Vibration test apparatus and method for controlling the vibration test apparatus

Abstract

To provide a vibration testing device that excites a specimen with desired displacement and phase to evaluate the specimen, and a control method for the vibration testing device.SOLUTION: A vibration testing device comprises: a table 9 on which a specimen 10 is arranged; a testing device driving unit for exciting the table 9; a displacement sensor S04 that detects displacement of the testing device driving unit; an acceleration sensor S06 that detects displacement of the specimen 10; a controller 2; and a user interface 1 that receives an operator's operation. The controller 2 includes: a first target signal setting unit 1b that reproduces a test pattern set by the operator; an excitation data storage unit 2a1; a filter adjustment unit 2a2 that, on the basis of, the displacement of the test piece 10 and the first target signal stored in the excitation data storage unit 2a1, designs a parameter of a filter for correcting the first target signal to calculate a second target signal; and a second target signal setting unit 2a3 that shapes a target signal of the first target signal setting unit by using the filter adjusted by the filter adjustment unit 2a2.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a vibration testing apparatus for vibrating and evaluating a test object, and a method for controlling the vibration testing apparatus. [Background technology]

[0002] Test equipment is known that evaluates the seismic performance of a structure by vibrating a model that mimics the characteristics of the structure (hereinafter referred to as a test specimen). These test equipment must reproduce test patterns that have a fast response in displacement and acceleration, such as earthquake waveforms, so hydraulic actuators with excellent response and driving force are often used.

[0003] Such vibration testing devices perform evaluation tests on a specimen by driving a hydraulic actuator in accordance with a predetermined test pattern (acceleration command or displacement command) determined by a user. The vibration test device is equipped with sensors that acquire the position, speed, and acceleration of the hydraulic actuator, and these signals are used for feedback control to reproduce the desired test waveform.

[0004] However, in the above configuration, although the displacement or velocity of the hydraulic actuator can be made to follow the test pattern, the displacement, velocity, and acceleration of the specimen cannot necessarily be made to follow the test pattern, and therefore it is not easy to meet the demands of a user (or operator) who wants to reproduce the patterns of displacement, velocity, and acceleration occurring at a specific point of the specimen.

[0005] Furthermore, since hydraulic actuators are used, there are variable factors such as changes in hydraulic characteristics and friction in the drive section, so unless appropriate control design is carried out, it is difficult to drive the displacement or speed of the hydraulic actuator in a desired pattern.

[0006] In response to these issues, Patent Document 1 presents a vibration testing device in which a displacement sensor and an acceleration sensor are attached to a specimen (test object), the signals are input to a servo control device, and the sensor information is used to change the test conditions (vibration pattern), thereby controlling the displacement and acceleration of the specimen. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] JP 2012-237634 A [Non-patent literature]

[0008] [Non-Patent Document 1] Osamu Kaneko, Takeo Nakamura, Taichi Ikezaki: A New Approach to Feedforward Controller Update in Two-Degree-of-Freedom Control Systems - Proposal of Estimated Response Iterative Tuning (ERIT) -, Transactions of the Society of Instrument and Control Engineers, 2018, Vol. 54, No. 12, p. 857-864 [Non-Patent Document 2] Ishihara, Tahara, and Hironaka: Feedforward Control Tuning of Vibration Testing Equipment Using Data-Driven Control, 62nd Japan Joint Conference on Automatic Control, 2019 Summary of the Invention [Problem to be solved by the invention]

[0009] The test equipment disclosed in Patent Document 1 is configured to be able to acquire the displacement and acceleration of specific locations on a test specimen, and by using these signals to perform appropriate control, it is possible to reproduce the test pattern desired by the user or operator of the test equipment. Specifically, in Patent Document 1, a test is performed to obtain the vibration characteristics of a specimen, and the displacement amount actually obtained from a sensor attached to the specimen is stored in response to the commanded displacement amount (or acceleration amount) in this test. The frequency and displacement amount of the waveform obtained by this vibration for characterization are stored as a database, and a characterization test is repeatedly performed in which the vibration command value is amplified until the specimen exceeds the maximum displacement amount, thereby determining a correction amount that can vibrate the specimen at the maximum displacement so as to cover the frequency range in which the actual test is to be performed. By using this correction amount to correct the test pattern, it becomes possible to vibrate the specimen at the desired displacement.

[0010] By using the above method, the actual displacement of the specimen can be adjusted to the displacement desired by the user of the testing device, making it an effective method for testing to evaluate the force or energy applied to the specimen. However, the technique disclosed in Patent Document 1 changes only the amplitude (gain) and does not perform phase compensation, so there may be cases where sufficient performance cannot be provided when dynamically changing test patterns.

[0011] A commonly known method for simultaneously compensating for gain and phase is to vibrate the control object (test equipment including the specimen) with a test pattern (chirp signal or random signal) containing various frequency components to obtain the transfer function of the control object, and then calculate the command value using the inverse transfer function, which is the inverse characteristic of the obtained function.

[0012] However, the dynamics of a vibration test system (equation of motion) is described by an n-th order differential equation. In other words, the transfer function of a vibration test system is a strictly proper transfer function in which the order of the denominator (n) is greater than the order of the numerator. Therefore, the inverse characteristic is an improper transfer function in which the order of the numerator is greater than the order of the denominator. In other words, a non-proper transfer function contains a differential element. The differential indicates the slope between the current time (t=k) and the time one step ahead (t=k+1). In other words, to calculate the differential at time t=k, information about the future (t=k+1) is required, and causality does not hold. For this reason, it is not easy to implement a differential element in a computer (controller). For the reasons mentioned above, a compensator that utilizes the inverse characteristic of a transfer function cannot necessarily be used in a vibration testing device.

[0013] Therefore, the present invention provides a vibration testing apparatus and a control method for a vibration testing apparatus that enables the realization of a desired specimen response, i.e., the adjustment of the amount of displacement (gain) and phase, in as simple a manner as possible, without obtaining the inverse transfer characteristic of the controlled object. [Means for solving the problem]

[0014] In order to solve the above problems, a vibration testing apparatus according to the present invention is a vibration testing apparatus including a specimen installation section for installing a specimen to be evaluated, a test apparatus driving section for exciting the specimen installation section, a driving section displacement detection section for detecting the displacement of the test apparatus driving section, a specimen displacement detection section for detecting the displacement of the specimen, a controller for controlling the displacement amount of the test apparatus driving section so that it follows a specific target displacement, and a user interface for receiving an operation from an operator, the vibration testing apparatus including a first target signal setting section for reproducing a test pattern set by an operator, a vibration data storage section for storing the displacement of the specimen detected by the specimen displacement detection section when the test apparatus is driven with the output of the first target signal setting section as a target value, a filter adjustment section for designing parameters of a filter for calculating a second target signal by correcting the first target signal based on the displacement of the specimen stored in the vibration data storage section and the first target signal set in the first target signal setting section, and a second target signal setting section for shaping the target signal of the first target signal setting section using the filter adjusted by the filter adjustment section. a target signal switching unit that switches a target value for which the controller performs tracking control between an output of the first target signal setting unit and an output of the second target signal setting unit, and a target signal converter, the target signal converter having the excitation data storage unit, the filter adjustment unit, the second target signal setting unit, and the target signal switching unit, the target signal switching unit switches the target value for which the controller performs tracking control to the output of the second target signal setting unit after driving the test device with the target value of the first target signal setting unit. It is characterized by the fact that A control method for a vibration test apparatus according to the present invention includes a specimen installation section for arranging a specimen to be evaluated, a test apparatus drive section for exciting the specimen installation section, a drive section displacement detection section for detecting the displacement of the test apparatus drive section, a specimen displacement detection section for detecting the displacement of the specimen, a controller for controlling the displacement amount of the test apparatus drive section to follow a specific target displacement, and a user interface for receiving an operation from an operator, the control method comprising the steps of: when the test apparatus is driven with an output of a first target signal setting section for reproducing a test pattern set by an operator as a target value, storing the displacement of the specimen detected by the specimen displacement detection section in a vibration data storage section; based on the displacement of the specimen stored in the vibration data storage section and the first target signal set in the first target signal setting section, a filter adjustment section designs parameters of a filter for correcting the first target signal to calculate a second target signal; and shaping the target signal of the first target signal setting section using the filter adjusted by the filter adjustment section. and setting the second target signal as the target signal, and a target signal switching unit drives the test device with the target value of the first target signal setting unit, and then switches the target value that the controller performs tracking control to the second target signal. It is characterized by the above. Effect of the Invention

[0015] According to the present invention, it is possible to provide a vibration testing apparatus and a control method for a vibration testing apparatus that enable the realization of a desired test specimen response, i.e., the adjustment of the amount of displacement (gain) and phase, in as simple a manner as possible, without obtaining the inverse transfer characteristic of the controlled object. Problems, configurations and effects other than those described above will become apparent from the following description of the embodiments. [Brief description of the drawings]

[0016] [Figure 1] 1 is an overview diagram showing a hydraulically driven vibration testing device according to an embodiment of the present invention; [Diagram 2] 2 is a diagram illustrating the relationship between the operation of the hydraulic piston shown in FIG. 1 and a displacement sensor and a pressure sensor. [Diagram 3] FIG. 1 is a functional block diagram of a vibration testing device of a first embodiment according to an embodiment of the present invention. [Figure 4A] FIG. 2 illustrates a transfer function of a control loop. [Figure 4B] FIG. 2 illustrates a transfer function of a control loop. [Figure 5A] FIG. 11 is a diagram showing an example of a waveform obtained when the first target signal r is not corrected. [Figure 5B] FIG. 1 is a diagram showing a waveform obtained when the method disclosed in Patent Document 1 is applied. [Figure 5C] 5C is a diagram showing an integral value of the difference between the waveform zm desired by the user and the actual waveform z in the waveform of FIG. 5B. [Figure 5D] FIG. 11 is a diagram showing a state in which the difference between the ideal response zm and the actual response z of the test specimen at each time becomes smaller. [Figure 5E] FIG. 13 is a diagram illustrating a state before the order is increased by a filter adjustment unit. [Figure 6] 4 is a flowchart relating to a control method of the vibration testing apparatus. [Figure 7] FIG. 11 is a functional block diagram of a vibration testing device according to a second embodiment of the present invention. [Figure 8] FIG. 8 is a diagram showing a modification of the vibration testing device of the second embodiment shown in FIG. [Figure 9] FIG. 11 is a schematic configuration diagram of a target signal switching unit according to a third embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] Fig. 1 is a schematic overview of a hydraulically driven vibration testing apparatus according to an embodiment of the present invention. In this specification, for the sake of simplicity, a single-axis hydraulically driven vibration testing apparatus is used as an example for explanation, but the present invention is not limited to single-axis hydraulically driven vibration testing apparatuses. In Fig. 1, dotted lines indicate signal lines, and solid lines indicate piping.

[0018] 1, a user interface 1 is used by a user or operator of a test device to set various test patterns. The operator sets a desired excitation waveform via the user interface 1. Since the user interface 1 is a device that generates a target signal, it is not limited to a dedicated terminal, and may be composed of multiple devices such as a combination of an operation terminal and a signal generator. The operation terminal may be a normal personal computer (PC) or a tablet PC.

[0019] The dimension of the excitation waveform set by the user interface 1 may be any of displacement, velocity, and acceleration. The operator designs the excitation waveform in an arbitrary pattern to reproduce the waveform of an actual earthquake that occurred in the past or to excite a specific behavior. The user interface 1 (signal generator or PC) that generates a target signal for testing corresponds to the target signal generating device in the present invention.

[0020] The controller 2 executes various control calculations to operate the hydraulic vibration testing device according to the target set in the user interface 1. The controller 2 acquires the target excitation waveform set in the user interface 1 and the values ​​of various sensors S01 to S06 (described later), and calculates the operation amount of the servo amplifier 3. The detailed configuration of the controller 2 will be described later.

[0021] The servo amplifier 3 converts the command (voltage) output from the controller 2 into a current value for driving the servo valve 4 . The servo valve 4 adjusts the pressure oil flowing from the hydraulic power source 5 to the hydraulic cylinder 6 by opening and closing the valve in accordance with the current value received from the servo amplifier 3. A temperature sensor S01 is provided between the servo valve 4 and the hydraulic power source 5 to detect the temperature of the pressure oil.

[0022] The pressure oil supplied to the hydraulic cylinder 6 via the servo valve 4 drives the hydraulic piston 7. At this time, the driving direction of the hydraulic piston 7 is changed depending on whether the pressure oil is supplied from the left or right port of the servo valve 4 in FIG. 1. The pressure oil discharged from the servo valve 4 can be detected by flow sensors S02a and S02b. Since the path through which the pressure oil flows changes depending on the driving direction of the hydraulic piston 7, the flow sensor used may be changed as appropriate depending on the driving direction.

[0023] The hydraulic piston 7 applies a force to the table 9 via a coupling 8, thereby vibrating the table 9. The hydraulic piston 7 is equipped with a speed sensor S03 and a displacement sensor S04. It is not necessary to provide both the speed sensor S03 and the displacement sensor S04. For example, when only the displacement sensor S04 is provided, the difference between the detected values ​​may be used as an approximation of the speed. When only the speed sensor S03 is provided, the integral value may be used as the amount of displacement. Furthermore, an acceleration sensor may be provided instead of or in addition to the speed sensor S03 and the displacement sensor S04. These sensors for detecting the displacement of the hydraulic piston 7 correspond to an actuator displacement detection unit of the present invention, which will be described later.

[0024] Fig. 2 is a diagram showing the relationship between the operation of the hydraulic piston shown in Fig. 1 and the displacement sensor and pressure sensor. As shown in Fig. 2, it is desirable for the displacement sensor S04 to output a displacement amount x=-a[m] when the hydraulic piston 7 is in its most contracted state and x=+a[m] when the hydraulic piston 7 is in its most extended state, taking the x-axis as the axis from the hydraulic piston 7 toward the table 9 and assuming the range of motion of the hydraulic piston 7 to be 2a[m]. The positive and negative speed of the speed sensor S03 also follow the above x-axis. The hydraulic cylinder 6 is provided with pressure sensors S05a and S05b for detecting the front and rear pressures of the hydraulic piston 7. When it is necessary to distinguish between these sensors, the pressure sensor S05a on the negative side of the x-axis will be called the rear pressure sensor, and the pressure sensor S05b on the positive side of the x-axis will be called the front pressure sensor.

[0025] The above-mentioned servo amplifier 3, servo valve 4, hydraulic power source 5, hydraulic cylinder 6, and hydraulic piston 7 constitute a test device drive unit in the present invention, which will be described later.

[0026] A structure to be tested (specimen 10) is attached to the table 9, and various evaluations are performed by exciting the specimen 10 according to the excitation waveform set by the user interface 1. The table 9 corresponds to the specimen installation section in this invention.

[0027] The specimen 10 is equipped with an acceleration sensor S06. The specimen velocity can be obtained by integrating the specimen acceleration acquired by the acceleration sensor S06, and the specimen displacement can be obtained by integrating this specimen velocity again. Therefore, the acceleration sensor S06 corresponds to the specimen displacement detection unit of the present invention.

[0028] In this embodiment, an example using the acceleration sensor S06 that can be easily attached to the specimen 10 is illustrated, but the present invention is not limited to this. For example, a laser displacement meter installed in a location independent (separate) from the test device may be used to obtain the displacement amount of the specimen 10, and this value may be used as the specimen displacement detection unit described later.

[0029] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the following, for the sake of simplicity, it is assumed that the excitation waveform is given in the dimension of displacement, but it goes without saying that the technical scope of the present invention also includes velocity control or acceleration control. EXAMPLES

[0030] Fig. 3 is a functional block diagram of a vibration testing device of Example 1 according to an embodiment of the present invention. Note that, for ease of understanding, some of the components shown in Fig. 1 are omitted in Fig. 3.

[0031] As shown in Fig. 3, the user interface 1 is composed of a user operation unit 1a, a first target signal setting unit 1b, and a monitor display unit 1d. The user operation unit 1a corresponds to an operation terminal where an operator inputs various data. The first target signal setting unit 1b corresponds to a signal generator that generates a test pattern. The monitor display unit 1d corresponds to a monitor (screen) of the operation terminal (PC, tablet).

[0032] The controller 2 is composed of a filter design unit 2a and a feedback control unit 2b (FB control unit in FIG. 3). The feedback control unit 2b performs feedback control of its own movement based on the output result of the actuator displacement detection unit (corresponding to the displacement sensor S04 in Fig. 1) so that the behavior of the test device drive unit, which is composed of the servo amplifier 3, servo valve 4, hydraulic power source 5, hydraulic cylinder 6, and hydraulic piston 7 in Fig. 1, is stabilized. PID control or the like is used for the feedback control.

[0033] The filter design unit 2a is composed of four functional blocks: an excitation data storage unit 2a1, a filter adjustment unit 2a2, a second target signal setting unit 2a3, and a target signal switching unit 2a4. The excitation data storage unit 2a1, the filter adjustment unit 2a2, the second target signal setting unit 2a3, and the target signal switching unit 2a4 are realized by a processor such as a CPU (Central Processing Unit) not shown, a ROM for storing various programs, a RAM for temporarily storing data in the calculation process, and a storage device such as an external storage device, and the processor such as the CPU reads and executes various programs stored in the ROM, and stores the calculation results, which are the execution results, in the RAM or the external storage device. The filter design unit 2a is a function that becomes effective after driving (test excitation) the test device at least once. Therefore, in a state where the test device has never been driven, the target value sent to the feedback control unit 2b by the target signal switching unit 2a4 is the first target signal set by the first target signal setting unit 1b.

[0034] The vibration data storage unit 2a1 records data acquired by a specimen displacement detection unit (corresponding to a value obtained by integrating the detection result of the acceleration sensor S06 in FIG. 1 twice) attached to the specimen 10. At the same time, the first target signal set by the first target signal setting unit 1b may be stored. However, since the first target signal is data recorded in the first target signal setting unit 1b, it is not necessarily required to store it in the vibration data storage unit 2a1.

[0035] The filter adjustment unit 2a2 modifies the first target signal based on the test data (specimen displacement) and the first target signal stored in the vibration data storage unit 2a1, and designs a filter that generates a second target signal, which will be described in detail later.

[0036] Here, the filter designed in the filter adjustment unit 2a2 will be described with reference to Fig. 4A and Fig. 4B. Fig. 4A and Fig. 4B are diagrams showing the transfer function of the control loop. In Fig. 4A and Fig. 4B, the transfer function of the feedback control unit 2b is C, the transfer function of the test device (from the servo command to the table displacement) is P, and the transfer function of the test piece (from the table displacement to the test piece displacement) is G. In addition, the target signal is r, the displacement of the test device is y, and the displacement of the test piece is z.

[0037] First, in FIG. 4A, the displacement z of the test specimen obtained when the vibration testing device is driven using the first target signal r can be expressed as the following equation (1) in transfer function representation.

[0038]

number

[0039] On the other hand, suppose that the ideal transfer function (reference model) from the first target signal r to the displacement z of the specimen desired by the user of the testing equipment is given by M. In this case, the ideal displacement zm of the specimen desired by the user can be expressed by the following equation (2). In other words, if the feedback control C can be designed to satisfy the following equation (3), the displacement response of the specimen desired by the user can be realized.

[0040]

number

[0041]

number

[0042] By solving equation (3) for feedback control C, we obtain the following equation (4).

[0043]

number

[0044] To realize equation (4), it is necessary to accurately obtain the transfer function P of the test device (from servo command to table displacement) and the transfer function G of the test piece (from table displacement to test piece displacement). In addition, the denominator of equation (4) contains the transfer function P of the test device, and the inverse transfer function P -1 As mentioned above, Transfer function G of the specimen Since the transfer function P of the test device is a strictly proper transfer function (the degree of the denominator is greater than the degree of the numerator), it is not easy to implement the feedback control C according to equation (4) on a computer.

[0045] For this reason, in this embodiment, instead of adjusting the feedback control C, a configuration is considered in which a filter F is added as a pre-filter type feedforward compensator as shown in FIG. 4B.

[0046] In this configuration, an ideal transfer function from the first target signal r to the displacement z of the test specimen can be given by the following equation (5).

[0047]

number

[0048] For convenience of explanation, the displacement of the specimen when there is no filter F (i.e., the transfer function F of the filter corresponds to 1) is z1, and the displacement of the specimen when there is filter F is z2. In this case, equation (6) is obtained from equation (1) and equation (5).

[0049]

number

[0050] From equation (6), if there is displacement data z1 of the specimen without filter F, it is possible to predict the response z2 when an arbitrary filter F is designed. This follows the idea of ​​data-driven prediction in Non-Patent Document 1.

[0051] The objective is to make the predicted response z2 when an arbitrary filter F that can be calculated using equation (6) is designed as close as possible to the ideal response zm. For example, the filter F is designed so as to minimize the evaluation function J given by the following equation (7).

[0052]

number

[0053] The evaluation function of equation (7) is an example designed to minimize the sum of squares of the error between the predicted response z2 and the ideal response zm (to achieve the least square error), and this embodiment is not limited to the derivation of the filter F that minimizes this evaluation function.

[0054] In designing a specific filter, the transfer function F of the filter is given by the following equation (8), and a total of 2m+1 coefficients ρ0 to ρ2m are calculated by numerical calculation.

[0055]

number

[0056] Equation (8) is a proper transfer function in which the degree of the numerator is never greater than the degree of the denominator for any of the coefficients ρ0 to ρ2m, so it can be easily implemented on a computer. Here, in order to make the transfer function F(ρ) a stable filter, it is desirable to impose constraints so that the real parts of the poles of the transfer function (the solution to the denominator part of equation (8)) are all negative. By imposing such constraints, it is possible to prevent the calculated value from diverging when the filter transfer function F(ρ) is implemented in a controller. Note that the larger the order m of the transfer function in equation (8), the wider the range of filters that can be realized. However, if the number of parameters to be calculated increases, the calculation time may become very long. For this reason, it is desirable to be able to change the order m of the transfer function from the user interface 1 so that the user can adjust it according to the accuracy of reproducibility of the experiment.

[0057] By performing the above calculations, a filter F that minimizes the evaluation function of equation (7) is derived. By using this filter F, the target signal can be corrected by utilizing the following equation (9).

[0058]

number

[0059] In equation (9), r is the original target signal (first target signal), and r' is the corrected target signal (second target signal).

[0060] The state of the response realized by the above-mentioned target signal correction algorithm will be described with reference to Figs. 5A to 5E. 5A to 5E, the solid line indicates the response zm desired by the user, and the dotted line indicates the actual response z of the specimen 10 realized by feedback control.

[0061] FIG. 5A is a diagram showing an example of a waveform obtained when the first target signal r is not corrected. Fig. 5B is a diagram showing a waveform obtained when the method disclosed in Patent Document 1 is applied. In the method disclosed in Patent Document 1, the target signal is corrected so that the maximum displacements match, but the phase is not improved. Therefore, as shown in Fig. 5B, the waveforms have the same amplitude but not the same phase.

[0062] In the case of the waveform in Figure 5B, the phases do not match, so the difference between the ideal response zm (corresponding to Mr in equation (7) from equation (2)) and the actual response z of the test specimen (corresponding to Fz1 in equation (7) from equation (6)) is large at each time. The evaluation function J in equation (7) corresponds to the integral value of the difference between the waveform zm desired by the user and the actual waveform z (the area of ​​the hatched part in Figure 5C), so its value is large. Therefore, if filter F is designed to minimize evaluation function J, it is difficult to obtain a response like that shown in Fig. 5B. In order to reduce evaluation function J, it is necessary to correct the target signal so as to realize the response shown in Fig. 5D, in which the difference between the ideal response zm at each time and the actual response z of the test specimen is small.

[0063] It should be noted that when the filter order m is low, it is difficult to reproduce the desired response with high accuracy as in FIG. 5D. In such a case, it is predicted that the response will be somewhat different from the desired response as in FIG. 5E. The value of the evaluation function J in FIG. 5E will be smaller than in FIG. 5A and FIG. 5B, but will never be J=0 (corresponding to FIG. 5D). When such a result is obtained, the operator can adjust the realized response by increasing the order m of the filter F. The feature of this embodiment is that the amplitude (gain) and phase can be adjusted to a desired response simultaneously by the above-mentioned mechanism. In addition, when all the coefficients ρi (i = 0 to 2m) in formula (8) are 1, the filter F becomes 1, so the displacement z of the test specimen in Fig. 4A is the same as that in Fig. 4B. In other words, even when the test equipment is driven for the first time (test excitation), the filter F may be built into the circuit. In other words, the control circuit in Fig. 4B can be used.

[0064] The second target signal setting unit 2a3 calculates the second target signal r' by using the filter F(ρ) that reflects the coefficient ρ calculated by the filter adjustment unit 2a2. As described above, the second target signal r' is generated according to the equation (9). When the designed filter F(ρ) is applied, the realized displacement response z2 of the specimen can be predicted by equation (6) before the test apparatus is driven again. This prediction result (predicted value z2 of the specimen's displacement) is sent to the monitor display unit 1d, which then draws (displays) the prediction result on the monitor of the operation terminal. If the operator determines that the displayed predicted value z2 is sufficiently close to the desired test pattern, the filter F(ρ) is reflected from the user operation unit 1a. In conjunction with this operation, the target signal used by the target signal switching unit 2a4 is switched to the second target signal r'.

[0065] The method of displaying the predicted value on the monitor display unit 1d may be a comparison of specific waveforms as shown in Figures 5D and 5E, or an index showing the degree of match between the waveforms (for example, the mean square error or the maximum value of the error at each time) may be calculated and the value may be displayed.

[0066] Next, a method for driving the test apparatus of this embodiment will be described with reference to Fig. 6, which is a flow chart showing a method for controlling the vibration test apparatus. First, in preparation for starting up the vibration testing device, in step S11, the operator performs various settings. This corresponds to the operator operating the user operation unit 1a constituting the user interface 1 to set a test pattern, and by performing this operation, the test pattern (first target signal) is set in the first target signal setting unit 1b. In other words, the user operation unit 1a constituting the user interface 1 accepts the operator's operation for setting the test pattern, and outputs the test pattern (first target signal) to the first target signal setting unit 1b, thereby setting the first target signal in the first target signal setting unit 1b (initial setting). Moreover, in the controller 2, at the timing when the operator sets a test pattern (first target signal) in the first target signal setting unit 1b, all of the coefficients ρi (i=0 to 2m) of the filter F (Equation (8)) of the filter adjustment unit 2a2 constituting the filter design unit 2a are set to 1. Also, the order m of the filter F is set to an initial value (for example, m=3). When all the processes of this step S11 are completed, the process proceeds to step S12.

[0067] In step S12, the test device driving unit executes a vibration test using the test pattern (first target signal) set in the first target signal setting unit 1b. The vibration data storage unit 2a1 constituting the filter design unit 2a becomes effective immediately before the start of vibration, and the displacement of the specimen until the end of the vibration pattern is acquired from the specimen displacement detection unit and continues to be stored. This data storage operation corresponds to the vibration data acquisition process in step S13.

[0068] Next, in step S14, when the experimental data (displacement z1 of the specimen during test vibration) is stored in the vibration data storage unit 2a1 constituting the filter design unit 2a, the filter adjustment unit 2a2 constituting the filter design unit 2a starts a calculation to design the filter F(ρ) using this data. The specific processing is as described above, and each coefficient ρi (i=0 to 2m) is optimized so as to minimize a specific evaluation function (for example, equation (7)). When the optimization calculation is completed, the process proceeds to step S15.

[0069] In step S15, the filter adjustment unit 2a2 constituting the filter design unit 2a calculates the predicted value z2 of the displacement of the specimen obtained when the filter F(ρ) reflecting each coefficient ρi (i=0 to 2m) obtained in step S14 is applied according to the formula (6), and presents this result on the user interface 1. This prediction process corresponds to the specimen displacement prediction unit. Moreover, the presentation on the user interface 1 is executed by the monitor display unit 1d.

[0070] In step S16, the operator checks the predicted value z2 of the specimen displacement displayed on the monitor display unit 1d constituting the user interface 1, and judges whether the specimen response obtained when using the filter F(ρ) matches the test purpose. In other words, the monitor display unit 1d constituting the user interface 1 supports the operator's judgment by displaying the predicted value z2 of the specimen displacement. If it is judged to match the test purpose (YES), the process proceeds to step S18, and if it is judged not to match the test purpose (NO), the process proceeds to step S17.

[0071] When the process proceeds to step S17, an operation is performed to change the order m of the filter F(ρ) set in step S11. The higher the filter order, the easier it is to achieve the conditions determined by the operator, but the calculation time also increases, so it is desirable to increase m by "1" (for example, if m=3 in the initial setting (step S11), change it to m=4 in step S17). After the order change is performed in step S17, the process returns to step S14 and calculates each coefficient of the filter F(ρ) again. This process is repeated with increasing filter order m until the operator determines YES in step S16.

[0072] On the other hand, when the process proceeds to step S18, the second target signal setting unit 2a3 constituting the filter design unit 2a determines the filter F(ρ) and calculates the second target signal r′ using equation (9). Then, the process proceeds to step S19.

[0073] In step S19, when the second target signal r' is generated, the operator performs the main excitation. It should be noted that there is a difference in that in the trial excitation, a first target signal r is sent to the feedback control unit 2b, whereas in the main excitation, a second target signal r' is sent to the feedback control unit 2b.

[0074] In this embodiment, the filter design unit 2a has a target signal switching unit 2a4, but the present invention is not limited to this. For example, the filter design unit 2a may be configured to transmit the second target signal r' calculated by the second target signal setting unit 2a3 constituting the filter design unit 2a to the feedback control unit 2b.

[0075] As described above, according to this embodiment, it is possible to provide a vibration testing apparatus and a control method for a vibration testing apparatus that enable the realization of a desired specimen response, i.e., the adjustment of the amount of displacement (gain) and phase, in as simple a manner as possible, without obtaining the inverse transfer characteristic of the controlled object. EXAMPLES

[0076] 7 is a functional block diagram of a vibration testing device of Example 2 according to another embodiment of the present invention. In the above-mentioned Example 1, the controller 2 has a filter design unit 2a, whereas in this Example, the user interface 1 has a filter design unit 1c02, which is a difference from Example 1. The same components as those in Example 1 are given the same reference numerals, and the following description that overlaps with Example 1 will be omitted.

[0077] As shown in FIG. 7, the vibration testing device of this embodiment is similar to the above-described embodiment 1 in that it includes a user interface 1 and a controller 2, so only the differences will be described below.

[0078] A user interface 1 constituting the vibration testing device of this embodiment is made up of a user operation section 1a, a target signal setting section 1c, and a monitor display section 1d. The target signal setting unit 1c includes a first target signal setting unit 1c01 and a filter design unit 1c02. The filter design unit 1c02 includes an excitation data storage unit 1c03, a filter adjustment unit 1c04, a second target signal setting unit 1c05, and a target signal switching unit 1c06. The excitation data storage unit 1c03, the filter adjustment unit 1c04, the second target signal setting unit 1c05, and the target signal switching unit 1c06 are realized by a processor such as a CPU (Central Processing Unit) (not shown), a ROM for storing various programs, a RAM for temporarily storing data in the calculation process, and a storage device such as an external storage device, and the processor such as the CPU reads and executes various programs stored in the ROM, and stores the calculation results, which are the execution results, in the RAM or the external storage device.

[0079] The vibration data memory unit 1c03 corresponds to the vibration data memory unit 2a1 in the first embodiment, the filter adjustment unit 1c04 corresponds to the filter adjustment unit 2a2 in the first embodiment, the second target signal setting unit 1c05 corresponds to the second target signal setting unit 2a3 in the first embodiment, and the target signal switching unit 1c06 corresponds to the target signal switching unit 2a4 in the first embodiment.

[0080] The filter design unit 1c02 corresponds to the filter design unit 2a in the first embodiment and has the same functions. The filter design unit 1c02 designs a filter F(ρ) using the specimen response z1 obtained by the test excitation and calculates the second target signal r′ using the equation (9).

[0081] The controller 2 executes feedback control in a feedback control section 2c according to a target signal received from the user interface 1. The feedback control section 2c is similar to the feedback control section 2b in FIG.

[0082] That is, the filter design unit 2a of the first embodiment shown in Fig. 3 and the filter design unit 1c02 of this embodiment shown in Fig. 7 are essentially the same, except that the filter design unit is implemented in the user interface 1 or the controller 2. Therefore, the operation of the vibration testing device of this embodiment is exactly the same as that of the first embodiment. In this manner, the configuration of the vibration testing apparatus of this embodiment has the advantage that even if it is difficult to rewrite the program of the controller 2, it is possible to achieve an improvement in the test specimen response similar to that of the above-mentioned embodiment 1 by rewriting the program of the user interface 1.

[0083] Fig. 8 is a diagram showing a modified example of the vibration testing apparatus of the embodiment 2 shown in Fig. 7. As shown in Fig. 8, in addition to the user interface 1 and the controller 2, the same function can be provided in a vibration testing apparatus in which a target signal converter 11 having the function of a filter design unit 11a (filter design unit 2a in Fig. 3, filter design unit 1c02 in Fig. 7) is incorporated as a separate terminal.

[0084] According to this embodiment, in addition to the effects of the first embodiment, it is possible to easily improve the response of the test specimen even at a site where it is difficult to update the program of the controller 2, such as an existing vibration test apparatus. EXAMPLES

[0085] FIG. 9 is a schematic configuration diagram of a target signal switching unit of Example 3 according to another embodiment of the present invention. In the above-described Example 1 and Example 2, it is assumed that the vibration testing apparatus is driven by a first target signal r determined by the operator for obtaining the response of the specimen. In order to perform such a trial excitation, it is a prerequisite that the specimen does not break or undergo plastic deformation. This embodiment is different from Example 1 and Example 2 in that it has a target signal switching unit that enables suitable adjustment of the specimen response when the specimen does not satisfy such conditions. The same reference numerals are given to the same components as in Example 1, and the following description overlapping with Example 1 will be omitted.

[0086] It is assumed that the vibration testing apparatus and the response of the specimen in the above-described Example 1 and Example 2 can be represented by block diagrams of transfer functions as shown in FIGS. 4A and 4B. That is, it is assumed that linearity holds for both the vibration testing apparatus and the specimen. When linearity holds, it is known that even if the target signal r is scaled by a scaling factor S (0 < S ≦ 1) to obtain a scaled target signal Sr and the filter F(ρ) is calculated using the data obtained by exciting with the target signal Sr, the same ρ is obtained as when the filter F(ρ) is calculated using the data obtained by exciting with the target signal r as it is (Non-Patent Document 2).

[0087] In this embodiment, this fact is utilized, and the target signal switching unit 2a4 in FIG. 3 is realized with the configuration shown in FIG. 9. The target signal switching unit 2a4 of this embodiment receives various signals from a first target signal setting unit 1b, a second target signal setting unit 2a3, and a user operation unit 1a. The target signal switching unit 2a4 of this embodiment is composed of a scaling 2a4-1 and a switch 2a4-2.

[0088] During trial excitation, a target signal Sr obtained by scaling the first target signal r set by the first target signal setting unit 1b by a coefficient S is transmitted to the feedback control unit 2b. For example, if S is set to 0.1, the specimen is excited with a minute displacement, so the possibility that the specimen breaks during trial excitation is greatly reduced.

[0089] On the other hand, during the actual excitation, the second target signal r' set by the second target signal setting unit 2a3 is sent to the feedback control unit 2b without being scaled. This allows the test pattern intended by the operator to be actually executed during the actual excitation.

[0090] According to this embodiment, in addition to the effects of the first embodiment, it is possible to greatly reduce the possibility of the specimen being damaged during test vibration.

[0091] The present invention is not limited to a hydraulic piston as a driving method, but can also be applied to an electrically-operated linear actuator.

[0092] The present invention is not limited to the above-mentioned embodiment, but includes various modified examples. For example, the above-mentioned embodiment has been described in detail to easily explain the present invention, and the present invention is not necessarily limited to those including all of the configurations described. In addition, it is possible to replace a part of the configuration of one embodiment with the configuration of another embodiment, and it is also possible to add the configuration of another embodiment to the configuration of one embodiment. [Explanation of symbols]

[0093] 1. User interface 1a...User operation section 1b,1c01...1st target signal setting section 1c…Target signal setting section 1d…Monitor display section 2. Controller 2a, 1c02, 11a…Filter design section 2b, 2c...Feedback control section 2a1, 1c03, 11a1...Vibration data storage section 2a2, 1c04, 11a2...Filter adjustment section 2a3,1c05,11a3...Second target signal setting section 2a4, 1c06, 11a4...Target signal switching section 2a4―1…Scaling 2a4―2…switch 3...Servo amplifier 4. Servo valve 5...Hydraulic source 6...Hydraulic cylinder 7…Hydraulic piston 8...Coupling 9…Table 10…Specimen 11...Target signal converter S01...Temperature sensor S02...Flow sensor S03…Speed ​​sensor S04...Displacement sensor S05…Pressure sensor S06…Acceleration sensor

Claims

1. A vibration testing apparatus comprising: a specimen installation section for installing a specimen to be evaluated; a test apparatus drive section for vibrating the specimen installation section; a drive section displacement detection section for detecting a displacement of the test apparatus drive section; a specimen displacement detection section for detecting a displacement of the specimen; a controller for controlling the displacement amount of the test apparatus drive section so that it follows a specific target displacement; and a user interface for receiving operations from an operator, a first target signal setting unit that reproduces a test pattern set by an operator; a vibration data storage unit that stores the displacement of the specimen detected by the specimen displacement detection unit when the test apparatus is driven with the output of the first target signal setting unit as a target value; a filter adjustment unit that designs parameters of a filter that corrects the first target signal to calculate a second target signal based on the displacement of the specimen stored in the vibration data storage unit and the first target signal set in the first target signal setting unit; and a second target signal setting unit that shapes the target signal of the first target signal setting unit using the filter adjusted by the filter adjustment unit; a target signal switching unit that switches a target value for which the controller performs tracking control between an output of the first target signal setting unit and an output of the second target signal setting unit; a target signal converter; the target signal converter includes the vibration data storage unit, the filter adjustment unit, the second target signal setting unit, and the target signal switching unit, a target signal switching unit that switches a target value that the controller follows to an output of the second target signal setting unit after driving the test apparatus with the target value of the first target signal setting unit.

2. 2. The vibration testing apparatus according to claim 1, The controller: The vibration data storage unit, the filter adjustment unit, the second target signal setting unit, and the target signal switching unit, a feedback control section for performing feedback control using the output of the target signal switching section as a target displacement, said feedback control section being characterized in that:

3. 2. The vibration testing apparatus according to claim 1, The user interface includes: The first target signal setting unit, the vibration data storage unit, the filter adjustment unit, the second target signal setting unit, and the target signal switching unit, A vibration testing apparatus comprising: a controller configured to transmit an output of the target signal switching unit;

4. 2. The vibration testing apparatus according to claim 1, A vibration testing apparatus comprising a specimen displacement prediction unit which predicts the specimen displacement response realized when the filter is applied using the displacement of the specimen stored in the vibration data storage unit and the filter adjusted by the filter adjustment unit, and which presents the prediction result of the specimen displacement prediction unit on a user interface.

5. 2. The vibration testing apparatus according to claim 1, the filter adjustment unit selects filter adjustment parameters so that a least square error between an ideal response obtained as an output when a first target signal determined by the first target signal setting unit is given as an input to a predetermined reference model, and a specimen response predicted value obtained as an output when a displacement of the specimen stored in the vibration data storage unit is given as an input to a filter having adjustment parameters, is minimized.

6. 2. The vibration testing apparatus according to claim 1, a target signal switching unit which switches a target value for tracking control by the controller between a modified first target signal obtained by scaling the first target signal of the first target signal setting unit by a predetermined positive value and an output of a second target signal setting unit.

7. A method for controlling a vibration testing apparatus comprising: a specimen installation section for placing a specimen to be evaluated; a test apparatus drive section for vibrating the specimen installation section; a drive section displacement detection section for detecting displacement of the test apparatus drive section; a specimen displacement detection section for detecting displacement of the specimen; a controller for controlling the displacement amount of the test apparatus drive section so that it follows a specific target displacement; and a user interface for accepting operations from an operator, a test device is driven with an output of a first target signal setting unit, which reproduces a test pattern set by an operator, as a target value, and the displacement of the specimen detected by the specimen displacement detection unit is stored in a vibration data storage unit; a filter adjustment unit designs parameters of a filter that corrects the first target signal and calculates a second target signal based on the displacement of the specimen stored in the vibration data storage unit and the first target signal set in the first target signal setting unit; shaping the target signal of the first target signal setting unit using the filter adjusted by the filter adjustment unit and setting the result as a second target signal; a target signal switching unit that switches a target value that the controller follows to the second target signal after driving the testing apparatus with the target value of the first target signal setting unit.

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