JP2010112237A - Control apparatus and control method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a control apparatus and a control method which can prevent the erroneous detection of an abnormality of an ion sensor or the occurrence of preignition even is noise is superimposed in an ion signal. <P>SOLUTION: The control apparatus (10) includes: an ignition plug control unit (14) for controlling an ignition plug (41) by which fuel is combusted; and an executive unit (11) executing: input processing for inputting an ion signal from an ion sensor (51) detecting an ion current generated by fuel combustion in a combustion chamber of an internal combustion engine; output process for outputting an ignition signal to the ignition plug control unit based on the ion signal inputted by the input processing and an input signal from an crank angle sensor; preignition detection processing for detecting preignition based on the ion signal inputted by the input processing; and abnormality detection processing for detecting an abnormality of the ion sensor based on the ion signal inputted by the input processing when the preignition detection processing is not executed. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a control device and a control method, and more particularly to a control device and a control method for detecting an abnormality in an ignition device for an internal combustion engine.

  Based on the ignition command signal, the ignition plug is ignited by applying a predetermined current to the ignition plug disposed in the combustion chamber of the internal combustion engine, and the ionic current generated at the time of ignition is detected to detect the ignition command. An abnormality detection device that determines pre-ignition in fuel injection control of an internal combustion engine based on a signal and a detected ion current is known (see, for example, Patent Document 1).

  Based on an ignition command signal transmitted from an engine control circuit to an igniter, a spark discharge is generated in a spark plug, and an ionic current generated at that time is detected to detect pre-ignition (for example, Patent Document 2).

JP 11-294249 A JP 2005-252066 A

  FIG. 1 is a timing chart showing the relationship between the ignition signal to the spark plug and the ion signal from the ion sensor.

  FIG. 1A is a diagram illustrating an example of an ignition signal. The ignition signal rises at time t1, and the ignition signal falls at time t4. It is assumed that a current flows through the spark plug in response to the fall of the ignition signal (time t4) and spark discharge occurs.

  FIG.1 (b) is a figure which shows an example of the ion signal (1) from a normal ion sensor. In response to the rising of the ignition signal, the ion signal (1) is a current that flows through the detection circuit at the start of energization, so the output voltage once drops to 0 (V) but immediately returns to 5 (V) (see P1). . In response to the fall of the ignition signal, the output voltage of the ion signal (1) drops to 0 (V) for a predetermined time due to spark discharge of the spark plug (see P2). In such a case, when the ion signal (1) at time t2 is detected and the output voltage exceeds the determination voltage, it can be recognized that the ion sensor is in a normal state with no ground fault. In addition, when the ion sensor (1) is detected at time t3 when the ion sensor is normal and the output voltage exceeds the determination voltage, pre-ignition (hereinafter referred to as “pre-grab”) has not occurred. Can be recognized.

  FIG.1 (c) is a figure which shows an example of the ion signal (2) in case the prag has generate | occur | produced. In the ion signal (2), pre-ignition occurs and the air-fuel mixture burns earlier than a predetermined timing to generate ions, so that the output voltage at time t3 is 0 (V) (see P3).

  FIG.1 (d) is a figure which shows an example of the ion signal (3) in case the ion sensor has a ground fault. As shown in FIG.1 (d), when the ion sensor has a ground fault, the output voltage becomes all 0 (V). In such a case, the ion signal (3) at time t2 is detected, and when the output voltage is 0 (V), it can be recognized that the ion sensor is in an abnormal state that is grounded. (Refer to P4).

  FIG.1 (e) is a case where an example of other ion signals (4) in case the ion sensor has a ground fault is shown. As shown in FIG. 1 (e), since the ion sensor has a ground fault, its output voltage should all be 0 (V) in principle, but by chance, noise occurs around time t2. The output voltage at that time may exceed the determination voltage (see P5). In such a case, actually, the ion sensor is recognized as being normal even though the ion sensor is grounded. Therefore, since the output at time t3 is 0 (V) (see P6), there is a possibility that it is misunderstood that a paging has occurred.

  FIG.1 (f) is a figure which shows an example of the other ion signal (5) at the time of the pre-generation | generation. As shown in FIG. 1 (f), by chance, noise occurs around time t2, and the output voltage at that time may be lower than the determination voltage (see P7). In such a case, although the ion sensor is actually normal, there is a possibility that the ion sensor is mistakenly recognized as having an abnormality.

  As described above, noise is generated in the ion signal based on the ion sensor for detecting the prag, so that it may be erroneously detected that the ion sensor is abnormal, or may be detected that the prig is erroneously generated. There is. If it is detected that there is an abnormality in the ion sensor, it will normally stop the detection of the plague based on the subsequent ion signal and request replacement of the ion sensor. However, the ion sensor is usually placed near the combustion chamber. In many cases, the replacement requires a lot of labor and cost.

  Therefore, an object of the present invention is to provide a control device and a control method that can solve the above-described problems.

  Further, the present invention provides a control device capable of preventing an ion sensor from being erroneously detected as having an abnormality or being detected as having been prematurely generated even if noise is superimposed on the ion signal. And it aims at providing a control method.

  In the control device according to the present invention, an ion signal from an ignition plug control unit for controlling an ignition plug for burning fuel and an ion sensor for detecting an ion current generated in the combustion chamber of the internal combustion engine as the fuel is burned. , An input process for outputting an ignition signal to the spark plug controller based on an ion signal input by the input process or an input signal from a crank angle sensor, and an ion input by the input process Performing a Pule detection process for detecting Pleig based on the signal, and an abnormality detection process for performing abnormality detection of the ion sensor based on the ion signal input by the input process when the Pleig detection process is not executed. It has an execution part.

  In the control method according to the present invention, the step of inputting an ion signal from an ion sensor for detecting an ion current generated as the fuel is burned in the combustion chamber of the internal combustion engine, and the ion signal and crank input by the input process are performed. Outputting an ignition signal to an ignition plug controller for controlling an ignition plug for burning fuel based on an input signal from an angle sensor, detecting a plague based on an input ion signal, In the case where the detection is not performed, the method includes a step of performing abnormality detection of the ion sensor based on the input ion signal.

  According to the present invention, it is possible to prevent erroneous determination of abnormality of an ion sensor by detection in a period in which noise is difficult to occur or determination multiple times.

  According to the present invention, since the abnormality detection of the ion sensor is performed during the period when the prag does not occur, the detection of the prag is not performed immediately after the abnormality detection of the ion sensor is erroneously performed due to noise or the like. It becomes possible to prevent an erroneous determination of the Plague.

  Embodiments according to the present invention will be described below in detail with reference to the drawings. The technical scope of the present invention is not limited to these embodiments, but covers the invention described in the claims and equivalents thereof. Moreover, it is also possible to implement with the form which added the various change in the range which does not deviate from the meaning of this invention.

  FIG. 2 is a block diagram showing a schematic configuration of the system.

  An electronic control unit (EFI-ECU) 10 that performs fuel injection control and the like for an internal combustion engine includes a CPU 11, a ROM 12, a RAM 13, a driver 14, and the like.

  The EFI-ECU 10 receives a crank angle signal and an engine speed (rpm) signal from a crank angle sensor 20 disposed inside the vehicle, an acceleration signal from an acceleration sensor 21, and an ignition switch (IG-SW) 22 via an in-vehicle network or the like. IG-SW ON / OFF signal, starter motor drive signal from starter motor 23, and vibration detection signal from knocking sensor 24 for detecting vehicle vibration.

  A first spark plug 41 to a fourth spark plug 44 are disposed in each combustion chamber of a four-cylinder four-cycle engine (not shown), and a first ion sensor 51 to a fourth ion sensor 54 are disposed in each spark plug, respectively. Comes with. Further, the first spark plug 41 to the fourth spark plug 44 are connected to the first igniter 31 to the fourth igniter 34 which are engine ignition devices, respectively. -It is connected with ECU10. Furthermore, the EFI-ECU 10 is also connected to a first injector 61 to a fourth injector 64 for injecting fuel via the drive 14.

  FIG. 3 is an explanatory diagram of the engine ignition system.

  Hereinafter, the ignition system will be described by taking the first igniter 31, the first spark plug 41, and the first ion sensor 51 illustrated in FIG. 3 as an example, but the same applies to other igniters, spark plugs, and ion sensors. .

  A predetermined voltage charge is started in the first igniter 31 in response to the rise (see time t1) of the ignition signal (see FIG. 1 (a)) from the EFI-ECU 10, and the fall of the ignition signal (see time t4). Accordingly, a spark discharge is generated in the first spark plug 341 by the charged high voltage. In the first igniter 31, a discharge current due to spark discharge is detected, and an ignition monitor signal is generated and output to the EFI-ECU 10.

  The first ion sensor 51 detects an ion current caused by ions generated when the air-fuel mixture containing fuel burns in the cylinder, generates an ion signal, and outputs the ion signal to the EFI-ECU 10 via the first igniter 31. To do. In this example, the ion sensor is configured to be incorporated in the spark plug. However, the present invention is not limited to this, and the ion sensor may be disposed at another location in the cylinder. In that case, it is not necessary to output the ion signal to the EFI-ECU 10 via the igniter, and the ion signal may be output directly or indirectly.

  As described above, the first ion sensor 51 detects an ion current caused by ions generated when the air-fuel mixture burns in the cylinder and generates an ion signal, so that an ignition signal (see FIG. 1A) and From the relationship with the ion signal (see FIGS. 1B and 1C), it is possible to detect whether or not pre-ignition has occurred.

  FIG. 4 is a diagram showing a control flow (1).

  The control flow (1) shown in FIG. 4 is mainly executed by the CPU 11 in accordance with a program stored in advance in the ROM 12 of the EFI-ECU 10 on the system shown in FIG. Note that the CPU 11 is configured to input the ion signal from the first ion sensor 51 to the fourth ion sensor 54, and / or the driver 14 based on the input ion signal and / or the crank angle signal from the crank angle sensor 20. It is assumed that an output process for outputting an ignition signal is performed.

  First, the CPU 11 determines whether or not the IG-SW is turned on based on a signal received from the IG-SW 22 (S10).

  Only when the IG-SW is turned on, the CPU 11 detects the ground fault of the first ion sensor 51 to the fourth ion sensor 54 (S11), and whether the ion sensor is grounded based on the detection. Is set (S12). In S12, for example, when a ground fault is detected, a flag indicating that is turned on in the RAM 13, and a warning (not shown) arranged on the front panel of the vehicle or the like while the flag is on. The lamp is turned on to notify the user that there is an abnormality in the ion sensor, and the pre-figure determination based on the ion sensor thereafter is stopped. Further, the flag indicating that the ion sensor is grounded is preferably rewritten every time S12 is executed.

  Next, the engine is started in conjunction with turning on the IG-SW (S13). The engine is started with the rotation of the starter motor 23 and the like by the engine control ECU.

  Next, the CPU 11 starts energization of the ignition signal (S14), detects pre-ignition based on the ion signal at a predetermined timing slightly before the fall of the ignition signal (S15), and the ignition plug is ignited. (S16).

  The CPU 11 determines whether or not a signal indicating that the IG-SW has been turned off has been received from the IG-SW 22 (S17). When the IG-SW has been turned off, the series of processing ends. Further, the CPU 11 repeatedly executes S14 to S17 at a predetermined timing until the IG-SW is turned off.

  FIG. 5 is a timing chart corresponding to the control flow (1) shown in FIG.

  FIG. 5A shows an example of an ignition signal to the first igniter 31, and FIG. 5B shows an example of an ion signal (1) when the first ion sensor 51 is normal and no plague is generated. FIG. 5 (c) shows an example of the ion signal (2) when the first ion sensor 51 is normal but pre-generated, and FIG. 5 (d) shows the first ion sensor 51 having a ground fault. An example of the ion signal (3) in the case of being closed is shown.

  In FIG. 5, IG-SW is turned on at time t5 (S10), ground fault detection of the first ion sensor 51 is performed at time t6 (S11), and energization of the ignition signal is started at time t1 (S14). A pre-ignition is detected at time t3 (S15), and time t4 corresponds to the state where the first ignition has occurred (S16). In FIG. 5, the ignition signal to the first igniter 31 and the ion signal from the first ion sensor 51 are described, but the EFI-ECU 10 outputs the ignition signal to each preg at a predetermined timing and the predetermined timing. Thus, the control signal is output to each injector to control the injection control of each cylinder of the engine.

  As shown in FIG. 5, in the control flow shown in FIG. 4, the ground fault detection of the ion sensor is performed from when the IG-SW 22 is turned on until the engine is started (time t <b> 6). The start of engine start can be determined, for example, as the start of rotation of the starter motor 23.

  At this timing, since the engine is not started, the possibility that noise is superimposed on the ion signal is extremely low, and the possibility that the ion sensor is erroneously recognized as a ground fault is very low. Therefore, as shown in FIG. 5D, it is possible to detect that the first ion sensor 51 is grounded only when the first ion sensor 51 is truly grounded. In the control flow of FIG. 4, the ground fault detection of the first ion sensor 51 is performed after the IG-SW 22 is turned on until the engine is started, and then the IG-SW 22 is temporarily turned off. After that, the ground fault detection of the first ion sensor 51 is not performed until it is turned on again. Further, at this timing, the engine has not yet been started, and therefore, no plague is detected based on the ion signal. Therefore, even if it is erroneously determined that the ion sensor has a ground fault, it is possible to prevent the erroneous determination of the Plague because the Pregue is not detected immediately.

  FIG. 6 is a diagram showing another control flow (2).

  The control flow (2) shown in FIG. 6 is mainly executed by the CPU 11 according to a program stored in advance in the ROM 12 of the EFI-ECU 10 on the system shown in FIG.

  First, the CPU 11 determines whether or not the IG-SW is turned on based on a signal received from the IG-SW 22 (S20).

  Next, the engine is started in conjunction with turning on the IG-SW (S21). The engine is started with the rotation of the starter motor 23 and the like by the engine control ECU.

  Next, the CPU 11 starts energization of the ignition signal (S22), determines whether or not the plag is not detected based on the current ion signal (S23), and detects the preg based on the current ion signal. In the case of not doing so, the ground faults of the ion sensors 51 to 54 are detected in a predetermined cycle (T1) (S24), and based on the detection, setting is made as to whether the ion sensor is grounded (S25). The ignition plug is ignited (S26). In S25, for example, when a ground fault is detected, a flag indicating that is turned on in the RAM 13, and a warning (not shown) arranged on the front panel of the vehicle or the like while the flag is on. The lamp is turned on to notify the user that there is an abnormality in the ion sensor, and the pre-figure determination based on the ion sensor thereafter is stopped. Further, the flag indicating that the ion sensor is grounded is preferably rewritten every time S25 is executed.

  In S23, when the present situation is a situation where a prag is detected using an ion sensor, the peg is detected at a predetermined timing without detecting the ground fault of the ion sensor (S27).

  Next, the CPU 11 determines whether or not a signal indicating that the IG-SW has been turned off has been received from the IG-SW 22 (S28). If the IG-SW has been turned off, the series of processing ends. . Further, the CPU 11 repeatedly executes S22 to S28 at a predetermined timing until the IG-SW is turned off.

  The situation where the prag is not detected using the ion sensor is, for example, an idling state where the engine speed is 1200 rpm or less, and the plag can be detected effectively based on the vibration detection signal from the knocking sensor 24. Say. In this case, the CPU 11 determines whether or not the engine speed is 1200 rpm or less based on the engine speed (rpm) signal from the crank angle sensor 20 (S23). Ground fault detection (S24) will be performed.

  FIG. 7 is a timing chart corresponding to the control flow (2) shown in FIG.

  FIG. 7A shows an example of an ignition signal to the first igniter 31, and FIG. 7B shows an example of an ion signal when the first ion sensor 51 is normal and no plague is generated. .

  FIG. 7 shows a situation where the pre-ignition is not judged by the ion sensor 51 whose engine speed is 1200 rpm or less, and the time t1, t1 ′, t1 ″, t1 ″ ″ is a state where energization of the ignition signal is started. Correspondingly (S22), the times t4, t4 ′, t4 ″, t4 ″ ″ correspond to the state where ignition occurs (S26). Under such circumstances, ground fault detection of the first ion sensor 51 is performed at a predetermined cycle (T1) such as time t7, time t8, and time t9 (S24). The predetermined cycle (T1) can be set to 16 ms, for example, but at a timing not related to the rise and fall of the ignition signal, it does not cause a heavy load on the execution of the EFI-ECU software. It is preferable to select the timing.

  Since the ground fault detection of the ion sensor is performed at a timing that is not related to the rise and fall of the ignition signal, the output voltage of the ion sensor may originally be 0 (V). Moreover, there is a possibility that noise of the ion signal may be accidentally superimposed at the timing of detecting the ground fault of the ion sensor. Therefore, in a situation where the paging determination is not performed based on the ion signal, the ground fault detection of the ion sensor is performed a plurality of times, and when the output voltage of the predetermined number or more (for example, 80% or more) exceeds the determination voltage. It is preferable to determine that the ion sensor has a ground fault.

  As described above, in the control flow (2) shown in FIG. 6, since the ground fault detection of the ion sensor is performed in the situation where the detection of the prag is not performed, even if the noise of the ion signal is accidentally superimposed, immediately thereafter Since the prag detection is not performed, it is possible to prevent an erroneous determination of the prag.

  FIG. 8 is a diagram showing still another control flow (3).

  The control flow (3) shown in FIG. 8 is mainly executed by the CPU 11 in accordance with a program stored in advance in the ROM 12 of the EFI-ECU 10 on the system shown in FIG.

  First, the CPU 11 determines whether the IG-SW is turned on based on a signal received from the IG-SW 22 (S30).

  Next, the engine is started in conjunction with turning on the IG-SW (S31). The engine is started with the rotation of the starter motor 23 and the like by the engine control ECU.

  Next, the CPU 11 starts energization of the ignition signal (S32), detects the pre-age based on the ion signal at a predetermined timing slightly before the fall of the ignition signal (S33), and ignites the ignition plug. (S34), the ground fault of the ion sensor is detected (S35).

  Next, the CPU 11 determines whether or not the results of the Pleig detection in S33 and the ground fault detection of the ion sensor in S35 satisfy the predetermined condition 1 (S36). Specific contents of condition 1 will be described later.

  If the condition is satisfied in S36, the CPU 11 increases the counter by “1” (S37), determines whether the counter is equal to or greater than a predetermined number (n) (S38), and determines the predetermined number (n). When it is above, the ground fault determination plug on the RAM 13 indicating that the ion sensor is in the ground fault state is turned on (S39). For example, when the ground fault determination plug is turned on, a warning lamp (not shown) arranged on the front panel of the vehicle is turned on to notify the user that there is an abnormality in the ion sensor and the subsequent ion sensors The fuel injection control based on the pre-age detection based on is stopped.

  Next, the CPU 11 determines whether or not a signal indicating that the IG-SW has been turned off has been received from the IG-SW 22 (S40). When the IG-SW has been turned off, the series of processing ends. . Further, the CPU 11 repeatedly executes S32 to S40 at a predetermined timing until the IG-SW is turned off. Therefore, the CPU 11 detects the ground fault of the ion sensor based on the ion signal in a period between the falling edge of the ignition signal and the rising edge (that is, a period in which no pre-ignition is detected).

  For example, in S36, the ground fault detection of the ion sensor is performed three times in S35, and the output voltage is LOW even once among the total of four detections of three detections in S35 and detection in S33. If it is detected, the counter is incremented assuming that the condition 1 is satisfied (S37). Further, when the initial value of the counter is set to “0” and the predetermined number of times (n) is set to 6 times, and the counter becomes 6 or more, it can be determined that each ion sensor has a ground fault.

  FIG. 9 is a timing chart corresponding to the control flow (3).

  FIG. 9A shows an example of an ignition signal to the first igniter 31, and FIG. 9B shows an example of the ion signal (1) when the first ion sensor 51 is normal and no pre-ignition is generated. FIG. 9C shows an example of the ion signal (2) in the case where the first ion sensor 51 is normal but pre-generated, and FIG. 9D shows the first ion sensor 51 having a ground fault. An example of the ion signal (3) in the case of being closed is shown.

  In FIG. 9, energization of the first ignition signal is started at time t1 (S32), pre-ignition is detected at time t3 (S33), and time t4 corresponds to a state where ignition has occurred (S34). Thereafter, the ground fault detection of the first ion sensor 51 is performed over three times at times t10, t11, and t12 (S35). Thereafter, energization of the next ignition signal is started at time t1 ′ (S32).

  That is, in the control flow (3) shown in FIG. 8, a period in which no paging occurs normally (ie, a period in which no prag is detected) between the fall of the ignition signal (time t4) and the rise (time t1 ′). , The ground fault detection of the first ion sensor 51 is performed a plurality of times (time t10, t11 and t12) based on the ion signal, and the counter is incremented based on the detection result and the result of the preg detection (time t3). When the counter reaches a predetermined number or more (for example, 6 times), it is determined that the first ion sensor 51 is grounded. As described above, since the ground fault determination is performed based on the plurality of detection results, even if noise is superimposed on the ion signal at the time of the ground fault detection or the plague detection by accident, the first ion sensor 51 can be used alone. Is not determined to be ground fault. For this reason, it is possible to prevent the ground fault determination and the plague determination of the ion sensor from being erroneously performed due to noise.

  In a four-cycle engine, a suction cycle for sucking the air-fuel mixture into the cylinder, a compression cycle for compressing the air-fuel mixture, an explosion cycle in which an explosion occurs due to the ignited air-fuel mixture, and an exhaust cycle for discharging combustion gas outside the cylinder However, there is a low possibility of occurrence of plague in the absorption cycle and the discharge cycle. Therefore, it is not necessary to detect the prag in the absorption cycle and the discharge cycle. Therefore, instead of the period between the fall (time t4) and the rise (time t1 ′) of the ignition signal in the control flow (3) shown in FIG. Is possible. In this case, the CPU 11 determines whether or not each cylinder is in the period of the absorption cycle and the discharge cycle based on the crank angle detection signal from the crank angle sensor 20, the acceleration detection signal from the G sensor 21, and the like. Only in this case, the ground fault detection (S35) of the ion sensor may be performed.

  FIG. 10 is a diagram showing still another control flow (4).

  The control flow (4) shown in FIG. 10 is mainly executed by the CPU 11 in accordance with a program stored in advance in the ROM 12 of the EFI-ECU 10 on the system shown in FIG.

  First, the CPU 11 determines whether the IG-SW is turned on based on a signal received from the IG-SW 22 (S50).

  Next, the engine is started in conjunction with turning on the IG-SW (S51). The engine is started with the rotation of the starter motor 23 and the like by the engine control ECU.

  Next, the CPU 11 starts energization of the ignition signal (S52), performs the first ground fault detection of the ion sensor (S53), and then performs the second ground fault detection of the ion sensor (S54). .

  Next, the CPU 11 detects the pre-ignition based on the ion signal at a predetermined timing just before the fall of the ignition signal (S55), and ignites the spark plug (S56).

  Next, the CPU 11 determines whether or not the ground fault detection of the ion sensor twice in S53 and S54 and the result of the pre-figure determination in S55 satisfy the predetermined condition 2 (S57). Specific contents of Condition 2 will be described later.

  In S57, when the condition 2 is satisfied, the CPU 11 increments the counter by “1” (S58), determines whether the counter is equal to or greater than a predetermined number (n) (S59), and determines the predetermined number (n). When it is above, the ground fault determination flag which shows that the ion sensor is in a ground fault state is turned ON (S60). For example, when the ground fault determination flag is turned on, a warning lamp (not shown) arranged on the front panel of the vehicle is turned on to notify the user that there is an abnormality in the ion sensor and the subsequent ion sensors The fuel injection control based on the pre-ignition determination based on the above is stopped.

  Next, the CPU 11 determines whether or not a signal indicating that the IG-SW has been turned off has been received from the IG-SW 22 (S61). When the IG-SW has been turned off, the series of processing ends. . Further, the CPU 11 repeatedly executes S52 to S61 at a predetermined timing until the IG-SW is turned off. Therefore, the CPU 11 performs the ground fault detection of the ion sensor based on the ion signal in the period between the fall of the ignition signal and the rise.

  For example, in S57, only when it is detected that the ground fault detection results of the two ion sensors in S53 and S54 are the same and that the output voltage is equal to or lower than the determination voltage, Condition 2 Is satisfied (S58). In addition, when the ground fault detection results of the two ion sensors in S53 and S54 are different, the determination is retained and the determination is performed again in the next cycle without determining that it is abnormal. Further, when the initial value of the counter is set to “0” and the predetermined number (n) is set to 6 times, and the counter becomes 6 or more, it can be determined that the ion sensor 51 is grounded.

  FIG. 11 is a timing chart corresponding to the control flow (4) shown in FIG.

  FIG. 11A shows an example of an ignition signal to the first igniter 31, and FIG. 11B shows an example of an ion signal (1) when the first ion sensor 51 is normal and no plague is generated. FIG. 11 (c) shows an example of the ion signal (2) when the first ion sensor 51 is normal but plague is generated, and FIG. 11 (d) shows that the first ion sensor 51 is grounded. FIG. 11 (e) shows an example of the ion signal (3) when the ion signal is closed, and FIG. 11 (e) shows a case where the first ion sensor 51 is grounded but noise is superimposed on the ion signal. FIG. 11C shows a case where the first ion sensor 51 is normal, but noise is superimposed on the ion signal and plague is generated.

  In FIG. 11, energization of the ignition signal is started at time t1 (S14), pre-ignition is determined at time t3 (S52), and first ground fault detection of the first ion sensor 51 is performed at time t2 (S53). ), The second ground fault detection of the first ion sensor 51 is performed at time t13 (S54), the pre-ignition detection is performed at time t3 (S55), and time t4 corresponds to the state where the first ignition has occurred. (S56).

  That is, in the control flow (4) shown in FIG. 10, the ground fault detection of the ion sensor is performed a plurality of times (for example, twice) between the rise of the ignition signal (time t1) and the detection of the plague (time t3), When the detection results of a plurality of times are the same and the output voltages are both LOW, it is determined that the first ion sensor 51 is grounded. Therefore, for example, as shown in FIGS. 11E and 11F, even if accidental noise of the ion signal is superimposed, it is possible to prevent the ground fault determination and the plague determination of the ion sensor from being erroneously performed as a result. It becomes possible.

It is a figure which shows the relationship between the ignition signal to an ignition plug, and the ion signal from an ion sensor. It is a block diagram which shows schematic structure of a system. It is explanatory drawing of an engine ignition system. It is a figure which shows a control flow (1). It is a timing chart corresponding to the control flow (1) shown in FIG. It is a figure which shows another control flow (2). It is a timing chart corresponding to the control flow (2) shown in FIG. It is a figure which shows other control flow (3). It is a timing chart corresponding to the control flow (3) shown in FIG. It is a figure which shows another control flow (4). It is a timing chart corresponding to the control flow (4) shown in FIG.

Explanation of symbols

10 EFI-ECU
11 CPU
12 ROM
13 RAM
14 Driver 20 Crank angle sensor 21 G sensor 22 IG-SW
23 Starter motor 24 Knock sensor 31, 32, 33, 34 Igniter 41, 42, 43, 44 Spark plug 51, 52, 53, 54 Ion sensor 61, 62, 63, 64 Injector

Claims (5)

A control device for controlling an internal combustion engine,
A spark plug controller for controlling a spark plug for burning fuel;
An input process for inputting an ion signal from an ion sensor for detecting an ion current generated by combustion of fuel in a combustion chamber of an internal combustion engine, an ion signal input by the input process, and an input signal from a crank angle sensor Output processing for outputting an ignition signal to the spark plug control unit based on the above, a Plague detection processing for detecting Plague based on an ion signal input by the input processing, and the input when the Plague detection processing is not executed. An abnormality detection process for detecting an abnormality of the ion sensor based on an ion signal input by the process;
Control device.   The control device according to claim 1, wherein when the pre-ignition detection process is not executed, the start of the internal combustion engine is not started.   The control device according to claim 1, wherein when the pre-ignition detection process is not executed, the idling period of the internal combustion engine is set.   The said execution part is a control apparatus as described in any one of Claims 1-3 which performs the said abnormality detection process in multiple times before the said preg detection process. A control method for controlling an internal combustion engine,
Inputting an ion signal from an ion sensor that detects an ionic current generated as fuel is burned in a combustion chamber of an internal combustion engine;
Outputting an ignition signal to an ignition plug control unit for controlling an ignition plug for burning fuel based on an ion signal input by the input process or an input signal from a crank angle sensor;
A stage for detecting a preg based on the input ion signal;
A stage of performing an ion sensor anomaly detection based on an input ion signal when not performing the pre-ignition detection;
A control method.

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