JP2009013954A - Control device for internal combustion engine - Google Patents

Abstract

A control device for an internal combustion engine is provided that can reduce a shock that is generated when the gear position is actually switched, and can improve the responsiveness in the output control of the internal combustion engine.
Detecting means for detecting an operating state of an internal combustion engine, which is applied to an internal combustion engine 2 provided with an automatic transmission 5 for performing a shift change in which a gear ratio is small and large. (24 etc.), estimation means (20) for estimating the shift timing at which the shift change is completed, correction means (20) for correcting the estimated shift timing based on a predetermined map, and the corrected shift timing. Based on the map change means (20) for changing the predetermined map, and calculation for calculating the engine required torque of the internal combustion engine based on the output torque difference of the automatic transmission that can occur before and after the shift change. Means (20) for controlling the internal combustion engine so that the calculated engine demand torque is output from the output shaft at the time of shift change; Comprises control means (20), the.
[Selection] Figure 1

Description

  The present invention relates to a control device applied to an internal combustion engine provided with an automatic transmission that is connected to an output shaft of the internal combustion engine and can be switched to a plurality of transmission gear ratios having different sizes.

  As a control device for an internal combustion engine equipped with an automatic transmission, it is large when the output rotation speed of the automatic transmission is multiplied by the speed ratio after downshifting, and the change rate of the load of the internal combustion engine is large, and the change rate is small. There has been known one that performs torque reduction control of an internal combustion engine from when a value obtained by subtracting a predetermined value that is sometimes set smaller than the rotational speed of the internal combustion engine (Patent Document 1). In addition, Patent Documents 2 and 3 exist as prior art documents related to the present invention.

JP-A-6-135263 Japanese Patent Laid-Open No. 2003-41987 JP-A-8-232696

  However, in the torque reduction control in Patent Document 1 or the like, the learning map after reflecting the learning value is constantly updated with a value obtained by multiplying the learning map before reflecting the learning value by a predetermined coefficient smaller than 1. Therefore, the start of various control processes for suppressing shocks that occur during gear shifting is delayed. This gives a shock to the driver. Specifically, when the learning map is constantly updated with a value multiplied by a predetermined coefficient smaller than 1, an actual measurement value of the timing at which the gear shift is completed and an estimated value of the timing at which the gear shift is completed. Based on the difference, the time interval for appropriately updating the learning map becomes long. For this reason, since the driver repeatedly and continuously feels the shock generated at the time of the shift until the learning map acquires the optimum value, the driver feels uncomfortable in driving operation.

  Accordingly, the present invention has been made in view of the above-described problems, for example, and can reduce shocks that occur when actually changing the shift speed and improve responsiveness during output control of the internal combustion engine. It is an object to provide a control device for an internal combustion engine.

  An internal combustion engine control apparatus according to the present invention includes an automatic transmission that is connected to an output shaft of an internal combustion engine and is capable of switching to a plurality of gear ratios having different sizes, a detection unit that detects an operating state of the internal combustion engine, Estimating means for estimating a shift timing at which the shift change is completed when a shift change to be switched from one to the other of the small gear ratio and the large gear ratio is performed in the automatic transmission, and the detected driving state A correction unit that corrects the estimated shift timing based on a predetermined map that uses a variable that defines the input as input information, a map change unit that changes the predetermined map based on the corrected shift timing, and During a shift change, the engine required torque of the internal combustion engine can be generated before and after the shift change. Comprising calculating means for calculating, based on the click difference, during the shift change, the, the engine control means for controlling the internal combustion engine so as to output the calculated engine demand torque from the output shaft.

  According to the control apparatus for an internal combustion engine of the present invention, the estimation means estimates the shift timing at which the shift change is completed when the shift change (so-called shift speed switching) is performed by the automatic transmission. The correction means corrects the estimated shift timing based on a predetermined map that uses as input information a variable that defines the detected driving state. Here, the driving state according to the present invention may mean a running state that can be defined by various variables such as a rotational speed and a rotational force (torque) detected by the rotation system sensor.

  The predetermined map is changed based on the corrected shift timing by the map changing means. The calculation means calculates the engine required torque of the internal combustion engine based on the output torque difference of the automatic transmission that can occur before and after the shift change. The internal combustion engine is controlled by the engine control means so that the calculated required engine torque is output from the output shaft during the shift change. As a result, it is possible to effectively reduce the shock generated at the time of shift change and to significantly improve the responsiveness at the time of output control of the internal combustion engine.

  In one aspect of the control device for an internal combustion engine of the present invention, the automatic transmission includes the pump connected to the output shaft of the internal combustion engine and a torque converter including a turbine combined with the pump. Connected to the output shaft of the engine, the estimation means multiplies the output rotational speed of the automatic transmission by the speed ratio after the shift change in the process from the start to the completion of the shift change as the shift timing. The marginal rotation speed given as the difference between the target rotation speed and the turbine rotation speed of the turbine is estimated in consideration of the respective temporal changes of the target rotation speed and the turbine rotation speed, and the correction means includes the predetermined map. The estimated margin rotational speed is corrected based on the map, and the map changing means is configured to correct the predetermined margin rotational speed based on the corrected margin rotational speed. Tsu may be to vary the-flops.

  According to this aspect, it is possible to change the predetermined map with high accuracy quantitatively or qualitatively based on the corrected margin rotation speed.

  According to the aspect relating to the correction means described above, the correction means uses, as the predetermined map, a variable that defines an operation state at the time of the shift change as input information, and a correction value for correcting the margin rotation speed. The estimated shift timing may be corrected based on a map used as output information.

  If comprised in this way, it is possible to correct | amend the estimated shift timing quantitatively or qualitatively based on a map.

  According to the aspect relating to the map changing means described above, the map changing means (i) in addition to or in place of not changing the predetermined map when the corrected absolute value of the margin rotation speed is smaller than a predetermined value. (Ii) The predetermined map may be changed when the corrected absolute value of the marginal rotation speed is larger than a predetermined value.

  With this configuration, the shift timing learning process is stable in consideration of whether or not the shift timing learning process is performed, such as whether or not the absolute value of the marginal rotation speed is greater than a predetermined value. If so, the shift timing learning process is stopped.

  If the learning process of the shift timing is constantly reflected on the predetermined map, for example, due to measurement errors of various sensors, the overall control of the internal combustion engine including the output control of the internal combustion engine corresponding to the shift timing May diverge and hunting may occur. As a result, the determination of whether or not the shift stage has actually been completed is always changed and unstable, and the driver repeatedly feels the shock that occurs during the shift. I feel uncomfortable in operation.

  On the other hand, according to this aspect, the shift timing of the shift timing is considered in consideration of whether or not the shift timing learning process is performed, such as whether or not the absolute value of the marginal rotation speed is greater than a predetermined value. When the learning process is stable, the shift timing learning process is stopped.

  As a result, the overall control of the internal combustion engine including the output control of the internal combustion engine corresponding to the shift timing can be quickly converged to a stable state. Therefore, it is possible to realize overall control of the internal combustion engine that responds more appropriately, more stably, and more quickly to the shift timing.

  According to the aspect relating to the map changing means described above, the map changing means may: (i) if the estimated shift timing is earlier than the actual timing at which the shift change is actually completed, In addition to or instead of changing the predetermined map by adding an offset amount, (ii) when the estimated shift timing is later than the actual timing when the shift change is actually completed, the predetermined map The predetermined map may be changed by multiplying a predetermined coefficient larger than 1.

  With this configuration, when the measured value of the timing at which the shift change is completed is later than the estimated value of the timing at which the shift change is completed on the time axis, the predetermined map after the change is compared with the predetermined map before the change. For example, the value is updated by adding a value obtained by multiplying a predetermined coefficient b smaller than 1. Therefore, in a driving state in which various control processes for suppressing a shock that occurs during a shift are executed before the timing at which the shift change is actually completed, the shift timing learning process is performed with higher accuracy and Done properly.

  As a result, the overall control of the internal combustion engine including the output control of the internal combustion engine corresponding to the shift timing can be quickly converged to a stable state. Therefore, it is possible to realize overall control of the internal combustion engine that responds more appropriately, more stably, and more quickly to the shift timing.

  On the other hand, according to this aspect, when the measured value of the timing when the shift change is completed is earlier on the time axis than the estimated value of the timing when the shift change is completed, the predetermined map after the change is changed to the predetermined map before the change. On the other hand, for example, it is updated with a value obtained by multiplying a predetermined coefficient larger than 1.

  As a result, if a shock that occurs at the time of a shift occurs once in the operating state where the measured value of the timing when the shift change is completed is earlier than the estimated value of the timing when the shift change is completed, the shift change is The certainty of delaying the actual completion timing later than the estimated value of the completion timing of the shift change can be significantly increased. Accordingly, it is possible to quickly eliminate the driver from repeatedly and continuously feeling the shock generated at the time of the shift change, and to eliminate almost or completely the discomfort in the driving operation.

  According to the aspect relating to the map changing means described above, the map changing means has the time change of the turbine rotational speed and the time change of the target rotational speed at the time of the shift change being equal as the actual timing. Based on the timing, the estimated shift timing may be specified to be earlier or later than the actual timing.

  According to this configuration, the estimated shift timing is identified with high accuracy based on the timing at which the time change in the turbine rotation speed and the time change in the target rotation speed are equal. Is possible.

  As described above, according to the control apparatus for an internal combustion engine of the present invention, the actual value of the shift speed switching timing is compared with the estimated value estimated by the learning map, and the learning map is appropriately changed. Thus, it is possible to effectively reduce the shock generated at the time of the shift change and to significantly improve the responsiveness at the time of output control of the internal combustion engine.

(First form)
FIG. 1 schematically shows a vehicle equipped with an internal combustion engine to which the control device of the present invention is applied. An internal combustion engine 2 is mounted on the vehicle 1 as a driving power source. The internal combustion engine 1 is configured as an in-line four-cylinder gasoline engine, and an automatic transmission 5 is connected to a crankshaft 3 as an output shaft via a torque converter 4. The torque converter 4 is a well-known one having a pump 4a connected to the crankshaft 3 and a turbine 4b connected to the input shaft 6 of the automatic transmission 5 in combination with the pump 4a. The automatic transmission 5 is configured to be switchable to a plurality of gear ratios having different sizes, and is switched to an appropriate gear ratio according to the traveling state of the vehicle 1 and the operating state of the internal combustion engine 2. The automatic transmission 5 shown in the figure has a gear ratio of 4 forward speeds and 1 reverse speed. The rotation of the output shaft 7 of the automatic transmission 5 is transmitted to the drive wheels 10 via the differential device 8.

  The internal combustion engine 2 and the automatic transmission 5 are controlled by an engine control unit (ECU) 20. The ECU 20 is configured as a computer including a microprocessor and peripheral devices such as ROM and RAM necessary for its operation. The ECU 20 outputs an engine rotation speed sensor 21 that outputs a signal corresponding to the rotation speed of the internal combustion engine 2, that is, the rotation speed of the crankshaft 3, and a signal corresponding to the amount of operation of the accelerator pedal by the driver, that is, the accelerator opening. The accelerator opening sensor 22, the turbine rotational speed sensor 23 for outputting a signal corresponding to the rotational speed of the turbine 4b, the turbine torque sensor 24 for outputting a signal corresponding to the torque of the turbine 4b, and the output shaft 7 of the automatic transmission 5. Output signals from a transmission output rotational speed sensor 25 that outputs a signal corresponding to the rotational speed and a transmission output torque sensor 26 that outputs a signal corresponding to the torque of the output shaft 7 of the automatic transmission 5 are input.

  Although the control performed by the ECU 20 is diverse, the following description will focus on the control related to the present invention. FIG. 2 is a flowchart showing an example of a control routine for engine output torque control performed by the ECU 20. The program for this routine is held in the ROM of the ECU 20, and is repeatedly executed at a predetermined calculation cycle. First, the ECU 20 detects an acceleration request from the driver in step S1. Specifically, the accelerator opening Acc is acquired with reference to the output signal of the accelerator opening sensor 22. Next, in step S3, referring to the output signals of the engine rotation speed sensor 21, the turbine rotation speed sensor 23, and the transmission output rotation speed sensor 25, the operation state of the internal combustion engine 2 is set to the rotation speed of the internal combustion engine 2. A certain engine rotation speed Ne, a turbine rotation speed Nt that is the rotation speed of the turbine 4b, a transmission output rotation speed No that is the rotation speed of the output shaft 7 of the automatic transmission 5, and a load TRQ of the internal combustion engine are acquired. Note that the load TRQ of the internal combustion engine can be defined quantitatively or qualitatively by the fuel injection amount, for example, in the case of a diesel engine.

  Next, in step S3, a shift stage Sft_b before switching of the automatic transmission 5 and a shift stage Sft_a after switching are detected. These shift speeds Sft_b and Sft_a can be obtained from processing information of shift control (not shown) executed by the ECU 20 in parallel with FIG. In this shift control, the shift speed Sft_a after switching is determined based on the shift diagram shown in FIG. The shift line diagram of FIG. 11 associates the respective shift stages with the rotational speed No of the output shaft 7 of the automatic transmission 5 and the accelerator opening degree Acc as variables, and the solid line indicates the upshift and the broken line indicates the downshift, respectively. Show.

  Next, in step S4, the shift speed Sft_b and the shift speed Sft_a are compared to determine whether or not a downshift is performed. Needless to say, in the case of a downshift, the gear ratio after switching becomes larger than the gear ratio before switching. When the downshift is not performed, the process proceeds to step S11, and 0 (zero) is substituted for the output torque difference ΔTo that can occur before and after the downshift, and the process proceeds to step S9. When downshift is performed, the process proceeds to step S5 to estimate the shift timing.

  FIG. 3 is an explanatory diagram for explaining the outline of the shift timing estimation process in step S5, and FIG. 4 is a flowchart showing details of the shift timing estimation process. First, the outline of the shift timing estimation process will be described with reference to FIG.

  FIG. 3 shows temporal changes between the turbine rotational speed Nt and the target rotational speed NoSft from the downshift start time t0 to the completion time t1, where time tn is the current calculation time, and time tn-1 is Time tn + 1 indicates the previous calculation time, and time tn + 1 indicates the next calculation time. As shown in FIG. 3, the feature of the present embodiment is that a marginal rotation speed Nmarg given as a difference between the target rotation speed NoSft and the turbine rotation speed Nt is set to a target rotation speed from the previous calculation time tn-1 to the current calculation time tn. The point is that the prediction is performed in consideration of the respective time changes ΔNoSft and ΔNt of NoSft and turbine rotational speed Nt. That is, the surplus rotational speed Nmarg at the next computation time tn + 1 is calculated at the current computation time tn, and the timing at which the surplus rotational speed Nmarg falls below a predetermined value of zero is specified as the shift timing at which the downshift is completed. As a result, it can be determined whether or not the shift timing comes between the current calculation timing tn and the next calculation timing tn + 1, so that the shift timing can be accurately captured without losing the shift timing.

  Next, the shift timing estimation process will be specifically described with reference to FIG. First, in step S51, the target rotational speed NoSft is calculated by Equation 1.

NoSft = No × Ratio (Sft_a) ……………………… 1
Here, Ratio (x) is a function that gives a gear ratio according to the gear stage x, Ratio (Sft_a) means a gear ratio after the gear shift, and Ratio (Sft_b) means a gear ratio before the gear shift.

  Next, a time change ΔNt of the turbine rotation speed Nt is calculated by Equation 2 in step S52.

ΔNt = Nt−Ntold …… 2
Here, Nold is the turbine rotation speed at the previous calculation.

  Next, the time change ΔNoSft of the target rotational speed NoSft is calculated by Equation 3 in step S53.

ΔNoSft = NoSft−NoSftold 3
Here, NoSftold is the target rotational speed at the time of the previous calculation.

  Next, in step S54, the current turbine rotational speed Nt is replaced with the previous turbine rotational speed Nold, and the current target rotational speed NoSft is replaced with the previous target rotational speed NoSftold. That is, Nold = Nt and NoSftold = NoSft.

  Next, a marginal rotation speed Nmarg is calculated by Equation 4 in step S55.

Nmarg = NoSft−Nt−α (ΔNt−ΔNoSft) ……………… 4
Here, α is a coefficient of 1 or more that is set to a larger value as the load of the internal combustion engine 2 is larger, and is provided for estimating how much the turbine rotational speed and the target rotational speed will change by the next calculation timing. .

  Next, a shift timing learning process is performed (step S500). The shift timing learning process will be described later.

(Shifting timing learning process)
Here, the shift timing learning process will be described in detail with reference to FIGS. FIG. 5 is a flowchart showing a flow of a shift timing learning process according to this embodiment. FIG. 6 shows the relationship between the turbine rotational speed Nt corresponding to the rotational speed on the input side of the automatic transmission 5 and the transmission output rotational speed No when the gear position is actually switched according to the present embodiment. It is the shown graph. FIG. 7 is a schematic diagram schematically showing the rotational speed corresponding to the estimated value of the shift timing and the rotational speed corresponding to the actually measured value of the shift timing in the shift timing learning process according to the present embodiment (FIG. 7 (a) to FIG. 7 (c)). FIG. 8 shows a change in torque corresponding to a comparison on the time axis between the actual measurement value of the timing at which the shift stage switching is completed and the estimated value of the timing at which the shift stage switching is completed, according to the present embodiment. It is a graph (FIG.8 (b)) which showed the graph (FIG.8 (a)) and the change of the acceleration of a vehicle.

  As shown in FIG. 5, a correction value for correcting the surplus rotational speed Nmarg is determined based on the learning map Nmarg_mod_map corresponding to the actual shift state (step S501). Here, the learning map Nmarg_mod_map according to the present embodiment uses, as input information, a variable that defines the actual shift state, and output information includes a correction value for correcting the margin rotation speed Nmarg calculated in step S55 described above. It may mean a map to do.

  More specifically, this learning map Nmarg_mod_map corresponds to the load TRQ of the internal combustion engine, corresponding to each of a plurality of types of shift speeds Sft_a after switching of the automatic transmission 5, which is the target shift speed of the driver. The turbine rotation speed Nt, which is the rotation speed of the turbine 4b, may be defined as input information, and a correction value for correcting the margin rotation speed Nmarg may be defined as output information. Alternatively, the learning map Nmarg_mod_map may use, as input information, the load and torque on the input side of the automatic transmission 5 instead of the turbine rotational speed Nt that is the rotational speed of the turbine 4b. Alternatively, the learning map Nmarg_mod_map may use the engine rotational speed Ne, which is the rotational speed of the internal combustion engine 2, as input information instead of the load TRQ of the internal combustion engine.

  Further, the learning map Nmarg_mod_map corresponds to a plurality of types of shift speeds Sft_a after switching of the automatic transmission 5, and instead of the shift speed Sft_a after switching of the automatic transmission 5 and before switching of the automatic transmission 5. A plurality of types of combinations (patterns) may be respectively associated with the first gear Sft_b. The learning map Nmarg_mod_map constitutes a specific example of the predetermined map according to the present invention.

  Next, the margin rotation speed Nmarg calculated in step S55 described above is corrected by the correction value determined in step S501 described above, so that a margin rotation speed Nmarg_mod after correction is acquired (step S502). Specifically, the corrected marginal rotational speed Nmarg_mod is acquired by the following equation 50.

Nmarg_mod = Nmarg + Nmarg_mod_map ……………… 50
Next, based on the turbine rotation speed Nt and the transmission output rotation speed No corresponding to the rotation speed on the input side of the automatic transmission 5, it is determined whether or not the shift speed switching has actually been completed (step). S503). Specifically, as shown in FIG. 6, for example, when the gear position is switched in the downshift direction, the time change ΔNt of the turbine rotation speed during the shift is the time change Δ (No × Ratio of the target rotation speed). (Sft_a)) is a sufficiently large value. On the other hand, when the switching of the shift speed is completed, the turbine 4b and the input shaft of the automatic transmission 5 are mechanically and mechanically connected, so the time change ΔNt of the turbine rotation speed and the time of the target rotation speed The change Δ (No × Ratio (Sft_a)) is almost the same value. Therefore, it is possible to determine whether or not the shift speed switching is actually completed based on whether or not the following conditional expression 51 is satisfied.

| ΔNt | <| Δ (No × Ratio (Sft_a)) × a |
However, a may mean a constant in a range exceeding 1. Further, for example, the case where the gear position is switched in the upshift direction may be determined by a substantially similar method. “| X |” indicates an absolute value of the real number x.

  Next, as a result of the determination in step S503 described above, when it is determined that the shift stage switching has actually been completed (step S503: Yes), in response to the fact that the shift stage switching has actually been completed, As shown in the equation 52, the corrected margin rotational speed Nmarg_mod is substituted into the margin rotational speed learning value Nstd (step S504).

Nstd = Nmarg_mod ......... 52
When the learning value Nstd of the marginal rotation speed takes a positive value based on the above-described equation 4, the shift speed switching is actually completed as shown in FIGS. 7 (a) and 7 (b). The timing (so-called actually measured value) may mean that it is later on the time axis than the timing (so-called estimated value) estimated or predicted to complete the shift stage switching.

  On the other hand, when the learning value Nstd of the marginal rotation speed takes a negative value based on the above-described formula 4, the shift speed is actually switched as shown in FIGS. 7 (a) and 7 (c). The completed timing (so-called actually measured value) may mean that it is earlier on the time axis than the timing (so-called estimated value) estimated or predicted to complete the shift speed change.

  Next, the shift timing determination flag Nmarg_jdg may be set in order to notify the ECU 20 that the shift stage switching has actually been completed. In other words, “1” may be substituted for the variable Nmarg_jdg ( Step S505).

  Next, it is determined whether or not the absolute value of the margin rotation speed learning value Nstd is greater than a predetermined threshold value Njdg (step S506). Here, the predetermined threshold value Njdg according to the present embodiment may mean a time change ΔNt of the turbine rotation speed, or may mean a value obtained by multiplying the time change ΔNt of the turbine rotation speed by a predetermined coefficient larger than 1. . Alternatively, the predetermined threshold value Njdg corresponds to the load of the internal combustion engine or the turbine rotational speed Nt, which is the rotational speed of the turbine 4b, as input information corresponding to each of a plurality of types of speed stages Sft_a after the automatic transmission 5 is switched. It may be specified by a map or function. Alternatively, the predetermined threshold value Njdg corresponds to a plurality of types of combinations (patterns) of the shift speed Sft_a after switching of the automatic transmission 5 and the shift speed Sft_b before switching of the automatic transmission 5, You may prescribe | regulate by the map and function which use the rotational speed of the input side of the automatic transmission 5 as input information. More specifically, the predetermined threshold value Njdg is set to be larger than the ratio of measurement errors in various sensors that can be defined based on the engine speed of the internal combustion engine, for example, to improve the accuracy of learning of the shift timing. Is preferable.

  If the learning process of the shift timing is always reflected in the learning map Nmarg_mod_map, the internal combustion engine including the output control of the internal combustion engine corresponding to the shift timing is caused, for example, due to measurement errors of various sensors. The overall control may diverge and hunting may occur. As a result, the determination of whether or not the shift stage has actually been completed is always changed and unstable, and the driver repeatedly feels the shock that occurs during the shift. I feel uncomfortable in operation.

  On the other hand, according to the present embodiment, for example, whether or not the shift timing learning process is performed, such as whether or not the absolute value of the margin rotation speed learned value Nstd is greater than a predetermined threshold Njdg. When the shift timing learning process is stabilized, the shift timing learning process is stopped. As a result, the overall control of the internal combustion engine including the output control of the internal combustion engine corresponding to the shift timing can be quickly converged to a stable state. As a result, overall control of the internal combustion engine that responds more appropriately, more stably, and more quickly to the shift timing can be realized.

  Next, it is determined whether or not the learning value Nstd of the surplus rotational speed is greater than 0, that is, whether or not it takes a positive value (step S507). Here, when it is determined that the learning value Nstd of the marginal rotation speed takes a positive value (step S507: Yes), the learning value Nstd is reflected on the learning map Nmarg_mod_map by one method, and this learning value is used. The map Nmarg_mod_map is changed while being updated (step S508). Specifically, when it is determined that the learned value Nstd of the marginal rotation speed takes a positive value, the timing at which the shift speed is actually completed (so-called measured value of the timing at which the shift speed is completed) is Since it is later in time on the time axis than the estimated or predicted timing (so-called estimated value of timing for completing gear shift switching) that the gear shift is completed, the shock that occurs during gear shifting is suppressed. Various control processes for this purpose have already been executed. Therefore, the degree of reflection of the learning value may be gradually performed with time. More specifically, as shown in the following Expression 53, the learning map Nmarg_mod_map after reflecting the learning value is set to a learning value Nstd smaller than 1 with respect to the learning map Nmarg_mod_map before reflecting the learning value. You may update by adding the value which multiplied the coefficient b.

Nmarg_mod_map = Nmarg_mod_map + Nstd × b
…………… 53
On the other hand, as a result of the determination in step S507, when it is not determined that the learning value Nstd of the marginal rotation speed takes a positive value, that is, when it is determined that the learning value Nstd takes a negative value (step S507: No), the learning value Nstd is The learning map Nmarg_mod_map is reflected by the other method, and the learning map Nmarg_mod_map is changed while being updated (step S509). Specifically, when the learning value Nstd of the marginal rotation speed takes a negative value, the timing at which the shift speed is actually completed (the so-called measured value at which the shift speed is completed) is Various timings for suppressing a shock that occurs during a shift earlier on the time axis than the timing estimated or predicted that the switching is completed (so-called estimated value of the timing when the shift stage is completed). Since the start of the control process is also delayed, the learning value may be reflected more quickly and appropriately with time. More specifically, as shown in the following equation 54, the learning map Nmarg_mod_map after reflecting the learning value is multiplied by the predetermined coefficient c larger than 1 to the learning map Nmarg_mod_map before reflecting the learning value. It is good as a value.

Nmarg_mod_map = Nstd × c ………… 54
If the learning map Nmarg_mod_map after reflecting the learning value is constantly updated with a value obtained by multiplying the learning map Nmarg_mod_map before reflecting the learning value by a predetermined coefficient smaller than 1, this occurs at the time of shifting. Since the start of various control processes for suppressing the shock is delayed, the driver feels shocked. Specifically, when the learning map Nmarg_mod_map is constantly updated with a value multiplied by a predetermined coefficient smaller than 1, an actual measurement value of the timing at which the gear shift is completed and an estimation of the timing at which the gear shift is completed. Based on the difference from the value, the time interval for appropriately updating the learning map becomes long. For this reason, since the driver repeatedly and continuously feels the shock generated at the time of the shift until the learning map acquires the optimum value, the driver feels uncomfortable in driving operation.

  Specifically, as shown in FIG. 8A, for example, when the actual measurement value of the timing at which the shift stage is completed is later on the time axis than the estimated value of the timing at which the shift stage is completed. In other words, when the estimated value is earlier on the time axis than the actually measured value, the torque change that occurs at the time of gear shift switching is performed earlier than the actual gear shift timing. Therefore, as shown in FIG. 8B, it becomes difficult to quickly reduce the change in the acceleration of the vehicle, and it takes a long time for the acceleration to converge to a constant value.

  Or, specifically, as shown in FIG. 8A, for example, the actual measurement value of the timing at which the shift speed change is completed is greater than the estimated value of the timing at which the shift speed change is completed on the time axis. If it is early, in other words, if the estimated value is later on the time axis than the actually measured value, a change in torque that occurs when the gear is switched is performed later than the actual gear shift timing. Therefore, as shown in FIG. 8B, the change in the acceleration of the vehicle becomes large, causing the driver to repeatedly and continuously feel the shock generated at the time of shifting. In addition, since it takes a long time for the acceleration to converge to a constant value, the driver feels uncomfortable in driving operation.

  On the other hand, according to the present embodiment, in accordance with step S508 described above, the actual measurement value of the timing at which the shift stage is completed is later on the time axis than the estimated value of the timing at which the shift stage is completed. Then, the learning map Nmarg_mod_map after reflecting the learning value is updated by adding a value obtained by multiplying the learning value Nstd by a predetermined coefficient b to the learning map Nmarg_mod_map before reflecting the learning value. Therefore, in a driving state in which various control processes for suppressing a shock that occurs during a shift are executed before the timing at which the shift stage is actually completed, the shift timing learning process is more advanced. Accurate and appropriate. Specifically, as shown in FIG. 8A, when the actual measurement value of the timing at which the gear shift is completed is approximately equal to the estimated value of the timing at which the gear shift is completed, the gear shift is performed. The change in torque generated at this time is substantially equal to the actual shift timing of the shift speed. Therefore, as shown in FIG. 8B, it is possible to quickly reduce the change in the acceleration of the vehicle, and to quickly converge the acceleration to a constant value.

  As a result, the overall control of the internal combustion engine including the output control of the internal combustion engine corresponding to the shift timing can be quickly converged to a stable state. Therefore, it is possible to realize overall control of the internal combustion engine that responds more appropriately, more stably, and more quickly to the shift timing.

  On the other hand, according to the present embodiment, when the measured value of the timing at which the shift stage is completed is earlier on the time axis than the estimated value of the timing at which the shift stage is completed, the learning value is obtained in accordance with step S509 described above. Is updated with a value obtained by multiplying the learning map Nmarg_mod_map before reflecting the learning value by a predetermined coefficient c greater than 1.

  As a result, when a shock that occurs during a shift occurs once in the operating state where the measured value of the timing at which the gear shift is completed is earlier on the time axis than the estimated timing at which the gear shift is completed Thus, it is possible to remarkably increase the certainty of delaying the timing at which the shift stage is actually completed from the estimated value of the timing at which the shift stage is completed. Accordingly, it is possible to quickly eliminate the driver from repeatedly and continuously feeling the shock generated at the time of shifting, and to almost or completely eliminate discomfort in driving operation.

  As a result of the above, a shock that occurs when the shift speed is actually switched by comparing the measured value of the shift speed switching timing with the estimated value estimated by the learning map and appropriately changing the learning map. Can be effectively reduced, and at the same time, the responsiveness during the output control of the internal combustion engine can be significantly improved.

  On the other hand, as a result of the determination in step S503 described above, when it is not determined that the shift speed switching has actually been completed (step S503: No), it is further determined whether the marginal rotation speed Nmarg is 0 or less (step S510). ). Here, when the marginal rotation speed Nmarg is 0 or less (step S510: Yes), the shift timing determination flag Nmarg_jdg is set, in other words, “1” is substituted into the variable Nmarg_jdg (step S511). In addition to this, the ECU 20 may be notified that the switching of the shift speed is actually completed.

  On the other hand, if the result of the determination in step S510 is that the marginal rotation speed Nmarg is not 0 or less (No in step S510), the determination flag Nmarg_jdg is cleared, in other words, “0” is substituted into the variable Nmarg_jdg (step S512). ). In addition to this, the ECU 20 may not be notified of the fact that the shift stage switching has actually been completed. As a result, the learning process of the above-described series of shift timings is repeatedly performed, so that the timing at which the shift stage switching is actually completed, the timing estimated or predicted that the shift stage switching is completed, and Are corrected in the direction in which they substantially coincide with each other, so that the timing estimated or predicted as the completion of the shift speed change is optimized.

  And it progresses to step S6 of FIG. 2 mentioned above.

  In step S6 of FIG. 2, the output torque difference ΔTo at the shift timing is estimated. FIG. 9 is a flowchart showing details of the output torque difference estimation process executed in step S6. As shown in FIG. 9, first, in step S61, the turbine torque Tt is detected by referring to the signal from the turbine torque sensor 24, and in the subsequent step S62, the signal of the transmission output torque sensor 26 is referred to to determine the transmission. The output torque To is detected.

  Next, in step S63, a pre-shift output torque To_b that is an output torque of the output shaft 7 of the automatic transmission 5 before the shift is calculated. Here, the transmission output torque To detected in step S62 is defined as the pre-shift output torque To_b. Next, in step S64, a post-shift output torque To_a that is an output torque of the output shaft 7 of the automatic transmission 5 after the shift is calculated by Formula 5.

To_a = Tt × Ratio (Sft_a) 5
Next, in step S65, the output torque difference ΔTo is calculated using equation 6, and the process proceeds to step S7 in FIG.

ΔTo = To_a−To_b ……………………… 6
In step S7 of FIG. 2, it is determined whether or not the shift timing determination flag Nmarg_jdg is set. If it is set, the process proceeds to step S8. Otherwise, the process proceeds to step S11, and the output torque difference ΔTo is set. Zero.

  In step S8, the resonance frequency fv in the drive system of the internal combustion engine 2 is read. The resonance frequency fv is preset for each gear position, that is, for each gear ratio, and the corresponding relationship is stored in the ROM of the ECU 20. Thereby, ECU20 functions as a resonance frequency memory | storage means. After reading the resonance frequency fv corresponding to the gear position after the downshift in step S8, the process proceeds to step S9 to calculate the engine required torque Te_dem.

  FIG. 10 is a flowchart showing details of the engine required torque calculation process executed in step S9 of FIG. First, in step S91, referring to the output signal of the transmission output torque sensor 26, the transmission output torque To is detected. Next, in step S92, a transmission required torque addition value To_fill is calculated. This torque addition value To_fill is obtained by removing the component corresponding to the resonance frequency fv from the output torque difference ΔTo, and corresponds to the amount of change in the transmission required torque according to the present invention. This torque addition value To_fill can be obtained by using, for example, a band elimination filter that blocks passage of a component corresponding to the resonance frequency fv and allows passage of other components.

  Next, in step S93, the transmission required torque To_dem is calculated by Equation 7.

To_dem = To + To_fill ……………………… 7
Next, in step S94, the torque ratio t of the torque converter 4 is calculated. The calculation of the torque ratio t can be realized, for example, by preparing in advance a map that gives the torque ratio t using the ratio Nt / Ne between the turbine speed Nt and the engine speed Ne as a variable, and referring to the map.

  Next, in step S95, the gear ratio required torque To_dem is converted into the engine required torque Te_dem. Here, a map for giving the engine required torque Te_dem is prepared using the transmission required torque To_dem, the shift stage Sft_a after the shift and the torque ratio t as variables, and this conversion is realized by referring to the map. Then, the process proceeds to step S10 in FIG.

  In step S10 of FIG. 2, the fuel injection amount of the internal combustion engine 2 is controlled so that the engine required torque Te_dem calculated in step S9 is output from the crankshaft 3, and this routine is finished.

By executing the above control routine, the engine required torque Te_dem that can suppress resonance with the drive system of the internal combustion engine 2 is output from the internal combustion engine 2 on the condition that the shift timing has been reached, and the engine required torque Te_dem Is calculated based on the output torque difference ΔTo that can occur before and after the downshift. As a result, it is possible to reduce the shock that occurs during the downshift, and it is possible to prevent the output torque of the internal combustion engine 2 from excessively decreasing in order to reduce the shock. Accordingly, it is possible to sharpen the torque rise from the start to the end of the downshift while reducing the shock that occurs during the downshift.
(Second form)
Next, a second embodiment of the present invention will be described with reference to FIG. This form is the same as the first form except for the content of the engine required torque calculation process executed in step S9 of FIG. Therefore, the description of the same part as the first embodiment is omitted below. FIG. 12 shows the contents of the engine required torque calculation process according to the second embodiment. The same processes as those in the engine required torque calculation process shown in FIG. 10 according to the first embodiment are denoted by the same reference numerals and description thereof is omitted. After calculating the torque ratio t in step S94, the process proceeds to step S951, and the turbine required torque Tt_dem is calculated using Equation 8.

Tt_dem = To_dem × Ratio (Sft_a) + It × ΔNt ...... 8
Here, It is the inertia torque of the turbine 4b.

  Next, proceeding to step S952, the turbine required torque Tt_dem is converted into the engine required torque Te_dem. Here, a map that provides the engine required torque Te_dem with the turbine required torque Tt_dem and the torque ratio t as variables is prepared, and this conversion is realized by referring to the map.

According to the second mode, since the turbine required torque Tt_dem is calculated in accordance with the gear ratio after the downshift, it is necessary to consider the gear position in order to calculate the engine required torque Te_dem as in the first mode. There is no. Accordingly, there is an advantage that the map variable is reduced by one as compared with the first form, and the map information amount can be reduced.
(Third form)
Next, a third embodiment of the present invention will be described with reference to FIG. This form is the same as the first form except for the content of the engine required torque calculation process executed in step S9 of FIG. Therefore, the description of the same part as the first embodiment is omitted below. FIG. 13 shows the contents of the engine required torque calculation processing according to the third embodiment. The same process as the engine required torque calculation process shown in FIG. After calculating the turbine required torque Tt_dem in step S951, the process proceeds to step S953, and the engine speed change ΔNe is calculated. This time change means a change in the engine speed Ne from the previous calculation time to the current calculation time. Next, the process proceeds to step S954, and the pump request torque Tp_dem of the pump 4a of the torque converter 4 is calculated based on Equation 9.

Tp_dem = Tt_dem / t ……………………… 9
Next, the pump request torque Tp_dem is converted into the engine request torque Te_dem based on Expression 10.

Te_dem = Tp_dem + Ip × ΔNe ………………………… 10
Here, Ip is the inertia torque of the pump 4a.

According to the third embodiment, since no map is required to calculate the engine required torque Te_dem, there is an advantage that labor for creating the map can be reduced. Further, since the inertia of the torque converter 4 is taken into account in the process of calculating the engine required torque Te_dem, the calculation accuracy of the engine required torque Te_dem is improved.
(4th form)
Next, a fourth embodiment of the present invention will be described with reference to FIG. This mode is characterized by the method of estimating the output torque difference, and can be applied to each mode described above. Hereinafter, description of common parts with the above-described embodiments will be omitted. In each of the embodiments described above, the turbine torque Tt and the transmission output torque To are detected by the torque sensors 24 and 26 in steps S61 and S62 of FIG. 9 in order to estimate the output torque difference. Then, the output torque difference is estimated without providing these torque sensors. FIG. 14 is a flowchart showing details of the output torque difference estimation processing according to the fourth embodiment. First, in step S261, the ECU 20 calculates the engine output torque Te, which is the output torque of the crankshaft 3, based on the accelerator opening Acc and the engine rotational speed Ne. Calculation of the engine output torque Te can be realized by preparing a map for giving the engine output torque Te using the engine speed Ne and the accelerator opening Acc as variables as shown in FIG. 15 and referring to the map.

  Next, in step S262, the pre-shift output torque To_b is calculated using Equation 11.

To_b = Te × Ratio (Sft_b) 11
Next, in step S263, the post-shift output torque To_a is calculated using Equation 12.

To_a = Te × Ratio (Sft_a) ……………………… 12
Next, in step S264, the output torque difference ΔTo is calculated by the above-described equation 6, and the process proceeds to step S7 in FIG.

The pre-shift output torque To_b and the post-shift output torque To_a can also be calculated by other methods described below.
(Calculation of pre-shift output torque To_b)
(1-1) Assuming that the torque is not completely transmitted by the automatic transmission 5 immediately before the completion of the shift, the pre-shift output torque To_b may be calculated as 0 (zero) based on the assumption.
(1-2) It is assumed that the torque is not completely transmitted by the automatic transmission 5 immediately before the completion of the shift and is in a driven state by the drive wheels 10, and based on the assumption, the output torque To_b before the shift is obtained by Expression 13. May be calculated.

To_b = (R / L) × r / R_dif × b ……………………… 13
Here, R / L is a running resistance, and is calculated by a map or function using the running speed V of the vehicle 1 as a variable. The traveling speed V of the vehicle 1 is detected based on an output signal from a vehicle speed sensor (not shown). Also, r is the rotation radius of the drive wheel 10, R_dif is the gear ratio of the differential device 8, b is the efficiency of the differential device 8, and these are held in the ECU 20 in advance.
(1-3) The pre-shift output torque To_b can also be calculated by the formula (14) taking into account the longitudinal acceleration G of the vehicle in the method (1-2).

To_b = (G × M + R / L) × r / R_dif × b ……………………… 14
Here, M is the weight of the vehicle 1. The acceleration G can be detected by providing an acceleration sensor in the vehicle 1 and can be detected from the acceleration sensor, or can be calculated by time differentiation of the vehicle speed.
(1-4) Before the shift is completed, most of the turbine torque is used for increasing the rotation. Therefore, Formula 15 is established between the turbine torque Tt and the pump torque Tp in consideration of the inertia of the turbine.

Tt = Tp × t−It × ΔNt 15
Here, the pump torque Tp can be obtained by Expression 16.

Tp = C × Ne2 ……………………… 16
C in Expression 16 is a capacity coefficient of the torque converter. Based on the turbine torque Tt obtained by Expression 15, the output torque To_b before shifting can be calculated by Expression 17.

To_b = Tt × Ratio (Sft_b) ……………………… 17
(Calculation of post-shift output torque To_a)
(2-1) First, the engine output torque Te is calculated by the above-described method, and the pump torque Tp is calculated by Expression 18 using the engine output torque Te and the temporal change ΔNe of the engine speed.

Tp = Te−Ip × ΔNe …………………… 18
The pump torque Tp obtained by Expression 18 is substituted into Expression 15 to obtain the turbine torque Tt, and the turbine torque Tt is substituted into Expression 19 to calculate the post-shift output torque To_a. Note that, when obtaining the turbine torque Tt in Expression 15, it may be considered that ΔNt = 0 in consideration of the fact that ΔNt becomes smaller immediately after the shift.

To_a = Tt × Ratio (Sft_a) ……………………… 19
(2-2) Further, the post-shift output torque To_a can be calculated in the same manner as (1-4) above. That is, the pump torque Tp is obtained by Expression 16, the pump torque Tp is substituted into Expression 15, the turbine torque Tt is calculated, and the post-shift output torque To_a can be calculated by Expression 19. Note that, when obtaining the turbine torque Tt in Expression 15, it may be considered that ΔNt = 0 in consideration of the fact that ΔNt becomes smaller immediately after the shift.

  In Step S262 and Step S263 in FIG. 14, the above method is appropriately selected, and the output torque difference ΔTo without using the torque sensors 24 and 26 is calculated by calculating the output torque To_b before the shift and the output torque To_a after the shift, respectively. Can be estimated in various ways.

  In each of the above embodiments, by executing the process of step S5 (FIG. 4) of FIG. 2, the ECU 20 executes the process of step S6 (FIG. 9 or FIG. 14) of FIG. 2 as the shift timing estimating means according to the present invention. As a result, the ECU 20 executes the process of step S9 (FIG. 10, FIG. 12, or FIG. 13) of FIG. 2 as the output torque difference estimating means according to the present invention, whereby the ECU 20 serves as the engine required torque calculating means according to the present invention. The ECU 20 functions as engine control means by executing the processing of step S10 in FIG.

  Further, by executing the processing of step S51 to step S55 in FIG. 4, the ECU 20 functions as a surplus rotation speed predicting unit, and by executing the processing of step S56 to step S58 in FIG. Function.

  Further, by executing the processing of steps S91 to S93 of FIGS. 10, 12, and 13, the ECU 20 can perform step S95 of FIG. 10, step S952 of FIG. By executing the process of step S955 in step 13, the ECU 20 functions as a conversion unit according to the present invention.

  However, the present invention is not limited to the above embodiments, and can be implemented in various forms within the scope of the gist of the present invention. In each of the above embodiments, the control device according to the present invention is applied to an internal combustion engine in which an automatic transmission is connected to a crankshaft via a torque converter. However, the control device according to the present invention includes an electromagnetic clutch instead of a torque converter. The present invention can also be applied to the provided internal combustion engine.

  In the above-described embodiment, the learning map for learning the shift timing has been described, but a function, a mathematical model, a linear combination, or the like for learning the shift timing is applied theoretically, experimentally, empirically, or in a simulation. You can do it.

  The present invention is not limited to the above-described embodiment, and can be appropriately changed without departing from the gist or concept of the invention that can be read from the claims and the entire specification, and the control of the internal combustion engine accompanying such a change. The apparatus is also included in the technical scope of the present invention.

The figure which showed the outline of the vehicle carrying the internal combustion engine to which the control apparatus which concerns on this invention was applied. The flowchart which showed an example of the control routine of engine output torque control. Explanatory drawing explaining the outline | summary of a shift timing estimation process. 5 is a flowchart showing details of a shift timing estimation process. 7 is a flowchart showing a series of flow rate learning process. The graph which showed the relationship between the turbine rotational speed Nt corresponding to the rotational speed of the input side of the automatic transmission 5, and transmission output rotational speed No when the gear stage is actually switched. The schematic diagram which showed typically the rotational speed corresponding to the estimated value of the shift timing in the learning process of shift timing, and the rotational speed corresponding to the actual value of the shift timing. A graph showing a change in torque corresponding to a comparison on the time axis between an actual measurement value of the timing at which the gear shift is completed and an estimated value of the timing at which the gear change is completed, and a change in the acceleration of the vehicle. Graph. The flowchart which showed the detail of the output torque difference estimation process. The flowchart which showed the detail of the engine request torque calculation process. The figure which showed an example of the shift map. The flowchart which showed the detail of the engine required torque calculation process which concerns on a 2nd form. The flowchart which showed the detail of the engine required torque calculation process which concerns on a 3rd form. The flowchart which shows the detail of the output torque difference estimation process which concerns on a 4th form. The figure which showed an example of the map for calculating an engine output torque.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Vehicle 2 Internal combustion engine 3 Automatic transmission 4 Torque converter 4a Pump 4b Turbine 20 ECU (estimation means, correction means, map change means, calculation means, engine control means)
24 sensor (detection means)

Claims (6)

An automatic transmission that is connected to the output shaft of the internal combustion engine and is capable of switching to a plurality of gear ratios of different sizes;
Detecting means for detecting an operating state of the internal combustion engine;
Estimating means for estimating a shift timing at which the shift change is completed when a shift change to be switched from one to the other among the small and large gear ratios is performed in the automatic transmission;
Correction means for correcting the estimated shift timing based on a predetermined map using as input information a variable defining the detected driving state;
Map changing means for changing the predetermined map based on the corrected shift timing;
Calculating means for calculating an engine required torque of the internal combustion engine based on an output torque difference of the automatic transmission that can occur before and after the shift change at the time of the shift change;
Engine control means for controlling the internal combustion engine so that the calculated engine required torque is output from the output shaft during the shift change;
A control device for an internal combustion engine, comprising: The automatic transmission is connected to the output shaft of the internal combustion engine via a torque converter including a pump connected to the output shaft of the internal combustion engine and a turbine combined with the pump.
In the process from the start to the completion of the shift change, the estimation means calculates a target rotational speed obtained by multiplying the output rotational speed of the automatic transmission by the speed ratio after the shift change and the turbine rotation of the turbine as the shift timing. A marginal rotational speed given as a difference from the speed is estimated in consideration of the respective temporal changes of the target rotational speed and the turbine rotational speed,
The correction means corrects the estimated marginal rotation speed based on the predetermined map,
2. The control apparatus for an internal combustion engine according to claim 1, wherein the map changing means changes the predetermined map based on the corrected marginal rotation speed.   The correction means is configured to perform the estimation based on a map having, as the predetermined map, a variable that defines an operation state at the time of the shift change as input information and a correction value for correcting the marginal rotation speed as output information. 3. The control apparatus for an internal combustion engine according to claim 2, wherein the shift timing is corrected.   (Ii) In addition to or instead of not changing the predetermined map when the absolute value of the corrected margin rotational speed is smaller than a predetermined value, (ii) the corrected margin rotational speed 4. The control apparatus for an internal combustion engine according to claim 2, wherein the predetermined map is changed when the absolute value of is larger than a predetermined value.   The map changing means (i) adds the predetermined amount of offset to the predetermined map when the estimated shift timing is earlier than the actual timing when the shift change is actually completed, thereby In addition to or instead of changing, (ii) if the estimated shift timing is later than the actual timing when the shift change is actually completed, the predetermined map is multiplied by a predetermined coefficient greater than 1, The control device for an internal combustion engine according to any one of claims 2 to 4, wherein the predetermined map is changed.   The map changing means determines the estimated shift timing based on a timing at which the time change of the turbine rotation speed and the time change of the target rotation speed are equal during the shift change as the actual timing. The control device for an internal combustion engine according to claim 5, wherein the control device specifies that the timing is earlier or later than the actual timing.

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