JP2016118175A - Anomaly detection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To readily and reliably detect anomaly of an intake pipe pressure sensor or atmospheric pressure sensor.SOLUTION: The intake pipe pressure sensor 48 detects the pressure of an intake pipe 32 provided in an engine 12. The atmospheric pressure sensor 64 detects atmospheric pressure. An engine ECU 56 obtains a detection result of the intake pipe pressure sensor 48 when the engine 12 is stopped. A local ECU 62 calculates a difference between the detection result of the intake pipe pressure sensor 48 and the detection result of the atmospheric pressure sensor 64 to notify an error when the calculated difference is equal to or higher than a threshold.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an abnormality detection device, and more particularly to an abnormality detection device that detects an abnormality of a sensor related to the operation of a brake mechanism.

  In an automobile brake using a vacuum booster, a driver's braking force is assisted by utilizing a difference between a negative pressure generated by an engine or the like and an atmospheric pressure. Therefore, the detection results of each of the negative pressure sensor and the atmospheric pressure sensor are important parameters for grasping the relationship between the brake depression force and the degree of braking effectiveness. In other words, if an abnormality occurs in the negative pressure sensor or the atmospheric pressure sensor, the relationship between the brake pedal force and the degree of goodness of the brake cannot be accurately grasped, and there is a risk that safe driving of the automobile becomes difficult.

  In addition, when atmospheric pressure is detected using an atmospheric pressure sensor, the atmospheric pressure sensor indicates whether there is an abnormality in the detected difference because the fluctuation of the atmospheric pressure itself is large or the atmospheric pressure sensor itself has an error. It is difficult to distinguish alone.

  In view of this, in Patent Document 1, the gradient angle and the vehicle body acceleration are detected using the longitudinal acceleration sensor and the wheel speed sensor, and the altitude change amount and the atmospheric pressure change amount are estimated based on the detected gradient angle and vehicle body acceleration. The abnormality of the atmospheric pressure sensor is detected from the estimated value of the atmospheric pressure change amount.

JP 2011-117770 A

  However, Patent Document 1 has a problem that complicated calculation is required to detect an abnormality in the atmospheric pressure sensor.

  SUMMARY OF THE INVENTION Therefore, a main object of the present invention is to provide an abnormality detection device that can easily and reliably detect an abnormality of a sensor.

  An abnormality detection device according to the present invention is an abnormality detection device that detects an abnormality in a first sensor that detects the pressure of an intake pipe provided in an internal combustion engine or a second sensor that detects atmospheric pressure. Computation means for computing the difference between the detection result and the detection result of the second sensor while the internal combustion engine is stopped, and notification means for notifying an error when the difference calculated by the calculation means is equal to or greater than a threshold value.

  An abnormality detection device according to the present invention is an abnormality detection device that detects an abnormality of a first sensor that detects pressure in an intake pipe provided in an internal combustion engine or a second sensor that detects atmospheric pressure, and flows through the intake pipe. A throttle valve that adjusts the air amount, a calculation unit that calculates the difference between the detection result of the first sensor and the detection result of the second sensor when the opening of the throttle valve is equal to or greater than the first threshold, and the calculation unit Informing means for informing an error when the difference is equal to or greater than the second threshold value is provided.

  When the internal combustion engine is stopped, the intake pipe pressure matches the atmospheric pressure. Based on this, the difference between the intake pipe pressure and the atmospheric pressure is calculated when the internal combustion engine is stopped, and an error is notified when the calculated difference exceeds a threshold value. Thereby, it is possible to easily and reliably detect the abnormality of the sensor.

  Further, the intake pipe pressure approaches the atmospheric pressure as the opening of the throttle valve increases. Based on this, the difference between the intake pipe pressure and the atmospheric pressure is calculated when the opening of the throttle valve is equal to or greater than the first threshold, and an error is notified when the calculated difference exceeds the second threshold. Yes. Thereby, it is possible to easily and reliably detect the abnormality of the sensor.

  The above object, other objects, features and advantages of the present invention will become more apparent from the following detailed description of embodiments with reference to the drawings.

It is a block diagram which shows a part of principal part structure of the vehicle of this Example. It is a graph which shows an example of transition of an intake pipe pressure and atmospheric pressure. It is a flowchart which shows a part of operation | movement of engine ECU applied to this Example. It is a flowchart which shows a part of operation | movement of local ECU applied to this Example. (A) is a graph which shows an example of transition of an engine speed, (B) is a graph which shows an example of transition of an intake pipe pressure and atmospheric pressure. It is a graph which shows an example of transition of an intake pipe pressure and atmospheric pressure. It is a flowchart which shows a part of operation | movement of local ECU applied to another Example.

  Referring to FIG. 1, a vehicle 10 of this embodiment includes a 4-stroke engine (internal combustion engine) 12 as a power source. An intake pipe 32 is connected to the combustion chamber 16 provided in the cylinder 14 via an intake valve 18, and an exhaust pipe 34 is connected via an exhaust valve 20. 1, only a single cylinder 14 is shown, but the engine 12 has a plurality of cylinders 14, 14,. The intake pipe 32 branches to each cylinder 14 at a position upstream of the intake valve 18.

  The intake pipe 32 has a single throttle valve 36 whose opening degree changes according to the depression force of the accelerator pedal 58 disposed in the driver's seat, and fuel injection assigned to each cylinder 14 to inject fuel into the intake pipe 32. A device 38 is provided. A surge tank 46 for leveling the air flow rate is provided at a position downstream of the throttle valve 36 and upstream of the fuel injection device 38 (a branch position of the intake pipe 32).

  A single bypass flow path 40 that bypasses the throttle valve 36 is also connected to the intake pipe 32. Further, the bypass flow path 40 is provided with an ISCV 42. The ISCV 42 is an electronic open / close valve that uses the stepper motor 44 as a drive source. The opening of the ISCV 42 changes according to the rotational position of the stepper motor 44. The air flow rate in the bypass channel 40 depends on the opening degree of the ISCV 42 as described above.

  When an IG ON operation is performed by an ignition key (not shown) provided in the driver's seat, the engine 12 is started by the engine ECU 56. In the idle state, the throttle valve 36 is closed, and air is supplied to the combustion chamber 16 via the bypass passage 40. The air flow rate in the bypass flow path 40, that is, the opening degree of the ISCV 42 is controlled based on the rotational speed of the engine 12. Further, the amount of fuel injected from the fuel injection device 38 is controlled based on the opening of the ISCV 42.

  When an accelerator pedal 58 provided in the driver's seat is depressed, the engine ECU 56 opens the throttle valve 36. The air flow rate in the intake pipe 32 depends on the opening degrees of the ISCV 42 and the throttle valve 36. The amount of fuel injected from the fuel injection device 38 is controlled based on the air flow rate in the intake pipe 32 (openings of the throttle valve 36 and the ISCV 42).

  The air-fuel mixture obtained by mixing the fuel with the intake air is supplied to the combustion chamber 16 when the intake valve 18 is opened. The supplied air-fuel mixture is ignited by the spark plug 24 immediately before the piston 22 connected to the crankshaft 28 via the connecting rod 26 reaches the top dead center. The piston 22 moves up and down by the explosion of the air-fuel mixture, whereby the crankshaft 28 rotates. The air after combustion of the air-fuel mixture, that is, the exhaust gas, is discharged to the exhaust pipe 34 when the exhaust valve 20 is opened.

  A flywheel 30 is attached to the crankshaft 28, and fluctuations in the rotational speed of the crankshaft 28, that is, the rotational speed of the engine 12 are suppressed by the flywheel 30. The rotational force of the crankshaft 28 is transmitted to a drive shaft (not shown), whereby the vehicle 10 moves forward or backward.

  When the brake pedal 54 provided in the driver's seat is depressed, the brake depression force is transmitted to the brake mechanism (not shown) via the vacuum booster 52, thereby decelerating the vehicle 10. When the vehicle 10 stops after deceleration, the engine ECU 56 considers that the idle stop condition is satisfied, and stops the engine 12. The engine 12 transitions to the idle stop state. When the foot is released from the brake pedal 54 in this state, the engine ECU 56 assumes that the idle start condition is satisfied and restarts the engine 12.

  The negative pressure chamber of the vacuum booster 52 is connected to the intake pipe 32 via the check valve 50. The pressure in the negative pressure chamber is higher than the pressure in the intake pipe 32 as much as the check valve 50 is provided. The intake pipe pressure sensor 48 is provided in the vicinity of the surge tank 46 and detects the pressure of the intake pipe 32 as “P1”. The detected intake pipe pressure P1 is given to the engine ECU 56. On the other hand, the atmospheric pressure sensor 64 detects the atmospheric pressure as “P2” and gives the detected atmospheric pressure P2 to the local ECU 62.

  The door courtesy SW 60 is turned on when the door is opened and turned off when the door is closed. Engine ECU 56 also detects the on / off state of door courtesy SW60. Further, the engine ECU 56 is always activated, while the local ECU 62 is activated only during a period from the IG on operation to the IG off operation. The local ECU 62 activated in response to the IG on operation establishes CAN communication with the engine ECU 56.

  The vacuum booster 52 assists the driver's brake pedal force by utilizing the difference between the pressure in the intake pipe 32 and the atmospheric pressure. Therefore, the pressure of the intake pipe 32 and the atmospheric pressure are important parameters in grasping the relationship between the brake pedal force and the degree of effectiveness of the brake mechanism. In other words, if an abnormality occurs in the intake pipe pressure sensor 48 or the atmospheric pressure sensor 64, the relationship between the brake pedal force and the degree of use of the brake mechanism cannot be accurately grasped, and there is a risk that safe driving of the automobile becomes difficult.

  Therefore, in this embodiment, the processing shown in FIG. 3 is executed by the engine ECU 56, and the processing shown in FIG. 4 is executed by the local ECU 62, thereby detecting an abnormality in the intake pipe pressure sensor 48 or the atmospheric pressure sensor 64. ing. Therefore, the abnormality detection device of the present invention is constituted by engine ECU 56 and local ECU 62.

  The process shown in FIG. 3 is repeatedly executed, and the process shown in FIG. 4 is executed only once immediately after the local ECU 62 is started (the engine 12 is stopped). Further, a program corresponding to the process shown in FIG. 3 is stored in the memory 56m, and a program corresponding to the process shown in FIG. 4 is stored in the memory 62m.

  Referring to FIG. 3, in step S1, it is determined whether or not the current timing is the timing before the IG on operation (whether or not engine 12 is stopped). In step S3, door courtesy SW 60 is switched from the off state to the on state. It is determined whether or not a transition is made to (whether or not the door is opened). If the determination result in step S1 or S3 is NO, the current process is immediately terminated. On the other hand, if both the determination results in steps S1 and S3 are YES, the process proceeds to step S5, and the intake pipe pressure P1 detected by the intake pipe pressure sensor 48 is acquired. The acquired intake pipe pressure P1 is stored in the memory 56m. This process ends after the intake pipe pressure P1 is stored.

  Referring to FIG. 4, CAN communication with engine ECU 56 is established at step S11, and intake pipe pressure P1 stored in memory 56m is acquired via engine ECU 56 at step S13. In step S15, the atmospheric pressure P2 detected by the atmospheric pressure sensor 64 is acquired. When the engine 12 is stopped, the intake pipe pressure P1 and the atmospheric pressure P2 change, for example, as shown in FIG. In step S17, a difference ΔP between the intake pipe pressure P1 and the atmospheric pressure P2 is calculated. In step S19, it is determined whether or not the calculated difference ΔP is greater than or equal to a threshold value THp1.

  If the determination result is NO, it is considered that both the intake pipe pressure sensor 48 and the atmospheric pressure sensor 64 are normal (the difference ΔP is considered to be within the error range), and the current process is terminated. On the other hand, if the determination result is YES, it is considered that an abnormality has occurred in the intake pipe pressure sensor 48 or the atmospheric pressure sensor 64, and an error is notified to the driver by voice in step S21. This process ends after the error is notified.

  When the engine 12 is stopped, the pressure in the intake pipe 32 matches the atmospheric pressure. Based on this, in this embodiment, the difference ΔP between the intake pipe pressure P1 and the atmospheric pressure P2 is calculated when the engine 12 is stopped, and an error is generated when the calculated difference ΔP is equal to or greater than the threshold value THp1. I am trying to inform you. Thereby, the abnormality of the intake pipe pressure sensor 48 or the atmospheric pressure sensor 64 can be detected easily and reliably.

  Note that the pressure in the intake pipe 32 matches the atmospheric pressure even in the idle stop state. That is, when transitioning from the idle state to the idle stop state, the rotational speed of the engine 12 changes as shown in FIG. 5 (A), and the intake pipe pressure P1 changes as shown in FIG. 5 (B). Therefore, the process shown in FIG. 4 may be executed only once in response to the transition to the idle stop state. However, the altitude of the vehicle 10 at the time of transition to the idle stop state may be different from the altitude of the vehicle 10 at the time when the IG-on operation is performed. For this reason, preferably, the intake pipe pressure P1 is acquired again at the time of transition to the idle stop state.

  Further, the pressure of the intake pipe 32 approaches the atmospheric pressure as the opening of the throttle valve 36 increases (see FIG. 6). Therefore, it is possible to easily and reliably detect an abnormality in the intake pipe pressure sensor 48 or the atmospheric pressure sensor 64 by repeatedly executing the process shown in FIG. 7 instead of the process shown in FIG.

  Referring to FIG. 7, in step S31, the same processing as step S11 shown in FIG. 4 is executed, and in step S33, the opening degree of throttle valve 36 is detected through engine ECU 56. In step S35, it is determined whether or not the detected opening is equal to or greater than a threshold value THs. If the determination result is NO, the current process is immediately terminated. If the determination result is YES, the engine ECU 56 is determined in step S37. To detect the latest intake pipe pressure P1. In steps S39 to S41, the same processing as in steps S15 to S17 shown in FIG. 4 is executed, and in step S43, it is determined whether or not the difference ΔP is greater than or equal to a threshold value THp2.

  If the determination result is NO, it is considered that both the intake pipe pressure sensor 48 and the atmospheric pressure sensor 64 are normal, and the current process is terminated as it is. On the other hand, if the determination result is YES, it is considered that an abnormality has occurred in the intake pipe pressure sensor 48 or the atmospheric pressure sensor 64, and an error is notified to the driver by voice in step S45. This process ends after the error is notified.

DESCRIPTION OF SYMBOLS 10 ... Vehicle 12 ... Engine 18 ... Intake valve 20 ... Exhaust valve 38 ... Throttle valve 48 ... Intake pipe pressure sensor 52 ... Vacuum booster 54 ... Brake pedal 56 ... Engine ECU
62 ... Local ECU
64… Atmospheric pressure sensor

Claims (2)

An abnormality detection device for detecting an abnormality in a first sensor for detecting pressure in an intake pipe provided in an internal combustion engine or a second sensor for detecting atmospheric pressure,
A calculation means for calculating a difference between the detection result of the first sensor and the detection result of the second sensor while the internal combustion engine is stopped; and an error when the difference calculated by the calculation means is equal to or greater than a threshold value. An abnormality detection device comprising notification means for notification. An abnormality detection device for detecting an abnormality in a first sensor for detecting pressure in an intake pipe provided in an internal combustion engine or a second sensor for detecting atmospheric pressure,
A throttle valve for adjusting the amount of air flowing through the intake pipe;
Calculating means for calculating a difference between the detection result of the first sensor and the detection result of the second sensor when the opening of the throttle valve is equal to or greater than a first threshold; and the difference calculated by the calculating means is a second An abnormality detection device comprising notification means for notifying an error when a threshold value is exceeded.

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