Test equipment

Abstract

To provide a testing device that can improve the accuracy of tests. [Solution] In the test apparatus 1, a first sensor 35 for controlling the power supplied by the servo amplifier 72 to the linear motor vibrator 3 and a second sensor 36 for updating the control target value by the control unit 712 are provided independently. This eliminates the need for information processing time in the servo amplifier 72, reduces the time lag from measurement by the second sensor 36 to information acquisition by the control unit 712, suppresses delays in updating the control target value, makes it easier to generate vibrations according to the desired control target value, and improves the accuracy of the test.

Description

Technical Field

[0001] The present invention relates to a test apparatus that imparts vibrations to a specimen to measure its characteristics.

Background Art

[0002] Generally, a test apparatus that imparts vibrations to a specimen such as a shock absorber to measure the characteristics of the specimen is known. In such a test apparatus, an upper control unit determines what kind of vibrations to impart to the specimen, and in order to realize these vibrations, a servo amplifier, which is a lower control unit, may feedback-control a vibration generating excitation means. As an apparatus using the above control unit and servo amplifier, an electronic component mounting apparatus equipped with a host computer and a servo amplifier has been proposed (see, for example, Patent Document 1). In the electronic component mounting apparatus described in Patent Document 1, a command from the host computer is sent to the servo amplifier via a motion controller, and a linear motor and a linear encoder are attached to a mover, and position information is fed back from the linear encoder to the servo amplifier.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] An electronic component mounting device, such as the one described in Patent Document 1, is equipped with a servo amplifier, a linear motor, and a linear encoder for the purpose of moving a movable element to a predetermined position, and the measurement value of the linear encoder is used for moving the movable element. In other words, it is sufficient for the movable element to eventually move to the desired position, and time delays are not a problem. In contrast, in a test device for measuring the characteristics of a test specimen, the measurement value of a sensor that measures the physical quantity of the motion state becomes the measurement result, and it is also necessary to change the applied vibration based on the vibration that actually occurs. In this case, if the upper-level control unit acquires the measurement value of the sensor via the servo amplifier, processing time occurs in the servo amplifier, which tends to cause a time lag. Such a time lag can affect the measurement result and the change in applied vibration, and there is a risk that the accuracy of the test will decrease.

[0005] The objective of the present invention is to provide a testing apparatus that can improve the accuracy of testing. [Means for solving the problem]

[0006] The present invention relates to a test apparatus for measuring the characteristics of a test specimen by applying vibration to the specimen, comprising: an electrically powered vibration generating means that generates vibration when power is supplied; a first sensor and a second sensor that measure the physical quantity of the motion state of the output section of the vibration generating means; a control unit that generates a control target value for the vibration generating means; and a servo amplifier that receives the control target value and the measurement value of the first sensor as input and controls the power supplied to the vibration generating means based on the control target value and the measurement value of the first sensor, wherein the control unit receives the measurement value of the second sensor as input and updates the control target value based on the measurement value of the second sensor.

[0007] According to the present invention as described above, a first sensor for controlling the power supplied by the servo amplifier to the excitation means and a second sensor for updating the control target value are provided independently, unlike a configuration in which the sensor's measured value is input to the control unit via the servo amplifier. This eliminates the need for information processing time in the servo amplifier. As a result, the time lag between measurement by the second sensor and acquisition of information by the control unit can be reduced. Therefore, delays in updating the control target value can be suppressed, making it easier to generate vibrations according to the desired control target value and improving the accuracy of the test.

[0008] Furthermore, the present invention relates to a test apparatus for measuring the characteristics of a test specimen by applying vibration to the specimen, comprising: an electrically powered vibration generating means that generates vibration when power is supplied; a first sensor and a second sensor that measure the physical quantity of the motion state of the output section of the vibration generating means; a control unit that generates a control target value for the vibration generating means; a servo amplifier that receives the control target value and the measurement value of the first sensor as input and controls the power supplied to the vibration generating means based on the control target value and the measurement value of the first sensor; and a processing unit that processes the measurement results of the characteristics of the test specimen, wherein the processing unit receives the measurement value of the second sensor as input.

[0009] As described above, the present invention provides a first sensor for controlling the power supplied by the servo amplifier to the excitation means and a second sensor for obtaining measurement results of the characteristics of the test specimen. Unlike a configuration in which the sensor's measurement value is input to the processing unit via the servo amplifier, this eliminates the need for information processing time in the servo amplifier. This reduces the time lag between measurement by the second sensor and acquisition of information by the processing unit. Consequently, it becomes easier to achieve more real-time measurement of the test specimen's motion state, improve the accuracy of the time the measurement value is obtained, and improve the accuracy of the test.

[0010] In this case, the test apparatus of the present invention may be used to measure the characteristics of a shock absorber by applying vibration to it as the test specimen. With such a configuration, the vibration characteristics of the shock absorber can be measured with high accuracy.

[0011] Furthermore, in the test apparatus of the present invention, the first sensor and the second sensor may measure displacement as a physical quantity of the motion state. Based on the measured displacement of the output unit, the velocity and acceleration of the output unit can also be calculated.

[0012] Furthermore, in the test apparatus of the present invention, the control unit may generate a target value for controlling the velocity of the excitation means.

[0013] Furthermore, in the test apparatus of the present invention, it is preferable that the resolution of the second sensor is higher than that of the first sensor. With such a configuration, the accuracy of the test can be further improved by using the measurement values ​​of the second sensor, which has a higher resolution, to update the control target value or to obtain measurement results of the characteristics of the test specimen. Note that the resolution of a sensor is a concept that includes both the resolution of the measurement value (number of digits that can be measured) and the measurement frequency (temporal interval of measurement). In other words, it is sufficient if the second sensor has a higher resolution of the measurement value, a higher measurement frequency, or both, than the first sensor. [Effects of the Invention]

[0014] The testing apparatus of the present invention can improve the accuracy of the test. [Brief explanation of the drawing]

[0015] [Figure 1] This is a front view showing a test apparatus according to an embodiment of the present invention. [Figure 2] This is a cross-sectional view showing the vibration means of the test apparatus. [Figure 3] Another cross-sectional view showing the vibration means of the aforementioned test apparatus. [Modes for carrying out the invention]

[0016] Embodiments of the present invention will be described with reference to the drawings. As shown in Figure 1, The test apparatus 1 uses the shock absorber 100 as a test specimen, applies vibrations along the longitudinal direction (expansion and contraction direction) of the shock absorber 100, and measures various characteristics of the shock absorber 100 during vibration.

[0017] Examples of the characteristics of the shock absorber 100 to be measured include the expansion and contraction speed of the shock absorber 100, the piston load, the displacement in the vibration direction, etc. Note that characteristics related to position and time (displacement, speed, acceleration) can be converted into other characteristics by measuring the time change for one characteristic, and the characteristics (physical quantities) to be directly measured can be appropriately selected. That is, an appropriate type of sensor may be used according to the characteristics of the shock absorber 100, test conditions, etc. In this embodiment, as will be described later, the first sensor 35 and the second sensor 36, which are linear encoders, are used, but other sensors may be used instead or additionally. Also, as the test specimen, the shock absorber 100 alone may be used, or the shock absorber 100 combined with other parts such as springs may be used.

[0018] The test apparatus 1 includes a main body frame 2, a linear motor shaker 3 as an electric vibration means, a relay means 4, a holding means 5, a brake means 6, a control unit 7, and a display device 8 such as a display. Hereinafter, the horizontal plane is taken as the XY plane, the vertical direction is taken as the Z direction, and the up and down in the Z direction may simply be referred to as up and down.

[0019] The main body frame 2 has a lower frame 21, an upper frame 22, and a lifting cylinder 23 that connects the lower frame 21 and the upper frame 22.

[0020] The lower frame 21 is placed on the floor surface of a test site or the like, the linear motor shaker 3 is provided, and a support base 211 is provided above the linear motor shaker 3. A plurality of guide parts 212 for guiding a rod 42 described later are provided on the support base 211.

[0021] The upper frame 22 is arranged at a predetermined height with respect to the lower frame 21, and the holding means 5 is suspended.

[0022] The lifting cylinder 23 is configured to be able to adjust the height of the upper frame 22 with respect to the lower frame 21 by expanding and contracting. That is, the lifting cylinder 23 may be appropriately expanded and contracted according to the length of the shock absorber 100.

[0023] As shown in FIGS. 2 and 3, the linear motor shaker 3 includes a case 31, a pair of motor coils 32 fixed to the inner surface of the case 31, an output portion 34 disposed inside the motor coil 32 so as to be linearly movable and protruding outside the case 31, a magnet 33 fixed to the output portion 34, and first and second sensors 35 and 36 provided independently of each other. The linear motor shaker 3 is arranged such that the vibration direction is the Z direction. The output portion 34 is formed in a flat plate shape extending along the YZ plane and penetrates the support base 211 in the Z direction. Note that FIGS. 2 and 3 are cross-sectional views along cross-sections orthogonal to each other, and it is only necessary that the Z direction shown in FIGS. 2 and 3 coincides with the Z direction in FIG. 1. The directions of the X and Y directions when the linear motor shaker 3 is provided in the test device 1 are arbitrary.

[0024] The first sensor 35 and the second sensor 36 measure the physical quantity of the motion state of the output portion 34. Specifically, they are displacement sensors that measure displacement by detecting the position of the output portion 34. More specifically, they are linear encoders each including linear scales 351 and 361 and encoder heads 352 and 362. In the present embodiment, the linear scales 351 and 361 are fixed to the output portion 34 which is the movable part, and the encoder heads 352 and 362 are fixed to the case 31 which is the fixed side. The pair of motor coils 32 are arranged on both sides of the magnet 33 and the output portion 34, and the first sensor 35 and the second sensor 36 are located on the magnet The motor coils 32 and the second sensor 36 are positioned on both sides of the output unit 34. The opposing directions of the pair of motor coils 32 and the opposing directions of the first sensor 35 and the second sensor 36 are substantially perpendicular to each other. However, the arrangement of the motor coils 32 and sensors 35 and 36 with respect to the output unit 34 is not limited to the above. By measuring the time change in the displacement of the output unit 34, the velocity and acceleration of the output unit 34 can be calculated. Due to the connection structure described later, the output unit 34 vibrates integrally with the cylinder portion 100A of the shock absorber 100, so the displacement, velocity and acceleration of the cylinder portion 100A can be measured by the second sensor 36.

[0025] The resolution of the second sensor 36 is higher than that of the first sensor 35. That is, the second sensor 36 has either a higher resolution of the measured value (number of digits that can be measured), a higher measurement frequency (time interval between measurements), or both, than the first sensor 35. As described above, if the second sensor 36 is a displacement sensor and also a linear encoder, the resolution of the measured value can be increased by reducing the pitch of the linear scale. Alternatively, the resolution can also be increased by increasing the measurement frequency of the encoder head.

[0026] It is preferable to use displacement sensors such as linear encoders that have excellent frequency characteristics in the range of several Hz to several hundred Hz as the first sensor 35 and the second sensor 36. Furthermore, in the following description, an example will be given in which linear encoders are used as displacement sensors for both the first sensor 36 and the second sensor 36, and the processing unit 711 performs processing to convert the displacement into velocity.

[0027] The relay means 4 comprises a support base 41 as the relay unit body and four metal rods 42. The support base 41 is formed as a rectangular plate shape extending along the XY plane, and its upper surface 411 also extends along the XY plane. The rods 42 are guide rods, arranged near the four corners of the support base 41 and extending along the Z direction. That is, two pairs of rods are formed by two rods 42 aligned in the X direction, and two pairs of rods are formed by two rods 42 aligned in the Y direction. Each rod 42 penetrates the support base 211 in the Z direction and is inserted into the guide portion 212.

[0028] The guide section 212 is, for example, a linear bearing having multiple guide rollers, and is provided at two locations, above and below, for each rod 42 on the support base 211. The rods 42 are guided along the Z direction by the guide rollers, and the support base 41 moves along the Z direction accordingly.

[0029] The support base 41 is connected to the shock absorber 100 via a connecting jig 200. The jig 200 is shaped to match the shape of the shock absorber 100. In this embodiment, since the shock absorber 100 has a connecting portion 101 on the side of the cylinder portion 100A, the jig 200 is formed in an L-shape, having a portion fixed to the connecting portion 101 and a portion fixed to the upper surface 411 of the support base 41. The upper surface 411 has a plurality of recesses, and the jig 200 can be fixed by placing nuts in these recesses and fastening them with bolts. The tip of the output portion 34 of the linear motor vibrator 3 is fixed to the lower surface of the support base 41. In this way, the relay means 4 transmits vibrations by connecting the output portion 34 of the linear motor vibrator 3 to the connecting portion 101, which is one end of the shock absorber 100.

[0030] The holding means 5 includes a displacement mechanism 51, a load sensor, and a support block 53.

[0031] The displacement mechanism 51 is fixed so as to be suspended from the upper frame 22 and includes a first displacement section 511 that causes displacement in the X direction, a second displacement section 512 that causes displacement in the Y direction, and a fixed block 513 that is fixed to the upper frame 22.

[0032] The load sensor is capable of measuring load in at least the Z direction, and in this embodiment, it is composed of a 3-axis load cell 52 and a load control load cell (not shown). The heavy-duty control load cell is just one example, and the load sensor is not limited to this. The three-axis load meter 52 is installed below the displacement mechanism 51 and above the support block 53. In the displacement mechanism 51, a second displacement part 512 is provided below the first displacement part 511, and the three-axis load meter 52 is positioned so as to be sandwiched in the Z direction between the second displacement part 512 and the support block 53, and measures the load in the X, Y, and Z directions generated between the second displacement part 512 and the support block 53. The measurement method of the three-axis load meter 52 is not particularly limited and may be a strain gauge type or a piezoelectric type. The upper measurement limit of the three-axis load meter 52 is, for example, 10 to 30 kN in each direction.

[0033] The support block 53 is formed in a flat plate shape extending along the XY plane and is connected to the shock absorber 100 via a connecting jig 300. Specifically, the lower surface of the support block 53 has a plurality of recesses, and the jig 300 can be fixed by placing nuts in these recesses and fastening them with bolts. The upper part of the jig 300, which is rectangular in shape when viewed from the Y direction, is fixed to the support block 53, and the lower part of the jig 300 is fixed to the upper end 102 of the shaft portion 100B of the shock absorber 100 (the other end of the shock absorber 100). At this time, a load control load cell (not shown) is provided between the support block 53 and the jig 300.

[0034] The load-controlled load cell measures the load in the Z direction, and its upper measurement limit is, for example, several kN (e.g., 1 to 3 kN), which is different from the upper measurement limit of the three-axis load cell 52. The load-controlled load cell, the three-axis load cell 52 as described above, and the three-axis load cell 52 and the load-controlled load cell as described above constitute the load measurement unit, and each of these acts as a measurement unit. When the lateral load applied by the displacement mechanism 51 is relatively small, it is preferable to measure the load in the Z direction using both the three-axis load cell 52 and the load-controlled load cell (or the load-controlled load cell only). When the lateral load is relatively large, it is preferable to remove the load-controlled load cell and measure the load in the Z direction using only the three-axis load cell 52.

[0035] As described above, the connecting portion 101, which is one end of the shock absorber 100, is fixed to the relay means 4 via the jig 200, and the relay means 4 is immovable in the XY plane relative to the lower frame 21. Therefore, the connecting portion 101 is immovable in the XY plane relative to the lower frame 21. Furthermore, the upper end portion 102, which is the other end of the shock absorber 100, is fixed to the holding means 5 via the jig 300, and the holding means 5 is fixed to the upper frame 22. Therefore, when the displacement mechanism 51 is locked, the upper end portion 102 is immovable in the XY plane relative to the upper frame 22. Since the lower frame 21 and the upper frame 22 are immovable relative to each other in the XY plane, the connecting portion 101 and the upper end portion 102 are immovable relative to each other in the XY plane. Therefore, the three-axis load cell 52 measures the load in the XY plane (X direction and Y direction) as a lateral load generated between the connection part 101 and the upper end part 102 of the shock absorber 100, and also measures the load in the Z direction generated between the connection part 101 and the upper end part 102 of the shock absorber 100. The load control load cell measures the load in the Z direction generated between the connection part 101 and the upper end part 102 of the shock absorber 100.

[0036] Furthermore, in the Z direction, only the load due to the vibration of the linear motor vibrator 3 is applied between the connection part 101 and the upper end part 102, and this load is measured by the three-axis load cell 52.

[0037] The braking means 6 stops the movement of the relay means 4 by, for example, gripping the rod 42, and stops the movement of the output unit 34.

[0038] The control unit 7 includes a measurement control device 71 and a servo amplifier 72. The measurement control device 71 includes a processing unit 711 and a control unit 712. This could be, for example, a central processing unit (CPU). Furthermore, although the processing unit 711 and the control unit 712 are functionally distinguished in this embodiment, a single device (such as a central processing unit) can function as both the processing unit 711 and the control unit 712 by possessing both processing and control functions. That is, in the following description, from a functional standpoint, the measurement values ​​of the second sensor 36 are assumed to be input to the processing unit 711 and the control unit 712; however, in actual equipment, the measurement values ​​of the second sensor 36 are input to a single device (i.e., the measurement control device 71). Also, information transmission and reception in each part may be performed by either wireless or wired communication.

[0039] The processing unit 711 processes the measurement results of the characteristics of the test specimen, receiving measurement signals from the load sensor and the second sensor 36, and inputting the respective measurement values. There are two cases in which the processing unit 711 receives measurement signals: one from the 3-axis load cell 52 of the load sensors, and the other from both the 3-axis load cell 52 and the load control load cell of the load sensors. In the following, both of these cases will be treated collectively as the processing unit 711 receiving measurement signals from the load sensors. In this case, the measurement value is input directly (without going through the servo amplifier 72) from the second sensor 36 to the processing unit 711. The processing unit 711 performs calculations on the received measurement signals based on predetermined calculation procedures, displays information related to the measurement signals on the display device 8, or stores it in a storage unit (not shown). Processing the measurement results by the processing unit 711 includes calculations, displaying the results on other devices, and storing the results in other devices, and the processing unit 711 only needs to perform at least one of these actions.

[0040] The control unit 712 generates the control target value for the linear motor vibrator 3 and is a higher-level control unit located upstream of the servo amplifier. The control unit 712 transmits the generated control target value as a signal to the servo amplifier 72. The control unit 712 receives the measured value as input by receiving the measurement signal from the second sensor 36. At this time, the measured value is input directly from the second sensor 36 to the control unit 712 (without going through the servo amplifier 72). As will be described later, the control unit 712 updates the control target value based on the measured value from the second sensor 36.

[0041] As described above, when a single device (such as a central processing unit) functions as both a processing unit 711 and a control unit 712 by having both processing and control functions, when the measurement value from the second sensor 36 is input to a single device (i.e., the measurement control device 71), the measurement signal from the second sensor 36 is processed, and then a control target value is generated based on the processing result. In other words, focusing on the functionality of the measurement control device 71, the processing of the processing unit 711 is performed first, and the generation of the control target value by the control unit 712 is performed later. As an example of the processing in the processing unit 711 and the generation of the control target value in the control unit 712 when the measurement value from the second sensor 36 is input to a single device (i.e., the measurement control device 71), a predetermined calculation is performed in the processing unit 711 on the measurement value from the second sensor 36 to calculate a post-calculated measurement value, which is a physical quantity different from the physical quantity directly measured by the second sensor 36, and the control unit 712 generates a control target value based on the post-calculated measurement value.

[0042] The servo amplifier 72 receives a control target value signal from the control unit 712 and a measurement signal from the first sensor 35, and controls the power supplied to the linear motor exciter 3 based on the control target value and the measurement value from the first sensor 35. In this embodiment, the control target value is a speed target value, and the servo amplifier 72 performs feedback control so that the speed of the output unit 34 of the linear motor exciter 3 becomes the target value, specifically by controlling the current value in a constant voltage state to adjust the speed of the output unit 34.

[0043] Here, a specific example of the processing procedure for the test apparatus 1 of this embodiment will be described. First, the operator (tester) conducting the test inputs the test conditions to be performed to the control unit 7. The control unit 712 generates a control target value based on the input information and transmits a signal to the servo amplifier 72. The servo amplifier 72 receives this control target value and the measured value of the first sensor 35. Based on the deviation, the linear motor vibrator 3 is feedback controlled. At this time, the control unit 712 acquires the measurement value from the second sensor 36 and updates the control target value based on the vibration that is actually occurring, thereby achieving predetermined test conditions or correcting deviations from the test conditions.

[0044] As described above, when the servo amplifier 72 performs feedback control of the linear motor vibrator 3, the processing unit 711 acquires measurement values ​​from the second sensor 36. The processing unit 711 displays information related to the measurement signal on the display device 8 and stores it in a memory unit (not shown). The information displayed or stored may be the measurement value itself, a calculated measurement value obtained by applying a predetermined calculation process to the measurement value (for example, a calculated measurement value that is a different physical quantity from the physical quantity measured by the second sensor 36), or information that has been processed in combination with other measurement values.

[0045] According to this embodiment, the first sensor 35 for controlling the power supplied by the servo amplifier 72 to the linear motor vibrator 3 and the second sensor 36 for updating the control target value in the control unit 712 are provided independently. Unlike a configuration in which the sensor's measured value is input to the control unit 712 via the servo amplifier 72, the time required for information processing in the servo amplifier 72 is eliminated. This reduces the time lag between measurement by the second sensor 36 and acquisition of information by the control unit 712. Therefore, delays in updating the control target value are suppressed, making it easier to generate vibrations according to the desired control target value and improving the accuracy of the test.

[0046] Furthermore, because the first sensor 35 and the second sensor 36 for obtaining measurement results of the characteristics of the shock absorber 100 are provided independently, unlike a configuration in which the sensor's measured value is input to the processing unit 711 via the servo amplifier 72, the time required for information processing in the servo amplifier 72 is eliminated. This reduces the time lag from measurement by the second sensor 36 to information acquisition by the processing unit 711. Consequently, it becomes easier to achieve more real-time measurement of the motion state of the shock absorber 100, improve the accuracy of the time when the measured value is obtained, and improve the accuracy of the test.

[0047] Furthermore, since the measured values ​​are input directly from the second sensor 36 to the measurement control device 71 without going through the servo amplifier 72, it is possible to suppress time lags caused by communication and a decrease in information resolution due to the limitation of the amount of communication information of the servo amplifier 72, thereby improving the accuracy of the test.

[0048] Furthermore, since the first sensor 35 and the second sensor 36 are provided independently, the degree of freedom in sensor selection can be improved. The servo amplifier 72 can select the first sensor 35 according to the required performance, and the processing unit 711 and control unit 712 can select the second sensor 36 according to the required performance. In addition, since the first sensor 35 and the second sensor 36 are provided independently, compared to a configuration in which a single sensor transmits measurement information to the servo amplifier 72 and simultaneously transmits measurement information to the processing unit 711 and control unit 712 (i.e., a configuration in which there are multiple destinations for information transmission), the number of destinations for signals from the sensor is reduced, which helps to suppress the high cost of the sensor.

[0049] Furthermore, by using the measurement values ​​from the second sensor 36, which has a higher resolution than the first sensor 35, and updating the control target value with the control unit 712, and obtaining the measurement results of the characteristics of the shock absorber 100, the accuracy of the test can be further improved.

[0050] Furthermore, by applying vibration to the shock absorber 100 as a test specimen and measuring its characteristics, accuracy can be improved in tests that require real-time measurement. Yes, it is possible. In other words, measuring the characteristics of the shock absorber 100 includes measuring the damping force characteristics with respect to piston speed. When performing such measurements, it is preferable to simultaneously measure the load applied to the shock absorber 100 and the piston speed, and to minimize the time difference in the timing at which the processing unit 711 acquires these measurement signals. In this case, the processing unit 711 is directly connected to the load sensor (i.e., the 3-axis load meter 52 and the load control load cell) and the second sensor 36, so there is little delay between the measurement of any of the measurement signals and their arrival at the processing unit 711. Therefore, the processing unit 711 can minimize the time difference in acquiring each of the simultaneously measured load and piston speed measurement signals. In contrast, in a configuration where the sensor measurement signals reach the processing unit via a servo amplifier, even if the measurement timing is the same, the acquisition timing of the speed measurement signal tends to lag behind the load measurement signal.

[0051] Furthermore, measuring the characteristics of the shock absorber 100 includes measuring the phase difference between the phase of the time change of the shock absorber 100's velocity and the phase of the time change of the load. By directly inputting the measurement signal from the second sensor 36 to the processing unit 711 (without going through the servo amplifier 72), the time difference in acquiring the simultaneously measured load and piston velocity signals can be reduced, as described above, thereby improving the accuracy of the phase difference measurement.

[0052] It should be noted that the present invention is not limited to the embodiments described above, and includes other configurations that can achieve the objectives of the present invention, and modifications such as those shown below are also included in the present invention. For example, in the embodiments described above, the measured value of the second sensor 36 is used in the processing unit 711 and the control unit 712, but in cases where the processing unit and the control unit are composed of mutually independent units (such as a central processing unit), the measured value of the second sensor 36 may be input to and used only in the processing unit, or to and used only in the control unit. In such cases, three independent sensors may be provided, and the measured value of one sensor may be input to the servo amplifier, the measured value of one sensor may be input to the processing unit, and the measured value of one sensor may be input to the control unit.

[0053] Furthermore, in the above embodiment, the characteristics were measured by applying vibration to a shock absorber 100 as the test specimen, but the test specimen is not limited to a shock absorber. Also, the excitation means for generating vibration may be an electrical type that generates vibration when power is supplied (i.e., utilizes the magnetic force generated by the electric current), and may be an electrodynamic type, for example.

[0054] Furthermore, in the above embodiment, the first sensor 35 and the second sensor 36 measure displacement as a physical quantity of the motion state, but the physical quantity of the motion state measured by each sensor may be velocity or acceleration. Also, the physical quantities of the motion state measured by the first sensor and the second sensor may be different from each other.

[0055] Furthermore, in the above embodiment, the control unit 712 generates a target value for the speed of the linear motor exciter 3. However, the target value can be any target value for any parameter related to the operation of the exciter, and for example, it may generate a target value for vibration displacement or acceleration.

[0056] Furthermore, in the above embodiment, the resolution of the second sensor 36 is set to be higher than that of the first sensor 35. However, sensors can be appropriately selected according to the required performance and cost requirements. Two sensors with equal resolution may be used, or the first sensor may have a higher resolution than the second sensor.

[0057] Furthermore, in the above embodiment, the test apparatus 1 has a linear motor excitation means having a pair (two) motor coils 32 for applying vibration to the shock absorber 100. The system is equipped with a motor 3, with one servo amplifier 72 provided for each linear motor vibrator 3, and one first sensor 35 and one second sensor 36 provided for each linear motor vibrator 3. However, the number of motors and other components constituting the vibration means, and the number of servo amplifiers provided for each motor and other component, are arbitrary. In addition, it is sufficient to provide the same number of first sensors as the number of servo amplifiers.

[0058] For example, the test apparatus may be equipped with one linear motor vibrator, and a servo amplifier corresponding to each motor coil 32 may be provided according to the number of motor coils 32 that make up the linear motor vibrator. That is, if one linear motor vibrator is equipped with one pair (two) of motor coils, two servo amplifiers may be provided. In this case, two first sensors should be provided for the linear motor vibrator.

[0059] Alternatively, the test apparatus may be equipped with two (a pair of) linear motor exciters, and one servo amplifier may be provided for each linear motor exciter (a total of two servo amplifiers). In this case, one first sensor may be provided for each of the two (a pair of) linear motor exciters (a total of two first sensors).

[0060] Alternatively, the test apparatus may be equipped with two (a pair of) linear motor exciters, and each of the pair of motor coils 32 of each linear motor exciter may be provided with a corresponding servo amplifier (a total of four servo amplifiers). In this case, one first sensor may be provided for each linear motor exciter (a total of four first sensors may be provided).

[0061] Although embodiments of the present invention have been described in detail above with reference to the drawings, the specific configuration is not limited to these embodiments, and any design changes, etc., that do not depart from the spirit of the present invention are also included. [Explanation of symbols]

[0062] 1…Test apparatus, 3…Linear motor vibrator (vibration means), 34…Output unit, 35…First sensor, 36…Second sensor, 711…Processing unit, 712…Control unit, 72…Servo amplifier, 100…Shock absorber (test specimen)

Claims

1. A test apparatus for measuring the characteristics of a test specimen by applying vibration to the specimen, An electrically powered vibration excitation method that generates vibrations when electricity is supplied, A first sensor and a second sensor for measuring the physical quantities of the motion state of the output section of the vibration excitation means, A control unit that generates a control target value for the vibration excitation means, The system includes a servo amplifier that receives the control target value and the measurement value of the first sensor as input, and controls the power supplied to the excitation means based on the control target value and the measurement value of the first sensor, The test apparatus is characterized in that the control unit receives the measurement value from the second sensor and updates the control target value based on the measurement value from the second sensor.

2. A test apparatus for measuring the characteristics of a test specimen by applying vibration to the specimen, An electrically powered vibration excitation method that generates vibrations when electricity is supplied, A first sensor and a second sensor for measuring the physical quantities of the motion state of the output section of the vibration excitation means, A control unit that generates a control target value for the vibration excitation means, A servo amplifier receives the control target value and the measurement value of the first sensor as input and controls the power supplied to the excitation means based on the control target value and the measurement value of the first sensor. The system includes a processing unit for processing the measurement results of the characteristics of the test specimen, The test apparatus is characterized in that the measurement value of the second sensor is input to the processing unit.

3. The test apparatus according to claim 1 or 2, characterized in that vibration is applied to a shock absorber as the test specimen to measure its characteristics.

4. The test apparatus according to claim 1 or 2, characterized in that the first sensor and the second sensor measure displacement as a physical quantity of the motion state.

5. The test apparatus according to claim 3, characterized in that the control unit generates a control target value for the velocity of the excitation means.

6. The test apparatus according to claim 1 or 2, characterized in that the resolution of the second sensor is higher than the resolution of the first sensor.

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