JPS63103935A - Fault diagnostic device for vehicle - Google Patents

Abstract

PURPOSE:To obtain a diagnostic device which can retry a diagnostic from the last stage even if an inspection result is inputted erroneously by retrieving knowledge data regarding the fault of a vehicle by a reasoning means and reasoning the cause of the fault while taking the diagnosis properly. CONSTITUTION:Conditions and inspection results are inputted to the reasoning means 3 from a input means 2 for conditions, etc. Further, the reasoning means 3 retrieves the knowledge data regarding the fault of the vehicle stored in a knowledge data storage means 1 and reasons the cause of the fault while taking the diagnosis properly. Diagnostic contents and reasoning results are reported from an informing means 4. Then, a diagnostic state storage means 5 stores the diagnostic state which is already finished until the end of a next process and when there is a command for a state change from a state change command means 6 which commands a diagnostic state to be put back to the last diagnostic state, a state control means 7 refers to the storage contents of the storage means 5 to put the diagnostic state back to the last diagnostic state.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a vehicle failure diagnosis device as a so-called expert system.

[Description of Prior Art] Examples of expert systems include mycin (
There is something called MYCi N).

MYCi N's rule is, "If X, do Y."
This is a typical example of a so-called production system that has an if~then~ rule of the form. This is aimed at diagnosing blood infections, so specifically if
The infection is primary and the culture medium is non-productive;
Moreover, if the gastrointestinal tract is suspected as the point of entry of bacteria, there is a high possibility that it is Bacteroides (with a probability of 0.7)'' - Nikkei Computer '83.6.27>, which has a set of rules. By applying these rules and repeating interviews with the user, a predetermined diagnosis is made.

By the way, when considering the application of such a production system to vehicle failure diagnosis, there are many cause candidates Y (Y+, Y2) for symptom X.

Y3...Yi...) exists, each cause candidate Y
It is conceivable to pursue the true cause by conducting interviews regarding i one by one.

However, the vehicle accident diagnosis Ig
With the i-device, if you make a mistake in inputting the inspection results, you will proceed to the next 111 theory based on the incorrect input results, so in such cases, the diagnostician will have to restart the diagnostic work from the beginning. The problem was that I ended up having to do it.

[Objective of the Invention 1] It is an object of the present invention to improve the above-mentioned problems and to provide a vehicle fault diagnosis device that allows the user to start over from the previous interview even if the operator makes a mistake in inputting the inspection results.

[Summary of the Invention] To achieve the above object, the present invention provides a vehicle failure diagnosis device, as shown in FIG. Symptom input means 2 for inputting information such as symptoms, etc., inference means 3 for inferring the cause of the failure while searching the knowledge data and conducting appropriate interviews, and notification means 4 for notifying the contents of the interview and the results of the inference, etc.
An interview state storage means 5 stores the already completed interview state until the next step is completed, a state change command means 6 commands to return the diagnostic state to the previous interview state, and a state change command is issued from the means 6. and a state control means 7 which returns the state of the medical examination 1 to the previous state of the medical examination by referring to the stored contents of the medical examination state storage means 5 when the state change command means 6 receives a state change command. It is now possible to return to the previous interview state.

[Example] The present invention will be described in detail below with reference to the accompanying drawings.

FIG. 2 is a block diagram of a vehicle fault diagnosis device according to an embodiment of the present invention.

As shown in the figure, the vehicle fault diagnosis device includes a knowledge data storage device 8, an input device, an inference processing device 10, a display device 11, two temporary storage devices d12.13, and the device 1.
2.13 and a correspondence table 14 located between the two.

Knowledge data memory bag! r8 is information such as ``If intermediate hypothesis A exists and symptom B is confirmed, intermediate hypothesis C holds true'' or ``If intermediate hypothesis C exists,
And if symptom E is confirmed, conclusion F holds.
This information is stored in a rule format. FIG. 3 shows an example of a search tree formed by these rules.

The input device 9 is formed of a keyboard capable of inputting symptoms, inspection results, and commands to return the diagnostic work to the previous interview state if the inspection results are input incorrectly.

The inference processing device 10 is constituted by a computer, and searches the search tree shown in FIG. 3 while appropriately asking questions, and pursues the cause of the input symptom.

The display device 11 displays the inference status of the inference processing device 10, and also prompts the diagnostician to make appropriate checks during the interview.
It displays inspection commands and inference results.

The temporary storage ffi device 12 is for temporarily storing knowledge data required by the inference processing device during inference, such as intermediate hypotheses during inference.

The temporary storage device 13 temporarily stores the display contents of the display device 11 until the next display step is completely completed.

The correspondence table 14 associates the screen contents stored in the temporary storage device 13 with the positions on the search tree shown in FIG. 3, and stores the progress of the interview.

Figure 4(a) is a flowchart of the diagnostic process;
b) is a flowchart of the interview routine.

As shown in FIG. 4<a>, the diagnostic process is performed at step 40.
Step 1 allows you to proceed while extracting hypotheses.

In step 402, a checking method necessary for the extracted hypothesis to hold true is extracted.

In step 403, it is determined whether or not an inspection with the same contents has already been performed for the inspection method extracted in step 402.

If it is determined in step 403 that the same inspection has already been carried out, the process moves to step 404 and uses the already carried out inspection results as +M, but if it has not been carried out, the process moves to step 405, which is the interview routine. do.

Here, in step 403, it is assumed that it is determined that the same inspection results have already been carried out, and in step 404, the inspection results are used. The interview routine at step 405 will be explained with reference to FIG. 4(a).

In step 406, step 400 refers to the inspection results.
It is determined whether the hypothesis extracted in step 1 holds true, and if the hypothesis holds true, the process moves to step 407, and if it does not hold, the process moves to step 408.

In step 407, the extracted hypothesis is saved as a conclusion, and then the process moves to step 408.

In step 408, it is determined whether there are any remaining hypotheses that have not been extracted. If there are, the process returns to step 401, but if there are none, the process proceeds to step 409, where the conclusion is displayed.

As shown in FIG. 4(b), the medical interview is performed by displaying the details of the inspection in step 410. In this step, the contents of the inspection are displayed on the display device 11, such as "Please inspect part B and input the inspection results."

Here, the diagnostician decides whether or not to proceed with this inspection.

This is because, for example, in view of the fact that an inspection order has been issued for an unusual area, it is discovered at this point that the inspection results entered in the previous interview were entered incorrectly, or that the key operation was incorrect. This is because it often happens.

Therefore, the diagnostician presses the rYesJ button if he or she thinks it is okay to proceed with the inspection without any problems, and presses the rNoJ button if there is a problem with the previous interview results.

In step 411, it is determined whether or not to carry out an inspection for the currently displayed inspection command. If the inspection is to be carried out, the process moves to step 412. If the content of the inspection command displayed this time is not to be carried out, the process moves to step 417.
The processing after step 417 will be described later.

In step 412, the diagnostician actually performs the inspection.

In step 414, the display contents are saved in the temporary storage device 13. Here, assuming that the diagnosis process is in the state 3i and the interview state is in the state Qi, the temporary storage device 13
The state screen of the interview state Q1 is stored in .

. In step 415, the inspection results are saved.

In step 416, the correspondence table 14 is corrected to a predetermined state (Si) based on the displayed content (Qi'), and the process returns to step 406.

After step 406, the process returns to step 401 via step 408, where the diagnostic state becomes 3i+1, or via steps 404 and 408, the process returns to step 401.
2, but the storage state of the temporary storage device 13 remains the previous interview state Qi, and the correspondence table 14
also remains in the previous diagnostic state Qi.

Now, suppose that it is determined in step 411 that the inspection cannot be performed, that is, that there was an error in inputting the previous inspection result, and the process moves to step 417.

In step 417, the previous screen Qt is displayed based on the temporary storage device 13.

In step 418, the process Si leading to the previous display screen Qi is reconstructed based on the correspondence table 14.

In step 419, the reconstruction result Si is stored in the temporary storage device 1.
2 and returns to step 408.

As a result, the screen of the display device 11 is returned to the interview state Qi, the diagnosis state is returned to 3i, and the inspection results can be re-inputted.

As described above, according to this embodiment, the temporary storage device 13,
Since the previous interview state and diagnosis state can be stored by the correspondence-pull 14, if the search tree is traced by mistake, it is possible to easily and immediately return to the previous interview state.

Another embodiment is shown in FIG.

In this embodiment, the display content storage device 11a of the display device 11 is
In part 11b of 4P, -n, the search progress to date (interview status screen and correspondence table) is recorded. That is, the normal display device 11 utilizes the fact that a blank space remains in the notation area of the display content storage device 11a in the display device 11, and stores the above search process in this blank space. It is something.

This example has the advantage that the device can be made more compact.

It should be noted that the present invention is not limited to the embodiments shown above, but can also be implemented in the form of Haku by making other changes in the design of the currency.

[Effects of the Invention] As described above, according to the vehicle failure diagnosis (gi system) according to the present invention, even if you make a mistake in inputting the inspection results, you can start over from the previous interview again, and there is no need to start over from the beginning. Therefore, it is possible to correct only the erroneous part while using the inspection results conducted in the past as they are, so that a quick and reliable failure diagnosis is possible.

[Brief explanation of the drawing]

Fig. 1 is a diagram showing an overview of the present invention, Fig. 2 and the following show an embodiment, Fig. 2 is a block diagram of a vehicle failure diagnosis device according to an embodiment of the invention, and Fig. 3 is a search tree. Explanatory diagram, 4th
Figure (a) is a flowchart of the medical examination process, Figure 4 (b)
) is a flowchart of the interview process, and FIG. 5 is a block diagram of a vehicle failure diagnosis device showing an embodiment of the present invention. 1...Knowledge data storage means 2...Symptom input means 3...Inference means 4...Notification means 5...Interview state storage means 6...State change command means 7...Status control Means Agent Patent Attorney Yasuo Miyoshi Figure 1 Figure 2 Figure 3rA 4th country (a) 4rXl (b)

Claims (1)

[Claims] knowledge data storage means for storing knowledge data regarding vehicle failure; symptom input means for inputting symptoms, inspection results, etc.; inference means for searching the knowledge data and inferring the cause of the failure while conducting appropriate interviews; Notifying means for notifying contents and inference results; interrogation state storage means for storing the already completed interrogation state until the next step is completed; state change command means for instructing to return the diagnostic state to the previous interrogation state; A fault diagnosis device for a vehicle, comprising: state control means for returning a diagnostic state to a previous interrogation state by referring to the stored contents of the interrogation state storage means when a command to change the state is received from the means.