JP2011179369A - Abnormality determination device of rotation angle detection system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an abnormality detection device, highly accurately determining an abnormality of a rotation angle detection system. <P>SOLUTION: The device is applied to a rotation angle detection system having a main sensor and a sub sensor which output pulse signals shifted in phase with each other according to change in crank angle. The system determines a specified state when output signals of a sub sensor in change of output signals of a main sensor are high signals sequentially predetermined number of times, and outputs a diagnosis high signal as a crank signal NE. When the crank signal NE is the diagnosis high signal and has a value indicating that the crankshaft has been rotated (S402:YES), it is determined that an abnormality has occurred in a rotation angle detection system (S403). When operation of the internal combustion engine is automatically stopped, and a transmission is in an operating status selected in travelling of a vehicle (S401:YES), determination of occurrence of an abnormality is prohibited. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an abnormality determination device that determines the occurrence of an abnormality in a rotation angle detection system that outputs a signal corresponding to the amount and direction of rotation of an output shaft of an internal combustion engine.

  In recent years, in order to reduce fuel consumption and emissions, a hybrid vehicle having an internal combustion engine and an electric motor as a vehicle drive source, or a vehicle that temporarily stops the operation of the internal combustion engine when the vehicle stops at an intersection or the like As described above, it has been proposed and put into practice to execute control (intermittent stop control) for intermittently stopping the operation of the internal combustion engine when the vehicle is operated.

  In such vehicles, when the internal combustion engine is automatically stopped in intermittent stop control, the rotation angle of the output shaft is accurately grasped, so that engine control (fuel injection control, etc.) is appropriately executed when the internal combustion engine is subsequently restarted. It is possible to perform the restart properly and complete it promptly.

  By the way, the output shaft of the internal combustion engine does not always rotate in one direction, and may temporarily rotate in the opposite direction (reverse direction) to the direction during normal operation (forward direction) during the stop process or stop. is there. Therefore, if only a sensor for detecting the rotation amount of the output shaft of the internal combustion engine is provided and a signal corresponding to the output signal of the sensor is output as the rotation angle detection system, the output shaft of the internal combustion engine is When rotating in the opposite direction, this cannot be grasped from the output signal of the system. Therefore, a deviation occurs between the actual rotation angle and the rotation angle of the output shaft of the internal combustion engine, which is determined by the output signal of the rotation angle detection system, and the internal combustion engine can be restarted properly. Disappear.

  Therefore, conventionally, a rotation angle detection system has been proposed in which the rotational direction of the output shaft of the internal combustion engine is grasped together with the rotational direction, and a signal corresponding to the detected rotational amount and rotational direction is output (for example, Patent Document 1). By calculating the rotation angle of the output shaft of the internal combustion engine based on the output signal of such a rotation angle detection system, it is possible to accurately determine the rotation angle of the output shaft of the internal combustion engine in consideration of rotation in the reverse direction. become.

  This system includes a disk-shaped signal rotor attached to the output shaft of the internal combustion engine and two sensors (a first sensor and a second sensor) provided in the vicinity of the signal rotor. A large number of protrusions are formed on the outer periphery of the signal rotor for each predetermined angle, and both sensors output a pulse-like signal each time the protrusions of the signal rotor pass nearby, and these sensors are pulses that are out of phase with each other. A signal is output. Based on the number of pulse signals output from each sensor, the amount of rotation of the output shaft of the internal combustion engine is grasped, and the change mode of the output signal of the first sensor (change from low signal to high signal [rise] Or the change [falling] from the high signal to the low signal) and the output value (high signal or low signal) of the second sensor, the rotation direction of the engine output shaft is grasped.

Japanese Patent Laying-Open No. 2005-233622 (page 5-6, FIG. 2-3)

  By the way, in the above rotation angle detection system, when an abnormality occurs and the output signal of the second sensor does not change from a constant value (high signal or low signal), the output shaft of the internal combustion engine rotates in one direction. Thus, the forward direction and the reverse direction are detected alternately as the rotation direction. Therefore, at this time, a deviation occurs between the actual rotation angle of the output shaft of the internal combustion engine and the rotation angle obtained based on the output signal of the system, and the restart of the internal combustion engine cannot be completed promptly. There is a fear.

  In order to appropriately deal with the occurrence of such an abnormality, it is desirable to accurately determine the occurrence. However, it is difficult to accurately determine the occurrence of the abnormality for the following reason.

  When rotation of the output shaft of the internal combustion engine stops, compression and expansion of intake air filled in the combustion chamber of the internal combustion engine are alternately repeated, so that the output shaft swings alternately in the forward direction and the reverse direction. A phenomenon (so-called chattering phenomenon) may occur. When such chattering occurs, even if the signal is normally output from the second sensor, the output shaft of the internal combustion engine actually rotates alternately in the forward and reverse directions. A constant value (high signal or low signal) is continuously output from the second sensor while a pulse signal is output from one sensor. For this reason, it is difficult to accurately determine whether this is due to the occurrence of the abnormality or the chattering phenomenon even when the output signal of the second sensor does not change from a constant value. It can be said that it is difficult to accurately determine the occurrence of this.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide an abnormality detection device capable of accurately determining an abnormality in a rotation angle detection system.

In the following, means for achieving the above object and its operational effects will be described.
The invention according to claim 1 is provided in a vehicle in which an output shaft of an in-vehicle internal combustion engine is connected to a drive wheel via a transmission, and intermittent stop control for intermittently stopping the operation of the internal combustion engine is executed. And a first sensor and a second sensor for outputting a pulse-like signal in response to a change in the rotation angle of the output shaft, and for outputting signals whose phases are shifted from each other. The amount of rotation of the output shaft is detected based on at least one of the output signals of one sensor and the second sensor, and the change mode of the output signal when the output signal of the first sensor changes and the output of the second sensor When the rotation direction of the output shaft is detected based on the relationship with the signal, and the output signal of the second sensor at the time of change of the output signal of the first sensor becomes the same state continuously for a predetermined number of times Special And is applied to a rotation angle detection system that outputs a signal including information on the detected rotation amount and rotation direction and information on the specific state, and an output signal of the rotation angle detection system is It is determined that an abnormality has occurred in the rotation angle detection system when a determination condition is established that the output shaft has reached a value indicating that the output shaft has rotated under a condition that indicates a specific state. A situation in which the determination condition is satisfied when the operation of the internal combustion engine is intermittently stopped through the abnormality determination means and the intermittent stop control and the transmission is in an operating state selected when the vehicle travels. Even so, the gist of the invention is to include determination prohibiting means for prohibiting the determination that the abnormality has occurred.

  In the above configuration, when an abnormality occurs in which the output signal of the second sensor does not change from a constant value during operation of the internal combustion engine, the output signal of the second sensor at the time of change of the output signal of the first sensor continues for a predetermined number of times. In this state, the output signal of the rotation angle detection system becomes a value indicating that the output shaft of the internal combustion engine has rotated. Therefore, in this case, it can be properly determined that an abnormality has occurred in the rotation angle detection system.

  Further, when the chattering phenomenon described above occurs during the intermittent stop of the internal combustion engine, the output signal of the second sensor at the time of change of the output signal of the first sensor may become the same state continuously for a predetermined number of times. Since the rotation of the output shaft of the internal combustion engine stops at, the output signal of the rotation angle detection system does not become a value indicating that the output shaft of the internal combustion engine has rotated. Therefore, in this case, it is avoided that it is erroneously determined that an abnormality has occurred in the rotation angle detection system.

  Further, even when the operation of the internal combustion engine is stopped, when the transmission is in an operation state selected when the vehicle is traveling, the output shaft of the internal combustion engine is caused by the vehicle sliding down on the slope. May rotate. Therefore, even when the internal combustion engine is intermittently stopped, it can be said that the output signal of the rotation angle detection system may become a value indicating that the output shaft of the internal combustion engine has rotated, and this causes an abnormality in the rotation angle detection system. May be mistakenly determined. In this regard, in the above configuration, even when the output signal of the rotation angle detection system becomes a value indicating that the output shaft of the internal combustion engine has rotated in this way, it is not determined that an abnormality has occurred in the system. . Therefore, in this case as well, it is avoided that it is erroneously determined that an abnormality has occurred in the rotation angle detection system.

  Thus, according to the above configuration, when the output signal of the second sensor does not change from a certain value, it is accurately determined that this is due to the occurrence of the abnormality, and the rotation angle detection system Abnormalities can be accurately determined.

  According to a second aspect of the present invention, in the abnormality determination device for the rotation angle detection system according to the first aspect, the rotation angle detection system further continues the same state after it is determined to be in the specific state. In some cases, only the information about the specific state is output for a predetermined period immediately after the determination.

  According to the above configuration, when the specific state is entered, in other words, when the reliability of the rotation angle detection system is reduced, the output of the information about the rotation amount and the information about the rotation direction from the system is stopped. Therefore, it is possible to suppress the execution of engine control based on an inappropriate signal. In addition, in the above configuration, when the specific state is continued for a predetermined period, the output of the information about the rotation amount of the output shaft of the internal combustion engine and the information about the rotation direction is resumed, and the output signal of the rotation angle detection system is output from the internal combustion engine. The value indicates that the output shaft has rotated, and it is determined that an abnormality has occurred in the system. Thus, according to the above configuration, it is possible to determine the occurrence of an abnormality in the rotation angle detection system when the specific state is continued for a predetermined period. Therefore, it is possible to avoid an erroneous determination due to an unnecessary change in the output signal due to the superimposition of noise on each output signal, and it is possible to accurately determine the occurrence of abnormality.

  According to a third aspect of the present invention, in the abnormality determination device for the rotation angle detection system according to the first aspect, the rotation angle detection system further continues the same state after it is determined that the specific state is present. In this case, only the information on the specific state is output during a period until the number of times that the same state continues reaches a predetermined number, and the output shaft rotates in the positive direction after the lapse of the period. The gist of the present invention is to output information indicating that the rotation is detected, information regarding the detected rotation amount, and information regarding the specific state.

  According to the above configuration, when the specific state is entered, in other words, when the reliability of the rotation angle detection system is reduced, the output of the information about the rotation amount and the information about the rotation direction from the system is stopped. Therefore, it is possible to suppress the execution of engine control based on an inappropriate signal.

  When the specific state is continued for a predetermined period, information on the rotation amount detected by the first sensor or the second sensor is output together with information that the output shaft of the internal combustion engine is rotating in the positive direction. Therefore, the engine operation can be executed based on the information, and the traveling function of the vehicle can be maintained.

  In addition, in the above configuration, when the information about the rotation direction and the information about the rotation amount are output in this way, the output signal of the rotation angle detection system becomes a value indicating that the output shaft of the internal combustion engine has rotated. As a result, it is determined that an abnormality has occurred in the system. Thus, according to the above configuration, it is possible to determine the occurrence of an abnormality in the rotation angle detection system when the specific state is continued for a predetermined period. Therefore, it is possible to avoid an erroneous determination due to an unnecessary change in the output signal due to the superimposition of noise on each output signal, and it is possible to accurately determine the occurrence of abnormality.

  According to a fourth aspect of the present invention, in the rotation angle detection system abnormality determination device according to the second or third aspect of the invention, the rotation angle detection system is configured to detect the second sensor when the output signal of the first sensor changes. When the output signal is continuously in the same state for the first predetermined number of times, the output of the information about the rotation amount of the output shaft and the information about the rotation direction is prohibited, and the output of the first sensor When the output signal changes, when the output signal of the second sensor is continuously in the same state for a second predetermined number of times that is greater than the first predetermined number of times, the specific state is determined. This is the gist.

  According to the above configuration, when the output signal of the second sensor at the time of the change of the output signal of the first sensor becomes the same state continuously for the first predetermined number of times, that is, the reliability of the rotation angle detection system is lowered. When there is a possibility, the output of the information about the rotation amount of the engine output shaft and the information about the rotation direction from the rotation angle detection system can be stopped. Thereby, execution of engine control based on an inappropriate signal can be suppressed.

  As described above, even when the chattering phenomenon occurs, the output signal of the second sensor when the output signal of the first sensor changes may be in the same state continuously for the first predetermined number of times. . However, in this case, the above situation does not last long. In this regard, according to the above configuration, since it is determined that the specific state has been obtained on the condition that the above situation has been continued, it is possible to suppress erroneous determination that the specific state has occurred due to the occurrence of the chattering phenomenon. be able to.

  The invention according to claim 5 is the abnormality determination device for the rotation angle detection system according to any one of claims 1 to 4, provided that the output shaft is in an engine operating state that rotates only in the positive direction. The rotation angle is detected when the number of times that the specific state is determined is equal to or greater than a determination value based on an output signal of the rotation angle detection system at predetermined intervals. The gist of the present invention is to further include an abnormality occurrence determination means for determining that an abnormality has occurred in the system.

  According to the above configuration, the number of times determined to be the specific state when the output shaft of the internal combustion engine is in an operating state in which the output shaft rotates only in the positive direction, that is, in an engine operating state in which chattering does not occur. And the occurrence of an abnormality in the rotation angle detection system can be determined based on the number of times. For this reason, it is possible to suppress erroneous determination that an abnormality has occurred in the rotation angle detection system due to the occurrence of the chattering phenomenon. Moreover, since the abnormality determination by the abnormality occurrence determination means is executed in addition to the abnormality determination by the abnormality determination means described above, the execution of the fail safe control for the engine control is started by the abnormality determination by one of them, and thereafter It is possible to deal with the occurrence of an abnormality in the rotation angle detection system with a high degree of freedom, such as notifying that there is an abnormality by abnormality determination by the other.

  The gist of the invention described in claim 6 is that the abnormality determination device of the rotation angle detection system according to claim 5 executes the reset of the determined number of times in an execution cycle longer than the predetermined cycle.

  According to the above configuration, the abnormality determination by the abnormality occurrence determination unit can be performed only when the frequency at which it is determined that the specific state is high, due to the influence of the occurrence of chattering phenomenon and the superimposition of noise on each output signal. It is possible to accurately determine the occurrence of an abnormality in the rotation angle detection system while suppressing the influence.

  The invention according to claim 7 is the abnormality determination device for the rotation angle detection system according to any one of claims 1 to 6, wherein the rotation angle detection system uses the detected rotation amount as an output signal. A pulse-shaped signal that is generated based on the rotation of the output shaft and is a signal whose pulse width is changed according to the rotation direction of the output shaft, and is determined to be in the specific state The gist of the present invention is to output a signal having a different voltage when a high signal is output when it is not determined.

  According to the above configuration, the rotation amount of the output shaft of the internal combustion engine can be grasped by counting the number of output of the pulse signal for the output signal of the rotation angle detection system, and the rotation direction of the output shaft can be determined by the pulse width. It can be grasped, and it can be determined whether or not it is in a specific state by the voltage when it becomes a high signal. Therefore, based on one signal output from the rotation angle detection system, the rotation amount and rotation direction of the output shaft of the internal combustion engine can be grasped, and further whether or not the specific state is established. It will be possible to judge.

BRIEF DESCRIPTION OF THE DRAWINGS Schematic which shows schematic structure of the vehicle with which the abnormality determination apparatus of the rotation angle detection system concerning one embodiment which actualized this invention is applied. The flowchart which shows the execution procedure of an automatic stop process. The flowchart which shows the execution procedure of a restart process. The table | surface which shows the relationship between the change aspect of the output signal of a main sensor, the output signal of a sub sensor, and the information about the rotation direction of the crankshaft output by an output device. The timing chart which shows transition of each output signal at the time of forward rotation of a crankshaft. The timing chart which shows transition of each output signal at the time of reverse rotation of a crankshaft. The timing chart which shows transition of each output signal when the output signal of a sub sensor stops changing from a high signal. The flowchart which shows the execution procedure of a system side process. The flowchart which shows the execution procedure of an apparatus side process. The timing chart which shows transition of each parameter at the time of abnormality occurrence. The timing chart which shows transition of each parameter at the time of generation | occurrence | production of a chattering phenomenon. The flowchart which shows the execution procedure of alerting | reporting process.

Hereinafter, an embodiment in which an abnormality determination device for a rotation angle detection system according to the present invention is embodied will be described.
FIG. 1 shows a schematic configuration of a vehicle to which an abnormality determination device for a rotation angle detection system according to the present embodiment is applied.

  As shown in FIG. 1, an internal combustion engine 11 as a drive source is mounted on the vehicle 10. Drive wheels 14 are connected to a crankshaft 12 that is an output shaft of the internal combustion engine 11 via an automatic transmission 13. The power generated by the internal combustion engine 11 is transmitted to the drive wheels 14 via the automatic transmission 13. Further, the vehicle 10 is provided with a warning lamp 16 for notifying the occupant of the occurrence of abnormality.

  A motor 17 is connected to the crankshaft 12. The motor 17 functions as an electric motor when the internal combustion engine 11 is started by an operation of an operation switch (not shown) by an occupant or when the internal combustion engine 11 is automatically started as described later. Specifically, the crankshaft 12 of the internal combustion engine 11 is forcibly rotated (cranked) by driving the motor 17, and an auxiliary torque for starting the internal combustion engine 11 is applied to the crankshaft 12.

  Air is sucked into the combustion chamber 18 of the internal combustion engine 11 through the intake passage 19 and fuel injected from the fuel injection valve 20 is supplied. When the air-fuel mixture composed of the intake air and the injected fuel is ignited by the spark plug 21, the air-fuel mixture burns, the piston 22 reciprocates, and the crankshaft 12 of the internal combustion engine 11 rotates. . The air-fuel mixture after combustion is sent out from the combustion chamber 18 of the internal combustion engine 11 to the exhaust passage 23 as exhaust.

  The abnormality determination device according to the present embodiment includes an electronic control device 30 that executes various controls for driving the vehicle 10. The electronic control unit 30 includes a central processing unit (CPU) that executes various arithmetic processes related to various controls, a non-volatile memory (ROM) that stores programs and data necessary for the arithmetic operation, and the arithmetic results of the CPU. A volatile memory (RAM) that is temporarily stored, an input / output port for inputting / outputting signals to / from the outside, and the like are provided.

  Various sensors are connected to the input port of the electronic control unit 30. As such sensors, for example, a speed sensor 31 for detecting the traveling speed SPD of the vehicle 10, an accelerator sensor 32 for detecting an amount of depression of an accelerator pedal (not shown) (accelerator depression amount AC), and the accelerator pedal. An idle switch 33 is provided for detecting the presence or absence of depression. Also, a brake switch 34 for detecting whether or not a brake pedal (not shown) is depressed, a throttle sensor 36 for detecting the opening degree (throttle opening degree TA) of the throttle valve 24 provided in the intake passage 19, An air amount sensor 37 for detecting the amount of air passing through the intake passage 19 (passage air amount GA) is provided. In addition, a water temperature sensor 38 for detecting the temperature THW of the cooling water of the internal combustion engine 11 and a rotation angle for detecting the rotation speed (engine rotation speed) and rotation angle (crank angle “° CA”) of the crankshaft 12. A detection system 40 and the like are also provided.

  The electronic control unit 30 grasps the operating state of the internal combustion engine 11 such as the engine speed and the engine load KL based on the output signals of various sensors. The engine load KL is calculated based on the intake air amount of the internal combustion engine 11 and the engine speed determined based on the accelerator depression amount AC, the throttle opening degree TA, and the passage air amount GA. The electronic control unit 30 outputs command signals to various drive circuits connected to the output port in accordance with the operation state of the internal combustion engine 11 that is grasped as described above. In this way, the electronic control device 30 controls the operation of the automatic transmission 13, the drive control of the motor 17, the operation control of the fuel injection valve 20 (fuel injection control), the operation control of the spark plug 21 (ignition timing control), Various controls such as operation control (throttle control) of the throttle valve 24 are executed.

  The vehicle 10 according to the present embodiment automatically stops the internal combustion engine 11 when the vehicle 10 stops at an intersection or the like in order to improve fuel efficiency and reduce emissions, and at the same time, stop the internal combustion engine 11 at any timing during the automatic stop. An automatic stop / start function is provided that allows the vehicle 10 to start automatically.

  Hereinafter, a process for automatically stopping the internal combustion engine 11 (automatic stop process) and a process for automatically starting the internal combustion engine 11 (restart process) will be described with reference to FIGS. FIG. 2 is a flowchart showing the procedure of the automatic stop process, and FIG. 3 is a flowchart showing the procedure of the restart process. The series of processes shown in these flowcharts is executed by the electronic control unit 30 as an interrupt process for each predetermined period.

Here, first, the procedure of the automatic stop process will be described with reference to FIG.
As shown in FIG. 2, in this process, first, the operation states of the vehicle 10 and the internal combustion engine 11 are read through the output signals of the various sensors (step S101), and the automatic stop condition is determined from these operation states. It is determined whether or not it is established (step S102). Specifically, for example, when all the following conditions [Condition 1] to [Condition 5] are satisfied, it is determined that the automatic stop condition is satisfied.
[Condition 1] The warm-up of the internal combustion engine 11 has been completed (the coolant temperature THW is higher than the water temperature lower limit value).
[Condition 2] The accelerator pedal is not depressed (the idle switch is “ON”).
[Condition 3] The brake pedal is depressed (the brake switch is “ON”).
[Condition 4] The vehicle 10 is stopped.
[Condition 5] After all [Condition 1] to [Condition 4] are satisfied, there is no history that the internal combustion engine 11 has been automatically stopped.

  If any one of [Condition 1] to [Condition 5] is not satisfied (step S102: NO), the automatic stop condition is not satisfied, and the internal combustion engine 11 is automatically stopped. Assuming that the condition is not satisfied, the present process is temporarily terminated. Thereafter, when it is determined that the automatic stop condition is satisfied, for example, when the vehicle 10 stops at an intersection (step 102: YES), for example, the fuel supply to the internal combustion engine 11 is stopped. Then, the operation of the internal combustion engine 11 is stopped (step S103). Thereafter, this process is temporarily terminated.

Next, with reference to FIG. 3, the processing procedure of the restart process will be described.
As shown in FIG. 3, in this process, first, the operation states of the vehicle 10 and the internal combustion engine 11 are read through the output signals of the various sensors (step S201), and the restart condition is determined from these operation states. It is determined whether or not it is established (step S202). Specifically, under the condition that the internal combustion engine 11 is in a stopped state through the automatic stop process described above, if any one of [Condition 1] to [Condition 4] is not satisfied, the restart condition is satisfied. Is determined to have been established.

  When the internal combustion engine 11 is not automatically stopped or when the internal combustion engine 11 is automatically stopped, if all of the above [condition 1] to [condition 4] are satisfied (step) S202: NO), the restart condition is not satisfied, and it is determined that the restart condition of the internal combustion engine 11 is not satisfied. Thereafter, when any one of the above [condition 1] to [condition 4] is not satisfied in the automatic stop state of the internal combustion engine 11 (step S202: YES), the internal combustion engine 11 is restarted on the assumption that the restart condition is satisfied. Processing is executed (step S203). Specifically, the motor 17 is driven and execution of the cranking operation is started. In addition to this, well-known fuel injection control and ignition timing control are executed, and the internal combustion engine 11 is restarted. Thereafter, this process is temporarily terminated.

  Here, in the vehicle 10 (FIG. 1), by accurately grasping the crank angle when the internal combustion engine 11 is automatically stopped through the automatic stop process, the engine is restarted when the internal combustion engine 11 is restarted through the subsequent restart process. Control (fuel injection control, ignition timing control, etc.) can be appropriately executed, and the restart can be appropriately executed and completed promptly.

  The crankshaft 12 does not always rotate in one direction, and temporarily rotates in a direction (forward direction) opposite to the direction during normal operation of the internal combustion engine 11 (forward direction) during the stoppage of the crankshaft 12 or during the stoppage. There are things to do. Therefore, if a system that outputs only a signal corresponding to the amount of rotation of the crankshaft 12 is adopted as the rotation angle detection system, this can be grasped from the output signal of the system when the crankshaft 12 rotates in the reverse direction. Therefore, there is a deviation between the crank angle obtained from the output signal of the rotation angle detection system and the actual crank angle.

  In the present embodiment, as the rotation angle detection system 40, the rotation direction is detected in addition to detecting the rotation amount of the crankshaft 12, and a signal (crank angle NE) corresponding to the detected rotation amount and rotation direction is detected. The output is adopted. By obtaining the crank angle by the electronic control unit 30 based on the crank signal NE, the crank angle can be obtained with high accuracy while considering the rotation of the crankshaft 12 in the reverse direction.

Incidentally, in the apparatus of the present embodiment, the phenomenon in which the crankshaft 12 rotates in the reverse direction is a phenomenon that occurs only during the process of the rotation stopping or during the stopping, and therefore a period during which the same phenomenon may occur (details) Are detected by the electronic control unit 30 only in the reverse rotation detection period). Specifically, the signal indicating the reverse rotation in the output signal of the rotation angle detection system 40 is valid during the reverse rotation detection period, and the signal indicating the reverse rotation is invalid during the period other than the reverse rotation detection period. And As the reverse rotation detection period, a period from when the following [start condition] is satisfied to when the [end condition] is satisfied is set.
[Starting condition] Fuel injection from the fuel injection valve 20 is stopped in order to automatically stop the internal combustion engine 11, and the engine rotational speed is a predetermined speed (for example, 400 revolutions / minute) or less.
[End condition] The crankshaft 12 has rotated a predetermined number (for example, one rotation) or more in the forward direction after the operation of the motor 17 is started to restart the internal combustion engine 11.

Next, a specific configuration of the rotation angle detection system 40 will be described.
The rotation angle detection system 40 includes a disk-shaped signal rotor 41 that is attached to the crankshaft 12 and rotates integrally with the crankshaft 12, and two sensors (a main sensor 42 and a sub sensor provided near the signal rotor 41. 43) and an output device 44 that outputs a signal (crank signal NE) corresponding to a change in the crank angle. In the present embodiment, the main sensor 42 functions as a first sensor, and the sub sensor 43 functions as a second sensor.

  Projections are formed on the outer periphery of the signal rotor 41 at predetermined angles (10 ° CA). Further, the signal rotor 41 includes a portion where no protrusion is formed, that is, a so-called chipped portion. Each of the main sensor 42 and the sub sensor 43 outputs a pulse-like signal (pulse signal) each time the projection of the signal rotor 41 passes in the vicinity as the crankshaft 12 rotates, and is at a predetermined angle (5 °). It is attached at a position where a pulse signal whose phase is shifted by CA) is output. The output device 44 takes in the output signals of the main sensor 42 and the sub sensor 43, and forms and outputs a crank signal NE that changes with a change in the crank angle based on the output signals.

The crank signal NE is formed based on the following idea.
FIG. 4 shows the relationship between the change mode of the output signal when the output signal of the main sensor 42 changes, the output signal of the sub sensor 43, and information about the rotation direction of the crankshaft 12 output by the output device 44. .

  As shown in [Condition A] in FIG. 4, when the output signal of the sub sensor 43 is a high signal when the output signal of the main sensor 42 changes (falls) from a high signal to a low signal, the crankshaft 12 is positive. It is detected that the crank angle has reached a predetermined angle by rotating in the direction. Also, as shown in [Condition B] in FIG. 4, when the output signal of the sub sensor 43 is a high signal when the output signal of the main sensor 42 changes (rises) from a low signal to a high signal, the crankshaft 12 It is detected that the crank angle has reached a predetermined angle by rotating in the reverse direction. As described above, in the present embodiment, the rotation of the crankshaft 12 and the rotation direction thereof are determined based on the relationship between the change mode of the output signal when the output signal of the main sensor 42 changes and the output signal of the sub sensor 43. Detected.

The crank signal NE is generated and output as follows based on the information.
FIG. 5 shows the relationship among the output signal of the main sensor 42, the output signal of the sub sensor 43, and the crank signal NE when the crankshaft 12 is rotating in the forward direction.

  As shown in FIG. 5, the crank signal NE, which is a high signal, is from the timing when the above [Condition A] (see FIG. 4) is satisfied until a predetermined period T1 elapses (time t11 to t11). At t12, t13 to t14, t15 to t16), the signal is changed to a low signal.

  The electronic control unit 30 detects the crank angle by counting the number of pulse signals of the crank signal NE and obtaining a value corresponding to the crank angle (specifically, the count value of the crank counter shown in FIG. 5). . In this case, every time the crank signal NE changes from a high signal to a low signal, the count value of the crank counter is incremented (time t11, t13, t15). The count value of the crank counter is a value indicating that the crank angle is larger as the value is larger. When the value is equivalent to 720 ° CA, the count value is equivalent to [0 ° CA]. Further, when the electronic control unit 30 detects that the chipped portion has passed based on the crank signal NE, it is determined that the crank angle has become a reference angle (for example, 0 ° CA), and the crank counter counts. The value is changed to a value corresponding to the reference angle.

FIG. 6 shows a relationship among the output signal of the main sensor 42, the output signal of the sub sensor 43, and the crank signal NE when the crankshaft 12 rotates in the reverse direction.
As shown in FIG. 6, in this case, the crank signal NE, which is a high signal, is from the timing when the above [Condition B] (see FIG. 4) is satisfied until a predetermined period T2 elapses. The signal is changed to a low signal at (time t21 to t23, t24 to t26, t27 to t29). As the predetermined period T2, a period longer than the predetermined period T1 (see FIG. 5) when the crankshaft 12 is rotating in the forward direction is set.

  In this case, the count value of the crank counter) is obtained by the electronic control unit 30 as follows. That is, first, when the crank signal NE changes from a high signal to a low signal, the count value of the crank counter is once incremented (time t21, t24, t27). Thereafter, when the period during which the crank signal NE is a low signal becomes equal to or greater than the determination value (however, the predetermined period T1 <determination value <predetermined period T2) (time t22, t25, t28), the pulse width of the crank signal NE is Assuming that the value indicates the rotation of the crankshaft 12 in the reverse direction, “2” is subtracted from the count value of the crank counter. The count value of the crank counter is decremented through a series of these operations.

  As shown in FIG. 7, when an abnormality occurs in the rotation angle detection system 40 and the output signal of the sub sensor 43 does not change from the high signal, when the crankshaft 12 is rotating in the positive direction, the crank signal NE is obtained. A signal indicating rotation in the forward direction and a signal indicating rotation in the reverse direction are alternately output. At this time, since the increment of the count value of the crank counter (time t31, t33, t35, t37) and decrement (time t32, t34, t36) are repeated alternately, the crankshaft 12 is rotating in the forward direction. Nevertheless, the count value does not increase, and a deviation occurs between the crank angle detected by the electronic control unit 30 and the actual crank angle. As a result, the restart of the internal combustion engine 11 may not be completed promptly.

  When the rotation of the crankshaft 12 stops, the compression and expansion of the intake air filled in the combustion chamber 18 of the internal combustion engine 11 are alternately repeated, whereby the crankshaft 12 is alternately turned in the forward direction and the reverse direction. A shaking phenomenon, a so-called chattering phenomenon may occur. When such a chattering phenomenon occurs, even if the signal is normally output from the sub sensor 43, the crankshaft 12 actually rotates alternately in the forward direction and the reverse direction. A high signal is continuously output from the sub sensor 43 while the pulse signal is output.

  In the present embodiment, a process for determining an abnormality of the rotation angle detection system 40 is executed. Through this processing, when the output signal of the sub sensor 43 does not change from the high signal, it is accurately determined whether this is due to the occurrence of the abnormality or the chattering phenomenon, and the occurrence of the abnormality is determined. Judged with high accuracy. Based on such a determination, the occurrence of the abnormality can be appropriately dealt with.

Hereinafter, an execution procedure of processing for determining an abnormality of the rotation angle detection system 40 will be described.
Here, first, a process (system side process) executed by the rotation angle detection system 40 for determining the occurrence of abnormality will be described.

  FIG. 8 shows the execution procedure of the system side processing. The series of processes shown in the flowchart of FIG. 7 conceptually shows the execution procedure of the system side process, and the actual process is executed by the output device 44.

  As shown in FIG. 8, in this process, when the output signal of the sub sensor 43 at the time of change of the output signal of the main sensor 42 continues to be a high signal (step S301: NO, step S302: NO, step S303: YES). ), A high signal is output as the crank signal NE (step S304). That is, at this time, there is a possibility that the output signal of the sub sensor 43 does not change from the high signal, and it is assumed that the reliability of the rotation angle detection system 40 is reduced. Output of the information and the information about the rotation direction from the rotation angle detection system 40 is prohibited. As a result, the crank angle detected by the electronic control unit 30 based on the crank signal NE does not change, and the fuel injection by the fuel injection valve 20 and the ignition operation by the spark plug 21 are stopped. Execution of engine control based on the crank signal NE is suppressed.

  After that, when the output signal of the sub sensor 43 at the time of change of the output signal of the main sensor 42 continues for a predetermined number of times C1 (8 times in the present embodiment) (step S301: NO, step S302: YES). ), A high signal is output as the crank signal NE (step S305), assuming that there is a very high possibility (specific state) that the abnormality has occurred.

  Also in this case, the information about the rotation amount of the crankshaft 12 and the information about the rotation direction are prohibited from being output from the rotation angle detection system 40. In the present embodiment, even when a high signal is output as the crank signal NE, the output voltage (specifically, 5.0 V) when determined to be in the specific state is not The voltage is set higher than the output voltage (specifically, 4.0 V). Thereby, information about the specific state is output from the rotation angle detection system 40. Hereinafter, the high signal when in a specific state is referred to as a “diag high signal” in order to distinguish the high signal when it is not. In the present embodiment, the predetermined number of times C1 functions as a second predetermined number of times.

  Thus, in the present embodiment, the crank signal NE is a pulse-like signal generated as the crankshaft 12 rotates, and the signal whose pulse width is changed according to the rotation direction of the crankshaft 12. And when the signal is determined to be in the specific state and when it is not determined, a signal having a different voltage when a high signal is output is output. Therefore, by monitoring the crank signal NE and counting the number of output of the pulse signal, the rotation amount of the crankshaft 12 can be grasped, and the rotation direction of the crankshaft 12 can be grasped by the pulse width, It is possible to determine whether or not a specific state is set based on the voltage when the signal becomes a high signal. Therefore, based on one signal output from the rotation angle detection system 40, the rotation amount and the rotation direction of the crankshaft 12 can be grasped, and further, it can be determined whether or not it is in a specific state. .

  Here, as described above, even when the chattering phenomenon occurs, the output signal of the sub sensor 43 when the output signal of the main sensor 42 changes may continuously become a high signal for a predetermined number of times C1. However, in this case, the above situation usually does not last long. In the present embodiment, when the output signal of the main sensor 42 changes, the state where the output signal of the sub sensor 43 is a high signal continues for a predetermined number of times C1, that is, on the condition that the above situation is continued. Therefore, it is possible to accurately suppress the erroneous determination that the specific state has occurred due to the occurrence of the chattering phenomenon.

  Thereafter, when the state in which the output signal of the sub sensor 43 at the time of the change of the output signal of the main sensor 42 continues for a predetermined number of times C2 (120 times in the present embodiment) (step S301: YES), the crank signal NE Output of a pulse signal indicating that the crankshaft 12 is rotating under the assumption that the crankshaft 12 is rotating in the forward direction while maintaining the state where the diagnostic high signal is output. Is canceled (step S306). That is, only the output of a pulse signal indicating the rotation of the crankshaft 12 in the positive direction is allowed. Thereby, as the crank signal NE, information on the rotation amount of the crankshaft 12 detected based on the output signal of the main sensor 42 and the output signal of the sub sensor 43 in addition to the information that the crankshaft 12 is rotating in the forward direction. (Pulse signal) is output. Therefore, the engine operation can be executed by obtaining the crank angle based on the crank signal NE, and the traveling function of the vehicle 10 can be maintained.

  If the state in which the output signal of the sub sensor 43 is a high signal at the time of change of the output signal of the main sensor 42 is not continuous (“NO” in all of steps S301 to S303), a normal signal is used as the crank signal NE. Is output (step S307). That is, in this case, information about the rotation amount of the crankshaft 12 and information about the rotation direction detected based on the output signal of the main sensor 42 and the output signal of the sub sensor 43 are output.

Next, a process (apparatus side process) executed by the electronic control unit 30 for determining the occurrence of the abnormality will be described.
FIG. 9 is a flowchart showing an execution procedure of the apparatus-side process. A series of processes shown in this flowchart is a process executed by the electronic control unit 30 as an interrupt process every predetermined cycle (for example, several milliseconds). is there.

As shown in FIG. 9, in this process, first, it is determined whether or not both of the following [prohibition condition 1] and [prohibition condition 2] are satisfied (step S401).
[Prohibition Condition 1] The internal combustion engine 11 is automatically stopped through the automatic stop process.
[Prohibition Condition 2] The automatic transmission 13 is in an operating state selected when the vehicle 10 travels forward.

If both [prohibition condition 1] and [prohibition condition 2] are satisfied (step S401: YES), it is determined whether or not the following [determination condition] is satisfied (step S402).
[Determination condition] The crank signal NE has become a value indicating that the crankshaft 12 has rotated. Specifically, the crank signal NE has changed from a diagnosis high signal to a low signal.

  Here, if it is determined that [determination condition] is satisfied (step S402: YES), after the fail safe flag is turned on (step S403), the present process is temporarily terminated. In the present embodiment, when the fail-safe flag is turned on, it is assumed that there is an abnormality in which the output signal of the sub sensor 43 does not change from the high signal, and thereafter the fail-safe control for the driving control of the vehicle 10 is executed. Will come to be. In the present embodiment, the process of step S402 functions as an abnormality determination unit.

  In this fail-safe control, for example, automatic stop of the internal combustion engine 11 through automatic stop processing is prohibited. Further, when the internal combustion engine 11 is automatically stopped, it is prohibited to start the engine through a start method suitable for restarting the internal combustion engine 11 (a start method suitable for a situation in which the crank angle is known in advance). Then, the engine is started through a starting method (starting method suitable for a situation where the crank angle is unknown) suitable for normal starting of the internal combustion engine 11 (starting by operating the operation switch). This is because if the restart of the internal combustion engine 11 is executed based on the crank angle obtained and stored by the electronic control unit 30, that is, the crank angle whose reliability is lowered due to the abnormality of the rotation angle detection system 40, This is because it may take a long time to start the engine or the engine start cannot be completed.

  In the fail-safe control, the operation of the count value of the crank counter is prohibited when the crank signal NE has a value indicating the reverse rotation of the crankshaft 12. That is, since there is a high possibility that the reverse rotation of the crankshaft 12 cannot be properly detected based on the crank signal NE, the detection is prohibited. Even if an abnormality occurs in which the output signal of the sub sensor 43 does not change from the high signal, the rotation of the crankshaft 12 in the positive direction is based on the pulse signal indicating the rotation in the positive direction of the crank signal NE. Since it is possible to detect this, its detection is allowed.

  Further, in the fail safe control, the crank angle obtained by the electronic control unit 30 is reset to a predetermined initial value. In the present embodiment, the time from when the output signal of the sub sensor 43 at the time of the change of the output signal of the main sensor 42 becomes a high signal continuously until it is determined that an abnormality has occurred in the rotation angle detection system 40. The crank signal NE is held as a high signal. Therefore, the crank angle obtained by the electronic control unit 30 based on the crank signal NE and the actual crank angle are shifted. In order to cancel such a state, the crank angle is once reset.

  On the other hand, if the [judgment condition] is not satisfied (step S402: NO), the process is temporarily terminated without turning on the failsafe flag (jumping the process of step S403).

  On the other hand, even when one of [prohibition condition 1] and [prohibition condition 2] is not satisfied (step S401: YES), the process of step S402 and the process of step S403 are jumped without turning on the fail-safe flag. This process is once terminated. In the present embodiment, the process of step S401 functions as a determination prohibiting unit.

Hereinafter, an operation of executing the above-described system side processing and apparatus side processing will be described.
Here, first, an operation when an abnormality occurs in which the output signal of the sub sensor 43 does not change from the high signal will be described.

FIG. 10 shows the transition of each parameter when the abnormality occurs.
When an abnormality occurs at time t41 and the state where the output signal of the sub sensor 43 is a high signal when the output signal of the main sensor 42 is changed continues (time t42), the crank signal NE is maintained as a high signal thereafter. Thereby, the operation of the count value of the crank counter in the electronic control device 30 is stopped, and the crank angle obtained by the electronic control device 30 does not change. Therefore, it is possible to suppress the engine control from being executed based on an inappropriate crank signal NE with low reliability.

  Thereafter, when the state in which the output signal of the sub sensor 43 is a high signal at the time of the change of the output signal of the main sensor 42 continues for a predetermined number of times C1 (time t43), it is in a specific state where the possibility of occurrence of the abnormality is extremely high. As a result, a diagnosis high signal is output as the crank signal NE.

  Furthermore, when the state in which the output signal of the sub sensor 43 is a high signal after the change of the output signal of the main sensor 42 continues for a predetermined number of times C2 (time t44), the crankshaft 12 is rotating in the forward direction. The prohibition of the output of the pulse signal indicating that the crankshaft 12 is rotating under the assumption is released.

  In this example, since the crankshaft 12 is rotating at this time, the crankshaft detected based on the information that the crankshaft 12 is rotating in the forward direction, the output signal of the main sensor 42 and the output signal of the sub sensor 43. The crank signal NE including information (pulse signal) on the 12 rotation amounts is output. Therefore, the count value of the crank counter changes based on the crank signal NE, the crank angle obtained by the electronic control unit 30 changes, and the engine operation is executed, so that the traveling function of the vehicle 10 is maintained. Will come to be.

  At this time, since the [determination condition] that the crankshaft 12 has reached a value indicating that the crankshaft 12 has rotated under the situation where the crank signal NE is a diagnosis high signal is satisfied, the rotation angle detection system 40 has an abnormality. If it occurs, the fail safe flag is turned on and fail safe control is executed. Thus, in the present embodiment, it is possible to determine the occurrence of an abnormality in the rotation angle detection system 40 when the specific state is continued for a predetermined period (time t43 to t44). Thereby, it is possible to avoid erroneous determination due to an unnecessary change in each output signal (specifically, the output signal of the main sensor 42, the output signal of the sub sensor 43, or the crank signal NE) due to noise superposition, The occurrence of abnormality can be accurately determined.

Next, an operation when the output signal of the sub sensor 43 no longer changes from the high signal due to the occurrence of the chattering phenomenon will be described.
FIG. 11 shows the transition of each parameter when the chattering phenomenon occurs.

  When a chattering phenomenon occurs at the time of automatic stop of the internal combustion engine 11 (time t51) and the output signal of the sub sensor 43 at the time of change of the output signal of the main sensor 42 continues (time t52), the cranking is thereafter performed. The signal NE is maintained as a high signal. As a result, it is possible to suppress engine control from being executed based on an inappropriate crank signal NE having low reliability.

  Thereafter, when the chattering phenomenon continues and the state in which the output signal of the sub sensor 43 is a high signal when the output signal of the main sensor 42 changes continues for a predetermined number of times C1 (time t53), a diagnosis high signal is output as the crank signal NE. Is done.

  Since this chattering phenomenon does not continue for a long time, the rotation of the crankshaft 12 is stopped before the state where the output signal of the sub sensor 43 at the time of the change of the output signal of the main sensor 42 is a high signal reaches the predetermined number of times C2. Both the change of the output signal of the main sensor 42 and the change of the output signal of the sub sensor 43 are stopped. Therefore, in this case, the crank signal NE does not become a value indicating that the crankshaft 12 has rotated, and it is avoided that it is erroneously determined that an abnormality has occurred in the rotation angle detection system 40.

  However, even when the operation of the internal combustion engine 11 is stopped, when the automatic transmission 13 is in an operation state selected when the vehicle 10 is traveling, the cranking is caused by the vehicle 10 sliding down on the slope. The shaft 12 may rotate (after time t54). In this case, since the crank signal NE has a value indicating that the crankshaft 12 has rotated, there is a risk that it is erroneously determined that an abnormality has occurred in the rotation angle detection system 40. In the present embodiment, in such a case (when both the [prohibition condition 1] and the [prohibition condition 1] are satisfied), even if the [judgment condition] is satisfied, the rotation angle detection system 40 is informed. It is not determined that an abnormality has occurred, and the failsafe flag is not turned on. Therefore, in this case as well, it is avoided to erroneously determine that an abnormality has occurred in the rotation angle detection system 40.

  Thereafter, a normal signal is output as the crank signal NE, and the count value of the crank counter is operated every time the crank signal NE becomes a low signal (time t54, t55).

  In the present embodiment, a process (notification process) for turning on the warning lamp 16 is performed in addition to a process of executing fail-safe control when an abnormality occurs in the rotation angle detection system 40. In the present embodiment, this notification process functions as an abnormality occurrence determination unit.

Hereinafter, the notification process will be described in detail.
FIG. 12 is a flowchart showing a specific execution procedure of the notification process, and a series of processes shown in the flowchart is executed by the electronic control unit 30 as a process for every predetermined cycle (for example, several milliseconds).

As shown in FIG. 12, in this process, it is first determined whether or not the internal combustion engine 11 is in normal operation (step S501). It is determined that the internal combustion engine 11 is in normal operation when both of the following conditions are satisfied.
The automatic stop of the internal combustion engine 11 through the automatic stop process has not been executed.
-The restart of the internal combustion engine 11 through the restart process is completed.

  If the internal combustion engine 11 is in normal operation (step S501: YES), a process for operating the count value of the abnormality counter is executed. Specifically, when the crank signal NE is a diagnosis high signal (step S502: YES), the count value of the abnormality counter is incremented (step S503), while when the crank signal NE is not a diagnosis high signal (step S502: NO). ) The count value is not incremented (the process of step S503 is jumped).

  Thereafter, occurrence of an abnormality in the rotation angle detection system 40 is determined based on the count value of the abnormality counter. That is, first, when the count value of the abnormality counter is greater than or equal to a determination value (for example, several tens) (step S504: YES), it is determined that an abnormality has occurred in the rotation angle detection system 40, and the warning lamp 16 is turned on. Lights up (step S505). On the other hand, when the count value of the abnormality counter is less than the determination value (step S504: NO), the warning lamp 16 is not turned on (the process of step S505 is jumped).

  Here, during the normal operation of the internal combustion engine 11, the crankshaft 12 rotates only in the positive direction, so that chattering does not occur. In the present embodiment, the number of times that the crank signal NE is determined to be a diagnosis high signal in the engine operating state in which no chattering phenomenon occurs is counted, and the number of times counted (specifically, abnormal The occurrence of an abnormality in the rotation angle detection system 40 is determined based on the count value of the counter. Therefore, it is possible to suppress erroneous determination that an abnormality has occurred in the rotation angle detection system 40 due to the occurrence of the chattering phenomenon.

  Then, when it is determined that an abnormality has occurred in the rotation angle detection system 40, the warning lamp 16 is turned on to notify the passenger of the abnormality, and the vehicle 10 is brought into a maintenance shop. The occupant can be encouraged to deal with the abnormal occurrence.

  Moreover, in the present embodiment, in addition to the above-described abnormality determination by the system-side process and apparatus-side process, the abnormality determination by the notification process is executed. For this reason, the execution of fail-safe control for the operation of the vehicle 10 is started by abnormality determination by the system-side processing or the apparatus-side processing, and notification of abnormality is made by abnormality determination by the notification processing. It becomes possible to deal with the occurrence of an abnormality in the rotation angle detection system 40 with a degree.

  In this process, regardless of whether the internal combustion engine 11 is in normal operation or not (step S506: YES), every time the crankshaft 12 rotates a predetermined number of times (for example, several tens of rotations) (reset timing). ), The reset process of resetting the count value of the abnormality counter to “0” (step S507) is executed. Then, after such reset processing, this processing is temporarily terminated.

  By executing such a reset process, the determination of the occurrence of abnormality of the rotation angle detection system 40 by the notification process is performed only when the frequency at which the crank signal NE is determined to be a diagnosis high signal is high. Therefore, it is possible to accurately determine the occurrence of abnormality in the rotation angle detection system 40 while suppressing the influence due to the occurrence of the chattering phenomenon and the influence due to the superimposition of noise on each output signal.

As described above, according to the present embodiment, the effects described below can be obtained.
(1) When an abnormality occurs in which the output signal of the sub sensor 43 does not change from the high signal during operation of the internal combustion engine 11, the output signal of the sub sensor 43 at the time of change of the output signal of the main sensor 42 continues continuously for a predetermined number of times C1. In this state, the crank signal NE becomes a value indicating that the crankshaft 12 has rotated. Thereby, it can be appropriately determined that an abnormality has occurred in the rotation angle detection system 40. Further, when a chattering phenomenon occurs during the automatic stop of the internal combustion engine 11, the output signal of the sub sensor 43 when the output signal of the main sensor 42 changes may continuously become a high signal for a predetermined number of times C1, but immediately after cranking Since the rotation of the shaft 12 stops, the crank signal NE does not become a value indicating that the crankshaft 12 has rotated. Therefore, in this case, erroneous determination that an abnormality has occurred in the rotation angle detection system 40 is avoided. Further, even when the crank signal NE has become a value indicating that the crankshaft 12 has rotated due to the vehicle 10 being lowered during the automatic stop of the internal combustion engine 11, it is determined that an abnormality has occurred in the rotation angle detection system 40. Is not made. Therefore, in this case as well, it is avoided to erroneously determine that an abnormality has occurred in the rotation angle detection system 40. Thus, according to the present embodiment, when the output signal of the sub sensor 43 does not change from the high signal, it is accurately determined that this is due to the abnormality of the rotation angle detection system 40, and An abnormality of the rotation angle detection system 40 can be determined with high accuracy.

  (2) When the state in which the output signal of the sub sensor 43 is a high signal when the output signal of the main sensor 42 is changed after it is determined to be in the specific state continues, the number of times that the state continues is a predetermined number of times. In the period until reaching C2, only the information on the specific state is output as the crank signal NE. Further, after the lapse of the above period, as the crank signal NE, information that the crankshaft 12 is rotating in the forward direction, information on the rotation amount of the crankshaft 12 detected by the main sensor 42 and the sub sensor 43, Information about the specific state is output. Therefore, when a specific state is entered, in other words, when the reliability of the rotation angle detection system 40 is reduced, the output of information about the rotation amount and information about the rotation direction from the rotation angle detection system 40 is stopped. Therefore, execution of engine control based on an inappropriate crank signal NE can be suppressed. Further, when the specific state is continued for a predetermined period, information on the rotation amount detected by the main sensor 42 and the sub sensor 43 is output together with information that the crankshaft 12 is rotating in the forward direction. The engine operation can be executed based on the information, and the traveling function of the vehicle 10 can be maintained. In addition, when the information about the rotation direction and the information about the rotation amount are output in this way, it is assumed that the crank signal NE has become a value indicating that the crankshaft 12 has rotated. Is determined to have occurred. As described above, according to the present embodiment, it is possible to determine the occurrence of an abnormality in the rotation angle detection system 40 based on the fact that the specific state has continued for a predetermined period, and the output caused by the superimposition of noise on each output signal. An erroneous determination due to an unnecessary change in the signal can be avoided, and the occurrence of an abnormality in the rotation angle detection system 40 can be accurately determined.

  (3) When the state in which the output signal of the sub sensor 43 is a high signal at the time of the change of the output signal of the main sensor 42 continues, the output of the information about the rotation amount of the crankshaft 12 and the information about the rotation direction is prohibited. I made it. Further, when the output signal of the main sensor 42 changes, when the output signal of the sub sensor 43 becomes a high signal continuously for a predetermined number of times C1, it is determined that the specific state is present. For this reason, when the output signal of the sub sensor 43 continuously becomes a high signal when the output signal of the main sensor 42 changes, that is, when the reliability of the rotation angle detection system 40 may be lowered. The output of the information about the rotation amount of the crankshaft 12 and the information about the rotation direction from the rotation angle detection system 40 can be stopped. Thereby, execution of engine control based on an inappropriate signal can be suppressed. In addition, since it is determined that the specific state has been obtained on the condition that the output signal of the sub sensor 43 becomes a high signal when the output signal of the main sensor 42 changes, the chattering phenomenon occurs. It is possible to suppress erroneous determination that the specific state has been reached.

  (4) The number of times that the crank signal NE is determined to be a diagnostic high signal is counted during normal operation of the internal combustion engine 11, in other words, in an engine operating state in which chattering does not occur. Based on the above, the occurrence of abnormality in the rotation angle detection system 40 is determined. Therefore, it is possible to suppress erroneous determination that an abnormality has occurred in the rotation angle detection system 40 due to the occurrence of the chattering phenomenon. Moreover, in addition to the abnormality determination by the system side process or the apparatus side process, the abnormality determination by the notification process is executed. For this reason, the execution of fail-safe control for the operation of the vehicle 10 is started by abnormality determination by the system-side processing and the apparatus-side processing, and a notification of abnormality is given by abnormality determination by the notification processing. Thus, it is possible to deal with the occurrence of an abnormality in the rotation angle detection system 40.

  (5) Regardless of whether or not the internal combustion engine 11 is in normal operation, a reset process for resetting the count value of the abnormality counter to “0” at every time the crankshaft 12 rotates by a predetermined rotation is executed. I tried to do it. Therefore, it is possible to determine whether the rotation angle detection system 40 is abnormal due to the notification process only when the frequency at which the crank signal NE is determined to be a diagnosis high signal is high. It is possible to accurately determine the occurrence of an abnormality in the rotation angle detection system 40 while suppressing the influence of noise superimposed on the signal.

  (6) The crank signal NE is a pulse-like signal generated along with the rotation of the crankshaft 12, and a signal whose pulse width is changed according to the rotation direction of the crankshaft 12, and the specified A signal having a different voltage when a high signal is output depending on whether the state is determined or not determined is output. Therefore, based on one signal output from the rotation angle detection system 40, the rotation amount and the rotation direction of the crankshaft 12 can be grasped, and further, it is determined whether or not it is in a specific state. be able to.

The embodiment described above may be modified as follows.
The period during which only the information about the specific state (diag high signal) is output as the crank signal NE after it is determined that it is in the specific state can be appropriately changed, for example, by setting a predetermined time. By setting such a period, it is possible to suppress the execution of engine control based on an inappropriate crank signal NE when the engine enters a specific state, in other words, when the reliability of the rotation angle detection system 40 is reduced. . In addition, when the specific state is continued for a predetermined period, the output of the information about the rotation amount of the crankshaft 12 and the information about the rotation direction is resumed, and the crank signal NE becomes a value indicating that the crankshaft 12 has rotated. Thus, it is determined that an abnormality has occurred in the rotation angle detection system 40.

  Information about the amount of rotation of the crankshaft 12 when the output signal of the sub sensor 43 at the time of change of the output signal of the main sensor 42 continues for a predetermined number of times C3 (where C3 ≧ 3 times); You may make it prohibit the output of the information about a rotation direction. In short, if the number of times that the output signal of the sub sensor 43 can be accurately determined at an early stage that there is a possibility of an abnormality that does not change from the high signal is obtained in advance, and the same number is set as the predetermined number C3. Good. In the above configuration, the predetermined number of times C3 functions as the first predetermined number of times, and in the above-described embodiment, two times functions as the first predetermined number of times.

  When the state in which the output signal of the sub sensor 43 at the time of the change of the output signal of the main sensor 42 continues for a predetermined number of times C1 (8 times in the above embodiment), it is determined that the specific state is present. However, the predetermined number of times C1 can be arbitrarily changed. In short, the number of times that the specific state can be properly determined while avoiding erroneous determination of the specific state due to the occurrence of the chattering phenomenon is obtained in advance, and the same number is determined in advance. What is necessary is just to set as the frequency | count C1.

  -Information about the amount of rotation of the crankshaft 12, information about the direction of rotation, and information about a specific state are output as separate signals, or the information is divided into two signals and output. Are not necessarily output by the same signal (crank signal NE).

  When the rotation angle detection system 40 is determined to be abnormal in the notification process, a buzzer may be heard instead of or in addition to turning on the warning lamp 16. In short, it is only necessary to notify the passenger that an abnormality has occurred.

  The timing for resetting the number of times determined to be a diagnosis high signal in the notification process is not limited to the timing at which the crankshaft 12 rotates a predetermined number of times, and can be arbitrarily changed. In short, it suffices if the determined number of resets can be executed in a cycle longer than the notification processing execution cycle.

The reset process in the notification process may be omitted if a decrease in determination accuracy regarding the occurrence of an abnormality in the rotation angle detection system 40 is suitably suppressed.
In the notification process, the period for counting the number of times that the crank signal NE is determined to be a diagnosis high signal is not limited to the period in which the internal combustion engine 11 is normally operated, but the engine in which the crankshaft 12 rotates only in the forward direction. Any period can be arbitrarily selected as long as it can be appropriately determined that the vehicle is in an operating state. As such a period, for example, a period in which any of the following [Condition A] to [Condition C] is satisfied can be set.
[Condition A] The motor 17 is operating.
[Condition B] The motor 17 is in operation and the operation state of the automatic transmission 13 is in a state of releasing the connection between the crankshaft 12 and the drive wheels 14.
[Condition C] The motor 17 is operating, the operating state of the automatic transmission 13 is selected when the vehicle 10 is traveling, and the vehicle 10 is traveling (traveling speed SPD> 0 km). Must be at least every hour).

-Notification processing may be omitted.
The present invention determines that the crankshaft is rotating in the positive direction when the output signal of the sub sensor at the rising edge of the output signal of the main sensor is a low signal, while the output signal of the main sensor is at the falling edge. In the rotation angle detection system that determines that the crankshaft is rotating in the reverse direction when the output signal of the sub sensor is a low signal, an abnormality determination device that determines the occurrence of an abnormality in which the output signal of the sub sensor does not change from the low signal It can also be applied to.

  The present invention is not limited to a vehicle having an automatic stop / start function as long as the vehicle is subjected to intermittent stop control for intermittently stopping the operation of the internal combustion engine as a vehicle drive source. The present invention can also be applied to a hybrid vehicle equipped with an electric motor.

  DESCRIPTION OF SYMBOLS 10 ... Vehicle, 11 ... Internal combustion engine, 12 ... Crankshaft, 13 ... Automatic transmission, 14 ... Drive wheel, 16 ... Warning light, 17 ... Motor, 18 ... Combustion chamber, 19 ... Intake passage, 20 ... Fuel injection valve, DESCRIPTION OF SYMBOLS 21 ... Spark plug, 22 ... Piston, 23 ... Exhaust passage, 24 ... Throttle valve, 30 ... Electronic control unit, 31 ... Speed sensor, 32 ... Accelerator sensor, 33 ... Idle switch, 34 ... Brake switch, 36 ... Throttle sensor, 37 ... Air amount sensor, 38 ... Water temperature sensor, 40 ... Rotation angle detection system, 41 ... Signal rotor, 42 ... Main sensor, 43 ... Sub sensor, 44 ... Output device.

Claims (7)

The output shaft of the in-vehicle internal combustion engine is connected to the drive wheel via a transmission, and is provided in a vehicle in which intermittent stop control for intermittently stopping the operation of the internal combustion engine is executed,
Both have a first sensor and a second sensor that output a pulse-like signal in response to a change in the rotation angle of the output shaft, and output signals that are out of phase with each other. The amount of rotation of the output shaft is detected based on at least one of the output signals of the second sensor, and the relationship between the change mode of the output signal when the output signal of the first sensor changes and the output signal of the second sensor The rotation direction of the output shaft is detected based on the output signal, and when the output signal of the first sensor is changed, the output signal of the second sensor is in the same state continuously for a predetermined number of times. And is applied to a rotation angle detection system that outputs a signal including information about the detected rotation amount and rotation direction and information about the specific state,
When the determination condition that the output shaft has reached a value indicating that the output shaft has rotated under a situation in which the output signal of the rotation angle detection system is a value indicating the specific state, the rotation angle is satisfied. An abnormality determination means for determining that an abnormality has occurred in the detection system;
Even if the determination condition is satisfied when the operation of the internal combustion engine is intermittently stopped through the intermittent stop control and the transmission is in an operating state selected when the vehicle travels, An abnormality determination device for a rotation angle detection system, comprising: a determination prohibiting unit that prohibits determination that the abnormality has occurred. In the abnormality determination device of the rotation angle detection system according to claim 1,
The rotation angle detection system outputs only information on the specific state over a predetermined period immediately after the determination when the same state continues further after it is determined that the specific state is detected. An abnormality determination device for a rotation angle detection system. In the abnormality determination device of the rotation angle detection system according to claim 1,
When the same state continues further after the rotation angle detection system is determined to be in the specific state, the specific state is maintained in a period until the number of times the same state continues reaches a predetermined number of times. Only the information about the output axis, and after the elapse of the period, the information that the output shaft is rotating in the positive direction, the information about the detected rotation amount, and the information about the specific state are output. An abnormality determination device for a rotation angle detection system. In the abnormality determination device of the rotation angle detection system according to claim 2 or 3,
The rotation angle detection system is configured to detect the rotation amount of the output shaft when the output signal of the second sensor at the time of change of the output signal of the first sensor becomes the same state continuously for a first predetermined number of times. And the second predetermined number of times that the output signal of the second sensor when the output signal of the first sensor changes is greater than the first predetermined number of times. An abnormality determination device for a rotation angle detection system, characterized in that it is determined to be in the specific state when the same state continues continuously. In the abnormality determination device of the rotation angle detection system according to any one of claims 1 to 4,
Based on the output signal of the rotation angle detection system every predetermined cycle, provided that the output shaft is in an engine operating state that rotates only in the positive direction, the specific state is determined. An abnormality determination device for a rotation angle detection system, further comprising abnormality occurrence determination means for determining that an abnormality has occurred in the rotation angle detection system when the number of times determined to be present exceeds a determination value. In the abnormality determination device of the rotation angle detection system according to claim 5,
An abnormality determination device for a rotation angle detection system, wherein the reset is performed for the determined number of times with an execution period longer than the predetermined period. In the abnormality determination device of the rotation angle detection system according to any one of claims 1 to 6,
The rotation angle detection system is a pulse-like signal that is generated based on the rotation of the output shaft and is generated based on the detected rotation amount as an output signal, and according to the rotation direction of the output shaft. Rotation characterized in that it is a signal whose pulse width is changed and which outputs a signal having a different voltage when it becomes a high signal when it is determined to be in the specific state and when it is not determined Abnormality judgment device for angle detection system.

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