Motor control device, motor control method, and motor control program

Abstract

To provide a motor control device that can control a speed and torque of a motor at a high speed.SOLUTION: A motor control device 10 is provided with: a control part 12 comprising a reference speed command generating part 121 that generates a reference speed command to a motor 4 that generates rotation power; a speed correction amount generating part 111 that generates a speed correction amount in response to the reference speed command; a speed subtractor 114 that subtracts the reference speed command corrected based on the speed correction amount and the measured speed of the motor 4 to calculate a speed deviation; a speed deviation converting part 115 that converts the speed deviation to a reference torque command to the motor 4; a torque correction amount generating part 116 that generates a torque correction amount in response to the reference torque command; a torque subtractor 118 that subtracts the reference torque command corrected based on the torque correction amount and the measured torque of the motor 4 to calculate a torque deviation; and a torque deviation converting part 119 that converts the torque deviation to electric power to be applied to the motor 4, which further is provided with a driving part 11 whose processing cycle is shorter than a processing cycle in the control part 12.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a motor control device and the like. [Background technology]

[0002] Patent Document 1 discloses a motor control device that compensates for the speed and torque of a motor that generates rotational power. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 9-161357 Summary of the Invention [Problem to be solved by the invention]

[0004] When motor operation needs to be precisely controlled in a short time, such as during sudden acceleration or deceleration, a motor control device with a long processing cycle may not be able to compensate for speed and torque in time.

[0005] The present invention has been made in view of the above circumstances, and has as its object to provide a motor control device and the like that can control the speed and torque of a motor at high speed. [Means for solving the problem]

[0006] In order to solve the above problem, one aspect of the present invention provides a motor control device comprising: a control unit having a reference speed command generation unit that generates a reference speed command for a motor that generates rotational power; a speed correction amount generation unit that generates a speed correction amount for the reference speed command; a speed subtractor that calculates a speed deviation by subtracting the reference speed command corrected by the speed correction amount from the measured motor speed; a speed deviation conversion unit that converts the speed deviation into a reference torque command for the motor; a torque correction amount generation unit that generates a torque correction amount for the reference torque command; a torque subtractor that calculates a torque deviation by subtracting the reference torque command corrected by the torque correction amount from the measured motor torque; and a torque deviation conversion unit that converts the torque deviation into power to be applied to the motor; and a drive unit whose processing cycle is shorter than the processing cycle of the control unit.

[0007] In this aspect, the speed correction amount and torque correction amount are generated in the drive unit, which has a shorter processing cycle than the control unit, so that the speed and torque of the motor can be controlled at high speed.

[0008] Another aspect of the present invention is a motor control method comprising: a reference speed command generating step, executed by a control unit, for generating a reference speed command for a motor that generates rotational power; a speed correction amount generating step, executed by a drive unit having a processing cycle shorter than that of the control unit, for generating a speed correction amount for the reference speed command; a speed subtraction step, calculating a speed deviation by subtracting the reference speed command corrected by the speed correction amount from the measured motor speed; a speed deviation converting step, converting the speed deviation into a reference torque command for the motor; a torque correction amount generating step, generating a torque correction amount for the reference torque command; a torque subtraction step, calculating a torque deviation by subtracting the reference torque command corrected by the torque correction amount from the measured motor torque; and a torque deviation converting step, converting the torque deviation into power applied to the motor.

[0009] Any combination of the above components and any conversion of these expressions into methods, devices, systems, recording media, computer programs, etc. are also encompassed by the present invention. [Effects of the Invention]

[0010] According to the present invention, the speed and torque of the motor can be controlled at high speed. [Brief explanation of the drawings]

[0011] [Figure 1] 1 shows a schematic configuration of a transport control device. [Figure 2] FIG. 2 is a functional block diagram of the motor control device. [Figure 3] A specific example of the speed correction amount for the reference speed command will be shown below. [Figure 4] A specific example of the speed correction amount for the reference speed command will be shown below. [Figure 5] A specific example of the torque correction amount for the reference torque command will be shown below. [Figure 6] 10 shows a modified example of the torque correction amount generating unit. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, a mode for carrying out the present invention (hereinafter also referred to as an embodiment) will be described in detail with reference to the drawings. In the description and / or drawings, identical or equivalent components, members, processes, etc. will be assigned the same reference numerals, and redundant explanations will be omitted. The scale and shape of each part shown in the drawings are set for convenience to simplify the explanation, and should not be interpreted as limiting unless otherwise specified. The embodiment is an example and does not limit the scope of the present invention in any way. All features and combinations thereof described in the embodiment are not necessarily essential to the present invention.

[0013] FIG. 1 is a schematic diagram showing the configuration of a conveyance control device 1 that controls the conveyance operation of a conveyance device 2 that conveys a conveyed object 3. The conveyed object 3 can be, for example, a linear object such as a string or wire, or a planar object such as paper, cloth, film, foil, or rubber. In this embodiment, a roll-to-roll conveyance device 2 that conveys a planar substrate as the conveyed object 3 in a conveyance direction (the left-right direction in FIG. 1) is described. The conveyance device 2 may be part of a device that applies any processing to the conveyed object, such as a coater or applicator that applies a coating to the conveyed object, a printer that prints on the conveyed object, a stretching device that applies tension to the conveyed object to stretch it, or a box-making machine that assembles cardboard boxes or the like into boxes while conveying the conveyed object.

[0014] The conveying device 2 includes a conveying roller group 20 and a dancer 24. The conveying roller group 20 includes a plurality of conveying rollers as a plurality of conveying sections that convey the conveyed object 3. In the example of FIG. 1, the conveying roller group 20 includes three conveying roller pairs arranged in series along the conveying direction of the conveyed object 3. The plurality of conveying rollers are adjacent to each other in the conveying direction. Each conveying roller pair includes a driving roller 211-213 that is rotationally driven by each of the driving units 11A-11C described below, and a driven roller 221-223 that rotates in conjunction with the driving roller 211-213, sandwiching the conveyed object 3 between the driving roller 211-213. The three conveying roller pairs 211 / 221-213 / 223 and the three corresponding driving units 11A-11C provided in the conveying control device 1 can be configured similarly to each other. Therefore, the following will explain the first conveying roller pair 211 / 221 and the first drive unit 11A, and will omit redundant explanations of the other conveying roller pairs 212 / 222, 213 / 223, and the other drive units 11B and 11C. Note that the number of conveying roller pairs provided in the conveying roller group 20 may be any number (any integer greater than or equal to 1).

[0015] The drive roller 211 and the driven roller 221 are transport rollers that serve as one aspect of a transport unit that transports the transported object 3, and are rotatable around a rotation axis that is perpendicular to the transport direction (the left-right direction in FIG. 1) (the direction perpendicular to the plane of FIG. 1). A motor (not shown in FIG. 1) that is provided alongside the drive roller 211 is rotationally driven by the drive unit 11A based on a reference rotation speed command generated by the control unit 12, which, together with the drive units 11A to 11C, constitutes the motor control device 10 of this embodiment. When the transport direction of the transported object 3 in FIG. 1 is rightward, the drive roller 211 is rotationally driven in the clockwise direction by the drive unit 11A, and the driven roller 221 rotates counterclockwise in conjunction with the drive roller 211. By individually rotating and driving each of the drive rollers 211 to 213 that make up the conveying roller group 20 by each of the drive units 11A to 11C of the conveying control device 1, the speed and tension of each part of the conveyed object 3 can be finely controlled, thereby optimizing the conveying operation of the conveying device 2 for the conveyed object 3 and the processing by various devices in which the conveying device 2 is installed.

[0016] The dancers 24 are provided upstream (left side in FIG. 1) and downstream (right side in FIG. 1) in the conveying direction of the conveying roller group 20, so as to sandwich the conveying roller group 20 from both sides in the conveying direction. The two dancers 24 shown in the figure can be configured similarly, so only the dancer 24 on the left side will be described.

[0017] The dancer 24 applies tension in the conveying direction to the transported object 3. The dancer 24 includes a pair of rollers 241, 242 provided on the transport path of the transported object 3 (the path in the left-right direction along which the transported object 3 extends in FIG. 1), and a dancer roller 243 provided between the pair of rollers 241, 242 at a position deviated from the transport path of the transported object 3. The dancer roller is also called a dancer roll.

[0018] The dancer rollers 243 are provided so as to be movable between upper ends 243A and lower ends 243B in a direction perpendicular to the conveyance path of the transported object 3 (the up-down direction in FIG. 1). The air cylinder 244, which serves as a thrust applying unit, generates a thrust that urges or pressurizes the dancer rollers 243 in a direction away from the conveyance path of the transported object 3 (downward in FIG. 1). This thrust is based on the air pressure of the air cylinder 244, which is connected to the dancer rollers 243 via a piston rod or a connecting rod. The air pressure of the air cylinder 244 is generated by a thrust control unit 17, which is composed of an electro-pneumatic regulator or the like that electrically controls the air pressure. A substantially constant voltage is generally applied to the electro-pneumatic regulator (thrust control unit 17), and the air pressure of the air cylinder 244, i.e., the thrust of the dancer rollers 243, is controlled to be substantially constant. It should be noted that instead of the air cylinder 244, a thrust applying unit that applies thrust to the dancer rollers 243 based on another principle (for example, a linear motor that applies thrust to the dancer rollers 243 based on electricity) may be provided.

[0019] The dancer rollers 243, which are biased or pressurized downward by the thrust from the air cylinder 244, apply tension to the transported object 3 by pulling the transported object 3 in a direction away from the transport path. At this time, the dancer rollers 243 come to rest at a position where the downward thrust received from the air cylinder 244 and the upward tension received from the transported object 3 are balanced. As described above, the downward thrust received by the dancer rollers 243 from the air cylinder 244 is generally maintained or controlled to be approximately constant, so the vertical position of the dancer rollers 243 represents the tension of the transported object 3.

[0020] The position of the dancer rollers 243 in the thrust direction (the vertical direction in FIG. 1 ) is detected as an electric signal by the position detection unit 245 or a position sensor, and is provided to the subtractor 14 of the conveyance control device 1. In addition, the subtractor 14 receives a position command for the dancer rollers 243 in the thrust direction, which is generated by the position command generation unit 13 of the conveyance control device 1. As described above, the position of the dancer rollers 243 approximately corresponds to the tension of the conveyance object 3, and therefore the position command for the dancer rollers 243 generated by the position command generation unit 13 approximately corresponds to the tension command for the conveyance object 3. The speed control unit 15 of the conveyance control device 1 generates a speed command for reducing the deviation of the position of the dancer rollers 243 or the tension of the conveyance object 3, which is provided by the subtractor 14. This speed command is a command for the conveyance speed of the conveyance object 3, and more specifically, a command for the rotational speed of the drive roller 251, which will be described below.

[0021] The drive unit 16 of the conveyance control device 1 drives and rotates the drive roller 251, which is provided immediately after the dancer 24, in response to a speed command provided by the speed control unit 15. The drive roller 251 is a conveyance roller that can rotate around a rotation axis perpendicular to the conveyance direction of the conveyed object 3. When the drive roller 251 is driven and rotated clockwise in FIG. 1, the driven roller 252 rotates counterclockwise in conjunction with the drive roller 251. In addition, a drive roller 231 similar to the drive roller 251 and a driven roller 232 similar to the driven roller 252 are also provided immediately before the dancer 24. The drive roller 231 is driven and rotated at a constant rotation speed, for example, by a drive unit (not shown). In contrast, the rotation speed of the drive roller 251 is adaptively controlled in response to deviations in position and / or tension. In this way, the drive roller 251 and the driven roller 252 convey the conveyed object 3 sandwiched between them, while applying a desired tension to the conveyed object 3 in accordance with the position command of the dancer roller 243 generated by the position command generating unit 13, i.e., the tension command of the conveyed object 3. In the example of Fig. 1, two dancers 24 are provided immediately before and after the group of conveying rollers 20 in the conveying direction, so that the tension of the conveyed object 3 at the entrance portion (left end in Fig. 1) and exit portion (right end in Fig. 1) of the group of conveying rollers 20 can be controlled to a desired value.

[0022] As described above, the conveying device 2 can be installed in various devices such as coaters, printing machines, stretching machines, and box-making machines. However, there may arise a need to rapidly accelerate or decelerate the conveyed object 3 to optimize various processes. When motor operation needs to be precisely controlled in a short period of time, conventional motor control devices with long processing cycles may not be able to compensate for the speed and torque in time. The motor control device 10 of the present embodiment, described below, enables high-speed control of the motor speed and torque. As shown in FIG. 1, the motor control device 10, which constitutes part of the conveying control device 1, is composed of drive units 11A to 11C (hereinafter collectively referred to as drive unit 11) and a control unit 12.

[0023] FIG. 2 is a functional block diagram of the motor control device 10. The control unit 12 of the motor control device 10 includes a reference speed command generation unit 121. The drive unit 11 of the motor control device 10 includes a speed correction amount generation unit 111, a speed correction amount adder 112, a rotational position differentiator 113, a speed subtractor 114, a speed deviation conversion unit 115, a torque correction amount generation unit 116, a torque correction amount adder 117, a torque subtractor 118, and a torque deviation conversion unit 119. These functional blocks are realized by the cooperation of hardware resources such as a computer's central processing unit, memory, input devices, output devices, and peripheral devices connected to the computer, as well as software executed using these resources. Regardless of the type of computer or its installation location, each of the above functional blocks may be realized by the hardware resources of a single computer or by combining hardware resources distributed across multiple computers.

[0024] The reference speed command generation unit 121 generates a reference speed command for the motor 4 that generates rotational power for rotating and driving each of the drive rollers 211 to 213. As will be described in detail below, the drive unit 11, which is provided downstream of the control unit 12 or on the motor 4 side, applies speed correction or speed compensation using a speed correction amount and torque correction or torque compensation using a torque correction amount to the reference speed command provided by the reference speed command generation unit 121, and then generates power to be applied to the motor 4, such as three-phase AC.

[0025] Because the processing cycle in drive unit 11 is shorter than the processing cycle in control unit 12, speed correction and torque correction in drive unit 11 can be performed faster than control unit 12. Specifically, the processing cycle in drive unit 11 is, for example, about several hundred microseconds, while the processing cycle in control unit 12 is, for example, about several milliseconds, with the former being approximately one-tenth or less of the latter. By generating speed correction amounts and torque correction amounts quickly in drive unit 11 in this way, rapid acceleration and deceleration of transported object 3 required by transport device 2 to optimize various processes can be reliably performed.

[0026] The speed correction amount generation unit 111 of the drive unit 11 generates a speed correction amount for the reference speed command generated by the reference speed command generation unit 121 of the control unit 12. Specific examples of the speed correction amount will be described later. The speed correction amount adder 112 adds the speed correction amount generated by the speed correction amount generation unit 111 to the reference speed command generated by the reference speed command generation unit 121 of the control unit 12. The rotational position differentiator 113 calculates the rotational speed of the motor 4 by differentiating the rotational position of the motor 4 measured by a rotational position measurement device 41 called a PG (Position Generator). The speed subtractor 114 calculates a speed deviation by subtracting the reference speed command corrected by the speed correction amount adder 112 using the speed correction amount and the speed of the motor 4 measured by the rotational position differentiator 113. The speed deviation conversion unit 115 converts the speed deviation calculated by the speed subtractor 114 into a reference torque command for the motor 4.

[0027] The torque correction amount generation unit 116 generates a torque correction amount for the reference torque command generated by the speed deviation conversion unit 115. Specific examples of the torque correction amount will be described later. The torque correction amount adder 117 adds the torque correction amount generated by the torque correction amount generation unit 116 to the reference torque command generated by the speed deviation conversion unit 115. The torque subtractor 118 calculates a torque deviation by subtracting the reference torque command corrected by the torque correction amount adder 117 with the torque correction amount and the measured torque of the motor 4. The torque deviation conversion unit 119 converts the torque deviation calculated by the torque subtractor 118 into power to be applied to the motor 4.

[0028] 3 and 4 show specific examples of speed correction amounts generated by the speed correction amount generator 111 of the drive unit 11 relative to a reference speed command. In these figures, the horizontal axis represents the rotational position of the motor 4 measured by the rotational position measurer 41, and the vertical axis represents the speed correction amount generated by the speed correction amount generator 111, which is added in the speed correction amount adder 112 to the reference speed command generated by the reference speed command generator 121. With respect to the reference speed command corresponding to the center or origin of the vertical axis, the speed correction amount above represents the amount of acceleration relative to the reference speed command, and the speed correction amount below represents the amount of deceleration relative to the reference speed command. Therefore, in the examples of FIGS. 3 and 4, the motor 4, which was controlled to a speed according to the reference speed command up to the "acceleration / deceleration start" rotation position, goes through deceleration, acceleration, and deceleration, and then returns to the speed according to the reference speed command at the "acceleration / deceleration end" rotation position.

[0029] The reference speed command generated by the reference speed command generating unit 121 can be updated in the processing cycle (for example, on the order of several milliseconds) of the control unit 12. However, when the motor 4 rotates at high speed or when the motor 4 is accelerated or decelerated finely in a time shorter than the processing cycle of the control unit 12, the long processing cycle of the control unit 12 is insufficient. Therefore, in this embodiment, the speed correction amount generating unit 111 of the drive unit 11, which has a short processing cycle (for example, on the order of several hundred microseconds), generates speed correction amount patterns for the reference speed command as shown in FIGS. 3 and 4 at high speed.

[0030] Here, it is preferable to set an acceleration / deceleration pattern of the speed correction amount in advance so that it can be handled even by the drive unit 11, which has fewer control resources than the control unit 12. Specifically, as shown in FIGS. 3 and 4, it is preferable that the speed correction amount generator 111 generates the speed correction amount according to a predetermined pattern corresponding to the rotational position of the motor 4. The speed correction amount pattern may be defined by the rotational position and acceleration / deceleration amount coordinates (X1, Y1), (X2, Y2), (X3, Y3), (X4, Y4), and (X5, Y5) of each change point of the speed correction amount, as shown in FIG. 3, or may be defined by parameters of each rotational position section, such as a deceleration section (DEC1, DEC2), a constant speed section (CST1, CST2), and an acceleration section (ACC1, ACC2) (e.g., the width of the rotational position section, the slope of the speed correction amount, etc.), or may be defined by a gain by which a reference speed command is multiplied according to the rotational position of the motor 4.

[0031] FIG. 5 shows a specific example of a torque correction amount generated by the torque correction amount generation unit 116 of the drive unit 11 relative to a reference torque command. In this figure, the horizontal axis represents the speed of the motor 4 obtained by the rotational position differentiator 113, and the vertical axis represents the torque correction amount generated by the torque correction amount generation unit 116, which is added in the torque correction amount adder 117 to the reference torque command generated by the speed deviation conversion unit 115. With respect to the reference torque command corresponding to the center or origin of the vertical axis, the torque correction amount above represents the torque increase relative to the reference torque command, and the torque correction amount below represents the torque decrease relative to the reference torque command. The torque correction amount generation unit 116 of the drive unit 11, which has a shorter processing cycle (e.g., on the order of several hundred microseconds) than the control unit 12, quickly generates a pattern of torque correction amounts relative to the reference torque command as shown in FIG. 5.

[0032] 3 and 4, it is preferable to set a torque correction amount increase / decrease pattern in advance so that the drive unit 11, which has fewer control resources than the control unit 12, can also be used. Specifically, as shown in FIG. 5, it is preferable that the torque correction amount generation unit 116 generates the torque correction amount according to a predetermined pattern corresponding to the speed of the motor 4. As shown in FIG. 5, the torque correction amount pattern may be defined by the coordinates (0, Y0), (X1, Y1), (X2, Y2), (X3, Y3), (X4, Y4), etc. of the speed and torque increase / decrease amount at each change point of the torque correction amount, or may be defined by parameters of each speed section (e.g., the width of the speed section, the slope of the torque correction amount, etc.) as in FIG. 4, or may be defined by a gain by which the reference torque command is multiplied according to the speed of the motor 4.

[0033] The present invention has been described above based on the embodiments. Various modifications are possible to the combinations of the components and processes in the exemplary embodiments, and it will be obvious to those skilled in the art that such modifications are included within the scope of the present invention.

[0034] 6, the torque correction amount generation unit 116 may generate a torque correction amount for a reference torque command based on the speed deviation calculated by the speed subtractor 114. Specifically, the torque correction amount generation unit 116 includes a speed deviation differentiator 116A that calculates an acceleration deviation by differentiating the speed deviation calculated by the speed subtractor 114, and an acceleration compensation gain multiplier 116B that calculates the torque correction amount by multiplying the acceleration deviation by an acceleration compensation gain. Here, the acceleration compensation gain of the acceleration compensation gain multiplier 116B is preferably determined according to a predetermined pattern corresponding to the speed of the motor 4, as shown in FIG.

[0035] The configuration, operation, and function of each device and method described in the embodiments can be realized by hardware resources, software resources, or a combination of hardware and software resources. Examples of hardware resources include processors, ROMs, RAMs, and various integrated circuits. Examples of software resources include operating systems, applications, and other programs. [Explanation of symbols]

[0036] 1 conveyance control device, 2 conveyance device, 3 conveyed object, 4 motor, 10 motor control device, 11 drive unit, 12 control unit, 20 conveyance roller group, 41 rotational position measuring device, 111 speed correction amount generation unit, 112 speed correction amount adder, 113 rotational position differentiator, 114 speed subtractor, 115 speed deviation conversion unit, 116 torque correction amount generation unit, 116A speed deviation differentiator, 116B acceleration compensation gain multiplier, 117 torque correction amount adder, 118 torque subtractor, 119 torque deviation conversion unit, 121 reference speed command generation unit, 211 drive roller.

Claims

1. a control unit including a reference speed command generating unit that generates a reference speed command for a motor that generates rotational power; a speed deviation conversion unit that converts the speed deviation into a reference torque command for the motor; a torque correction amount generation unit that generates a torque correction amount for the reference torque command; a torque subtractor that calculates a torque deviation by subtracting the reference torque command corrected by the torque correction amount from the measured torque of the motor; and a torque deviation conversion unit that converts the torque deviation into power to be applied to the motor, the drive unit having a processing cycle shorter than the processing cycle of the control unit; A motor control device comprising:

2. The motor control device according to claim 1 , wherein the speed correction amount generating unit generates the speed correction amount according to a predetermined pattern corresponding to a rotational position of the motor.

3. The motor control device according to claim 1 , wherein the torque correction amount generator generates the torque correction amount in accordance with a predetermined pattern corresponding to the speed of the motor.

4. 4. The motor control device according to claim 1, wherein the torque correction amount generation unit comprises: a speed deviation differentiator that calculates an acceleration deviation by differentiating the speed deviation; and an acceleration compensation gain multiplier that multiplies the acceleration deviation by an acceleration compensation gain to calculate the torque correction amount.

5. a reference speed command generating step, executed in the control unit, of generating a reference speed command for a motor that generates rotational power; a speed correction amount generating step of generating a speed correction amount for the reference speed command, which is executed in a drive unit having a processing cycle shorter than that of the control unit; a speed subtraction step of calculating a speed deviation by subtracting the reference speed command corrected by the speed correction amount from the measured speed of the motor; a speed deviation converting step of converting the speed deviation into a reference torque command of the motor; a torque correction amount generating step of generating a torque correction amount for the reference torque command; a torque subtraction step of calculating a torque deviation by subtracting the reference torque command corrected by the torque correction amount from the measured torque of the motor; and a torque deviation converting step of converting the torque deviation into an applied power to the motor. A motor control method comprising:

6. a reference speed command generating step, executed in the control unit, of generating a reference speed command for a motor that generates rotational power; a speed correction amount generating step of generating a speed correction amount for the reference speed command, which is executed in a drive unit having a processing cycle shorter than that of the control unit; a speed subtraction step of calculating a speed deviation by subtracting the reference speed command corrected by the speed correction amount from the measured speed of the motor; a speed deviation converting step of converting the speed deviation into a reference torque command of the motor; a torque correction amount generating step of generating a torque correction amount for the reference torque command; a torque subtraction step of calculating a torque deviation by subtracting the reference torque command corrected by the torque correction amount from the measured torque of the motor; and a torque deviation converting step of converting the torque deviation into an applied power to the motor. A motor control program that causes a computer to execute the above.

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