JP3257932B2 - Engine control method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control method for an engine control device equipped with a microprocessor.

[0002]

2. Description of the Related Art Today's engine control devices are being integrated to control the fuel injection amount of an engine and to perform other controls, particularly, mission control of an automatic vehicle. The fuel injection amount of the engine is calculated in synchronization with the engine pulse, and the parameters of the mission control are calculated at regular intervals. Jobs for performing these calculations are executed by the microprocessor. A job performed in synchronization with an engine pulse (hereinafter, referred to as an engine pulse synchronous job) and a job performed at regular intervals (hereinafter, referred to as a processing job at regular intervals).
Are asynchronous with each other, there may be cases where processing requests overlap. At this time, in order to reduce the amount of RAM used due to stack saving and simplify the software design, the processing job is executed at regular intervals (for example, every 10 ms) as shown in FIG. In the timer interrupt, the basic cycle is counted, and processing is performed by executing the job that has reached the execution timing.

[0003]

However, in the above-described conventional engine control method, as the required performance of the control device increases, the amount of calculation increases, and the time required for processing by the microprocessor increases. An engine pulse synchronous job desirably has a small startup delay from an interrupt request due to an engine pulse. However, if the processing time of a processing job is fixed at regular time intervals, an engine pulse synchronous job interrupt request is issued during execution of this job. In this case, the time until the start is long, and the control performance is reduced.

More specifically, when a job is directly executed during a basic cycle interrupt according to the flow chart of FIG. 5, as shown in FIG. 6, a 10 ms job, a 20 ms job, a 40 ms job, and an 80 ms job are successively executed. There is
If an engine pulse synchronous interrupt request occurs during this interrupt, the interrupt delay time Td is 10 ms or less at the maximum.
This is the total execution time of the 80 ms job.

To avoid this, if the level of the interrupt for executing the engine pulse synchronous job is set higher than the level of the interrupt for executing the processing job at regular time intervals, as described above, the amount of use of the RAM increases, and There is a problem that software design becomes complicated.

An object of the present invention is to solve such a conventional problem and to provide an engine control method capable of reducing an interrupt delay time for an engine pulse and suppressing an amount of RAM used. I do.

[0007]

According to the present invention, in order to achieve the above-mentioned object, a process job is executed at regular intervals by a process interrupt at regular intervals, and an interrupt request for this interrupt is issued at a basic cycle. Timer interrupts, which are generated by timer interrupts and are performed for each basic cycle, control the job generation cycle of each different cycle, and when there is a job generation request, set the corresponding job processing request flag, and set the processing request flag. If at least one exists, a processing interrupt is generated at regular time intervals. In the process interrupt at regular time intervals, the process request flag is checked in ascending order of the processing cycle of the corresponding job, and if the process request flag exists, the corresponding job is executed and the process request flag is cleared. To end the interrupt. At the end of the processing, it is checked whether or not there is another processing request flag, and if there is, a processing interrupt is activated again at regular intervals. Also, the engine pulse synchronous interrupt and the processing interrupt at regular intervals are at the same level, and if they occur simultaneously, the engine pulse synchronous interrupt is set to be performed with priority.

[0008]

According to the present invention, when it is necessary to execute a plurality of processing jobs each having a different processing cycle and at a certain time interval, at a certain timing, a plurality of processing request flags are set by timer processing performed for each basic cycle. At the same time, a processing interrupt is generated at regular time intervals. For example, a plurality of processing request jobs are respectively 10 ms, 20 ms,
In the case of 40 ms, in the processing interrupt every fixed time,
In order to check in the shortest processing cycle, first execute a 10 ms job, clear the 10 ms job request flag,
Since another requested job still remains, a processing interrupt is started again at regular intervals, and a 20 ms job, 40
ms jobs are executed in order.

Here, if an interrupt request for an engine pulse synchronous job is issued during the execution of the first 10 ms job,
Although the engine pulse synchronous interrupt request and the processing interrupt request at regular time intervals according to the next 20 ms job are present at the same time, the engine pulse synchronous interrupt has a higher priority than the processing interrupt at regular time intervals. A sync job is executed, then 20
An ms job and a 40 ms job are executed.

In the conventional engine control method, a 10 ms job, a 20 ms job, and a 40 ms job are continuously performed, and after the job is completed, the engine pulse synchronous job is executed. Although the time until the synchronous job is executed is long, in the present invention, the waiting time is only the time for executing the 10 ms job, and the control performance is improved.
In other words, if there are a plurality of processing jobs at regular time intervals,
The response can be improved by executing this one by one by one interruption and giving an execution opportunity to the engine pulse synchronous job each time the job is completed. In addition, by checking the job request flag in ascending order of processing cycle in the processing interrupt at regular time intervals, the occurrence of jobs can be checked in descending order of the occurrence frequency, and the job with the highest occurrence frequency can be preferentially performed.

[0011]

FIG. 1 is a flowchart of a basic cycle timer interrupt process according to one embodiment of the present invention. In this embodiment, 1
The four jobs of 0 ms, 20 ms, 40 ms, and 80 ms are controlled. The interruption of the basic cycle timer is executed every 10 ms. In the flowchart of FIG. 1, a 10 ms job request flag is first set by a counter that counts from 0 to 7 (step 1), and the counter counts the number of counts (step 2). At a predetermined timing,
20ms job request flag (step 3), 40m
The s job request flag (step 4) and the 80 ms job request flag (step 5) are set. Thereafter, in the interrupt occurrence judging process (Step 6), it is checked whether any job request flag is set (Step 7), and if any one is set, a process interrupt is generated at regular intervals (Step 8). ).

FIG. 2 is a flow chart of the interrupt processing for every fixed time. Here, the processing request flags set in the basic cycle timer interrupt processing are checked in the order of the 10 ms job request flag, the 20 ms job request flag, the 40 ms job request flag, and the 80 ms job request flag (steps 11 to 14). If there is, execute the corresponding job (steps 15-18), clear the processing request flag (steps 19-22),
The end determination processing (step 23) is performed without checking other job processing request flags. In this end determination process,
It is checked whether any of the processing request flags have been set (step 24). If any of the processing request flags have been set, a processing interrupt is generated again at regular intervals (step 25).

Therefore, at the same time, 10 ms, 20 ms,
When it is time to generate a 40 ms or 80 ms job, as shown in FIG. 3, a processing request flag corresponding to each job is set by a basic cycle timer interrupt, and a processing interrupt is started at regular intervals, and first, a 10 ms job is executed. And the processing request flag is cleared. Thereafter, the flag is checked in the end determination processing, and since the processing request flag is still set, the processing interrupt is restarted at regular intervals. Here, the interrupt is temporarily terminated, but a processing interrupt occurs again at regular time intervals.
The job is executed, then repeat this for 40ms,
An 80 ms job is executed. That is, the processing interrupt is executed four times in a row at regular intervals.

Here, as shown in FIG. 4, when an engine pulse synchronous interrupt request is issued during execution of a 10 ms job,
Since the interrupt level being executed and the interrupt level are the same, 10
The engine pulse synchronization interrupt is kept waiting until the end of the ms job. When the 10 ms job is completed, there are an engine pulse synchronization interrupt request and a processing interrupt request at regular intervals corresponding to the 20 ms job. Since the hardware is configured to be prioritized, the engine pulse synchronization interrupt is received first, and the engine pulse synchronization job is executed. After that, each job of 20 ms, 40 ms, and 80 ms is executed. Therefore, as shown in FIG. 4, the interrupt delay time Td from the engine pulse synchronous interrupt request to the execution of the corresponding job is at most 1 as shown in FIG.
The execution time is equal to or shorter than the 0 ms job execution time Tj, which is greatly improved as compared with the conventional example shown in FIG. 6, and the control performance can be improved.

[0015]

As described above, according to the present invention, the engine pulse synchronous job is executed preferentially at the end timing of the processing job at regular intervals, so that the interrupt delay time for the engine pulse can be reduced. As a result, engine control performance can be improved. Also, since interrupts are performed in order and are not executed in multiple
Can be suppressed, and an excellent engine control method can be realized.

[Brief description of the drawings]

FIG. 1 is a flowchart of basic timer interrupt processing according to an embodiment of the present invention.

FIG. 2 is a flowchart of a process interrupt process performed at regular time intervals according to an embodiment of the present invention;

FIG. 3 is a timing chart of interrupt processing according to an embodiment of the present invention;

FIG. 4 is a timing chart in a case where an engine pulse synchronous interrupt occurs in one embodiment of the present invention.

FIG. 5 is a flowchart of basic timer interrupt processing in a conventional example.

FIG. 6 is a timing chart when an engine pulse synchronous interrupt occurs in a conventional example.

[Explanation of symbols]

 Td Interrupt delay time Tj 10ms Job execution time

Claims (3)

(57) [Claims] 1. A job which is executed in synchronization with an engine pulse and a plurality of jobs which are executed asynchronously and at predetermined time intervals different from each other, and which are executed in synchronization with the engine pulse, , A plurality of jobs that are executed at an interrupt that is started in synchronization with the engine pulse and that are performed at regular time intervals having different periods,
If there are a plurality of jobs that are executed in a processing interrupt at regular time intervals and are executed at regular time intervals, the jobs are executed one by one with one interrupt, and each time the job is ended, the jobs are executed in synchronization with the engine pulse. An engine control method that gives an opportunity to execute. 2. The method according to claim 1, wherein the processing interrupt at predetermined time intervals is a timer interrupt executed at every basic cycle, wherein at least one of job processing request flags set according to an execution cycle of a plurality of jobs performed at fixed time intervals. When one is set, the interrupt that is started in synchronization with the engine pulse and the processing interrupt at fixed time intervals are the same level interrupt, and if there is a simultaneous request, it is started in synchronization with the engine pulse 2. The engine control method according to claim 1, wherein the interrupt to be performed is performed with priority. 3. In a processing interrupt at regular time intervals, a job processing request flag set by a timer interrupt executed every basic cycle is checked in ascending order of job execution cycle, and a job corresponding to a flag found first is determined. 3. The engine control method according to claim 2, further comprising: executing the processing request flag, checking whether there is another processing request flag, and restarting the processing interrupt every predetermined time if the processing request flag is present.