JP5376171B2 - Vehicle output control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an output control apparatus for a vehicle capable of calculating torque that an internal combustion engine can output without increasing the memory capacity of an ECU. <P>SOLUTION: The apparatus includes: setting a clip value for restricting a maximum value for a variation of an intake air flow rate due to pulsation in a full open region by an electronic control throttle valve in engine rotation speed Ne in an air flow sensor clip value setting block (B110a); setting an EGR rate in an EGR rate setting block (B110b) based on the clip value and an A/F value in an A/F value setting block (B110c), respectively; calculating an equivalent ratio from the EGR rate and the A/F value in an equivalent ratio calculation block (B110d); and calculating a maximum Pi from the clip value, the equivalent ratio, and an ignition timing correction value in a maximum Pi calculation block (B110d). <P>COPYRIGHT: (C)2012,JPO&amp;INPIT

Description

  The present invention relates to a vehicle output control apparatus, and more particularly to a technique for optimizing output torque with respect to required torque in an internal combustion engine.

For example, in a vehicle equipped with an internal combustion engine (engine), the electronic control unit (ECU) independently controls the opening degree of the electronically controlled throttle valve in accordance with the accelerator pedal operation information, etc. Torque-based control is known in which output torque is controlled by torque requests from a step transmission and a vehicle attitude control system.
As shown in FIG. 2, in the torque-based control, the indicated mean effective pressure Pi (accelerator request Pia) or continuously variable in the accelerator request Pi calculation block B10 as an index of the required torque based on the driver's accelerator operation and the engine speed Ne. The indicated mean effective pressure Pi (external demand Pio) is calculated in the external demand Pi calculation block B12 based on the required torque from the transmission, the vehicle attitude control system, etc., and in the target Pi calculation block B14 based on the accelerator demand Pia and the external demand Pio. A target value (target Pi) of the indicated mean effective pressure Pi as an index of the target torque is calculated, a target value (target Ec) of charging efficiency is calculated in the target Ec calculation block B16 based on the target Pi, and a target is determined based on the target Ec. In the intake flow rate Qt calculation block B18, the target value of the intake air flow rate that passes through the electronically controlled throttle valve ( The target intake air flow rate Qt) is calculated, and based on the target intake air flow rate Qt, a target throttle valve opening calculation target value (target throttle valve opening) is calculated and output to the electronically controlled throttle valve in the target throttle valve opening calculation block B20. A signal is supplied, the opening degree of the electronically controlled throttle valve is adjusted in the throttle valve opening degree adjusting block B22 based on the opening degree information of the electronically controlled throttle valve, and further in the actual intake flow rate Qr calculating block B24 based on the information from the air flow sensor. The actual intake air flow rate (actual intake flow rate Qr) at the adjusted opening degree of the electronically controlled throttle valve is calculated, and the actual charging efficiency (actual Ec) is calculated in the actual Ec calculation block B26 based on the actual intake flow rate Qr. In the actual Pi calculation block B28 based on the actual Ec, the actual indicated mean effective pressure Pi (actual i) is intended to calculate the.

  Then, as a prior art of the calculation method of the accelerator demand Pia in the torque base control, the maximum torque (maximum Pi) and the minimum torque (minimum Pi) as a function of the engine speed are mapped in advance, and the output torque ( A calculation method for calculating the indicated mean effective pressure Pi) that can be output is known (Patent Document 1).

JP 2003-129876 A

As described above, in the calculation method described in Patent Document 1, the indicated mean effective pressure Pi that can be output by mapping the maximum Pi and the minimum Pi as a function of the engine rotational speed in advance is calculated.
However, since the engine speed is a function and the maximum Pi and the minimum Pi are all mapped, when the prior art is applied in torque-based control, the map needs to be added and the control map increases. As a result, the memory capacity of the ECU increases, which is not preferable.

  The present invention has been made to solve such a problem, and an object of the present invention is to provide a vehicle capable of calculating an output torque that can be output by the internal combustion engine without increasing the memory capacity of the ECU. To provide an output control device.

In order to achieve the above object, a vehicle output control device according to claim 1 is a vehicle output control device that calculates a required torque for an internal combustion engine and controls the output torque of the internal combustion engine in accordance with the required torque. When the intake air flow rate adjusting means for adjusting the intake air flow rate sucked into the internal combustion engine and the intake air flow rate adjusting means are in a fully open range, the maximum value of the intake air flow rate with respect to the fluctuation of the intake air flow rate is set. Intake air flow rate clip value setting means for setting an intake air flow rate clip value to be limited; maximum torque calculation means for calculating a maximum torque that is an upper limit that can be output by the internal combustion engine based on the intake air flow rate clip value; an accelerator operation degree detecting means for detecting an operation degree of an accelerator which is provided in the vehicle, the required load on the basis of the accelerator operation degree detected by the accelerator operation degree detecting means Required load factor calculating means for calculating the required torque, a required torque calculating means for calculating the required torque based on the minimum torque that is a combustible lower limit, the maximum torque, and the required load factor, and an actual torque for calculating the current actual torque A suction means of the internal combustion engine that realizes the flow rate of the intake air of the internal combustion engine that realizes the required torque calculated by the calculation means and the required torque calculation means and the current actual torque that is calculated by the actual torque calculation means A flow rate ratio calculating unit that calculates a ratio with the flow rate of air as a flow rate ratio, and the required torque calculation unit multiplies the required torque by the flow rate ratio when the flow rate ratio is greater than 1.0. Then, the required torque is corrected, and when the flow rate ratio does not exceed 1.0, the required torque is multiplied by 1.0 .

  According to a second aspect of the present invention, there is provided the vehicle output control apparatus according to the first aspect, wherein an equivalent ratio calculating means for calculating an equivalent ratio with respect to the intake air sucked into the internal combustion engine and a reference ignition timing of the ignition timing of the internal combustion engine. Ignition timing correction amount setting means for setting an advance angle amount or a retard angle amount as an ignition timing correction value, and the maximum torque calculation means includes a torque increase / decrease rate according to the ignition timing correction value in the intake air flow rate clip value. And the torque increase / decrease rate according to the equivalence ratio, or the torque increase / decrease rate according to the ignition timing correction value or the torque increase / decrease rate according to the equivalence ratio to the intake air flow rate clip value. It is characterized by calculating.

According to a third aspect of the present invention, there is provided the vehicle output control apparatus according to the first or second aspect, wherein the internal combustion engine includes an intake valve that performs communication between the combustion chamber of the internal combustion engine and an intake passage, and an intake valve; It has a variable valve operating means capable of changing at least one of the valve opening timing, the valve opening amount, or the valve opening period.
According to a fourth aspect of the present invention, there is provided the vehicle output control apparatus according to any one of the first to third aspects, wherein the internal combustion engine includes a rotational speed detecting means for detecting a rotational speed of the internal combustion engine, and the intake air flow rate clip value. The setting means provides the intake air flow rate clip value in advance for each rotational speed of the internal combustion engine, and the maximum torque calculation means further rotates the internal combustion engine in which the maximum torque is detected by the rotational speed detection means. The calculation is performed according to the speed.

  According to the first aspect of the present invention, the intake air flow rate clip value setting means restricts the maximum value of the intake air flow rate with respect to fluctuations in the intake air flow rate when the intake air flow rate adjustment means is in the fully open range. The maximum torque calculation means calculates the maximum torque that is the upper limit that can be output by the internal combustion engine based on the intake air flow clip value, and the required torque calculation means requests from the maximum torque and the accelerator operation degree. The torque is calculated.

Thus, since the maximum torque is calculated from the intake air flow rate clip value, it is not necessary to set the maximum torque as dedicated data in the memory of the ECU.
Therefore, it is not necessary to set the maximum torque as dedicated data in the ECU memory, and the memory capacity of the ECU can be suppressed.
Further, the maximum torque calculated from the intake air flow rate clip value is used to calculate the required torque, and is set based on the intake air flow rate clip value in the same manner as the maximum torque when the intake air flow rate adjusting means is in the fully open range. Since consistency between the fuel injection amount and the required torque can be ensured, as a result, consistency between the output torque and the fuel injection amount can be ensured.
Furthermore, by optimizing the required torque according to the actual speed according to the flow rate ratio, the target intake air flow rate that has been estimated or calibrated by performing different arithmetic processing in the critical region and non-critical region in the past. Can be appropriately estimated according to the actual situation without dividing the critical region into the critical region and the non-critical region.
According to the second aspect of the present invention, the intake air flow rate clip value setting means sets the intake air flow rate clip value that limits the maximum value of the intake air flow rate in a region where the intake air flow rate adjustment means is in a fully open region and the intake air flow rate varies. The maximum torque calculating means calculates the maximum torque that is the upper limit that can be output by the internal combustion engine by adding the equivalence ratio and the ignition timing correction value to the intake air flow clip value, so that the intake air flow rate is calculated. The memory capacity of the ECU can be suppressed while easily calculating the maximum torque from the clip value, the equivalence ratio, and the ignition timing correction value.

  According to the third aspect of the present invention, the internal combustion engine adopts the variable valve operating means. Conventionally, in the internal combustion engine that employs the variable valve operating mechanism, the intake air flow rate adjusting means is fully opened by the operation of the variable valve operating mechanism. Since the intake air flow rate is variable even if it exists, it is necessary to set the maximum torque in the ECU memory as dedicated data depending on the operating state of the variable valve mechanism, but the maximum torque is calculated from the intake air flow clip value. As a result, it is not necessary to set dedicated data in the memory of the ECU, and the memory capacity of the ECU can be further reduced.

  According to the invention of claim 4, the maximum torque is calculated according to the rotational speed of the internal combustion engine. Conventionally, it has been necessary to set the maximum torque in the memory in the ECU for each rotational speed. Since the torque is calculated from the intake air flow rate clip value for each rotation speed, there is no need to set dedicated data in the ECU memory, and the memory capacity of the ECU can be suppressed.

It is a schematic block diagram of the output control apparatus of the vehicle which concerns on this invention. 1 is a control block diagram illustrating an overall configuration of a vehicle output control device according to the present invention. It is a control block diagram which shows the calculation procedure of request | requirement Pia in the accelerator request | requirement Pi calculation block of the vehicle output control apparatus which concerns on this invention. It is a control block diagram which shows the calculation procedure of the maximum Pi in the accelerator request Pi calculation block of the output control apparatus of the vehicle which concerns on this invention. It is a figure which shows the relationship between a pressure ratio and a flow velocity. Demand Pias (dashed line), optimized request Pias (dashed line), first-order delayed request Pia, and thus target intake flow rate Qt (solid line) over time changes for critical region (a) and non-critical region (b), respectively. FIG.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
Referring to FIG. 1, there is shown a schematic configuration diagram of a vehicle output control apparatus according to the present invention.
As shown in FIG. 1, an engine 1 (internal combustion engine) is an intake pipe injection type 4-cycle in-line four-cylinder engine, and FIG. 1 shows a longitudinal section of one of the cylinders. In addition, illustration and description are abbreviate | omitted as what has the same structure also about another cylinder.

As shown in FIG. 1, the engine 1 is configured by mounting a cylinder head 3 on a cylinder block 2.
A piston 5 is provided in a cylinder 4 formed in the cylinder block 2 so as to be slidable up and down. The piston 5 is connected to a crankshaft 7 via a connecting rod 6.

Further, the engine 1 is provided with a crank angle sensor (rotational speed detecting means) 8 that detects the rotational speed of the engine 1.
A combustion chamber 9 is formed by the cylinder head 3, the cylinder 4 and the piston 5.
The cylinder head 3 is provided with a spark plug 10 so as to face the combustion chamber 9.

The cylinder head 3 has an intake port 11 formed from the combustion chamber 9 toward one side of the cylinder head 3, and an exhaust port 12 formed from the combustion chamber 9 toward the other side of the cylinder head 3. Yes.
In addition, the cylinder head 3 is provided with an intake valve 13 that communicates and shuts off the combustion chamber 9 and the intake port 11, and an exhaust valve 14 that communicates and shuts off the combustion chamber 9 and the exhaust port 12.

Camshafts 17 and 18 having cams 15 and 16 for driving the intake valve 13 and the exhaust valve 14 are provided on the cylinder head 3.
A variable valve timing mechanism (variable valve operating means) 19 and 20 is provided at one end of each of the camshafts 17 and 18.
The variable valve timing mechanisms 19 and 20 include, for example, a hydraulic actuator in a cam sprocket that drives the camshafts 17 and 18, and the cam rotation phase angle is set by supplying and discharging the hydraulic pressure to the hydraulic actuator. It is possible to freely advance and retard. The hydraulic pressure can be supplied and discharged by, for example, oil control valves (variable valve operating means) 21 and 22. The oil control valves 21 and 22 are provided in the variable valve timing mechanisms 19 and 20, respectively. The hydraulic pressure can be supplied to and discharged from the actuator.

Further, the cylinder head 3 is provided with a fuel injection valve 23 for injecting fuel into the intake port 11.
An intake manifold 24 is connected to one side surface of the cylinder head 3 so as to communicate with the intake port 11. The intake manifold 24 is provided with an intake pressure sensor 25 for detecting intake pressure, and an intake pipe 26 is connected to the intake upstream end.

The intake pipe 26 is provided with an electronically controlled throttle valve (intake air flow rate adjusting means) 27 for adjusting the intake air flow rate. The electronically controlled throttle valve 27 is provided with a throttle position sensor 28 for detecting the degree of opening of the throttle valve.
An air flow sensor 29 that detects the intake air flow rate is provided upstream of the intake pipe 26, and an air cleaner 30 is provided at the intake upstream end of the intake pipe 26.

On the other hand, an exhaust manifold 31 is connected to the other side surface of the cylinder head 3 so as to communicate with the exhaust port 12. The exhaust manifold 31 is provided with an exhaust pressure sensor 33 for detecting the exhaust pressure and an air-fuel ratio sensor (A / F sensor) 34 for detecting the air-fuel ratio of the exhaust. An exhaust pipe is provided at the exhaust downstream end of the exhaust manifold 31. 32 is connected.
Further, an EGR pipe 35 is connected to the exhaust manifold 31 so as to communicate with the intake manifold 24. The EGR pipe 35 is provided with an EGR valve 36 that adjusts the recirculation amount of the exhaust gas to the intake air.

The EGR valve 36 is provided with an EGR valve opening sensor 37 that detects the degree of opening of the valve.
The crank angle sensor 8, the intake pressure sensor 25, the throttle position sensor 28, the air flow sensor 29, the exhaust pressure sensor 33, the A / F sensor 34, the EGR valve opening sensor 37, and an accelerator pedal that performs acceleration / deceleration operations of the engine 1. Various sensors such as an accelerator position sensor 41 for detecting the accelerator opening of 40 and various external system elements 50 for an engine such as a continuously variable transmission and a vehicle attitude control system are electronic control units (ECUs) mounted on the vehicle. ) 60 is electrically connected to the input side, and detection information from these sensors is input to the ECU 60.

  On the other hand, various devices such as the spark plug 10, oil control valves 21, 22, fuel injection valve 23, electronic control throttle valve 27, EGR valve 36 and the like are electrically connected to the output side of the ECU 60. The device includes a throttle valve opening calculated based on detection information from various sensors, fuel injection amount, fuel injection timing, ignition timing, intake valve 13 and exhaust valve 14 valve timing, EGR valve 36 opening command, etc. Are output respectively.

The operation of the vehicle output control apparatus according to the present invention configured as described above will be described below.
FIG. 2 is a control block diagram showing the overall configuration of the vehicle output control apparatus according to the present invention that is periodically executed in the ECU 60.
As shown in the figure, the ECU 60 includes an accelerator request signal from the accelerator position sensor 41, an engine rotational speed Ne detected by the crank angle sensor 8, an A / F value detected by the A / F sensor 34, and an intake pressure. The intake pressure detected by the sensor 25, the exhaust pressure detected by the exhaust pressure sensor 33, the EGR valve opening degree detected by the EGR valve opening sensor 37, and the intake air flow rate (actual intake flow rate Qr detected by the air flow sensor 29) ) Based on an external request from an external system element 50, an accelerator request Pi calculation block B10 that calculates an indicated average effective pressure Pi as an index of the required torque as an accelerator request Pi (request Pia) (request torque). External request Pi calculation block B12 for calculating Pi as an external request Pi (request Pio), access A target Pi calculation block B14 for calculating a target value (target Pi) of the indicated mean effective pressure Pi as an index of the target torque based on the request Pi and the external request Pi, and a target value (target Ec) of the charging efficiency based on the target Pi. A target Ec calculation block B16 for calculating, a target intake flow rate Qt calculation block B18 for calculating a target value (target intake flow rate Qt) of the intake air flow rate passing through the electronic control throttle valve 27 based on the target Ec, and an electronic device based on the target intake flow rate Qt. A target throttle valve opening calculation block B20 for calculating a target value (target throttle valve opening) of the control throttle valve 27 and supplying an output signal to the electronic control throttle valve 27; an electronic control throttle valve from the throttle position sensor 28; The throttle which adjusts the opening degree of the electronically controlled throttle valve 27 based on the opening degree information of 27. An actual intake air flow rate Qr calculation block B24 for calculating the actual intake air flow rate (actual intake air flow rate Qr) at the adjusted opening of the electronically controlled throttle valve 27 based on the information from the air flow sensor 29. An actual Ec calculation block B26 for calculating the actual charging efficiency (actual Ec) based on the actual intake flow rate Qr, an actual Pi calculation block B28 for calculating the actual indicated mean effective pressure Pi (actual Pi) based on the actual Ec, and the engine is idle Electronic control is performed while performing engine rotational speed feedback control (Ne-F / B) so that the engine rotational speed Ne detected by the crank angle sensor 50 based on the actual Pi becomes the target idle rotational speed when in the operating state. An F / B control block B30 for performing feedback control of the throttle valve 27 is included. Therefore, a control program for controlling engine operating parameters is configured.

  That is, in the vehicle output control apparatus according to the present invention, the ECU 60 performs so-called torque base control based on the output torque of the engine 1 by periodically performing the control according to the control block diagram of FIG. The target torque index is obtained from the required torque index, and the electronic control throttle valve 27 is adjusted to an appropriate opening degree based on the target torque index so as to obtain a desired output torque in the engine 1. Thus, the electronic control throttle valve 27 can be accurately controlled based on the target torque index, and a desired output torque can be reliably obtained in the engine 1.

Incidentally, in the accelerator request Pi calculation block B10, the request Pia is calculated based on the accelerator request signal from the accelerator position sensor 41 as described above. Specifically, as described above, the intake air flow rate actually has a first order lag behavior. As shown, first-order lag processing is performed for the request Pia correlated with the intake air flow rate.
Referring to FIG. 3, the calculation procedure of the request Pia in the accelerator request Pi calculation block B10 of the vehicle output control apparatus of the present invention is shown in a control block diagram, and FIG. 4 shows the maximum in the accelerator request Pi calculation block B10. A procedure for calculating the indicated mean effective pressure Pi (maximum Pi, maximum torque) is shown in a control block diagram, and the calculation procedure of the request Pia according to the present invention will be described in detail below with reference to FIG.

  The accelerator request signal from the accelerator position sensor 41 and the engine rotation speed Ne detected by the crank angle sensor 8 are supplied to a required load factor calculation block (required load factor calculation means) B110, and the required load factor is calculated in the required load factor calculation block B110. Is calculated. The required load factor is a value that is interpolated based on the accelerator request signal and the engine speed Ne, assuming that the load in which the engine 1 is in an idling state is 0% and the load capable of generating the maximum torque is 100%. It is set as a required load factor map using the engine speed Ne as a parameter. The required load factor calculated in this way is the target Pi during idling from the maximum Pi that is the maximum value of the indicated mean effective pressure Pi calculated as shown in FIG. 4 based on the following equation (1). The value obtained by subtracting the idle target Pi (minimum torque) is multiplied, and the idle target Pi is further added. Thereby, an instantaneous value (request Pias) of the request Pia is obtained (request torque calculation means).

Request Pias = (Maximum Pi−Idle target Pi) × Request load ratio + Idle target Pi (1)
As shown in FIG. 4, the maximum Pi is obtained by supplying the engine speed Ne detected by the crank angle sensor 8 to the air flow sensor clip value setting block (intake air flow rate clip value setting means) B110a, and the air flow sensor clip value setting block. In B110a, an air flow sensor clip value (intake air flow rate clip value) at the engine rotation speed Ne is set. The air flow sensor clip value is a value that restricts the maximum value with respect to fluctuations in the air flow sensor signal, that is, the intake air flow rate, due to the influence of pulsation in the fully open region of the electronically controlled throttle valve 27 for each engine rotation speed. Ne is set as a parameter.

The airflow sensor clip value set by the engine speed Ne is supplied to the EGR rate setting block B110b, and the EGR rate that is the ratio of the recirculated exhaust gas contained in the intake air is set in the EGR rate setting block B110b. The
The airflow sensor clip value is supplied to the A / F value setting block B110c, and the A / F value is determined by the fuel injection amount and the airflow sensor clip value set based on the airflow sensor clip value in the A / F value setting block B110c. Is set.

The EGR rate set in the EGR rate setting block B110b and the A / F value set in the A / F value setting block B110c are supplied to the equivalent ratio calculation block (equivalent ratio calculation means) B110d, and the equivalent ratio calculation block In B110d, the ratio between the stoichiometric air-fuel ratio and the air-fuel ratio of the supplied air-fuel mixture (theoretical air-fuel ratio / air-fuel ratio of the air-fuel mixture), that is, the equivalent ratio is calculated.
Further, the advance amount or delay of the ignition timing set by the air flow sensor clip value setting block B110a, the equivalent ratio calculated by the equivalent ratio calculation block B110d, or the ignition timing correction value setting means. The ignition timing correction value, which is a correction value of the angular amount, is supplied to the maximum Pi calculation block (maximum torque calculation means) B110e. In the maximum Pi calculation block B110e, the torque increase / decrease rate corresponding to the equivalence ratio and the ignition timing correction value are set. The corresponding torque increase / decrease rate is calculated, and the maximum Pi is calculated based on the air flow sensor clip value, the torque increase / decrease rate corresponding to the equivalence ratio, and the torque increase / decrease rate corresponding to the ignition timing correction value.

The engine speed Ne and the request Pias obtained as described above are supplied to the request flow rate calculation block B112, and the flow rate of intake air corresponding to the request Pias, that is, the request flow rate is calculated in the request flow rate calculation block B112. The required flow velocity is set in advance as a required flow velocity map using the required Pias and the engine speed Ne as parameters.
When the request Pias is supplied to the required flow velocity calculation block B112, the atmospheric pressure is corrected in the atmospheric pressure correction block B116. That is, since the required flow velocity map is set at the standard atmospheric pressure, the required Pias is divided by a value (BP / 101.3) obtained by dividing the atmospheric pressure (BPkPa) that changes according to the altitude by the standard atmospheric pressure (101.3 kPa). Then, the required Pias is corrected so as to match the required flow velocity map.

On the other hand, the engine rotational speed Ne is supplied to the actual flow velocity calculation block B114 together with the actual Pi calculated in the actual Pi calculation block B28. In the actual flow velocity calculation block B114, the flow velocity of intake air corresponding to the actual Pi, that is, the actual flow velocity is Calculated. The actual flow velocity is set in advance as an actual flow velocity map using the actual Pi and the engine rotational speed Ne as parameters.
Also in this case, since the actual flow velocity map is set at the standard pressure as in the request Pias, the atmospheric pressure is corrected so that the actual Pi matches the actual flow velocity map.

When the required flow rate and the actual flow rate are calculated in this way, the ratio between the requested flow rate and the actual flow rate (actual flow rate / required flow rate), that is, the flow rate ratio is easily obtained by dividing the actual flow rate by the requested flow rate.
Here, the flow rate ratio is obtained from the ratio of the required flow velocity of the intake air corresponding to the required Pias and the actual flow velocity of the intake air corresponding to the actual Pi, but the required flow velocity of the intake air corresponding to the required Pias is The actual flow rate of intake air corresponding to the actual Pi corresponds to the required flow rate of intake air corresponding to the pressure ratio at the target intake pressure, and the pressure ratio at the current intake pressure detected by the intake pressure sensor. It can be replaced with the actual flow rate of the intake air. Therefore, essentially, the required flow rate of intake air corresponding to the pressure ratio at the target intake pressure and the actual flow rate of intake air corresponding to the pressure ratio at the intake pressure detected by the current intake pressure sensor are obtained. The flow rate ratio should be obtained based on this. Further, the required flow velocity may be obtained based on the intake pressure detected by the intake pressure sensor 25 in the previous calculation cycle and the intake pressure detected by the intake pressure sensor 25 in the current calculation cycle. The intake pressure detected by the intake pressure sensor 25 in the previous calculation cycle is detected by the intake pressure sensor 25 in the current calculation cycle to the required flow rate of intake air corresponding to the request Pias in the previous calculation cycle. The intake air pressure may be replaced with the required flow velocity of the intake air corresponding to the required Pias in the current calculation cycle, and the flow velocity ratio may be obtained. The required flow rate can be easily obtained from the above, and the flow rate ratio can be easily obtained from these ratios.

However, when the flow rate ratio is obtained based on the required flow rate of intake air corresponding to the previous request Pias and the required flow rate of intake air corresponding to the current request Pias, the required flow rate of intake air corresponding to the previous request Pias. In order to obtain the flow rate ratio, it is easier to use the actual flow velocity of the intake air corresponding to the actual Pi calculated simultaneously with the request Pias as described above.
And it is discriminate | determined whether the flow rate ratio calculated | required in this way is larger than the value 1.0 in the comparison block B118. When the flow rate ratio is larger than 1.0, the obtained flow rate ratio is directly adopted and multiplied by the request Pias. On the other hand, when the flow rate ratio does not exceed the value 1.0, the value 1.0 is requested. Pias is multiplied.

  In this way, the flow rate ratio is obtained by dividing the actual flow rate by the required flow rate, and when the flow rate ratio is larger than 1.0, the request Pias is multiplied by the request Pias. As a result, the request Pias is optimized. In other words, in a situation where the opening degree of the electronically controlled throttle valve 27 is close to full open and the pressure ratio (intake pressure / atmospheric pressure) is in a so-called non-critical region exceeding a predetermined value (for example, 0.5283), As shown in the relationship between the pressure ratio and the flow rate in FIG. 3, the flow rate of the intake air becomes slower as the opening degree of the electronic control throttle valve 27 increases. However, when the driver operates the accelerator pedal in a stepped manner (operation from the critical range to the non-critical range), there is no inflow of intake air at the beginning of the change when the flow velocity of the intake air changes from the fast side to the slow side. Since there is no change in the atmospheric pressure, the opening degree of the electronically controlled throttle valve 27 increases while the flow rate of the intake air remains high, and the intake air flow rate actually passing through the electronically controlled throttle valve 27 is overshooted by the inertial force of the intake air. Will be. Therefore, it is possible to optimize the request Pias to a value corresponding to the intake air flow rate of the intake air passing through the electronically controlled throttle valve 27 that has overshot.

On the other hand, in a situation where the pressure ratio is in a so-called critical range where the pressure ratio is less than a predetermined value, the flow rate of the intake air does not change at the sonic speed as shown in FIG. The intake air passing through 27 does not overshoot, the flow rate ratio is 1.0, the request Pias is multiplied by the value 1.0, and the request Pias is optimized with the value as it is.
When the request Pias is optimized based on the flow rate ratio, the request Pia is obtained by performing the first-order lag processing on the optimized request Pias in the first-order lag processing block B120. Specifically, the calculation is performed based on the following first-order lag equation (2).

k × a + (1−k) × b (2)
Here, k is an appropriately set first-order lag filter coefficient, a is the previous value of the request Pia as the target output, and b is the optimized request Pias as the input.
In this way, the request Pias is optimized in accordance with the actual flow rate ratio, and the request Pia is obtained by first-order lag processing of the optimized request Pias. Estimate the target intake air flow rate Qt estimated by performing arithmetic processing or calibrating it appropriately according to the actual situation using one first-order lag equation (2) without dividing it into critical and non-critical regions. Is possible.

  For example, when the driver depresses the accelerator pedal 40 to accelerate the engine 1, that is, when the accelerator request signal changes from the small side to the large side, the request Pia that has been subjected to the first-order delay processing compared to the request Pias. In comparison block B122, the request Pias is compared with the request Pia subjected to the first-order lag processing. If the request Pias is equal to or more than the optimized request Pias or smaller than the request Pia that has been subjected to the first-order delay processing, the request Pia that has been subjected to the first-order delay processing is finally output as the request Pia, while the request Pias is optimized. If the request Pias is smaller than the request Pias and is equal to or greater than the request Pia that has been subjected to the first-order delay processing (appropriate request Pias> request Pias and request Pia ≦ request Pias), the request Pia is clipped to the request Pias, Is finally output as a request Pia.

  Here, referring to FIG. 6, for example, a request Pias (one-dot chain line) based on an accelerator request signal and an optimized request when the driver operates the accelerator pedal 40 stepwise to accelerate the engine 1 from an idle operation state. The time change of Pias (broken line) and the request Pia and the target intake air flow rate Qt (solid line) processed by the first-order lag are shown separately in the case of the critical region (a) and the case of the non-critical region (b). However, as shown in the figure, in the critical region, the required Pia and thus the target intake air flow rate Qt gradually increases in accordance with the actual actual intake air flow rate Qr and converges to the required Pias as in the conventional case. The demand Pia and thus the target intake air flow rate Qt converges to the demand Pias while changing so as to substantially maintain the demand Pias according to the actual actual intake air flow rate Qr.

Thus, according to the vehicle output control apparatus of the present invention, when the request Pias is obtained based on the maximum Pi, the air flow sensor clip value is set in advance for each engine speed, and the engine detected by the crank angle sensor 8 is detected. An airflow sensor clip value is calculated according to the rotation speed, and the maximum Pi is calculated using the airflow sensor clip value.
Therefore, since the maximum Pi is calculated from the airflow sensor clip value, it is not necessary to set the maximum Pi in the memory (ROM) of the ECU as dedicated data, and the memory capacity of the ECU can be suppressed.

In particular, in the engine 1 that employs the variable valve timing mechanisms 19 and 20, the intake air flow rate varies even when the electronically controlled throttle valve 27 is fully open by the operation of the variable valve timing mechanisms 19 and 20, but the maximum Pi is the air flow. By calculating from the sensor clip value, the memory capacity of the ECU can be well suppressed.
Further, since the air flow sensor clip value is also used for calculating the fuel injection amount, when the opening degree of the electronically controlled throttle valve 27 is in the fully open region, the consistency between the demand Pi determined from the maximum Pi and the fuel injection amount is satisfied. There will be.

Therefore, there is consistency between the request Pi and the fuel injection amount, and the output torque is calculated from the request Pi. As a result, consistency between the output torque and the fuel injection amount can be ensured.
Although the description of the vehicle output control device according to the present invention has been completed above, the present invention is not limited to the above embodiment.
For example, in the above-described embodiment, the variable valve timing mechanisms 19 and 20 that change the opening and closing timings of the intake valve 13 and the exhaust valve 14 are used as the variable valve mechanisms. However, the present invention is not limited to this and is not necessarily variable. The valve timing mechanisms 19 and 20 may not be provided, and the lift amount of at least one of the intake valve 13 and the exhaust valve 14 or a variable valve mechanism that makes the lift amount and the opening / closing timing variable may be used.

1 engine (internal combustion engine)
8 Crank angle sensor (rotational speed detection means)
19, 20 Variable valve timing mechanism (variable valve operating means)
21, 22 Oil control valve (variable valve operating means)
27 Electronically controlled throttle valve (intake air flow rate adjusting means)
41 Accelerator position sensor (Accelerator operation degree detection means)
50 External system element 60 ECU
B10 Accelerator request Pi calculation block B110 Required load factor calculation block B110a Air flow sensor clip value setting block (intake air flow rate clip value setting means)
B110b EGR rate setting block B110c A / F value setting block B110d Equivalence ratio calculation block (equivalence ratio calculation means)
B110e Maximum Pi calculation block (maximum torque calculation means)

Claims (4)

An output control device for a vehicle that calculates a required torque for an internal combustion engine and controls an output torque of the internal combustion engine according to the required torque,
Intake air flow rate adjusting means for adjusting the intake air flow rate taken into the internal combustion engine;
An intake air flow rate clip value setting means for setting an intake air flow rate clip value that restricts the maximum value of the intake air flow rate with respect to fluctuations in the intake air flow rate when the intake air flow rate adjustment means is in a fully open range;
Maximum torque calculating means for calculating a maximum torque that is an upper limit that can be output by the internal combustion engine based on the intake air flow rate clip value;
An accelerator operation degree detection means for detecting an operation degree of an accelerator provided in the vehicle;
Required load factor calculating means for calculating a required load factor based on the accelerator operation degree detected by the accelerator operation degree detecting means;
A required torque calculating means for calculating the required torque based on a minimum torque that is a combustible lower limit, the maximum torque, and the required load factor;
An actual torque calculating means for calculating a current actual torque;
The flow rate of the intake air of the internal combustion engine that realizes the required torque calculated by the required torque calculation unit, and the flow rate of the intake air of the internal combustion engine that realizes the current actual torque calculated by the actual torque calculation unit A flow rate ratio calculating means for calculating the ratio of
The required torque calculation means corrects the required torque by multiplying the required torque by the flow rate ratio when the flow rate ratio is greater than 1.0, and when the flow rate ratio does not exceed 1.0. , Wherein the required torque is multiplied by 1.0 . Equivalent ratio calculating means for calculating an equivalent ratio with respect to intake air sucked into the internal combustion engine;
Ignition timing correction amount setting means for setting an advance amount or a retard amount of the ignition timing of the internal combustion engine with respect to a reference ignition timing as an ignition timing correction value;
The maximum torque calculation means adds the torque increase / decrease rate according to the ignition timing correction value and the torque increase / decrease rate according to the equivalence ratio to the intake air flow clip value, or adds the ignition timing to the intake air flow clip value. 2. The vehicle output control device according to claim 1, wherein the maximum torque is calculated in consideration of a torque increase / decrease rate according to a correction value or a torque increase / decrease rate according to the equivalence ratio. The internal combustion engine
An intake valve that communicates and shuts off the combustion chamber of the internal combustion engine and the intake passage;
3. The variable valve operating means according to claim 1, further comprising variable valve operating means capable of varying at least one of a valve opening timing, a valve opening amount, or a valve opening period of the intake valve. Vehicle output control device. The internal combustion engine includes a rotation speed detection means for detecting a rotation speed of the internal combustion engine,
The intake air flow clip value setting means is provided in advance with the intake air flow clip value for each rotational speed of the internal combustion engine,
The said maximum torque calculation means calculates the said maximum torque according to the rotational speed of the said internal combustion engine detected by the said rotational speed detection means, The Claim 1 thru | or 3 characterized by the above-mentioned. Output control device for an internal combustion engine.

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