WO2023248303A1

WO2023248303A1 - Control system

Info

Publication number: WO2023248303A1
Application number: PCT/JP2022/024566
Authority: WO
Inventors: 伸悟川内; 孝輔 ▲辻▼川; 宗洋村田
Original assignee: 三菱電機株式会社
Priority date: 2022-06-20
Filing date: 2022-06-20
Publication date: 2023-12-28
Also published as: CN118202310A; JP7209906B1; JPWO2023248303A1

Abstract

This control system comprises a data acquisition unit (1311) and an analysis unit. The data acquisition unit (1311) acquires to-be-held object information indicating information about a to-be-held object held by a holding device of an industrial machine, the holding state of the to-be-held object held by the holding device, and machine information indicating information about the industrial machine. The analysis unit derives the cutoff frequency to be set in a filtering process by a motor control device that controls a control target provided for the industrial machine, as the natural frequency of a machine construction that occurs in the machine construction comprising the control target and the holding device when the to-be-held object is held by the holding device. The analysis unit derives the natural frequency of the machine construction that occurs when a machining process is performed with the to-be-held object being held by the holding device of the industrial machine, from the to-be-held object information, the holding state, and the machine information acquired by the data acquisition unit (1311).

Description

control system

The present disclosure relates to a control system that controls industrial machinery such as machine tools.

Control devices that control the operation of industrial machinery such as machine tools generally employ a feedback control method. By employing a feedback control method, the control device can stably follow the target value sent from the host controller and can also cope with the influence of disturbances.

However, even if a feedback control method is used, mechanical resonance depending on the rigidity, mass, etc. of the controlled object may occur. If the feedback gain is set to a large value when mechanical resonance occurs, the mechanical resonance may increase and the control system may oscillate. In order to suppress such a phenomenon, conventionally, a method has been used in which a notch filter, which is a filter that attenuates only specific frequency components, is provided in the control loop. However, in order to set a cutoff frequency, which is a specific frequency to be attenuated or cut off, in a notch filter, the frequency to be cut off must be determined in advance by actual measurement, and a dedicated measuring instrument is required. Furthermore, some machine tools perform a holding operation on an object to be held, such as a workpiece. In such a machine tool, the resonant frequency also changes as the characteristics of the object to be held, such as its structure and material, and whether or not the object is being held, that is, the state in which it is held, change. Therefore, the method of determining the cutoff frequency in advance using a dedicated measuring instrument may not be able to sufficiently suppress the above phenomenon.

In order to address the above-mentioned problems, Patent Document 1 discloses that the resonant frequency, which changes depending on the characteristics and state of the object to be held, is calculated using current commands in the control loop, position and current feedback obtained from sensors, etc. A control system that estimates from information is disclosed. The control system described in Patent Document 1 determines the estimated resonance frequency as the cutoff frequency of the notch filter, thereby making it possible to suppress vibration even when the controlled object changes.

Patent No. 6639758

However, in the method described in Patent Document 1, when a machine tool is in a state where the resonant frequency is not known, after mechanical resonance actually occurs in an industrial machine such as a machine tool, It is necessary to estimate the resonance frequency when mechanical resonance occurs using data such as feedback information including the current command and the detection result by the detector. Therefore, in order to determine the cutoff frequency of the notch filter, an operation for generating mechanical resonance is required, which may have an undesirable effect on industrial machinery.

The present disclosure has been made in view of the above, and is intended to be used to estimate the resonant frequency of mechanical resonance that occurs in accordance with the natural frequency that changes depending on the state of industrial machines such as machine tools. The present invention aims to provide a control system that can suppress mechanical resonance in industrial machinery without requiring operations that generate mechanical resonance.

In order to solve the above-mentioned problems and achieve the objectives, the control system of the present disclosure includes a data acquisition section and an analysis section. The data acquisition unit acquires held object information indicating information on the held object held in the holding device of the industrial machine, the holding state of the held object in the holding device, and machine information indicating information on the industrial machine. do. The analysis section calculates the cutoff frequency set by filtering processing in a motor control device that controls a controlled object installed in an industrial machine, including the controlled object and the holding device when the held object is held in the holding device. It is derived as the natural frequency of the mechanical configuration that occurs in the mechanical configuration consisting of . The analysis unit analyzes the machine configuration that occurs when processing is performed with the held object held in the holding device of the industrial machine, based on the held object information, holding state, and machine information acquired by the data acquisition unit. Derive the natural frequency of.

The control system according to the present disclosure is an operation that actually causes mechanical resonance in an industrial machine such as a machine tool in order to estimate the resonance frequency of machine resonance that occurs according to the natural frequency that changes depending on the state of the industrial machine. This has the effect of suppressing mechanical resonance in industrial machinery without requiring any.

A diagram schematically showing an example of the configuration of a control system according to Embodiment 1. A diagram schematically showing an example of the configuration of a filter generation unit in the control system according to Embodiment 1. A diagram schematically showing an example of the configuration of a calculation device in the control system according to Embodiment 1. Flowchart showing an example of a processing procedure in a filter generation unit in the control system according to Embodiment 1 A diagram illustrating an example of the configuration of a processing circuit according to Embodiment 1. A diagram schematically showing another example of the configuration of the control system according to Embodiment 1. A diagram schematically showing another example of the configuration of the control system according to Embodiment 1. A block diagram showing an example of the configuration of a computer system that implements the arithmetic unit of the control system according to Embodiment 1.

Below, a control system according to an embodiment of the present disclosure will be described in detail based on the drawings.

Embodiment 1.
FIG. 1 is a diagram schematically showing an example of the configuration of a control system according to the first embodiment. The control system 20 of the first embodiment includes a motor control device 1 and a higher-level controller 2 that controls the motor control device 1. Control system 20 controls machine tool 30. In the first embodiment, it is assumed that the machine tool 30 that is the control target of the control system 20 is a machine tool that performs cutting, but the control target of the control system 20 is not limited to a machine tool that performs cutting. Any industrial machine may be used as long as it is capable of holding the workpiece 6 to be processed.

In the example shown in FIG. 1, the machine tool 30 includes a motor 3, a reduction gear 8, a chuck device 5, and a cutting tool 7. The machine tool 30 can hold the workpiece 6. The workpiece 6 is an example of an object that can be held by the machine tool 30. Further, the workpiece 6 is a target to be processed by the machine tool 30. The chuck device 5 is an example of a holding device for the machine tool 30. Specifically, the machine tool 30 fixes the workpiece 6 using the chuck device 5. The chuck device 5 fixes the work 6 when receiving a chuck signal from the host controller 2 indicating that the work 6 is to be held. The motor 3 is controlled by a motor control device 1. The rotational motion of the motor 3 is transmitted to the chuck device 5 via a speed reducer 8. As a result, the workpiece 6 rotates together with the chuck device 5. The workpiece 6 is machined by the cutting tool 7 while rotating. Further, the position of the motor 3, that is, the rotational position of the motor 3 is detected by the detector 4. The position of the motor 3 detected by the detector 4 is input to the motor control device 1. The motor control device 1 directly controls the motor 3 and indirectly controls the reducer 8 that converts the rotational motion of the motor 3, and the motor 3 and the reducer 8 are controlled by the motor control device 1. This is an example of a controlled object. Note that the objects to be controlled by the motor control device 1 may include not only the motor 3 and the speed reducer 8, but also a member that transmits the driving force of the motor 3, such as a ball screw (not shown).

In the example shown in FIG. 1, the chuck device 5 is an example in which the workpiece 6 is held by a chuck mechanism, but the chuck device 5 is not limited to the chuck mechanism, and may be a holding device that holds the workpiece 6 by another mechanism. . Further, in the example shown in FIG. 1, the chuck device 5 holds one end of the work 6 extending in one direction, but may hold the work 6 at any position.

Furthermore, in the example shown in FIG. 1, the machine tool 30 has one set of machining parts including the motor 3, the reducer 8, the chuck device 5, and the cutting tool 7; It may have a part. In this case, the processing section including the motor 3, reducer 8, chuck device 5, and cutting tool 7 may be arranged symmetrically. As a result, a state where both processing sections hold the workpiece 6 may change to a state where one processing section holds the workpiece 6 and the other processing section does not hold the workpiece 6. In such a case, the resonant frequency of the entire machine tool 30 will change.

The upper controller 2 generates commands, control signals, control information, etc. for controlling the machining of the machine tool 30. Specifically, the host controller 2 generates a position command, which is a command regarding the position of the motor 3, and outputs it to the motor control device 1. In one example, the host controller 2 generates commands, control signals, control information, etc. for controlling machining of the machine tool 30 according to a machining program. The motor control device 1 generates a current for controlling the motor 3 based on the position command received from the host controller 2 and the position of the motor 3 input from the detector 4, and outputs it to the motor 3. do.

Additionally, the host controller 2 generates a control signal indicating whether the chuck device 5 fixes or releases the workpiece 6 and outputs it to the chuck device 5. Here, it is assumed that the control signal indicating whether to fix or release the workpiece 6 is a chuck signal that is output while the workpiece 6 is being fixed. The chuck device 5 performs an operation of fixing the workpiece 6 while receiving a chuck signal from the host controller 2, and performs an operation of releasing the workpiece 6 when not receiving a chuck signal. Note that the control signal indicating whether to fix or release the workpiece 6 is not limited to this example, and may be a signal output at the start and end of the workpiece 6, or may be a signal outputted at the start and end of the workpiece 6, or may be a signal outputted when the workpiece 6 is fixed or released depending on the voltage value of the signal, etc. It may also indicate the fixation and release of. Further, although an example in which the workpiece 6 is fixed by the chuck device 5 has been shown, any fixing method may be used as long as the host controller 2 can grasp whether or not the workpiece 6 is fixed to the machine tool 30. .

The host controller 2 knows the holding state of the workpiece 6. The holding state is, for example, information indicating whether the workpiece 6 is fixed to the machine tool 30 or not. In the configuration example shown in FIG. 1, the holding state is, for example, whether the workpiece 6 is fixed to the chuck device 5 or not. In one example, this holding state is designated by a machining program. The host controller 2 can determine the holding state of the workpiece 6 based on the machining program. Furthermore, the holding state may be inputtable by the operator of the machine tool 30. In one example, the operator inputs the holding state of the workpiece 6 using an input means (not shown) of the host controller 2 . Alternatively, the motor control device 1 may include an input means, and the operator may input the holding state of the workpiece 6 to the motor control device 1. Further, when machining is performed using the machine tool 30, work information that is information regarding the work 6 and machine information that is information regarding the machine tool 30 are input as machining conditions. The upper controller 2 controls machining by the machine tool 30 based on machining conditions. The workpiece information includes the holding position, structure, and material of the workpiece 6. The workpiece information corresponds to the held object information. The holding position is information indicating the length from the end of the workpiece 6 to the holding location of the workpiece 6 held by the chuck device 5. In the example shown in FIG. 1, the holding position is the length from the end where the work 6 is not held to the end where the work 6 is held by the chuck device 5. Become. The structure is information indicating the shape of the workpiece 6. The material is information indicating the material that constitutes the workpiece 6. The machine information is information about the machine tool 30, and includes the inertia and structure of the motor 3 that is controlled by the motor control device 1, the reducer 8 that changes the rotational speed of the motor 3, and the chuck device 5 that holds the workpiece 6. include. The host controller 2 outputs the holding state of the workpiece 6, workpiece information that is information about the workpiece 6, and machine information that is information about the machine tool 30 to the motor control device 1. Workpiece information and machine information may also be determined based on the machining program, or may be inputtable by the operator. Note that the held object information is information indicating information about the held object such as the work 6. Further, the machine information is information indicating information on an industrial machine such as the machine tool 30.

Next, the configuration of the motor control device 1 will be explained. As shown in FIG. 1, the motor control device 1 includes a position control section 11, a speed control section 12, a filter generation section 13, a current control section 14, and a speed conversion section 15. The position control unit 11 calculates a speed command based on the position command received from the host controller 2 and the position input from the detector 4, and outputs the speed command to the speed control unit 12. Specifically, the speed command is calculated based on the difference between the position command and the position input from the detector 4. The speed converter 15 calculates the speed by differentiating the position input from the detector 4, and outputs the calculated speed to the speed controller 12.

The speed control unit 12 calculates a current command based on the speed command and the speed input from the speed conversion unit 15, and outputs the current command to the filter generation unit 13. Specifically, the speed control section 12 calculates the current command based on the difference between the speed command and the speed input from the speed conversion section 15. That is, the speed control section 12 is a command generation section that generates a command for controlling the machine tool 30 through feedback control. Specifically, this command is a command for controlling the motor 3 of the machine tool 30 by feedback control. In the first embodiment, an example will be described in which a filter generation unit 13 (described later) performs filtering processing on a current command for controlling the motor 3. This is an example of a command for controlling by feedback control, and the target of the filtering process in the first embodiment may be any command to control a motor provided in the machine tool 30, and is not limited to a current command.

The filter generation unit 13 performs filtering processing on a command for controlling the machine tool 30 by feedback control, in this example a current command, and outputs the current command after the filtering processing to the current control unit 14. The filtering process in the filter generation unit 13 is a filtering process that attenuates a component of a cutoff frequency that is a specific frequency, that is, blocks a component of a cutoff frequency. Machine resonance can be suppressed by setting the cutoff frequency cut off by the filter generation unit 13 to the frequency at which resonance occurs in the machine tool 30, that is, the resonance frequency. On the other hand, the frequency at which mechanical resonance is generated changes depending on the natural frequency of the mechanical configuration of the machine tool 30, which includes the control target of the motor control device 1 and the chuck device 5. This natural frequency depends on the state in which the workpiece 6 is held by the machine tool 30, the structure and material of the workpiece 6, and the like. Therefore, if the cutoff frequency to be removed by the filter generation unit 13 is determined without reflecting the holding state of the workpiece 6, the structure and material of the workpiece 6, etc., the holding state of the workpiece 6, the structure and material of the workpiece 6, etc. In some cases, resonance may not be suppressed. Therefore, in the first embodiment, the filter generation unit 13 determines the cutoff frequency to be removed by filtering processing based on the work information, holding state, and machine information received from the host controller 2. As a result, in the first embodiment, the cutoff frequency can be determined by reflecting the holding state of the work 6, the structure and material of the work 6, and the like. Therefore, even if the natural frequency of the workpiece 6 changes, mechanical resonance can be suppressed. Details of the filter generation unit 13 will be described later. In one example, when the holding state of the workpiece 6 changes, from a state in which the workpiece 6 is held in each of two processing sections, the workpiece 6 is removed from one processing section, and the workpiece 6 is removed from the other processing section. An example of this is when the state changes to a state where it is held.

The current control unit 14 controls the current output to the motor 3 based on the current command output from the filter generation unit 13. The current command output from the filter generation unit 13 is a current command obtained by removing the cutoff frequency from the current command output from the speed control unit 12 by the filter generation unit 13. The motor 3 performs rotational motion according to the current output from the current control section 14. Through the above operations, the motor control device 1 can control the motor 3 to the position according to the position command received from the host controller 2. By controlling the motor 3 to a position according to the position command, the workpiece 6 can be controlled to a desired position via the reducer 8 and the chuck device 5.

Next, details of the filter generation section 13 will be explained. The filter generation unit 13 obtains a vibration frequency using information including workpiece information, holding state, and machine information, and performs filtering processing on the current command according to the vibration frequency. The filter generation unit 13 includes an arithmetic unit that derives a natural frequency from information including workpiece information, holding state, and machine information through vibration analysis using a finite element method (FEM) model. Vibration analysis using a finite element method model is a well-known technique, so its explanation will be omitted.

FIG. 2 is a diagram schematically showing an example of the configuration of a filter generation section in the control system according to the first embodiment. The filter generation unit 13 includes an arithmetic unit 131 and a notch filter 132. The calculation device 131 derives the natural frequency of the machine configuration by inputting the work information, holding state, and machine information received from the host controller 2. When deriving the natural frequency, the arithmetic unit 131 generates a shape model for the analysis target from the work information, the holding state, and the machine information, and performs vibration analysis on this shape model using an FEM model. The notch filter 132 performs filtering processing on the current command using the natural frequency output by the arithmetic device 131 as a cutoff frequency. In one example, the filter generation unit 13 is a functional block that causes an IC (Integrated Circuit), a microcomputer, etc. to function as the filter generation unit 13. The functional block functions as a notch filter 132 by setting the cutoff frequency derived by the arithmetic unit 131.

FIG. 3 is a diagram schematically showing an example of the configuration of a calculation device in the control system according to the first embodiment. The arithmetic device 131 includes a data acquisition section 1311 and an FEM analysis section 1312.

The data acquisition unit 1311 acquires work information, holding state, and machine information of the work 6 from the upper controller 2 as input data in vibration analysis using the FEM model, and inputs the input data to the FEM analysis unit 1312.

The FEM analysis unit 1312 calculates the cutoff frequency set by the filtering process in the motor control device 1 that controls the controlled object provided in the machine tool 30 as the natural frequency of the machine configuration that occurs when the workpiece 6 is held. Derive. Specifically, the FEM analysis unit 1312 performs processing on the workpiece 6 held in the chuck device 5 of the machine tool 30 based on the workpiece information, holding state, and machine information acquired by the data acquisition unit 1311. The natural frequency of the mechanical structure that sometimes occurs is derived as the frequency to be cut off. At this time, the FEM analysis unit 1312 derives the natural frequency by performing vibration analysis using the finite element method. That is, the FEM analysis unit 1312 derives a cutoff frequency to be applied to the notch filter 132 by performing vibration analysis on the input data input from the data acquisition unit 1311 using a FEM model using the finite element method. The FEM analysis section 1312 corresponds to an analysis section.

FIG. 4 is a flowchart illustrating an example of a processing procedure in the filter generation unit in the control system according to the first embodiment. The data acquisition unit 1311 of the arithmetic device 131 acquires data (step S11). Specifically, the data acquisition unit 1311 of the arithmetic unit 131 acquires work information, holding state, and machine information of the workpiece 6 held in the machine tool 30 as input data for vibration analysis, and transfers the input data to the FEM analysis unit 1312. Enter. Here, the data acquisition unit 1311 acquires work information, holding state, and machine information of the work 6 from the host controller 2.

The FEM analysis unit 1312 derives the natural frequency, which is the vibration frequency when the workpiece 6 is held by the machine tool 30, by performing vibration analysis using the FEM model based on the input data (step S12).

Next, the FEM analysis unit 1312 outputs the natural frequency derived in step S12 to the notch filter 132 (step S13). The notch filter 132 performs settings according to the data output from the FEM analysis section 1312 (step S14). Specifically, the notch filter 132 sets the cutoff frequency to the natural frequency calculated by the calculation device 131, and performs filtering processing on the current command. This completes the process.

Through the above-described operation, the filter generation unit 13 can suppress the natural frequency corresponding to the combination of workpiece information, holding state, and machine information through filtering processing. Even if at least one of them changes, mechanical resonance of the machine tool 30 can be suppressed. That is, even if the workpiece 6 is replaced or the holding of the workpiece 6 is released during machining, the workpiece information, holding state, and machine information after changes in at least one of the workpiece 6 and the holding state are changed. The natural frequency corresponding to the combination of is calculated by the calculation device 131 and set in the notch filter 132. Therefore, even after the change, mechanical resonance of the machine tool 30 can be suppressed. Since the control system 20 uses the calculation device 131 to calculate the natural frequency corresponding to the combination of workpiece information, holding state, and machine information, there is no need for an operation that actually generates mechanical resonance in the machine tool 30, and there is no need to perform an operation that actually causes mechanical resonance. The frequency can be derived.

Here, the hardware configuration of the motor control device 1 will be explained. Each part of the motor control device 1 is realized by a circuit. The current control unit 14 includes a converter circuit that converts AC power to DC power or an inverter circuit that converts DC power to desired AC power, and supplies current to the motor 3 so as to follow the current command. The position control section 11, speed control section 12, filter generation section 13, and speed conversion section 15 are realized by a processing circuit. The processing circuit may be a circuit including a processor or may be dedicated hardware.

If the processing circuit is a circuit that includes a processor, the processing circuit is a control circuit that includes a processor and a memory. FIG. 5 is a diagram illustrating an example of a configuration of a processing circuit according to the first embodiment. The processing circuit 100 shown in FIG. 5 includes a processor 101 and a memory 102. When the position control section 11, speed control section 12, filter generation section 13, and speed conversion section 15 are realized by a control circuit, these are realized by the processor 101 reading and executing a program stored in the memory 102. be done. That is, when the position control section 11, speed control section 12, filter generation section 13, and speed conversion section 15 are realized by the control circuit shown in FIG. 5, these functions are realized using a program that is software. . Memory 102 is also used as a work area for processor 101. The processor 101 is a CPU (Central Processing Unit) or the like. The memory 102 is, for example, a RAM (Random Access Memory), a ROM (Read Only Memory), a nonvolatile or volatile semiconductor memory such as a flash memory, a magnetic disk, or the like.

When the position control unit 11, speed control unit 12, filter generation unit 13, and speed conversion unit 15 are dedicated hardware, the processing circuit is, for example, an FPGA (Field Programmable Gate Array) or an ASIC (Application Specific Integrated Circuit). be. Note that the position control section 11, speed control section 12, filter generation section 13, and speed conversion section 15 may be realized by combining a processing circuit including a processor and dedicated hardware. The position control section 11, speed control section 12, filter generation section 13, and speed conversion section 15 may be realized by a plurality of processing circuits.

In the example shown in FIG. 1, the host controller 2 sends the filter generation unit 13 of the motor control device 1 the workpiece information and retention information about the workpiece 6 held in the chuck device 5, which is the control target of the motor control device 1. It provided status and machine information. However, the workpiece information, holding state, and machine information regarding the workpiece 6 may be input using an input means (not shown) of the motor control device 1. In this case, the configuration of the control system 20 for setting the cutoff frequency includes the motor control device 1.

In the example shown in FIG. 1, the control system 20 includes a motor control device 1 and a host controller 2, and has a configuration in which the filter generation unit 13 of the motor control device 1 includes a calculation device 131 that calculates a natural frequency. However, the configuration of the control system 20 is not limited to this.

FIG. 6 is a diagram schematically showing another example of the configuration of the control system according to the first embodiment. Note that the same components as those in the above description are given the same reference numerals, and the description thereof will be omitted. In the control system 20a shown in FIG. 6, the filter generation unit 13 of the motor control device 1 does not have the calculation device 131, and the host controller 2 has the calculation device 21 that calculates the natural frequency. is different. The configuration of the arithmetic unit 21 is similar to that shown in FIG. In this case, the data acquisition section of the arithmetic device 21 of the host controller 2 acquires work information, holding state, and machine information about the workpiece 6 held in the chuck device 5, and the FEM analysis section uses the FEM model to analyze the workpiece 6. The natural frequency of the machine configuration in the machine tool 30 having the workpiece 6 determined by the information, the holding state, and the machine information is derived. Then, the calculation device 21 sets the derived natural frequency in the filter generation section 13 of the motor control device 1.

FIG. 7 is a diagram schematically showing another example of the configuration of the control system according to the first embodiment. Note that the same components as those in the above description are given the same reference numerals, and the description thereof will be omitted. The control system 20b shown in FIG. 7 further includes a calculation device 50 in addition to the motor control device 1 and the host controller 2. The motor control device 1, the host controller 2, and the arithmetic device 50 are connected via a communication line, and the arithmetic device 50 can communicate with the host controller 2 and the motor control device 1. Furthermore, the filter generating section 13 of the motor control device 1 does not include the arithmetic device 131. The configuration of the arithmetic device 50 is similar to that shown in FIG. In this example, the data acquisition section of the arithmetic device 50 acquires work information, holding state, and machine information regarding the workpiece 6 held in the chuck device 5, and the FEM analysis section uses the FEM model to obtain work information, holding state, and machine information. The natural frequency of the machine configuration in the machine tool 30 having the workpiece 6 defined by the state and machine information is derived. Then, the FEM analysis section of the arithmetic device 50 sets the derived natural frequency to the filter generation section 13 of the motor control device 1.

The arithmetic device 50 in this case is configured by a computer system, for example. That is, the computing device 50 in FIG. 7 functions as the computing device 50 by executing a program on the computer system, which is a computer program in which a process for deriving a natural frequency is described. FIG. 8 is a block diagram illustrating an example of the configuration of a computer system that implements the arithmetic unit of the control system according to the first embodiment. As shown in FIG. 8, this computer system includes a control section 81, an input section 82, a storage section 83, a display section 84, a communication section 85, and an output section 86, which are connected via a system bus 87. ing.

In FIG. 8, the control unit 81 is, for example, a processor such as a CPU, and executes a program in which processing in the arithmetic device 50 according to the first embodiment is described. Note that a part of the control unit 81 may be realized by dedicated hardware such as a GPU (Graphics Processing Unit) or FPGA. The input unit 82 is composed of a keyboard, a mouse, etc., and is used by a user of the computer system to input various information. The storage unit 83 includes various memories such as RAM and ROM, and storage devices such as a hard disk, and stores programs to be executed by the control unit 81, necessary data obtained in the process of processing, and the like. The storage unit 83 is also used as a temporary storage area for programs. The display unit 84 is composed of a display, a liquid crystal display panel, etc., and displays various screens to the user of the computer system. The communication unit 85 is a receiver and a transmitter that perform communication processing. The output unit 86 is a printer, a speaker, or the like. Note that FIG. 8 is an example, and the configuration of the computer system is not limited to the example of FIG. 8.

Here, an example of the operation of the computer system until the above program becomes executable will be described. In a computer system having the above configuration, for example, a computer program is stored in a storage unit from a CD-ROM or DVD-ROM set in a CD (Compact Disc)-ROM drive or a DVD (Digital Versatile Disc)-ROM drive (not shown). Installed on 83. Then, when the program is executed, the program read from the storage section 83 is stored in the main storage area of the storage section 83. In this state, the control unit 81 executes processing as the arithmetic device 50 in FIG. 7 according to the program stored in the storage unit 83.

In the above description, a CD-ROM or DVD-ROM is used as a recording medium to provide a program that describes processing in the arithmetic unit 50. Depending on the capacity, for example, a program provided via a transmission medium such as the Internet via the communication unit 85 may be used.

In one example, this computer program causes a computer system to execute the processing procedure shown in FIG. 4.

As described above, in the

control systems

20, 20a, and 20b according to the first embodiment, the state in which the workpiece 6 is actually held by the machine tool 30 and the state in which the workpiece 6 is actually held are determined based on the workpiece information, holding state, and machine information of the workpiece 6. Using a shape model showing the shape and material of the machine tool 30 and mechanical information of the machine tool 30, it is possible to calculate how the mechanical configuration of the machine tool 30 that reflects the holding state of the workpiece 6 vibrates. In the conventional technology, machining processing is executed with the workpiece 6 held by the machine tool 30, and feedback information such as a current command and a detection result by a detector is used to determine the resonance frequency at which the machine actually resonates using feedback control. The resonant frequency obtained for the notch filter 132 was set as the cutoff frequency. However, in the first embodiment, as described above, before actually performing machining processing on the machine tool 30, the natural frequency is calculated without using feedback control, and the calculation result is filtered to the filter of the motor control device 1. It can be set in the generation unit 13. This eliminates the need to perform machining with the machine tool 30 holding the workpiece 6, to actually generate machine resonance, and then to suppress the machine resonance in order to find the resonant frequency. Therefore, vibrations occurring in the workpiece 6 at the natural frequency can be suppressed. In other words, the mechanical resonance of the industrial machine, such as the machine tool 30, is suppressed without requiring an operation for estimating the resonance frequency of the machine resonance that occurs in accordance with the natural frequency that changes depending on the state of the industrial machine. It has the effect of being able to Further, since it is not necessary to generate mechanical resonance for estimating the natural frequency after the state changes, it is possible to suppress undesirable effects of mechanical resonance on the machine tool 30.

The configuration shown in the above embodiments is an example, and it is possible to combine it with another known technology, and a part of the configuration can be omitted or changed without departing from the gist. It is possible.

1 Motor control device, 2 Upper controller, 3 Motor, 4 Detector, 5 Chuck device, 6 Workpiece, 7 Cutting tool, 8 Reducer, 11 Position control section, 12 Speed control section, 13 Filter generation section, 14 Current control section , 15 Speed conversion unit, 20, 20a, 20b Control system, 21, 50, 131 Arithmetic unit, 30 Machine tool, 132 Notch filter, 1311 Data acquisition unit, 1312 FEM analysis unit.

Claims

Data for acquiring held object information indicating information on a held object held in a holding device of an industrial machine, a holding state of the held object in the holding device, and machine information indicating information on the industrial machine. an acquisition department;
The cutoff frequency set by a filtering process in a motor control device that controls a controlled object provided in the industrial machine is determined by the control object and the holding device when the held object is held by the holding device. an analysis unit that derives a natural frequency of the mechanical configuration that occurs in the mechanical configuration that includes;
Equipped with
The analysis unit performs a processing process on the held object while it is held in the holding device of the industrial machine, based on the held object information, the holding state, and the machine information acquired by the data acquisition unit. A control system characterized by deriving the natural frequency of the mechanical configuration that occurs when the mechanical configuration is performed.
The object to be held is a workpiece to be processed by the industrial machine,
The control system according to claim 1, wherein the held object information includes a holding position, structure, and material of the held object.
The control according to claim 2, wherein the holding position is information indicating a length from an end of the holding object to a holding location of the holding object held by the holding device. system.
The control system according to any one of claims 1 to 3, wherein the holding state is information indicating whether the object to be held is fixed to the holding device.
The machine information is information including the structure and inertia of a motor included in the control target of the motor control device, a speed reducer that changes the rotational speed of the motor, and a holding device that holds the object to be held. A control system according to any one of claims 1 to 4.
The analysis unit derives the natural frequency by performing vibration analysis using a finite element method based on the held object information, the held state, and the machine information. 5. The control system according to any one of 5.
Claim further comprising: a filter generation unit that performs the filtering process on a command for controlling the industrial machine by feedback control as a cutoff frequency for removing vibrations of the natural frequency derived by the analysis unit. 7. The control system according to any one of 1 to 6.