JP5853752B2 - Control device for internal combustion engine - Google Patents

Description

  The present invention relates to a control device for an internal combustion engine, and more particularly, to a control device for an internal combustion engine that performs calculations using a multi-core processor having a plurality of cores.

  Conventionally, as disclosed in, for example, Japanese Patent Laid-Open No. 2008-269487, in an electronic control device for engine control including a microcomputer adopting at least one of a multi-core configuration and a cache memory mounting configuration, power consumption during engine stop Techniques for reducing the above are disclosed. Both the CPU core and the cache memory are elements with high power consumption in the microcomputer. Therefore, in the above-described conventional technology, a mode is selected in which the CPU core and the cache memory are fully used while the engine is operating and the highest processing capacity is exhibited. A mode for reducing the amount of cache memory used compared to when the engine is operating is selected.

JP 2008-269487 A

  By the way, in model-based control of an internal combustion engine using a control model in recent years, it is possible to speed up computation by performing parallel computation processing using a multi-core processor having a plurality of cores. However, as the number of cores used increases, the calculation load increases, and power consumption tends to increase accordingly. For this reason, from the viewpoint of reducing power consumption, it is preferable to perform efficient calculation resource allocation according to the calculation load. In this regard, in the above-described conventional apparatus, no consideration is given to the calculation resource allocation during the engine operation, and there is still room for improvement.

  The present invention has been made to solve the above-described problems, and in an internal combustion engine that performs arithmetic processing using a multi-core processor having a plurality of cores, an efficient use core according to the arithmetic load of the internal combustion engine It is an object of the present invention to provide a control device for an internal combustion engine capable of performing distribution.

In order to achieve the above object, a first invention includes an intercooler disposed in an intake passage, and a throttle disposed on the downstream side of the intercooler in the intake passage. A control device for an internal combustion engine that performs a prediction calculation of a throttle opening,
An arithmetic means having a multi-core processor equipped with a plurality of cores, assigning various arithmetic tasks related to the operation of the internal combustion engine to the plurality of cores, and performing arithmetic operations in parallel,
Control means for reducing the number of cores used for the calculation means when operating the throttle opening fully open , compared to before opening to full open ;
Estimating means for estimating the fuel injection amount and engine speed of the internal combustion engine a predetermined time ahead;
Predicting means for predicting the throttle opening degree in a predetermined time ahead based on the fuel injection amount and engine speed estimated by the estimating means;
Control means for reducing the number of cores used for the computing means when the throttle opening at a predetermined time ahead predicted by the prediction means is fully open, compared to before the operation to full open ;
It is characterized by having.

According to a second invention, in the first invention,
The control means is characterized by increasing the number of cores used for the computing means when the throttle opening is operated from the fully open to the closed direction as compared to before the operation.

According to a third invention, in the first or second invention,
The calculation means includes: allocation means for assigning a task of prediction calculation using the engine model to one or a plurality of designated cores designated from the plurality of cores;
The control means stops the designated core when the throttle is fully opened.

A fourth invention is any one of the first to third inventions,
The calculation means performs a calculation related to the dynamics of the intercooler as a prediction calculation using the engine model.

According to a fifth invention, in any one of the first to fourth inventions,
The estimation means performs delay control that delays a change in the actual fuel injection amount for a predetermined time with respect to a change in the target fuel injection amount calculated from the accelerator opening, and determines the fuel injection amount that will be achieved in the future as the target throttle opening. It is characterized by predicting from.

According to the first aspect of the invention, when the throttle opening is fully opened , the number of cores used is reduced compared to before the operation. When the throttle opening is fully open , there is no need to solve the differential equation representing the energy conservation law and mass conservation law of the intercooler, so the order of the model equation to be solved is reduced compared to before the operation. . For this reason, according to the present invention, the number of used cores can be reduced according to the reduction of the calculation load, so that efficient use core distribution according to the calculation load of the internal combustion engine can be performed.
Further, according to the present invention, the opening degree of the throttle ahead of a predetermined time is predicted based on the fuel injection amount and the engine speed ahead of the predetermined time. For this reason, according to the present invention, it is possible to grasp in advance the time when the throttle opening is fully opened, so that efficient use core allocation according to the future calculation load of the internal combustion engine can be performed in advance. Become.

According to the second aspect of the present invention, when the throttle opening is operated from the fully open position to the closing direction, the number of cores used is increased compared to before the operation. For this reason, according to the present invention, the number of used cores can be increased in accordance with the increase in the model order to be solved, so that it is possible to efficiently allocate the used cores in accordance with the calculation load of the internal combustion engine. .

According to the third invention, the task of predicting the throttle opening using the engine model is assigned to the designated core, and the use of the designated core is stopped when the throttle opening is fully opened. For this reason, according to the present invention, it is possible to efficiently stop the model prediction calculation that becomes unnecessary when the throttle opening is fully opened, and to effectively allocate the calculation resources as the entire apparatus.

According to the fourth aspect of the invention, a calculation task related to the dynamics of the intercooler is assigned to one or a plurality of designated cores. Then, when the throttle opening is fully opened, the use of the designated core is stopped. For this reason, according to the present invention, it is possible to effectively stop computations that are not required when the throttle opening is fully opened, and to perform efficient use core allocation according to the computation load of the internal combustion engine.

According to the fifth aspect of the present invention, since the fuel injection amount that will be achieved in the future can be predicted by performing the delay control of the fuel injection amount, the predicted fuel injection amount is used and the throttle ahead for a predetermined time. It becomes possible to grasp the state of opening of the in advance.

It is a figure for demonstrating schematic structure of the internal combustion engine system as embodiment of this invention. It is a flowchart of the routine performed in Embodiment 1 of the present invention. It is a flowchart of the routine performed in Embodiment 2 of this invention.

  Embodiments of the present invention will be described below with reference to the drawings. In addition, the same code | symbol is attached | subjected to the element which is common in each figure, and the overlapping description is abbreviate | omitted. The present invention is not limited to the following embodiments.

Embodiment 1 FIG.
[Configuration of Embodiment 1]
FIG. 1 is a diagram for explaining a schematic configuration of an internal combustion engine system as an embodiment of the present invention. As shown in FIG. 1, the system of the present embodiment includes a four-cycle internal combustion engine 10 having a plurality of cylinders (four cylinders in FIG. 1). It is assumed that the internal combustion engine 10 is mounted on a vehicle and used as a power source.

  Each cylinder of the internal combustion engine 10 is provided with an injector 12 for directly injecting fuel into the cylinder. The injectors 12 of each cylinder are connected to a common common rail 14. Fuel in a fuel tank (not shown) is pressurized to a predetermined fuel pressure by a supply pump 16, stored in the common rail 14, and supplied from the common rail 14 to each injector 12.

  An exhaust passage 18 of the internal combustion engine 10 is branched by an exhaust manifold 20 and connected to an exhaust port (not shown) of each cylinder. The exhaust passage 18 is connected to the exhaust turbine of the turbocharger 24. A post-treatment device 26 for purifying exhaust gas is provided downstream of the turbocharger 24 in the exhaust passage 18.

  An air cleaner 30 is provided near the inlet of the intake passage 28 of the internal combustion engine 10. The air drawn through the air cleaner 30 is compressed by the intake compressor of the turbocharger 24 and then cooled by the intercooler 32. The intake air that has passed through the intercooler 32 is distributed by an intake manifold 34 to intake ports (not shown) of each cylinder.

  A diesel throttle 36 is installed between the intercooler 32 and the intake manifold 34 in the intake passage 28. An air flow meter 52 for detecting the amount of intake air is installed in the intake passage 28 near the downstream of the air cleaner 30.

  The system according to the present embodiment includes an ECU (Electronic Control Unit) 50 as shown in FIG. The ECU 50 is configured as a multi-core ECU having a processor on which n cores (core_1 to core_n) are mounted, and can control the use / stop of each core independently. In addition to the air flow meter 52 described above, an accelerator position sensor 54 for detecting the amount of depression of the accelerator pedal (accelerator opening) and a crank angle sensor 56 for detecting the crank angle of the internal combustion engine 10 are input to the ECU 50. Various sensors for controlling the internal combustion engine 10 are connected. In addition to the injector 12 and the diesel throttle 36 described above, various actuators for controlling the internal combustion engine 10 are connected to the output unit of the ECU 50. The ECU 50 executes a predetermined control algorithm for driving various actuators based on the various types of input information.

[Characteristic operation of the first embodiment]
Next, the characteristic operation of the first embodiment will be described. The internal combustion engine 10 according to the present embodiment includes various actuators for controlling the internal combustion engine 10 such as an injector 12 and a diesel throttle 36 as actuators for controlling the operation thereof. The control device according to the present embodiment controls the internal combustion engine by so-called model-based control. The control state is estimated by frequently using model prediction, and the control amounts of the various actuators described above are determined.

  In the system of the present embodiment, the intake air amount control of the diesel engine is realized by model-based control. Specifically, the ECU 50 implements an intake model that predicts an output related to intake (for example, throttle opening) by calculating the dynamics of the intercooler 32. In addition, since many literatures are already well-known about the model structure of an intake model, the detailed description is abbreviate | omitted.

  In the system according to the present embodiment including the multi-core ECU, the model-based control is executed in one or a plurality of designated cores selected from a plurality of cores. The designated core is a core selected as a core dedicated to performing the supercharging prediction calculation, and is set to the number of cores that can effectively use the calculation resources in consideration of the core usage status of the system. It is preferable. When performing parallel calculation processing using a plurality of designated cores, for example, a known parallel compiler such as OSCAR (Optimally Scheduled Advanced Multiprocessor) is used to divide the supercharge prediction calculation algorithm of the supercharge model, Assign tasks to each designated core. As described above, when parallel calculation processing is performed, the calculation load is effectively reduced as compared with the case of performing sequential calculation processing with a single core.

  Here, in the model-based control described above, when the diesel throttle 36 is fully opened, there is no need to solve the dynamics calculation such as the mass conservation law and the energy conservation law of the intercooler. Therefore, in such a case, there is no particular problem even if the above calculation is stopped. Rather, it is preferable to stop these calculations from the viewpoint of reducing the calculation load.

  Therefore, in the system of the present embodiment, when the diesel throttle 36 is fully opened, the number of cores used for the calculation is reduced. Specifically, a task for predicting the throttle opening using the intake model described above is assigned to one or a plurality of designated cores among the plurality of cores, and the diesel throttle 36 is fully opened. During this period, the designated core assigned to the model will be stopped. As a result, the core on which unnecessary calculations are performed can be effectively stopped, and the calculation load can be reduced as a whole system by effectively allocating the remaining calculation resources. Thereby, it is possible to avoid the task omission and to control the internal combustion engine with high accuracy.

  Further, in the system according to the present embodiment, when the diesel throttle 36 is operated in the closing direction from the fully open state, the calculation in the stopped core is restarted. Thereby, the increase in the calculation load accompanying the start of the model prediction calculation can be effectively compensated by increasing the number of used cores.

[Specific Processing in Embodiment 1]
Next, with reference to FIG. 2, the specific content of the process performed in this Embodiment is demonstrated. FIG. 2 is a flowchart of a routine in which the ECU 50 increases or decreases the number of used cores used for calculation. Note that the routine shown in FIG. 2 is repeatedly executed during operation of the internal combustion engine 10. In addition, as a premise for executing the routine shown in FIG. 2, here, one or a plurality of designated cores that perform the prediction calculation of the throttle opening using the intake model are already selected, and the task of the prediction calculation is the designated core. Is assigned.

  In the routine shown in FIG. 2, it is first determined whether or not the diesel throttle 36 is fully opened (step 100). As a result, when it is determined that the diesel throttle 36 is fully open, it is determined that the model prediction calculation of the throttle opening is unnecessary, and the process proceeds to the next step, and the model prediction calculation of the throttle opening is assigned. The designated core is stopped (step 102). On the other hand, when it is determined in step 100 that the diesel throttle is not fully open, model prediction calculation of the throttle opening is executed by the designated core (step 104).

  As described above, according to the system of the present embodiment, when the diesel throttle 36 is fully opened, the core to which the model prediction calculation of the throttle opening is assigned is stopped. As a result, the core on which unnecessary calculations are performed can be effectively stopped, and the calculation load can be reduced as a whole system by effectively allocating the remaining calculation resources.

  In the embodiment described above, when the diesel throttle 36 is fully opened, the designated core to which the model prediction calculation of the throttle opening is assigned is stopped. It is not limited to the designated core. That is, while the diesel throttle 36 is fully opened, the calculation load related to the model prediction calculation is reduced. For this reason, one of the cores is stopped while the diesel throttle 36 is fully opened, and the task of the stopped core is distributed to the remaining used cores, so that the number of used cores is reduced and the efficiency corresponding to the calculation load of the internal combustion engine is reduced. It is possible to allocate the cores used.

  Further, in the first embodiment described above, the calculation for predicting the throttle opening using the engine model is exemplified as the calculation that is not required when the diesel throttle 36 is fully opened. However, the calculation is not required when the diesel throttle 36 is fully opened. It can also be applied to other model operations.

Embodiment 2. FIG.
[Features of Embodiment 2]
Next, a second embodiment of the present invention will be described with reference to FIG. The second embodiment can be realized by executing a routine shown in FIG. 3 described later using the system shown in FIG.

  In the system of the first embodiment described above, the number of cores used by the ECU 50 is increased or decreased based on the current opening degree of the diesel throttle 36. However, during transient operation of the internal combustion engine 10, the increase or decrease in the number of cores used is not in time for the change in the opening degree of the diesel throttle 36, causing calculation problems such as missing tasks in the calculation process and continuing unnecessary calculations. It is also assumed that

  Therefore, in the system according to the second embodiment, the future fuel injection amount and the engine speed, for example, 32 ms are predicted as future operating conditions. Specifically, delay control is performed to delay the change in the actual fuel injection amount of the injector 12 with respect to the change in the target fuel injection amount calculated from the accelerator opening, etc., and the fuel injection amount that is achieved in the future (that is, the engine load) ). Further, the rotational speed of the crankshaft is calculated using the indicated torque calculated using the operating condition parameters and the total value of the auxiliary machine torque and the friction torque, and the engine speed to be achieved in the future is predicted. Then, with reference to the opening degree information defined in the base map of the diesel throttle 36, when these operating conditions belong to a region corresponding to full opening, the diesel throttle 36 is fully opened according to the operating conditions to be achieved in the future. It can be determined that Therefore, in this case, if the designated core to which the throttle opening prediction calculation of the intake model is assigned is stopped, the core on which unnecessary calculation is performed can be effectively stopped. As a result, the remaining computing resources can be effectively distributed, so that the calculation load can be reduced as a whole system, and the control of the internal combustion engine can be realized with high accuracy by avoiding task omission.

  In the system according to the present embodiment, when it is determined that the diesel throttle 36 is operated in the closing direction from the fully open state according to the operating condition to be achieved in the future, the calculation in the stopped core is restarted. And Thereby, the increase in the calculation load accompanying the start of the prediction calculation of the intake model can be effectively compensated by increasing the number of used cores.

[Specific Processing in Second Embodiment]
Next, with reference to FIG. 3, the specific content of the process performed in this Embodiment is demonstrated. FIG. 3 is a flowchart of a routine in which the ECU 50 increases or decreases the number of used cores used for calculation. Note that the routine shown in FIG. 3 is repeatedly executed during operation of the internal combustion engine 10. In addition, as a premise for executing the routine shown in FIG. 3, here, one or a plurality of designated cores that perform the prediction calculation of the throttle opening using the intake model have already been selected, and the task of the prediction calculation is the designated core. Is assigned.

  In the routine shown in FIG. 3, first, the engine speed and the fuel injection amount in the future of 32 ms are predicted (step 200). Specifically, the ECU 50 calculates the target fuel injection amount from the accelerator opening measured by the accelerator position sensor 54, and changes the actual fuel injection amount of the injector 12 with respect to the change of the target fuel injection amount. By implementing delay control to delay, the fuel injection amount to be achieved in the future of 32 ms is predicted.

Further, the ECU 50 calculates the indicated torque τ and the combined value τf of the friction torque and the auxiliary torque using the parameters of the current operating condition. The friction torque is torque due to mechanical friction of each fitting portion such as friction between the piston and the inner wall of the cylinder, and the auxiliary machine torque is torque due to mechanical friction of the auxiliary machines. The total value τf can be specified using, for example, a map that defines the relationship between the engine operating state and the total value τf. Then, the angular acceleration dω / dt of the crankshaft is calculated by substituting the calculated indicated torque τ and the total value τf of the friction torque and the auxiliary torque into the following equation (1) in accordance with the equation of motion.
I · dω / dt = τ−τf (1)

  Here, I is an inertia moment (inertia) of a member (crankshaft or the like) driven by the combustion of the air-fuel mixture, and is a constant determined based on the hardware configuration of the internal combustion engine 10. Then, the engine speed in the future of 32 ms is calculated using the crankshaft rotational speed ω obtained from the angular acceleration dω / dt.

  Next, it is determined whether or not the diesel throttle 36 is fully opened in the future in 32 ms (step 202). Here, specifically, it is determined whether or not the 32 ms future operating condition predicted in step 200 belongs to the fully open region of the diesel throttle 36. As a result, when it is determined that the future operating conditions of 32 ms belong to the fully open region of the diesel throttle 36, it is determined that the prediction calculation of the throttle opening using the intake model will be unnecessary in the future, and the next step is performed. The designated core to which the model prediction calculation is assigned is stopped (step 204). On the other hand, if it is determined in step 202 that the 32 ms future operating condition does not belong to the fully open region of the diesel throttle 36, the model prediction calculation is executed by the designated core (step 206).

  As described above, according to the system of the present embodiment, when the diesel throttle 36 is fully opened in the future, the core to which the throttle opening prediction calculation using the intake model is assigned is stopped. . As a result, the core on which unnecessary calculations are performed can be effectively stopped, and the calculation load can be reduced as a whole system by effectively allocating the remaining calculation resources.

  By the way, in the above-described embodiment, when the diesel throttle 36 is fully opened in the future, the designated core to which the model prediction calculation of the throttle opening is assigned is stopped. It is not limited to the designated core. That is, while the diesel throttle 36 is fully opened, the calculation load related to the prediction calculation of the intake model is reduced. For this reason, when the diesel throttle 36 is fully opened, one of the cores is stopped, and the task of the stopped core is distributed to the remaining used cores, thereby reducing the number of used cores and increasing the calculation load of the internal combustion engine. This makes it possible to efficiently allocate the cores used.

  In the above-described embodiment, the fuel injection amount and the engine speed are predicted as future operating conditions, and the future opening of the diesel throttle 36 is predicted based on these. The method of predicting the opening degree is not limited to this. That is, for example, only the future fuel injection amount may be used as an operating condition necessary for the prediction, or the future opening of the diesel throttle 36 is predicted by a known method using other operating conditions. Also good.

  In the above-described embodiment, the calculation of the throttle opening using the supercharging model is exemplified as the calculation that is not required when returning from the idle operation. However, the calculation that is not required when the diesel throttle 36 is fully opened is illustrated. This can also be applied to the model calculation.

10 Internal combustion engine
12 Injector 18 Exhaust passage 28 Intake passage 32 Intercooler 36 Diesel throttle 50 ECU (Electronic Control Unit)
54 Accelerator position sensor 56 Crank angle sensor

Claims (5)

A control apparatus for an internal combustion engine, comprising: an intercooler disposed in an intake passage; and a throttle disposed downstream of the intercooler in the intake passage, wherein the throttle opening prediction calculation is performed using an engine model Because
An arithmetic means having a multi-core processor equipped with a plurality of cores, assigning various arithmetic tasks related to the operation of the internal combustion engine to the plurality of cores, and performing arithmetic operations in parallel,
Estimating means for estimating the fuel injection amount and engine speed of the internal combustion engine a predetermined time ahead;
Predicting means for predicting the throttle opening degree in a predetermined time ahead based on the fuel injection amount and engine speed estimated by the estimating means;
Control means for reducing the number of cores used for the computing means when the throttle opening at a predetermined time ahead predicted by the prediction means is fully open , compared to before the operation to full open;
A control device for an internal combustion engine, comprising:   2. The internal combustion engine according to claim 1, wherein the control means increases the number of cores used for the calculation means when the throttle opening is operated from a fully open position to a closing direction as compared to before the operation. 3. Control device. The calculation means includes: allocation means for assigning a task of prediction calculation using the engine model to one or a plurality of designated cores designated from the plurality of cores;
3. The control device for an internal combustion engine according to claim 1, wherein the control unit stops the designated core when the throttle is fully opened. 4.   The control device for an internal combustion engine according to any one of claims 1 to 3, wherein the calculation means performs a calculation related to the dynamics of the intercooler as a prediction calculation using the engine model.   The estimation means performs delay control for delaying a change in the actual fuel injection amount by a predetermined time with respect to a change in the target fuel injection amount calculated from the accelerator opening, and predicts a fuel injection amount to be achieved in the future. The control apparatus for an internal combustion engine according to any one of claims 1 to 4.

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