JP3659171B2 - Engine control device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an engine control device that calculates various control amounts for engine control based on an accelerator operation amount.
[0002]
[Prior art]
In the engine control device, the accelerator operation amount is widely used as one parameter for monitoring the operating state. That is, various control amounts are calculated based on the accelerator operation amount, and the engine is controlled based on the calculated control amounts, so that the output is in the driving state, specifically, the driver's acceleration / deceleration request. It is adjusted appropriately according to the shape. In such an engine control device, usually, the accelerator operation amount is detected every predetermined time in order to accurately detect the driver's acceleration / deceleration request.
[0003]
On the other hand, the fuel injection amount, which is one of the control amounts, is calculated at a predetermined crank angle timing immediately before each injection because it is necessary to reflect the operation state for each injection.
By the way, it is desirable that the fuel injection amount is calculated based on the engine operating state at that time immediately before fuel injection is performed in order to reflect the latest engine operating state. However, when the engine speed increases, the time from the start of calculation of the fuel injection amount to the actual injection of fuel is shortened, and the calculation of the fuel injection amount is calculated before the fuel injection starts. It cannot be completed.
[0004]
Therefore, conventionally, the calculation of the fuel injection amount is divided into pre-processing and post-processing and executed. Specifically, of these two processes, the post-processing is executed at a predetermined crank angle timing immediately before injection, while the pre-processing is executed at a crank angle timing slightly before the post-processing. Thus, by calculating the fuel injection amount through a plurality of processes executed at different crank angle timings, the calculation of the fuel injection amount can be completed before fuel injection is started.
[0005]
In addition, in the case where the process for calculating the fuel injection amount is divided into two processes as described above, if the accelerator operation amount is updated as needed according to the driver's accelerator operation, the accelerator operation amount referred to in both of these processes Have different values. Therefore, the conventional engine control device prohibits updating of the accelerator operation amount for a predetermined period from pre-processing to post-processing, so that both processes are executed with reference to the same accelerator operation amount. I have to.
[0006]
[Problems to be solved by the invention]
Here, the relationship between the update timing of the accelerator operation amount and the update prohibition period is shown in FIG. In FIG. 5, (a) shows the transition of the operating state of the fuel injection valve, and (b) shows the update prohibition period of the accelerator operation amount. 5C and 5D show the update timing of the accelerator operation amount at different engine speeds.
[0007]
As shown in FIG. 5C, when the cycle T1 of the accelerator operation amount update prohibition period is different from the update period T2 of the accelerator operation amount, the accelerator operation is performed in a period other than the update prohibition period. Since the amount is updated, the latest accelerator operation amount updated in this way (accelerator operation amount updated at timings t1 and t2 in FIG. 5) is referred to in the pre-processing and post-processing.
[0008]
As shown in FIG. 5 (d), the period T1 of the update prohibition period of the accelerator operation amount changes with a change in the engine speed, and the same period T1 coincides with the update period T2 of the accelerator operation amount. When the update times t1 ′ and t2 ′ come within the update prohibition period, the accelerator operation amount is not updated. Therefore, in this case, the change in the accelerator operation amount cannot be immediately reflected in the fuel injection amount. Although these problems occur only when the engine speed matches the predetermined speed, it is an improvement in terms of calculating the exact fuel injection amount in accordance with changes in the accelerator operation amount. It is something that leaves room.
[0009]
Note that such a problem is not limited to the calculation of the fuel injection amount. For example, even for the throttle valve opening and ignition timing, the control amount is calculated through a plurality of processes executed at different predetermined crank angle timings. In addition, the engine control apparatus that sets the period during which the update of the accelerator operation amount is prohibited for the calculation is generally common.
[0010]
The present invention has been made in view of the above circumstances, and an object of the present invention is to calculate a control amount for engine control through a plurality of processes executed at different crank angle timings. An object of the present invention is to provide an engine control device that can be suitably calculated according to changes in the accelerator operation amount.
[0011]
[Means for Solving the Problems]
In the following, means for achieving the above object and its effects are described.
First, the invention according to claim 1 is an engine in which a specific control amount among various engine control amounts calculated based on an accelerator operation amount is calculated through a plurality of processes executed at different crank angle timings. In the control device, the accelerator operation amount is detected in time synchronization, and the accelerator operation amount referred to in calculating the specific control amount is provided with detection means for detecting the accelerator operation amount in crank angle synchronization. The gist.
[0012]
According to the above configuration, among the control amounts calculated based on the accelerator operation amount, the specific control amount calculated through a plurality of processes executed at different crank angle timings is detected in synchronization with the crank angle at the time of calculation. The accelerator operation amount is referred to. Therefore, by detecting the accelerator operation amount at the crank angle timing suitable for the calculation of the specific control amount, the accelerator operation amount can be reliably detected in accordance with the calculation of the control amount regardless of the engine speed. Will be able to. Accordingly, when the control amount for engine control is calculated through a plurality of processes executed at different crank angle timings, the control amount can be suitably calculated according to the change in the accelerator operation amount. .
[0013]
According to the configuration of the first aspect of the invention, for example, when the detected accelerator operation amount is gradually changed and used as the final accelerator operation amount, the accelerator operation detected in time synchronization is used. This gradual change process can also be suitably executed based on the amount.
[0014]
According to a second aspect of the present invention, in the engine control apparatus according to the first aspect, the detection means uses an accelerator operation amount used for calculating the specific control amount as a first process among the plurality of processes. The gist is to detect at a predetermined crank angle timing immediately before starting.
[0015]
According to the above configuration, the latest accelerator operation amount can be reflected when calculating the specific control amount.
The invention according to claim 3 is the engine control apparatus according to claim 1 or 2, wherein the specific control amount is a fuel injection amount.
[0016]
According to the above configuration, the fuel injection amount calculated at the predetermined crank angle timing can be suitably calculated according to the change in the accelerator operation amount.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of an engine control device according to the present invention will be described. FIG. 1 shows a schematic configuration of an engine control apparatus according to the present embodiment. Note that a diesel engine is assumed as the engine of the present embodiment.
[0018]
As shown in FIG. 1, a crank sensor 31 is provided in the vicinity of the crankshaft 11 of the engine 10 for outputting a pulsed detection signal PL every time the crankshaft 11 rotates by a predetermined angle. An accelerator sensor 32 that outputs a detection signal PA corresponding to the operation amount is provided in the vicinity of the accelerator pedal 12.
[0019]
Further, the engine control device according to the present embodiment includes an electronic control device 20 composed of, for example, a microcomputer, and the electronic control device 20 includes each output from the sensors 31 and 32. Signals PL and PA are captured. The electronic control unit 20 detects the engine rotation speed and the rotation angle of the crankshaft 11 based on the detection signal PL of the crank sensor 31, that is, the crank angle, and the accelerator pedal based on the detection signal PA of the accelerator sensor 32. A tread amount of 12, that is, an accelerator operation amount is detected.
[0020]
The electronic control unit 20 calculates the fuel injection amount at a predetermined crank angle timing based on the detected engine rotation speed, crank angle, accelerator operation amount, and the like. Note that the processing procedure for calculating the fuel injection amount is assumed to be divided into two processes of pre-processing and post-processing, as in the conventional processing procedure described above.
[0021]
Furthermore, in the engine control apparatus according to the present embodiment, the accelerator operation amount referred to in calculating various control amounts related to engine control is basically detected in time synchronization, and one of these control amounts is detected. In particular, the accelerator operation amount referred to when calculating the fuel injection amount is detected in synchronization with the crank angle.
[0022]
Hereinafter, a processing procedure for detecting the accelerator operation amount will be described.
First, a processing procedure for detecting the accelerator operation amount in time synchronization will be described with reference to FIG. The process shown in FIG. 2 is executed by the electronic control unit 20 as an interrupt process every predetermined time (for example, every 8 ms).
[0023]
As shown in FIG. 2, in this process, first, the accelerator operation amount is detected based on the detection signal PA of the accelerator sensor 32 (step S10). Then, after the corrected accelerator operation amount is calculated by performing correction as necessary in accordance with the calculation of various control amounts, for example, gradually changing the detected accelerator operation amount (step S11), This process is temporarily terminated.
[0024]
Next, a processing procedure for detecting the accelerator operation amount referred to when calculating the fuel injection amount will be described with reference to FIG.
As shown in FIG. 3, in this process, it is first determined whether or not it is the calculation timing of the fuel injection amount (step S20). Specifically, it is determined whether or not the crank angle has reached a predetermined crank angle A1 immediately before fuel injection is started.
[0025]
If it is determined that the calculation timing has come (step S20: YES), the accelerator operation amount is detected based on the accelerator operation amount signal PA (step S21). After the accelerator operation amount is detected in this way, or when it is determined that it is not the timing for calculating the fuel injection amount (step S20: NO), this process is temporarily ended.
[0026]
Through these processes (steps S20 and S21), the accelerator operation amount is detected in synchronization with the crank angle.
Hereinafter, the operation according to the present embodiment will be described.
[0027]
As shown in FIG. 4, in the present embodiment, the accelerator operation amount is detected at a predetermined crank angle A1, and then pre-processing for calculating the fuel injection amount is started. For this reason, the accelerator operation amount can be reliably detected in accordance with the calculation of the fuel injection amount regardless of the engine speed. Therefore, the fuel injection amount can be suitably calculated according to the change in the accelerator operation amount. As described above, the accelerator operation amount for calculating the fuel injection amount is detected only immediately before the calculation of the fuel injection amount is started. You do n’t even need it.
[0028]
As described above, according to the present embodiment, the effects described below can be obtained.
(1) Regarding the fuel injection amount among the control amounts calculated based on the accelerator operation amount, the accelerator operation amount detected in synchronization with the crank angle is referred to when calculating the fuel injection amount. Therefore, by detecting the accelerator operation amount at the crank angle timing suitable for the calculation of the fuel injection amount, the accelerator operation amount is reliably detected in accordance with the calculation of the fuel injection amount regardless of the engine speed. Will be able to. Therefore, when the fuel injection amount is calculated through a plurality of processes executed at different crank angle timings, the fuel injection amount can be suitably calculated according to changes in the accelerator operation amount.
[0029]
(2) After detecting the accelerator operation amount at a predetermined crank angle A1, preprocessing for calculating the fuel injection amount is started. For this reason, when calculating the fuel injection amount, the latest accelerator operation amount can be reflected.
[0030]
(3) For example, when the detected accelerator operation amount is gradually changed and used as the final accelerator operation amount, the gradually changing process is preferably performed based on the accelerator operation amount detected in time synchronization. Be able to run.
[0031]
The embodiment described above may be modified as follows.
In the above embodiment, when calculating the fuel injection amount, this is divided into two processes such as pre-processing and post-processing, but the calculation processing is executed at different crank angle timings. It may be divided into two or more processes.
[0032]
In the above embodiment, the engine control device according to the present invention is applied to a diesel engine, but may be applied to a gasoline engine instead.
[0033]
In the above embodiment, the control amount calculated based on the accelerator operation amount detected by crank angle synchronization is the fuel injection amount. However, the control amount is calculated through a plurality of processes executed at different crank angle timings. If present, this may be the throttle valve opening, ignition timing, or the like. Even with such a configuration, it is possible to achieve an effect according to the above embodiment.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a schematic configuration of an engine control apparatus according to the present invention.
FIG. 2 is a flowchart showing a processing procedure when an accelerator operation amount is detected in time synchronization.
FIG. 3 is a flowchart showing a processing procedure when an accelerator operation amount is detected in synchronization with a crank angle.
FIG. 4 is a timing chart showing the relationship between the accelerator operation amount detection timing and the fuel injection amount calculation timing.
FIG. 5 is a timing chart showing the relationship between the update timing and the update prohibition period for the accelerator operation amount.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... Engine, 11 ... Crankshaft, 12 ... Accelerator pedal, 20 ... Electronic control unit, 31 ... Crank sensor, 32 ... Accelerator sensor

Claims (3)

In an engine control apparatus that calculates a specific control amount among various control amounts of an engine calculated based on an accelerator operation amount through a plurality of processes executed at different crank angle timings,
Control of an engine characterized by comprising: detecting means for detecting the accelerator operation amount in time synchronization and detecting the accelerator operation amount referenced in calculating the specific control amount in synchronization with a crank angle. apparatus. The engine control apparatus according to claim 1, wherein the detection unit detects an accelerator operation amount used for calculation of the specific control amount at a predetermined crank angle timing immediately before execution of a first process among the plurality of processes. The engine control apparatus according to claim 1, wherein the specific control amount is a fuel injection amount.

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