JP5817578B2 - 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 JP-A-4-41931 JP 2007-125950 A JP 2008-38604 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 a turbocharger having a turbine installed in an exhaust passage and a compressor installed in an intake passage, and uses a turbine model of the turbocharger. A control device for an internal combustion engine that performs a prediction calculation of an output caused by rotation of the turbine,
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 computing means when the internal combustion engine belongs to the non-supercharged area as compared to the case of belonging to the supercharged area ;
It is characterized by having.

According to a second invention, in the first invention,
The control means increases the number of cores used for the calculation means when the non-supercharged area shifts to the supercharged area.

According to a third invention, in the first or second invention,
The control means includes determination means for determining whether the internal combustion engine belongs to the non-supercharged area or the supercharged area depending on whether or not the supercharging pressure of the internal combustion engine is equal to or lower than atmospheric pressure. It is characterized by.

According to a fourth invention, in any one invention of the first to third,
The calculation means includes an assignment means for assigning a task of prediction calculation using the turbine model to one or a plurality of designated cores designated from the plurality of cores,
The control means stops the designated core when the internal combustion engine belongs to the non-supercharged region.

A fifth invention is the fourth invention,
The calculation means calculates the dynamics of the turbine as a prediction calculation using the turbine model.

A sixth invention, in any one invention of the first to fifth,
Estimating means for estimating an in-cylinder air amount and an engine speed of the internal combustion engine a predetermined time ahead;
Based on the in-cylinder air amount and the engine rotational speed estimated by the estimation means further comprises prediction means for predicting a supercharging state of the internal combustion engine in a predetermined time later, a,
The control means is characterized by increasing or decreasing the number of cores used for the calculation means based on a supercharging situation at a predetermined time ahead predicted by the prediction means.

A seventh invention is the sixth invention, wherein
The estimation means performs delay control for delaying the change in the actual throttle opening with respect to the change in the target throttle opening calculated from the accelerator opening, and determines the in-cylinder air amount to be achieved in the future from the target throttle opening. It is characterized by prediction.

  According to the first invention, when the supercharging pressure of the internal combustion engine is equal to or lower than the predetermined supercharging pressure, the number of cores used is reduced as compared with the case where it is higher than the predetermined supercharging pressure. When the internal combustion engine is not supercharged, it is not necessary to perform a prediction calculation using a turbine model, so the order of the model formula to be solved is reduced as compared with the supercharging. 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 first aspect, when the internal combustion engine belongs to the non-supercharged region, the number of cores used is reduced compared to the case where it belongs to the supercharged region. When the internal combustion engine is not supercharged, it is not necessary to perform a prediction calculation using a turbine model, so the order of the model formula to be solved is reduced as compared with the supercharging. 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.

According to the second invention, when the internal combustion engine shifts from the non-supercharged region to the supercharged region, the number of cores used is increased as compared with that 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 aspect of the present invention, it can be effectively determined whether the internal combustion engine belongs to the non-supercharging region or the supercharging region depending on whether the supercharging pressure of the internal combustion engine is equal to or lower than the atmospheric pressure.

According to the fourth aspect of the invention, a prediction calculation task using the turbine model is assigned to the designated core, and the use of the designated core is stopped when it belongs to the non-supercharged region. For this reason, according to the present invention, it is possible to efficiently stop the prediction calculation of the turbine model that is not required at the time of non-supercharging, and to effectively distribute the calculation resources as the entire apparatus.

According to the fifth aspect of the present invention, calculation tasks related to turbine dynamics are assigned to one or more designated cores. And when it belongs to the non-supercharging region, 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 at the time of non-supercharging, and to perform efficient use core allocation according to the computation load of the internal combustion engine.

According to the sixth aspect of the present invention, the supercharging situation ahead of a predetermined time is predicted based on the in-cylinder air amount and the engine speed ahead of the predetermined time. For this reason, according to the present invention, the time belonging to the non-supercharged region can be grasped in advance, so that efficient use core allocation according to the future calculation load of the internal combustion engine can be performed in advance. .

According to the seventh aspect of the present invention, the cylinder air amount that will be achieved in the future can be predicted by performing the delay control of the throttle. It becomes possible to grasp the salary situation 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 according to the present embodiment includes an internal combustion engine 10. The internal combustion engine 10 is a spark ignition type 4-stroke reciprocating engine, which is mounted on a vehicle and used as a power source. An intake passage 12 is connected to the intake side of the internal combustion engine 10. An air cleaner 14 is provided near the inlet of the intake passage 12. An exhaust passage 16 is connected to the exhaust side of the internal combustion engine 10. A post-treatment device 18 for purifying exhaust gas is provided in the middle of the exhaust passage 16.

  The internal combustion engine 10 of the present embodiment includes a turbocharger 20. The turbocharger 20 includes a turbine 20a that is operated by exhaust energy of exhaust gas, and a compressor 20b that is rotationally driven by exhaust energy of exhaust gas input to the turbine 20a. The turbine 20a and the compressor 20b are integrally connected by a turbine shaft 20c.

  The turbine 20 a and the compressor 20 b of the turbocharger 20 are respectively disposed in the exhaust passage 16 and the intake passage 12. An intercooler 22 and an electronically controlled throttle valve 24 are arranged in this order further downstream of the compressor 20b in the intake passage 12. The air sucked through the air cleaner 14 is compressed by the compressor 20 b of the turbocharger 20 and then cooled by the intercooler 22. The intake air that has passed through the intercooler 22 is distributed to an intake port (not shown) of each cylinder by an intake manifold.

  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 be used / stopped for each core. An input unit of the ECU 50 controls an internal combustion engine 10 such as an accelerator position sensor for detecting an accelerator pedal depression amount (accelerator opening), a crank angle sensor for detecting a crank angle of the internal combustion engine 10, and the like. Various sensors are connected. In addition to the throttle valve 24 described above, various actuators for controlling the internal combustion engine 10 are connected to the output portion 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 operation. 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.

  Model-based control executed in the system according to the present embodiment includes, for example, prediction calculation of turbine output using a turbine model of the turbocharger 20. Specifically, the turbine model calculates the output due to the rotation of the turbine (for example, mass flow rate, output temperature, and the like) by calculating the rotation dynamics of the turbine 20a of the turbocharger 20 and the rotation dynamics of the turbine shaft 20c. And output etc.). In addition, since many literatures are already well-known about the model structure of a turbine model, the detailed description is abbreviate | omitted.

  In the system of the present embodiment including a 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. Further, when performing parallel arithmetic 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 prediction arithmetic algorithm using the turbine 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 internal combustion engine 10 is not supercharged, there is no need to solve the output prediction calculation of the turbine model such as the calculation of the rotation dynamics of the turbine 20a and the rotation dynamics of the turbine shaft 20c. Therefore, in such a period, 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 according to the present embodiment, the number of cores used for the calculation is reduced while the operating condition of the internal combustion engine 10 belongs to the non-supercharging region. Specifically, a task of prediction calculation using the above-described turbine model is assigned to one or a plurality of designated cores designated from among the plurality of cores, and the period belonging to the non-supercharged region is the turbine model. The designated core to which the output prediction calculation 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. Thereby, it is possible to avoid the task omission and to control the internal combustion engine with high accuracy.

  Whether or not the operating condition of the internal combustion engine 10 belongs to the non-supercharging region can be determined based on the supercharging pressure. That is, the target value of the supercharging pressure is defined in the supercharging pressure target value map using the in-cylinder air amount and the engine speed as parameters. Therefore, referring to the map, whether the target boost pressure corresponding to the current operating condition is equal to or lower than a predetermined boost pressure (for example, atmospheric pressure) corresponding to the boundary between the supercharge region and the non-supercharge region By determining whether or not, it can be determined whether or not it belongs to the non-supercharging range.

  Further, in the system according to the present embodiment, at the time when the system belongs to the supercharged area from the non-supercharged area, the calculation in the stopped core is restarted. Thereby, the increase in the calculation load accompanying the start of the output prediction calculation of the turbine model 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 a prediction calculation using the turbine model are already selected, and the task of the output prediction calculation is assigned to these designated cores. It shall be.

  In the routine shown in FIG. 2, first, it is determined whether or not the current operating condition of the internal combustion engine 10 belongs to the non-supercharging region (step 100). As a result, when it is determined that the engine belongs to the non-supercharged region, it is determined that the prediction calculation using the turbine model is unnecessary, and the process proceeds to the next step, and the prediction calculation using the turbine model is assigned. The designated core is stopped (step 102). On the other hand, if it is determined in step 100 that the engine belongs to the supercharging region, a prediction calculation using the turbine model is executed by the designated core (step 104).

  As described above, according to the system of the present embodiment, the core to which the prediction calculation using the turbine model is assigned is stopped during the period belonging to the non-supercharged region. 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 embodiment mentioned above, when it belongs to the non-supercharging range, it is supposed that the designated core to which the prediction calculation using the said turbine model is allocated will be stopped, but the core which can be stopped is restricted to the said designated core. Absent. That is, at the time of no supercharging, first, the prediction calculation using the turbine model is stopped, and then any core is stopped if necessary, and the task is distributed to the remaining cores. . This makes it possible to efficiently allocate the used cores according to the calculation load of the internal combustion engine while reducing the used cores.

  Moreover, in Embodiment 1 mentioned above, although the prediction calculation using a turbine model was illustrated as a calculation which becomes unnecessary in the period which belongs to a non-supercharging area | region, with respect to the other model calculation which becomes unnecessary at the time of non-supercharging Even can be applied.

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 supercharging situation. However, during the transient operation of the internal combustion engine 10, the increase / decrease in the number of cores used does not keep up with the change in the supercharging status, and calculation failures such as missing tasks may occur in the calculation processing, or unnecessary calculations may continue. is assumed.

  Therefore, in the system of the second embodiment, the future in-cylinder air amount and the engine speed are predicted as future operating conditions, for example, 32 ms. Specifically, delay control is performed to delay the change in the actual opening of the throttle valve 24 with respect to the change in the target throttle opening calculated from the accelerator opening, and the in-cylinder air amount that will be achieved in the future is reduced. Predict from the degree. 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, referring to the supercharging pressure information defined in the supercharging pressure target value map, these operating conditions belong to the region corresponding to the non-supercharging region (that is, the region where the supercharging pressure is equal to or lower than the atmospheric pressure). In this case, it can be determined that the vehicle belongs to the non-supercharging range depending on the operating condition to be achieved in the future. Therefore, in this case, if the designated core to which the prediction calculation using the turbine model is assigned is stopped, the core on which the 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, the calculation in the stopped core is started again when it is determined that it belongs to the supercharging region according to the operating condition to be achieved in the future. Thereby, the increase in the calculation load accompanying the start of the prediction calculation using the turbine 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 a prediction calculation using a turbine model are already selected, and the task of the prediction calculation is assigned to these designated cores. It shall be.

  In the routine shown in FIG. 2, first, the engine speed and the in-cylinder air amount in the future of 32 ms are predicted (step 200). Specifically, the ECU 50 calculates the target throttle opening from the accelerator opening measured by an accelerator opening sensor (not shown), and performs the actual operation of the throttle valve 24 with respect to the change in the target throttle opening. By implementing delay control that delays the change in opening, the cylinder air amount that will be achieved in the future for 32 ms is predicted from the target throttle opening.

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 it belongs to the non-supercharging region 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 non-supercharging region. As a result, when it is determined that it belongs to the non-supercharged region, it is determined that a prediction calculation using the turbine model will be unnecessary in the future, the process proceeds to the next step, and the prediction calculation using the turbine model is performed. The assigned designated core is stopped (step 204). On the other hand, when it is determined in step 202 that the engine does not belong to the non-supercharged region (that is, it belongs to the supercharged region), the prediction calculation using the turbine model is executed by the designated core (step 206). .

  As described above, according to the system of the present embodiment, when it belongs to the non-supercharging region in the future, the core to which the prediction calculation using the turbine model is assigned is stopped. As a result, the core on which unnecessary computation is performed can be stopped in advance, so that the computation load can be reduced as a whole system by effectively allocating the remaining computation resources.

  By the way, in the above-described embodiment, the designated core to which the prediction calculation using the turbine model is assigned is stopped when it belongs to the non-supercharged area in the future. Not limited to. That is, at the time of no supercharging, first, the prediction calculation using the turbine model is stopped, and then any core is stopped if necessary, and the task is distributed to the remaining cores. . This makes it possible to efficiently allocate the used cores according to the calculation load of the internal combustion engine while reducing the used cores.

  Further, in the above-described embodiment, the in-cylinder air amount and the engine speed are predicted as future operating conditions, and the future supercharging situation is predicted based on these. It is not limited to this. That is, for example, only the future in-cylinder air amount may be used as the operating condition necessary for the prediction, or the future supercharging situation may be predicted by a known method using other operating conditions. .

  Further, in the above-described embodiment, the prediction calculation using the turbine model is exemplified as the calculation that is not required during the period belonging to the non-supercharging region. Can also be applied.

10 Internal combustion engine
12 Intake passage 16 Exhaust passage 20 Turbocharger 20a Turbine 20b Compressor 20c Turbine shaft 50 ECU (Electronic Control Unit)

Claims (7)

An internal combustion engine that includes a turbocharger having a turbine installed in an exhaust passage and a compressor installed in an intake passage, and that uses a turbine model of the turbocharger to perform prediction calculation of output due to rotation of the turbine An engine control device,
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 computing means when the internal combustion engine belongs to the non-supercharged area as compared to the case of belonging to the supercharged area ;
A control device for an internal combustion engine, comprising: Wherein, wherein, when a transition to the supercharging zone from the non-supercharging zone, the control apparatus for an internal combustion engine according to claim 1, characterized in that increasing the number of cores used in the calculation means. The control means includes determination means for determining whether the internal combustion engine belongs to the non-supercharged area or the supercharged area depending on whether or not the supercharging pressure of the internal combustion engine is equal to or lower than atmospheric pressure. 3. The control device for an internal combustion engine according to claim 1 , wherein the control device is an internal combustion engine. The calculation means includes an assignment means for assigning a task of prediction calculation using the turbine model to one or a plurality of designated cores designated from the plurality of cores,
The control device for an internal combustion engine according to any one of claims 1 to 3 , wherein the control means stops the designated core when the internal combustion engine belongs to the non-supercharged region. 5. The control apparatus for an internal combustion engine according to claim 4 , wherein the calculation means calculates the dynamics of the turbine as a prediction calculation using the turbine model. Estimating means for estimating an in-cylinder air amount and an engine speed of the internal combustion engine a predetermined time ahead;
Based on the in-cylinder air amount and the engine rotational speed estimated by the estimation means further comprises prediction means for predicting a supercharging state of the internal combustion engine in a predetermined time later, a,
Said control means on the basis of the supercharging status during a predetermined time later predicted by the prediction means, any one of claims 1 to 5, characterized in that the cores of the increase or decrease used in the calculation means Control device for internal combustion engine. The estimation means performs delay control for delaying the change in the actual throttle opening with respect to the change in the target throttle opening calculated from the accelerator opening, and determines the in-cylinder air amount to be achieved in the future from the target throttle opening. The control apparatus for an internal combustion engine according to claim 6 , wherein prediction is performed.

Images