JP2001256063A - Controller and engine controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform proper control by preventing that a processing with high real time features is not performed without intention even when scale of a control program is increased by using a CPU similar to the conventional one. SOLUTION: A processing to be performed in real time exists in processing programs with relatively low performance priority, on the other hand, a processing which is not to be performed in real time exists in processing programs with relatively high performance priority. Fur that reason, a load factor 1f of the CPU is calculated, when the load factor 1f exceeds a first threshold (LF1-OF) (S300: YES), or when the load factor 1f is equal to or less than the first threshold (LF1-OF) and exceeds a second threshold (LF2-OF) (S300: NO, S330: NO) and the load factor 1f exists in the increasing direction (S360: YES), a control pattern is switched to a suppression control pattern (S380) and the processing with relatively low necessity of performance is suppressed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for preventing a delay or omission of processing that requires real-time processing when a processing program is executed with a predetermined execution priority.

[0002]

2. Description of the Related Art For example, an engine control program is subdivided into a plurality of processing programs as execution units and described. The execution state of such a processing program is called a task, is managed by the OS, and is executed based on a predetermined execution priority (task level).

[0003] The engine control program is divided into a rotation synchronization process, a time synchronization process, and an idle process in descending order of execution priority. In the rotation synchronization processing, for example, when the crankshaft is 3
This is a process synchronized with the rotation of the engine, which is performed every time the engine rotates 0 degrees, and includes a fuel injection / ignition process as an example. Time synchronization processing is, for example, 8 ms, 16
This is a periodic process executed at a predetermined time interval such as ms, and corresponds to a shift process and the like. The idle process is a process not directly related to engine control, and includes a process of updating a register of a computer system.

[0004] These processes are performed on the basis of the execution priority determined in advance as described above, based on an electronic control unit (ECU).
For example, it is executed by one CPU. As the engine rotation speed increases, the number of times of execution of the rotation synchronization processing naturally increases, so that the usage rate of the CPU in the rotation synchronization processing increases. In such a situation, a process with a higher execution priority is executed with priority, and a process may occur in which a process with a lower execution priority is delayed or not executed. That is, when the number of times of execution of the rotation synchronization processing increases, the idle processing is first delayed, and furthermore, the idle processing is not executed. However,
Since the idle processing is not processing that requires real-time processing, no particular problem occurs. However, when the usage rate of the CPU due to the rotation synchronization processing further increases, the time synchronization processing may be delayed or may not be executed. The time synchronization process has a lower real-time property than the rotation synchronization process, but includes a speed change process that requires a certain degree of real-time property. Therefore, in such a situation, a delay in shifting is caused, and the user feels strange.

Therefore, the CPU is usually designed so that the CPU is not occupied by the rotation synchronization processing even when the engine rotation is maximized. That is, by adjusting the program amount in advance, even if the number of times of execution of the rotation synchronization processing increases, the adjustment is performed so that the time synchronization processing is executed at a predetermined cycle. This is conceptually shown in FIG. FIG. 8A shows the CPU usage rate by the rotation synchronization process and the time synchronization process with respect to the engine speed. As can be seen from FIG. 8A, the time synchronization process is executed even when the engine speed becomes maximum.

[0006]

However, the scale of the engine control program tends to increase with the trend of purifying exhaust gas and reducing fuel consumption in automobiles and market needs for comfort and safety. When the scale of the engine control program is increased, it is assumed that, when the engine rotates at a high speed, the usage rate of the CPU by the rotation synchronization processing increases, and the time synchronization processing is delayed or not executed.

For example, FIG. 9 shows how the number of times the rotation synchronization process is executed increases as the engine speed increases, and the time synchronization process and the idle process are delayed or omitted. FIG. 9 shows the case where the engine speed is increased from (a) to (d) in order.

In FIG. 9A, during a period T, the rotation synchronization processing is executed only once and the time synchronization processing is executed three times. That is, the rotation synchronization process is performed in a period from time t4 to time t5 (hereinafter, a period from time α to time β is defined as a period [α,
β]. ), While the time synchronization process is executed in the periods [t2, t3], [t5, t6] and [t8, t9]. Then, a period in which the rotation synchronization process and the time synchronization process are not performed, that is, a period [t0, t2], a period [t3, t4], and a period [t
6, t8], the idle process is assigned.

In FIG. 9B, since the engine speed has increased, the rotation synchronization processing is executed three times in total in the period [t1, t2], the period [t4, t5], and the period [t7, t8]. Since the time synchronization process is not affected by the engine speed, it is executed only three times in the same period as in FIG. Note that, as the number of times of execution of the rotation synchronization processing increases, idle processing with a low execution priority is not executed.

FIG. 9 (c) shows a state where the engine speed is further increased as compared with FIG. 9 (b). Here, the period [t0, t1], the period [t2, t3], the period [t4, t5], the period [t6, t7], and the period [t8,
At t9], the rotation synchronization processing is executed five times in total. Therefore, as shown by a two-dot chain line in FIG.
t3] and the time synchronization process that should be executed in the period [t8, t9] are executed from time t3 and time t9, respectively. This is because the execution priority of the time synchronization process is lower than that of the rotation synchronization process. Therefore, the time synchronization process executed in the period T is two times in total. At this time, the idle processing is hardly executed.

In FIG. 9D, the engine speed is further increased as compared with FIG. 9C, and the rotation synchronization processing is executed nine times throughout the period T. Therefore, in this case, not only the idle processing but also the time synchronization processing are not executed in the period T. Fig. 8 shows this together.
(B). The processing execution states shown in FIGS. 9A to 9D correspond to the engine speeds indicated by the symbols A, B, C, and D, respectively. At the engine speed indicated by the symbol C, the CPU is almost occupied by the execution of the rotation synchronization process and the time synchronization process. Therefore, when the rotation speed is exceeded, not only the idle processing but also part of the time synchronization processing is not executed, and the time synchronization processing is not executed at the maximum engine speed indicated by the symbol D at all.

As a method for solving this, it is conceivable to use a CPU having a high arithmetic performance or to increase the number of CPUs to perform distributed processing. However, these methods are not preferable because they increase costs. SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and it is intended to perform processing with high real-time performance even when a CPU similar to the conventional one is used and the scale of the control program is increased. An object of the present invention is to perform appropriate control while preventing the program from being executed without being executed.

[0013]

Means for Solving the Problems and Effects of the Invention In the control device according to the present invention, the processing executing means executes a plurality of processing programs based on a preset execution priority. Each of these processing programs is an execution unit, and the execution state of the processing program is called a task, and a control target is controlled by executing these processing programs. At this time, the plurality of processing programs include a processing program whose number of executions increases or decreases according to the control situation of the control target.

On the premise of such a configuration, in the present invention, in particular, the processing load measuring means measures the processing load of the processing executing means which changes according to the increase / decrease of the number of executions of the processing program.
Based on the processing load, the processing execution unit suppresses the execution of the processing based on the processing program having relatively small execution necessity in the control situation of the control target.

As described above, when the number of executions of the processing program increases and the CPU utilization rate increases, a situation occurs in which the processing programs are not executed in order from the processing program having a relatively lower execution priority. Then, there is a problem that there is a process to be executed in real time in such a process.

Therefore, in the present invention, attention has been paid to the fact that, depending on the control situation of the control target, there is a process based on a processing program having relatively small execution necessity, in addition to a predetermined execution priority. That is, while there is a process to be executed in real time in a processing program with a relatively low execution priority, a process that does not need to be executed in real time in a processing program with a relatively high execution priority Exists. This is because execution priorities cannot be physically set in consideration of all control situations. Therefore, in the present invention, execution of processing based on a processing program having relatively small execution necessity in the control situation of the control target is dynamically suppressed. In addition, "dynamically" intends to suppress in real time during processing execution. In addition, when the processing load of the processing execution unit is not large, it is not necessary to suppress the execution of the process. Therefore, the suppression of the execution of the process is performed based on the processing load measured by the processing load measurement unit.

According to the present invention, execution of a process based on a processing program having a relatively small execution necessity is suppressed, and accordingly, even a processing program having a relatively low execution priority is executed. The likelihood increases. as a result,
Using a CPU similar to the conventional one, even when the scale of the control program becomes large, it is possible to prevent the execution of the process with high real-time property, and to perform appropriate control.

Note that "suppressing the execution of a process" may mean prohibiting the execution of a process. Further, the execution interval of the processing may be increased. “Execution of processing based on a processing program” is intended to include not only a case where execution is suppressed for each processing program as an execution unit but also a case where some processing in a certain processing program is suppressed. Therefore, when a certain processing program P includes three processes p, q, and r, not only the case where the execution of the processing program P is suppressed to suppress all three processes p, q, and r, For example, a case where only one processing p in the processing program P is suppressed is included. In this case, the realization method may be to prepare another processing program Q including only the processings q and r, and to execute the another processing program Q instead of the processing program P.

Further, since the execution of the processing is suppressed based on the processing load, it is conceivable to change the suppressed processing stepwise based on the processing load, for example. But,
In a simpler implementation, for example, as described in claim 2, the processing execution means normally executes all of the processing programs based on the execution priority based on the processing load measured by the processing load measurement means. It may be realized by switching between a control pattern and a suppression control pattern that suppresses execution of a predetermined process. Thus 2
It is needless to say that the above-described effect can be obtained even when the configuration is configured to switch the three patterns to suppress the processing execution.

The two control patterns described above are:
For example, the switching may be performed as described in claim 3. That is, the processing execution unit switches to the suppression control pattern when the processing load measured by the processing load measurement unit exceeds a predetermined first threshold, and on the other hand, sets a second predetermined value equal to or smaller than the first threshold. Is switched to the normal control pattern when the threshold value becomes equal to or less than the threshold value. Where the first threshold
Although the second threshold value may be the same value, it is preferable to set a different value that satisfies the relationship of the first threshold value> the second threshold value. This is to prevent hunting in which control patterns are alternately switched.

[0021] Assuming that the first threshold value and the second threshold value are set as different values, the processing execution means may execute the processing measured by the processing load measurement means. When the load is equal to or less than the first threshold and exceeds the second threshold, the processing is switched to the suppression control pattern when the processing load is increasing, while the normal control is performed when the processing load is decreasing. It is good to switch to a pattern. That is, before the processing load actually exceeds the first threshold value or before the processing load becomes equal to or less than the second threshold value, the control pattern is switched by predicting them. In this way, it is possible to prevent the processing from being temporarily delayed or missing due to the control pattern switching delay.

The more the processing whose execution is suppressed by the above-described suppression control pattern, the more the processing load fluctuates when the control pattern is shifted. If half of the processing program is suppressed, the processing load is reduced to about half.
Therefore, even if the first and second thresholds are set to different values as described above, there is a possibility that hunting occurs in which the control pattern is alternately switched.

In view of the above, the first and second thresholds may be provided corresponding to the normal control pattern and the suppression control pattern, respectively. In other words, the first and second threshold values corresponding to the normal control pattern are set in consideration of the processing load when the processing is executed in each control pattern, and the first and second threshold values are set separately from these threshold values. That is, the first and second threshold values are set. At this time, the processing execution unit switches to the normal control pattern or the suppression control pattern and performs the first
And switch the second threshold value to the corresponding one. In this way, even if the processing load greatly changes at the time of the shift of the control pattern, the threshold value is switched to an appropriate threshold value, so that hunting in which the control pattern is alternately switched can be prevented.

It is conceivable that the processing load measuring means measures the processing load based on the number of executions of a predetermined processing program having a relatively low execution priority. As the processing load increases, the number of executions of the processing program whose execution priority is relatively low decreases. Therefore,
The processing load can be measured based on the number of executions. With this configuration, the function of the processing load measuring unit can be realized by using software, so that the number of components is reduced in configuring the present apparatus.

Although the above has been described as an invention of a control device, an invention of an engine control device configured by using the above-described control device and controlling an engine mounted on a vehicle as a control target is described in claim 7. It can also be realized as. The engine control device includes a rotation synchronization processing program executed in synchronization with the rotation of the engine of the vehicle as a processing program having a relatively high execution priority. Therefore, the number of executions of the rotation synchronization processing program increases or decreases due to fluctuations in engine rotation. At this time, the processing execution means is based on at least one of the rotation synchronization processing program and a time synchronization processing program executed at a predetermined time interval having a low execution priority with respect to the rotation synchronization processing program. Suppress processing.

In this case, since the processing load increases due to the high rotation of the engine, the processing which is relatively unnecessary to be executed when the engine rotates at high speed is suppressed. For example, ISC (Idle Speed Control
ol) It is possible to prohibit valve control processing. It is conceivable to increase the execution interval of the failure diagnosis processing, which is also executed as time synchronization processing, for example, to twice as long. Further, it is conceivable to prohibit engine stall determination processing and the like in the injection / ignition processing executed as rotation synchronization processing.

In such an engine control apparatus, the processing load measuring means measures the processing load based on the number of times of execution of the idle processing having a lower execution priority than the time synchronous processing. It is better to do it. This is because the function of the processing load measuring means can be realized by software and the number of components can be reduced, as in the case of the above-described control device.

[0028]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram illustrating a configuration of an engine control device (hereinafter, referred to as “ECU”) 1 embodying the present invention. The ECU 1 controls an internal combustion engine mounted on the vehicle.

The ECU 1 outputs a pulse angle signal every time the crankshaft of the engine rotates by a predetermined angle. Each time a piston of a specific cylinder of the engine comes to a predetermined position (for example, TDC: TDC). Inputs signals from various sensors 30 that detect the operating state of the engine, such as a reference position sensor that outputs a pulse-like signal, a water temperature sensor that detects the temperature of engine cooling water, and an oxygen concentration sensor that measures oxygen concentration. An input circuit 21 for performing waveform shaping and A / D conversion, and a microcomputer (hereinafter referred to as “microcomputer”) 10 for performing various processes for controlling the engine based on the sensor signal from the input circuit 21. Actuators such as an injector (fuel injection device) and an igniter (ignition device) attached to the engine according to a control signal from the microcomputer 10. Output circuit 22 for driving the over motor 40
And

The microcomputer 10 includes a well-known CPU (central processing unit) 11 for executing a program,
ROM 1 that stores a program executed by PU 11 and control data referred to when the program is executed
2 and R for storing the calculation result and the like by the CPU 11.
An AM 13, an I / O 14 for exchanging signals between the input circuit 21 and the output circuit 22, various registers, a free-run counter, and the like (not shown) are provided.

The ECU 1 configured as described above performs an engine control process for driving the actuator 40 connected to the output circuit 22 based on signals input from the various sensors 30 via the input circuit 21. The engine control program for implementing the engine control is stored in the ROM 12 included in the microcomputer 10 as described above. The engine control program is subdivided and described for each execution unit. The plurality of processing programs as execution units include a rotation synchronization processing program that is executed in synchronization with the rotation of the engine to be controlled and a time period that is executed at predetermined time intervals such as 8 ms, 16 ms, and 32 ms. The synchronous processing program is divided into an idle processing program executed during a period in which the CPU is not used by the rotation synchronization processing or the time synchronization processing.

Specifically, the rotation synchronization processing program is as follows:
It is composed of processing programs for realizing the fuel injection / ignition processing, and is a group of processing programs most required in real time. The time synchronization processing program includes a processing program for realizing a shift of the automatic transmission and an ISC (Idle Speed Control) control for performing an ISC (Idle Speed Control) control.
The processing program group includes processing programs for realizing SC valve driving, processing programs for realizing failure diagnosis and exhaust gas purification, and the like. Also, idle processing
The processing program group includes processing programs for updating registers of the microcomputer 10 that are not directly related to engine control, and does not require real-time processing.

Each processing program as an execution unit is executed based on a preset execution priority (task level). A processing program with a relatively high execution priority is executed prior to a processing program with a relatively low execution priority. The execution states of these processing programs are called tasks, and are managed by the OS.

By the way, it is known that as the engine speed increases, the number of times the rotation synchronization processing program is executed increases, so that the usage rate of the CPU 11 in the rotation synchronization processing increases. Normally, the amount of the processing program is adjusted so that the time synchronization processing program is executed even when the engine speed reaches the maximum.However, given the current situation where the scale of the control program is increasing, It is assumed that the CPU 11 is occupied by the synchronization processing.

Therefore, the ECU 1 of the present embodiment executes the CPU load factor calculation process described below and the control pattern switching process called from the CPU load factor calculation process, thereby executing the rotation synchronization process.
Is not occupied, and execution of the time synchronization process is ensured.

Next, the CPU load factor calculation process is described in FIG.
A description will be given based on the flowchart of FIG. This CPU load factor calculation process is executed at time intervals of 8 ms. First, in a first step (hereinafter, the steps are simply indicated by a symbol S) 100, the idle process value K is updated by subtracting the passing variable F from the idle process value K. This idle process value K is initialized to “100” immediately before the execution of the CPU load factor calculation process. Also, the passing variable F
When the idle process is executed as shown in FIG. 3, various processes are executed (S200), and then set to "1" (S210). Therefore, the idle process value K is decremented by one when the idle process is being executed.

In S110, "0" is substituted for the passing variable F, and reset. Then, in the next S120, it is determined whether or not the counter C is “100”. The counter C counts the number of executions of the CPU load factor calculation process. Here, when it is determined that C = 100 (S120: YES), the process proceeds to S130. On the other hand, if it is determined that C ≠ 100 (S120: N
O), in step S170, the counter C is incremented, and thereafter, the CPU load factor calculation process ends.

In S130, the idle process value K is set to the CPU
The load factor is substituted for the load factor If. If the idle process is executed only 20 times while the CPU load factor calculation process is executed 100 times, the idle process value K becomes 80, and the load factor If becomes “80”.

At S140, control pattern switching processing is called. Then, after executing the control pattern switching process, the process proceeds to S150. This control pattern switching process will be described later. In S150, the idle process value K is reset to “100”, and in S160, the counter C is reset.
Is reset to “0”, and thereafter, the CPU load factor calculation process ends.

Here, the above-described CPU load factor calculation processing will be specifically described with reference to the timing chart of FIG. At the top of FIG. 4, the execution periods of the rotation synchronization processing, the time synchronization processing, and the idle processing are shown. FIG.
When the idle process is executed, the passing variable F is set to "1" (S210).
Therefore, the period [t0, t1] and the period [t4, t5]
And the passing variable F becomes “1” in the period [t6, t7].

On the other hand, the counter C counts from "1" to "100" after being reset to "0" in the CPU load factor calculation process executed every 8 ms (S120, FIG. 3). (S160, S170), the load factor If is calculated every 800 ms (S130). That is, in the example shown in FIG. 4, the load factor If is calculated at times t6 and t7 when the counter C becomes "100".

In the period [t0, t6], the period [t0, t1] in which the passing variable is set to “1” and the period [t
[4, t5], the idle process value K is decremented, and the value of the idle process value K at time t6 becomes the load factor If. In the period [t6, t7], the passing variable F is “1” in the entire period. This is because the rotation synchronization processing and the time synchronization processing have not been executed. Therefore, the idle process value K is decremented throughout the period [t6, t7], and becomes “0” at time t7. Therefore, at time t7, the load factor If is calculated as “0”.

Next, the control pattern switching processing called in S140 will be described. The control pattern switching process is a process of switching between two control patterns, a normal control pattern and a suppression control pattern. In the normal control pattern, all of the plurality of processing programs described as the above-described engine control program are to be executed, and are executed based on the execution priority. On the other hand, the suppression control pattern is a processing program for realizing the rotation synchronization processing and the time synchronization processing, which hardly requires real-time operation at the time of high engine rotation, that is, suppresses the execution of processing that is relatively small in execution necessity. It is. For example,
The process includes a drive process and a failure determination process of the ISC valve in the time synchronization process, and an engine stall determination process during the fuel injection / ignition process in the rotation synchronization process. Suppression of processing execution specifically refers to prohibiting the execution of the processing or increasing the processing execution interval. At this time, it is conceivable to prohibit the execution of the processing program in units (execution units) or to increase the execution interval. Further, the execution of some processes in the processing program may be prohibited, or the execution interval may be increased. That is, when a certain processing program P includes three processes p, q, and r, the execution of the processing program P is suppressed and the three processes p, q, and r are suppressed.
Are suppressed, as well as a case where, for example, only one process p in the processing program P is suppressed.
In this case, the realization method may be to prepare another processing program Q including only the processings q and r, and to execute the another processing program Q instead of the processing program P.

As a method of switching control patterns,
For example, list information of a processing program to be executed is prepared in the apparatus (for example, in the ROM 12), and the CPU 11 executes the processing program with reference to the list information. If the list information is switched, the control pattern can be switched. For example, all the processing programs are described in the list information corresponding to the normal control pattern, while a predetermined processing program is not described in the list information corresponding to the suppression control pattern. By doing so, it is possible to prohibit execution of only a predetermined processing program. In the case where some processing in the processing program is suppressed, the processing program P including all three processings is described in the list information corresponding to the normal control pattern as described above. The processing program Q including the processing q and r excluding p may be described in the list information corresponding to the suppression control pattern. When the execution interval of the processing program is increased, the execution interval is described in the list information as processing every 8 ms, processing every 16 ms, and the corresponding processing corresponds to the normal control pattern. The list information may be described as an 8 ms process, while the list information corresponding to the suppression control pattern may be described as a 16 ms process.

Such switching of the control pattern is performed based on the above-mentioned load factor If as shown in the flowchart of FIG. First, in first S300, it is determined whether or not the load factor If is greater than a value obtained by subtracting the determination offset value OF from the first determination value LF1. Here, (LF1-OF) corresponds to the “first threshold value”. Therefore, this processing determines whether the load factor If exceeds the first threshold. lf> (LF1-
OF) (S300: YES),
That is, when the load factor If exceeds the first threshold value, the determination control value OF becomes the suppression control offset value OF.
2 (S310), switch to the suppression control pattern (S320), and proceed to S410. On the other hand, if ≦
(LF1-OF) (S300:
NO), that is, if the load factor If is equal to or less than the first threshold, the process proceeds to S330.

In S330, it is determined whether or not the load factor If is equal to or less than a value obtained by subtracting the determination offset value OF from the second determination value LF2. Here, LF2 <LF1, and (LF2-OF) corresponds to the “second threshold value”. Therefore, this processing is to determine whether the load factor If is equal to or less than the second threshold. Where lf ≦ (LF
2-OF) (S330: YE)
S), that is, when the load factor If is equal to or less than the second threshold value, the normal control offset value O
F1 is substituted (S340), the control mode is switched to the normal control pattern (S350), and the process proceeds to S410. On the other hand, if>
(LF2-OF) (S330:
NO), that is, if the load factor If is equal to or less than the first threshold and exceeds the second threshold, the process proceeds to S360.

In S360, it is determined whether or not the value obtained by subtracting the previous load factor lf 'from the load factor If is larger than "0". That is, it is determined whether the load factor If is in the increasing direction or the decreasing direction. Here, if (lf−lf ′)> 0 (S360: YE
S), that is, when the load factor If is increasing,
The suppression control offset value OF2 is substituted for the determination offset value OF (S370), the control pattern is switched to the suppression control pattern (S380), and the process proceeds to S410. On the other hand, (lf−l
f ′) ≦ 0 (S360: NO), that is, when the load factor If is in the decreasing direction, the normal control offset value OF1 is substituted for the determination offset value OF (S39).
0), switching to the normal control pattern (S400), and S
It moves to 410.

S320, S350, S380, S400
In S410, the load factor lf is changed to l
f ′, and then the control pattern switching process ends. As described above, when the switching from the normal control pattern to the suppression control pattern is performed, the execution of the predetermined processing is suppressed, so that the load factor If decreases. Therefore, the amount of change in the load factor If accompanying the switching of the control pattern is set as the determination offset value OF, and the magnitude of the load factor If is determined using the determination offset value OF. Specifically, a load factor that decreases due to the suppression of the processing is set as the determination offset value OF. In the present embodiment, under the assumption that the load factor is reduced by "30" when switching from the normal control pattern to the suppression control pattern, when switching to the suppression control pattern, the suppression control offset value OF2 (= 30) is added to the determination offset value OF. ) Is substituted, and when switching to the normal control pattern, the normal control offset value OF1 (= 0) is substituted for the determination offset value OF.

To facilitate understanding of the control pattern switching process described above, the relationship between the load factor If and the control pattern will be specifically described with reference to FIG. FIG.
In the graph, the horizontal axis indicates time, and the vertical axis indicates a value obtained by adding the load factor If and the determination offset value OF.

In the period T1, if + OF ≦ LF2
(S330: YES), the control pattern is the normal control pattern (S350). At this time, the determination offset value OF becomes the normal control offset value OF1 (= 0) (S
340). In the period T2, LF1 ≧ lf + OF>
LF2 (S300: NO, S330: N
O) and if is in the increasing direction (S360: Y
ES), and becomes the suppression control pattern (S380). At this time, the load factor lf decreases by “30” to shift from the normal control pattern to the suppression control pattern. However, since the suppression control offset value OF2 (= 30) is substituted for the determination offset value OF (S370), the value of lf + OF is obtained. The value does not change.

In the period T3, if + OF> LF1
(S300: YES), it becomes the suppression control pattern (S320). The suppression control offset value OF2 is substituted for the determination offset value OF (S310).
In the period T4, LF1 ≧ lf + OF> LF2 is satisfied (S300: NO, S330: NO), and
If is in the decreasing direction (S360: NO), the normal control pattern is set (S400). At this time, the load factor If increases by 30 to shift from the suppression control pattern to the normal control pattern, but the normal control offset value OF1 (= 0) is substituted for the determination offset value OF (S39).
0), the value of If + OF does not change.

The period T5 is the same as the period T1. That is, if + OF ≦ LF2 (S3
30: YES), the normal control offset value OF1 (= 0) is substituted for the determination offset value OF (S340), and the normal control pattern is obtained (S350).

In summary, it can be seen that the normal control pattern is used in the periods T1, T4 and T5, and the suppression control pattern is used in the periods T2 and T3. As described in detail above, in the ECU 1 of the present embodiment, even if the load factor If increases, the CPU usage rate in the rotation synchronization process and the time synchronization process is 100%.
% So that the control pattern is switched from the normal control pattern to the suppression control pattern (S320, S35 in FIG. 5).
0, S380, S400). As a result, the execution of a process based on a processing program having a relatively small execution necessity is suppressed, and accordingly, there is a high possibility that a processing program having a relatively low execution priority is executed. As a result, even when the size of the control program is increased using the same CPU as in the related art, it is possible to prevent unintentional omission of processing with high real-time properties and to perform appropriate control. . This situation is shown in FIG. The hatched portions are suppressed, and as a result, even when the engine speed is maximized, the execution of the highly real-time processing of the rotation synchronization processing and the time synchronization processing is ensured under the circumstances. .

The ECU 1 of this embodiment sets first and second determination values LF1 and LF2 (LF1> LF2), and determines the first and second determination values LF1 and LF2 and the determination offset value OF. Using a first threshold (LF1-O
F) and a second threshold (LF2-OF). Then, the normal control pattern is switched to the normal control pattern and the normal control offset value OF1 is substituted for the determination offset value OF (S3
40, S390) On the other hand, the control is switched to the suppression control pattern, and the suppression control offset value OF2 is substituted for the determination offset value OF (S310, S370). That is, the load factor l when the process is executed in each control pattern
In consideration of f, the first and second threshold values corresponding to the normal control pattern are set using OF1 corresponding to the normal control pattern, and independently of these threshold values, the OF2 corresponding to the suppression control pattern is used. The first corresponding to the suppression control pattern
And a second threshold value. As a result, even if the load factor If changes greatly when the control pattern shifts, an appropriate threshold value is set, and hunting in which the control pattern is alternately switched can be prevented.

Further, in the ECU 1 of this embodiment, when the load factor If is equal to or less than the first threshold (LF1-OF) and exceeds the second threshold (LF2-OF) (S300:
(NO, S330: NO), it is determined whether the load factor If is in the increasing direction or in the decreasing direction (S360). If it is in the increasing direction, it is switched to the suppression control pattern (S380). The control pattern is switched (S400). That is, before the processing load actually exceeds the first threshold value or before the processing load becomes equal to or less than the second threshold value, the control pattern is switched by predicting them. As a result, it is possible to prevent the processing from being temporarily delayed or missing due to the control pattern switching delay.

Further, as shown in FIG. 2, the ECU 1 of the present embodiment calculates the load factor If based on the number of times of executing the idle process. Since the calculation of the load factor If is realized by software, the number of parts can be reduced. Note that the CPU 11 of the present embodiment corresponds to “processing executing means” and “processing load measuring means”. In addition, the CPU load factor calculation processing illustrated in FIG. 2 corresponds to a processing load measurement unit,
The control pattern switching process shown in FIG. 5 corresponds to the control pattern switching process.

As described above, the present invention is not limited to the above embodiments, and can be implemented in various modes without departing from the gist of the present invention. In the above embodiment,
Although the two control patterns, ie, the normal control pattern and the suppression control pattern, are switched based on the load factor If, it is of course possible to adopt a configuration in which two or more control patterns are switched.

In the above-described embodiment, the present invention is applied to the engine control apparatus which controls the engine mounted on the vehicle. However, the control object whose execution frequency of the processing program increases or decreases according to the control situation of the control object. Can be similarly applied.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a schematic configuration of an engine control device according to an embodiment.

FIG. 2 is a flowchart illustrating a CPU load factor calculation process.

FIG. 3 is a flowchart illustrating idle processing.

FIG. 4 is a timing chart illustrating CPU load factor calculation processing.

FIG. 5 is a flowchart showing a control pattern switching process.

FIG. 6 is an explanatory diagram specifically showing a control pattern switching process.

FIG. 7 is an explanatory diagram showing an effect in the engine control device of the embodiment.

FIG. 8A is an explanatory diagram illustrating a state in which execution of the time synchronization process is ensured, and FIG. 8B is an explanatory diagram illustrating a state in which the time synchronization process is not executed.

FIG. 9 is an explanatory diagram showing delays and omissions in the time synchronization processing.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... ECU 10 ... Microcomputer 11 ... CPU 12 ... ROM 13 ... RAM 14 ... I / O 21 ... Input circuit 22 ... Output circuit 30 ... Sensor 40 ... Actuator

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Hirotaka Sakai 1-1-1 Showa-cho, Kariya-shi, Aichi F-term in Denso Corporation (reference) 3G084 BA05 CA03 DA04 DA05 EA07 EA11 EB00 EB02 EB05 EB11 FA00 FA34 5B098 GA04 GA08 GC03 GC10 9A001 DD07 HH34 LL08

Claims (8)

[Claims] A plurality of processing programs as an execution unit are
A control device, comprising: a processing execution unit that executes processing based on a preset execution priority, and controlling a control target by executing the processing program by the processing execution unit. A processing program that increases / decreases the number of executions according to the control situation; and includes a processing load measuring unit that measures a processing load of the processing execution unit that changes according to an increase / decrease in the number of executions of the processing program. Controlling dynamically executing processing based on a processing program whose execution necessity is relatively small in the control situation of the control target based on the processing load measured by the processing load measuring means. apparatus. 2. The control device according to claim 1, wherein the processing execution unit executes all of the processing programs based on the processing load measured by the processing load measurement unit based on the execution priority. Normal control pattern,
A control device for dynamically switching between a suppression control pattern in which execution of a predetermined process is suppressed. 3. The control device according to claim 2, wherein the processing execution unit switches to the suppression control pattern when a processing load measured by the processing load measurement unit exceeds a predetermined first threshold. On the other hand, the control device switches to the normal control pattern when the value becomes equal to or less than a second threshold value which is predetermined as a value equal to or less than the first threshold value. 4. The control device according to claim 3, wherein the processing execution means is configured to determine that the processing load measured by the processing load measuring means is equal to or less than the first threshold value and the second processing threshold value is equal to or less than the second threshold value.
If the processing load increases, the control pattern is switched to the suppression control pattern, while if the processing load is reduced, the control pattern is switched to the normal control pattern. Control device. 5. The control device according to claim 3, wherein the first and second thresholds are provided in correspondence with the normal control pattern and the suppression control pattern, respectively. A control device that switches to the normal control pattern or the suppression control pattern and switches the first and second threshold values to corresponding ones. 6. The control device according to claim 1, wherein the processing load measuring means determines the processing load based on the number of executions of the predetermined processing program whose execution priority is relatively low. A control device for measuring. 7. An engine control device configured using the control device according to claim 1 and controlling an engine mounted on a vehicle as the control target, wherein the execution priority is relatively high. A rotation synchronization processing program executed in synchronization with the rotation of the engine is provided as a processing program, and the number of executions of the rotation synchronization processing program increases or decreases in accordance with the fluctuation of the engine rotation. Suppressing processing based on at least one of the rotation synchronization processing program or the time synchronization processing program executed at a predetermined time interval having a lower execution priority with respect to the rotation synchronization processing program. An engine control device characterized by the above-mentioned. 8. The engine control device according to claim 7, wherein the processing load measuring unit measures the processing load based on the number of times of executing the idle processing program having a lower execution priority than the time synchronous processing. An engine control device, characterized in that: