TWO-DIRECTIONAL INCLINATION SENSOR AND METHOD FOR MANUFACTURING THE SAME

Abstract

Provided herein are a two-directional inclination sensor for sensing an inclination of a structure and a method for manufacturing the same. The two-directional inclination sensor includes a main body of a monolithic piece configured to be installed in the structure for sensing the inclination. The main body includes a first section, a second section, a first resilient device connected between the first section and the second section and susceptible of bending along a first direction, a third section including a single-piece weight, and a second resilient device connected between the second section and the third section and susceptible of bending along a second direction. The main body is formed by a machining process to remove parts of a monolithic blank.

Claims

1. A method for manufacturing a two-directional inclination sensor for sensing an inclination of a structure or in-ground, wherein the two-directional inclination sensor includes a main body configured to be installed in the structure for sensing the inclination, the method comprising the steps of: providing a monolithic blank; and integrally forming the main body by a machining process to remove parts of the monolithic blank to comprise: a first section; a second section; a first resilient device connected between the first section and the second section and susceptible of bending along a first direction; a third section; and a second resilient device connected between the second section and the third section and susceptible of bending along a second direction.

2. The method of claim 1, wherein the first section has two first spaces, the second section has two first spaces and two second spaces and the third section has two second spaces, the method further comprising: placing two first pre-tensioned FBG sensors between the first and second sections and fixing two ends of the two first pre-tensioned FBG sensors respectively to the first spaces of the first section and the second section; and placing two second pre-tensioned FBG sensors between the second and third sections and fixing two ends of the two second pre-tensioned FBG sensors respectively to the second spaces of the second section and the third section.

3. The method of claim 1, wherein the third section is integrally extending a single-piece weight.

4. The method of claim 1, wherein the main body further comprises a single-piece weight connected to the third section.

5. The method of claim 1, wherein the first resilient device comprises two first spring leaves on a first plane, and the second resilient device comprises two second spring leaves on a second plane.

6. The method of claim 5, wherein the first plane and the second plane are perpendicular to each other.

7. A two-directional inclination sensor for sensing an inclination of a structure or in-ground, comprising: a main body of a monolithic piece configured to be installed for sensing the inclination, the main body comprising: a first section; a second section; a first resilient device connected between the first section and the second section and susceptible of bending along a first direction; a third section including a single-piece weight; and a second resilient device connected between the second section and the third section and susceptible of bending along a second direction.

8. The two-directional inclination sensor of claim 7, wherein the first section has two first spaces, the second section has two first spaces and two second spaces and the third section has two second spaces, the two-directional inclination sensor further comprising: two first pre-tensioned FBG sensors placed between the first and second sections, wherein two ends of the two first pre-tensioned FBG sensors are respectively fixed to the first spaces of the first section and the second section; and two second pre-tensioned FBG sensors placed between the second and third sections, wherein two ends of the two second pre-tensioned FBG sensors are respectively fixed to the second spaces of the second section and the third section.

9. The two-directional inclination sensor of claim 8, further comprising a first set of set screws and a second set of set screws, wherein the first set of set screws are configured to fix the two ends of the two first pre-tensioned FBG sensors across the first section and the second section and the second set of set screws are configured to fix the two ends of the two second pre-tensioned FBG sensors across the second section and the third section.

10. The two-directional inclination sensor of claim 8, wherein: a first bending curvature of the first resilient device and a second bending curvature of the second resilient device are sensed by the two first pre-tensioned FBG sensors and the two second pre-tensioned FBG sensors to obtain an inclination along the first direction and an inclination along the second direction, respectively; and when there are inclinations along both the first direction and the second direction, the inclination along the first direction and the inclination along the second direction are vectorially summed to determine a resultant inclination.

11. The two-directional inclination sensor of claim 7, wherein the first resilient device comprises two first spring leaves on a first plane, and the second resilient device comprises two second spring leaves on a second plane.

12. The two-directional inclination sensor of claim 11, wherein the first plane and the second plane are perpendicular to each other.

13. The two-directional inclination sensor of claim 12, wherein: a first bending curvature of the two first spring leaves and a second bending curvature of the two second spring leaves are sensed by the two first pre-tensioned FBG sensors and the two second pre-tensioned FBG sensors to obtain an inclination along an x-x direction and an inclination along a y-y direction, respectively; and when there are inclinations along both the x-x direction and the y-y direction, the inclination along the x-x direction and the inclination along the y-y direction are vectorially summed to determine a resultant inclination.

14. A two-directional inclination sensor for sensing an inclination of a structure or in-ground, comprising: a main body configured to be installed for sensing the inclination, the main body comprising: a first section; a second section; a first resilient device connected between the first section and the second section and susceptible of bending along a first direction; a third section; and a second resilient device connected between the second section and the third section and susceptible of bending along a second direction; and a single-piece weight connected to the third section.

15. The two-directional inclination sensor of claim 14, wherein the first section has two first spaces, the second section has two first spaces and two second pieces and the third section has two second spaces, the two-directional inclination sensor further comprising: two first pre-tensioned FBG sensors placed between the first and second sections, wherein two ends of the two first pre-tensioned FBG sensors are respectively fixed across the first spaces of the first section and the second section; and two second pre-tensioned FBG sensors placed between the second and third sections, wherein two ends of the two second pre-tensioned FBG sensors are respectively fixed across the second spaces of the second section and the third section.

16. The two-directional inclination sensor of claim 15, further comprising a first set of set screws and a second set of set screws, wherein the first set of set screws are configured to fix the two first pre-tensioned FBG sensors across the first section and the second section, and the second set of set screws are configured to fix the two second pre-tensioned FBG sensors across the second section and the third section.

17. The two-directional inclination sensor of claim 15, wherein: a first bending curvature of the first resilient device and a second bending curvature of the second resilient device are sensed by the two first pre-tensioned FBG sensors and the two second pre-tensioned FBG sensors to obtain an inclination along the first direction and an inclination along the second direction, respectively; and when there are inclinations along both the first direction and the second direction, the inclination along the first direction and the inclination along the second direction are vectorially summed to determine a resultant inclination.

18. The two-directional inclination sensor of claim 14, wherein the main body is of a monolithic piece, the first resilient device comprises two first spring leaves on a first plane, and the second resilient device comprises two second spring leaves on a second plane.

19. The two-directional inclination sensor of claim 18, wherein the first plane and the second plane are perpendicular to each other.

20. The two-directional inclination sensor of claim 19, wherein: a first bending curvature of the two first spring leaves and a second bending curvature of the two second spring leaves are sensed by the two first pre-tensioned FBG sensors and the two second pre-tensioned FBG sensors to obtain an inclination along an x-x direction and an inclination along a y-y direction, respectively; and when there are inclinations along both the x-x direction and the y-y direction, the inclination along the x-x direction and the inclination along the y-y direction are vectorially summed to determine a resultant inclination.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The above embodiments and advantages of the present disclosure will become more readily apparent to those ordinarily skilled in the art after reviewing the following detailed descriptions and accompanying drawings:

[0020] FIG. 1 is a schematic diagram showing the principle of light reflection from an FBG.

[0021] FIG. 2 is a schematic diagram showing the use of an inclinometer probe to measure the lateral ground displacement distribution.

[0022] FIG. 3 is a schematic diagram showing a prior art FBG inclination sensor.

[0023] FIG. 4 is a schematic diagram showing the connection of an FBG sensor and an optic fiber at fixation ends.

[0024] FIG. 5A is a schematic diagram showing a two-directional inclination sensor according to a preferred embodiment of the present disclosure, where a first resilient device is susceptible of bending in the x-x direction.

[0025] FIG. 5B is a schematic diagram showing a two-directional inclination sensor according to a preferred embodiment of the present disclosure, where a second resilient device is susceptible of bending in the y-y direction.

[0026] FIG. 5C is a top view of a two-directional inclination sensor according to a preferred embodiment of the present disclosure.

[0027] FIG. 6A is a three-dimensional (3D) schematic diagram showing a monolithic blank according to a preferred embodiment of the present disclosure.

[0028] FIG. 6B is a 3D schematic diagram showing a two-directional inclination sensor according to a preferred embodiment of the present disclosure.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0029] Please refer to all figures of the present disclosure when reading the following detailed description, wherein all Figures of the present disclosure demonstrate different embodiments of the present disclosure by showing examples, and help the skilled person in the art to understand how to implement the present disclosure. The present examples provide sufficient embodiments to demonstrate the spirit of the present disclosure, each embodiment does not conflict with the others, and new embodiments can be implemented through an arbitrary combination thereof, i.e., the present disclosure is not restricted to the embodiments disclosed in the present specification. Unless there are other restrictions defined in the specific example, the following definitions apply to the terms used throughout the specification.

[0030] The present disclosure mainly provides a two-directional inclination sensor 10 as shown in FIG. 5A to FIG. 5C made from a monolithic blank 9 in FIG. 6A. The two-directional inclination sensor 10 uses a single-piece weight 1. Other than two first pre-tensioned FBG sensors 2 in a first direction and two second pre-tensioned FBG sensors 3 in a second direction, fixation ends 21 and 31 (4 for the two first pre-tensioned FBG sensors 2 and 4 for the two second pre-tensioned FBG sensors 3), corresponding set screws 6 configured to fix the two first pre-tensioned FBG sensors 2 in the first direction and set screws 7 configured to fix the two first pre-tensioned FBG sensors 2 in the second direction, the two-directional inclination sensor 10 is made from the monolithic blank 9 (as shown in FIG. 6A), with unwanted parts carved out mechanically leaving necessary spaces. In the present embodiment, the first direction is the x-x direction and the second direction is the y-y direction.

[0031] In some embodiments, a first resilient device 4 in the x-x direction as viewed from the A-A side of FIG. 5A has the thickness far less than the width as viewed from the B-B side of FIG. 5B, and a second resilient device 5 in the y-y direction as viewed from the A-A side of FIG. 5A has the width far more than the thickness as viewed from the B-B side of FIG. 5B. Therefore, when the single-piece weight 1 tilts in the x-x direction or the A-A plane, the first resilient device 4 in the x-x direction deflects significantly more than the second resilient device 5 in the y-y direction. On the other hand, when the single-piece weight 1 tilts in the y-y direction or the B-B plane, the second resilient device 5 in the y-y direction deflects significantly more than the first resilient device 4 in the x-x direction. The amount of deflection and thus inclination of the first resilient device 4 in the x-x direction and the second resilient device 5 in the y-y direction are determined by the two first pre-tensioned FBG sensors 2 in the x-x direction and the two second pre-tensioned FBG sensors 3 in the y-y direction, respectively. When the single-piece weight 1 tilts in both the x-x direction (or the A-A plane) and the y-y direction (or the B-B plane), the inclination measurements are vectorially summed to determine the combined inclination. In the present embodiment, the first resilient device 4 includes two first spring leaves on a first plane, and the second resilient device 5 includes two second spring leaves on a second plane. In one embodiment, the first plane and the second plane are perpendicular to each other.

[0032] FIG. 4 is a schematic diagram showing the connection of an FBG sensor and an optic fiber at fixation ends. FIG. 4 is an example of the connection of the FBG sensor 2 and an optical fiber 200, and the connection of the FBG sensor 3 and an optic fiber 300 is the same as that of the FBG sensor 2 and an optical fiber 200. Independent from the fabrication of the main body 8 in FIG. 5A, a total of 4 FBG sensors, divided into two sets, with fixation ends as shown in FIG. 4 are made. The diameter/length of the fixation ends are compatible with the spaces 84, 85, 86 and 87 reserved in the main body 8. The distances between the fixation ends 21 and 31 are respectively compatible with the distances between the corresponding set screws 6 and 7 in the x-x and y-y directions. During fabrication, taking an optical fiber 200, as later shown in FIG. 5A and FIG. 5B, for example, the optical fiber 200 containing FBG sensors 2 is inserted through a hole at the center of two fixation ends 21. Then, the optical fiber 200 is epoxied to the fixation ends 21 leaving the FBG sensors 2 at the middle of the corresponding fixation ends 21. After the fixation ends 21 are disposed inside the main body 8, the two first pre-tensioned FBG sensors 2 in the x-x direction and the two second pre-tensioned FBG sensors 3 in the y-y direction along with their respective fixation ends 21 and 31 are fixed in the main body 8 by tightening the set screws 6 and 7 while maintaining a tension on the optical fibers 200 and 300. FIG. 6B shows the schematic diagram of a completed two-directional inclination sensor 10.

[0033] As shown in FIG. 5A to FIG. 5C, the monolithic blank for manufacturing the two-directional inclination sensor 10 may include stainless steel, aluminum or copper. The selected material and size are determined according to the planned range and resolution of measurements and expected weight of the single-piece weight 1 of the two-directional inclination sensor 10. Necessary machining methods that may include milling, lathing, drilling, and wire cutting are used to carve out the space to house the two first pre-tensioned FBG sensors 2 in the x-x direction and the two second pre-tensioned FBG sensors 3 in the y-y direction along with their respective set screws 6 and 7. The material around the first resilient device 4 in the x-x direction and the second resilient device 5 in the y-y direction is removed to yield the desired thickness, width, and length for the respective resilient devices 4 and 5.

[0034] The two first pre-tensioned FBG sensors 2 in the x-x direction and the two second pre-tensioned FBG sensors 3 in the y-y direction are inserted into the corresponding spaces 84, 85, 86 and 87 reserved in the main body 8, and then the set screws 6 are used to fix the two first pre-tensioned FBG sensors 2 in the x-x direction and the set screws 7 are used to fix the two second pre-tensioned FBG sensors 3 in the y-y direction.

[0035] FIG. 5A to FIG. 5C are schematic diagrams showing a two-directional inclination sensor according to a preferred embodiment of the present disclosure. In FIG. 5A, the two-directional inclination sensor 10 includes: a main body 8, two x-x direction FBG sensors 2 and two y-y direction FBG sensors 3. The main body 8 includes a single-piece weight 1, two x-x direction spring pieces 4, two y-y direction spring pieces 5, 4 set screws 6 for the FBG sensors 2 in the x-x direction, 4 set screws 7 for the FBG sensors 3 in the y-y direction, a first section 81, a second section 82, a third section 83, two first spaces 84 in the first section 81, two first spaces 85 in the second section 82, two second spaces 86 in the second section 82 and two second spaces 87 in the third section 83.

[0036] FIG. 6A is a three-dimensional (3D) schematic diagram showing a monolithic blank according to a preferred embodiment of the present disclosure. As shown in FIG. 6A, a 3D schematic diagram of a monolithic blank 9 is shown.

[0037] FIG. 6B is a 3D schematic diagram showing a two-directional inclination sensor according to a preferred embodiment of the present disclosure. In FIG. 6B, the two-directional inclination sensor 10 of the present disclosure includes a main body 8, two x-x direction FBG sensors 2, two y-y direction FBG sensors 3 and other components (as shown in FIG. 5A).

[0038] The present disclosure further provides a method for manufacturing a two-directional inclination sensor for sensing an inclination of a structure. In one embodiment, for example, the structure (not shown) may be at a certain point in the ground. Referring to FIG. 5A to FIG. 5C, the two-directional inclination sensor 10 includes a main body 8 configured to be installed in the structure for sensing the inclination. The method includes the following steps as described herein.

[0039] First, a monolithic blank 9 (as shown in FIG. 6A) is provided. In one embodiment, the monolithic blank 9 may include stainless steel, aluminum or copper. Then, a machining process is performed to remove unwanted parts of the monolithic blank 9 to integrally form the main body 8 that includes a first section 81, a second section 82, a first resilient device 4 connected between the first section 81 and the second section 82 and susceptible of bending along a first direction, a third section 83, and a second resilient device 5 connected between the second section 82 and the third section 83 and susceptible of bending along a second direction. In one embodiment, the machining process may be performed using a drilling machine, a milling machine or a wire cutting machine to remove the unwanted parts of the monolithic blank 9 in two first spaces 84 in the first section 81, two first spaces 85 in the second section 82, two second spaces 86 in the second section 82 and two second spaces 87 in the third section 83.

[0040] In one embodiment, the method may further include the following steps. Two first pre-tensioned FBG sensors 2 are placed between the first and second sections 81 and 82, and two ends of the two first pre-tensioned FBG sensors 2 are fixed respectively to the first spaces 84 and 85 of the first section 81 and the second section 82. Then, two second pre-tensioned FBG sensors 3 are placed between the second and third sections 82 and 83, and two ends of the two second pre-tensioned FBG sensors 3 are fixed respectively to the second spaces 86 and 87 of the second section 82 and the third section 83.

[0041] In one embodiment, the third section 83 is integrally extending a single-piece weight 1. Alternatively, the main body 8 may further include a single-piece weight 1 connected to the third section 83.

[0042] In one embodiment, the first resilient device 4 may include two first spring leaves on a first plane, and the second resilient device 5 may include two second spring leaves on a second plane. In one embodiment, the first plane and the second plane are perpendicular to each other.

[0043] In one embodiment, the method may further include the following steps. A first set of set screws 6 are provided to fix the two ends of the two first pre-tensioned FBG sensors 2 across the first section 81 and the second section 82. A second set of set screws 7 are provided to fix the two ends of the two second pre-tensioned FBG sensors 3 across the second section 82 and the third section 83.

[0044] The present disclosure provides a two-directional inclination sensor for sensing an inclination of a structure. In one embodiment, for example, the structure (not shown) may be at a certain point in the ground. Referring to FIG. 5A to FIG. 5C, the two-directional inclination sensor 10 includes a main body 8 of a monolithic piece configured to be installed in a structure or in-ground for sensing inclination. The main body 8 includes a first section 81, a second section 82, a first resilient device 4 connected between the first section 81 and the second section 82 and susceptible of bending along a first direction, a third section 83, and a second resilient device 5 connected between the second section 82 and the third section 83 and susceptible of bending along a second direction. In one embodiment, the third section 83 includes a single-piece weight 1. Alternatively, a single-piece weight 1 may be connected to the third section 83.

[0045] In one embodiment, the first section 81 has two first spaces 84, the second section 82 has two first spaces 85 and two second spaces 86, and the third section 83 has two second spaces 87. The two-directional inclination sensor 10 further includes two first pre-tensioned FBG sensors 2 placed between the first section 81 and the second section 82, and two second pre-tensioned FBG sensors 3 placed between the second section 82 and the third section 83. Two ends of the two first pre-tensioned FBG sensors 2 are fixed respectively to the first spaces 84 and 85 of the first section 81 and the second section 82. Two ends of the two second pre-tensioned FBG sensors 3 are fixed respectively to the second spaces 86 and 87 of the second section 82 and the third section 83.

[0046] In one embodiment, the two-directional inclination sensor 10 further includes a first set of set screws 6 and a second set of set screws 7. The first set of set screws 6 are configured to fix the two ends of the two first pre-tensioned FBG sensors 2 across the first section 81 and the second section 82. The second set of set screws 7 are configured to fix the two ends of the two second pre-tensioned FBG sensors 3 across the second section 82 and the third section 83.

[0047] In one embodiment, a first bending curvature of the first resilient device 4 and a second bending curvature of the second resilient device 5 are sensed by the two first pre-tensioned FBG sensors 2 and the two second pre-tensioned FBG sensors 3 to obtain an inclination along the first direction and an inclination along the second direction, respectively. When there are inclinations along both the first direction and the second direction, the inclination along the first direction and the inclination along the second direction are vectorially summed to determine a resultant inclination.

[0048] In one embodiment, the first resilient device 4 includes two first spring leaves on a first plane, and the second resilient device 5 includes two second spring leaves on a second plane. In one embodiment, the first plane and the second plane are perpendicular to each other. In one embodiment, a first bending curvature of the two first spring leaves and a second bending curvature of the two second spring leaves are sensed by the two first pre-tensioned FBG sensors and the two second pre-tensioned FBG sensors to obtain an inclination along an x-x direction and an inclination along a y-y direction, respectively. When there are inclinations along both the x-x direction and the y-y direction, the inclination along the x-x direction and the inclination along the y-y direction are vectorially summed to determine a resultant inclination.

[0049] While the disclosure has been described in terms of what is presently considered to be the most practical and preferred embodiments, it is to be understood that the disclosure need not be limited to the disclosed embodiments. On the contrary, it is intended to cover various modifications and similar arrangements included within the spirit and scope of the appended claims which are to be accorded with the broadest interpretation so as to encompass all such modifications and similar structures.