JP5823716B2 - Motor drive control device, motor drive control method, and program - Google Patents

Description

  The present invention relates to a motor drive control device, a motor drive control method, and a program for controlling the drive of a motor.

  In a tape storage device provided with a motor (DC motor or stepping motor) for driving an accessor, the motor drive condition (for example, drive current or A method of changing the PWM (Pulse Width Modulation) drive duty ratio) and retrying again under the changed condition is employed. In other words, since this is a reactive method, motor driving has not always been performed in an optimal state. Patent document 1 is mentioned as this example. In the motor drive control of Patent Document 1, since the torque of the motor being driven is not detected (detected), naturally, the detection result of the torque is not reflected in the drive of the motor. Therefore, the motor drive is not always performed in an optimal state.

Japanese Patent Laid-Open No. 2005-237094

  As described above, in order to always drive the motor in the optimum state, it is necessary to perform control (feedback control, closed loop control) that detects the torque of the motor being driven and reflects the detection result in the motor drive. . On the other hand, the detection of torque is preferably realized by simple means and methods.

  The present invention has been made in view of the above circumstances, and in performing control that reflects the detection result of torque in the drive of the motor, a motor drive control device and motor drive control that can easily realize the detection of torque. An object is to provide a method and a program.

  In order to achieve such an object, a motor drive control device of the present invention includes a motor for driving an object, a torque detection means for detecting the torque of the motor by being pressurized by the object driven by the motor, and torque detection Control means for controlling the drive of the motor based on the detection result by the means, and the torque detection means is provided at an end of the drive range of the object.

  The motor drive control method of the present invention is a motor drive control method for controlling a motor that drives an object, and receives the pressure of the object driven by the motor at the end of the drive range of the object and receives the torque of the motor. And driving of the motor is controlled based on the detection result.

  The program of the present invention is a program for controlling a motor that drives an object, and is a process for detecting the torque of the motor by receiving pressurization of the object driven by the motor at the end of the driving range of the object. And a process of controlling the driving of the motor based on the detection result.

  According to the present invention, it is possible to easily realize torque detection when performing control that reflects the torque detection result in driving the motor.

It is a figure which shows the structural example of the motor drive control apparatus which concerns on one Embodiment of this invention. It is a graph which shows an example of the general relationship of a torque, a rotational speed, and a voltage pulse in each of a stepping motor and a DC motor. It is a figure which divides and shows an example of several motor drive conditions preset to the motor drive control apparatus which concerns on one Embodiment of this invention in each case of a stepping motor and a DC motor. It is a flowchart which shows the operation example of the motor drive control apparatus which concerns on one Embodiment of this invention.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments (embodiments) for carrying out the present invention will be described in detail with reference to the accompanying drawings. In the following description, a case where the motor drive control device of the present invention is applied to a tape storage device will be described as an example. In the following description, an accessor that plays a role of transporting a medium (for example, a magnetic tape) to a magazine cell or a drive will be described as an example of a mechanism unit (an object driven by a motor) with motor driving. The accessor includes an X motor (a drive actuator for moving the accessor in the horizontal direction), a Y motor (a drive actuator for moving the accessor in the vertical direction), a picker motor (a medium for the magazine cell and drive in the accessor). A drive actuator for inserting / removing). As these motors, either DC motors or stepping motors are used. In the following description, an X motor will be described as an example of a drive control target.

  As shown in FIG. 1, the tape storage device of the present embodiment is mainly configured by a motor 10, an accessor 11, a metal plate 13, a piezoelectric element 14, an output voltage amplification circuit 15, an output voltage comparison circuit 16, a CPU (Central Processing). Unit) 17, nonvolatile memory 18, and motor drive circuit 19.

  The motor 10 is, for example, an X motor as described above, and moves the accessor 11 in the horizontal direction.

  The accessor 11 carries and removes / inserts the medium from / to the magazine cell and the drive (both not shown). In the example of FIG. 1, the accessor 11 is driven by the X motor and moves in a horizontal direction along a predetermined traveling path. The travel path is a range (driving range, moving range) in which the accessor 11 can move in the horizontal direction. As shown in FIG. 1, the accessor 11 is provided with a protrusion 12. The protrusion 12 is used to concentrate pressure by pressing (contacting) a surface of a metal plate 12 described later. Thus, by applying pressure with a single pole concentration using the protrusion 12, the metal plate 13 is easily bent and a voltage described later is easily output.

  As shown in FIG. 1, a metal plate 13 and a piezoelectric element 14 are provided at the end of the access path of the accessor 11. One end of the metal plate 13 is fixedly supported by the support portion. One surface of the metal plate 13 is temporarily pressed by the protrusion 13 of the accessor 11 moving in the horizontal direction along the arrow in the figure. By this pressing (pressing), a pressing force (= torque) is applied to the metal plate 13 and the metal plate 13 is bent. As a result, the piezoelectric element 14 affixed to the back surface of the pressed surface is also deflected, resulting in minute displacement / distortion. The piezoelectric element 14 outputs a minute voltage (= torque) corresponding to the minute displacement / strain that has occurred. This minute voltage is also called “output voltage”. The output voltage increases as the micro displacement / distortion of the piezoelectric element 14 increases.

  For this reason, the metal plate 13 and the piezoelectric element 14 can be called means for detecting the torque of the motor 10 (torque detection means). As described above, in this embodiment, the metal plate 13 and the piezoelectric element 14 are provided on the extension line of the movement range of the accessor 11, so that the accessor 11 moves normally to the end of the movement range (for example, at the time of initialization operation). The torque of the motor 10 can be detected simply by moving. Therefore, according to the present embodiment, torque detection is realized with a simple configuration.

  The output voltage amplifier circuit 15 inputs and amplifies the output voltage from the piezoelectric element 14, and then outputs it to the output voltage comparison circuit 16.

  When the output voltage from the output voltage amplifier circuit 15 is input, the output voltage comparison circuit 16 compares the output voltage with the reference voltage 20 stored in advance in the nonvolatile memory 18 and outputs the comparison result to the CPU 17. The reference voltage 20 is a value actually measured / calculated based on a technical evaluation or the like, and is a lower limit value at which it can be determined that the motor 10 is normally driven and deterioration (life) is not progressing. The reference voltage 20 is stored in the nonvolatile memory 18 at the time of manufacturing a tape storage device, for example.

  The CPU 17 (an example of a control means) determines whether to maintain or change the motor driving condition being set according to the comparison result from the output voltage comparison circuit 16, and controls the control signal (how to The motor driving condition 19) is output to the motor driving circuit 19. Details of the motor drive condition determination operation of the CPU 17 will be described later.

  The motor drive circuit 19 drives the motor 10 based on the motor drive condition indicated by the control signal from the CPU 17.

  As described above, in the example shown in FIG. 1, the torque of the motor 10 being driven is detected, and feedback control (closed loop control) for reflecting the detection result on the driving of the motor 10 is performed.

  Here, the motor drive condition determination operation of the CPU 17 will be described. When the comparison result from the output voltage comparison circuit 16 is higher than the reference voltage, the CPU 17 performs control so that the motor driving condition being set is maintained without being changed. For example, when the motor driving condition being set is “motor driving condition 1” among the plurality of motor driving conditions 1 to n stored in advance in the nonvolatile memory 18, the CPU 17 performs motor driving according to the motor driving condition 1. A control signal instructing to continue driving is output to the motor drive circuit 19. On the other hand, when the comparison result from the output voltage comparison circuit 16 indicates that the output voltage is lower than the reference voltage, the CPU 17 controls to change the motor driving condition being set. For example, when the motor drive condition being set is “motor drive condition 1” among the plurality of motor drive conditions 1 to n stored in advance in the nonvolatile memory 18, the CPU 17 sets the motor drive condition 1 as a motor. A control signal for instructing to start the motor driving by changing to the driving condition 2 is output to the motor driving circuit 19.

  The plurality of motor driving conditions 1 to n are stored in the non-volatile memory 18 as the motor driving condition table 21 when the tape storage device is manufactured, for example. The plurality of motor driving conditions 1 to n are determined based on the characteristics of a general motor shown in FIG. FIG. 2A shows the characteristics of a general stepping motor. As shown in FIG. 2A, the stepping motor generally has a high rotational speed and a small torque when the number of pulse voltages (duty ratio) is dense, while the number of pulse voltages is sparse. When the rotation speed becomes slow, the torque increases. FIG. 2B shows characteristics of a general DC motor. As shown in FIG. 2B, in general, a DC motor has a high rotational speed and a small torque when the pulse voltage width is wide (long), while the pulse voltage width is narrow (short). When the rotation speed becomes slow, the torque increases. An example of the motor drive condition table 21 (a plurality of motor drive conditions 1 to n) reflecting such characteristics is shown in FIG.

  FIG. 3A shows motor driving conditions 1 to n of the stepping motor, and FIG. 3B shows motor driving conditions 1 to n of the DC motor. That is, depending on whether the motor 10 is a stepping motor or a DC motor, either one of the motor driving conditions 1 to n shown in FIG. 3A or 3B is prepared in the nonvolatile memory 18 in advance.

  In FIG. 3A, the number of pulse voltages is the most dense in motor driving condition 1, and the number of pulse voltages gradually decreases (by a predetermined number) with motor driving conditions 2 and 3, and the last motor In the driving condition n, the number of pulse voltages is sparse. Therefore, when the motor 10 is a stepping motor and a plurality of motor driving conditions 1 to n shown in FIG. 3A are defined, for example, torque (output voltage) when driving under the motor driving condition 1 ) Falls below the reference voltage, the CPU 107 controls to change from the motor driving condition 1 to the motor driving condition 2 in order to increase the torque.

  In FIG. 3B, the width of the pulse voltage is the longest in the motor driving condition 1, the width of the pulse voltage is gradually shortened (by a predetermined width) with the motor driving conditions 2 and 3, and the last motor driving condition n However, the width of the pulse voltage is the shortest. Therefore, when the motor 10 is a DC motor and a plurality of motor driving conditions 1 to n shown in FIG. 3B are defined, for example, torque (output voltage) when driving under the motor driving condition 1 ) Falls below the reference voltage, the CPU 107 controls to change from the motor driving condition 1 to the motor driving condition 2 in order to increase the torque.

  The motor driving conditions 1 to n shown in FIGS. 3A and 3B are determined within the range of the rated voltage and the rated current. That is, the number of motor driving conditions to be determined is arbitrary as long as it is within the range.

  Further, when the operation of the tape storage apparatus is finished, the CPU 17 stores in the nonvolatile memory 18 which one of the motor driving conditions set at that time is 1 to n (for example, 1 to n). Flag one of them). Then, the CPU 17 sets the stored motor driving conditions when the operation of the tape storage apparatus starts next time. Note that the motor driving condition when the motor is driven for the first time after the product shipment of the tape storage device is, for example, the motor driving condition 1 (default setting).

  An example of the operation of the tape storage device configured as described above will be described with reference to FIG.

  When the power is turned on by the user (operator) and the tape storage device is activated (S1), the accessor 11 is moved to each magazine cell or drive and an initialization operation is performed (S2). At this time, the CPU 17 reads the motor drive conditions at the end of the previous operation stored in the nonvolatile memory 18 (the default motor drive conditions for the first operation after product shipment), and performs the initialization operation according to the motor drive conditions. The motor drive circuit 19 is controlled to perform. The motor drive condition used for this initialization operation is the “motor drive condition being set”.

  In the initialization operation, when the accessor 11 driven by the motor 10 (for example, X motor) moves in the horizontal direction on the travel path and moves to the end of the travel path as shown in FIG. Is temporarily pressed (S3). By this pressing, a minute voltage (output voltage) is output from the piezoelectric element 14 as described above, and this minute voltage is amplified by the output voltage amplifier circuit 15.

  The output voltage comparison circuit 16 compares the amplified output voltage with the reference voltage 20 stored in advance in the nonvolatile memory 18 (S4). Then, as a result of the comparison, the output voltage comparison circuit 16 outputs to the CPU 17 whether or not the output voltage exceeds the reference voltage 20.

  As a result of the comparison in S4, when the output voltage exceeds the reference voltage 20 (S4 / YES), the CPU 17 maintains the motor driving condition being set (the motor driving condition used in the most recent initialization operation), and the condition Is instructed to drive the motor drive circuit 19 (S5).

  The motor drive circuit 19 drives the motor 10 under the instructed motor drive condition. As a result, the normal operation (inserting / removing or transporting of the medium by the accessor 11) is started in the tape storage device (S6). When the normal operation ends in the tape storage device, the CPU 17 stores the motor drive condition currently set in the nonvolatile memory 18. The motor drive conditions stored at this time are read out and used for the initialization operation when the tape storage device is started next time.

  On the other hand, if the output voltage is lower than the reference voltage 20 as a result of the comparison in S4 (S4 / NO), the CPU 17 refers to the motor drive condition table 21 of the nonvolatile memory 18 and further changes the motor drive condition being set. It is determined whether there is a possible motor driving condition (S7). That is, since the torque of the motor 10 is small, the CPU 17 determines whether or not other motor driving conditions that can increase the torque than the motor driving conditions being set are stored.

  If there is a motor drive condition that can be changed as a result of the determination in S7 (S7 / YES), the CPU 17 changes the motor drive condition being set to another motor drive condition, and initializes again under the changed motor drive condition. The motor drive circuit 19 is instructed to perform the operation (S10). For example, in FIG. 1, when the motor driving condition being set is 1, there are motor driving conditions 2 to n that can increase the torque more than the motor driving condition 1. Therefore, the CPU 17 sets the motor driving condition being set. The condition is changed from 1 to 2, and control is performed so that the initialization operation is performed under the motor driving condition 2. Note that it is preferable to change the method step by step, so that the motor drive condition 2 is changed next to the motor drive condition 1, for example.

  On the other hand, if there is no changeable motor drive condition as a result of the determination in S7 (S7 / NO), for example, if the motor drive condition being set is n and n + 1 is not set, the CPU 17 starts normal operation. Is instructed to stop the motor drive circuit 19 (S8). Then, the CPU 17 performs a notification that prompts the user to replace at least one of the motor 10 and the accessor 11. As the notification method, for example, a display unit (not shown) of the tape storage device may be used, or a display device (not shown) that can communicate with the tape storage device may be used.

  As described above, according to the present embodiment, the accessor that has moved to the end of the traveling path at the time of the initialization operation is provided by including the metal plate and the piezoelectric element at the end of the traveling path of the accessor. A metal plate is pressed, whereby a voltage (torque) is output from the piezoelectric element. Therefore, it is possible to easily detect the torque of the motor. In the present embodiment, the motor drive feedback control (closed loop control) is performed based on the comparison result between the voltage output from the piezoelectric element and a predetermined reference voltage. The motor can be driven while maintaining the above.

  Conventionally, it has been difficult to directly detect deterioration (life) of a motor directly in a tape storage device that does not monitor the driving state of a motor in a timely manner as in the present embodiment. That is, in such a tape storage device, when the operation time of the tape storage device or the number of operations of the accessor exceeds a specified value, a notification that prompts replacement of the motor or the accessor is performed. However, this method is effective in terms of preventive replacement before a fatal motor failure occurs, but sometimes non-degraded or remaining-life motors and accessors may be replaced wastefully. There was a typical aspect. On the other hand, according to the present embodiment, since it is possible to detect in advance that the motor and the accessor are deteriorated and the life is advanced, it is possible to prompt them to replace them before a fatal failure occurs, It is also possible to improve the conventional non-economic aspect in which non-deteriorated and remaining life motors and accessors are replaced wastefully.

  In the above description of the present embodiment, the X motor of the accessor has been described as an example. However, the present invention can be similarly applied to a Y motor or a picker motor using a DC motor or a stepping motor.

  As mentioned above, although embodiment of this invention was described, it is not limited to the said embodiment, A various deformation | transformation is possible in the range which does not deviate from the summary.

  For example, the operation in the above-described embodiment can be executed by hardware, software, or a combined configuration of both.

  When executing processing by software, a program in which a processing sequence is recorded may be installed and executed in a memory in a computer incorporated in dedicated hardware. Or you may install and run a program in the general purpose computer which can perform various processes.

  For example, the program can be recorded in advance on a hard disk or a ROM (Read Only Memory) as a recording medium. Alternatively, the program is stored on a removable recording medium such as a CD-ROM (Compact Disc Read Only Memory), an MO (Magneto Optical) disc, a DVD (Digital Versatile Disc), a USB (Universal Serial Bus) memory, a magnetic disc, and a semiconductor memory. It is possible to store (record) temporarily or permanently. Such a removable recording medium can be provided as so-called package software.

  The program may be wirelessly transferred from the download site to the computer in addition to being installed on the computer from the removable recording medium as described above. Or you may wire-transfer to a computer via networks, such as LAN (Local Area Network) and the internet. The computer can receive the transferred program and install it on a recording medium such as a built-in hard disk.

  In addition to being executed in time series in accordance with the processing operations described in the above embodiment, the processing capability of the apparatus that executes the processing, or a configuration to execute in parallel or individually as necessary Is also possible.

DESCRIPTION OF SYMBOLS 10 Motor 11 Accessor 12 Protrusion part 13 Metal plate 14 Piezoelectric element 15 Output voltage amplification circuit 16 Output voltage comparison circuit 17 CPU
18 Nonvolatile memory 19 Motor drive circuit 20 Reference voltage 21 Motor drive condition table

Claims (5)

A motor for driving the object;
Torque detecting means for detecting the torque of the motor by being pressurized to the object driven by the motor;
The drive of the motor is controlled based on the detection result by the torque detection means, and the detection result by the torque detection means falls below a preset lower limit value indicating that the motor has not deteriorated. Control means for performing control to increase the torque of the motor ,
The torque detecting means includes
A motor drive control device provided at an end of a drive range of the object. The control means includes
Even if the control for increasing the torque of the motor is performed up to the upper limit of a predetermined range, if the detection result by the torque detection means falls below the lower limit value, a notification that prompts replacement of the motor and the object is performed. The motor drive control device according to claim 1, wherein: The torque detecting means includes
A metal plate whose predetermined surface is pressed by the object driven by the motor;
A piezoelectric element provided on the back of the pressed surface of the metal plate,
The object is
A protrusion that abuts against the surface to be pressed of the metal plate;
A voltage corresponding to the torque of the motor is output from the piezoelectric element by pressing the metal plate by the protrusion.
The control means includes
When the voltage output from the piezoelectric element falls below a preset lower limit value indicating that the motor has not deteriorated, control is performed to increase the torque of the motor. The motor drive control device according to claim 1 or 2 . A motor drive control method for controlling a motor for driving an object,
At the end of the drive range of the object, the pressure of the object driven by the motor is received to detect the torque of the motor,
When the drive of the motor is controlled based on the detection result, and the detection result falls below a preset lower limit value indicating that the motor has not deteriorated, the motor The motor drive control method characterized by performing control which raises a torque . A program for controlling a motor that drives an object,
A process of detecting the torque of the motor by receiving pressurization of the object driven by the motor at an end of the driving range of the object;
When the drive of the motor is controlled based on the detection result, and the detection result falls below a preset lower limit value indicating that the motor has not deteriorated, the motor Processing to increase torque, and
A program that causes a computer to execute.

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