Control parameter generation method, control parameter generation program product and storage medium

Abstract

A control parameter generation method, a control parameter generation program product, and a storage medium for generating a control parameter in accordance with the quality of a conveyed object, includes: a time characteristic acquisition of inputting a scan signal having a time characteristic in which a signal value frequency varies over time into a motor to acquire a motor speed and an elapsed time characteristic; speed processing: calculating a processing speed for performing absolute value processing and low-pass filtering on the motor speed; a minimum value acquisition step of calculating the minimum value of the machining speed of the motor speed for each elapsed time acquired after a predetermined standby time has elapsed from the input of the scanning signal, and acquiring a first time at which the minimum value reaches the minimum value for the first time and the minimum value; inertia calculation: calculating the inertia of the motor based on the motor speed acquired from the lapse of the standby time to a first moment when the minimum value is acquired and a mathematical model; mass calculation, wherein the mass of the conveying object is calculated based on the calculated inertia and the approximation expression; and parameter calculation: calculating a control parameter based on the calculated mass of the conveying object.

Description

Technical Field

[0001] The present invention relates to a control parameter generation method, a control parameter generation program product and a storage medium for controlling a motor of a conveying device. Background Art

[0002] Patent Document 1 discloses a mechanical modeling method for controlling a motor including a mechanical drive mechanism. In Patent Document 1, a command generator generates a sweeping sine wave signal and sends it to a current controller to drive the motor. A detector detects the motor's movement, which includes information about the mechanical movement, and sends it as a response signal to a signal processor. The response signal has a resonant characteristic that depends on the mechanical frequency. The signal processor detects the time and amplitude at which the absolute value of the response signal reaches a maximum, and detects the resonant frequency of the machine based on the relationship between the time and frequency of the sweeping sine wave signal.

[0003] Patent Document 1: Japanese Patent Application Laid-Open No. 2003-348871 Summary of the Invention

[0004] In Patent Document 1, a sine wave signal is scanned across all frequencies and input into a current controller. The corresponding motor motion is then captured and graphed, and the mechanical resonant frequency is calculated by identifying the maximum and minimum values. This requires a large amount of memory to store the response signals over the entire time series, and the resonant frequency detection requires querying all response signal data, resulting in a significant computational load.

[0005] An object of the present invention is to provide a control parameter generation method, a control parameter generation program product, and a storage medium capable of calculating control parameters for controlling a motor of a conveying device at a low load.

[0006] To achieve the above-mentioned object, the present invention provides a control parameter generation method for generating control parameters used by a motor control device of a conveying device for conveying a conveying object in accordance with the mass of the conveying object, the conveying device including a motor, the motor control device for controlling the motor, and a transmission mechanism for transmitting power generated by the motor to the conveying object, the control parameter generation method comprising: a time characteristic acquisition step for inputting a scanning signal into the motor to acquire characteristics of the motor speed and elapsed time of the motor, the scanning signal having a time characteristic in which the frequency of the signal value changes with the elapse of time; a speed processing step for calculating an absolute value of the acquired motor speed; a minimum value acquisition step for calculating the minimum value of the processing speed of the motor speed at each elapsed time obtained after a prescribed standby time from the input of the scanning signal, and acquiring a first moment indicating that the minimum value first reaches the minimum value and the minimum value; an inertia calculation step for calculating the inertia of the motor based on the motor speed acquired during the period from the elapse of the standby time to the first moment at which the minimum value is acquired and a mathematical model; a mass calculation step for calculating the mass of the conveying object based on the calculated inertia and an approximate expression; and a parameter calculation step for calculating the control parameter based on the calculated mass of the conveying object.

[0007] In the control parameter generation method, the processing speed is calculated sequentially by successively acquiring the characteristics of motor speed and elapsed time, converting the motor speed into an absolute value, and performing low-pass filtering. This allows the minimum value to be calculated from the processing speed, thereby calculating the motor inertia based on the motor speed before the update time at which the minimum value was first obtained. The mass of the conveyed object is then calculated from the inertia to calculate the motor control parameters. This control parameter generation method uses less storage capacity and a lower computational load than a method that acquires the characteristics of motor speed and elapsed time over the entire period and then calculates the parameters based on the entire period after the acquisition is completed, thus allowing implementation on inexpensive hardware.

[0008] In the control parameter generation method of the present invention, in the inertia calculation step, the inertia is calculated using a successive least squares method so as to minimize the difference between the motor speed and the motor speed estimate calculated in advance from the mathematical model. In the control parameter generation method, by successively calculating the inertia using the successive least squares method, less memory capacity and a lower computational load are required than by recalculating the inertia from scratch each time the motor speed is acquired, thereby enabling implementation on inexpensive hardware.

[0009] The control parameter generation method of the present invention further includes: a mass display step for displaying the mass of the conveying object calculated in the mass calculation step; and a judgment input step for receiving input regarding whether the displayed mass is appropriate, and terminating the calculation of the control parameters in the parameter calculation step if a judgment is input regarding inappropriateness of the mass. In the control parameter generation method, the user determines whether the calculated mass result is appropriate. If the calculated mass is significantly different from the mass of the conveying object due to interference, for example, the calculation of the control parameters based on the mass can be terminated, thereby preventing the motor from being controlled with inappropriate parameters.

[0010] The control parameter generation method of the present invention further includes a resonance frequency acquisition step for calculating and acquiring the frequency input to the motor at the first moment when the processing speed reaches the minimum value based on the time characteristics of the scanning signal, as the resonance frequency of the conveying object. In the parameter calculation step, the control parameter is calculated based on the calculated resonance frequency of the conveying object and the mass. The calculated resonance frequency of the conveying object corresponds to the anti-resonance frequency of the motor. Therefore, in the control parameter generation method, for example, by calculating the control parameter so that the closed-loop gain characteristic of the motor speed is attenuated at the resonance frequency of the conveying object, the resonance of the conveying object can be suppressed, thereby achieving control of the motor and stably conveying the conveying object.

[0011] The control parameter generation method of the present invention further includes: a maximum value acquisition step for calculating the maximum value of the processing speed of the motor speed at each elapsed time after the waiting time has elapsed since the input of the scanning signal, and acquiring a second time instant indicating the first time the maximum value reaches the maximum value and the maximum value; and a motor resonance frequency acquisition step for calculating and acquiring, based on the time characteristics of the scanning signal, the frequency input to the motor at the second time instant when the processing speed reaches the maximum value as the resonance frequency of the motor, wherein in the parameter calculation step, the control parameters are calculated based on the calculated resonance frequency of the conveying object, the resonance frequency of the motor, and the mass. In the control parameter generation method, for example, by calculating the control parameters so that the closed-loop gain characteristics of the motor speed are attenuated at the resonance frequency of the conveying object and the resonance frequency of the motor, the resonance of the conveying object and the motor can be suppressed, thereby achieving control of the motor and ensuring stable conveyance of the conveying object.

[0012] In the control parameter generation method of the present invention, the minimum value acquisition step sequentially calculates the minimum value of the processing speed of the motor speed, updates the minimum value, and defines the value that has not been updated for a predetermined first period as the minimum value. In the control parameter generation method, by acquiring the minimum value based on the sequentially calculated minimum values ​​of the processing speed, compared to acquiring the characteristics of the motor speed and elapsed time over the entire period and calculating the processing speed after the acquisition is completed and acquiring its minimum value, the control parameter generation method utilizes less storage capacity and a lower computational load, thereby enabling implementation on inexpensive hardware.

[0013] The control parameter generation method of the present invention includes the following steps: the minimum value acquisition step sequentially calculates the minimum value of the motor speed of the processing speed, updates the minimum value, and sets the value that has not been updated for more than a predetermined first time as the minimum value; the maximum value acquisition step sequentially calculates the maximum value of the motor speed of the processing speed, updates the maximum value, and sets the value that has not been updated for more than a predetermined second time as the maximum value; the control parameter generation method further includes: a maximum value initialization step for initializing the maximum value when the first time has elapsed from the first moment; and a minimum value initialization step for initializing the minimum value when the second time has elapsed from the second moment. In the control parameter generation method, by acquiring the minimum and maximum values ​​based on the sequentially calculated minimum and maximum values ​​of the processing speed, less memory capacity and a lower computational load are used than in a method of acquiring the characteristics of the motor speed and the elapsed time over the entire period and calculating the processing speed and acquiring its minimum value after the acquisition is completed, thereby enabling implementation on inexpensive hardware.

[0014] In the control parameter generation method of the present invention, the conveying device is used in a sewing device, the conveying object is a holding mechanism that holds a workpiece, the transmission mechanism is a feed mechanism that causes the holding mechanism to move relative to a needle bar mechanism that drives a needle bar, and the motor is a motor that drives the feed mechanism. By controlling the motor using the control parameters generated by the control parameter generation method, the sewing device can suppress resonance of the holding mechanism that secures the workpiece, thereby stably conveying the holding mechanism including the workpiece.

[0015] To achieve the above-mentioned object, the present invention provides a control parameter generation program product for generating control parameters used by a motor control device of a conveying device for conveying a conveying object according to the mass of the conveying object, the conveying device including a motor, the motor control device for controlling the motor, and a transmission mechanism for transmitting power generated by the motor to the conveying object, the control parameter generation program product causing a computer of the conveying device to execute: a time characteristic acquisition step for inputting a scanning signal into the motor to acquire characteristics of the motor speed and elapsed time of the motor, the scanning signal having a time characteristic in which the frequency of the signal value changes with the elapse of time; a speed processing step for calculating the speed of the acquired motor. The processing speed is obtained by converting the speed to an absolute value and performing low-pass filtering; a minimum value acquisition step is used to calculate the minimum value of the processing speed of the motor speed at each elapsed time after a predetermined waiting time has passed since the input of the scanning signal, and obtain the first moment when the minimum value first reaches the minimum value and the minimum value; an inertia calculation step is used to calculate the inertia of the motor based on the motor speed acquired between the waiting time and the first moment when the minimum value is acquired and a mathematical model; a mass calculation step is used to calculate the mass of the conveying object based on the calculated inertia and an approximate expression; and a parameter calculation step is used to calculate the control parameter based on the calculated mass of the conveying object. Therefore, the same technical effects as described above are achieved.

[0016] In order to achieve the above-mentioned object, the present invention provides a storage medium storing a program, wherein the program is used to generate control parameters used by a motor control device of a conveying device that conveys a conveying object in accordance with the mass of the conveying object, the conveying device including a motor, the motor control device for controlling the motor, and a transmission mechanism for transmitting power generated by the motor to the conveying object, the program causing a computer of the conveying device to execute: a time characteristic acquisition step for inputting a scanning signal into the motor to acquire characteristics of the motor speed and elapsed time of the motor, the scanning signal having a time characteristic in which the frequency of the signal value changes as time passes; a speed processing step for calculating the acquired motor speed The processing speed is converted to an absolute value and low-pass filtered; a minimum value acquisition step is used to calculate the minimum value of the processing speed of the motor speed at each elapsed time after a predetermined waiting time has passed since the input of the scanning signal, and obtain the first moment when the minimum value first reaches the minimum value and the minimum value; an inertia calculation step is used to calculate the inertia of the motor based on the motor speed acquired between the waiting time and the first moment when the minimum value is acquired and a mathematical model; a mass calculation step is used to calculate the mass of the conveying object based on the calculated inertia and an approximate expression; and a parameter calculation step is used to calculate the control parameter based on the calculated mass of the conveying object. Therefore, the same technical effects as described above are achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a perspective view of the sewing machine 1 .

[0018] Figure 2 1 is a block diagram showing the electrical configuration of the sewing machine 1 .

[0019] Figure 3 4 is a diagram showing a servo control system of the drive circuit 43 .

[0020] Figure 4 This is a diagram illustrating the control parameter generation process.

[0021] Figure 5 This is a continuation of the diagram explaining the control parameter generation process.

[0022] Figure 6 This is a flowchart of the control parameter generation process.

[0023] Figure 7 This is a flowchart of the inertia and resonance frequency calculation process.

[0024] Figure 8 This is a flowchart of the inertia calculation process.

[0025] Figure 9 4 is a flowchart of the resonance frequency calculation process.

[0026] Figure 10 This is a flowchart of a modified example of the resonance frequency calculation process.

[0027] Figure 11 This is a continuation of the flowchart of a modification of the resonance frequency calculation process. DETAILED DESCRIPTION

[0028] The following describes embodiments of the present invention with reference to the accompanying drawings. The accompanying drawings illustrate the technical features of the present invention. The device structures and other aspects described are not intended to be limiting and are merely illustrative examples. The following description uses arrows in the drawings to indicate left-right, front-back, and up-down directions.

[0029] Figure 1 The sewing machine 1 shown is an example of a conveying device that generates control parameters using the control parameter generation method of the present invention and controls the driving of a motor using the control parameters to convey a conveying object. The sewing machine 1 is a gate-type sewing machine that can sew sewn objects. The sewing machine 1 includes: a base 2, a pair of support parts 3 and 4, a synchronization mechanism 31 (see Figure 2 ), conveying mechanism 9 (refer to Figure 2 ), holding mechanism 8, beam portion 5, needle bar mechanism 6, shuttle mechanism 7, feed mechanism 10 (refer to Figure 2 ), and operating unit 15.

[0030] The base 2 includes a base 21, a pair of front and rear guide rails, a frame 22, and a pair of lower guide rails. The base 21 is generally rectangular. A horizontally extending, flat retaining surface 21A is formed on the upper surface of the base 21. A retaining plate 23 is provided at the front end of the base 21, extending forward along the retaining surface 21A. A accordion 21R is provided near the right end of the retaining surface 21A, extending in the front-to-back direction. A accordion 21L is provided near the left end of the retaining surface 21A, extending in the front-to-back direction. The pair of front and rear guide rails are provided below the accordions 21L and 21R. The pair of front and rear guide rails support the retaining mechanism 8 (described later) in a manner that allows for forward and backward movement. The accordions 21R and 21L extend and retract as the retaining mechanism 8 reciprocates back and forth. The frame 22 is a lattice-like structure that supports the base 21 from below. The pair of lower guide rails extend in the left-right direction below the base 21. The pair of lower guide rails support the shuttle mechanism 7 (described later) in a manner that allows for left-right movement. The base portion 2 has a lower belt, a lower spline shaft, and a shuttle mechanism 7 , which will be described later, arranged below the base portion 21 .

[0031] The pair of support columns 3 and 4 are each roughly quadrangular in shape. Support column 3 extends upward from the right end of base 21 of base 2, slightly forward of the center in the front-to-back direction. Support column 3 is located to the right of bellows 21R in the left-to-right direction. Support column 4 extends upward from the left end of base 21 of base 2, slightly forward of the center in the front-to-back direction. Support column 4 is located to the left of bellows 21L in the left-to-right direction. Support columns 3 and 4 are spaced apart from each other in the left-to-right direction.

[0032] Synchronous mechanism 31 (see Figure 2 ) is a mechanism for synchronously driving the needle bar mechanism 6 and the shuttle mechanism 7, and has a main motor 32 (refer to Figure 2 ), upper spline shaft, lower spline shaft, transmission mechanism. The main motor 32 is supported by the support part 3. The upper spline shaft and the lower spline shaft extend in the left-right direction between the support parts 3 and 4. The transmission mechanism of the synchronization mechanism 31 is housed in the support part 3, and transmits the power of the main motor 32 to the upper spline shaft and the lower spline shaft. The conveying mechanism 9 (refer to Figure 2 ) can move the shuttle mechanism 7 and the needle bar mechanism 6 in the left and right directions parallel to the horizontal direction relative to the holding mechanism 8 holding the sewn object, and has an X motor 95 (refer to Figure 2 ), upper belt, lower belt, and transmission mechanism. The X-motor 95 is a servo motor supported by the support column 4. The transmission mechanism of the conveyor mechanism 9 is housed in the support column 4 and transmits the power of the X-motor 95 to the upper and lower belts. The upper belt is fixed to the back of the needle bar mechanism 6. The lower belt is fixed to the back of the shuttle mechanism 7. The shuttle mechanism 7 and the needle bar mechanism 6 move left and right with the rotation of the X-motor 95.

[0033] The beam portion 5 is mounted between the pillar portions 3 and 4. The beam portion 5 extends in the left-right direction between a pair of pillar portions 3 and 4. The beam portion 5 has a shell 51. The shell 51 extends between the upper end portion and the rear end portion of each of the pillar portions 3 and 4. A pair of upper guide rails are provided in the space enclosed by the pillar portions 3, 4 and the shell 51. The upper guide rails are rod-shaped and mounted between the pillar portions 3 and 4. The upper guide rails support the needle bar mechanism 6 in a manner that allows it to move in the left-right direction. The serpentine 52 is provided between the front end portions of each of the pillar portions 3 and 4 and the shell 51 and the left and right ends of the needle bar mechanism 6. The serpentine 52 covers the front side of the upper guide rail, the upper belt, and the upper spline shaft. The serpentine 52 expands and contracts as the needle bar mechanism 6 reciprocates in the left-right direction along the upper guide rail.

[0034] The needle bar mechanism 6 is provided on the front side of the beam portion 5. The needle bar mechanism 6 comprises a needle bar 61, a presser foot 62, a thread take-up mechanism 63, a thread clamping device 64, an upper shaft, etc. The needle bar 61 extends in the vertical direction, and a sewing needle can be mounted on the lower end portion. The needle bar 61 can move in the vertical direction. The presser foot 62 has a through hole for the sewing needle to pass through as the needle bar 61 moves, pressing the sewn object from the upper side. The thread take-up mechanism 63 operates as the needle bar 61 moves in the vertical direction, lifting the upper thread. The thread clamping device 64 adjusts the tension of the upper thread. The back of the needle bar mechanism 6 is connected to the upper belt. The upper guide rail in the beam portion 5 supports the needle bar mechanism 6 in a manner that allows it to move in the left-right direction. Therefore, the needle bar mechanism 6 can move in the left-right direction along the front end portion of the beam portion 5. The upper shaft extends in the left-right direction within the needle bar mechanism 6. The transmission mechanism of the synchronization mechanism 31 transmits the power of the upper spline shaft to the upper shaft. The needle bar 61 extends in the vertical direction, is connected to the upper shaft, and moves up and down as the main motor 32 is driven.

[0035] The shuttle mechanism 7 is arranged below the needle bar mechanism 6 and inside the machine base 2. The shuttle mechanism 7 has a lower shaft, a shuttle, and a transmission mechanism. The housing is box-shaped, and a needle plate is provided at the upper left end. The needle plate has a needle hole for inserting a sewing needle. The needle hole is located below the needle bar 61. The back of the shuttle mechanism 7 is connected to the lower belt. The shuttle mechanism 7 passes through the lower spline shaft. The shuttle mechanism 7 is supported by the lower guide rail. The shuttle mechanism 7 moves left and right along the lower guide rail synchronously with the needle bar mechanism 6 as driven by the conveying mechanism 9. The transmission mechanism of the shuttle mechanism 7 transmits the power of the lower spline shaft to the lower shaft. The shuttle is connected to the lower shaft and rotates synchronously with the up and down movement of the needle bar 61 as driven by the main motor 32.

[0036] Feed mechanism 10 (see Figure 2 ) A Y motor 96 is provided below the holding plate 23 (see Figure 2 ), connecting parts 11, 12, a transmission mechanism, and a pair of belts. The Y motor 96 is a servo motor. The lower left end of the connecting part 11 is arranged on the front and rear guide rails on the left side of the machine base 2. The lower right end of the connecting part 12 is arranged on the front and rear guide rails on the right side of the machine base 2. The connecting parts 11, 12 are connected to the holding mechanism 8. The holding mechanism 8 is capable of holding the sewn object. The transmission mechanism of the feed mechanism 10 transmits the power of the Y motor 96 to the pair of belts fixed on the connecting parts 11, 12. The holding mechanism 8 moves along the pair of front and rear guide rails of the machine base 2 as the Y motor 96 rotates, and moves back and forth relative to the needle bar mechanism 6 and the shuttle mechanism 7. The holding mechanism 8 has an upper frame 81, a lower frame 82, and cylinders 83, 84. The upper frame 81 and the lower frame 82 are rectangular frames when viewed from above, and are used to clamp the sewn object. The upper frame 81 is opened and closed up and down relative to the lower frame 82 with the cylinders 83, 84 as the driving source.

[0037] The operating unit 15 is supported by the left end of the base 21. The operating unit 15 includes a switch group 13 and a display unit 14. The switch group 13 inputs various instructions according to the operator's operation. The display unit 14 is a liquid crystal display that can display various images.

[0038] Reference Figure 2 , explaining the electrical structure of the sewing machine 1. The control unit 25 of the sewing machine 1 has a CPU 16, a ROM 17, a RAM 18, a storage device 19, an input / output interface (I / O) 20, and drive circuits 41 to 45. The CPU 16 controls the operation of the sewing machine 1 as a whole. The ROM 17 pre-stores programs for executing various processes, etc. The RAM 18 temporarily stores various information generated when executing various processes. The storage device 19 is a non-volatile storage device that stores various setting values. The storage device 19 stores a program for executing control parameter generation processing. The program is provided via a storage medium such as a DVD-ROM or a flash memory, is connected to the sewing machine 1 via a reading device connected to an external interface not shown in the figure, and is installed in the storage device 19.

[0039] The drive circuits 41 to 45, encoders 56 to 58, and the switch group 13 are connected to the I / O 20. The drive circuit 41 is connected to the main motor 32 of the synchronization mechanism 31 and drives the main motor 32 according to the control instructions of the CPU 16. The drive circuit 42 is connected to the X motor 95 of the conveying mechanism 9 and drives the X motor 95 according to the control instructions of the CPU 16. The drive circuit 43 is connected to the Y motor 96 of the feed mechanism 10 and drives the Y motor 96 according to the control instructions of the CPU 16. The drive circuit 44 is connected to the cylinders 83 and 84 of the holding mechanism 8 and drives the cylinders 83 and 84 according to the control instructions of the CPU 16. The drive circuit 45 is connected to the display unit 14 and displays various information on the display unit 14 according to the control instructions of the CPU 16.

[0040] Encoder 56 detects the rotational position and rotational speed of the output shaft of main motor 32 and inputs the detection results to I / O 20. The detection results of encoder 56 indicate the vertical position of needle bar 61 and sewing needle. Encoder 57 detects the rotational direction, rotational position, and rotational speed of the output shaft of X motor 95 and inputs the detection results to I / O 20. The detection results of encoder 57 indicate the left-right position of needle bar mechanism 6 and shuttle mechanism 7. Encoder 58 detects the rotational direction, rotational position, and rotational speed of the output shaft of Y motor 96 and inputs the detection results to I / O 20. The detection results of encoder 58 indicate the front-back position of holding mechanism 8. Switch group 13 detects various indications and inputs the detection results to I / O 20.

[0041] The control parameter generation method of the present invention is used, for example, to generate control parameters for driving the Y motor 96 of the feed mechanism 10, which is used to move the holding mechanism 8 holding the sewn material in the front-to-back direction. The drive circuit 43 that drives the Y motor 96 constitutes a servo control system. By setting the velocity integral gain and velocity proportional gain as control parameters, the drive circuit 43 attenuates the gain characteristics of the velocity closed-loop transfer function at the resonant frequency of the holding mechanism 8, thereby suppressing vibration of the holding mechanism 8.

[0042] Reference Figure 3 , describing the servo control system of the drive circuit 43. The encoder 58 of the Y motor 96 outputs the current position information of the Y motor 96 as a position feedback signal to the adder 72. The CPU 16 of the sewing machine 1 generates a position command based on the sewing program to move the holding mechanism 8 in the front-to-back direction when sewing a workpiece. The command is then output to the drive circuit 43. The drive circuit 43 controls the command current output to the Y motor 96 based on the position command, thereby operating the Y motor 96.

[0043] Adder 72 of drive circuit 43 calculates the position deviation between the position command and the position feedback signal, and multiplies this position deviation by the position proportional gain to calculate a speed command. Adder 73 calculates the speed deviation between the obtained speed command, the speed command output from CPU 16, and the actual speed (i.e., the speed feedback signal obtained by differentiating the position feedback signal via differentiator 74). Adder 77 generates a command current by adding the following: the current command obtained by multiplying the speed deviation calculated by adder 73 by the speed proportional gain; and the current command obtained by integrating the speed deviation via integrator 75 and multiplying the integrated result by the speed integral gain. Current control unit 78 adds the command current generated by adder 77 to the command current obtained by multiplying the acceleration command output from CPU 16 by the acceleration FF gain, and controls the current supply to Y motor 96.

[0044] The following describes the flow of generating control parameters using the control parameter generation method. In order to suppress the vibration of the holding mechanism 8 caused by the resonance of the Y motor 96, a verification test was conducted to detect the resonance frequency of the holding mechanism 8. In the verification test, a scanning sine wave signal with a constant amplitude and positive and negative values ​​and a frequency that gradually changes over time after the output starts was input to the Y motor 96 as the command current of the Y motor 96 (see Figure 4 (A) in FIG. 1 ). The speed of the Y motor 96 (motor speed) was measured over time (refer to Figure 4 (B)) and the speed of the holding mechanism 8 (mechanism speed) that changes with time (refer to Figure 4By performing a fast Fourier transform on these data, the relationship between the gain and frequency of the motor speed obtained by inputting the command current to the Y motor 96 (motor speed gain characteristics) can be obtained (refer to Figure 4 (D)) and the relationship between the gain and frequency of the mechanism speed of the holding mechanism 8 driven by the power of the Y motor 96 (mechanism speed gain characteristics) (refer to Figure 4 (E) in FIG. 1 ). The verification test results show that the resonant frequency of the holding mechanism 8 and the anti-resonant frequency of the Y motor 96 are substantially consistent.

[0045] Each time the sewing material is changed according to the sewing task, the mass of the sewing material and the holding mechanism 8 that holds it changes, causing the resonant frequency of the holding mechanism 8 to change. Therefore, the sewing machine 1 needs to regenerate control parameters every time the sewing task is changed. Generating control parameters requires storing the speed data measured during the entire input period of the sweeping sinusoidal wave signal, and performing a fast Fourier transform places an extremely high computational load on the CPU 16. Therefore, calculating the resonant frequency of the holding mechanism 8 using the steps performed in the verification test is impractical.

[0046] Therefore, the control parameter generation method of the present invention uses the algorithms described below (1) to (5) to estimate the resonant frequency of the holding mechanism 8 holding the sewn article. At the same time, the algorithms described in (11) to (16) are used to estimate the mass of the holding mechanism 8. Then, the control parameters are generated based on the mass, thereby reducing the computational load of the CPU 16.

[0047] [Estimation of resonance frequency]

[0048] (1) Generate a scanning sine wave signal and input it to the Y motor 96.

[0049] (2) Standby mode is used from the time Y motor 96 starts driving until a predetermined standby time (e.g., 3 seconds) has elapsed. Verification tests have shown that the frequency that changes between the time the scanning sinusoidal wave signal starts outputting and the predetermined time elapses is different from the resonant frequency of the holding mechanism 8. Therefore, by not performing any calculations from the time Y motor 96 starts driving until the predetermined time has elapsed, the CPU 16 can further reduce its computational load.

[0050] (3) After the Y motor 96 starts driving and the waiting time has passed, the calculation is started, the motor speed calculated based on the detection result of the encoder 58 is converted to an absolute value, and a low-pass filter (LPF) is applied (see Figure 5 (A) in the figure). This allows the maximum and minimum values ​​of the motor speed to be calculated using positive values. The absolute value of the motor speed and the application of the LPF are performed successively, so Figure 5The motor speed shown in (A) is a schematic diagram showing the absolute value of the motor speed when a sweeping sine wave signal is input for a full time (e.g., 15 seconds) and after LPF application.

[0051] (4) Calculate the minimum value of the processed motor speed one by one (refer to Figure 5 (B) in the figure). If the minimum value is updated, the update time (the time elapsed since the motor started) is obtained each time. If the minimum value is not updated and a predetermined first time (e.g., 1 second) has passed, the last updated minimum value is regarded as the minimum value, and its update time (e.g., 6.6 seconds) is stored.

[0052] (5) The frequency of the sweep sine wave signal input at the stored minimum value update time is the anti-resonance frequency of the Y motor 96, and according to the verification test results, it is also the resonant frequency of the holding mechanism 8.

[0053] [Estimation of mass]

[0054] (11) Generate a scanning sine wave signal and input it to the Y motor 96.

[0055] (12) The system waits until a predetermined time (eg, 3 seconds) has elapsed since the Y motor 96 started driving.

[0056] (13) The mathematical model for estimating the motor speed based on the command current of the Y motor 96 is set to 1 / Js, and the motor speed estimate is calculated. Here, J is the inertia of the Y motor 96, and s is the Laplace operator.

[0057] (14) The inertia J is calculated using the successive least squares method so that the difference between the motor speed calculated based on the detection result of the encoder 58 and the motor speed estimate calculated in (13) is small.

[0058] (15) The calculation of the inertia J is completed at the update time when the minimum value (the anti-resonance frequency of the Y motor 96) is detected in (4).

[0059] (16) Perform a verification test in advance to find the approximate relationship between the mass M of the holding mechanism 8 and the inertia J of the Y motor 96, "M = aJ + b" (see Figure 5 (C) in (15). Substitute the inertia J finally calculated in (15) into the approximate formula to calculate the mass M of the holding mechanism 8 (including the mass of the sewn article).

[0060] If the estimated mass M of the holding mechanism 8 is close to the actual mass of the holding mechanism 8, the estimated value of the inertia J is reliable. When the drive circuit 43 controls the current supply to the Y motor 96, it multiplies the estimated value of the inertia J by the acceleration command, which serves as the acceleration FF gain, to generate a command current that matches the mass of the holding mechanism 8. The velocity integral gain and velocity proportional gain are then calculated based on the velocity closed-loop transfer function and set as control parameters.

[0061] Reference Figures 6 to 9 , which explains the control parameter generation process performed in the sewing machine 1. For example, when the user changes the product being made in the sewing machine 1 and starts making another product, the sewing program is changed, and a different workpiece is placed on the holding mechanism 8 for sewing. Due to the change of the workpiece, the total mass of the workpiece and the holding mechanism 8 will be different from before. The change in total mass will cause the resonant frequency of the holding mechanism 8 to change, and therefore, the holding mechanism 8 may vibrate during sewing. Therefore, when the user changes the sewing program, he or she instructs the execution of the maintenance action by operating the switch group 13 of the operating unit 15.

[0062] like Figure 6 As shown, the CPU 16 of the sewing machine 1 reads the program from the ROM 17 and begins the control parameter generation process. The CPU 16 determines the waveform of the sweeping sine wave signal input to the Y motor 96 (S11). In other words, the CPU 16 determines parameters such as the amplitude of the sweeping sine wave, the output time, the frequency at the start and end of the output. The CPU 16 then performs the inertia and resonant frequency calculation process (S12).

[0063] like Figure 7 As shown, the CPU 16 starts to input the scanning sine wave signal that determines the waveform to the Y motor 96 (S21) and starts to count the elapsed time (S22). The elapsed time is the time that has passed since the input of the scanning sine wave signal. The CPU 16 stands by (S23: No) until the elapsed time exceeds the standby time. The standby time is the standby time (for example, 3 seconds) from the input of the scanning sine wave signal to the start of the calculation by the CPU 16. When the standby time has passed since the input of the scanning sine wave signal and the elapsed time exceeds the standby time (S23: Yes), the CPU 16 obtains the time characteristic of the Y motor 96 (S24). The time characteristic is the motor speed of the Y motor 96 corresponding to the elapsed time.

[0064] The CPU 16 executes the inertia calculation process (S26). Figure 8As shown, when the predetermined calculation end time has passed (S31: YES), the CPU 16 stops calculating the inertia and returns to the inertia and resonant frequency calculation process. In this embodiment, the CPU 16 terminates the inertia calculation when the anti-resonant frequency of the Y motor 96 is calculated (extracted). However, the inertia calculation may also be terminated when a sufficient number of calculations are performed within the elapsed time.

[0065] If the specified calculation end time has not passed (S31: No), the CPU 16 calculates the inertia using the successive least squares method (S32). As previously described, the CPU 16 calculates the inertia using the successive least squares method to minimize the difference between the motor speed estimate calculated using the mathematical model based on the command current and the actual measured motor speed. After the calculation, the CPU 16 returns to the inertia and resonant frequency calculation process.

[0066] like Figure 7 As shown in FIG. 1 , the CPU 16 executes the resonance frequency calculation process (S27). Figure 9 As shown, the CPU 16 converts the motor speed obtained as a time characteristic into an absolute value and applies a low-pass filter (S41). This allows the minimum value of the motor speed to be obtained as a positive value. For convenience, the motor speed converted into an absolute value and applied with a low-pass filter is referred to as the processing speed. The CPU 16 determines whether the processing speed has updated the minimum value (S42). If the processing speed has updated the minimum value (S42: Yes), the CPU 16 stores the minimum value and the update time in the storage device 19 (S43). The update time is the elapsed time when the processing speed updates the minimum value. The CPU 16 resets the non-update time (S44) and returns to the inertia and resonance frequency calculation process. The non-update time counts the time that has passed when the minimum value is not updated. Therefore, when the minimum value is updated, the non-update time is reset.

[0067] like Figure 7 As shown, if the resonant frequency of the Y motor 96 is not extracted in the resonant frequency calculation process (S28: No), and the full-time (e.g., 15-second) signal (full waveform) input of the sweep sine wave signal is not completed (S29: No), the process returns to S24. The CPU 16 obtains the time characteristics of the next timing (S24) and repeats the inertia calculation process (S26) and the resonant frequency calculation process (S27) for the obtained motor speed.

[0068] like Figure 9As shown, in S42 of the resonance frequency calculation process, if the minimum machining speed value has not been updated (S42: No), the CPU 16 begins counting the non-update time (S46). Therefore, when the minimum machining speed value is updated, the non-update time is reset; when the minimum value has not been updated, the non-update time continues. If the non-update time has not exceeded a predetermined first time (S47: No), the CPU 16 returns to the inertia and resonance frequency calculation process. The first time is a reference time, for example, one second, for the duration that the minimum value has not been updated.

[0069] If the non-update time exceeds the first time (S47: YES), the CPU 16 extracts the frequency corresponding to the elapsed time equal to the update time stored in the storage device 19 from the scan waveform (S48). Specifically, the update time in this case is the time when the updating of the minimum value stops. Furthermore, the stored minimum value is the minimum value among the successively updated minimum values. The extracted frequency corresponds to the anti-resonance frequency of the Y motor 96, that is, the resonant frequency of the holding mechanism 8. The CPU 16 stores the resonant frequency of the holding mechanism 8 in the storage device 19. The CPU 16 returns to the inertia and resonant frequency calculation process.

[0070] like Figure 7 As shown, the CPU 16 extracts the resonant frequency of the Y motor 96 during the resonant frequency calculation process (S28: Yes), and thus returns to the control parameter generation process. If the scan end time is reached (S29: Yes) while the minimum value has not been updated and the non-update time has not exceeded the specified time, the CPU 16 also returns to the control parameter generation process. The scan end time is when the full-time input of the scanning sine wave signal is completed, that is, when the elapsed time reaches, for example, 15 seconds.

[0071] like Figure 6 As shown, the CPU 16 calculates the mass of the holding mechanism 8 by substituting the inertia calculated by the successive least squares method into the approximate formula (S13). The CPU 16 displays the mass of the holding mechanism 8 on the display unit 14 of the operation unit 15 (S14). The displayed mass includes the mass of the sewn material held by the holding mechanism 8.

[0072] The user determines whether the displayed quality is appropriate and inputs the determination result by operating the switch group 13. If the CPU 16 determines that the displayed quality is inappropriate based on the user's operation (S16: No), the CPU 16 terminates the control parameter generation process without changing the control parameters. If the quality is determined to be appropriate (S16: Yes), the CPU 16 calculates the control gains (speed proportional gain and speed integral gain) based on the speed closed-loop transfer function (S17). The CPU 16 displays a query on the display unit 14 of the operation unit 15 asking whether to change the control parameters using the calculated control gains. If the user chooses not to change the control parameters (S18: No), the CPU 16 terminates the control parameter generation process without changing the control parameters. If the user chooses to change the control parameters (S18: Yes), the CPU 16 sets the calculated control gains as the control parameters (S19) and terminates the control parameter generation process.

[0073] As described above, in the control parameter generation process, the motor speed and elapsed time characteristics are sequentially acquired, the motor speed is converted to an absolute value, and low-pass filtered to sequentially calculate the processing speed. This allows the minimum value to be calculated from the processing speed, thereby calculating the inertia J of the Y motor 96 based on the motor speed immediately before the update time at which the minimum value is first obtained. Then, the control parameters of the Y motor 96 are calculated by calculating the mass M of the holding mechanism 8 including the sewn article from the inertia J. This control parameter generation method uses less storage capacity and a lower computational load than a method in which the motor speed and elapsed time characteristics are acquired over the entire period and the parameters are calculated based on the entire period after the acquisition is completed. Therefore, it can be implemented on inexpensive hardware.

[0074] In the control parameter generation process, the inertia J is calculated successively using the successive least squares method. This uses less storage capacity and lowers the computational load than calculating the inertia from scratch each time the motor speed is acquired, and can therefore be implemented on inexpensive hardware.

[0075] In the control parameter generation process, the user determines whether the calculation result of the mass M is appropriate. When a mass significantly different from the mass M of the retaining mechanism 8 including the sewn object is calculated due to interference, etc., the calculation of the control parameters based on the mass can be terminated, thereby avoiding the Y motor 96 from being controlled with inappropriate parameters.

[0076] The calculated resonant frequency of the holding mechanism 8 including the sewn article corresponds to the anti-resonant frequency of the Y motor 96. Therefore, in the control parameter generation process, for example, by calculating the control parameters so that the closed-loop gain characteristics of the motor speed are attenuated at the resonant frequency of the holding mechanism 8 including the sewn article, the resonance of the holding mechanism 8 including the sewn article can be suppressed, thereby achieving control of the motor so that the holding mechanism 8 including the sewn article can be stably conveyed.

[0077] By controlling the Y motor 96 using the control parameters generated by the control parameter generation process, the sewing machine 1 can suppress the resonance of the holding mechanism 8 including the sewn object and stably convey the holding mechanism 8 including the sewn object.

[0078] In addition, in the control parameter generation process, by obtaining the minimum value based on the minimum value of the processing speed calculated successively, less storage capacity and lower computational load are used compared to the case where the characteristics of the motor speed and the elapsed time are obtained during the entire period and the processing speed is calculated and its minimum value is obtained after the acquisition is completed, so it can be implemented on inexpensive hardware.

[0079] In the above description, the Y motor 96 is an example of the "motor" of the present invention. The drive circuit 43 is an example of the "motor control device" of the present invention. The sewing machine 1 is an example of the "conveyance device" and "sewing device" of the present invention. The CPU 16 that executes the S24 process is an example of the "time characteristic acquisition step" of the present invention. The CPU 16 that executes the S41 process is an example of the "speed processing step" of the present invention. The CPU 16 that executes the S43 process is an example of the "minimum value acquisition step" of the present invention. The CPU 16 that executes the S32 process is an example of the "inertia calculation step" of the present invention. The CPU 16 that executes the S13 process is an example of the "mass calculation step" of the present invention. The CPU 16 that executes the S17 process is an example of the "parameter calculation step" of the present invention.

[0080] The CPU 16 executing S14 is an example of the "quality presentation step" of the present invention. The CPU 16 executing S16 is an example of the "judgment input step" of the present invention. The CPU 16 executing S48 is an example of the "resonance frequency acquisition step" of the present invention.

[0081] The present invention is not limited to the above-mentioned embodiment, and various changes can be made. In the above-mentioned embodiment, the calculation of the resonance frequency of the holding mechanism 8 is ended when the minimum value of the processing speed is obtained as the minimum value, but the resonance frequency of the holding mechanism 8 at two or more different frequencies can also be calculated. In addition, the resonance frequency of the Y motor 96 can be calculated based on the maximum value of the processing speed, and similarly, the resonance frequency of the Y motor 96 at two or more different frequencies can be calculated. Specifically, as Figure 10 As shown, when executing the modified example of the resonance frequency calculation process, the CPU 16 converts the motor speed acquired as the time characteristic in S24 into an absolute value and applies a low-pass filter (S61).

[0082] The CPU 16 determines whether the minimum value update setting has been set (S62). In a modified example of the resonance frequency calculation process, the minimum and maximum values ​​of the processing speed are calculated alternately, and which value is calculated is determined by setting the minimum value update setting or the maximum value update setting as the mode setting. By default, the minimum value update setting is set. If the mode setting is the minimum value update setting (S62: Yes), the CPU 16 determines whether the processing speed has been updated to the minimum value (S71). If the processing speed has been updated to the minimum value (S71: Yes), the CPU 16 stores the minimum value and the minimum value update time in the storage device 19 (S72). The CPU 16 resets the minimum value non-update time (S73) and returns to the inertia and resonance frequency calculation process.

[0083] In S71, if the minimum value of the machining speed has not been updated (S71: No), the CPU 16 counts the minimum value non-update time (S74). If the minimum value non-update time has not exceeded the first time (S76: No), the CPU 16 returns to the inertia and resonant frequency calculation process. If the minimum value non-update time has exceeded the first time (S76: Yes), the CPU 16 extracts the frequency corresponding to the same elapsed time as the minimum value update time stored in the storage device 19 from the scan waveform (S77). The extracted frequency corresponds to the anti-resonance frequency of the Y motor 96, that is, the resonant frequency of the holding mechanism 8. The CPU 16 stores the Nth resonant frequency of the holding mechanism 8 in the storage device 19. N is a variable, and in the initial setting, N=1. The CPU 16 resets the maximum value and increases the value of N by 1 (S78). The CPU 16 changes the mode setting to the maximum value update setting (S79) and returns to the inertia and resonant frequency calculation process.

[0084] If the mode setting is the maximum value update setting (S62: No), as Figure 11 As shown, the CPU 16 determines whether the maximum value of the machining speed has been updated (S81). If the machining speed has been updated (S81: Yes), the CPU 16 stores the maximum value and the maximum value update time in the storage device 19 (S82). The CPU 16 resets the maximum value non-update time (S83) and returns to the inertia and resonance frequency calculation process.

[0085] In S81, if the maximum processing speed has not been updated (S81: No), the CPU 16 counts the maximum non-update time (S84). If the maximum non-update time does not exceed a predetermined second time (e.g., 1 second) (S86: No), the CPU 16 returns to the inertia and resonant frequency calculation process. If the maximum non-update time exceeds the second time (S86: Yes), the CPU 16 extracts the frequency corresponding to the same elapsed time as the maximum update time stored in the storage device 19 from the scan waveform (S87). The extracted frequency corresponds to the resonant frequency of the Y motor 96, i.e., the anti-resonant frequency of the holding mechanism 8. The CPU 16 stores the Mth resonant frequency of the Y motor 96 in the storage device 19. M is a variable, and in the initial setting, M=1. The CPU 16 resets the minimum value and increments M by 1 (S88). The CPU 16 changes the mode setting to the minimum value update setting (S89) and returns to the inertia and resonant frequency calculation process.

[0086] In the above description, the maximum value update time is an example of the "second moment" of the present invention. The CPU 16 executing S82 is an example of the "maximum value acquisition step" of the present invention. The CPU 16 executing S88 is an example of the "minimum value initialization step" of the present invention. The CPU 16 executing S78 is an example of the "maximum value initialization step" of the present invention. The CPU 16 executing S87 is an example of the "motor resonance frequency acquisition step" of the present invention.

[0087] When executing the modified example of the above-mentioned resonant frequency calculation process, the process of S28 in the inertia and resonant frequency calculation process may not be executed, and S29 may be entered after S27. In addition, in the process of S21 or S22, a default setting may be defined (the mode setting is the minimum value update setting, N = 1, M = 1). In the control parameter generation process, for example, by calculating the control parameters so that the closed-loop gain characteristics of the motor speed are attenuated at the resonant frequency of the holding mechanism 8 including the sewn object and the resonant frequency of the motor, the resonance of the holding mechanism 8 including the sewn object and the motor can be suppressed, thereby achieving control of the Y motor 96, so that the holding mechanism 8 including the sewn object can be conveyed more stably.

[0088] In addition, in this variant, by obtaining the minimum value and the maximum value based on the minimum and maximum values ​​of the processing speed calculated successively, less storage capacity and lower computational load are used compared to the case where the characteristics of the motor speed and the elapsed time are obtained during the entire period and the processing speed is calculated and the minimum value is obtained after the acquisition is completed, so it can be implemented on inexpensive hardware.

[0089] In the inertia and resonant frequency calculation process, various calculations are started after the waiting time exceeds the standby time. However, it is also possible to not set the standby time and instead input the scanning sine wave signal after deleting the waveform corresponding to the standby time from the scanning waveform into the Y motor 96. In S14 and S16, the user is asked whether the calculated mass is appropriate, but this step can be omitted. In S16, if the calculated mass is determined to be inappropriate, the control parameter generation process is terminated, but it is also possible to return to S11 and re-execute the control parameter generation process. In addition, the scanning waveform can be changed at this time. In S18, the user is asked to confirm whether the control gain is set as the control parameter, but it is also possible to directly set the control gain as the control parameter without confirmation.

Claims

1. A control parameter generation method for generating control parameters for use by a motor control device of a conveying device that conveys an object, based on the mass of the object, wherein the conveying device includes a motor, the motor control device for controlling the motor, and a transmission mechanism for transmitting power generated by the motor to the object, the control parameter generation method comprising: a time characteristic acquisition step for inputting a sweep signal to the motor to acquire characteristics of a motor speed and elapsed time of the motor, the sweep signal having a time characteristic in which a frequency of a signal value changes with elapsed time; a speed processing step for calculating a processing speed by converting the acquired motor speed into an absolute value and performing a low-pass filtering; a minimum value acquisition step for calculating a minimum value of the processing speed of the motor speed at each elapsed time after a predetermined waiting time has elapsed since the input of the scanning signal, and acquiring a first moment indicating that the minimum value first reaches the minimum value and the minimum value; an inertia calculation step for calculating the inertia of the motor based on the motor speed obtained during the period from the standby time to the first moment when the minimum value is obtained and a mathematical model; a mass calculating step for calculating the mass of the transport object based on the calculated inertia and an approximate formula; as well as A parameter calculation step is for calculating the control parameter based on the calculated mass of the transport object.

2. The control parameter generation method according to claim 1, characterized in that: In the inertia calculation step, the inertia is calculated using a successive least squares method so that a difference between the motor speed and a motor speed estimate value calculated in advance from the mathematical model is small.

3. The control parameter generation method according to claim 1 or 2, characterized in that: Also includes: a quality prompting step for prompting the mass of the transported object calculated in the mass calculating step; as well as a judgment input step for receiving an input of whether the quality indicated is appropriate, When a judgment that the quality is inadequate is input, the calculation of the control parameter in the parameter calculation step is terminated.

4. The control parameter generation method according to claim 1, characterized in that: The method further includes a resonance frequency acquisition step for calculating and acquiring, based on the time characteristics of the scanning signal, the frequency input to the motor when the processing speed reaches the minimum value at the first moment as the resonance frequency of the conveying object. In the parameter calculation step, the control parameter is calculated based on the calculated resonance frequency and mass of the transport object.

5. The control parameter generation method according to claim 4, characterized in that: Also includes: a maximum value acquisition step for calculating the maximum value of the processing speed of the motor speed at each elapsed time after the waiting time has elapsed since the input of the scanning signal, and acquiring a second moment indicating that the maximum value first reaches the maximum value and the maximum value; as well as a motor resonance frequency acquisition step for calculating and acquiring, based on the time characteristics of the scanning signal, the frequency input to the motor at the second moment when the processing speed reaches the maximum value, as the motor resonance frequency; In the parameter calculation step, the control parameter is calculated based on the calculated resonance frequency of the transport object, the resonance frequency of the motor, and the mass.

6. The control parameter generation method according to claim 1 or 4, characterized in that: The minimum value acquisition step sequentially calculates the minimum value of the machining speed of the motor speed, updates the minimum value, and defines a value that has not been updated for a predetermined first time as the minimum value.

7. The control parameter generation method according to claim 5, characterized in that: The minimum value acquisition step successively calculates the minimum value of the machining speed of the motor speed, updates the minimum value, and takes the value that has not been updated for a predetermined first time as the minimum value. The maximum value acquisition step successively calculates the maximum value of the machining speed of the motor speed, updates the maximum value, and sets the value that has not been updated for a predetermined second time as the maximum value. The control parameter generation method further includes: a maximum value initialization step for initializing the maximum value when the first time has passed since the first moment; and The minimum value initialization step is used to initialize the minimum value when the second time has passed since the second moment.

8. The control parameter generation method according to claim 1, characterized in that: The conveying device is used for sewing device, The transport object is a holding mechanism holding the sewn object, The transmission mechanism is a feeding mechanism that enables the holding mechanism to move relative to the needle bar mechanism that drives the needle bar. The motor drives the feeding mechanism.

9. A control parameter generation program product for generating control parameters for use by a motor control device of a conveying device that conveys an object to be conveyed, in accordance with the mass of the object to be conveyed, the conveying device comprising a motor, the motor control device for controlling the motor, and a transmission mechanism for transmitting power generated by the motor to the object to be conveyed, the control parameter generation program product causing a computer of the conveying device to execute: a time characteristic acquisition step for inputting a sweep signal to the motor to acquire characteristics of a motor speed and elapsed time of the motor, the sweep signal having a time characteristic in which a frequency of a signal value changes with elapsed time; a speed processing step for calculating a processing speed by converting the acquired motor speed into an absolute value and performing a low-pass filtering; a minimum value acquisition step for calculating a minimum value of the processing speed of the motor speed at each elapsed time after a predetermined waiting time has elapsed since the input of the scanning signal, and acquiring a first moment indicating that the minimum value first reaches the minimum value and the minimum value; an inertia calculation step for calculating the inertia of the motor based on the motor speed obtained during the period from the standby time to the first moment when the minimum value is obtained and a mathematical model; a mass calculating step for calculating the mass of the transport object based on the calculated inertia and an approximate formula; as well as A parameter calculation step is for calculating the control parameter based on the calculated mass of the transport object.

10. A storage medium storing a program for generating, in a conveying device that conveys an object to be conveyed, a control parameter used by a motor control device of the conveying device according to the mass of the object to be conveyed, the conveying device comprising a motor, the motor control device for controlling the motor, and a transmission mechanism for transmitting power generated by the motor to the object to be conveyed, the program causing a computer of the conveying device to execute: a time characteristic acquisition step for inputting a sweep signal to the motor to acquire characteristics of a motor speed and elapsed time of the motor, the sweep signal having a time characteristic in which a frequency of a signal value changes with elapsed time; a speed processing step for calculating a processing speed by converting the acquired motor speed into an absolute value and performing a low-pass filtering; a minimum value acquisition step for calculating a minimum value of the processing speed of the motor speed at each elapsed time after a predetermined waiting time has elapsed since the input of the scanning signal, and acquiring a first moment indicating that the minimum value first reaches the minimum value and the minimum value; an inertia calculation step for calculating the inertia of the motor based on the motor speed obtained during the period from the standby time to the first moment when the minimum value is obtained and a mathematical model; a mass calculating step for calculating the mass of the transport object based on the calculated inertia and an approximate formula; as well as A parameter calculation step is for calculating the control parameter based on the calculated mass of the transport object.

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