JP2001086639A - Method for detecting failure of inductive load drive and device thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To attain a method for detecting failure, at low cost, in an energizing path including inductive load and a device thereof, in an inductive load drive driving a plurality of inductive loads. SOLUTION: An energizing path corresponding to the failure detection time which is set in a timer circuit 10 is stored by a failure detection execution flag (S140). When the failure detection time of one energizing path corresponding to a control signal changed in the signal level is to be set, the failure detection execution flag is referred to for determining whether the failure detection time of the other energizing path is set (S60). When the failure detection time of the other energizing path is not set, the failure detection time of one energizing path is set in the timer circuit. As a result, in failure detection of a plurality of energizing paths, the failure detection time of the energizing paths varying from each other can be set in a common timer circuit.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for detecting an abnormality in each current path including an inductive load itself in an inductive load driving device for driving a plurality of inductive loads.

[0002]

2. Description of the Related Art Conventionally, an inductive load driving device for driving an inductive load (for example, a solenoid constituting an actuator such as an electromagnetic valve) is provided on an energizing path for driving the inductive load. A predetermined control signal is output from a control circuit (microcomputer or the like) to the drive circuit (comprising a switching element or the like) and the signal path of the control signal is changed to connect (turn on) and cut off (turn on) the current path. Off) to drive the inductive load.

[0003] In this type of inductive load driving device, abnormalities such as disconnection or short circuit in the "energization path including the inductive load" (for example, open failure of switching element, disconnection of inductive load, switching element or inductive element). When a short circuit occurs at both ends of the load, for example, it becomes impossible to normally drive the inductive load by the control signal, and thus such an abnormality is detected.

[0004] Abnormality detection of an energized path including an inductive load is performed by:
When a control signal is output to the drive circuit to drive the inductive load, a signal (hereinafter, referred to as a monitor signal) indicating an energized state of the inductive load (that is, a drive state) is obtained from the drive circuit, and the control signal and This is performed by checking the correspondence with the monitor signal. For example, the potential at a predetermined location on the current path (for example, between an inductive load and a switching element) is
The energized state of the inductive load (that is, the energized state of the energized path)
Therefore, if the potential is detected as a monitor signal and the correspondence between the monitor signal and the control signal is determined, it is determined whether or not an abnormality has occurred in the inductive load or its energizing path. You can do it.

By the way, even if the on / off state of the current path is switched by changing the signal level of the control signal, the change in the current state (that is, depending on the on / off state of the current path) is caused by the inductive action of the inductive load. Of the monitor signal). Therefore, to detect such abnormalities,
It is necessary to wait until a predetermined time elapses from the change timing of the signal level of the control signal and the ON / OFF state of the energization path is reflected in the monitor signal.

Therefore, conventionally, the abnormality detection by the above method has been specifically performed as follows. That is, a predetermined time can be set, and a timer (for example, formed of a counter circuit) configured to output a signal to that effect at the set time is prepared. If there are a plurality of energizing paths, prepare them for each energizing path). Then, when the signal level of the control signal for interrupting a certain energizing path changes, a time delayed by a predetermined time from the change timing is set in a timer circuit corresponding to the energizing path. Then, when the set time comes and the timer outputs a signal to that effect, this is used as a trigger to detect an abnormality.

[0007]

However, in the prior art, since the same number of timer circuits as the number of energizing paths are used, a large number of inductive loads (that is, energized loads) such as a vehicle engine and an automatic transmission are used. When controlling a control target provided with a route, a large number of timer circuits are required. Further, in the future, as the number of inductive loads increases along with the sophistication of the control target, the number of timers used for abnormality detection further increases,
The manufacturing cost of the abnormality detection device will increase. For example, as such a timer, a so-called internal timer built in a microcomputer constituting a control circuit is often used. In this case, a plurality of times can be set simultaneously (that is, a plurality of timer functions are provided). ) An expensive microcomputer is required.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and provides a method and apparatus for detecting an abnormality in an energizing path including an inductive load at a low cost in an inductive load driving apparatus for driving a plurality of inductive loads. The purpose is to provide.

[0009]

Means for Solving the Problems and Effects of the Invention An abnormality detecting method according to the present invention (described in claim 1) for solving the above problems is provided for each of the plurality of inductive load energizing paths. In the inductive load driving device that outputs each control signal to the switching means, changes the signal level of each control signal, disconnects each energizing path, and drives each inductive load, A method for detecting an abnormality in an energization path (including each inductive load itself; the same applies hereinafter), wherein abnormality detection based on an energization state of each energization path and each control signal is performed using a timer means. This is performed at a time (anomaly detection time) delayed by a predetermined time from the change timing of the signal level of the control signal. The timer means is capable of setting a time, and is configured to output a notification when the set time is reached.

[0010] In particular, in the abnormality detection method according to the present invention (claim 1), regarding the abnormality detection time set in the timer means, an energization path to be detected at the abnormality detection time is stored. Keep it. Then, when the signal level of the control signal corresponding to any of the energizing paths changes, it is determined based on the stored contents whether or not the abnormality detection time of the other energizing paths has already been set in the timer means,
If the result of this determination is that the abnormality detection time of another energized path is not set in the timer means, the abnormality detection time of the energized path corresponding to the control signal whose signal level has changed is set in the timer means. Then, when the timer means outputs an abnormality detection time, an energized path to be subjected to abnormality detection is specified based on the stored contents, and an abnormality of the specified energized path is detected.

That is, in the abnormality detection method of the present invention (claim 1), an abnormality detection time is set for one energization path (that is, an energization path corresponding to a control signal having a changed signal level; the same applies hereinafter). In this case, first, it is determined whether or not the abnormality detection time of another energized path (an energized path other than the one energized path described above; the same applies hereinafter) is not set, and the abnormality detected time of the other energized path is set. If not, the abnormality detection time of the one energization path is set in the timer means.

Therefore, according to the abnormality detection method of the present invention (claim 1), when performing abnormality detection on a plurality of energized paths, it is possible to set the abnormality detection times of different energized paths to a common timer means. Becomes That is, it is possible to reduce the number of timer means required for detecting an abnormality in a plurality of energized paths as compared with the conventional case, and it is possible to suppress the cost required for the abnormality detection.

In the abnormality detecting method according to the first aspect, when an abnormality detection time of one energizing path (that is, an energizing path corresponding to a control signal having a changed signal level) is set in the timer means, When the abnormality detection time of the other energization path has already been set in the timer means, various methods can be considered as to how to set the abnormality detection time of the one energization path. It is also conceivable to stop setting the abnormality detection time. However, if the setting is stopped, the number of times of abnormality detection for one energizing path may be reduced depending on the relative relationship between the drive timings of the inductive loads.

Therefore, it is preferable to adopt a method as described in claim 2. That is, as a result of determining whether or not the abnormality detection time of another energizing path has already been set in the timer means, if it has been already set, then the abnormality detection of the energizing path corresponding to the control signal whose signal level has changed is detected. A comparison is made as to which of the time and the abnormality detection time of the other energization path is earlier, and as a result, the earlier abnormality detection time is determined to be set in the timer means, and the later abnormality detection is performed. The time is determined that the setting of the timer should be suspended.
Then, the timer means is set to “the abnormality detection time determined to be set in the timer means”, and after the abnormality detection at the set abnormality detection time is completed, the “setting to the timer means” is performed. The abnormality detection time determined to be suspended is set in the timer means.

That is, in the abnormality detection method according to the second aspect, when the abnormality detection time of one energized path is set to the timer means, the abnormality detection time of another energized path is set. Also, according to the order of the abnormality detection time of one energization path and the abnormality detection time of the other energization path, the earlier abnormality detection time is set to the timer means first, and the earlier abnormality detection time is set. After the abnormality is detected in, the later abnormality detection time is set. Therefore, the abnormality detection time of the one energization path can be set in the timer means, and the abnormality detection of the one energization path can also be performed reliably.

Even if the abnormality detection time of one energization path is earlier than the abnormality detection time of another energization path,
Alternatively, even if it is late, as described above, the timers are set in order from the earliest one, so that the abnormality detection of both energization paths can be performed at appropriate timing.

In the method of claim 2, as described above, the anomaly detection time of one energization path to be set in the timer means and the anomaly detection time of another energization path that has already been set. However, it is also possible that the abnormality detection time of another energization path has already passed at the time before performing this comparison determination, or that it has passed while performing the comparison determination, etc. Conceivable.
In such a case, without making the above comparison,
It is considered that the abnormality detection time of the other energization path is earlier, and measures are taken so that abnormality detection of the other energization path can be performed promptly (for example, a predetermined operation such as comparison judgment is omitted. May be necessary.

According to a third aspect of the present invention, there is provided an abnormality detecting method according to the second aspect, wherein the abnormality detection time of another energized path has already passed at the present time, or It is determined whether it is within a predetermined time from. When the abnormality detection time of the other energization path has already passed at the present time or within a predetermined time from the current time, it is determined that the abnormality detection time should be set in the timer means, and the control in which the signal level has changed is performed. It is determined that the setting of the abnormality detection time of the energization path corresponding to the signal to the timer means should be suspended.

In other words, according to the abnormality detection method of the present invention, when the abnormality detection time of another energized path has already passed at the present time or within a predetermined time from the present time, the comparison judgment is performed. In other words, it is possible to quickly determine which of the abnormality detection times should be set pending and which of the abnormality detection times should be set. In addition to omitting the above-described comparison determination, it is possible to take measures to quickly detect an abnormality in another energized path.

In order to determine whether the abnormality detection time of the other energized paths has already passed at the present time or within a predetermined time from the present time, first, from the viewpoint of urgency, "whether or not the current time has already passed" And then, "
It is preferable to determine whether it is within a predetermined time from the present time.

By the way, in the abnormality detecting method according to the second or third aspect, "an abnormality detection time determined to be set in the timer means" is set in the timer means. The abnormality detection time determined to hold the setting in the timer means is set in the timer means. However, if the time interval between the two abnormality detection times is small, the latter is the time set in the timer means. It is possible that it has already passed. In such a case, it is necessary to promptly detect an abnormality in the energized path, which should have been performed at the abnormality detection time.

Therefore, prior to setting the "abnormality detection time determined to be deferred to the setting to the timer means" to the timer means, the abnormality detection time is set to the present value. It is preferable to determine whether or not the current time has already passed, and if the current time has already passed, stop the setting of the abnormality detection time in the timer means and detect the abnormality of the energization path corresponding to this.

According to the abnormality detection method of the fourth aspect, at the end of the abnormality detection at the abnormality detection time previously set in the timer, the abnormality detection time determined to be set in the timer is set. "Has already passed, it is possible to start detecting its abnormality as soon as possible,
The delay can be suppressed.

Next, an abnormality detecting apparatus for an inductive load driving apparatus according to a fifth aspect is an apparatus for realizing the method according to the first aspect, wherein the inductive load driving apparatus includes each inductive load. This is an abnormality detection device for detecting an abnormality in each energization path. In the abnormality detecting device according to the fifth aspect, the abnormality detecting means is configured to be able to detect the energized state of each energizing path including each inductive load, and to control the detected energized state and intermittent of each energizing path. Abnormality of each energization path is detected based on the control signal for performing the operation. Further, in order to perform the abnormality detection by the abnormality detection means at an abnormality detection time delayed by a predetermined time from the change timing of the signal level of the control signal, the timer means is configured to be able to set the abnormality detection time, When the set abnormality detection time comes, it outputs that fact. The timer setting means is configured to set the abnormality detection time of the predetermined energization path in the timer means. When the timer means outputs the abnormality detection time, the abnormality detection control means Means for detecting an abnormality in a predetermined energization path.

In particular, in the abnormality detecting device according to the fifth aspect, when an abnormality detection time is set in the timer means, the detection target storage means is a target of abnormality detection to be performed at the set abnormality detection time. When the signal level of the control signal corresponding to any one of the energization paths changes, the setting state determination unit refers to the storage content of the detection target storage unit and stores another energization path. It is configured to determine whether or not the abnormality detection time of the route is set in the timer means.

Further, when the timer setting means determines that the abnormality detection time of the other energized path is not set in the timer means as a result of the determination by the setting state judging means, the energized path corresponding to the control signal whose signal level has changed is set. The abnormality detection time is set in the timer means, and when the timer means outputs that the abnormality detection time has been reached, the abnormality detection control means performs the abnormality detection with reference to the contents stored in the detection target storage means. Specify the target of abnormality detection to be performed.

Therefore, according to the abnormality detecting device of the fifth aspect, the method of the first aspect can be realized, and when performing the abnormality detection on a plurality of energized paths, the abnormality detection time of the different energized paths is set to a common time. Of the timer means can be set. That is, it is possible to reduce the number of timer means required for detecting an abnormality in a plurality of energization paths as compared with the conventional example, and to suppress the manufacturing cost of the abnormality detection device.

An abnormality detecting apparatus according to a sixth aspect is for realizing the method according to the second aspect, and includes an arbitration unit and a holding target storage unit that operate as follows. That is, the arbitration unit determines the result of the determination by the setting state determination unit,
When the abnormality detection time of another energization path is set in the timer means, which of the abnormality detection time of the energization path corresponding to the control signal whose signal level has changed and the abnormality detection time of the other energization path is earlier. Is compared. Then, according to the result of the comparison judgment, the earlier abnormality detection time is determined to be set in the timer means, and the later abnormality detection time is determined to be suspended in the timer. Further, the hold target storage means stores the energization path corresponding to the abnormality detection time determined to hold the setting of the timer means.

Further, the timer setting means sets the abnormality detection time determined to be set to the timer means by the arbitration means to the state set in the timer means, and sets the abnormality detection time at the set abnormality detection time. After the detection is completed, the abnormality detection time of the energization path stored in the hold target storage unit is set in the timer unit.

Therefore, according to the abnormality detecting device of the sixth aspect, the abnormality detecting method of the second aspect can be realized, and the same effect as the abnormality detecting method can be obtained. That is, in the abnormality detecting device according to the sixth aspect, even when the abnormality detection time of one energization path is set to the timer means, the abnormality detection time of the other energization path is set. Depending on the order of the abnormality detection time of the current path and the abnormality detection time of the other current paths, the earlier abnormality detection time is set to the timer means first, and the abnormality at the earlier abnormality detection time is set. After detection, the later abnormality detection time is set. Therefore, it is possible to set the abnormality detection time of the one energization path in the timer means,
Abnormality detection for the one energization path can be reliably performed.

Further, even if the abnormality detection time of one energization path is earlier than the abnormality detection time of another energization path,
Alternatively, even in the case where the current is late, it is possible to detect abnormality of both the current supply paths at appropriate timing. An abnormality detection device according to a seventh aspect is for realizing the method according to the third aspect, and the arbitration means is configured as follows. That is, the arbitration unit determines whether the abnormality detection time of the other energization paths has already passed at the present time or is within a predetermined time from the present time before performing the comparison determination, and determines whether the abnormality detection time has already passed at the present time. Or if it is within a predetermined time from the present time, it is determined that the abnormality detection time should be set in the timer means, and the abnormality detection time of the energization path corresponding to the control signal whose signal level has changed is set in the timer means. Decide what to hold.

Therefore, according to the abnormality detecting device of the seventh aspect, the abnormality detecting method of the third aspect can be realized, and the same effect as this method can be obtained. That is, according to the abnormality detection device of the seventh aspect, if the abnormality detection time of the other energization path has already passed at the present time or is within a predetermined time from the current time, the above-described comparison determination is not performed, and " The determination of which abnormality detection time should be suspended and which abnormality detection time should be set can be made quickly. In addition to omitting the above-described comparison determination, it is possible to take measures to quickly detect an abnormality in another energization path.

In order to determine whether the abnormality detection time of another energized path has already passed at the present time or within a predetermined time from the present time, first, from the point of urgency, "whether the current time has already passed" And then, "
It is preferable to determine whether it is within a predetermined time from the present time.

An abnormality detecting device according to claim 8 is for realizing the method according to claim 4, and the abnormality detecting control means is configured as follows. That is, the abnormality detection control means determines whether or not the abnormality detection time has already passed at the present time before the abnormality detection time of the energization path stored in the hold target storage means is set in the timer means. If the time has passed at the present time, the setting of the abnormality detection time is prohibited, and the abnormality detection means is caused to immediately execute the abnormality detection of the current path.

Therefore, according to the abnormality detecting device of the eighth aspect, the abnormality detecting method of the fourth aspect can be realized, and the same effect as this method can be obtained. That is, according to the abnormality detection device of the eighth aspect, at the time of the end of the abnormality detection at the abnormality detection time set earlier in the timer means,
Even if the abnormality detection time determined to be set in the timer means has already passed, the abnormality detection can be started as soon as possible, and the delay can be suppressed.

[0036]

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is an explanatory diagram showing an electrical configuration of an inductive load driving device as one embodiment to which the abnormality detection device of the present invention is applied. This inductive load driving device has two
An electronic control unit (E) for driving two “inductive loads” (the first solenoid Sa and the second solenoid Sb), and for driving and controlling these solenoids Sa and Sb.
CU) 2.

The ECU 2 is provided on each energizing path from the battery 12 to the ground via each of the solenoids Sa and Sb, and is capable of intermittently connecting each energizing path to the driving circuits 4a and 4a.
b, and by outputting a control signal to these driving circuits 4a and 4b at a predetermined timing,
and a control circuit 6 for driving the solenoids Sa and Sb by intermittently connecting the respective energizing paths respectively corresponding to a and 4b. The control circuit 6 is composed of a microcomputer, and includes a CPU 8 for performing various arithmetic processes,
The program executed by the CPU 8 is stored.
And a timer circuit 10 configured to be able to measure time in response to a command from the CPU 8. The signal level of a control signal from the control circuit 6 to each of the drive circuits 4a and 4b is controlled by the CPU 8.

The drive circuits 4a and 4b function as "switching means" in the claims. That is, a switching element is built in the drive circuits 4a and 4b, and when the control signal from the control circuit 6 is "High", the energizing path for driving the solenoid is connected, and the control signal is "Low".
Is set to the cutoff state. That is, the control circuit 6 outputs a “High” control signal when the solenoid is to be driven (energized state), and when the solenoid is to be in the non-driven state (non-energized state): A "Low" control signal is output.

On the other hand, the driving circuits 4a and 4b
A monitor signal, which is a signal indicating a drive state (energized state) of each solenoid (a signal indicating whether the solenoid is in an energized state or a non-energized state), is sent to. That is, the driving circuit 4a,
4b also functions as a part of the "abnormality detecting means" in the claims. In this embodiment, the signal level of the monitor signal is "High" when the solenoid is in the driving state, and is "Low" when the solenoid is not in the driving state. Therefore, when there is no abnormality in the solenoid, the control signal from the CPU 8 to the drive circuit 4a (4b) and the drive circuit 4
The monitor signal from a (4b) should match, and when these do not match, it can be determined that some abnormality has occurred in the solenoid energization path.

When the monitor signal is "Low" in spite of the control signal being "High", it can be estimated that a short-circuit abnormality of the solenoid (a state where both ends of the solenoid are short-circuited) has occurred. When the monitor signal is "High" in spite of the signal being "Low", the drive circuit 4 is operated so that it can be estimated that a solenoid disconnection abnormality (a state in which the solenoid is disconnected) has occurred.
a and 4b are configured. Therefore, in the description of the present embodiment, abnormality detection performed when the control signal is “High” is referred to as “short-circuit abnormality detection”, and abnormality detection performed when the control signal is “Low” is referred to as “disconnection abnormality”. Detection ”.

The timer circuit 10 functions as a "timer means" of the present invention, and operates in synchronization with a clock signal from a clock generation circuit (not shown) incorporated in the control circuit 6. Is configured as That is, the timer circuit 10 counts the number of clock signals input every predetermined time (for example, 1 μs), so that the count value Tcnt is HEX.
The value increases from $ 0000 to $ FFFF. Then, when the count value Tcnt becomes $ FFFF, it is returned to $ 0000 at the next timing (that is, the next clock signal input).

The count value Tcnt increases from $ FFFF to $ 000
When shifting to 0 (that is, when a so-called overflow occurs), the timer circuit 10 outputs an interrupt signal to the CPU 8. As described later, if a predetermined condition (interrupt permission flag = “1”) is satisfied when the interrupt signal is output, the CPU 8 determines that the first solenoid Sa or the second solenoid Sb is abnormal. A TCNT overflow interrupt process for selective execution is activated.

The timer circuit 10 is configured so that the count value Tcnt can be set to an arbitrary value by an input from the CPU 8. That is, the CPU 8 can set the timing (time) at which the interrupt signal is input from the timer circuit 10 by setting the count value Tcnt of the timer circuit 10 to an appropriate value. In other words, the CPU 8 can set the activation timing of the TCNT overflow interrupt processing, and further, the timing of performing abnormality detection (abnormality detection time). The count value Tcnt of the timer circuit can be referred to by the CPU 8.

Next, the processing executed by the CPU 8 in the inductive load driving device of the present embodiment configured as described above will be described. The ECU 2 included in the inductive load driving device is mounted on the vehicle, and performs various processes for controlling the vehicle in the main routine when the process related to abnormality detection is not performed. ing.

First, FIG. 2 shows a state in which the control signal Sa (hereinafter referred to as "Sa control signal") output to the drive circuit 4a provided in the energization path of the first solenoid Sa is activated every time the signal level changes. It is a flowchart which shows an output interruption process. Note that, even if the signal level of the Sa control signal changes, if another process (for example, a TCNT overflow interrupt process described later) is being executed, the process is started after the execution is completed. Is done.

As shown in FIG. 2, when the Sa output interrupt processing is started, first, in step S5, the Sa execution flag is set to "0".
Is set (ie, reset). The Sa abnormality detection execution flag indicates that the Sa abnormality detection time is set in the timer circuit 10 (that is, the state is reserved at the Sa abnormality detection time to execute the Sa abnormality detection process (described later)). It is a flag to indicate. Further, the Sa abnormality detection time is a timing at which an abnormality in the energization path of the first solenoid Sa should be detected (ie, a timing at which the Sa abnormality detection processing should be performed).

The reason why the Sa abnormality detection execution flag is reset in S5 is as follows. That is, even if the Sa abnormality detection time has already been set in the timer circuit 10, if the Sa output interrupt process is newly activated before the Sa abnormality detection time arrives, the Sa abnormality detection time Is calculated again. Then, the new Sa abnormality detection time is set in the timer circuit 10 (at S130 to be described later), and the old Sa abnormality detection time is deleted.

After S5, next, the Sa control signal becomes "High".
And "Low" (S10). Here, when the Sa control signal is “High”, it is determined that “short-circuit abnormality detection” is to be performed as the abnormality detection of the first solenoid Sa, and the Sa abnormality detection time for performing the short-circuit abnormality detection is calculated. At the same time as (S20), "1 (High)" is set to the Sa detection signal flag (S30).

That is, in S20, the count value Tcnt of the timer circuit 10 is set so that the interrupt signal is output from the timer circuit 10 at the timing when the short-circuit abnormality detection should be performed (Sa abnormality detection time). The power value is calculated. The storage unit 9 of the control circuit 6 stores each solenoid S
For each of a and Sb, "data indicating how much delay (short-circuit detection time) is to be performed from the rise of the control signal to detect a short-circuit abnormality" is stored, and the CPU 8 determines a timer circuit based on the data. A value to be set as the count value Tcnt of 10 is calculated. The first solenoid Sa
Is referred to as “Sa short detection time”, and the short detection time corresponding to the second solenoid Sb is referred to as “S short detection time”.
b Short-circuit detection time. "

The Sa detection signal flag is a flag for indicating (or storing) the state of the Sa control signal at the time when the Sa abnormality detection time is calculated. When the Sa detection signal is "High", "1" is set. (High) "
When the Sa detection signal is "Low", "0 (Low)" is set.

On the other hand, in S10, the Sa control signal becomes "Low".
, It is determined that “disconnection abnormality detection” is to be performed as the abnormality detection of the first solenoid Sa, and the Sa abnormality detection time for detecting the disconnection abnormality is calculated (S4).
At the same time, the Sa detection signal flag is set to "0" (S50).

That is, in S40, a value to be set as the count value Tcnt of the timer circuit 10 is calculated so that the interrupt signal is output from the timer circuit 10 at the timing when the disconnection abnormality is to be detected (Sa abnormality detection time). It is. In the storage unit 9 of the control circuit 6, for each of the solenoids Sa and Sb,
"Data indicating how much delay (disconnection detection time) from the fall of the control signal for disconnection abnormality detection"
Is stored, and the CPU 8 calculates a value to be set as the count value Tcnt of the timer circuit 10 based on the data. The disconnection detection time corresponding to the first solenoid Sa is referred to as “Sa disconnection detection time”, and the disconnection detection time corresponding to the second solenoid Sb is referred to as “Sb disconnection detection time”. In addition, the time when the Sa abnormality is detected is determined by the timer circuit 10.
The value set as the count value Tcnt is described as “TcntSa”, and the Sb abnormality detection time is set in the timer circuit 10.
The value to be set as the count value Tcnt is set as “TcntSb”.

In other words, in the processing of S10 to S50, "short-circuit abnormality" is detected in accordance with a control signal for driving the inductive load as abnormality detection of the current path of the inductive load.
Then, it is determined which of "wire disconnection abnormality" is to be detected, and the timing (error detection time) at which the abnormality should be detected is determined.

Thereafter, it is determined whether the Sb abnormality detection execution flag is "0" or "1" (S6).
0). The Sb abnormality detection execution flag is a state in which the Sb abnormality detection time is set in the timer circuit 10 and reserved to execute the Sb abnormality detection process (described later) at the Sb abnormality detection time (at this time, The flag value is "1")
Is a flag that indicates The Sb abnormality detection time is a timing at which an abnormality in the energization path of the second solenoid Sb should be detected (a timing at which the Sb abnormality detection processing should be executed).

That is, when the Sb abnormality detection execution flag is “0”, it can be determined that the Sb abnormality detection time is not set in the timer circuit 10. Therefore, when it is determined in S60 that the Sb abnormality detection execution flag is “0”, the process proceeds to S130, and the value TcntSa calculated in S20 or S40 is set as the count value Tcnt of the timer circuit 10. .

After the Sa abnormality detection time is set in the timer circuit 10 (S130), the process goes to S140, S150, S160, and S160 to terminate the Sa output interrupt processing and return to the main routine. That is, first, in S140, the Sa abnormality detection execution flag is set to “1”, and the Sa abnormality detection standby flag is set to “0”. The Sa abnormality detection standby flag is a flag indicating that the state of “setting the Sa abnormality detection time in the timer circuit 10 (that is, reservation of the Sa abnormality detection process)” is on hold. S130 above
Since the Sa abnormality detection time is set in the timer circuit 10 in step S140, the Sa abnormality detection standby flag is reset in S140.

In S150, "1" is set to the interrupt permission flag, and the activation of the interrupt process (TCNT overflow interrupt process) by the interrupt signal from the timer circuit 10 is permitted. The interrupt permission flag is a flag indicating whether or not an interrupt process by an interrupt signal from the timer circuit 10 is permitted (in this case, “1”).

At S160, the timer interrupt flag is set to "0". The timer interrupt flag is used to indicate whether or not an interrupt signal has been input from the timer circuit 10, and is automatically set when an interrupt signal is input from the timer circuit 10 to the CPU 8. Is the flag to be used. When the timer interrupt flag changes from “0” to “1”, the CPU 8 recognizes that an interrupt signal has been input from the timer circuit 10. That is, since the Sa abnormality detection time is set in the timer circuit 10 in S130, the timer interrupt flag is reset in S160 in order to wait for an interrupt signal to be input from the timer circuit 10 at the set time. -ing

If it is determined in S60 that the Sb abnormality detection execution flag is "1", the flow shifts to S70, where the value of the count value Tnct of the timer circuit 10 and "$ 800"
By comparing with “0”, it is determined whether the abnormality detection time for the second solenoid Sb has passed.

That is, in the configuration of this embodiment, the count value Tcnt changes from “$ 8000” to “$ FFFF” and “$ FFFF”.
0000 ”is the above“ short circuit detection time ”
And the value set as the count value Tcnt by the CPU 8 is always “$ 8
000 "or more. That is, in the timer circuit 10, a value smaller than "$ 8000" is not set as the count value Tcnt.

Therefore, the Sb abnormality detection execution flag is "1" (S60: "1"), and the timer circuit 1
When the count value Tcnt of 0 <“$ 8000” (S7
0: YES), it can be seen that the Sb abnormality detection time has already passed at this time. Then, in this case, the S
It is necessary to immediately terminate the output interrupt processing and immediately detect the abnormality of the second solenoid Sb.

Therefore, in S70, the timer circuit 10
Is determined to be smaller than "$ 8000", it is determined that the setting of the Sa abnormality detection time in the timer circuit 10 is to be suspended, and the process proceeds to S170.
After setting the Sa abnormality detection waiting flag to “1”, the Sa output interrupt processing is temporarily ended. This makes it possible to quickly activate a TCNT overflow interrupt process described later.

Returning to S70, the description will be continued. on the other hand,
If the count value Tcnt of the timer circuit 10 is equal to or larger than "$ 8000" (S70: NO), it is understood that the Sb abnormality detection time has not yet passed at the present time (the execution time of S70). However, if the Sb abnormality detection time arrives in a very near future (for example, within 10 μs),
It is necessary to immediately terminate the output interrupt processing and immediately detect the abnormality of the second solenoid Sb.

Therefore, the count value Tcnt of the timer circuit 10
If ≧ “$ 8000” (S70: NO),
Further, in S80, the value obtained by adding the predetermined value α to the count value Tcnt (that is, Tcnt + α) is “$ 10000 (= $ FF)
FF + $ 0001) ”is determined.
This α is a value by which the count value Tcnt of the timer circuit 10 increases during a predetermined time (10 μs in this embodiment).
That is, in S80, it is determined whether or not the Sb abnormality detection time has arrived within a predetermined time (10 μs) predetermined from the present time.

If it is determined that the Sb abnormality detection time has come within the predetermined time (that is, the count value Tcnt + α ≧ ＄ 10000) (S80: YES), the flow shifts to S170, where the Sa abnormality detection standby flag is set. After setting “1”, the Sa output interrupt processing is temporarily ended.

On the other hand, the count value Tcnt + α <$ 10000
(S80: NO), it can be understood that the Sb abnormality detection time does not arrive so early. Therefore, in this case, it is determined which of the abnormality detection times of the first solenoid Sa and the second solenoid Sb (that is, the Sa abnormality detection time and the Sb abnormality detection time) comes first. (S90). This determination is based on the count value Tcnt of the timer circuit 10 at the present time.
And the value TcntSa calculated in S20 or S40 to set the Sa abnormality detection time. Specifically, when the value Tcnt at the present time is larger (Tcnt> TcntSa), it is determined that the Sb abnormality detection time is earlier (S90: YES), and the value calculated in S20 or 40 is larger. When it is large (Tcnt ≦ TcntSa),
It is determined that the Sa abnormality detection time is earlier (S90: N
O)

If the Sa abnormality detection time is earlier (S90: NO), S100 is set in order to set the Sa abnormality detection time in place of the Sb abnormality detection time currently set in the timer circuit 10. And 110, the above S1
Move to 30. First, in S100, the Sb abnormality detection execution flag is set to “0”, and the Sb abnormality detection standby flag is set to “1”. The Sb abnormality detection standby flag is a state in which “setting of Sb abnormality detection time in the timer circuit 10 (that is, reservation of Sb abnormality detection processing)” is suspended (at this time, the flag is “1”). It is a flag to indicate.

In S110, a value TcntSb to be set as the count value Tcnt is calculated in order to set the Sb abnormality detection time in the timer circuit 10. That is,
As described later (FIG. 3: S270), the Sb abnormality detection time is
After the abnormality detection (Sa abnormality detection processing) for the first solenoid Sa, the timer T is set in the timer circuit 10. At that time, a value TcntSb to be set as the count value Tcnt of the timer circuit 10 is calculated again. (Specifically, the current count value Tcnt and S20
Or, it is calculated based on the value TcntSa calculated in 40).

On the other hand, if the Sb abnormality detection time is earlier (S90: YES), the process goes through S120 to S17.
Move to 0. In S120, the count value Tc is set in order to set the Sa abnormality detection time in the timer circuit 10.
Calculate the value TcntSa to be set as nt. That is, as described later (FIG. 3: S370), the Sa abnormality detection time is determined by the abnormality detection of the second solenoid Sb (Sb abnormality detection processing).
After that, the value TcntSa to be set as the count value Tcnt of the timer circuit 10 is recalculated at that time (specifically,
Count value Tcnt at present and S20 or S40
Is calculated based on the value TcntSa calculated in (2).

As described above, the Sa output interrupt processing is
It is started at each switching timing of the control signal (Sa control signal) corresponding to the first solenoid Sa (that is, at each timing of changing the signal level), but is output to the drive circuit 4b provided in the energization path of the second solenoid Sb. Also at each switching timing of the control signal (Sb control signal), the same process as the Sa output interrupt process (Sb output interrupt process) is performed.

The Sb output interruption process is a process in which the first solenoid Sa and the second solenoid Sb are replaced in the Sa output interruption process. That is, the Sb output interrupt processing is
In the Sa output interruption processing, the Sa control signal⇔Sb control signal, the Sa abnormality detection time⇔Sb abnormality detection time, the Sa abnormality detection execution flag⇔Sb abnormality detection execution flag, the Sa abnormality detection standby flag⇔Sb abnormality detection standby flag, the Sa This is easily explained by exchanging "Sa" and "Sb", such as "detection signal flag @ Sb detection signal flag". Therefore, regarding the Sb output interrupt processing,
Illustration and explanation of the flowchart are omitted.

Here, the correspondence with the claims in relation to the Sa (Sb) output interrupt processing of FIG. 2 is summarized as follows. First, a process (S10, S30, S50) of detecting a Sa (Sb) control signal and taking an operation corresponding thereto is performed.
It functions as "abnormality detecting means". In addition, Sa (S
b) Process for operating (set / reset) the abnormality detection execution flag and the value of these flags (S5, S100, S
140) function as “detection target storage means”. Further, the processing (S60) of referring to the Sa (Sb) abnormality detection execution flag functions as a "setting state determination means",
a (Sb) The process of setting the abnormality detection time in the timer circuit 10 (S130) and the process of calculating the value to be set as the counter value (S20, S40, S110, S120)
Function as “timer setting means”.

The processing of S70, S80 and S90 is
Processes (sets / resets) that function as "arbitration means" and operate (set / reset) the Sa (Sb) abnormality detection standby flag and the values of these flags.
0) functions as a “holding target storage unit”.

Next, FIG. 3 shows that when an overflow occurs in the timer circuit 10 and an interrupt signal is input from the timer circuit 10 to the CPU 8 (that is, the timer interrupt flag is changed from "0" to "0"). TCN activated when it changes to "1"
It is a flowchart which shows T overflow interrupt processing. It should be noted that, even if an interrupt signal is input from the timer circuit 10, if another process (for example, the Sa output interrupt process or the Sb output interrupt process) is being executed, Triggered after its execution has finished. This process is started when the interrupt permission flag is “1”,
If it is "0", it will not be started.

As shown in FIG. 3, when the TCNT overflow interrupt processing is started, it is first determined in S210 whether or not the Sa abnormality detection execution flag is "1". S
a When the abnormality detection execution flag is "1" (S210:
YES), it is determined that the TCNT overflow interrupt processing has been started by the interrupt signal at the Sa abnormality detection time, so the process proceeds to S230 to determine whether the first solenoid Sa has an abnormality. Sa
An abnormality detection process (described later with reference to FIG. 4) is executed.

On the other hand, if the Sa abnormality detection execution flag is not "1" (S210: NO), the flow shifts to S220 to determine whether the Sb abnormality detection execution flag is "1". If the Sb abnormality detection execution flag is “1” (S220: YES), it is determined that the TCNT overflow interrupt processing has been started by the interrupt signal at the Sb abnormality detection time, and thus S33
The process proceeds to 0, and an Sb abnormality detection process for determining whether or not the second solenoid Sb has an abnormality is executed.

If the Sb abnormality detection execution flag is not "1" (S220: NO), the TCNT overflow interrupt processing is started by the interruption signal at the Sa abnormality detection time or the Sb abnormality detection time. I understand that it is not. Therefore, in this case (S220: NO), the process proceeds to S320 to reset the interrupt permission flag, and then temporarily ends the TCNT overflow interrupt process.

That is, in S210 and S220, the “TC
NT overflow interrupt processing has been started to perform abnormality detection for which solenoid "
The operator selects whether to perform the Sa abnormality detection processing, the Sb abnormality detection processing, or not to perform abnormality detection for any of the solenoids.

Now, in S230, the Sa abnormality detection processing is started, and this processing will be described with reference to FIG.
This Sa abnormality detection processing functions as a part of the “abnormality detection means” in the claims. When this processing is started, first, in S510, the current signal level of the Sa output signal is “High”. Or “Low”. Here, if the Sa control signal is “High”,
Proceeds to S520, where the Sa detection signal flag is “1 (High)”
It is determined whether or not the Sa control signal and the Sa detection signal flag correspond to each other by determining whether or not.

The Sa detection signal flag is determined when the Sa abnormality detection time is calculated (that is, immediately after the signal level of the Sa control signal changes) as described in the above description of FIG. 2 (S30 or S50). In step S520, the state of the Sa detection signal flag is “1”.
(High), the Sa abnormality detection processing is immediately terminated.

That is, the Sa detection signal flag = “0 (Low)
)), When the Sa control signal is "High" at the time of S510, it is considered that the Sa control signal has just changed further, and the driving state of the first solenoid Sa is accurately Sa. It is unknown whether it is reflected in the monitor signal. In such a case, since the level of the Sa control signal and the level of the Sa monitor signal cannot be correctly compared, the erroneous determination is prevented by immediately terminating the Sa abnormality detection processing. It is.

On the other hand, the Sa detection signal flag = “1 (Hig
h) ”(S520: YES), S530
Thereafter (especially in steps S540, 550, and 560), abnormality detection (that is, short-circuit abnormality detection) when the Sa control signal is “High” is performed. That is, the process first proceeds to S530, and determines whether the Sa abnormality detection inhibition flag is “1”. The Sa abnormality detection prohibition flag is a flag indicating that abnormality detection of the energization path of the first solenoid Sa is prohibited (at this time, “1”). If the Sa abnormality detection inhibition flag is "1" (S
530: YES), the Sa abnormality detection process is immediately terminated, but if the Sa abnormality detection prohibition flag is not “1” (S530: NO), the process proceeds to S540.

At S540, it is determined whether the signal level of the Sa monitor signal is "High" or "Low". If the Sa monitor signal is "High", it means that the signal level of the Sa control signal and the signal level of the Sa monitor signal match, so it is determined that "the energization path of the first solenoid Sa is normal". In step S550, the Sa abnormality flag is reset (set to “0”). On the other hand, when the Sa monitor signal is “Low”
"Means that the signal level of the Sa control signal does not match the signal level of the Sa monitor signal.
It is determined that "there is an abnormality in the energization path of the first solenoid Sa", and the Sa abnormality flag is set to "1" in S560. The Sa abnormality flag is a flag for storing a result of abnormality detection regarding the energization path of the first solenoid Sa.

After the processing of S550 or 560, the process proceeds to S570. In S570, it is determined again whether the Sa control signal is “High” or “Low”,
It is determined whether the Sa control signal has changed from “High” to “Low” during a period from 510 to S570. Here, when the Sa control signal is “High” (S5
In 70), since it is considered that the Sa control signal has not changed, it is considered that the abnormality detection in S550 or 560 was correctly performed.

Therefore, in this case, the Sa abnormality detection processing is ended via S580. In S580, by setting the Sa abnormality detection prohibition flag to “1”, the first
The abnormality detection for the energization path of the solenoid Sa is prohibited (that is, the result of the abnormality detection is determined).

On the other hand, if the Sa control signal is "Low" (S570), the Sa abnormality detection processing is immediately terminated. That is, if the Sa control signal changes from “High” to “Low” during the period from S510 to S570, is the drive state of the first solenoid Sa correctly reflected in the Sa monitor signal? Since it is not clear whether or not it is unknown, the Sa abnormality detection process is temporarily terminated without finalizing the result of the abnormality detection in S540 to S560.

As will be described later with reference to FIG. 5, the abnormality detection apparatus of the present embodiment statistically processes the results of the abnormality detection (for example, accumulates the frequency of determining that an abnormality has occurred, etc.) In accordance with the result of the process, a necessary operation (fail-safe operation or the like) required at the time of abnormality is configured. However, this statistical process is performed only when the Sa abnormality detection inhibition flag is “1”. (See FIG. 5). S57
If it is determined at 0 that the Sa control signal has changed from "High" to "Low", "1" is not set to the Sa abnormality detection prohibition flag (S580 is not performed). The results of the abnormality detection in steps S560 to S560 are not reflected in the statistical processing.

Returning to S510, if the Sa control signal is "Low", the process proceeds to S620, where it is determined whether or not the Sa detection signal flag is "0 (Low)". It is determined whether the Sa detection signal flag correctly corresponds to the flag. If the Sa detection signal flag is not "0 (Low)" (S620: N
In O), the Sa abnormality detection processing ends immediately.

That is, the Sa detection signal flag = “1 (Hig
h), when the Sa control signal is "Low" at the time of S510, it is considered immediately after the Sa control signal is switched, and the driving state of the first solenoid Sa is accurately determined. It is unknown whether it is reflected in the monitor signal. In such a case, even if the level of the Sa control signal and the level of the Sa monitor signal are compared, accurate abnormality determination cannot be performed. The decision is prevented.

On the other hand, the Sa detection signal flag = “0 (Low)
) "(S620: YES), S630
From then on (especially S640, 650, 660), abnormality detection (that is, disconnection abnormality detection) when the Sa control signal is "Low" is performed. That is, the flow shifts to S630, where it is determined whether or not the Sa abnormality detection prohibition flag is “1”. If it is “1” (S630: YES), the Sa abnormality detection processing is immediately terminated. On the other hand, if the Sa abnormality detection inhibition flag is not “1” (S630: NO), S6
Move to 40.

In S640, the Sa monitor signal is "High"
Or “Low”. If the Sa monitor signal is "Low", it means that the signal level of the Sa control signal matches the signal level of the Sa monitor signal, so it is determined that "the energization path of the first solenoid Sa is normal". , S65
At 0, the Sa abnormality flag is reset ("0" is set).
On the other hand, if the Sa monitor signal is “High”, it means that the signal level of the Sa control signal and the signal level of the Sa monitor signal do not match, so that “there is an abnormality in the energization path of the first solenoid Sa”. In S660, the Sa abnormality flag is set to "1".

After the processing of S650 or S660,
Next, the process proceeds to S670. In S670, whether the Sa control signal has changed from "Low" to "High" between S610 and S670 is determined again by determining whether the Sa control signal is "High" or "Low". Judge. Here, when the Sa control signal is “Low” (S670), it is considered that the Sa control signal has not changed, and that the abnormality detection in S650 or S660 has been correctly performed. Therefore, in this case, S6
After 80, the Sa abnormality detection processing ends. S680
Is the same as the processing in S580, and a description thereof will be omitted.

On the other hand, when the Sa control signal is "High" (S670), the Sa abnormality detection processing is immediately terminated. That is, if the Sa control signal changes from "Low" to "High" during the period from S610 to S670, is the drive state of the first solenoid Sa correctly reflected in the Sa monitor signal? Since it is unclear whether the result of the abnormality detection in S640 to S660 is finalized, the Sa abnormality detection process is temporarily terminated.

Returning to FIG. 3, the description will be continued. The Sa abnormality detection process started in S230 is as described above, but the Sb abnormality detection process started in S330 is Sa
This is a process in which the processing target in the abnormality detection process is replaced by the first solenoid Sa to the second solenoid Sb. That is,
The Sb abnormality detection process is performed in the Sa abnormality detection process.
Control signal ⇒ Sb control signal, Sa abnormality detection prohibition flag ⇒ S
b. Abnormality detection prohibition flag, Sa detection signal flag ⇒ Sb detection signal flag, Sa monitor signal ⇒ Sb monitor signal, Sa abnormality flag ⇒ Sb abnormality flag, which is easily explained by replacing “Sa” with “Sb”. Things. Therefore, the illustration and description of the flowchart of the Sb abnormality detection processing will be omitted. In addition,
The Sb abnormality detection process also functions as a part of the “abnormality detection unit” in the claims.

When the Sa abnormality detection process started in S230 is completed, the Sa abnormality detection execution flag is reset accordingly (S240), and it is determined whether the Sb abnormality detection standby flag is "1". (S250). Sb
If the abnormality detection standby flag is not "1" (S25
0: NO), resets the interrupt permission flag in S320, and ends the TCNT overflow interrupt process. On the other hand, if the Sb abnormality detection standby flag is “1” (S250: YES), it can be determined that the setting of the Sb abnormality detection time in the timer circuit 10 is in a suspended state. After resetting the detection standby flag, the process proceeds to S260.

In S260, it is determined whether the Sb abnormality detection time has already passed at the present time. This is determined as follows. That is, since the Sb abnormality detection standby flag = “1”, the value TcntSb to be set as the count value Tcnt of the timer circuit 10 for performing the Sb abnormality detection process should have been calculated. The value TcntSb indicates the Sb abnormality detection time.
Also, the count value Tcnt of the timer circuit 10 at the present time is
At the start of the Sa abnormality detection process in S230 (specifically, at the start of the TCNT overflow interrupt process)
It shows how much time has passed since Therefore, whether the Sb abnormality detection time has already passed can be determined from the current count value Tcnt and the value TcntSb.

If it is determined in S260 that the Sb abnormality detection time has not passed yet (NO), the above value TcntSb is set as the count value Tcnt of the timer circuit 10, whereby the Sb abnormality detection time is set. Is set in the timer circuit 10 (S270). Then, the Sb abnormality detection execution flag is set to "1" (S280), and the interrupt permission flag is set to "1" to permit the activation of the next TCNT overflow interrupt processing (S280).
290) Thereafter, the TCNT overflow interrupt processing ends.

On the other hand, if it is determined in S260 that the Sb abnormality detection time has already passed (YES), the same Sb abnormality detection processing as described above is immediately started (S30).
0). When the Sb abnormality detection process ends, the Sb abnormality detection execution flag is reset (S310), and
After resetting the interrupt permission flag (S320), the T
The CNT overflow interrupt processing ends.

Next, the processing after the Sb abnormality detection processing in S330 will be described. When the Sb abnormality detection process started in S330 ends, the Sb abnormality detection execution flag is reset accordingly (S340), and it is determined whether the Sa abnormality detection standby flag is “1” (S350).

If the Sa abnormality detection standby flag is not "1" (S350: NO), the TCNT overflow interrupt processing is terminated after resetting the interrupt permission flag in S320. If it is "1" (S350: YES), it can be determined that the setting of the Sa abnormality detection time in the timer circuit 10 is in a suspended state, so that after resetting the Sa abnormality detection standby flag in S355, The process moves to S360.

Then, in S360, it is determined whether or not the Sa abnormality detection time has already passed. This is determined as follows. That is, since the Sa abnormality detection standby flag is “1”, the value TcntSa to be set as the count value Tcnt of the timer circuit 10 for performing the Sa abnormality detection process should have been calculated. This value TcntSa indicates the Sa abnormality detection time. Also, the count value Tcnt of the timer circuit 10 at the present time is
At the start of the Sb abnormality detection process in S330 (specifically, at the start of the TCNT overflow interrupt process)
It shows how much time has passed since Therefore, whether or not the Sa abnormality detection time has already passed can be determined from the current count value Tcnt and value TcntSa.

In S360, if it is determined that the Sa abnormality detection time has not yet passed (NO), the value TcntSa is set as the count value Tcnt of the timer circuit 10 to determine the Sa abnormality detection time. Is set in the timer circuit 10 (S370). Then, "1" is set to the Sa abnormality detection execution flag (S380), and "1" is set to the interrupt permission flag, thereby permitting activation of the next TCNT overflow interrupt processing (S380).
290) Thereafter, the TCNT overflow interrupt processing ends.

On the other hand, if it is determined in S360 that the Sa abnormality detection time has already passed (YES), the same Sa abnormality detection processing as described above is immediately started (S40).
0). Then, when the Sa abnormality detection processing is completed, the Sa abnormality detection execution flag is reset (S410), the interrupt permission flag is reset (S320), and then the TCN is reset.
The T overflow interrupt processing ends.

The correspondence between the TCNT overflow interrupt processing shown in FIG. 3 and the claims is summarized as follows. First, S210, S220, S260, S36
The process of 0 functions as “abnormality detection control means”. S
240, S340, S280, S310, S380, S
The process of 410 functions as “detection target storage means”,
The processing of S255 and S355 functions as a “holding target storage unit”. Also, the processing of S270 and S370 is
Functions as "timer setting means".

Next, FIG. 5 shows the state at a predetermined time interval (for example, 20 ms).
9 is a flowchart showing a Sa detection result handling process performed every time). This Sa detection result handling process is a process for performing an operation in accordance with the abnormality detection result (ie, the value of the Sa abnormality flag) for the energization path of the first solenoid Sa.
Note that, even if an interrupt signal from the timer circuit 10 is input, this process performs another process (for example, Sa output interrupt process, S
If the b output interrupt processing, the TCNT overflow interrupt processing, etc.) are being executed, the processing is started after the execution ends.

When the processing for responding to the Sa detection result is started, as shown in FIG. 5, it is first determined in S710 whether or not the Sa abnormality detection inhibition flag is "1". Sa
If the abnormality detection prohibition flag is not “1” (NO),
It is determined that the abnormality detection for the energization path of the first solenoid Sa has not been performed yet, and the processing for dealing with the Sa detection result is immediately terminated.

On the other hand, if the Sa abnormality detection prohibition flag is "1" (YES), it is determined that abnormality has been detected in the energization path of the first solenoid Sa, and the S abnormality flag = "1" in S720. Is determined.
Then, according to the determination result, S730 and S740
Is performed, and in step S750, the Sa abnormality detection prohibition flag is reset, and then the Sa detection result handling process ends.

That is, if the Sa abnormality flag is not "1" (S720: NO), the normal Sa processing is executed in S730, and if the Sa abnormality flag is "1", the Sa abnormal processing is performed in S740. Execute The Sa abnormality processing is performed by accumulating the number of activations of the own device, thereby obtaining the Sa abnormality flag =
This is a process of calculating the number NfSa of abnormalities determined to be “1” and performing a fail-safe operation or the like when the number NfSa of abnormalities exceeds a predetermined value. The normal-time process is a process for calculating the number of normality determination NtSa every time the computer is started, and canceling the fail-safe operation when the number of normality determination NtSa exceeds a predetermined value.

As described above, the process for handling the Sa detection result is a process that is performed with respect to the result of detecting an abnormality in the energization path of the first solenoid Sa.
Regarding the abnormality detection result for the energization path b,
The same process as the detection result handling process (Sb detection result handling process) is performed. The Sb detection result handling process is the first solenoid Sa in the Sa detection result handling process.
Is replaced with the second solenoid Sb. In other words, the Sb detection result handling process is performed by replacing “Sa” with “Sb” in the Sa detection result handling process, such as a Sa abnormality detection inhibition flag → Sb abnormality detection inhibition flag and a Sa abnormality flag → Sb abnormality flag. It is easily explained. Therefore, the illustration and description of the flowchart of the Sb detection result handling process are omitted.

As described above, the CPU 8 of the inductive load driving device according to the present embodiment executes the above-described processing (described with reference to FIGS. 2 to 5) in order to detect an abnormality in the energization path of the solenoid. However, an operation example of abnormality detection realized by these processes will be described with reference to a timing chart of FIG.

First, at time t1, the Sb control signal goes high.
, The Sb output interrupt process is started, and after this time, after the Sb short circuit detection time (ie, Sb abnormality detection time t3)
The count value Tcnt of the timer circuit 10 is set so that the Sb abnormality detection process is performed in the following manner. Then, at time t2, Sa
When the control signal changes to “High”, the timer circuit 10 is set to perform the Sa abnormality detection processing after the Sa short detection time (ie, the Sa abnormality detection time t5) from this point.
The Sa output interrupt process is started.

However, in this case, the Sb abnormality detection time t3 has already been set in the timer circuit 10, and the Sb abnormality detection time t3 is earlier than the Sa abnormality detection time t5. Therefore, the Sa abnormality detection time t5 is equal to the current time t5.
In 2, the setting for the timer circuit 10 is suspended.
Then, in the TCNT overflow interrupt process started at time t3, it is set after the end of the Sb abnormality detection process (time t4). After that, at time t5
Then, at time t6, Sb abnormality detection processing is performed.
When the control signal changes to "Low", the Sb output interrupt processing is started, and after this time, the Sb disconnection detection time (ie, Sb
The count value Tcnt of the timer circuit 10 is set so that the Sb abnormality detection processing is performed at the abnormality detection time t10). When the Sa control signal changes to "Low" at time t7, the Sa circuit is set so that the Sa abnormality detection process is performed after the Sa disconnection detection time (ie, Sa abnormality detection time t8) from this point. Output interrupt processing is started.

In this case, the Sb abnormality detection time t10 is already set in the timer circuit 10, but the Sb abnormality detection time t10 is later than the Sa abnormality detection time at time t8. Therefore, at the current time t7, the Sa abnormality detection time t
8 is set in the timer circuit 10 and the Sb abnormality detection time t
In 10, the setting for the timer circuit 10 is suspended. Then, the Sb abnormality detection time t10 is set after the end of the Sa abnormality detection processing in the TCNT overflow interrupt processing started at time t7 (time t9). After that, at time t10, an Sb abnormality detection process is performed.

When the Sb control signal changes to "High" again at time t11, the Sb output interrupt process is started, and
The count value Tcnt of the timer circuit 10 is set so that the Sb abnormality detection process is performed after the Sb short-circuit detection time (ie, Sb abnormality detection time t12) from this point. As a result, at time t12, the TCNT overflow interrupt process is started, and the Sb abnormality detection process is started therein.

Then, as shown in FIG. 6, even if the Sa control signal changes during execution of the TCNT overflow interrupt processing (t13), the Sa output interrupt processing is not activated. In this case, the Sa output interrupt processing is started after the end of the TCNT overflow interrupt processing (t14), and at this time t14
After the Sa short detection time (that is, the Sa abnormality detection time t1)
In order to perform the Sa abnormality detection process in 5), the timer circuit 1
A count value Tcnt of 0 is set. And as a result,
At time t15, the Sa abnormality detection processing is performed. In the Sa abnormality detection process at time t15, since the Sa monitor signal is "Low" despite the Sa control signal being "High", it is determined that the first solenoid Sa is abnormal. Will be done.

According to the abnormality detecting device for the inductive load driving device of the present embodiment, which is constructed and operated as described above, the following effects can be obtained. (1) When the abnormality detection time is set in the timer circuit 10,
Which of the energization paths is the abnormality detection time is determined by Sa
(Sb) The data is stored using the abnormality detection execution flag (S140). Then, one energization path corresponding to the control signal whose signal level has changed (the first solenoid Sa in FIG. 2).
In order to set the abnormality detection time of the current path (the current path of the second solenoid Sb in FIG. 2), the Sa (Sb) abnormality detection execution flag is first referred to. It is determined whether an abnormality detection time has not been set (S60). Then, when the abnormality detection time of the other energization path is not set, the abnormality detection time of the one energization path is set in this timer circuit 10. Therefore, when performing abnormality detection on a plurality of energized paths, it is possible to set the abnormality detection times of the mutually different energized paths in the common timer circuit 10. That is, it is possible to reduce the number of timer circuits required for detecting an abnormality in a plurality of energized paths as compared with the conventional case, and it is possible to suppress the cost required for the abnormality detection.

(2) When trying to set the abnormality detection time of one energization path corresponding to the control signal whose signal level has changed to the timer circuit, the abnormality detection time of the other energization path is set. However, depending on the order of the abnormality detection time of one energization path and the abnormality detection time of another energization path,
The timer circuit 10 is set to set the earlier abnormality detection time first, and after the abnormality detection at the earlier abnormality detection time, the later abnormality detection time is set. Therefore, the abnormality detection time of the one energization path can be set in the timer circuit 10, and the abnormality detection of the one energization path can be reliably performed. Further, even if the abnormality detection time of one energization path is earlier or later than the abnormality detection time of the other energization path, abnormality detection of both energization paths is performed at appropriate timing. be able to.

(3) Comparison judgment for comparing the abnormality detection time of one energization path with the abnormality detection time of another energization path (S9)
Before performing (0), it is determined whether the abnormality detection time of another energization path has already passed at the present time (S70) or whether it is within a predetermined time from the present time (S80). If the abnormality detection time of the other energization path has already passed at the present time or is within a predetermined time from the current time, it is determined that the abnormality detection time should be set in the timer means, and the control in which the signal level has changed is performed. It is determined that the setting of the abnormality detection time of the energization path corresponding to the signal to the timer means should be suspended. Therefore, if the abnormality detection time of the other energization paths has already passed at the present time or is within a predetermined time from the current time, the setting of “which abnormality detection time is suspended, Should be set as soon as the abnormality detection time can be set, and the abnormality of other energized paths can be promptly determined, for example, by omitting comparison judgment (S90) and recalculation of TcntSa (S120). A countermeasure can be taken so that processing can be shifted to detection.

(4) In order to determine whether the abnormality detection time of another energized path has already passed at the present time or within a predetermined time from the present time, first, it is determined whether “the current time has already passed (S70)”. Next, it is determined whether or not the current time is within a predetermined time (S80). Therefore, more detailed measures can be taken according to the urgency.

(5) Before setting the timer circuit 10 with the “abnormality detection time determined to be the one for which the setting to the timer circuit 10 should be suspended (Sa (Sb) abnormality detection standby flag ← 1)”, It is determined whether or not the time has already passed at the present time (S260, S360). If the time has already passed at this time, the setting of the abnormality detection time in the timer means is stopped, and the abnormality detection of the energizing path corresponding to the time is stopped. (S300, S40)
0). Therefore, even if the “abnormality detection time determined to be set in the timer circuit 10” has already passed at the end of the abnormality detection at the abnormality detection time previously set in the timer circuit 10, the abnormality detection is immediately performed. Can be started,
The delay can be suppressed.

As described above, one embodiment of the present invention has been described. However, the present invention is not limited to the above-described embodiment, and can take various forms. For example, in the above embodiment,
The inductive load has been described as driving two solenoids (the first solenoid Sa and the second solenoid Sb), but the invention is not limited to this. The present invention can be applied to a case where a plurality of inductive loads more than that are driven. That is, even if the number of inductive loads to be driven increases, if the abnormality detection execution flag and the abnormality detection standby flag as described above are defined for each inductive load, the timer circuit 10 detects an abnormality based on these flags. It will be possible to determine whether there is an energized path for which the time is set,
The energization path in which the setting of the abnormality detection time in the timer circuit 10 is suspended can be stored, and the present invention can be realized.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram illustrating an electrical configuration of an inductive load driving device according to an embodiment.

FIG. 2 is a flowchart illustrating a Sa output interrupt process.

FIG. 3 is a flowchart showing a TCNT overflow interrupt process.

FIG. 4 is a flowchart illustrating a Sa abnormality detection process.

FIG. 5 is a flowchart showing a Sa detection result handling process.

FIG. 6 is a time chart showing an example of an abnormality detection operation in the inductive load driving device.

[Explanation of symbols]

2 ... Electronic control unit (ECU), 4a, 4b ... Drive circuit,
6: control circuit, 8: CPU, 9: storage unit, 10: timer circuit, 12: battery, Sa: first solenoid, Sb ...
Second solenoid.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI theme coat ゛ (Reference) G01R 31/02 G01R 31/02 G05F 1/10 304 G05F 1/10 304A F-term (Reference) 2G014 AA02 AA03 AB28 AB49 AB51 AB57 AC18 3G084 BA13 BA15 DA31 EA07 EB03 EB11 EB22 EC06 EC08 3G301 JB04 LC01 MA11 MA18 NB12 ND17 NE23 5G053 AA02 AA07 BA04 CA01 DA01 EA01 EA03 EC02 FA05 5H410 BB04 CC02 DD02 DD05 DD01 EB37 EB37 EB37 EB37

Claims (8)

[Claims] 1. A control signal is output to switching means disposed for each of the plurality of inductive load energizing paths, and each of the energizing paths is intermittently switched by changing the signal level of each control signal. Then, in the inductive load driving device for driving each of the inductive loads, the time is settable, and when the set time is reached, timer means for outputting the fact is used, and the inductive load driving device includes the inductive loads. An abnormality detection method for performing abnormality detection of each energization path based on the energization state of each energization path and the control signal at an abnormality detection time delayed by a predetermined time from a change timing of a signal level of the control signal. Storing an energization path to be detected at the abnormality detection time set in the timer means, and a signal level of a control signal corresponding to any of the energization paths. Is changed, it is determined whether or not the abnormality detection time of another energized path is set in the timer means based on the stored content. As a result of the determination, the abnormality detection time of the other energized path is determined by the timer means. When not set to, the abnormality detection time of the energization path corresponding to the control signal whose signal level has changed is set in the timer means, and when the fact that the abnormality detection time has come is output from the timer means, A method for detecting an abnormality in an inductive load drive device, comprising: identifying an energized path to be subjected to abnormality detection based on stored contents; 2. The abnormality detection method for an inductive load driving device according to claim 1, wherein, as a result of the determination, when the abnormality detection time of the other energization path has already been set in the timer means, the signal level is reduced. Of the energized path corresponding to the changed control signal and the abnormality detected time of the other energized paths are compared to determine which is earlier. Based on the result of the comparison, the earlier abnormality is detected. The time is determined to be set in the timer means, and the later abnormality detection time is determined to be suspended in the timer, and the abnormality detection time determined to be set in the timer means is determined in accordance with the abnormality detection time. The timer means is set to a state, and after the end of the abnormality detection at the set abnormality detection time, the abnormality detection time determined to suspend the setting of the timer is transmitted to the timer means. A method for detecting an abnormality of an inductive load driving device, wherein the method is set. 3. The abnormality detection method for an inductive load driving device according to claim 2, wherein the abnormality detection time of the other energization path has already passed at the present time or a predetermined time from the present time before the comparison judgment is performed. It is determined whether or not the abnormality detection time is already passed at the present time or within a predetermined time from the current time, and it is determined that the abnormality detection time is to be set in the timer means, and the signal level is changed. An abnormality detection time of an energization path corresponding to the control signal determined to be set to be deferred to the timer means. 4. The abnormality detection method for an inductive load driving device according to claim 2, wherein the abnormality detection time determined to be suspended from being set in the timer means is set in the timer means. It is determined whether or not the abnormality detection time has already passed at the present time. If the abnormality detection time has passed at this time, the setting of the abnormality detection time in the timer means is stopped, and the abnormality detection time is set. A method for detecting an abnormality in an inductive load driving device, wherein the method detects an abnormality in a current supply path. 5. A control signal is output to switching means arranged for each of the plurality of inductive load energizing paths, and each of the energizing paths is intermittently changed by changing the signal level of each control signal. The inductive load driving device that drives each of the inductive loads is configured to be capable of detecting an energized state of each energizing path including the inductive load, and the detected energized state and the control signal are provided. Abnormality detecting means for detecting an abnormality in each of the energizing paths, and performing abnormality detection by the abnormality detecting means at an abnormality detection time delayed by a predetermined time from a change timing of a signal level of the control signal. Therefore, the abnormality detection time is configured to be settable, and when the set abnormality detection time is reached, a timer means is output to that effect, and the timer means is provided with an abnormality detection time of a predetermined energization path. A timer setting means for determining the abnormality detection time, and an abnormality detection control means for causing the abnormality detection means to detect an abnormality in a predetermined energization path when the timer means outputs an abnormality detection time. A detection device, wherein when an abnormality detection time is set in the timer unit, a detection target storage unit that stores an energization path that is a target of abnormality detection to be performed at the set abnormality detection time; When the signal level of the control signal corresponding to the energized path changes, the setting state for determining whether or not the abnormality detection time of another energized path is set in the timer means by referring to the storage content of the detection target storage means. The timer setting means determines when the abnormality detection time of the other energization path is not set in the timer means as a result of the determination by the setting state determining means. An abnormality detection time of the energization path corresponding to the control signal whose signal level has changed is set in the timer means, and the abnormality detection control means outputs the abnormality detection time from the timer means, An abnormality detection device for an inductive load drive device, characterized in that an abnormality detection target to be performed by the abnormality detection unit is specified by referring to storage contents of a detection target storage unit. 6. The abnormality detecting device for an inductive load driving device according to claim 5, wherein as a result of the determination by the setting state determining means, an abnormality detection time of the other energization path is set in the timer means. Which determines which of the abnormality detection time of the energization path corresponding to the control signal whose signal level has changed and the abnormality detection time of the other energization path is earlier, and according to the result of the comparison judgment, Arbitration means for determining that one of the abnormality detection times should be set in the timer means, and deciding that the later abnormality detection time should be set to suspend the timer; and Storage means for storing an energization path corresponding to the abnormality detection time determined to be suspended in the setting of the timer. The abnormality detection time determined to be set in the means is set to the state set in the timer means, and is stored in the suspension target storage means after the abnormality detection by the abnormality detection means at the set abnormality detection time is completed. An abnormality detection device for an inductive load driving device, wherein the abnormality detection time of the energized path is set in the timer means. 7. The abnormality detection device for an inductive load driving device according to claim 6, wherein the arbitration unit determines whether the abnormality detection time of the other energization path has already passed at the present time before performing the comparison determination. Or, it is determined whether it is within a predetermined time from the present time, and when the abnormality detection time has already passed at the present time or within a predetermined time from the present time, it is determined that the abnormality detection time should be set in the timer means, An abnormality detection device for an inductive load driving device, wherein an abnormality detection time of an energization path corresponding to a control signal having a changed signal level is determined to be set to suspend the setting of the timer means. 8. The abnormality detection device for an inductive load drive device according to claim 6, wherein the abnormality detection control unit sets the abnormality detection time of the energization path stored in the suspension target storage unit to the timer setting. Before setting the timer means by the means, it is determined whether or not the abnormality detection time has already passed at the present time, and when the abnormality detection time has passed at the present time, the timer setting means sends a signal to the timer means. An abnormality detection device for an inductive load drive device, wherein setting of the abnormality detection time is prohibited, and the abnormality detection means is caused to execute abnormality detection of the conduction path.