JP4911364B2 - Control device for internal combustion engine - Google Patents

Description

  The present invention relates to a control device for an internal combustion engine provided with a crank angle sensor that outputs a reverse rotation signal when the internal combustion engine rotates in the reverse rotation direction.

  In general, during operation of an internal combustion engine, the cylinder is determined based on the output signals of the crank angle sensor and the cam angle sensor, and the crank angle is detected to perform ignition control and fuel injection control. At the time of start-up, until the internal combustion engine is cranked by the starter and the determination of the specific cylinder is completed (that is, until a signal of a predetermined crank angle of the specific cylinder is detected), the cylinder to be initially ignited / injected is unknown.

  In order to solve this problem, as described in Patent Document 1 (Japanese Patent Laid-Open No. 60-240875), a crank angle (stop position of the crankshaft) when the rotation of the internal combustion engine is stopped is stored in a memory. The ignition control is performed based on the crank angle at the time of the stoppage of the internal combustion engine stored in the memory until the first detection of the predetermined crank angle signal of the specific cylinder at the start of the next internal combustion engine. In addition, there is one that improves startability and exhaust emission at start-up by starting fuel injection control.

  However, even after an internal combustion engine stop command (ignition switch off signal or idle stop command) is generated and ignition and fuel injection are stopped, the internal combustion engine rotates inertially for a while, so ignition and fuel injection are stopped. If the crank angle at that time is stored, the actual stop position of the internal combustion engine (the start position of the next internal combustion engine) is erroneously determined. Therefore, it is necessary to continue detection of the crank angle after the ignition or fuel injection is stopped until the rotation of the internal combustion engine is completely stopped. However, the internal combustion engine is compressed by the compression pressure of the compression stroke immediately before the rotation of the internal combustion engine is stopped. Therefore, it is impossible to accurately detect the crank angle when the rotation of the internal combustion engine is stopped (the conventional general crank angle sensor cannot detect reverse rotation).

Therefore, as described in Patent Document 2 (Japanese Patent Laid-Open No. 2005-233622) and Patent Document 3 (Japanese Patent Laid-Open No. 2005-256842), a crank angle sensor with a reverse rotation detection function has been developed. These crank angle sensors are configured to output a pulse signal having a pulse width different from that during forward rotation when the internal combustion engine is reversely rotated.
JP-A-60-240875 (2nd page etc.) JP-A-2005-233622 (second page, etc.) JP-A-2005-256842 (second page, etc.)

  By the way, in the system including the crank angle sensor with the reverse rotation detection function described above, an abnormality in the forward rotation signal output system of the crank angle sensor (pulse signal output system during forward rotation) can be easily detected. It is difficult to detect an abnormality in the reverse signal output system (pulse signal output system during reverse rotation) for the following reason.

  In other words, since the internal combustion engine always rotates in the normal direction from the start to immediately before the stop, if the pulse signal at the time of starting or after the start of the crank angle sensor is not output, the normal rotation signal output system malfunctions. Can be determined. However, since the internal combustion engine does not always reverse immediately before stopping, and may stop without reverse rotation, when the pulse signal at the time of reverse rotation of the crank angle sensor is not output immediately before stopping, the internal combustion engine It is not possible to distinguish whether the crank angle sensor is in an abnormal state in which a pulse signal at the time of reverse rotation is not output from the crank angle sensor or the internal combustion engine is not in reverse. An abnormality in the reverse signal output system cannot be detected. Furthermore, there is a problem that proper processing (fail safe) cannot be performed even if an abnormality occurs in the reverse rotation signal output system of the crank angle sensor.

  The present invention has been made in view of such circumstances. Accordingly, a first object of the present invention is to detect an abnormality in the reverse rotation signal output system of a crank angle sensor with a reverse rotation detection function. The second object is to enable appropriate processing to be performed when the reverse rotation signal output system of the crank angle sensor with the reverse rotation detection function is abnormal.

To achieve the above object, the invention according to claim 1 outputs a forward rotation signal every time the internal combustion engine rotates by a predetermined crank angle in the forward rotation direction, and outputs a reverse rotation signal every time the internal combustion engine rotates by a predetermined crank angle in the reverse rotation direction. In a control device for an internal combustion engine equipped with a crank angle sensor for output (a crank angle sensor with a reverse rotation detection function), reverse rotation control for controlling the rotation direction of the internal combustion engine to reverse is executed by the reverse rotation control means, and the reverse rotation control is performed. When the reverse rotation signal is not output from the crank angle sensor when it is executed, it is a first feature that the abnormality diagnosis means determines that there is an abnormality in the reverse rotation signal output system of the crank angle sensor. When the engine is stopped, the internal combustion engine and / or its auxiliary equipment is controlled so that reverse rotation is likely to occur. Not output state in which the second determining means determines that there is abnormality in the reverse rotation signal output system of the crank angle sensor when continued for a predetermined time period.

  In other words, if a reverse rotation signal is not output from the crank angle sensor even if reverse rotation control is performed so that the rotation direction of the internal combustion engine is reversed, the crank direction is reversed although the rotation direction of the internal combustion engine is reversed. It is determined that the reverse rotation signal is not output from the angle sensor, and it is determined that there is an abnormality in the reverse rotation signal output system of the crank angle sensor. Thereby, it is possible to detect an abnormality in the reverse rotation signal output system of the crank angle sensor with the reverse rotation detection function.

In this case, the invention according to claim 1 executes the reverse rotation control by controlling the internal combustion engine and / or its auxiliary machine so that the reverse rotation is likely to occur when the rotation of the internal combustion engine stops as the reverse rotation control. There is a technical feature in that it is determined that there is an abnormality in the reverse rotation signal output system of the crank angle sensor when a state where no reverse rotation signal is output from the crank angle sensor continues for a predetermined period. Thus, if the internal combustion engine and the auxiliary machine are controlled so that the reverse rotation is likely to occur when the rotation of the internal combustion engine stops, a hardware configuration for reversing the internal combustion engine is newly added. Therefore, it is possible to perform abnormality diagnosis of the reverse rotation signal output system of the crank angle sensor with the reverse rotation detection function, and it is possible to satisfy the demand for cost reduction.

Specifically, as in claim 2 , at least one of the throttle opening, the valve timing, and the valve lift amount in a direction in which the compression pressure of the compression stroke increases when the rotation of the internal combustion engine stops as the reverse rotation control. May be controlled. In this way, the piston is easily pushed back by the compression pressure in the compression stroke immediately before the internal combustion engine is stopped, and reverse rotation is likely to occur.

Further, as in the third aspect , when the rotation of the internal combustion engine is stopped as the reverse rotation control, the rotational speed and / or the auxiliary load of the internal combustion engine is controlled so that the crank angle at which the reverse rotation is likely to occur immediately before the stop is obtained. Anyway. If the rotational speed of the internal combustion engine and the load on the auxiliary machine are controlled so that the crank angle (for example, the crank angle corresponding to immediately before the compression top dead center) is likely to be reversed immediately before the internal combustion engine is stopped, the internal combustion engine is immediately stopped. In addition, the piston is easily pushed back by the compression pressure in the compression stroke, and reverse rotation is likely to occur.

Further, when the present invention is applied to a hybrid system including an internal combustion engine and a motor as a power source for a vehicle as in claim 4, the internal combustion engine is forcibly driven by the power of the motor while the internal combustion engine is stopped as reverse control. Control for reversing the engine may be executed. In this way, the internal combustion engine can be reversely rotated reliably and promptly, and the presence or absence of abnormality in the reverse rotation signal output system of the crank angle sensor can be detected accurately and promptly.

Furthermore, as according to claim 5, a crank angle sensor for outputting a reverse rotation signal per rotation of a predetermined crank angle in the reverse direction to output a normal rotation signal each time the engine rotates a predetermined crank angle in the forward direction, In a control apparatus for an internal combustion engine having a cam angle sensor that outputs a cam angle signal at a predetermined cam angle, a stop crank angle at which the rotation of the internal combustion engine stops is detected based on an output signal of the crank angle sensor when the internal combustion engine is stopped Stop position detecting means for performing, and provisional crank angle detecting means for temporarily detecting a crank angle (hereinafter referred to as “temporary crank angle”) based on a stop crank angle and an output signal of the crank angle sensor when the internal combustion engine is started, Cylinder discrimination based on the crank angle sensor output signal and the cam angle sensor output signal to detect the crank angle (hereinafter referred to as “crank angle after cylinder discrimination”) after cylinder discrimination And a rank angle detecting means, be determined by the abnormality diagnosis means the presence or absence of a reverse rotation signal output system of the abnormality of the crank angle sensor is compared with the Interim crank angle and cylinder discrimination after the crank angle at the start of the internal combustion engine good.

If both the forward rotation signal output system and the reverse rotation signal output system of the crank angle sensor are normal, the provisional crank angle and the crank angle after cylinder discrimination should almost match, but the forward rotation signal output system of the crank angle sensor Alternatively, when the reverse rotation signal output system becomes abnormal, the provisional crank angle and the crank angle after cylinder discrimination do not match. Therefore, if the provisional crank angle is compared with the crank angle after cylinder discrimination when the internal combustion engine is started, it is possible to accurately determine whether there is an abnormality in the reverse rotation signal output system of the crank angle sensor. In this case, it is possible to perform abnormality diagnosis of the reverse rotation signal output system of the crank angle sensor with the reverse rotation detection function without newly adding a hardware configuration, and it is possible to satisfy the demand for cost reduction.

Also, as in claim 6, to automatically stop the internal combustion engine when a predetermined automatic stop condition is satisfied, executing the automatic stop and start control for automatically starting the internal combustion engine when a predetermined automatic start condition is satisfied A crank angle sensor that is applied to the system and outputs a forward rotation signal every time the internal combustion engine rotates by a predetermined crank angle in the forward rotation direction and outputs a reverse rotation signal every time the internal combustion engine rotates by a predetermined crank angle in the reverse rotation direction; In a control apparatus for an internal combustion engine having a cam angle sensor that outputs a cam angle signal, a stop position detection that detects a stop crank angle at which the rotation of the internal combustion engine stops based on an output signal of the crank angle sensor when the internal combustion engine is stopped. Tentatively detecting the crank angle (hereinafter referred to as “temporary crank angle”) based on the stop means and the output signal of the crank angle sensor when the internal combustion engine is started Rank angle detection means, and cylinder discrimination post-cylinder discrimination crank angle detection means for detecting the crank angle (hereinafter referred to as “cylinder discrimination after cylinder discrimination”) based on the output signal of the crank angle sensor and the output signal of the cam angle sensor. Further, the abnormality diagnosis means determines whether or not there is an abnormality in the reverse rotation signal output system of the crank angle sensor, and when it is determined that there is no abnormality in the reverse rotation signal output system of the crank angle sensor, the internal combustion is performed based on the provisional crank angle. When the engine is automatically started and it is determined that there is an abnormality in the reverse rotation signal output system of the crank angle sensor, the internal combustion engine is automatically started based on the crank angle after cylinder discrimination or automatic stop / start control is prohibited. Fail-safe control means may be provided.

  That is, if it is determined that there is no abnormality (normal) in the reverse rotation signal output system of the crank angle sensor, the stop crank angle can be accurately detected even if reverse rotation occurs when the internal combustion engine is stopped. When the engine is started, it is determined that the provisional crank angle can be accurately detected based on the stop crank angle, and the internal combustion engine is automatically started based on the provisional crank angle that can be detected earlier than the crank angle after cylinder discrimination. It is possible to start automatically quickly by executing the operation at an early stage.

  On the other hand, if it is determined that there is an abnormality in the reverse rotation signal output system of the crank angle sensor, the stop crank angle cannot be accurately detected when the reverse rotation occurs when the internal combustion engine is stopped. A crank angle sensor by determining that the detection accuracy of the provisional crank angle based on the stop crank angle is sometimes reduced and automatically starting the internal combustion engine based on the crank angle after cylinder discrimination without using the provisional crank angle. It is possible to start automatically without being affected by the abnormality of the reverse signal output system. Alternatively, by prohibiting the automatic stop / start control, it is possible to prevent deterioration of the automatic startability due to an abnormality in the reverse rotation signal output system of the crank angle sensor.

In this case, as in claim 7, may be prohibited automatic stop and start control if it is determined that there disconnection or circuit failure of the reverse rotation signal output system of the crank angle sensor. In other words, when it is determined that the crank angle sensor reverse signal output system is disconnected or there is a circuit failure, it is determined that there is a continuous abnormality, and automatic stop / start control is prohibited.

Further, as in claim 8 , when the number of times that the provisional crank angle and the crank angle after cylinder discrimination are determined not to be equal to or less than a predetermined value, the internal combustion engine is automatically started based on the crank angle after cylinder discrimination. The automatic stop / start control may be prohibited when the number of times that it is determined that the provisional crank angle and the crank angle after cylinder discrimination do not match exceeds a predetermined value. That is, if the number of times that the provisional crank angle and the crank angle after cylinder discrimination are determined not to coincide with each other is equal to or less than a predetermined value (for example, once), there is a possibility of a temporary abnormality due to the influence of noise or the like. It is determined that there is an automatic stop / start control and the internal combustion engine is automatically started based on the crank angle after cylinder discrimination, and the provisional crank angle and the crank angle after cylinder discrimination do not match. If the number of times exceeds the predetermined value, it is determined that there is a continuous abnormality, and automatic stop / start control is prohibited. As a result, it is possible to prevent the automatic stop / start control from being prohibited due to a temporary abnormality due to the influence of noise or the like, thereby suppressing deterioration in fuel consumption.

  Several embodiments embodying the best mode for carrying out the present invention will be described below.

A first embodiment of the present invention will be described with reference to FIGS.
First, a schematic configuration of the entire engine control system will be described with reference to FIG.
An air cleaner 13 is provided at the most upstream portion of the intake pipe 12 of the engine 11 that is an internal combustion engine, and an air flow meter 14 that detects the intake air amount is provided downstream of the air cleaner 13. A throttle valve 16 whose opening is adjusted by a motor 15 and a throttle opening sensor 17 for detecting the opening (throttle opening) of the throttle valve 16 are provided on the downstream side of the air flow meter 14.

  Further, a surge tank 18 is provided on the downstream side of the throttle valve 16, and an intake pipe pressure sensor 19 for detecting the intake pipe pressure is provided in the surge tank 18. The surge tank 18 is provided with an intake manifold 20 for introducing air into each cylinder of the engine 11, and a fuel injection valve 21 for injecting fuel is attached in the vicinity of the intake port of the intake manifold 20 of each cylinder. Yes. An ignition plug 22 is attached to the cylinder head of the engine 11 for each cylinder, and the air-fuel mixture in the cylinder is ignited by spark discharge of each ignition plug 22.

  On the other hand, the exhaust pipe 23 of the engine 11 is provided with an exhaust gas sensor 24 (air-fuel ratio sensor, oxygen sensor, etc.) for detecting the air-fuel ratio or rich / lean of the exhaust gas. A catalyst 25 such as a three-way catalyst for purifying gas is provided.

  Further, the engine 11 is provided with an intake side variable valve timing device 29 that changes the valve timing (opening / closing timing) of the intake valve 28 and an exhaust side variable valve timing device 31 that changes the valve timing of the exhaust valve 30. Yes. A cooling water temperature sensor 26 for detecting the cooling water temperature and a knock sensor 27 for detecting knocking vibration are attached to the cylinder block of the engine 11.

  A crank angle sensor 34 is installed facing the outer periphery of the signal rotor 33 attached to the crankshaft 32 of the engine 11. The crank angle sensor 34 is a crank angle sensor with a reverse rotation detection function, and outputs a forward rotation pulse signal every time the signal rotor 33 (crank shaft 32) rotates a predetermined crank angle (for example, 10 ° C. A) in the forward rotation direction. Whenever the signal rotor 33 rotates a predetermined crank angle (for example, 10 ° C. A) in the reverse direction, a reverse pulse signal is output. In this case, the crank angle sensor 34 can distinguish between the normal rotation pulse signal and the reverse rotation pulse signal by outputting the normal rotation pulse signal and the reverse rotation pulse signal with different pulse widths. Alternatively, the forward rotation signal output terminal and the reverse rotation signal output terminal are separately provided in the crank angle sensor 34, the forward rotation pulse signal is output from the forward rotation signal output terminal, and the reverse rotation pulse signal is output from the reverse rotation signal output terminal. Thus, the forward pulse signal and the reverse pulse signal may be distinguished. Further, the signal rotor 33 is provided with a missing tooth portion (not shown) in which the interval between pulse signals output from the crank angle sensor 34 at a specific crank angle is increased.

  Further, a cam angle sensor 35 is installed facing the outer periphery of a signal rotor (not shown) attached to the cam shaft of the engine 11. The cam angle sensor 35 outputs a cam angle signal (pulse signal) at a predetermined cam angle in synchronization with the rotation of the signal rotor (cam shaft), and the G signal for cylinder discrimination is turned on based on the cam angle signal. / OFF is switched every 360 ° A, for example.

  Outputs of these various sensors are input to a control circuit (hereinafter referred to as “ECU”) 36. The ECU 36 is mainly composed of a microcomputer, and executes various engine control programs stored in a built-in ROM (storage medium) to thereby determine the fuel injection amount of the fuel injection valve 21 according to the engine operating state. The ignition timing of the spark plug 22 is controlled, and automatic stop / start control (so-called idle stop control) is executed.

  In this automatic stop / start control, when the driver stops the vehicle during engine operation and the automatic stop condition is satisfied, the fuel injection and ignition are stopped to stop the engine 11 automatically. When the driver performs an operation to start the vehicle while the engine is stopped (for example, accelerator operation, brake release, shift lever operation, etc.) and an automatic start condition is satisfied, a starter (not shown) is turned on to inject fuel and Start control for starting ignition and automatically restarting the engine 11 is executed.

  Further, as shown in the time chart of FIG. 2, the ECU 36 counts the pulse signal output from the crank angle sensor 34 with a crank counter Ccr10, and detects the crank angle based on the count value.

  Specifically, first, when the engine 11 is started by turning on the starter when the engine 11 is normally started (for example, immediately after the ignition switch is turned on), an interval between pulse signals output from the crank angle sensor 34 is started. During the period until the missing tooth timing at which is increased, the count value of the crank counter Ccr10 is maintained at an initial value (for example, -1).

  After that, when the tooth missing timing is reached, the cylinder is discriminated based on whether or not the G signal is on. If the G signal is on, the count value of the crank counter Ccr10 is a count corresponding to the tooth missing timing when the G signal is on. Set to a value (eg 10). On the other hand, if the G signal is OFF, the count value of the crank counter Ccr10 is set to a count value (for example, 46) corresponding to the missing tooth timing when the G signal is OFF.

  Thereafter, every time the crankshaft 32 of the engine 11 rotates a predetermined crank angle (for example, 10 ° C. A) in the forward rotation direction and the forward rotation pulse signal is output from the crank angle sensor 34, the count value of the crank counter Ccr10 is changed to “ 1 "is counted up, and the crank angle (crank angle after cylinder discrimination) is detected based on the count value. In this manner, the function of detecting the crank angle after cylinder discrimination by determining the cylinder using the missing tooth timing based on the output signal of the crank angle sensor 34 and the G signal based on the output signal of the cam angle sensor 35 is disclosed. It serves as a crank angle detection means after cylinder discrimination in the claims.

  Thereafter, when the automatic stop condition of the engine 11 is satisfied and an automatic stop request is generated, the fuel injection and ignition are stopped to automatically stop the engine 11 and the crank counter when the rotation of the engine 11 is stopped. The stop crank angle is detected based on the count value of Ccr10. At this time, if the rotation direction of the engine 11 is reversed immediately before the engine 11 is stopped, the crankshaft 32 of the engine 11 rotates a predetermined crank angle (for example, 10 ° C.) in the reverse rotation direction, and the reverse rotation pulse is output from the crank angle sensor 34. Every time a signal is output, the count value of the crank counter Ccr10 is counted down by “1”. Thus, the function of detecting the stop crank angle at which the rotation of the engine 11 is stopped based on the output signal of the crank angle sensor 34 when the engine 11 is automatically stopped serves as the stop position detecting means in the claims. Fulfill.

  Thereafter, when the automatic start condition of the engine 11 is satisfied and an automatic start request is generated, the starter is turned on to start fuel injection and ignition, and the engine 11 is automatically restarted. At that time, during the period until the missing tooth timing at which the interval of the pulse signals output from the crank angle sensor 34 becomes long, the count value (stop crank angle) of the crank counter Ccr10 at the previous automatic stop is set as an initial value. Every time the crankshaft 32 of the engine 11 rotates a predetermined crank angle (for example, 10 ° C. A) in the forward rotation direction and the forward rotation pulse signal is output from the crank angle sensor 34, the count value of the crank counter Ccr10 is counted by “1”. The crank angle (provisional crank angle) is tentatively detected based on the count value. Thus, when the engine 11 is automatically started, the function of detecting the provisional crank angle based on the stop crank angle at the previous automatic stop and the output signal of the crank angle sensor 34 has the provisional crank angle detection in the claims. Acts as a means.

  Thereafter, when the missing tooth timing at which the interval between the pulse signals output from the crank angle sensor 34 becomes longer, the cylinder is determined depending on whether or not the G signal is on. If the G signal is on, the crank counter Ccr10 The count value is set to a count value (for example, 10) corresponding to the missing tooth timing when the G signal is on. On the other hand, if the G signal is OFF, the count value of the crank counter Ccr10 is set to a count value (for example, 46) corresponding to the missing tooth timing when the G signal is OFF.

  Thereafter, every time the crankshaft 32 of the engine 11 rotates a predetermined crank angle (for example, 10 ° C. A) in the forward rotation direction and the forward rotation pulse signal is output from the crank angle sensor 34, the count value of the crank counter Ccr10 is changed to “ 1 "is counted up, and the crank angle (crank angle after cylinder discrimination) is detected based on the count value.

  The ECU 36 also functions as reverse rotation control means for performing reverse rotation control for performing reverse rotation control when the rotation of the engine 11 stops by executing routines of FIGS. 3 and 4 described later. At the same time, when the reverse rotation control is executed, if the reverse rotation pulse signal is not output from the crank angle sensor 34, the reverse rotation signal output system of the crank angle sensor 34 functions as an abnormality diagnosing means that determines that there is an abnormality.

Further, the ECU 36 executes a routine shown in FIG. 5 described later, and if it is determined that there is no abnormality (normal) in the reverse rotation signal output system of the crank angle sensor 34, the temporary crank angle ( Early auto start of the engine 11 by starting fuel injection and ignition at an early stage based on the crank angle temporarily detected based on the stop crank angle at the previous automatic stop and the output signal of the crank angle sensor 34) When the engine is started and it is determined that there is an abnormality in the reverse rotation signal output system of the crank angle sensor 34, the crank angle after cylinder discrimination at the time of automatic start of the engine 11 (the tooth missing timing based on the output signal of the crank angle sensor 34). And the crank angle detected by cylinder discrimination using the G signal based on the output signal of the cam angle sensor 35 and starting fuel injection and ignition based on Gin 11 functions as a fail-safe control means for inhibiting or automatic stop and start control executes the normal automatic start of automatic startup.
Hereinafter, the processing content of each routine of FIG. 3 thru | or FIG. 5 which ECU36 performs is demonstrated.

[Reverse signal output system abnormality diagnosis routine]
The reverse rotation signal output system abnormality diagnosis routine shown in FIG. 3 is executed at a predetermined cycle while the ECU 36 is powered on. When this routine is started, first, at step 101, it is determined whether or not an automatic stop condition is satisfied. If it is determined that the automatic stop condition is satisfied, the routine proceeds to step 102, where an automatic stop / start prohibition flag is set. It is determined whether Ffail2 is “0” indicating that automatic stop / start control is permitted and the abnormality diagnosis completion flag Fjdg is “0” indicating that abnormality diagnosis is not completed.

  If it is determined in step 102 that the automatic stop / start prohibition flag Ffail2 is "0" and the abnormality diagnosis completion flag Fjdg is "0", the process proceeds to step 103, and a reverse rotation control routine of FIG. Then, reverse rotation control is performed to control the engine rotation speed and the auxiliary machine load of the engine 11 (for example, the load of the alternator) so that the reverse rotation is likely to occur when the rotation of the engine 11 is stopped.

  Thereafter, the process proceeds to step 104, where the count value of the reverse rotation control counter Cstp for counting the execution time of the reverse rotation control is incremented by “1”, and then the process proceeds to step 105, where the reverse rotation pulse signal is output from the crank angle sensor 34. Determine whether or not.

  If it is determined in step 105 that the reverse rotation pulse signal is output from the crank angle sensor 34, the process proceeds to step 106, where the count value of the reverse rotation pulse signal counter Crev that counts the reverse rotation pulse signal is incremented by "1". If it is determined in step 105 that the reverse rotation pulse signal is not output from the crank angle sensor 34, the count value of the reverse rotation pulse signal counter Crev is maintained as it is.

  Thereafter, the routine proceeds to step 107, where it is determined whether or not the count value of the reverse rotation control counter Cstp is equal to or greater than a predetermined value Kstp (for example, 3 to 5), and the count value of the reverse rotation control counter Cstp is equal to or greater than the predetermined value Kstp. When the determination is made, the routine proceeds to step 108 where it is determined whether or not the count value of the reverse pulse signal counter Crev is “0”.

  If it is determined in step 108 that the count value of the reverse rotation pulse signal counter Crev is “0”, that is, a state where no reverse rotation pulse signal is output from the crank angle sensor 34 when the reverse rotation control is executed continues for a predetermined period. If it is determined that the rotation direction of the engine 11 has been reversed, it is determined that the reverse rotation pulse signal is not output from the crank angle sensor 34, and the routine proceeds to step 109 where the reverse rotation of the crank angle sensor 34 is detected. It is determined that there is an abnormality in the signal output system, the reverse signal output system abnormality flag Frev is set to “1”, and the automatic stop / start prohibition flag Ffail2 is set to “1” which means prohibition of automatic stop / start control. The abnormality diagnosis completion flag Fjdg is set to “1” which means completion of abnormality diagnosis.

  On the other hand, when it is determined in step 108 that the count value of the reverse rotation pulse signal counter Crev is not “0”, that is, when the reverse rotation control is executed, the reverse rotation pulse signal is output from the crank angle sensor 34. If YES in step 110, the routine proceeds to step 110, where it is determined that there is no abnormality (normal) in the reverse rotation signal output system of the crank angle sensor 34, and the reverse rotation signal output system abnormality flag Frev is reset or maintained at "0". The stop / start prohibition flag Ffail2 is reset or maintained to “0”, and the abnormality diagnosis completion flag Fjdg is set to “1”.

[Reverse control routine]
The reverse rotation control routine shown in FIG. 4 is a subroutine executed in step 103 of the reverse rotation signal output system abnormality diagnosis routine of FIG. 3, and when the rotation of the engine 11 stops, the crank angle at which reverse rotation is likely to occur immediately before the stop. Reverse rotation control is performed to control the engine rotation speed and the auxiliary machine load of the engine 11 (for example, the load of the alternator) so that the rotation angle becomes equal to (e.g., the crank angle corresponding to the compression top dead center), and the rotation of the engine 11 is stopped. To make it easy for reverse rotation to occur.

  When this routine is started, first, at step 201, the coolant temperature THW, the throttle opening degree TA, the auxiliary machine load state Thoki (for example, an estimated driving torque of an air conditioner or an alternator driven by the power of the engine 11), and the like. The target idle rotation speed NEtag corresponding to is calculated by a map or a mathematical expression.

  Thereafter, the routine proceeds to step 202, where it is determined whether or not the count value of the crank counter Ccr10 has reached a predetermined target value Kcr10 (a count value corresponding to the target crank angle at which reverse rotation control is started), and the count value of the crank counter Ccr10 is determined. Is determined to have reached the target value Kcr10, the routine proceeds to step 203, where it is determined whether or not the engine speed NE is near the target idle speed NEtag (NEtag−K1 <NE ≦ NEtag + K1).

  If it is determined in step 203 that the engine rotational speed NE is not near the target idle rotational speed NEtag, the process proceeds to step 204 where the ISC opening degree (in order that the engine rotational speed NE matches the target idle rotational speed NEtag). (Throttle opening or idle speed control valve opening) is corrected.

  Thereafter, when it is determined at step 202 that the count value of the crank counter Ccr10 has reached the target value Kcr10 and when it is determined at step 203 that the engine speed NE is near the target idle speed NEtag, the routine proceeds to step 205. Then, after stopping the fuel injection, the routine proceeds to step 206 so that when the rotation of the engine 11 stops, the crank angle (for example, the crank angle corresponding to immediately before the compression top dead center) is likely to be reversed immediately before the stop. The auxiliary machine load (for example, the load of the alternator) of the engine 11 is controlled. As a result, the piston 37 is easily pushed back by the compression pressure in the compression stroke immediately before the engine 11 is stopped, and reverse rotation is likely to occur.

[Automatic start control routine]
The automatic start control routine shown in FIG. 5 is executed at a predetermined cycle while the ECU 36 is powered on. When this routine is started, first, at step 301, it is determined whether or not the automatic start condition is satisfied. If it is determined that the automatic start condition is satisfied, the routine proceeds to step 302 and the count value of the crank counter Ccr10 is reached. It is determined whether or not is 0 or more.

  If it is determined in step 302 that the count value of the crank counter Ccr10 is smaller than 0 (initial value), the process proceeds to step 305, where fuel injection and ignition are started based on the crank angle after cylinder discrimination, and the engine is started. A normal automatic start for automatically starting 11 is executed.

  On the other hand, if it is determined in step 302 that the count value of the crank counter Ccr10 is equal to or greater than 0, the routine proceeds to step 303, where the normal automatic start permission flag Ffail1 is set to normal automatic start based on the crank angle after cylinder discrimination. It is determined whether or not “1” indicating permission is set.

  If it is determined in step 303 that the normal automatic start permission flag Ffail1 is "0", that is, if it is determined that there is no abnormality (normal) in the reverse rotation signal output system of the crank angle sensor 34, the engine 11 Even if reverse rotation occurs during automatic stop, the stop crank angle can be detected with high accuracy, so it is determined that the temporary crank angle can be detected with high accuracy based on the stop crank angle at the next automatic start. Then, the routine proceeds to step 304, where early automatic start is performed in which fuel injection and ignition are started early based on the provisional crank angle to automatically start the engine 11.

  On the other hand, if it is determined in step 303 that the normal automatic start permission flag Ffail1 is set to “1”, that is, if it is determined that there is an abnormality in the reverse rotation signal output system of the crank angle sensor 34, When the reverse rotation occurs during the automatic stop of the engine 11, the stop crank angle cannot be detected with high accuracy, so that the temporary crank angle detection accuracy based on the stop crank angle is reduced at the next automatic start, Proceeding to 305, normal automatic starting is executed in which fuel injection and ignition are started based on the crank angle after cylinder discrimination without using the provisional crank angle, and the engine 11 is automatically started.

  In the first embodiment described above, the reverse rotation control that controls the engine rotation speed and the auxiliary machine load of the engine 11 (for example, the load of the alternator) so that the rotation direction is easily reversed when the rotation of the engine 11 stops. When the reverse rotation control is executed and the state in which the reverse rotation pulse signal is not output from the crank angle sensor 34 continues for a predetermined period, the crank angle sensor 34 detects that the rotation direction of the engine 11 is reverse. Since it is determined that the reverse rotation pulse signal is not output and it is determined that there is an abnormality in the reverse rotation signal output system of the crank angle sensor 34, the reverse rotation signal output system of the crank angle sensor 34 with the reverse rotation detection function is determined. Abnormalities can be detected.

  Moreover, in the first embodiment, when the rotation of the engine 11 is stopped, the engine rotation speed and the auxiliary load of the engine 11 (for example, the load of the alternator) are controlled to execute the reverse rotation control. Abnormal diagnosis of the reverse rotation signal output system of the crank angle sensor 34 with the reverse rotation detection function can be performed without newly adding a hardware configuration for reverse rotation, and the demand for cost reduction can be satisfied.

  Further, in the first embodiment, when it is determined that there is no abnormality (normal) in the reverse rotation signal output system of the crank angle sensor 34, the stop crank angle is accurately determined even if reverse rotation occurs during the automatic stop of the engine 11. Because it can be detected, it is determined that the provisional crank angle can be accurately detected based on the stop crank angle at the next automatic start, and the provisional crank that can be detected from a time earlier than the crank angle after cylinder discrimination Since the early automatic start based on the corner is executed, the automatic start can be promptly performed.

  On the other hand, if it is determined that there is an abnormality in the reverse rotation signal output system of the crank angle sensor 34, the reverse crank angle cannot be accurately detected when the reverse rotation occurs when the engine 11 is automatically stopped. Since it is determined that the detection accuracy of the provisional crank angle based on the stop crank angle at the time of automatic start of the engine is lowered, the normal automatic start based on the crank angle after cylinder discrimination is performed without using the provisional crank angle. The automatic start can be performed without being affected by the abnormality of the reverse rotation signal output system of the crank angle sensor 34.

Next, Embodiment 2 of the present invention will be described with reference to FIG. However, the description of the substantially same parts as those of the first embodiment will be simplified, and different parts from the first embodiment will be mainly described.
In the second embodiment, a reverse rotation control routine for controlling the throttle opening and the valve timing in a direction in which the compression pressure of the compression stroke increases when the rotation of the engine 11 stops by executing a reverse rotation control routine of FIG. 6 described later. Is executed so that the reverse rotation easily occurs when the rotation of the engine 11 stops.

  In the reverse rotation control routine shown in FIG. 6, first, in step 401, after fuel injection is stopped, the routine proceeds to step 402, where it is determined whether or not the engine rotational speed NE has dropped below a predetermined rotational speed Kne (for example, 500 rpm). When it is determined that the engine rotational speed NE has decreased below the predetermined rotational speed Kne, the routine proceeds to step 403 where a value obtained by adding a predetermined raising amount Kta (for example, 20 deg) to the current throttle opening TA is set as the target throttle. By setting the opening degree TAtag and controlling the motor 15 of the throttle valve 16 so that the actual throttle opening degree TA matches the target throttle opening degree TAtag, the throttle opening degree TA is increased and the compression pressure of the compression stroke is increased. increase.

  Thereafter, the routine proceeds to step 404 where the intake side variable valve timing device 29 is controlled to advance the valve timing of the intake valve 28 to the most advanced position, and the valve timing of the exhaust valve 30 is delayed to the most retarded position. By controlling the exhaust-side variable valve timing device 31 so as to make the angle, the actual compression ratio is increased and the compression pressure in the compression stroke is increased. If an intake side variable valve lift device that changes the valve lift amount of the intake valve 28 is provided, the intake side variable valve lift device is controlled so as to increase the valve lift amount of the intake valve 28. Also good. As a result, the piston 37 is easily pushed back by the compression pressure in the compression stroke immediately before the engine 11 is stopped, and reverse rotation is likely to occur.

  Note that only one of the processing in step 403 and the processing in step 404 may be executed to increase the compression pressure in the compression stroke.

Also in the second embodiment, substantially the same effect as in the first embodiment can be obtained.
In each of the first and second embodiments, when it is determined that there is an abnormality in the reverse rotation signal output system of the crank angle sensor 34, the normal automatic start based on the crank angle after cylinder discrimination is performed. You may make it prohibit start control. Alternatively, when it is determined that there is an abnormality in the reverse rotation signal output system of the crank angle sensor 34, it is determined whether the reverse rotation signal output system of the crank angle sensor 34 is disconnected or there is a circuit failure, and the reverse rotation signal output of the crank angle sensor 34 is output. When it is determined that there is a disconnection of the system or a circuit failure, it may be determined that there is a continuous abnormality, and automatic stop / start control may be prohibited.

  Next, Embodiment 3 of the present invention will be described with reference to FIGS. However, the description of the substantially same part as the first embodiment will be simplified, and the different part from the first embodiment will be mainly described.

  In the third embodiment, an abnormality diagnosis routine shown in FIGS. 7 and 8 to be described later is executed, so that the temporary crank angle (the stop crank angle at the previous automatic stop and the output signal of the crank angle sensor 34) at the time of automatic start of the engine 11 is executed. And the crank angle after cylinder discrimination (the missing tooth timing based on the output signal of the crank angle sensor 34 and the G signal based on the output signal of the cam angle sensor 35). And the presence or absence of abnormality in the forward rotation signal output system or the reverse rotation signal output system of the crank angle sensor 34 with the reverse rotation detection function.

  If both the normal rotation signal output system and the reverse rotation signal output system of the crank angle sensor 34 are normal, the provisional crank angle and the crank angle after cylinder discrimination should almost coincide with each other. If the output system or the reverse rotation signal output system becomes abnormal, the provisional crank angle and the crank angle after cylinder discrimination do not match. Therefore, if the temporary crank angle is compared with the crank angle after cylinder discrimination when the engine 11 is automatically started, it is possible to accurately determine whether there is an abnormality in the forward rotation signal output system or the reverse rotation signal output system of the crank angle sensor 34. .

  The abnormality diagnosis routine shown in FIGS. 7 and 8 is started by an interrupt process every time a pulse signal (forward rotation pulse signal or reverse rotation pulse signal) is output from the crank angle sensor 34. When this routine is started, first, at step 501, it is determined whether or not the count value of the crank counter Ccr10 is 0 or more, and it is determined that the count value of the crank counter Ccr10 is smaller than 0 (initial value). If YES in step 502, the flow advances to step 502 to determine whether or not the current interrupt process is an interrupt process based on the output of the normal pulse signal, and if it is determined to be an interrupt process based on the output of the normal pulse signal, Proceeding to step 503, it is determined whether or not it is the missing tooth timing at which the interval of the pulse signals output from the crank angle sensor 34 becomes long.

  When it is determined in this step 503 that it is a missing tooth timing, the process proceeds to step 504, where cylinder determination is made based on whether or not the G signal is on, and if it is determined that the G signal is on, In step 505, the count value of the crank counter Ccr10 is set to a count value (for example, 10) corresponding to the missing tooth timing when the G signal is on.

  On the other hand, if it is determined in step 504 that the G signal is off, the process proceeds to step 506, where the count value of the crank counter Ccr10 is a count value corresponding to the missing tooth timing when the G signal is off (eg 46). Set to.

  Thereafter, when it is determined in step 501 that the count value of the crank counter Ccr10 is equal to or greater than 0, the process proceeds to step 507, where it is determined whether or not the current interrupt process is an interrupt process by outputting a normal rotation pulse signal. If it is determined that the interrupt process is based on the output of the normal rotation pulse signal, the process proceeds to step 508 to increment the count value of the crank counter Ccr10 by “1”. Thereafter, the process proceeds to step 509, where it is determined whether or not the count value of the crank counter Ccr10 is equal to or less than an upper limit value (eg 71). When the count value of the crank counter Ccr10 exceeds the upper limit value, the process proceeds to step 510. The count value of the crank counter Ccr10 is reset to a lower limit value (for example, 0).

  On the other hand, if it is determined in step 507 that the interrupt process is not based on the output of the forward pulse signal (that is, the interrupt process is based on the output of the reverse pulse signal), the process proceeds to step 511 and the count value of the crank counter Ccr10 is reached. Is counted down by “1”. Thereafter, the process proceeds to step 512, where it is determined whether or not the count value of the crank counter Ccr10 is equal to or greater than a lower limit value (for example, 0), and when the count value of the crank counter Ccr10 falls below the lower limit value, the process proceeds to step 513. The count value of the crank counter Ccr10 is reset to an upper limit value (eg 71).

Thereafter, the process proceeds to step 514 in FIG. 8 to determine whether or not it is a missing tooth timing at which the interval between the pulse signals output from the crank angle sensor 34 is long. When it is determined that it is a missing tooth timing, Proceeding to step 515, the cylinder is discriminated based on whether or not the G signal is on. If it is determined that the G signal is on, the process proceeds to step 516, where the current count value of the crank counter Ccr10 and the G signal are on. A deviation Dcr from a count value (for example, 10) corresponding to the missing tooth timing at the time is calculated by the following equation.
Dcr = | Ccr10-10 |

  In the case of the missing tooth timing when the G signal is turned on for the first time when the engine 11 is automatically started, the current count value of the crank counter Ccr10 corresponds to the provisional crank angle, and the count corresponds to the missing tooth timing when the G signal is turned on. Since the value (for example, 10) corresponds to the crank angle after cylinder discrimination, the deviation Dcr corresponds to the deviation between the provisional crank angle and the crank angle after cylinder discrimination.

On the other hand, if it is determined in step 515 that the G signal is off, the process proceeds to step 517, where the current count value of the crank counter Ccr10 and the count value corresponding to the missing tooth timing when the G signal is off (for example, 46) is calculated by the following equation.
Dcr = | Ccr10-46 |

  In the case of the missing tooth timing when the G signal is initially turned off when the engine 11 is automatically started, the current count value of the crank counter Ccr10 corresponds to the provisional crank angle, and the count corresponds to the missing tooth timing when the G signal is turned off. Since the value (for example, 46) corresponds to the crank angle after cylinder discrimination, the deviation Dcr corresponds to the deviation between the provisional crank angle and the crank angle after cylinder discrimination.

  Thereafter, the process proceeds to step 518, in which it is determined whether or not the deviation Dcr is smaller than an abnormality determination value Kdcr (for example, 4), and the deviation Dcr becomes the abnormality determination value Kdcr at the first missing tooth timing when the engine 11 is automatically started. If the crank angle sensor 34 is determined to be smaller than that, the provisional crank angle and the crank angle after cylinder discrimination are substantially the same, so it is determined that the crank angle sensor 34 is not abnormal (normal), and the process proceeds to step 519. Determine whether the signal is on.

  If it is determined in step 519 that the G signal is on, the process proceeds to step 520, where the count value of the crank counter Ccr10 is set to a count value (for example, 10) corresponding to the missing tooth timing when the G signal is on, The normal automatic start permission flag Ffail1 is reset or maintained to “0”. On the other hand, if it is determined in step 519 that the G signal is off, the process proceeds to step 521 where the count value of the crank counter Ccr10 is set to a count value (for example, 46) corresponding to the missing tooth timing when the G signal is off. Then, the normal automatic start permission flag Ffail1 is reset or maintained to “0”.

  On the other hand, if it is determined in step 518 that the deviation Dcr is equal to or greater than the abnormality determination value Kdcr at the first missing tooth timing when the engine 11 is automatically started, the provisional crank angle and the cylinder after cylinder determination are determined. Since the angle does not match (the difference between the two is large), it is determined that there is an abnormality in the forward rotation signal output system or the reverse rotation signal output system of the crank angle sensor 34, and the routine proceeds to step 522, where the count value of the crank counter Ccr10 Is reset to an initial value (for example, -1), and a normal automatic start permission flag Ffail1 is set to "1".

  In the third embodiment described above, when the engine 11 is automatically started, the provisional crank angle (tentatively detected based on the stop crank angle at the previous automatic stop and the output signal of the crank angle sensor 34) and the cylinder The crank angle after comparison is compared with the crank angle (crank angle detected by cylinder discrimination using the missing tooth timing based on the output signal of the crank angle sensor 34 and the G signal based on the output signal of the cam angle sensor 35). Since the presence / absence of abnormality of the forward rotation signal output system or the reverse rotation signal output system of the angle sensor 34 is determined, abnormality diagnosis of the crank angle sensor 34 with the reverse rotation detection function is performed without adding a new hardware configuration. Can meet the demand for cost reduction.

  In each of the first and second embodiments, when it is determined that there is an abnormality in the reverse rotation signal output system of the crank angle sensor 34, the normal automatic start based on the crank angle after cylinder discrimination is performed. When it is determined that there is an abnormality in the reverse signal output system of the angle sensor 34, it is determined whether or not the provisional crank angle and the crank angle after cylinder discrimination coincide with each other when the engine 11 is automatically started (the difference between the two is small). If the number of times that the provisional crank angle and the crank angle after cylinder discrimination are determined to be not equal to or less than a predetermined value (for example, once) is determined, there may be a temporary abnormality due to the influence of noise or the like. Normal automatic start based on the crank angle after cylinder discrimination is performed without prohibiting automatic stop / start control, and it is determined that the provisional crank angle does not match the crank angle after cylinder discrimination. The number of times If it exceeds the value, it is determined that the continuous abnormalities may be prohibited automatic stop and start control. As a result, it is possible to prevent the automatic stop / start control from being prohibited due to a temporary abnormality due to the influence of noise or the like, thereby suppressing deterioration in fuel consumption.

  Next, a fourth embodiment in which the present invention is applied to a hybrid electric vehicle will be described with reference to FIGS. 9 and 10. However, substantially the same parts as those in the first embodiment are denoted by the same reference numerals, and the description will be simplified. The parts different from the first embodiment will be mainly described.

  First, the configuration of a vehicle drive control system for a hybrid electric vehicle will be described with reference to FIG. The hybrid electric vehicle is equipped with an engine 11 (internal combustion engine) and a starter AC motor 38 as drive sources, and these powers are transmitted to a differential device 41 via a torque converter 39 and a transmission 40 for further driving. It is transmitted to the drive wheel 43 via the shaft 42.

  The powertrain control device 44 receives information on the engine operating state detected by the crank angle sensor 34, the cam angle sensor 35, the air flow meter 14, the cooling water temperature sensor 26, and the vehicle state information transmitted from the vehicle control device 45. Based on this, the intake air amount, fuel injection amount, and ignition timing of the engine 11 are controlled to control the output torque of the engine 11, the torque generated by the AC motor 38 is controlled, and the lock-up state of the torque converter 39 The gear ratio of the transmission 40 is controlled.

  On the other hand, the vehicle control device 45 is configured to output signals from various sensors such as an accelerator pedal sensor 46, a shift sensor 47, a vehicle speed sensor 48, and a brake master cylinder pressure sensor 49, and an engine operating state transmitted from the power train control device 44. The traveling state of the vehicle is controlled based on the information. Specifically, the vehicle control device 45 includes a power train control device 44, an inverter 50, an auxiliary battery control device 51 (DC / DC converter), the engine 11, an AC motor 38, a transmission 40, a high-voltage DC battery. 52, the auxiliary battery 53 and the like are cooperatively controlled to execute automatic stop / start control (so-called idle stop control) of the engine 11 and to control start, acceleration assist, deceleration regeneration, and the like.

  In the start control, after the AC motor 38 (starter) is started to increase the rotational speed of the engine 11 to a predetermined rotational speed, the fuel pump 55 is started by the fuel pump control device 54 and the power train control device 44 The engine 11 is started by starting fuel injection and ignition.

  The auxiliary battery control device 51 controls the charge amount of the auxiliary battery 53 based on signals from the vehicle control device 45 and output signals of various sensors such as the auxiliary battery current sensor 56 and the auxiliary battery temperature sensor 57. To do. Further, the vehicle control device 45 has a self-diagnosis function, and when an abnormality / failure of each part of the vehicle drive control system is detected, the abnormality / failure content is displayed on the warning display unit 58 (warning means) as a warning. Warning the driver.

  A fuel pump 55 that pumps up fuel in a fuel tank (not shown) and supplies it to the engine 11 incorporates a brushed DC motor (not shown) as a drive source and is driven using the voltage of the auxiliary battery 53 as a power supply voltage. Is done. The fuel pump control device 54 that controls the fuel pump 55 controls the drive current of the fuel pump 55 based on output signals from the auxiliary battery voltage sensor 59, the fuel pump coil temperature sensor 60, and the like.

  Further, the vehicle control device 45 executes a reverse rotation control to forcibly reverse the engine 11 with the power of the AC motor 38 while the engine is stopped by executing a reverse rotation signal output system abnormality diagnosis routine of FIG. 10 described later. It functions as a reverse rotation control means and also functions as an abnormality diagnosis means that determines that there is an abnormality in the reverse rotation signal output system of the crank angle sensor 34 when the reverse rotation pulse signal is not output from the crank angle sensor 34 when this reverse rotation control is executed. To do.

  In the reverse rotation signal output system abnormality diagnosis routine shown in FIG. 10, first, in step 601, it is determined whether or not the engine is stopped. In the next step 602, it is determined whether or not the transmission 40 is in a neutral state. To do. As a result, when it is determined in step 601 that the engine is not stopped (engine is running), or in step 602, it is determined that the transmission 40 is not in the neutral state (power transmission state). In this case, this routine is terminated without performing the processing from step 603 onward.

  On the other hand, if it is determined in step 601 that the engine is stopped, and if it is determined in step 602 that the transmission 40 is in the neutral state, the process proceeds to step 603 where the abnormality diagnosis completion flag Fjdg is abnormally diagnosed. Whether or not the abnormality diagnosis completion flag Fjdg is "0", the process proceeds to step 604, and the engine is forcibly driven by the power of the AC motor 38. 11 performs reverse rotation control to reverse 11.

  Thereafter, the process proceeds to step 605, where it is determined whether or not the reverse rotation pulse signal is output from the crank angle sensor 34. If it is determined that the reverse rotation pulse signal is not output from the crank angle sensor 34, the engine 11 It is determined that the reverse rotation pulse signal is not output from the crank angle sensor 34 despite the reverse rotation, and the process proceeds to step 606, where it is determined that there is an abnormality in the reverse rotation signal output system of the crank angle sensor 34, The reverse signal output system error flag Frev is set to “1”, the automatic stop / start prohibition flag Ffail2 is set to “1” which means prohibition of automatic stop / start control, and the abnormality diagnosis completion flag Fjdg is abnormal. Set to “1”, meaning the diagnosis is complete.

  On the other hand, if it is determined in step 605 that the reverse rotation pulse signal has been output from the crank angle sensor 34, the process proceeds to step 607, where there is no abnormality (normal) in the reverse rotation signal output system of the crank angle sensor 34. The reverse rotation signal output system abnormality flag Frev is reset or maintained to “0”, and the automatic stop / start prohibition flag Ffail2 is reset or maintained to “0”, and the abnormality diagnosis completion flag Fjdg is set to “1”. Set to.

In the fourth embodiment described above, since the reverse rotation control for forcibly rotating the engine 11 with the power of the AC motor 38 is executed while the engine is stopped, the engine 11 can be reliably and quickly reversed. The presence or absence of abnormality in the reverse rotation signal output system of the crank angle sensor 34 can be detected accurately and promptly.
Needless to say, the techniques described in the first to third embodiments are not limited to a general vehicle using only the engine 11 as a power source, and may be applied to a hybrid electric vehicle.

  Further, in a system including a reverse rotation prevention mechanism that prevents the engine 11 from rotating in reverse and a general crank angle sensor that does not include a reverse rotation detection function, the provisional crank angle and the crank after cylinder discrimination are determined when the engine 11 is automatically started. Whether or not there is an abnormality in the reverse rotation prevention mechanism may be determined based on whether or not the angle matches. Further, when it is determined that there is no abnormality (normal) in the reverse rotation prevention mechanism, early automatic start based on the provisional crank angle is executed, and when it is determined that there is an abnormality in the reverse rotation prevention mechanism, it is based on the crank angle after cylinder discrimination. Ordinary automatic start may be executed or automatic stop / start control may be prohibited.

It is a schematic block diagram of the whole engine control system in Example 1 of this invention. It is a time chart explaining the detection method of the crank angle based on the count of a crank counter. 6 is a flowchart for explaining a processing flow of a reverse rotation signal output system abnormality diagnosis routine according to the first embodiment. 4 is a flowchart for explaining a process flow of a reverse rotation control routine according to the first embodiment. 6 is a flowchart for explaining a flow of processing of an automatic start control routine according to the first embodiment. 6 is a flowchart for explaining the flow of processing of a reverse rotation control routine of Embodiment 2. 10 is a flowchart (No. 1) for explaining the flow of processing of an abnormality diagnosis routine of Embodiment 3. 12 is a flowchart (No. 2) for explaining the flow of processing of the abnormality diagnosis routine of the third embodiment. It is a schematic block diagram of the whole vehicle drive control system of the hybrid electric vehicle of Example 4. 12 is a flowchart for explaining a processing flow of a reverse rotation signal output system abnormality diagnosis routine according to a fourth embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 11 ... Engine (internal combustion engine), 12 ... Intake pipe, 16 ... Throttle valve, 21 ... Fuel injection valve, 22 ... Spark plug, 23 ... Exhaust pipe, 32 ... Crankshaft, 34 ... Crank angle sensor, 35 ... Cam angle sensor 36 ... ECU (reverse rotation control means, abnormality diagnosis means, stop position detection means, provisional crank angle detection means, crank angle detection means after cylinder discrimination, fail safe control means), 38 ... AC motor, 39 ... torque converter, 40 ... Transmission, 44 ... Powertrain control device, 45 ... Vehicle control device (reverse rotation control means, abnormality diagnosis means), 50 ... Inverter, 52 ... High voltage DC battery

Claims (8)

In a control device for an internal combustion engine comprising a crank angle sensor that outputs a forward rotation signal every time the internal combustion engine rotates a predetermined crank angle in the forward rotation direction and outputs a reverse rotation signal every time the internal combustion engine rotates by a predetermined crank angle in the reverse rotation direction.
Reverse rotation control means for executing reverse rotation control for controlling the rotation direction of the internal combustion engine to be reversed;
An abnormality diagnosing means for determining that there is an abnormality in the reverse rotation signal output system of the crank angle sensor when the reverse rotation signal is not output from the crank angle sensor when the reverse rotation control is executed ,
The reverse rotation control means controls the internal combustion engine and / or its auxiliary machine so that the reverse rotation is likely to occur when the rotation of the internal combustion engine stops as the reverse rotation control,
The abnormality diagnosis means determines that there is an abnormality in the reverse rotation signal output system of the crank angle sensor when the reverse rotation signal is not output from the crank angle sensor when the reverse rotation control is executed for a predetermined period. A control device for an internal combustion engine characterized by the above. The reverse rotation control means controls at least one of the throttle opening, the valve timing, and the valve lift amount in the direction in which the compression pressure of the compression stroke increases when the rotation of the internal combustion engine stops as the reverse rotation control. The control apparatus for an internal combustion engine according to claim 1 , wherein the control apparatus is an internal combustion engine. The reverse rotation control means controls the rotational speed and / or auxiliary load of the internal combustion engine so that the crank angle at which the reverse rotation is likely to occur immediately before the stop when the rotation of the internal combustion engine stops as the reverse rotation control. The control apparatus for an internal combustion engine according to claim 1 or 2 . An internal combustion engine and a motor as a power source of the vehicle,
2. The control device for an internal combustion engine according to claim 1, wherein the reverse rotation control unit executes a control to forcibly reverse the internal combustion engine with the power of the motor while the internal combustion engine is stopped as the reverse rotation control. A crank angle sensor that outputs a forward rotation signal every time the internal combustion engine rotates by a predetermined crank angle in the forward rotation direction and outputs a reverse rotation signal every time the internal combustion engine rotates by a predetermined crank angle in the reverse rotation direction, and outputs a cam angle signal at a predetermined cam angle An internal combustion engine control device comprising a cam angle sensor
Stop position detecting means for detecting a stop crank angle at which the rotation of the internal combustion engine has stopped based on an output signal of the crank angle sensor when the internal combustion engine is stopped;
Provisional crank angle detection means for tentatively detecting a crank angle (hereinafter referred to as “provisional crank angle”) based on the stop crank angle and an output signal of the crank angle sensor when the internal combustion engine is started;
A post-cylinder discrimination crank angle detection means for detecting a crank angle (hereinafter referred to as “cylinder discrimination after cylinder discrimination”) based on an output signal of the crank angle sensor and an output signal of the cam angle sensor;
An abnormality diagnosing means for comparing the provisional crank angle with the crank angle after cylinder discrimination at the start of the internal combustion engine to determine whether there is an abnormality in the reverse rotation signal output system of the crank angle sensor. Control device for internal combustion engine. The system is applied to a system that executes automatic stop / start control that automatically stops an internal combustion engine when a predetermined automatic stop condition is satisfied and automatically starts the internal combustion engine when a predetermined automatic start condition is satisfied. A crank angle sensor that outputs a forward rotation signal every rotation of a predetermined crank angle in the rotation direction and outputs a reverse rotation signal every rotation of the predetermined crank angle in the reverse rotation direction, and a cam angle sensor that outputs a cam angle signal at a predetermined cam angle An internal combustion engine control device comprising:
Stop position detecting means for detecting a stop crank angle at which the rotation of the internal combustion engine has stopped based on an output signal of the crank angle sensor when the internal combustion engine is stopped;
Provisional crank angle detection means for tentatively detecting a crank angle (hereinafter referred to as “provisional crank angle”) based on the stop crank angle and an output signal of the crank angle sensor when the internal combustion engine is started;
A post-cylinder discrimination crank angle detection means for detecting a crank angle (hereinafter referred to as “cylinder discrimination after cylinder discrimination”) based on an output signal of the crank angle sensor and an output signal of the cam angle sensor;
An abnormality diagnosing means for determining whether there is an abnormality in the reverse rotation signal output system of the crank angle sensor;
When the abnormality diagnosis means determines that there is no abnormality in the reverse rotation signal output system of the crank angle sensor, the internal combustion engine is automatically started based on the temporary crank angle, and the reverse rotation of the crank angle sensor is performed by the abnormality diagnosis means. Fail-safe control means for automatically starting the internal combustion engine based on the crank angle after cylinder discrimination when it is determined that there is an abnormality in the signal output system, or prohibiting the automatic stop / start control. A control device for an internal combustion engine. The abnormality diagnosis means includes means for determining the presence or absence of a disconnection or circuit failure in the reverse rotation signal output system of the crank angle sensor,
The fail-safe control means, claim and inhibits the automatic stop and start control if it is determined that there disconnection or circuit failure of the reverse rotation signal output system of the crank angle sensor by the abnormality diagnosis means 6 The control apparatus of the internal combustion engine described in 1. The abnormality diagnosis means includes means for determining whether or not the provisional crank angle and the cylinder angle after cylinder discrimination coincide with each other when the internal combustion engine is started.
The fail-safe control means is configured to determine whether the provisional crank angle and the post-cylinder discrimination crank angle are not equal to each other based on the post-cylinder discrimination crank angle when the number of times that the provisional crank angle and the post-cylinder discrimination crank angle do not match each other An automatic start of the internal combustion engine is executed, and the automatic stop / start control is prohibited when the number of times that the provisional crank angle and the crank angle after cylinder discrimination are determined not to coincide with each other exceeds a predetermined value. The control device for an internal combustion engine according to claim 6 or 7 , characterized in that

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