JPH0816459B2 - Engine controller - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention obtains control data such as fuel injection amount and ignition timing according to the state of the engine, and controls the engine based on the control data. It relates to the device.

[Prior art]

In a control device for an internal combustion engine, control data such as a fuel injection amount and an ignition timing is obtained by arithmetic processing of a computer in synchronization with the rotation of the engine, and a method of controlling the engine based on the control data is used when the engine suddenly changes ( It is also desirable from the point of view of acceleration). Conventionally, as this type of control technology, there is one disclosed in JP-A-55-84860,
Interrupt processing is executed in synchronization with a predetermined rotation angle of the engine, and various arithmetic processing is executed by the interrupt processing.

By the way, the engine speed and the elapsed time of the predetermined rotation angle have the relationship shown in FIG. 2 (the predetermined rotation angle in this case is 180 degrees), and as shown in the figure, it was 15 msec at low rotation (1000 RPM). High angle rotation time (6000RPM)
Then it becomes 2.5msec. This means that the processing time that can be executed by interrupt processing has a large difference between low rotation and high rotation, and in order to synchronously perform arithmetic processing from low rotation to high rotation, execution of interrupt processing within the high rotation angle elapsed time I needed to save time. However, in the low rotation speed where the engine rotation fluctuation is large, it is necessary to improve the content of the arithmetic processing (to increase the execution time of the interrupt processing) in order to improve the followability to the fluctuation. As a method of solving such a problem, there is a method of changing the content of the arithmetic processing depending on the number of revolutions, which improves the followability to the fluctuation of the engine by performing the dense arithmetic operation at the low revolution as compared to the high revolution. Was there.

[Problems to be solved by the invention]

However, even with the control method that changes the contents of arithmetic processing (switches processing) as described above, in order to prevent the next interrupt processing from being delayed during the interrupt processing when the engine suddenly changes (acceleration), the next interrupt processing is delayed. In addition, the rotation side was set lower than the actual switching rotation speed. For this reason, there is a drawback that the number of revolutions that can be densely calculated is limited, and the followability to the engine rotation fluctuation is insufficient.

The present invention has been made in view of the above points, and in interrupt processing performed in synchronization with a predetermined rotation angle of the engine, the angle elapsed time from low rotation to high rotation can be effectively used, and tracking of engine fluctuations can be performed. It is to provide a control device for an engine that is improved in performance.

[Means for solving problems]

In order to solve the above-mentioned problems, the present invention performs interrupt processing in synchronization with a predetermined rotation angle of the engine by a signal indicating the state of the engine input from various sensors, obtains control data of the engine, In an engine control device that controls the engine with control data, when an interrupt processing request occurs again while the controller is executing interrupt processing, the current interrupt processing is forcibly ended by rewriting the stack pointer and the next interrupt processing is given priority. It is characterized in that means for executing is provided.

[Action]

By configuring the engine controller as described above, when an interrupt processing request occurs again during interrupt processing, the interrupt processing currently being executed is forcibly ended by rewriting the stack pointer and the next interrupt processing is executed. Since the execution is performed with priority, the interrupt processing can be executed without delay even if the engine speed changes, and the angle elapsed time can be effectively used for the interrupt processing from low rotation to high rotation.

〔Example〕

An embodiment of the present invention will be described below by taking an ignition timing control device as an example.

FIG. 1 is a block diagram showing the system configuration of an ignition timing control device that constitutes an embodiment of the present invention. The ignition timing control device 1 includes an A / D converter 2, a control circuit 3, a waveform shaping circuit 4, and an output control circuit 5. The A / D converter 2 receives a negative pressure signal from a negative pressure sensor that detects the engine load.
PB, a water temperature signal TW from a water temperature sensor that detects the temperature of the engine, and a battery voltage signal VB that is a power source of the control device 1 are input, and the waveform shaping circuit 4 is a sensor that detects the rotational speed and rotational angle position of the engine. The reference signal P1 and the angle signal P2 from are input. The negative pressure signal PB, the water temperature signal TW, and the battery signal VB that are input to the A / D converter 2 are converted from analog signals to digital signals by the A / D converter 2 and are stored in a computer that constitutes the control circuit 3. Stored in RAM. Further, the reference signal P1 and the angle signal P2, which are input to the waveform shaping circuit 4 and are synchronized with the rotation of the engine, are shaped by the waveform shaping circuit 4 into digital values of "1" and "0",
It is input to the control circuit 3. The angle signal P2 is used as an interrupt signal to activate an interrupt process synchronized with the rotation of the engine, and the reference signal P1 is used to detect the rotational position.

As described above, the engine state is detected from the negative pressure signal PB, the water temperature signal TW, and the battery voltage signal VB input to the control circuit 3, and the ignition timing and the energization timing, which are the control data for the ignition timing control, are controlled by the control circuit 3 It is obtained by the interrupt processing of the computer that constitutes An ON / OFF signal is given to the output circuit 5 from the control data relating to the ignition timing and the energization timing, and the ON / OFF signal is amplified by the output circuit 5 to control the ignition coil through the distributor.

FIG. 3 is a flowchart showing the flow of interrupt processing. Next, a processing method of interrupt processing will be specifically described with reference to the flowchart.

First, the processing at low rotation will be described. Interrupt processing is started and execution is started (step 10
0) Then, it is judged whether or not the interrupt is an interrupt being interrupted (step 101). Since it is normally NO, register protection is performed and at the same time the current stack pointer value is also protected (step 102). Next, it is judged whether the engine is high rotation (6000 RPM or higher) (step 103), and it is low rotation, so processing A
Is executed (step 104), and after performing an arithmetic operation for each interrupt processing, an instruction for permitting an interrupt is executed thereafter (step 105). Next, a calculation that may be interrupted by the re-interruption is performed (step 10
6) The contents protected in the register in step 102 are restored (step 107), and the interrupt processing is terminated.

Next, the flow of processing at high rotation will be described. The steps up to the steps 100, 101 and 102 of the interruption processing are the same as the low rotation interruption processing. In step 103, since the rotation speed is high (6000 RPM or more), the determination is YES and the process proceeds to step C (step 110). In step C, the contents of the process A of step 104 and the contents of the process B of step 106 are partly described. Is executed and the process proceeds to step 107 and step 108.

Finally, the operation when the next interrupt occurs during the interrupt processing will be described. When the next interrupt occurs after the re-interruption is permitted in step 105, the process jumps to step 100. Next, in step 101, it is judged that an interrupt is in progress, and the process proceeds to step 109, in which the stack protected in step 102 of the previous interrupt processing is
Set the pointer value to the stack pointer. This allows you to forcefully terminate the previous interrupt process,
Moreover, this time interrupt processing can also be executed without delay. The following processing is high rotation processing.

The interrupt processing is executed by a program stored in the ROM of the computer that constitutes the control circuit 3.

In the above embodiment, the ignition timing control device has been described as an example, but the technology relating to the engine control device of the present invention is not limited to this, and it goes without saying that it can be applied to, for example, control of the fuel injection amount. Is.

〔The invention's effect〕

As described above, according to the present invention, when the interrupt processing request is generated again during the execution of the interrupt processing, the current interrupt processing is forcibly ended by rewriting the stack pointer and the next interrupt processing is preferentially executed. The interrupt processing can be executed without delay even if the engine speed changes, and the predetermined angle elapsed time can be effectively used for the interrupt processing from low rotation to high rotation. Therefore, it is possible to obtain an excellent effect that the processing ability of the engine control device of this type and the followability of the variation of the engine can be improved.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of an ignition timing control device according to the present invention, FIG. 2 is a diagram showing a relationship between an engine speed and an elapsed time of a predetermined rotation angle, and FIG. 3 is an ignition shown in FIG. It is a flow chart which shows a flow of interruption processing of a timing control device. In the figure, 1 ... Ignition timing control device, 2 ... A / D converter, 3
...... Control circuit, 4 …… Wave shaping circuit, 5 …… Output circuit.

Claims (1)

[Claims] 1. A control unit executes an interrupt process in synchronization with a predetermined rotation angle of the engine by a signal input from various sensors to indicate an engine control data.
In the engine control device for controlling the engine by the control data, when an interrupt processing request is generated again while the interrupt processing is being executed in the control unit, the current interrupt processing is forcibly ended by rewriting the stack pointer and the next interrupt processing is performed. An engine control device, characterized in that means for preferentially executing is provided.