JPS62178192A - Controller for motor - Google Patents

Abstract

PURPOSE:To drive a motor automatically again by alternately applying forward- rotation conduction and reverse-rotation conduction to the motor at every fixed time until the release of overload is detected when overload is detected. CONSTITUTION:A micro-computer 1 controls the direction of rotation of a motor 5 driving an air mixing door 7 in response to a deviation between an opening set value and an output from an opening detecting circuit 8. When the currents of the motor 5 detected by a current detecting circuit 6 are larger than a predetermined value, the state of overload is decided, and forward- rotation conduction and reverse-rotation conduction are conducted alternately to the motor 5 at every fixed time. When the state of overload is released and motor currents lower, the control of the motor 5 is reopened. When motor currents do not drop even when a set time passes, the conduction of the motor 5 is stopped.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention is applicable to a motor control device that functions when the motor is overloaded. It can be effectively used as a control device for overloads of drive motors, blower motors, etc.

[Description of Prior Art J As one of the prior art related to the present invention, Japanese Patent Laid-Open No. 57
There is an overcurrent interrupting device for a small DC motor described in Japanese Patent No. -113726. This detects an overload N current in a small DC motor, and upon this detection stops the current supply to the motor. Once an overload current is detected, the state continues to stop the current supply to the motor. Unless the supply of power to the device is once stopped and then supplied again +If times, the state of power supply to the motor will not be released.

By the way, 1. For example, in the air conditioning door drive motor of the air me 2x door in an automatic air conditioning system, the blower pro-motor, etc., foreign objects may get caught in the air conditioning door drive system or the blower fan, which may cause the air conditioning door to rotate or The rotation of the fan may be inhibited, causing the motor to become overloaded or under high load.In such cases, if the motor is rotated in the opposite direction, the force applied to the object will be reversed, and this will cause the foreign object to In fact, there are many cases in which the motor comes off and returns to its normal state.Furthermore, the motor may be under high load due to stiffness in the link mechanism that drives the air mix door, but even in such cases, the motor cannot rotate normally. In many cases, the movement becomes smoother by repeating and reversing the movement.

However, in the above-mentioned conventional technology, once an overload condition is detected, the power to the motor is kept stopped, so as mentioned above, a force in the opposite direction is applied to the foreign object, or an action to remove the reluctance occurs. This cannot be expected at all, and even if the foreign object is removed or the astringency is removed, it is accompanied by the hassle of having to repeatedly manually operate a switch to stop and restart the power supply. There were problems such as:

[Object of the invention] The present invention has been made based on the above points, and the present invention has been made based on the above points.
The target is effective in removing causes of overload such as foreign objects getting stuck or stiffness, and moreover, the motor is overloaded! An object of the present invention is to provide a motor control device that can automatically re-drive a motor when the motor is out of E.

[Means for Achieving the Object] In the present invention, as shown in FIG. means for detecting an overload of the motor and a release of the overload based on the detected overload; means for controlling the motor drive circuit so that normal rotation and reverse energization are alternately applied during each rotation; The above object is achieved by a motor control device having means for controlling the motor drive circuit to stop the energization of the motor when the motor is de-energized for a period of time or a number of times.

[Embodiment of the Invention] FIG. 2 is a block diagram showing an embodiment of the invention. This example shows the case where it is applied to the drive system of an air mix door in an automobile air conditioning system.

In the figure, 1 is a microcomputer, CPU10I
, a ROM 102 for storing control programs and the like, a RAM 103 for storing data and the like, and an I10 boat 104.

I10 port 104 has multiplexer and A/D
Temperature setting device 3 via input circuit 2 including a cap to controller 8
set temperature information, sensor detection information of various sensors 4,
Load current information from a current detection circuit 6 that detects the load current of the motor 5 and opening information from an opening detection circuit 8 that detects the actual opening of the air mix door 7 are input.

The sensor detection information includes the indoor temperature and the outside temperature T, and these detection information and set temperature information are used to calculate the opening degree setting value of the airmic door 7. The motor 5 is provided in an actuator (not shown), and is controlled to rotate in forward and reverse directions by a drive circuit 9 placed under the control of a microcomputer 1. As is well known, the air mix door 7 determines the mixing ratio of cold air and warm air, and is connected to an actuator provided with a motor 5 and a link am
The motor 5 is connected to the motor 5 through the motor 5, and is driven by the rotation of the motor 5. Such opening degree control of the air mix door 7 is performed based on the calculated opening degree setting value and the actual opening degree information of the opening degree detection circuit 8. This is done by giving control from the microcomputer 1 to the drive circuit 9.

The RAM 103 of the microcomputer 1 is provided with count storage areas for soft counters CTR1, CTR2, CTR3 and CTR4.

The soft counter CTRI is used to determine, when the load current of the motor 5 reaches a predetermined value ■1 or more, whether it is caused by a mortar lock or an inrush current at startup. As will become clear in the operation explanation below, each time the program passes, +1
Incremented. To determine whether the motor is locked or there is an inrush current at startup, check the contents of CTRI and the predetermined value C.
This is done by comparison between I and I. In other words, the time it takes to count up to the predetermined value C1 is ! of the inrush current at startup. ! The continuous opening interval is also selected to be long, and the two are discriminated based on the length of time the overcurrent state lasts.

Soft counter CTR2 indicates normal rotation for motor 5.
It regulates the if time and the reverse energization time, and is incremented by +1 every time the program passes, as will become clear in the operation description below. Time regulation is CTR2
The count-up time up to the predetermined value c2 becomes the forward rotation energization time and the reverse rotation m'if time.

The soft counter CTR3 regulates the time (try time) for which forward/reverse verification continues, and as will become clear in the operation explanation below, it increases by +1 every time the program passes.
Incremented. The try time is regulated by comparing the contents of CTR3 with a predetermined value C3, and the count-up time up to the predetermined value C3 becomes the try time.

When motor lock is recognized, the motor 5 is energized in forward and reverse directions during this try time.

If the motor lock is not released even after this trial time has elapsed, as will be described later, the power supply to the motor 5 is stopped and an error message is displayed on the display device 1O.

If the load current of the motor 5 becomes a predetermined value 11 or less under a state in which the motor lock is recognized, the soft counter CTR4 determines whether the decrease in the load current is due to the motor lock being released, or Forward turn 'It! This is to determine whether the problem is caused by switching between : and reverse energization, and is incremented by +1 each time the program passes, as will become clear in the operation description below. The motor lock is released by comparing the contents of CTR4 and a predetermined ifi C4. That is, when the load current continues to be less than or equal to the predetermined value 11 until it counts up to the predetermined value C4, a determination is made to cancel the low-2 state.

In this example, the lock flag F (and rotation direction flag Fo
and are available. The lock flag F1 becomes "1" when the motor lock is recognized, and becomes "0" when the lock is released. The rotation direction flag FO is used to know the direction of the motor 5, and is set to "l" for forward energization and "O" for reverse energization.
”.

FIG. 3 is an operation flowchart of the configuration shown in FIG. 2, and the operation of the configuration shown in FIG. 2 will be explained below with reference to FIG.

When the power is applied, the program processing by the microcomputer 1 starts, and after initialization such as resetting the soft counters CTRI to 4 and setting rQJ of the flag F E+ F o is performed, the actual processing starts. First, the load current of the motor 5 is taken in, and after it is temporarily stored (step 20), the state of the lock flag F1 is determined (step 21).
is set to "0" during initialization, so step 2
Proceeding to step 2, a comparison is made between the loaded load current and a predetermined value ■1. Since the motor 5 is in a non-energized state and its load current is 0, the process moves to step 25 via steps 23 and 24, where sensor information and temperature setting are taken in and the opening setting value of the air mix door 7 is determined. Calculated.

Next, the actual opening degree of the air mix door 7 is taken in, and the error E between it and the opening degree set value is calculated (step 26), and in the next step 27, a comparison is made with a predetermined value El. . The predetermined value E1 is a reference value for determining whether or not to drive the motor 5. The absolute value of the error E is determined to stop at the predetermined value E1, and the drive is determined when the absolute value of the error E≧the predetermined value El. It will be done. When stopped, the motor 5 is not energized (step 28), and the process returns to step 20. For driving, the process moves to step 7 29, where it is determined whether the required driving is in the forward direction or in the reverse direction. This judgment is made depending on whether the error E is greater than 0 or not, and the error E
If >0, normal rotation, error Eg.

That is considered a reversal. In the case of forward rotation, after "l" is set in the rotation direction flag Fo (step 30),
A control process is performed to cause the motor 5 to rotate forward (11L) (step 31), and the process returns to step 20. In the case of reverse rotation, the one-rotation direction flag FD is set to "0" (step 32), and then a control process for energizing the motor 5 in the reverse direction is performed (step 33), and step 20
will be returned to.

When forward rotation or reverse rotation processing is performed, energization of the motor 5 is started and an inrush current flows. Therefore, the load current detected in step 20 temporarily exceeds the predetermined value 11, the process proceeds from step 22 to step 34, the soft counter CTRL is incremented by +1, and in the next step 35, the content of CTRI and the predetermined value Ct are A comparison is made between. Since the duration of the adult'I current is shorter than the time until CTRI counts up to the predetermined value C1, in the case of an inrush current at the time of starting the motor 5, step 2 is performed.
5, the opening degree of the air mix door 7 is controlled. If the inrush current disappears, step 2
Since the load current taken in at 0 becomes the predetermined value 11 or more,
The process moves from step 22 to step 23, where the contents of the soft counter CTR1 are reset.

The above operation is repeated when the motor 5 is not locked.

Next, while the motor 5 is being driven, for some reason the motor 5
If it locks, the lock current is taken in step 20. Since the lock flag F" is "0" when a lock occurs, the process proceeds from step 21 to step 22. Until the soft counter CTR1 reaches the predetermined value CI, the process proceeds to step 25 via steps 34 and 35, returns to step 20 via the opening degree control of the air mix door 7, and returns to step 21. 22, an operation of up-counting CTR1 is performed. When the soft counter CTR1 reaches a predetermined value of 14 C+, the occurrence of a lock is recognized in step 35, and the process proceeds to step 36, where the lock flag F[ is set to "l", and after CTR1 is reset (step 37), the rotation direction flag FD is set. If the motor 5 is locked by energization in the normal rotation direction, the rotation direction flag Fo becomes rlJ in the process in step 30, and the motor 5
If the is locked due to energization in the reverse direction, step 3
In the process in step 2, the rotational direction flag Fo is set to rOJ. If the motor 5 is locked with energization in the forward direction, the process proceeds from step 38 to step 39, where energization in the reverse direction is performed. On the other hand, if the motor 5 is locked by being energized in the reverse direction, the process proceeds from step 38 to step 40, where the motor 5 is energized in the forward direction. After the energization process in the reverse direction, the rotation direction flag FD is set to "0" (
Step 41), after the normal rotation direction energization process, the rotational force direction flag FD is set to rlJ (step 42), and then the soft counter CTR2.

CTR3 is incremented by +1 (step 43.4
4), the process returns to step 20. Soft counter CTR
2 regulates the energization time in the first rotation direction and the reverse direction, and the soft counter CTR3 regulates the try time which is the duration of energization in the forward and reverse directions.

When the process returns to step 20, a new load '-E flow is taken in, and then the process proceeds to step 21. Since the lock flag FL is set to rlJ in step 36, the process jumps from step 21 to step 45, where a comparison is made between the load current and the predetermined value 11. If the lock state is released, the load current will naturally become lower than the predetermined value ■1, but even if the lock state continues, the load current will be lower than the predetermined value due to switching between forward energization and reverse energization. It may be lower than the value II.

The predetermined value X1 in step 20 while the lock state continues.
As long as a load current larger than 1 is taken in, the process proceeds from step 45 to step 46 to step 47. In step 47, the trial time is determined by comparing the contents of the soft counter CTR3 and the predetermined value C3. It is determined whether or not the process has ended. If it is assumed that the try time has not yet ended, the process proceeds to the next step 48, and by comparing the contents of the soft counter CTR2 and the predetermined value C2, the end of the energization time in the current energization direction assigned to the motor 5 is determined. The presence or absence of r1 is determined. As a result, if the energization time has ended, (
Step 49), then proceed to step 38. Step 3
8, energization is switched to the opposite direction (steps 39 and 40), and after the corresponding rotation direction flag Fo is cleared (steps 41 and 42), the soft counters CTRL and CTR2 are incremented. (steps 43 and 44), and the process returns to step 20. on the other hand,
Assuming that the energization time in the current energization direction given to the motor 5 has not ended, steps 48 to 4
3, and in steps 43 and 44, the soft counter CT
R2.

After incrementing CTR3, step 2
Returned to 0. As long as a load IV larger than the predetermined value 1 is taken in the step 20 while the locked state continues, by repeating the operations described above, the motor 5 is alternately energized in 11:, reverse energization and reverse energization. Repeated.

When the end of the try time is recognized in step 47, the process moves from step 47 to step 50, an abnormality is displayed, and the power supply to the motor 5 is stopped (step 51), and the control program ends.

The load ' taken in in step 20 for releasing the locked state or switching energization between forward energization and reverse energization.
When the flow becomes lower than the predetermined flow rate, step 45 moves to step 52.

The soft counter CTR4 is incremented by +1, and then, by comparing the contents of CTR4 and a predetermined value 1p1C4, it is determined whether the decrease in load current is due to release of the lock state or due to energization between forward and reverse energization. A determination is made as to whether this is due to switching. If the decrease in the load current is due to energization switching, the load current will again exceed the predetermined value 11 after a short time and CTR4 will be reset in step 46, so CTR4 will not be counted up to the predetermined value C4. Soft counter C at 53
If the contents of TR4 are not far from the predetermined value C4, step 4
3, and in steps 43 and 44, the soft counter CT
After R2 and CTR3 are incremented, the process returns to step 20, where a new load current is taken in, and then passes through step 21 to step ++) and step 45. If the decrease in the load current is generally caused by normal switching, the process proceeds from step 45 to step 46 because CTR4 reaches the predetermined value 11 or more before being counted up to the predetermined value (tiIC^).

After resetting CTR4, overload control continues. On the other hand, if the drop in load current is due to unlocking,
Since the state of the predetermined value C1 or less continues, CTR4 reaches the predetermined value C4. As a result, the process proceeds to step 54, and after the lock flag F[ is set to "0," the soft counters CTR2, CTR3, and CTR4 are reset in step 55, and the process proceeds to step 25, in which the opening degree of the air mix door 7 is reset. Control will be resumed.

In the embodiment described above, the continuation of forward and reverse energization during locking is time-controlled using the software counter CTR3. , the power supply to the motor 5 may be stopped. Further, in the embodiment described above, control of an air mix door has been explained as an example, but it goes without saying that the present invention can be applied to a drive circuit for a pro-ar motor or other motors.

[Effects of the Invention] As explained above, according to the present invention, when an overload of the motor is detected, energization in the forward/reverse direction is performed instead of the original energization until the release of the overload is detected. We decided to cut off the current to the motor only when the overload is not removed even after alternately energizing for a predetermined time or a predetermined number of times, so if the cause of the overload is removed, the motor In addition, by applying forward/reverse AC IL energization during overload, it is easy to remove foreign matter and eliminate stiffness as a cause of overload (effects such as It is possible to provide a motor control device that performs the following functions.

[Brief explanation of drawings]

FIG. 1 is a block diagram of the present invention, FIG. 2 is a block diagram showing an embodiment of the present invention, and FIG. 3 is a flowchart of the operation of FIG.

Claims (1)

[Claims] a motor drive circuit that provides a drive output to a motor; a means for detecting a load on the motor; a means for detecting an overload of the motor and release of the overload based on the detected load; means for controlling the motor drive circuit so that forward rotation energization and reverse rotation energization are alternately applied to the motor at predetermined time intervals instead of the original drive output until the release of the overload is detected; and means for controlling the motor drive circuit so as to stop energizing the motor when the forward energization and reverse energization are performed for a predetermined time or number of times without overload being released. Characteristic motor control device.