Vibration suppression device, control method, and program

Abstract

This invention provides a vibration suppression device, control method, and program that can appropriately suppress vibrations even when there are mechanical or hardware limitations. [Solution] The sewing machine is equipped with a sensor, an actuator, and a CPU. The CPU acquires a detection signal from the sensor (S7). Based on the acquired detection signal, the CPU generates an inverted phase waveform using an adaptive algorithm for AFC (Adaptive Feedforward Cancellation) (S25, S33). The CPU transmits the generated inverted phase waveform to the actuator (S27, S35). If the amplitude A of the inverted phase waveform is less than or equal to a threshold (S21: NO), the CPU determines the first amplitude, which is the amplitude of the inverted phase waveform, based on the integration result (S23). If the amplitude A of the inverted phase waveform exceeds a threshold (S21: YES), the CPU determines the second amplitude, which is the amplitude of the inverted phase waveform, based on the integration result up to the threshold (S31).

Description

[Technical Field]

[0001] This invention relates to a vibration suppression device, a control method, and a program. [Background technology]

[0002] The sewing machine described in Patent Document 1 includes a sensor and a control unit. The sensor detects vibrations in the bed portion of the sewing machine. The control unit generates a control signal that interferes with the detected vibration so as to minimize the sensor's detected value. The control unit actively reduces the detected vibration by driving an actuator based on the generated control signal. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 7-213774 [Overview of the project] [Problems that the invention aims to solve]

[0004] Actuators have mechanical limitations in their range of motion, as well as hardware limitations such as the driver's rated current. Setting an upper limit on the absolute value of the control signal amplitude causes a loss of continuity in the control signal waveform. This results in the generation of a control signal that includes frequency components other than the vibration frequency to be reduced. Consequently, the control unit may not be able to adequately reduce the detected vibration.

[0005] The objective of the present invention is to provide a vibration suppression device, control method, and program that can appropriately suppress vibrations even when there are mechanical or hardware limitations. [Means for solving the problem]

[0006] The vibration suppression device according to the present invention comprises a sensor for detecting vibrations of a vibrating object, an actuator installed on the vibrating object, and a controller. The controller performs an acquisition process for acquiring a detection signal from the sensor, a generation process for generating an inverse phase waveform based on the detection signal acquired in the acquisition process using an adaptive algorithm of AFC (Adaptive Feedforward Cancellation), and a transmission process for transmitting the inverse phase waveform generated in the generation process to the actuator. The controller is characterized in that, in the generation process, if the index value based on the integral result of the amplitude parameter based on the detection signal is less than or equal to a threshold, it performs a first determination process to determine a first amplitude, which is the amplitude of the inverse phase waveform, based on the integral result, or if the index value based on the integral result of the amplitude parameter exceeds the threshold, it performs a second determination process to determine a second amplitude, which is the amplitude of the inverse phase waveform, based on the integral result up to the threshold or immediately before the threshold.

[0007] The above vibration suppression device can effectively suppress vibrations even when there are mechanical or hardware limitations.

[0008] In the present invention, the controller may further perform a specification process in the generation process to identify a plurality of vibration frequencies, and a calculation process to calculate the sum of the amplitudes of the AFC for each vibration frequency identified in the specification process as an index value. The vibration suppression device can appropriately suppress vibrations based on the relationship between the sum of the amplitudes of the AFCs and a threshold.

[0009] In the present invention, the threshold value may be set based on the movable range of the actuator. The vibration suppression device can appropriately suppress vibrations based on the movable range of the actuator.

[0010] In the present invention, the threshold value may be set based on the rated current of the actuator driver. The vibration suppression device can appropriately suppress vibrations based on the rated current of the driver.

[0011] In the present invention, the sensor may be an acceleration sensor. The vibration suppression device can appropriately suppress vibrations based on the output result of the acceleration sensor.

[0012] A control method according to a second aspect of the present invention is a control method for a vibration suppression device comprising a sensor for detecting vibrations of a vibrating object and an actuator installed on the vibrating object, comprising: an acquisition step of acquiring a detection signal from the sensor; a generation step of generating an inverse phase waveform based on the detection signal acquired in the acquisition step using an adaptive algorithm of AFC (Adaptive Feedforward Cancellation); and a transmission step of transmitting the inverse phase waveform generated in the generation step to the actuator, wherein the generation step comprises a first determination step of determining a first amplitude, which is the amplitude of the inverse phase waveform, based on the integral result of the amplitude parameter based on the detection signal, if the index value based on the integral result of the amplitude parameter is less than or equal to a threshold, or a second determination step of determining a second amplitude, which is the amplitude of the inverse phase waveform, based on the integral result up to or immediately before the threshold, if the index value based on the integral result of the amplitude parameter exceeds the threshold.

[0013] In the present invention, the generation step may further include a selection step of identifying a plurality of vibration frequencies, and a calculation step of calculating the sum of the amplitudes of the AFC for each vibration frequency identified in the selection step as an index value. The control method can appropriately suppress vibrations based on the relationship between the sum of the amplitudes of the AFCs and a threshold.

[0014] The above control method achieves the same effect as the vibration suppression device according to the first embodiment.

[0015] In the present invention, the threshold value may be set based on the movable range of the actuator. The control method can appropriately suppress vibrations based on the movable range of the actuator.

[0016] In the present invention, the threshold value may be set based on the rated current of the actuator driver. The control method can appropriately suppress vibrations based on the rated current of the driver.

[0017] In the present invention, the sensor may be an acceleration sensor. The control method can appropriately suppress vibrations based on the output result of the acceleration sensor.

[0018] A program according to a third aspect of the present invention causes a controller of a vibration suppression device, which includes a sensor for detecting vibrations of a vibrating object and an actuator installed on the vibrating object, to perform an acquisition step of acquiring a detection signal from the sensor; a generation step of generating an inverse phase waveform based on the detection signal acquired in the acquisition step using an adaptive algorithm of AFC (Adaptive Feedforward Cancellation); and a transmission step of transmitting the inverse phase waveform generated in the generation step to the actuator, wherein in the generation step, the controller is caused to perform a first determination step of determining a first amplitude, which is the amplitude of the inverse phase waveform, based on the integral result of the amplitude parameter based on the detection signal, if the index value based on the integral result of the amplitude parameter is less than or equal to a threshold, or a second determination step of determining a second amplitude, which is the amplitude of the inverse phase waveform, based on the integral result up to the threshold, or up to just before the threshold, if the index value based on the integral result of the amplitude parameter exceeds the threshold.

[0019] The above program achieves the same effect as the vibration suppression device according to the first embodiment.

[0020] In the present invention, in the generation step, the controller may further perform a selection step to identify a plurality of vibration frequencies, and a calculation step to calculate the sum of the amplitudes of the AFC for each vibration frequency identified in the selection step as an index value. The program can appropriately suppress vibrations based on the relationship between the sum of the amplitudes of the AFC and a threshold.

[0021] In the present invention, the threshold may be set based on the movable range of the actuator. The program can appropriately suppress vibration based on the movable range of the actuator.

[0022] In the present invention, the threshold may be set based on the rated current of the driver for the actuator. The program can appropriately suppress vibration based on the rated current of the driver.

[0023] In the present invention, the sensor may be an acceleration sensor. The program can appropriately suppress vibration based on the output result of the acceleration sensor. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] [Figure 1] Fig. 1 is a diagram showing a schematic configuration of a sewing machine 1. [Figure 2] Fig. 2 is a diagram showing an electrical configuration of the sewing machine 1. [Figure 3] Fig. 3 is a diagram showing a flowchart of vibration suppression processing. [Figure 4] Fig. 4 is a diagram showing frequency characteristics of vibration occurring in the sewing machine 1. [Figure 5] Fig. 5 is a diagram showing a frequency correction table. [Figure 6] Fig. 6 is a chart showing correction coefficients of a gain g at 3200 rpm. [Figure 7] Fig. 7 is a diagram showing an application algorithm of AFC (Adaptive Feedforward Cancellation). [Figure 8] Fig. 8 is a diagram showing a relationship between a vibration waveform and an anti-phase waveform. [Figure 9] Fig. 9 is a diagram showing a result of vibration reduction of the sewing machine 1 in a time domain. [Figure 10] Fig. 10 is a diagram showing a result of vibration reduction of the sewing machine 1 in a frequency domain. DETAILED DESCRIPTION OF EMBODIMENTS

[0025] Embodiments of the present invention will be described with reference to the drawings. The drawings are used to illustrate the technical features that the present invention may adopt. The configuration of the apparatus, etc., is not intended to limit the invention to that specific configuration, but is merely an illustrative example.

[0026] The sewing machine 1 shown in Figure 1 is capable of embroidery on the material being sewn. The material being sewn can be, for example, cloth or leather.

[0027] Sewing machine 1 is equipped with a sensor 11 and an actuator 15. The sensor 11 is installed, for example, on the base of sewing machine 1. Sensor 11 is an acceleration sensor. Sensor 11 detects vibrations that occur in sewing machine 1.

[0028] The actuator 15 is installed on the head of the sewing machine 1. The actuator 15 cancels out vibrations generated in the sewing machine 1, for example, by vibrating a weight. The inside of the head is the main source of vibration. Therefore, by installing the actuator 15 on the head of the sewing machine 1, vibrations generated in the sewing machine 1 can be effectively canceled out.

[0029] Referring to Figure 2, the electrical configuration of sewing machine 1 will be explained. Sewing machine 1 further includes a control unit 25, a main motor 51, and an encoder 41, etc.

[0030] The control unit 25 includes a CPU 21, ROM 22, RAM 23, storage device 24, input / output interface (I / O) 20, and drive circuits 31 and 35.

[0031] The CPU 21 provides overall control over the operation of the sewing machine 1. The ROM 22 stores programs and other data necessary for executing various processes. The RAM 23 temporarily stores various information generated during the execution of various processes.

[0032] The memory device 24 is non-volatile and stores various setting values. The memory device 24 stores the frequency correction table, which will be described later.

[0033] The drive circuit 31 and encoder 41 are connected to I / O 20. The drive circuit 31 is connected to the main motor 51 and drives the main motor 51 with control commands from the CPU 21. This causes the needle bar of the sewing machine 1 to move up and down. The encoder 41 detects the rotation angle θ of the output shaft of the main motor 51 and inputs the detection result to I / O 20.

[0034] Sensor 11 inputs the result of detecting vibrations generated in the sewing machine 1 to I / O 20.

[0035] The drive circuit 35 is connected to I / O 20. The drive circuit 35 is connected to the actuator 15 and is driven by control commands from the CPU 21. The actuator 15 receives an inverse phase waveform of the detected vibration. As a result, the actuator 15 vibrates, suppressing the vibration of the sewing machine 1.

[0036] Refer to Figure 3 to explain the vibration suppression process. When the user powers on the sewing machine 1, the CPU 21 reads and executes a program from the ROM 22. After executing the program, the CPU 21 performs the vibration suppression process.

[0037] The CPU 21 determines whether or not it has driven the main motor 51 (S1). If it determines that the main motor 51 has not been driven (S1: NO), the CPU 21 returns to processing S1 and waits.

[0038] If the CPU 21 determines that the main motor 51 has been driven (S1: YES), that is, if vibration is occurring in the sewing machine 1, the CPU 21 obtains the rotational speed of the main motor 51 (S3). For example, the rotational speed is set by the user. For example, the rotational speed is 3200 rpm.

[0039] The CPU 21 obtains the rotation angle θ from the information of the encoder 41 of the main motor 51 (S5).

[0040] The CPU 21 acquires a detection signal from the sensor 11 (S7).

[0041] The CPU 21 acquires the vibration frequency based on the detection signal from the sensor 11. The CPU 21 performs an FFT (Fast Fourier Transform) analysis on the detection signal from the sensor 11 to acquire the frequency characteristics of the vibration waveform. The CPU 21 acquires the acceleration at the point where the vibration peak occurs (S9).

[0042] For example, when the rotational speed of the main motor 51 is 3200 rpm, the CPU 21 obtains the frequency characteristics shown in Figure 4. The vibrations generated in the sewing machine 1 are integer multiples of the rotational speed of the main motor 51. As shown in Figure 4, the vibration frequencies at which acceleration peaks occur are 53 Hz for the first vibration, 106 Hz for the second vibration, and 212 Hz for the fourth vibration. The values ​​on the vertical axis for each vibration are accelerations a1, a2, and a4.

[0043] The CPU 21 identifies N vibration frequencies (where N is a positive number of 2 or more) that are subject to vibration suppression, for example, by referring to the results in Figure 4 (S11). The relationship between vibration frequency and rotational speed may be stored in advance as a table. In other words, the CPU 21 can identify the vibration frequencies that occur if the rotational speed of the main motor 51 is known. In this embodiment, N is 3.

[0044] The CPU 21 identifies N coefficients from the frequency correction table for each of the N vibration frequencies identified (S13).

[0045] For example, the frequency correction table shown in Figure 5 is based on JIS standards. The frequency correction table assigns weighted correction coefficients to each predetermined vibration frequency. Weighting means assigning a high correction coefficient to vibration frequencies that people can easily perceive, and a low correction coefficient to vibration frequencies that people cannot easily perceive. For example, people are most sensitive to vibrations around 10 Hz, and the correction coefficient is highest at this frequency. The correction coefficient decreases as the frequency approaches 1 Hz, with 10 Hz as the peak. The correction coefficient also decreases as the frequency approaches 500 Hz, with 10 Hz as the peak.

[0046] The diagram in Figure 6 shows an example where the motor speed is 3200 rpm. When the primary vibration frequency is 53 Hz, the correction factor is 0.35 according to the frequency correction table. Also, since the secondary vibration is 106 Hz, the correction factor is 0.15 according to the frequency correction table. Since the fourth vibration is 212 Hz, the correction factor is 0.06 according to the frequency correction table.

[0047] The CPU 21 applies the specified N coefficients to the gain g used in signal processing of the vibration detection signals for each of the N vibration frequencies (S15). Here, the gain g of the calculation unit C1 of AFC7A~7C, described later, is, for example, K as an initial value.

[0048] For example, when the rotational speed of the main motor 51 is 3200 rpm, a correction factor of 0.35 is applied to the gain g (K) of the calculation unit C1 of AFC7A, as described below. The gain g of the calculation unit C1 to which the correction factor is applied becomes 0.35K. A correction factor of 0.15 is applied to the gain g (K) of the calculation unit C1 of AFC7B, as described below. The gain g of the calculation unit C1 to which the correction factor is applied becomes 0.15K. A correction factor of 0.06 is applied to the gain g (K) of the calculation unit C1 of AFC7C, as described below. The gain g of the calculation unit C1 to which the correction factor is applied becomes 0.06K. Therefore, in the calculations of AFC7A to 7C, the CPU 21 weights the first-order vibrations, second-order vibrations, and fourth-order vibrations in that order.

[0049] CPU21 executes an adaptive algorithm for AFC (Adaptive Feedforward Cancellation) to generate an inverse phase waveform (S17). AFC (Adaptive Feedforward Cancellation) is a technique for suppressing periodic disturbances with respect to time. The basic principle of AFC is to cancel out disturbances by generating and adding an input that cancels out the disturbance.

[0050] Referring to Figure 7, the details of the AFC (Adaptive Feedforward Cancellation) application algorithm will be explained. In this embodiment, AFC7A to AFC7C are used to cancel out primary, secondary, and quaternary vibrations in particular.

[0051] The AFC7A receives the motor rotation angle θ obtained in S5 and the acceleration a1 obtained in S9 as input. The calculation unit C1 multiplies the acceleration a1 by 0.35K, which is obtained by applying the gain g, i.e., the correction coefficient.

[0052] Calculation unit C2 calculates nθ. Calculation unit C3 calculates cos(nθ). Calculation unit C4 calculates nθ+φ. Calculation unit C5 calculates cos(nθ+φ). Calculation unit C6 multiplies the result of calculation unit C5 and the result of calculation unit C1.

[0053] The calculation unit C7 integrates the result of the calculation unit C6 with respect to time. Let the integral result of the calculation unit C7 be α1. α1 will be used in the calculation of amplitude A described later. The calculation unit C8 multiplies the result of the calculation unit C3 and the result of the calculation unit C7.

[0054] The calculation unit C9 calculates sin(nθ). The calculation unit C10 calculates sin(nθ+φ). The calculation unit C11 multiplies the result of the calculation unit C10 by the result of the calculation unit C1.

[0055] The calculation unit C12 integrates the result of the calculation unit C11 with respect to time. The integral result of the calculation unit C12 is denoted as β1. β1 will be used in the calculation of amplitude A described later. The calculation unit C13 multiplies the result of the calculation unit C12 and the result of the calculation unit C9.

[0056] The calculation unit C14 adds the calculation results of calculation units C8 and C13 to calculate ud1(t). ud1(t) is then transmitted to the calculation unit C15.

[0057] The configuration of AFC7B is the same as that of AFC7A. The rotation angle θ of the main motor 51 and the acceleration a2 of the secondary vibration are input to AFC7B. The calculation unit C1 multiplies the acceleration a2 by the gain g to which the correction factor is applied, i.e., 0.15K to which the correction factor is applied.

[0058] AFC7B calculates α2 and β2 by integrating the calculation results of each calculation unit C6 and C11, respectively. AFC7B then calculates ud2(t). The calculation result is transmitted to calculation unit C15.

[0059] The configuration of AFC7C is the same as that of AFC7A and 7B. The motor rotation angle θ and the acceleration a4 of the fourth vibration are input to AFC7C. The calculation unit C1 multiplies the acceleration a4 by a gain g to which a correction factor has been applied, i.e., 0.06K to which the correction factor has been applied.

[0060] AFC7C calculates α3 and β3 by integrating the calculation results of each calculation unit C6 and C11, respectively. AFC7C then calculates ud3(t). The calculation result is sent to calculation unit C15.

[0061] The calculation unit C15 adds ud1(t) + ud2(t) + ud3(t). The result of the addition represents the inverse phase waveform ud(t) that is transmitted to the actuator 15.

[0062] The waveform shown in Figure 8 is an example of an inverted phase waveform generated by the application algorithms of AFC7A to AFC7C.

[0063] Here, the inverse phase waveform is affected by the current rating and mechanical limitations of the actuator 15. Therefore, it is not possible to output an unlimited amplitude. For this reason, a threshold Th is set for driving the actuator 15. The threshold Th is the maximum amplitude value that the actuator 15 can generate. For example, the threshold Th can be set based on the movable range of the actuator 15. Alternatively, the threshold Th may be set based on the rated current of the actuator 15's driver.

[0064] As shown in Figure 8(A), if the inverse phase waveform generated by the AFC exceeds the threshold Th, the inverse phase waveform undergoes saturation. In this case, the inverse phase waveform does not become a sine wave. Therefore, the actuator 15 generates vibrations that include frequency components other than the vibration frequency to be suppressed. Consequently, the inverse phase waveform in Figure 8(A) may not be able to adequately suppress vibrations.

[0065] Here, CPU21 calculates the amplitude A of the inverse-phase waveform (S19).

[0066] The amplitude A of the out-of-phase waveform is expressed by equation (1). The first term represents the amplitude of the first-order vibration in AFC7A. The second term represents the amplitude of the second-order vibration in AFC7B. The third term represents the amplitude of the fourth-order vibration in AFC7A. In other words, the amplitude A is the sum of the amplitudes of the AFC for each vibration frequency identified in S11.

number

[0067] CPU21 determines whether the amplitude A of the inverse-phase waveform is greater than the threshold Th (S21).

[0068] If the amplitude A of the inverse-phase waveform is less than or equal to the threshold Th (S21:NO), the CPU 21 determines the first amplitude, which is the amplitude of the inverse-phase waveform (S23). In this case, the result of the calculation in equation (1) becomes the first amplitude.

[0069] CPU21 generates an inverse phase waveform based on the first amplitude (S25). In this case, for example, the inverse phase waveform shown in Figure 8(B) is generated. An inverse phase waveform below the threshold Th is generated. Furthermore, since the calculations of AFC7A to AFC7C are performed with weighting based on the frequency correction table, an inverse phase waveform is generated that can suppress vibration frequencies that are easily perceived by humans.

[0070] The generated inverse-phase waveform is sent to the actuator 15 (S27). The CPU 21 proceeds to process S37.

[0071] On the other hand, if the amplitude A of the inverse-phase waveform exceeds the threshold Th (S21: YES), the CPU 21 stops the integration of the arithmetic units C7 and C12 (S29). As a result, the values ​​of α1~α3 and β1~β3 used to calculate the amplitude A in equation (1) are no longer updated.

[0072] The CPU 21 determines the second amplitude, which is the amplitude of the inverse-phase waveform, based on the integration result up to the threshold Th (S31). The CPU 21 calculates the second amplitude based on equation (1). In this case, the second amplitude is set to, for example, the threshold Th. Alternatively, a margin may be added from the threshold Th, for example, 90 percent of the threshold Th.

[0073] CPU21 generates an inverse phase waveform based on the second amplitude (S33). In this case, for example, an inverse phase waveform is generated where the amplitude A shown in Figure 8(C) is the threshold Th. Therefore, a saturated waveform is not generated. Furthermore, since the calculations of AFC7A to AFC7C are performed with weighting based on the frequency correction table, an inverse phase waveform is generated that can suppress vibration frequencies that are easily perceived by humans.

[0074] The CPU 21 sends the generated inverse-phase waveform to the actuator 15 (S35). The CPU 21 then proceeds to process S37.

[0075] The CPU 21 determines whether or not the rotational speed of the main motor 51 has been changed (S37).

[0076] If the CPU determines that the rotational speed of the main motor 51 has not changed (S37: NO), it only needs to maintain the inverse phase waveform, so it returns to S37 and waits.

[0077] On the other hand, if the CPU 21 determines that the rotational speed of the main motor 51 has changed (S37: YES), it returns to processing S1 in order to generate an inverse-phase waveform corresponding to the rotational speed of the main motor 51.

[0078] The output of sensor 11 shown in Figure 9(A) shows a constant acceleration value from 0 sec, the time when the AFC adaptive algorithm is not being executed, to time TA (approximately 6 sec). The same is true in Figure 9(C), which is a graph of the effective acceleration value based on the output of sensor 11 in Figure 9(A). On the other hand, since this is the time when the AFC adaptive algorithm is not being executed, the thrust in Figure 9(B), which is a graph of the thrust of actuator 15, is 0 N. The thrust is the command value of actuator 15, and is the value of the inverse phase waveform ud(t) in Figure 7.

[0079] Subsequently, the first amplitude is calculated from time TA (approximately 6 seconds) to time TB (approximately 9 seconds). As a result, the thrust of actuator 15 increases as shown in Figure 9(B), and the acceleration decreases as shown in Figure 9(A). This means that the vibration of the sewing machine 1 is suppressed by the vibration of the actuator 15 with an inverse phase waveform based on the first amplitude.

[0080] Theoretically, even after time TB (approximately 9 seconds), the vibration of the actuator 15 with an inverse phase waveform based on the first amplitude will continue to increase the thrust of the actuator 15 shown in Figure 9(B), and decrease the acceleration shown in Figure 9(A) until it reaches zero. An acceleration of zero means that the vibration of the sewing machine 1 is completely suppressed. However, as shown in Figure 8(A), if the amplitude A of the inverse phase waveform generated by AFC7A~7C exceeds the threshold Th, the inverse phase waveform undergoes saturation. In this case, the actuator 15 generates vibrations that include frequency components other than the vibration frequency to be suppressed. Therefore, the inverse phase waveform in Figure 8(A) may not be able to sufficiently suppress vibrations.

[0081] Therefore, the calculation of the second amplitude is performed after time TB (approximately 9 seconds). As a result, the increase in thrust of actuator 15 shown in Figure 9(B) stops. Consequently, the inverse-phase waveform ud(t) becomes a sine wave whose amplitude does not exceed the threshold Th, as shown in Figure 8(C). This reduces the possibility of generating vibrations containing frequency components other than the vibration frequency to be suppressed, thus preventing sufficient vibration suppression. The decrease in acceleration shown in Figure 9(A) stops. Although the decrease in acceleration stops, the acceleration can be maintained at a reduced state by comparing it with the acceleration value from 0 seconds to time TA (approximately 6 seconds) as shown in Figure 9(A). In other words, the state in which the vibration of sewing machine 1 is suppressed can be maintained.

[0082] Furthermore, Figure 10(A) shows the results of FFT analysis of the output results of sensor 11 from 0 sec to time TA (approximately 6 sec), as shown in Figure 9(A). Figure 10(B) shows the results of FFT analysis of the output results of sensor 11 from time TB (approximately 9 sec) onward, as shown in Figure 9(A). As shown in Figures 10(A) and 10(B), the primary vibration at 53 Hz is 5.1 m / sec. 2 from 0.7 m / sec 2 It can be seen that it has been reduced. Also, the secondary vibration at 106 Hz is 18.8 m / sec. 2 from 7.2 m / sec 2 It can be seen that the level has been reduced by about one-third. While there has been no significant improvement in the fourth-order vibration, this is because fourth-order vibrations are less perceptible to humans compared to first and second-order vibrations. As this result shows, it is clear that vibrations that humans can easily perceive are being effectively suppressed.

[0083] As explained above, if the acquired amplitude A is less than or equal to the threshold Th, the CPU 21 determines the first amplitude, which is the amplitude of the inverse-phase waveform, based on the integration result. If the acquired amplitude A exceeds the threshold Th, the CPU 21 determines the second amplitude, which is the amplitude of the inverse-phase waveform, based on the integration result up to the point where it exceeds the threshold Th.

[0084] The above sewing machine 1 can effectively suppress vibrations even when there are mechanical or hardware limitations.

[0085] The CPU 21 identifies multiple vibration frequencies based on the acquired detection signals. The CPU 21 calculates the sum of the amplitudes of AFC7A to 7C for each vibration frequency. The sewing machine 1 can appropriately suppress vibrations even when there are mechanical or hardware limitations, based on the sum of the amplitudes, i.e., amplitude A.

[0086] The threshold Th is set based on the range of motion of the actuator 15. The sewing machine 1 can appropriately suppress vibrations based on the range of motion of the actuator 15.

[0087] The threshold Th is set based on the rated current of the actuator 15's driver. The sewing machine 1 can appropriately suppress vibrations based on the rated current of the driver.

[0088] Sensor 11 is an acceleration sensor. The sewing machine 1 can appropriately suppress vibrations based on the output of the acceleration sensor.

[0089] In the above embodiment, the sewing machine 1 is an example of the "vibration suppression device" of the present invention. The control unit 25 and CPU 21 are examples of the "controller" of the present invention. The calculation results of the calculation units C6 and C11 are examples of the "amplitude parameters" of the present invention. Amplitude A is an example of the "index value". The CPU 21 that executes the process in S11 is an example of the "specific process" of the present invention. The CPU 21 that executes the process in S19 is an example of the "calculation process" of the present invention.

[0090] The CPU 21 that executes the process in S7 is an example of the "acquisition process" of the present invention. The CPU 21 that executes the processes in S25 and S33 is an example of the "generation process" of the present invention. The CPU 21 that executes the processes in S27 and S35 is an example of the "transmission process" of the present invention. The CPU 21 that executes the process in S23 is an example of the "first decision process" of the present invention. The CPU 21 that executes the process in S31 is an example of the "second decision process" of the present invention.

[0091] The present invention is not limited to the embodiments described above, and various modifications are possible without departing from the spirit of the invention.

[0092] In the above embodiment, vibration suppression targeting the sewing machine 1 has been described, but the present invention is not limited thereto. Vibration suppression processing may be performed on vibration of a device that generates vibration due to rotation of a motor.

[0093] In the above embodiment, a case where vibration occurs in the vertical direction is assumed, but the present invention is not limited thereto. For example, when vibration occurs in the left-right direction, the front-back direction, or the like, the vibration direction of the actuator 15 may be appropriately set.

[0094] In the above embodiment, the actuator 15 is provided on the head of the sewing machine 1, but the present invention is not limited thereto. For example, the actuator 15 may be provided on a table of the sewing machine 1. This makes it possible to efficiently suppress vibration at a location touched by a user when the sewing machine 1 operates. The actuator 15 may be appropriately provided at any location other than the head and the table.

[0095] In the above embodiment, the relationship between the amplitude A and the threshold Th is compared in the process of S17, but the present invention is not limited thereto. For example, the integration results of the arithmetic units C7 and C12, that is, α1 to α3 and β1 to β3 may be compared with a predetermined threshold. It is only required that the amplitude A of the finally generated anti-phase waveform does not exceed the threshold Th. For example, in the process of S31, the second amplitude may be calculated based not on the integration result until the amplitude A exceeds the threshold Th, but on the integration result until just before the amplitude A reaches the threshold Th. That is, before it is determined that the amplitude A exceeds the threshold Th in the process of S31 (S31: YES), it was lastly determined that the amplitude A of the anti-phase waveform is equal to or less than the threshold Th (S21: NO), and the first amplitude determined (S23) may be used as the second amplitude.

[0096] Further, instead of comparing the amplitude A with the threshold Th in S21, the sum of squared sums of the calculation results of the calculation units C6 and C11 at each frequency (α1 2 +β1 2 +α2 2 +β2 2 +α3 2 +β3 2 ) may be compared with the threshold Th. The threshold Th in this case may be set as appropriate.

[0097] In the above embodiment, the frequency correction table was based on JIS standards, but it is not limited to this. For example, a correction coefficient that weights vibration frequencies that are likely to affect sewing, rather than vibrations that are easily perceived by humans, may be used. The manufacturer may set the correction coefficient as appropriate.

[0098] In the above embodiment, a correction coefficient was applied using a frequency correction table, for example, but this is not limited to that. For example, a frequency correction table may not be applied. In this case, the frequency correction table does not need to be stored in the storage device 24.

[0099] For example, the gain g of AFC7A to 7C only needs to be set to the same value. Even in this case, the sewing machine 1 can generate an inverse-phase waveform based on the relationship between amplitude A and threshold Th, thereby appropriately suppressing vibration. In other words, the sewing machine 1 can suppress the occurrence of saturation. [Explanation of Symbols]

[0100] 1: Sewing machine 11: Sensor 15: Actuator 21:CPU 25: Control Unit A: Amplitude

Claims

1. A sensor that detects vibrations of a vibrating object, An actuator installed on the vibrating object, Controller and Equipped with, The aforementioned controller, An acquisition process for acquiring a detection signal from the aforementioned sensor, Based on the detection signal acquired in the acquisition process, a generation process is performed to generate an inverted phase waveform using an adaptive algorithm for AFC (Adaptive Feedforward Cancellation), A transmission process that transmits the inverse phase waveform generated in the generation process to the actuator. Execute, The controller, in the generation process, If the index value based on the integral result of the amplitude parameter based on the detection signal is less than or equal to a threshold, a first determination process is performed to determine the first amplitude, which is the amplitude of the inverse phase waveform, based on the integral result, or If the index value based on the integral result of the amplitude parameter exceeds the threshold, a second determination process is performed to determine the second amplitude, which is the amplitude of the inverse phase waveform, based on the integral result up to the point where the threshold is exceeded, or up to the point immediately before the threshold. A vibration suppression device characterized by performing the following actions.

2. The controller, in the generation process, A specific process to identify multiple vibration frequencies, The aforementioned index value is calculated as the sum of the amplitudes of the AFC for each vibration frequency identified in the aforementioned specific processing, and The vibration suppression device according to claim 1, further characterized by performing the following.

3. The vibration suppression device according to claim 1, characterized in that the threshold is set based on the movable range of the actuator.

4. The vibration suppression device according to claim 1, characterized in that the threshold is set based on the rated current of the actuator driver.

5. The vibration suppression device according to claim 1, characterized in that the sensor is an acceleration sensor.

6. A sensor that detects vibrations of a vibrating object, A control method for a vibration suppression device comprising an actuator installed on the vibrating object, An acquisition step of acquiring a detection signal from the aforementioned sensor, A generation step in which an inverted phase waveform is generated by an adaptive algorithm of AFC (Adaptive Feedforward Cancellation) based on the detection signal acquired in the acquisition step, A transmission step which transmits the inverse phase waveform generated in the generation step to the actuator. Equipped with, The generation step is, If the index value based on the integral result of the amplitude parameter based on the detection signal is less than or equal to a threshold, a first determination step is performed to determine the first amplitude, which is the amplitude of the inverse phase waveform, based on the integral result, or If the index value based on the integral result of the amplitude parameter exceeds the threshold, a second determination step is taken to determine the second amplitude, which is the amplitude of the inverse phase waveform, based on the integral result up to the point where the threshold is exceeded or immediately before the threshold. A control method characterized by comprising:

7. The generation step is, A specific step to identify multiple vibration frequencies, The aforementioned index value is calculated as the sum of the amplitudes of the AFC for each vibration frequency identified in the specified step, and The control method according to claim 6, further comprising the above.

8. The control method according to claim 6, characterized in that the threshold is set based on the movable range of the actuator.

9. The control method according to claim 6, characterized in that the threshold is set based on the rated current of the actuator driver.

10. The control method according to claim 6, characterized in that the sensor is an acceleration sensor.

11. A sensor that detects vibrations of a vibrating object, An actuator installed on the aforementioned vibrating object and A controller for a vibration suppression device equipped with: An acquisition step of acquiring a detection signal from the aforementioned sensor, A generation step in which an inverted phase waveform is generated by an adaptive algorithm of AFC (Adaptive Feedforward Cancellation) based on the detection signal acquired in the acquisition step, A transmission step which transmits the inverse phase waveform generated in the generation step to the actuator. Make it run, In the generation step, the controller If the index value based on the integral result of the amplitude parameter based on the detection signal is less than or equal to a threshold, a first determination step is performed to determine the first amplitude, which is the amplitude of the inverse phase waveform, based on the integral result, or If the index value based on the integral result of the amplitude parameter exceeds the threshold, a second determination step is taken to determine the second amplitude, which is the amplitude of the inverse phase waveform, based on the integral result up to the point where the threshold is exceeded or immediately before the threshold. A program characterized by causing the execution of a program.

12. In the generation step, the controller A selection step to identify the preceding multiple vibration frequencies, The aforementioned index value is calculated as the sum of the amplitudes of the AFC for each vibration frequency identified in the specified step, and The program according to claim 11, characterized by causing it to execute.

13. The program according to claim 11, characterized in that the threshold is set based on the movable range of the actuator.

14. The program according to claim 11, characterized in that the threshold is set based on the rated current of the actuator driver.

15. The program according to claim 11, characterized in that the sensor is an acceleration sensor.

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