Estimation device

Abstract

Provided is technology enabling improvement in efficiency of an evaluation step when a failure occurs due to vibration of actual processing. An estimation device 10 comprises: a display-side communication unit 12 that acquires, by communication, control information from a control unit 3 that controls a machine tool; a parameter acquisition unit 13 that acquires a control parameter of the control unit 3; a machining condition input unit 14 that inputs a machining condition of the machine tool; a machining program analysis unit 15 that analyzes a machining program; an estimated frequency calculation unit 16 that calculates an estimated frequency that is a frequency of vibration that can be generated, on the basis of at least one of the control parameter, the machining condition, and the machining program; an operation data acquisition unit 17 that acquires operation data of at least one of a position deviation, a speed, and a current value; a frequency analysis unit 18 that analyzes a frequency component of the operation data; a determination unit 19 that determines the magnitude of the frequency component; and an output unit 20 that outputs information for superimposing and displaying calculation results of the estimated frequency calculation unit and the frequency analysis unit, and switches whether or not to display the calculation result of the estimated frequency calculation unit according to the magnitude of the frequency component.

Description

Estimation device

[0001] This disclosure relates to an estimation device.

[0002] Conventionally, in a control device of a machine tool, a technique of displaying information related to machining, such as machining frequency, on a display device is known. For example, Patent Document 1 describes this type of technique.

[0003] Patent Document 1 describes a process of detecting machining vibration of a rotary tool, a process of analyzing the machining vibration by Fourier series expansion to obtain a machining frequency, a process of classifying the machining frequency into an idle frequency, a fundamental wave, a high frequency, a residual frequency, or a chatter frequency at which regenerative chatter occurs, a process of setting each frequency to a different color display, and a process of color-coding the strength of the machining vibration detected over time with a color display corresponding to each machining frequency obtained from each machining vibration and displaying it in a color-by-color integrated display window to monitor the machining state of a machine tool.

[0004] Japanese Unexamined Patent Application Publication No. 2021-068401

[0005] In the startup operation and development of a machine tool, it is necessary to adjust so as not to vibrate under various operating conditions, and it is important to confirm the frequency of vibration during the evaluation and troubleshooting of the machine tool. Currently, after acquiring the operation data of each axis of the machine tool, the user performs operations such as checking the frequency-analyzed data and comparing the values calculated manually from the machining conditions with known frequency components. If the user cannot handle it, the supplier of the machine tool will ask for information such as the motor used and the conditions of each operation and check whether there is a corresponding vibration frequency. Hearing from the supplier to the user takes time.

[0006] This disclosure has been made in view of the above problems, and an object thereof is to provide a technology that can realize the efficiency improvement of the evaluation process when a defect occurs due to the vibration of actual machining.

[0007] This disclosure relates to an estimation device comprising: a communication unit that acquires control information by communication from a control unit that controls a machine tool; a parameter acquisition unit that acquires control parameters of the control unit; a machining condition input unit that inputs machining conditions of the machine tool; a machining program analysis unit that analyzes a machining program; an estimated frequency calculation unit that calculates an estimated frequency which is the frequency of vibration that may occur based on at least one of the control parameters, the machining conditions, and the machining program; an operation data acquisition unit that acquires operation data which is at least one of position deviation, velocity, and current value; a frequency analysis unit that analyzes the frequency components of the operation data; a determination unit that determines the magnitude of the frequency components; and an output unit that outputs information for displaying the calculation results of the estimated frequency calculation unit and the frequency analysis unit superimposed, and switches whether or not to display the calculation results of the estimated frequency calculation unit according to the magnitude of the frequency components.

[0008] This disclosure provides a technology that can improve the efficiency of the evaluation process when defects occur due to vibration during actual processing.

[0009] This is a functional block diagram of a machine tool system to which the estimation device according to the first embodiment is applied. This is a diagram showing an example of machining program code. This is a graph showing the change in rotation angle and force data generated by motor control when motor cogging compensation is set to disabled. This is a graph showing the change in rotation angle and force data generated by motor control when motor cogging compensation is set to enabled. This is a graph of the first example showing different wave strengths (Magnitude) at different frequencies. This is a graph of the second example showing different wave strengths (Magnitude) at different frequencies. This is a diagram showing the first example of an image in which the estimated frequency calculated by the estimation frequency calculation unit is superimposed along with information showing the frequency components analyzed by the frequency analysis unit. This is a diagram showing the second example of an image in which the estimated frequency calculated by the estimation frequency calculation unit is superimposed along with information showing the frequency components analyzed by the frequency analysis unit. This is a functional block diagram of a machine tool system to which the estimation device according to the second embodiment is applied.

[0010] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. In the description of the second and subsequent embodiments, components common to the first embodiment will be denoted by the same reference numerals, and their descriptions will be omitted as appropriate.

[0011] [First Embodiment] Figure 1 is a functional block diagram of a machine tool system 1 to which the estimation device 10 according to the first embodiment is applied. The machine tool system 1 comprises a control device 2 that controls the machine tool and an estimation device 10 that displays various information related to machining.

[0012] The machine tool controlled by the control device 2 includes, for example, a mechanism that includes a motor to operate at least one spindle that rotates the tool and the workpiece relative to each other, and at least one feed axis that moves the tool relative to the workpiece.

[0013] The control device 2 is a numerical control device comprising a control unit 3 that controls the operation of the machine tool and a control-side communication unit 11 that communicates with the estimation device 10. The control unit 3 is configured, for example, using a computer equipped with memory such as ROM (read-only memory) and RAM (random access memory), and a CPU (central processing unit), which are connected to each other via a bus.

[0014] The control unit 3 receives a machining program that specifies the machining content, and multiple control parameters for axes 1 to N are set. The control unit 3 controls the movement of the tool and workpiece based on the machining program and control parameters.

[0015] Figure 2 shows an example of machining program code. In Figure 2, M03 is a command to rotate the spindle, and the underlined part following S is where a numerical value specifying the spindle speed is entered. The spindle speed is entered as a value that is standardly used for machine tools. G8.5 P2 is a command to turn on the command to start oscillating cutting, and the underlined part following I is where a numerical value specifying the oscillating frequency multiplier is entered, and the underlined part following K is where a numerical value specifying the oscillating amplitude multiplier is entered. Z0 is a command to oscillate the Z axis when creating a tapered or arc shape. The oscillating frequency multiplier I can be calculated using formula 1.

[0016] [Equation 1] I = Frq × 60 / S Frq: Oscillation frequency [Hz] I: Oscillation frequency multiplier [times] S: Spindle speed [min] －１ ]

[0017] In this machining program, oscillating cutting is performed by issuing the command G01, which commands the cutting feed rate, following the command G8.5 P2. Oscillating cutting is a machining method that increases operational efficiency by generating air cuts and shredding chips by oscillating the tool and workpiece relative to each other during machining, thereby reducing the frequency of problems such as chip clogging, entanglement, and workpiece damage. The underlined parts following Z and X in G01 are input values ​​that specify coordinates, and the underlined part following F is input value that specifies the feed rate. The feed rate is entered as a value that is standardly used for machine tools. G8.5 P0 is a command to turn off the command to start oscillating cutting, and M05 is a command to stop the spindle.

[0018] The oscillation frequency multiplier I and oscillation amplitude multiplier K, which are typically used in machine tools, can be set as control parameters. In the machining program, if I and K are omitted in the G8.5 P2 command, the oscillating cutting process will be performed using the oscillation frequency multiplier I and oscillation amplitude multiplier K set in the control parameters. Since the spindle speed S is specified in the machining program, the oscillation frequency will be determined based on the machining program and the control parameters.

[0019] Examples of other control parameters are described below. Control parameters include, for example, the setting value of the vibration damping filter (band-rejection filter), the setting value of the motor-driven vibration suppression function for the machine end point, the setting value of the acceleration sensor-driven vibration suppression function for the machine end point, the enable / disable setting of cogging correction, the number of magnetic poles (pairs), the gear ratio, etc.

[0020] The settings for the vibration damping filter are the center frequency, amplitude, and damping degree of the vibration. The settings for the motor-driven vibration suppression function at the machine's end point are the vibration frequency to be suppressed and the damping degree. The settings for the sensor-driven vibration suppression function at the machine's end point are the frequency near the vibration frequency to be suppressed.

[0021] Next, motor cogging correction will be explained with reference to Figures 3 and 4. Figure 3 is a graph showing the changes in rotation angle and force data generated by motor control when motor cogging correction is disabled. Figure 4 is a graph showing the changes in rotation angle and force data generated by motor control when motor cogging correction is enabled. Note that this embodiment can also be applied to linear motors that perform linear motion instead of rotational motion.

[0022] Due to the motor's structure, a force is generated that varies with position; for example, the magnetic attraction of the magnet strengthens near a certain rotation angle and weakens as it moves away. Therefore, as shown in Figure 3, when cogging correction is disabled, a vibration frequency equal to rotation speed × number of magnetic poles (pairs) × a constant is generated. As shown in Figure 4, enabling cogging correction suppresses fluctuations in the force generated by motor control.

[0023] The control-side communication unit 11 notifies the estimation device 10 of various information related to the processing. The estimation device 10 outputs various information based on the information notified by the control-side communication unit 11.

[0024] Next, the estimation device 10 will be described. When machining defects caused by vibration occur during the evaluation of actual machining, it is necessary to analyze the factors such as components caused by the internal structure of the motor, components dependent on the tool shape, and the influence of the measurement system when analyzing the frequency components of the generated vibration. The estimation device 10 takes the machining program and machine tool control parameters as well as machining conditions known to the on-site user as input, estimates the vibration frequencies that are likely to occur, and performs processing to visually present information to the user for estimating the vibration factors.

[0025] The estimation device 10 of this embodiment is configured, for example, using computers equipped with memory such as ROM (read-only memory) and RAM (random access memory), and a CPU (central processing unit), which are connected to each other via a bus.

[0026] The estimation device 10 of this embodiment includes a display-side communication unit 12, a parameter acquisition unit 13, a processing condition input unit 14, a processing program analysis unit 15, an estimated frequency calculation unit 16, an operation data acquisition unit 17, a frequency analysis unit 18, a determination unit 19, an output unit 20, and a display unit 21.

[0027] The display-side communication unit 12 acquires control information such as the processing program and control parameters of the control unit 3 via communication. In the first embodiment, the display-side communication unit 12 of the estimation device 10 acquires control information from the control unit 3 through the control-side communication unit 11 of the control device 2.

[0028] The parameter acquisition unit 13 acquires the control parameters of the machine tool's control device 2. The control parameters acquired by the parameter acquisition unit 13 are used to estimate the frequencies at which the machine is prone to vibration.

[0029] The machining condition input unit 14 inputs the machining conditions of the machine tool. The machining condition input unit 14 accepts machining conditions input by the user, for example. Some machining conditions affect the frequency. For example, the number of teeth of a gear multiplied by the rotational speed of the shaft during gear machining, vibrations of peripheral devices such as fans, and scratches on specific parts of a ball screw all affect the frequency during machining.

[0030] Vibrations from peripheral devices can affect the machine tool's frequency because these vibrations are transmitted to the machine tool when the peripheral devices operate at power supply frequencies of 50 Hz or 60 Hz. If vibrations from peripheral devices affect machining, the user can input the frequency at which the peripheral device vibrations occur into the estimation device 10 via the machining condition input unit 14. For example, if the user inputs a specific frequency under the item "influence of peripheral devices," the machining condition input unit 14 outputs the input frequency as a machining condition to the estimation frequency calculation unit 16, indicating that vibrations may occur due to the influence of peripheral devices.

[0031] Scratches at specific locations on a ball screw can cause vibrations only when the shaft passes a specific position, or cause the frequency to change depending on the shaft's movement speed. If scratches at specific locations on the ball screw affect the machining process, the user can input the frequency of vibrations occurring when the shaft passes a specific position into the estimation device 10 via the machining condition input unit 14. For example, if the user inputs a specific frequency for an item such as "ball screw," the machining condition input unit 14 outputs the input frequency as a machining condition to the estimation frequency calculation unit 16, indicating that vibrations may occur due to the ball screw.

[0032] The machining program analysis unit 15 analyzes the machining program. In the first embodiment, the machining program analysis unit 15 analyzes the machining program acquired from the control-side communication unit 11 of the control device 2 via the display-side communication unit 12. The analysis results from the machining program analysis unit 15 are output to the estimated frequency calculation unit 16.

[0033] The estimated frequency calculation unit 16 calculates an estimated frequency, which is the frequency of vibration that may occur based on at least one of the control parameters, processing conditions, and processing program. The calculation result of the estimated frequency calculation unit 16 is output to the output unit 20. An example of an estimated frequency calculated by the estimated frequency calculation unit 16 is described below.

[0034] The estimated frequency calculation unit 16 calculates the oscillation frequency as one of the estimated frequencies based on the machining program or the machining program and control parameters.

[0035] Furthermore, the estimated frequency calculation unit 16 calculates one of the estimated frequencies as a frequency at which the machine is prone to vibration (natural frequency), based on the center value and width of the vibration frequency, which are the setting values ​​of the vibration damping filter of the control parameters.

[0036] Furthermore, the estimated frequency calculation unit 16 calculates a vibration damping frequency at which the machine tool is prone to vibration as one of the estimated frequencies, based on the setting value of the motor-driven vibration suppression function of the control parameters. Similarly, the estimated frequency calculation unit 16 calculates a frequency near the vibration frequency to be suppressed as one of the estimated frequencies, based on the setting value of the sensor-driven vibration suppression function of the machine tool's end-point.

[0037] The control parameters include whether cogging correction is enabled or disabled, as well as the number of magnetic poles (pairs). If the rotational speed information is known, it is possible to determine whether the vibration frequency is due to cogging. Therefore, the estimated frequency calculation unit 16 calculates a frequency at which vibration is likely to occur as one of the estimated frequencies, based on the rotational speed of the axis in the machining program, the enabled / disabled status of cogging correction in the control parameters, and the number of magnetic poles (pairs).

[0038] Furthermore, the estimated frequency calculation unit 16 calculates one of the frequencies at which vibration is likely to occur, based on the number of teeth of the gear during gear machining, which is a machining condition input through the machining condition input unit 14, and the rotational speed of the shaft specified in the machining program.

[0039] Furthermore, the estimated frequency calculation unit 16 calculates a frequency at which vibration is likely to occur as one of the estimated frequencies based on information regarding the vibration of peripheral devices such as fans, which is input through the processing condition input unit 14. In addition, the estimated frequency calculation unit 16 calculates a frequency at which vibration is likely to occur as one of the estimated frequencies based on information regarding scratches at specific locations on the ball screw, which is input through the processing condition input unit 14.

[0040] The above describes an example of calculating the estimated frequency, but the calculation of the estimated frequency is not limited to this method. For example, the estimated frequency calculation unit 16 may acquire command frequencies such as aliases, dead zone components, machine resonance frequencies, and eccentric movements from the machining program, control parameters, or machining condition input unit 14, and calculate the estimated frequency based on the acquired information.

[0041] This section explains the superimposed representation of estimated frequencies based on aliasing. Depending on the relationship between the sampling frequency and the actual vibration frequency, aliasing frequencies may be visible. For example, if the sampling frequency is 1 kHz (1000 Hz) and a vibration with a true frequency of 600 Hz is measured, an incorrect frequency of 400 Hz will be observed. This is a phenomenon called aliasing, and can be expressed as "apparent frequency" = "sampling frequency" - "true frequency". In general terms, it can be expressed as shown in equation 2 below.

[0042] [Number 2] Fimage = |Ftrue - N × Fsample| Fimage: Apparent frequency Ftrue: True frequency Fsample: Sampling frequency N: Arbitrary integer

[0043] Next, the operation data acquisition unit 17 will be described. The operation data acquisition unit 17 acquires at least one of the operation data of the position deviation, speed, and current value. The operation data acquired by the operation data acquisition unit 17 is output to the frequency analysis unit 18.

[0044] The frequency analysis unit 18 analyzes the operation data of the machine tool acquired by the operation data acquisition unit 17. The frequency analysis unit 18 performs a Fourier transform on the operation data to acquire data indicating the frequency components. The actual frequency components analyzed by the frequency analysis unit 18 are output to the determination unit 19.

[0045] The determination unit 19 determines the magnitude of the frequency components. The determination unit 19 outputs the determination result to the output unit 20. Referring to FIGS. 5 and 6, the determination of the magnitude of the frequency components will be described. FIG. 5 is a graph of a first example showing the strength (Magnitude) of waves different in frequency. The graph of FIG. 5 plots the analysis result of the position deviation of the feed axis motor (the peak is on the low frequency side) and the analysis result of the speed data of the spindle motor (the peak is on the high frequency side). FIG. 6 is a graph of a second example showing the strength (Magnitude) of waves different in frequency. FIG. 6 plots the analysis result of the current value of the feed axis motor.

[0046] As shown in FIGS. 5 and 6, the degrees (Magnitude) of the strength of the waves of the frequency components are significantly different depending on the reference data. For example, in the graph of FIG. 5, the strength of the wave is about 0.14 at around 250 Hz at maximum, but in the graph of FIG. 6, the strength of the wave becomes 4.0 or more at around 35 Hz at maximum. Therefore, the determination unit 19 determines that the frequency component is large when detecting a wave strength that is clearly larger than the surrounding ones.

[0047] The determination criterion is, for example, that when the magnitude of the frequency component of a certain reference scale is n times (for example, 10 times) or more larger than the wave intensity of the frequency components in a predetermined range centered on that scale, it is determined that the frequency component of the reference scale is large. The frequency components targeted within the predetermined range here can be the frequency components of the immediately adjacent vertical scale. For example, in the graph of FIG. 5, the wave intensity of around 250 Hz of the reference scale, which is 0.14, is significantly larger than 10 times the wave intensity in the predetermined range, and the determination unit 19 determines that the frequency component of 250 Hz is large. Similarly, in the graph of FIG. 6, when the reference scale is 35 Hz, the wave intensity of 4.0 is significantly larger than 10 times the wave intensity in the predetermined range, and the determination unit 19 determines that the frequency component of 35 Hz is large.

[0048] Note that the predetermined range of the determination criterion is not limited to the adjacent scale, nor is the wave intensity limited to n times or more. Furthermore, the determination criterion may be configured to be set by the user through the processing condition input unit 14.

[0049] The output unit 20 outputs information for superimposing and displaying the calculation results of the estimated frequency calculation unit 16 and the frequency analysis unit 18 to the display unit 21. In addition, the output unit 20 also performs a process of switching the display presence or absence of the calculation result of the estimated frequency calculation unit 16 based on the determination result input from the determination unit 19.

[0050] When the determination result of the determination unit 19 is that it is determined that the frequency component analyzed by the frequency analysis unit 18 is large, the output unit 20 outputs information for superimposing and displaying the estimated frequency together with the information indicating the frequency component analyzed by the frequency analysis unit 18 to the display unit 21. On the other hand, when the determination result of the determination unit 19 is that there is no determination that the frequency component analyzed by the frequency analysis unit 18 is large, the output unit 20 displays the information indicating the frequency component analyzed by the frequency analysis unit 18 without superimposing and displaying the estimated frequency.

[0051] The display unit 21 is a display that displays various types of information related to processing in an image. Since the estimation device 10 includes the display unit 21 that displays an image, it can also be called a display device.

[0052] As described above, if the frequency analysis unit 18 determines that there are large frequency components, the display unit 21 superimposes information indicating the estimated frequency along with information indicating the frequency components analyzed by the frequency analysis unit 18, based on the information output from the output unit 20. If the frequency analysis unit 18 determines that there are no large frequency components, it displays information indicating the frequency components analyzed by the frequency analysis unit 18 as an image, based on the information output from the output unit 20.

[0053] Figure 7 shows a first example of an image in which the estimated frequency calculated by the estimated frequency calculation unit 16 is superimposed on information showing the frequency components analyzed by the frequency analysis unit 18. In the example image of Figure 7, a graph similar to the graph in Figure 5 is displayed as information showing the frequency components analyzed by the frequency analysis unit 18. Two pieces of information based on the estimated frequency calculated by the estimated frequency calculation unit 16 are then superimposed on this graph. The two estimated frequencies are displayed with different display modes (display attributes) to improve visibility. The display modes are distinguished, for example, by line type, color, or a combination thereof. Line type refers to the type of line, such as a solid line, dashed line, or chain line. Color refers to the color of the line, such as red, green, or blue.

[0054] The output unit 20 may output information to the display unit 21 so that the display mode differs when multiple estimated frequencies satisfy predetermined conditions. For example, the output unit 20 may display the same estimated frequencies with different display modes.

[0055] The first is the estimated frequency calculated based on the spindle speed of the machining program and the number of teeth in the machining conditions, and is shown by a dashed line. The strong waves (Magnitude) near this estimated frequency based on spindle speed and number of teeth can be estimated to be vibrations caused by the spindle speed and number of teeth.

[0056] The second is the estimated frequency calculated based on the spindle speed and control parameters of the machining program, the enabled / disabled status of the motor's cogging compensation, and the number of magnetic poles (pairs), and is shown by the dashed line. Strong waves (Magnitude) near the estimated frequency calculated based on the motor speed and number of magnetic poles (pairs) can be estimated to be vibrations caused by motor cogging.

[0057] Figure 8 shows a second example of an image in which the estimated frequency calculated by the estimated frequency calculation unit 16 is superimposed on information showing the frequency components analyzed by the frequency analysis unit 18. In the example image in Figure 7, the estimated frequency is shown as a line segment, but as shown in Figure 8, the estimated frequency may be set to have a certain width. The width of the estimated frequency may be set, for example, based on a predetermined ratio to the estimated frequency (a range of about 10% to 20% of the peak).

[0058] As described above, the estimation device 10 includes a display-side communication unit 12 that acquires control information from a control unit 3 that controls a machine tool via communication, a parameter acquisition unit 13 that acquires control parameters from the control unit 3, a machining condition input unit 14 that inputs machining conditions for the machine tool, a machining program analysis unit 15 that analyzes the machining program, an estimated frequency calculation unit 16 that calculates an estimated frequency which is the frequency of vibration that may occur based on at least one of the control parameters, machining conditions, and machining program, an operation data acquisition unit 17 that acquires operation data which is at least one of the position deviation, speed, and current value, a frequency analysis unit 18 that analyzes the frequency components of the operation data, a determination unit 19 that determines the magnitude of the frequency components, and an output unit 20 that outputs information for displaying the calculation results of the estimated frequency calculation unit 16 and the frequency analysis unit 18 superimposed, and switches whether or not to display the calculation results of the estimated frequency calculation unit 16 according to the magnitude of the frequency components.

[0059] This allows the estimated frequency, calculated based on the processing program, control parameters, and input processing conditions, to be superimposed on the frequency components, which are the data obtained through frequency analysis. Therefore, if the wave intensity is high near the estimated frequency, it can be inferred that the cause lies in the data from which the estimated frequency was calculated. This simplifies the analysis of vibration causes and shortens the investigation process, regardless of the user's knowledge and experience. Furthermore, the superposition of the estimated frequency can be toggled on or off depending on the magnitude of the frequency components, so it is possible to hide the superposition of the estimated frequency when it is not needed.

[0060] In this embodiment, the determination unit 19 determines whether there is a frequency component whose wave intensity is greater than a predetermined determination criterion compared to the surrounding area, and the output unit 20 outputs information for displaying the estimated frequency superimposed on the frequency component if there is a frequency component greater than the determination criterion.

[0061] This means that if the wave intensity required for vibration analysis cannot be observed, the estimated frequency will not be superimposed, making it easy and quick to determine the need for vibration factor analysis.

[0062] Furthermore, in this embodiment, the output unit 20 displays the estimated frequency so that it has a width.

[0063] This allows for easy estimation of the vibration cause based on the estimated frequency, even if the actual vibration frequency and the estimated frequency do not perfectly match, provided that the intensity of the frequency components included in the bandwidth is high.

[0064] Furthermore, in this embodiment, the output unit 20 displays each of the multiple estimated frequencies in a different manner when multiple estimated frequencies have been calculated. This allows for the distinction of multiple estimated frequencies based on their display manner, even when there are multiple possible causes of vibration. This makes it easy to estimate each cause even when there are multiple causes of vibration.

[0065] Furthermore, the estimation device 10 of this embodiment further includes a display unit 21 capable of superimposing the calculation results of the estimated frequency calculation unit 16 along with information indicating the calculation results of the frequency analysis unit 18 based on the information output by the output unit 20. This makes it possible to intuitively estimate the cause of vibration through the image displayed on the display unit 21.

[0066] [Second Embodiment] Next, with reference to Figure 9, the estimation device 10a of the second embodiment will be described. Figure 9 is a functional block diagram of a machine tool system 1a to which the estimation device 10a according to the second embodiment is applied. As shown in Figure 9, the control device 2a of the machine tool may be configured to integrally include a control unit 3 that performs machining control and an estimation device 10a that functions as a display device.

[0067] In addition to the configurations of the first and second embodiments, configurations may be added to notify or display methods for countermeasures against each frequency. For example, the control parameters used to calculate the estimated frequency may be displayed, or a guide display may be provided to transition to a screen for changing the control parameters. Furthermore, when displaying the estimated frequency related to the spindle speed and feed axis speed, the machining program modification screen may be displayed simultaneously. In addition, notifications may be provided to prompt the user to change the tool that causes vibration, or to provide information on how to deal with mechanical resonance. Furthermore, notifications may be provided to prompt the user to change the oscillation frequency, or a screen for changing the oscillation frequency may be displayed. In addition, notifications may be provided to ignore aliases or to prompt the user to consider smoothing correction.

[0068] Furthermore, while the first and second embodiments are configured to superimpose the estimated frequency onto the frequency component graph, the display method is not limited to this. For example, a table listing the contributing events along with the estimated frequency may be displayed on the display unit 21. In this case, the order in which the events are listed in the table may be set based on a predetermined priority, or in order of decreasing vibration.

[0069] This disclosure is not limited to the embodiments or modifications described above, and any modifications or improvements that can achieve the objectives of this disclosure are included.

[0070] The following additional information is disclosed regarding the above embodiments and modifications. (Note 1) An estimation device (10, 10a) comprising: a communication unit (12) that acquires control information by communication from a control unit (3) that controls a machine tool; a parameter acquisition unit (13) that acquires control parameters of the control unit (3); a machining condition input unit (14) that inputs machining conditions of the machine tool; a machining program analysis unit (15) that analyzes a machining program; an estimated frequency calculation unit (16) that calculates an estimated frequency which is the frequency of vibration that may occur based on at least one of the control parameters, the machining conditions, and the machining program; an operation data acquisition unit (17) that acquires operation data of at least one of position deviation, velocity, and current value; a frequency analysis unit (18) that analyzes the frequency components of the operation data; a determination unit (19) that determines the magnitude of the frequency components; and an output unit (20) that outputs information for displaying the calculation results of the estimated frequency calculation unit (16) and the frequency analysis unit (18) superimposed on each other, and switches whether or not to display the calculation results of the estimated frequency calculation unit (16) according to the magnitude of the frequency components.

[0071] (Note 2) In the estimation device (10, 10a) described in Note 1, the determination unit (19) determines whether there is a frequency component whose wave intensity is greater than a predetermined determination criterion than the surrounding area, and the output unit (20) outputs information for displaying the estimated frequency superimposed on the frequency component if there is a frequency component greater than the determination criterion.

[0072] (Note 3) In the estimation device (10, 10a) described in Note 1 or Note 2, the output unit (20) displays the estimated frequency with a width.

[0073] (Note 4) In the estimation device (10, 10a) described in any of Notes 1 to 3, the output unit (20) displays each of the multiple estimated frequencies in a different manner when multiple estimated frequencies have been calculated.

[0074] (Note 5) The estimation device (10, 10a) described in any of Notes 1 to 4 further comprises a display unit (21) capable of superimposing the calculation result of the estimated frequency calculation unit (16) together with information indicating the calculation result of the frequency analysis unit (18) based on the information output by the output unit (20).

[0075] 1, 1a Machine tool system 2, 2a Control device 3 Control unit 10, 10a Estimation device (display device) 11 Control-side communication unit 12 Display-side communication unit 13 Parameter acquisition unit 14 Machining condition input unit 15 Machining program analysis unit 16 Estimation frequency calculation unit 17 Operation data acquisition unit 18 Frequency analysis unit 19 Judgment unit 20 Output unit 21 Display unit

Claims

1. An estimation device comprising: a communication unit that acquires control information by communication from a control unit that controls a machine tool; a parameter acquisition unit that acquires control parameters from the control unit; a machining condition input unit that inputs machining conditions for the machine tool; a machining program analysis unit that analyzes a machining program; an estimated frequency calculation unit that calculates an estimated frequency which is the frequency of vibration that may occur based on at least one of the control parameters, the machining conditions, and the machining program; an operation data acquisition unit that acquires operation data which is at least one of position deviation, velocity, and current value; a frequency analysis unit that analyzes the frequency components of the operation data; a determination unit that determines the magnitude of the frequency components; and an output unit that outputs information for displaying the calculation results of the estimated frequency calculation unit and the frequency analysis unit superimposed, and switches whether or not to display the calculation results of the estimated frequency calculation unit according to the magnitude of the frequency components.

2. The estimation device according to claim 1, wherein the determination unit determines whether there is a frequency component whose wave intensity is greater than a predetermined determination criterion than the surrounding area, and the output unit outputs information for displaying the estimated frequency superimposed on the frequency component when there is a frequency component greater than the determination criterion.

3. The estimation device according to claim 1 or 2, wherein the output unit displays the estimated frequency with a width.

4. The estimation device according to any one of claims 1 to 3, wherein the output unit displays each of the multiple estimated frequencies in a different manner when multiple estimated frequencies have been calculated.

5. The estimation device according to any one of claims 1 to 4, further comprising a display unit capable of superimposing the calculation result of the estimated frequency calculation unit together with information indicating the calculation result of the frequency analysis unit based on the information output by the output unit.

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