JPH0379444A - Failure diagnostic device for electronic device of vehicle - Google Patents

Abstract

PURPOSE:To improve diagnostic accuracy by generating pseudo input signal instead of input signals from sensors and the like, dissolving necessity of vehicle operation by user for analysis of control information, and always giving appropri ate variation of input signal. CONSTITUTION:At failure diagnosis, unknown events in a knowledge base 1 in which information of required failure condition and diagnostic method are memorized, are searched with an inference mechanism 2. Next, the unknown event is judged whether it is control information output form an electronic control device 7 and analysed with a control information analysing device 5, or question display to an user output from an user input/output interface 3. Nexly, when it is analysis of control information, taking up information to confirm success or unsuccess of the event through a vehicle correspondence interface 6, a pseudo signal instead of input signals from sensors and the like is input from a pseudo signal generating device 4 to the electronic control device 7. Variation of control information in the electronic control device 7 is analysed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a failure diagnosis device for an electronic control device for an automobile such as an electronically controlled fuel injection device.

[Conventional technology]

FIG. 3 shows a block diagram of a conventional failure diagnosis device of this type. An inference mechanism 2 that derives the cause of failure using a knowledge base l, a user input/output interface 4 that displays questions to the user and obtains answers, and a control information interface 6 that transmits control information from an electronic control device 7. and a control information analysis device 5 which receives and analyzes the information via the control information analyzer 5.

Next, the flow of diagnosis by the failure diagnosis device will be explained with reference to the flowchart of FIG. Here, it is assumed that the knowledge in the knowledge base 1 is organized in a tree shape based on events such as symptoms and causes. First, in step 401, an unknown event at the top of a tree-like knowledge base corresponding to a symptom of a failure is searched.

Next, in step 402, if the means for confirming the success or failure of the unknown event searched above is analysis of the control information of the electronic control unit 7, the process proceeds to step 405, in which instructions are given for vehicle operations necessary for analysis. A message is displayed on the user input/output interface 3 to prompt the user to operate the vehicle. The information necessary for the analysis before and after the vehicle operation is imported from the electronic control unit 7 via the vehicle communication interface 6, the values of this imported information and the relationship between the information are analyzed, and the success or failure of the event is determined in step 406. do.

On the other hand, if the means for confirming the success or failure of the event in step 402 is a question to the user, the process proceeds to step 403 where the question is displayed on the user input/output interface 3, and in step 404 the answer to the question is received from the user. Then, in step 407, the success or failure of the event is determined based on the analysis results of the control information and the answers to the questions, and the information is propagated to lower and upper events in the tree-like knowledge base. In this way, in step 408, the unknown event becomes known due to information propagation, and by repeating zero or more steps of diagnosis for the remaining unknown events, all the events in the tree-like knowledge base are This becomes known, and the success or failure of the lowest event corresponding to the cause of the failure becomes clear.

This completes the failure diagnosis.

[Problem to be solved by the invention]

Conventional fault diagnosis equipment diagnoses using the method described above, so when analyzing control information to confirm the success or failure of an event, the user can view the vehicle information displayed on the user input/output interface 3 that is necessary for analysis. The operation had to be done properly.

In addition, there was a problem that data necessary for analysis could not be obtained because the analysis could not be carried out properly, leading to incorrect analysis results.

This invention was made to solve the above-mentioned problems, and allows diagnosis to be performed without leading to incorrect analysis results even if the user does not perform the necessary vehicle operations to analyze control information. The purpose is to obtain a failure diagnosis device.

[Means to solve the problem]

The fault diagnosis device according to the present invention includes a knowledge base storing information such as symptoms and diagnostic methods necessary for fault diagnosis, a vehicle communication interface for communicating with an automotive electronic control device, and control obtained by communicating with the vehicle electronic control device. In a fault diagnosis device that includes a control information analysis device that analyzes and determines information and an inference mechanism that derives the cause of failure using the knowledge base, a pseudo sensor signal is generated in place of the sensor input signal of the electronic control device. It is characterized by having a pseudo signal generator.

[For production]

In this invention, by equipping a conventional failure diagnosis device with a pseudo signal generator, patterns of changes in input signals of an electronic control device caused by user operations instructed when analyzing control information can be stored in advance. According to instructions from the control information analysis device, changes in input signals stored during the acquisition of control information are manually input to the electronic control device as pseudo input signals. Therefore, the user does not operate the vehicle.

[Example] Hereinafter, an example of the present invention will be described with reference to the drawings. 1st
The figure shows a block diagram of the failure diagnosis device according to the present invention,
In the figure, l is a knowledge base that stores events such as symptoms and causes necessary for failure diagnosis, as well as control information analysis logic and questions to confirm the success or failure of the event, and 2 is a knowledge base that stores events in this knowledge base 1. Reasoning mechanism for searching and deriving diagnostic results, 3
5 is a user input/output interface that displays questions for confirming the success or failure of an event and obtains answers to the questions; 5 is a control information unit that receives control information from the electronic control unit 7 via the vehicle communication interface 6 and analyzes it; It is an analysis device, and 4 is a pseudo signal generation device that generates a pseudo signal according to the analysis content from the control information analysis device 5. Further, this device 4 receives instructions from the control information analysis device 5,
A pseudo input signal is generated to replace the vehicle operation required for analysis conventionally performed by the user and is provided to the electronic control unit.

Next, the flow of diagnosis performed by the failure diagnosis apparatus according to the present invention will be explained with reference to the flowchart shown in FIG.

First, in step 201, the highest unknown event in the tree-like knowledge base 1 corresponding to a symptom of a failure is searched. Next, in step 202, it is determined whether the means for confirming the success or failure of the unknown event searched above is analysis of the control information of the electronic control device 7 or displaying a question to the user,
If the control information is to be analyzed, the process proceeds to step 205, in which input signals from the electronic control device Mahe sensor, etc. Input a pseudo signal in place of . Then, in step 206, it is analyzed how the control information of the electronic control device 7 has changed due to the input of the pseudo signal.

On the other hand, if the means for confirming the success or failure of the event is to ask the user a question, the process proceeds to step 203 where the question is displayed in the same way as in the past, and the answer is received at step 204. Then, in step 207, the success or failure of the event is determined based on the analysis results of these control information and the answers to the questions, and the information is propagated to lower and upper events in the tree-like knowledge base. Thus, in step 20, the unknown event becomes known due to the propagation of information, and 0 or more steps in which diagnosis is advanced are repeated until the success or failure of all events in the knowledge base is known, and the event that causes the failure is clarified. Make it.

In the embodiment, the knowledge base l has been described as having a tree shape, but it may have other shapes such as a network shape.

Further, in the embodiment, the target of failure diagnosis is described as an electronic control device for an automobile, but other electronic control devices may be the target of failure diagnosis.

(Effects of the Invention) As described above, according to the present invention, a pseudo signal generator is added that generates a pseudo input signal in place of an input signal from a sensor, etc., so that the user can operate the vehicle when analyzing control information. Moreover, since vehicle operation is not left to the user, there is no variation in input signal changes, and appropriate input signal changes are always given, so the accuracy of diagnosis in analysis of control information can be improved.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a fault diagnosis device according to an embodiment of the present invention, FIG. 2 is a flowchart showing the flow of diagnosis by this invention device, FIG. 3 is a block diagram of a conventional fault diagnosis device, and FIG. 4 1 is a flowchart showing the flow of diagnosis of a conventional device. l...Knowledge base, 2...Inference mechanism, 3...Verification means adjustment mechanism, 3...User human output interface, 4...Pseudo signal generator, 5...Control information analysis device, 6...Vehicle communication interface, 7...Electronic control device. Note that the same reference numerals in the figures indicate the same or equivalent parts. Figure 1

Claims (1)

[Claims] A knowledge base that stores information such as symptoms and diagnostic methods necessary for failure diagnosis, a vehicle communication interface for communicating with the automotive electronic control unit, and a control information analysis that analyzes and makes decisions on the control information obtained through communication. A fault diagnosis device comprising a device and an inference mechanism for deriving the cause of the failure using the knowledge base, characterized by comprising a pseudo signal generating device that generates a pseudo sensor signal in place of the sensor input signal of the electronic control device. A failure diagnosis device for vehicle electronic devices.