JP2009089072A - Control device for electromagnetic load device - Google Patents

Abstract

A control device for an electromagnetic load device capable of detecting an abnormality (disconnection or short circuit) of the electromagnetic load device with high accuracy.
An electric circuit (driving circuit 108) for driving an electromagnetic load device (linear solenoid 1), means for setting a target current value to be passed through the electric circuit (target current value setting unit 101), and the electric circuit A means for monitoring the flowing current value (current monitor circuit 4), a means for calculating the difference between the monitored current value and the target current value (current deviation calculation unit 102), and the monitoring based on the difference. The control means for controlling the output current value to the electromagnetic load device, and the difference between the monitored current value and the target current value or the output current value so that the current value to be matched with the target current value An integration unit (current deviation integration unit 104) that integrates for a predetermined time, and an abnormality determination unit (abnormality determination unit 105) that determines an abnormality of the electromagnetic load device by comparing the integrated value of the difference with a threshold value. Consists of.
[Selection] Figure 2

Description

  The present invention relates to a control device for an electromagnetic load device (for example, a linear solenoid for controlling the hydraulic pressure in an operating hydraulic pressure control system for an electronically controlled automatic transmission mounted on a vehicle), and more particularly, an abnormality in the electromagnetic load device. The present invention relates to a technique for detecting (at least one of disconnection and short circuit) with high accuracy.

The value of the current flowing through an electromagnetic load device such as a linear solenoid fluctuates due to the influence of disturbance factors such as temperature and power supply voltage. Therefore, the monitor current value is calculated based on the deviation between the measured value of the current (monitor current value) and the target current value. Feedback control for correcting the output current value to the electric circuit that drives the electromagnetic load device is performed so as to coincide with the target current value.
By the way, when an abnormality (disconnection or short circuit) occurs in the electromagnetic load device, the drive of the electromagnetic load device cannot be appropriately controlled, and the operation performance of the related equipment is degraded.

Therefore, in order to be able to switch the drive control of the electromagnetic load device to control for an abnormality when such an abnormality occurs, the one described in Patent Document 1 uses a monitor current value of a linear solenoid, a target current value, By detecting that the difference between the two exceeds a threshold value, the abnormality of the linear solenoid is detected.
Japanese Patent Laid-Open No. 7-194175

However, in the device described in Patent Document 1, when the target current value is small enough to be close to 0, the monitor current value becomes 0 at the actual disconnection, so that the difference between the monitor current value and the target current value is small. Since it falls within the normal range, it is difficult to detect disconnection.
In addition, even when the target current value is large enough to be close to the measurement limit value of the monitor current value, the monitor current value is saturated at the measurement limit value, so that the difference between the monitor current value and the target current value is reduced, so The short circuit cannot be detected.

In addition, even when the linear solenoid and its drive device are normal and normal, when the target current value fluctuates, the peak of the monitor current value transiently greatly exceeds the target current value during the response. Easily misjudged.
The present invention has been made in view of the conventional problems as described above, and provides an electromagnetic load device control device capable of detecting an abnormality (at least one of disconnection and short circuit) of the electromagnetic load device with high accuracy. With the goal.

For this reason, the invention according to claim 1
An electric circuit for driving the electromagnetic load device;
Means for setting a target current value to flow through the electric circuit;
Means for monitoring the value of current flowing through the electrical circuit;
Means for calculating a difference between the monitored current value and the target current value;
Control means for controlling an output current value to the electromagnetic load device based on the difference so that the monitored current value matches a target current value;
Integration means for integrating the difference between the monitored current value and the target current value or output current value for a predetermined time;
An abnormality determining means for determining an abnormality of the electromagnetic load device by comparing the integrated value of the difference with a threshold;
It is characterized by including.

The invention according to claim 2
The predetermined time is set in a direction going back to the past, starting from the time when the abnormality determination is requested.
The invention according to claim 3
The threshold has a positive threshold and a negative threshold,
When the difference is calculated by subtracting the target current value or the output current value from the monitored current value, the abnormality determination means is caused by a short circuit of the electromagnetic load device when the integrated value exceeds a positive threshold value. When it is determined as abnormal, and the integrated value falls below a negative threshold, it is determined as abnormal due to disconnection of the electromagnetic load device,
When the difference is calculated by subtracting the monitored current value from the target current value or the output current value, the abnormality determination means is caused by disconnection of the electromagnetic load device when the integrated value exceeds a positive threshold value. When it is determined as abnormal and the integrated value falls below a negative threshold, it is determined as abnormal due to a short circuit of the electromagnetic load device.

The invention according to claim 4
The threshold value is changed according to the target current value or the output current value.
The invention according to claim 5
When it is determined by the abnormality determining means that the electromagnetic load device is abnormal, fail safe control for an abnormality is performed on the electromagnetic load device.

The invention according to claim 6
When it is determined that there is an abnormality due to disconnection of the electromagnetic load device, fail safe control is performed to avoid inappropriate operation of the equipment controlled by the electromagnetic load device,
When it is determined that there is an abnormality due to a short circuit of the electromagnetic load device, fail-safe control is performed to disconnect the electric circuit from a power source and avoid an overcurrent of the electric circuit.

The invention according to claim 7 provides:
The integrating means includes
The integration of the difference calculated during the period from the change of the target current value to the steady state is prohibited.
The invention according to claim 8 provides:
When the target current value is greater than a first predetermined value,
Or
When the target current value is smaller than a second predetermined value smaller than the first predetermined value,
The determination by the abnormality determination means is performed.

  According to the first aspect of the present invention, the electromagnetic load is controlled so that the control unit matches the monitored current value with the target current value based on the difference between the monitored current value and the target current value. Controls the output current value to the device. At this time, the integrating means integrates the difference between the monitored current value and the target current value or the output current value for a predetermined time, and the abnormality determining means compares the integrated value of the difference with a threshold value. The abnormality of the electromagnetic load device is determined.

According to the second aspect of the present invention, the integration means integrates the difference calculated during a predetermined time set in a direction going back to the past from the time when the abnormality determination is requested.
According to the invention of claim 3, the abnormality determining means determines that the electromagnetic load device is abnormal when the integrated value exceeds a positive threshold or falls below a negative threshold.
According to the invention which concerns on Claim 4, the said threshold value is changed according to a target electric current value or an output electric current value.

According to the fifth aspect of the present invention, when the abnormality determining means determines that the electromagnetic load device is abnormal, fail safe control for an abnormality can be performed on the electromagnetic load device.
According to the invention which concerns on Claim 6, predetermined fail safe control can be performed at the time of abnormality by the disconnection of the said electromagnetic load apparatus, and the time of abnormality by a short circuit, respectively.
According to the invention of claim 7, the difference (the monitored current value and the target current value or the output current value) calculated in a period until the steady state is reached after the target current value changes. (Difference) is not reflected in the integrated value.

  According to the eighth aspect of the present invention, when the target current value is larger than the first predetermined value or when the target current value is smaller than the second predetermined value, the determination by the abnormality determination unit is performed.

Hereinafter, embodiments of the present invention will be described.
FIG. 1 is a system configuration diagram in which a control device for an electromagnetic load device according to the present invention is applied to a linear solenoid of a hydraulic control system for an electronically controlled automatic transmission mounted on a vehicle.
In FIG. 1, for example, a drive controller for a linear solenoid (electromagnetic load device) in a hydraulic control system for an automatic transmission supplies an electric circuit 2 for supplying a drive current to a linear solenoid 1, and supplies the linear solenoid 1 from the electric circuit 2. A current monitor resistor 3 used for monitoring the drive current to be monitored, a current monitor circuit 4 for monitoring the drive current supplied to the linear solenoid 1, and a CPU 5 serving as a control center.

In addition, the control apparatus of the electromagnetic load apparatus which concerns on this invention is applicable not only to the form of FIG. 1, but to various other forms which have an electromagnetic load apparatus.
The linear solenoid 1 shown in FIG. 1 is connected between a solenoid output terminal 6 that outputs a drive current to the linear solenoid 1 and a ground, and is continuously changed between on and off according to the amount of drive current. The drive is controlled based on the drive current supplied from the electric circuit 2. When the linear solenoid 1 is turned off (driving current is stopped), the current generated by the inductance component of the solenoid passes through the current monitoring resistor 3 and the solenoid output terminal 6 from the power ground terminal 7 through the recirculation diode 8, and the linear solenoid 1 Perfused.

The electric circuit 2 receives a drive signal (pulse signal) indicating a drive current (target current value) to be supplied to the linear solenoid 1 from the CPU 5 and generates a drive current based on the duty ratio of the drive signal. The generated drive current is supplied to the linear solenoid 1 via the current monitor resistor 3 and the solenoid output terminal 6.
The current monitor resistor 3 is connected between the electric circuit 2 and the solenoid output terminal 6 and monitors the drive current supplied to the linear solenoid 1 using the voltage drop of the resistor.

The current monitor circuit 4 inputs a voltage across the current monitor resistor 3, and based on the input voltage, a current monitor signal (corresponding to a drive current supplied to the linear solenoid 1 by a function of an internal integration circuit or the like) (Monitor current value) is given to the CPU 5.
The CPU 5 serves as a control center for detecting and controlling feedback drive control of the linear solenoid 1 and abnormality (both disconnection and short circuit) of the linear solenoid 1. The CPU 5 performs the drive control and the detection control based on a program stored therein.

In this embodiment, both the disconnection and the short circuit of the linear solenoid 1 are detected. However, the present invention includes one that detects only one of the disconnection or the short circuit.
FIG. 2 shows an energization control circuit of the linear solenoid.
In FIG. 2, a target current value setting unit 101 sets a target current value of the linear solenoid 1.

In the current deviation calculation unit 102, the current deviation between the target current value set by the target current value setting unit 101 and the current value (monitor current value) detected by the current monitor circuit 4 (from the monitor current value to the target current). The value obtained by subtracting the value is calculated.
The current deviation calculated by the current deviation calculation unit 102 is output to the current correction term calculation unit 103 and the current deviation integration unit 104.

The current correction term calculation unit 103 calculates a current correction term for feedback control so that the monitor current value matches the target current value based on the current deviation calculated by the current deviation calculation unit 102.
Further, the current deviation integrating unit 104 updates the integrated value of the current deviation by integrating the current deviations calculated within a predetermined time among the current deviations calculated by the current deviation calculating unit 102.

Here, the predetermined time is set in a direction that goes back to the past, starting from the time when the abnormality determination is requested. That is, the current deviation (including the current deviation calculated at the time of the abnormality determination request) calculated between the time when the abnormality determination is requested and the predetermined time has been traced back to the past. Accumulate.
The integrated value of the current deviation calculated by the current deviation integrating unit 104 is output to the abnormality determining unit 105.

The output (current correction term) of the current correction term calculation unit 103 is added to the target current value set by the target current value setting unit 101 in the correction term addition unit 106, and the correction term addition is performed in the duty conversion unit 107. The addition result of the unit 106 is converted into a duty (switching ON time ratio), and a final output duty is set.
The output duty, which is the output of the duty converter 107, is output to the electric circuit 2, and the electric circuit 2 performs PWM control of the power supply of the linear solenoid 1 based on the output duty.

In the current monitor circuit 4, the current flowing through the linear solenoid 1 is detected as a voltage across the terminals of the current monitor resistor 3 and is output to the current deviation calculation unit 102.
The abnormality determination unit 105 sets a disconnection determination threshold value and a short circuit determination threshold value, which will be described later, according to the target current value set by the target current value setting unit 101. Then, the disconnection determination threshold value or the short circuit determination threshold value is compared with the integrated value of the current deviation calculated by the current deviation integrating unit 104 to determine abnormality of the linear solenoid 1.

Here, as described above, since the current deviation integrating unit 104 integrates the difference calculated at a predetermined time before the time when the abnormality determination of the linear solenoid 1 is requested, such an abnormality determination request. Therefore, the integrated value of the difference can be immediately calculated, and the abnormality determination unit 105 can quickly and effectively determine the abnormality.
The abnormality detection of the linear solenoid 1 will be described in detail below.

3 shows that neither the linear solenoid 1 nor the electric circuit 2 is disconnected or short-circuited (hereinafter referred to as normal), the linear solenoid 1 is disconnected or short-circuited (hereinafter referred to as disconnected or short-circuited). The example of the relationship between time and monitor current value in is shown.
As shown in FIG. 3, when normal, the target current value is constant and the monitor current value is in a steady state (converged to the target current value), but when disconnected, the monitor current value drops below the target current value and becomes zero. When the short circuit occurs, the monitor current value increases from the target current value.

In this embodiment, the current deviation in FIG. 3 (a value obtained by subtracting the target current value from the monitor current value) is integrated, and the relationship between the integrated value and time is as shown in FIG.
In FIG. 4, since feedback control is performed so that the current deviation becomes substantially zero at the normal time, the integrated value of the current deviation converges to substantially zero. In FIG. 4, the target current value is in a steady state, but even if the target current value fluctuates, the positive and negative current deviations alternate between reaching the steady state. In order to respond so as to appear, the positive and negative current deviations cancel each other, and the integrated value of the current deviations converges to a value close to 0 while the increase in absolute value is suppressed.

On the other hand, at the time of disconnection, as shown in FIG. 3, the negative current deviation continues, so that the negative current deviation is repeatedly integrated, and the integrated value of the current deviation increases in the negative direction.
Further, when the short circuit occurs, the positive current deviation continues as shown in FIG. 3, so that the positive current deviation is repeatedly integrated, and the integrated value of the current deviation increases in the positive direction.
2 detects that the integrated value of the current deviation exceeds a predetermined disconnection determination threshold value in the negative direction, it is determined that the linear solenoid 1 is disconnected, and the integrated value is When it is detected that the predetermined short-circuit determination threshold is exceeded in the positive direction, it is determined that the linear solenoid 1 is short-circuited.

Note that the disconnection determination threshold and the short-circuit determination threshold are set to values that can reliably prevent the integrated value of the current deviation from reaching the normal value.
When the abnormality determining unit 105 determines that the linear solenoid 1 is disconnected, fail safe control is performed so that the linear solenoid 1 is not controllable and related devices such as an automatic transmission do not perform inappropriate operations.

On the other hand, when the abnormality determination unit 105 determines that the linear solenoid 1 is short-circuited, for example, fail-safe control is performed such that the electric circuit 2 is disconnected from the power source and performance degradation due to overcurrent of the electric circuit 2 is prevented.
Hereinafter, the effects produced by the present embodiment will be described in comparison with a conventional configuration.
In the conventional configuration (for example, described in Patent Document 1), when it is detected that the absolute value of the current deviation of the linear solenoid (the difference between the monitor current value and the target current value) exceeds the threshold, Is determined to be abnormal (disconnected or short-circuited). Therefore, when the target current value is small enough to be close to 0, as shown in FIG. 5, the absolute value of the current deviation becomes small and falls within the normal range because the monitor current value becomes 0 when the actual disconnection occurs. Therefore, it is difficult to detect disconnection.

  On the other hand, in the present embodiment, as shown in FIG. 4, the integrated value of the current deviation converges to approximately 0 in the normal state, whereas this is even if the current deviation has a small absolute value in the actual disconnection. Since the integrated value increases in the negative direction, a difference in the integrated value of the current deviation clearly appears between the normal time and the disconnection. The disconnection can be reliably detected by detecting that the integrated value of the current deviation exceeds the disconnection determination threshold value in the negative direction.

  Further, in the above-described conventional configuration, when the target current value of the linear solenoid is large enough to be close to the measurement limit value of the monitor current value (area E1 in FIG. 6), the actual current value is the measurement limit value at the time of the actual short circuit. Even if the value exceeds the value, the monitor current value saturates at the measurement limit value, so that the absolute value of the current deviation also decreases and falls within the normal range, so that it is difficult to detect a short circuit.

  On the other hand, in the present embodiment, the integrated value of the current deviation converges to approximately 0 in the normal state, whereas in the actual short circuit, even if the current deviation has a small absolute value, the integrated value is integrated. Since it increases in the positive direction, the difference in the integrated value of the current deviation clearly appears between the normal time and the short circuit. And a short circuit is reliably detectable by detecting that the integrated value of an electric current deviation exceeds a short circuit determination threshold value to a positive direction.

  In the region where the target current value is particularly small, the absolute value of the current deviation becomes extremely small at the time of actual disconnection, so the speed at which the integrated value of current deviation increases in the negative direction decreases, and the integrated value from the occurrence of disconnection decreases. There is a concern that disconnection detection may be delayed due to the length of time until the disconnection determination threshold is exceeded. Therefore, for example, as illustrated in FIG. 7, in a region where the target current value is particularly small (a region where the target current value is less than b1), the disconnection determination threshold value may be brought close to 0 to ensure the speed of disconnection detection. .

  Similarly, even in the region where the target current value is particularly close to the measurement limit value, the absolute value of the current deviation becomes extremely small at the time of actual short circuit, so the speed at which the integrated value of the current deviation increases in the positive direction decreases, There is a concern that detection of a short circuit may be delayed due to the length of time from the occurrence of a short circuit until the integrated value exceeds the short circuit determination threshold. Therefore, for example, as shown in FIG. 7, in a region where the target current value is particularly close to the measurement limit value (a region where the target current value is larger than b2), the short-circuit determination threshold is brought close to 0, thereby improving the speed of short-circuit detection. It may be secured.

  In FIG. 7, the disconnection determination threshold value in the region where the target current value is b1 or more is a1, and the short circuit determination threshold value in the region where the target current value is b2 or less is a2, but these a1 and a2 are the target current values in the normal state. Even if a monitor current value overshoot occurs due to fluctuations in the number of cycles, it is set so that erroneous determination of disconnection or short circuit does not occur. Therefore, it is preferable to obtain the overshoot amount of the monitor current value that can be generated in advance by measurement or the like.

  Here, in the region where the target current value in FIG. 7 is less than b1, when the target current value fluctuates into the region, the actual current value overshoot amount is the lower limit value ( The value obtained by subtracting the measurement limit value (here, 0) of the monitor current value from the monitor current value is exceeded. Therefore, in order to compensate for the actual current value that could not show a value less than 0 (negative) at the time of overshoot, the disconnection determination threshold is brought close to 0 in the region where the target current value is less than b1, thereby detecting the disconnection. Ensures accuracy.

  Further, in the region where the target current value in FIG. 7 is larger than b2, when the target current value fluctuates so as to increase to the region, the actual overshoot amount of the current value is normal from the measurement limit value of the monitor current value. The value obtained by subtracting the upper limit value of the control area (see FIG. 6) is exceeded. Therefore, in order to compensate for the portion of the actual current value that exceeds the measurement limit value of the monitor current value at the time of overshoot, the short-circuit determination threshold is brought close to 0 in the region where the target current value is larger than b2, thereby detecting the short-circuit detection accuracy. Is secured.

The change rate with respect to the target current value of the disconnection determination threshold value in the region where the target current value is less than b1 in FIG. 7 and the change rate with respect to the target current value of the short circuit determination threshold value in the region where the target current value is greater than b2 are appropriate by tuning or the like. It is good to set to.
In the conventional configuration, as shown in FIG. 8, the smaller the target current value is, the smaller the short-circuit determination threshold value of the monitor current value is set, and the difference between the short-circuit determination threshold value and the target current value becomes smaller. Yes. Therefore, even if it is actually normal, if the target current value fluctuates so as to decrease to a particularly small region (region E2 in FIG. 6), the peak of the monitor current value tends to exceed the short-circuit determination threshold during response. Easily misjudged as a short circuit.

  On the other hand, in the present embodiment, the feedback control of the current value flowing through the linear solenoid 1 makes a response so that a positive current deviation and a negative state appear alternately until the steady state is reached. Then, since the positive and negative current deviations cancel each other, as shown in FIG. 9, the integrated value of the current deviation attenuates within a range in which the increase in absolute value is suppressed and does not exceed the short circuit determination threshold, and approaches a value close to zero. Converge. In this way, by accumulating the current deviation, it is possible to reliably prevent erroneous determination as a short circuit during actual normality and improve the detection accuracy of the short circuit.

  It should be noted that the absolute value of the current deviation temporarily increases during the period until the monitored current value after the large fluctuation of the target current value reaches the steady state, and if the current deviation calculated during this period is integrated, the integrated value becomes large. Since there is a concern that it may be erroneously determined that the linear solenoid 1 is abnormal, the current deviation calculated during the period may not be reflected in the integrated value by prohibiting the integration. Thereby, the accuracy of the abnormality determination of the linear solenoid 1 can be ensured. In this case, the predetermined time may be extended to compensate for the integration prohibition period.

  Further, in the conventional configuration, in a region where the target current value of the linear solenoid is large enough to be close to the measurement limit value of the monitor current value (region E1 in FIG. 6), the short-circuit determination threshold value of the monitor current value is the measurement limit value. As shown in FIG. 10, the difference between the short-circuit determination threshold value and the target current value becomes small. Therefore, even if the actual value is normal, when the target current value fluctuates so as to increase to a region close to the measurement limit value (region E1 in FIG. 6), the peak of the monitor current value at the time of response is determined as the short circuit determination. It is easy to exceed the threshold value, and it is easy to mistakenly determine that it is a short circuit.

  On the other hand, in the present embodiment, the feedback control of the current value flowing through the linear solenoid 1 makes a response so that a positive current deviation and a negative state appear alternately until the steady state is reached. Then, since the positive and negative current deviations cancel each other, as shown in FIG. 11, the integrated value of the current deviation attenuates within a range in which the increase in absolute value is suppressed and does not exceed the short circuit determination threshold, and approaches a value close to zero. Converge. In this way, by accumulating the current deviation, it is possible to reliably prevent erroneous determination as a short circuit during actual normality and improve the detection accuracy of the short circuit.

  Further, in the above-described conventional configuration in which abnormality determination is performed by comparing the absolute value of the current deviation with a threshold value, as described above, the target current value is large enough to be close to the measurement limit value of the monitor current value (target current value). 6 is larger than the first predetermined value, and the region where the target current value is particularly small (region E2 in FIG. 6 where the target current value is smaller than the second predetermined value) is abnormal. Or the abnormality of the linear solenoid 1 cannot be detected. Therefore, only in the target current value region that is likely to cause such misjudgment or abnormality undetected, highly accurate abnormality determination based on the integrated value of the current deviation is performed, while on the other hand, when the target current value outside the region, As in the above-described conventional configuration, simple abnormality determination may be performed by comparing the absolute value of the current deviation with a threshold value.

  In the above description, the integrated value of the current deviation is obtained by integrating the difference (current deviation) between the target current value and the monitor current value. However, the present invention is not limited to this, and the output current value (the current correction term) And the current value obtained by adding the target current value) and the monitor current value may be integrated. In this case, the target current value on the horizontal axis in FIG. 7 may be read as the output current value, and the disconnection determination threshold value and the short circuit determination threshold value may be changed according to the output current value.

System configuration diagram of an embodiment of the present invention The figure which shows the electricity supply control circuit of embodiment of this invention The figure which shows the example of the relationship between time and monitor current value which concerns on embodiment of this invention The figure which shows the example of the relationship between the time which concerns on embodiment of this invention, and the integrated value of an electric current deviation The figure which shows the example of the relationship between the time at the time of the disconnection which concerns on the conventional structure, and a monitor electric current value The figure which shows the example of the relationship between the target electric current value and monitor current value in the conventional structure The figure which shows the example of the relationship between the target electric current value which concerns on embodiment of this invention, and a disconnection determination threshold value or a short circuit determination threshold value The figure which shows the example of the relationship between time and monitor electric current value when the target electric current value fluctuates at the normal time which concerns on the conventional structure The figure which shows the example of the relationship between time and the integrated value of an electric current deviation when the target electric current value fluctuates at the normal time which concerns on embodiment of this invention The figure which shows the example of the relationship between time and monitor electric current value when the target electric current value fluctuates at the normal time which concerns on the conventional structure The figure which shows the example of the relationship between time and the integrated value of an electric current deviation when the target electric current value fluctuates at the normal time which concerns on embodiment of this invention

Explanation of symbols

1 Linear Solenoid 2 Electrical Circuit 3 Current Monitor Resistor 4 Current Monitor Circuit 5 CPU

Claims (8)

An electric circuit for driving the electromagnetic load device;
Means for setting a target current value to flow through the electric circuit;
Means for monitoring the value of current flowing through the electrical circuit;
Means for calculating a difference between the monitored current value and the target current value;
Control means for controlling an output current value to the electromagnetic load device based on the difference so that the monitored current value matches a target current value;
Integration means for integrating the difference between the monitored current value and the target current value or output current value for a predetermined time;
An abnormality determining means for determining an abnormality of the electromagnetic load device by comparing the integrated value of the difference with a threshold;
A control device for an electromagnetic load device, comprising:   2. The control device for an electromagnetic load device according to claim 1, wherein the predetermined time is set in a direction going back to the past, with the abnormality determination request as a base point. The threshold has a positive threshold and a negative threshold,
When the difference is calculated by subtracting the target current value or the output current value from the monitored current value, the abnormality determination means is caused by a short circuit of the electromagnetic load device when the integrated value exceeds a positive threshold value. When it is determined as abnormal, and the integrated value falls below a negative threshold, it is determined as abnormal due to disconnection of the electromagnetic load device,
When the difference is calculated by subtracting the monitored current value from the target current value or the output current value, the abnormality determination means is caused by disconnection of the electromagnetic load device when the integrated value exceeds a positive threshold value. 3. The control device for an electromagnetic load device according to claim 1, wherein when the integrated value is determined to be abnormal and the integrated value falls below a negative threshold value, it is determined that the electromagnetic load device is abnormal due to a short circuit. 4.   The control device for an electromagnetic load device according to any one of claims 1 to 3, wherein the threshold value is changed according to the target current value or the output current value.   5. The fail-safe control for an abnormal time is performed on the electromagnetic load device when the abnormality determination unit determines that the electromagnetic load device is abnormal. 5. The control device of the electromagnetic load device described in 1. When it is determined that there is an abnormality due to disconnection of the electromagnetic load device, fail safe control is performed to avoid inappropriate operation of the equipment controlled by the electromagnetic load device,
6. The electromagnetic wave according to claim 5, wherein when it is determined that there is an abnormality due to a short circuit of the electromagnetic load device, fail-safe control is performed to disconnect the electric circuit from a power source and avoid an overcurrent of the electric circuit. Control device for load device. The integrating means includes
The control of the electromagnetic load device according to any one of claims 1 to 6, wherein integration of the difference calculated in a period from the change of the target current value to a steady state is prohibited. apparatus. When the target current value is greater than a first predetermined value,
Or
When the target current value is smaller than a second predetermined value smaller than the first predetermined value,
The control device for an electromagnetic load device according to claim 1, wherein the determination by the abnormality determination unit is performed.

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