JPH0463404B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a detection method for detecting an abnormality in an actuator system driven by an electronic control device such as a fuel injection valve in an internal combustion engine.

[Prior Art] Generally, in the case of electronic control devices that control internal combustion engines, etc., abnormalities in the operation and energization of the actuator, actuator drive circuit, and their connections (hereinafter collectively referred to as the actuator system) are detected. When an abnormality is detected, an appropriate compensation operation is performed to optimize and stabilize control.

Conventionally, abnormality detection in the actuator system was
For example, a signal representing the operating state of an actuator (operating state signal) is detected and supplied to an electronic control device, and the actuator operating state signal and an actuator drive command signal output from the electronic control device are constantly compared, and both are This is done by determining whether or not they match.

[Problems to be Solved by the Invention] However, according to the conventional method of constantly comparing the operating state signal and the drive command signal, an abnormality detection circuit consisting of a logic circuit or the like is provided to constantly compare both signals. There is a need. Therefore, the amount of processing information required to detect abnormalities in a large number of actuators or actuators that operate frequently is enormous, which complicates the circuit configuration of the abnormality detection circuit and increases costs.

Furthermore, in the case of an actuator placed near a noise generation source such as an ignition device, such as a fuel injection valve of a vehicle internal combustion engine, there is a problem of misjudgment due to temporary abnormality of the actuator due to the noise. Therefore, there is a desire for an anomaly detection method that can reliably detect true anomalies.

The present invention was made in view of the above circumstances, and
The purpose is to provide an actuator system detection method that can easily and reliably detect abnormalities in the actuator system.

[Means for Solving the Problems] In order to achieve the above object, the present invention detects a drive command signal supplied from an electronic control device to an actuator system and an operating state signal representing the operating state of the actuator system, In the actuator system abnormality detection method, the detected operating state signal and the drive command signal are compared, and an abnormality in the actuator system is detected based on the comparison result, wherein the electronic control device is synchronized with the output timing of the control signal pulse. and calculates the drive signal and outputs the drive command signal, and the value of the operating state signal detected at at least one of immediately before the calculation of the drive command signal and immediately after the start of output, and the time of the detection. Detecting the occurrence of the abnormality based on the comparison result with the value of the drive signal at , counting the number of occurrences of the abnormality in synchronization with the output timing of each control signal pulse, and counting the number of times the abnormality occurs within a first predetermined time. determining whether the number of times the abnormality has occurred is equal to or greater than a first predetermined number of times, and setting a second predetermined time when it is determined that the counted number of times the abnormality has occurred is the first predetermined number of times; , determining whether the counted number of occurrences of an abnormality within the second predetermined time is equal to or greater than a second predetermined number, and determining that the counted number of occurrences of anomaly is equal to or greater than the second predetermined number. When this occurs, it is determined that there is an abnormality in the actuator system.

[Example] Hereinafter, an example of the present invention will be described with reference to the drawings.

[First Embodiment] FIGS. 1 and 2 show an electronic control device (hereinafter referred to as
This figure shows the circuit configuration of the ECU (referred to as ECU). This ECU1
0 drives the fuel injection valves 21 to 24 as an actuator system of a vehicle internal combustion engine to supply the required amount of fuel to the engine according to the operating state of the engine, thereby optimizing various characteristics of the engine. In addition, the fuel injection valves 21 to 24 are configured to perform a compensation operation when an abnormality occurs.

The output signal from the engine rotation speed sensor (Ne sensor) 11 is input to the ECU 10, and after being waveform-shaped by the waveform shaping circuit 101, it is converted into a pulsed TDC.
It is applied as a signal to the Me counter 102 and the central processing unit (hereinafter referred to as CPU) 103.
The Me counter 102 sequentially counts the generation interval time of each TDC signal that is inputted sequentially, and the counted value Me is proportional to the reciprocal of the engine rotation speed Ne. The count value Me of this Me counter 102 is the data bus 1
12 and then supplied to the CPU 103.

In addition, each input signal from various engine parameter sensors such as an exhaust gas sensor (O ₂ sensor) 12, an absolute pressure sensor (P _BA sensor) 13, and an engine coolant temperature sensor (Tw sensor) 14 is sent to the ECU 10.
After being corrected to a predetermined voltage level by a level correction circuit 104, the signal is sequentially applied to an analog-to-digital converter (hereinafter referred to as an A-D converter) 106 at a predetermined timing by a multiplexer 105. The A-D converter 106 converts analog signals from the sensors 12 to 14 that are sequentially input into corresponding digital signals, and supplies the digital signals to the CPU 103 via the data bus 112. The CPU 103 is connected to a read-only memory (hereinafter referred to as
(hereinafter referred to as ROM) 107, random access memory (hereinafter referred to as RAM) 108, and output counter 1
09 is connected. ROM107 has CPU1
03, a basic injection time Ti map of the fuel injection valves 21 to 24, correction coefficient values or variable values corresponding to predetermined values of various engine parameters, etc. are stored. Also RAM1
08 temporarily stores the calculation results calculated by the CPU 103.

The CPU 103 synchronizes with the TDC signal and the ROM 107
The correction coefficient value _K1 or variable value _K2 corresponding to the signals from the various engine parameter sensors 12 to 14 described above is stored in the ROM according to the control program stored in the ROM.
Read from 107 and calculate the formula Tou _T = Ti × K ₁ + K ₂
The fuel injection time Tou _T is calculated by the following, and the calculated value is preset in the output counter 109 via the data bus 112. The output counter 109 is a down counter and outputs a signal to the injection valve drive circuit 110. The circuit 110 controls the fuel injection valves 21 to 2 while the signal from the output counter 109 is input.
A drive signal is output to the corresponding one of No. 4 to open the valve. In addition, each fuel injection valve 21 to 24
is connected to a battery 26 via an ignition switch 25.

The ECU 10 has a built-in abnormality detection circuit that detects abnormalities in the fuel injection valves 21 to 24. ECU10
An actuator system operating state signal, that is, a drive signal from a drive circuit 110 is supplied to the CPU 103 via a level converter 113, an input port 114, and a data bus 112. As mentioned later,
The CPU 103 compares the drive signal with the drive command signal, that is, the borrow terminal output from the counter 109, and controls the fuel injection valves 21 to 24 and these fuel injection valves.
It determines whether or not there is an abnormality in the fuel injection system (actuator system), which is made up of circuits and electric lines interposed between the CPU 103, and when it is determined that there is an abnormality, a failure display light is emitted that is connected to the ECU 10 via the alarm drive circuit 115. The diode (failure display LED) 27 is lit and an alarm is activated.

In addition, the abnormality occurrence counter 11 of the ECU 10
Reference numeral 6 temporarily stores information representing the number of mismatches between the drive command signal and the operating state signal, that is, the number of occurrences of an abnormality.

FIG. 2 is a diagram showing a part of the ECU 10 shown in FIG. 1 in detail, and the CPU 103 has a built-in timer 103a that operates as described later or has a timing function (program timer). Output counter 10
9. The drive circuit 110 and level converter 113 are
4 sets of preset down counters and AND circuits corresponding to each fuel injection valve 21 to 24, respectively;
It includes four transistor power amplification circuits and four level shifters (only those corresponding to the fuel injection valves 21 are shown). Regarding the illustrated portion, the counter 109a of the output counter 109 is
Fuel injection time data is preset at the same time as the load signal from CPU 103 is selectively applied, and the preset value is subtracted each time a clock signal is supplied. Then, until the preset value becomes zero, the high level borrow terminal output is transmitted to the transistor amplifier circuit 1 via the inverter 110a'.
10a, the transistors Tr ₁ and Tr ₂ of the circuit 110a are turned on, and the fuel injection valve 21 is opened. On the other hand, when the preset value becomes zero, the fuel injection valve 21 is opened by the low-level borrow terminal output, and the ND circuit 109a' is closed, thereby stopping the down-count operation. The four fuel injection valves 21 to 2 connected to the output counter 109 through the drive circuit 110 in this manner
4, the valves are sequentially opened in a predetermined order in synchronization with the TDC signal, and fuel is injected into the cylinder.

On the other hand, the drive signal from the drive circuit 110 is transmitted to the transistor Tr ₂ downstream of the transistor circuit 110a.
level shifter 113
After being corrected to a predetermined level at step a, the input port 114 and data bus 112 are used as operating state display signals.
It is supplied to the CPU 103 via.

By the way, the gist of the abnormality detection method of the present invention is to detect the presence or absence of an abnormality by intermittently comparing the actuator drive command signal from the electronic control unit with the operating state signal representing the operating state of the actuator system. This is what we do. That is, the fuel injection valves 21 to 24 of FIG. 1 as actuators
When detecting abnormalities, each
The engine parameter values are read in synchronization with the output timing of the TDC signal pulse (control signal pulse), the fuel injection time T _OUT of the fuel injection valves 21 to 24 is calculated based on the read parameter value, and the calculated fuel injection time is calculated. Injection valve 21 based on T _OUT
A drive command signal (borrow terminal output signal of counter 109) is output to 24. At this time, the operating state signal of the fuel injection valve (drive signal from the drive circuit 110) detected at least one of the time points immediately before the calculation of the fuel injection time T _OUT and immediately after the start of output of the drive command signal when the output is stable, and the Based on the comparison result with the drive command signal (borrow terminal output signal of the counter 109) at the time of detection, the fuel injection valves 21 to 24
Detect abnormalities in operation.

Next, the number of occurrences of an abnormality is counted in synchronization with the output timing of each TDC signal pulse, and only when the counted number of times of abnormality occurrence both exceed respective predetermined values within two predetermined times, it is determined that an abnormality has occurred. I try to judge. That is, for example, as shown in FIG. 4, the operation start time t ₁ of the timer 103a in FIG.
When the counted number of abnormality occurrences within the first predetermined time T1 from t2 _to time _t2 does not reach the first predetermined number, the timer is set to the same first value every time the first predetermined time _T1 elapses. It is determined that there is no abnormality by setting a predetermined time _T1 .

On the other hand, when the counted number of abnormality occurrences reaches the first predetermined number at time _t3 before the first predetermined time _T1 has elapsed, the timer 103a immediately
at a second predetermined time _T2 , and even before the second predetermined time _T2 elapses, that is, immediately when the number of abnormality occurrences counted at time _t4 reaches the second predetermined number. It is determined that there is an abnormality.

FIG. 5 shows a flowchart of a fuel injection valve abnormality detection subroutine according to an embodiment of the method of the present invention.

First, only when starting this program, the CPU
At the same time as initializing the data in the timer 103, the timer 103a is set to the first predetermined time _T1 , and the program from step 1 onward is synchronized with the timing of each TDC signal pulse (control signal pulse). and execute it. That is, the engine parameter signals from various sensors are expressed as shown in Fig. 1.
Read into the CPU 103 (step 1), and then read the drive signal supplied from the drive circuit 110 in FIG. 1 to the injection valve (INJ) that is scheduled to open during the current loop, that is, the collector voltage level of the drive transistor Tr ₂ . (Step 2) The read value (operating state signal) is compared with the borrow terminal output (drive command signal) of the counter 109 to determine whether the injection valve is actually in the closed state (Step 3).
If this determination result is affirmative (Yes), the valve closing operation of the injection valve is normal, so the fuel injection time Tou _T is calculated from the above calculation formula based on the engine parameter values read in step 1 ( Step 4)
To supply a drive command signal to the injection valve, a Tou _T value is preset in the output counter 109 (step 5). As a result, the drive circuit 110 outputs a drive signal at an energizing level (low level).

Next, after waiting for the level of the drive signal to stabilize, the actual level of the drive signal that should be at the energization level is read (step 6), and the read value (operating state signal) is read.
and the borrow terminal output (drive command signal) of the counter 109 to determine whether the injector is actually in the open state (step 7), and if the answer is affirmative (Yes), the injector is opened. Since the valve opening operation of F is normal, the process moves to step 8 and the first and second memory information _nF are stored.
It is determined whether or not both s ₁ and n _F s ₂ have a value of 1.
Both storage information n _F s ₁ and n _F s ₂ are stored at the first predetermined time, respectively.
T ₁ , the abnormality determination result at the second predetermined time T ₂ is shown,
These are flags or coded information for abnormality determination written in the first and second predetermined address areas of the RAM 108, respectively. In this embodiment, a value of 1 indicates an abnormal state, and a value of O indicates a normal state. Show it.

If the determination results in steps 3 and 7 are negative (No), the process proceeds to steps 9 and 10, respectively, and abnormality count processing is performed, respectively. That is, when it is determined that an abnormality has occurred in the closing or opening operation of the injection valve, the current value is calculated by adding the number of abnormality occurrences E _1NJ obtained up to the previous loop in step 1 of Fig. 6. Let the number of abnormalities occur E _lNJ , and then the number E _lNJ is the first
It is determined whether the predetermined number of times _E1NJFS1 is equal to (step 2). Note that this predetermined number of times is set to an appropriate value from several times to several tens of times. If the determination result in step 2 is negative (No), the abnormality counting process is terminated, and if step 9 in FIG.

If the determination result in step 8 of FIG. 5 is negative (No), it is determined whether the timer 103a of FIG. 2 has timed up (step 11), and if the answer is negative (No), this program is executed. finish.

When the first predetermined time T1 elapses with the number of abnormal occurrences _E1NJ being less than the first predetermined number _E1NJFS1 , the answer to step ₁₁ becomes affirmative (Yes), and the process moves to step 12, where the _E1NJ counter 116 is reset. Next, both memory information n _F s ₁ and n _F s ₂ are cleared (step 1).
3) The timer 103a is set to the first predetermined time _T1 and restarted (step 14), and this program is ended.

On the other hand, the determination result in step 2 of FIG. 6 is affirmative (Yes), that is, the number of abnormal occurrences E _1NJ before the first predetermined time T ₁ determined in step 11 of FIG. 5 has elapsed.
If it is determined that has reached the first predetermined number of times _E1NJFS1 , it is determined whether or not _the first stored information _nFs1 has the value 1 (step 3), and the answer is negative (No). If so, the value of the first stored information n _F s ₁ is set to 1 and the first abnormality detection is completed (step 4). Next, the abnormality occurrence count (E _INJ ) counter is reset (step 5), the timer 103a is set to a second predetermined time _T2 , and restarted (step 6), and the abnormality counting process is completed as shown in FIG. If step 9 ends, the process goes to step 4, and if step 10 ends, the process goes to step 8.

Thereafter, the above process is repeated until the second predetermined time _T2 determined in step 11 has elapsed.
In step 2 of FIG. 6, it is determined whether the number of abnormality occurrences E _INJ has reached a second predetermined number E _INJFS2 . If the number of abnormal occurrences has not reached the second predetermined number after the second predetermined time _T2 has elapsed, it is determined that the system is in a normal state even though an abnormality has been detected once, and step 11 in FIG. ~14, and returns to the initial state.

On the other hand, the number of abnormal occurrences E _INJ within the second predetermined time T ₂
When reaches the second predetermined number of times E _INJFS2 , the determination result in step 2 in FIG. 6 becomes affirmative (Yes), and
Since the first abnormality detection has already been completed, the determination result in step 3 is also affirmative (Yes). As a result, the value of the second stored information n _F S ₂ is set to 1 (step 7), and a second abnormality is detected. Therefore,
In this loop, the determination result in step 8 in FIG. 5 becomes affirmative (Yes), and the process moves to step 15, where an alarm is activated and, for example, a failure is displayed on the failure display light emitting diode 27.

In this way, according to the abnormality detection subroutine program shown in FIGS. 5 and 6, the drive signal calculation to the fuel injection valve (see FIG. 5) is performed in synchronization with the output timing of each TDC signal pulse (control signal pulse). The operating state signal (drive signal output from the drive circuit 10) detected immediately before step 4) and immediately after outputting the drive signal to the fuel injection valve (step 5 in Fig. 5) and the time of detection of the operating state signal If an abnormality is detected by comparing the drive command signal (borrow terminal output signal of counter 109) with the drive command signal (borrow terminal output signal of counter 109) (if Step 3 and Step 7 in Fig.
Proceed to 0 error count processing and count the number of error occurrences E _INJ
and the number of abnormal occurrences E _INJ counted in synchronization with the output timing of each TDC signal pulse within a first predetermined time _T1 reaches a first predetermined number E _INJFS1 ,
The number of abnormal occurrences E _INJ counted within the second predetermined time T ₂ starting from this point is the second predetermined number of times.
It is only when E _INJFS2 is reached that it is finally determined that there is an abnormality in the opening/closing valve operation of the fuel injection valve.
Note that, like the first predetermined number of times, the second predetermined number of times is set to an appropriate value from several times to several tens of times.

In the above embodiment, a series of processes such as checking whether the timer has timed up or not at each output timing of each TDC signal pulse, that is, steps 9 to 12 in FIG. The processing may also be performed using the following steps.

[Second Embodiment] Further, in the first embodiment, an abnormality is detected based on whether the cumulative number of abnormality occurrences of all fuel injectors is equal to or less than a predetermined number of times within the first and second predetermined times. However, the number of abnormalities occurring for each injection valve may be counted and abnormalities may be detected individually.

FIG. 7 shows a second embodiment of such individual abnormality discrimination detection, in which an abnormality occurrence count counter E _INJ i (i = 1 to 4) corresponding to each injection valve is provided, and the target injection valve at each loop is If there is an abnormality, update the number of abnormal occurrences _INJ i of the corresponding counter (step 1),
It is determined whether the number of times is equal to the predetermined number of times E _INJFS (step 2), and if the answer is affirmative (Yes), the abnormality display code Ki (=1, 2,
3, 4) is read out (step 3), and it is determined whether the first stored information n _F s ₁ is equal to the code Ki (step 4). If the determination result is negative (No), the first stored information _nFs1 is set to Ki (step 5), the corresponding abnormality occurrence counter is reset (step 6), and _the timer is restarted (step 7). After that, the timer is 1 until the timer is up.
When the number of times an abnormality has occurred in the injection valve for which an abnormality has been detected for the second time reaches a predetermined number, a second abnormality is detected using the second memory information n _F s ₂ as Ki (step 8). Display. In this embodiment, in step 8 of FIG. 5, it is determined whether or not both stored information n _F s ₁ and n _F s ₂ are equal to the abnormality display code Ki.

In each of the above embodiments, the occurrence of an abnormality is detected both immediately before the calculation of the drive signal to the fuel injection valve and immediately after the drive signal is output. good.

Further, in each of the above embodiments, the first and second predetermined times may be set equal and the first and second predetermined times may be set equally to simplify the process.

[Effects of the Invention] As described above, according to the present invention, the occurrence of an abnormality is detected by comparing the drive command signal supplied from the electronic control device to the actuator system and the operating state signal representing the operating state of the actuator system. In the detection method, when it is determined that the number of abnormal occurrences counted within the first predetermined time is equal to or greater than the first predetermined number, a second predetermined time is set, and the count is performed within the second predetermined time. Since it is determined that there is an abnormality in the actuator system when it is determined that the number of abnormality occurrences is greater than or equal to the second predetermined number, erroneous judgment due to temporary or accidental abnormality occurrence due to external noise etc. is avoided. This can be avoided, and since the abnormality occurrence detection is performed at least either immediately before the calculation of the drive command signal or immediately after the drive signal is output,
The amount of processing data required for abnormality detection can be significantly reduced, and abnormalities in a large number of frequently operated actuators and their peripheral circuits can be reliably and stably detected without requiring an enormous amount of circuitry.

[Brief explanation of the drawing]

1 is a block circuit diagram illustrating the circuit configuration of an electronic control device to which the method of the present invention is applied; FIG. 2 is a partial circuit diagram showing details of the injection valve drive circuit and its peripheral circuits in FIG. 3 and 4 are timing charts illustrating the outline of the method of the present invention, FIG. 5 is a flowchart of an abnormality detection execution subroutine according to the first embodiment of the present invention, and FIG. FIG. 7 is a flowchart of the abnormality counting processing execution subroutine according to the second embodiment. 10...Electronic control unit, 103...Central processing unit, 103a...Timer, 110...Injection valve drive circuit, 110a...Transistor power amplifier circuit, 112...Data bus, 113...Level converter, 114 ...Input port, 116... Abnormality occurrence counter.

Claims (1)

[Scope of Claims] 1. Detecting a drive command signal supplied from an electronic control device to an actuator system and an operating state signal representing the operating state of the actuator system, and detecting the detected operating state signal and the drive command signal. In the method for detecting an abnormality in the actuator system, the electronic control device calculates the drive command signal in synchronization with the output timing of the control signal pulse, and detects an abnormality in the actuator system based on the comparison result. A drive command signal is output, and the value of the operating state signal detected at at least one of immediately before the calculation of the drive command signal and immediately after the start of output is compared with the value of the drive signal at the time of the detection. The occurrence of the abnormality is detected based on the number of occurrences of the abnormality, and the number of occurrences of the abnormality is counted in synchronization with the output timing of each control signal pulse, and the counted number of occurrences of the abnormality within a first predetermined time is a first predetermined number of times. or more, and when it is determined that the counted number of abnormal occurrences is an abnormality for the first predetermined number of times, a second predetermined time is set, and the counting is performed within the second predetermined time. It is determined whether the number of times the abnormality has occurred is equal to or greater than a second predetermined number of times, and when it is determined that the counted number of times the abnormality has occurred is equal to or greater than the second predetermined number, it is determined that there is an abnormality in the actuator system. A method for detecting an abnormality in an actuator system. 2. When the counted number of abnormality occurrences reaches the first predetermined number before the first predetermined time elapses, the second predetermined time is set without waiting for the first predetermined time to elapse. , a patent for determining that there is an abnormality in the actuator system without waiting for the elapse of the second predetermined time when the number of abnormality occurrences counted before the elapse of the second predetermined time reaches the second predetermined number of times. A method for detecting an abnormality in an actuator system according to claim 1. 3. An abnormality detection method for an actuator system according to any one of claims 1 to 2, which determines an abnormality in an actuator system including a fuel injection valve that changes the operating state of a vehicle internal combustion engine.