JP5891797B2 - Engine control device - Google Patents

Description

  The present invention relates to an engine control device that controls a throttle opening based on a required torque required for an engine.

  As a control method for an engine mounted on a vehicle, torque base (torque demand) control for controlling intake air amount, fuel injection amount, ignition timing, etc. based on the magnitude of torque required for the engine is known. ing. In torque-based control, a target value of torque to be output by the engine is calculated based on the accelerator opening and the engine speed, and the engine operating state is controlled so that this target torque is obtained. Also, in vehicles equipped with external control systems such as automatic transmissions, auto cruise devices, and vehicle stabilizers, output requests from each external control system to the engine are converted into torque values and integrated in the engine control unit (engine ECU). The torque behavior of the engine is comprehensively controlled.

  For example, Patent Document 1 describes a control device that sets an engine target torque, estimates an output torque, and controls the intake air amount and ignition timing so that the output torque follows the target torque. In this technology, the target torque is set based on the accelerator opening, etc., and the target torque is also set by idle speed control and cruise control, and the final target torque is selected from these multiple target torques. Yes.

JP 2009-24677 A

  By the way, in the torque-based intake air amount control, the opening degree of the throttle valve is controlled so that an amount of air that causes a combustion reaction necessary and sufficient to generate the torque required for the engine is secured. For example, when the required torque is calculated based on the accelerator opening and the engine speed, the intake flow rate for obtaining the engine output torque having the same magnitude as the required torque is calculated, and the flow rate of the air passing through the throttle valve Is controlled so as to match the intake flow rate.

  On the other hand, as a torque characteristic of the throttle valve, the change in the engine output torque with respect to the change in the throttle opening is not necessarily linear, and the increase in the output torque decreases as the throttle opening increases. That is, the greater the required torque value that is the output target, the greater the change in the throttle opening when the value changes. For this reason, when the accelerator opening is close to full open, even if the accelerator opening is constant, the throttle opening changes greatly with only a slight change in the required torque as the engine speed changes. become. Such a rapid change in the throttle opening can make the behavior of the output torque unstable and greatly reduce the controllability of the engine.

One of the purposes of the present invention was devised in view of the above-described problems, and an engine capable of improving the control stability of output torque in torque-based control that calculates a required torque based on the accelerator opening. It is to provide a control device.
The present invention is not limited to this purpose, and is a function and effect derived from each configuration shown in the embodiments for carrying out the invention described later, and other effects of the present invention are to obtain a function and effect that cannot be obtained by conventional techniques. Can be positioned.

(1) An engine control device disclosed herein includes detection means for detecting an accelerator opening degree of a vehicle, and setting means for setting a virtual rotation speed larger than an actual rotation speed of an engine mounted on the vehicle. . A calculating means for calculating a required torque required for the engine based on the accelerator opening detected by the detecting means and the virtual rotational speed set by the setting means; Control means for controlling the throttle opening of the engine based on the required torque.
When the load required for the engine exceeds a predetermined load, the calculation means calculates the required torque based on the accelerator opening and the virtual rotational speed, and the load is equal to or less than the predetermined load. The required torque is calculated based on the accelerator opening and the actual rotational speed.
The accelerator opening is a parameter corresponding to the amount of depression of an accelerator pedal equipped in the vehicle.

Moreover, the said load here means the force which exerts resistance with respect to the said engine, a work rate (engine output, horsepower), and work (energy). Typically, the engine output required for the engine is treated as the load. That is, when there is some factor that decreases the engine output, the decrease in the engine output corresponds to the magnitude of the load. Further, when the control for increasing the engine output in advance is performed in anticipation of the decrease in the engine output, the increase in the engine output corresponds to the magnitude of the load.

  In general, the engine output is proportional to the product of the engine torque and rotational speed. Therefore, under the condition that the rotational speed is constant, the “load” can be read as “torque to be output by the engine”, “torque to be generated by the engine”, and “torque generated by the engine”. Similarly, under the condition that the torque is constant, the “load” can be read as “the rotational speed at which the engine is to rotate”, “the speed at which the engine is to be rotated”, and “the actual rotational speed of the engine”.

  Further, as the load, a load (accelerator load) given by the driving operation of the driver, a load given to the engine by the operation of an external load device, a load derived from the traveling environment of the vehicle, and the like can be considered. The external load device is an in-vehicle device controlled by various electronic control devices such as a brake control device, a transmission control device, a vehicle stability control device, an air conditioning control device, and an electrical component control device.

( 2 ) Moreover, it is preferable that the said calculating means has a full open time torque calculating means, an accelerator required torque calculating means, a required load factor calculating means, and a required torque calculating means. The fully-open torque calculation means, which calculates an output torque of the real rotational speed of the engine at the time of full opening of the throttle opening as a fully-open torque, the accelerator demanded torque calculation means, the accelerator opening Further, the accelerator required torque corresponding to the accelerator load is calculated based on the actual rotational speed.

  Further, the required load factor calculating means calculates a ratio of the accelerator required torque to the fully opened torque as a required load factor, and the required torque calculating means is a case where the required load factor exceeds a predetermined load factor. And calculating the required torque based on the accelerator opening and the virtual rotational speed, and when the required load factor is equal to or less than the predetermined load factor, the request based on the accelerator opening and the actual rotational speed. Torque is calculated.

  That is, when the required load factor is equal to or less than the predetermined load factor, it is preferable that the required torque is calculated using the actual rotational speed instead of the virtual rotational speed. On the contrary, when the required load factor is equal to or higher than the predetermined load factor, it is preferable that the virtual torque is used instead of the actual rotation rate to calculate the required torque.

( 3 ) Further, the calculating means calculates virtual accelerator required torque calculating means for calculating a virtual accelerator required torque based on the accelerator opening and the virtual rotational speed, and a ratio of the virtual accelerator required torque to the fully opened torque. It is preferable to have virtual required load factor calculating means for calculating as a virtual required load factor. In this case, it is preferable that the setting means sets the magnitude of the virtual rotational speed so that the virtual required load factor is equal to or less than the predetermined load factor.

( 4 ) In addition, it is preferable that the setting unit sets the virtual rotation speed by repeatedly adding a predetermined value to the actual rotation speed until the virtual required load ratio becomes equal to or less than the predetermined load ratio.
(5) The virtual rotational speed is the minimum rotational speed at which the virtual required load factor is equal to or lower than the predetermined load factor at the accelerator opening at that time, and the virtual required load factor is the accelerator opening and It is preferable that the virtual accelerator required torque calculated based on the virtual rotational speed is a parameter corresponding to a degree of acting as a load of the engine.

  In the disclosed engine control device, the required torque is calculated based on a virtual rotational speed larger than the actual rotational speed, and the throttle opening is controlled based on the required torque. A change in throttle opening can be suppressed. Thereby, the convergence property and controllability of the engine output torque can be improved, and the behavior of the vehicle can be stabilized.

It is a figure which illustrates the block configuration of the control apparatus of the engine which concerns on one Embodiment, and the structure of the engine to which this control apparatus was applied. It is a graph which illustrates the torque characteristic of the throttle valve concerning this control device. It is a graph which illustrates the equal throttle opening characteristic of the throttle valve concerning this control device. It is a block block diagram which illustrates the intake air amount control part of this control apparatus. It is a flowchart which illustrates the calculation method of the request torque in this control apparatus. It is a flowchart which illustrates the calculation method of the target throttle opening in this control apparatus. It is a graph which illustrates the equal accelerator opening characteristic of the vehicle carrying this control device.

  An engine control apparatus will be described with reference to the drawings. Note that the embodiment described below is merely an example, and there is no intention to exclude various modifications and technical applications that are not explicitly described in the following embodiment. Each configuration of the present embodiment can be implemented with various modifications without departing from the spirit of the present embodiment, and can be selected or combined as necessary.

[1. Device configuration]
[1-1. engine]
The engine control device of the present embodiment is applied to the in-vehicle gasoline engine 10 shown in FIG. Here, one of a plurality of cylinders provided in the multi-cylinder engine 10 is shown. The piston 16 is provided so as to be slidable back and forth along the inner peripheral surface of a cylinder 19 formed in a hollow cylindrical shape. The space surrounded by the upper surface of the piston 16 and the inner peripheral surface and top surface of the cylinder 19 functions as a combustion chamber 26 of the engine.
The lower portion of the piston 16 is connected to a crank arm having a central axis that is eccentric from the axis of the crankshaft 17 via a connecting rod. Thereby, the reciprocating motion of the piston 16 is transmitted to the crank arm and converted into the rotational motion of the crankshaft 17.

  An intake port 11 for supplying intake air into the combustion chamber 26 and an exhaust port 12 for discharging exhaust gas after combustion in the combustion chamber 26 are formed in the top surface of the cylinder 19. An intake valve 14 and an exhaust valve 15 are provided at the end of the intake port 11 and the exhaust port 12 on the combustion chamber 26 side. The intake valve 14 and the exhaust valve 15 are individually controlled in operation by a valve mechanism (not shown) provided in the upper part of the engine 10. A spark plug 13 is provided at the top of the cylinder 19 with its tip projecting toward the combustion chamber 26. The ignition timing by the spark plug 13 is controlled by the engine control device 1 described later.

[1-2. Intake and exhaust system]
An injector 18 for injecting fuel is provided in the intake port 11. Normally, the amount of fuel injected from the injector 18 is controlled according to the throttle opening (that is, the intake air amount) by the engine control device 1 described later. Further, an intake manifold 20 (hereinafter referred to as an intake manifold) is provided upstream of the injector 18 in the intake air flow. The intake manifold 20 is provided with a surge tank 21 for temporarily storing air flowing toward the intake port 11 side. The intake manifold 20 on the downstream side of the surge tank 21 is formed to branch toward the intake port 11 of each cylinder 19, and the surge tank 21 is located at the branch point. The surge tank 21 functions to alleviate intake pulsation and intake interference that can occur in each cylinder.

A throttle body 22 is connected to the upstream side of the intake manifold 20. An electronically controlled throttle valve 23 is built in the throttle body 22, and the amount of air flowing to the intake manifold 20 is adjusted according to the opening (throttle opening) of the throttle valve 23. The throttle opening is controlled by the engine control device 1.
An intake passage 24 is connected further upstream of the throttle body 22, and an air filter 25 is interposed further upstream of the intake passage 24. Thus, fresh air filtered by the air filter 25 is supplied to each cylinder 19 of the engine 10 via the intake passage 24 and the intake manifold 20.

[1-3. Detection system]
The crankshaft 17 of the engine 10 is provided with an engine rotation speed sensor 31 that detects the rotation angle. The amount of change (angular velocity) per unit time of the rotation angle is proportional to the actual rotation speed Ne (actual rotation number per unit time) of the engine 10. Therefore, the engine rotation speed sensor 31 has a function of acquiring the actual rotation speed Ne of the engine 10. The actual rotation speed Ne may be calculated inside the engine control device 1 based on the rotation angle detected by the engine rotation speed sensor 31.

An atmospheric pressure sensor 32 is provided inside the engine control device 1 or at an arbitrary position of the vehicle. The atmospheric pressure sensor 32 detects atmospheric pressure (atmospheric pressure) _BP . The atmospheric pressure B _P corresponds to the pressure at the inlet of the intake passage 24 (pressure upstream of the air filter 25).
In addition, an accelerator opening sensor 33 (detection means) that detects the amount of depression of the accelerator pedal (accelerator opening A _PS ) is provided at an arbitrary position of the vehicle (for example, in the vicinity of the accelerator pedal). The accelerator opening A _PS is a parameter corresponding to the driver's acceleration request, that is, corresponds to an output request to the engine 10.
Information about the actual rotational speed Ne, the atmospheric pressure B _P , and the accelerator opening A _PS acquired by the various sensors 31 to 33 is transmitted to the engine control device 1.

[1-4. Control system]
A vehicle equipped with the engine 10 is provided with an engine control device 1 (Engine Electronic Control Unit). The engine control device 1 is configured as, for example, an LSI device or a built-in electronic device in which a microprocessor, ROM, RAM, and the like are integrated, and is connected to a communication line of an in-vehicle network provided in the vehicle. Note that various known electronic control devices such as a brake control device, a transmission control device, a vehicle stability control device, an air conditioning control device, and an electrical component control device are communicably connected to each other on the in-vehicle network. An electronic control device other than the engine control device 1 is called an external control system, and a device controlled by the external control system is called an external load device.

  The engine control device 1 is an electronic control device that comprehensively controls a wide range of systems such as an ignition system, a fuel system, an intake / exhaust system, and a valve system related to the engine 10, and the amount of air supplied to each cylinder 19 of the engine 10. The fuel injection amount, the ignition timing of each cylinder 19 and the like are controlled. Here, torque base control based on the magnitude of torque required for the engine 10 is performed. Specific control targets of the engine control device 1 include the amount of fuel injected from the injector 18 and the injection timing, the ignition timing at the spark plug 13, the throttle opening of the throttle valve 23, and the like.

  The engine control device 1 calculates three types of required torque as torque required for the engine 10. The first required torque corresponds to the driver's acceleration request, and the second required torque corresponds to the request from the external load device. Both of these required torques can be said to be torques calculated based on the load acting on the engine 10. On the other hand, the third required torque is for rotational feedback control that maintains the actual rotational speed Ne of the engine 10, and is considered even in a no-load state in which no external load acts on the engine 10. Is the required torque. These required torques are automatically switched according to the operating conditions of the engine 10.

In the present embodiment, a calculation method of the required torque TRQ _TGT corresponding to the driver's acceleration request among these three types of required torque will be described in detail. Further, the control action will be described by taking as an example a case where the opening degree of the throttle valve 23 is controlled using the required torque TRQ _TGT corresponding to the acceleration request.

  Here, the torque characteristic of the throttle valve 23 will be described. FIG. 2 shows the magnitude of the output torque generated in the engine 10 when the throttle opening is gradually increased under the condition that the actual rotational speed Ne of the engine 10 is constant. When the throttle opening is relatively low, the output torque increases with a substantially constant gradient as the throttle opening increases. On the other hand, when the throttle opening increases to some extent, the increase gradient decreases rapidly, and the output torque does not easily increase. That is, the engine 10 has a characteristic that the increase in the output torque decreases as the throttle opening of the throttle valve 23 increases.

  Further, the solid line graph in FIG. 3 is a graph showing the relationship between the actual rotational speed Ne and the output torque under the condition that the throttle opening is constant. Here, the graphs when the throttle opening is changed to eight stages are overlaid. 3 corresponds to the case where the throttle opening is larger as the position is higher. The characteristics of the throttle valve 23 indicate how much the throttle opening should be opened if the torque required for the engine 10 and the actual rotational speed Ne at that time are determined.

  On the other hand, the operation region where the interval between these graphs is narrower is the operation region where the increment of the output torque is small when the throttle opening is increased. It is an area. In such an operating region, the change in the opening when the throttle opening is determined from the torque required for the engine 10 and the actual rotational speed Ne becomes extremely easy to increase and decrease, and the control stability related to intake air is reduced. It's easy to do.

Therefore, the engine control device 1 of the present embodiment, when determining the throttle opening based on characteristics shown in FIG. 3, not only the normal request torque, to variations of the actual rotational speed Ne and the accelerator opening degree A _PS A virtual required torque with a small amount of change is calculated, and the throttle opening is calculated based on one of these two types of required torque. Hereinafter, each of the above two types of required torque is referred to as “normal required torque” and “virtual required torque”, and the finally selected required torque is referred to as “required torque TRQ _TGT ”.

[2. Control device configuration]
As shown in FIG. 1, an engine speed sensor 31, an atmospheric pressure sensor 32, and an accelerator opening sensor 33 are connected to the input side of the engine control device 1. Further, an ignition plug 13, an injector 18, a throttle valve 23, and the like, which are control targets for torque base control, are connected to the output side of the engine control device 1.

  The engine control device 1 is provided with a setting unit 2, a calculation unit 3, and an intake air amount control unit 4. Each function of the setting unit 2, the calculation unit 3, and the intake air amount control unit 4 may be realized by an electronic circuit (hardware), may be programmed as software, or among these functions A part of may be provided as hardware and the other part may be software.

[2-1. Setting section]
The setting unit 2 (setting unit) sets a virtual rotational speed Nev (virtual engine rotational speed) having a value larger than the actual rotational speed Ne at that time. The virtual rotational speed Nev is one of the parameters for calculating the final required torque TRQ _TGT used in the torque-based control performed by the engine control device 1, and is the accelerator opening _APS at that time, which will be described later. _This is the minimum engine speed at which the virtual required load factor R _LOADV is less than or equal to the predetermined load factor R ₀ . In the torque-based control of the present embodiment, according to the operating state of the engine 10, required torque TRQ _TGT is calculated on the basis of the one and the accelerator opening A _PS actual rotation speed Ne or the virtual rotational speed Nev.

In the setting unit 2, the virtual rotational speed Nev is set when the load required for the engine 10 exceeds a predetermined load. For example, the virtual rotation speed Nev is set when the required load factor R _LOAD or the virtual required load factor R _{LOADV of the} engine 10 calculated by the calculation unit 3 described later is higher than a predetermined load factor R ₀ . The predetermined load here is arbitrarily determined according to the rotational speed of the engine 10 and the traveling environment conditions of the vehicle. The value of the predetermined load may be a fixed value set in advance, or may be a variable that is set as needed according to various parameters related to the actual rotational speed Ne and the driving environment conditions.
Further, the value of the virtual rotational speed Nev is set to a higher value as the load required for the engine 10 is larger. A specific method for setting the virtual rotational speed Nev in the setting unit 2 of the present embodiment will be described later. The value of the virtual rotation speed Nev set here is transmitted to the calculation unit 3.

[2-2. Calculation unit]
The calculation unit 3 (calculation means) calculates a required torque TRQ _TGT used in the torque base control. Here, as shown in FIG. 1, as shown in FIG. 1, a fully open torque calculation unit 3 </ b> A, an idle target torque calculation unit 3 </ b> B, an accelerator required torque calculation unit 3 </ b> C, a required load factor calculation unit 3 </ b> D, a virtual accelerator request torque calculation unit 3 </ b> E, A rate calculator 3F and a required torque calculator 3G are provided.

The fully open torque calculation unit 3A (fully open torque calculation means) is operated when the engine 10 is fully depressed (when the accelerator opening A _PS is maximum) at the actual rotational speed Ne of the engine 10 at that time. The torque corresponding to the maximum value of torque that can be output is calculated as the fully open torque TRQ _MAX . The fully open torque TRQ _MAX is calculated based on the actual rotational speed Ne of the engine 10, the front-rear pressure ratio of the throttle valve 23, and the like based on a preset correspondence map, mathematical expressions, relational expressions, and the like. Further, using the characteristics shown in FIG. 3, the calculation may be performed based on the graph corresponding to the fully open throttle opening (the graph positioned at the uppermost position) and the actual rotational speed Ne. This fully open torque TRQ _MAX is a value used as a reference when calculating the required load factor R _LOAD , and is transmitted to the required load factor calculator 3D and the virtual required load factor calculator 3F.

The idle target torque calculation unit 3B calculates an idle target torque TRQ _IDL , which is a torque target value during idle operation, based on the no-load loss of the engine 10. Here, no-load loss torque corresponding to the loss torque when the engine 10 is rotated at the target rotational speed N _obj is calculated, and the auxiliary load torque corresponding to the auxiliary load of the engine 10 or the individual of the engine 10 is calculated. A learning torque or the like for canceling the difference and the control deviation is calculated, and the sum of these is calculated as the idle target torque TRQ _IDL .

The idle target torque TRQ _IDL is a torque required to continue driving the engine 10 at the target rotational speed N _obj , and is a parameter serving as a base for an output target value when the engine 10 is idling. In other words, the idle target torque TRQ _IDL is a torque to be targeted when the engine 10 is in an operating state corresponding to no load (when the engine 10 is not working outside) (no load equivalent operation). Hour target torque). The value of the idle target torque TRQ _IDL calculated here is another reference value for calculating the required load factor, and is transmitted to the required load factor calculator 3D and the virtual required load factor calculator 3F. .

  The no-load loss torque is a torque corresponding to a loss inherent in the engine 10, and is a torque corresponding to a mechanical loss that does not depend on the magnitude of the load. This no-load loss torque includes, for example, a friction loss torque and a mechanical loss torque that are lost when the engine 10 is driven at a constant rotational speed when the accelerator pedal is not depressed, or an auxiliary machine of the engine 10 Auxiliary drive torque required to drive the is included.

The accelerator request torque calculator 3C (accelerator request torque calculator) calculates the accelerator request torque TRQ _APS required for the engine 10 based on the driver's accelerator operation. Here, the accelerator demand torque TRQ _APS is calculated on the basis of the actual rotational speed Ne and the accelerator opening A _PS of the engine 10. Accelerator demand torque TRQ _APS corresponds to the "normal required torque" of the above two kinds of the required torque, such as the corresponding map and equations between the actual rotational speed Ne and the accelerator opening degree A _PS and the accelerator demand torque TRQ _APS, relationship It is calculated based on an equation or the like.

However, the range that the accelerator required torque TRQ _APS can take is not less than the idle target torque TRQ _IDL calculated by the idle target torque calculation unit 3B and not more than the fully open torque TRQ _MAX calculated by the fully open torque calculation unit 3A. The The value of the accelerator required torque TRQ _APS calculated here is transmitted to the required load factor calculating unit 3D.
It should be noted that the accelerator required torque TRQ _APS may be obtained by interpolating between the idle target torque TRQ _IDL and the fully open torque TRQ _MAX using a required load rate R _LOAD described later. In this case, the accelerator required torque TRQ _APS can be obtained using the following Equation 1.

The required load factor calculator 3D (required load factor calculator) calculates the required load factor R _LOAD for the accelerator required torque TRQ _APS calculated by the accelerator required torque calculator 3C. The required load factor R _LOAD is a parameter corresponding to the degree to which the accelerator required torque TRQ _APS acts as a load on the engine 10, and is calculated on the basis of the fully open torque TRQ _MAX and the idle target torque TRQ _IDL .

For example, as shown in Equation 2, the ratio of the accelerator required torque TRQ _APS within the torque fluctuation range with the idle target torque TRQ _IDL as the lower limit and the fully open torque TRQ _MAX as the upper limit is calculated as the required load ratio R _LOAD. The The value of the required load factor R _LOAD calculated here is transmitted to the setting unit 2 and the required torque calculation unit 3G.

The above formula 2 is a modification of the formula 1. Fully-open torque TRQ _MAX and the accelerator demand torque TRQ _APS in Formula 2 may also be determined from the actual rotational speed Ne and the accelerator opening A _PS. Accordingly, a correspondence map, formula and relational expression between the actual rotational speed Ne and the accelerator opening A _PS and the required load factor _RLOAD are set in advance, and the required load factor R based on the correspondence map, formula and relational expression is set in advance. _LOAD may be calculated. In this case, the accelerator required torque TRQ _APS may be obtained using the value of the required load factor R _LOAD .

The virtual accelerator request torque calculator 3E (virtual accelerator request torque calculator) calculates a virtual accelerator request torque TRQ _APSV as a second accelerator request torque different from the request torque in the accelerator request torque calculator 3C. . Here, the virtual accelerator demanded torque TRQ _APSV is calculated based on the virtual rotational speed Nev set by the setting unit 2 and the accelerator opening degree A _PS.

The virtual accelerator required torque TRQ _APSV corresponds to the “virtual required torque” of the above two types of required torques. For example, based on the correspondence map preset in the accelerator required torque calculation unit 3C, instead of the actual rotational speed Ne. It is calculated by using the virtual rotation speed Nev. The range that the virtual accelerator required torque TRQ _APSV can take is equal to or higher than the idle target torque TRQ _IDL and lower than the fully open torque TRQ _MAX , similarly to the accelerator required torque TRQ _APS . The value of the virtual accelerator required torque TRQ _APSV calculated here is transmitted to the virtual required load factor calculating unit 3F.

Note that the virtual accelerator required torque TRQ _APSV may be obtained by interpolating between the idle target torque TRQ _IDL and the fully open torque TRQ _MAX using a virtual required load rate R _LOADV described later. In this case, the virtual accelerator required torque TRQ _APSV can be obtained using the following Equation 3.

The virtual required load factor calculator 3F (virtual required load factor calculator) calculates a virtual required load factor R _LOADV that is a required load factor for the virtual accelerator required torque TRQ _APSV calculated by the virtual accelerator required torque calculator 3E. Is. The virtual required load factor R _LOADV is a parameter corresponding to the degree to which the virtual accelerator required torque TRQ _APSV acts as a load on the engine 10, and, like the above-described required load factor R _LOAD , the fully open torque TRQ _MAX and the idle target Calculated based on torque TRQ _IDL .

For example, as shown in Equation 4, the ratio of the virtual accelerator required torque TRQ _APSV within the torque fluctuation range with the idle target torque TRQ _IDL as the lower limit and the fully open torque TRQ _MAX as the upper limit is _expressed as the virtual required load ratio R _LOADV Calculated. Equation 4 is a variation of Equation 3 above.

Note that the fully open torque TRQ _MAX and the virtual accelerator required torque TRQ _APSV in Equation 4 can also be obtained from the virtual rotational speed Nev and the accelerator opening A _PS . Therefore, correspondence maps, mathematical formulas, and relational expressions between the virtual actual rotational speed Nev and accelerator opening A _PS and the virtual demand load factor R _LOADV are set in advance, and virtual demands are based on these correspondence maps, mathematical formulas, and relational expressions. The load factor R _LOADV may be calculated. In this case, the virtual accelerator required torque TRQ _APSV may be obtained using the value of the virtual required load factor R _LOADV .

Here, a method for setting the virtual rotational speed Nev based on the required load factor R _LOAD and the virtual required load factor R _LOADV will be described. The setting unit 2 described above sets the virtual rotational speed Nev when the load required for the engine 10 exceeds a predetermined load, and sets the value of the virtual rotational speed Nev higher as the load increases. More specifically, it is determined based on the magnitude of the load that is required by the engine 10 to the required load factor R _LOAD and virtual required load factor R _LOADV, these required load factor R _LOAD and virtual required load factor R _LOADV value The value of the virtual rotational speed Nev is gradually increased until becomes a predetermined load factor R ₀ or less. The magnitude of the predetermined load factor R ₀ is a value corresponding to a relatively high load state, for example, 90 [%] or more (required load factor is 0.90 or more) or 95 [%] or more (required load factor is 0.95 or more). And

That is, in an operating state where the load required for the engine 10 is relatively small, the virtual rotational speed Nev is not set, that is, the virtual required load factor R _LOADV is not calculated. On the other hand, in an operation state where the load is relatively large, the virtual rotational speed Nev is set in a range larger than the actual rotational speed Ne, and the virtual required load ratio R _LOADV is calculated. Further, the magnitude of the load is determined from the value of the virtual required load rate R _LOADV , and when the load is large, the value of the virtual rotational speed Nev is reset to be larger. Such setting of the virtual rotational speed Nev and calculation of the virtual required load factor R _LOADV are repeatedly performed.

_If the value of the virtual required load factor R _LOADV decreases as the virtual rotational speed Nev increases, the virtual rotational speed Nev setting stops when the value falls below the specified load factor R ₀ , and the virtual required load factor R _LOADV computation also stops. Note that just because the virtual rotation speed Nev increases, the value of the virtual required load factor R _LOADV does not necessarily decrease. Therefore, _when the value of the virtual required load factor R _{LOADV does} not become the predetermined load factor R ₀ or less, the calculation is performed until the virtual rotational speed Nev reaches the upper limit rotational speed Nemax (for example, 6000 [rpm]) of the engine 10. Repeated. As described above, the value of the virtual required load factor R _LOADV finally obtained by the virtual required load factor calculator 3F is transmitted to the setting unit 2 and the required torque calculator 3G.

The required torque calculation unit 3G (required torque calculation means) is based on the required load factor R _LOAD calculated by the required load factor calculator 3D and the virtual required load factor R _LOADV calculated by the virtual required load factor calculator 3F. The required torque TRQ _TGT required for the engine 10 is calculated. Here, when the virtual required load factor R _LOADV is not transmitted from the virtual required load factor calculator 3F, the required torque TRQ _TGT is calculated based on the required load factor R _LOAD and the virtual required load factor R _LOADV is transmitted. If so, the required torque TRQ _TGT is calculated based on the virtual required load factor R _LOADV .

The specific calculation method of the required torque TRQ _TGT is arbitrary. For example, a map or a mathematical expression corresponding to the required torque TRQ _TGT and the rotational speed (including the actual rotational speed Ne and the virtual rotational speed Nev) and the load (including the required load ratio R _LOAD and the virtual required load ratio R _LOADV ) of the engine 10, A relational expression may be set in advance, and the required torque TRQ _TGT may be calculated based on these correspondence maps, mathematical expressions, and relational expressions. Alternatively, the required torque TRQ _TGT may be obtained based on the aforementioned accelerator required torque TRQ _APS or virtual accelerator required torque TRQ _APSV , or any one of these may be used as the required torque TRQ _TGT . The value of the required torque TRQ _TGT calculated here is transmitted to the intake air amount control unit 4.

[2-3. Intake amount control unit]
The intake air amount control unit 4 (control unit, intake control unit) controls the throttle opening based on the required torque TRQ _TGT calculated by the calculation unit 3. Here, the target throttle opening degree θ _TH is calculated so that a torque having a magnitude equal to the required torque TRQ _TGT is output from the engine 10. As shown in FIG. 4, the intake air amount control unit 4 includes a required intake manifold pressure calculating unit 4A, a required pressure ratio calculating unit 4B, a required flow rate calculating unit 4C, a required flow rate calculating unit 4D, a required area calculating unit 4E, a required opening A degree calculation unit 4F is provided.

The required intake manifold pressure calculation unit 4A calculates the required internal pressure of the intake manifold 20 (the pressure downstream of the throttle valve 23) based on the required torque TRQ _TGT and the actual rotational speed Ne or the virtual rotational speed Nev. _Calculated as pressure P _IMTGT . Here, for example, the required intake manifold pressure P _IMTGT is calculated based on a _preset map, a mathematical expression, a relational expression, etc. of the required torque TRQ _TGT and the engine speed Ne, Nev and the required intake manifold pressure P _IMTGT . As the engine rotational speed of this calculation, the virtual rotational speed Nev is used when the load required for the engine 10 exceeds a predetermined load, and the actual rotational speed Ne is used when the load is equal to or lower than the predetermined load. The value of the required intake manifold pressure P _IMTGT calculated here is transmitted to the required pressure ratio calculation unit 4B.

Required pressure ratio calculation unit 4B, based on the request intake manifold pressure P _IMTGT and the atmospheric pressure B _P, is for calculating a pressure ratio that is required for the throttle valve 23 parts as required pressure ratio R _PRS. Here, for example, a value obtained by dividing the required intake manifold pressure P _IMTGT by the atmospheric pressure B _P is calculated as the required pressure ratio R _PRS . The required pressure ratio R _PRS may be calculated using the upstream pressure of the throttle valve 23. In this case, a value obtained by subtracting the amount of pressure loss in the intake passage 24 from the atmospheric pressure B _P is obtained as an upstream pressure of the throttle valve 23, and a required pressure ratio R _PRS is obtained by dividing the required intake manifold pressure P _IMTGT by the upstream pressure. Good. The value of the required pressure ratio R _PRS calculated here is transmitted to the required flow velocity calculation unit 4C.

The required flow rate calculation unit 4C is required to make the flow rate of the intake air to be passed through the throttle valve 23 based on the required pressure ratio R _PRS (the actual pressure ratio of the throttle valve 23 is equal to the required pressure ratio R _PRS ). (Flow velocity) is calculated as the required flow velocity V _TH . Here, for example, the required flow velocity V _TH is calculated on the basis of a correspondence map, a mathematical expression, a relational expression, or the like, which is set in advance with the required pressure ratio R _PRS and the required flow velocity V _TH . The value of the required flow velocity calculated here is transmitted to the required area calculation unit 4E.

Based on the required torque TRQ _TGT and the actual rotational speed Ne or the virtual rotational speed Nev, the required flow rate calculation unit 4D calculates the intake flow rate (flow rate per unit time) that should pass through the throttle valve 23 as the required flow rate Q _THTGT . Is. Here, the required flow rate Q _THTGT is calculated based on, for example, a preset required torque TRQ _TGT , a correspondence map of the engine speed and the required flow rate Q _THTGT , a mathematical expression, a relational expression, and the like. As the engine rotational speed of this calculation, the virtual rotational speed Nev is used when the load required for the engine 10 exceeds a predetermined load, and the actual rotational speed Ne is used when the load is equal to or lower than the predetermined load. The value of the required flow rate Q _THTGT calculated here is transmitted to the required area calculation unit 4E.

The required area calculation unit 4E has an open area required for the throttle valve 23 based on the required flow rate V _TH calculated by the required flow rate calculation unit 4C and the required flow rate Q _THTGT calculated by the required flow rate calculation unit 4D. S _TH is calculated. The required area S _TH is obtained by dividing the required flow rate Q _THTGT by the required flow velocity V _TH . The value of the required area S _TH calculated here is transmitted to the required opening calculation unit 4F.

The required opening degree calculation unit 4F calculates the target throttle opening degree θ _TH based on the required area S _TH . Here, for example, the target throttle opening degree θ _TH is calculated on the basis of a correspondence map, a mathematical expression, a relational expression, or the like of a predetermined required area S _TH and the target throttle opening degree θ _TH . Further, a control signal corresponding to the target throttle opening θ _TH calculated here is output to the throttle valve 23, and the actual throttle opening is controlled.

[3. flowchart]
FIG. 5 is a flowchart for explaining the calculation procedure of the required torque TRQ _TGT executed by the engine control apparatus 1, and FIG. 6 is a flowchart for explaining the calculation procedure of the target throttle opening _θTH . The former mainly corresponds to the calculation content in the setting unit 2 and the calculation unit 3, and the latter mainly corresponds to the calculation content in the intake air amount control unit 4. These flowcharts are repeatedly executed at a predetermined cycle (for example, several tens [ms] cycles) set in advance.

[3-1. Calculation of required torque TRQ _TGT ]
The symbol n in the flowchart of FIG. 5 is a variable (0 or a positive integer) that indicates the number of repeated operations for gradually increasing the virtual rotational speed Nev of the engine 10, and the symbol Ne _(n) is set to the nth. It is a variable that means virtual rotation speed. Of the virtual rotational speed Ne ₍₀₎ in this flowchart, the 0th virtual rotational speed Ne ₍₀₎ corresponds to the actual rotational speed Ne, and the first and subsequent ones are larger than the actual rotational speed Ne. It corresponds to the above virtual rotation speed Nev having a value.

First, in step A10, the value of the variable n is initialized and n = 0 is set. In the subsequent step A20, the value of the accelerator opening A _PS detected by the accelerator opening sensor 33 is read into the calculation unit 3. In step A30, the actual rotational speed Ne acquired by the engine rotational speed sensor 31 is set by the setting unit 2 as the _0th virtual rotational speed Ne ₍₀₎ .
In Step A40, it is determined whether or not the value of the variable n is n = 0. Here, when n = 0 at the first determination after the execution of this flow, the process proceeds to step A100, and when n ≠ 0 after the second time, the process proceeds to step A50.

In step A100, the required load factor _RLOAD is calculated in the required load factor calculator 3D. Here, the required load factor R _LOAD is calculated based on the correspondence map f _LOAD between the virtual rotational speed Ne _{(n), the} accelerator opening A _PS, and the required load factor R _LOAD . The value of the required load factor R _LOAD which is calculated here when n = 0 is a one corresponding to the actual rotational speed Ne and the accelerator opening A _PS. Instead of such a method, the required load ratio R _LOAD may be obtained based on the fully open torque TRQ _MAX , the idle target torque TRQ _IDL, and the accelerator required torque TRQ _APS .

In step A110, the setting unit 2 or the required load factor calculating unit 3D determines whether or not the required load factor R _LOAD calculated in the previous step exceeds a predetermined load factor _R0 . If this condition is not satisfied, it is determined that the load required for the engine 10 is relatively small, and the process proceeds to Step A140.
In step A140, the required torque TRQ _TGT is calculated in the required torque calculation unit 3G. Here, the required torque TRQ _TGT is calculated based on the correspondence map f _TRQ between the virtual rotational speed Ne _(n) and the required load ratio R _LOAD and the required torque TRQ _TGT . The value of the demand torque TRQ _TGT that is calculated here when n = 0 is a one corresponding to the actual rotational speed Ne and the accelerator opening A _PS. Therefore, in an operating state where the required load factor R _LOAD is relatively low, control equivalent to conventional torque base control is performed.

On the other hand, when the condition of step A110 is satisfied, the process proceeds to step A120. In Step A120, it is determined whether or not the virtual rotational speed Ne _(n) is equal to or lower than the upper limit rotational speed Nemax. Here, if Ne _(n) ≦ Nemax, the value n + 1 is assigned to the variable n, and the process proceeds to step A40 again. If Ne _(n) > Nemax, the process proceeds to step A140.
In step A50 that proceeds when n ≠ 0 in step A40, it is determined whether or not the value of the variable n is n> 1. Here, when n> 1 is not satisfied (when n = 1), the process proceeds to step A60, and when n> 1 (when n is 2 or more), the process proceeds to step A90.

In Step A60, a preset predetermined rotational speed Ne ₀ is substituted as the value of the _first provisional virtual rotational speed Ne ₍₁₎ . The predetermined rotational speed Ne ₀ is given a relatively small value such as 500 [rpm] or 1000 [rpm]. In the subsequent step A70, it is determined whether or not the virtual rotational speed Ne ₍₁₎ set in the previous step is smaller than the actual rotational speed Ne.
If Ne ₍₁₎ <Ne, the process proceeds to step A80, where the value of the virtual rotational speed Ne ₍₁₎ at that time is a predetermined value A (for example, 100 [rpm], 500 [rpm], etc.) Is added to the virtual rotational speed Ne ₍₁₎ , and the process again proceeds to step A70. That is, the value of the first virtual rotational speed Ne ₍₁₎ until greater than or equal to the actual rotational speed Ne, operation increases the value of the virtual speed Ne ₍₁₎ by a predetermined value A is performed. Thereafter, when Ne ₍₁₎ ≧ Ne in Step A70, the process proceeds to Step A100.

At step A100, as described above, the virtual rotational speed Ne _(n) and the required load factor R _LOAD accelerator opening A _PS is calculated. The required load factor R _LOAD calculated when n = 1 is the required load factor R _LOAD (ie, the virtual rotational speed Ne ₍₁₎ having a value larger than the actual rotational speed Ne and the accelerator opening A _PS (ie, Virtual required load factor R _LOADV ), and a required load factor R _LOAD having a value different from that calculated when n = 0 is calculated.

In subsequent step A110, it is determined whether or not the required load factor R _LOAD calculated in the previous step exceeds a predetermined load factor R _{0. If} R _LOAD > R ₀ , the process proceeds to step A120, where R _LOAD ≦ If it is R ₀ , the process proceeds to step A140. In Step A120, it is determined again whether or not the virtual rotational speed Ne _(n) is equal to or lower than the upper limit rotational speed Nemax. If this condition is satisfied, the process proceeds to Step A130, and the value n + 1 is substituted for the variable n. Then, the process proceeds again to Step A40. In step A140, the demand torque TRQ _TGT is calculated based on the virtual rotational speed Ne _(n) and the required load factor R _LOAD. The value of the required torque TRQ _TGT calculated here when n ≧ 1 depends on the virtual rotational speed Nev and the accelerator opening A _PS .

When Step A40 is performed again and the value of the variable n is n = 2, control proceeds from Step A40 to Step A90 via Step A50. In Step A90, a value obtained by adding a predetermined value A to the virtual rotational speed Ne _(n-1) of the previous number is substituted into the virtual rotational speed Ne _(n) , and the process proceeds to Step A110. That is, the value of the virtual rotational speed Ne _(n) is set so as to gradually increase by a predetermined value A, and the calculation and determination of the required load factor R _LOAD are repeated in steps A100 to A120.

Such a gradual increase setting of the virtual rotational speed Ne _(n) is such that the required load factor R _LOAD determined in step A110 is equal to or lower than the predetermined load factor R _0, or the virtual rotational velocity Ne _(n) determined in step A120. Is repeated until the upper limit rotational speed Nemax is exceeded. When the required torque TRQ _TGT is calculated in step A140, the control shifts to the calculation flow of the target throttle opening θ _TH shown in FIG.

[3-2. Calculation of target throttle opening θ _TH ]
In step B 10 in FIG. 6, the value of the atmospheric pressure B _P detected by the atmospheric pressure sensor 32 and the value of the required torque TRQ _TGT calculated by the calculation unit 3 are read into the intake air amount control unit 4. In the subsequent step B20, the required intake manifold pressure calculation unit 4A calculates the required intake manifold pressure P _IMTGT . Here, the required intake manifold pressure P _IMTGT is calculated based on the correspondence map f _PIM between the virtual rotational speed Ne _(n) and the required load ratio R _LOAD and the required intake manifold pressure P _IMTGT .

In step B30, the required intake manifold pressure P _IMTGT is divided by the atmospheric pressure B _P in the required pressure ratio calculation unit 4B, and the required pressure ratio R _PRS is calculated. In step B40, the required flow rate V _TH is calculated by the required flow rate calculation unit 4C. Here, the required flow velocity V _TH is calculated based on the correspondence map f _VTH between the required pressure ratio R _PRS and the required flow velocity V _TH .
In step B50, the required flow rate calculation unit 4D calculates the required flow rate Q _THTGT . Here, the required flow rate Q _THTGT is calculated based on the correspondence map f _QTH between the virtual rotational speed Ne _(n) and the required load factor R _LOAD and the required flow rate Q _THTGT . In step B60, the request area calculation section 4E, which the computed required flow Q _THtgt divided by the request flow velocity V _TH calculated in step B40 is calculated as a request area S _TH in step B50.

In Step B70, the target throttle opening degree θ _TH is calculated by the required opening degree calculation unit 4F. Here, the target throttle opening degree θ _TH is calculated based on the correspondence map f _θTH between the required area S _TH and the target throttle opening degree θ _TH . Thereafter, the intake air amount control unit 4 outputs a control signal corresponding to the target throttle opening degree θ _TH to the throttle valve 23 to control the actual throttle opening degree.

[4. Action]
FIG. 7 is a graph illustrating an equal accelerator opening characteristic of a vehicle equipped with the engine control apparatus 1 described above, and each solid line graph shows the actual rotation of the engine 10 under the condition that the accelerator opening A _PS is constant. This is a schematic representation of the relationship between the speed Ne and the output torque. While the graph of FIG. 3 described above shows the output characteristic (equal throttle opening characteristic) when the throttle opening is made constant, the graph of FIG. 7 shows when the accelerator opening A _PS is made constant. This shows the output characteristics. Corresponding to the accelerator opening degree A _PS as those located above in FIG. 7 is large, the magnitude relationship is _{APS 0> APS 1> APS 2} > APS 3. Also, APS ₀ indicates characteristics when the accelerator opening degree A _PS is maximum, the thick solid line of the graph located uppermost corresponding to fully open time torque TRQ _MAX described above.

Since the accelerator opening A _PS and the throttle opening of the throttle valve 23 in the torque-based control do not necessarily correspond one-to-one, strictly speaking, the graph of FIG. 3 is different from the graph of FIG. However, these characteristics have similarities and similarities. For example, in the operation region where the interval between the equal accelerator opening lines indicated by the solid line in FIG. 7 is narrower, the increase in the output torque when the accelerator opening _APS increases is smaller. Moreover, even if the accelerator opening A _PS is kept constant, the output torque decreases rapidly when the actual rotational speed Ne exceeds a certain magnitude, and the output torque increases as the accelerator opening A _PS increases. The value of the actual rotational speed Ne that begins to decrease increases.

As described above, the engine control apparatus 1 calculates the required torque TRQ _TGT based on the required load factor R _LOAD and the virtual required load factor R _LOADV . The control action by the engine control device 1 will be described below while showing the operating state of the engine 10 consisting of the required torque TRQ _TGT obtained as a result of the calculation and the actual rotational speed Ne at that time, with points on the graph.

When the accelerator opening A _PS is the predetermined accelerator opening A _PS2 and the actual rotational speed Ne is the first actual rotational speed Ne ₁ , the operating state is represented by a point A on the graph. At this time, the value of the required torque TRQ _TGT calculated by the conventional torque base control is TRQ _A. Subsequently, when the actual rotational speed Ne gradually increases while the accelerator opening A _PS is constant, the operating state moves along a solid line graph of the predetermined accelerator opening A _PS2 . Therefore, when the actual rotational speed Ne changes from the first rotational speed Ne ₁ to the second rotational speed Ne ₂ , the value of the required torque TRQ _TGT calculated in the conventional torque base control is from TRQ _{A at} point _A to B After increasing to TRQ _B, it decreases to TRQ _C at point C. Such fluctuation of the required torque TRQ _TGT is a factor that causes a sudden change in the throttle opening in the conventional torque base control.

On the other hand, in the engine control apparatus 1 described above, when the operating state is located at the point A, the minimum engine rotation speed at which the virtual required load factor R _LOADV becomes equal to or less than the predetermined load factor R ₀ is calculated as the virtual rotation velocity Nev. Then, the required torque TRQ _TGT is calculated based on the virtual rotational speed Nev. The required load factor R _LOAD is the maximum (100 [%]) when the accelerator required torque TRQ _APS is equal to the fully open torque TRQ _MAX , so the predetermined load factor R ₀ is a value such as 90 [%] or 95 [%]. When possessed, the magnitude of the torque corresponding to the predetermined load factor R ₀ is slightly smaller than the fully open torque TRQ _MAX . That is, the torque graph corresponding to the predetermined load factor R ₀ is located slightly below the fully-open-time torque TRQ _MAX graph (thick solid line) as shown by a broken line in FIG.

Therefore, the virtual rotational speed Nev is a rotational speed of the coordinates of the intersection between the solid line and the broken line graph corresponding to the predetermined accelerator opening degree A _PS2 at that time. For example, the virtual rotational speed Nev calculated in the operation state at the point A is the second rotational speed Ne ₂ that is the rotational speed at the point C. The value of the required torque TRQ _TGT calculated at this time is TRQ _C.
Following this, even if the accelerator opening A _PS is constant and the actual rotational speed Ne gradually increases and the operating state moves from the point A, the accelerator opening A _PS is equal to the predetermined accelerator opening A _PS2 . If this is the case, the coordinates of the intersection of the solid line graph and the broken line graph do not change, so the value of the required torque TRQ _TGT is maintained at TRQ _C. That is, even when the actual driving state changes from point A to point C via point B, the required torque TRQ _TGT becomes a constant value TRQ _C.

When accelerator opening _APS is not constant, the coordinates of the intersection of the solid line graph and the broken line graph move, and the value of required torque TRQ _TGT varies. In this case, as the accelerator opening degree _APS increases, the coordinates of the intersection of the solid line graph and the broken line graph move to the right side in FIG. 7, and the virtual rotational speed Nev increases.

However, in the engine control apparatus 1, the virtual rotational speed Nev is calculated in the operation region where the required load factor R _LOAD exceeds the predetermined load factor R ₀ , that is, when the operation state is located above the broken line graph in FIG. The virtual rotational speed Nev is calculated. Then, the calculated value of the required torque TRQ _TGT is the torque at the coordinates on the broken line graph of the predetermined load factor R ₀ corresponding to the virtual rotational speed Nev. That is, the required torque TRQ _TGT is set by a broken line graph that defines the lower limit of the operation region in which the required load factor R _LOAD exceeds the predetermined load factor R ₀ .

Accordingly, when the load acting on the engine 10 is a relatively large operating state, the required load factor R _LOAD becomes a predetermined load factor as the actual rotational speed Ne increases regardless of the operating state. The required torque TRQ _TGT having a magnitude asymptotic to R ₀ is calculated, that is, the fluctuation of the required torque TRQ _TGT is suppressed.

[5. effect]
Thus, according to the engine control apparatus 1 of this embodiment, the following operations and effects can be obtained.
(1) In the engine control apparatus 1 described above, the required torque TRQ _TGT is calculated on the basis of the virtual rotational speed Nev that is larger than the actual rotational speed Ne of the engine 10 at that time. The fluctuation in output torque can be reduced. In other words, in torque-based control that controls the intake air amount, ignition timing, fuel injection amount, etc. based on the required torque TRQ _TGT , the required torque TRQ, which is a parameter for calculating the intake air amount, ignition timing, fuel injection amount, etc. Fluctuation in the high load region of _TGT can be suppressed.

Thereby, for example, a change in the target throttle opening degree θ _TH (actual throttle opening degree) due to an accelerator operation or a change in the actual rotational speed Ne can be suppressed. Therefore, the convergence property and controllability of the output torque of the engine 10 can be improved. Further, since the output characteristics of the engine 10 are stabilized, the behavior of the vehicle can be stabilized.

(2) In the engine control apparatus 1 described above, when the load required for the engine 10 is a high load exceeding the predetermined load factor R ₀ , the required torque TRQ _TGT is calculated based on the virtual rotational speed Nev. To be implemented. In other words, when the operating condition where the required torque TRQ _TGT fluctuates sensitively to changes in the accelerator opening A _PS , fluctuations in the output torque due to changes in the throttle opening can be reduced, and control stability can be improved. Can do.

On the other hand, when the load required for the engine 10 is low such that the load is equal to or less than the predetermined load factor R ₀ , the required torque TRQ _TGT is calculated based on the actual rotational speed Ne. Thereby, the required torque TRQ _TGT according to the driver's acceleration request and the rotation state of the engine 10 can be calculated, and a decrease in the power performance of the engine 10 can be suppressed.
Even if the load acting on the engine 10 is relatively high, if the actual rotational speed Ne increases, the load relatively decreases. Therefore, a request according to the driver's acceleration request or the rotation state of the engine 10 is required. Torque TRQ _TGT can be calculated.

(3) Further, in the engine control apparatus 1 calculates the percentage of the accelerator demanded torque TRQ _APS for the fully open time torque TRQ _MAX as the required load factor R _LOAD, is required by the engine 10 based on the required load factor R _LOAD The size of the load is judged. For example, when the required load factor R _LOAD is equal to or less than the predetermined load factor R ₀ , the required torque TRQ _TGT is calculated using the actual rotational speed Ne instead of the virtual rotational speed Nev. On the contrary, when the required load factor R _LOAD exceeds the predetermined load factor R ₀ , the required torque TRQ _TGT is calculated using the virtual rotational speed Nev instead of the actual rotational speed Ne.

Thus, by using the required load factor R _LOAD for the condition determination for performing the calculation of the required torque TRQ _TGT based on the virtual rotational speed Nev, the degree of load according to the rotational state of the engine 10 can be accurately grasped. be able to. Thereby, the fluctuation | variation of the output torque by throttle opening change can be suppressed effectively.

(4) In the engine control apparatus 1 described above, the magnitude of the virtual rotational speed Nev is set so that the virtual required load factor R _LOADV is equal to or less than the predetermined load factor R ₀ . For example, as shown in FIG. 7, the rotation speed at the coordinates of the intersection of the solid line graph corresponding to the accelerator opening A _PS at that time and the broken line graph corresponding to the predetermined load factor R ₀ is set as the virtual rotation speed Nev. . As a result, it is possible to calculate the required torque TRQ _TGT having an appropriate magnitude so that the engine load does not become excessive or excessive when the actual rotational speed increases, and outputs while suppressing the deterioration of the power performance of the engine 10 efficiently. Torque control stability can be improved.

(5) In the engine control apparatus 1 described above, the virtual rotational speed Nev is calculated by repeatedly adding the predetermined value A to the actual rotational speed Ne until the virtual required load ratio R _LOADV becomes equal to or less than the predetermined load ratio R _0. doing. Thereby, the minimum virtual rotation speed at which the virtual required load factor R _LOADV is equal to or less than the predetermined load factor R ₀ can be set easily and reliably.

For example, the calculation of the virtual rotational speed Nev by the engine control device 1 described above is performed when the actual operating state of the engine 10 is the state of the point A shown in FIG. Is desirable. In response to such a demand, the engine control apparatus 1 calculates the virtual rotational speed Nev so that the difference from the actual rotational speed Ne gradually increases, so that the virtual required load ratio R _LOADV is a predetermined load ratio R _0. The first virtual rotational speed Nev that has become below is the minimum virtual rotational speed Nev that satisfies the requirements. Therefore, the calculation accuracy and calculation speed of the virtual rotation speed Nev can be improved, and the controllability of the torque base control can be improved.

(6) Further, in the engine control apparatus 1 described above, the virtual rotational speed Nev is set to a larger value as the load required for the engine 10 is higher. That is, paying attention to the point C that is the intersection of the solid line graph and the broken line graph in FIG. 7, the accelerator opening A so that the point C moves to the right as the accelerator opening A _PS increases. _The virtual rotation speed Nev is set larger as _PS increases. Thereby, the fluctuation _| variation of request torque TRQ _TGT can be made small reliably.

(7) In the engine control apparatus 1 described above, the required torque TRQ _TGT calculated based on the virtual rotational speed Nev is applied to the opening degree control of the throttle valve 23. As a result, for example, as shown in FIG. 2, it is possible to greatly improve the change in the opening in the operation region where the amount of change in the throttle opening based on the output torque is large, and to improve the control stability regarding the intake air. Can do. In particular, in the control related to the intake of the vehicle, there is a concern that the power performance may be deteriorated due to the delay in the intake response. However, the above control can eliminate such a concern and improve the drive feeling. The behavior of the vehicle can be stabilized, and the vehicle merchandise can be improved.

[6. Modified example]
In the flowchart of the above-described embodiment, the calculation of the required load factor R _LOAD and the virtual required load factor R _LOADV based on the correspondence map f _LOAD is shown, but the calculation of the required load factor R _LOAD and the virtual required load factor R _LOADV is shown. The method is not limited to this. For example, the required load ratio R _LOAD may be obtained based on the fully open torque TRQ _MAX , the idle target torque TRQ _IDL and the accelerator required torque TRQ _APS , or the fully open torque TRQ _MAX , the idle target torque TRQ _IDL and the virtual accelerator required torque The virtual required load factor R _LOADV may be obtained based on TRQ _APSV .

Further, in the above-described embodiment, when the required load factor R _LOAD and the virtual required load factor R _LOADV exceed the predetermined load factor R ₀ , the calculation of the required torque TRQ _TGT based on the virtual rotational speed Nev has been described. The value of the predetermined load factor R ₀ may be a variable instead of a fixed value. For example, the predetermined load factor R ₀ may be set according to the accelerator opening A _PS and the actual rotational speed Ne. That is, the shape of the broken line graph shown in FIG. 7 can be arbitrarily modified and set.

In the embodiment described above has exemplified the one which calculates the required pressure ratio R _PRS on the basis of the request intake manifold pressure P _IMTGT and the atmospheric pressure B _P, and the demand torque TRQ _TGT calculated by the required torque calculating unit 3G The required pressure ratio R _PRS may be calculated based on the virtual fully open torque TRQ _MAXV . For example, the required pressure ratio calculation unit 4B calculates the ratio of the required torque TRQ _{TGT to} the virtual fully open torque TRQ _MAXV as the required pressure ratio R _PRS .

The virtual fully open torque TRQ _MAXV here can be output when the accelerator pedal is fully depressed (when the accelerator opening A _PS is maximum) while the engine 10 is rotating at the virtual rotational speed Nev. This is the torque corresponding to the maximum value of the torque. While the fully open torque TRQ _MAX calculated by the fully open torque calculator 3A corresponds to the maximum value of the torque at the actual rotational speed Ne of the engine 10, the virtual fully open torque TRQ _MAXV is a virtual rotation. Corresponds to the maximum value of torque at speed Nev.

There is a correlation between the ratio of the required torque TRQ _{TGT to} the virtual fully open torque TRQ _MAXV and the actual pressure ratio of the throttle valve 23 (value obtained by dividing the required intake manifold pressure P _IMTGT by the upstream pressure of the throttle valve 23). Therefore, even when the required pressure ratio R _PRS obtained by such a method is used, fluctuations in the required torque TRQ _TGT can be suppressed similarly to the above-described embodiment, and a sudden change in the target throttle opening θ _TH can be achieved. Can be prevented.

There is also a method of calculating the required pressure ratio R _PRS using the charging efficiency of the engine 10. The same calculation is performed by using the amount of air introduced into the cylinder 19 instead of the torque. For example, the target charging efficiency Ec _TGT and the virtual maximum charging efficiency Ec _MAXV may be used instead of the above-described required torque TRQ _TGT and virtual fully open torque TRQ _MAXV . In this case, the required pressure ratio calculation unit 4B calculates the ratio of the target charging efficiency Ec _{TGT to} the virtual maximum charging efficiency Ec _MAXV as the required pressure ratio R _PRS .

Target charging efficiency Ec _TGT is the target value of the charging efficiency corresponding to the amount of air to be introduced into the cylinder 19, corresponding map, the mathematical expression or the like to the demand torque TRQ _TGT and the target charging efficiency Ec _TGT for example preset Calculated based on The virtual maximum charging efficiency Ec _MAXV is obtained by _converting the virtual fully open torque TRQ _MAXV into the charging efficiency, and generates the fully open torque TRQ _MAX while the engine 10 is rotating at the virtual rotational speed Nev. Is the charging efficiency corresponding to the amount of air required for charging (charging efficiency when the throttle is fully open).

There is a correlation between the ratio of the target charging efficiency Ec _{TGT to} the virtual maximum charging efficiency Ec _MAXV and the actual pressure ratio of the throttle valve 23 part. Therefore, even when the required pressure ratio R _PRS obtained by such a method is used, fluctuations in the required torque TRQ _TGT can be suppressed similarly to the above-described embodiment, and a sudden change in the target throttle opening θ _TH can be achieved. Can be prevented.

In the flowchart of FIG. 5 in the above-described embodiment, the determination condition in step A120 is not satisfied because the required load factor R _LOAD does not become less than the predetermined load factor R ₀ no matter how the virtual rotational speed is increased. (The load is large enough). Therefore, the required torque TRQ _TGT may be calculated from the actual rotational speed Ne and the required load factor R _LOAD only when the determination condition in step A120 is not satisfied and the process proceeds to step A140. As a result, the required torque TRQ _TGT is allowed to fluctuate, so that the throttle opening θ _TH can be changed quickly and the control response of the output torque can be improved.

DESCRIPTION OF SYMBOLS 1 Engine control apparatus 2 Setting part (setting means)
3. Calculation unit (calculation means)
3A Fully open torque calculator (fully open torque calculator)
3B Idle target torque calculator 3C Accelerator required torque calculator (Accelerator required torque calculator)
3D required load factor calculator (required load factor calculator)
3E virtual accelerator required torque calculation unit (virtual accelerator required torque calculation means)
3F Virtual required load factor calculation unit (virtual required load factor calculation means)
3G Required torque calculation unit (Requested torque calculation means)
4 Intake amount control unit (control means, intake control means)
10 Engine 23 Throttle valve 31 Engine rotation speed sensor 33 Accelerator opening sensor (detection means)
A _PS accelerator opening
Ne Actual rotation speed
Nev, Ne _{(0) to} Ne _(n) Virtual rotation speed
TRQ _TGT required torque
R _LOAD required load factor
R ₀ Predetermined load factor

Claims (5)

Detection means for detecting the accelerator opening of the vehicle;
Setting means for setting a virtual rotation speed larger than the actual rotation speed of the engine mounted on the vehicle;
Arithmetic means for calculating a required torque required for the engine based on the accelerator opening detected by the detection means and the virtual rotational speed set by the setting means;
Control means for controlling the throttle opening of the engine based on the required torque calculated by the calculation means ,
The computing means is
When the load required for the engine exceeds a predetermined load, the required torque is calculated based on the accelerator opening and the virtual rotational speed,
The engine control device, wherein the required torque is calculated based on the accelerator opening and the actual rotational speed when the load is equal to or less than the predetermined load . The computing means is
A fully-open torque calculating means for calculating an output torque of the real rotational speed of the engine at the time of full opening of the throttle opening fully opened time torque,
Accelerator required torque calculating means for calculating an accelerator required torque corresponding to an accelerator load based on the accelerator opening and the actual rotational speed;
A required load factor calculating means for calculating a ratio of the accelerator required torque to the fully open torque as a required load factor;
When the required load factor exceeds a predetermined load factor, the required torque is calculated based on the accelerator opening and the virtual rotational speed, and when the required load factor is equal to or less than the predetermined load factor, the accelerator is opened. characterized by having a a required torque calculating means for calculating the required torque based on the degree and the actual rotation speed, the control device according to claim 1, wherein the engine. The computing means is
Virtual accelerator required torque calculating means for calculating a virtual accelerator required torque based on the accelerator opening and the virtual rotational speed;
Virtual required load factor calculating means for calculating a ratio of the virtual accelerator required torque to the fully opened torque as a virtual required load factor,
The engine control device according to claim 2 , wherein the setting means sets the magnitude of the virtual rotational speed so that the virtual required load factor is equal to or less than the predetermined load factor. Said setting means, until said virtual required load factor is equal to or less than the predetermined load ratio, and sets the virtual rotational speed by repeatedly adding a predetermined value the the actual rotational speed, according to claim 3, wherein Engine control device.   The virtual rotational speed is the minimum rotational speed at which the virtual required load factor is equal to or less than a predetermined load factor at the accelerator opening at that time point,
  The virtual required load factor is a parameter corresponding to the degree to which the virtual accelerator required torque calculated based on the accelerator opening and the virtual rotational speed acts as a load on the engine.
The engine control device according to any one of claims 1 to 4, wherein

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