Fiber optic displacement sensor with extended range

Abstract

The main problem solved by the present invention is how to extend the range of the fiber optic displacement sensor. The fiber optic displacement sensor with extended range is characterized in that it includes a probe and a fiber optic coupler. The probe includes a transmitting fiber optic port and a receiving fiber optic port. The transmitting fiber optic port can transmit light, and the receiving fiber optic port can receive the light reflected back by the object to be measured. The number of the receiving fiber optic ports is n, and n ≥ 2. Each of the receiving fiber optic ports can receive the light emitted by the transmitting fiber optic port. The number of the transmitting fiber optic port is one, and the fiber optic coupler has n input ports and one output port. The beneficial effect is that the n receiving fiber optic ports can enhance the received light by n times. After the reflected light intensity is enhanced, its change value per unit distance naturally increases. The distance range where the reflected light intensity was originally very weak can now also be distinguished, so its range will inevitably increase accordingly.

Description

Technical Field

[0001] The present invention relates to the field of optical fiber measurement technology, in particular to an optical fiber displacement sensor with extended range and a method thereof. Background Art

[0002] At present, fiber optic displacement sensors mainly refer to fiber optic probes (referred to as probes), which include a transmitting fiber optic port and a receiving fiber optic port. The transmitting fiber optic port emits light to illuminate the surface of the object to be measured. The light is reflected and then received by the receiving fiber optic port. The distance between the probe and the object surface is obtained based on the intensity of the received reflected light.

[0003] Fiber optic displacement sensors are widely used because they can accurately and economically perform measurements. However, as the measured distance exceeds a certain range, the intensity of the reflected light decreases rapidly, becoming too weak to be discerned. Consequently, their measuring range is limited, typically to just a few millimeters. However, gaps in bridges, pipelines, and other structures sometimes exceed this range, making current fiber optic displacement sensors insufficient. Their range needs to be further expanded for practical use. Summary of the Invention

[0004] The main problem solved by the present invention is how to extend the measuring range of the optical fiber displacement sensor.

[0005] An extended-range fiber optic displacement sensor is characterized by comprising a probe and a fiber optic coupler, wherein the probe comprises a transmitting fiber optic port and a receiving fiber optic port, wherein the transmitting fiber optic port is capable of transmitting light, and the receiving fiber optic port is capable of receiving the light reflected back by the object being measured, wherein the number of the receiving fiber optic ports is n, wherein n ≥ 2, and each of the receiving fiber optic ports is capable of receiving light emitted by the transmitting fiber optic port, and the number of the transmitting fiber optic port is one, wherein the fiber optic coupler has n input ports and one output port, wherein the n input ports are respectively connected to the n fiber optic receiving ports via optical fibers, and the one output port is connected to a main receiving fiber, wherein the fiber optic coupler couples the optical fibers of the n fiber optic receiving ports to the main receiving fiber, and the main receiving fiber is located in an optical cable connected to the fiber optic displacement sensor.

[0006] The beneficial effect is that the receiving fiber ports can all receive the light emitted by the transmitting fiber ports. Therefore, the n receiving fiber ports can enhance the received light by n times. After the reflected light intensity is enhanced, its variation value per unit distance naturally increases. The distance range where the reflected light intensity was originally very weak can now also be distinguished. Therefore, its range will inevitably increase accordingly. The number of transmitting fiber ports is one, that is, the transmission power can remain unchanged without increasing the transmission cost. The fiber coupler can converge the signals from multiple optical fibers into one optical fiber to facilitate unified signal transmission and management. Therefore, the fiber coupler can merge the optical fibers of the n optical fiber receiving ports into one optical fiber without increasing the transmission cost on the optical cable where the optical fiber displacement sensor is located. In addition, due to the enhanced reflected light intensity, its variation value per unit distance increases. Adapting the corresponding receiving optical modem can improve its measurement accuracy within all ranges. Increasing the number of receiving fiber ports can not only expand its range, but also improve its measurement accuracy, killing two birds with one stone.

[0007] The number of the receiving optical fiber ports is at least three, and they are centrally symmetrically distributed around the transmitting optical fiber port.

[0008] The beneficial effect is that the central symmetrical distribution makes the intensity of light received by the light displacement sensor theoretically just n times the current intensity, which is convenient for calculation and analysis. At the same time, the structure is symmetrical and compact, which is convenient for production and manufacturing.

[0009] Alternatively, the number of the receiving optical fiber ports is two, and they are distributed in a triangle with the optical fiber transmitting port.

[0010] The beneficial effect is that the triangular distribution structure is compact, which can reduce the overall volume of the optical fiber displacement sensor.

[0011] The device also includes a housing, which encloses the probe and the optical fiber coupler. The probe is flush with the front end of the housing, and the front end of the housing is open.

[0012] The beneficial effect is that the shell is the shell of the optical fiber displacement sensor, which can fix the positions of the probe and the optical fiber coupler and play a protective role; the front end of the shell is open, which is convenient for the probe to transmit and receive light.

[0013] It also includes a telescopic sleeve, one end of which is open, and the shell enters the telescopic sleeve through the opening. The port at the other end of the telescopic sleeve is provided with a cover, and the cover can close the telescopic sleeve. The longitudinal section of the telescopic sleeve is in the shape of a spring, and it is made of rubber material. After being longitudinally compressed, it can automatically stretch and recover. The telescopic sleeve can be extended and retracted back and forth outside the shell. During the process of extending and retracting, the telescopic sleeve is always compressed, and the cover is always against the surface of the object to be measured when in use.

[0014] The beneficial effect is that the shell enters the telescopic sleeve through the opening, that is, the telescopic sleeve covers the shell, and at the same time the cover can close the telescopic sleeve. The cover can be made of opaque materials such as metal. Therefore, dust and light in the environment will not enter the telescopic sleeve, will not enter the probe, and will not affect the accurate measurement of the reflected light intensity. At the same time, the inner surface of the cover can be made of a smooth material with good light reflectivity, which fully meets the requirements of the optical fiber displacement sensor. Compared with the surface of an ordinary object to be measured, the measurement is usually more accurate, and the accuracy of the distance measurement is jointly guaranteed. In addition, since the emitted and reflected light are only in the telescopic sleeve, even if dust adheres to the surface of the object to be measured, it will not affect the accurate measurement of the reflected light intensity, and the cover is always against the surface of the object to be measured during use, thereby ensuring that the distance measurement result is accurate.

[0015] A limiting ring is fixed on the shell, which limits the position of the telescopic sleeve and bears the elastic force after the telescopic sleeve is compressed; the length of the telescopic sleeve after compression is greater than or equal to the distance between the front end of the shell and the limiting ring.

[0016] The beneficial effect is that, in addition to limiting the position of the telescopic sleeve, the limiting ring can also fix one end of the telescopic sleeve to maintain the stability of its structure during use; the length of the telescopic sleeve after compression is greater than or equal to the distance between the front end of the shell and the limiting ring, that is, the distance between the front end of the shell and the limiting ring can accommodate the contracted telescopic sleeve, so that the telescopic sleeve can be measured after it is extended, thereby ensuring the measuring range of the optical fiber displacement sensor. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 . A schematic diagram of the internal structure of an embodiment;

[0018] Figure 2 .Side view of the internal structure;

[0019] Figure 3 .Schematic diagram of the structure after the shell is equipped;

[0020] Figure 4 . A schematic diagram of the internal structure of an embodiment;

[0021] Figure 5 .Side view of the internal structure;

[0022] Figure 6 .Schematic diagram of the structure after the shell is equipped;

[0023] Figure 7 .Schematic diagram of the overall structure with telescopic sleeve;

[0024] Figure 8 .Schematic diagram of the telescopic sleeve structure;

[0025] Figure 9.Schematic diagram of the overall structure after the telescopic sleeve is extended.

[0026] In the figure: 1. Probe, 11. Transmitting fiber port, 12. Receiving fiber port, 121. Main receiving fiber, 2. Fiber coupler, 3. Housing, 4. Telescopic sleeve, 41. Cover, 5. Limiting ring. DETAILED DESCRIPTION

[0027] Example

[0028] like Figure 1-3 As shown, a fiber optic displacement sensor with an extended range is characterized by including a probe and a fiber optic coupler, the probe including a transmitting fiber optic port and a receiving fiber optic port, the transmitting fiber optic port being capable of transmitting light, the receiving fiber optic port being capable of receiving the light reflected back by the object being measured, the number of the receiving fiber optic ports being n, wherein n≥2, the receiving fiber optic ports being capable of receiving the light emitted by the transmitting fiber optic port, the number of the transmitting fiber optic port being one, the fiber optic coupler having n input ports and one output port, the n input ports being respectively connected to the n fiber optic receiving ports via optical fibers, the one output port being connected to the main receiving fiber, the fiber optic coupler coupling the optical fibers of the n fiber optic receiving ports to the main receiving fiber, and the main receiving fiber being located in the optical cable connected to the fiber optic displacement sensor.

[0029] The number of the receiving optical fiber ports is at least three, and they are centrally symmetrically distributed around the transmitting optical fiber port.

[0030] The device also includes a housing, which encloses the probe and the optical fiber coupler. The probe is flush with the front end of the housing, and the front end of the housing is open.

[0031] Example

[0032] like Figure 4-6 As shown, a fiber optic displacement sensor with an extended range is characterized by including a probe and a fiber optic coupler, the probe including a transmitting fiber optic port and a receiving fiber optic port, the transmitting fiber optic port being capable of transmitting light, the receiving fiber optic port being capable of receiving the light reflected back by the object being measured, the number of the receiving fiber optic ports being n, wherein n≥2, the receiving fiber optic ports being capable of receiving the light emitted by the transmitting fiber optic port, the number of the transmitting fiber optic port being one, the fiber optic coupler having n input ports and one output port, the n input ports being respectively connected to the n fiber optic receiving ports via optical fibers, the one output port being connected to the main receiving fiber, the fiber optic coupler coupling the optical fibers of the n fiber optic receiving ports to the main receiving fiber, and the main receiving fiber being located in the optical cable connected to the fiber optic displacement sensor.

[0033] The number of the receiving optical fiber ports is two, and the receiving optical fiber ports and the optical fiber transmitting ports are distributed in a triangular pattern.

[0034] The device also includes a housing, which encloses the probe and the optical fiber coupler. The probe is flush with the front end of the housing, and the front end of the housing is open.

[0035] Example

[0036] like Figure 4-9 As shown, a fiber optic displacement sensor with an extended range is characterized by including a probe and a fiber optic coupler, the probe including a transmitting fiber optic port and a receiving fiber optic port, the transmitting fiber optic port being capable of transmitting light, the receiving fiber optic port being capable of receiving the light reflected back by the object being measured, the number of the receiving fiber optic ports being n, wherein n≥2, the receiving fiber optic ports being capable of receiving the light emitted by the transmitting fiber optic port, the number of the transmitting fiber optic port being one, the fiber optic coupler having n input ports and one output port, the n input ports being respectively connected to the n fiber optic receiving ports via optical fibers, the one output port being connected to the main receiving fiber, the fiber optic coupler coupling the optical fibers of the n fiber optic receiving ports to the main receiving fiber, and the main receiving fiber being located in the optical cable connected to the fiber optic displacement sensor.

[0037] The number of the receiving optical fiber ports is two, and the receiving optical fiber ports and the optical fiber transmitting ports are distributed in a triangular pattern.

[0038] The device also includes a housing, which encloses the probe and the optical fiber coupler. The probe is flush with the front end of the housing, and the front end of the housing is open.

[0039] It also includes a telescopic sleeve, one end of which is open, and the shell enters the telescopic sleeve through the opening. The port at the other end of the telescopic sleeve is provided with a cover, and the cover can close the telescopic sleeve. The longitudinal section of the telescopic sleeve is in the shape of a spring, and it is made of rubber material. After being longitudinally compressed, it can automatically stretch and recover. The telescopic sleeve can be extended and retracted back and forth outside the shell. During the process of extending and retracting, the telescopic sleeve is always compressed, and the cover is always against the surface of the object to be measured when in use.

[0040] A limiting ring is fixed on the shell, which limits the position of the telescopic sleeve and bears the elastic force after the telescopic sleeve is compressed; the length of the telescopic sleeve after compression is greater than or equal to the distance between the front end of the shell and the limiting ring.

Claims

1. The fiber optic displacement sensor with extended range is characterized by: The probe includes a probe and a fiber optic coupler. The probe includes a transmitting fiber optic port and a receiving fiber optic port. The transmitting fiber optic port can transmit light, and the receiving fiber optic port can receive the light reflected by the object to be measured. The number of the receiving fiber optic ports is n, where n ≥ 2. Each of the receiving fiber optic ports can receive the light emitted by the transmitting fiber optic port. The number of the transmitting fiber optic port is one. The fiber optic coupler has n input ports and one output port. The n input ports are respectively connected to the n fiber optic receiving ports through optical fibers. The one output port is connected to the main receiving fiber. The fiber optic coupler couples the optical fibers of the n fiber optic receiving ports to the main receiving fiber. The main receiving fiber is located in the optical cable connected to the fiber optic displacement sensor. The apparatus further comprises a housing, wherein the housing encloses the probe and the optical fiber coupler, the probe is flush with the front end of the housing, and the front end of the housing is open. It also includes a telescopic sleeve, one end of which is open, and the shell enters the telescopic sleeve through the opening. The port at the other end of the telescopic sleeve is provided with a cover, and the cover can close the telescopic sleeve. The longitudinal section of the telescopic sleeve is in the shape of a spring, and it is made of rubber material. After being longitudinally compressed, it can automatically stretch and recover. The telescopic sleeve can be extended and retracted back and forth outside the shell. During the process of extending and retracting, the telescopic sleeve is always compressed, and the cover is always against the surface of the object to be measured when in use.

2. The optical fiber displacement sensor with extended range according to claim 1, wherein: The number of the receiving optical fiber ports is at least three, and they are centrally symmetrically distributed around the transmitting optical fiber port.

3. The optical fiber displacement sensor with extended range according to claim 1, wherein: The number of the receiving optical fiber ports is two, and the receiving optical fiber ports and the optical fiber transmitting ports are distributed in a triangular pattern.

4. The optical fiber displacement sensor with extended range according to claim 1, wherein: A limiting ring is fixed on the shell, which limits the position of the telescopic sleeve and bears the elastic force after the telescopic sleeve is compressed; the length of the telescopic sleeve after compression is greater than or equal to the distance between the front end of the shell and the limiting ring.

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