JP2002089346A - Engine control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To precisely detect an analog sensor signal value (sensor value) at the time when a crank angle becomes a specified command angle on an engine control device. SOLUTION: The engine control device A/D converts the sensor value for each of constant time Tint during a sampling period of time from rising timing of a crank angle signal immediately before the crank angle becomes the command signal to rising timing of the crank angle signal immediately after the crank angle passes the command angle to detect the sensor value at the time of crank angle = command angle and measures time T1, T2 of the both timing. Thereafter, time T of crank angle = command angle is computed from the both time T1, T2, an angle B from the crank angle to the command angle at the former timing (time 1), an A/D converted value at a time nearest to the time T is selected from the A/D converted values for the sampling time and it is made a target sensor value.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to an engine control device.

[0002]

2. Description of the Related Art Conventionally, in an engine control device for a vehicle, a pulse edge in a specific direction is detected every time the crankshaft of the engine rotates by a predetermined angle from a crank angle sensor attached to the engine. A crank angle signal that generates a rising edge (generally, a rising edge) is input, and the rotation angle of the crankshaft (hereinafter, referred to as crank angle) is grasped based on the crank angle signal. Further, the value of an analog signal (hereinafter referred to as a sensor value) output from another sensor for detecting the state of the engine is A / D converted into a digital value by an A / D converter, and the engine is controlled. Used for

Here, in this type of engine control device, a sensor that outputs an analog signal is closely related to the crank angle, for example, a pressure sensor (combustion pressure sensor) for detecting the combustion pressure of a cylinder. In the case of a sensor for detecting a physical quantity, the sensor value when the crank angle reaches a specific angle (hereinafter, referred to as a command angle) is represented by A
It is necessary to detect by performing / D conversion.

[0004] In the conventional engine control device, a sensor value when the crank angle reaches the command angle is detected by the following method. First, in this type of engine control device, the crankshaft rotation speed (engine speed) is measured by measuring the time interval at which a pulse edge (in the following description, a rising edge) occurs in the crank angle signal. In the conventional engine control device, the crankshaft rotates by a unit angle (for example, 1 ° CA) from the measured time interval (ie, one cycle time of the crank angle signal). (Hereinafter, referred to as a time corresponding to a unit angle) is calculated.
“CA” is a suffix meaning a crank angle.

[0005] Of the timings at which a rising edge occurs in the crank angle signal, for example, at a timing immediately before the crank angle becomes the command angle, the crank angle is calculated from the time corresponding to the latest unit angle calculated at that time. Is calculated to be a command angle, and a timer interrupt process is started at the calculated time.
Set the internal timer.

Further, by the timer interrupt processing, the A / D converter is started to cause the A / D converter to A / D convert the sensor value, and the digital value obtained by the A / D conversion is converted into the command angle by the crank angle. Is acquired as the sensor value when That is, in the conventional engine control device, a time at which the crank angle is considered to be the command angle is calculated based on the cycle time of the past crank angle signal, and the A / D converter is started at that time. The D-converted digital value is obtained as a sensor value when the crank angle becomes the command angle.

However, in this method, the crank angle when the A / D converter is actually started tends to deviate from the true command angle due to the influence of engine-specific rotation fluctuation. The sensor value at the time of the occurrence cannot be accurately detected. In other words, it is directly affected by the rotation fluctuation generated each time combustion occurs in each cylinder, and a sensor value at a crank angle different from the really desired command angle is obtained.

On the other hand, in this type of engine control device, if the sensor for outputting an analog signal is a sensor for detecting a physical quantity closely related to the crank angle, such as the combustion pressure sensor, the crank angle Is configured to detect a crank angle when a sensor value reaches a specific value (for example, a maximum value or a minimum value) during a monitoring period from when the first angle reaches the second angle. In some cases.

In order to detect the crank angle when the sensor value reaches a specific value during the monitoring period according to the conventional technique, the following method may be adopted. First,
As described above, in this type of engine control device, one cycle time of the crank angle signal is measured. In this case as well, a time equivalent to a unit angle (crank shaft is measured in units of one unit) is calculated from the measured one cycle time. The angle (for example, the time required to rotate by 1 ° CA) is calculated.

In the monitoring period, the timing at which the crank angle becomes the first angle and a rising edge occurs in the crank angle signal (hereinafter referred to as monitoring start timing)
The period is set as a period until the timing when the crank angle becomes the second angle and a rising edge occurs in the crank angle signal (hereinafter, referred to as monitoring end timing).

When the monitoring start timing is reached among the timings at which the rising edge occurs in the crank angle signal, the latest calculation calculated at the monitoring start timing from that time until the monitoring end timing comes. The A / D converter is activated at every time corresponding to the unit angle of (1) to cause the A / D converter to A / D convert the sensor value.

Further, a digital value having a specific value (for example, a maximum value or a minimum value) is selected from the digital values obtained by the respective A / D conversions, and the selected digital value is converted to an A / D value. The crank angle at the time when the sensor value becomes a specific value is obtained from the converted order. For example, assuming that the unit angle is “1 ° CA” and the order is “N”, “(N−
1) × 1 ° CA ”is obtained as the crank angle at which the sensor value has reached a specific value.

However, even in this method, the crank angle at the time when the sensor value reaches a specific value cannot be accurately detected due to the influence of engine-specific rotational fluctuation. In other words, the time corresponding to the unit angle used as the A / D conversion execution cycle in the monitoring period is calculated based on the cycle time of the past crank angle signal. It tends to have a different value (that is, it tends to have an error), and as a result, it is difficult to accurately detect the target crank angle.

An object of the present invention is to make it possible for an engine control device to accurately detect a detection target value without being affected by fluctuations in engine rotation. A first object is to enable accurate detection of a sensor value at the time of occurrence, and a second object is to enable accurate detection of a crank angle when a sensor value reaches a specific value. .

[0015]

Means for Solving the Problems and Effects of the Invention In order to achieve the above object, the engine control device according to the first aspect of the present invention has an analog signal output from a predetermined sensor similarly to the conventional device. A / D conversion means for A / D converting a value (hereinafter referred to as a sensor value) into a digital value, and a crank angle signal in which a pulse edge in a specific direction is generated every time the crankshaft of the engine rotates a predetermined angle. , The rotation angle of the crankshaft (hereinafter, referred to as crank angle) is grasped. In particular, as means for detecting a sensor value when the crank angle reaches a predetermined command angle,
The apparatus includes sampling means, time measuring means, and sensor value calculating means.

The sampling means starts at a timing when the pulse angle in the specific direction occurs in the crank angle signal before the crank angle reaches the command angle (hereinafter referred to as a detection start timing) and after the crank angle passes the command angle. During the sampling period until the timing at which the pulse edge in the specific direction occurs in the crank angle signal (hereinafter, referred to as detection end timing), the A / D conversion means A / D converts the sensor value at regular intervals, and the A Each digital value obtained by the / D conversion is stored in a predetermined storage means.

The time measuring means measures the time of the detection start timing and the time of the detection end timing, respectively. Then, the sensor value calculating means calculates the two times measured by the time measuring means (ie, the start time and end time of the sampling period), the angle from the crank angle at the detection start timing to the command angle, and the predetermined angle (ie, , The crank angle of one cycle of the crank angle signal), the time when the crank angle becomes the command angle within the sampling period (hereinafter referred to as the command angle time) is calculated and stored in the storage means. The sensor value at the calculated command angle time is calculated from the digital value for the sampling period.

The sensor value calculation means selects one of the digital values stored in the storage means which is considered to be A / D converted at the timing closest to the calculated command angle time. Then, the selected digital value can be obtained as a sensor value at the command angle time. Further, for example, the sensor value calculating unit may select, from among the digital values stored in the storage unit,
A / D-converted digital value immediately before the calculated command angle time and A / D conversion immediately after the calculated command angle time
The converted digital value may be selected, and the sensor value at the command angle time may be calculated from the selected two digital values by interpolation processing.

In the engine control device of the first aspect, each cycle of the crank angle signal (ie, each period from the occurrence of a pulse edge in a specific direction to the occurrence of the next pulse edge in the crank angle signal). Since the period including the time when the crank angle becomes the command angle is used as the sampling period, the crank angle at the start and end of the sampling period is accurately grasped regardless of the engine rotation fluctuation. The respective times of the start and end of the sampling period are accurately measured by the clock means.

For this reason, the command angle time calculated by the sensor value calculating means is an accurate value which is hardly affected by the rotation fluctuation of the engine. In other words, each time of the start and end of the sampling period is accurately measured by the timer,
Also, since the crank angle at the detection start timing (at the start of the sampling period) is a value that can be accurately grasped,
The angle from the crank angle to the command angle is also an accurate value, and the predetermined angle, which is the crank angle for one cycle of the crank angle signal, is a known fixed value, and is calculated from such accurate information. The specified angle time is an accurate value that is hardly influenced by the rotation fluctuation of the engine.

The sensor value calculation means calculates the A / D conversion value (digital value obtained by A / D conversion of the sensor value) from the A / D conversion value for each fixed time during the sampling period based on the accurate command angle time. The target sensor value to be executed is also a value closer to the sensor value when the crank angle actually becomes the command angle, without being substantially affected by the rotation fluctuation of the engine.

Therefore, according to the engine control device of the first aspect, the sensor value at the time when the crank angle becomes the command angle is obtained by:
Detection can be performed with much higher accuracy than before. On the other hand, during the monitoring period from when the crank angle becomes the first angle to when the crank angle becomes the second angle, in order to detect the crank angle when the sensor value from the sensor becomes a specific value,
The configuration according to claim 2 is suitable. The specific value may be, for example, a maximum value, a minimum value, a local maximum value, a local minimum value, or a predetermined reference value.

That is, the engine control device according to the second aspect also has A / D conversion means for A / D conversion of a sensor value from a predetermined sensor into a digital value, similarly to the conventional device. The crank angle is determined based on a crank angle signal in which a pulse edge in a specific direction is generated every time the crankshaft of the engine rotates a predetermined angle. From the timing at which the pulse edge occurs (hereinafter referred to as monitoring start timing) to the timing at which the crank angle becomes the second angle and a pulse edge in a specific direction occurs in the crank angle signal (hereinafter referred to as monitoring end timing). Among them, as means for detecting the crank angle when the sensor value reaches a specific value, sampling means, time measuring means, specific value Raw time detecting means, and a crank angle calculating means.

During the monitoring period, the sampling means sends the sensor value to the A / D conversion means at regular time intervals.
D conversion is performed. In addition, the timing unit measures each time of each timing at which the pulse edge in the specific direction occurs in the crank angle signal during the monitoring period, including the monitoring start timing and the monitoring end timing. .

Still further, the specific value occurrence time detecting means may include A
The digital value that has become the specific value is selected from among the digital values that have been A / D converted by the / D conversion means, and a specific value generation that is the time at which the selected digital value was A / D converted is selected. Detect the time.

The crank angle calculating means specifies a cycle including the specific value occurrence time in each cycle of the crank angle signal in the monitoring period, and determines a start time and an end time of the specified cycle. From the measurement result of the clock means, and further, the obtained start time and end time, the specific value generation time, the crank angle at the start time, and the predetermined angle (that is, 1 of the crank angle signal). The crank angle at the specific value occurrence time is calculated as the crank angle when the sensor value reaches a specific value.

That is, in the engine control device according to the second aspect, unlike the conventional device, the target crank angle is not determined by using the cycle time of the past crank angle signal.
From the digital values obtained by A / D conversion of the sensor value at regular time intervals, a digital value which has become a specific value is selected, and a specific value generation which is the A / D conversion time of the selected digital value is selected. In the monitoring period, the period of the crank angle signal including the specific value occurrence time is specified, and the start time and end time of the specified period, the specific value occurrence time, and the time at the start time are determined. The crank angle when the sensor value reaches a specific value is calculated from the crank angle and the predetermined angle which is the crank angle for one cycle of the crank angle signal.

Therefore, according to the engine control device of the second aspect, the crank angle at the time when the sensor value reaches a specific value is significantly higher than the conventional one without being largely affected by the rotation fluctuation of the engine. It can be detected with high accuracy. If the monitoring period is not a plurality of periods of the crank angle signal but only one period, the crank angle calculating means sets the monitoring period itself as a period of the crank angle signal including the specific value occurrence time. Thus, the monitoring start timing and the monitoring end timing are obtained as the start time and the end time of the cycle of the crank angle signal including the specific value occurrence time.

On the other hand, in the engine control apparatus according to the first and second aspects, the shorter the set time (hereinafter, also referred to as a sampling cycle) as a cycle for A / D conversion of the sensor value, the smaller the detection accuracy. However, if the sampling period is set to an extremely short time, the processing load for the A / D conversion and the required capacity of the storage means for storing the A / D conversion value are greatly increased. Therefore, the sampling period depends on the processing load and hardware constraints,
What is necessary is just to set suitably according to the balance with detection accuracy. For this reason, it is preferable that the sampling period be set to a value such that the A / D conversion is performed at every crank angle (for example, 1 ° CA) having a somewhat small value even when the engine is operated at the maximum allowable rotation speed. .

[0030]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a vehicle engine control device according to an embodiment to which the present invention is applied will be described with reference to the drawings. First, FIG. 1 is a block diagram showing a configuration of an engine control device (hereinafter referred to as an ECU) 1 of the present embodiment together with an engine 3 to be controlled.

As shown in FIG. 1, the ECU 1 includes a crank angle sensor 5 attached to the engine 3, a combustion pressure sensor 9 provided one for each cylinder 7 of the engine 3,
An injector 11 for injecting and supplying fuel to each of the cylinders 7 is connected. The crank angle sensor 5 is
A pulsar that rotates with the crankshaft of the engine 3,
And a detection unit that outputs a pulse signal as a crank angle signal every time when passage of a large number of teeth provided at predetermined angular intervals on the outer periphery of the pulsar is detected. The crank angle signal output from the crank angle sensor 5 (specifically, the detection unit) is a rising edge (that is, from a low level) every time the crankshaft rotates a predetermined angle (10 ° in this embodiment). (A pulse edge toward a high level). Further, in the following description, such a rising edge of the crank angle signal is particularly referred to as a “NE pulse”. On the other hand, the combustion pressure sensor 9 is a sensor that outputs an analog signal (hereinafter, also referred to as a combustion pressure signal) representing the combustion pressure of each cylinder 7.

The ECU 1 has a CPU 13, a ROM
15, a RAM 17, an A / D converter 19, and a well-known microcomputer (hereinafter referred to as a microcomputer) 23 including an internal bus 21 for connecting them, a crank angle signal from the crank angle sensor 5 and a combustion pressure sensor 9. Circuit 2 for inputting the combustion pressure signal to the microcomputer 23
5, and an output circuit 27 for operating various actuators such as the injector 11 in accordance with a control signal from the microcomputer 23.

Here, the crank angle signal from the crank angle sensor 5 is shaped by the input circuit 25 and input to the CPU 13 of the microcomputer 23. The combustion pressure signal from each combustion pressure sensor 9 is supplied to the input circuit 2
5, the value of the combustion pressure signal (sensor value) is converted into a digital value by the A / D converter 19.
/ D conversion.

The CPU 13 performs various processes for controlling the engine according to a program stored in the ROM 15. For example, based on the crank angle signal, the CPU 13 obtains the current crank angle (the rotation angle of the crankshaft) and the engine speed by a known method. Specifically, the current crank angle is detected by counting the number of times the NE pulse has been generated since the crank angle became the reference position, and the time interval of the NE pulse is measured.
Detect the current engine speed. The CPU 13
Controls the A / D converter 19 as A / D conversion means to detect the sensor value of the combustion pressure sensor 9. Further, the CPU 13 controls the operating state of the engine 3 by outputting a control signal to the output circuit 27 based on the detection results and appropriately operating the injector 11 and the like.

Next, two types of processing (processing 1 and processing 2) performed by the ECU 1 on the sensor value of the combustion pressure sensor 9 will be described. Note that these processes are performed on the combustion pressure sensor 9 of each cylinder 7, but since the processing contents are common, one cylinder (here, the first cylinder # 1 of the plurality of cylinders 7) is used. Only the combustion pressure sensor 9 will be described. The processing described below is executed by the CPU 13 of the microcomputer 23. [Processing 1: Processing for Detecting Sensor Value when Crank Angle at Command Angle] First, referring to FIGS. 2 to 5, detecting a sensor value when the crank angle at a predetermined command angle is detected. Process 1 for the following will be described.

In the present embodiment, the crank angle of the first cylinder # 1 is set at the top dead center of the compression stroke (hereinafter referred to as TDC).
The rising edge (N) of the crank angle signal at each timing of 10 ° CA including the timing of
E pulse). The desired command angle for which a sensor value is to be detected is 1 TDC from the first cylinder # 1.
It is assumed that the crank angle is advanced by 5 ° CA (ATDC 15 ° CA).

FIG. 2 is a flowchart showing the NE interrupt processing executed by the CPU 13 for the processing 1. The NE interrupt processing is executed every time a rising edge occurs in the crank angle signal (every time an NE pulse is generated). Is done. As shown in FIG. 2, when the CPU 13 starts executing the NE interrupt processing, first, a step (hereinafter simply referred to as “S”) is executed.
At 110, the current NE pulse generation timing is the generation timing of the NE pulse immediately before the crank angle becomes the command angle, and the AD activation as the detection start timing at which sampling of the combustion pressure signal should be started It is determined whether it is timing. In this example, the AD start timing is the timing of the crank angle (ATDC 10 ° CA) advanced by 10 ° CA from the TDC of the first cylinder # 1 (see FIG. 5).

If it is determined in S110 that it is the AD start timing, the process proceeds to S120 and A / A
Activate the D converter 19 to cause the A / D converter 19 to A / D convert the sensor value, which is the value of the combustion pressure signal. At the next step S130, after a certain time Tint from the time, a compare interrupt request is issued in the microcomputer 23. The time at which the compare interrupt request is generated is set so as to generate a so-called timer interrupt request, and in the next S140, the activation of the compare interrupt process of FIG. 3 corresponding to the compare interrupt request is permitted. Further, in subsequent S150, this is the activation time of the current NE interrupt processing, which is the time of the current AD activation timing (time T1 in FIG. 5).
Is stored in the RAM 17 and the NE interruption process ends.

The CPU 13 treats the value of the free running counter, which is constantly counted up in the microcomputer 23, as time. Therefore, at time T1 in FIG.
Assuming that the NE pulse corresponding to the AD activation timing has been generated at S150, the CPU 13 determines in step S150 that the time T1
Is stored in the RAM 17 as the time T1.

On the other hand, the CPU 13 determines in step S110 that A
If it is determined that it is not the D start timing, S160
, The current NE pulse generation timing is the NE pulse generation timing immediately after the crank angle has passed the command angle, and the AD end timing as the detection end timing at which sampling of the combustion pressure signal should be ended. Is determined. In this example, A
D end timing is 20 ° from TDC of the first cylinder # 1.
This is the timing of the crank angle advanced by CA (ATDC 20 ° CA) (see FIG. 5).

If it is determined in S160 that it is the AD end timing, the process proceeds to S170. As in the case of S150 described above, the start time of the current NE interrupt process is determined. The timing time (time T2 in FIG. 5) is stored in the RAM 17.
Further, in subsequent S180, an AD end request for a compare interrupt process of FIG.
The E interrupt processing ends. Note that the AD end request is actually a flag referred to in the compare interrupt processing of FIG. 3, and in S180, the flag for the AD end request is set.

The CPU 13 determines in step S160 that A
If it is determined that it is not the D end timing, S190
To determine whether or not there is an AD processing end notification. still,
This AD processing end notification is a flag set in S360 of the compare interrupt processing of FIG.
In step 90, the process refers to the AD processing end notification flag, and determines that there is an AD processing end notification when the flag is set.

Then, if there is an AD processing end notification, the process proceeds to S200, and the AD processing end notification and the S
The flags for the AD end request set in 180 are cleared. Further, in the following S210, a sensor value calculation processing request for the sensor value calculation processing of FIG. 4 described later is set, and the NE interruption processing ends. Note that the sensor value calculation process request is actually a flag that is referred to in the sensor value calculation process of FIG. 4, and in S210, a flag for the sensor value calculation process request is set.

On the other hand, if the CPU 13 determines in step S190 that there is no AD processing completion notification (the flag for AD processing completion notification is not set), the CPU 13 terminates the NE interruption processing as it is. Next, NE of FIG.
When a predetermined time Tint elapses from the setting of the compare interrupt request generation time in S130 in the interrupt process, a compare interrupt request is generated in the microcomputer 23, and the CPU 13 starts executing the compare interrupt process of FIG. Become.

Then, as shown in FIG. 3, when the CPU 13 starts executing the compare interrupt processing, first, at S31
At 0, a digital value (A / D converted value of the combustion pressure signal, hereinafter also referred to as an AD value) which has been A / D converted at that time is read from the A / D converter 19, and the AD value is read.
The value is stored in a predetermined area of the RAM 17.

In step S310, if the compare interrupt processing is started due to the setting of the compare interrupt request generation time in step S130 of FIG.
AD value from the / D converter 19 (in this case, FIG.
Of the A / D converter 19 started in S120 of FIG.
Value) as the 0th AD value (AD [0])
7 is stored. Then, at S180 in FIG.
Until the D end request is set (that is, until the AD end timing arrives), the AD value from the A / D converter 19 is changed to the first AD value (AD [1 ]), The second AD value (AD
[2]), the third AD value (AD [3]), etc., are stored in the RAM 17 in association with the numbers incremented by one.

Then, in S320, the CPU 13 determines whether or not the above-described AD end request has been set, and if the AD end request has not been set (S32).
0: no), the process proceeds to S330, and the A / D converter 19
To cause the A / D converter 19 to A / D convert the sensor value (the value of the combustion pressure signal). And further, the following S3
At 40, the compare interrupt request generation time is set so that the compare interrupt request is generated again after a predetermined time Tint from the activation time of the current compare interrupt processing,
This compare interrupt processing ends. Therefore, S32
If it is determined at 0 that the AD end request has not been set, the A / D converter 19 is started again, and the compare interrupt process is started again after a predetermined time Tint.

In this embodiment, the predetermined time T
int repeats the sensor value to the A / D converter 19
/ D conversion cycle (sampling cycle). The constant time Tint is set to a value such that the A / D conversion is performed at every small crank angle such as 1 ° CA even when the engine 3 is operated at the maximum allowable rotation speed. . For example, in the present embodiment, the maximum allowable rotation speed of the engine 3 is 5000 rpm, and the fixed time Tint is set to 30 μs. Therefore, if the engine 3 is higher than the maximum allowable rotation speed,
Even if the motor is operated at pm, A / D conversion of the sensor value is performed every time corresponding to about 1 ° CA. Further, this is the same for processing 2 described later.

On the other hand, if it is determined in S320 that the AD end request has been set (S320: Yes),
Proceeding to S350, the activation of this compare interrupt processing is prohibited, and in S360, an AD processing end notification is made for the NE interrupt processing of FIG. In other words, the flag for AD processing end notification is set, and the A / A of the sensor value in the sampling period from the AD start timing as the detection start timing to the AD end timing as the detection end timing is set for the NE interrupt processing in FIG.
Notifies that all D conversion has been completed. Then, the compare interrupt process ends.

With the above-described NE interrupt processing in FIG. 2 and the compare interrupt processing in FIG.
As shown in FIG. 5, when the AD start timing as the detection start timing arrives at time T1 (when the NE pulse corresponding to the AD start timing occurs), from that time, the AD end timing as the detection end timing at time T2 The A / D converter 19 is activated every fixed time Tint during the sampling period until the arrival of the signal (until the NE pulse corresponding to the AD end timing is generated), and the AD value for each fixed time Tint is stored in the RAM 17. They are stored sequentially. In FIG. 5, the start timing of the A / D converter 19 is indicated by a triangle.

That is, when the AD start timing as the detection start timing arrives at time T1 in FIG. 5, at that time, the A / D converter 19 is first started by S120 in FIG. The converted AD value is
In S310 of the first compare interrupt processing (FIG. 3) executed after a predetermined time Tint from S130 in FIG.
17 is stored. Further, at S330 of the current compare interrupt process, the A / D converter 19 is started again, and the AD value converted at this time is executed after a predetermined time Tint from the current compare interrupt process. In S310 of the next compare interrupt processing (FIG. 3),
This will be stored in the RAM 17. And thereafter, FIG.
At time T2, the AD end timing as the detection end timing arrives, and until the AD end request is set in S180 of FIG. 2 (that is, it is determined that the AD end request is set in S320 of FIG. 3). Up to this point), the compare interrupt process is executed at regular intervals of Tint, and the start of the A / D converter 19 and the storage of the AD value in the RAM 17 are repeatedly performed by S330 and S310 of the compare interrupt process.

The time T1 of the AD start timing as the detection start timing and the time T2 of the AD end timing as the detection end timing correspond to S150 in FIG.
And S170 are stored in the RAM 17.
Then, in the present ECU 1, the AD end timing as the detection end timing comes, and S180 in FIG.
, An AD end request is set, and a flag for AD processing end notification is set in step S360 in FIG. 3. When the next NE pulse is generated (that is, the crank angle is set next to time T2 in FIG. 5). N when the signal rises)
In the E interrupt processing, a negative determination is made in both S110 and S160, and in S190, it is determined that there is an AD processing end notification. Further, in S210 of the NE interruption process, a sensor value calculation process request is set.

Then, in response to the request for the sensor value calculation process, the sensor value calculation process of FIG. 4 is substantially executed, and the target sensor value (ie, the sensor value when the crank angle reaches the command angle) is obtained. It will be calculated. That is, the sensor value calculation process of FIG.
When U13 starts execution of the sensor value calculation process, first, in S410, it is determined whether a sensor value calculation process request (specifically, a sensor value calculation request flag) is set.

If it is determined in S410 that the request for sensor value calculation processing has not been set, the present sensor value calculation processing is terminated without doing anything, but the request for sensor value calculation processing is set in S410. If it is determined that there is, the process proceeds to S420. In S420, the flag of the sensor value calculation processing request is cleared, and in S430, the process proceeds to S420.
AD stored in the RAM 17 in S150 and S170
The time T1 of the start timing and the time T2 of the AD end timing are read, and the interval time Tk between the NE pulses including the command angle (that is, the interval time of the sampling period) Tk is obtained by the following equation 1.

Tk = T2−T1 (Equation 1) Further, in the following S440, the interval time Tk obtained in S430 and the crank angle at the AD start timing as the detection start timing (that is, at the time T1 in FIG. 5). In this embodiment, the crank angle is ATDC10 ° C.
A) to the command angle (ATDC 15 ° C in this embodiment)
A) up to A) (see FIG. 5) and 1 of the crank angle signal.
From the predetermined angle α (10 ° CA in the present embodiment) which is the crank angle for the cycle, the command angle time (that is, the time when the crank angle becomes the command angle) T target is calculated by the following equation 2.
Is calculated.

Ttarget = (Tk ÷ α) × β (Equation 2) The value of the command angle time Ttarget calculated here is a value based on the AD start timing (time T1 in FIG. 5) as the detection start timing. It is. And the following S45
At 0, first, the cycle index i is initialized to 0.

Next, in S460, the product of the cycle index i and the fixed time Tint, which is the sampling cycle, is “i × Tint
Is smaller than the command angle time Ttarget calculated in S440, and if an affirmative determination is made, the process proceeds to S47.
After the period index i is incremented by 1 at 0, the process returns to S4
A determination of 60 is made.

If it is determined in S460 that the product "i.times.Tint" is not smaller than the command angle time Ttarget, the flow shifts to S480, where R is determined in the processing of FIGS.
Among the AD values for the current sampling period stored in the AM 17, the i-th AD value (AD value [i]) specified by the cycle index i at that time is set to the command angle time Ttarget
(That is, the sensor value when the crank angle becomes the command angle) ANS, and then the present sensor value calculation process ends.

That is, by the processing of S450 to S480, each A stored in the RAM 17
From the D values, the command angle time Ttarg calculated in S440
The A / D-converted AD value (in FIG. 5, the A / D-converted A / D-converted AD value in FIG. 5 at the timing indicated by the symbol “ANS”) immediately after the timing exceeds the command angle time Ttarget The selected AD value is treated as the target sensor value ANS when the crank angle becomes the command angle.

In the ECU 1 of the present embodiment as described above,
In each cycle of the crank angle signal, the cycle including the time when the crank angle becomes the command angle is set as the sampling period. Therefore, the crank angle at the start and the end of the sampling period depends on the rotation fluctuation of the engine 3. Regardless, it is accurately grasped, and the times T1 and T2 at the start and end of the sampling period are accurately measured by S150 and S170 of the NE interrupt process in FIG.

For this reason, the command angle time Ttarget calculated in the sensor value calculation processing of FIG. 4 is an accurate value which is hardly affected by the rotation fluctuation of the engine 3. That is, the times T1 and T2 at the start and end of the sampling period are accurately measured, and the crank angle at the detection start timing (at the start of the sampling period) T1 is a value that can be accurately grasped. Angle β from crank angle to command angle
Is also an accurate value, and the predetermined angle α, which is the crank angle for one cycle of the crank angle signal, is a known fixed value. Ttarget is an accurate value that is hardly affected by the rotation fluctuation of the engine 3.

Then, by the sensor value calculation processing of FIG.
Based on such an accurate command angle time Ttarget, the target sensor value ANS selected from the AD value for each fixed time Tint during the sampling period is almost unaffected by the rotation fluctuation of the engine 3 and the crank angle Is closer to the sensor value when the angle actually reaches the command angle.

Therefore, according to the ECU 1 of the present embodiment,
The sensor value when the crank angle becomes the command angle can be detected with much higher accuracy than in the past. In the present embodiment, S110 in the NE interrupt processing of FIG.
To S140, S160, and S180 to S210 and FIG.
2 corresponds to the sampling means of claim 1 and corresponds to S15 in the NE interrupt processing of FIG.
0 and S170 correspond to the timing means of claim 1. The sensor value calculation processing in FIG. 4 corresponds to a sensor value calculation unit.

On the other hand, in S450 to S480 in FIG. 4, for example, the command angle time T calculated in S440 from the AD values for the sampling period stored in the RAM 17 is used.
The A / D-converted AD value at the timing immediately before the target and the A / D conversion at the timing immediately after the command angle time Ttarget
/ D converted AD value is selected, and the command angle time Ttarg is determined from the selected two AD values by interpolation processing.
The sensor value of et may be calculated. By doing so, the detection accuracy can be further improved. [Processing 2: Processing for Detecting Crank Angle When Sensor Value Has Maximum Value] Next, referring to FIGS. 6 to 9, in order to detect the crank angle when the sensor value has maximum value. The process 2 of will be described.

In the following description, among the timings at which the NE pulse is generated, the ATD of the first cylinder # 1
ATDC of the first cylinder # 1 from the timing of C10 ° CA
The period of 20 ° CA up to the timing of 30 ° CA is
It is assumed that the monitoring period is set to detect the crank angle when the sensor value reaches the maximum value. That is, here, ATDC10 ° CA is the first angle corresponding to the monitoring start timing (ie, the start timing of the monitoring period), and ATDC 30 ° CA corresponds to the monitoring end timing (ie, the end timing of the monitoring period). Let it be the second angle.

FIG. 6 is a flowchart showing an NE interrupt process executed by the CPU 13 for the process 2. This NE interrupt process is executed every time an NE pulse which is a rising edge of the crank angle signal is generated. . As shown in FIG. 6, when the CPU 13 starts execution of the NE interrupt processing, first, in S510, the generation timing of the current NE pulse is set to the AD start timing as the monitoring start timing (start timing of the monitoring period) (this example). Then, it is determined whether or not it is the timing of ATDC10 ° CA of the first cylinder # 1).

If it is determined in S510 that it is the AD start timing, the process proceeds to S520, where A / A
The D / A converter 19 is activated to cause the A / D converter 19 to A / D convert the sensor value, which is the value of the combustion pressure signal.
In this case, a compare interrupt request generation time is set so that a compare interrupt request is generated in the microcomputer 23 after 30 μs). Then, in S540, the compare interrupt processing of FIG. 7 corresponding to the compare interrupt request is started. Allow Then, in S550, the start time of the current NE interrupt processing, that is, the time of the current AD start timing, is stored in the RAM 17, and the NE interrupt processing ends.

On the other hand, the CPU 13 determines in step S510 that A
If it is determined that it is not the D start timing, S560
, And the generation timing of the current NE pulse is determined to be the AD end timing (the A cylinder of the first cylinder # 1 in this example) as the monitoring end timing (end timing of the monitoring period).
TDC 30 ° CA).

If it is determined in S560 that it is the AD end timing, the process proceeds to S570, and the start time of the current NE interrupt process and the time of the current AD end timing are stored in the RAM 17. Then, in S580, an AD end request for a compare interrupt process of FIG. 7 described later is set, and the NE interrupt process ends. Note that the AD end request is actually a flag referred to in the compare interrupt processing of FIG.
In S580, the flag for the AD end request is set.

The CPU 13 determines in step S560 that A
If it is determined that it is not the D end timing, S590
Then, it is determined whether or not the AD processing is being performed (that is, during the monitoring period). In S590, when the NE pulse generated this time is the NE pulse generated between the AD start timing and the AD end timing, it is determined that the AD processing is being performed.

If it is determined in step S590 that the AD processing is being performed, the process proceeds to step S600, where the current NE is executed.
The start time of the interrupt processing, that is, the time of occurrence of the current NE pulse, is stored in the RAM 17, and the NE interrupt processing ends. On the other hand, the CPU 13 determines that AD
If it is determined that the processing is not being performed, the process proceeds to S610, and it is determined whether there is an AD processing end notification. In addition, this A
The D processing end notification is a flag that is set in S760 of the compare interrupt processing of FIG. 7 described later. In S610, by referring to the AD processing end notification flag, if the flag is set, It is determined that there is an AD processing end notification.

If there is an AD processing end notification, the process proceeds to S620, where the AD processing end notification and the above S
The flags for the AD end request set in 580 are cleared. Then, in S630, a request for calculating a maximum value generation angle for the calculation of a maximum value generation angle in FIG. 8 described later is set, and the NE interruption process ends.
Note that the maximum value generation angle calculation processing request is actually a flag referred to in the maximum value generation angle calculation processing in FIG.
At 630, a flag for requesting the maximum value generation angle calculation processing is set.

The CPU 13 determines in step S610 that A
If it is determined that there is no D processing end notification (the AD processing end notification flag is not set), the NE interruption processing is terminated as it is. Note that, also in the present processing 2, the CPU 13 treats the value of the free running counter constantly counted up in the microcomputer 23 as time.

In particular, in S550, the activation time of the current NE interrupt process (the time of the AD activation timing)
Is stored in the RAM 17 as the first time T [1]. Therefore, if an NE pulse of ATDC10 ° CA corresponding to the AD start timing is generated at time Ta in FIG. 9, the CPU 13 sets the value of the free running counter at time Ta to the first time at S550. T
This is stored in the RAM 17 as [1].

In S600, if it is the next execution that is determined to be the AD start timing in S510,
The generation time of the current NE pulse is stored in the RAM 17 as the second time T [2]. And after that, S56
0, the time when the NE pulse is generated is set to the third time T [3] and the fourth time T
[4],..., Etc., are stored in the RAM 17 in association with the numbers incremented by one.

Further, at S570, the activation time of this NE interruption processing (the time of the AD end timing)
Is stored in the RAM 17 as the time following the number of the time last stored in S600. However, in this example, as shown in FIG.
It is the timing of ATDC10 ° CA for cylinder # 1,
D end timing is ATDC 30 ° CA of the first cylinder # 1
Therefore, the process of S600 is executed only at the timing of ATDC20 ° CA of the first cylinder # 1.

Therefore, in this example, at time Tb in FIG.
If an NE pulse of TDC 20 ° CA is generated, C
In S600, the PU 13 sets the value of the free running counter at the time Tb as the second time T [2] and sets the RA
M17, and thereafter, at time Tc in FIG.
Assuming that the NE pulse of ATDC 30 ° CA corresponding to the AD end timing is generated at
At 570, the value of the free running counter at time Tc is stored in the RAM 17 as the third time T [3].

Next, S in the NE interrupt processing of FIG.
When a predetermined time Tint (= 30 μs) elapses after the compare interrupt request generation time is set in 530, a compare interrupt request is generated in the microcomputer 23, and the CPU
Step 13 starts the execution of the compare interrupt processing of FIG.

Then, as shown in FIG. 7, when the CPU 13 starts execution of the compare interrupt processing, first, in S71,
At 0, the digital value (AD value) that has been A / D converted at that time is read from the A / D converter 19, and the AD value is stored in a predetermined area of the RAM 17.

Next, the CPU 13 proceeds to step S715.
By the processing of S710, the A / D converter 19
And the maximum value of the AD values obtained from
/ D converted time (corresponding to the specific value occurrence time; hereinafter,
The maximum value and the maximum value occurrence time T are stored in the RAM 17. Note that the maximum value and the maximum value occurrence time T are determined by S
The processing of 715 is performed starting from the case where the compare interrupt processing is executed in accordance with the setting of the compare interrupt request occurrence time in S530 of FIG.

Then, in subsequent S720, CPU 13 determines whether or not the above-described AD end request has been set, and if the AD end request has not been set (S72).
0: none), the process proceeds to S730, and the A / D converter 19
To cause the A / D converter 19 to A / D convert the sensor value (the value of the combustion pressure signal). And further, the following S7
At 40, the compare interrupt request generation time is set so that the compare interrupt request is generated again after a fixed time Tint (= 30 μs) from the start time of the current compare interrupt processing, and the compare interrupt processing is terminated. Therefore, if it is determined in S720 that the AD end request has not been set, the A / D converter 19 is started again, and the compare interrupt process is started again after the predetermined time Tint. .

On the other hand, if it is determined in S720 that the AD end request has been set (S720: Yes),
Proceeding to S750, the activation of this compare interrupt processing is prohibited, and in S760, AD processing end notification is performed for the NE interrupt processing of FIG. That is, a flag for AD processing end notification is set, and the A / A of the sensor value in the monitoring period from the AD start timing as the monitoring start timing to the AD end timing as the monitoring end timing is set for the NE interrupt processing in FIG. Notifies that all D conversion has been completed. Then, the compare interrupt process ends.

By the above-described NE interrupt processing of FIG. 6 and the compare interrupt processing of FIG. 7, in the processing 2 of the ECU 1, as shown in FIG. When it arrives (when an NE pulse corresponding to the AD start timing is generated), from that time until the AD end timing as the monitoring end timing arrives at time Tc (until the NE pulse corresponding to the AD end timing is generated). During the monitoring period, the A / D converter 19 is activated at every fixed time Tint, and the CPU 13 sets the AD at every fixed time Tint.
The values are obtained sequentially. Note that, in FIG. 9, as in FIG. 5, the start timing of the A / D converter 19 is indicated by a triangle.

That is, when the AD start timing as the monitoring start timing arrives at time Ta in FIG. 9, at that time, the A / D converter 19 is first started by S520 in FIG. The converted AD value is
In S710 of the first compare interrupt processing (FIG. 7) executed after a fixed time Tint from S530 in FIG.
The data is read from the converter 19 to the CPU 13. Further, at S730 of the compare interrupt processing of the time,
The A / D converter 19 is activated again, at which time the A / D
The converted AD value is read from the A / D converter 19 to the CPU 13 in S710 of the next compare interrupt process (FIG. 7) executed after a predetermined time Tint from the current compare interrupt process. Thereafter, at time Tc in FIG.
The D end timing has arrived, and until the AD end request is set in S580 of FIG. 6 (that is, A is set in S720 of FIG. 7).
Until it is determined that the D end request has been set), the compare interrupt processing is executed at fixed time intervals Tint, and the start of the A / D converter 19 and the A / D converter are performed by S730 and S710 of the compare interrupt processing. 1
The reading of the AD value from No. 9 is repeatedly performed.

Then, the CPU 13 proceeds to S71 of FIG.
By the process of step 5, an AD value having a maximum value as a specific value (hereinafter, also simply referred to as a “maximum value”) is selected from among a large number of AD values for the monitoring period, and A of the maximum value is selected. The maximum value occurrence time T, which is the / D conversion time, is detected.

More specifically, the selection of the maximum value in S715 includes comparing the AD value acquired this time in S710 with the maximum value so far, and storing the larger one as the latest maximum value. Done in steps. Further, the detection of the maximum value occurrence time T in S715 is performed by a fixed time Tint from the start time of the compare interrupt processing in the case where the AD value set as the maximum value in the above selection is acquired from the A / D converter 19.
The previous time is set as the maximum value occurrence time T.

Note that a large number of AD values acquired during the monitoring period in S710 are all stored in the RAM 17, and after the monitoring period ends, the maximum value is selected from among those AD values. The maximum value generation time T may be obtained from the number of sampling cycles from the AD start timing at which the A / D conversion is performed and the time of the AD start timing.

In the processing 2 of the ECU 1, the timings of the generation of the NE pulse during the monitoring period, ie, the AD start timing as the monitoring start timing, and the monitoring start timing are determined by S550, S570 and S600 in FIG. The time of each timing including the AD end timing as the end timing is measured, and each time is numbered in the order of T [1], T [2],. Is stored in

Then, in the process 2 of the ECU 1,
When the AD end timing as the monitoring end timing arrives, the AD end request is set in S580 of FIG. 6, and accordingly, the flag for AD processing end notification is set in S760 of FIG. (Ie, when the crank angle signal rises after time Tc in FIG. 9) in the NE interrupt processing,
0, S560, and S590 are all negative, and S
At 610, it is determined that there is an AD processing end notification. Further, the S63 of the NE interruption processing of that time
At 0, the maximum value generation angle calculation processing request is set.

Then, in response to the request for calculating the maximum value generation angle, the maximum value generation angle calculation processing shown in FIG. 8 is substantially executed, and the target crank angle (that is, when the sensor value reaches the maximum value) is obtained. Crank angle) is calculated. That is, the maximum value generation angle calculation process in FIG. 8 is a process that is periodically executed. When the CPU 13 starts executing this process, first, in the first step S810, a maximum value generation angle calculation process request (for details, It is determined whether or not the flag for requesting the maximum value generation angle calculation process is set.

If it is determined in step S810 that the request for calculating the maximum value generation angle has not been set, the process ends without performing any processing, but the request for calculating the maximum value generation angle is set in step S810. If it is determined that there is, the process proceeds to S820. In S820, the flag of the maximum value generation angle calculation processing request is cleared, and in S830, the time index m is first initialized to 0.

Next, at S840, S550 and S550 in FIG.
570 and the time T [m + 1] of the number (m + 1) obtained by adding 1 to the time index m at that time among the times stored in the RAM 17 by S600 in S715 of FIG.
(Ie, the maximum value generation time T is equal to the time T [m] and the time T [m +
1], and if a negative determination is made, the time index m is incremented by one in S850, and the determination in S840 is performed again.

If it is determined in S840 that the time T [m + 1] is greater than the maximum value occurrence time T,
The process proceeds to S860. That is, by the processing of S830 to S850, the interval between the NE pulses including the maximum value occurrence time T is specified among the NE pulses during the monitoring period (that is, each cycle of the crank angle signal). S84
When the determination is affirmative at 0, S550 and S57 in FIG.
0, and the time T of the number of the time index m at that time among the times of each number stored in the RAM 17 by S600.
An interval between NE pulses from [m] to a time T [m + 1] of a number obtained by adding 1 to the time index m at that time is specified as an interval between NE pulses including the maximum value occurrence time T.

At S860, the RAM 17 reads the time T which is the start time between NE pulses including the maximum value occurrence time T.
[M] and the end time T [m + 1] between the NE pulses are read out, and the following equation 3 is used to calculate the interval time between the NE pulses including the maximum value occurrence time T and the start time between the NE pulses. From the time to the maximum value occurrence time T is calculated.

R = (T−T [m]) ÷ (T [m + 1] −T [m]) Expression 3 Then, in S870, the ratio R obtained in S860 and the time T [m] Crank angle CAm and 1NE
From the predetermined angle α (10 ° CA in the present embodiment) which is the crank angle between pulses (one cycle of the crank angle signal), the crank angle γ at the maximum value occurrence time T is calculated by the following equation 4. Then, the crank angle γ is stored in the RAM 17 as the crank angle when the sensor value reaches the maximum value.
After that, the maximum value generation angle calculation processing ends.

Γ = α × R + CAm (Equation 4) In other words, in the processing of S860 and S870, the start time and end time (T [m], T [m + 1]) between NE pulses including the maximum value occurrence time T, The maximum value occurrence time T obtained in S715 of FIG. 7 and the crank angle C at the start time described above.
From the Am and the crank angle α for one NE pulse, the crank angle γ at the maximum value generation time T is calculated as the crank angle when the sensor value reaches the maximum value.

By such a maximum value generation angle calculation process, as shown in FIG. 9, the maximum value generation time T obtained in S715 of FIG. 7 is the first NE pulse from the AD start timing as the monitoring start timing. If it is included in the time interval, the time T [1] to the time T [1] stored in the RAM 17
T [1] and T [2] of [3], the maximum value generation time T, and the crank angle (ATDC1
0 ° CA) and the crank angle α for one NE pulse, the crank angle γ at the maximum value generation time T is determined. The crank angle γ is used as the crank angle when the sensor value reaches the maximum value. It is stored in the RAM 17 and used for controlling the engine 3.

As described above, in the ECU 1 of the present embodiment,
Instead of using the cycle time of the past crank angle signal to determine the target crank angle as in the conventional device, the maximum value is selected from the AD values obtained by A / D conversion of the sensor value at fixed time intervals Tint. Is selected, and the selected AD
The maximum value occurrence time T, which is the A / D conversion time of the value, is determined, and between the NE pulses including the maximum value occurrence time T is specified in the monitoring period, and the start time and the end time between the specified NE pulses are determined. The crank angle when the sensor value reaches the maximum value is calculated from the time, the maximum value generation time T, the crank angle at the start time, and the crank angle α for one cycle of the crank angle signal. ing.

Therefore, the crank angle at the time when the sensor value reaches the maximum value can be detected with a remarkably higher accuracy than the conventional one without being substantially affected by the fluctuation of the rotation of the engine 3. In the present embodiment, S510 to S540, S560, S580, and S59 in the NE interrupt processing of FIG.
0 and S610 to S630 and S710 and S720 to S760 in the compare interrupt processing of FIG.
S550, S570, and S600 in the NE interrupt processing of FIG.
Corresponds to the timing means of claim 2. And FIG.
S715 in the compare interrupt process corresponds to the specific value occurrence time detection means, and the maximum value occurrence angle calculation processing in FIG. 8 corresponds to the crank angle calculation means.

On the other hand, in the example of the process 2, the crank angle at the time when the sensor value reaches the maximum value is obtained. For example, when the sensor value becomes the minimum value, the crank angle becomes the predetermined reference value. The crank angle at the time when the value reaches another specific value, such as when the value exceeds (exceeds or falls below), when the value reaches a local maximum value, or when the value reaches a local minimum value, can be obtained in a similar procedure.

As described above, one embodiment of the present invention has been described, but it goes without saying that the present invention can take various forms. For example, in the above embodiment, the combustion pressure sensor 9 is provided for each cylinder 7 of the engine 3, but may be configured to measure only the combustion pressure of one cylinder (for example, the first cylinder # 1).

In the above embodiment, the combustion pressure sensor 9
However, the analog signal to be detected may be a signal from another sensor. On the other hand, in the above embodiment, the fixed time Tint, which is the A / D conversion cycle (sampling cycle), is always a fixed value (30 μm).
However, for example, the constant time Tint is set to a large value when the engine speed is low and to a small value when the engine speed is high, according to the engine speed. You may do it. In this way, especially in the above process 1, when the engine speed is low, A
The memory area for storing the D value can be reduced.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of an engine control device (ECU) of an embodiment together with an engine to be controlled.

FIG. 2 is a flowchart illustrating an NE interrupt process executed by a CPU for a process 1;

FIG. 3 is a flowchart illustrating a compare interrupt process executed by a CPU for process 1;

FIG. 4 is a flowchart illustrating a sensor value calculation process executed by a CPU for a process 1;

FIG. 5 is a time chart showing the operation of the processing of FIGS. 2 to 4;

FIG. 6 is a flowchart illustrating NE interrupt processing executed by a CPU for processing 2;

FIG. 7 is a flowchart illustrating a compare interrupt process executed by the CPU for process 2;

FIG. 8 is a flowchart illustrating a maximum value generation angle calculation process executed by a CPU for process 2;

FIG. 9 is a time chart illustrating the operation of the processing in FIGS. 6 to 8;

[Explanation of symbols]

1 ... Engine control device (ECU), 3 ... Engine, 5 ...
Crank angle sensor, 7: cylinder, 9: combustion pressure sensor, 11
... Injector, 13 ... CPU, 15 ... ROM, 17 ...
RAM, 19 A / D converter, 21 internal bus, 2
3 ... microcomputer, 25 ... input circuit, 27 ... output circuit

 ────────────────────────────────────────────────── ─── Continuing from the front page (72) Inventor Hiroki Mori 1-1-1 Showa-cho, Kariya-shi, Aichi F-term in DENSO Corporation (reference) 3G084 DA04 EA05 EB06 FA21 FA33 FA38

Claims (2)

[Claims] An analog signal output from a predetermined sensor (hereinafter referred to as a sensor value) is converted into a digital value by A / A.
A / D conversion means for D / D conversion is provided, and a rotation angle of the crankshaft (hereinafter referred to as a crank angle) based on a crank angle signal that generates a pulse edge in a specific direction every time the crankshaft of the engine rotates a predetermined angle. Means for detecting the sensor value when the crank angle reaches a predetermined command angle, wherein the crank angle signal is specified before the crank angle reaches the command angle. From a timing at which a pulse edge in the direction occurs (hereinafter referred to as detection start timing) to a timing at which a pulse edge in the specific direction occurs in the crank angle signal after the crank angle has passed the command angle (hereinafter referred to as detection end timing). During the sampling period, the A / D converter converts the sensor value into an A / D signal at regular time intervals. Sampling means for storing each digital value obtained by the A / D conversion in a predetermined storage means; clock means for measuring the time of the detection start timing and the time of the detection end timing, respectively; From the two times measured by the timing means, the angle from the crank angle at the detection start timing to the command angle, and the predetermined angle, the time when the crank angle becomes the command angle within the sampling period ( (Hereinafter referred to as a command angle time), and a sensor value calculating means for calculating a sensor value of the calculated command angle time from a digital value for the sampling period stored in the storage means. An engine control device, characterized in that: 2. A / D conversion of a value of an analog signal (hereinafter referred to as a sensor value) output from a predetermined sensor into a digital value.
A / D conversion means for D / D conversion is provided, and a rotation angle of the crankshaft (hereinafter referred to as a crank angle) based on a crank angle signal that generates a pulse edge in a specific direction every time the crankshaft of the engine rotates a predetermined angle. In the engine control device, the crank angle becomes a second angle from the timing at which the crank angle becomes the first angle and the pulse edge in the specific direction occurs in the crank angle signal (hereinafter referred to as monitoring start timing). Detecting a crank angle when the sensor value reaches a specific value during a monitoring period until a pulse edge of the specific direction is generated in the crank angle signal in the crank angle signal (hereinafter referred to as monitoring end timing). During the monitoring period, the A / D converter causes the A / D converter to A / D convert the sensor value at regular intervals. A sampling unit, and a timer for measuring each time at which the pulse edge in the specific direction occurs in the crank angle signal during the monitoring period, including the monitoring start timing and the monitoring end timing. Means for selecting the digital value which has become the specific value from the digital values which have been A / D converted by the A / D conversion means, and the time at which the selected digital value is A / D converted (Hereinafter referred to as a specific value occurrence time) a specific value occurrence time detecting means for detecting a cycle including the specific value occurrence time among the respective cycles of the crank angle signal in the monitoring period, The start time and the end time of the cycle are obtained from the measurement result of the clock means, and the start time and the end time, the specific value occurrence time, and the Crank angle calculating means for calculating, from the crank angle and the predetermined angle, a crank angle at the specific value occurrence time as a crank angle when the sensor value reaches the specific value. An engine control device characterized by the above-mentioned.