TWI852460B - Structural vibration measurement device - Google Patents

Abstract

A structural vibration measuring device includes a frame unit, a swing unit, a laser light source, a grating and an imaging unit. The frame unit includes a front end, a rear end spaced apart from the front end, and a mounting base connecting the front end and the rear end. The swing unit includes a swing arm that can swing back and forth relative to the frame unit under a vibration external force. The laser light source is disposed at the front end of the frame unit and is used to emit laser light. The grating is mounted at one end of the swing arm away from the mounting base and generates a diffracted light spot as the swing arm swings and allows the laser light to pass through. The imaging unit is mounted on the frame unit and is used to obtain a vibrating image of the diffracted light spot.

Description

Structural vibration measurement device

The present invention relates to a device for measuring acceleration, deceleration, and acceleration mutation, and more particularly to a structural vibration measuring device.

Taiwan is located in the Pacific Rim, where earthquakes occur frequently due to plate compression. Seismic observatories in various locations continuously record plate activity and issue earthquake warnings in a timely manner, allowing residents to take appropriate evacuation measures.

Most earthquake monitoring instruments use the electromagnetic induction pendulum's magnetic field changes to generate induced current strength signals to detect the occurrence and intensity of earthquakes. In addition, there are also micro-accelerometers such as MEMS, which measure the changes in electrical signals through the physical property changes of objects during accelerated motion to monitor the occurrence of earthquakes.

Since both of the above methods use electrical signals to monitor the occurrence of earthquakes, a vibration measurement device with a different structure is required.

Therefore, an object of the present invention is to provide a structural vibration measuring device with a simple structure.

Therefore, the structural vibration measuring device of the present invention includes a frame unit, a swing unit, a laser light source, a grating and an imaging unit.

The frame unit includes a front end, a rear end spaced from the front end, and a mounting base connecting the front end and the rear end. The swing unit includes a swing arm that can swing back and forth relative to the frame unit under a vibration external force. The laser light source is arranged at the front end of the frame unit and is used to emit laser light. The grating is installed at an end of the swing arm away from the mounting base and swings with the swing arm and allows the laser light to pass through to generate a diffusive light spot. The imaging unit is installed on the frame unit and is used to obtain a vibrating image of the diffusive light spot.

The utility of the present invention is to obtain the vibration image by utilizing the optical characteristics of the swing arm that swings back and forth relative to the frame unit under the vibration external force and the laser light diffracted by the grating. The vibration image can detect the change of the diffracted light spot along with the vibration distance, and further detect the occurrence of vibration such as earthquake. The present invention utilizes optical characteristics to detect vibration such as earthquake, and has a simple structure.

Before the present invention is described in detail, it should be noted that similar components are represented by the same reference numerals in the following description.

1 to 3, a first embodiment of the structural vibration measuring device 100 of the present invention comprises a frame unit 2, a swing unit 3 that swings back and forth under a vibration external force, a laser light source 41 mounted on the frame unit 2, a grating 42 mounted on the swing unit 3, an imaging unit 5, and an electronic device 6. The first embodiment is placed on a continuous vibration platform (not shown) to simulate the vibration external force of an earthquake.

The frame unit 2 includes a base 21 extending along a front-back direction X, a plurality of pillars 22 extending upward from the base 21 along a vertical direction Z perpendicular to the front-back direction X, a mounting seat 23 opposite to the base 21 in the vertical direction Z and connected to the top of the pillars 22, and a connecting rod 24 extending along a left-right direction Y perpendicular to the front-back direction X and the vertical direction Z and connecting the two pillars 22 on the front side. A front end 201 is formed by the two pillars 22 on the front side, a rear end 202 spaced apart from the front end 201 is formed by the two pillars 22 on the rear side, and the mounting seat 23 connects the front end 201 and the rear end 202. The mounting seat 23 of the first embodiment is a rectangular frame and has two through holes 231 spaced apart in the left-right direction Y.

The swing unit 3 is disposed on the mounting seat 23, and includes a shaft 31 fixed to the through holes 231 of the mounting seat 23 along the left-right direction Y, and a swing arm 32 pivoted on the shaft 31 and capable of swinging back and forth relative to the frame unit 2. The swing arm 32 has at least one arm body 321 pivoted on the shaft 31, a platform 322 mounted on one end (i.e., the bottom end) of the arm body 321 away from the mounting seat 23, and a bearing 323 mounted on the arm body 321 and through which the shaft 31 is installed. The arm body 321 has an axis hole 324 for mounting the bearing 323. The swing arm 32 of the first embodiment is a single-arm swing arm having one arm body 321, but in other variations, the swing arm 32 can also be a double-arm swing arm having two arm bodies 321, but is not limited to this, as long as the swing arm 32 can swing back and forth relative to the frame unit 2 when subjected to a vibration external force.

The carrier 322 has a surface 325 substantially perpendicular to the arm body 321, and a mounting surface 326 extending from the surface 325 toward the shaft 31. The mounting surface 326 of the first embodiment is perpendicular to the surface 325.

The laser light source 41 is disposed at the front end 201 of the frame unit 2 and fixed to the connecting rod 24 to emit laser light. The laser light source 41 is, for example but not limited to, a red laser diode.

Referring to FIG. 1 , FIG. 2 and FIG. 4 , the grating 42 is mounted on the carrier 322 of the swing arm 32 and aligned with the laser light source 41 in the vertical direction Z. The grating 42 allows the laser light to pass through. The grating 42 abuts against the mounting surface 326 of the carrier 322. The grating 42 of the first embodiment is, for example but not limited to, a grating sheet with 300 vertical slits/mm. After the laser light passes through the grating 42, a diffracted light spot as shown in FIG. 4 is obtained. The diffracted light spot that maintains the original direction of travel of the laser light is called zero-order diffraction, and the diffracted light spots that expand on the upper and lower sides of the zero-order diffraction are called first-order, second-order, and third-order diffraction, respectively. During the vibration process, the swing arm 32 swings back and forth to generate arc-shaped simple harmonic motion, and causes the grating 42 to be divided into a near end close to the laser light source 41 and a far end far away from the laser light source 41. As the swing arm 32 drives the grating 42 to swing, the distance of each order diffraction light spot relative to the zero-order diffraction light spot will dynamically change.

Referring to FIG. 5 and FIG. 6 , a variation of the carrier 322 is shown, wherein the mounting surface 326 extends backward and upwardly tilted to form an angle A with the surface 325, and the angle A is between 90 and 150 degrees. By tilting the mounting surface 326, the grating 42 (see FIG. 2 ) can be tilted to the swing arm 32 to increase the distance between the diffracted light spots, thereby increasing the variation range of the distance and improving the detection sensitivity of the first embodiment. The carrier 322 also has a slot 327 for the arm body 321 to be detachably mounted, thereby being able to replace the carrier 322 with a different angle A.

Referring to FIG. 1 , FIG. 2 and FIG. 7 , the imaging unit 5 includes a camera 51 mounted on the base 21 and located between the swing unit 3 and the laser light source 41, and a screen 52 disposed at the rear end 202 of the frame unit 2 and projecting the circumferential light spot. The camera 51 is used to record the screen 52 to obtain a shaky image of the circumferential light spot, and the shaky image is the dynamic position change of each level of circumferential light spot as the swing arm 32 swings. The camera 51 is, for example but not limited to, an IPEVO 4K camera.

The electronic device 6 includes a processing module 61 for receiving and analyzing the vibration image and generating a measurement data including time and distance, a communication module 62 connected to the processing module 61 by signal, and a display module 63 for displaying the vibration image and the measurement data. The electronic device 6 of the first embodiment is a computer, and is installed with software programs such as but not limited to Excel, Photopea, Tracker and Python. The Tracker software is used to obtain the distance between a specific diffraction light spot and a zero-order diffraction light spot, and then other software is used to convert the data and produce a light spot distance change magnification diagram in which the distance change magnification changes with time.

Referring to Fig. 8, the light spot distance variation magnification diagram obtained by installing the grating 42 on the stage 322 at three different angles A (90 degrees, 128.6 degrees, and 143.1 degrees from left to right and respectively referred to as vertical, medium angle, and large angle grating sheets). The upper row of the diagrams is obtained under the condition that the vibration intensity value of the continuous vibration platform is 17.94, and the lower row of the diagrams is obtained under the condition that the vibration intensity value of the continuous vibration platform is 26.01. As can be seen from FIG8 , regardless of whether the vibration intensity is high or low, the variation range of the light spot distance variation factor of the large-angle grating sheet is greater than that of the medium-angle and vertical grating sheets, proving that the larger the angle A (see FIG6 ) of the mounting surface 326 is, the more helpful it is to improve the sensitivity of the first embodiment.

From the above, it can be seen that the present invention utilizes the optical properties of grating diffraction and measures the distance change of the diffracted light spot with vibration, so as to effectively detect the occurrence of vibrations such as earthquakes.

Referring to FIG. 2, FIG. 7 and FIG. 9, the following further describes the method of using the present invention to detect earthquakes in real time, and the application of combining the network transmission with line notify to issue an alarm notification:

The laser light of the laser light source 41 is diffracted by the grating 42 and presents a diffracted light spot on the screen 52. When the first embodiment is subjected to the external force of earthquake vibration, the swing arm 32 will produce inertial swing, causing the diffracted light spot to produce a distance change, and the camera 51 will shoot the diffracted light spot on the screen 52 to obtain the shaking image. The shaking image is input into the electronic device 6 and the distance change of the specific diffracted light spot is tracked by software, and the measurement data containing time and distance is generated through the preset image processing. When the processing module 61 determines that the measured data exceeds a preset alarm value, it will send an alarm message 91 to multiple user communication devices 9 via the Internet of Things through the communication module 62, thereby achieving the purpose of real-time monitoring and alarm.

Referring to FIG. 10 , the second embodiment of the present invention is similar to the first embodiment, except that:

The image capturing unit 5 is a linear image sensor (CCD linear image sensor), such as but not limited to Toshiba model TCD1209DG. The image capturing unit 5 is disposed at the rear end 202 of the frame unit 2, so that the diffracted light spot is directly projected on the image capturing unit 5. The image capturing unit 5 is electrically connected to the electronic device 6, and the vibration image of the image capturing unit 5 is read in real time, and the position change of the light spot is tracked in real time through software and the measurement data is output. The second embodiment can omit the image recognition and analysis step, reduce the variation of the signal in the conversion process, and improve the detection efficiency.

However, the above is only an embodiment of the present invention and should not be used to limit the scope of implementation of the present invention. All simple equivalent changes and modifications made according to the scope of the patent application of the present invention and the content of the patent specification are still within the scope of the present patent.

100: Structural vibration measuring device 2: Frame unit 201: Front end 202: Rear end 21: Base 22: Pillar 23: Mounting seat 231: Through hole 24: Connecting rod 3: Swing unit 31: Shaft 32: Swing arm 321: Arm body 322: Carrier 323: Bearing 324: Shaft hole 325: Surface 326: Mounting surface 327: Slot 41: Laser light source 42: Grating 5: Image acquisition unit 51: Camera 52: Screen 6: Electronic equipment 61: Processing module 62: Communication module 63: Display module 9: User communication device 91: Warning message Z: Up and down direction Y: Left and right direction X: Front and back direction A: Angle

Other features and effects of the present invention will be clearly presented in the embodiments with reference to the drawings, in which: Figure 1 is a schematic diagram of the first embodiment of the structural vibration measurement device of the present invention combined with the Internet of Things; Figure 2 is a side view schematic diagram of the first embodiment; Figure 3 is a top view schematic diagram of the first embodiment; Figure 4 is a diffraction spot diagram generated by the laser light of a laser light source of the first embodiment passing through a grating; Figure 5 is an incomplete three-dimensional exploded diagram, illustrating a variation example of a carrier of the first embodiment; Figure 6 is a cross-sectional view of the carrier; Figure 7 is a use schematic diagram, illustrating that an electronic device of the first embodiment sends a warning message through the Internet of Things; Figure 8 is a spot distance variation ratio diagram obtained by installing the grating on different carriers and under different vibration intensities; FIG. 9 is a flow chart of earthquake detection using the first embodiment; and FIG. 10 is a schematic diagram of the use of a second embodiment of the present invention.

100: Structural vibration measurement device

2: Frame unit

201: Front end

202: rear end

21: Base

22: Pillar

23: Mounting seat

3: Swing unit

31: Shaft

32: Swing arms

321: Arm body

322: Carrier

323: Bearings

324: shaft hole

325: Surface

326: Mounting surface

41: Laser light source

42: Grating

5: Imaging unit

51: Camera

52: Screen

Z: Up and down direction

X: front and back direction

Claims (9)

A structural vibration measuring device comprises: a frame unit, including a front end, a rear end spaced from the front end, and a mounting base connecting the front end and the rear end; a swing unit, the swing unit including a swing arm that can swing back and forth relative to the frame unit under a vibration external force; a laser light source, arranged at the front end of the frame unit and used to emit laser light; a grating, mounted at one end of the swing arm away from the mounting base and swinging with the swing arm and allowing the laser light to pass through to generate a diffraction light spot; and an imaging unit, mounted on the frame unit and used to obtain a vibrating image of the diffraction light spot. The structural vibration measuring device as described in claim 1 further comprises an electronic device for receiving the vibration image and generating measurement data including time and distance. A structural vibration measuring device as described in claim 2, wherein the electronic equipment includes a processing module for analyzing the vibration image and outputting the measurement data, and a communication module connected to the processing module by a signal. When the processing module determines that the measurement data exceeds a preset alarm value, it transmits a warning message to a plurality of user communication devices through the communication module. A structural vibration measuring device as described in claim 1, wherein the swing unit further includes a shaft arranged on the mounting base along a left-right direction, the swing arm has at least an arm body pivoted on the shaft, and a carrier arranged on the arm body and for mounting the grating, the carrier has a surface substantially perpendicular to the arm body, and a mounting surface extending from the surface toward the shaft and for the grating to abut against, the surface and the mounting surface form an angle between 90 degrees and 150 degrees. A structural vibration measuring device as described in claim 4, wherein the carrier also has a slot for detachably mounting the arm body. A structural vibration measuring device as described in claim 4, wherein the arm body has an axial hole, and the swing arm also has a bearing installed in the axial hole and provided on the shaft. A structural vibration measuring device as described in claim 1, wherein the frame unit further includes a base opposite to the mounting seat in an up and down direction, a plurality of pillars extending upward from the base and connected to the mounting seat, and a connecting rod connecting two of the pillars and for mounting the laser light source. A structural vibration measuring device as described in claim 1, wherein the imaging unit includes a camera and a screen arranged at the rear end of the frame unit, the screen is used for projecting the diffracted light spot, and the camera records the screen to obtain the vibrating image of the diffracted light spot. The structural vibration measuring device as described in claim 1 also includes an electronic device connected to the imaging unit by a signal. The imaging unit is arranged at the rear end of the frame unit. The diffracted light spot is directly projected onto the imaging unit. The electronic device is used to receive the vibration image and generate a measurement data containing time and distance.