JP2010209881A - Engine control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To accurately control engine torque according to the atmospheric pressure. <P>SOLUTION: An engine is controlled according to a torque demand amount set based on an accelerator opening. The torque demand amount is corrected according to an intake amount detected by an airflow meter. The torque demand amount is corrected to become larger as the atmospheric pressure becomes lower. The torque demand amount is corrected to be low until learning of the correction amount of the torque demand amount determined according to the intake amount is completed. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an engine control device, and more particularly to a technique for correcting an operation amount of an adjustment mechanism that adjusts a target value of engine output or an intake air amount according to atmospheric pressure.

  Conventionally, an engine in which the intake air amount is adjusted according to the throttle opening of the throttle valve or the lift amount of the intake valve is known. The engine output torque (engine torque) or the like changes according to the intake air amount. When a vehicle travels in a high altitude area where the atmospheric pressure is low, the intake air amount can decrease compared to the low altitude area even if the throttle opening or lift amount is the same due to the low air density. . Therefore, the output torque can be reduced. In view of this, a technique for correcting the throttle opening and the like in accordance with the atmospheric pressure has been put into practical use, as in the engine control device described in Japanese Patent Application Laid-Open No. 11-153058 (Patent Document 1).

Japanese Patent Laid-Open No. 11-153058

  By the way, the correction of the throttle opening degree according to the atmospheric pressure is executed when a predetermined condition is satisfied. Therefore, after the throttle opening is corrected so as to adapt to a state where the atmospheric pressure is low, if the vehicle moves to a lowland without satisfying the conditions for correction, the engine torque may increase more than necessary.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide an engine control device that can accurately control the output of the engine in accordance with the atmospheric pressure.

  An engine control apparatus according to a first aspect of the present invention is an engine control apparatus provided with an adjustment mechanism that adjusts an intake air amount in accordance with a magnitude of an operation amount. The control device includes a control unit for controlling the adjustment mechanism in accordance with a target value of the engine output, and a first for correcting at least one of the target value and the operation amount in accordance with the intake air amount. A correction means, a learning means for learning a correction amount determined according to the intake air amount of at least one of the target value and the operation amount, an estimation means for estimating the atmospheric pressure from the intake air amount, The second correction means for correcting at least one of the target value and the operation amount so as to increase as the atmospheric pressure decreases and until the learning of the correction amount determined according to the intake air amount is completed. Reverse correction means for correcting so as to reduce at least one of the target value of the output and the operation amount.

  According to this configuration, the intake amount of the engine is adjusted according to the amount of operation of the adjustment mechanism. The adjusting mechanism is controlled according to the target value of the engine output. At least one of the target value and the operation amount is corrected according to the intake air amount. The correction amount is learned. As a result, a desired intake air amount can be ensured even if the channel resistance increases due to deposits or the like attached to the adjustment mechanism. Further, at least one of the target value of the engine output and the operation amount of the adjustment mechanism is corrected so as to increase as the atmospheric pressure estimated from the intake air amount decreases. As a result, it is possible to compensate for the decrease in engine output due to the decrease in atmospheric pressure. Therefore, a desired output can be obtained even at high altitudes. If the vehicle moves to a place where the atmospheric pressure is high, the target value of the engine output or the operation amount of the adjusting mechanism is corrected again based on the high atmospheric pressure. However, especially when the intake air amount is small, the amount of change in the intake air amount accompanying the change in atmospheric pressure is small. Therefore, it is difficult to distinguish whether the change in the intake air amount is due to a change in atmospheric pressure or the influence of deposits or the like attached to the adjustment mechanism. For this reason, correction based on atmospheric pressure may be erroneously performed due to the influence of deposits and the like attached to the adjustment mechanism. While the correction based on the atmospheric pressure can be erroneously performed due to the deposit or the like attached to the adjustment mechanism, the correction based on the atmospheric pressure should not be performed. However, if the target value of the engine output or the operating amount of the adjustment mechanism is corrected in an environment where the atmospheric pressure is low, if the correction is not made in a state where the atmospheric pressure is high, the engine output will increase more than necessary. obtain. Therefore, until learning of the correction amount determined according to the intake air amount is completed, that is, while learning is not completed, instead of performing correction based on the atmospheric pressure, the target value of the engine output or the adjustment mechanism The operating amount is reduced. As a result, if correction based on atmospheric pressure can be erroneously performed due to deposits or the like adhering to the adjustment mechanism, the target value of the engine output or operation of the adjustment mechanism is not performed without performing correction based on atmospheric pressure. The amount can be reduced. Therefore, even if the target value of the engine output or the operating amount of the adjusting mechanism is corrected to be large based on the low atmospheric pressure in an environment where the atmospheric pressure is high, the engine output does not become excessive. Can be. Therefore, it is possible to provide an engine control device that can accurately control the output of the engine according to the atmospheric pressure.

  In the engine control apparatus according to the second invention, in addition to the configuration of the first invention, the reverse correction means predetermines a correction amount of at least one of the target value of engine output and the operation amount. Means for limiting at a specified limit value.

  According to this configuration, if the target value of the engine output or the operation amount of the adjustment mechanism is appropriately corrected based on the high atmospheric pressure, an unnecessary reduction amount of the engine output can be limited. .

  In the engine control apparatus according to the third aspect of the invention, in addition to the configuration of the second aspect of the invention, the engine is mounted on the vehicle. The limit value is determined in consideration of the magnitude of shock generated in the vehicle.

  According to this configuration, even if the target value of the engine output or the operation amount of the adjustment mechanism is corrected based on the low atmospheric pressure, the shock that can be generated in the vehicle can be reduced. .

  In the engine control apparatus according to the fourth aspect of the invention, in addition to the configuration of the second aspect of the invention, the engine is mounted on a vehicle. The limit value is determined in consideration of the strength of the vehicle.

  According to this configuration, even if the target value of the engine output or the operation amount of the adjustment mechanism remains corrected based on the low atmospheric pressure, the increase amount of the engine output is considered in consideration of the strength of the vehicle. Can be kept within an acceptable range.

  In the engine control apparatus according to the fifth invention, in addition to the configuration of any one of the first to fourth inventions, the target value is a target value of the output torque.

  According to this configuration, the output torque of the engine can be accurately controlled according to the atmospheric pressure.

  In the engine control apparatus according to the sixth invention, in addition to the configuration of any one of the first to fifth inventions, the adjustment mechanism is a throttle valve.

  According to this configuration, the operation amount of the throttle valve, that is, the throttle opening can be accurately controlled according to the atmospheric pressure.

It is a schematic block diagram which shows the power train of a vehicle. It is a skeleton figure which shows the planetary gear unit of an automatic transmission. It is a figure which shows the operation | movement table | surface of an automatic transmission. It is a figure which shows the hydraulic circuit of an automatic transmission. It is a functional block diagram of ECU. It is a figure which shows a torque requirement amount and an engine torque. It is a figure which shows the amount of torque requirements. It is a figure which shows the torque requirement amount correct | amended so that an engine torque may not exceed the torque which can be permitted on drivability. It is a figure which shows the torque requirement amount correct | amended so that an engine torque may not exceed the torque allowable on intensity | strength. It is a figure which shows the engine torque implement | achieved. It is a flowchart which shows the control structure of the program which engine ECU performs. It is a flowchart which shows the control structure of the program which ECT-ECU performs.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, the same parts are denoted by the same reference numerals. Their names and functions are also the same. Therefore, detailed description thereof will not be repeated.

  With reference to FIG. 1, the power train 100 in this Embodiment is demonstrated. The vehicle provided with the power train 100 is an FR (Front engine Rear drive) vehicle. A vehicle other than FR may be used.

  The power train 100 includes an engine 1000, an automatic transmission 2000, a torque converter 2100, a planetary gear unit 3000 that forms part of the automatic transmission 2000, a hydraulic circuit 4000 that forms part of the automatic transmission 2000, and a propeller shaft 5000. And a differential gear 6000. The power train 100 is controlled by an ECU (Electronic Control Unit) 8000.

  The engine 1000 is an internal combustion engine that ignites an air-fuel mixture of fuel and air injected from an injector (not shown) with an ignition plug 1002 and burns it in a combustion chamber of a cylinder. The piston in the cylinder is pushed down by the combustion, and the crankshaft is rotated. The auxiliary power 1004 such as an alternator and an air conditioner is driven by the driving force of the engine 1000.

  Automatic transmission 2000 is connected to engine 1000 via torque converter 2100. Automatic transmission 2000 changes the rotational speed of the crankshaft to a desired rotational speed by forming a desired gear stage.

  The driving force output from automatic transmission 2000 is transmitted to left and right rear wheels 7000 via propeller shaft 5000 and differential gear 6000.

  The ECU 8000 includes a position switch 8006 for the shift lever 8004, an accelerator opening sensor 8010 for the accelerator pedal 8008, a pedaling force sensor 8014 for the brake pedal 8012, a throttle opening sensor 8018 for the electronic throttle valve 8016, and an engine speed sensor 8020. The input shaft rotational speed sensor 8022, the output shaft rotational speed sensor 8024, the oil temperature sensor 8026, and the air flow meter 8028 are connected via a harness or the like.

  The position (position) of shift lever 8004 is detected by position switch 8006, and a signal representing the detection result is transmitted to ECU 8000. Corresponding to the position of the shift lever 8004, the gear stage of the automatic transmission 2000 is automatically formed. Further, a manual shift mode in which the driver can select an arbitrary gear stage may be selected according to the driver's operation.

  Accelerator opening sensor 8010 detects the opening of accelerator pedal 8008 and transmits a signal representing the detection result to ECU 8000. The pedaling force sensor 8014 detects the pedaling force of the brake pedal 8012 (the force with which the driver steps on the brake pedal 8012), and transmits a signal representing the detection result to the ECU 8000.

  The throttle opening sensor 8018 detects the opening of the electronic throttle valve 8016 whose opening is adjusted by the actuator, and transmits a signal representing the detection result to the ECU 8000. Electronic throttle valve 8016 adjusts the amount of air taken into engine 1000 (output of engine 1000).

  Instead of or in addition to the electronic throttle valve 8016, the amount of air drawn into the engine 1000 can be reduced by changing the lift amount of the intake valve (not shown) or the exhaust valve (not shown) and the opening / closing phase. You may make it adjust.

  Engine rotation speed sensor 8020 detects the rotation speed of the output shaft (crankshaft) of engine 1000 and transmits a signal representing the detection result to ECU 8000. Input shaft rotational speed sensor 8022 detects input shaft rotational speed NI of automatic transmission 2000 (turbine rotational speed NT of torque converter 2100), and transmits a signal representing the detection result to ECU 8000. Output shaft rotational speed sensor 8024 detects output shaft rotational speed NO of automatic transmission 2000 and transmits a signal representing the detection result to ECU 8000.

  Oil temperature sensor 8026 detects the temperature (oil temperature) of oil (ATF: Automatic Transmission Fluid) used for the operation and lubrication of automatic transmission 2000, and transmits a signal indicating the detection result to ECU 8000.

  Air flow meter 8028 detects the intake amount of engine 1000 and transmits a signal representing the detection result to ECU 8000.

  The ECU 8000 includes a position switch 8006, an accelerator opening sensor 8010, a pedaling force sensor 8014, a throttle opening sensor 8018, an engine speed sensor 8020, an input shaft speed sensor 8022, an output shaft speed sensor 8024, an oil temperature sensor 8026, and an air flow meter. Based on a signal sent from 8028 or the like, a map and a program stored in a ROM (Read Only Memory), the devices are controlled so that the vehicle is in a desired running state.

In the present embodiment, ECU 8000 has the forward 1st to 8th gears when the shift lever 8004 is in the D (drive) position and the D (drive) range is selected as the shift range of automatic transmission 2000. Automatic transmission 2000 is controlled so that one of these gears is formed. The automatic transmission 2000 can transmit a driving force to the rear wheel 7000 by forming any one of the first to eighth forward gears. In the D range, it may be possible to form a higher gear than the eighth gear. The gear stage to be formed is determined based on, for example, a shift diagram prepared in advance by experiments or the like using the vehicle speed and the target driving force as parameters.

  As shown in FIG. 1, ECU 8000 includes an engine ECU 8100 that controls engine 1000 and an ECT (Electronic Controlled Transmission) -ECU 8200 that controls automatic transmission 2000.

  Engine ECU 8100 and ECT-ECU 8200 are configured to be able to transmit and receive signals to and from each other.

  The planetary gear unit 3000 will be described with reference to FIG. Planetary gear unit 3000 is connected to a torque converter 2100 having an input shaft 2102 coupled to the crankshaft.

  The planetary gear unit 3000 includes a front planetary 3100, a rear planetary 3200, a C1 clutch 3301, a C2 clutch 3302, a C3 clutch 3303, a C4 clutch 3304, a B1 brake 3311, a B2 brake 3312, and a one-way clutch (F). 3320.

  The front planetary 3100 is a double pinion type planetary gear mechanism. Front planetary 3100 includes a first sun gear (S1) 3102, a pair of first pinion gears (P1) 3104, a carrier (CA) 3106, and a ring gear (R) 3108.

  The first pinion gear (P1) 3104 meshes with the first sun gear (S1) 3102 and the first ring gear (R) 3108. The first carrier (CA) 3106 supports the first pinion gear (P1) 3104 so that it can revolve and rotate.

  First sun gear (S1) 3102 is fixed to gear case 3400 so as not to rotate. First carrier (CA) 3106 is coupled to input shaft 3002 of planetary gear unit 3000.

  The rear planetary 3200 is a Ravigneaux type planetary gear mechanism. The rear planetary 3200 includes a second sun gear (S2) 3202, a second pinion gear (P2) 3204, a rear carrier (RCA) 3206, a rear ring gear (RR) 3208, a third sun gear (S3) 3210, a third Pinion gear (P3) 3212.

  Second pinion gear (P2) 3204 meshes with second sun gear (S2) 3202, rear ring gear (RR) 3208, and third pinion gear (P3) 3212. Third pinion gear (P3) 3212 meshes with third sun gear (S3) 3210 in addition to second pinion gear (P2) 3204.

  The rear carrier (RCA) 3206 supports the second pinion gear (P2) 3204 and the third pinion gear (P3) 3212 so that they can revolve and rotate. Rear carrier (RCA) 3206 is coupled to one-way clutch (F) 3320. The rear carrier (RCA) 3206 becomes non-rotatable when driving the first gear (when traveling using the driving force output from the engine 1000). Rear ring gear (RR) 3208 is coupled to output shaft 3004 of planetary gear unit 3000.

  The one-way clutch (F) 3320 is provided in parallel with the B2 brake 3312. That is, the outer race of the one-way clutch (F) 3320 is fixed to the gear case 3400, and the inner race is connected to the rear carrier (RCA) 3206.

  FIG. 3 shows an operation table showing the relationship between each gear position and the operation state of each clutch and each brake. By operating the brakes and the clutches in the combinations shown in the operation table, a forward 1st to 8th gear and a reverse 1st and 2nd gear are formed.

  As apparent from the operation table of FIG. 3, for example, when upshifting from the third forward gear to the fourth forward gear, the C3 clutch 3303 is changed from the engaged state to the released state, and the C4 clutch 3304 is released. To the engaged state.

  The main part of the hydraulic circuit 4000 will be described with reference to FIG. The hydraulic circuit 4000 is not limited to the one described below.

  The hydraulic circuit 4000 includes an oil pump 4004, a primary regulator valve 4006, a manual valve 4100, a solenoid modulator valve 4200, an SL1 linear solenoid (hereinafter referred to as SL (1)) 4210, and an SL2 linear solenoid (hereinafter referred to as “the solenoid valve”). SL2 (described as SL (4)) 4220, SL3 linear solenoid (hereinafter referred to as SL (3)) 4230, SL4 linear solenoid (hereinafter referred to as SL (4)) 4240, and SL5 linear solenoid (hereinafter referred to as SL (3)). , SL (5)) 4250, SLT linear solenoid (hereinafter referred to as SLT) 4300, and B2 control valve 4500.

  Oil pump 4004 is connected to the crankshaft of engine 1000. As the crankshaft rotates, the oil pump 4004 is driven to generate hydraulic pressure. The hydraulic pressure generated by the oil pump 4004 is regulated by the primary regulator valve 4006 to generate a line pressure.

  Primary regulator valve 4006 operates using the throttle pressure regulated by SLT 4300 as a pilot pressure. The line pressure is supplied to the manual valve 4100 via the line pressure oil passage 4010.

  Manual valve 4100 includes a drain port 4105. From the drain port 4105, the oil pressure in the D range pressure oil passage 4102 and the R range pressure oil passage 4104 is discharged. When the spool of the manual valve 4100 is in the D position, the line pressure oil passage 4010 and the D range pressure oil passage 4102 are communicated, and hydraulic pressure is supplied to the D range pressure oil passage 4102. At this time, the R range pressure oil passage 4104 and the drain port 4105 are communicated, and the R range pressure of the R range pressure oil passage 4104 is discharged from the drain port 4105.

  When the spool of the manual valve 4100 is in the R position, the line pressure oil passage 4010 and the R range pressure oil passage 4104 are communicated, and the oil pressure is supplied to the R range pressure oil passage 4104. At this time, the D range pressure oil passage 4102 and the drain port 4105 are communicated, and the D range pressure in the D range pressure oil passage 4102 is discharged from the drain port 4105.

  When the spool of the manual valve 4100 is in the N position, both the D range pressure oil passage 4102 and the R range pressure oil passage 4104 are connected to the drain port 4105, and the D range pressure and R of the D range pressure oil passage 4102 are communicated. The R range pressure of the range pressure oil passage 4104 is discharged from the drain port 4105.

  The hydraulic pressure supplied to the D range pressure oil path 4102 is finally supplied to the C1 clutch 3301, the C2 clutch 3302, and the C3 clutch 3303. The hydraulic pressure supplied to the R range pressure oil passage 4104 is finally supplied to the B2 brake 3312.

  The solenoid modulator valve 4200 adjusts the hydraulic pressure (solenoid modulator pressure) supplied to the SLT 4300 to a constant pressure using the line pressure as the original pressure.

  SL (1) 4210 regulates the hydraulic pressure supplied to the C1 clutch 3301. SL (2) 4220 regulates the hydraulic pressure supplied to C2 clutch 3302. SL (3) 4230 regulates the hydraulic pressure supplied to the C3 clutch 3303. SL (4) 4240 regulates the hydraulic pressure supplied to C4 clutch 3304. SL (5) 4250 regulates the hydraulic pressure supplied to the B1 brake 3311.

  The SLT 4300 adjusts the solenoid modulator pressure in accordance with a control signal from the ECU 8000 based on the accelerator opening detected by the accelerator opening sensor 8010, and generates a throttle pressure. The throttle pressure is supplied to the primary regulator valve 4006 via the SLT oil passage 4302. The throttle pressure is used as a pilot pressure for the primary regulator valve 4006.

  SL (1) 4210, SL (2) 4220, SL (3) 4230, SL (4) 4240, SL (5) 4250, and SLT 4300 are controlled by a control signal transmitted from ECU 8000.

  The B2 control valve 4500 selectively supplies hydraulic pressure from one of the D range pressure oil passage 4102 and the R range pressure oil passage 4104 to the B2 brake 3312. A D range pressure oil passage 4102 and an R range pressure oil passage 4104 are connected to the B2 control valve 4500. The B2 control valve 4500 is controlled by the hydraulic pressure supplied from the SLU solenoid valve (not shown) and the biasing force of the spring.

  When the SLU solenoid valve is on, the B2 control valve 4500 is in the state on the left side in FIG. In this case, the B2 brake 3312 is supplied with the hydraulic pressure adjusted from the D range pressure using the hydraulic pressure supplied from the SLU solenoid valve as a pilot pressure.

  When the SLU solenoid valve is off, the B2 control valve 4500 is in the state on the right side in FIG. In this case, the R range pressure is supplied to the B2 brake 3312.

  The ECU 8000 will be further described with reference to FIG. The functions of ECU 8000 described below may be realized by hardware or may be realized by software.

  Engine ECU 8100 of ECU 8000 includes a torque control unit 8110, an intake air amount correction unit 8120, a learning unit 8122, an atmospheric pressure estimation unit 8130, and an atmospheric pressure correction unit 8132.

  Torque control unit 8110 controls the ignition timing of ignition plug 1002, the throttle opening of electronic throttle valve 8016, and the like so that torque corresponding to the torque request amount requested from ECT-ECU 8200 is output from engine 1000. That is, the throttle opening and ignition timing are determined according to the torque requirement.

  For example, the throttle opening is determined so as to increase as the torque request amount increases. Instead of or in addition to the throttle opening, a VVL (Variable Valve Lift) mechanism may be provided in the engine 1000, and the lift amount of the intake valve may be determined according to the required torque amount.

  The torque request amount indicates a target value of engine torque. Instead of the torque request amount, a target value of engine output power may be determined. The target value of input power of automatic transmission 2000 may be used as the target value of engine output power.

  The intake air amount correction unit 8120 corrects the required torque amount according to the intake air amount detected by the air flow meter 8028. For example, a condition that the atmospheric pressure is lower than the threshold value, a condition that the throttle opening is smaller than the threshold value, and a condition that the load is stable (the load fluctuation amount within a predetermined time is less than the threshold value). The required torque amount is corrected in accordance with the intake air amount. More specifically, the required torque amount is corrected based on the intake air amount and the accelerator opening. When the accelerator opening is a predetermined value, if the intake air amount is smaller than the threshold value, the torque request amount is corrected so as to increase. That is, correction is made so that the torque requirement amount increases as the intake air amount decreases. The correction amount of the torque request amount according to the intake air amount is learned (stored) by the learning unit 8122.

  Instead of correcting the required torque amount, the throttle opening degree determined in accordance with the required torque amount may be increased as the intake air amount is smaller.

  The atmospheric pressure estimation unit 8130 estimates the atmospheric pressure from the intake air amount. For example, the atmospheric pressure is estimated according to a map created in advance using the accelerator opening and the intake air amount as parameters based on the results of experiments and simulations. The method for estimating the atmospheric pressure is not limited to this.

  The atmospheric pressure correction unit 8132 corrects the torque request amount according to the estimated atmospheric pressure. For example, the required torque amount is corrected according to a map created in advance using atmospheric pressure as a parameter based on results of experiments and simulations.

  In view of the fact that the actual engine torque can be lower than the torque request amount as the atmospheric pressure is lower, the torque request amount is larger as shown in FIG. The pressure is corrected so as to increase as the atmospheric pressure decreases. As a result, as indicated by a broken line in FIG. 6, even if the atmospheric pressure is low, it is possible to realize a torque request amount before correction, that is, an engine torque close to the torque required by the driver.

  Instead of correcting the torque request amount, the throttle opening degree determined in accordance with the torque request amount may be increased as the atmospheric pressure is lower.

  Returning to FIG. 5, ECT-ECU 8200 of ECU 8000 includes a torque request unit 8210 and a reverse correction unit 8220.

  Torque requesting unit 8210 sets a target value of output torque of engine 1000, in other words, a torque request amount that automatic transmission 2000 requests engine 1000 based on the accelerator opening and the like. For example, the target driving force of the vehicle is set according to a map created in advance using the accelerator opening as a parameter, and the torque that realizes the set target driving force is set as the torque request amount. Note that the torque request amount may be set directly from the accelerator opening.

  Instead of calculating the target value of output torque of engine 1000 as the required torque amount, the target value of input torque of automatic transmission 2000 may be used as the required torque amount.

  The reverse correction unit 8220 performs correction so as to reduce the required torque amount. If the vehicle is moving to a lower altitude, and if the opportunity to correct the torque demand according to the increased atmospheric pressure cannot be obtained, the torque demand is erroneously increased. As shown in FIG. 7, the torque request amount is corrected so that the torque request amount before the correction amount determined according to the atmospheric pressure is added is reduced.

  Further, the required torque amount is corrected so as to decrease until learning of the correction amount of the required torque amount determined according to the intake air amount is completed. That is, while the learning of the correction amount of the torque request amount according to the intake air amount is not completed, the torque request amount is corrected to be low. After the learning of the correction amount of the torque request amount according to the intake air amount is completed, the correction for reducing the torque request amount is not performed.

  Furthermore, the correction amount (reduction amount) of the torque request amount is limited by a predetermined limit value. More specifically, the correction amount of the torque request amount is limited to a limit value determined in consideration of the magnitude of shock generated in the vehicle or the strength of the vehicle.

  That is, as shown in FIG. 8, the engine torque realized by the limit value being corrected so that the required torque amount is increased based on the low atmospheric pressure, for example, in a place where the atmospheric pressure is high, The torque is determined to be less than the allowable torque.

  Alternatively, as shown in FIG. 9, for example, in a place where the atmospheric pressure is high, the engine torque realized by remaining corrected so that the required torque amount becomes large based on the low atmospheric pressure is Of the torque (including the strength of the engine 1000 and the automatic transmission 2000) and the allowable torque or less.

  Note that the torque that is allowable in terms of vehicle strength is larger than the torque that is allowable in terms of drivability.

  When the vehicle moves from a place with a high altitude to a place with a low altitude, if the opportunity to correct the torque requirement according to the increased atmospheric pressure cannot be obtained, this is indicated by a one-dot chain line in FIG. Engine torque is realized. An opportunity to correct the required torque amount according to the increased atmospheric pressure can be obtained, and if the correction amount according to the atmospheric pressure is zero, the engine torque indicated by a two-dot chain line in FIG. 10 is realized.

  A control structure of a program executed by engine ECU 8100 will be described with reference to FIG.

  In step (hereinafter step is abbreviated as S) 100, engine ECU 8100 determines whether or not an execution condition for correcting the required torque amount according to the intake air amount is satisfied. For example, the condition that the atmospheric pressure is lower than the threshold value, the condition that the throttle opening is smaller than the threshold value, and the load are stable (the fluctuation amount of the load at a predetermined time is smaller than the threshold value). This condition is included in the execution condition. The execution condition is not limited to this.

  When the execution condition for correcting the torque request according to the intake air amount is satisfied (YES in S100), the process proceeds to S102. If not (NO in S100), the process proceeds to S110.

  In S102, engine ECU 8100 corrects the required torque amount in accordance with the intake air amount detected by air flow meter 8028.

  In S104, a correction amount corresponding to the intake air amount of the torque request amount is learned (stored). For example, when the correction amount corresponding to the intake air amount exceeds the threshold value, the correction amount is learned.

  In S110, engine ECU 8100 estimates the atmospheric pressure based on the intake air amount detected by air flow meter 8028.

  In S112, engine ECU 8100 determines whether or not learning of the correction amount determined according to the intake amount of the torque request has been completed. When learning of the correction amount determined according to the intake air amount is completed (YES in S112), the process proceeds to S114. If not (NO in S112), the process proceeds to S120.

  In S114, engine ECU 8100 corrects the required torque amount according to the estimated atmospheric pressure.

  In S120, engine ECU 8100 controls engine 1000 in accordance with the required torque amount. That is, the ignition timing by the ignition plug 1002, the throttle opening of the electronic throttle valve 8016, and the like are controlled so that torque corresponding to the torque request amount is output from the engine 1000.

  With reference to FIG. 12, the control structure of the program executed by ECT-ECU 8200 will be described.

In S130, ECT-ECU 8200 sets a torque request amount.
In S132, ECT-ECU 8200 determines whether or not the atmospheric pressure has decreased. For example, it is determined whether or not the atmospheric pressure has changed from a state higher than a threshold value to a lower state.

  When the atmospheric pressure decreases (YES in S132), the process proceeds to S134. If not (NO in S132), the process returns to S130.

  In S134, ECT-ECU 8200 determines whether or not learning of the correction amount determined according to the intake air amount of the torque request has been completed. When the learning of the correction amount determined according to the intake air amount is completed (YES in S134), the process returns to S130. If learning of the correction amount determined according to the intake air amount has not been completed (NO in S134), the process proceeds to S136.

In S136, ECT-ECU 8200 corrects the torque request amount to be reduced.
An engine torque control mode based on the above-described structure and flowchart will be described.

  When the torque request amount is set (S130), engine 1000 is controlled so that torque corresponding to the torque request amount is output from engine 1000 (S120).

  By the way, if a deposit adheres to the electronic throttle valve 8016 or the like, the intake air amount is reduced. Therefore, the accuracy of the engine torque realized with respect to the torque requirement amount can be deteriorated.

  Therefore, when a predetermined execution condition is satisfied (YES in S100), the required torque amount is corrected according to the intake air amount detected by the air flow meter 8028 (S102). The correction amount is learned (S104). As a result, a desired intake air amount can be ensured even if the flow path resistance increases due to deposits or the like attached to the electronic throttle valve 8016.

  By the way, in places with low atmospheric pressure such as highlands, the density of air is smaller than in places with high atmospheric pressure such as lowlands. Therefore, the intake air amount can be further reduced as the atmospheric pressure increases. Therefore, the engine torque that is realized can decrease as the atmospheric pressure increases. That is, the accuracy of the engine torque realized with respect to the required torque amount can be deteriorated.

  Therefore, the atmospheric pressure is estimated based on the intake air amount detected by the air flow meter 8028 (S110), and the required torque amount is corrected according to the estimated atmospheric pressure (S114). As a result, it is possible to compensate for the decrease in engine output due to the decrease in atmospheric pressure. Therefore, a desired output can be obtained even at high altitudes.

  However, particularly when the throttle opening is small, the amount of change in the intake air amount due to the change in atmospheric pressure is small, so it is determined whether the change in intake air amount is due to atmospheric pressure or the deposit attached to the electronic throttle valve 8016. It is hard to do.

  Therefore, when learning of the correction amount according to the intake air amount is completed (YES in S112), the required torque amount is corrected according to the estimated atmospheric pressure (S114). That is, the torque request amount is corrected according to the atmospheric pressure only when learning of the correction amount of the torque request amount determined according to the intake air amount is completed. As a result, the required torque amount can be accurately corrected according to the atmospheric pressure.

  Thereafter, if the vehicle moves from a place where the atmospheric pressure is low to a place where the atmospheric pressure is high, the required torque amount is corrected again based on the high atmospheric pressure (S114). However, as described above, the torque request amount is corrected according to the atmospheric pressure only when learning of the correction amount determined according to the intake amount of the torque request amount is completed.

  Therefore, even after the vehicle moves from a place where the atmospheric pressure is low to a place where the atmospheric pressure is high, there may be a period in which the torque request amount remains corrected so as to increase according to the low atmospheric pressure. During this period, the output of the engine can be larger than necessary.

  Therefore, when the atmospheric pressure becomes low (YES in S132) and learning of the correction amount according to the intake amount of the torque request is not completed (NO in S134), the torque request amount is reduced. It is corrected (S136).

  As a result, when correction based on atmospheric pressure can be erroneously performed due to deposits or the like attached to the electronic throttle valve 8016, the required torque amount can be reduced without executing correction based on atmospheric pressure. . Therefore, even if it is corrected so that the required torque amount is increased based on the low atmospheric pressure in an environment where the atmospheric pressure is high, the engine torque can be prevented from becoming excessive. Therefore, the engine torque can be accurately controlled according to the atmospheric pressure.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  100 power train, 1000 engine, 1002 ignition plug, 2000 automatic transmission, 2100 torque converter, 3000 planetary gear unit, 4000 hydraulic circuit, 5000 propeller shaft, 6000 differential gear, 7000 rear wheel, 8016 electronic throttle valve, 8018 throttle opening sensor, 8028 air flow meter, 8000 ECU, 8100 engine ECU, 8110 torque control unit, 8120 intake air amount correction unit, 8122 learning unit, 8130 atmospheric pressure estimation unit, 8132 atmospheric pressure correction unit, 8200 ECT-ECU, 8210 torque request unit, 8220 inverse Correction unit.

Claims (6)

An engine control device provided with an adjustment mechanism for adjusting an intake air amount according to a magnitude of an operation amount,
Control means for controlling the adjusting mechanism according to a target value of engine output;
First correction means for correcting at least one of the target value and the operation amount according to an intake air amount;
Learning means for learning a correction amount determined according to an intake air amount of at least one of the target value and the operation amount;
An estimation means for estimating the atmospheric pressure from the intake air amount;
Second correction means for correcting at least one of the target value and the operation amount so as to increase as the atmospheric pressure decreases,
Reverse correction means for correcting so as to reduce at least one of the target value of the engine output and the operation amount until learning of the correction amount determined according to the intake air amount is completed. , Engine control device.   2. The reverse correction unit according to claim 1, wherein the reverse correction unit includes a unit for limiting a correction amount of at least one of a target value of the engine output and the operation amount with a predetermined limit value. Engine control device. The engine is mounted on a vehicle,
The engine control device according to claim 2, wherein the limit value is determined in consideration of a magnitude of a shock generated in the vehicle. The engine is mounted on a vehicle,
The engine control device according to claim 2, wherein the limit value is determined in consideration of strength of the vehicle.   The engine control apparatus according to claim 1, wherein the target value is a target value of output torque.   The engine control device according to claim 1, wherein the adjustment mechanism is a throttle valve.

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