Control device for an electric motor, mechanical system and control method

Abstract

In an industrial machine having a motor, an instruction to the motor is sometimes corrected based on a feedback value from a sensor. A technology capable of appropriately performing such correction has been sought in the past. A control device (14) is provided with: a feedback acquisition section (52) that acquires a feedback value from an industrial machine (12) that is operated by an action of a motor (24); a correction section (62) that corrects an instruction for causing the motor (24) to act based on the feedback value; a filter section (44) that performs filter processing that reduces values of a prescribed frequency band on the feedback value supplied to the correction section (62); an operation state determination section (66) that determines whether or not an operation state of the industrial machine has changed; and a filter switching section (46) that switches a frequency band of the filter processing performed by the filter section (44) from a first frequency band to a second frequency band when it is determined that the operation state has changed.

Description

Technical Field

[0001] This disclosure relates to a control device, mechanical system, and control method for an electric motor. Background Technology

[0002] A control device for an electric motor is known (e.g., Patent Document 1).

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2011-123646 Summary of the Invention

[0006] The problem the invention aims to solve

[0007] In industrial machinery with electric motors, commands to the motor are sometimes corrected based on feedback values ​​from sensors. Previously, a technique was sought that could properly perform this correction.

[0008] Solution for solving the problem

[0009] In one aspect of this disclosure, a control device for controlling an electric motor of industrial machinery includes: a feedback acquisition unit that acquires feedback values ​​from the industrial machinery operating by the operation of the electric motor; a correction unit that corrects commands for operating the electric motor based on the feedback values; a filter unit that performs filtering processing on the feedback values ​​supplied to the correction unit to reduce the value of a predetermined frequency band; an operation state determination unit that determines whether the operation state of the industrial machinery has changed; and a filter switching unit that switches the frequency band of the filtering processing performed by the filter unit from a first frequency band to a second frequency band when the operation state determination unit determines that the operation state has changed.

[0010] In other embodiments of this disclosure, a method for controlling an electric motor of industrial machinery obtains feedback values ​​from the industrial machinery that operates through the action of the electric motor; corrects commands for actuating the electric motor based on the feedback values; performs filtering on the feedback values ​​used for the correction to reduce the value of a specified frequency band; determines whether the operating state of the industrial machinery has changed; and when it is determined that the operating state has changed, switches the frequency band of the filtering process performed from a first frequency band to a second frequency band.

[0011] The effects of the invention

[0012] According to this disclosure, and according to this embodiment, by switching the frequency band of the filtering process performed by the filter unit according to the operating state of the industrial machinery, the correction of the correction unit can be performed appropriately. Attached Figure Description

[0013] Figure 1It is a block diagram of a mechanical system involved in one implementation method.

[0014] Figure 2 This is a diagram of industrial machinery involved in one implementation method.

[0015] Figure 3 It is shown Figure 1 A block diagram illustrating an example of the control flow of an electric motor in a mechanical system.

[0016] Figure 4 The frequency characteristics of the filtering process are shown.

[0017] Figure 5 The frequency characteristics of noise components caused by changes in the operating state of industrial machinery are shown.

[0018] Figure 6 The frequency characteristics of the filtering process are shown.

[0019] Figure 7 The frequency characteristics of the filtering process are shown.

[0020] Figure 8 It is shown Figure 1 The flowchart shows an example of the filtering control process of the mechanical system.

[0021] Figure 9 It is shown Figure 1 Block diagrams of other examples of the control flow of an electric motor in the mechanical system shown.

[0022] Figure 10 It is shown Figure 1 Block diagrams of other examples of the control flow of an electric motor in the mechanical system shown.

[0023] Figure 11 It is shown Figure 1 Block diagrams of other examples of the control flow of an electric motor in the mechanical system shown.

[0024] Figure 12 This is a block diagram of the mechanical system involved in other embodiments.

[0025] Figure 13 These are diagrams of industrial machinery involved in other implementation methods.

[0026] Figure 14 It is shown Figure 12 A block diagram illustrating an example of the control flow of an electric motor in a mechanical system.

[0027] Figure 15 This is a block diagram of a mechanical system involved in yet another embodiment.

[0028] Figure 16This is a diagram of industrial machinery involved in yet another embodiment.

[0029] Figure 17 It is shown Figure 15 A block diagram illustrating an example of the control flow of an electric motor in a mechanical system.

[0030] Figure 18 This is a block diagram of a mechanical system involved in yet another embodiment.

[0031] Figure 19 This is a diagram of industrial machinery involved in yet another embodiment.

[0032] Figure 20 It is shown Figure 18 A block diagram illustrating an example of the control flow of an electric motor in a mechanical system. Detailed Implementation

[0033] The embodiments of this disclosure will now be described in detail with reference to the accompanying drawings. Furthermore, in the various embodiments described below, the same elements will be labeled with the same reference numerals, and repeated descriptions will be omitted. First, refer to... Figure 1 and Figure 2 A mechanical system 10 according to one embodiment is described. The mechanical system 10 includes industrial machinery 12 and a control device 14 for controlling the industrial machinery 12.

[0034] In this embodiment, the industrial machine 12 is a machine tool for processing workpieces. Specifically, the industrial machine 12 includes a tool 16, a driven body 18, a moving mechanism 20, and a sensor 22. The moving mechanism 20 moves the tool 16 relative to the driven body 18. More specifically, the moving mechanism 20 includes a motor 24 and a ball screw mechanism 26. The ball screw mechanism 26 includes a ball screw 26a extending straight along axis A and a nut member 26b threadedly engaged with the ball screw 26a. One end of the ball screw 26a is connected to the output shaft 24a of the motor 24.

[0035] In this embodiment, the driven body 18 is a workpiece stage having a planar workpiece setting surface 18a, on which the workpiece W is set by means of a fixture (not shown). The nut member 26b of the ball screw mechanism 26 is fixed to the driven body 18. The motor 24, for example a servo motor, rotates the ball screw 26a according to instructions from the control device 14, thereby causing the driven body 18 to reciprocate along axis A.

[0036] Sensor 22 is an encoder (or Hall element) or similar device that detects the rotational position (or rotational angle) of motor 24. Sensor 22 continuously (e.g., periodically) detects the rotational speed V of motor 24 by performing time differentiation on the detected rotational position of motor 24, and uses this as a speed feedback value FB. V The supplies are sequentially supplied to the control device 14.

[0037] The control device 14 is a computer having a processor 30, a memory 32, and an I / O interface 34. The processor 30 is connected to the memory 32 and the I / O interface 34 in a communicative manner via a bus 35, and communicates with the memory 32 and the I / O interface 34 to perform arithmetic processing for implementing various functions described later.

[0038] The memory 32 has RAM or ROM, etc., to temporarily or permanently store various data. The I / O interface 34 has, for example, an Ethernet port, a USB port, a fiber optic connector, or an HDMI terminal, to communicate with external devices via wired or wireless means based on instructions from the processor 30.

[0039] exist Figure 3 The diagram shows the control flow for the electric motor 24. The control device 14 includes a position command generation unit 36, a speed command generation unit 38, a torque command generation unit 40, a current control unit 42, a filter unit 44, a filter switching unit 46, and a gain unit 48. The processor 30 performs computational processing to implement the functions of the position command generation unit 36, the speed command generation unit 38, the torque command generation unit 40, the current control unit 42, the filter unit 44, the filter switching unit 46, and the gain unit 48.

[0040] The control flow for the electric motor 24 is described below. The processor 30 obtains the speed feedback value FB from the sensor 22 of the industrial machine 12 via the I / O interface 34. V The speed feedback value FB V It is a time series data representing the amplitude value of the rotational speed V of the motor 24.

[0041] In this embodiment, the processor 30 serves as the receiver for acquiring the feedback value FB from the industrial machinery 12. V Feedback Acquisition Department 52 Figure 1 (This function is performed.) The speed feedback value FB obtained from sensor 22... V The values ​​are input to subtractor 54 and integrator 56, respectively. Integrator 56 provides feedback on the input speed value FB. V Perform time integration and use it as the location feedback value FB. P Output to subtractor 58.

[0042] Additionally, the feedback value FB obtained from sensor 22 V It is input to filter section 44. Filter section 44 processes the feedback value FB. V Filtering is performed. Details of this filtering process will be described later. The filter unit 44 outputs a filter to the feedback value FB. V The filter is applied and output to gain 48. Gain 48 is based on the speed feedback value FB output from filter section 44. V Apply gain G1 to generate velocity correction value C V And output it to adder 60.

[0043] When the electric motor 24 is activated to operate the industrial machinery 12, the position command generation unit 36 ​​generates a position command PC according to the operation program OP and outputs it to the subtractor 58. The subtractor 58 subtracts the position feedback value FB from the position command PC. P The position deviation δP is then output to the speed command generation unit 38. The speed command generation unit 38 generates a speed command VC based on the position deviation δP and outputs it to the adder 60.

[0044] Adder 60 combines the speed command VC with the speed correction value C V The values ​​are added together to generate the corrected speed command VC'. In this way, gain 48 is based on the speed feedback value FB obtained by filtering by filter unit 44. V To generate the speed correction value C V Adder 60 uses this speed correction value C V The correction speed command VC. Therefore, in this embodiment, the gain 48 and the adder 60 constitute a configuration based on the feedback value FB. V The calibration section 62 of the VC instruction is used to calibrate.

[0045] Here, during the operation of the industrial machinery 12, the driven body 18 and the workpiece W sometimes experience slight vibrations due to the elasticity of the components of the industrial machinery 12 (such as the driven body 18, the ball screw mechanism 26, the output shaft 24a of the motor 24, etc.). In this embodiment, the correction unit 62 is configured to perform correction for eliminating such slight vibrations.

[0046] The corrected speed command VC' output from adder 60 is input to subtractor 54. Subtractor 54 subtracts the speed feedback value FB from the corrected speed command VC'. V The speed deviation δV' is then output as the torque command. The torque command generation unit 40 generates the torque command TC based on the speed deviation δV' and outputs it to the current control unit 42.

[0047] The current control unit 42 generates a voltage signal VS (e.g., a PWM control signal) based on the torque command value TC and sends it to the servo amplifier 64 via the I / O interface 34. The servo amplifier 64 amplifies the voltage signal VS and inputs it to the motor 24 of the industrial machine 12. The motor 24 drives the driven body 18 (i.e., the workpiece W) according to the input voltage signal VS.

[0048] In this document, the signal transmitted from the position command generation unit 36 ​​to the control circuit of the motor 24 is defined as a "command" for operating the motor 24. Therefore, in this embodiment, the position command PC, position deviation δP, speed command VC, speed correction command VC', speed deviation δV', torque command TC, and voltage signal VS constitute the command for operating the motor 24.

[0049] In this way, the processor 30 controls the operation of the motor 24 by generating instructions PC, δP, VC, VC', δV', TC, and VS according to the action program OP. Then, the processor 30 causes the industrial machinery 12 to operate, so that the driven body 18 can be moved by the operation of the motor 24 and the workpiece W can be processed by the tool 16.

[0050] The filter section 44 supplies the feedback value FB (in this embodiment, the velocity feedback value FB) to the correction section 62. V ) Perform filtering processing (FR) to reduce the value of the specified frequency band. In Figure 4 The image shows an example of the filtering process FR performed by the filter unit 44. Figure 4 The filter processing FR shown A In the middle, the filter section 44 adjusts the feedback value FB to a frequency greater than the cutoff frequency f. a High frequency band [f>f a The amplitude value of the wave is reduced by filtering (i.e., low-pass filtering).

[0051] In addition, the filter unit 44 performs filtering processing FR on the feedback value FB. A Not limited to low-pass filtering, for example, it could also be used to further reduce the frequency band [f > f]. a ] and contained in the cutoff frequency f a Low frequency band [f≤f a Bandpass filtering of a specific frequency (or frequency band) within a given range, or notch filtering of a specific frequency (or frequency band) within a given range.

[0052] FR is processed by this filter A It can remove high-frequency noise components N1 caused by electrical noise, etc., from the feedback value FB supplied to the correction unit 62. Therefore, the cutoff frequency f aThe operator determines the frequency that is lower than the frequency band of noise component N1 that can remove noise component N1.

[0053] On the other hand, when the operating state of the industrial machinery 12 changes as described later, sometimes the constituent elements of the industrial machinery 12 (such as the driven body 18, the ball screw mechanism 26, the output shaft 24a of the electric motor 24, etc.) are subjected to mechanical impact. At this time, the feedback value FB detected by the sensor 22 (specifically, the speed feedback value FB) V It contains the noise component N2 caused by mechanical impact.

[0054] exist Figure 5 An example of such a noise component N2 is shown in the diagram. Figure 5 In the example shown, the noise component N2 is distributed more than the filtered FR. A cutoff frequency f a Low frequency band f b ~f c Therefore, when such noise component N2 is contained in the feedback value FB, the above-described filtering process FR... A The noise component N2 could not be removed.

[0055] exist Figure 6 The image shows an example of a filter processing FR capable of removing such noise component N2. Figure 6 The filter processing FR shown B In the middle, the filter section 44 compares the feedback value FB with the cutoff frequency f. d (<f b High frequency band [f > f d Filtering to reduce amplitude (low-pass filtering). This filtering process is applied to FR... B It can remove the noise component N2 from the feedback value FB supplied to the correction unit 62.

[0056] exist Figure 7 Other examples of filtering processes FR that can remove noise component N2 are shown. Figure 7 The filter processing FR shown C In the middle, the filter unit 44 performs a function on the feedback value FB for the cutoff frequency f. d up to the cutoff frequency f e (f c <f e <f a ) frequency band [f d <f<f e and the cutoff frequency f a High frequency band [f>f a Filtering to reduce amplitude values. Such filtering... FR C For example, it can be achieved by blocking fd <f<f e Notch filtering and blocking of frequency bands f>f a This is achieved through a combination of low-pass filtering processing of the frequency band.

[0057] FR is processed by this filter C This filtering process can remove noise component N2 from the feedback value FB supplied to the correction unit 62. C Frequency band: Delineate f d <f<f e cutoff frequency f d and f e For example, the frequency characteristics of the noise component N2 can be determined in advance through experimental methods or simulations to set the frequency characteristics.

[0058] In this embodiment, the filter unit 44 is configured to perform digital filtering (FIR filtering or IIR filtering, etc.) processing. The filter unit 44 uses the feedback value FB and the specified filtering coefficient α. A (tap coefficients, etc.) are used to perform filtering. A The filter coefficient α A It determines the filtering process FR A frequency band [f>f a The parameters of ].

[0059] In addition, the filter section 44 uses the feedback value FB and the specified filter coefficient α. B To perform filtering FR B The filter coefficient α B It determines the filtering process FR B frequency band [f d The parameters of <f]. Additionally, the filter section 44 uses the feedback value FB and the specified filter coefficients α. C To perform filtering FR C The filter coefficient α C It determines the filtering process FR C frequency band [f d <f<f e f a The parameter of <f].

[0060] In this embodiment, the filter switching unit 46 changes the frequency band of the filtering process FR from the frequency band of the filtering process FR according to the change in the operating state of the industrial machinery 12. A frequency band [f > f a (First frequency band) switched to filtering FR B frequency band [f>f d (Second frequency band), or filtered FR C frequency band [f d <f<fe f a <f] (second frequency band).

[0061] For example, the filter switching unit 46 switches from the filter processing FR A frequency band [f>f a The corresponding filter coefficient α A (First filter coefficient) is switched to the filter processing FR B frequency band [f>f d The corresponding filter coefficient α B (Second filter coefficient) to reduce the frequency band f of the filtered FR from the frequency band [f > f a Switch to frequency band [f > f] d ].

[0062] Alternatively, the filter switching unit 46 can switch from the filter coefficient α A Switch to FR filtering C frequency band [f d <f<f e f a The filter coefficient α corresponding to <f] C (Second filter coefficient) to reduce the frequency band of the filtered FR from the frequency band [f > f a Switch to frequency band [f] d <f<f e f a <f].

[0063] In addition, such as Figure 6 As shown, in this embodiment, the filtering process FR B frequency band [f>f d [Includes filtering processing FR] A frequency band [f>f a Low frequency band: f d <f<f a Additionally, such as Figure 7 As shown, the filtering process FR C frequency band [f d <f<f e f a <f] contains the ratio of filtering to FR A frequency band [f>f a Low frequency band: f d <f<f e .

[0064] Below, refer to Figure 8 Explain the filter control process. Figure 8The process shown begins when the processor 30 receives a filter control start command from a host controller, operator, or computer program. This filter control start command is sent, for example, when the processor 30 starts operating the industrial machinery 12.

[0065] In step S1, processor 30 begins acquiring the feedback value FB. Specifically, processor 30 begins acquiring the speed feedback value FB from sensor 22. V The action. In step S2, the processor 30 functions as a filter unit 44, processing the feedback value FB. Figure 4 The filter processing FR shown A In step S3, the processor 30 functions as the correction unit 62, and begins to use the feedback value FB (in this embodiment, the speed feedback value FB) V This is used to correct the actions of the VC instruction.

[0066] In step S4, the processor 30 determines whether the operating state of the industrial machinery 12 has changed. As an example, the processor 30... Figure 8 After the process begins, the commands PC, δP, VC, VC', δV', TC or VS for the motor 24 are monitored. When the changes of the commands PC, δP, VC, VC', δV', TC or VS exceed the predetermined threshold β, it is determined that the operating state of the industrial machinery 12 has changed.

[0067] For example, during the operation of industrial machinery 12, when tool 16 comes into contact with workpiece W and begins processing, the aforementioned mechanical impact occurs. When tool 16 comes into contact with workpiece W and begins processing, the operating state of industrial machinery 12 is considered to have changed. When tool 16 comes into contact with workpiece W and begins processing, the torque command TC and voltage signal VS in the commands to motor 24 change drastically (e.g., increase).

[0068] Therefore, by detecting changes in the torque command TC or voltage signal VS, the processor 30 can detect the start of machining of the workpiece W (that is, the operating state of the industrial machine 12 has changed). In this step S4, when the change in the torque command TC or voltage signal VS exceeds the threshold β1, the processor 30 determines that the operating state of the industrial machine 12 has changed (i.e., "yes").

[0069] Furthermore, when the speed or acceleration of the driven body 18 (i.e., the electric motor 24) relative to the tool 16 changes drastically, the aforementioned mechanical shock occurs. When the speed or acceleration of the driven body 18 (electric motor 24) changes drastically in this way, the operating state of the industrial machinery 12 is considered to have changed.

[0070] When the speed or acceleration of the driven body 18 (motor 24) changes drastically, the instructions PC, VC, VC', TC, or VS for the motor 24 will also change drastically. In this step S4, the processor 30 determines that the operating state of the industrial machinery 12 has changed (i.e., "yes") when the change in instructions PC, VC, VC', TC, or VS exceeds the threshold β2. Alternatively, the processor 30 may also obtain the slope of the instruction by performing time differentiation on the instruction PC, VC, VC', TC, or VS, and determine "yes" if the slope exceeds the threshold β3.

[0071] As another example, the processor 30 monitors the feedback value FB from the sensor 22. When the change in the feedback value FB exceeds a predetermined threshold γ, it determines that the operating state of the industrial machinery 12 has changed. Here, the feedback value FB from the sensor 22 changes drastically when the tool 16 comes into contact with the workpiece W and begins processing, or when the speed or acceleration of the driven body 18 (motor 24) changes drastically. Therefore, by detecting the change in the feedback value FB, the processor 30 can detect that the operating state of the industrial machinery 12 has changed.

[0072] Specifically, in step S4, the processor 30 receives the speed feedback value FB from the sensor 22. V If the value exceeds a predetermined threshold γ1, it is judged as "yes". Alternatively, the processor 30 can determine "yes" based on the speed feedback value FB. V Perform time differentiation to obtain the acceleration feedback value FB A At this acceleration feedback value FB A If the value exceeds a predetermined threshold γ2, it is judged as "yes".

[0073] Alternatively, the processor 30 can also obtain the current feedback value FB from the motor 24 via the I / O interface 34. I Or load torque FB τ This is used as the feedback value FB. Alternatively, the processor 30 can use the current feedback value FB... I Or load torque FB τ If the value exceeds the predetermined threshold γ3, it is judged as "yes".

[0074] As another example, the processor 30 may determine that the operating state of the industrial machinery 12 has changed when the operating mode DM of the industrial machinery 12, as specified by the action program OP, is switched. An example of the operating mode DM is explained in Table 1 below.

[0075] [Table 1]

[0076]

[0077] Table 1

[0078] In the example shown in Table 1, the operating mode DM includes a positioning mode specified by the command "G00" of the action program OP and a machining mode specified by the command "G01" of the action program OP. Here, in the positioning mode, the processor 30 executes a feed action that moves the driven body 18 to the work preparation position at a speed V1.

[0079] On the other hand, in the machining mode, the processor 30 executes an approach action that moves the driven body 18 from the work preparation position to the machining start position where the tool 16 contacts the workpiece W at a speed of V2 (<V1). After that, it executes a machining action that moves the driven body 18 and performs machining on the workpiece W through the tool 16. The processor 30 switches the operating mode DM between the positioning mode and the machining mode according to the command texts "G00" and "G01" of the action program OP.

[0080] When the operating mode DM switches from positioning mode to machining mode to begin machining workpiece W, the aforementioned mechanical impact occurs. When the operating mode DM switches in this way, it is considered that the operating state of the industrial machine 12 has changed. For example, in step S4, the processor 30 determines "yes" at the point when the operating mode DM switches from positioning mode to machining mode. More specifically, the processor 30 determines "yes" when it receives the command message "G01" during the execution of the command message "G00" in the action program OP.

[0081] Alternatively, the processor 30 may also determine "yes" when a predetermined time t1 has elapsed since the point at which the self-operating mode DM switches from the positioning mode to the machining mode. Here, as described above, after switching from the positioning mode (command "G00") to the machining mode (command "G01"), a proximity action is performed, and then the tool 16 comes into contact with the workpiece W and machining begins. Therefore, the actual contact between the tool 16 and the workpiece W is the point in time after the time t1 required for the proximity action has elapsed since the point at which the positioning mode (command "G00") switches to the machining mode (command "G01").

[0082] Alternatively, in step S4, the processor 30 times the elapsed time t from the point when the self-operating mode DM switches from positioning mode to processing mode, and determines "yes" when the elapsed time t reaches time t1. This time t1 can be predetermined by the operator to be consistent with the time required for the approach action.

[0083] Alternatively, the processor 30 sequentially acquires the rotational position of the motor 24 detected by the sensor 22, and based on this rotational position, acquires the distance d that the driven body 18 has moved since the point in time when the operation mode DM switches from the positioning mode to the processing mode. Here, in the aforementioned approach action, the driven body 18 moves a predetermined distance d1.

[0084] Alternatively, in step S4, the processor 30 determines "yes" when the distance d obtained after the operation mode DM switches from positioning mode to processing mode reaches a predetermined threshold d1. This threshold d1 can be predetermined by the operator to be consistent with the distance moved by the driven body 18 during the approach action.

[0085] For other examples of operating mode DM, please refer to Table 2 below for explanation.

[0086] [Table 2]

[0087] Mode switching signal 00 01 Operating mode First processing mode Second processing mode action Light cutting action Heavy cutting action

[0088] Table 2

[0089] In the example shown in Table 2, the operating mode DM includes a first processing mode executed when the mode switching signal is "00" (or "OFF") and a second processing mode executed when the mode switching signal is "01" (or "ON"). The mode switching signal (e.g., the PMC signal) is stored in memory 32, for example, and switches between "00" (OFF) and "01" (ON) synchronously with the action program OP.

[0090] In this way, the first machining mode and the second machining mode are the operating modes specified by the action program OP through the mode switching signal. Here, in the first machining mode, the processor 30 executes a light cutting action that pushes the tool 16 against the workpiece W with force F1 and moves the driven body 18 relative to the tool 16 at a speed V3 while cutting the workpiece W.

[0091] On the other hand, in the second machining mode, the processor 30 performs a heavy cutting action, pressing the tool 16 against the workpiece W with a force F2 (>F1) and moving the driven body 18 relative to the tool 16 at a speed V4 (>V3), while simultaneously cutting the workpiece W with a cutting amount greater than that of a light cutting action. The processor 30 switches the operating mode DM between the first machining mode and the second machining mode according to the mode switching signals "00" and "01". When the operating mode DM switches between the first and second machining modes, the aforementioned mechanical impact occurs. When the operating mode DM switches in this way, it is considered that the operating state of the industrial machinery 12 has changed.

[0092] For example, suppose in Figure 8After the process begins and the first processing mode is executed, in step S4, the processor 30 determines "yes" when the operating mode DM switches from the first processing mode to the second processing mode. More specifically, the processor 30 determines "yes" when the mode switching signal switches from "00" to "01".

[0093] On the other hand, assuming in Figure 8 After the process begins, the second processing mode is executed. In step S4, the processor 30 determines "yes" when the operating mode DM switches from the second processing mode to the first processing mode. More specifically, the processor 30 determines "yes" when the mode switching signal switches from "01" to "00".

[0094] As described above, processor 30 is based on instructions (PC, δP, VC, VC', δV', TC, VS) for motor 24 and feedback value FB (FB). V FB A The processor 30 is used to determine whether the operating state of the industrial machinery 12 has changed, either by the processor itself or by the operation program (OP) of the industrial machinery 12. Therefore, in this embodiment, the processor 30 serves as the operating state determination unit 66 for determining whether the operating state of the industrial machinery 12 has changed. Figure 1 The processor 30 proceeds to step S5 if it determines "yes" in step S4, and proceeds to step S8 if it determines "no".

[0095] In step S5, the processor 30 functions as a filter switching unit 46, switching the frequency band of the filtering process FR performed by the filter unit 44 from the first frequency band to the second frequency band. For example, the processor 30 switches the filtering process FR from step S2... A frequency band [f>f a ]( Figure 4 Switch to filtering FR B frequency band [f>f d ]( Figure 6 As another example, processor 30 will filter the frequency band of FR starting from the filtering process FR in step S2. A frequency band [f>f a Switch to filtering FR C frequency band [f d <f<f e f a <f]( Figure 7 ).

[0096] At this point, it is also possible that the processor proceeds in 30 stages (i.e., discontinuously) from the first frequency band [f > f]. a Towards the second frequency band [f>f d ] or [fd <f<f e f a Switching is performed using <f]. For example, when switching from the first frequency band [f>f]... a Towards the second frequency band [f>f d In the case of switching, processor 30 can switch from the first frequency band [f > f] in one stage. a The cutoff frequency f a Switch to the second frequency band [f > f] d The cutoff frequency f d Alternatively, it can be divided into n stages (n being a positive number greater than 2) starting from the first frequency band [f > f] a The cutoff frequency f a To the second frequency band [f>f d The cutoff frequency f d Switching can be performed. Alternatively, it can be done from the first frequency band [f > f]. a Towards the second frequency band [f d <f<f e f a When switching <f] occurs, processor 30 switches in the following manner: forming f in a stage. d <f<f e The frequency band, or formed in multiple stages. d <f<f e The frequency band.

[0097] Alternatively, the processor 30 may also vary the frequency band from the first frequency band [f > f] in a manner that makes the frequency band change continuously over time. a Towards the second frequency band [f>f d ] or [f d <f<f e f a Switching is performed using <f]. For example, it could also be done by switching from the first frequency band [f>f]. a Towards the second frequency band [f>f d In the event of a switching operation, the processor 30 changes the cutoff frequency from f in a manner that makes the cutoff frequency change continuously over time. a To the cutoff frequency f d Switch to another device.

[0098] Alternatively, it could be from the first frequency band [f > f] a Towards the second frequency band [f d <f<f e f a When switching from <f], processor 30 gradually forms f. d <f<f eThe frequency band is switched in a manner that (e.g., the frequency band is gradually expanded). In this way, by making the frequency band of the filtering process FR change continuously, it is possible to prevent mechanical shocks caused by the switching of the filtering process FR.

[0099] In step S6, the processor 30 determines whether a predetermined condition CD is met. This condition CD refers to the condition used to process the filtered data after the switch in step S5. B frequency band [f>f d ] or FR C frequency band [f d <f<f e f a <f] Switch back to the filtering process of step S2 FR A frequency band [f>f a ] conditions.

[0100] Here, the noise component N2 caused by the aforementioned mechanical impact is not generated continuously over a long period, but mostly instantaneously. Therefore, after the noise component N2 disappears, in order to restore the filtered FR to the filtered FR of step S2... A The operator sets condition CD to the condition that the effect of noise component N2 disappears.

[0101] For example, condition CD can be determined as a predetermined time t0 elapsed since the operating state of industrial machinery 12 changed. In this case, processor 30, for example, counts the elapsed time t from the time point in step S4 when "yes" was determined (or the start or end time point of step S5). Then, processor 30 determines that condition CD (i.e., "yes") is met when the elapsed time t reaches the predetermined time t0.

[0102] Alternatively, commands PC, δP, VC, VC', δV', TC or VS for motor 24, or feedback value FB from sensor 22, can also be used. V or FB A The condition CD is determined. For example, the processor 30 may determine that condition CD is met (i.e., "yes") when the number of rotations of the motor 24 (or the distance traveled by the driven body 18) specified by the position instruction PC reaches a predetermined threshold. If the determination is "yes", the processor 30 proceeds to step S7; otherwise, if the determination is "no", it proceeds to step S9.

[0103] In step S7, the processor 30 functions as a filter switching unit 46, switching the frequency band of the filter processing FR from the second frequency band to the first frequency band. As an example, in step S5, the switching is performed to filter processing FR... B frequency band [f>f dIn the case of [f > f], processor 30 operates from the frequency band [f > f] d Switch to filtering FR A frequency band [f>f a As another example, in step S5, the process is switched to filtering FR. C frequency band [f d <f<f e f a In the case of <f], processor 30 operates from frequency band [f] d <f<f e f a <f] switches to frequency band [f>f a ].

[0104] In step S8, the processor 30 determines whether the operation of the industrial machinery 12 has ended. For example, the processor 30 can determine whether the processing of workpiece W has ended based on the operation program OP. If the processor 30 determines "yes" when the processing of workpiece W has ended, it stops the operation of the motor 24, thereby ending the operation of the industrial machinery 12. Furthermore, the processor 30 terminates... Figure 8 The process is shown. On the other hand, if the processor 30 determines "no", it returns to step S4.

[0105] If the determination in step S6 is "No", in step S9, the processor 30, in the same manner as in step S8, determines whether the operation of the industrial machinery 12 has ended. If the determination is "Yes", the processor 30 ends the operation of the industrial machinery 12, thereby concluding the process. Figure 8 The process shown, on the other hand, returns to step S6 if the result is "no".

[0106] As described above, in this embodiment, when the processor 30 determines that the operating state of the industrial machinery 12 has changed (step S4: "Yes"), it changes the frequency band of the filtered FR from the first frequency band [f > f]. a Switch to the second frequency band [f > f] d ] or [f d <f<f e f a <f]. According to this structure, by setting the second frequency band in such a way that the second frequency band includes the frequency band of the noise component N2 caused by the above-mentioned mechanical impact, the noise component N2 can be removed from the feedback value FB supplied to the correction unit 62.

[0107] On the other hand, assuming that no change in the operating state of the industrial machinery 12 is detected (continuously judged as "no" in step S4), the processor 30 performs filtering processing FR on the feedback value FB by the filter unit 44. AIt can remove the high-frequency noise component N1 caused by electrical noise, etc. from the feedback value FB.

[0108] At the same time, because the filter section 44 reduces the cutoff frequency f in the feedback value FB... a The following wide frequency bands (f≤f) a Therefore, the correction unit 62 can correct the frequency band command VC over a wider range, thus improving the correction effect of the correction unit 62. In this way, according to this embodiment, by switching the frequency band of the filtering process FR performed by the filter unit 44 according to the operating state of the industrial machinery 12, the correction of the correction unit 62 can be performed appropriately.

[0109] Furthermore, in this embodiment, the processor 30 is based on the instructions (PC, δP, VC, VC', δV', TC, VS) for the motor 24 and the feedback value FB (FB). V FB A The processor 30 determines whether the operating state has changed by using the operation program (OP) of the industrial machinery 12 or the instruction or feedback value. For example, the processor 30 determines that the operating state has changed when the change in instruction or feedback value exceeds the threshold β or γ.

[0110] Alternatively, the processor 30 determines that the operating state has changed when the operating mode DM specified by the action program OP is switched (specifically, the time point at which the operating mode DM is switched, when a specified time t1 has elapsed from that time point, or when a specified distance d1 has been moved from that time point). According to this structure, the timing of changes in the operating state can be determined with high precision.

[0111] In addition, in this embodiment, the processor 30 functions as a filter unit 44, using the feedback value FB and the filter coefficient α. A α B or α C To perform filtering as a digital filtering process FR A FR B or FR C Then, the processor 30 functions as a filter switching unit 46, by adjusting the filter coefficient α at coefficient α A α B and α C Switching between frequencies allows the filtering band of FR to be in the first frequency band [f > f]. a ] and the second frequency band [f>f d ] or [f d <f<f e and f a Switching between <f]. Based on this architecture, the processor 30 can quickly and accurately switch the frequency band of the filtering process FR.

[0112] In addition, in this embodiment, the processor 30 functions as a filter switching unit 46. After switching the frequency band of the filter processing FR to the second frequency band in step S5, it switches the frequency band from the second frequency band to the first frequency band according to the predetermined condition CD (steps S6 and S7).

[0113] Based on this structure, when the operating state of industrial machinery 12 changes, FR can be filtered and processed. B or FR C On the one hand, the noise component N2 is blocked; on the other hand, after condition CD is met (i.e., after the noise component N2 disappears), it is restored to the filtered state FR. A It can remove high-frequency noise component N1 and improve the correction effect of correction unit 62.

[0114] In addition, it can also be obtained from Figure 8 Steps S6, S7, and S9 are omitted in the illustrated process. For example, if the operating mode DM of the industrial machinery 12 is switched from the first processing mode to the second processing mode as shown in Table 2 during operation, the processor 30 may proceed to step S8 without executing steps S6, S7, and S9 after step S5. If the result in step S8 is "no", step S8 is repeated. In this case, the processor 30 continuously executes the filtering process FR after the switch in step S5. B or FR C This continues until the result is "yes" in step S8.

[0115] Next, refer to Figure 9 Other examples illustrating the control flow of motor 24. In Figure 9 In the control device 14 shown, the subtractor 54 subtracts the speed feedback value FB from the sensor 22 from the speed command VC output by the speed command generation unit 38. V The speed deviation δV is then output as the output. Next, the torque command generation unit 40 generates a torque command TC based on the speed deviation δV.

[0116] On the other hand, the speed feedback value FB obtained from sensor 22 V The input is fed into differentiator 68. Differentiator 68 provides feedback on the input speed value FB. V Perform the time derivative, and use it as the acceleration feedback value FB. A The output is sent to the filter unit 44. Similarly to the embodiment described above, the filter unit 44 processes the acceleration feedback value FB. A Selectively perform filtering processing FR A FR B or FR C .

[0117] In this case, the filter section 44 provides feedback on the acceleration value FB. A FR Filtering Processing A cutoff frequency f a Filtering FR B cutoff frequency f d Or filter FR C cutoff frequency f d f e and f a It can also be with Figure 3 The method shown (i.e., for the speed feedback value FB) V (The same cutoff frequency as the filtering process) or it can be applied to the acceleration feedback value FB. A Specifically, different cutoff frequencies were determined.

[0118] Filter section 44 pairs of acceleration feedback values ​​FB A Perform filtering FR A FR B or FR C The input is then fed into gain 48. Gain 48 uses the input acceleration feedback value FB. A Apply gain to generate acceleration correction value C A The torque command TC generated by the torque command generation unit 40 is input to the adder 60. The adder 60 inputs the torque command TC generated by the torque command generation unit 40 and the acceleration correction value C. A The values ​​are added together to generate the corrective torque command TC'. Therefore, gain 48 and adder 60 constitute a combination based on the feedback value FB. A The correction unit 62 is used to correct the torque command TC.

[0119] exist Figure 9 Similarly, in the manner shown, processor 30 executes... Figure 8 The process shown involves adjusting the frequency band of the filtering process FR performed by the filter unit 44 from the first frequency band [f > f] based on changes in the operating state of the industrial machinery 12. a Switch to the second frequency band [f > f] d ] or [f d <f<f e f a <f].

[0120] Next, refer to Figure 10 This is yet another example illustrating the control flow of motor 24. Figure 10 In the manner shown, with Figure 3 Similarly, as shown, the speed feedback value FB from sensor 22... V It is supplied to the filter section 44A, and after the filter section 44A performs the filtering process FR, it is supplied to the correction section 62A, which consists of the gain 48A and the adder 60A.

[0121] On the other hand, with Figure 9 Similarly, as shown, the speed feedback value FB from sensor 22... V After passing through differentiator 68, the signal is supplied to filter section 44B. After filtering FR is performed by filter section 44B, the signal is supplied to correction section 62B, which consists of gain 48B and adder 60B. Filter switching section 46 switches the frequency band of filtering FR performed by filter sections 44A and 44B respectively.

[0122] exist Figure 10 Similarly, in the manner shown, processor 30 executes... Figure 8 The process shown involves adjusting the frequency band of the filtering process FR performed by filter units 44A and 44B from the first frequency band [f > f] according to the changes in the operating state of the industrial machinery 12. a Switch to the second frequency band [f > f] d ] or [f d <f<f e f a <f].

[0123] In addition, the filter section 44A provides the speed feedback value FB. V FR (FR) filter processing performed A FR B or FR C The cutoff frequency and the acceleration feedback value FB of the filter section 44B. A FR (FR) filter processing performed A FR B or FR C The cutoff frequencies of the ) can be the same or different.

[0124] For example, in the filter section 44A, the feedback value FB V Perform filtering FR A Filter section 44B provides feedback value FB A Perform filtering FR A In this case, the filtering process FR performed by the filter section 44A A cutoff frequency f a_A FR filtering process performed by filter unit 44B A cutoff frequency f a_B They can be the same as each other, or they can be different.

[0125] Additionally, in the filter section 44A, the feedback value FB is... V Perform filtering FR B Filter section 44B provides feedback value FB A Perform filtering FR BIn this case, the filtering process FR performed by the filter section 44A B cutoff frequency f d_A FR filtering process performed by filter unit 44B B cutoff frequency f d_B They can be the same as each other, or they can be different.

[0126] Additionally, in the filter section 44A, the feedback value FB is... V Perform filtering FR C Filter section 44B provides feedback value FB A Perform filtering FR C In this case, the filtering process FR performed by the filter section 44A C cutoff frequency f d_A f e _A and f a_A FR filtering process performed by filter unit 44B C cutoff frequency f d_B f e_B and f a_B They can be the same (f) d_A =f d_B f e _ A =f e_B f a_A =f a_B ), or they can be different (f) d_A ≠f d_B f e _ A ≠f e_B f a_A ≠f a_B ).

[0127] Alternatively, when the processor 30 switches the frequency bands of filter units 44A and 44B from the first frequency band to the second frequency band in step S5, the second frequency bands of filter units 44A and 44B may be different. For example, in step S5, the processor 30 may change the filtering process FR performed by filter unit 44A from the filtering process FR... A Switch to FR filtering B (or FR) C On the other hand, the filtering process FR performed by the filter unit 44B is transferred from the filtering process FR. A Switch to FR filtering C (or FR) B ).

[0128] Next, refer to Figure 11 This is yet another example illustrating the control flow of motor 24. Figure 11 In the manner shown, with Figure 9 Similarly, in the embodiment shown, the speed feedback value FB obtained from sensor 22 V After passing through differentiator 68, filter section 44, and gain 48, it becomes the acceleration correction value C. A It is output to adder 60.

[0129] On the other hand, the torque command generation unit 40 has a proportional gain 70, an integral gain 72, and an integrator 74. The proportional gain 70 sets the torque command T1 by applying gain G2 to the speed deviation δV output from the subtractor 54 and outputs it to the adder 76. On the other hand, the integral gain 72 sets the torque command T2 by applying gain G3 to the speed deviation δV output from the subtractor 54 and outputs it to the adder 60.

[0130] Adder 60 modulates the torque command T2 output from integral gain 72 with the acceleration correction value C output from gain 48. A The torque command T2' is generated by adding the two commands. The integrator 74 integrates the torque command T2' and outputs it to the adder 76. The adder 76 generates the torque command TC by adding the torque command T1 output from the proportional gain 70 to the torque command T2' and outputs it to the current control unit 42.

[0131] Here, torque commands T1 and T2, along with the corrective torque command T2', constitute a torque command TC for controlling the torque of the motor 24. This torque command TC constitutes a command for operating the motor 24 as described above. Thus, in this embodiment, the correction unit 62, composed of a gain 48 and an adder 60, corrects the signal (torque command T2) used in the torque command generation unit 40 to generate the torque command TC.

[0132] Similarly, in this embodiment, processor 30 executes... Figure 8 The process shown involves adjusting the frequency band of the filtering process FR performed by the filter unit 44 from the first frequency band [f > f] based on changes in the operating state of the industrial machinery 12. a Switch to the second frequency band [f > f] d ] or [f d <f<f e f a <f].

[0133] Furthermore, in this embodiment, the correction unit 62 is described as correcting the signal T2 used in the torque command generation unit 40 to generate the command TC. However, it is not limited to this and may also be configured to correct the signal used in the speed command generation unit 38 or the current control unit 42 to generate the command VC or VS.

[0134] Next, refer to Figure 12 and Figure 13 The mechanical system 80 described in other embodiments is explained. The mechanical system 80 includes an industrial machine 82 and a control device 14 for controlling the industrial machine 82. Here, the industrial machine 82 differs from the industrial machine 12 described above in that it also includes a sensor 84.

[0135] Sensor 84, such as a linear scale or displacement sensor, is configured to face the driven body 18 (or workpiece W). Sensor 84 continuously (e.g., periodically) detects the position P (e.g., coordinate) of the driven body 18 (or workpiece W) in the direction of axis A, providing it as a position feedback value FB. P2 The data is sequentially sent to the I / O interface 34 of the control device 14.

[0136] The processor 30 of the control device 14 functions as a feedback acquisition unit 52, sequentially acquiring position feedback values ​​FB from the sensor 84 via the I / O interface 34. P2 The location feedback value is FB. P2 It is a time series data representing the position P of the driven body 18.

[0137] exist Figure 14 The diagram shows an example of the control flow of the electric motor 24 in the mechanical system 80. Figure 14 The control flow shown is similar to the control flow in the following aspects. Figure 10 Different. Specifically, the position feedback value FB obtained from sensor 84 P2 The input is fed into the differentiator 86. The differentiator 86 provides feedback value FB to the input position. P2 Perform time differentiation, and use it as the velocity feedback value FB. V2 The output is sent to the filter section 44A and the differentiator 68.

[0138] and Figure 10 Similarly, as shown, the speed feedback value FB V2 After being filtered by the filter section 44A, the FR is supplied to the correction section 62A, which consists of the gain 48A and the adder 60A. Additionally, the speed feedback value FB... V2 After time differentiation by differentiator 68 and filtering by filter unit 44B, the signal is supplied to correction unit 62B, which consists of gain 48B and adder 60B.

[0139] Next, refer to Figure 8 This describes the filtering control flow executed by the processor 30 of the mechanical system 80. The flow in this embodiment differs from that in the embodiment described above in step S4. In step S4, the processor 30 determines whether the operating state of the industrial machinery 82 has changed based on the distance L between the industrial machinery 82 and the workpiece W.

[0140] Specifically, after step S1 begins, the processor 30, based on the position feedback value FB obtained from the sensor 84... P2 Calculate the distance L between the industrial machinery 82 and the workpiece W. For example, the processor 30 will use the position data of the tool 16 of the industrial machinery 82 and the position feedback value FB. P2 Get them together.

[0141] Then, the processor 30 uses the position data and position feedback value FB from the tool 16. P2 Find the distance L between tool 16 and workpiece W. Figure 13 In this embodiment, the processor 30 acts as a processor based on the feedback value FB. P2 Find the distance L to obtain part 88 ( Figure 12 To fulfill its function.

[0142] Then, in step S4, the processor 30 functions as the operating state determination unit 66, and determines that the operating state of the industrial machinery 82 has changed (i.e., "yes") when the distance L becomes smaller than the predetermined threshold ε. Here, when the distance L is smaller than the predetermined threshold ε, it can be considered that the tool 16 has come into contact with the workpiece W and processing has begun.

[0143] Then, in step S5, the processor 30 functions as a filter switching unit 46, switching the frequency band of the filtering processes FR performed by the filter units 44A and 44B from the first frequency band [f > f]. a Switch to the second frequency band [f > f] d ] or [f d <f<f e f a <f].

[0144] As described above, in this embodiment, the processor 30 determines whether the operating state of the industrial machinery 82 has changed (specifically, whether the tool 16 is in contact with the workpiece W) based on the distance L. According to this structure, the processor 30 can determine the timing of changes in the operating state of the industrial machinery 82 with higher precision. Furthermore, the processor 30 can switch the frequency band of the filtering process FR in the filter units 44A and 44B to a frequency band [f > f] capable of removing the noise N2 generated by the change when the operating state changes. d ] or [f d <f<f e f a <f].

[0145] Next, refer to Figure 15 and Figure 16This describes another embodiment of a mechanical system 90. The mechanical system 90 includes an industrial machine 92 and a control device 14 for controlling the industrial machine 92. The industrial machine 92 differs from the industrial machine 82 described above in that it includes a sensor 94.

[0146] Sensor 94 is an acceleration sensor disposed on the driven body 18. Sensor 94 continuously (e.g., periodically) detects the acceleration of the driven body 18 (or workpiece W) and uses it as the acceleration feedback value FB. A2 The data is sequentially sent to the I / O interface 34 of the control device 14.

[0147] The processor 30 of the control device 14 functions as a feedback acquisition unit 52, sequentially acquiring acceleration feedback values ​​FB from the sensor 94 via the I / O interface 34. A2 The acceleration feedback value FB A2 It is a time series data representing the amplitude value of the acceleration of the driven body 18.

[0148] exist Figure 17 The diagram shows an example of the control flow for the electric motor 24 in the mechanical system 90. Figure 17 The control flow shown is Figure 9 They differ in the following aspects. Specifically, the acceleration feedback value FB obtained from sensor 94... A2 The input is fed to the filter section 44. The filter section 44 processes the acceleration feedback value FB. A2 After performing the filtering process FR, the signal is supplied to the correction unit 62, which consists of a gain 48 and an adder 60.

[0149] exist Figure 17 Similarly, in the manner shown, processor 30 executes... Figure 8 The process shown involves adjusting the frequency band of the filtering process FR performed by the filter unit 44 from the first frequency band [f > f] based on changes in the operating state of the industrial machinery 12. a Switch to the second frequency band [f > f] d ] or [f d <f<f e f a <f].

[0150] Next, refer to Figure 18 and Figure 19 The mechanical system 100 according to another embodiment is described. The mechanical system 100 includes industrial machinery 102 and a control device 14 for controlling the industrial machinery 102. The industrial machinery 102 is a stamping machine. Specifically, the industrial machinery 102 includes driven bodies 18A and 18B, a first moving mechanism 108, a second moving mechanism 110, and sensors 22A, 22B, 84, and 112.

[0151] The driven body 18B is a die cushion for the stamping machine, configured to move in the direction of axis A. A workpiece (not shown) is placed on the driven body 18B. On the other hand, the driven body 18A is a sliding member of the stamping machine, positioned above the driven body 18B and facing it, so as to be movable in the direction of axis A.

[0152] The first moving mechanism 108 has an electric motor 24A and a crankshaft mechanism 114. The electric motor 24A drives the output shaft 24a to rotate according to instructions from the control device 14. The crankshaft mechanism 114 converts the rotational motion of the output shaft 24a of the electric motor 24A into the reciprocating motion of the driven body 18A in the direction of axis A.

[0153] The second moving mechanism 110 includes a motor 24B, pulleys 116 and 118, a belt 120, a ball screw 122, and a direct drive unit 124. The motor 24B drives the output shaft 24a to rotate according to instructions from the control device 14. Pulley 116 is fixedly mounted on the output shaft 24a of the motor 24B and has teeth formed on its outer circumferential surface. Pulley 118 is fixedly mounted on the lower end of the ball screw 122 and has teeth formed on its outer circumferential surface.

[0154] The belt 120 has teeth formed on its inner circumferential surface and is tensioned on the outer circumferential surfaces of pulleys 116 and 118. The teeth formed on the outer circumferential surfaces of pulleys 116 and 118 engage with the teeth formed on the inner circumferential surface of the belt 120. Thus, the rotational force of the output shaft 24a of the motor 24B is transmitted to the ball screw 122 via pulleys 116 and 118 and the belt 120, causing the ball screw 122 to rotate about axis A. The direct drive unit 124 is configured to move in the direction of axis A and is fixed to the driven body 18B.

[0155] A bolt member 126 is fixedly installed in the center of the direct-drive section 124, and the ball screw 122 is threadedly engaged with the bolt member 126. As the motor 24B rotates the ball screw 122, the bolt member 126 reciprocates, thereby causing the driven body 18B to reciprocate in the direction of axis A.

[0156] Sensor 22A is an encoder (or Hall element) or similar device that detects the rotational position of motor 24A. Similar to sensor 22 described above, sensor 22A detects the rotational speed V of motor 24A by performing time differentiation on the detected rotational position of motor 24A, and uses this as the speed feedback value FB. V The supplies are sequentially supplied to the control device 14.

[0157] Similarly, sensor 22B is an encoder (or Hall element) or similar device that detects the rotational position of motor 24B. Like sensor 22 described above, sensor 22B detects the rotational speed V of motor 24B by performing time differentiation on the detected rotational position of motor 24B, and uses this as the speed feedback value FB. V The supplies are sequentially supplied to the control device 14.

[0158] Sensor 84, such as a linear scale or displacement sensor, is configured to face the driven body 18A. Sensor 84 continuously (e.g., periodically) detects the position P (e.g., coordinate) of the driven body 18A in the direction of axis A and uses it as a position feedback value FB. P2 The data is sequentially sent to the I / O interface 34 of the control device 14.

[0159] Sensor 112 is a force sensor or pressure sensor that detects the force F3 exerted by the driven body 18B on the driven body 18A. Furthermore, in this text, force F3 refers not only to force (unit: N) but sometimes also to pressure (unit: N / m). 2 In this embodiment, sensor 112 is built into the driven body 18B. Sensor 112 continuously (e.g., periodically) detects the force F3 generated by the driven body 18B and uses it as a force feedback value FB. F The data is sequentially sent to the I / O interface 34 of the control device 14.

[0160] The processor 30 functions as a feedback acquisition unit 52, sequentially acquiring speed feedback values ​​FB through the I / O interface 34. V Location feedback value FB P2 and force feedback value FB F The processor 30 independently controls motors 24A and 24B to move driven body 18A downward to clamp the workpiece disposed on driven body 18B between driven body 18A and driven body 18B. Then, driven bodies 18A and 18B move downward synchronously to perform stamping processing on the workpiece through a mold (not shown).

[0161] exist Figure 20 An example of the control flow for motor 24B is shown. While clamping the workpiece between driven bodies 18A and 18B and moving them downwards, processor 30 uses the force feedback value FB obtained from sensor 112. F To maintain force F3 at a predetermined target value F α Force control.

[0162] Specifically, processor 30 generates force instruction FC (= target value F) αThen, the processor 30 subtracts the force feedback value FB obtained from the sensor 112 from the force command value FC using a subtractor (not shown). F This force deviation δF is output to the speed command generation unit 38. As a result, the motor 24B maintains the force F3 at the target value F. α And cause the driven body 18B to move downward synchronously with the driven body 18A.

[0163] On the other hand, the position feedback value FB obtained from sensor 84 P2 The input is fed into differentiator 86, where it is differentiated in time and used as the velocity feedback value FB. V2 It is output to filter section 44. Filter section 44 processes the speed feedback value FB. V2 After the filtering process FR is performed, the signal is supplied to the correction unit 62, which consists of a gain of 48 and an adder 60. The correction unit 62 uses the speed correction value C. V The speed command VC generated by the speed command generation unit 38 is corrected. In this embodiment, the correction unit 62 is configured to perform correction to reduce the force deviation δF caused by the movement of the driven body 18A.

[0164] Next, refer to Figure 8 Explain the filtering control process in mechanical system 100. Figure 8 After the process shown begins, similarly to the above-described implementation, the processor 30 of the mechanical system 100 begins acquiring the feedback value FB (speed feedback value FB) in step S1. V Location feedback value FB P2 and force feedback value FB F Then, similarly to the embodiment described above, the processor 30 begins filtering processing FR by the filter unit 44 in step S2. A In step S3, the calibration unit 62 begins to calibrate the command VC.

[0165] In step S4, the processor 30 determines whether the operating state of the industrial machinery 102 has changed. For example, the processor 30 determines the change based on the feedback value FB (e.g., the force feedback value FB). F Current feedback value FB I Or load torque FB τ When the change exceeds a predetermined threshold γ, it is judged as "yes". As another example, when the change of the instruction (e.g., torque instruction TC or voltage signal VS) for the motor 24B exceeds the threshold β, the processor 30 judges that the operating state of the industrial machinery 102 has changed (i.e., "yes").

[0166] As another example, the processor 30 functions as a distance acquisition unit 88, based on the position feedback value FB acquired from the sensor 84.P2 Calculate the distance L between the industrial machinery 102 and the workpiece. Specifically, the processor 30 calculates the distance L based on the position feedback value FB. P2 Using the position data of the driven body 18B, the processor 30 calculates the distance L between the driven body 18A and the workpiece (or the driven body 18B). Then, the processor 30 determines "yes" when the distance L decreases beyond a predetermined threshold ε.

[0167] Then, in step S5, the processor 30 changes the frequency band of the filtered FR from the first frequency band [f > f]. a Switch to the second frequency band [f > f] d ] or [f d <f<f e f a <f]. Here, Figure 20 The filtering process FR performed by the filter unit 44 shown A cutoff frequency f a Filtering FR B cutoff frequency f d Or filter FR C cutoff frequency f d f e and f a It can also be with Figure 3 or Figure 9 The cutoff frequency is the same as shown, or it can be specifically determined for mechanical system 100 to be a different cutoff frequency.

[0168] Subsequently, similarly to the above-described implementation, the processor 30 sequentially executes steps S6 to S9. Likewise, in the mechanical system 100, when the operating state of the industrial machinery 102 changes, FR can also be processed through filtering. B or FR C To block the feedback value FB V2 The noise component N2. Furthermore, it should be understood that, as the control flow for motors 24A or 24B, applications such as... Figure 3 , Figure 9 , Figure 10 , Figure 11 , Figure 14 ,or Figure 17 The control flow is shown.

[0169] In the above-described embodiments, the filter switching unit 46 may, when switching the frequency band of the filter processing FR, determine the filter processing FR based on the commands PC, δP, VC, VC', δV', TC, VS for the motors 24, 24A, and 24B, or the feedback value FB from the sensors 22, 22A, 22B, 84, 94, and 112. B frequency band [f>fd Or filter FR C frequency band [f d <f<f e f a <f].

[0170] For example, processor 30 may generate a learning model LM representing the correlation between a command for the motor or a feedback value FB from a sensor and the frequency characteristics of the noise component N2, and determine the frequency band of the filtering process FR based on the command or feedback value FB and the learning model LM.

[0171] Below is an example illustrating the learning method of the learning model LM. The processor 30 repeatedly attempts to operate the industrial machine 12 to change the operating state of the industrial machine 12, and obtains the time variation characteristics or frequency characteristics of the instruction or feedback value FB obtained at this time, as well as the frequency characteristics (bandwidth) of the noise component N2 generated in the feedback value FB, as the learning dataset DS.

[0172] Then, processor 30 performs, for example, supervised learning using the learning dataset DS, thereby generating a learning model LM representing the correlation between the instruction or feedback value and the frequency characteristics of the noise component N2. Whenever the processor 30 repeatedly attempts to operate the industrial machinery 12, it executes a learning loop to acquire the learning dataset DS and update the learning model LM. This allows the learning model LM to be guided to the optimal solution.

[0173] Then, in step S5 above, the processor 30 inputs the instruction or feedback value obtained when the operating state changes into the learning model LM. Thus, the learning model LM outputs the frequency characteristics of the noise component N2, which is correlated with the instruction or feedback value when the operating state changes. The processor 30 can then filter the FR... B FR C The frequency band (i.e., the cutoff frequency f) d f e The frequency band for the output noise component N2 is determined. In this way, the processor 30 can determine the frequency band for the filtering process FR based on instructions for the motor or feedback values ​​FB from the sensor.

[0174] also, Figure 4 , Figure 6 as well as Figure 7 The filter processing FR shown A FR B and FR CThe frequency characteristics are one example; they can also be configured to have arbitrary frequency characteristics corresponding to the noise components to be blocked. Furthermore, the aforementioned industrial machinery 12 may also include multiple moving mechanisms that move the driven body 18 in multiple directions. In this case, the processor 30 may execute the aforementioned filtering control process for the motor of each moving mechanism. Alternatively, the position command generation unit 36 ​​may be omitted from the above embodiment. In this case, the position command generation unit 36 ​​may be provided in a host controller, and the processor 30 may receive position commands (PC) from that host controller.

[0175] Furthermore, in the above embodiments, the following situation was described: Figure 8 In step S4, the processor 30 (operation state determination unit 66) determines the operating state based on the instructions (PC, δP, VC, VC', δV', TC, VS) for the motor 24 and the feedback value FB (FB). V FB A The operating status of the industrial machinery 12 can be determined by either the operation program (OP) of the industrial machinery 12 or the operation procedure of the industrial machinery 12.

[0176] However, it is not limited to this; it is also possible that the processor 30 estimates, for example, the time t when the operating state changes (e.g., the industrial machinery 12 comes into contact with the workpiece). V In step S4, the elapsed time since the start of operation reaches the specified time t. V The time t is judged as "yes". V For example, it can make estimates based on the action sequence.

[0177] Furthermore, in the above embodiment, the case where the filter unit 44 is configured as a digital filter was described. However, the filter unit 44 may also be configured as an analog filter. For example, the filter unit 44 may also have a filter filter capable of performing filtering processing. A The analog filter section 44α and the FR capable of performing filtering processing B The analog filter section 44β or FR is capable of performing filtering processing. C The analog filter section 44γ.

[0178] Furthermore, the processor 30 can also switch the frequency band of the filtering process FR by switching between the analog filter section 44α and the analog filter section 44β or 44γ. The present disclosure has been described above through embodiments, but the above embodiments are not intended to limit the invention covered by the claims.

[0179] Explanation of reference numerals in the attached figures

[0180] 10, 80, 90, 100: Mechanical systems; 12, 82, 92, 102: Industrial machinery; 14: Control devices; 22, 22A, 22B, 84, 94, 112: Sensors; 24, 24A, 24B: Electric motors; 30: Processors; 44, 44A, 44B, 44α, 44β, 44γ: Filter units; 46: Filter switching units; 62, 62A, 62B: Calibration units; 66: Operating status judgment units; 88: Distance acquisition units.

Claims

1. A control device for controlling the electric motor of industrial machinery, the control device comprising: The feedback acquisition unit acquires feedback values ​​from the industrial machinery that operates through the action of the electric motor; A correction unit that corrects the command used to operate the motor based on the feedback value; The filter section performs filtering processing on the feedback value supplied to the correction section to reduce the value of a specified frequency band; The operation status determination unit determines whether the operation status of the industrial machinery has changed, and determines that the operation status has changed when the instruction or the feedback value increases beyond a predetermined threshold. as well as The filter switching unit switches the frequency band of the filtering process performed by the filter unit from a first frequency band to a second frequency band that is lower than the first frequency band when the operating state determination unit determines that the operating state has changed.

2. The control device according to claim 1, wherein, The instructions include torque instructions for the electric motor. When the torque command increases beyond the threshold, the operating state determination unit determines that the operating state has changed.

3. The control device according to claim 1, wherein, It also includes a distance acquisition unit, which calculates the distance between the industrial machinery and the workpiece based on the feedback value. When the distance decreases beyond a predetermined threshold, the operation status determination unit determines that the operation status has changed.

4. The control device according to claim 1, wherein, When the operating mode of the industrial machinery, as defined by the action program, is switched, the operating state determination unit determines that the operating state has changed.

5. The control device according to any one of claims 1 to 4, wherein, The filter unit uses the feedback value and the specified filter coefficients to perform the filtering process. The filter switching unit switches from the first frequency band to the second frequency band by switching from a first filter coefficient corresponding to the first frequency band to a second filter coefficient corresponding to the second frequency band.

6. The control device according to any one of claims 1 to 4, wherein, The filter switching section switches from the first frequency band to the second frequency band in stages, or switches from the first frequency band to the second frequency band in a manner that makes the frequency band change continuously over time.

7. The control device according to claim 5, wherein, The filter switching section switches from the first frequency band to the second frequency band in stages, or switches from the first frequency band to the second frequency band in a manner that makes the frequency band change continuously over time.

8. The control device according to any one of claims 1 to 4, wherein, After switching the frequency band of the filtering process, the filter switching unit switches the frequency band from the second frequency band to the first frequency band according to predetermined conditions.

9. The control device according to claim 5, wherein, After switching the frequency band of the filtering process, the filter switching unit switches the frequency band from the second frequency band to the first frequency band according to predetermined conditions.

10. The control device according to claim 6, wherein, After switching the frequency band of the filtering process, the filter switching unit switches the frequency band from the second frequency band to the first frequency band according to predetermined conditions.

11. The control device according to claim 7, wherein, After switching the frequency band of the filtering process, the filter switching unit switches the frequency band from the second frequency band to the first frequency band according to predetermined conditions.

12. A mechanical system comprising: The control device according to any one of claims 1 to 11; and The industrial machinery has the electric motor and a sensor that acquires the feedback value and supplies it to the control device.

13. A control method for controlling the electric motor of industrial machinery, wherein, Feedback values ​​are obtained from the industrial machinery that operates through the movement of the electric motor; The command used to operate the motor is corrected based on the feedback value; The feedback value used for the correction is subjected to filtering to reduce the value in a specified frequency band; Determine whether the operating status of the industrial machinery has changed, and determine that the operating status has changed when the command or the feedback value increases beyond a specified threshold; as well as When it is determined that the operating state has changed, the frequency band of the filtering process to be performed is switched from the first frequency band to a second frequency band that is lower than the first frequency band.

Images