JP2007318908A - Apparatus and method for controlling multiple-oscillatory-wave-motor power unit, program, and storage medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a control method for a multiple-oscillatory-wave-motor power unit wherein the power unit can be started without fail. <P>SOLUTION: The multiple-oscillatory-wave-motor power unit includes: a gear 2 on which a final output shaft 1 is fixed; three pinions 3, 4, 5 engaged with the gear 2 to rotate the gear 2; and oscillatory-wave motors 6, 7, 8 with the pinions 3, 4, 5 installed on their output shafts. A controller for the multiple oscillatory-wave motor power unit includes: a rotary encoder 9 incorporated in the oscillatory-wave motor 6, so that it is rotated at a speed synchronized with the rotation of the oscillatory-wave motor 6; drive circuits 10, 11, 12 for driving the oscillatory-wave motors 6, 7, 8; an oscillation circuit 13 for supplying driving signals to the drive circuits 10, 11, 12; and a control circuit 14 for directively notifying the oscillation circuit 13 of the rotational speeds of the oscillatory-wave motors 6, 7, 8. All the oscillatory-wave motors 6, 7, 8 are once rotated in the direction opposite to a target direction of rotation, and then all the oscillatory-wave motors 6, 7, 8 are rotated in the target direction of rotation. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a control method of a multiple vibration wave motor power unit, a program, and a storage medium.

  The multiple vibration wave motor power unit is configured to drive a large gear, which is a single output means, using a plurality of vibration wave motors (see, for example, Patent Document 1).

  The multiple vibration wave motor power unit includes a large gear with a final output shaft fixed, and three vibration wave motors with three small gears meshed with the large gear to rotate the large gear, each attached to the output shaft. Prepare. A rotary encoder is mounted on one of the vibration wave motors, and the rotary encoder rotates at a speed synchronized with the rotation of one of the vibration wave motors.

  The control device for the multiple vibration wave motor power unit obtains rotation information of the vibration wave motor mounted on the rotary encoder from the rotary encoder and compares it with a target speed to perform speed feedback control.

  FIG. 5 is a flowchart showing the procedure of the starting process of the conventional multiple vibration wave motor power unit.

In FIG. 5, the controller for the multiple vibration wave motor power unit lowers the command frequency from the initial frequency fa at the time of activation (FIG. 6) in the direction of the arrow when starting the multiple vibration wave motor power unit (step S51). Frequency output is performed (step S52). When a signal is acquired from the rotary encoder (YES in step S53), the frequency at that time is recognized as the activation frequency fs, and then the process shifts to speed feedback control.
Japanese Patent Laid-Open No. 2001-205190

  However, as shown in FIG. 7, in the multiple vibration wave motor power unit, the large gear 22 fixed to the final rotating shaft cannot be driven only by combining the outputs of two or less vibration wave motors. That is, the large gear 22 cannot be driven unless the outputs of all three vibration wave motors 23, 24, 25 are combined. Here, it is needless to say that backlash is secured at the contact portion between the large gear 22 and the small gears 23, 24, and 25.

  When the contact state of each gear of the multiple vibration wave motor power unit immediately before starting is the state shown in FIGS. 7 and 8, the small gear 23 fixed to the vibration wave motor equipped with the rotary encoder after starting is shown in FIG. Try to rotate in the direction of the arrow. However, since it is in contact with the tooth surface of the large gear 22, it cannot move to the place where the first pulse from the rotary encoder is received. Meanwhile, the small gears 24 and 25 fixed to other vibration wave motors move in the direction of the arrow. While the small gears 24 and 25 are moving, the vibration wave motor equipped with the rotary encoder sweeps the frequency lower, so that the small gears 24 and 25 reach the tooth surface of the large gear 22 in the target rotation direction. Therefore, when the large gear 22 starts to rotate, the speed is higher than the original starting speed. As a result, in the subsequent speed feedback control, it takes time to return due to the difference between the target speed and the current speed, so the characteristics of the vibration wave motor with high response characteristics are fully demonstrated. Can not.

  At low temperatures, the torque characteristics of the vibration wave motor also deteriorate. Therefore, the vibration wave motor equipped with the rotary encoder cannot generate torque before the small gears 24 and 25 reach the tooth surface of the large gear 22 in the traveling direction. It gets into the area and in the worst case it can't be activated.

  An object of the present invention is to provide a control method for a multiple vibration wave motor power unit that can reliably start the multiple vibration wave motor power unit without being affected by a torque drop in a low temperature environment.

  In order to achieve the above object, a controller for a multiple vibration wave motor power unit according to claim 1 includes a first gear, a plurality of second gears meshed with the first gear, and the plurality of gears. In a control device for a multiple vibration wave motor power unit comprising a plurality of vibration wave motors each having a second gear attached thereto, first, the plurality of the plurality of vibration waves so that the first gear rotates in a direction opposite to the target rotation direction. Control means is provided for rotating the vibration wave motor, and then rotating the plurality of vibration wave motors so that the first gear rotates in the target rotation direction.

  The control method of the multiple vibration wave motor power unit according to claim 5 is provided with a first gear, a plurality of second gears meshed with the first gear, and the plurality of second gears, respectively. In a control method of a multiple vibration wave motor power unit including a plurality of vibration wave motors, first, the plurality of vibration wave motors are rotated so that the first gear rotates in a direction opposite to a target rotation direction, and then And a control step of rotating the plurality of vibration wave motors so that the first gear rotates in the target rotation direction.

  The program according to claim 9 includes a first gear, a plurality of second gears meshed with the first gear, and a plurality of vibration wave motors to which the plurality of second gears are respectively attached. In the control program for the multiple vibration wave motor power unit, first, the plurality of vibration wave motors are rotated so that the first gear rotates in a direction opposite to a target rotation direction, and then the first gear is A control module that rotates the plurality of vibration wave motors to rotate in a target rotation direction is executed by a computer.

  A computer-readable storage medium according to a tenth aspect stores the program according to the ninth aspect.

  According to the present invention, it is possible to reliably start a multiple vibration wave motor power unit without being affected by torque reduction in a low temperature environment.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a diagram schematically showing a configuration of a control device for a multiple vibration wave motor power unit according to an embodiment of the present invention.

  In FIG. 1, a multiple vibration wave motor power unit includes a large gear 2 as a first gear to which a final output shaft 1 is fixed, and three second gears meshed with the large gear 2 to rotate the large gear 2. Small gears 3, 4, and 5 are provided as gears. Further, vibration wave motors 6, 7 and 8 having these small gears 3, 4 and 5 attached to the output shaft are provided. Instead of the final output shaft 1, another output gear may be engaged with the large gear 2 and power may be taken out through the output gear.

  The control device for the multiple vibration wave motor power unit includes a rotary encoder 9 mounted on the vibration wave 6 to rotate at a speed synchronized with the rotation of the vibration wave motor 6. In addition, drive circuits 10, 11, and 12 that drive the vibration wave motors 6, 7, and 8 and an oscillation circuit 13 that supplies drive signals to the drive circuits 10, 11, and 12 are provided. Furthermore, a control circuit 14 for instructing the oscillation circuit 13 to rotate the rotational speeds of the vibration wave motors 6, 7, and 8 and a power supply circuit 15 for supplying predetermined power to each circuit are provided. The control circuit 14 is configured to receive the rotational speed information of the vibration wave motor 6 from the rotary encoder 9.

  The control circuit 14 sends a frequency command corresponding to the target speed of the large gear 2 to the oscillation circuit 13, and the oscillation circuit 13 converts the frequency command into a frequency and sends it to the drive circuits 10, 11, and 12. The drive circuits 10, 11, 12 apply the drive signal including the conversion frequency component to the vibration wave motors 6, 7, 8 to cause the large gear 2 and eventually the final output shaft 1 to pass through the small gears 3, 4, 5. Rotate. The control circuit 14 performs speed feedback control by acquiring rotation information of the vibration wave motor 6 from the rotary encoder 9 and comparing it with a target speed.

  FIG. 2 is a flowchart showing the procedure of the starting process of the multiple vibration wave motor power unit of FIG.

  In the present embodiment, as shown in FIG. 3, the small gear 3 fixed to the vibration wave motor 6 mounted on the rotary encoder 9 is in contact with the tooth surface of the large gear 2 in the target rotation direction. Then, it is assumed that the small gears 4 and 5 of the other vibration wave motors 7 and 8 are in contact with the tooth surfaces of the large gear 2 on the side opposite to the target rotation direction.

  In FIG. 2, first, the rotational directions of all the vibration wave motors 6, 7, and 8 are once set in the direction opposite to the target rotational direction (step S21), and then the command frequency is lowered (step S22). Output is performed (step S23). And it is discriminate | determined whether the output was acquired from the rotary encoder 9 (step S24).

  Specifically, first, a drive signal set to a frequency sufficiently higher than the resonance frequency is supplied to each of the vibration wave motors 6, 7, and 8, and then gradually increased in order to increase the rotational speed of the vibration wave motor to some extent. Decrease the set value of the frequency of the drive signal. Then, after a lapse of a predetermined time sufficient for all of the gears 3, 4, 5 fixed to the vibration wave motors 6, 7, 8 to contact the tooth surface in the direction opposite to the target rotation direction of the large gear 2, It is determined whether or not the rotation information of the vibration wave motor 6 has been acquired from the encoder.

  As a result of the determination in step S24, when the output is obtained from the rotary encoder 9, all the small gears 3, 4, 5 fixed to the vibration wave motors 6, 7, 8 are large in the direction opposite to the target rotation direction. It can be determined that they are in contact with the tooth surface of the gear 2 (FIG. 4). When the output is not acquired from the rotary encoder 9, any of the small gears 3, 4, 5 is not in contact with the tooth surface on the target rotation direction side of the large gear 2 due to some accident. Here, the reason for waiting for a predetermined time before detecting the output signal of the rotary encoder is to ensure the time until the gear of the vibration wave motor connected to the rotary encoder reaches the same side surface of the gear 16. It is.

  Next, after setting the rotational direction of all the vibration wave motors 3, 4, 6 to the target rotational direction (step S 25), the frequency output is performed (step S 27) while lowering the command frequency (step S 26). And it is discriminate | determined whether the output signal was acquired from the rotary encoder 9 (step S28). The specific operation is the same as described above.

  As a result of the determination in step S28, when a signal is acquired from the rotary encoder 9, all the small gears 3, 4, and 5 fixed to the vibration wave motors 6, 7, and 8 are connected to the teeth of the large gear 2 in the target rotation direction. It can be determined that the surfaces are in contact with each other. As a result, it is assumed that the multiple vibration wave motor power unit has been successfully started, and the flow shifts to speed feedback control.

  According to the process of FIG. 2, all the vibration wave motors 6, 7, and 8 are once rotated in the direction opposite to the target rotation direction (steps S21 to S23). Therefore, all the small gears 3, 4, 5 fixed to the vibration wave motors 6, 7, 8 can be brought into contact with the tooth surfaces of the large gear 2 in the direction opposite to the target rotation direction. As a result, when all the vibration wave motors 6, 7, 8 are then rotated in the target rotation direction (steps S 21 to S 23), all the small gears 3, 4, 5 are moved to the large gear 2 in the target rotation direction. It can be brought into contact with the tooth surface. Therefore, the multiple vibration wave motor power unit can be reliably activated without being affected by torque reduction in a low temperature environment.

  Another object of the present invention is to supply a storage medium storing software program codes for realizing the functions of the embodiments to a system or apparatus, and the computer (or CPU, MPU, etc.) of the system or apparatus stores the storage medium. It is also achieved by reading out and executing the program code stored in.

  In this case, the program code itself read from the storage medium realizes the functions of the above-described embodiments, and the program code and the storage medium storing the program code constitute the present invention.

  Examples of the storage medium for supplying the program code include a floppy (registered trademark) disk, a hard disk, a magneto-optical disk, a CD-ROM, a CD-R, a CD-RW, a DVD-ROM, a DVD-RAM, and a DVD. -RW, DVD + RW, magnetic tape, nonvolatile memory card, ROM, etc. can be used. Alternatively, the program code may be downloaded via a network.

Further, by executing the program code read by the computer, not only the functions of the above-described embodiments are realized, but also an OS (operating system) running on the computer based on the instruction of the program code. This includes a case where part or all of the actual processing is performed and the functions of the above-described embodiments are realized by the processing.
Further, after the program code read from the storage medium is written in a memory provided in a function expansion board inserted into the computer or a function expansion unit connected to the computer, the function expansion is performed based on the instruction of the program code. This includes a case where the CPU or the like provided in the board or the function expansion unit performs part or all of the actual processing and the functions of the above-described embodiments are realized by the processing.

It is a figure which shows schematically the structure of the control apparatus of the multiple vibration wave motor power unit which concerns on the form of embodiment of this invention. It is a flowchart which shows the procedure of the starting process of the multiple vibration wave motor power unit of FIG. FIG. 2 is a schematic diagram for explaining a contact state between a large gear and three small gears fixed to three vibration wave motors in the multiple vibration wave motor power unit of FIG. 1, and corresponds to step S <b> 21 of FIG. 2. 2 is a schematic diagram for explaining a contact state between a large gear and three small gears fixed to three vibration wave motors in the multiple vibration wave motor power unit of FIG. 1, and corresponds to step S25 of FIG. It is a flowchart which shows the procedure of the starting process of the conventional multiple vibration wave motor power unit. It is a figure explaining the relationship of the frequency-rotation speed and starting direction of a vibration wave motor. It is a figure explaining the contact state of the three small gears each fixed to the large gearwheel and the three vibration wave motors in a multiple vibration wave motor power unit. FIG. 8 is a diagram schematically illustrating FIG. 7.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Final rotating shaft 2 Large gears 3, 4, 5 Small gears 6, 7, 8 Vibration wave motor 9 Rotary encoder 10, 11, 12 Drive circuit 13 Oscillation circuit 14 Control circuit 15 Power supply circuit

Claims (10)

Control of a multiple vibration wave motor power unit comprising a first gear, a plurality of second gears meshed with the first gear, and a plurality of vibration wave motors to which the plurality of second gears are respectively attached. In the device
The plurality of vibration wave motors are rotated so that the first gear rotates in a direction opposite to the target rotation direction, and then the plurality of vibration waves are rotated so that the first gear rotates in the target rotation direction. A control apparatus for a multiple vibration wave motor power unit, comprising control means for rotating the motor.   2. The control unit according to claim 1, wherein after the first gear rotates in the reverse direction, the control unit rotates the plurality of vibration wave motors so as to rotate in a target rotation direction after a predetermined time. Control device for multiple vibration wave motor power unit.   3. The control of a multiple vibration wave motor power unit according to claim 2, wherein the predetermined time is a time sufficient for all of the plurality of second gears to contact the tooth surfaces of the first gear. apparatus.   The control means includes a rotary encoder mounted on one of the vibration wave motors to rotate at a speed synchronized with one of the plurality of vibration wave motors, and based on the output of the rotary encoder, 4. The control device for a multiple vibration wave motor power unit according to any one of claims 1 to 3, wherein speed feedback control of a gear is performed. Control of a multiple vibration wave motor power unit comprising a first gear, a plurality of second gears meshed with the first gear, and a plurality of vibration wave motors to which the plurality of second gears are respectively attached. In the method
The plurality of vibration wave motors are rotated so that the first gear rotates in a direction opposite to the target rotation direction, and then the plurality of vibration waves are rotated so that the first gear rotates in the target rotation direction. A control method of a multiple vibration wave motor power unit comprising a control step of rotating a motor.   6. The control step according to claim 5, wherein after the first gear rotates in the reverse direction, the plurality of vibration wave motors are rotated so as to rotate in a target rotation direction after a predetermined time. Control method of multiple vibration wave motor power unit.   7. The control of a multiple vibration wave motor power unit according to claim 6, wherein the predetermined time is a time sufficient for all of the plurality of second gears to contact the tooth surface of the first gear. Method.   The control step includes a rotary encoder mounted on one of the vibration wave motors to rotate at a speed synchronized with one of the plurality of vibration wave motors, and the first step is based on an output of the rotary encoder. 8. The control method of a multiple vibration wave motor power unit according to claim 5, wherein speed feedback control of a gear is performed. Control of a multiple vibration wave motor power unit comprising a first gear, a plurality of second gears meshed with the first gear, and a plurality of vibration wave motors to which the plurality of second gears are respectively attached. In the program
The plurality of vibration wave motors are rotated so that the first gear rotates in a direction opposite to the target rotation direction, and then the plurality of vibration waves are rotated so that the first gear rotates in the target rotation direction. A program for causing a computer to execute a control module for rotating a motor.   A computer-readable storage medium storing the program according to claim 9.

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