JPH05171996A - Abnormality diagnosing device for internal combustion engine control device - Google Patents

Abstract

PURPOSE:To provide an abnormality diagnosing device for an internal combus tion engine control device which can accurately detect an abnormal state, and does not diagnose an abnormality in an engine speed sensor system wrongly even when an abnormality occurs in an electric control device in a starter-on state. CONSTITUTION:An abnormality diagnosing device is provided with a means 101 for detecting that a master switch is turned-on, a means 102 for detecting the engine speed of an internal combustion engine, and a means 103 for starting the count when an ''on'' state of the master switch is not detected. Further, a means 104 for memorizing that the means 102 is abnormal when the counted value of the means 103 reaches a first specified value, and a means 106 for clearing the memory in which the means 102 stored in the means 104 is abnormal when the counted value of the means 105 reaches a second specified value which is larger than the first specified value.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an abnormality diagnosing device for an electronic control unit for an internal combustion engine, and more particularly to an abnormality diagnosing device for preventing erroneous detection of a starter-on state.

[0002]

2. Description of the Related Art With the recent progress of so-called microcomputer technology, electronic control devices using a microcomputer system have been widely used as control devices for internal combustion engines for automobiles. This electronic control device aims to improve fuel efficiency by inputting internal combustion engine speed, intake pressure, etc. to control the fuel injection amount, ignition timing, etc. to keep exhaust gas clean. ..

In order to accurately execute these controls,
First, it is necessary to read the operating state of the internal combustion engine normally, that is, to confirm that each sensor that detects the operating state is normal. Therefore, in order to achieve this object, a so-called abnormality diagnosis function is incorporated in the electronic control unit to detect the abnormality of the sensor at an early stage.

The internal combustion engine rotational speed is used to determine the timing of fuel injection amount control and ignition timing control, and abnormality diagnosis of the rotational speed sensor system is particularly important. In the conventional electronic control unit, the abnormality diagnosis of the rotation speed sensor system is executed by the following logic. That is, condition 1: cranking by the starter continues for 2 seconds or more.

Condition 2: No rotation speed signal is input during that time. It was determined that the rotation speed sensor system was abnormal when the above two conditions were satisfied at the same time.

[0006]

However, in this abnormality diagnosis, once it is determined that the rotation speed sensor system is abnormal, the stored contents are stored unless the flag indicating the rotation speed sensor system abnormality turns off the battery power. Is not cleared is stored in the standby memory. Therefore, the rotation speed sensor system abnormality cannot be cleared by the driver himself, and the battery power must be turned off at the repair shop.

Therefore, when the transmission path for transmitting to the electronic control unit whether or not the starter is turned on is abnormal in a state indicating the starter is on, the master key of the automobile is turned on. Even if the starter is not turned on, an abnormality in the rotation speed sensor system will be detected, and repair at a repair shop is required. The present invention has been made in view of the above problems, and even when an abnormality occurs in the electronic control unit in a starter-on state, it is possible to accurately detect this abnormal state and erroneously determine that the rotation speed sensor system is abnormal An object of the present invention is to provide an abnormality diagnosis device for an internal combustion engine control device.

[0008]

FIG. 1 is a basic configuration diagram of an abnormality diagnosing apparatus for an internal combustion engine control apparatus according to the present invention, in which a master switch ON state detection for detecting that a master switch is in a starter ON state is shown. Means 101, rotation speed detection means 102 for detecting the rotation speed of the internal combustion engine, and master switch ON state detection means 101, when the starter ON state of the master switch is detected, the rotation speed detection means 102 does not detect the rotation speed. When the count value of the rotation speed detection means abnormality determination timer means 103 for starting the counting and the rotation speed detection means abnormality determination timer means 103 reaches the first predetermined value, the rotation speed detection means 102 is abnormal. Rotation speed detection means for storing the abnormality storage means 1
04, the rotation speed detection means normal determination timer means 105 for starting counting when the rotation speed detection means 102 detects no rotation speed when the master switch on-state detection means 101 detects the starter on-state of the master switch. And the rotation speed detection means stored in the rotation speed detection means abnormality storage means 104 when the count value of the rotation speed detection means normality judgment timer means 105 reaches a second predetermined value which is larger than the first predetermined value. An abnormal memory clearing unit 106 for clearing a memory 102 is abnormal.

[0009]

In the abnormality diagnosing device for the internal combustion engine controller according to the present invention, the rotation speed detecting means is provided when the rotation speed signal is not detected for the first predetermined time after the master switch is in the starter-on state. It is determined to be abnormal and the state is stored. Further, when the rotation speed signal is not detected for the second predetermined time which is longer than the first predetermined time after the master switch is turned on, the rotation speed detecting means is not abnormal and the signal transmission path is abnormal. Therefore, the memory that the rotation speed detecting means is abnormal is cleared.

[0010]

1 is a block diagram of an embodiment of the present invention, which is configured as a so-called microcomputer system. Car master key 201 is usually OF
It has four positions of F, ACC, IG, and START, and controls on / off of the electric power from the battery 220.

That is, when it is put in the ACC position, power is supplied to auxiliary equipment such as a radio. Next, when it is put in the IG position, the contacts 201a and 201b are turned on, the power supply system to the starter motor 230 of the automobile enters the standby state, the power supply to the electronic control unit 210 is started, and the electronic control unit 210 starts. The control calculation is started.

Further, when the master key 201 is pushed to the START position, the contacts 201c and 201d are turned on. When the contact 201d is turned on, the starter motor 23
Zero power supply is started, and cranking of the internal combustion engine is started. The contact 201c is in the ON state at the same time as the contact 20
The signal 1d is input to the electronic control unit 210 as a signal indicating that the starter motor is operating.

The number of revolutions of the internal combustion engine is detected by counting pulses generated by the electronic control unit 210 when the switch 202 incorporated in the distributor is repeatedly turned on and off in synchronization with the rotation. The electronic control unit 210 has a bus 210a as a center, a CPU 210b, an input interface 210c, an output interface 210d,
It is composed of a memory 210e and a standby memory 210f.

When the master key 201 is pushed to the IG position, power supply to the CPU 210b, the input interface 210c, the output interface 210d and the memory 210e is started. The standby memory 210f is directly connected to the battery 220, maintains an operating state regardless of the position of the master key 201, and is used to store important data that should not be cleared by turning off the master key 201.

A diagnostic start command switch 240 is provided on the input interface 210c and an output interface 2 is provided.
A display device 250, which is an LED, for example, is connected to 10d and is used to know the abnormality diagnosis result stored in the standby memory in the repair shop. FIG. 3 is a flowchart of a main routine executed by the electronic control unit 210, which is executed for each predetermined cam angle of 720 degrees, for example.

In step 301, the master key 2
The state of the contact 201c of 01 is read. If the contact 201c is on, an affirmative decision is made in step 302, but if the signal reading transmission path fails in the same state as when the contact 201c is on, an affirmative decision is likewise made.

If an affirmative decision is made in step 302, the process proceeds directly to step 304. If the result in step 302 is negative, the process proceeds to step 303, the counter CNT is reset, and the process proceeds to step 304. At step 304, it is judged if the counter CNT is larger than the first predetermined time τ ₁ . Here, the first predetermined time τ ₁ is set to a time, for example, 2 seconds until cranking is started by the starter motor 230 and a rotation speed pulse is naturally output.

If an affirmative decision is made at step 304, then the routine proceeds to step 305, at which a flag XFAIL indicating that the rotation speed sensor system is abnormal is set to "1", and the main processing of the main routine is executed to proceed to step 306. move on. If a negative determination is made in step 304, the original process of the main routine is immediately executed and the process proceeds to step 306.

In step 306, it is determined whether the counter CNT is equal to or longer than a second predetermined time τ ₂ which is longer than the first predetermined time. Here, the second predetermined time τ ₂ is set to a sufficiently long time in which the starter motor is not continuously operated, for example, 60 seconds. And step 30
If a negative determination is made in 6, the process proceeds to step 307, and the standby memory 210f storage flag XSTBY is set to the flag XF.
AIL.

If the affirmative judgment is made in step 306, that is, if it is judged that the starter motor is continuously operated for the second predetermined time τ ₂ or more, it is a state that cannot occur in the actual operation, and the contact 201c. It is considered that the read transmission path of the fault has failed in the same state that the contact 201c is turned on, and two flags XFAIL are determined in step 308.
And clear XSTBY.

In step 309, the diagnosis start command switch 2
It is determined whether or not 40 is turned on, and if it is turned on, the set state of the flag is displayed on the display device 250 in step 310. FIG. 4 is a flowchart of the rotation signal interruption routine, which is executed for each predetermined cam angle of, for example, 30 degrees, and after the flag XFAIL and the counter CNT indicating that the rotation speed sensor system is abnormal are reset in step 401. , The original processing is executed.

That is, the rotation signal interrupt routine is activated more frequently than the main routine, and the flag XFAIL and the counter CNT are constantly reset. Therefore, as long as the rotation speed sensor system is normal, the flag XFAIL is not set and the rotation speed sensor system is not diagnosed as abnormal. On the contrary, if the rotation speed signal is not input for the first predetermined time τ ₁ or more, the flag XFAIL is set and it is determined that the rotation speed sensor system is abnormal.

However, if the rotation speed signal is not input for the second predetermined time τ ₂ or more, the flags XFAIL and XSTBY are set.
Is reset and the rotation speed sensor system is not abnormal, but the rotation speed sensor system error flag indicates that an error has occurred in the starter motor operating status reading transmission line.
It is prevented from being stored in 10f.

[0024]

According to the present invention, even if the starter motor operating condition reading transmission path becomes abnormal while the starter motor is operating, a flag indicating the rotation speed sensor system abnormality is stored in the standby memory. This eliminates the need for repairs or parts replacement in the repair shop.

[Brief description of drawings]

FIG. 1 is a basic configuration diagram of an abnormality diagnosis device for an internal combustion engine controller according to the present invention.

FIG. 2 is a block diagram of one embodiment.

FIG. 3 is a flowchart of a main routine.

FIG. 4 is a flowchart of a rotation signal interrupt routine.

[Explanation of symbols]

 101 ... Master switch ON state detecting means 102 ... Rotation speed detecting means 103 ... Rotation speed detecting means Abnormality judging timer means 104 ... Rotating speed detecting means Abnormal memory means 105 ... Rotating speed detecting means Normal judgment timer means 106 ... Abnormal memory clearing means

Claims (1)

[Claims] 1. A master switch ON state detecting means (101) for detecting that a master switch is in a starter ON state, and a rotation speed detecting means (102) for detecting a rotation speed of an internal combustion engine.
And a rotation speed detection means for starting counting when the rotation speed detection means (102) does not detect the rotation speed when the master switch on-state detection means (101) detects the starter on-state of the master switch. An abnormality determination timer means (103) and a rotation for storing that the rotation number detection means (102) is abnormal when the count value of the rotation number detection means abnormality determination timer means (103) reaches a first predetermined value. An abnormality diagnosing device for an internal combustion engine control device, comprising: a number detecting means abnormality storing means (104); A rotation speed detection means normal determination timer means (105) which starts counting when the rotation speed is not detected by the rotation speed detection means (102). When the count value of the rotation speed detection means normality judgment timer means (105) reaches a second predetermined value which is larger than the first predetermined value, it is stored in the rotation speed detection means abnormality storage means (104). An abnormality diagnosis device for an internal combustion engine controller further comprising an abnormality memory clearing means (106) for clearing a memory that the rotation speed detecting means (102) is abnormal.