KR970010786B1 - Diagnosis device of a car - Google Patents

Abstract

An ECU receives signals of sensor and drive element. The level of the sensor group(S1-Sn, Sm-Sx) are parallel inputted to the A/D converter(110) and offered, digitalized thru input-output(I/O) interface(111). The I/O interface(111) has the microcomputer(112), MODEM(113), touch screen module(114), I/O module(115) and data bus(117) in common, and the microcomputer(112), thru I/O port of the monitor(118) via the video port, is connected with the printer(119), and I/O module is connected with the control switch(120).

Description

Vehicle condition diagnosis method and device

1 is an illustration of a conventional electronically controlled vehicle diagnostic apparatus.

2 is an exemplary fuse box in which the connector of FIG. 1 is installed.

3 is an exemplary view illustrating a state output display of a self-diagnostic apparatus connected to FIG. 2.

4 is a block diagram of a conventional vehicle condition diagnoser.

5 is a block diagram of the present invention.

6 is a flow chart showing a vehicle diagnostic process according to the present invention.

7 is a flow chart showing a cranking test according to the present invention.

* Explanation of symbols for main parts of the drawings

N ₁ . Nn, Nm... N _X : common node S ₁ . Sn, Sm... S _X : Sensor

110: A / D converter 111: I / O interface

112: micom 113: modem

114: touch screen module 115: I / O module

117: data bus 118: monitor

119: linter 120: control switch

R: Partial and comprehensive diagnostic process S: Precision part measurement process

T: process of identifying and analyzing relevant sensors and outputs

U: Automatic Diagnosis

The present invention relates to a method and apparatus for diagnosing a vehicle state, and in particular, by detecting the level of each diagnosis part in parallel to enable high-speed detection and rapid determination, and to diagnose the normality of each part state and quickly synthesize the vehicle state. The present invention relates to a vehicle condition diagnosis method and a diagnostic device for automatic diagnosis.

Recently, the electronics of automobiles are remarkable, and electronic control units (hereinafter referred to as ECUs) mounted on automobiles are also installed corresponding to each function. These ECUs include, for example, suspension ECUs, automatic transmission ECUs, automatic cruise ECUs, fuel injection ECUs, and the like. In each ECU, an error code of the ECU and a so-called self-diagnosis output signal include one signal line. It is to be output from. As shown in FIG. 1, the self-diagnosis output signals output from the _n electronic controllers and the ECUs _{1 to} ECU _n are, for example, the self-diagnosis connector 12 installed in the fuse box 11 shown in FIG. Are focused on. Insert the connector of the self-diagnosis tester (not shown) for each part into the self-diagnosis connector 12 and flash the light emitting diode 21 installed in the self-diagnosis tester as shown in FIG. 3 by the self-diagnosis output signal. Since it is necessary, it is set to a low speed signal with a long pulse width. Such self-diagnostic code is unilaterally transmitted data from the ECU side, and because the transmission speed is low, the high-speed processing cannot be performed on the self-diagnosis tester side. In addition, the data processed by the ECU of the self-diagnosis tester cannot be displayed, and sufficient data cannot be obtained for the diagnosis of the vehicle.

For this purpose, the self-diagnosis code can be processed at high speed, and the test signal can be sent to the electronic control device, and at the same time, it can be self-checked when the connection of the ROM pack (Read only memory pack) that stores the ECU format and free unique data is lost. A self-diagnosis multifunction tester capable of checking a pulse signal output from an electronic control device with a buzzer sound has been proposed in Korean Patent Publication No. 91-2804.

The diagram is an electronic control unit (ECU) 8 for the vehicle as shown in the four (ECU ₁ ~ECU _8), for example if it is mounted, the engine ECU ₁ as the relationship, the steering ECU ₂ as the relationship, as the suspension ECU ₃ Time-alarm electronic control system for centralized control of relations, brake relations for ECU ₄ , ECU ₅ for speed relations, ECU ₆ for transmission relations, ECU ₇ for transmission relations, ECU ₈ for timer functions and alarm functions It can be illustrated that the (Electric Time and Alarm Control System) is mounted.

Each of the ECUs _{1 to 8} ECUs has a data output terminal TX and a data input terminal RX, and the signal lines from the output terminal TX and the input terminal RX are grouped in one line and connected to the first type connector 41a through the signal lines L _{1 to} L ₈ . ) Is connected. In each ECU ₁ to ₈ , the switching terminal CH is connected to the first type connector 41a via the signal line C and the signal lines L _{1 to} L ₈ . Serial ECUs (Serial / Diag) switching terminal CH are installed in each ECU ₁ to ₈ , and as described below, the transmission method of data output from the output terminal TX is different depending on the logic level input to the switching terminal CH. You lose.

The switching terminals CH of the respective ECUs _{1 to 8} are connected to the first type connector 41a together with the signal lines L _{1 to} L ₈ through the signal lines C. The first type connector 41a is connected to the second type connector 41b on the tester 31 side. When the connector 41a and 41b are connected, the ground potential (logical L) is supplied to the signal line C. Signal lines L _{1 to} L ₈ are connected to signal lines m1 to m8 on the tester side. The signal lines m1 to m8 are selected by the multiplexer 42 and connected to the output terminal TX and the input terminal RX of the CPU 43. The CPU 43 is supplied with 5V power through the 5V constant voltage circuit 44 with the power from the cigarette lighter 33. And if the voltage from the cigarette lighter 33 continues for more than 3 second to 10 V or less, a buzzer (not shown) will sound. The display device 32 also displays various data via the display interface 45. The signal input from the key board 46 is converted by the input / output encoder 47 and input to the CPU 43. In addition, 48 denotes a program e-ROM (EPROM: erasable porgrammable read-only memory) in which the control program of the CPU 43 is stored, and 49 denotes a buzzer.

However, ECU _{1 to} ECU ₈ are also limited in the improvement of the processing speed because the input / output is still input / output in the serial state by the multiplexer 42, which causes the variation of the sensor to be several micron seconds or less. There is a problem that an error that is sensitively changed in units cannot be detected and its reliability is lowered. The present invention is to solve this problem, the sensor output of the vehicle diagnostic area is drawn out in parallel with the ECU providing stage and then detected and adjusted by A / D (analog-to-digital) conversion so that instantaneous fluctuation errors of several μs can be quickly diagnosed. For the purpose of

To this end, the present invention is a vehicle state diagnosis including an analog-to-digital converter (A / D converter) that directly receives the output level of the diagnostic portion of the vehicle at the same time in parallel with the ECU providing stage to provide a separate digital signal to the diagnostic device To provide a device.

In addition, the present invention is a partial intelligent diagnostic process for comparing each diagnostic part of the vehicle with a set level, and a comprehensive functional diagnostic process for sequentially comparing the tests of the partial intelligent diagnosis process, and a precision part for displaying and confirming the selective diagnosis part. Vehicle status, including measurement and marking of multiple waveforms of user scopes at the same time to identify and analyze relevant sensors and outputs, and parallel storage and analysis of multiple channel waveforms for automatic diagnostics by intelligent diagnostic algorithms To provide a diagnostic method. Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

The ECU shown in FIG. 4 is provided with a signal of a sensing and driving element (sensor). In FIG. 5, the ECU is not described in detail (only common nodes N _{1 to} N _X ). S _{1 to} S _n ) and (S _{m to} S _X ). The levels of the sensor (driving element) groups S _{1 to} S _n and S _{m to} S _X are input to the A / D converter 110 in parallel with the ECU connection terminal and are input / output I in a digital state. / O interface 111, the I / O interface 111 shares the microcomputer 112, modem 113, touch screen module 114, I / O module 115 and data bus 117 It is done forever. The microcomputer 112 is connected to the monitor 118 through the video port, the printer 119 through the I / O port, and the I / O module 115 is connected to the control switch 120. .

In the microcomputer 112, an algorithm for performing the present invention should be memorized. As shown in FIG. 6, a part and a comprehensive intelligent diagnosis process R, a precision part measurement process S, and a process of identifying and analyzing a relevant sensor and output (T) and automatic diagnostic procedures (U).

The diagnostic procedure R will be described as an example, but each sensor will be described without specifying a sign.

KEY Key OFF test

With the engine key off, the sensor and ECU terminal voltages are compared and analyzed to determine whether they are defective.

How to display: Display in order step by step, normal in green letters, bad in red.

㉯ key ON check

With the engine key on, the sensor and ECU terminal voltages are compared and analyzed to determine whether they are defective.

How to display: Display in order step by step, normal in green letters, bad in red.

㉰ Throttle position sensor (hereinafter referred to as TPS) Noise test The accelerator (accelera-tor) is operated to determine the position and abnormality of the TPS.

㉱ Cranking test

The negative pressure (-) side of the coil is controlled so that the engine does not start, and the angular velocity for each cylinder during cranking is estimated.

It is also determined whether the ignition side is sparked by reading the injector simultaneous injection and the start signal.

㉲ idle test

It extracts information such as injector heterogeneous check, injector change, and poor contact by injector peak voltage to check power TR (poewr transistor) status, ignition coil characteristics, power TR earth fault by primary voltage. Analyzes spark plug status, breakage of high pressure coil and leakage.

Measure the vacuum of the engine to estimate the pressure inside the cylinder, measure the fuel pressure to check the function of the fuel pump, check the fuel filter and fuel hose bent, check the throttle body carbon accumulation, and cross check these situations to Determine the cause of the assistance.

In addition, the waveform of the step motor is analyzed to determine whether the step motor is defective or the wiring of the step motor is changed.

㉳ Medium speed measurement

Maintain the engine speed at 1800 ~ 2400RPM to measure the oxygen sensor response and check the feedback control (measured over 600mv time and less than 600mv time of oxygen sensor) and crank position sensor Analyze the cause of engine relief by measuring the angular speed.

㉴ Rapid acceleration test

The engine accelerates and decelerates twice to determine the TPS rise time and the 600mv rise time of the oxygen sensor to determine the fuel stiffness and richness, to determine the ignition timing, to analyze the rapid acceleration characteristics, and to measure the ignition waveform Determination of the characteristics of heat value and power TR, and analysis of engine rotation deviation through CPS to determine the degree of looseness and tightness of timing belt. Simultaneous injection at rapid acceleration and fuel cut at golden acceleration Check if this is done.

For example, the process (S), power TR and injector speed sensor inspection, compression pressure inspection, etc. can be displayed and confirmed in a precise waveform using a user scope.

Taking the above process (T) as an example, the waveform of one channel of the four channel current of the user scope is simultaneously displayed and the related sensor and output are identified and analyzed.

For example, the process (U)

㉮ Current Waveform Display

Selective analysis is possible from 1 channel to 8 channels according to the option of each vehicle among 64 channels, and the time and magnitude of the waveform can be changed in several steps.When the name of the sensor is selected, the waveform is automatically displayed on the waveform. Static analysis is also possible. Using two cursors, the principle of the waveform can read the voltage at the location and indicate the time and frequency between the cursors. The trigger of cylinder 1 enables analysis of the ignition waveform and each sensor waveform at the time of synchronization.

㉯ Save Waveform

It is possible to select and save the number of sensors arbitrarily, as well as to automatically select the sensor according to the vehicle type among the 64 channel inputs, and to set the sampling time to 6 types. Always save In case of a fault or when you want to stop saving, press the stop switch or any key on the keyboard to stop. The data volume is kept at least 5M bytes from the time of pressing, and you can give the name of the storage file arbitrarily if you want to save it.

㉰ Waveform Analysis Function

Ⓐ Manual Analysis

In addition to selecting and analyzing one paring from the saved files by waveform storage, one to eight sensors can be selected and displayed on one screen, and the voltage size and time axis can be reduced and enlarged. The graph and voltage are displayed on the basis of the maximum value, and the time axis can be analyzed by two cursors. This function is used to analyze the causes of intermittent failures.

Ⓑ Automatic analysis function

It is a function to diagnose automatically by applying algorithm of intelligent diagnosis function.

An example of the preferable inspection item of the said process (R) is shown below.

[1] initial testing

1) Key OFF test

end. Battery (hereinafter referred to as BATT) inspection

I. Earth leakage shop

2) Key ON inspection

end. BATT inspection

I. Current inspection

All. Sensor power test

la. IDLE S / W (idle switch) ON check

hemp. Inspection of motor position sensor (hereinafter referred to as MPS)

bar. TPS inspection

four. Other sensors inspection

Ah. TPS Noise Check

[2] cranking tests

1. CPS inspection

2. Inspection of top dead center (hereinafter referred to as TDC)

3. Check for co-injection

4. Checking start signal (hereinafter called ST SIG)

5. Compression pressure inspection

6. High pressure generation inspection

7. Injector Line Inspection

8. Boot point checking

9. Fuel Pressure Inspection

l0. Inspect piston rings, valves and gaskets

[3] static tests

1. Fuel pressure pump, fuel filter, fuel hose inspection

2. Injector line inspection

3. Ignition Primary Power TR Inspection

4. Ignition coil distributor inspection

5. Spark plug contamination, power cable leakage test

6. Plug clearance inspection

7. Air flow sensor status and heterogeneous product inspection

8. Vacuum degree inspection

9. Throttle Body Carbon Inspection

10. Air conditioner switch inspection

11. Idle speed control gear clearance inspection

12. Step motor (hereinafter referred to as STM) inspection

13. Inspection of idle speed allowance valve (hereinafter referred to as ISA)

14. Checking STM Wiring Changes

15. Check the engine mount

[4] medium speed tests

1. AFS inspection

2. Exhaust gas recirculantion (hereinafter referred to as EGR) valve, EGR hose inspection

3. Injector wiring inspection

4. Oxygen sensor shield wire inspection

5. Oxygen sensor performance test

6. Fuel lean / rich determination

[5] acceleration testing

1. Timing belt play check

2. Fuel pump, fuel filter, fuel hose bending inspection

3. Inspection of bad fuel (water inflow)

4. Injector connection relationship inspection

5. Injector heterogeneity inspection

6. Spark plug degradation relationship inspection

7. Distributor Assembly Inspection

8. Timing belt assembly inspection

9. Bearing play and run out inspection

10. MPS wiring inspection

11.ISA stuckness check

In this case, the preferred inspection point according to the state of the vehicle is as follows.

1. No strength → Experiment 1,2,3 of [3]

2. Assist in orbit → 5,7,8,9,11,12,13,14 in [3]

3,5 of [5]

3. Relief during cold → 3,5,7,11,12,13 in [3]

4. Relief during turbulence → 3,4,9,11,12,13,14 in [3]

5. High speed degradation → [3] 5,6

1,2,7,8,9 experiments of [5]

A program implementation based on this algorithm will be described with a flow chart of FIG.

1. KEY OFF

ㅇ Check all terminals of ECU and display abnormal message (after 2 seconds of KEY OFF)

→ Message preparation according to each terminal fault condition (BATT, BACK UP, Current)

→ BATT voltage failure (less than 11V)

2. KEY ON

(All terminal voltages should be recorded for 20 seconds) (64 channel recording)

o Check all terminals of the ECU and display abnormal messages.

o BATT, BACK UP, Sensor Power, TPS, MPS, IDLE S / W

→ One item (ITEM) is displayed and normal is green and abnormal is red.

o initial default message

① Check if the idle speed adjustment is normal.

② IDLE S / W adjustment is normal

ON / OFF → Can be checked by serial data

KEY ON must be 'ON' unconditionally

TPS Noise Test

Indication: Depress and release the accelerator pedal.

TPS noise → When 20mv or more is captured under 5ms

Indication: Noise has been picked up by the TPS.

HELP: TPS itself is bad

I. Poor TPS output line connection is expected.

The cranking test in the present invention can be represented as the prochart of FIG. 7, and the program implementation based on this can be illustrated as follows.

3. Crank

If CPS and TDC signals are not detected → CPS

Display: CPS signal is not detected

HELP: Replace the CPS after checking wiring.

Pulse is detected but abnormal → Low level voltage is over 1.4V

Indication: The CPS Earthline is bad. Press 'HELP'

HELP: check the CPS earthline

HIGH level detection → When HIGH level voltage is below 3.5V

Indication: The CPS main line is bad. Press 'HELP'

HELP: Poor CPS main line contact or bad CPS.

(Check the same for TDC)

Conclusion 1-1: Relative evaluation of cranking current for each cylinder → Compression pressure measurement

If injector co-injection does not work, is NO → ST SIG wound?

NO → DISPLAY: ST SIG is not entered.

HELP: Check the relevant wiring.

YES → Display: The injectors do not fire at the same time.

HELP: ECU check is required.

The crank signal is normal.

Conclusion 1-2: Relative Velocity Relative Evaluation by CPS for Each Cylinder

Manual → The cylinder compression pressure is low. Press 'HELP'.

HELP → Check the valve or valve automatic clearance regulator or piston ring.

Please let go of the key.

Conclusion 1-3: Secondary high pressure occurrence → Ignition device check → Ignition flame voltage (minimum voltage day)

Is not detected). Enjoy 'HELP'

HELP: Check the voltage of the power TR base and the ignition primary voltage.

Conclusion 1-4: Injector surge occurs → The voltage (minimum voltage data required) is low.

Press 'HELP'.

HELP: Make a precise diagnosis of the injector line.

Conclusion 1-5: Check start ignition timing Angle before top dead center

Is BTDC) 5 °? ¡Æ unless BTDC 5 °

Indication: The start ignition timing is not correct. Press 'HELP'.

Regulatory value: BTDC 5 °.

Measured value: BTDC △ °.

HELP: Check ECU after distributing condition, timing belt check.

Conclusion 1-6: Is the fuel pressure regulated? (Model specific data required)

Low → Show: Fuel pressure is low. Press 'HELPF'

Regulation value: ○○ kg / m.

Measured value: △△ kg / m.

HELP: Check the filter and check the fuel pump for clogs or bends at the hose inlet.

Check the condition and wiring connectors.

High → indicated: Fuel pressure is high. Press 'HELP'

HELP: Check fuel regulator / return pipe.

Conclusion 1-6-1: If low pressure is detected by Conclusion 1-1 or Conclusion 1-2

Indication: The cylinder compression pressure deviation is detected.

Press 'HELPF'

HELP: Applicable cylinder valve status, automatic gap regulator, piston ring head deformation,

The gasket may be defective. Manually detail compression pressure

Measure again

In manual…

Measure cylinder 1

When measuring and recording (maximum pressure during measurement), recording (waveform)

Measure cylinder 2

Record up to 4 times and compare it with the reference value and display it in grapho or numerical value (kg / m ³ ).

(Deviation ± 10%)

As described above, the present invention can detect and analyze the error by recognizing the occurrence of the error of several thousandths (μsec) by receiving the data in parallel and receiving the data in parallel.

Claims (2)

In the vehicle condition diagnosis method, a part-intelligent diagnosis process in which data of each diagnosis part of a vehicle is drawn out from an analog-to-digital converster in parallel with an electronic control unit (ECU) and compared with a set level, respectively. Comprehensive intelligent diagnostic process that sequentially checks and tests of the partial intelligent diagnosis process and precision partial measurement process that displays and confirms the selected diagnosis site with the scope and the multi-channel waveform of the user scope at the same time to identify and analyze related sensors and outputs And a step of automatically storing and analyzing multiple channel waveforms in parallel and automatically diagnosing the same by an intelligent diagnosis algorithm. In the vehicle condition diagnosis device, an A / D converter (angalog-to-digital converster) which receives each output level in parallel with the ECU and provides a parallel digital signal directly to the diagnosis device, is provided. Vehicle condition diagnostic apparatus comprising a.