 will be explained.

The learning routine shown in FIG. 3 is executed at predetermined intervals (for example, every 2 m5).

In step 1 (denoted as Sl in the figure; the same applies hereinafter), it is determined whether or not the gear is being shifted. If the gear is being changed, proceed to step 2.

In step 2, the signal from the torque sensor 19 (output shaft torque TRQ) and the signal from the input shaft rotation sensor 20 (transmission input shaft rotation speed NA) are sampled, and in the next step 3, the flag F is reset. Indicates that sampling is in progress. As a result, as shown in FIG. 7, the waveform of the output shaft torque TRQ and the transmission input shaft rotational speed N
Changes in T can be detected. Here, step 1
3 corresponds to the torque waveform detection means.

If the gear is not being shifted, proceed to step 4, and flag F is set to 1.
Determine whether or not. If the flag F is not 1, it means that the shift has ended (sampling has ended), so proceed to step 5, execute a learning routine for the overall correction amount based on the shift time as shown in Fig. 4, and proceed to step 6. , a learning routine for the partial correction amount at the phase change point as shown in FIG. 5 is executed. Then, in step 7, a failure flag F indicating the end of learning is set to 1.

If F=1 in step 4, it indicates that learning has been completed, and the routine is ended without performing learning.

Next, the aforementioned overall correction amount learning routine shown in FIG. 4 will be explained.

In step 11, based on the sampled rotational speed N of the transmission input shaft, a shift time T is calculated by measuring the time from the point at which the change in rotational speed N starts to the point at which it ends. This part corresponds to the shift time measuring means.

Step 12 is the engine rotation speed N and the basic fuel injection amount T.
The target T is searched based on the actual N and Tp by referring to a map in the ROM that defines the target shift time (target T) for each area of the engine operating state determined by p.

Step 13 is the type of gear shift (1st gear → 2nd gear, 2nd gear → 3rd gear)
A map of the overall correction amount PH03 (PH
A PHOS map corresponding to the type of shift at that time is selected from the OS map.

In step 14, referring to the selected PHOS map,
Based on the engine rotational speed N and the basic fuel injection amount Tp, the overall correction amount PH03 (initial value is O) to be updated is searched.

In step 15, the deviation Δ between the actual shift time T and the target T is
Calculate T (=T - target T).

In step 16, the absolute value 1ΔT1 of the deviation is the predetermined value T.

Determine whether or not the value is greater than or equal to the value. If it is above, the process proceeds to step 17, and if it is less than that, it is determined that there is no need to rewrite the entire correction amount and the routine is ended.

In step 17, it is determined whether ΔT is positive or negative, and if it is positive, that is, if the shift time is longer than the target value, the process proceeds to step 18, in which the overall correction amount is increased in order to increase the line pressure. A new overall correction amount PH03 is calculated by adding a correction amount according to the deviation to the current overall correction amount according to the following formula.

PH03=PHOS+ΔT xK+K1 is a constant.

If it is negative, that is, if the shift time is shorter than the target value, the process advances to step 19, and in order to reduce the line pressure, the overall correction amount is decreased according to the deviation from the current overall correction amount according to the following formula. A new overall correction amount PH03 is calculated by subtracting the correction amount.

PH0S=PHO3-ΔT xK In step 20, the data of the overall correction amount PH03 in the corresponding area of the PH0S map is rewritten with the new data calculated in step 18 or step 19. Here, steps 14 to 20 correspond to the overall correction amount updating means.

Next, the partial correction amount learning routine shown in FIG. 5 will be explained.

Step 31 is the torque TRQ detected by sampling the output shaft torque in the learning routine of FIG.
The torque waveform shown in FIG. 16 is obtained by analyzing the waveform and filtering.

In step 32, similar to the learning of the overall correction amount, engine operation is determined by the engine speed N and the basic fuel injection amount Tp, which is provided for each type of shift (1st gear → 2nd gear, 2nd gear → 3rd gear, etc.). A map of the partial correction amount PH03P that determines the partial correction amount PH03P for each area of the state (referred to as a PHOSP map)
From this, a PH03P map corresponding to the type of gear change at that time is selected. Here, the PH03P map is provided for each of the 2nd and 4th phases during shifting, which will be described later, and includes a PH03P1 map that stores the 2nd phase partial correction amount PH03PI and a PH03P2 map that stores the 4th phase partial correction amount PH03P2. be.

In step 33, the selected PH03P1 map and PH03P2 map are referred to, and the partial correction amounts PH03P1 and PH03P2 to be updated are determined based on the engine rotational speed N and the basic fuel injection amount Tp (both initial values are
).

In step 34, based on the actual torque waveform and the filtered torque waveform, the two-phase overshoot amount S1 during the shift shown in FIG. 8 (bl) is calculated as an integral value of the torque fluctuation amount.

In step 35, it is determined whether the overshoot amount S1 is equal to or higher than a predetermined threshold level 882. Here, if the threshold level is 882 or higher, it is determined that the torque fluctuation amount is large, and the process proceeds to step 36.
A new partial correction amount PH03PI is calculated by subtracting the correction amount (St XK2) corresponding to the overshoot amount S1 from the current partial correction amount PH03PI. Then, in step 37, the data of the partial correction amount PH03P1 in the corresponding area of the PH03PI map is rewritten with new data.

If it is less than the threshold level SSP, it is determined that there is no need to rewrite the partial correction amount and the process proceeds to step 38.

In step 38, the undershoot amount S2 of the four phases during the shift shown in FIG. 8(b) is calculated as an integral value of the torque fluctuation amount.

In step 39, it is determined whether the undershoot amount S2 is equal to or higher than a predetermined threshold level 33M. If the threshold level is 33M or higher, it is determined that the torque fluctuation amount is large, and the process proceeds to step 40, where a correction amount (2 to S2×) corresponding to the undershoot amount S2 is added to the current partial correction amount PH03P2, and a new A partial correction amount PH03P2 is calculated. Then, in step 41, P
Partial correction amount PH0 of the corresponding area of the H03P2 map
Rewrite the 3P2 data with new data. If it is less than the threshold level 33M, no rewriting is performed. Here, steps 34.38 correspond to calculating means, and steps 33.35 to 37.39 to 4I correspond to partial correction amount updating means.

Further, the two-phase to four-phase detection may be performed, for example, by a gear ratio that is the ratio of the rotational speeds of the input shaft and output shaft of the transmission.

Next, the line pressure control routine shown in FIG. 6 will be explained.

In step 51, it is determined whether or not the gear is being changed. here,
If the gear is not being shifted, proceed to step 52, refer to a normal map that predetermines the optimal line pressure PL according to the throttle valve opening TVO, search for and set the line pressure PL from the actual throttle valve opening TVO. do. Then, the process proceeds to step 63, where a duty corresponding to this line pressure PL is outputted to drive the electromagnetic valve 10, thereby obtaining the optimum line pressure. If the gear is being changed, steps 53 to 62 are executed and the process proceeds to step 63 in order to control the line pressure during the gear change.

In step 53, depending on the type of shift, a plurality of basic line pressure maps (PLO map), a total correction amount map (PHOS map), and one partial correction amount map (PHO3P map) are prepared.
Select one each from I map and PH03P2 map). In this embodiment, since the basic line pressure is changed and controlled for each phase (1 phase to 4 phases) during gear shifting, the PLO map (PLO, ~PLO, map) of each phase is also selected. be exposed.

In step 54, the PH0S map is referred to, and the overall correction amount P is determined based on the engine rotational speed N and the basic fuel injection amount Tp.
Search for H03.

In step 55, the phase during gear change is determined. The phase can be detected, for example, from the rotational speed ratio (gear ratio) of the transmission input shaft 3c and the transmission output shaft 7,
Set the boundary gear ratios of 1-phase and 2-phase, 2-phase and 3-phase, and 3-phase and 4-phase in advance, and when the actual gear ratio reaches each boundary gear ratio, it is assumed that the phase has changed. do. Then, when the shift starts, the P L
With reference to the O+ map, the basic line pressure PLO+ of this phase is searched and set based on the throttle valve opening TVO. Then, the process proceeds to step 62, where the searched overall correction amount PH03 is added to the basic line pressure PLo to set the one-phase line pressure PL, and in step 63, the duty corresponding to this line pressure is output.

When the phase shifts to the 2nd phase, the process proceeds to step 57, where the 2nd phase P
Referring to the LO□ map, similarly search for and set the two-phase basic line pressure PLO□, proceed to step 58, refer to the two-phase partial correction amount map, and set the partial correction amount PH03PI.
is searched and added to the basic line pressure PLO. Then, the process proceeds to step 62, where the total correction amount P is added to the added value.
The two-phase line pressure PL is set by adding H03, and in step 63, the duty corresponding to this line pressure is output.

When transitioning to 3-phase, step 59 is performed as in the case of 1-phase.
In step 62, the three-phase basic line pressure PLO3 is searched and set by referring to the three-phase PLo3 map, and in step 62, the overall correction amount PH0S is added to the basic line pressure PLOG, and the three-phase line pressure PL is set. In step 63, a duty corresponding to this line pressure is output.

If the transition is to 4-phase, repeat step 6 in the same way as for 2-phase.
0, 4-phase PLo, basic line pressure P with reference to the map.
LO4 is searched, and in step 61, the partial correction amount PH03P2 is searched with reference to the 4-phase partial correction amount map, and the basic line pressure PLO is determined.

Add to. Then, the process proceeds to step 62, where the total correction amount PH03 is added to the above-mentioned addition value to set the four-phase line pressure PL, and in step 63, the duty corresponding to this line pressure is output. Here steps 56.57.59.
60 corresponds to basic line pressure setting means, and step 54.
58 and 61 correspond to a search means, step 62 corresponds to a line pressure calculation means, and step 63 corresponds to a line pressure control means.

In addition, in line pressure control, as shown in FIG.
The determination of transition from phase to phase 2 and from phase 3 to phase 4 is set to be determined earlier than the actual change point (determination point in the partial correction amount learning routine), taking into account the delay in oil pressure.

In this way, by learning the line pressure as a whole during shifting, and also learning it individually at phase change points, it is possible to suppress spike-like torque fluctuations at phase change points, improving shift shock performance. can.

<Effects of the Invention> As explained above, according to the present invention, in addition to learning the line pressure as a whole during gear shifting, the line pressure is also learned at each phase change point where torque fluctuation is large. Since the line pressure is learned in detail, shift shock performance can be significantly improved.

[Brief explanation of the drawing]

Fig. 1 is a block diagram explaining the present invention in detail, Fig. 2 is a system diagram showing an embodiment of the present invention, Fig. 3 is a flowchart of the learning routine, and Fig. 4 is a flowchart of the overall correction amount learning in the learning routine. Flowchart, Fig. 5 is a flowchart of learning the partial correction amount in the learning routine, Fig. 6 is a flowchart of the line pressure control routine, Fig. 7 is a diagram showing the line pressure control state during shifting, and Fig. 8 is a diagram showing the torque during shifting. FIG. 9 is an explanatory diagram of the calculation of the amount of variation, and is an explanatory diagram of the conventional problems. l... Engine 2... Automatic transmission 3... Torque converter 3c... Transmission input shaft 7...
Output shaft 8...Oil pump lO...Solenoid valve
11...Pressure modifier valve 12...
・Pressure regulator valve 13...Control unit 15...Throttle sensor 19・
...Torque sensor 20...Input shaft rotation sensor Patent applicant Japan Electronics Co., Ltd.

Claims (1)

[Claims] A line pressure learning control device for an automatic transmission that learns and controls line pressure during gear shifting includes a basic line pressure setting unit that sets the basic line pressure based on at least the engine load, and a total correction amount and control unit for each area of the engine operating state. a rewritable storage means for storing the partial correction amount; a search means for searching the storage means for the overall correction amount and the partial correction amount based on the engine operating state; A line pressure calculation means for calculating line pressure, a line pressure control means for controlling the line pressure by driving a line pressure actuator based on the calculated line pressure, and a shifting time measuring means for measuring the shifting time during shifting. , torque waveform detection means for detecting a torque waveform during gear shifting by sampling a signal from a torque sensor that detects output shaft torque of the automatic transmission; phase change point detection means for detecting a phase change point during gear shifting; Calculation means for calculating the amount of overshoot or undershoot of the output shaft torque at the time of phase change as an integral value of the amount of torque fluctuation from the torque waveform during shifting, and comparing the shifting time with the target value to match the target value. overall correction amount updating means for increasing or decreasing the overall correction amount in the direction of increasing or decreasing the overall correction amount and rewriting data of the overall correction amount in the storage means; A line pressure learning control device for an automatic transmission, comprising partial correction amount updating means for increasing or decreasing a partial correction amount in the direction and rewriting data of the partial correction amount in the storage means.