JPS6379031A - Trouble diagnosing apparatus for vehicle - Google Patents

Abstract

PURPOSE:To enable accurate pursuit of the cause of a trouble utilizing a trouble analyzer, by searching cause-effect information for the symptom of a vehicle trouble inputted to analyze time-dependent vehicle data pertaining thereto. CONSTITUTION:A vehicle data memory means 1 and a trouble information memory means 2 store values of input and output signals of respective onboard electronic devices or causeeffect information of a vehicle trouble. Then, when the symptom of the vehicle trouble is inputted by a symptom input means 3, cause-effect information is searched for the symptom by an analysis/inference means 4 and time-dependent data of input and output signals are analyzed for candidate causes to reduced the number of candidate causes as much as possible while the occurrence timing of the trouble is detected. Then, vehicle data at a time zone near the occurrence timing detected is analyzed to infer the true cause of the trouble. The results of inference are announced by an announcing means 5 thereby making the best of vehicle data for diagnosis of troubles.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a fault diagnosis device for a vehicle.

[Prior Art] Conventionally, something called a "failure analysis device" has been used in diagnosing vehicle failures.

The failure analysis device is a vehicle data recorder that stores input/output signals of the on-vehicle electronic control device over time. The system is comprised of a device and a display device that displays the stored contents of the storage device, and the displayed vehicle data is viewed and analyzed by an expert with data analysis ability to investigate the cause of the failure.

However, although these conventional failure analysis devices can output the vehicle data necessary for analysis, the analysis work itself has to be entrusted to a small number of experts, which narrows the scope of use 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 can improve the above-mentioned problems and accurately pursue the cause of failure while utilizing a failure analysis device.

[Summary of the Invention] In order to achieve the above object, the present invention, as shown in FIG. a vehicle data storage means 1 for storing causal information of a vehicle failure; a symptom input means 3 for inputting symptoms of a vehicle failure; By searching for and analyzing the temporal data of each input/output signal related to the cause candidates, we narrow down the cause candidates, detect the time of occurrence, and analyze vehicle data in the time period around the detected time of occurrence. It is configured to include an analysis/inference means 4 for inferring the true cause and a notification means 5 for notifying the result of the inference, so that vehicle data can be utilized for fault diagnosis.

[Example] Hereinafter, the present invention will be described in detail using the accompanying drawings.

First, to briefly explain 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 on-vehicle electronic control device, and FIG. 3 is a block diagram of a vehicle failure diagnosis device according to an embodiment of the present invention. FIG. 4 is a block diagram showing the internal configuration. FIG. 4 is an explanatory diagram showing the contents stored in the memory. Further, FIG. 5 is an explanatory diagram of a fault tree, and FIG. 6 is a flowchart of diagnostic processing.

As shown in FIG. 2, the vehicle fault diagnosis device includes a vehicle data storage device 7 disposed in a vehicle electronic control device (control unit) 9, and a connector 8 (8a) connected to the device 7.
, 8b), and a diagnostic device main body 9, which is detachably connected to the diagnostic device body 9.

The control unit 6 controls fuel injection (EGI') υI
I, ignition (IGN) control, exhaust (EGR) control, rotation speed (ISO) control, etc. are carried out efficiently.Inside it, in addition to the vehicle data storage device 7, there is also a central processing unit (not shown). and control members for performing various controls are stored.

The control unit 6 has a large number of terminals, each terminal is connected to various actuators and various sensors, and the signal line connecting each terminal and each actuator or sensor is
The following signals S1 to 817 are respectively sent.

SL: Control signal for the injector 10, S2, S3: Control signal for the VCM valve 11 S4; Detection signal S5 for the vehicle speed sensor 12; Detection signal S6 for the air conditioner switch 13; Drive signal $7 for the fuel pump relay 14; Position detection signal S8; detection signal S9 of idle switch 16; detection signal S10 of neutral detection switch 17; advance angle detection signal S11 of distributor 18
:Advance control signal S12 of distributor 18:Ignition timing control signal S13 of ignition coil 19;Detection signal S14 of 02 sensor 20:Detection signal S15 of water temperature sensor 21;Start signal 816 of ignition key switch 22:Ignition relay 23 ON signal $17: Power supply voltage of battery 24 As shown in FIG.
6, a memory 27, a memory freeze trigger section 28, and a playback output interface 29.

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

The data recording/reproduction processing section 26 writes the data taken in by the data input interface 25 into the memory 27, and also suspends further writing in response to a trigger signal from the memory freeze trigger section 28. Furthermore, when a data request signal from an inference section 32, which will be described later, is input, the data recording/reproduction processing section 26 extracts vehicle data corresponding to the requested content from the memory 27, and outputs this to the reproduction output interface.

As shown in FIG. 4, the memory 27 stores the ignition pulse width obtained from the ignition timing control signal @S12 of the ignition coil 19, the fuel injection pulse width obtained by 1q from the control signal $1 of the injector 10, and the position detection of the air flow meter 15. Each piece of data is stored in time series in accordance with the type of data such as the amount of air in the airflow meter obtained from the signal S7.

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

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

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

The inference unit 32 is configured similarly to the inference unit of a so-called expert system, searches the rules stored in the knowledge data unit 33, and issues data requests to the data recording/reproduction processing unit 26 in order to transfer predetermined vehicle data in a timely manner. While sending signals, the data sent to the storage device 31 is analyzed to infer the cause of the failure.

The knowledge data unit 33 has a large number of knowledge data (rules) in the ifX', thenY format, which form the fault tree shown in FIG. There is.

Rule 1 if the engine stalls then Ignition pulse failure Rule 2 if the engine stalls then Fuel injection failure Rule 3 1 "Fuel injection failure then The intake air level of the air flow meter decreases C
RT34 is for reporting the progress of reasoning and the results of W theory.

The keyboard 35 is for accepting input of symptoms and the like.

An example of the diagnostic processing of the vehicle fault diagnosis device with the above configuration is shown below.
This will be explained with reference to the flowchart of FIG. 5, assuming that the engine stalls.

In step 601, symptoms and requirements are input from the keyboard 34.

In step 602, the inference unit 32 determines the data type to be analyzed based on the symptom.

This decision is made, for example, in FIG. 5, where the cause of the "engine stall" is a faulty ignition pulse or a faulty fuel injection.

. . . Therefore, for example, in order to examine ignition pulse failure, the ignition pulse width data shown in FIG. 4 is first determined as vehicle data.

In step 60'3, the inference unit 32 sends a data request signal to the data recording/reproduction processing unit 26 to request that data related to the data determined to be transferred be transferred around the time when the vehicle failure occurred. The point of time at which this occurs may be any time, for example, during the V8 period when input is made from the keyboard 35. The reason for setting the time limit is to reduce the amount of data to be transferred. As a result, predetermined ignition pulse width data is transferred to the storage device 31 and stored therein.

In step 604, the inference unit 32 refers to the transferred data and examines whether 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 a fuel injection failure (see FIG. 5), in step 603, the fuel injection shown in FIG. Transfer the injection pulse width data.

As a result, data on the fuel injection pulse width is stored in the storage device 31.

Next, if it is determined in step 604 that there is an abnormality in the fuel injection pulse width data, the process proceeds to step 605 assuming that a fuel injection failure is the cause of the failure.

In step 605, the time at which the abnormality detected in step 604 occurs is confirmed, and a command is given to transfer all input and output data at the same time. Note that at this time, the fuel injection pulse becomes extremely thin. Suppose it is discovered that the fuel is too low.

Next, in step 606, based on the data of all input/output signals newly transferred to the storage device 31, for example,
We will verify the causal relationship that the intake air amount of the air flow meter is small and this is causing fuel injection failure.

In step 607, based on the main cause element obtained in step 606, the cause is investigated even for portions that cannot be read from the data in the memory 27, and it is inferred what kind of failure is causing the cause element.

For example, assuming that the condition ``the vehicle stalled while passing through an uneven road'' was input as an additional condition of the symptom input in step 601, the inference unit 3
2 is Rule 4 1f When the sensor output value becomes abnormal when the vehicle vibration is large, then Search for the rule ``Poor contact of the sensor connector'' and determine that the most likely cause of the failure is poor contact of the air flow meter connector. That's what I do.

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

As described above, the vehicle failure diagnosis apparatus shown in this example can accurately estimate the cause of a vehicle failure while analyzing the vehicle data shown in FIG. 4.

In addition, vehicle data is searched for types directly related to the cause candidate according to the inference, and then for all data at the time of cause occurrence, so data analysis is efficient and inferences can be made accurately and quickly. can be done.

Furthermore, since the vehicle fault diagnosis device shown in this example automatically analyzes vehicle data, it does not necessarily require a high level of knowledge from the diagnostician, such as a service person, and the scope of its operation is expanded. .

Note that the computer devices constituting the inference section 32 and the knowledge data section 33 can be composed of general computers, but it is easier to maintain data and program them by using an expert system as shown in this example. 9.It is superior in terms of diagnostic certainty.

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

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

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an overview of the present invention, FIG. 2 is a block diagram showing an example in which a vehicle fault diagnosis device according to an embodiment of the present invention is attached to a vehicle-mounted one-child system TL device, and FIG. FIG. 4 is an explanatory diagram showing the contents of memory, FIG. 5 is an explanatory diagram of a fault tree, and FIG. 6 is a flowchart of diagnostic processing. 7...Vehicle data recording device 9...Diagnostic device body 27...Memory for storing vehicle data 32...Inference unit 33...Knowledge Data Department Agent Patent attorney Yasu Miyoshi -J

Claims (1)

[Claims] Vehicle data storage means for recording input/output signal values of the on-vehicle electronic control unit over time as vehicle data; failure information storage means for storing causal information of vehicle failure; and symptom input means for inputting symptoms of vehicle failure. , the causal information is searched for the symptoms input to the means, and the cause candidates are narrowed down by analyzing the temporal data of each input/output signal regarding the cause candidates, and the time of occurrence thereof is detected. A fault diagnosis device for a vehicle, comprising an analysis/inference means for inferring the true cause by analyzing vehicle data in a time period around the time of occurrence, and a notification means for notifying the inference result.