JP6560977B2 - Electronic control unit - Google Patents

Description

  The present invention relates to an electronic control device for an internal combustion engine, and more particularly, to an electronic control device having an abnormality detection function of a crank angle sensor that detects a crank angle of the internal combustion engine.

  In recent years, a control device for an internal combustion engine provided in a vehicle such as a motorcycle includes an injector opening timing, opening time, and ignition coil based on crank angle information detected by a crank angle sensor and an operating state of the internal combustion engine. An electronic control device for controlling the energization timing and energization time is provided.

  In such an electronic control device, when the control timing of the injector and the ignition coil cannot be determined due to the occurrence of an abnormality such as a failure of the crank angle sensor or disconnection of the electrical wiring, it becomes impossible to perform desired fuel injection and ignition control. There is a possibility of unnecessarily affecting the output of the internal combustion engine and the driving state of the vehicle. For this reason, when an abnormality of the crank angle sensor occurs, it is necessary to promptly notify the driver of the vehicle of the failure diagnosis result.

  Against this background, there has been proposed a technique for detecting a failure of the crank angle sensor itself by determining whether or not a signal from the crank angle sensor is detected under the condition that the crank angle sensor outputs a signal. .

  Under such circumstances, Patent Document 1 relates to a crank angle sensor failure diagnosis method for an internal combustion engine, and determines whether the internal combustion engine is in a cranking state by monitoring a change in battery voltage. A configuration for detecting a failure of the crank angle sensor when the state is the cranking state is disclosed.

JP 2001-82240 A

  However, according to the study of the present inventor, in the configuration described in Patent Document 1, in order to determine whether the state of the internal combustion engine is in the cranking state based on the battery voltage, the determination itself is mounted on the vehicle. It tends to be easily affected by the applied electrical load and the deteriorated battery itself. As a result, there is a possibility that abnormality of the crank angle sensor cannot be detected with high accuracy. In particular, an inexpensive system that eliminates intake pressure sensors and airflow sensors for small motorcycles has a low battery capacity, and the battery tends to deteriorate because the battery is not easily replaced over a long period. It is considered that there is a high possibility that the abnormality (meaning that there is no output from the crank angle sensor due to the failure of the crank angle sensor itself and the disconnection of the electrical wiring system including the connector) cannot be detected accurately.

  The present invention has been made through the above-described studies, and provides an electronic control device capable of accurately detecting an abnormality of a crank angle sensor in a mode in which the influence of an electrical load is suppressed even in an inexpensive system. With the goal.

In order to achieve the above object, the present invention is an electronic control device for controlling the operating state of an internal combustion engine equipped with an AC generator and a crank angle sensor, and generates a voltage signal corresponding to the output voltage of the AC generator. And a signal generation circuit that determines whether or not the alternator is rotating based on the voltage signal, and when it is determined that the alternator is rotating, a crank from the crank angle sensor A determination unit that determines that there is an abnormality in either the crank angle sensor or its electrical wiring when the input of a pulse signal is not detected, and the signal generation circuit includes the output voltage of the AC generator A first potential corresponding to a voltage portion of the output voltage of the AC generator that exhibits a positive voltage with respect to the reference potential of the AC generator, and a negative voltage with respect to the reference potential. The voltage signal is generated so as to have a second potential corresponding to a voltage portion of the output voltage, and the determination unit includes the first potential and the first potential that are consecutive in time series in the voltage signal. 2 to detect whether or not the AC generator is rotating, and the determination unit further determines that the voltage signal corresponds to the negative voltage of the output voltage of the AC generator. during the period exhibiting the second potential, when detecting no input of the crank pulse signal from the crank angle sensor, that you determined that there is an abnormality in one of the crank angle sensor and the electric wiring Let it be the first aspect.

According to the above electronic control device according to the first aspect of the present invention, the determination unit determines whether or not the alternator is rotating based on a voltage signal corresponding to the output voltage of the alternator. When it is determined that the alternator is rotating and the crank pulse signal input from the crank angle sensor is not detected, it is determined that either the crank angle sensor or its electrical wiring is abnormal. der is, the signal generating circuit, a first potential corresponding to the voltage portion of the output voltage of the AC generator exhibiting a positive voltage with respect to the reference potential of the output voltage of the AC generator, negative with respect to the reference potential And a second potential corresponding to the voltage portion of the output voltage of the AC generator that exhibits the voltage of the first voltage, and the determination unit includes a first potential that is continuous in time series with the voltage signal. And detecting a negative second potential Thus, during the period in which the voltage signal exhibits a second potential corresponding to the negative voltage of the output voltage of the AC generator. , when no input is detected crank pulse signal from the crank angle sensor, der because what determines that there is an abnormality in one of the crank angle sensor and the electric wiring, even in inexpensive system, the internal combustion engine It is possible to accurately determine whether or not the engine is rotating, and to detect an abnormality of the crank angle sensor with high accuracy in a manner that further suppresses the influence of the electrical load.

FIG. 1 is a schematic configuration diagram illustrating a configuration of an electronic control device according to an embodiment of the present invention. FIG. 1A illustrates a current flow when an ACG output voltage is positive with respect to a reference potential. FIG. 1B is a diagram showing a current flow when the ACG output voltage is negative with respect to the reference potential. FIG. 2 is a flowchart showing the flow of abnormality detection processing in the present embodiment. FIG. 3 is a timing chart for explaining the flow of the abnormality detection process in the present embodiment. FIG. 4A to FIG. 4C are configuration diagrams schematically showing configurations of modifications of the electronic control device in the present embodiment.

  Hereinafter, an electronic control device according to an embodiment of the present invention will be described in detail with reference to the drawings as appropriate.

〔Constitution〕
First, the configuration of the electronic control device in the present embodiment will be described with reference to FIG.

  FIG. 1 is a schematic configuration diagram showing a configuration of an electronic control device according to the present embodiment, and FIG. 1A is a diagram showing a current flow when an ACG output voltage is positive with respect to a reference potential. FIG. 1B is a diagram showing a current flow when the ACG output voltage is negative with respect to the reference potential.

  As shown in FIGS. 1A and 1B, an electronic control unit (ECU) 1 according to the present embodiment is mounted on a vehicle such as a motorcycle, and an alternating current generator (Alternating Current Generator): ACG) is a device for controlling the operating state of an internal combustion engine (not shown) to which the crank angle sensor 3 and the crank angle sensor 3 are attached. The rotation shaft of ACG 2 is typically directly connected to a crankshaft (not shown) of the internal combustion engine.

  The ECU 1 includes a connector 11, a diode element D1, a transistor element T1, a diode element D2, and a CPU (Central Processing Unit) 12 as main components. Here, the connector 11, the diode element D1, the transistor element T1, and the diode element D2 constitute a signal generation circuit, and details of the function of the circuit will be described later.

  The connector 11 is electrically connected to the connector 21 on the ACG 2 side. The connector 21 on the ACG 2 side is connected to the ACG 2 via the electrical wiring 22 and the output terminal 23. An output voltage of ACG 2 (ACG output voltage) is applied to the connector 11. In FIG. 1A, a waveform exhibiting an ACG output voltage that is positive with respect to the reference potential is schematically shown below the output terminal 23, and in FIG. 1B, it is negative with respect to the reference potential. A waveform showing the ACG output voltage is schematically shown below the output terminal 23.

  The diode element D1 is disposed on the electrical wiring 13 that electrically connects the connector 11 and the CPU 12. In the diode element D1, its anode terminal is connected to the electrical wiring 13 on the CPU 12 side, and its cathode terminal is connected to the electrical wiring 13 on the connector 11 side.

  The transistor element T1 is an NPN type transistor element, and is disposed in the electric wiring 13 between the diode element D1 and the diode element D2. In the transistor element T1, its emitter terminal is connected to the electrical wiring 13 on the diode element D1 side, its collector terminal is connected to the electrical wiring 13 on the diode element D2 side, and its base terminal is connected to the ground potential via the resistance element R1. It is connected. Further, the emitter terminal and the base terminal are connected via a resistance element R2.

  The diode element D2 is disposed in the electrical wiring 13 between the transistor element T1 and the CPU 12. In the diode element D2, its anode terminal is connected to the electric wiring 13 on the transistor element T1 side, and its cathode terminal is connected to the electric wiring 13 on the CPU 12 side.

  A power supply voltage Vcc is connected to the electrical wiring 13 between the transistor element T1 and the diode element D2 via a resistance element R3. In addition, the electric wiring 13 between the diode element D2 and the CPU 12 is connected to the ground potential via the resistance element R4.

  The CPU 12 is connected to the electrical wiring 13 via the ACG output monitoring port 12a. Further, the CPU 12 is connected to the crank angle sensor 3 through the electric wiring 14 and a connector or electric wiring (not shown). The crank angle sensor 3 inputs to the CPU 12 a crank pulse signal corresponding to the rotation angle of the crankshaft that is the crankshaft of the internal combustion engine.

  The CPU 12 functions as the determination unit 12b and the control unit 12c by executing a control program stored in a memory (not shown). The controller 12c controls the overall operation of the ECU 1. Details of the function of the determination unit 12b will be described later.

Here, the electronic control unit 1, as shown in FIG. 1 (a), if ACG output voltage is positive with respect to the reference potential, no current flows from the base terminal of the transistor element T 1 to the emitter terminal side, transistor element T 1 is turned off. As a result, a current flows from the power supply voltage Vcc to the CPU 12 (arrow A1), and a positive voltage is applied to the ACG output monitoring port 12a of the CPU 12, so that the ACG output monitoring port 12a has a high potential (first potential). ).

On the other hand, when the ACG output voltage is negative with respect to the reference potential, as shown in FIG. 1 (b), a current flows from the base terminal of the transistor element T 1 to the emitter terminal side (arrow A2), the base terminal by the voltage between the emitter terminal becomes equal to or higher than the threshold and the transistor element T 1 is turned on. As a result, a current flows from the power supply voltage Vcc toward the transistor element T1, and no voltage is applied to the ACG output monitoring port 12a of the CPU 12. Therefore, the ACG output monitoring port 12a exhibits a low potential (second potential).

In the electronic control apparatus 1 having the above-described configuration, the CPU 12 executes the abnormality detection process described below, so that the crank angle sensor 3 itself and its electric power can be obtained without being affected by an electric load even in an inexpensive system. Enables accurate detection of wiring system abnormalities. The operation of the CPU 12 when executing the abnormality detection process will be described below with reference to FIGS.
[Abnormality detection processing]

  FIG. 2 is a flowchart showing the flow of abnormality detection processing in the present embodiment. FIG. 3 is a timing chart for explaining the flow of abnormality detection processing in the present embodiment.

  The flowchart shown in FIG. 2 starts when the starter switch (not shown) is turned on and the ECU 1 is activated and operates (time t = t0 shown in FIG. 3), and the abnormality detection process is performed in step S1. move on. Such an abnormality detection process is repeatedly executed every predetermined control period while the ECU 1 is operating.

  In the process of step S1, the determination unit 12b determines whether or not the ACG 2 is rotating. Specifically, the determination unit 12b changes the potential of the ACG output monitoring port 12a from a positive potential (high potential) to a lower potential (low potential) (for example, time t = t1 shown in FIG. 3). , It is determined that ACG2 is rotating. By such determination, even in an inexpensive system, it is possible to simplify the processing process and accurately determine whether or not the internal combustion engine is rotating in a manner in which the influence of the electrical load is suppressed. As a result of the determination, when the ACG 2 is rotating, the determination unit 12b advances the abnormality detection process to the process of step S2. On the other hand, when the ACG 2 is not rotating, the determination unit 12b ends the current series of abnormality detection processing.

  In the process of step S2, the determination unit 12b determines whether or not the potential of the ACG output monitoring port 12a is a low potential. As a result of the determination, when the potential of the ACG output monitoring port 12a is a low potential, the determination unit 12b advances the abnormality detection process to the process of step S3. On the other hand, when the potential of the ACG output monitoring port 12a is not a low potential, the determination unit 12b ends the current series of abnormality detection processing.

  In the process of step S <b> 3, the determination unit 12 b determines whether or not an input of a crank pulse signal from the crank angle sensor 3 is detected via the electrical wiring 14. If the input of the crank pulse signal is detected as a result of the determination, the determination unit 12b advances the abnormality detection process to the process of step S4. On the other hand, when the input of the crank pulse signal is not detected, the determination unit 12b advances the abnormality detection process to the process of step S5. For example, if an abnormality occurs in either the crank angle sensor 3 itself or its electrical wiring 14 system at time t = t5 shown in FIG. 3, the input of the crank pulse signal is not detected after time t = t5.

  In the process of step S4, the determination unit 12b determines that the crank angle sensor 3 itself and its electrical wiring 14 system are normal. Thereby, the process of step S4 is completed and a series of this abnormality detection process is complete | finished.

  In the process of step S5, the determination unit 12b increments the value of the program counter for counting the number of times that the output signal of the crank angle sensor 3 has not been detected. Thereby, the process of step S5 is completed, and the abnormality detection process proceeds to the process of step S6. For example, when an abnormality occurs in either the crank angle sensor 3 itself or its electrical wiring 14 system at time t = t5 shown in FIG. 3, the determination unit 12b determines that the time between time t = t6 and time t = t7 and the time t = T8 The value of the program counter is incremented by 1 between time t = t9.

  In the process of step S6, the determination unit 12b determines whether or not the number of crank pulse signal inputs is not detected by determining whether or not the value of the program counter is equal to or greater than a predetermined value. Is determined. As a result of the determination, when the number of times the input of the crank pulse signal is not detected is equal to or greater than the predetermined number, the determination unit 12b advances the abnormality detection process to the process of step S7. On the other hand, if the number of times the input of the crank pulse signal has not been detected is less than the predetermined number, the determination unit 12b ends the current series of abnormality detection processing.

  In the process of step S7, the determination unit 12b determines that there is an abnormality in either the crank angle sensor 3 itself or its electrical wiring 14 system. Since such a determination is based on the low potential of the ACG output monitoring port 12a corresponding to the negative voltage portion of the output voltage of the AGC 2, even in an inexpensive system, the influence of the electrical load is further suppressed. While simplifying the processing steps, it is possible to detect an abnormality of the crank angle sensor with high accuracy. Thereby, the process of step S7 is completed and a series of this abnormality detection process is complete | finished.

  As is clear from the above description, in the electronic control device 1 according to the present embodiment, the determination unit 12b rotates the ACG 2 based on the voltage signal corresponding to the output voltage of the ACG 2 applied to the ACG output monitoring port 12a. If the input of the crank pulse signal from the crank angle sensor 3 is not detected when it is determined that the ACG 2 is rotating, any of the crank angle sensor 3 and its electric wiring 14 system is determined. It is determined that there is an abnormality. Thereby, even in an inexpensive system, an abnormality of the crank angle sensor 3 can be accurately detected in a manner in which the influence of the electrical load is suppressed.

[Modification]
Finally, a modification of the electronic control device 1 shown in FIG. 1 will be described with reference to FIG.

  FIG. 4A to FIG. 4C are configuration diagrams schematically showing configurations of modifications of the electronic control device in the present embodiment.

  In Modification 1 shown in FIG. 4A, the transistor element T1 and the resistance elements R1 and R2 in the electronic control device 1 shown in FIG. 1 are omitted. Also in the first modification, when the ACG output voltage is positive with respect to the reference potential, a current flows from the power supply voltage Vcc to the CPU 12 (arrow A4), and the ACG output voltage is negative with respect to the reference potential. Since a current flows from the power supply voltage Vcc toward the ACG 2 (arrow A5), the abnormality of the crank angle sensor 3 can be detected by executing the abnormality detection process described above. In addition, according to such a configuration, the circuit scale of the electronic control device 1 can be reduced by the amount corresponding to the transistor element T1 and the resistance elements R1 and R2, thereby reducing the size and cost.

  In the second modification shown in FIG. 4B, in the first modification shown in FIG. 4A, the Zener diode element D3 is disposed in the electrical wiring 13 between the connector 11 and the diode element D1, and The electrical wiring 13 between the Zener diode element D3 and the diode element D1 is connected to the ground potential via the resistance element R5. According to such a configuration, in addition to the operation and effect of the first modification, the negative voltage of the ACG output voltage can be adjusted by the Zener diode element D3 to stabilize the negative voltage.

In the third modification shown in FIG. 4C, the resistor R6, the PNP transistor element T 2 , and the resistor element R7 are connected to the electrical wiring 13 between the diode element D1 and the CPU 12 in the electronic control unit 1 shown in FIG. Is arranged. The emitter terminal of the transistor element T 2 are connected to the power supply voltage Vcc, the collector terminal is connected to the resistor element R7, and the base terminal is connected to the resistor element R6. The emitter and base terminals are connected via the resistance element R8, electrical wiring 13 between the collector terminal of the resistor R7 and the transistor element T 2 is connected to the ground potential via the resistor element R9. Also in Modification 3, when the ACG output voltage is positive with respect to the reference potential, a current flows from the power supply voltage Vcc toward the CPU 12 (arrow A4), and the ACG output voltage is negative with respect to the reference potential. Since a current flows from the power supply voltage Vcc toward the ACG 2 (arrow A5), the abnormality of the crank angle sensor 3 can be detected by executing the abnormality detection process described above. Further, according to such a configuration, it is possible to adjust the operation timing of the transistor element T 2 by adjusting the resistance value of the resistance element.

  In the present invention, the type, shape, arrangement, number, and the like of the members are not limited to the above-described embodiment, and the gist of the invention is appropriately replaced such that the constituent elements are appropriately replaced with those having the same operational effects. Of course, it can be changed as appropriate without departing from the scope.

  As described above, the present invention can provide an electronic control device capable of accurately detecting an abnormality of a crank angle sensor in an inexpensive system in a mode in which the influence of an electrical load is suppressed. It is expected that it can be widely applied to an internal combustion engine control device for a vehicle such as a motorcycle because of its universal character.

1 ... Electronic control unit (ECU)
2 ... Alternator (AGC)
3 ... Crank angle sensor 11, 21 ... Connector 12 ... CPU
12a ... ACG output monitoring port 12b ... determination unit 12c ... control unit 13, 14, 22 ... electric wiring 23 ... output terminal D1, D2, D3 ... diode elements R1, R2, R3, R4, R5, R6, R7, R8, R9: Resistance element T1, T2: Transistor element

Claims (1)

In an electronic control device for controlling the operating state of an internal combustion engine equipped with an AC generator and a crank angle sensor,
A signal generation circuit for generating a voltage signal according to the output voltage of the AC generator;
It is determined whether the AC generator is rotating based on the voltage signal, and when it is determined that the AC generator is rotating, an input of a crank pulse signal from the crank angle sensor is detected. If not, a determination unit that determines that there is an abnormality in either the crank angle sensor or its electrical wiring;
Equipped with a,
The signal generation circuit includes a first potential corresponding to a voltage portion of the output voltage of the AC generator, which exhibits a positive voltage with respect to a reference potential of the output voltage of the AC generator, and the reference potential. Generating the voltage signal to have a second potential corresponding to a voltage portion of the output voltage of the AC generator that exhibits a negative voltage,
The determination unit determines whether the AC generator is rotating by detecting the first potential and the second potential that are continuous in time series in the voltage signal,
Further, the determination unit detects an input of a crank pulse signal from the crank angle sensor during a period in which the voltage signal exhibits the second potential corresponding to the negative voltage of the output voltage of the AC generator. the electronic control unit when not is characterized that you determined that there is an abnormality in one of the crank angle sensor and the electric wiring.

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