Material Testing Machine

Abstract

To make it possible to reduce labor of an operator in adjusting a control parameter 543.SOLUTION: A tensile tester 1 comprises a testing machine body 2 having a hydraulic actuator 25, and an estimation unit 534 that estimates a response characteristic of the tensile tester 1, wherein the estimation unit 534 obtains a response characteristic of the testing machine body 2 in a state where a first set value used in a tensile test performed by the tensile tester 1 is set in a control parameter 543 that defines an operation of the hydraulic actuator 25, and the estimation unit estimates a response characteristic of the tensile tester 1 in a state where a second set value different from the first set value is set in the control parameter 543 based on the obtained response characteristic of the testing machine body 2.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a materials testing machine. [Background technology]

[0002] Control parameters that define the operation of an actuator included in a testing machine are known. For example, Patent Document 1 discloses a motor that raises and lowers a crosshead as an actuator included in a testing machine, and discloses a PID control gain that controls the drive of the motor as a control parameter that defines the operation of the motor. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2009-002900 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the testing machine described in Patent Document 1, when an operator adjusts the value of a control parameter, a test is conducted to obtain the response characteristics of the material testing machine each time the value of the control parameter is changed, and whether the value of the changed control parameter is appropriate is confirmed.

[0005] The present invention has been made in view of the above circumstances, and has an object to provide a materials testing machine that can reduce the labor required by an operator in adjusting control parameters. [Means for solving the problem]

[0006] The material testing machine according to the present invention is a material testing machine including a testing machine main body having an actuator, and includes: a receiving unit that receives a plurality of setting values ​​from a user; an estimating unit that estimates a response characteristic of the material testing machine; a first measurement unit that measures the response characteristics of the material testing machine in a state where a first set value used in a material test performed by the material testing machine is set to a control parameter that defines the operation of the actuator; a second measurement unit that measures the response characteristics of the material testing machine in a state where a second set value that is different from the first set value and that is received by the receiving unit is set to the control parameter; and a display control unit that displays the response characteristics of the material testing machine estimated by the estimating unit. and the estimation unit estimates the control parameters as No.A response characteristic of the testing machine main body in a state where one setting value is set is obtained, and the control parameter is adjusted based on the response characteristic of the testing machine main body that has been obtained. No. a first response characteristic that is a response characteristic of the material testing machine when two set values ​​are set, and a second response characteristic that is a response characteristic of the material testing machine when a third set value that is a set value different from the second set value and that is received by the receiving unit is set to the control parameter; When the display control unit is not set to display the response characteristics of the material testing machine measured by the second measurement unit, the display control unit displays the first response characteristic, the second response characteristic, and the response characteristics of the material testing machine measured by the first measurement unit in an overlapping manner, and when the display control unit is set to display the response characteristics of the material testing machine measured by the second measurement unit, the display control unit displays the first response characteristic, the second response characteristic, the response characteristics of the material testing machine measured by the first measurement unit, and the response characteristics of the material testing machine measured by the second measurement unit in an overlapping manner. . [Effects of the Invention]

[0007] According to the present invention, it is possible to obtain the response characteristics of a materials testing machine when the value of a control parameter is changed, so that an operator can adjust the control parameters without conducting a test to obtain the response characteristics of the materials testing machine, thereby reducing the operator's effort in adjusting the control parameters. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a diagram showing an example of the configuration of a tensile tester according to an embodiment of the present invention. [Figure 2] FIG. 2 is a diagram illustrating an example of the configuration of a control device. [Figure 3] FIG. 2 illustrates an example of the configuration of a feedback control unit. [Figure 4] FIG. 10 is a gain diagram showing the results of an experiment to confirm the estimation accuracy of the estimation unit. [Figure 5] FIG. 10 is a diagram illustrating an example of a gain diagram displayed by a display control unit. [Figure 6] FIG. 10 is a diagram showing an example of a phase diagram displayed by a display control unit. [Figure 7] FIG. 10 is a diagram illustrating an example of a gain diagram displayed by a display control unit. [Figure 8] FIG. 10 is a diagram showing an example of a phase diagram displayed by a display control unit. [Figure 9] FIG. 10 is a diagram illustrating an example of a gain diagram displayed by a display control unit. [Figure 10] FIG. 10 is a diagram showing an example of a phase diagram displayed by a display control unit. [Figure 11] 10 is a flowchart showing an example of processing by a control unit. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0010] [1. Configuration of tensile testing machine] FIG. 1 is a diagram showing an example of the configuration of a tensile tester 1 according to this embodiment. The tensile tester 1 of this embodiment applies a test force to a specimen SP to perform a tensile test to measure mechanical properties of the specimen SP, such as tensile strength, yield point, elongation, reduction of area, etc. The test force is a tensile force. The tensile tester 1 includes a tester main body 2 that applies a test force to a specimen SP, which is a material to be tested, to perform a tensile test, and a control unit 3 that controls the tensile test operation performed by the tester main body 2. The tensile tester 1 corresponds to an example of a "material testing machine." A tensile test corresponds to an example of a "material test."

[0011] As shown in FIG. 1, the testing machine main body 2 is configured by forming a load frame on a base 20 with a pair of support columns 21 and 22 and a yoke 23, and by fixing a crosshead 24 to the support columns 21 and 22.

[0012] A hydraulic actuator 25 is disposed on the base 20, and a lower grip 26 for gripping the lower end of the specimen SP is attached to a piston rod 25A of the hydraulic actuator 25. An upper grip 28 for gripping the upper end of the specimen SP is attached to the crosshead 24 via a load cell 27. The hydraulic actuator 25 corresponds to an example of an "actuator."

[0013] The hydraulic actuator 25 has a servo valve 29 that controls the direction and amount of pressure oil, thereby extending and retracting the piston rod 25A. As a result, the distance between the upper grip 28 and the lower grip 26 extends and contracts, and a test force is applied to the specimen SP fixed between the upper grip 28 and the lower grip 26. The stroke of the hydraulic actuator 25, i.e., the displacement of the specimen SP, is detected by a differential transformer 30 attached to the hydraulic actuator 25.

[0014] The load cell 27 is a sensor that measures a test force, which is a tensile load applied to the specimen SP, and outputs a test force measurement signal SG1 to the control unit 3. The differential transformer 30 is a sensor that measures the amount of displacement of the specimen SP and outputs to the control unit 3 a displacement measurement signal SG2 corresponding to the amount of displacement.

[0015] A displacement sensor 31 is placed on the specimen SP. The specimen SP may be, for example, a dumbbell-shaped specimen that is constricted in the center. The displacement sensor 31 is a sensor that measures the distance between a pair of gauge points on the specimen SP to measure an elongation measurement value ED and outputs an elongation measurement signal SG3 to the control unit 3. The pair of gauge points are placed above and below the constricted region of the specimen SP.

[0016] The testing machine main body 2 further includes an electric power source GE and a hydraulic power source GP. The power source GE supplies power to each part of the testing machine main body 2. The power source GE supplies power to, for example, various motors to drive them. The power source GE also supplies power to hydraulic pumps and hydraulic control valves (not shown) to drive them. The power source GE is configured as, for example, a voltage source. The power source GE supplies the corresponding voltage to each part of the testing machine main body 2. For example, the power source GE supplies a voltage of 100 V to the hydraulic pump and various motors, and a voltage of 10 V to the control unit 3.

[0017] The hydraulic power source GP supplies hydraulic pressure to a hydraulic device constituting the testing machine main body 2. The hydraulic power source GP supplies hydraulic pressure to, for example, the hydraulic actuator 25, and drives the hydraulic actuator 25. That is, the hydraulic actuator 25 is driven by the hydraulic pressure supplied from the hydraulic power source GP, and the piston rod 25A is extended and retracted. The hydraulic power source GP is equipped with a hydraulic pump and a hydraulic control valve (not shown), and generates hydraulic pressure by driving the hydraulic pump. The hydraulic pump is supplied with power from a power source GE. The hydraulic control valve adjusts the hydraulic pressure output from the hydraulic power source GP.

[0018] The control unit 3 includes a signal input / output device 40 and a control device 50. The signal input / output device 40 constitutes an input / output interface circuit that transmits and receives signals to and from the testing machine main body 2. The signal input / output device 40 of this embodiment has a first sensor amplifier 41, a second sensor amplifier 42, a third sensor amplifier 43, and a servo amplifier 44.

[0019] The first sensor amplifier 41 is a device that amplifies the test force measurement signal SG1 output by the load cell 27 to generate a test force measurement value FD, and outputs the test force measurement value FD to the control device 50. The test force measurement value FD indicates the test force applied to the specimen SP. The second sensor amplifier 42 is a device that amplifies the extension measurement signal SG3 output by the displacement sensor 31 to generate an extension measurement value ED, and outputs the extension measurement value ED to the control device 50. The extension measurement value ED indicates the extension of the specimen SP. The third sensor amplifier 43 is a device that amplifies the displacement measurement signal SG2 output by the differential transformer 30 to generate a displacement measurement value XD, and outputs the generated displacement measurement value XD to the control device 50. The displacement measurement value XD indicates the displacement X of the hydraulic actuator 25. The servo amplifier 44 is a device that controls the servo valve 29 in accordance with the control of the control device 50. The control device 50 generates a command value CD based on at least one of the test force measurement value FD and the displacement measurement value XD, and outputs the generated command value CD to the servo amplifier 44. The servo amplifier 44 generates a command signal SG4 indicative of the command value CD, and outputs the generated command signal SG4 to the servo valve 29. The servo valve 29 controls the pressure oil direction and pressure oil amount for the hydraulic actuator 25 in accordance with the command signal SG4 output from the servo amplifier 44.

[0020] [2. Control device configuration] Based on operations from the user, the control device 50 controls the operation of the testing machine main body 2. Furthermore, the control device 50 causes the testing machine main body 2 to carry out a tensile test. In this embodiment, the “user” includes an operator who adjusts the control parameters 543 .

[0021] The control device 50 includes a computer having a storage device such as an HDD (Hard Disk Drive) or an SSD (Solid State Drive), interface circuits with the signal input / output device 40 and the operation panel 51, and various electronic circuits. The control device 50 is not limited to a computer, and may be configured by one or more appropriate circuits such as an integrated circuit, such as an IC chip or an LSI.

[0022] FIG. 2 is a diagram showing an example of the configuration of the control device 50. As shown in FIG. The control device 50 includes an operation panel 51 and a control unit 52 .

[0023] The operation panel 51 includes a touch panel 511 and an input device 512 other than the touch panel 511, such as buttons and a numeric keypad. The touch panel 511 includes an LCD (Liquid Crystal Display) or the like, and displays various images on the LCD in accordance with instructions from the control unit 52. The touch panel 511 also includes a touch sensor arranged along the display surface of the LCD. The touch sensor detects a touch with the user's fingertip or pen, and transmits a detection signal to the control unit 52.

[0024] The control unit 52 is configured by, for example, a personal computer, and controls the operation of the control device 50. The control unit 52 includes a processor 53 and a memory . The processor 53 is composed of a CPU (Central Processing Unit), an MPU (Micro-Processing Unit), and the like. The memory 54 is configured by a ROM (Read Only Memory), a RAM (Random Access Memory), etc. The memory 54 stores a control program 541, target data 542, and control parameters 543.

[0025] The target data 542 is time-series data that indicates the temporal fluctuation of the target value of a physical quantity in a material test. In this embodiment, the target data 542 is time-series data of the target value of the test force in a tensile test.

[0026] The control parameters 543 are parameters that define the operation of the hydraulic actuator 25. In this embodiment, the operation of the hydraulic actuator 25 is controlled by two-degree-of-freedom PID control. Therefore, the control parameters 543 in this embodiment include a proportional gain P, a differential gain D, an integral gain I, a first coefficient b, and a second coefficient c.

[0027] The control unit 52 is not limited to a personal computer, and may be configured by one or more appropriate circuits such as an integrated circuit, such as an IC chip or an LSI. The control unit 52 may also be configured by, for example, a tablet terminal, a smartphone, or the like. The control unit 52 may also include programmed hardware such as a DSP (Digital Signal Processor) or an FPGA (Field Programmable Gate Array), etc. The control unit 52 may also include a SoC (System-on-a-Chip)-FPGA.

[0028] [3. Control Unit Configuration] As shown in FIG. 2, the control unit 52 includes a communication unit 531, a feedback control unit 532, a reception unit 533, an estimation unit 534, a first measurement unit 535, a second measurement unit 536, and a display control unit 537. Specifically, the processor 53 of the control unit 52 executes the control program 531 stored in the memory 54, thereby functioning as a communication unit 531, a feedback control unit 532, a reception unit 533, an estimation unit 534, a first measurement unit 535, a second measurement unit 536, and a display control unit 537.

[0029] The communication unit 531 controls communication with the signal input / output device 40 . The communication unit 531 receives, for example, the test force measurement value FD, the elongation measurement value ED, and the displacement measurement value XD from the signal input / output device 40. In addition, the communication unit 531 transmits, for example, a command value CD to the signal input / output device 40.

[0030] [3-1. Feedback control section configuration] The feedback control unit 532 feedback controls the hydraulic actuator 25 during the tensile test. In this embodiment, a case will be described in which the feedback control unit 532 performs position control on the test force measurement signal SG1 output by the load cell 27. In this case, the feedback control unit 532 calculates a command value CD of the displacement measurement signal SG2 so that the test force measurement value FD coincides with the test force target value FE, and outputs a command signal SG4 indicating the command value CD to the servo valve 29. Position control refers to controlling a detected value measured by a sensor or the like so that it coincides with a target value.

[0031] In this embodiment, a case where position control is performed on the test force measurement value FD will be described, but the feedback control unit 532 may also perform position control on the elongation measurement value ED. In this case, the feedback control unit 532 calculates a command value CD for the displacement measurement value XD so that the elongation measurement value ED measured by the displacement sensor 31 coincides with the target elongation value, and outputs a command signal SG4 indicating the command value CD to the servo valve 29.

[0032] Furthermore, the feedback control unit 532 may execute position control for the displacement measurement value XD. In this case, the feedback control unit 532 calculates a command value CD for the displacement measurement value XD so that the displacement measurement value XD coincides with a target displacement value, and outputs a command signal SG4 indicating the command value CD to the servo valve 29.

[0033] The feedback control unit 532 may also perform speed control on the test force measurement value FD. In this case, the feedback control unit 532 calculates a command value CD of the displacement measurement value XD so that the test force measurement value speed coincides with the target value of the test force speed, and outputs a command signal SG4 indicating the command value CD to the servo valve 29. The test force measurement value speed indicates the amount of change in the test force measurement value FD per unit time, and the target value of the test force speed indicates the target value of the test force measurement value speed. The speed control refers to controlling the amount of change per unit time of a detected value measured by a sensor or the like so that it coincides with a target value.

[0034] The feedback control unit 532 may also perform speed control on the elongation measurement value ED. In this case, the feedback control unit 532 calculates a command value CD for the displacement measurement value XD so that the elongation measurement value speed coincides with the target elongation speed, and outputs a command signal SG4 indicating this command value CD to the servo valve 29. The elongation measurement value speed indicates the amount of change in the elongation measurement value ED per unit time, and the target elongation speed indicates the target value for the elongation measurement value speed.

[0035] Furthermore, the feedback control unit 532 may execute speed control for the displacement measurement value XD. In this case, the feedback control unit 532 calculates a command value CD for the displacement measurement value XD so that the displacement measurement value speed coincides with the displacement speed target value, and outputs a command signal SG4 indicating the command value CD to the servo valve 29. The displacement measurement value speed indicates the amount of change in the displacement measurement value XD per unit time, and the displacement speed target value indicates a target value for the displacement measurement value speed. Furthermore, other measurement values, such as dynamic strain gauges, pressure gauges, and accelerometers, may be input to the signal input / output device 40, and feedback control may be performed on the measurement values.

[0036] FIG. 3 is a diagram showing an example of the configuration of the feedback control unit 532. As shown in FIG. In this embodiment, two-degree-of-freedom PID (Proportional-Integral-Differential) control is used for the feedback control. The feedback control unit 532 includes a proportional unit 5321, an integrator 5322, and a differentiator 5323. The feedback control unit 532 also includes a first multiplier 5324, a second multiplier 5325, a first subtractor 5326, a second subtractor 5327, a third subtractor 5328, a first adder 5329, and a second adder 5330.

[0037] The first multiplier 5324 outputs a first multiplied value MV1 obtained by multiplying the test force target value FE by a first coefficient b to the first subtractor 5326. The first subtractor 5326 outputs a first deviation E1 obtained by subtracting the test force measurement value FD from the first multiplied value MV1 to the differentiator 5323. The differentiator 5323 outputs a first manipulated variable U1 to the first adder 5329.

[0038] The second multiplier 5325 outputs a second multiplied value MV2 obtained by multiplying the test force target value FE by the second coefficient c to the second subtractor 5327. The second subtractor 5327 outputs a second deviation E2 obtained by subtracting the test force measurement value FD from the second multiplied value MV2 to the first adder 5329.

[0039] The third subtractor 5328 outputs a third deviation E3 obtained by subtracting the test force measurement value FD from the test force target value FE to the integrator 5322. The integrator 5322 outputs a second manipulated variable U2 to the first adder 5329.

[0040] The first adder 5329 outputs a first sum KV1 obtained by adding the first manipulated variable U1, the second deviation E2, and the second manipulated variable U2 to the proportional adjuster 5321. The proportional adjuster 5321 outputs a third manipulated variable U3 to the second adder 5330. The second adder 5330 outputs a manipulated variable U obtained by adding the disturbance d to the third manipulated variable U3 to the testing machine main body 2. The manipulated variable U input to the testing machine main body 2 indicates, for example, the opening / closing amount of the servo valve 29.

[0041] Returning to the explanation of FIG. 2, when the user adjusts the control parameter 543, the reception unit 533 receives a second setting value as a candidate for the setting value to be set in the control parameter 543. The second setting value indicates a setting value different from a first setting value, which will be described later, and does not indicate a specific setting value. The reception unit 533 can receive a plurality of candidates with different values ​​by receiving a third setting value different from the second setting value. The reception unit 533 may receive a candidate from the user via the operation panel 51, or may receive a candidate determined by a function unit that automatically determines a candidate. The third setting value indicates a setting value different from the second setting value, and does not indicate a specific setting value.

[0042] [3-2. Configuration of the estimation unit] When the receiving unit 533 receives the second set value, the estimating unit 534 estimates the response characteristics of the tensile tester 1 in a state in which the second set value is set in the control parameter 543. In other words, the estimating unit 534 estimates the response characteristics of the tensile tester 1 when the second set value is set in the control parameter 543. The estimating unit 534 estimates, as the response characteristics of the tensile tester 1, a gain characteristic that is a characteristic of gain with respect to frequency and a phase characteristic that is a characteristic of phase with respect to frequency.

[0043] The estimation unit 534 estimates the response characteristics of the tensile tester 1 based on the following formulas (1) and (2). Note that the response characteristics of the tensile tester 1 are the response characteristics of a system including the testing machine main body 2, the specimen SP attached to the testing machine main body 2, and the control unit 3.

[0044]

number

[0045]

number

[0046] The estimation performed by the estimation unit 534 will now be described in detail. Here, Gry(s) calculated by the estimation unit 534 is represented as Gry_predict(s).

[0047] The estimation unit 534 calculates P(s) when the control parameters 543 are set to a first set value. This P(s) is denoted as P_actual(s). The first set value is the set value of the control parameters 543 used in the tensile test performed by the tensile tester 1, and is the set value set in the control parameters 543 when the estimation unit 534 makes the estimation. The first set value includes a value of the proportional gain P, a value of the integral gain I, a value of the differential gain D, a value of the first coefficient b, and a value of the second coefficient c. Here, the value of the proportional gain P included in the first set value is denoted as P_actual. The value of the differential gain D included in the first set value is denoted as D_actual. The value of the integral gain I included in the first set value is denoted as I_actual. The value of the first coefficient b included in the first set value is denoted as b_actual. The value of the second coefficient c included in the first set value is denoted as c_actual. The first set value is included in the control parameters 543 stored in the memory 54.

[0048] The estimation unit 534 finds P_actual(s) by substituting P_actual for P in equation (2), substituting D_actual for D in equation (2), substituting I_actual for I in equation (2), substituting b_actual for b in equation (2), substituting c_actual for c in equation (2), and substituting Gry_actual(s) for Gry(s) in equation (2).

[0049] Gry_actual(s) is the actually measured transfer function of the tensile tester 1. Gry_actual(s) is determined, for example, by system identification in an autoregressive moving average model (ARMA model). Gry_actual(s) is determined by the estimation unit 533. Note that Gry_actual(s) may be determined in advance before the estimation unit 533 estimates the response characteristics of the tensile tester 1, or may be determined when the estimation unit 534 estimates the response characteristics of the tensile tester 1.

[0050] When estimating Gry_actual(s) by system identification in the ARMA model, the estimation unit 533 calculates Gry_actual(s) based on the following equations (3) and (4).

[0051]

number

[0052]

number

[0053] The estimation unit 533 uses data of y, which is a response value, and data of u, which is a target value, to calculate φ1, φ2, . . . φ based on an algorithm in the ARMA model. p ,θ1,θ2,···θ q Then, the estimation unit 533 calculates the calculated φ1, φ2, . . . φ p ,θ1,θ2,···θ q into equation (4) to find G(Z) in equation (4). Note that when the estimation unit 534 finds Gry_actual(s) to estimate the response characteristics of the tensile tester 1, data on y, which is the response value, and data on u, which is the target value, are stored in the memory 54.

[0054] The variable Z in the Z transformation is e sTwhere e is the Napier's constant, s is a variable in the Laplace transform, and T is a sampling period in the Z transform. The estimation unit 533 calculates Z=e sT Then, the obtained G(Z) is transformed into G(s) by Laplace transform. The estimation unit 533 then obtains the transformed G(s) as Gry_actual(s).

[0055] The estimation unit 534 calculates Gry_predict(s) by substituting the calculated P_actual(s) and the second setting value received by the receiving unit 533 into equation (1). The second setting value includes a value of proportional gain P, a value of integral gain I, a value of derivative gain D, a value of first coefficient b, and a value of second coefficient c. Here, the value of proportional gain P included in the second setting value is represented as P_candidate. The value of derivative gain D included in the second setting value is represented as D_candidate. The value of integral gain I included in the second setting value is represented as I_candidate. The value of first coefficient b included in the second setting value is represented as b_candidate. The value of second coefficient c included in the second setting value is represented as c_candidate.

[0056] The estimation unit 534 substitutes the obtained P_actual(s) into P(s) in equation (1), substitutes P_candidate for P in equation (1), substitutes D_candidate for D in equation (1), substitutes I_candidate for I in equation (1), substitutes b_candidate for b in equation (1), and substitutes c_candidate for c in equation (1) to obtain Gry_predict(s).

[0057] The estimation unit 534 estimates the gain characteristic and the phase characteristic as the response characteristic of the tensile tester 1 based on the calculated Gry_predict(s).

[0058] When the receiving unit 533 receives a third set value in addition to the second set value, the estimating unit 534 estimates a first response characteristic which is the response characteristic of the tensile tester 1 when the second set value is set in the control parameter 543, and a second response characteristic which is the response characteristic of the tensile tester 1 when the third set value is set in the control parameter 543. The estimating unit 534 estimates the second response characteristic in the same manner as the estimation for the second set value described above.

[0059] [3-3. Experimental results of estimation accuracy] The results of an experiment to confirm the estimation accuracy of the estimation unit 534 will be described. FIG. 4 is a gain diagram showing the results of an experiment to confirm the estimation accuracy of the estimation unit 534.

[0060] Graph G1 in Fig. 4 shows the gain characteristic estimated by estimation unit 534. Graph G2 in Fig. 4 shows the gain characteristic that was actually measured. The gain characteristic shown in graph G2 is the gain characteristic measured in a state where the second setting value used when estimating the gain characteristic shown in graph G1 is set in control parameter 543. The gain characteristic shown in graph G2 is the characteristic obtained by an experiment in which the frequency was increased linearly from 1 Hz to 50 Hz over 49 seconds with the amplitude range set to ±0.3 mm.

[0061] The amplitude values ​​shown by the graph G1 and the amplitude values ​​shown by the graph G2 are roughly the same, and it can be seen that the estimation unit 534 can estimate the response characteristics of the tensile tester 1 with high accuracy.

[0062] Returning to FIG. 2, the first measurement unit 535 measures the response characteristics of the tensile tester 1 in a state where the first setting value is set in the control parameter 543. In a state where the first setting value is set in the control parameter 543, the first measurement unit 535 inputs a random wave or a sweep wave to the two-degree-of-freedom PID control shown in FIG. 3. In this way, the first measurement unit 535 measures the response characteristics of the tensile tester 1 in a state where the first setting value is set in the control parameter 543. The first measurement unit 535 measures the gain characteristic and the phase characteristic as the response characteristics of the tensile tester 1.

[0063] The second measurement unit 536 measures the response characteristics of the tensile tester 1 in a state where the second setting value received by the reception unit 533 is set as the control parameter 543. The second measurement unit 536 inputs a random wave or a sweep wave to the two-degree-of-freedom PID control shown in Fig. 3 in a state where the second setting value received by the reception unit 533 is set as the control parameter 543. In this way, the second measurement unit 436 measures the response characteristics of the tensile tester 1 in a state where the second setting value is set as the control parameter 543. The second measurement unit 536 measures the gain characteristic and the phase characteristic as the response characteristics of the tensile tester 1.

[0064] The display control unit 537 displays the response characteristics of the tensile tester 1 estimated by the estimation unit 534 on the touch panel 511. The display control unit 543 displays the response characteristics of the tensile tester 1 estimated by the estimation unit 534 and the response characteristics of the tensile tester 1 measured by the first measurement unit 535 in an overlapping manner. The display control unit 537 displays the response characteristics of the tensile tester 1 by displaying a Bode plot.

[0065] Fig. 5 is a diagram showing an example of a gain diagram displayed by the display control unit 537. Fig. 6 is a diagram showing an example of a phase diagram displayed by the display control unit 537.

[0066] Graphs G3 and G5 show the response characteristics of the tensile tester 1 measured by the first measuring unit 535. In the first set values ​​set in the control parameters 543 when measuring the response characteristics of the tensile tester 1 shown in graphs G3 and G5, the value of the proportional gain P is "203", the value of the integral gain I is "0.031", the value of the differential gain D is "0.00", the value of the first coefficient b is "0.51", and the value of the second coefficient c is "0.5".

[0067] Graphs G4 and G6 are response characteristics of the tensile tester 1 estimated by the estimation unit 534, and show the response characteristics of the tensile tester 1 in a state where the second set values ​​are set in the control parameters 543. The second set values ​​used in estimating the response characteristics shown in graphs G4 and G6 are a proportional gain P of "202", an integral gain I of "0.144", a differential gain D of "24.00", a first coefficient b of "0.91", and a second coefficient c of "0.5".

[0068] 5 and 6, the display control unit 537 displays the response characteristic of the tensile tester 1 estimated by the estimation unit 534 and the response characteristic of the tensile tester 1 measured by the first measurement unit 535 in an overlapping manner. Therefore, even without performing a test to obtain the response characteristic of the tensile tester 1 when the setting value of the control parameter 543 is changed, the user can confirm the difference between the response characteristic of the tensile tester 1 before changing the setting value of the control parameter 543 and the response characteristic of the tensile tester 1 when the setting value of the control parameter 543 is changed. Therefore, the user's effort in adjusting the control parameter 543 is reduced, and the user can easily determine an appropriate value for the control parameter 543.

[0069] When the estimation unit 534 estimates a plurality of response characteristics of the tensile tester 1, the display control unit 537 displays the plurality of response characteristics of the tensile tester 1 in an overlapping manner. That is, when the estimation unit 534 estimates a first response characteristic and a second response characteristic, the display control unit 537 displays the first response characteristic and the second response characteristic in an overlapping manner.

[0070] Fig. 7 is a diagram showing an example of a gain diagram displayed by the display control unit 537. Fig. 8 is a diagram showing an example of a phase diagram displayed by the display control unit 537.

[0071] The response characteristics of the tensile testing machine 1 shown by graphs G8 and G13, the response characteristics of the tensile testing machine 1 shown by graphs G9 and G14, the response characteristics of the tensile testing machine 1 shown by graphs G10 and G15, and the response characteristics of the tensile testing machine 1 shown by graphs G11 and G16 each correspond to an example of a first response characteristic and a second response characteristic.

[0072] Graph G7 shows the gain characteristics measured by first measuring unit 535. The first set values ​​set in control parameters 543 in the measurement of the gain characteristics shown in graph G7 are: proportional gain P = "168", integral gain I = "5", derivative gain D = "40", first coefficient b = "1", and second coefficient c = "1".

[0073] Graphs G8, G9, G10, and G11 show gain characteristics estimated by the estimation unit 534. The setting value candidates used in the estimation of the gain characteristics shown by graphs G8, G9, G10, and G11 correspond to examples of the second setting value and the third setting value.

[0074] The candidate setting values ​​used in estimating the gain characteristics shown in graph G8 are a proportional gain P of "192", an integral gain I of "0.047", a differential gain D of "50", a first coefficient b of "1", and a second coefficient c of "1". The candidate setting values ​​used in estimating the gain characteristics shown in graph G9 are a proportional gain P of "184", an integral gain I of "0.062", a differential gain D of "45", a first coefficient b of "1", and a second coefficient c of "1". The candidate setting values ​​used in estimating the gain characteristics shown in graph G10 are a proportional gain P value of "176", an integral gain I value of "0.083", a differential gain D value of "52", a first coefficient b value of "1", and a second coefficient c value of "1". The candidate setting values ​​used in estimating the gain characteristics shown in graph G11 are a proportional gain P of "165", an integral gain I of "0.12", a differential gain D of "63", a first coefficient b of "1", and a second coefficient c of "1".

[0075] 8, graph G12 shows the phase characteristics measured by first measuring unit 535. The first setting value set in control parameter 543 in the measurement of the phase characteristics shown in graph G12 is the same as the first setting value set in control parameter 543 in the measurement of the gain characteristics shown in graph G7.

[0076] In FIG. 8, graphs G13, G14, G15, and G16 indicate phase characteristics estimated by the estimation unit 534. The setting value candidates used in the estimation of the phase characteristics indicated by graph G13 are the same as the setting value candidates used in the estimation of the gain characteristics indicated by graph G8. The setting value candidates used in the estimation of the phase characteristics indicated by graph G14 are the same as the setting value candidates used in the estimation of the gain characteristics indicated by graph G9. The setting value candidates used in the estimation of the phase characteristics indicated by graph G15 are the same as the setting value candidates used in the estimation of the gain characteristics indicated by graph G10. The setting value candidates used in the estimation of the phase characteristics indicated by graph G16 are the same as the setting value candidates used in the estimation of the gain characteristics indicated by graph G11.

[0077] 7 and 8, the display control unit 537 displays the response characteristics of multiple tensile testers 1 in an overlapping manner. Therefore, the user can check how the response characteristics of the tensile tester 1 change when the set values ​​of the control parameters 543 are changed, even without conducting a test to obtain the response characteristics of the tensile tester 1. This reduces the user's effort in adjusting the control parameters 543, and allows the user to easily determine appropriate values ​​for the control parameters 543.

[0078] The display control unit 537 can display the response characteristic of the tensile tester 1 measured by the second measuring unit 536 superimposed on the response characteristic of the tensile tester 1 estimated by the estimation unit 534.

[0079] Fig. 9 is a diagram showing an example of a gain diagram displayed by the display control unit 537. Fig. 10 is a diagram showing an example of a phase diagram displayed by the display control unit 537.

[0080] Graphs G17 and G20 show the response characteristics of the tensile tester 1 measured by the first measuring unit 535. The first set values ​​set in the control parameters 543 in measuring the response characteristics shown in graphs G17 and G20 were: proportional gain P = "168", integral gain I = "5", derivative gain D = "40", first coefficient b = "1", and second coefficient c = "1".

[0081] Graphs G18 and G21 are response characteristics of the tensile tester 1 estimated by the estimation unit 534, and show the response characteristics of the tensile tester 1 in a state where the second set value is set in the control parameter 543. The second set values ​​substituted into equation (1) when estimating the response characteristics of the tensile tester 1 shown in graphs G18 and G21 are: proportional gain P = "192", integral gain I = "0.047", differential gain D = "50", first coefficient b = "1", and second coefficient c = "1".

[0082] Graphs G19 and G22 show the response characteristics of the tensile testing machine 1 measured by the second measuring unit 536. The second set values ​​set in the control parameters 543 in measuring the response characteristics shown in graphs G19 and G22 were: proportional gain P = "192", integral gain I = "0.047", derivative gain D = "50", first coefficient b = "1", and second coefficient c = "1".

[0083] 9 and 10, the display control unit 537 displays the response characteristic of the tensile tester 1 estimated by the estimation unit 534 and the response characteristic of the tensile tester 1 measured by the second measurement unit 536 in an overlapping manner. This allows the user to easily check the accuracy of the estimated response characteristic of the tensile tester 1.

[0084] [4. Processing of control unit] FIG. 11 is a flowchart showing an example of the processing of the control unit 52. Next, in step S1, the estimation unit 534 estimates the response characteristic of the tensile tester 1. When the reception unit 533 receives a plurality of candidates, the estimation unit 534 estimates a plurality of response characteristics of the tensile tester 1.

[0085] Next, in step S2, the display control unit 537 generates graph data showing the response characteristics of the tensile tester 1 estimated by the estimation unit 534.

[0086] Next, in step S3, the display control unit 537 generates graph data showing the response characteristics of the tensile tester 1 measured by the first measuring unit 535.

[0087] Next, in step S4, the display control unit 537 determines whether or not the response characteristics of the tensile tester 1 measured by the second measuring unit 536 are set to be displayed.

[0088] If the display control unit 537 determines that the setting is not to display the response characteristics of the tensile testing machine 1 measured by the second measuring unit 536 (step S4: NO), in step S5, the display control unit 537 displays the response characteristics of the tensile testing machine 1 estimated by the estimation unit 534 and the response characteristics of the tensile testing machine 1 measured by the first measuring unit 535 in an overlapping manner.

[0089] If the display control unit 537 determines that the setting is not to display the response characteristics of the tensile testing machine 1 measured by the second measuring unit 536 (step S4: YES), then in step S6, it generates graph data showing the response characteristics of the tensile testing machine 1 measured by the second measuring unit 536.

[0090] Next, in step S7, the display control unit 537 displays the response characteristics of the tensile testing machine 1 estimated by the estimation unit 534, the response characteristics of the tensile testing machine 1 measured by the first measuring unit 535, and the response characteristics of the tensile testing machine 1 measured by the second measuring unit 536 in an overlapping manner.

[0091] In the above description, the display control unit 537 is configured to display the response characteristic of the tensile tester 1 estimated by the estimating unit 537 and the response characteristic of the tensile tester 1 measured by the first measuring unit 535 in an overlapping manner. However, the display control unit 537 may be configured to display only the response characteristic of the tensile tester 1 estimated by the estimating unit 534.

[0092] [5. Embodiments and Effects] It will be understood by those skilled in the art that the above-described embodiments are examples of the following aspects.

[0093] (Section 1) The material testing machine of this embodiment is a material testing machine equipped with a testing machine main body having an actuator, and is equipped with an estimation unit that estimates the response characteristics of the material testing machine, and the estimation unit calculates the response characteristics of the testing machine main body when a control parameter that specifies the operation of the actuator is set to a first set value used in a material test conducted by the material testing machine, and based on the calculated response characteristics of the testing machine main body, estimates the response characteristics of the material testing machine when a second set value different from the first set value is set to the control parameter.

[0094] According to the materials testing machine described in paragraph 1, it is possible to obtain the response characteristics of the materials testing machine when the values ​​of the control parameters are changed, so the operator can adjust the control parameters without conducting a test to obtain the response characteristics of the materials testing machine. This reduces the operator's effort in adjusting the control parameters.

[0095] (Section 2) The material testing machine according to claim 1 further comprises a display control unit that displays the response characteristics of the material testing machine estimated by the estimation unit.

[0096] According to the materials testing machine described in paragraph 2, the operator can check the response characteristics of the materials testing machine when the value of the control parameter is changed, and therefore the operator can adjust the control parameters without conducting a test to obtain the response characteristics of the materials testing machine. This reduces the operator's effort in adjusting the control parameters.

[0097] (Section 3) In the material testing machine described in the second aspect, the estimation unit estimates a first response characteristic which is the response characteristic of the material testing machine when the control parameter is set to the second set value, and a second response characteristic which is the response characteristic of the material testing machine when the control parameter is set to a third set value which is different from the second set value, and the display control unit displays the first response characteristic estimated by the estimation unit and the second response characteristic estimated by the estimation unit in an overlapping manner.

[0098] According to the materials testing machine described in paragraph 3, an operator can check how the response characteristics of the materials testing machine change when the control parameter settings are changed, without having to conduct a test to obtain the response characteristics of the materials testing machine. This reduces the operator's workload when adjusting the control parameters, and allows the operator to easily determine appropriate control parameter values.

[0099] (Section 4) In the material testing machine described in paragraph 2 or 3, a first measurement unit is provided that measures the response characteristics of the material testing machine when the first setting value is set for the control parameter, and the display control unit displays the response characteristics of the material testing machine estimated by the estimation unit and the response characteristics of the material testing machine measured by the first measurement unit in an overlapping manner.

[0100] According to the materials testing machine described in paragraph 4, an operator can confirm the difference between the response characteristics of the materials testing machine before changing the control parameter setting values ​​and the response characteristics of the materials testing machine when the control parameter setting values ​​are changed, without having to conduct a test to obtain the response characteristics of the materials testing machine when the control parameter setting values ​​are changed. This reduces the operator's effort in adjusting the control parameters, and allows the operator to easily determine appropriate control parameter values.

[0101] (Section 5) In the material testing machine described in any one of paragraphs 2 to 4, a second measurement unit is provided that measures the response characteristics of the material testing machine when the second set value is set for the control parameter, and the display control unit displays the response characteristics of the material testing machine estimated by the estimation unit and the response characteristics of the material testing machine measured by the second measurement unit in an overlapping manner.

[0102] According to the material testing machine described in paragraph 5, an operator can visually compare the estimated response characteristics of the material testing machine with the response characteristics of the material testing machine, so that the operator can easily check the accuracy of the estimated response characteristics of the material testing machine.

[0103] 6. Other Embodiments The tensile testing machine 1 according to this embodiment is merely an example of an embodiment of a material testing machine according to the present invention, and can be modified and applied as desired within the scope of the present invention.

[0104] For example, in the above-described embodiment, the material testing machine is a tensile testing machine 1, but this embodiment is not limited to this. The material testing machine may apply a test force to the specimen SP and deform the specimen SP to perform a material test. For example, the material testing machine may be a compression testing machine, a bending testing machine, or a torsion testing machine.

[0105] 1 and 2 indicate functional configurations, and the specific implementation form is not particularly limited. In other words, it is not necessary to implement hardware corresponding to each functional unit individually, and it is of course possible to implement a configuration in which a single processor executes a program to realize the functions of multiple functional units. Furthermore, some of the functions realized by software in the above embodiments may be realized by hardware, or some of the functions realized by hardware may be realized by software.

[0106] 11 is divided according to the main processing content to facilitate understanding of the processing of the control unit 52. There is no limitation to the manner in which the processing units are divided or the names thereof shown in the flowchart of FIG. 11, and the processing units can be divided into more processing units according to the processing content, or one processing unit can be divided to include more processes. Furthermore, the processing order of the above flowchart is not limited to the example shown in the figure.

[0107] The control device 50 of the tensile tester 1 causes the processor 53 included in the control unit 52 to execute a control program 541 corresponding to the control method of the tensile tester 1. The control program 541 can also be recorded on a computer-readable recording medium. Examples of the recording medium include magnetic and optical recording media, and semiconductor memory devices. Specific examples include portable or fixed recording media such as flexible disks, HDDs, CD-ROMs (Compact Disk Read Only Memory), DVDs, Blu-ray (registered trademark) discs, magneto-optical disks, flash memories, and card-type recording media. The recording medium may also be a non-volatile storage device such as RAM, ROM, or HDD, which is an internal storage device included in the control unit 52. The control program 541 may also be stored in a server device or the like, and downloaded from the server device to the control unit 52. [Explanation of symbols]

[0108] 1. Tensile testing machine (material testing machine) 2 Testing machine body 25 Hydraulic Actuator (Actuator) 534 Estimation Department 535 First Measurement Division 536 Second Measurement Division 537 Display control unit 543 Control Parameters

Claims

[Claim 1] A material testing machine including a testing machine body having an actuator, a reception unit that receives a plurality of setting values ​​from a user; an estimation unit that estimates a response characteristic of the material testing machine; a first measurement unit that measures a response characteristic of the material testing machine in a state where a first set value used in a material test performed by the material testing machine is set as a control parameter that defines an operation of the actuator; and a second measurement unit that measures a response characteristic of the materials testing machine in a state where a second set value that is different from the first set value and that is accepted by the accepting unit is set as the control parameter; a display control unit that displays the response characteristics of the materials testing machine estimated by the estimation unit, The estimation unit determining a response characteristic of the testing machine main body in a state in which the first set value is set for the control parameter; Based on the response characteristics of the testing machine body thus determined, a first response characteristic is the response characteristic of the materials testing machine in a state in which the control parameter is set to the second set value, and a second response characteristic is the response characteristic of the materials testing machine in a state in which the control parameter is set to a third set value that is different from the second set value and that has been accepted by the accepting unit; The display control unit When the setting is not to display the response characteristic of the material testing machine measured by the second measurement unit, the first response characteristic, the second response characteristic, and the response characteristic of the material testing machine measured by the first measurement unit are displayed in an overlapping manner; When the setting is such that the response characteristics of the material testing machine measured by the second measurement unit are displayed, the first response characteristic, the second response characteristic, the response characteristics of the material testing machine measured by the first measurement unit, and the response characteristics of the material testing machine measured by the second measurement unit are displayed in an overlapping manner. Material testing machine.

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