Waveform data analysis system of servo press and waveform data analysis program of servo press

Abstract

To provide a waveform data analysis system of a servo press and a waveform data analysis program of a servo press capable of deriving an appropriate basic waveform from a large number of waveform data being an execution result of processing a workpiece.SOLUTION: A device comprises a waveform data storage part 27, input means 23, display means 26, a filter 25a that performs filter processing, and an envelope creation part 25b, wherein the filter 25a performs filter processing with a temporary reference waveform as a reference, the envelope creation part 25b creates an upper limit waveform, a lower limit waveform, and an average waveform with the temporary reference waveform as a reference from waveform data after filter processing, the filter 25a performs new filter processing with a new temporary reference waveform as a reference, and the envelope creation part 25b performs recalculation of newly creating an upper limit waveform, a lower limit waveform, and an average waveform with the new temporary reference waveform as a reference from new waveform data after filter processing, and repeats the recalculation to derive a reference waveform.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a waveform data analysis system and a waveform data analysis program for a servo press that derive a reference waveform from waveform data that is the execution result of machining a workpiece for a servo press in which a ram is driven by a servo motor. [Background technology]

[0002] Servo presses, which use a servo motor to drive a reciprocating ram, have been known as press machines. Servo presses can perform tasks such as press forming of metal parts, press-fitting of parts, and assembly of parts. Servo presses can monitor time-series changes in load, position, and other parameters. For example, they can acquire numerical data and waveform data regarding the relationship between the position (stroke) of the ram and the load applied to the ram. Furthermore, the acquired waveform data can be evaluated using a reference waveform to evaluate the results of press operation.

[0003] For example, a forming load measuring device for a press machine described in Patent Document 1 sets upper and lower limits for the waveform during normal forming, making it possible to monitor whether the forming load during forming is normal or abnormal. A press machine described in Patent Document 2 makes it possible to confirm whether the measured waveform is correctly pressurized according to the reference waveform. Patent Document 3 discloses that the normal range of a waveform is defined as a probability range for a basic waveform obtained by taking the average value of past values. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Utility Model Application Publication No. 58-125699 [Patent Document 2] Japanese Patent Publication No. 2021-133418 [Patent Document 3] Japanese Patent Application Publication No. 11-218451 Summary of the Invention [Problem to be solved by the invention]

[0005] However, Patent Documents 1 and 2 assume that a reference waveform is prepared in advance, and do not disclose the specific process for deriving the reference waveform. Patent Document 3 merely describes that a basic waveform is derived from a past average value.

[0006] On the other hand, even if a reference waveform is available, accurate evaluation cannot be achieved unless it is appropriate. Therefore, the issue is how to derive an appropriate basic waveform.

[0007] In view of the above-described background, an object of the present invention is to provide a servo press waveform data analysis system and a servo press waveform data analysis program that are capable of deriving an appropriate basic waveform from a large amount of waveform data that is the execution result of machining a workpiece. [Means for solving the problem]

[0008] In order to achieve the above object, the waveform data analysis system of the present invention for a servo press is a system for analyzing waveform data for deriving a reference waveform that serves as a standard for evaluating waveform data from a plurality of actually measured waveform data, the waveform data indicating the relationship between the amount of displacement related to the position of the ram of the servo press and the load received by the ram, and the system is equipped with a waveform data storage unit that stores the waveform data to be analyzed, input means for selecting waveform data, display means for displaying the waveform data, a filter that performs filtering processing to exclude waveform data outside a set range from the waveform data, and an envelope creation unit, and the filter The filter processing is performed based on a tentative reference waveform selected by the input means, and the envelope creation unit creates an upper limit waveform, a lower limit waveform, and an average waveform from the waveform data after the filter processing based on the tentative reference waveform, and when the average waveform is set as a new tentative reference waveform, the filter performs new filter processing based on the new tentative reference waveform, and the envelope creation unit performs recalculation to create new upper limit waveform, lower limit waveform, and average waveform from the waveform data after the new filter processing based on the new tentative reference waveform, and the recalculation is repeated to derive the reference waveform.

[0009] The waveform data analysis program for a servo press of the present invention is a program for causing a computer to execute waveform data analysis for deriving a reference waveform, which serves as a standard for evaluating waveform data, from a plurality of actually measured waveform data, the waveform data indicating the relationship between the amount of displacement related to the position of the ram of the servo press and the load received by the ram, and the program causes the computer to execute a waveform data saving step for saving waveform data to be analyzed, an input step for selecting waveform data, a display step for displaying the waveform data, a filtering step for excluding waveform data outside a set range from the waveform data, and an envelope creation step, and in the filtering step, a tentative reference waveform selected in the envelope step, wherein an upper limit waveform, a lower limit waveform, and an average waveform are created from the waveform data after the filter processing using the tentative reference waveform as a reference in the envelope step, and when the average waveform is set as a new tentative reference waveform in the filter processing step, new filter processing is performed using the new tentative reference waveform as a reference in the envelope creating step, and recalculation is performed to create new upper limit waveform, lower limit waveform, and average waveform from the waveform data after the new filter processing using the new tentative reference waveform as a reference in the envelope creating step, and the reference waveform is derived by repeating the recalculation.

[0010] In the servo press waveform data analysis system of the present invention, it is preferable that a selection range of the displacement amount related to the position can be set for the tentative reference waveform selected by the input means and displayed on the display means. In the servo press waveform data analysis program of the present invention, a selection range of the displacement amount related to the position can be set for the tentative reference waveform selected in the input step and displayed in the display step. [Effects of the Invention]

[0011] According to the present invention, it is possible to derive an appropriate fundamental waveform while performing filter processing with a simple operation. By configuring the selection range of the displacement amount related to position to be settable, it is possible to exclude the vicinity of the rise of the load and the vicinity of the peak load from the load calculation range, allowing the filter processing to function correctly. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is an overall configuration diagram of a servo press system according to an embodiment of the present invention; [Figure 2] FIG. 10 is a diagram showing an example of an envelope. [Figure 3] 1 is a block diagram showing the configuration of a waveform data analysis system according to an embodiment of the present invention. [Figure 4] 4 is a flowchart showing an overview of a process for deriving a reference waveform in one embodiment of the present invention. [Figure 5] FIG. 4 is a diagram showing an example of a waveform data selection screen in the embodiment of the present invention. [Figure 6] FIG. 4 is a diagram showing an example of a tentative reference waveform selection screen in the embodiment of the present invention. [Figure 7] FIG. 10 is a diagram showing an example of a load calculation range setting screen in one embodiment of the present invention. [Figure 8] FIG. 10 is a diagram showing an example of a filter detail setting screen in the embodiment of the present invention. [Figure 9] FIG. 10 is a diagram showing an example of an envelope confirmation screen in one embodiment of the present invention. [Figure 10] FIG. 10 is a diagram showing an example of a confirmation screen for a recalculated envelope in one embodiment of the present invention. [Figure 11] FIG. 10 is a diagram showing an example of a confirmation screen for a recalculated envelope in one embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0013] The present invention relates to a waveform data analysis system and a waveform data analysis program for a servo press that derive a reference waveform from waveform data resulting from machining a workpiece using a servo press. First, a servo press will be described with reference to FIG. 1. FIG. 1 shows an overall configuration diagram of a servo press system according to one embodiment of the present invention. In this embodiment, the mechanical part of the servo press system that machines the workpiece is referred to as a servo press 10. The servo press 10 is controlled by control means that includes a servo press controller 20, a motor driver 21, and an operation terminal 22.

[0014] The servo press 10 is fixed to a support base 15 of a support body 14. The support body 14 is a structure in which a support 17 is interposed between a lower base 16 and an upper support base 15. The servo press 10 has a ram 2 and a ball screw 3 housed inside a cylinder case 5. As the ball screw 3 rotates, the nut 4 slides in the axial direction of the ball screw 3, and the ram 2 slides integrally with the nut 4 along a guide (not shown) (arrows a and b). The ball screw 3 is rotated by the rotation of a servo motor 6 being transmitted to a reducer 8 via a timing belt 7.

[0015] By lowering the ram 2 (arrow a), the ram 2 can press against an object. This allows the servo press 10 to perform operations such as press-fitting, molding, caulking, inspection, welding / joining, assembly, and cutting. In FIG. 1, a plug 12 is attached to the tip of the ram 2, and by lowering the ram 2, the plug 12 can be pressed into a recess in a workpiece 13 (molded product) on a work table 18.

[0016] In Fig. 1, an operation terminal 22 issues various commands to a servo press controller 20. The servo press controller 20 issues commands to a motor driver 21 based on the commands from the operation terminal 22, load information detected by the load cell 9, and encoder pulses from the encoder 11. This controls the motor current and drives and controls the servo press 10. The encoder pulses are also input to the motor driver 21, and the motor current is appropriately corrected by feedback control.

[0017] In this embodiment, the stroke is the amount of displacement from the starting position (origin position) of the ram 2 descending. The load is the load applied to the ram 2 from the outside. The stroke is calculated by accumulating the encoder pulses from the encoder 11. The load is calculated from the load information detected by the load cell 9.

[0018] The servo press controller 20 controls the servo press 10 according to a program. During this control, constantly changing stroke data of the ram 2 and data on the load received by the ram 2 at each stroke are input to the servo press controller 20. Using these data, waveform data showing the relationship between stroke and load can be obtained.

[0019] A large number of waveform data can be displayed as an envelope. An envelope is the waveform shape that appears when hundreds of waveform data items are plotted on a single graph, and the overlapping waveform data lines fill in the area. In other words, an envelope is the area or shape enclosed by the envelopes of the maximum and minimum values ​​of multiple waveforms.

[0020] The envelope can be used to determine whether waveform data is normal or abnormal. FIG. 2 shows an example of an envelope. It also shows a reference waveform 30, an upper limit waveform 31, a lower limit waveform 32, and a measured waveform 33 (the waveform to be determined). The reference waveform 30 is a waveform that serves as a reference for determination and is determined based on a large amount of waveform data measured in advance. The upper limit waveform 31 is a waveform that indicates an upper threshold value relative to the reference waveform 30. The lower limit waveform 32 is a waveform that indicates a lower threshold value relative to the reference waveform 30. In FIG. 2, the measured waveform 33 deviates from the reference waveform 30, but is within the area surrounded by the upper limit waveform 31 and the lower limit waveform 32, and is therefore determined to be normal. Hereinafter, in this embodiment, the display of at least the reference waveform 30, the upper limit waveform 31, and the lower limit waveform 32 is referred to as an envelope.

[0021] Because the upper limit waveform 31 and the lower limit waveform 32 are waveforms obtained based on the reference waveform 30, accurate judgment cannot be made unless the reference waveform 30 is appropriate. The servo press waveform data analysis system (hereinafter referred to as the "waveform data analysis system") and servo press waveform data analysis program (hereinafter referred to as the "waveform data analysis program") according to this embodiment are capable of deriving an appropriate basic waveform. A specific description will be given below.

[0022] FIG. 3 is a block diagram showing the configuration of a waveform data analysis system 1. The waveform data analysis system 1 is a computer, such as a personal computer, having a waveform data analysis program installed. A reference waveform is derived by analysis means 25, which includes a filter 25a and an envelope creation unit 25b. When analyzing waveform data to derive the reference waveform, waveform data is obtained in advance by performing test punches several hundred times. The initially obtained waveform data is stored in the servo press controller 20 shown in FIG. 1. This waveform data is then re-saved in a waveform data storage unit 27, which may be the waveform storage unit of the servo press controller 20.

[0023] The waveform data is not limited to waveform data for one servo press 10, but may also be waveform data for multiple servo presses 10. The servo press 10 is controlled according to a program, and different programs are used for different workpieces. Furthermore, the same press operation is typically performed multiple times. For this reason, multiple (large numbers of) waveform data are stored in the waveform data storage unit 27, and these may be waveform data for multiple servo presses 10. Furthermore, each piece of waveform data 27 includes not only data on the waveform itself, but also data on the axis number (a number assigned to each servo press 10), program number, and execution date and time.

[0024] FIG. 4 is a flowchart outlining the reference waveform derivation process. The flowchart in FIG. 4 is a flowchart illustrating the process of deriving a reference waveform using the waveform data analysis system 1 shown in FIG. 3. The waveform data analysis system 1 is used by having a computer execute a waveform data analysis program. Therefore, the process of deriving a reference waveform using the waveform data analysis system 1 is also a process that progresses while the computer is executing the waveform data analysis program. In FIG. 3, the waveform data analysis program causes the computer to execute the following steps: a waveform data storage step of storing waveform data to be analyzed in analysis target waveform data storage unit 24; an input step of selecting waveform data using input means 23; a display step of displaying the waveform data on display means 26; a filtering step of excluding waveform data outside a set range from the waveform data using filter 25a; and an envelope creation step of creating an upper limit waveform, a lower limit waveform, and an average waveform using envelope creation unit 25b from the waveform data processed by the filtering step.

[0025] The process of deriving a reference waveform will be explained with reference to Figure 4. First, in Figure 3, waveform data to be analyzed is selected from the waveform data displayed on display means 26 using input means 23 such as a keyboard (step 100 in Figure 4). Figure 5 shows an example of a waveform data selection screen. The screen in Figure 5 is a screen on display means 26 (Figure 3), and the same applies to the various screens below. Waveform data group display group 34 displays four waveform data groups classified by the date of measurement of the waveform data. This display is an example, and there is no particular limit to the number of waveform data groups. The operator selects at least one from the displayed waveform data groups.

[0026] Next, the operator selects an axis number from the axis number display section 35 and a program number from the program number display section 36. At least one axis number can be selected, but all axis numbers may be selected. Since the reference waveforms differ for different programs, one program number is usually selected. The collection of selected waveform data is saved in the waveform data saving section 24 for analysis target shown in Figure 3.

[0027] After selecting the waveform data (step 100 in FIG. 4), a tentative reference waveform is selected (step 101 in FIG. 4). FIG. 6 shows an example of the tentative reference waveform selection screen. This figure shows the case where axis number 1 is selected from axis number display section 35 shown in FIG. 5, and program number 1 is selected from program number display section 36. A portion of the selected waveform data is displayed in waveform data display section 37, and all of the selected waveform data can be displayed by scrolling the screen.

[0028] The operator selects one waveform data from the waveform data display group 37. The selected waveform data is a provisional, temporary reference waveform, so any one waveform data may be selected. In the example of FIG. 6, waveform number 8 is selected (shaded area). With this selection, the waveform of waveform number 8 is displayed in the waveform display section 38 as a provisional reference waveform. The waveform displayed in the waveform display section 38 shows the relationship between the stroke of the ram 2 of the servo press 10 shown in FIG. 1 and the load received by the ram 2. The horizontal axis may represent the amount of displacement related to the position of the ram 2, or may represent the rotation angle of the servo motor 6 (FIG. 1).

[0029] After selecting the tentative reference waveform (step 101 in FIG. 4), the weight calculation range is set (step 102 in FIG. 4). In the subsequent steps, the upper and lower limit waveforms are set using the weight of the tentative reference waveform as a reference to create an envelope. Setting the weight calculation range sets the range of the weight when setting the upper and lower limit waveforms. In other words, setting the weight calculation range sets the selection range of the stroke that increases in time series. FIG. 7 shows an example of a setting screen for the weight calculation range. The waveform selected on the selection screen in FIG. 6 is displayed in the waveform display section 40. The area between the start line 41 and the end line 42 is the weight calculation range.

[0030] The position of the start line 41 can be changed by clicking the start position change button 43 and then clicking near the start line 41. Similarly, the position of the end line 42 can be changed by clicking the end position change button 44 and then clicking near the end line 42. Alternatively, the start and end positions may be set by directly inputting numerical values ​​into the start position display section 45 or the end position display section 46. In this embodiment, as described above, the load calculation range can be arbitrarily set, so that the areas near where the load rises and the peak load can be excluded from the load calculation range. This is because the load value changes significantly in these areas, which may cause the filter (described later) to not function properly, making them unsuitable as the basis for the upper and lower limit waveforms.

[0031] After the load calculation range is set (step 102 in FIG. 4), detailed settings of the filter 25a shown in FIG. 3 are made (step 103 in FIG. 4). FIG. 8 shows an example of a detailed filter setting screen. The filter setting display section 47 displays various setting items and setting value input sections for the filter 25a. By setting the filter, waveform data useful for deriving a reference waveform is extracted, and waveform data that is not useful for deriving a reference waveform is excluded. Each setting item is explained below.

[0032] By setting the "peak stroke tolerance range," waveform data whose peak stroke (maximum stroke value) is within the set range relative to the peak stroke of the tentative reference waveform is extracted. For the same type of workpiece, the peak stroke will be almost constant. Therefore, by excluding waveform data outside the set range, it is possible to exclude waveform data that is abnormal in relation to the tentative reference waveform.

[0033] By setting the "peak load tolerance range," waveform data where the peak load is within the set range relative to the peak load of the provisional reference waveform is extracted. The "peak load tolerance range" is not an effective filter for workpieces where the peak load fluctuates greatly, so this setting may be omitted.

[0034] By setting the "stroke start position tolerance range," waveform data where the stroke start position is within the set range relative to the stroke start position of the tentative reference waveform is extracted. The stroke start position may differ for each workpiece type, and this setting is effective for excluding waveform data for different types of workpieces. If each waveform data is based on the same type of workpiece, this setting can be omitted.

[0035] By setting the "allowable load range for each stroke," waveform data is extracted in which the load for each stroke falls within the allowable range for the load for each stroke of the tentative reference waveform. In the example of Figure 8, a lower limit of 30% and an upper limit of 300% are entered. This numerical range means that the range is from minus 30% to plus 300% with 100% (the value of the tentative reference waveform) as the base.

[0036] The target section for this setting is the load calculation range set on the load calculation range setting screen in Fig. 7. The stroke interval of the load for each stroke is the stroke interval displayed in the stroke interval display section 46 in Fig. 8. The stroke interval is set in the stroke interval display section 48. In the example in Fig. 8, 0.01 mm is set in the stroke interval display section 48, and the allowable range of the load is calculated in increments of 0.01 mm.

[0037] By setting "Exclude waveforms with return strokes", you can exclude waveforms with return strokes within the calculation range. Waveforms with return strokes can interfere with envelope creation.

[0038] The above explains the detailed filter settings, but these are just examples and you can add more as needed. For example, if the peak stroke bottoms out as in the waveform in Figure 7, performing stroke correction based on the peak stroke may increase the correlation of the waveform. For this reason, you can add a setting item for "stroke correction based on peak stroke value" and perform stroke correction if necessary.

[0039] After the detailed filter settings have been made (step 103 in FIG. 4), filter processing is performed by the filter 25a (FIG. 3) (step 104 in FIG. 4), and then the envelope creation unit 25b (FIG. 3) creates an envelope (step 105 in FIG. 4). FIG. 9 shows an example of an envelope confirmation screen. In FIG. 9, the waveform display unit 49 displays four waveforms: a tentative reference waveform 60, an upper limit waveform 61, a lower limit waveform 62, and an average waveform 63.

[0040] These four waveforms can be switched between display and non-display in the waveform display selection unit 50. In the waveform display selection unit 50, the reference waveform corresponds to a tentative reference waveform 60, the envelope (upper limit) corresponds to an upper limit waveform 61, the envelope (lower limit) corresponds to a lower limit waveform 62, and the average value corresponds to an average waveform 63.

[0041] In the waveform display unit 49, there is a discrepancy between the tentative reference waveform 60 and the average waveform 63. This is because the tentative reference waveform 60 is merely a tentative reference waveform arbitrarily selected from the selected waveforms. Therefore, when the operator compares the tentative reference waveform 60 with the average waveform 63 (step 106 in FIG. 4), the tentative reference waveform 50 and the average waveform 53 usually do not match.

[0042] If the tentative reference waveform 60 and the average waveform 63 do not match, the average waveform 63 is set as the tentative reference waveform 50 (step 107 in FIG. 4), and a new filter process is performed (step 104 in FIG. 4), followed by creating an envelope (step 105 in FIG. 4). That is, a recalculation is performed, and the recalculation is executed by clicking the recalculation button 51 in FIG. 9. During the recalculation, the average waveform 63 becomes the new tentative reference waveform. FIG. 10 shows a confirmation screen of the envelope after recalculation. After the recalculation, a new waveform is displayed in the waveform display section 49. The tentative reference waveform 60a is the new tentative reference waveform, and is the same waveform as the average waveform 63 in the waveform display section 49 in FIG. 9.

[0043] During recalculation, filtering and envelope generation are performed using a new tentative reference waveform 60a as a reference (steps 104 and 105 in FIG. 4), so the upper limit waveform 61a, lower limit waveform 62a, and average waveform 63a in the waveform display section 49 in FIG. 10 will be different from the waveforms at the time of the initial calculation shown in FIG. 9. In particular, during recalculation in FIG. 10, the degree of deviation between the tentative reference waveform 60a and the average waveform 63a is smaller than during the initial recalculation in FIG. 9.

[0044] However, in the waveform display of Fig. 10, the tentative reference waveform 60a and the average waveform 63a do not match, so the average waveform 63a is set as the tentative reference waveform again (steps 106 and 107 in Fig. 4). That is, when the operator clicks the recalculation button 51 in Fig. 10, recalculation is performed, and filtering and envelope generation are performed using the new tentative reference waveform as a reference (steps 104 and 105 in Fig. 4).

[0045] FIG. 11 shows the envelope confirmation screen after recalculation. As a result of the recalculation, a new waveform is displayed in the waveform display unit 49. The tentative reference waveform 60b is a new tentative reference waveform, and is the same waveform as the average waveform 63a in the waveform display unit 49 in FIG. 10. During recalculation, filtering and envelope generation are performed based on the new tentative reference waveform 60b (steps 104 and 105 in FIG. 4). Therefore, the upper limit waveform 61b, the lower limit waveform 62b, and the average waveform 63b in the waveform display unit 49 in FIG. 11 are different from the waveforms obtained during the first recalculation shown in FIG. 10. During the second recalculation in FIG. 11, the tentative reference waveform 60b and the average waveform 63b match. When the two waveforms match or nearly match, the current average waveform 63b is designated as the final reference waveform.

[0046] As described above, according to this embodiment, a tentative reference waveform is first arbitrarily selected, filter processing and envelope creation are performed, and then recalculation is performed using the average waveform as the tentative reference waveform. By repeating this process, the final reference waveform is obtained. With this configuration, simply selecting the tentative reference waveform sets the reference values ​​in the filter setting display section 47 in Figure 8, and in particular sets the reference for the "allowable range of load for each stroke," making it possible to perform filter processing with simple operations.

[0047] In this embodiment, the average waveform obtained by the first envelope creation is not the average waveform of the entire waveform, but the average waveform after filtering. Furthermore, the average waveform obtained by recalculation is the average waveform after filtering based on a new tentative reference waveform. Therefore, each time recalculation is performed, the average waveform approaches the appropriate reference waveform. With this configuration, the appropriate reference waveform can be derived simply by repeatedly clicking the recalculation button 51.

[0048] The above describes an embodiment of the present invention, but the embodiment is merely an example and may be modified as appropriate. For example, the target waveform may be evaluated numerically. In the above embodiment, filtering leaves waveform data useful for deriving the reference waveform as valid data, while excluding waveform data that is not useful as excluded data. In this case, the degree of similarity between the valid data and the excluded data and the tentative reference waveform or the final reference waveform (hereinafter referred to as the "tentative reference waveform, etc.") may be evaluated numerically.

[0049] For example, at any stroke value, the difference in weight between the target waveform and the tentative reference waveform or the like is calculated, and this is done for each stroke value, and the sum of the differences is converted into a score. The score is an index that reaches its maximum value (e.g., 100) if the sum of the differences is zero (the target waveform and the tentative reference waveform or the like match). The stroke interval used to calculate the difference may be the stroke interval displayed in the stroke interval display section 46 in FIG. 8.

[0050] By calculating the score, the target waveforms can be sorted by score, and it is also possible to sort not only all data but also valid data and excluded data. By verifying the sorted waveform data against the displayed waveform, it becomes easy to grasp the trend in the relationship between the score and waveform, making verification easier and more specific. [Explanation of symbols]

[0051] 1. Waveform data analysis system 2. Ram 6 servo motors 10 Servo Press 23 Input Methods 24 Waveform data storage section for analysis 25 Analysis methods 25a filter 25b Envelope Creation Section 26 Display means 27 Waveform data storage section 60, 60a, 60b Temporary reference waveform 61,61a,61b Upper limit waveform Lower limit waveforms of 62, 62a, and 62b 63,63a Average Waveform 63b Average Waveform (Reference Waveform)

Claims

1. 1. A waveform data analysis system for a servo press that performs waveform data analysis to derive a reference waveform that serves as a basis for evaluating waveform data from a plurality of actually measured waveform data, the waveform data indicates a relationship between a displacement amount related to a position of a ram of the servo press and a load applied to the ram, a waveform data storage unit for storing waveform data to be analyzed; an input means for selecting waveform data; a display means for displaying waveform data; a filter that performs filtering processing to remove waveform data outside a set range from the waveform data; An envelope creating unit is provided. the filter performs the filtering process based on the tentative reference waveform selected by the input means; the envelope generating unit generates an upper limit waveform, a lower limit waveform, and an average waveform from the filtered waveform data using the tentative reference waveform as a reference; When the average waveform is set as a new tentative reference waveform, the filter performs new filtering using the new tentative reference waveform as a reference; the envelope generating unit performs recalculation to generate new upper limit waveforms, lower limit waveforms, and average waveforms from the new filtered waveform data using the new tentative reference waveform as a reference; A servo press waveform data analysis system characterized in that the recalculation is repeated to derive the reference waveform.

2. 2. The servo press waveform data analysis system according to claim 1, wherein a selection range of displacement amounts related to the position can be set for the provisional reference waveform selected by the input means and displayed on the display means.

3. A waveform data analysis program for a servo press for causing a computer to execute waveform data analysis for deriving a reference waveform that serves as a basis for evaluating waveform data from a plurality of actually measured waveform data, the program comprising: the waveform data indicates a relationship between a displacement amount related to a position of a ram of the servo press and a load applied to the ram, a waveform data storage step for storing the waveform data to be analyzed; an input step for selecting waveform data; a display step for displaying waveform data; a filtering step for excluding waveform data outside a set range from the waveform data; and causing the computer to execute an envelope creation step; In the filtering step, filtering is performed using the tentative reference waveform selected in the input step as a reference; In the envelope step, an upper limit waveform, a lower limit waveform, and an average waveform are created from the waveform data after the filtering process using the tentative reference waveform as a reference; When the average waveform is set as a new tentative reference waveform in the filtering step, new filtering is performed using the new tentative reference waveform as a reference; In the envelope creation step, recalculation is performed to create new upper limit waveforms, lower limit waveforms, and average waveforms from the waveform data after the new filter processing, using the new tentative reference waveform as a reference; A servo press waveform data analysis program, characterized in that the recalculation is repeated to derive the reference waveform.

4. 2. The servo press waveform data analysis program according to claim 1, wherein a selection range of displacement amounts related to the position can be set for the tentative reference waveform selected in the input step and displayed in the display step.

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