JPH0733984B2 - Vehicle failure diagnosis device - Google Patents

Description

The present invention relates to a vehicle failure diagnosis device.

[Prior Art] Conventionally, what is called a "fault analysis device" is used for diagnosing a vehicle fault.

The failure analysis device includes a vehicle data storage device that stores input / output signals of the vehicle-mounted electronic control device over time, and a display device that displays the stored contents of the storage device, and displays the displayed vehicle data as data. The cause of the failure is sought by visual inspection and analysis by an expert with analysis ability.

However, although such a conventional failure analysis device can output vehicle data required for analysis, the analysis work itself has to be entrusted to a few specialists, thus narrowing the operation range for failure diagnosis. There was a problem.

[Object of the Invention] It is an object of the present invention to provide a vehicle failure diagnosis device that solves the above-mentioned problems and can appropriately investigate the cause of a failure while utilizing a failure analysis device.

[Outline of the Invention] In order to achieve the above object, according to the present invention, as shown in FIG. 1, a vehicle failure diagnosis device records the value of an input / output signal of an in-vehicle electronic control device as vehicle data over time. Vehicle data storage means 1, failure information storage means 2 for storing causal information of vehicle failure, symptom input means 3 for inputting symptoms of vehicle failure, and the causal information for the symptoms input to the means 3. By searching and analyzing the temporal data of each input / output signal related to the cause candidate, the cause candidates are narrowed down, the occurrence time is detected, and the vehicle data in the time zone around the detected occurrence time is analyzed. The analysis / inference means 4 for inferring the cause of the above and the informing means 5 for informing the inference result are configured to utilize the vehicle data for the failure diagnosis.

Embodiments Embodiments of the present invention will be described below with reference to the accompanying drawings.

First, briefly explaining the drawings, FIG. 2 is a block diagram showing an example in which a vehicle failure diagnosis device according to an embodiment of the present invention is attached to an in-vehicle electronic control device, and FIG. 3 is a vehicle failure diagnosis device. FIG. 4 is a block diagram showing the internal structure, and FIG. 4 is an explanatory diagram showing the contents stored in the memory. Further, FIG. 5 is an explanatory diagram of the fault tree, and FIG. 6 is a flowchart of the diagnostic process.

As shown in FIG. 2, the vehicle failure diagnosis device includes a vehicle data storage device 7 arranged in an in-vehicle electronic control device (control unit) 9 and a connector 8 (8a, 8a, 8a) for the device 7.
The diagnostic device main body 9 is detachably connected via b).

The control unit 6 is for efficiently performing fuel injection (EGI) control, ignition (IGN) control, exhaust (EGR) control, rotational speed (ISC) control, etc., and internally stores the vehicle data storage. In addition to the device 7, a central processing unit (not shown) and a control member for performing each control are stored.

The control unit 6 has a large number of terminals, each terminal is connected to various actuators and various sensors, and a signal line connecting each terminal to each actuator or sensor is
The following signals S1 to S17 are sent respectively.

S1; control signal for injector 11 S2, S3; control signal for VCM valve 11 44; detection signal for vehicle speed sensor 12 S5; detection signal for air conditioner switch S6; drive signal for fuel pump relay 14 S7; position detection for air flow meter 18 Signal S8: Idle switch 16 detection signal S9: Neutral detection switch 17 detection signal S10: Distributor 18 advance angle detection signal S11: Distributor 18 advance angle control signal S12; Ignition coil 19 ignition timing control signal S13; as shown in the power supply voltage Figure 3 of the battery 24; O ₂ detection signal S14 of the sensor 20; detection signal S15 of the water temperature sensor 24; oN signal S17 of ignition Tsu sucrose relay 23; start of the ignition key switch 22 signal S16 The vehicle data storage device 7 includes a data input interface 25 and a data recording / reproducing processing unit 26.
A memory 27, a memory freeze trigger unit 28, and a reproduction output interface 29.

The data input interface 25 is connected to each signal terminal of the control unit 6 and takes in the state data of each input / output signal at predetermined time intervals.

The data recording / reproducing processing unit 26 writes the data taken in by the data input interface 25 in the memory 27, and stops the subsequent writing in response to a trigger signal from the memory freezing trigger unit 28. Further, when the data request signal from the inference unit 32, which will be described later, is input, the data recording / reproducing processing unit 26 extracts the vehicle data corresponding to the request content from the memory 27 and outputs this to the reproduction output interface.

As shown in FIG. 4, the memory 27 has an ignition pulse width obtained from the ignition timing control signal S12 of the ignition coil 19, a fuel injection pulse width obtained from the control signal S1 of the injector 10, and a position detection signal S7 of the air flow meter 15. Each data is stored in time series corresponding to the data type such as the air amount of the air flow meter obtained from.

Referring again to FIG. 3, the diagnostic device main body 9 includes an input interface 30, a storage device 31, an inference unit 32, and a knowledge data unit 33, a CRT 34, and a keyboard 35 connected to the inference unit 32. There is.

The input interface 30 is connected to the reproduction output interface 29 via the connector 8 and outputs the data reproduced by the data recording / reproduction processing unit 26 to the storage device 31.

The storage device 31 temporarily stores the data sent from the input interface 30 and provides it to the inference unit 32.

The inference unit 32 is configured similarly to the so-called expert system inference unit, searches for rules stored in the knowledge data unit 33, and requests the data recording / reproducing processing unit 26 to transfer predetermined vehicle data in a timely manner. The reason for the failure is inferred by analyzing the data sent to the storage device 31 while sending a signal.

The knowledge data section 33 uses if if the cause Y is considered for the symptom X and forms the fault tree shown in FIG.
It has a lot of knowledge data (rules) in X, then Y format as follows.

Rule 1 if Engine stall then Ignition pulse failure Rule 2 if Engine stall then Fuel injection failure ……… Rule 3 if Fuel injection failure then Air flow meter intake air volume decreased …………… CRT34 is for notifying the progress and reasoning result. Is.

The keyboard 35 is for accepting inputs such as symptoms.

An example of the diagnosis processing of the vehicle failure diagnosis device having the above configuration will be described with reference to the flowchart of FIG. 5, assuming that the failure is “stalled”.

In step 601, the symptom and the necessary condition are input from the keyboard 34.

In step 602, the inference unit 32 determines the data type as the analysis target based on the symptom.

In this determination, for example, in FIG. 5, ignition pulse failure, fuel injection failure, etc. may be considered as the cause of “stalling”. Therefore, for example, in order to study ignition pulse failure, vehicle data is first shown in FIG. The ignition pulse width data is determined as described above.

In step 603, the inference unit 32 sends a data request signal to the data recording / reproducing processing unit 26 so as to transfer the data around the time when the vehicle failure occurs with respect to the data decided to be transferred. The point of time of occurrence may be an ordinary point, for example, a time zone input from the keyboard 35. The reason for limiting the time is to minimize the amount of transferred data. As a result, the predetermined ignition pulse width data is transferred to and stored in the storage device 31.

In step 604, the inference unit 32 refers to the transfer data and examines whether or not there is an abnormal value immediately before the failure occurrence time.

Here, for example, if no abnormality is found in the ignition pulse width, the process returns to step 602, and then, assuming that fuel injection is defective (see FIG. 5), the fuel shown in FIG. Transfers ejection pulse width data. As a result, the storage device 31 stores and stores the data of the fuel injection pulse width.

Next, when it is determined in step 604 that the data of the fuel injection pulse width is abnormal, it is assumed that the defective fuel injection is the cause of the failure, and the process proceeds to step 605.

At step 605, the time at which the abnormal value found at step 604 has occurred is confirmed, and the transfer of all input / output data at the same time is instructed. It is assumed that at this time, it was discovered that the fuel injection pulse became extremely thin and the fuel was insufficient.

Next, at step 606, based on the data of all the input / output signals newly transferred to the storage device 31, for example, the intake air amount of the air flow meter has become small, which causes fuel injection failure. Verify the causal relationship that

In step 607, based on the main causal element obtained in step 606, the cause is sought for the part that cannot be read from the data in the memory 27, and what kind of failure the causative element causes is inferred.

For example, as an incidental condition of the symptom input in step 601, "the vehicle stalled while passing through a bumpy road"
Assuming that the condition is input, the inference unit 32
Rule 4 if The output value of the sensor becomes abnormal when the vibration of the vehicle is large, then search for the rule that the sensor connector has poor contact, and determine that the cause of the failure is the poor contact with the air flow meter connector. Of.

In step 608, the cause of failure and the reason for its inference are displayed.

As described above, the vehicle failure diagnosis apparatus shown in this example can accurately estimate the vehicle failure cause while analyzing the vehicle data shown in FIG.

In addition, since the vehicle data is searched for the type that is directly related to the cause candidate according to the inference, and then for all the data of the cause occurrence time, the data analysis is efficient, and the inference is accurate and quick. Can be done.

Further, in the vehicle failure diagnosis device shown in this example, since the vehicle data is automatically analyzed, it does not necessarily require a high degree of knowledge to a diagnostician, for example, a service person, and the operation range thereof is expanded. .

Note that the computer device forming the inference unit 32 and the knowledge data unit 33 can be formed of a general computer, but using an expert system as shown in this example facilitates maintenance of data and programming. In terms of diagnostic certainty, it excels.

The present invention is not limited to the above embodiments, but can be implemented in other modes by making appropriate design changes.

[Advantages of the Invention] As described above, according to the vehicle failure diagnosis device of the present invention, it is possible to accurately investigate the cause of the failure while utilizing the vehicle data.

[Brief description of drawings]

FIG. 1 is a diagram showing an outline of the present invention, FIG. 2 is a block diagram showing an example in which a vehicle failure diagnosis device according to an embodiment of the present invention is attached to an on-vehicle electronic control unit, and FIG. 3 is a vehicle failure. FIG. 4 is a block diagram showing an internal configuration of the diagnostic device, FIG. 4 is an explanatory diagram showing stored contents of a memory, FIG.
The figure is a flowchart of the diagnostic process. 7: Vehicle data recording device 9: Diagnostic device main body 27: Memory for storing vehicle data 32: Inference unit 33: Knowledge data unit

Claims (1)

[Claims] 1. Vehicle data storage means for recording the values of input / output signals of an on-vehicle electronic control device as vehicle data over time,
Failure information storage means for storing causal information of vehicle failure, symptom input means for inputting symptom of vehicle failure, the causal information for the symptom input to the means, and each input / output signal related to cause candidate By analyzing the temporal data of, the cause candidates are narrowed down, the occurrence time is detected, and the vehicle data in the time zone around the detected occurrence time is analyzed to infer the true cause. A failure diagnosis device for a vehicle, comprising: an informing unit for informing an inference result.