Motor controller

Abstract

To provide a motor controller capable of improving positioning accuracy.SOLUTION: A motor controller according to the present embodiment includes: an adjustment part that adjusts a position command of a driving mechanism operated by a motor as a position command of the motor according to a linear function and adjusts a detection value of an angle sensor for detecting an angle of the motor as a detection position of the driving mechanism according to the linear function; and a movement amount correction part that corrects a movement amount of the motor based on a difference between an output by the adjustment part according to the linear function and an output by the driving mechanism according to a transfer function.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] An embodiment according to the present invention relates to a motor control device. [Background technology]

[0002] In some cases, a servo amplifier is used to position a machine (drive mechanism). In this case, the correction of the motor movement amount relative to the minimum command unit of the movement amount of the drive mechanism is sometimes handled by the gear setting of the servo amplifier. Since this gear setting is proportional (a linear function), if the drive mechanism is a quadratic function such as a link mechanism, there is a possibility that a slight error will occur in the positioning of the drive mechanism. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 4-175906 [Patent Document 2] Japanese Patent Application Publication No. 5-337729 Summary of the Invention [Problem to be solved by the invention]

[0004] An object of the present invention is to provide a motor control device capable of improving positioning accuracy. [Means for solving the problem]

[0005] The motor control device according to this embodiment includes an adjustment unit that adjusts the position command of the drive mechanism operated by the motor using a linear function as a position command of the motor, and adjusts the detection value of an angle sensor that detects the angle of the motor using a linear function as a detected position of the drive mechanism, and a movement amount correction unit that corrects the movement amount of the motor based on the difference between the output of the adjustment unit using the linear function and the output using the transfer function of the drive mechanism. [Brief description of the drawings]

[0006] [Figure 1] 1 is a block diagram showing an example of a configuration of a higher-level device and a motor control device according to a first embodiment. [Diagram 2] 1 is a block diagram showing an example of a configuration of a servo amplifier according to a first embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0007] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. The present invention is not limited to this embodiment. The drawings are schematic or conceptual, and the ratio of each part is not necessarily the same as the actual one. In the specification and drawings, elements similar to those described above with respect to the previous drawings are given the same reference numerals, and detailed descriptions are omitted as appropriate.

[0008] (First embodiment) FIG. 1 is a block diagram showing an example of the configuration of a host device 100 and a motor control device 200 according to the first embodiment.

[0009] The upper device 100 transmits a machine command position to the motor control device 200. The machine command position is a position command for a drive mechanism. The drive mechanism will be described later.

[0010] The motor control device 200 includes a motor 10, an angle detector 20, and a servo amplifier 50.

[0011] At least a part of the motor control device 200 including the servo amplifier 50 is used in, for example, a loom, but may also be used in industrial machinery or the like.

[0012] The motor 10 is connected to a drive mechanism (not shown) and operates the drive mechanism. The transfer function of the drive mechanism is not a linear function. The drive mechanism has, for example, a quadratic transfer function. The drive mechanism is, for example, a link mechanism. More specifically, the drive mechanism is, for example, a pile motion mechanism used in a loom. The drive mechanism according to this embodiment may be another drive mechanism as long as it has a fixed transfer function.

[0013] The angle detector (angle sensor) 20 detects the angle (position) of the motor 10. The angle detector 20 transmits the detection value of the angle detector 20 to the servo amplifier 50. The angle detector 20 is, for example, an encoder or a resolver.

[0014] The servo amplifier 50 receives a machine command position from the higher-level device 100, and receives the detection value of the angle detector 20 from the angle detector 20. The servo amplifier 50 performs feedback control of the motor 10 using the received detection value of the angle detector 20. In addition, the servo amplifier 50 corrects errors that occur when positioning the drive mechanism, as will be described later with reference to FIG.

[0015] Next, the correction of positioning errors by the servo amplifier 50 will be described in detail.

[0016] FIG. 2 is a block diagram showing an example of the configuration of the servo amplifier 50 according to the first embodiment.

[0017] The servo amplifier 50 includes a first amplifier section 30 and a second amplifier section 40.

[0018] The first amplifier unit 30 performs a correction process for the positioning error. The second amplifier unit 40 performs a feedback control to control the position of the motor 10. The correction process by the first amplifier unit 30 is performed in the same processing cycle as the position control by the second amplifier unit 40.

[0019] The first amplifier section 30 has a differentiator D30, an electronic gear 31, an adder A30, a subtractor S30, an electronic gear 32, an integrator I30, and a movement amount correction section 33. The second amplifier section 40 has a subtractor S40 and a position loop calculation section 41. The motor control device 200 further includes an integrator I1, an integrator I2, and an integrator I3.

[0020] The differentiator D30 receives a machine command position generated by the higher-level device 100. The differentiator D30 differentiates the machine command position and transmits a distribution command.

[0021] The integrator I1 receives the distributed command from the differentiator D30. The integrator I1 integrates the distributed command and transmits the machine command coordinates.

[0022] The electronic gear 31 receives a distribution command from the differentiator D30. The electronic gear 31 adjusts the distribution command in command units of the drive mechanism to a position command of the motor 10 in motor sensor pulse units using a predetermined ratio (proportional relationship). That is, the electronic gear (adjustment unit) 31 adjusts the position command (distribution command) of the drive mechanism operated by the motor 10 as a position command of the motor 10 using a linear function. The electronic gear 31 transmits the position command of the motor 10.

[0023] The adder A30 receives a position command for the motor 10 from the electronic gear 31, and receives a movement correction amount per unit time (control cycle) from the movement amount correction unit 33. The adder A30 adds the movement correction amount per unit time to the position command for the motor 10, and transmits the position command for the motor 10 to which the movement correction amount per unit time has been added.

[0024] Integrator I2 receives the position command from adder A30. Integrator I2 integrates the position command and provides a motor sensor pulse command value.

[0025] The subtractor S40 receives a position command from the adder A30, and receives position feedback (motor sensor pulses) from the angle detector 20. The position feedback is a detection value of the angle detector 20. The subtractor S40 subtracts the position feedback from the position command of the motor 10, and transmits the amount of position deviation per unit time.

[0026] The position loop calculation unit 41 receives the amount of position deviation per unit time from the subtractor S40. The position loop calculation unit 41 generates a speed command from the position command of the motor 10 by calculation of position loop processing, and transmits the speed command. Note that the position loop calculation unit 41, including the subtractor S40, may be called a position control unit. Thereafter, a current command is generated from the speed command, and the current command is input to the motor 10.

[0027] Integrator I3 receives position feedback from angle detector 20. Integrator I3 integrates the position feedback and delivers the motor sensor pulse current value.

[0028] The subtractor S30 receives position feedback from the angle detector 20, and receives the movement correction amount per unit time from the movement amount corrector 33. The subtractor S30 subtracts the movement correction amount per unit time from the position feedback, and transmits the position feedback from which the movement correction amount per unit time has been subtracted.

[0029] The electronic gear 32 receives position feedback from the subtractor S30. The electronic gear 32 adjusts the position feedback in motor sensor pulse units to position feedback in command units of the drive mechanism using a predetermined ratio (proportional relationship). That is, the electronic gear (adjustment unit) 32 adjusts the detection value of the angle detector 20 as the detected position of the drive mechanism using a linear function. The ratio of the electronic gear 32 is the reciprocal of the ratio of the electronic gear 31. The electronic gear 32 transmits position feedback.

[0030] An integrator I30 receives position feedback from electronic gear 32. Integrator I30 integrates the position feedback and transmits the current machine position, which may be monitored, for example, by a user.

[0031] The movement amount correction unit 33 corrects the movement amount of the motor 10 based on the difference between the output of the linear function of the electronic gears 31, 32 and the output of the transfer function of the drive mechanism. The movement amount correction unit 33 has a correction calculation unit 331 and a differentiator D33.

[0032] The correction calculation unit 331 receives the current machine position from the integrator I30. The correction calculation unit 331 calculates a correction amount absolute value from the current machine position using a function (transfer function) of the drive mechanism, and transmits the correction amount absolute value. More specifically, the correction calculation unit 331 calculates the original position of the drive mechanism from the current machine position using the transfer function of the drive mechanism. The correction calculation unit 331 calculates the correction amount absolute value as the difference between the current machine position and the original position of the drive mechanism. That is, the correction calculation unit 331 calculates a correction amount (correction amount absolute value) for the movement amount of the motor 10 using the transfer function of the drive mechanism based on the detected position of the drive mechanism (current machine position).

[0033] The differentiator D33 receives the correction amount absolute value from the correction calculation unit 331. The differentiator D33 differentiates the correction amount absolute value and transmits a movement correction amount per unit time. This makes it possible to perform correction for position control in a discrete value system.

[0034] As described above, the adder A30 adds the movement correction amount per unit time to the position command of the motor 10. As a result, the movement amount correction unit 33 corrects the movement amount of the motor 10 with respect to the position command of the motor 10. As a result, the actual position of the drive mechanism can be corrected. Note that, depending on the calculation method of the movement correction amount per unit time, subtraction may be performed instead of addition. Therefore, "correcting the movement amount of the motor 10" by the movement amount correction unit 33 is not limited to addition and may be subtraction.

[0035] As described above, subtractor S30 subtracts the movement correction amount per unit time from the position feedback. As a result, movement amount correction unit 33 subtracts the correction of the movement amount of motor 10 from the detection value of angle detector 20. As a result, the correction is applied to internal position control, and the current position of the drive mechanism (current machine position) becomes the unit system before correction by movement amount correction unit 33. Note that, depending on the calculation method of the movement correction amount per unit time, addition may be performed instead of subtraction. Therefore, "subtracting the correction of the movement amount of motor 10" by movement amount correction unit 33 is not limited to subtraction, and may be addition.

[0036] As described above, according to the first embodiment, the movement amount correction unit 33 corrects the movement amount of the motor 10 based on the difference between the output of the linear function of the electronic gears 31 and 32 and the output of the transfer function of the drive mechanism. This makes it possible to suppress positioning errors and improve positioning accuracy.

[0037] (First Comparative Example) As a first comparative example, a case in which the movement amount correcting section 33 is not provided will be described.

[0038] When positioning the drive mechanism, the motor movement amount is adjusted relative to the minimum command unit of the movement amount of the drive mechanism by setting the electronic gears 31, 32. When the transfer function of the drive mechanism is a linear function, such as a ball screw, the positioning can be performed appropriately. However, when the transfer function of the drive mechanism is a quadratic function, a difference may occur between the output of the linear function of the electronic gears 31, 32 and the output of the transfer function of the drive mechanism. Therefore, an error may occur between the position of the motor 10 and the actual position of the drive mechanism. As a result, a positioning error of the drive mechanism may occur.

[0039] In contrast to this, in the first embodiment, the error in the amount of movement can be corrected by providing the movement amount correction unit 33. As a result, the positioning accuracy can be improved.

[0040] (Second Comparative Example) As a second comparative example, a case where pitch error correction is performed will be described.

[0041] In pitch error compensation, the amount of positioning error (compensation amount) is obtained for each pitch and then compensated. However, a compensation table is required, and it can be difficult to set the compensation value. In addition, in pitch error compensation, linear interpolation or other interpolation is performed between pitches.

[0042] In contrast, in the first embodiment, the correction amount is calculated using a transfer function. That is, the calculation of the correction amount is expressed as a function. This makes it possible to reduce the table storage area and to further simplify the settings related to error correction. Also, the correction amount can be appropriately obtained at any position including between pitches.

[0043] At least a part of the data processing method in the motor control device according to the present embodiment may be configured with hardware or software. In the case of configuring with software, a program for realizing at least a part of the functions of the data processing method may be stored in a recording medium such as a flexible disk or a CD-ROM, and may be read and executed by a computer. The recording medium is not limited to a removable one such as a magnetic disk or an optical disk, but may be a fixed recording medium such as a hard disk device or a memory. In addition, a program for realizing at least a part of the functions of the data processing method may be distributed via a communication line (including wireless communication) such as the Internet. Furthermore, the program may be encrypted, modulated, or compressed and distributed via a wired line or wireless line such as the Internet, or stored in a recording medium.

[0044] Although some embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the scope of the invention and its equivalents described in the claims, as well as in the scope and spirit of the invention. [Explanation of symbols]

[0045] 200 motor control device, 10 motor, 20 angle detector, 30 first amplifier section, 31 electronic gear, 32 electronic gear, 33 movement amount correction section, 40 second amplifier section, 50 servo amplifier

Claims

1. an adjustment unit that adjusts a position command of a drive mechanism operated by a motor as a position command of the motor using a linear function, and adjusts a detection value of an angle sensor that detects an angle of the motor as a detected position of the drive mechanism using the linear function; a movement amount correction unit that corrects a movement amount of the motor based on a difference between an output of the adjustment unit based on a linear function and an output of the drive mechanism based on a transfer function; A motor control device comprising:

2. The motor control device according to claim 1 , wherein the movement amount correction unit calculates a correction amount for the movement amount of the motor by using a transfer function of the drive mechanism, based on the detected position of the drive mechanism.

3. the movement amount correction unit corrects the movement amount of the motor in response to the motor position command; The motor control device according to claim 1 , wherein the movement amount correction unit subtracts a correction for the movement amount of the motor from the detection value of the angle sensor.

4. The motor control device according to claim 1 , wherein a transfer function of the drive mechanism is a quadratic function.

5. The motor control device according to claim 1 , wherein the adjustment unit is an electronic gear.

6. The motor; The angle sensor; The motor control device of claim 1 further comprising:

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