JP2009281339A - Control device for engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a control device of an engine capable of enhancing estimation precision of output torque of the engine. <P>SOLUTION: A first state quantity estimation part 10 calculates a first estimation intake pipe pressure Pm(1) based on an engine speed and an intake air quantity, a second state quantity estimation part 20 calculates a second estimation intake pipe pressure Pm(2) based on the engine speed and a throttle opening, a third state quantity estimation part 30 calculates a third estimation intake pipe pressure Pm(3) based on the engine speed and an atmospheric pressure. An estimation intake pipe pressure is calculated based on characteristic data acquired beforehand by a reference performance investigation of the engine and a relational expression. An error detection part 40 detects error of physical quantities (the intake air quantity, the throttle opening and the atmospheric pressure) by judging consistency among the estimation intake pipe pressures Pm(1), Pm(2), Pm(3). An estimation value correction part 50 estimates a final intake pipe pressure Pm(E) by correcting erroneous physical quantities based on remaining physical quantities. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an engine control device, and more specifically, to a technique for controlling an adjustment mechanism that calculates a target torque of an engine and adjusts an output of the engine based on the target torque.

  Conventionally, in an engine, the output is adjusted by adjusting the amount of air taken in (the amount of air charged in a cylinder), the ignition timing, and the like. For example, the throttle valve, swirl control valve, spark plug, intake valve, exhaust valve, ACIS (Acoustic Control Induction System) that changes the length of the intake pipe (hereinafter these mechanisms are also referred to as adjustment mechanisms), etc. The output is adjusted. At this time, when the target torque of the engine is calculated according to the opening degree of the accelerator pedal (hereinafter also referred to as the accelerator opening degree) operated by the driver, the adjustment mechanism operates so as to realize the target torque. Is controlled.

For example, in Japanese Patent Application Laid-Open No. 2002-309993 (Patent Document 1), a required torque calculation unit that calculates a required torque based on an accelerator opening, and a required air amount that is supplied to an engine based on the calculated required torque. A required air amount calculating means for calculating and a required air pressure calculating means for calculating a required air pressure required to achieve the required air amount, and for achieving the required air amount from the required air amount and the required air amount; A control device for an internal combustion engine that calculates a throttle valve opening degree to be controlled is disclosed.
JP 2002-309993A JP-A-8-240146 JP 2005-256712 A

  Here, control of the amount of air taken into the engine, ignition timing, etc., is characteristic data or relations acquired by a test conducted on a specific number of engines, also referred to as a reference performance survey, at the engine development stage. It is generally performed based on an expression (hereinafter also referred to as a reference performance).

  Specifically, an ECU (Electronic Control Unit) that controls the engine refers to the reference performance stored in the ROM when signals indicating the operation amount of the adjustment mechanism and the operating state of the engine are input from various sensors. Thus, the current engine output torque is estimated from these input signals. The throttle opening, ignition timing, fuel injection timing, fuel injection amount, intake / exhaust valve opening / closing timing, etc. are set so that the estimated torque becomes the torque required for the engine (requested torque) according to the driving state of the vehicle. To control.

  However, this reference performance may vary between engines due to tolerances based on the dimensional accuracy and assembly accuracy of the adjustment mechanism and sensors in the mass production process. Further, the engine output may deviate greatly from the standard performance due to deterioration or failure of the adjusting mechanism and sensors over time. Therefore, in these cases, the current output torque can no longer be accurately estimated based on the reference performance. As a result, there is a problem that fine adjustment of the output torque cannot be performed and control stability cannot be ensured.

  Therefore, the present invention has been made to solve such a problem, and an object of the present invention is to provide an engine control device capable of improving the estimation accuracy of the output torque of the engine.

  An engine control device according to an aspect of the present invention includes an adjustment mechanism that adjusts an output of an engine, a required torque calculation unit that calculates a required torque for the engine based on a driving state of the vehicle, and a current output torque of the engine. A torque estimation unit that estimates, and a torque control unit that sets the target torque of the engine based on the deviation between the estimated current output torque and the required torque, and controls the operation amount of the adjustment mechanism based on the target torque With. The torque estimation unit includes a plurality of sensors that detect a plurality of physical quantities each indicating an operating state of the engine or an operation amount of the adjustment mechanism, and a plurality of physical quantities detected by the plurality of sensors, and a physical quantity and an engine operation A relationship between the first control parameter representing the state and the first performance parameter is estimated in advance by a plurality of estimation units that estimate the first control parameter with reference to the reference performance for each physical quantity. Based on the plurality of first control parameters, an error detection means for detecting an error in the physical quantity, and an error included in the physical quantity in which the error is detected by the error detection means is estimated based on the remaining physical quantity, and is estimated. Based on the correction means for correcting the physical quantity using the error, the remaining physical quantity and the physical quantity corrected by the correction means, And a torque estimating means for estimating the torque.

  Preferably, the error detection unit determines consistency of the plurality of first control parameters, and diagnoses a physical quantity used for estimating the first control parameter determined to be inconsistent as an error.

  Preferably, the correction means sets an allowable range in consideration of engine tolerance with respect to the reference performance in advance, and limits an error of a physical quantity in which an error is detected to fall within the allowable range.

  Preferably, the torque estimation means calculates a first control parameter based on the remaining physical quantity and the physical quantity corrected by the correction means, and estimates the current output torque based on the calculated first control parameter.

  Preferably, the adjustment mechanism adjusts the amount of air taken into the engine according to the operation amount. The first control parameter is the intake pipe pressure.

  Preferably, the adjustment mechanism adjusts the output torque of the engine according to the operation amount. The first control parameter is torque.

  According to this invention, the estimation accuracy of the output torque of the engine can be increased. As a result, the actual output of the engine can be matched with the target torque with high accuracy.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same reference numerals indicate the same or corresponding parts.

  FIG. 1 is a schematic configuration diagram of an engine equipped with a control device according to an embodiment of the present invention. The control device according to the present embodiment is realized, for example, when an ECU (Electronic Control Unit) 200 shown in FIG. 1 executes a program stored in a ROM (Read Only Memory).

  Referring to FIG. 1, an air cleaner 102 is provided at the most upstream portion of intake pipe 101 of engine 100, and an air flow meter 304 for detecting an intake air amount is provided downstream of air cleaner 102. A throttle valve 104 is provided on the downstream side of the air flow meter 304. The amount of air taken into engine 100 is adjusted by throttle valve 104. The throttle valve 104 is an electric motor controlled throttle valve that is driven by a motor 105. The opening degree of the throttle valve 104 (throttle opening degree) is detected by a throttle opening degree sensor 306.

  Further, a surge tank 107 is provided on the downstream side of the throttle valve 104. The surge tank 107 is provided with an intake pipe pressure sensor 308 that detects the intake pipe pressure. The surge tank 107 is connected to an intake manifold 109 that introduces air into each cylinder.

  Air is mixed with fuel in the cylinder 106 (combustion chamber). Fuel is directly injected into the cylinder 106 from the injector 108. That is, the injection hole of the injector 108 is provided in the cylinder 106. The fuel is injected from the intake side (the side where air is introduced) of the cylinder 106.

  The fuel is injected in the intake process. The time when fuel is injected is not limited to the intake process. In the present embodiment, engine 100 is described as a direct injection engine in which an injection hole of injector 108 is provided in cylinder 106. However, in addition to direct injection injector 108, a port injection injector is provided. It may be provided. Alternatively, instead of the direct injection injector 108, a port injection injector may be provided.

  A spark plug 110 is attached to the cylinder head for each cylinder, and the air-fuel mixture in the cylinder 106 is ignited by the spark plug 110 and burned. The air-fuel mixture after combustion, that is, the exhaust gas is purified by the three-way catalyst 112 and then discharged outside the vehicle. The piston 114 is pushed up by the combustion of the air-fuel mixture, and the crankshaft 116 rotates. The crank angle sensor 302 is attached to a cylinder block or the like, and detects the rotation speed of the crankshaft 116 (engine rotation speed) and the rotation angle of the crankshaft 116.

  An intake valve 118 and an exhaust valve 120 are provided at the top of the cylinder 106. The amount and timing of air introduced into the cylinder 106 are controlled by the intake valve 118, and the amount and timing of exhaust gas discharged from the cylinder 106 are controlled by the exhaust valve 120. The intake valve 118 is driven by a cam 122, and the exhaust valve 120 is driven by a cam 124.

  The amount of air charged in the cylinder 106, that is, the output torque of the engine 100, is determined by the variable valve timing (VVT) mechanism provided also in the cam 122 and the cam 124, and the opening / closing timing of the intake valve 118 and the exhaust valve 120. It is adjusted by changing. The opening / closing timing of the intake valve 118 and the exhaust valve 120 is controlled according to the throttle opening.

  For example, the cylinder is filled by adjusting the overlap amount between the intake valve 118 and the exhaust valve 120 according to the throttle opening, that is, according to the load, or adjusting the closing timing of the intake valve 118. The amount of air, internal EGR (Engine Gas Recirculation), and the like are adjusted, and the output torque of engine 100 is finely controlled.

  The ECU 200 controls the throttle opening, ignition timing, fuel injection timing, fuel injection amount, intake / exhaust valve opening / closing timing, and the like so that the engine 100 is in a desired operating state. ECU 200 receives a signal representing intake air amount Q from air flow meter 304, a signal representing throttle opening TA from throttle opening sensor 306, and a signal representing intake pipe pressure Pm from intake pipe pressure sensor 308. A signal representing the engine speed NE is input from the crank angle sensor 302.

  Further, the engine 100 is provided with an atmospheric pressure sensor 310 that detects the pressure of the atmosphere around the engine 100 or the pressure of the air sucked into the intake pipe 101, and the ECU 200 receives the atmospheric pressure sensor 310 from the atmospheric pressure sensor 310. A signal representing the atmospheric pressure Pa is input. Further, although not shown in the figure, ECU 200 receives a signal representing the accelerator pedal opening (accelerator opening) ACC operated by the driver from the accelerator opening sensor.

  Signals input from these sensors are input to a CPU (Central Processing Unit) that controls the entire engine 100 via an input processing circuit including an A / D (Analog to Digital) converter. The CPU executes a predetermined program stored in a ROM (not shown) based on input signals from these sensors, and outputs control signals to the spark plug 110, the throttle valve 104, the injector 108, and the like.

  In this way, the output (for example, output torque) of the engine 100 is controlled by controlling the intake air amount (the amount of air charged in the cylinder), the ignition timing, and the like by the spark plug 110, the throttle valve 104, the injector 108, and the like. Adjusted. That is, the spark plug 110, the throttle valve 104, the injector 108, and the like constitute an “adjustment mechanism” for adjusting the output of the engine 100.

  At this time, control such as the intake air amount and ignition timing is performed in the engine development stage by characteristic data or a relational expression (reference performance obtained by a test conducted on a specific number of engines, also referred to as a reference performance survey. ) Is executed based on.

  Specifically, when the signals representing the operation amount of the adjusting mechanism and the operating state of the engine 100 are input from the various sensors illustrated in FIG. 1, the ECU 200 refers to the reference performance stored in the ROM, and The current output torque of engine 100 is estimated from the input signal. The throttle opening, ignition timing, fuel injection timing, fuel injection amount, intake / exhaust valve opening / closing timing are set so that the estimated torque becomes the torque (requested torque) required for the engine 100 in accordance with the driving state of the vehicle. Control etc.

  However, this reference performance may vary between engines due to tolerances based on the dimensional accuracy and assembly accuracy of the adjustment mechanism and sensors in the mass production process. Further, the engine output may deviate greatly from the standard performance due to deterioration or failure of the adjusting mechanism and sensors over time. Therefore, in these cases, it is no longer possible to accurately estimate the current output torque based on the reference performance. As a result, there is a problem that fine adjustment of the output torque cannot be performed and control stability cannot be ensured.

  Therefore, in the present embodiment, ECU 200 estimates the current output torque of engine 100 in consideration of engine tolerance, deterioration with time, and the like. Then, when ECU 200 calculates the final target torque of engine 100 based on the deviation between the estimated torque and the required torque, the target value (the target throttle opening) of the operation amount of each adjustment mechanism is realized so as to realize this target torque. Degree).

Hereinafter, a control structure in ECU 200 according to the present embodiment will be described in detail.
FIG. 2 is a block diagram showing a control structure in ECU 200 according to the embodiment of the present invention. Each function block shown in FIG. 2 is typically realized by the ECU 200 executing a program stored in advance, but part or all of the function may be implemented as dedicated hardware.

  Referring to FIG. 2, ECU 200 includes a first state quantity estimation unit 10, a second state quantity estimation unit 20, a third state quantity estimation unit 30, an error detection unit 40, an estimated value correction unit 50, A torque converter 60, a target torque calculator 70, and a target throttle opening calculator 80 are provided.

  The state quantity estimation units 10, 20, and 30 estimate common control parameters based on different physical quantities detected by different sensors. The control parameter is a parameter that represents the operating state of engine 100 and is controlled to achieve the target torque. In the present embodiment, the intake pipe pressure Pm is estimated as an example, but the torque may be estimated. Hereinafter, the physical quantity used for the estimation of the control parameter is also simply referred to as an estimation element.

  Specifically, the first state quantity estimating unit 10 estimates the intake pipe pressure Pm based on the engine speed NE from the crank angle sensor 302 and the intake air quantity Q from the air flow meter 304. The first state quantity estimating unit 10 outputs the estimated intake pipe pressure (hereinafter also referred to as a first estimated intake pipe pressure) Pm (1) to the error detecting unit 40.

  The second state quantity estimating unit 20 estimates the intake pipe pressure Pm based on the engine speed NE from the crank angle sensor 302 and the throttle opening degree TA from the throttle opening degree sensor 306. The second state quantity estimating unit 20 outputs the estimated intake pipe pressure (hereinafter also referred to as second estimated intake pipe pressure) Pm (2) to the error detection unit 40.

  The third state quantity estimating unit 30 estimates the intake pipe pressure Pm based on the engine speed NE from the crank angle sensor 302 and the atmospheric pressure Pa from the atmospheric pressure sensor 310. The third state quantity estimating unit 30 outputs the estimated intake pipe pressure (hereinafter also referred to as a third estimated intake pipe pressure) Pm (3) to the error detecting unit 40.

  Here, the estimation of the intake pipe pressure Pm from each physical quantity is performed based on the characteristic data or the relational expression (reference performance) acquired by the above-described reference performance investigation of the engine. FIG. 3 shows a correlation between each physical quantity and the intake pipe pressure Pm as an example of the reference performance.

  Specifically, FIG. 3 (1) shows the correlation between the intake air amount Q and the intake pipe pressure Pm, and FIG. 3 (2) shows the correlation between the throttle opening degree TA and the intake pipe pressure Pm. FIG. 3 (3) shows the correlation between the atmospheric pressure Pa and the intake pipe pressure Pm. Both correlations are indicated by solid lines in the figure.

  The reference performance is acquired for each engine operating region. As an example, the correlation shown in FIGS. 3 (1) to 3 (3) is such that the engine speed is changed in stages (800 rpm, 1600 rpm, 2400 rpm, 3200 rpm, etc.) and the engine is operated at each stage. Are obtained by actually measuring the physical quantities Q, TA, Pa and the intake pipe pressure Pm, or by substituting the physical quantities at each stage into a predetermined intake pipe model.

  Further, in each of FIGS. 3 (1) to 3 (3), the upper limit performance and the lower limit performance are indicated by a one-dot chain line and a broken line, respectively, with reference performance indicated by a solid line interposed therebetween. The upper limit performance and the lower limit performance indicate the allowable range in the output performance of the engine with respect to variations that may occur in the intake pipe pressure Pm due to tolerances of the adjusting mechanism and sensors.

  The first state quantity estimating unit 10 has the correlation shown in FIG. 3A as a map in advance, receives the engine speed NE from the crank angle sensor 302, and receives the intake air quantity Q from the air flow meter 304. The intake pipe pressure Pm corresponding to the engine speed NE and the intake air amount Q input with reference to the map is extracted. Then, the extracted intake pipe pressure Pm is output to the error detection unit 40 as the first estimated intake pipe pressure Pm (1).

  The second state quantity estimation unit 20 has the correlation shown in FIG. 3B as a map in advance, receives the engine speed NE from the crank angle sensor 302, and receives the throttle opening TA from the throttle opening sensor 306. Then, the intake pipe pressure Pm corresponding to the engine speed NE and the throttle opening TA input with reference to the map is extracted. Then, the extracted intake pipe pressure Pm is output to the error detection unit 40 as the second estimated intake pipe pressure Pm (2).

  The third state quantity estimation unit 30 has the correlation shown in FIG. 3 (3) as a map in advance, receives the engine speed NE from the crank angle sensor 302, and receives the atmospheric pressure Pa from the atmospheric pressure sensor 310. The intake pipe pressure Pm corresponding to the engine speed NE and the atmospheric pressure Pa input with reference to the map is extracted. Then, the extracted intake pipe pressure Pm is output to the error detection unit 40 as the third estimated intake pipe pressure Pm (3).

  Referring to FIG. 2 again, error detection unit 40 receives estimated intake pipe pressures Pm (1), Pm (2), and Pm (3) from state quantity estimation units 10, 20, and 30, respectively. Intake pipe pressure Pm is received from 308. The error detection unit 40 detects an error in the physical quantity based on the deviation between the estimated intake pipe pressures Pm (1), Pm (2), Pm (3) and the intake pipe pressure Pm.

  Specifically, the error detection unit 40 firstly calculates the deviation ΔPm1 (= | Pm (1) −Pm |) between the first estimated intake pipe pressure Pm (1) and the intake pipe pressure Pm, and the second estimated intake pipe. Deviation ΔPm2 (= | Pm (2) −Pm |) between pressure Pm (2) and intake pipe pressure Pm, and deviation ΔPm3 (= | Pm () between third estimated intake pipe pressure Pm (3) and intake pipe pressure Pm 3) -Pm |) is calculated respectively. Then, the error detection unit 40 determines whether or not the calculated deviations ΔPm1, ΔPm2, and ΔPm3 are included in an allowable range of variation that can occur in the intake pipe pressure Pm (FIG. 3).

  For example, with respect to the deviation ΔPm1 between the first estimated intake pipe pressure Pm (1) and the intake pipe pressure Pm, the error detection unit 40 determines the intake pipe pressure from the intake pipe pressure sensor 308 based on the correlation shown in FIG. An allowable range of variation in the intake pipe pressure Pm when Pm is used as the reference performance is calculated. Then, it is determined whether or not the calculated allowable range includes the first estimated intake pipe pressure Pm (1). At this time, if the first estimated intake pipe pressure Pm (1) is not included in the permissible range, the error detection unit 40 is a physical quantity used for estimating the first estimated intake pipe pressure Pm (1). It is determined that the intake air amount Q is abnormal.

  Here, the reason why the physical quantity is abnormal may be a failure of a sensor that detects the physical quantity or a malfunction of an adjustment mechanism that controls the physical quantity. In any case, the estimation accuracy of the control parameter It becomes difficult to ensure. For this reason, in the present embodiment, the physical quantity determined to be abnormal is excluded from the estimation elements.

  On the other hand, when each of the deviations ΔPm1, ΔPm2, and ΔPm3 is included in the allowable range of variation in the intake pipe pressure Pm, the error detection unit 40 determines each physical quantity (intake air amount Q, throttle opening TA). , Atmospheric pressure Pa) is determined to be normal. In this case, the error detection unit 40 further detects an error (error) in the physical quantity in order to increase the accuracy as the physical quantity estimation element. This error in physical quantity means that the physical quantity is recognized as being normal (within an allowable range), but has an error with respect to the true physical quantity due to tolerance, deterioration with time, and the like.

  Specifically, the error detection unit 40 determines consistency between the estimated intake pipe pressures Pm (1), Pm (2), and Pm (3), and derives the estimated intake pipe pressure determined to be inconsistent. It is determined that the physical quantity used for the error is an error. Hereinafter, the physical quantity determined to be an error is also simply referred to as an error element. For example, the error detection unit 40 identifies the estimated intake pipe pressure corresponding to the largest deviation among the deviations ΔPm1, ΔPm2, and ΔPm3, and determines that the identified estimated intake pipe pressure is inconsistent. Then, the physical quantity used to derive the estimated intake pipe pressure is determined to be an error. The error detection unit 40 outputs a signal Err representing a physical quantity (error element) determined to be an error to the estimated value correction unit 50.

  The estimated value correction unit 50 estimates an error (error amount) of the error element based on the input signal Err from the error detection unit 40, and corrects the error element using the estimated error amount. The estimated value correcting unit 50 estimates the intake pipe pressure Pm again using the corrected error element. The estimated intake pipe pressure Pm (E) is output to the torque converter 60.

  Specifically, when the estimated value correction unit 50 estimates the intake pipe pressure Pm using the remaining estimation elements excluding the error element, the estimation value correction unit 50 estimates the intake element pressure with reference to the reference performance (correlation in FIG. 3) of the error element. A physical quantity corresponding to the intake pipe pressure Pm is extracted, and the extracted physical quantity is estimated as a true physical quantity. At this time, the estimated value correcting unit 50 estimates a deviation between the estimated true physical quantity and the current physical quantity as an error quantity.

  For example, when the error detection unit 40 determines that the intake air amount Q is an error factor among the intake air amount Q, the throttle opening degree TA, and the atmospheric pressure Pa, the estimated value correction unit 50 determines the throttle opening degree TA. Then, the intake pipe pressure Pm is estimated using the atmospheric pressure Pa. This estimation is performed, for example, by calculating the intake pipe pressure using an intake pipe model built in advance. Then, the estimated value correction unit 50 estimates the intake air amount Q corresponding to the intake pipe pressure Pm as a true intake air amount with reference to the correlation (solid line in FIG. 3) in FIG. The deviation between the intake air amount and the intake air amount Q is estimated as the error amount.

  Here, the estimated value correction unit 50 determines whether or not the estimated error amount exceeds the tolerance of the adjustment mechanism and the sensors. At this time, when the error amount exceeds the tolerance, the estimated value correction unit 50 limits the error amount to be within the tolerance. This is because by correcting the error element beyond the tolerance, the accuracy as the estimation element may be lowered.

  Finally, the estimated value correction unit 50 corrects the error element based on the estimated error amount, and estimates the final intake pipe pressure Pm (E) using the corrected error element and the remaining estimation element. To do. The intake pipe pressure Pm (E) can be calculated, for example, by applying a corrected error element and a remaining estimation element to a pre-built intake pipe model.

  As described above, according to the present embodiment, by using each of a plurality of physical quantities constituting the estimation element of the output torque and estimating it as a common control parameter, an error in the physical quantity is determined based on the consistency of the estimation result. It can be detected. Furthermore, the error amount can be corrected using a physical amount that is not an error. Thereby, it is possible to estimate the final intake pipe pressure using a plurality of physical quantities each of which the accuracy as the estimation element is guaranteed. As a result, it is possible to improve the estimation accuracy of the intake pipe pressure.

  The torque converter 60 converts the estimated intake pipe pressure Pm (E) into torque T (E). Conversion from intake pipe pressure Pm (E) to torque T (E) is performed according to a predetermined map. This converted torque T (E) is equivalent to the estimated value (estimated torque) of the current output torque of engine 100.

The target torque calculation unit 70 receives the torque T (E) from the torque conversion unit 60, receives the engine speed NE from the crank angle sensor 302 (FIG. 1), and receives the accelerator opening ACC from the accelerator opening sensor. The final target torque T ^* of the engine 100 is calculated based on the input information.

Specifically, target torque calculation unit 70 calculates required torque T (D) for engine 100 based on accelerator opening ACC and engine speed NE. Then, target torque calculation unit 70 calculates target torque T ^* based on the deviation between current output torque T (E) of engine 100 and required torque T (D).

Target throttle opening degree calculation unit 80 calculates a target throttle opening for realizing the calculated target torque T ^* TA ^*, instructs the target throttle opening TA ^* to the motor 105 of the throttle valve 104. As a result, the throttle valve 104 is controlled to achieve the target throttle opening degree TA ^* .

  Regarding the correspondence relationship between the control structure of the ECU 200 shown in FIG. 2 and the present invention, the state quantity estimating units 10 to 30, the error detecting unit 40, the estimated value correcting unit 50, and the torque converting unit 60 constitute a “torque estimating unit”. The target torque calculation unit 70 and the target throttle opening calculation unit 80 constitute a “torque control unit”. In particular, for a plurality of parts constituting the “torque estimation unit”, the state quantity estimation units 10 to 30 correspond to “a plurality of estimation units” and the error detection unit 40 corresponds to “an error detection unit”. Further, the estimated value correcting unit 50 and the torque converting unit 60 correspond to a “correcting unit” and a “torque estimating unit”, respectively.

  The engine control according to the present embodiment described above is executed by the ECU 200 according to the routines shown in FIGS. The processing contents of these routines will be described below. 4 to 6 is realized by the ECU 200 functioning as each control block shown in FIG. 2 for each predetermined control cycle.

  When this routine is started with reference to the error element detection processing routine of FIG. 4, first, the ECU 200 starts the engine speed NE from the crank angle sensor 302, the intake air amount Q from the air flow meter 304, the throttle opening degree. The throttle opening degree TA from the sensor 306, the atmospheric pressure Pa from the atmospheric pressure sensor 310, and the intake pipe pressure Pm from the intake pipe pressure sensor 308 are acquired (step S01).

  Next, ECU 200 estimates first intake pipe pressure Pm (1) based on engine speed NE and intake air amount Q (step S02). Further, ECU 200 estimates second intake pipe pressure Pm (2) based on engine speed NE and throttle opening degree TA (step S03). Further, ECU 200 estimates third intake pipe pressure Pm (3) based on engine speed NE and atmospheric pressure Pa (step S04).

  Next, the ECU 200 calculates deviations ΔPm1, ΔPm2, and ΔPm3 from the intake pipe pressure Pm from the intake pipe pressure sensor 308 for each of the estimated intake pipe pressures Pm (1), Pm (2), and Pm (3). To do. Then, the ECU 200 determines whether or not the calculated deviation ΔPm1 is included in the allowable range of variation that can occur in the intake pipe pressure Pm, using the correlation shown in FIG. Step S05). When deviation ΔPm1 is not included in the allowable range of the variation (NO in step S05), ECU 200 has an abnormal intake air amount Q used for estimating first estimated intake pipe pressure Pm (1). It is determined that there is an intake air amount Q from the estimation element (step S06).

  On the other hand, when deviation ΔPm1 is included in the allowable range of variation (YES in step S05), ECU 200 further uses calculated correlation ΔPm2 using the correlation shown in FIG. It is determined whether or not the intake pipe pressure Pm is within an allowable range of variation that can occur (step S07). If deviation ΔPm2 is not included in the allowable range of the variation (NO in step S07), ECU 200 indicates that the throttle opening degree TA used for estimating second estimated intake pipe pressure Pm (2) is abnormal. It is determined that the throttle opening degree TA is present, and the throttle opening degree TA is excluded from the estimation elements (step S08).

  On the other hand, when deviation ΔPm2 is included in the allowable range of variation (YES in step S07), ECU 200 further uses calculated correlation ΔPm3 using the correlation shown in FIG. It is determined whether or not the intake pipe pressure Pm is within an allowable range of variation that can occur (step S09). When deviation ΔPm3 is not included in the allowable range of variation (in the case of NO in step S09), ECU 200 has an abnormal atmospheric pressure Pa used for estimating third estimated intake pipe pressure Pm (3). And atmospheric pressure Pa is excluded from the estimated elements (step S10).

  On the other hand, when deviation ΔPm3 is included in the allowable range of variation (YES in step S09), ECU 200 determines the consistency of the estimated intake pipe pressure between physical quantities determined to be normal. Thus, a physical quantity error is detected (step S11). At this time, the ECU 200 determines that the estimated intake pipe pressure corresponding to the largest deviation among the deviations ΔPm1, ΔPm2, and ΔPm3 is inconsistent, and determines that the physical quantity used to derive the estimated intake pipe pressure is an error. (Step S12).

  In the estimated value correction processing routine of FIG. 5, first, the error element detected by the error element detection processing routine of FIG. 4 is corrected.

  Specifically, the ECU 200 determines whether or not the detected error element is the intake air amount Q (step S20). When the error element is the intake air amount Q (YES in step S20), the ECU 200 performs the intake air amount Q based on the remaining estimated elements of the throttle opening TA and the atmospheric pressure Pa by the above-described method. Is estimated (step S23). Then, the ECU 200 limits the estimated error amount so as to be within the tolerance of the intake air amount Q (step S24).

  On the other hand, when the error element is not the intake air amount Q (NO in step S20), the ECU 200 determines whether or not the error element is the throttle opening degree TA (step S21). When the error element is the throttle opening degree TA (in the case of YES in step S21), the ECU 200 performs the throttle opening degree TA based on the intake air amount Q and the atmospheric pressure Pa, which are remaining estimation elements, by the above-described method. Is estimated (step S27). Then, ECU 200 limits the estimated error amount so as to be within the tolerance of throttle opening degree TA (step S28).

  On the other hand, when the error element is not throttle opening degree TA (NO in step S21), ECU 200 further determines whether or not the error element is atmospheric pressure Pa (step S22). When the error factor is atmospheric pressure Pa (YES in step S22), ECU 200 determines the atmospheric pressure Pa based on the intake air amount Q and the throttle opening TA, which are remaining estimation elements, by the method described above. An error amount is estimated (step S25). Then, ECU 200 limits the estimated error amount so as to be within the tolerance of atmospheric pressure Pa (step S26).

  Next, the ECU 200 corrects the error element according to the error amount estimated in steps S23 to S28 (step S29). Finally, the ECU 200 calculates a final estimated intake pipe pressure Pm (E) based on the corrected error element and the remaining estimated element (step S30).

  Finally, in the engine torque control processing routine of FIG. 6, the estimated intake pipe pressure Pm (E) calculated through the processing routines of FIGS. 4 and 5 is converted into torque, and the converted torque is used as the current torque of the engine 100. The output torque T (E) is estimated (step S40).

When ECU 200 calculates required torque T (D) based on accelerator opening degree ACC, engine speed NE, and the like (step S41), ECU 200 is based on the deviation between current output torque T (E) and required torque T (D). The target torque T ^* is calculated (step S42). Then, ECU 200 calculates a target throttle opening degree TA ^* for realizing the calculated target torque T ^* , and commands the target throttle opening degree TA ^* to the motor 105 of the throttle valve 104 (step S43). As a result, the throttle valve 104 is controlled to achieve the target throttle opening degree TA ^* .

  As described above, the engine control apparatus according to the present embodiment detects errors caused by engine tolerance and deterioration with time in the physical quantity used to estimate the current output torque based on the reference performance of the physical quantity. Then, the physical quantity is corrected using the detected error. As a result, the accuracy as an estimation element of the physical quantity can be guaranteed, so that the current output torque can be accurately estimated. As a result, fine adjustment of the output torque can be performed, and control stability can be improved.

  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.

It is a schematic block diagram of the engine carrying the control apparatus which concerns on embodiment of this invention. It is a block diagram which shows the control structure in ECU according to embodiment of this invention. It is a figure for demonstrating the standard performance acquired by the standard performance investigation of the engine. It is a flowchart which shows the flow of a process of an error element detection process routine. It is a flowchart which shows the flow of a process of an estimated value correction process routine. It is a flowchart which shows the flow of a process of an engine torque control process routine.

Explanation of symbols

  10 first state quantity estimating section, 20 second state quantity estimating section, 30 third state quantity estimating section, 40 error detecting section, 50 estimated value correcting section, 60 torque converting section, 70 target torque calculating section, 80 target throttle opening Degree calculation unit, 100 engine, 101 intake pipe, 102 air cleaner, 104 throttle valve, 105 motor, 106 cylinder, 107 surge tank, 108 injector, 109 intake manifold, 110 spark plug, 112 three-way catalyst, 114 piston, 116 crankshaft , 118 Intake valve, 120 Exhaust valve, 122,124 Cam, 302 Crank angle sensor, 304 Air flow meter, 306 Throttle opening sensor, 308 Intake pipe pressure sensor, 310 Atmospheric pressure sensor.

Claims (6)

An adjustment mechanism for adjusting the output of the engine;
A required torque calculation unit for calculating a required torque for the engine based on a driving state of the vehicle;
A torque estimator for estimating a current output torque of the engine;
A torque control unit configured to set a target torque of the engine based on a deviation between the estimated current output torque and the required torque, and to control an operation amount of the adjustment mechanism based on the target torque; Prepared,
The torque estimator is
A plurality of sensors each detecting a plurality of physical quantities indicating an operating state of the engine or an operation amount of the adjusting mechanism;
For each of the plurality of physical quantities detected by the plurality of sensors, a relationship between the physical quantity and the first control parameter representing the operating state of the engine is previously stored as a reference performance, and the reference performance is referred to for each physical quantity. A plurality of estimating means for estimating the first control parameter;
Error detection means for detecting an error in the physical quantity based on the plurality of first control parameters respectively estimated by the plurality of estimation means;
A correction unit that estimates an error included in a physical quantity in which an error is detected by the error detection unit based on a residual physical quantity, and corrects the physical quantity using the estimated error;
An engine control device comprising: torque estimation means for estimating the current output torque based on the remaining physical quantity and the physical quantity corrected by the correction means.   The error detection means determines consistency of the plurality of first control parameters, and diagnoses a physical quantity used for estimation of the first control parameter determined to be inconsistent as an error. Engine control device.   The correction means preliminarily sets an allowable range in consideration of a tolerance of the engine with respect to the reference performance, and limits an error of a physical quantity in which the error is detected to be within the allowable range. The engine control apparatus according to 2.   The torque estimation means calculates the first control parameter based on the remaining physical quantity and the physical quantity corrected by the correction means, and calculates the current output torque based on the calculated first control parameter. The engine control device according to claim 3, wherein the controller is estimated. The adjustment mechanism adjusts the amount of air sucked into the engine according to the operation amount,
The engine control device according to any one of claims 1 to 4, wherein the first control parameter is an intake pipe pressure. The adjustment mechanism adjusts the output torque of the engine according to the operation amount,
The engine control device according to claim 1, wherein the first control parameter is a torque.

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