JPS593507A - Device for diagnosing fault of vehicle - Google Patents

Abstract

PURPOSE:To raise the diagnosing accuracy and reliability, by displaying a fact of a fault in case when it can be decided exactly, and displaying the information for decision in case when it cannot be decided, in a fault diagnosing process. CONSTITUTION:A computer 4 executes diagnosis by comparing a value measured by a sensor processing means 3 with a reference value of a reference value storage means 6 in accordance with procedures of a diagnostic procedure storage means 5. In this diagnosing process, in case when faulty parts can be decided exactly, they are displayed on a display means 7. Also, in case when faulty parts cannot be decided exactly, information which becomes helpful to its decision is displayed on the display means 7. In this way, in case when the faulty parts cannot be decided exactly, the information for decision is displayed, therefore, the diagnosing accuracy and reliability can be raised.

Description

[Detailed description of the invention] The present invention relates to improvements in devices for diagnosing vehicle failures.

2. Description of the Related Art Conventional diagnostic devices of this type include those shown in FIGS. 1 and 2. In Figure 1, a keyboard or the like is used as the input means 1, and information data such as the model of the vehicle to be diagnosed, the engine type, the content of the 9-year inspection (for example, 1-year legal inspection, engine failure diagnosis, etc.), and the name of the owner of the vehicle. is entered.

The input means 2 is kept at hand by the service person, and the service person may send information to the device, or conversely, information from the device may be displayed. The display on the input means 2 is supplementary to the optical display means T, which will be described later, if it is provided, but the display means 7 may be omitted and the input means 2 may perform all display functions.

The sensor/signal processing means 3 is each part and part of the car.

The sensors that detect the functions of each system and the signals from those sensors are formatted so that they can be input to the computer 4.

It consists of a signal processing circuit that performs processing such as amplification.

The computer 4 has at least a memory, ROM, and RAM.

It is configured with a CPU to control the device, perform calculations and judgments, and control peripheral input/output devices.

There are many types depending on the scale and processing performance, from those mounted on one chip to the CPU, and those that are separated into individual chips.

The diagnostic procedure storage means 5 stores, for example, the contents and instruction procedures to be given to a service person for diagnosing the function of the engine's ignition system or the function of the fuel system, and how to judge the actually input signal. A procedure is also stored, and the computer 477) CPU issues commands to control peripheral devices according to this procedure.

The reference value storage means 6 stores reference values such as normality, failure, caution, etc. for each car model and engine type, and the CPU of the computer 4 uses the sensor/signal processing means 3 to perform measurements according to the diagnostic procedure storage means 50 procedure. Diagnosis is performed by comparing the obtained value with the reference value.

The display means 7 generally uses C)tT, etc., and displays the contents to be displayed to the service person with one device.

For example, the contents input using the input means 1, the contents of instructions given to the service person, the measured values, and the diagnostic results are displayed. Note that, as described above, when the displayable range of the input means 2 is wide, it is sometimes omitted. The recording means 8 is capable of hard copying, such as a printer, and prints out the measured values 1, diagnosis results, and vehicle information as necessary. Next, typical operations using the apparatus shown in FIG. 1 and the operation of the apparatus will be explained according to the flowchart shown in FIG.

After turning on the power switch at the start (step 100), vehicle information (for example, registration number, etc.) and required diagnosis@type are input into the input means 1. Next, the sensor is attached (step 1o2). Here, the sensors include a high-pressure probe that detects ignition voltage, a current probe that can detect the current flowing in a wire by pinching it, a pressure sensor that detects the pressure of engine intake and exhaust pipes, cylinders, various engine control devices, etc. Necessary items are prepared depending on the diagnostic function, such as a clip that clips the terminal of the electrical wiring and detects the voltage.

When the sensor installation is completed, the service engineer inputs that information into input means 2 (remote) (step 103).
. The computer 4 also uses the diagnostic procedure storage means 5 to retrieve the diagnostic procedures that are judged to be necessary, and thereafter processes are carried out according to the contents thereof. The diagnosis of ignition advance angle will be explained as an example.

First, the computer 4 causes the display means 7 to display "Increase the engine rotation to 200 rpm" in accordance with the contents of the diagnostic procedure (step 104). The serviceman followed the display and stepped on the accelerator to set the engine to f-20001-pm. The engine speed may be checked with the vehicle's tachometer or monitored and displayed by a diagnostic device. Then, when the rotation speed reaches 200 Orpm, the service person inputs this information into the computer 4 using the input means 2 (step 105). With this input, the sensor/signal processing means 3
The ignition advance angle is calculated by inputting the signals from the top dead center detection sensor and the ignition timing sensor, and the result is temporarily stored in the RAM. Next, the vehicle to be diagnosed 9 in the reference value storage means 6. Deriving standard values corresponding to the engine type. This reference value and RA first
The value stored in M is compared with the value stored in step 107), and the result is ranked as normal, failure, caution required, etc. If a failure is determined here, the failure location, system, etc. are diagnosed from the measured value and information such as the values of other sensors, and the results are displayed on the display means 7 (step 108). In order to diagnose this failure part, use the configuration shown in Figure 1.

Something is needed to store information for diagnosis.

If the failure prevents further disconnection, the serviceman will repair it at that point and perform the diagnosis again (step 110).

If there is no need to repair immediately, pass repair 1. , and then performs the predetermined diagnoses one after another. Of course, if it is normal, we will perform the next diagnosis. In this way, a diagnosis is performed according to the procedures prepared in the 1-diagnosis procedure storage means 5, and when all the prepared diagnoses are completed, a message to that effect is displayed on the CRT of the display means 7, and the measurement values and diagnosis performed so far are displayed. Necessary data such as results are output to the printer of the recording means 8.

However, in such conventional diagnostic equipment,
Because the system was configured to perform predetermined calculations or processing on the input signal from the sensor, and then compare it with pre-stored reference values to make a judgment and display the final diagnosis result, only the information that was originally given was used. Even if it could not be determined, some kind of judgment was made and displayed. This can lead to unnecessary misunderstandings. In particular, in cases where the service personnel who accept the results of the judgments are too mature, they instill a sense of distrust in the diagnostic equipment, leading to problems such as people not trusting the judgments that should be trusted. .

The present invention has been made by focusing on such conventional problems.In the failure diagnosis process, if it can be reliably determined, that fact is displayed, and if it cannot be determined, the input information or possible determination is displayed. It is an object of the present invention to provide a vehicle failure diagnosis device which solves the above-mentioned problems by increasing diagnosis accuracy and reliability.

1. The present invention will be explained below based on illustrated embodiments.

If the outline of the configuration is shown as a block diagram, it will be the same as that in FIG. 1 of the conventional example, so it will be explained using FIG. 1 with the same reference symbols. The contents of the reference value storage means 6 are greatly different from the conventional ones, and the method of displaying the diagnosis results is particularly effective for failure diagnosis, as will be described later. That is, as described above, the input means 1, 2 .
If the component that is clearly the cause of the failure can be determined from the information from the sensor signal processing means 3, the determination result is displayed on the display means 7, as usual. The recording means 8 is used to inform the service person or the diagnosis requester. If the part that is the cause of the failure cannot be determined and a possible failure system can be determined, or if the failure system of the vehicle cannot be determined either, the respective judgment results indicating that the failure cannot be determined are displayed and the judgment is left to the service person. It also provides information that can help service personnel make decisions. A concept similar to this is used in the field of control.
Fuzzy was proposed by A. Zatleh several years ago.
It originates from set theory.

In other words, all phenomena include ambiguity, and ON/
Phenomena that can be expressed in binary logic as OFF are special solutions to the phenomenon of ambiguity. However, as a matter of course, (all minor phenomena are expressed as a single set with blurred boundaries.In this logic, all the relationships and operations between the sets are strictly defined, but in the present invention, there is no direct relationship between them.) In other words, control based on fuzzy logic recognizes the ambiguous phenomenon and does not use binary logic to achieve the control goal as seen in PI control, but requires many inputs. The present invention has been adopted in the field of vehicle failure diagnosis to achieve the goal.In particular, the present invention has been adopted in the field of vehicle failure diagnosis.In particular, the conventional computer-based diagnostic equipment has resolved the ambiguity and has become a universal Computers are generally considered to be objects, and service personnel also tend to do so.However, computers themselves do not have any ability to make decisions; they are merely a means of judgment.
In order to make the device effective, if there is something ambiguous that the designer cannot incorporate the know-how into and cannot judge, it will be indicated as such, and at the same time, by displaying the materials for judgment, the service person and the diagnostic device will be able to communicate, and both will be able to communicate. The purpose is to diagnose failures by organically linking them. To achieve this objective, the present invention provides diagnostic procedure storage means5. The content of the reference value storage means 6 is different from the conventional one. Embodiments will be described below with reference to FIGS. 3 and 4.

In this embodiment, the present invention is applied to a BGI (electronic fuel injection system) specification vehicle that employs an air-fuel ratio control system using a three-way catalyst.

Steps 200 to 20 in the flowchart of FIG.
6 is step 100 of the conventional example (flow chart in FIG. 2)
- Same as 106. In step 206, a sensor signal necessary for diagnosis at an engine speed of 20,001 pm is taken in through the computer 4 (7) l1041 and latched into the RAM 43. The reference value for this sensor signal is also read out from the reference value storage means 6 and compared with each other to determine whether or not there is a failure (step 20
6'). If it is not a failure, the process proceeds to step 212 to perform diagnosis in other modes, and if it is a failure, it is determined in step 207 whether or not the failure part can be determined. This reference value is different from that of the conventional example, and has a fairly narrow range, and is certainly within a normal range. Cases in which a failure can be clearly determined by comparing these many values are stored in advance in the diagnostic procedure storage means 5, and at the same time as the determination is made, the failed function and the name of the failed part are displayed on the display means 7, CB and T. An example of this display is shown in FIG. 4(A).

If the faulty function has been determined in step 207, but the faulty part cannot be determined, it is determined in the same manner as described above whether or not the faulty system can be limited to the fuel system, ignition system, air-fuel ratio control system, etc. (step 209). If the fault system can be determined here, the fault function and the systems likely to be the cause of the fault are displayed in order of likelihood.

Furthermore, measurement values that are necessary for a service engineer to examine the faulty system are displayed. A specific example thereof is shown in FIG. 4 CB). In this example, the air-fuel ratio function of the EGI is found to be defective based on the CO value, the control cycle of the three-way catalyst system, and other values, but the faulty part that is the cause cannot be determined. In other words, there are a plurality of measured values connected to each component that exhibit abnormal values, and the cause-and-effect relationship is also multiple, so it cannot be determined. However, due to the experience of strange voices, the battery, charging system,
Possible failures in the gGI control unit system, EGI, and 02 sensor system are stored in advance in the diagnostic procedure storage means 5 in this order, and based on the know-how, the information is displayed on the CRT of the display means 7 (step 210). . The necessary measurement values are similarly displayed on the CRT after further narrowing down the possible cause of the failure. become.

If the service engineer needs measured values other than those shown, he inputs them using input means j or input means 2, and furthermore, the service engineer adjusts the engine speed to 200 or
By setting it to pm, that data will be added and displayed.

At this point, the service engineer decides whether to repair the failure on the spot (step 211), and if it is determined that the failure does not pose a problem for continued diagnosis, the service person passes the repair and checks other diagnostic modes. (Step 212).

10,000, if the serviceman determines that the repair should be made on the spot and performs the repair (step 213), he inputs the completion of the repair using the input means 2 to check whether the repair is appropriate, and then the engine rotational speed is is set to 2000 γpm, that effect is input again using the input means 2, and the above-described routine is repeated.

If the failure system cannot be determined in step 209, this is displayed, and the measured value and vehicle inspection point) are displayed (
step 214). A specific example thereof is shown in FIG. 4(C). This item is also stored in advance in the diagnostic procedure storage means 5 as described above, and requests for other items from the service personnel can also be met. In this case as well, as in step 211, it is determined whether or not to repair on the spot, and if the repair is to be canceled, the process goes to the next diagnosis mode or goes through the routine of carrying out the repair.

The above-mentioned judgments are made one after another in other diagnostic modes (step 212), and when all the diagnoses are completed, the results and judgment materials are displayed on a CRT or printed out as a hard copy, if necessary.

Naturally, this display and printout may be performed for each diagnostic mode. - As explained above, according to the present invention, when the faulty part cannot be determined, the diagnostic know-how stored in one diagnostic device is displayed in various situations and the information is provided to the service personnel. It can be significantly reduced and speed up failure diagnosis. Furthermore, in order to make a more reliable diagnosis, the diagnostic reference values are narrowed down and failed parts are displayed.If it cannot be diagnosed reliably, possibilities are displayed according to the level, and the information necessary for service personnel to perform the diagnosis is provided. Diagnosis accuracy is improved because the configuration allows for higher diagnostic accuracy.

This improves reliability, enables man-machine communication between service personnel and diagnostic equipment, and contributes to the improvement of service personnel's skills.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an example of a conventional vehicle failure diagnosis device, FIG. 2 is a flowchart showing a control flow of the same device, and FIG. 3 is a block diagram showing an example of a conventional vehicle failure diagnosis device. Flowchart showing the failure flow, FIG. 4 (5), (B), (Q is a diagram showing display examples of different faults diagnosed in the above embodiment, FIG. 5 is still another display example in the above embodiment) 1... Input means 2... Input means 3... Sensor signal processing means 4... Computer 5...
・Diagnostic procedure storage means 6...Reference value storage means T
...Indication means patent applicant Nissan Motor Co., Ltd. agent Patent attorney Tsujio Sasajima Proceedings (spontaneous) August 1988 Commissioner of the Japan Patent Office Kazuo Wakasugi, Indication of the case Showa 1957 Patent Application No. 111428 2 Name of the invention Vehicle failure diagnosis device 3 Relationship with the case of the person making the amendment Patent applicant address 2 Takaracho, Kanayō Ward, Yokohama City, Kanagawa Prefecture Name (
399) Nissan Motor Co., Ltd. Representative Ishihara
Shun 4, Agent address 11 Daisan Mori Building, 1-4-10 Nishi-Shinbashi, Minato-ku, Tokyo 508-9577 Name Patent attorney (7833) Fujio Sasashima 5 Detailed explanation of the invention subject to amendment In Column 6, page 9, line 15 of the statement of contents of the amendment, the words "cannot be incorporated" should be changed to [
It was something to incorporate. The present invention does not allow designers to incorporate their know-how.''that's all

Claims (1)

[Claims] An input means for inputting information about a vehicle to be subjected to failure diagnosis, a sensor processing means for detecting the operating state of a predetermined part of the vehicle and processing the detection signal, and a diagnostic procedure memory storing procedures and methods for diagnosing vehicle failures. a reference value storage means for storing reference values necessary for diagnosis; a display means for giving diagnostic instructions, monitoring, and displaying results; and a computer for operating and processing these means according to a preset program. In the vehicle fault diagnosis device, when a faulty part can be clearly determined, this is displayed in the diagnostic procedure storage means and the reference value storage means, and when the faulty part cannot be clearly determined, information for determining this is displayed. A vehicle failure diagnosis device characterized in that data to be displayed is stored.1.