JP4532516B2 - Engine control device - Google Patents

Description

  The present invention relates to an engine control device mounted on an automobile, and more particularly to a technique for avoiding deterioration of exhaust gas and inflow of unburned gas into a catalyst.

  2. Description of the Related Art Conventionally, in an engine control apparatus for an automobile, an air flow sensor (hereinafter referred to as “AFS”) is used to detect an intake air amount to the engine and control an injection amount of fuel (gasoline).

  As this type of AFS, a thermal AFS that captures a heat change caused by an air flow and measures an air flow rate is generally used. However, the thermal AFS outputs an abnormal value due to adhesion of a water droplet or the like to a sensing unit. Sometimes. For example, when an abnormal value due to water droplet adhesion is used, the engine control unit recognizes that a larger amount of air has flowed than the actually measured air amount, and is larger than the appropriate amount for the actual intake air amount. Since fuel is injected, the engine may misfire due to excessive fuel (overrich).

When such an improper misfire occurs, the exhaust gas of the engine deteriorates and unburned gas flows into the catalyst, which can cause damage to the catalyst due to combustion in the catalyst.
Therefore, a conventional engine control device for avoiding the above problem has been proposed (for example, see Patent Document 1).

  In the conventional apparatus described in Patent Document 1, a steady state in which the rate of change in the throttle valve opening is smaller than a predetermined value and the rate of change in the engine speed is smaller than a predetermined value is detected, When the amount of change in the AFS sensor output value (hereinafter referred to as “sensor value”) is greater than a predetermined value, it is determined that water droplets have adhered to the AFS. The intake air amount is obtained based on the minimum output value.

Japanese Patent Laid-Open No. 7-77094

The conventional engine control device detects that the amount of change in the sensor value due to water droplets adhering to the AFS is larger than a predetermined value only under steady state conditions, and determines the intake air amount based on the minimum value of the output of the AFS. Therefore, when the throttle valve opening is suddenly changed (transient operation state), there is a problem that the intake air amount cannot be obtained based on the minimum value of the AFS output even if water droplets adhere to the AFS.
In particular, when water droplets adhere to the AFS under transient operation conditions, more fuel than necessary is injected, so the engine is likely to misfire, and exhaust gas deterioration and catalyst damage cannot be avoided. was there.

  The present invention has been made to solve the above problems, and obtains the intake air amount with an abnormal value due to water droplets adhering to the AFS not only under steady-state conditions but also under transient operation conditions. It is an object of the present invention to obtain an engine control apparatus that can prevent the deterioration of exhaust gas and catalyst damage due to engine misfire.

An engine control apparatus according to the present invention comprises a sensor means for detecting an operating state of an engine, an input means for taking in a sensor signal from the sensor means, various control means for performing various controls of the engine based on the sensor signal, Sampling means for sampling the input value every predetermined time, and limiting means for limiting the current sampling value based on the previous sampling value by the sampling means, various control means, the current control is limited by the limiting means In an engine control apparatus that uses a sampling value as a control sensor value for various engine controls, the sensor means includes an air flow sensor that detects the amount of intake air to the engine, and the limiting means is used for the control sensor value. Add the increase side limit value to the previous sampling value In addition to setting the upper limit value for judgment, subtracting the judgment limit value on the decrease side from the previous sampling value to set the lower limit value for this abnormal value judgment, the current sampling value by the sampling means is the upper limit value or When an abnormal value exceeding the lower limit value is indicated, the current sensor value for control is set to the upper limit value or the lower limit value, and either the increase-side determination limit value or the decrease-side determination limit value is set to the input means. It is set to the maximum value of the dynamic range.

According to the present invention, it is possible to prevent the intake air amount from being determined based on the abnormal value due to water droplets adhering to the AFS, not only in the steady state but also in the transient operation state, so that exhaust gas deterioration and catalyst damage due to engine misfire can be reliably ensured. Can be prevented. In addition, the followability can be improved when the sensor value returns to the normal value.

Embodiment 1 FIG.
Embodiment 1 of the present invention will be described below with reference to the drawings.
FIG. 1 is a block diagram showing an engine control apparatus according to Embodiment 1 of the present invention together with peripheral elements, and shows an engine control apparatus using an electronic throttle system as a specific example.

  In FIG. 1, the engine control device is an electronic control device (hereinafter referred to as “ECU”) 5 including various sensors and various actuators (described later) related to the engine 11 and a microcomputer (hereinafter referred to as “microcomputer”) 10. It is comprised by. The ECU 5 calculates control amounts for various actuators based on various sensor information indicating the operating state of the engine 11, and drives the various actuators.

  The engine 11 is provided with an intake pipe 12 having a surge tank (intake manifold), an exhaust pipe 13 for discharging exhaust gas after combustion, and an ignition device (igniter) 14 for driving to discharge a spark plug in the combustion chamber. It has been. The crankshaft of the engine 11 is provided with a crank angle sensor 7 that outputs a number of pulse signals (crank angle signals) corresponding to the engine rotational speed Ne, and the coolant temperature Wt is set on the outer periphery of the engine coolant. A water temperature sensor 8 for detection is provided.

Further, an injector 4 for injecting fuel into the intake air to the engine 11 is provided on the downstream side of the intake pipe 12. The fuel from the fuel tank 16 is supplied to the injector 4 via a delivery pipe.
On the other hand, the exhaust pipe 13 of the engine 11 is provided with an O2 sensor 9 for detecting the oxygen concentration in the exhaust gas and a catalyst 19 for purifying the exhaust gas.

  On the upstream side of the intake pipe 12, an AFS1 that detects the intake air amount Qa to the engine 11, an electronic throttle 15 that adjusts the intake air amount Qa, and a throttle position sensor that detects the actual throttle opening Tp ( (Hereinafter referred to as “TPS”) 2 and a throttle actuator (hereinafter simply referred to as “actuator”) 3 for driving the throttle 15 are provided.

Further, a pressure sensor 18 for detecting the intake manifold pressure Pb is provided on the surge tank of the intake pipe 12 located on the downstream side of the throttle 15.
The accelerator pedal 17 operated by the driver is provided with an accelerator position sensor (hereinafter referred to as “APS”) 6 that detects the accelerator opening Ap.

  AFS1, TPS2, APS6, crank angle sensor 7, water temperature sensor 8, O2 sensor 9, pressure sensor 18, and other sensors (not shown) constitute various sensors that detect the operating state of engine 11. Each detection information is input into ECU5 (for example, it comprises a fuel-injection control apparatus).

The throttle actuator 3, the injector 4, the ignition device 14, and other actuators (not shown) constitute various actuators that drive the engine 11, and are each driven under the control of the ECU 5.
In the intake pipe 12, the throttle actuator 3 is provided on the upstream side of the pressure sensor 18.

The ECU 5 receives the output signals of the AFS 1, the crank angle sensor 7, the water temperature sensor 8, the O 2 sensor 9 that detects the oxygen concentration in the exhaust gas, and the pressure sensor 18, and the injector 4 and the ignition device provided in each cylinder of the engine 11. 14 is controlled.
For example, the microcomputer 10 in the ECU 5 calculates the fuel amount corresponding to the intake air amount Qa measured by the AFS 1 and determines the pulse width of the injection pulse signal to the injector 4.

Next, a specific configuration of the ECU 5 will be described with reference to the functional block diagram of FIG.
In FIG. 2, the ECU 5 includes a microcomputer 10, input means (input interfaces) 21 and 26 for the microcomputer 10, and fuel control means 27 and ignition control means 28 constituting various control means for driving the actuator.

  The input means 21 takes in the intake air amount Qa (sensor signal) from the AFS 1 and inputs it to the microcomputer 10 as an AD conversion value. Further, the input means 26 takes in a pulse signal (corresponding to the engine rotational speed Ne) from the crank angle sensor 7 and inputs it to the microcomputer 10.

  The fuel control means 27 drives the injector 4 under the control of the microcomputer 10 to control the fuel injection amount and fuel injection timing to the engine 11. The ignition control means 28 drives the ignition device 14 under the control of the microcomputer 10 to control the ignition timing of the engine 11.

The microcomputer 10 in the ECU 5 is connected to the sampling unit 22 connected to the input unit 21, the limiting unit 23 connected to the sampling unit 22, the load information calculation unit 24 connected to the limiting unit 23, and the input unit 26. The engine rotation calculation means 25 is provided.
The load information Le from the load information calculation unit 24 and the engine rotation speed Ne from the engine rotation calculation unit 25 are input to the fuel control unit 27 and the ignition control unit 28.

The sampling unit 22 samples the AD conversion value of the intake air amount Qa via the input unit 21 at predetermined time intervals.
The limiting unit 23 limits the current sampling value based on the previous sampling value by the sampling unit 22. That is, a limit is given to the change of the sampling value toward the increase side or the decrease side.
The load information calculation unit 24 calculates the load information Le of the engine 11 based on the current sampling value restricted by the restriction unit 23.

The engine rotation calculation unit 25 calculates the engine rotation speed Ne based on a crank angle signal (corresponding to the engine rotation speed Ne) via the input unit 26.
The engine rotation calculating means 25 constitutes various control means for the engine 11 in association with the fuel control means 27 and the ignition control means 28.

  The fuel control means 27 and the ignition control means 28 use the load information Le calculated as the control sensor value for the current sampling value restricted by the restriction means 23 for engine control, and the load information Le and the crank angle sensor 7 The injector 4 and the ignition device 14 are driven and controlled using the engine rotation speed Ne.

Next, basic operations of the sampling means 22 and the limiting means 23 according to the first embodiment of the present invention shown in FIGS. 1 and 2 will be described with reference to the flowchart of FIG.
In FIG. 3, the sampling means 22 in the ECU 5 first determines whether or not a predetermined time (corresponding to the sampling timing) has elapsed (step S1), and if the predetermined time has not elapsed (that is, NO). If it is determined, the processing routine of FIG.

On the other hand, if it is determined in step S1 that the predetermined time has elapsed (that is, YES), the process proceeds to sampling processing (steps S2 to S6) after the predetermined time has elapsed.
First, the sensor value (voltage value) Sns (n) corresponding to the intake air amount Qa from the AFS 1 is subjected to sampling measurement by A / D conversion (step S2).

  Subsequently, the limiting means 23 stores the sensor value of the previous AFS 1 (before one sampling) used for various controls of the engine 11 as the previous sampling value Cont (n−1) (step S3), and the previous sampling value. Cont (n−1) and the increase-side determination limit value Th_A are added to calculate the increase-side control limit value Cont_U (n) as in the following equation (1) (step S4).

  Cont_U (n) = Cont (n−1) + Th_A (1)

  However, in Expression (1), the determination limit value Th_A on the increase side is set to a value larger than the maximum change amount of the normal sensor signal in a state where the AFS 1 is normal (no water droplets or the like are attached).

  Next, the limiting unit 23 subtracts the decrease-side determination limit value Th_D from the previous sampling value Cont (n−1), and the decrease-side control limit value Cont_L ( n) is calculated (step S5).

  Cont_L (n) = Cont (n−1) −Th_D (2)

  However, in the equation (2), the decrease-side determination limit value Th_D is the same as the increase-side determination limit value Th_A in the equation (1) in a state where the AFS1 is normal (no water droplets or the like are attached). Usually, it is set to a value larger than the maximum change amount of the sensor signal.

  Finally, the limiting means 23 uses the increase-side control limit value Cont_U (n) calculated in step S4 and the decrease-side control limit value Cont_L (n) calculated in step S5, and uses the following formula (3 ), The control sensor value Cont (n) of the intake air amount Qa used for various controls of the engine 11 is updated with restriction (step S6).

  Cont (n) = Min [Cont_U (n), max {Sns (n), Cont_L (n)}] (3)

  However, in Equation (3), Min [] means that the smaller one of the variables in [] is selected, and similarly, max {} means that the larger one of the variables in {} is selected. It is.

Next, the control operation will be described more specifically with reference to the timing chart of FIG.
In FIG. 4, the thin solid line is the voltage value Sns when the sensor value of AFS1 is sampled at each time (n−2, n−1, n,...) At a predetermined time interval (sampling period t). Sampling points at the timing of each time are indicated by “black circles ●”.

  Also, the broken line in FIG. 4 is an upper limit value Cont_U obtained by adding the increase-side determination limit value Th_A to the previous control sensor value, and the one-dot chain line indicates a decrease-side determination limit value from the previous control sensor value. It is a lower limit value Cont_L obtained by subtracting Th_D, and a thick solid line is a control sensor value Cont used for various controls.

  The upper limit value Cont_U (refer to the dotted line) is a value obtained by adding the determination limit value Th_A on the increase side to the sensor value obtained at the sampling point at time n−1, and the lower limit value Cont_L (refer to the one-dot chain line) is determined at time n. This is a value obtained by subtracting the decreasing determination limit value Th_D from the sensor value obtained at the sampling point of -1.

  For example, at the timing of time n−1, the sensor value Sns (see the thin solid line) exists within the range between the upper limit value Cont_U and the lower limit value Cont_L, and the control sensor value Cont (thick solid line) used for various controls. Since the reference) is not limited, it becomes the same value as the actually sampled sensor value Sns.

On the other hand, when an abnormal value occurs due to water droplets adhering to the AFS 1 at the timing of the next time n, the sensor value Sns (see the thin solid line) behaves as indicated by “B”, but is used for various controls. The control sensor value Cont (see the thick solid line) is limited by the upper limit value Cont_U, as indicated by “A”.
When an abnormal value of the sensor value Sns occurs on the lower limit value Cont_L side, the lower limit value Cont_L is similarly limited.

As described above, according to the basic configuration of the first embodiment of the present invention, the sensor means (AFS1, TPS2, APS6, crank angle sensor 7, temperature sensor 8, O2 sensor 9, pressure sensor) that detects the operating state of the engine 11 Sensor 18) and input means 21 for taking in sensor signals (intake air amount Qa, throttle opening Tp, accelerator opening Ap, engine speed Ne, cooling water temperature Wt, air-fuel ratio signal, intake manifold pressure Pb) from the sensor means, 26 and various control means (fuel control means 27, ignition control means 28) for performing various controls of the engine 11 based on the sensor signal, the input value of the sensor signal (intake air amount Qa) is Sampling means 22 for sampling every predetermined time, and the current sampling based on the previous sampling value by the sampling means Limiting means 23 for limiting the engine value, and various control means (fuel control means 27, ignition control means 28) use the current sampling value restricted by the restriction means 23 as the control sensor value Cont. 11 used for various controls.

  Further, the limiting unit 23 adds the increase-side determination limit value Th_A to the previous sampling value (previous control sensor value Cont (n−1)) used for the control sensor value Cont, and this abnormality The upper limit value Cont_U for value determination is set and the lower limit value Cont_L for abnormal value determination is set by subtracting the decreasing determination limit value Th_D from the previous sampling value. When the value indicates an abnormal value exceeding the upper limit value Cont_U or the lower limit value Cont_L, the current control sensor value Cont (n) is set to the upper limit value Cont_U or the lower limit value Cont_L.

In addition, load information calculating means 24 for calculating load information Le of the engine 11 based on the current sampling value restricted by the restricting means 23 is further provided, and various control means (fuel control means 27, ignition control means 28) are provided. Various controls of the engine 11 are performed according to the load information Le.
Further, the sensor means includes an AFS 1 that detects an intake air amount Qa to the engine 11 and a crank angle sensor 7 that detects rotation information of the engine 11 (engine rotational speed Ne). The sampling means 22 includes an intake air amount. Qa is sampled at predetermined time intervals, and various control means include an engine rotation calculation means 25 for calculating the engine rotation speed Ne based on the rotation information, and a fuel control means for controlling the injector 4 for injecting fuel to the engine 11. 27 and an ignition control means 28 for controlling the ignition device 14 for igniting the engine 11. The fuel control means 27 and the ignition control means 28 are provided with load information Le based on the intake air amount Qa, and the engine rotational speed Ne. Are used to control the injector 4 and the ignition device 14.

  As a result, the control sensor value Cont is limited to the normal range not only in the steady state but also in the transient operation state, and therefore the intake air amount for control is obtained based on the abnormal value due to water droplets adhering to the AFS 1. It is possible to reliably prevent deterioration of exhaust gas and damage to the catalyst 19 due to misfire of the engine 11.

Although not mentioned in the above description, in consideration of the characteristics of the AFS 1, in order to improve the return followability from the sensor abnormal value to the normal value, only one of the increase side and the decrease side is limited in the limiting means 23. It is desirable to limit
Hereinafter, a case where only one of the increase side and the decrease side is limited with respect to the sampling value will be described.

  In this case, the basic configuration and control operation of the engine control device are as shown in FIGS. 1 to 3. For example, when limiting only on the decrease side, in step S4 in FIG. A very large value for control (maximum value of the dynamic range of A / D conversion at the input means 21) is set as the determination limit value Th_A of the input signal. In step S5, an appropriate subtraction amount is set as the decrease-side determination limit value Th_D. Is set. Thereby, the limit value (upper limit value) on the increase side in step S4 can be invalidated.

  On the other hand, when limiting only on the increasing side, in step S5 in FIG. 3, a very large value for control (the dynamic range of the A / D conversion in the input means 21) is set as the determination limit value Th_D on the decreasing side. In step S4, an appropriate addition amount is set as the increase-side determination limit value Th_A. Thereby, the limit value (lower limit value) on the decrease side in step S5 can be invalidated.

  As described above, by restricting only one of the increase side and the decrease side, it is possible to improve the followability when returning from the abnormal value output state of the AFS 1 to the normal value due to disturbance.

Hereinafter, the effect of the control operation of the first embodiment of the present invention will be specifically described with reference to the timing chart of FIG.
In the same manner as described above (see FIG. 4), FIG. 5 shows that the sensor value of AFS1 (voltage value sampled at a predetermined time) Sns (see a thin solid line) and the previous sampling value (control sensor value) are increased. An upper limit value Cont_U (see the dotted line) obtained by adding the limit addition amount Th_A, a lower limit value Cont_L (see the one-dot chain line) obtained by subtracting the decreasing limit subtraction amount Th_D from the previous sampling value (control sensor value), and various controls The current control sensor value Cont (see a thick solid line) is used.

In FIG. 5, similarly to the first embodiment described above, the control sensor value Cont (thick solid line) when the upper limit value Cont_U (see the broken line) and the lower limit value Cont_L (see the one-dot chain line) are respectively set to appropriate values. Behavior).
In the case of FIG. 5, paying attention to the fact that an abnormal value at the time of water droplet adhesion to the AFS 1 occurs on the increasing side, the lower limit value Cont_L (see the one-dot chain line) is invalidated, and the upper limit value Cont_U (see the broken line) In order to apply the limit, it is necessary to set only the increase-side determination limit value Th_A to the above-described appropriate value and set the decrease-side determination limit value Th_D to the maximum value of the dynamic range of the input unit 21 and invalidate it. is there.

In FIG. 5, first, as indicated by “C” (sampling point at time n), it is assumed that an abnormal value occurs in a very short time (<sampling period) after a water droplet adheres to the AFS 1.
At this time, as shown in FIG. 5, when the limit value is set to both the increase side and the decrease side, the sensor value Sns is limited to the increase side by the upper limit value Cont_U at the sampling point at time n.

  Next, as indicated by “D” (sampling point at time n + 1), when the sensor value Sns returns to the normal value, the lower limit value Cont_L (see the one-dot chain line) is applied to the sensor value Sns. The control sensor value Cont is set to the lower limit value Cont_L.

Further, at the sampling point at the next time n + 2 and at the sampling point at time n + 3, as in the case of the sampling point at time n + 1, the sensor value Sns is restricted by the lower limit value Cont_L.
Therefore, in the case of FIG. 5, the convergence of the control sensor value Cont to the normal sensor value Sns is delayed until “E” (sampling point at time n + 3).

On the other hand, in the operation example of FIG. 5, in consideration of the case where the reduction limit (lower limit value Cont_L) is invalidated, as shown in “D” (sampling point at time n + 1) in FIG. When the normal value is restored, it can be seen that the control sensor value Cont used for various controls immediately behaves so as to coincide with the sensor value Sns.
Accordingly, it is possible to improve the followability when the sensor value Sns of AFS1 is restored to the normal value.

As described above, according to the first embodiment of the present invention, one of the increase-side and decrease-side determination limit values is set to the maximum value of the dynamic range of the input means 21, and when water droplets adhere to the AFS1. Depending on the sensor output phenomenon at the time of abnormality (whether the abnormal value of the sensor value Sns is output on the increase side or the decrease side), only one of the increase side or the decrease side is limited Thus, the followability can be improved when the sensor value Sns from the AFS 1 returns to the normal value.

Further, when the abnormal value of the sensor value Sns occurs, considering that the limiting unit 23 functions as a failure determination unit, the AFS1 failure determination information is not a control sensor value Cont but a sampling value (sensor value). Since Sns) is used, failure determination in a short time is possible, and there is also an effect that detection sensitivity until failure determination is not impaired.
Hereinafter, the effect at the time of the failure determination will be described with reference to the timing chart of FIG. FIG. 6 shows the control operation at the time of sensor failure determination of AFS1, and each line shows the same value as described above (see FIG. 5).

In FIG. 6, first, at “F” (sampling point at time n−1) when an abnormal value has occurred in the sensor value Sns, it is identified whether the output is abnormal due to water droplet adhesion to the AFS 1 or the sensor is broken. I can't do it.
At this time, as described above, by using the control sensor value Cont provided with the restriction by the restricting means 23, a device that does not use the suddenly changed intake air amount Qa is provided, so the control sensor value Cont is As shown by a thick solid line in FIG. 6, it increases in steps, and excessive control behavior does not occur in various controls for the engine 11.

  However, if a sensor failure of the AFS 1 occurs and the failure is determined using the limited control sensor value Cont, the timing of transition to fail safe at the time of failure determination is delayed. That is, in the conventional apparatus, the failure determination at “G” (between time n + 1 and time n + 2) is later than the “G” point, and the failure determination is performed at “H” (sampling point at time n + 4). As a result, failure detection sensitivity is reduced.

  Therefore, in the failure determination of the AFS1, by using the sampled sensor value Sns instead of using the limited control sensor value Cont, it is possible to determine the failure at the “G” point as in the past. It is possible to shift to the fail-safe operation state at the time of failure of the AFS 1 without reducing the detection sensitivity of failure determination as compared with the conventional device.

  As described above, according to the first and second embodiments of the present invention, the limiting unit 23 includes the sensor failure determination unit, and the sampling value (sensor value Sns) by the sampling unit 22 is equal to the upper limit value Cont_U or the lower limit value Cont_L. When it exceeds, since the failure of the sensor means (AFS1) is determined, the engine 11 can be promptly shifted to the fail-safe operation state when the sensor failure determination occurs.

1 is an overall configuration diagram of a fuel supply control device including an engine control device according to Embodiment 1 of the present invention. It is a control block diagram of this invention. It is a control flowchart of this invention. It is a chart which shows the control action of this invention. It is a chart which shows the control action in this invention at the time of abnormal value output of a sensor. It is a chart which shows the control action at the time of the sensor failure in this invention.

Explanation of symbols

  1 AFS (air flow sensor), 2 TPS (throttle position sensor), 3 throttle actuator, 4 injectors, 5 ECU (electronic control unit), 6 APS (accelerator position sensor), 7 crank angle sensor, 8 water temperature sensor, 9 O2 sensor DESCRIPTION OF SYMBOLS 10 Microcomputer (microcomputer), 11 Engine, 12 Intake pipe, 13 Exhaust pipe, 14 Ignition device, 15 Throttle, 16 Fuel tank, 18 Pressure sensor, 19 Catalyst, 21, 26 Input means, 22 Sampling means, 23 Limiting means , 24 Load information calculation means, 25 Engine rotation calculation means, 27 Fuel control means, 28 Ignition control means, Ap accelerator opening, Le load information, Ne engine rotation speed, Pb intake manifold pressure, Qa intake air amount, Tp throttle opening (measurement ), Wt Cooling water temperature, Cont, Cont (n) Control sensor value, Sns, Sns (n) Sampled sensor value, Th_A increase-side determination limit value, Th_C decrease-side determination limit value, Cont_U increase-side control Limit value (upper limit value), Cont_L Decrease control limit value (lower limit value).

Claims (4)

Sensor means for detecting the operating state of the engine;
Input means for capturing sensor signals from the sensor means;
Various control means for performing various controls of the engine based on the sensor signal ;
Sampling means for sampling the input value of the sensor signal every predetermined time;
Limiting means for limiting the current sampling value based on the previous sampling value by the sampling means, and
The various control means, in an engine control device that uses the current sampling value restricted by the restriction means as a control sensor value for various controls of the engine,
The sensor means includes an air flow sensor that detects an intake air amount to the engine,
The limiting means is
While adding an increase-side determination limit value to the previous sampling value used for the control sensor value, and setting an upper limit value for the current abnormal value determination,
Subtract the decrease-side determination limit value from the previous sampling value, and set the lower limit value for the current abnormal value determination,
When the current sampling value by the sampling means indicates an abnormal value exceeding the upper limit value or the lower limit value, the current control sensor value is set to the upper limit value or the lower limit value,
One of the increase-side determination limit value and the decrease-side determination limit value is set to the maximum value of the dynamic range of the input means.   The restricting means includes a sensor failure determining means, and when the sampling value by the sampling means exceeds the upper limit value or the lower limit value, the sensor means determines a failure and puts the engine in a fail safe operation state. The engine control device according to claim 1, wherein the engine control device is shifted. Load information calculating means for calculating the load information of the engine using the current sampling value limited by the limiting means as the control sensor value,
The engine control apparatus according to claim 1, wherein the various control units perform various controls of the engine in accordance with the load information. It said sensor means includes a crank angle sensor for detecting the rotation information of the engine,
The sampling means samples the intake air amount every predetermined time,
The various control means include
Engine rotation calculation means for calculating the engine rotation speed based on the rotation information;
Fuel control means for controlling an injector for injecting fuel into the engine;
Ignition control means for controlling an ignition device for igniting the engine,
The said fuel control means and the said ignition control means control the said injector and the said ignition device using the load information based on the said intake air amount, and the said engine speed. Engine control device.

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