JP2001056276A - Loading test device and its force control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a loading test device and its force control method capable of matching a waveform of a response wave showing a displacement of a test object with a target triangular waveform without deviation. SOLUTION: This force control method, is a force control methods for exciting a test object so that a response wave showing a displacement of the test object has a triangular waveform. As a command signal wave, a trapezoid wave having a larger amplitude than the amplitude of the response wave, reaching the maximum amplitude earlier than the time when the response wave reaches the maximum amplitude, and rising after the response wave reaches the maximum amplitude, is inputted and, this loading test device is equipped with a command signal wave generation part 21 for generating the command signal wave, a force control part 23 for executing control of the test object based on the command signal wave generated by the command signal wave generation part 21, and a loading part for applying force to the test object by the control of the force control part 23.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a force test apparatus for deforming a test object in a test of compression deformation and shear deformation and a method of controlling the force.

[0002]

2. Description of the Related Art Conventionally, there has been known a force test apparatus for testing a compression deformation and a shear deformation of an object. In such a force test apparatus, it is important that the force applied to the test object is accurately controlled in order to perform the test accurately.

In a conventional force test apparatus, a hydraulic actuator or the like is used to apply a force to a test object, and the control of the hydraulic actuator or the like is performed by a feedback control circuit. That is, a command signal wave of a desired displacement response waveform of the test object is input to the control circuit, and a hydraulic actuator or the like is feedback-controlled based on the command signal wave and a response from the actuator, and a force applied to the test object is controlled. Had control.

[0004] In this specification, "displacement" includes both positional displacement of a test object and load displacement applied to the test object.

[0005]

However, the above-mentioned force test apparatus has the following problems. That is,
When a command signal wave having a desired displacement response waveform of the test object is input to the control circuit, the response wave indicating the displacement of the test object has a response delay due to the rigidity of the test object.

Here, the case where the desired displacement response wave to be tested is a triangular waveform will be described. As shown in FIG. 5, the response wave 52 does not reach the target level (the maximum amplitude of the desired response wave) even at times t0 and t1 when the command signal wave 51 is at the maximum level in the above-described force test apparatus, and A deviation occurs at the maximum level. In addition, since the deviation varies depending on the rigidity of the object to be tested, it is difficult to accurately control the force with respect to various test objects by the above-described force test apparatus, which hinders an accurate test.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and to provide a force test apparatus and a force control method thereof capable of accurately matching a waveform of a response wave of displacement of a test object to a desired triangular waveform. With the goal.

[0008]

According to the present invention, there is provided a force test apparatus for vibrating a test object such that a response wave indicating a displacement of the test object has a triangular waveform.
A command signal wave generator that generates a command signal wave, a force controller that controls a force applied to the test object based on the command signal wave generated by the command signal wave generator, and a force controller. A force applying section for applying an force to the test object in accordance with the force control,
The command signal wave generated in the command signal wave generator has an amplitude larger than the amplitude of the response wave, reaches the maximum amplitude earlier than the time when the response wave reaches the maximum amplitude, and stands after the response wave reaches the maximum amplitude. It is characterized by falling. By providing a command signal wave generation unit that generates a command signal wave having an amplitude greater than the amplitude of the response wave in this way, by inputting the command signal wave generated by the command signal wave generation unit to the force control unit, A target triangular waveform response wave can be obtained.

A force control method according to the present invention is directed to a force control method for exciting a test object such that a waveform of a response wave indicating displacement of the test object becomes a triangular waveform. A wave generation step, and a force control step of controlling the force applied to the test object based on the command signal wave generated in the command signal wave generation step, wherein the command signal is generated in the command signal wave generation step. The wave has an amplitude larger than the amplitude of the response wave, reaches the maximum amplitude earlier than the time when the response wave reaches the maximum amplitude, and is generated so that the response wave falls after reaching the maximum amplitude. By generating a command signal wave having an amplitude larger than the amplitude of the response wave and inputting the command signal wave to the force control unit, a target triangular waveform response wave can be obtained.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described with reference to the drawings. In each of the drawings, the same elements are denoted by the same reference numerals, and redundant description will be omitted. In the embodiment, a description will be given of a multiaxial force test device 1 capable of applying force from two directions.

FIG. 1 is a view showing a multiaxial force test apparatus 1 according to an embodiment, and FIG. 2 is a block diagram showing a horizontal force unit 3 and a control unit 20 of the multiaxial force test apparatus 1 according to the embodiment. It is.

The multiaxial force test apparatus 1 according to the embodiment includes a vibration table 2 on which a test object A such as a vibration-isolating rubber is placed, and a force applied to the vibration table 2 to move the vibration table 2 in a horizontal direction. , A vertical force plate 4, which faces the vibration table 2 via the test object A, and is arranged to abut on the test object A; And two vertical force applying devices 5 for applying a force in the vertical direction (see FIG. 1). As shown in FIG. 2, the horizontal force applicator 3 amplifies signals from the hydraulic actuator 11 for applying force to the vibration table 2, the servo valve 12 for operating the hydraulic actuator 11, and the control unit 20. And a servo amplifier 13 for transmitting the signal to the servo valve 12. In addition, horizontal force applicator 3
Has a position displacement amplifier 14 and a load displacement amplifier 15 for amplifying the detected position displacement Δx and load displacement Δw of the hydraulic actuator.

Next, the configuration of the control unit 20 will be described. As shown in FIG. 2, the multiaxial force test apparatus 1 of the embodiment
The control unit 20 includes a command signal wave generation unit 21 that generates a command signal wave, and a force control unit 23 that controls the horizontal force unit 3 based on the command signal wave.

The command signal wave generation section 21 has a response determination section 22, and the response determination section 22 is connected to the position displacement amplifier 14 or the load displacement amplifier 15 of the horizontal force applying device 3 via a changeover switch 24. .

The force control unit 23 includes an integrator 25 for integrating and amplifying the command signal wave, an arithmetic unit 28 for adding the signal amplified by the integrator 25 and the input command signal wave, And a proportional amplifier 26 for amplification. A computing unit 27 is provided at an input section of the force control unit 23. The computing unit 27 is connected to the position displacement amplifier 14 or the load displacement amplifier 15 of the horizontal force unit 3 by a changeover switch 24.
Connected through. The calculator 27 performs feedback control based on the difference between the command signal wave and the response wave.

FIG. 2 shows the horizontal force applying device 3 and its control unit 20, but the vertical force applying device 5 and its control unit include:
The description is omitted because it is the same as the horizontal force applying unit 3 and the control unit 20 thereof.

Next, the operation of the multi-axial load test apparatus 1 according to the embodiment will be described. Before that, the application of the multi-axial load test apparatus 1 will be described.

This multi-axial force test apparatus 1 is applied to a performance inspection test of a test object A, etc., in a state where a load is applied to a test object A by a vertical force device 5 in a direction of pressing against a vibration table 2. The performance test is performed by vibrating the vibration table 2 with the horizontal force device 3.

Now, the operation of the above-described performance test will be described. FIG. 3 is a time chart illustrating a command signal wave generated by the command signal wave generation unit 21 and a response wave of the displacement of the test object A.

First, the vertical load plate 4 is moved by the vertical load device 5.
Is moved toward the vibration table 2, and a load in the direction toward the vibration table 2 is applied to the test object A on the vibration table 2. In this state, the command signal wave generator 21 generates the command signal wave 31 shown in FIG.
In the force control unit 23, feedback control for amplifying the difference between the input command signal wave 31 and the actual displacement (response) of the test object A according to the gain of the force control unit 23 is performed. You. The signal thus amplified controls the horizontal exciter 3 to excite the excitation table 2. The displacement of the test object A by the multiaxial force test apparatus 1 of the embodiment is shown by a response wave 32 in FIG.

Next, a description will be given of a command signal wave 31 generated by the command signal wave generator 21 which is a feature of the multiaxial force test apparatus 1 of the present embodiment. The command signal wave 31 used in the multiaxial force test apparatus 1 of the present embodiment is a trapezoidal wave having substantially the same cycle as the response wave 32 (see FIG. 3). The maximum level of the amplitude of the signal generated as the command signal wave 31 (hereinafter, referred to as “command wave target level”) is determined by the amplitude of the response wave 32 and the required quick response and stability of the response waveform. It is calculated by adding the compensation level CL. Therefore, the command signal wave has an amplitude larger than the amplitude of the desired response wave. Specific methods for determining the compensation level CL and the gain constants of the integrator 25 and the proportional amplifier 26 are as follows.
Perform a simulation in advance using test object A,
It is determined that the control of the test object A is performed with the required accuracy. At this time, the gradients of the rise and fall of the command signal wave 31 are also determined by simulation. Since the feedback control involves a response delay, these gradients need to be steeper than the response wave 32.

The trapezoidal wave (command signal wave) having the command wave target level and the gradient determined as described above is generated according to the flow shown in FIG.

Start of test by multiaxial force test apparatus 1 S41
At the same time, a command signal wave 31 having a predetermined rising gradient is generated (S42). Next, it is determined whether or not the level of the command signal wave 31 has reached the command wave target level (S43). When the level of the command signal wave 31 has not reached the target command wave level, the level of the command signal wave 31 is continuously increased. When the level of the command signal wave 31 has reached the command wave target level, the level of the command signal wave 31 is held at the command wave target level (S44).

On the other hand, the response of the test object A from the position displacement amplifier 14 or the load displacement amplifier 15 of the horizontal loader 3 is input to the response determination unit 22 of the command signal wave generation unit 21. After the level of the command signal wave 31 reaches the command wave target level,
The response determination unit 22 determines whether the level of the response wave 32 has reached the target level (S45). When the response wave 32 does not reach the target level, the level of the command signal wave 31 is continuously held at the command wave target level. Response wave 3
2 has reached the target level, the level of the command signal wave 31 is decreased at a predetermined gradient (S
46).

Next, when the command signal wave 31 reaches the lower command wave target level in FIG. 3, the same control as the above flow is performed (the rise and fall of the level of the command signal wave 31 are opposite to each other). Become). That is, the level of the command signal wave 31 is held at the command wave target level, and the level of the command signal wave 31 is increased again (in a direction in which the level becomes 0) from the time when the response wave 32 reaches the target level. Hereinafter, the command signal wave generation unit 21 repeatedly performs the same control until the end of the test (S47), and generates a trapezoidal wave (command signal wave 31) having substantially the same cycle as the desired response wave 32.

The multi-axial force test apparatus 1 of this embodiment includes a command signal wave generator 2 for generating a trapezoidal wave as the command signal wave 31.
1 is provided. By inputting the command signal wave 31 generated by the command signal wave generation unit 21 to the force control unit 23 and controlling the force unit 3, a response wave 32 having a target triangular waveform can be obtained ( (See FIG. 3).

The force control method of the present invention obtains a response from the force applying unit 3 and compares the response with a target level to generate a command signal wave 31 (see FIG. 4), thereby obtaining a target signal. The deviation between the triangular waveform and the response wave 32 can be reduced.

The embodiments of the present invention have been described in detail above, but the present invention is not limited to the above embodiments.

In the present embodiment, the force control circuit 23 has the integrator 25 and the proportional amplifier 26, but the control circuit may have another configuration. For example, a configuration using only a proportional amplifier may be used, or a configuration using an integrator, a proportional amplifier, and a differentiator may be used.

In this embodiment, the multi-axial force test device 1 capable of applying force from two directions has been described. However, the direction of the force is not limited to two directions, and the multi-axial force test device capable of applying force from three directions. A force test device may be used, or a single-axis force test device that applies a force only in one direction may be used.

[0031]

According to the present invention, a target triangular response wave can be obtained with high accuracy by using a trapezoidal wave having an amplitude larger than a desired response wave as a command signal wave.

As a result, an accurate force is applied to the test object, and an accurate test can be performed.

[Brief description of the drawings]

FIG. 1 is a diagram showing a multiaxial force test apparatus 1 according to an embodiment.

FIG. 2 is a block diagram showing a horizontal force unit and a control unit included in the multiaxial force test apparatus 1 according to the embodiment.

FIG. 3 is a time chart showing a command signal wave and a displacement response wave according to the embodiment.

FIG. 4 is a flowchart of command signal wave generation.

FIG. 5 is a time chart showing a conventional command signal wave and a displacement response wave.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Test object, 2 ... Exciting table, 3 ... Horizontal force applying device, 4 ... Vertical force applying plate, 5 ... Vertical force applying device,
11 hydraulic actuator, 12 servo valve, 13 servo amplifier, 14 position displacement amplifier 15 load displacement amplifier, 20 control unit, 21
... Command signal wave generator, 22 ... Response determiner, 23
... Force control unit, 24... Changeover switch, 25.
・ Integrator, 26 ・ ・ ・ Proportional amplifier, 31 ・ ・ ・ Command signal wave, 32 ・ ・ ・ Response wave, 51 ・ ・ ・ Command signal wave, 52 ・
..Response waves.

Claims (2)

[Claims] 1. A force test apparatus for vibrating a test object such that a waveform of a response wave indicating displacement of the test object becomes a triangular waveform, a command signal wave generation unit for generating a command signal wave, and the command signal A force control unit configured to control a force applied to the test object based on the command signal wave generated by the wave generation unit; and a force applied to the test object in accordance with the force control of the force control unit. A command signal wave generated in the command signal wave generation unit, has an amplitude larger than the amplitude of the response wave, reaches the maximum amplitude earlier than the time when the response wave has the maximum amplitude, The force test device, wherein the response wave falls after reaching the maximum amplitude. 2. A force control method for exciting a test object such that a waveform of a response wave indicating displacement of the test object becomes a triangular waveform, wherein a command signal wave generating step of generating a command signal wave; Based on the command signal wave generated in the wave generation step, a force control step of applying a force while controlling the force to the test object, the command signal wave in the command signal wave generation step The response wave has an amplitude larger than the amplitude of the response wave, reaches the maximum amplitude earlier than the time when the response wave reaches the maximum amplitude, and is generated so as to fall after the response wave reaches the maximum amplitude. Force control method.