TWI808712B - Motor control device, motor control system and motor control method - Google Patents

Abstract

The motor control device (100), including: speed detector (5), detects the speed of the motor (2); the speed controller (4), according to the speed and speed instruction of the motor, generate a torque instruction to the motor; correct the calculator (6), the correction torque instruction generates a correction torque instruction; Excessive motor; vibration detector (8), detect the vibration amplitude and vibration frequency generated by the motor; and the parameter setting the changeer (9) to change the parameter of the speed controller. When the vibration amplitude is larger than the threshold value, the correction calculator calculates the correction torque command for the feedback control system composed of the motor, the speed detector, the speed controller, the correction calculator and the current controller, so as to stabilize the transfer characteristic of the vibration frequency; when the vibration amplitude decreases after the transfer characteristic is stabilized, the parameter setting changer changes the parameters of the speed controller.

Description

Motor control device, motor control system and motor control method

The present disclosure relates to a motor control device, a motor control system, and a motor control method for performing feedback control on a motor connected to a mechanical device.

In a mechanical device that requires high-precision control of state quantities such as position or speed, a motor is used as a drive source for feedback control. In order to realize high-response to commands and high-precision feedback control, the parameters of the feedback control calculation must be properly designed. If the parameters are out of the appropriate range, not only will it be impossible to achieve high-response and high-precision feedback control, but the feedback control system will be unstable and the action will vibrate.

The parameters of the feedback control system must be set in accordance with the characteristics of the load machinery connected to the motor. Examples of mechanical characteristics include the inertia and rigidity of the load machine, and parameters must be set in accordance with these characteristics.

In addition, in the load machine driven by a motor, there may be those whose mechanical properties change during operation. For example, in a roll-to-roll device that unwinds, rolls, and processes sheet-like materials from a roller, the inertia applied to the motor that rotates the roller changes due to the amount of material wound on the roller. In particular, in the roll-to-roll device, the change is quite large, and the inertia may change tens of times due to the difference in the amount of material wound around the roller. In such a device, if the parameters are set so that the magnitude of the inertia is biased toward either state, the control system may become unstable in the opposite state. In order to prevent this situation, it is necessary to prepare a mechanism that can grasp the inertia change to set the parameters to be stable in the whole range, and change the predetermined parameter setting in response to the inertia change. The workload for starting up the device increases. In addition, since it is necessary to grasp the characteristics of the entire variation range, it becomes difficult to use the automatic adjustment function at the time of operation of starting the device.

Patent Document 1 discloses a motor system. In order to prevent vibration of the feedback control system in a mechanical device with variable inertia, an inertia detection component or a vibration detection component is provided. The parameters of the feedback control system are changed according to the detection results of each component to suppress the vibration of the motor. [Prior Art Literature] [Patent Document]

Patent Document 1: Japanese Patent Laid-Open No. 2016-35676

[Problem to be solved by the invention]

However, the occurrence of vibration has multiple causes such as external disturbance and instability of the control system, and different measures must be taken according to the cause, but the cause of the phenomenon cannot be determined only by information such as the occurrence of vibration or the increase in amplitude. Therefore, the motor system described in Patent Document 1 may not be able to appropriately change parameter settings. In addition, since the inertia detection means must operate with acceleration, it may be difficult to detect inertia depending on the operation mode.

In view of the above problems, the present disclosure aims to obtain a motor control device capable of stabilizing the operation when the load of the motor connected to the control object changes. [means used to solve a problem]

In order to solve the above problems and achieve the purpose, the present disclosure is a motor control device for controlling a motor driving a load machine, including: a speed detector for detecting the speed of the motor; a speed controller for generating a torque command for the motor according to the speed and speed command of the motor; a correction calculator for generating a corrected torque command for the corrected torque command; a current controller for making current flow through the motor according to the torque command and the corrected torque command; parameters of the controller. When the vibration amplitude is larger than the threshold value, the correction calculator calculates the correction torque command for the feedback control system composed of the motor, the speed detector, the speed controller, the correction calculator and the current controller, so that the transition characteristic of the vibration frequency detected by the vibration detector is stabilized; when the vibration amplitude detected by the vibration detector decreases after the transition characteristic is stabilized, the parameter setting changer changes the parameters of the speed controller. [Efficacy of the invention]

The motor control device of the present disclosure can achieve stable operation when the load of the motor connected to the control object changes.

[Mode for Carrying Out the Invention]

Hereinafter, a motor control device, a motor control system, and a motor control method according to embodiments of the present disclosure will be described based on the drawings.

[First Embodiment] FIG. 1 is a block diagram showing a configuration example of a motor control system realized by using the motor control device of Embodiment 1. As shown in FIG.

The motor control system 200 of Embodiment 1 includes a motor control device 100 , a motor 2 controlled by the motor control device 100 , and a load machine 1 connected to the motor 2 .

The motor 2 receives electric current supplied from the motor control device 100 , generates torque, and drives the load machine 1 .

The motor control device 100 includes a current controller 3 , a speed controller 4 , a speed detector 5 , a correction calculator 6 , a position controller 7 , a vibration detector 8 , and a parameter setting changer 9 . The speed detector 5 is composed of a position detector 51 and a differential calculator 52 .

The current controller 3 controls the current supplied to the motor 2 based on the correction torque command input from the correction calculator 6 .

The speed controller 4 generates a torque command according to the speed command input by the position controller 7 and the speed detection value input by the speed detector 5 . Specifically, the speed controller 4 performs operations including proportional calculation and integral calculation to generate a torque command in order to make the detected speed value follow the speed command.

The position detector 51 of the speed detector 5 detects the position of the motor 2 , specifically, the position of a rotor (not shown) of the motor 2 . The differential calculator 52 of the speed detector 5 differentiates the position detection value indicating the position detection result of the motor 2 detected by the position detector 51 to calculate the speed of the motor 2 . The speed of the motor 2 refers to the rotational speed of the rotor of the motor 2 . The speed of the motor 2 calculated by the differential calculator 52 is output to the speed controller 4 and the vibration detector 8 as a speed detection value.

The correction calculator 6 performs correction calculation on the command output by the speed controller 4 to generate a correction torque command when the vibration vibration and frequency detected by the vibration detector 8 meet predetermined conditions. The correction calculator 6 outputs the input torque command as a correction torque command when the vibration and frequency do not satisfy the predetermined conditions.

The position controller 7 performs calculations including proportional calculations to generate a speed command so that the detected position value of the motor 2 detected by the position detector 51 follows a position command input from the outside.

The vibration detector 8 detects the amplitude and frequency of the vibration contained in the waveform of the speed detection value output by the speed detector 5, and outputs the detected amplitude (that is, the vibration amplitude) and the detected frequency (that is, the vibration frequency) to the correction calculator 6 and the parameter setting changer 9.

The parameter setting changer 9 changes the parameters of the speed controller 4 and the position controller 7 according to the vibration amplitude and frequency detected by the vibration detector 8 .

Next, the operation of the motor control device 100 shown in FIG. 1 will be described. The purpose of this motor control device 100 is to perform an operation in which the load machine 1 and the motor 2 follow the position command.

In the motor control device 100, the position controller 7 performs calculations including proportional calculations to generate a speed command in order to make the position detection value detected by the position detector 51 and indicating the position of the motor 2 follow the position command. The operation of the position controller 7 is expressed as formula (1) using the proportional calculation coefficient Kp.

[Formula 1] Speed command = Kp × (position command - position detection value)...(1)

The speed controller 4 performs operations including proportional calculation and integral calculation to calculate the torque command so that the detected speed value of the motor 2 calculated by the differential calculator 52 of the speed detector 5 follows the speed command output by the position controller 7 . The calculation of the speed controller 4 to calculate the torque command is expressed as Equation (2) using the proportional calculation coefficient Kv and the integral calculation Ki. s in formula (2) is the Laplacian operator, and 1/s represents integral calculation.

[Formula 2] Torque command=Kv×(1+Ki×1/s)×(position command-position detection value)…(2)

The torque command output by the speed controller 4 is converted into a corrected torque command by the correction calculator 6 , and the current controller 3 supplies the current corresponding to the value of the corrected torque command to the motor 2 , and the motor 2 generates torque and rotates. In this way, the motor control device 100 performs calculations performed under the feedback loop composed of the position controller 7, the speed controller 4, the correction calculator 6, the current controller 3, the position detector 51, the speed detector 5, the motor 2, and the load machine 1, that is, the feedback (hereinafter, referred to as FB) control calculation, thereby realizing the action of the load machine 1 and the motor 2 following the position command. In this case, the transition function h(s) used in the calculation of the correction torque command by the correction calculator 6 is h(s)=1, and the torque command is the same as the correction torque command. The details will be described later, but the correction calculator 6 corrects the torque command to generate a corrected torque command when the amplitude of the vibration detected by the vibration detector 8 exceeds a predetermined threshold value, that is, performs calculation by setting the transition function h(s) to h(s)=1, and outputs a corrected torque command having the same value as the input command.

The FB control system with the above-mentioned structure is mostly used in the case where the motor 2 is used to control the position or speed. In order to make the load machine 1 and the motor 2 follow the position command with high response and high precision, it is necessary to set the FB control system to have appropriate characteristics. The characteristics of the FB control system can be adjusted with the characteristics of the position controller 7 and the speed controller 4, and the coefficients of the proportional calculation and the integral calculation performed by these respective controllers become parameters. The parameter setting of the FB control system not only has the characteristics of high response and high precision, but also must consider the stability. If the FB control system is unstable, there may sometimes be a large vibration phenomenon, so it is necessary to set parameters to make the control system stable and have high response and high precision characteristics.

Next, a case where the motor 2 drives the load machine 1 whose inertia changes will be described. For example, when the load machine 1 is a roll of a roll-to-roll device that unwinds, rolls, and processes sheet-like materials from the roll, the inertia of the roll, that is, the inertia of the load machine 1, changes due to the amount of material wound on the roll. In the roll-to-roll device, there is a large change in inertia, depending on the amount of material wound on the roll, and even the inertia changes by tens of times.

Now, the influence on the FB control system when the inertia of the load machine 1 increases from the initial state will be described. For example, consider a case where the inertia of the load machine 1 increases from an initial state where the motor inertia ratio is 5 times to a final motor inertia ratio of 250 times.

FIG. 2 is a Bode diagram of the motor 2 driven by the motor control device 100 of the first embodiment. The Bode diagram in Fig. 2 shows the transition characteristics of the inertia of the load machine 1 from the input of the motor 2 (that is, the current) to the speed detection value of the motor 2 when the motor inertia ratio is 5 times, 31 times, and 250 times.

FIG. 3 is a Bode diagram of the open-loop transfer function of the FB control system of the motor control device 100 of Embodiment 1. FIG. The Bode diagram in Fig. 3 shows that for the load machine 1 in the initial state whose inertia is 5 times the motor inertia ratio, set the parameters of the position controller 7 and the speed controller 4, and do not change this parameter setting, the open-loop transfer function of the FB control system when the inertia of the load machine 1 increases. In addition, although the resonance characteristics around 180 Hz are suppressed by the band-pass filter, there is almost no influence due to the change of the inertia of the load machine 1, and the detailed description is omitted because it has nothing to do with this embodiment. FIG. 4 is a Nyquist diagram of the open-loop transfer function of the FB control system of the motor control device 100 of Embodiment 1. Referring to FIG. It can be seen from Figure 3 and Figure 4 that when the inertia of the load machine 1 increases to 31 times the motor inertia ratio, the FB control system reaches the limit of stability.

5 shows an example of an operation waveform when the motor control device 100 of Embodiment 1 becomes unstable, and an example of a waveform of a speed detection value showing a process in which the inertia of the load machine 1 increases. In the speed detection value shown in FIG. 5 , at the time of 3 seconds, the inertia of the load machine 1 is 31 times the motor inertia ratio, and oscillation of 7.5 Hz occurs due to instability. In addition, in Figure 5, in order to see the oscillation waveform, a double-pass filter is used to remove the component of the speed waveform following the speed command.

The vibration detector 8 calculates the amplitude and frequency of the vibration included in the waveform of the speed detection value output from the speed detector 5 . When the vibration shown in FIG. 5 occurs, the amplitude is calculated at 6.5 seconds to be 0.5 r/min, and the frequency is 7.5 Hz. When the amplitude of 0.5 r/min is regarded as a threshold value and it is determined that vibration occurs, the correction calculator 6 performs a correction operation on the torque command to temporarily stabilize the characteristics of the FB control system near the vibration frequency, and generates a corrected torque command, that is, a corrected torque command. The correction calculator 6 performs a correction calculation using the transition function h(s) shown in the formula (3), and calculates a correction torque.

[Formula 3] ...(3)

In the formula (3), ω _h is set to ω _h =ω ₀ ×2.5[rad/s] with respect to the detected vibration frequency ω ₀ =7.5×2π[rad/s]. The Bode plot of the transfer function h(s) at this time is shown in Figure 6. FIG. 6 is a Bode diagram of the transfer function of the correction calculator 6 of the motor control device 100 of the first embodiment. The Bode diagram of the open-loop transfer function of the FB control system when the correction calculator 6 performs the correction operation is shown in Figure 7, and the Nyquist diagram is shown in Figure 8. The FB control system is stabilized by the correction calculation of the correction calculator 6. FIG. 7 is a Bode diagram of the open-loop transfer function of the FB control system of the motor control device 100 of Embodiment 1. Referring to FIG. FIG. 8 is a Nyquist diagram of the open-loop transfer function of the FB control system of the motor control device 100 of the first embodiment.

When the FB control system is stabilized, as shown in Fig. 9, the oscillation is suppressed and the vibration amplitude is reduced. From the point that the stabilization of the FB control system reduces vibration, it can be determined that oscillation is an important factor for destabilization of the FB control system. FIG. 9 shows operation waveforms when the FB control system of the motor control device 100 according to Embodiment 1 is stabilized. The parameter setting changer 9 changes the coefficient Kp calculated by the ratio of the position controller 7 and the coefficient Ki calculated by the integral of the speed controller 4 according to this waveform, that is, when the vibration amplitude decreases after the vibration amplitude reaches the above-mentioned threshold value of 0.5r/min, and changes each coefficient to a value of Kp=Ki=7.5×2π/4 according to the detected vibration frequency, thereby stabilizing the FB control system. FIG. 10 shows a Bode diagram showing the open-loop transfer function of the FB control system in this way, and FIG. 11 shows a Nyquist diagram. FIG. 10 is a Bode diagram of an open-loop transfer function when the FB control system of the motor control device 100 of Embodiment 1 is stabilized. FIG. 11 is a Nyquist diagram of an open-loop transfer function when the FB control system of the motor control device 100 according to Embodiment 1 is stabilized.

Also, in the motor control device 100 , after the parameters of the position controller 7 and the speed controller 4 are changed by the parameter setting changer 9 , the transition function used for the correction calculation by the correction calculator 6 is returned to h(s)=1. In addition, the stabilization obtained by the correction calculation of the transition function using the above-mentioned formula (3) cannot obtain a large stability margin, so although it can be used for temporarily stabilizing the FB control system, it is not suitable for the purpose of obtaining normal stabilization. In the state of stabilizing only by changing the transfer function of the correction calculator 6, if the inertia of the load machine 1 increases, a slight increase will destabilize the FB control system again.

Next, a case where the main cause of vibration is external disturbance will be described. FIG. 12 shows the operation waveform of the motor control device 100 of Embodiment 1 when there is external disturbance vibration. The operation waveform in Fig. 12 shows the operation when external disturbance of 7.5 Hz occurs. When an external disturbance is input at a time point of 3 seconds, the vibration detector 8 calculates a vibration amplitude of 0.8 r/min and a frequency of 7.5 Hz from the speed detection value. Accompanying this, the correction calculator 6 starts the correction calculation using the transition function of the above formula (3), but the vibration amplitude does not change. From this result, the motor control device 100 determines that the generation of the vibration is not an instability of the FB control system. Therefore, the parameter setting changer 9 does not change the parameter settings of the position controller 7 and the speed controller 4 . In addition, the correction calculator 6 returns the transition function used in the correction calculation to h(s)=1 when a fixed time elapses after starting the correction calculation using the transition function of the above-mentioned expression (3). The time point at which the correction calculator 6 returns the transition function to h(s)=1 will be after a necessary time for determining whether the vibration of the speed detection value is caused by external disturbance or the instability of the FB control system.

When the above-mentioned operation of the motor control device 100 to suppress the oscillation of the motor 2 is displayed as a flowchart, it will be as shown in FIG. 13 . FIG. 13 is a flowchart showing an example of the operation of the motor control device 100 according to Embodiment 1 to suppress the vibration of the motor 2 .

When the motor control device 100 is controlling the state of the motor 2, it determines whether there is vibration of the motor 2 according to the flow chart of FIG.

That is, the motor control device 100 controlling the motor 2 compares the vibration amplitude of the speed of the motor 2 with a threshold value (step S1 ), and if the vibration amplitude is below the threshold value (step S1 : No), step S1 is repeated. When the vibration amplitude is larger than the threshold value (step S1: Yes), the motor control device 100 changes the transition function h(s) of the correction calculator 6 (step S2). Specifically, the transition function h(s) used by the correction calculator 6 for the correction calculation of the torque command is changed to the above-mentioned formula (3). The motor control device 100 then checks whether the vibration amplitude of the speed of the motor 2 has decreased (step S3 ). For example, the motor control device 100 continues to monitor the vibration amplitude until a predetermined time elapses after changing the transition function of the correction calculator 6 in step S2, and determines whether the vibration amplitude has decreased. When the vibration amplitude decreases (step S3: Yes), the motor control device 100 adjusts the parameters of the position controller 7 and the speed controller 4 (step S4). After adjusting the parameters of the position controller 7 and the speed controller 4 , the motor control device 100 changes the transition function h(s) of the correction calculator 6 (step S5 ). In this step S5, the transition function h(s) is changed to the state before the execution of the above-mentioned step S2, that is, h(s)=1. Also, when the vibration amplitude does not decrease after changing the transfer function of the correction calculator 6 in step S2 (step S3 : No), the motor control device 100 executes step S5 and changes to h(s)=1. The motor control device 100 returns to step S1 after executing step S5, and repeats the processing of steps S1 to S5.

As described above, in the motor control device 100, when the amplitude of the vibration detected by the vibration detector 8 is larger than the threshold value, the correction calculator 6 is used to correct the transition function of the calculation, and the frequency of the detected vibration is changed to change the characteristics of the FB control system. Then, the main cause of the vibration that occurs when the inertia of the load machine 1 increases from the initial state is discriminated from the subsequent state of change in the vibration amplitude. Also, when the main cause of vibration is destabilization of the FB control system, the parameter setting changer 9 changes the parameters of the position controller 7 and the speed controller 4 to suppress large-amplitude oscillations. Also, when the cause is not the instability of the FB control system, the parameter setting changer 9 does not change the parameters of the position controller 7 and the speed controller 4, that is, does not change the characteristics of the FB control system. Thereby, the parameter settings of the position controller 7 and the speed controller 4 can be changed only when the FB control system becomes unstable and the motor 2 vibrates as the inertia of the load machine 1 increases. In other words, it is possible to prevent the situation where the parameters of the position controller 7 and the speed controller 4 are changed to make the control unstable when vibration is temporarily generated due to external disturbance, and the operation of the motor control system 200 can be stabilized.

In addition, in the above description, as an example of the load machine 1 whose inertia changes, a roll-to-roll device in which the inertia of the roll changes due to the amount of material wound on the roll is mentioned, but it is not limited to this. Even in the case of a device in which the inertia applied to the motor changes due to changes in the presence or absence or placement of objects serving as loads, such as a transfer machine or an arm robot, the same method can be used to suppress vibration and stabilize the FB control system.

In addition, the motor control system 200 of this embodiment includes a load machine 1, a motor 2 for driving the load machine 1, a speed detector 5 for detecting the speed of the motor 2, a speed controller 4 for generating a torque command to the motor 2 based on the speed of the motor 2 and a speed command, a correction calculator 6 for correcting the torque command and generating a corrected torque command, a current controller 3 for flowing current to the motor 2 based on the torque command and the corrected torque command, a vibration detector 8 for detecting the vibration amplitude and frequency of vibration generated by the motor 2, and a device for changing the parameters of the speed controller 4. Parameter setting changer9.

In addition, the motor control method executed by the motor control device 100 of the present embodiment is used in the FB control system, which detects the position of the motor 2 driving the load machine 1, generates a speed command based on the position of the motor 2 and the position command by calculation including proportional calculation, detects the speed of the motor 2, generates a torque command for the motor 2 based on the speed of the motor 2 and the speed command by calculation including proportional calculation and integral calculation, and corrects the torque command to generate a corrected torque command. 2. When the vibration amplitude and vibration frequency of the generated vibration are larger than the threshold value, the position detection of the motor 2, the generation of the speed command, the detection of the speed of the motor 2, the generation of the torque command, the generation of the correction torque command, and the current flow to the motor are repeated. On the other hand, the motor control method stabilizes the transition characteristic of the vibration frequency generated by the motor 2. When the vibration amplitude decreases after the transition characteristic is stabilized, the parameters of the calculation for generating the speed command (that is, the coefficient of the proportional calculation) are changed, and the parameters of the calculation for generating the torque command (that is, the coefficient of the integral calculation) are changed.

In addition, the vibration detector 8 of the motor control device 100 of the present embodiment calculates the amplitude and frequency of the vibration from the waveform of the velocity value, but it may also be configured to calculate the amplitude and frequency of the vibration from the waveform of the position detection value, velocity command, torque command, corrected torque command, and current.

In addition, when the motor control device 100 of this embodiment determines that the main cause of the vibration is the instability of the FB control system, the coefficient Kp calculated by the proportional calculation of the position controller 7 and the coefficient Ki calculated by the integral calculation of the speed controller 4 are changed according to the detected vibration frequency, respectively, Kp=Ki=7.5×2π/4, that is, set to 1/4 times the vibration frequency, but not limited to 1/4 times, and the coefficients Kp and Ki can also be changed to values smaller than the vibration frequency. Specifically, if the coefficients Kp and Ki are changed to be smaller than 1/2 times the vibration frequency × 2π, the destabilization of the FB control system can be suppressed. In addition, it is also possible to change the coefficients Kp and Ki before the change to 1/4 times, for example, to values smaller than the coefficients Kp and Ki before the change, so that if they are smaller than 1/2 times the values before the change, the instability of the FB control system can be suppressed.

Furthermore, in the motor control device 100 of this embodiment, the position controller 7 generates a speed command according to formula (1), and the speed controller 4 generates a torque command according to formula (2), but other structures are also possible. For example, a speed I-P control system may be used, or a differential calculator may be added. In this case, the parameters may be changed according to the detected vibration frequency to achieve the characteristic changes shown in FIGS. 10 and 11 .

Also, in the motor control device 100 of the present embodiment, the correction calculator 6 changes the characteristics of the FB control system using the transition function h(s) of the formula (3), but other transition functions may also be used. For example, these methods can also be used: setting a low-pass filter to change the characteristics of the FB control system, using a phase advance compensator to change the characteristics of the FB control system, adding the waveform of the shaping speed detection value to the torque command as shown in the following equation (4) to change the characteristics of the FB control system, etc. The same function can be realized also when using these methods.

Next, hardware for realizing the motor control device 100 of the present embodiment will be described.

In the motor control device 100 of this embodiment, the architecture for changing the characteristics of the FB control system, specifically the position controller 7, the speed controller 4, the correction calculator 6, the vibration detector 8, and the parameter setting changer 9 can be realized by a dedicated processing circuit, or can be realized by a general-purpose processor for executing programs. An example of a dedicated processing circuit is an ASIC (Application Specific Integrated Circuit), an FPGA (Field Programmable Gate Array), or a combination thereof. In the case of implementing the above architecture with a processor, for example, a control circuit composed of a processor 101 and a memory 102 as shown in FIG. 14 is used. FIG. 14 shows an example of hardware for realizing the motor control device 100 of the first embodiment. The processor 101 is a CPU (also referred to as a Central Processing Unit, a central processing unit, a processing unit, an arithmetic unit, a microprocessor, a microcomputer, and a DSP (Digital Signal Processor)), a system LSI (Large Scale Integration), or the like. The memory 102 is RAM (Random Access Memory), ROM (Read Only Memory), EPROM (Erasable Programmable Read Only Memory), EEPROM (registered trademark) (Electrically Erasable Programmable Read Only Memory), or the like. Programs are stored in the memory 102 , and the respective functions of the position controller 7 , the speed controller 4 , the correction calculator 6 , the vibration detector 8 , and the parameter setting changer 9 are programmed. Processor 101 operates as position controller 7 , speed controller 4 , correction calculator 6 , vibration detector 8 , and parameter setting changer 9 by executing the programs stored in memory 102 . In addition, the position controller 7, the speed controller 4, the correction calculator 6, the vibration detector 8, and the parameter setting changer 9 can be realized by dedicated processing circuits, and the remaining parts can be realized by the control circuit shown in FIG. 14 .

The speed detector 5 of the motor control device 100 is realized by an encoder. The current controller 3 is realized as an electronic circuit, and outputs a current corresponding to the value of the correction torque command input by the correction calculator 6 .

[Embodiment 2] FIG. 15 is a block diagram showing a configuration example of a motor control system 200a realized using the motor control device 100a of Embodiment 2. As shown in FIG. A motor control device 100a shown in FIG. 15 includes a parameter setting changer 9a for changing parameters of a speed controller 4 instead of the parameter setting changer 9 of the motor control device 100 of Embodiment 1 shown in FIG. 1 . The other constituent elements with the same symbols are the same as those in FIG. 1 , and therefore description thereof will be omitted.

Next, the operation of the motor control device 100a shown in FIG. 15 will be described. The motor control device 100a is the same as the motor control device 100 of Embodiment 1, and its purpose is to make the load machine 1 and the motor 2 operate following the position command, and the components with the same symbols as in FIG. The parameter setting changer 9a changes the parameters of the speed controller 4 according to the amplitude and frequency of the vibration calculated by the vibration detector 8 when it is determined that the FB control system composed of the position controller 7, the speed controller 4, the speed detector 5, the correction calculator 6, the current controller 3, the motor 2, and the load machine 1 is unstable.

Next, in the motor control system 200a of Embodiment 2, when the inertia of the load machine 1 decreases from the initial state, the influence on the FB control system and the operation of the motor control device 100a will be described. Consider a case where the inertia of the load machine 1 eventually decreases from an initial state where the motor inertia ratio is 250 times to 5 times the motor inertia ratio. The Bode diagram showing the transition characteristic from the input (current) of the motor 2 to the speed detection value of the motor 2 is the same as that of FIG. 2 .

FIG. 16 is a Bode diagram of the open-loop transfer function of the FB control system of the motor control device 100a of the second embodiment. The Bode diagram in FIG. 16 shows the open-loop transition function of the FB control system when the inertia of the load machine 1 decreases when the parameters of the position controller 7 and the speed controller 4 are set for the load machine 1 in the initial state and the settings are not changed. When the inertia of the load machine 1 is reduced to about 5.5 times the motor inertia ratio, the FB control system reaches the stable limit. In addition, although the resonance characteristics near 180 Hz are suppressed by the band-pass filter, there is almost no influence due to the change of inertia of the load machine 1, and a detailed description is omitted because it is irrelevant to this embodiment. FIG. 17 shows an example of the waveform of the speed detection value of the motor 2 during the inertia reduction process of the load machine 1 . The speed detection values shown in FIG. 17 show that the inertia of the load machine 1 reached 5.5 times the motor inertia ratio at 7 seconds, and oscillation at 52 Hz occurred due to instability. In addition, in FIG. 17, in order to see the oscillating waveform, a double-pass filter is used to remove the component of the velocity waveform following the velocity command.

Similar to the first embodiment, the vibration detector 8 calculates the amplitude and frequency of the vibration generated in the speed detection value. When the vibration shown in FIG. 17 occurs in the speed detection value, the vibration detector 8 calculates the amplitude of the vibration at 0.5 r/min and the frequency at 52 Hz at the time point of 8 seconds. When 0.5 r/min is regarded as the detected amplitude of vibration generation, the correction calculator 6 judges that vibration occurs at the time point of 8 seconds, performs a correction operation on the torque command to temporarily stabilize the characteristics of the FB control system near the vibration frequency, and generates a corrected torque command. Specifically, the correction calculator 6 calculates the correction torque command using the calculation of the transition function h(s) shown in the formula (3). In the formula (3), ω _h is set to ω _h =ω ₀ ×2.5 [rad/s] with respect to the vibration frequency ω ₀ =52×2π[rad/s] detected by the vibration detector 8 . The Bode diagram of the open-loop transfer function of the FB control system when the correction calculator 6 uses the transfer function h(s) of formula (3) to perform the correction calculation is shown in Figure 18. The FB control system is stabilized by the correction calculation of the correction calculator 6. FIG. 18 is a Bode diagram of the open-loop transfer function of the FB control system of the motor control device 100a of the second embodiment. When the FB control system is stabilized, as shown in Fig. 19, the oscillation is suppressed and the vibration amplitude is reduced. FIG. 19 shows operation waveforms when the FB control system of the motor control device 100a of Embodiment 2 is stabilized. From the fact that the stabilization of the FB control system reduces the vibration amplitude, it can be judged that the main cause of the oscillation is destabilization of the FB control system. The parameter setting changer 9a changes the coefficient Kv calculated by the ratio of the speed controller 4 based on this determination, and stabilizes the FB control system. The coefficient Kv after the change is, for example, a value obtained by changing the coefficient Kv before the change to 1/2 times. The Bode plot of the open-loop transfer function of the FB control system in this case is shown in Fig. 20. FIG. 20 is a Bode diagram of the open-loop transfer function when the feedback control system of the motor control device 100a of the embodiment 2 is stabilized.

In addition, the correction calculator 6 returns the transition function used for the correction calculation to h(s)=1 after changing the parameters of the speed controller 4 by the parameter setting changer 9a, as in the first embodiment. The reason for returning the transition function of the correction calculator 6 to h(s)=1 is the same as that described in Embodiment 1, where the inertia of the loading machine 1 increases from the initial state.

Next, a case where the main cause of vibration is external disturbance will be described. FIG. 21 shows an operation waveform of the motor control device 100a of Embodiment 2 when there is external disturbance vibration. Fig. 21 shows the waveform of the speed detection value when a disturbance of 52 Hz occurs. When an external disturbance is input at a time point of 3 seconds, the vibration detector 8 calculates a vibration amplitude of 0.5 r/min and a frequency of 52 Hz based on the speed detection value. Accompanying this, the correction calculator 6 starts the correction calculation using the transition function of the above-mentioned formula (3), but the vibration amplitude does not change. Therefore, it is determined from this result that the generation of the vibration is not an instability of the FB control system. Therefore, the parameter setting changer 9 a does not change the parameter settings of the position controller 7 and the speed controller 4 . Also, the correction calculator 6 returns the transition function used in the correction calculation to h(s)=1 when a predetermined time elapses after starting the correction calculation using the transition function of the above-mentioned expression (3).

The above-described operation of the motor control device 100a to suppress the vibration of the motor 2 can be represented by the flowchart of FIG. 13 similarly to the operation of the motor control device 100 of Embodiment 1 to suppress the vibration of the motor 2 . However, in the case of the operation of the motor control device 100a, step S4 in FIG. 13 is to adjust the parameters of the speed controller 4 .

As described above, in the motor control device 100a, when the amplitude of the vibration detected by the vibration detector 8 is larger than the threshold value, the correction calculator 6 is used to correct the transition function in the calculation, and the frequency of the detected vibration is changed to change the characteristics of the FB control system. Then, the main cause of the vibration that occurs when the inertia of the load machine 1 decreases from the initial state is discriminated from the subsequent state of change in the vibration amplitude. Also, when the main cause of the vibration is the destabilization of the FB control system, the parameter setting changer 9 a changes the parameters of the speed controller 4 to suppress large-amplitude oscillation. Also, when the main cause of the vibration is not the destabilization of the FB control system, the parameter setting changer 9a does not change the parameters of the speed controller 4, that is, does not change the characteristics of the FB control system. Thereby, the parameter setting of the speed controller 4 can be changed only when the FB control system is destabilized and the motor 2 vibrates due to the reduction of the inertia of the load machine 1 . In other words, it is possible to prevent the situation where the parameters of the speed controller 4 are changed to cause the control to become unstable when vibration is temporarily generated due to external disturbance, and the operation of the motor control system 200a can be stabilized.

In addition, the motor control device 100a of the present embodiment includes a parameter setting changer 9a for changing the parameters of the speed controller 4 instead of the parameter setting changer 9 of the motor control device 100 of the first embodiment. The other constituent elements are the same.

In addition, the motor control method executed by the motor control device 100a of the present embodiment is used in the FB control system, which detects the position of the motor 2 driving the load machine 1, generates a speed command based on the position of the motor 2 and the position command by calculation including proportional calculation, detects the speed of the motor 2, generates a torque command for the motor 2 based on the speed and speed command of the motor 2, and generates a corrected torque command by correcting the torque command. The vibration amplitude and vibration frequency of the vibration, when the vibration amplitude is greater than the threshold value, the detection of the position of the motor 2, the generation of the speed command, the detection of the speed of the motor 2, and the generation of the torque command are repeated. The motor control method stabilizes the transition characteristic in the vibration frequency generated by the motor 2, and when the vibration amplitude decreases after the transition characteristic is stabilized, changes the parameter of the calculation when the torque command is generated, that is, changes the coefficient of the proportional calculation.

In addition, although the vibration detector 8 of the motor control device 100a of this embodiment calculates the amplitude and frequency of vibration from the waveform of the speed detection value, it may also calculate the amplitude and frequency of vibration from the waveform of the position detection value, speed command, torque command, corrected torque command, and current.

In addition, when the motor control device 100a of this embodiment determines that the main cause of the vibration is the instability of the FB control system, the coefficient Kv calculated by the proportional calculation of the speed controller 4 is changed to 1/2 times the coefficient Kv before the change, but it is not limited to 1/2 times, and the coefficient Kv may be changed to a value smaller than the coefficient Kv before the change. For example, change the coefficient Kv to 1/ If the times are smaller, the destabilization of the FB control system can be suppressed.

Also, in the motor control device 100a of this embodiment, the position controller 7 generates a speed command according to formula (1), and the speed controller 4 generates a torque command according to formula (2), but other structures are also possible. For example, a speed I-P control system may be used, or a differential calculator may be added. In this case, it is only necessary to change the parameters according to the detected vibration frequency to achieve the characteristic change shown in FIG. 20 .

Also, in the motor control device 100a of the present embodiment, the correction calculator 6 changes the characteristics of the FB control system using the transition function h(s) of the formula (3), but other transition functions may also be used. For example, set a low-pass filter to change the characteristics of the FB control system, use a phase advance compensator to change the characteristics of the FB control system, add the waveform of the shape speed detection value to the torque command as shown in equation (4) to change the characteristics of the FB control system, etc. The same function can be realized also when using these methods.

[Embodiment 3] FIG. 22 is a block diagram showing a configuration example of a motor control system 200b realized using the motor control device 100b of Embodiment 3. As shown in FIG. In the motor control device 100b shown in FIG. 22, a characteristic change direction storage unit 10 is added to the motor control device 100 of Embodiment 1 shown in FIG. The other constituent elements with the same symbols are the same as those in FIG. 1 , and therefore description thereof will be omitted.

Next, the operation of the motor control device 100b shown in FIG. 22 will be described. The motor control device 100b is the same as the motor control device 100 of Embodiment 1 and the motor control device 100a of Embodiment 2. The purpose is to make the load machine 1 and the motor 2 operate in accordance with the position command, and the components with the same symbols as those in FIG.

The characteristic change direction storage unit 10 stores information on the direction of increase or decrease in the inertia of the load machine 1 when the inertia changes from the initial state, that is, information on the direction of inertia increase or decrease.

Vibration detector 8a calculates the amplitude and frequency of vibration after filtering the speed detection value input from speed detector 5 according to the increase and decrease direction of inertia of load machine 1 stored in characteristic change direction storage unit 10 . For example, when the inertia of the load machine 1 increases, the vibration generated when the FB control system becomes unstable occurs at a frequency near the frequency obtained by the coefficient Kp calculated by the proportional calculation of the position controller 7 and the coefficient Ki calculated by the integral calculation of the speed controller 4. Therefore, by using a band-pass filter or a double-band-pass filter or the like that passes this frequency band, it is possible to extract and process the vibration component related to destabilization. Also, when the inertia of the load machine 1 decreases, the vibration generated when the FB control system becomes unstable occurs at a frequency near the frequency obtained by the coefficient Kv calculated from the ratio of the speed controller 4, or at a frequency near the frequency of the limit characteristic obtained when the FB control system is adjusted in the initial state. Therefore, by using a band-pass filter or a double-band-pass filter or the like that passes this frequency band, it is possible to extract and process the vibration component related to destabilization. That is, the vibration detector 8a performs filtering processing corresponding to the direction of increase and decrease of inertia of the load machine 1 on the speed detection value input from the speed detector 5, and calculates the amplitude and frequency of vibration using the speed detection value after the filtering processing.

When the parameter setting changer 9b determines that the FB control system composed of the position controller 7, the speed controller 4, the position detector 51, the speed detector 5, the correction calculator 6, the current controller 3, the motor 2, and the load machine 1 is unstable, it changes the parameters of the position controller 7 or the speed controller 4 in accordance with the direction of increase or decrease of the inertia of the load machine 1 stored in the characteristic change direction storage unit 10. When the inertia of the load machine 1 increases, the parameter setting changer 9b changes the coefficient of the proportional calculation of the position controller 7 and the coefficient of the integral calculation of the speed controller 4 based on the amplitude and frequency of the vibration calculated by the vibration detector 8a, similarly to the parameter setting changer 9 of the motor control device 100 of Embodiment 1. Also, when the inertia of the load machine 1 decreases, the parameter setting changer 9b changes the proportional calculation coefficient of the speed controller 4 based on the amplitude and frequency of the vibration calculated by the vibration detector 8a similarly to the parameter setting changer 9a of the motor control device 100a of Embodiment 2.

The operation of suppressing the vibration of the motor 2 by the motor control device 100b described above is similar to the operation of suppressing the vibration of the motor 2 by the motor control device 100 of Embodiment 1, and can be shown in the flowchart of FIG. However, in the case of the operation of the motor control device 100b, the parameters of both the position controller 7 and the speed controller 4, or the parameters of the speed controller 4 are adjusted in step S4 of FIG.

As described above, in the motor control device 100b, when the amplitude of the vibration detected by the vibration detector 8a is larger than the threshold value, the correction calculator 6 uses the transition function used for the correction calculation to change the characteristic of the FB control system according to the frequency of the detected vibration. Then. Based on the change state of the vibration amplitude afterward, the main cause of the vibration is discriminated. Also, when the main cause of vibration is the instability of the FB control system caused by the change in the characteristics of the load machine 1, the parameter setting changer 9b changes the coefficient of the proportional calculation of the position controller 7 and the coefficient of the integral calculation of the speed controller 4, or the coefficient of the proportional calculation of the speed controller 4, according to the direction of the characteristic change of the load machine 1 stored in the characteristic change direction storage unit 10, that is, the direction of increase or decrease when the inertia of the load machine 1 changes from the initial state. Thereby, the parameter settings of the position controller 7 and the speed controller 4 can be changed only when the FB control system is destabilized and the vibration of the motor 2 occurs due to a change in the inertia of the load machine 1, and large-amplitude oscillations can be suppressed. Also, when the main cause of the vibration is not the destabilization of the FB control system, it is possible not to change the characteristics of the FB control system. That is, it is possible to prevent the situation where the parameters of the position controller 7 and the speed controller 4 are changed when vibration is temporarily generated by external disturbances, so that the control becomes unstable instead, and the operation of the motor control system 200b can be stabilized.

In addition, the motor control device 100b of the present embodiment has a characteristic change direction storage unit 10 added to the motor control device 100 of the first embodiment, a vibration detector 8a instead of the vibration detector 8, and a parameter setting changer 9b instead of the parameter setting changer 9. The other components are the same as those of the motor control device 100 .

In addition, the motor control method implemented by the implementation of this type of motor control device is used for the FB control system. It detects the position of the motor 2 of the driving load mechanical 1. According to the position and position instruction of the motor 2, the speed instruction is generated by the calculation of the calculation of the proportion. Damn 2 to generate torque instructions, modify the torque instructions to generate a correction torque instruction, according to the torque instructions and correction torque instructions to flow the current over the motor 2, storage motor 2 drive load mechanical 1 inertial increase or decrease direction, change the position, speed of the motor 2 in the direction of the amount of load mechanical 1 in response to the inertia direction of the load mechanical 1, or the filtering of the driver -based driver -based driver waveform. Treatment, detect the vibration amplitude and vibration frequency of the vibration generated by the motor 2 according to the filtering drive waveform. When the vibration amplitude generated by the motor 2 is repeatedly performed at the position of the motor 2, the speed of the speed instruction, the speed of the motor 2, the generation of the torque instruction, and the current flow over the motor. 2. The motor control method stabilizes the transition characteristic in the vibration frequency generated by the motor 2, and when the vibration amplitude decreases after the transition characteristic is stabilized, the coefficients of the proportional calculation included in the calculation when the speed command is generated when the inertia of the load machine 1 increases and the coefficients of the integral calculation included in the calculation when the torque command is generated are changed, and the coefficients of the proportional calculation included in the calculation when the torque command is generated when the inertia of the load machine 1 decreases.

In addition, the vibration detector 8a of the motor control device 100b of the present embodiment calculates the vibration amplitude and frequency from the waveform of the speed detection value, but may also calculate the vibration amplitude and frequency from the position detection value, speed command, torque command, corrected torque command, and current waveform.

In addition, in the motor control device 100b of this embodiment, the position controller 7 generates a speed command according to formula (1), and the speed controller 4 generates a torque command according to formula (2), but other configurations are also possible. For example, a speed I-P control system may be used, or a differential calculator may be added. In this case, the parameters may be changed according to the detected vibration frequency to achieve the characteristic changes shown in FIGS. 10 , 11 , and 20 .

Also, in the motor control device 100b of the present embodiment, the correction calculator 6 changes the characteristics of the FB control system using the transition function h(s) of the formula (3), but other transition functions may also be used. For example, set a low-pass filter to change the characteristics of the FB control system, use a phase advance compensator to change the characteristics of the FB control system, add the waveform of the shape speed detection value to the torque command as shown in equation (4) to change the characteristics of the FB control system, etc. The same function can be realized also when using these methods.

[Embodiment 4] Fig. 23 is a block diagram showing a configuration example of a motor control system 200c realized using the motor control device 100c of Embodiment 4. In the motor control device 100c shown in FIG. 23, the position controller 7 is deleted from the motor control device 100b of Embodiment 3 shown in FIG. 22, and a parameter setting changer 9c is provided instead of the parameter setting changer 9b. The other constituent elements with the same reference numerals are the same as those in FIG. 22 , and therefore description thereof will be omitted.

Next, the operation of the motor control device 100c shown in FIG. 23 will be described. The purpose of the motor control device 100c is to make the load machine 1 and the motor 2 operate following the speed command input from the outside, and the components with the same symbols as in FIG.

Vibration detector 8a calculates the amplitude and frequency of vibration after filtering the speed detection value input from speed detector 5 according to the increase and decrease direction of inertia of load machine 1 stored in characteristic change direction storage unit 10 . For example, when the inertia of the load machine 1 increases, the vibration generated when the FB control system becomes unstable occurs at a frequency near the frequency obtained by the coefficient of the integral calculation of the speed controller 4 . Therefore, by using a band-pass filter or a double-band-pass filter or the like that passes this frequency band, it is possible to extract and process the vibration component related to destabilization. Also, when the inertia of the load machine 1 is reduced, the vibration generated when the FB control system becomes unstable occurs at a frequency near the frequency obtained by the coefficient of the proportional calculation of the speed controller 4, or at a frequency near the frequency of the limit characteristic obtained when the FB control system is adjusted in the initial state. Therefore, by using a band-pass filter or a double-band-pass filter or the like that passes this frequency band, it is possible to extract and process the vibration component related to destabilization.

When the parameter setting changer 9c determines that the FB control system composed of the speed controller 4, the speed detector 5, the correction calculator 6, the current controller 3, the motor 2, and the load machine 1 is unstable, it changes the parameters of the speed controller 4 in accordance with the direction of increase or decrease of the inertia of the load machine 1 stored in the characteristic change direction storage unit 10. The parameter setting changer 9c changes the coefficient of the integral calculation of the speed controller 4 based on the amplitude and frequency of the vibration calculated by the vibration detector 8a when the inertia of the load machine 1 increases. Also, when the inertia of the load machine 1 decreases, the parameter setting changer 9c changes the proportional calculation coefficient of the speed controller 4 based on the amplitude and frequency of the vibration calculated by the vibration detector 8a, similarly to the parameter setting changer 9a of the motor control device 100a of Embodiment 2.

The operation of suppressing the vibration of the motor 2 by the motor control device 100c described above is similar to the operation of suppressing the vibration of the motor 2 by the motor control device 100 of Embodiment 1, and can be shown in the flowchart of FIG. However, in the case of the operation of the motor control device 100c, in step S4 of FIG. 13, the parameter of the speed controller 4 is adjusted.

As described above, in the motor control device 100c, when the amplitude of the vibration detected by the vibration detector 8a is larger than the threshold value, the correction calculator 6 uses the transition function used for the correction calculation to change the characteristic of the FB control system according to the frequency of the detected vibration. Then. Based on the change state of the vibration amplitude afterward, the main cause of the vibration is discriminated. In addition, when the main cause of vibration is that the FB control system is destabilized due to a change in the characteristics of the load machine 1, the parameter setting changer 9c changes the coefficient of the integral calculation or the proportional calculation of the speed controller 4 in accordance with the direction of the characteristic change of the load machine 1 stored in the characteristic change direction storage unit 10, that is, the direction of increase or decrease when the inertia of the load machine 1 changes from the initial state. Thereby, the parameter setting of the speed controller 4 can be changed only when the FB control system is destabilized and vibration of the motor 2 occurs due to a change in the inertia of the load machine 1 , and large-amplitude oscillation can be suppressed. Also, when the main cause of the vibration is not the destabilization of the FB control system, it is possible not to change the characteristics of the FB control system. That is, it is possible to prevent a situation in which the parameters of the speed controller 4 are changed when vibrations are temporarily generated due to external disturbances, so that the control becomes unstable instead, and it is also possible to stabilize the operation of the motor control system 200c.

Furthermore, the motor control device 100c of the present embodiment deletes the position controller 7 from the motor control device 100b of the third embodiment, and includes a parameter setting changer 9c instead of the parameter setting changer 9b. The other constituent elements are the same as those of the motor control device 100b.

In addition, the motor control method implemented by the motor control device 100c of this embodiment is used in the FB control system, which detects the speed of the motor 2 driving the load machine 1, generates a torque command to the motor 2 based on the speed of the motor 2 and the speed command through calculations including proportional calculations and integral calculations, and corrects the torque command to generate a corrected torque command. Change the position and speed of the motor 2 or filter the drive waveform based on the torque, detect the vibration amplitude and vibration frequency of the vibration generated by the motor 2 based on the filtered drive waveform, and when the vibration amplitude of the vibration generated by the motor 2 is larger than the threshold, the detection of the speed of the motor 2, the generation of the torque command, the generation of the corrected torque command, and the current flow through the motor 2 are repeated. The motor control method stabilizes the transition characteristic in the vibration frequency generated by the motor 2, and when the vibration amplitude decreases after the transition characteristic is stabilized, changes the coefficient of the integral calculation included in the calculation when the torque command is generated when the inertia of the load machine 1 increases, and changes the coefficient of the proportional calculation included in the calculation when the torque command is generated when the inertia of the load machine 1 decreases.

In addition, the vibration detector 8a of the motor control device 100c of the present embodiment calculates the vibration amplitude and frequency from the waveform of the speed detection value, but may also calculate the vibration amplitude and frequency from the torque command, corrected torque command, and current waveform.

In addition, in the motor control device 100c of the present embodiment, the speed controller 4 generates the torque command according to the formula (2), but other configurations are also possible. For example, a speed I-P control system may be used, or a differential calculator may be added. In this case, the parameters may be changed according to the detected vibration frequency to achieve the characteristic changes shown in FIGS. 10 , 11 , and 20 .

In addition, in the motor control device 100c of the present embodiment, the correction calculator 6 changes the characteristics of the FB control system using the transition function h(s) of the formula (3), but other transition functions may also be used. For example, set a low-pass filter to change the characteristics of the FB control system, use a phase advance compensator to change the characteristics of the FB control system, add the waveform of the shape speed detection value to the torque command as shown in equation (4) to change the characteristics of the FB control system, etc. The same function can be realized also when using these methods.

The architecture shown in the above embodiments is just an example, and it can also be combined with other known technologies, and the implementation types can also be combined, and part of the architecture can be omitted or changed within the scope of not departing from the gist.

1: load machinery 2: motor 3: Current controller 4: Speed controller 5: Speed detector 6: Correction calculator 7: Position controller 8,8a: Vibration detector 9,9a,9b,9c: parameter setting changer 10:Characteristic change direction storage unit 51: Position detector 52: Differential Calculator 100, 100a, 100b, 100c: motor control device 101: Processor 102: memory 200, 200a, 200b, 200c: Motor Control Systems

FIG. 1 is a block diagram showing a configuration example of a motor control system realized using the motor control device of Embodiment 1. As shown in FIG. FIG. 2 is a Bode diagram of the motor driven by the motor control device of Embodiment 1. FIG. FIG. 3 is a Bode diagram of the open-loop transfer function of the feedback control system of the motor control device of Embodiment 1. FIG. FIG. 4 is a Nyquist diagram of the open-loop transfer function of the feedback control system of the motor control device of Embodiment 1. FIG. Fig. 5 shows an example of an operation waveform when the motor control device according to Embodiment 1 becomes unstable. FIG. 6 is a Bode diagram of a transfer function of a correction calculator of the motor control device of Embodiment 1. FIG. FIG. 7 is a Bode diagram of the open-loop transfer function of the feedback control system of the motor control device of Embodiment 1. FIG. FIG. 8 is a Nyquist diagram of the open-loop transfer function of the feedback control system of the motor control device of Embodiment 1. FIG. FIG. 9 shows operation waveforms when the feedback control system of the motor control device of Embodiment 1 is stabilized. 10 is a Bode diagram of the open-loop transfer function when the feedback control system of the motor control device of Embodiment 1 is stabilized. 11 is a Nyquist diagram of the open-loop transfer function when the feedback control system of the motor control device of Embodiment 1 is stabilized. FIG. 12 shows the operation waveform of the motor control device of Embodiment 1 when there is external disturbance vibration. 13 is a flowchart showing an example of the operation of the motor control device according to Embodiment 1 to suppress vibration of the motor. FIG. 14 shows an example of hardware for realizing the motor control device of the first embodiment. Fig. 15 is a block diagram showing a configuration example of a motor control system realized using the motor control device of the second embodiment. FIG. 16 is a Bode diagram of the open-loop transfer function of the feedback control system of the motor control device of Embodiment 2. FIG. FIG. 17 shows an example of the waveform of the speed detection value of the motor during the inertia reduction process of the load machine. FIG. 18 is a Bode diagram of the open-loop transfer function of the feedback control system of the motor control device of Embodiment 2. FIG. FIG. 19 shows the operation waveforms when the feedback control system of the motor control device of Embodiment 2 is stabilized. FIG. 20 is a Bode diagram of the open-loop transfer function when the feedback control system of the motor control device of Embodiment 2 is stabilized. FIG. 21 shows the operation waveform of the motor control device of Embodiment 2 when there is external disturbance vibration. Fig. 22 is a block diagram showing a configuration example of a motor control system realized using the motor control device of the third embodiment. Fig. 23 is a block diagram showing a configuration example of a motor control system realized using the motor control device according to the fourth embodiment.

1: load machinery

2: motor

3: Current controller

4: Speed controller

5: Speed detector

6: Correction calculator

7: Position controller

8: Vibration detector

9: Parameter setting changer

51: Position detector

52: Differential Calculator

100: Motor control device

200:Motor control system

Claims (11)

A motor control device for controlling a motor driving a load machine, comprising: a speed detector for detecting the speed of the motor; a speed controller for generating a torque command for the motor according to the speed of the motor and a speed command; a correction calculator for correcting the torque command to generate a corrected torque command; a current controller for making current flow through the motor according to the torque command and the corrected torque command; a vibration detector for detecting the vibration amplitude of the vibration generated by the motor and the vibration frequency of the vibration frequency; The characteristic change direction storage part stores the increase and decrease direction when the inertia of the load machine changes, wherein when the vibration amplitude is larger than the threshold value, the correction calculator calculates a correction torque command for the feedback control system composed of the motor, the speed detector, the speed controller, the correction calculator and the current controller, so that the transition characteristic of the vibration frequency detected by the vibration detector is stabilized. The changer changes the parameters of the speed controller. The speed controller generates the torque command through an operation including proportional calculation and integral calculation. The parameter setting changer changes the coefficient of the integral calculation when the increase and decrease direction stored in the characteristic change direction storage unit is an increasing direction, and changes the coefficient of the proportional calculation when the increase and decrease direction is a decreasing direction. The motor control device according to claim 1, wherein: the parameter setting changer changes the coefficient of the integral calculation of the speed controller to a value smaller than a value before the change, or to a value smaller than the vibration frequency when the increase and decrease direction is an increase direction. The motor control device according to claim 1, wherein the parameter setting changer changes the coefficient of the proportional calculation of the speed controller to a value smaller than a value before the change when the increase/decrease direction is a decrease direction. The motor control device according to claim 1, wherein: the vibration detector performs different filtering processes for the driving waveform according to the position, speed or torque of the motor, when the increasing and decreasing direction stored in the characteristic change direction storage unit is an increasing direction and a decreasing direction, and detects the vibration amplitude and the vibration frequency from the filtered driving waveform. The motor control device according to any one of Claims 1 to 4, further comprising: a position detector, which detects the position of the motor; and a position controller, which generates the speed command according to the position of the motor and the position command, using an operation including proportional calculation, wherein the parameter setting changer changes the coefficient of the proportional calculation of the position controller to a value smaller than the value before the change, or to a value smaller than the vibration frequency when the direction of increase and decrease is an increase direction. A motor control system, comprising: the motor control device according to any one of claims 1 to 5; the motor controlled by the motor control device; and the load machine driven by the motor. A motor control method, executed by a motor control device, the motor control device is used to control a motor that drives a load machine, the motor control method includes: a first step, detecting the speed of the motor; a second step, outputting a torque command to the motor according to the speed of the motor and a speed command; a third step, correcting the torque command to generate a corrected torque command; The fourth step is to make the current flow through the motor according to the torque command and the corrected torque command; the fifth step is to detect the vibration amplitude of the vibration amplitude generated by the motor and the vibration frequency of the vibration frequency; the sixth step is to repeatedly perform the detection of the speed of the motor, the generation of the torque command, the generation of the corrected torque command, and the feedback control system that makes the current flow through the motor to stabilize the transfer characteristics of the vibration frequency; When the vibration amplitude decreases after the transition characteristic is stabilized, change the parameters of the calculation for generating the torque command, wherein: in the second step, the torque command is generated by calculation including proportional calculation and integral calculation; in the seventh step, the coefficient of the integral calculation is changed when the inertia of the load machine increases, and the coefficient of the proportional calculation is changed when the inertia of the load machine decreases. The motor control method according to claim 7, wherein: in the seventh step, when the inertia increases, the coefficient of the integral calculation is changed to a value smaller than that before the change, or a value smaller than the vibration frequency. The motor control method according to claim 7, wherein: in the seventh step, when the inertia decreases, the coefficient for the proportional calculation is changed to a value smaller than the value before the change. The motor control method according to claim 7, wherein: in the fifth step, for the driving waveform according to the position, speed or torque of the motor, different filtering processes are performed when the inertia increases and when the inertia decreases, and the vibration amplitude and the vibration frequency are detected from the filtered driving waveform. The motor control method according to any one of claims 7 to 10, further comprising: step 8, detecting the position of the motor; In the ninth step, the speed command is generated by calculation including proportional calculation based on the position of the motor and the position command; and in the tenth step, when the inertia increases, the coefficient of the proportional calculation in the ninth step is changed to a value smaller than the value before the change, or to a value smaller than the vibration frequency.

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