JP2020005377A - Motor drive monitoring device - Google Patents

Abstract

To monitor whether a DC motor has started normally.SOLUTION: In a motor drive monitoring device 10 including a control unit 20 for stopping drive of a DC motor 3 assuming that an abnormality has occurred when a motor drive command is given to the DC motor 3 to drive the DC motor 3, and a current equal to or more than a predetermined stall current threshold continuously flows through the DC motor 3 for a predetermined lock monitoring time, when a current equal to or greater than a stop current threshold has flowed through the DC motor 3 before a start monitoring time shorter than a lock monitoring time has elapsed since a motor drive command was given, the control unit 20 determines that the DC motor 3 starts normally, and when a current equal to or greater than a stall current threshold does not flow through the DC motor 3 before the start monitoring time elapses after the motor drive command is given, it determines that the DC motor 3 is abnormally activated.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a drive monitoring device for a motor, for example, to a drive monitoring device for a DC motor constituting a drive source of a transport mechanism for transporting coins.

  Conventionally, a coin processing device applied as a change machine has been provided for each denomination by discriminating coins received by being inserted into a slot, sorting coins identified as genuine coins by denomination. The coins stored in the coin storage are stored by denomination. When a coin dispensing command, which is a change dispensing request, is given from an external device or the like, this coin processing device causes coins corresponding to the requested amount to be paid out from the corresponding coin storage, and is conveyed to the dispensing port by a conveying mechanism. (For example, see Patent Document 1).

JP-A-2006-71662

  Incidentally, a DC motor is generally used as a drive source of the transport mechanism. The DC motor has such a characteristic that the current becomes low at the time of rotational driving, while it becomes large at the time of stop such as when the output shaft is locked (stop current).

  Therefore, the drive of the DC motor is monitored, and the output shaft is locked or the like due to the occurrence of a coin jam or the like in the transport mechanism. There is known a motor drive monitoring device that stops the drive of a DC motor when an error has occurred for a monitoring time or more.

  However, such a motor drive monitoring device can detect that the DC motor is not driven due to a failure of the transport mechanism or the like, but determines whether the DC motor has been normally driven (started) based on the drive command. I couldn't.

  Here, the DC motor constituting the drive source of the transport mechanism of the coin processing device has been described. However, it goes without saying that such a problem also occurs in DC motors other than the drive source of the transport mechanism.

  The present invention has been made in view of the above circumstances, and has as its object to provide a motor drive monitoring device that can monitor whether a DC motor has started normally.

  In order to achieve the above object, a motor drive monitoring device according to the present invention provides a drive command to a DC motor to drive the DC motor, and a current equal to or more than a predetermined stall current threshold is supplied to the DC motor. In a motor drive monitoring device including a control unit that stops driving of the DC motor when an error has occurred continuously for a predetermined lock monitoring time or more, the control unit provides the drive command. If a current equal to or greater than the stall current threshold has flowed into the DC motor before the startup monitoring time shorter than the lock monitoring time has elapsed since then, the DC motor is determined to be normally started while the drive command If the current equal to or greater than the stall current threshold does not flow through the DC motor until the start monitoring time has elapsed since the start of the DC motor, the DC motor is determined to be abnormally started. And butterflies.

  The present invention also relates to the motor drive monitoring device, wherein the control unit supplies the DC motor with the stall current from when the drive command is given to the DC motor until a drive stop command is given to the DC motor. It is characterized in that it is monitored whether a current equal to or larger than the steady-state current threshold smaller than the threshold continuously flows.

  Further, according to the present invention, in the motor drive monitoring device, the control unit does not supply a current equal to or more than the stall current threshold to the DC motor until the start monitoring time elapses after giving the drive command. In this case, a retry process is performed in which a drive command is given to the DC motor again to determine whether or not a current equal to or larger than the stall current threshold value flows to the DC motor.

  According to the present invention, in the motor drive monitoring device, the DC motor constitutes a drive source of a transport mechanism that transports coins.

  According to the present invention, when a current equal to or more than the stall current threshold value flows into the DC motor after the drive command is given and the start monitoring time shorter than the lock monitoring time elapses after the drive command is given, the DC motor Is determined to be a normal start, while if a current equal to or greater than the stall current threshold does not flow through the DC motor until the start monitoring time elapses after the drive command is given, the DC motor is determined to be abnormally started. Thus, it is possible to monitor whether or not the DC motor has started normally.

FIG. 1 is a schematic diagram schematically showing a circuit configuration of a motor drive monitoring device according to an embodiment of the present invention. 2A and 2B are time charts showing an example of the operation of the drive monitoring device shown in FIG. 1, wherein FIG. 2A shows a current flowing through a DC motor, and FIG. 2B shows a current from a first binarization circuit to a control unit. (C) shows a signal given to the control unit from the second binarization circuit, and (d) shows ON / OFF of a motor drive command by the control unit. FIG. 3 is a flowchart illustrating the processing content of a drive monitoring control process performed by the control unit illustrated in FIG. 1.

  Hereinafter, preferred embodiments of a motor drive monitoring device according to the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 is a schematic diagram schematically showing a circuit configuration of a motor drive monitoring device according to an embodiment of the present invention. The motor drive monitoring device 10 exemplified here is a drive monitoring target of a forward / reverse rotatable DC motor 3 constituting a drive source of a transport mechanism 2 that transports coins in a coin processing device 1 such as a change machine. And a driver circuit 11, a first binarization circuit 13, and a second binarization circuit 14.

  The driver circuit 11 is connected to the DC motor 3 and to a control unit 20 described later. The driver circuit 11 supplies power to the terminals of the DC motor 3 when a motor drive command is given from the control unit 20, and supplies the DC motor 3 when a motor drive stop command is given from the control unit 20. The supply of electric power to the terminal is stopped. Reference numeral 12 in FIG. 1 denotes a current detection resistor that detects a current flowing through the DC motor 3.

  The first binarization circuit 13 includes a comparator 13a for stall current, and when the current flowing through the DC motor 3 is equal to or greater than a preset stall current threshold, the first binarization circuit 13 equals or exceeds the stall current threshold. And a signal to that effect is given to the control unit 20. That is, when the current flowing through the DC motor 3 is less than the stall current threshold, the first binarization circuit 13 determines that there is no current equal to or greater than the stall current threshold and gives a signal to that effect to the control unit 20. Things. Here, the stall current threshold is a threshold that is large enough to detect that a stall current has flowed through the DC motor 3.

  The second binarization circuit 14 includes a comparator 14a for a steady-state current, and when the current flowing through the DC motor 3 is equal to or greater than a preset steady-state current threshold, the current equal to or greater than the steady-state current threshold is set. A signal to that effect is given to the control unit 20. That is, when the current flowing through the DC motor 3 is less than the steady-state current threshold, the second binarization circuit 14 gives a signal indicating that there is no current equal to or greater than the steady-state current threshold to the control unit 20. is there. Here, the steady-state current threshold is a value smaller than the above-mentioned stall current threshold, and is a threshold large enough to detect that the steady-state current has flowed through the DC motor 3.

  The control unit 20 controls the operation of the drive monitoring device 10 according to programs and data stored in a memory (not shown). Note that the control unit 20 may be realized, for example, by causing a processing device such as a CPU (Central Processing Unit) to execute a program, that is, realized by software, or realized by hardware such as an IC (Integrated Circuit). Alternatively, it may be realized by using software and hardware together.

  Such a control unit 20 determines that the signal provided from the first binarization circuit 13 is continuously provided for a predetermined lock monitoring time or more, that is, the DC motor 3 Is continuously transmitted for more than the lock monitoring time, a motor drive stop command is given assuming that a lock abnormality has occurred in the transport mechanism 2 due to, for example, a jammed coin. The control unit 20 performs a drive monitoring control process described later.

  2A and 2B are time charts illustrating an example of the operation of the drive monitoring device 10 illustrated in FIG. 1, wherein FIG. 2A illustrates a current flowing through the DC motor 3, and FIG. FIG. 3C shows a signal supplied to the control unit 20, FIG. 4C shows a signal supplied from the second binarization circuit 14 to the control unit 20, and FIG. 4D shows ON / OFF of a motor drive command by the control unit 20. .

  When the control unit 20 sends a motor drive command to the driver circuit 11 at the time point t1, it is assumed that a current flows in the DC motor 3 as shown in FIG. In FIG. 2A, (b) indicates a stall current threshold, and (c) indicates a steady current threshold.

  At time t2 when the current flowing through the DC motor 3 becomes equal to or more than the stall current threshold, the first binarization circuit 13 gives a signal indicating that there is a current equal to or more than the stall current threshold to the control unit 20, and The binarization circuit 14 gives a signal to the control unit 20 that there is a current equal to or greater than the steady-state current threshold. Thereafter, the current flowing through the DC motor 3 decreases as the rotation speed of the DC motor 3 increases, and at time t3 when the current becomes less than the stall current threshold value, the first binarization circuit 13 A signal indicating that there is no current equal to or greater than the current threshold is given to the control unit 20. When the DC motor 3 is driven to rotate stably, the current flowing through the DC motor 3 is equal to or greater than the steady-state current threshold. Therefore, the second binarization circuit 14 determines that there is a current equal to or greater than the steady-state current threshold. A signal to that effect is continuously provided to the control unit 20.

  By the way, at time t4 when the current flowing through the DC motor 3 becomes equal to or more than the stall current threshold value for some reason, the first binarization circuit 13 determines that there is a current equal to or more than the stall current threshold value and controls the signal to that effect. To the part 20.

  If the signal indicating that there is a current equal to or larger than the stall current threshold is continuously given from the first binarization circuit 13 to the time t5 when the lock monitoring time has elapsed from the time t4, the control unit 20 determines that an abnormality has occurred. As an occurrence, the motor drive command is turned off, that is, a motor drive stop command is sent to the driver circuit 11 at time t6 immediately after. As a result, the driving of the DC motor 3 is stopped, and the second binarization circuit 14 gives a signal to that effect to the control unit 20 that there is no current equal to or greater than the steady-state current threshold.

  As described above, in the drive monitoring device 10, the control unit 20 determines that an abnormality has occurred when the current equal to or greater than the stall current threshold has continuously flowed to the DC motor 3 for the lock monitoring time, and determines that an abnormality has occurred. Is stopped to protect the DC motor 3. The control unit 20 monitors whether a current equal to or higher than the steady-state current threshold value is continuously flowing through the DC motor 3 from when the motor drive command is given to the driver circuit 11 to when the motor drive stop command is given. .

  FIG. 3 is a flowchart showing the processing content of the drive monitoring control processing performed by the control unit 20 shown in FIG. The operation of the drive monitoring device 10 will be described while describing the details of the drive monitoring control process. A part of the following description overlaps with the description of the operation based on FIG.

  In the drive monitoring control process, the control unit 20 sends a motor drive command to the driver circuit 11 (step S101), and after the motor drive command is sent, a preset start monitoring time shorter than the lock monitoring time. Until the elapse, it is determined whether or not a signal indicating that there is a current equal to or greater than the stall current threshold from the first binarization circuit 13 is continuously input for a predetermined reference time (steps S102 and S103). , Step S104).

  If a signal indicating that there is a current equal to or greater than the stall current threshold is input continuously for the reference time before the startup monitoring time elapses (Step S102: Yes, Step S103: Yes, Step S104: No), the control unit 20 It is determined whether a signal indicating that there is no current equal to or greater than the stall current threshold is input from the first binarization circuit 13 before the lock monitoring time elapses (steps S105 and S106).

  If a signal indicating that there is no current equal to or greater than the stall current threshold before the lock monitoring time elapses (step S105: Yes, step S106: No), the control unit 20 determines that the motor has started normally. (Step S107) Then, the procedure is returned, and the current process ends. According to this, it can be determined that the DC motor 3 has started normally.

  On the other hand, when a signal indicating that there is no current equal to or more than the stall current threshold is not input before the lock monitoring time elapses (Step S105: No, Step S106: Yes), that is, the DC motor 3 If the current continues to flow for the lock monitoring time or longer, the control unit 20 sends a motor drive stop command to the driver circuit 11 and determines that a lock abnormality has occurred (steps S108 and S109). The procedure is returned to end the current processing.

  According to this, it is possible to prevent the DC motor 3 from being damaged or the like and to protect the DC motor 3. When it is determined that a lock abnormality has occurred, the control unit 20 preferably performs a notification process such as displaying the fact on a display unit (not shown).

  By the way, when a signal indicating that there is a current equal to or more than the stall current threshold is not input continuously for the reference time before the start monitoring time elapses (step S102: No, step S103: No, step S104: Yes), If the startup monitoring time has elapsed without inputting a signal indicating that a current equal to or greater than the dynamic current threshold is present, the control unit 20 sends a motor drive stop command to the driver circuit 11 (step S110). The control unit 20 counts the number of processes in step S110 (step S111), and determines whether the count is equal to or greater than a predetermined reference number (for example, three) (step S112).

  If the counted number is less than the reference number (step S112: No), the control unit 20 repeats the processing from step S101. That is, the control unit 20 performs a retry process. On the other hand, when the count number is equal to or more than the reference number (step S112: Yes), the control unit 20 determines that an abnormality has occurred in activation (abnormal activation determination) (step S113), and thereafter returns to the procedure. To end the current processing.

  According to this, it can be determined that the DC motor 3 has not been started. When the abnormal activation determination is performed, it is preferable that the control unit 20 performs a notification process such as displaying the fact on a display unit (not shown).

  As described above, according to the drive monitoring device 10 according to the embodiment of the present invention, the control unit 20 supplies the DC motor 3 with the stop current threshold value until the start monitoring time elapses after the motor drive command is given. When the above-described current flows, the DC motor 3 is determined to be normally started, and a current equal to or more than the stop current threshold value flows to the DC motor 3 until the start monitoring time elapses after the motor drive command is given. If not, the DC motor 3 is determined to be abnormally activated, so that it is possible to monitor whether the DC motor 3 has been activated normally.

  According to the drive monitoring device 10, the control unit 20 controls the drive circuit 11 (DC motor 3) during a period from when the drive command is given to the driver circuit 11 (DC motor 3) until the drive stop command is given to the driver circuit 11 (DC motor 3). Since it is monitored whether or not a current equal to or greater than the steady-state current threshold value is continuously flowing through the DC motor 3, it is possible to properly detect even when power supply to the DC motor 3 is cut off due to, for example, a power failure.

  According to the drive monitoring device 10, in the drive monitoring control process, the control unit 20 determines whether a signal indicating that there is a current equal to or greater than the stall current threshold from the first binarization circuit 13 is continuously input for the reference time. Since the determination is made, a signal based on noise or the like can be eliminated, and the accuracy of current detection of the DC motor 3 can be improved.

  The preferred embodiment of the present invention has been described above, but the present invention is not limited to this, and various modifications can be made.

  In the above-described embodiment, in the drive monitoring control process, the number of times of the process of step S110 is counted, and when the count is less than the reference number, the retry process of repeating the process of step S101 is performed. In the present invention, the retry process may not be performed. In the case of performing the retry process, if a drive command to drive the DC motor 3 in the forward rotation was sent last time, a drive command to drive the DC motor 3 in the reverse rotation is sent next time. Good.

  In the above-described embodiment, the first binarization circuit 13 and the second binarization circuit 14 are provided, and the control unit 20 has a signal indicating that the current is equal to or larger than the stall current threshold, However, in the present invention, the control unit 20 inputs the current flowing through the DC motor 3 to determine whether there is a current equal to or more than the stall current threshold, The presence or absence of a current equal to or greater than the current threshold may be determined.

  Each configuration illustrated in the above-described embodiment is a schematic function and does not necessarily need to be physically configured as illustrated. That is, the form of distribution / integration of each device and component is not limited to the illustrated one, and all or a part of the apparatus / function can be functionally or physically distributed / integrated in arbitrary units according to various usage situations. Can be configured.

DESCRIPTION OF SYMBOLS 1 Coin processing apparatus 2 Transport mechanism 3 DC motor 10 Drive monitoring device 11 Driver circuit 13 1st binarization circuit 14 2nd binarization circuit 20 Control part

Claims (4)

An abnormality occurs when a drive command is given to the DC motor to drive the DC motor, and when a current equal to or greater than a predetermined stall current threshold continuously flows through the DC motor for a predetermined lock monitoring time or more, In a motor drive monitoring device comprising a control unit for stopping the drive of the DC motor as
The control unit is configured such that, when a current equal to or more than the stall current threshold flows through the DC motor before the start monitoring time shorter than the lock monitoring time has elapsed since the drive command was given, the DC motor On the other hand, when it is determined that the DC motor is normally started, if a current equal to or more than the stall current threshold does not flow through the DC motor until the start monitoring time elapses after the drive command is given, the DC motor is determined to have an abnormal start. A drive monitoring device for a motor, characterized by determining.   The control unit is configured such that a current equal to or higher than a steady-state current threshold smaller than the stall current threshold continues to be supplied to the DC motor from the time the drive command is given to the DC motor until the drive stop command is given to the DC motor. The motor drive monitoring device according to claim 1, wherein the device monitors whether the flow is flowing.   The control unit, when a current equal to or greater than the stall current threshold does not flow through the DC motor until the start monitoring time elapses after giving the drive command, gives a drive command again to the DC motor and The motor drive monitoring device according to claim 1, wherein a retry process is performed to determine whether or not a current equal to or greater than the stall current threshold value flows to the DC motor.   The motor drive monitoring device according to any one of claims 1 to 3, wherein the DC motor constitutes a drive source of a transport mechanism that transports coins.

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