JP2004251897A - Instantaneous power interruption detection system for vehicle electric system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an instantaneous power interruption detection system for a vehicle electric system which can detect a temporary contact failure of an electric system. <P>SOLUTION: VSC-ECU 1 comprises an input processing circuit 3 which processes electric signals sent from various sensors and EFI-EUC through a signal conductor 2 (wiring harness), a signal status determining circuit 4 which determines whether the electric signal processed at the input processing circuit is in a normal condition or not, a latch circuit 5 which stores the result as a latch signal when the electric signal is determined as in an abnormal condition by the signal status determining circuit 4, and an output circuit 6 which outputs the latch signal. When an abnormal signal is detected at the signal status determining circuit 4, the latch circuit 5 generates a latch signal in synchronism with the detection, and keep the latch signal for a certain period. Therefore, by monitoring the latch signal by connecting a tester device 7 to the output circuit 6, for example, instantaneous power interruption of an electric system can be detected. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

    The present invention relates to a vehicle electrical system momentary interruption detection system capable of detecting an instantaneous interruption due to a temporary contact failure occurring in an electric system of a vehicle.

  As a prior art, for example, there is a failure diagnosis device for an electronic control unit for a vehicle described in JP-A-2001-65403.

  In this conventional technique, an abnormality (disconnection) of a wire harness connected to an ECU is detected by a failure diagnosis function built in an ECU (electronic control device). Specifically, it is determined whether a signal (sensor signal) input to the ECU through the wire harness is within a normal range, and when it is determined that the signal is not within a normal range (temporary determination), the abnormality determination counter Increment the value. Thereafter, it is determined whether or not the value of the abnormality determination counter has exceeded a predetermined value. If the value has exceeded the predetermined value (for example, if the tentative determination has been performed four times consecutively), it is finally determined that a failure has occurred.

  However, in the above-described conventional technology, the final failure determination is not performed until the value of the abnormality determination counter exceeds a predetermined value (that is, until the provisional determination reaches a predetermined number of times). It cannot detect anything other than a failure (for example, a failure of the sensor itself or a break in the wire harness). That is, in the case of a temporary contact failure (momentary interruption), such as a loose contact (incomplete connection of the connector), the abnormal state does not always continue, and thus cannot be dealt with by the above-described conventional technology (temporary). A poor contact failure cannot be detected).

  Conventionally, when a final failure determination is made by the above method or the like, the control system including the failure factor is stopped, so that an abnormal state cannot be confirmed in real time, and the failure factor cannot be identified. It was difficult.

  The present invention has been made based on the above circumstances, and an object of the present invention is to provide a vehicle electrical system momentary interruption detection system capable of detecting an electrical system interruption (temporary contact failure).

  Another object of the present invention is to provide an instantaneous interruption detection system capable of checking an abnormal state in real time without stopping the control system.

  According to the first aspect of the present invention, a) a state in which an electric signal input from the signal generating means (11 to 15) for generating an electric signal through the signal line (2) changes from a normal state to an abnormal state is referred to as a signal abnormality. Then, a signal abnormality detecting means (4) for detecting the signal abnormality, and b) a holding means (5) for holding the detection result as a latch signal when the signal abnormality is detected by the signal abnormality detecting means. It is characterized by having.

  According to this configuration, when a signal abnormality is detected by the signal abnormality detecting means, the detection result is held by the holding means, so that a signal abnormality (temporary interruption) due to a temporary contact failure such as a loose contact is detected. It is possible to do. As a result, instantaneous interruption detection of the electric system can be performed in a short time in a vehicle dealer, a service factory (repair shop), or the like.

  According to the second aspect of the present invention, a) an electric signal wirelessly transmitted from the signal generating means (11 to 15) for generating an electric signal is inputted, and it is determined that the electric signal has changed from a normal state to an abnormal state. If it is called signal abnormality, signal abnormality detection means (4) for detecting the signal abnormality, and b) hold means for holding the detection result as a latch signal when the signal abnormality detection means detects the signal abnormality ( 5). With such a configuration, the same effect as that of the first aspect can be obtained.

  The instantaneous interruption detection system for a vehicle electrical system according to claim 1 or 2, may further include a warning unit (7) for warning that a signal abnormality has been detected, as described in claim 3. . With this configuration, the instantaneous interruption part of the electric system leading to the signal abnormality can be specified by the warning of the warning means, so that the inspection and repair can be performed at an early stage.

  According to a fourth aspect of the present invention, in the instantaneous interruption detection system for a vehicle electrical system according to the first or second aspect, an output circuit (6) capable of outputting a latch signal is provided. According to such a configuration, a latch signal can be extracted from the output circuit, and by monitoring the extracted latch signal, it is possible to confirm an instantaneous interruption portion of the electric system. Further, since the output circuit is provided, a tester device or the like can be connected to the output circuit, so that it is possible to display the instantaneous interruption part of the electric system on the tester device. In this case, it is not necessary to provide a display function for specifying the instantaneous interruption part of the electric system in the present system (instantaneous interruption detection system), so that the present system can be realized at low cost.

  According to a fifth aspect of the present invention, in the instantaneous interruption detection system for a vehicle electric system according to the fourth aspect, an external connection means (7) which can be connected to an output circuit to input a latch signal is provided. The means is provided with a warning means for warning that a signal abnormality has been detected. Even with such a configuration, the same effect as that of the third aspect can be obtained.

  According to a sixth aspect of the present invention, in the vehicle electrical system instantaneous interruption detection system according to any one of the first to fifth aspects, the electric signal generated by the signal generating means conforms to a predetermined communication protocol. A signal abnormality detecting means that, when a signal according to a predetermined communication protocol is transmitted from the signal generating means, a state in which a signal according to the predetermined communication protocol is continuously input is a normal state. It is characterized in that a state in which the signal according to the predetermined communication protocol is interrupted even though a signal according to the predetermined communication protocol is transmitted from the signal generating means is determined to be an abnormal state. .

In this case, the signal abnormality detection means can detect the interruption of the signal according to the predetermined signal protocol as a signal abnormality.
In the invention according to claim 7, in the instantaneous interruption detection system for a vehicle electric system according to any one of claims 1 to 5, the electric signal generated by the signal generating means is a digital pulse signal, The signal abnormality detection means determines that a state where the pulse signal is continuously input at a fixed time interval when the pulse signal is transmitted from the signal generation means is a normal state, and the signal generation means transmits the pulse signal. In spite of this, a state where the pulse signal is interrupted for a time longer than a predetermined time interval is determined as an abnormal state.

  In this case, the signal abnormality detection means can detect the interruption of the pulse signal as a signal abnormality.

  According to the invention described in claim 8, in the instantaneous interruption detection system for a vehicle electric system according to any one of claims 1 to 5, the electric signal generated by the signal generating means has a constant signal level (ON state). A digital signal to be maintained, wherein the signal abnormality detecting means determines that a state in which the digital signal is input while maintaining the ON state when the digital signal is transmitted from the signal generating means is a normal state, Although the digital signal is transmitted from the, a state where the digital signal is interrupted is determined to be an abnormal state.

  In this case, the signal abnormality detection means can detect that the digital signal has been interrupted (a state in which the signal level has changed) as a signal abnormality.

  According to a ninth aspect of the present invention, in the instantaneous interruption detection system for a vehicle electrical system according to any one of the first to fifth aspects, the electric signal generated by the signal generation unit is an analog signal, and the signal abnormality detection unit Determines that a state where the analog signal is continuously input when the analog signal is transmitted from the signal generating means is a normal state, and that the analog signal is transmitted from the signal generating means even though the analog signal is transmitted. A state in which the analog signal is interrupted (a state in which the signal level changes) is determined as an abnormal state.

  In this case, the signal abnormality detection means can detect the interruption of the analog signal as a signal abnormality.

  In addition, the code | symbol in the parenthesis of each said means shows the correspondence with the concrete means described in embodiment mentioned later.

  Next, an embodiment of the present invention will be described with reference to the drawings.

  In the present embodiment, an instantaneous interruption detection system for a vehicle electric system (hereinafter, referred to as the present system) according to the present invention, that is, an instantaneous interruption for detecting a temporary contact failure (instantaneous interruption) occurring in an electric system of a vehicle. The case where the detection system is incorporated in a control system of the side slip prevention device will be described as an example. The sideslip prevention device performs control called VSC (Vehicle Stability Control) in order to secure stability during turning of the vehicle. Hereinafter, the control system in the anti-skid device is abbreviated as VSC system.

  FIG. 1 is a diagram schematically showing a state in which a tester 7 for detecting an instantaneous interruption is connected to a VSC system.

  The VSC system includes a VSC-ECU 1, an actuator 1 a driven by the VSC-ECU 1, an EFI-ECU (electronic control unit) 11 for controlling a fuel supply device (EFI) connected to the VSC-ECU 1 via a signal line 2, The vehicle includes various sensors 12 to 15 for detecting vehicle information at the time of turning. The various sensors 12 to 15 are constituted by a vehicle speed sensor 12, a yaw rate sensor 13, a G sensor 14, a steering sensor 15, and the like, and output electric signals indicating detection results regarding a vehicle speed, a yaw angle, an acceleration, and a steering angle, respectively. Each electric signal is inputted to the VSC-ECU 1 through the signal line 2.

  The VSC-ECU 1 outputs a control signal to the actuator 1 a to perform VSC based on an electric signal indicating the fuel supply amount from the EFI-ECU 11 and each detection signal from the various sensors 12 to 15, It plays the role of detecting momentary interruption in the system.

  Specifically, the VSC-ECU 1 has a configuration including an input processing circuit 3, a control circuit 10, a signal state determination circuit 4, a latch circuit 5, and an output circuit 6.

  The input processing circuit 3 processes electric signals sent from the EFI-ECU 11 and the various sensors 12 to 15 through the signal line 2.

  The control circuit 10 performs various calculations based on the electric signals of the sensors 12 to 15 processed by the input processing circuit 3 and determines whether or not VSC needs to be performed according to the calculation results. Is performed, a control signal for that is generated.

  The signal state determination circuit 4 determines whether the electric signal processed by the input processing circuit 3 is in a normal state or an abnormal state, and corresponds to a signal abnormality detection unit of the present invention. The signal state determination circuit 4 takes in the electric signal (pulse signal) processed by the input processing circuit 3, and determines that the state in which the pulse signal is continuously input at predetermined time intervals is a normal state. On the other hand, if the pulse signal processed by the input processing circuit 3 is interrupted for a longer time than a certain time interval, despite the fact that the electric signal is transmitted from the various sensors and the EFI-ECU 11, an abnormal state is determined. Is determined. In this case, the signal state determination circuit 4 outputs a signal indicating that the electric signal has changed from the normal state to the abnormal state, that is, a signal abnormality is detected.

  The latch circuit 5 holds the determination result as a latch signal when the signal state determination circuit 4 determines that the state is abnormal, and corresponds to the holding means of the present invention. When a signal abnormality is detected by the signal state determination circuit 4, the latch circuit 5 generates a latch signal in synchronization with the signal abnormality and holds the latch signal for a predetermined time.

  FIG. 2 is a diagram showing a relationship between an electrical signal (sensor signal) from any one of the various sensors 12 to 15 and a latch signal when an abnormality is detected. As shown in this figure, in a normal state, the sensor signal is repeatedly turned on and off at predetermined intervals. When an abnormal state occurs due to an instantaneous interruption of the signal line 2 or the like, the sensor signal does not repeatedly turn on and off during that time, for example, as shown in FIG. This state is detected as an abnormal state by the signal state determination circuit 4, and the latch signal is held by the latch circuit 5. In FIG. 2, the latch signal is always at a level (high level) indicating an abnormal state after detecting the abnormal state, but returns to the original level (low level) after a predetermined time.

  The output circuit 6 receives a signal generated by the control circuit 10 and outputs the signal to the actuator 1a, or outputs a latch signal held by the latch circuit 5. A tester device 7 corresponding to an external connection means can be connected to the output circuit 6. When the tester device 7 is output to the output circuit 6, a latch signal is taken into the tester device 7. I have.

  The tester device 7 is attached to the output circuit 6 by, for example, a vehicle dealer or a service factory (repair shop) when the VSC system 1 has a disconnection failure or the like. The tester device 7 is provided with a warning unit (not shown) for issuing a warning such as turning on a lamp or sounding a buzzer when a latch signal is input.

  Further, the actuator 1a is constituted by, for example, an actuator for ABS provided with a solenoid valve, a motor, and the like. The braking force applied can be adjusted.

  Next, a procedure for detecting an instantaneous interruption will be described with reference to FIGS.

  FIG. 3 shows one of the various sensors 12 to 15 connected to the VSC-ECU 1 as the sensor 8 as a representative, and the other sensors and the EFI-ECU 11 are momentarily interrupted by the same procedure. Detection is performed. Here, as shown in FIG. 3, when the sensor 8 is connected to the VSC-ECU 1 via the intermediate connector 10, specifically, the rest of the intermediate connector 10 and the VSC-ECU 1 are connected by the signal line 2a. And a configuration in which the sensor 8 and a part of the intermediate connector 10 are connected by the signal line 2a.

  For example, when a momentary interruption or the like occurs at any part of the VSC system and the user notices the failure, or when performing an inspection at a vehicle dealer or a service factory (repair shop), a vehicle dealer or service is required. The tester device 7 is connected to the output circuit 6 of the VSC-ECU 1 at a factory (repair shop) or the like, and abnormality detection is performed according to the following steps 1 to 3. FIG. 4 schematically shows these Steps 1 to 3.

[Step1]
As shown in FIG. 4, vibration is applied to the portion 1) shown in FIG. 3, that is, the connector 9 or the wire harness 2a connected to the VSC-ECU 1, and the latch signal is monitored by the tester device 7. Here, when a temporary contact failure (momentary interruption) occurs, a signal abnormality is detected by the signal state determination circuit 4 and, at the same time, is held as a latch signal by the latch circuit 5 (see FIG. 2). When the latch signal is taken into the tester device 7, a warning means (an abnormal display, a tester abnormal display lamp, a buzzer, or the like) provided in the tester device 7 issues a warning, thereby confirming that an instantaneous interruption has occurred.

  In this case, since the connection failure of the connector 9 (loose contact) can be considered as a cause of the instantaneous interruption, the fitting state of the connector 9 is checked. Thereafter, the connector 9 or the wire harness 2a is again vibrated, and the tester device 7 monitors the latch signal. Here, if the warning unit of the tester device 7 does not issue a warning, it can be determined that the improper fitting of the connector 9 has caused the instantaneous interruption.

[Step 2]
Subsequently, as shown in FIG. 4, vibration is applied to the portion 2) shown in FIG. 3, ie, the intermediate connector 10 or the wire harnesses 2a and 2b, and the latch signal is monitored by the tester device 7. Similarly to the case of Step 1 described above, when the warning unit of the tester device 7 issues a warning, it is considered that a poor fitting (loose contact) of the intermediate connector 10 is a cause of an instantaneous interruption. Then, vibration is applied to the intermediate connector 10 or the wire harnesses 2a and 2b again, and the tester device 7 monitors the latch signal. Here, if the warning means of the tester device 7 does not issue a warning, it can be determined that the improper fitting of the intermediate connector 10 caused the instantaneous interruption.

[Step 3]
Finally, as shown in FIG. 4, vibration is applied to the portion 3) shown in FIG. 3, that is, the connector 11 or the wire harness 2b connected to the sensor 8, and the tester device 7 monitors the latch signal. As in the case of Step 1 and Step 2, when the warning means of the tester device 7 issues a warning, the poor connection of the connector 11 (loose contact) is considered to be the cause of the instantaneous interruption. After that, vibration is again applied to the connector 11 or the wire harness 2b, and the tester device 7 monitors the latch signal. Here, if the warning means of the tester device 7 does not issue a warning, it can be determined that the improper fitting of the connector 11 caused the momentary interruption.

  As described above, according to the VSC system in the present embodiment, when a temporary contact failure of the electric system (when the failure is not a continuous failure) occurs, a signal abnormality is detected, and the signal abnormality is detected. It can be held as a latch signal. Therefore, by monitoring the latch signal, a temporary contact failure such as a loose contact can be detected.

  Further, in the VSC system, even when a signal abnormality is detected, there is no need to stop the control system to be detected, so that a temporary contact failure can be confirmed in real time. As a result, the instantaneous interruption of the electric system can be reproduced in a vehicle dealer or a service factory (repair shop) while the control system is operated, so that the instantaneously interrupted portion can be easily and quickly identified by the tester device 7. be able to.

  Further, in this embodiment, since the VSC-ECU 1 is provided with the output circuit 6, the output circuit 6 can be connected to the tester device 7 or the like by using the output circuit 6 as external connection means. Therefore, it is also possible to cause the tester device 7 to display the instantaneous interruption part of the electric system. In this case, it is not necessary to provide a display function for specifying the instantaneous interruption part of the electric system in the present system (instantaneous interruption detection system), so that the present system can be realized at low cost.

(Modification)
It is needless to say that the present system is not limited to the VSC system described in the above embodiment, but can be applied to other control systems.

  In the above-described embodiment, the example in which the tester device 7 is provided with the warning unit is described. However, for example, the control system (VSC system) may include the warning unit. In this case, when a signal abnormality is detected by the signal state determination circuit 4, the VSC-ECU 1 can operate the warning means, so that when a momentary interruption occurs in the electric system, the driver can recognize the occurrence of the abnormality in real time. Can be sensed.

  The input processing circuit 3 converts the input signal into a pulse signal. However, the input signal is not limited to the pulse signal. For example, the input processing circuit 3 may convert the input signal into a digital signal that maintains a constant signal level (for example, a 5V voltage). In this case, the signal state determination circuit 4 determines that a state where the digital signal processed by the input processing circuit 3 is input while maintaining a constant signal level is a normal state, and a signal generation unit (in the above-described embodiment, various sensors). 12 to 15 and the EFI-ECU 11), a state in which the digital signal is interrupted (a state in which the digital signal is not input to the signal state determination circuit 4) can be determined as an abnormal state.

  The electric signals (signals generated by the signal generating means) taken into the input processing circuit 3 include not only the pulse signals described in the embodiment or the digital signals maintaining a constant signal level (ON state) but also analog signals. But it's fine. Alternatively, a signal according to a predetermined communication protocol (for example, a signal used for CAN communication) may be used. That is, the interruption of the pulse signal, the digital signal, the analog signal, or the signal according to the communication protocol may be detected as a signal abnormality.

  The tester device 7 may be provided with a function capable of displaying the instantaneous interruption site on the screen based on the latch signal, in addition to the warning unit.

  This system does not necessarily need to be connected to the signal generation means by a signal line, but inputs an electric signal transmitted wirelessly from the signal generation means, detects an abnormality in the electric signal, and latches the detection result. It can also be held as a signal.

  The detection of such an abnormal signal may be left as a history.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a configuration diagram schematically showing an instantaneous interruption detection system for a vehicle electric system. FIG. 3 is an output diagram of a sensor signal and a latch signal for explaining a function of a latch circuit. It is a block diagram of the instantaneous interruption detection system using a tester device. It is a flowchart which shows the procedure of instantaneous interruption detection.

Explanation of reference numerals

DESCRIPTION OF SYMBOLS 1 ... VSC-ECU, 1a ... Actuator, 2 ... Signal line, 3 ... Input processing circuit,
4 signal state determination circuit, 5 latch circuit, 6 output circuit, 7 tester,
10: control circuit, 11: EFI-ECU, 12 to 15: sensor.

Claims (9)

a) When a change in the electric signal input from the signal generation means (11 to 15) for generating an electric signal through the signal line (2) from a normal state to an abnormal state is called a signal abnormality, the signal abnormality is detected. Signal abnormality detection means (4);
b) A momentary interruption detection system for a vehicle electric system, comprising: a holding means (5) for holding a detection result as a latch signal when the signal abnormality is detected by the signal abnormality detecting means. a) An electric signal transmitted wirelessly from signal generating means (11 to 15) for generating an electric signal is input, and a change in the electric signal from a normal state to an abnormal state is referred to as a signal abnormality. Signal abnormality detection means (4) for detecting abnormality;
b) A momentary interruption detection system for a vehicle electric system, comprising: a holding means (5) for holding a detection result as a latch signal when the signal abnormality is detected by the signal abnormality detecting means. The instantaneous interruption detection system for a vehicle electrical system according to claim 1 or 2,
An instantaneous interruption detection system for a vehicular electric system, comprising a warning unit (7) for warning that the signal abnormality has been detected. The instantaneous interruption detection system for a vehicle electrical system according to claim 1 or 2,
An instantaneous interruption detection system for a vehicle electric system, comprising an output circuit (6) capable of outputting the latch signal. The instantaneous interruption detection system for a vehicle electric system according to claim 4,
An external connection means (7) connected to the output circuit and capable of inputting the latch signal is provided, and the external connection means is provided with a warning means for warning that the signal abnormality has been detected. Vehicle electrical system instantaneous interruption detection system. An instantaneous interruption detection system for a vehicle electric system according to any one of claims 1 to 5,
The electric signal generated by the signal generating means is a signal according to a predetermined communication protocol,
The signal abnormality detecting means changes a state in which a signal according to the predetermined communication protocol is continuously input when a signal according to the predetermined communication protocol is transmitted from the signal generating means to the normal state. It is determined that the state in which the signal according to the predetermined communication protocol is interrupted even though the signal according to the predetermined communication protocol is transmitted from the signal generation unit is the abnormal state. Characteristic instantaneous interruption detection system for vehicle electrical system. An instantaneous interruption detection system for a vehicle electric system according to any one of claims 1 to 5,
The electric signal generated by the signal generating means is a digital pulse signal,
The signal abnormality detecting means, when the pulse signal is transmitted from the signal generating means, determines that a state in which the pulse signal is continuously input at a constant time interval is the normal state, and the signal generating means Detecting an instantaneous interruption of the vehicular electric system, wherein a state where the pulse signal is interrupted for a time longer than the predetermined time interval is determined as the abnormal state, even though the pulse signal is transmitted from system. An instantaneous interruption detection system for a vehicle electric system according to any one of claims 1 to 5,
The electric signal generated by the signal generating means is a digital signal that maintains a constant signal level (ON state),
When the digital signal is transmitted from the signal generation unit, the signal abnormality detection unit determines that a state in which the digital signal is input while maintaining the ON state is the normal state. An instantaneous interruption detection system for a vehicular electric system, wherein a state in which a digital signal is interrupted even though a digital signal is transmitted is determined as the abnormal state. An instantaneous interruption detection system for a vehicle electric system according to any one of claims 1 to 5,
The electric signal generated by the signal generation means is an analog signal,
When the analog signal is transmitted from the signal generation unit, the signal abnormality detection unit determines that a state in which the analog signal is continuously input is the normal state. An instantaneous interruption detection system for a vehicular electric system, wherein a state in which an analog signal is interrupted (a state in which a signal level is changed) is determined as the abnormal state despite being transmitted.

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