Bending fiber optic multi-parameter sensor based on bionic side line

Abstract

The application discloses a kind of based on bionic lateral line's curved optical fiber multi-parameter sensor, one end of input optical fiber is connected with light source emission end, the other end is sequentially penetrated through the sensor base and artificial cilium cantilever beam and bare optical fiber fixed connection;The other end of bare optical fiber is fixedly connected with output optical fiber;The other end of output optical fiber is penetrated through artificial cilium cantilever beam and is connected with the light source receiving end communication connection.The sensor of the application can monitor the size of flow velocity, flow velocity direction, salinity and other multiple parameters simultaneously, and can meet the multidimensional monitoring demand under complex marine environment.Meanwhile, by imitating the structure of fish lateral line hair cell, using flexible artificial cilium cantilever beam as core perception element, the accurate detection of water flow velocity size and direction can be realized.In addition, the sensor is directly contacted with fluid through bare optical fiber part, and the detection of fluid salinity is realized by using the difference of different fluid refractive index.

Description

Technical Field

[0001] This invention relates to the field of fiber optic sensor technology, and in particular to a multi-parameter sensor for bent optical fibers based on biomimetic sidelines. Background Technology

[0002] With the accelerated development of marine resources, marine environmental monitoring has become an important research field globally, especially in the real-time monitoring of parameters such as water flow velocity and fluid salinity, which has led to an increasing demand for sensor technology. Traditional marine sensors mainly rely on microelectromechanical systems (MEMS) technology. These sensors are expensive and, while possessing relatively high sensitivity and accuracy to a certain extent, face many challenges in the complex marine environment.

[0003] Secondly, existing sensors often only monitor a single parameter. However, with the diversification and increasing sophistication of marine monitoring needs, single-parameter detection can no longer meet the multi-dimensional monitoring requirements of complex marine environments. Current technologies have limited capabilities in simultaneous multi-parameter detection, failing to simultaneously monitor multiple parameters such as flow velocity, flow direction, and salinity.

[0004] Finally, existing sensors have limitations in directional sensing capabilities. Traditional directional sensors often rely on fixed structures or single sensing elements, making it difficult to flexibly detect subtle changes in the direction of fluid flow. This limits the accuracy of sensors in detecting changes in water flow direction, especially in complex flow field environments, where it is difficult to achieve accurate perception of changes in flow field direction.

[0005] Traditional water flow sensors, such as hot-wire sensors, Doppler laser velocimeters, and acoustic velocimeters, are mostly bulky, expensive, susceptible to electromagnetic interference, and have poor scalability. They can only perform a single task and have complex structures. These limitations make it difficult for traditional sensors to meet the needs of the increasingly digital, intelligent, and array-based marine monitoring network construction. Furthermore, their structural design also makes integration difficult. Summary of the Invention

[0006] This invention discloses a multi-parameter sensor based on a biomimetic lateral line bending optical fiber, which overcomes the technical problems of existing sensors such as insufficient directional sensing capability, poor anti-electromagnetic interference and anti-corrosion performance, and difficulty in realizing multi-parameter detection.

[0007] To achieve the above objectives, the technical solution of the present invention is as follows:

[0008] A multi-parameter sensor based on a biomimetic lateral line bending optical fiber includes: an artificial cilia cantilever beam, a sensor base, an input optical fiber, an output optical fiber, a bare optical fiber, and multiple light source receivers.

[0009] The artificial cilia cantilever beam is provided with a first through hole and a second through hole, the axes of the first through hole and the second through hole are both parallel to the axis of the artificial cilia cantilever beam.

[0010] One end of the input optical fiber is connected to the light source emitting end, and the other end passes through the sensor base and through the artificial fiber cantilever beam via the first through hole, and is fixedly connected to the exposed optical fiber.

[0011] The other end of the exposed optical fiber is fixedly connected to one end of the output optical fiber;

[0012] The other end of the output optical fiber passes through the second through hole through the artificial ciliary cantilever beam and is communicatively connected to the light source receiver to obtain the flow field direction, flow field velocity and flow field salinity based on the voltage signal received by the light source receiver.

[0013] The artificial cilia cantilever beam is fixedly connected to the sensor base.

[0014] Furthermore, the sensor base is provided with a groove along its axial direction, and the interior of the groove is provided with a third through hole, a fourth through hole, a fifth through hole, a sixth through hole and a seventh through hole coaxial with the groove;

[0015] The input optical fiber passes through the sensor base via the third through hole; light source receivers are fixedly installed in the fourth, fifth, sixth, and seventh through holes;

[0016] The fourth, fifth, sixth, and seventh through holes are evenly arranged with the axis of the output optical fiber as the center.

[0017] Furthermore, the artificial cilia cantilever beam includes a first artificial cilia cantilever beam segment and a second artificial cilia cantilever beam segment; the first artificial cilia cantilever beam segment and the second artificial cilia cantilever beam segment are coaxially fixed.

[0018] One end of the input optical fiber passes through the first through hole in sequence through the first artificial fiber cantilever beam segment and the second artificial fiber cantilever beam segment.

[0019] The outer wall of the first artificial cilia cantilever beam segment is fixedly connected to the inner wall of the groove, and a space for optical signal transmission is formed between the bottom surface of the first artificial cilia cantilever beam segment and the bottom surface of the groove.

[0020] Furthermore, the artificial fibrous cantilever beam is made of flexible thermoplastic polyurethane material.

[0021] Furthermore, the artificial cilia cantilever beam has a cylindrical structure.

[0022] Furthermore, the formula used to obtain the flow velocity of the flow field is as follows:

[0023] max{|y4-y2|,|y3-y1|}=Ax 3 +Bx 2 In the formula +Cx+D: y1, y2, y3, and y4 are the voltage signals received by the first, second, third, and fourth light source receivers, respectively, and are arranged sequentially in a clockwise direction; x represents the flow velocity; A, B, C, and D represent the cubic coefficient, square coefficient, linear coefficient, and constant term, respectively.

[0024] Furthermore, the formula used to obtain the salinity of the flow field is as follows:

[0025] y1=an f +b

[0026] Where y1 is the voltage signal received by the first light source receiver, and n f Let be the refractive index of the liquid, a be the voltage decreasing coefficient with respect to refractive index, and b be the initial voltage signal received by the first light source.

[0027] n f =n0+k·S

[0028] Where, n f Let n be the refractive index of the liquid, n0 be the refractive index of pure water, S be the salinity, and k be the refractive index variation coefficient of salinity.

[0029] Beneficial Effects: This invention provides a multi-parameter sensor based on a biomimetic lateral line curved fiber. One end of the input fiber is connected to a light source transmitter, and the other end passes through the sensor base and the artificial ciliate cantilever beam, and is fixedly connected to the exposed fiber. The other end of the exposed fiber is fixedly connected to the output fiber. The other end of the output fiber passes through the artificial ciliate cantilever beam and is communicatively connected to the light source receiver, so as to obtain the flow direction, flow velocity, and flow salinity based on the voltage signal received by the light source receiver. This sensor can simultaneously monitor multiple parameters such as flow velocity, flow direction, and salinity, meeting the multi-dimensional monitoring needs of complex marine environments. Furthermore, by mimicking the structure of fish lateral line hair cells and using a curved artificial ciliate cantilever beam as the core sensing element, it can achieve accurate detection of the magnitude and direction of water flow velocity. In addition, the sensor directly contacts the fluid through the exposed fiber portion, utilizing the difference in refractive index of different fluids to detect fluid salinity. Attached Figure Description

[0030] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0031] Figure 1 This is a schematic diagram of the overall structure of the biomimetic lateral wire-based bent fiber multi-parameter sensor of the present invention;

[0032] Figure 2 This is a schematic diagram showing the connection between the artificial fiber cantilever beam of the present invention and the input optical fiber, output optical fiber and bare optical fiber;

[0033] Figure 3 This is a schematic diagram of the artificial cilia cantilever beam of the present invention;

[0034] Figure 4 This is a schematic diagram of the sensor base in an embodiment of the present invention;

[0035] Figure 5 This is a schematic diagram illustrating the relationship between voltage, refractive index, and salinity in an embodiment of the present invention;

[0036] Figure 6 This is a schematic diagram of the voltage difference in opposite directions at different speeds in an embodiment of the present invention. Detailed Implementation

[0037] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0038] This embodiment provides a multi-parameter sensor based on a biomimetic lateral line bending optical fiber, such as... Figure 1-4 As shown, it includes: an artificial fiber cantilever beam 1, a sensor base 5, an input optical fiber 2, an output optical fiber 3, a bare optical fiber 4, and multiple light source receivers 6.

[0039] The artificial cilia cantilever beam 1 is provided with a first through hole 11 and a second through hole 12, and the axes of the first through hole 11 and the second through hole 12 are both parallel to the axis of the artificial cilia cantilever beam 1.

[0040] One end of the input optical fiber 2 is connected to the light source emitting end, and the other end passes through the sensor base 5 and through the artificial ciliary cantilever beam 1 via the first through hole 11, and is fixedly connected to the exposed optical fiber 4.

[0041] The other end of the exposed optical fiber 4 is fixedly connected to one end of the output optical fiber 3;

[0042] The other end of the output optical fiber 3 passes through the artificial ciliary cantilever beam 1 via the second through hole 12 and is communicatively connected to the light source receiver 6; so as to obtain the flow field direction, flow field velocity and flow field salinity based on the voltage signal received by the light source receiver.

[0043] The artificial cilia cantilever beam 1 is fixedly connected to the sensor base 5.

[0044] Preferably, the sensor base 5 is provided with a groove 56 along its axial direction, and the interior of the groove 56 is provided with a third through hole 51, a fourth through hole 52, a fifth through hole 53, a sixth through hole 54 and a seventh through hole 55 coaxial with the groove 56;

[0045] The input optical fiber 2 passes through the sensor base 5 via the third through hole 51; a light source receiving end is fixedly installed in the fourth through hole 52, the fifth through hole 53, the sixth through hole 54 and the seventh through hole 55;

[0046] The fourth through hole 52, the fifth through hole 53, the sixth through hole 54 and the seventh through hole 55 are evenly arranged with the axis of the output optical fiber 3 as the center.

[0047] Preferably, the artificial cilia cantilever beam 1 includes a first artificial cilia cantilever beam segment 13 and a second artificial cilia cantilever beam segment 14; the first artificial cilia cantilever beam segment 13 and the second artificial cilia cantilever beam segment 14 are coaxially fixed.

[0048] One end of the input optical fiber 2 passes through the first through hole 11 and sequentially through the first artificial fiber cantilever beam segment 13 and the second artificial fiber cantilever beam segment 14.

[0049] The outer wall of the first artificial cilia cantilever beam segment 13 is fixedly connected to the inner wall of the groove 56, and a space for optical signal transmission is formed between the bottom surface of the first artificial cilia cantilever beam segment 13 and the bottom surface of the groove 56.

[0050] Specifically, the sensor base 5 has a blind hole structure with a central groove. The inner diameter of the blind hole matches the outer diameter of the first artificial cilia cantilever beam segment 13, and the depth of the blind hole is half the thickness of the sensor base 5. Additionally, four through holes (top, bottom, left, and right) form a symmetrical distribution centered on the center point, with equal distances between them, used to fix the light source receiver 6.

[0051] The sensor base 5 is used to fix the artificial fiber cantilever beam 1 and the fiber optic sensing module. It has five through holes, of which the third through hole 51 is used to fix the input fiber 2, and the inner diameter of the third through hole 51 matches the outer diameter of the input fiber 2. The other four through holes are used to fix the light source receiver 6, and are evenly distributed inside the blind holes of the sensor base with the axis of the output fiber as the center. The inner diameters of the fourth through hole 52, the fifth through hole 53, the sixth through hole 54 and the seventh through hole 55 match the fiber ends of the fixed light source receiver, and are used to fix the fiber and receive the beam signal output by the output fiber 3.

[0052] Preferably, the artificial fibrous cantilever beam 1 is made of flexible thermoplastic polyurethane material.

[0053] Specifically, the fiber optic sensing module described in this embodiment includes an input fiber 2, an output fiber 3, a bare fiber 4, and a light source receiver 6; wherein the input fiber 2 and the output fiber 3 are fixed in the artificial fiber cantilever beam 1, and as the artificial fiber cantilever beam 1 deforms, the output fiber 3 will change the direction of the output light, thereby affecting the light intensity received by the light source receiver 6 set in the sensor base 5. The artificial ciliary cantilever beam 1 mimics the lateral line hair cell structure of fish that sense environmental changes. One end is fixed to the sensor base 5, and the other end is exposed to the fluid. The artificial ciliary cantilever beam 1 is made of flexible thermoplastic polyurethane (TPU) material, which can deform under the action of water flow. The first through hole 11 and the second through hole 12 are provided on it to fix the input optical fiber 2 and the output optical fiber 3, respectively. The light source receiving end 6 has four independent optical fiber ports, which are fixed through the fourth through hole 52, the fifth through hole 53, the sixth through hole 54 and the seventh through hole 55, respectively. Each optical fiber port is the same size and uses the same optical fiber to receive the light beam emitted by the output optical fiber 3 to obtain light intensity in different directions.

[0054] Preferably, the artificial cilia cantilever beam 1 is a cylindrical structure.

[0055] Specifically, in this embodiment, the artificial fiber cantilever beam 1 is a cylindrical structure with two through holes, and its length is 30mm. The inner diameter of the two through holes is matched with the outer diameter of the input optical fiber and the output optical fiber used, respectively.

[0056] Specifically, in this embodiment, the artificial fiber cantilever beam 1, together with the input fiber 2, output fiber 3, and exposed fiber 4, constitute a complete fiber structure. The input fiber 2, exposed fiber 4, and output fiber 3 are different regions of the same optical fiber divided by the artificial fiber cantilever beam 1. The two ends of the exposed fiber are connected to the parallel input and output fibers, respectively, forming a U-shaped structure. The input fiber 2 passes through the first through-hole of the sensor base 5 to transmit light to the fiber structure, its range extending from the light source to the end of the U-shaped structure connected to the exposed fiber 4. The exposed fiber 4 is the fiber core excluding the fiber sheath; it is a U-shaped curved structure exposed outside the artificial fiber cantilever beam 1 to detect changes in the external environment. The output fiber 3 is mostly encased within the artificial fiber cantilever beam 1, with a small protruding section at its end to constrain changes in the beam angle caused by deformation of the artificial fiber cantilever beam 1.

[0057] Specifically, the output optical fiber 3 is suspended on the light source receiving end 6, and the center points of the two are coincident, so that the output beam of the output optical fiber 3 can be perpendicularly irradiated to the center point of the light source receiving end 6.

[0058] The four fiber optic heads fixed to the light source receiver 6 are used to transmit the received optical signals. They are connected to the back-end acquisition circuit. Specifically, a photodiode is used to convert the optical signals into voltage signals, and a collector is used to record the voltage signals. The four voltage signals represent four directions for direction determination.

[0059] The artificial ciliated cantilever beam 1 is made of flexible thermoplastic polyurethane (TPU); the sensor base 5 is made of PLA (polylactic acid); the sensor base 5 and the artificial ciliated cantilever beam 1 are fixed with a solid adhesive, the main component of which is ethylene-vinyl acetate copolymer. This method solves the problems of existing MEMS sensors' poor performance in electromagnetic interference and corrosion resistance, and the influence of electromagnetic interference and high salinity water in marine environments on sensors, leading to inaccurate measurement data or equipment damage. Furthermore, the flexible thermoplastic polyurethane (TPU) material of the artificial ciliated cantilever beam 1 in this embodiment can effectively reduce the corrosion of the sensor by chemical components and biological adhesion in seawater, extending the sensor's service life. Therefore, in long-term monitoring, the sensor of this embodiment has unparalleled advantages in addressing the insufficient durability and stability of existing sensors.

[0060] Specifically, such as Figure 1-4As shown, the artificial fibrillated cantilever beam 1 is a long, cylindrical, flexible structure. Its upper half, along with the bare optical fiber 4, is exposed to the flow field. Under the shear stress of the flow field, it deforms. Simultaneously, the input optical fiber 2 and output optical fiber 3, fixed in the artificial fibrillated cantilever beam 1, also deform due to the deformation of the upper half. This causes a shift in the beam output from the output optical fiber 3, resulting in changes in the light intensity received by the four optical fibers at the light source receiver 6, thus enabling the determination of the flow velocity magnitude and direction. The artificial fibrillated cantilever beam 1 has two through holes. After fixing the input optical fiber 2 and output optical fiber 3, a solid adhesive is applied to the through holes for waterproofing. The five through holes at the light source receiver 6 are treated in the same way. The lower half of the artificial fibrillated cantilever beam 1 is embedded in the blind holes of the sensor base. The embedding distance is controlled to ensure the sensor is in its most sensitive state and to guarantee that when the artificial fibrillated cantilever beam 1 is not deformed, the beam output from the output optical fiber 3 is perpendicularly illuminating the center point of the four optical fibers at the light source receiver 6. Finally, a solid adhesive is used for fixation.

[0061] Specifically, bare fiber 4 is the fiber core with the outer sheath removed. It has a U-shaped bent structure with a bending diameter of 3mm. Bare fiber 4 is obtained by removing the buffer layer and cladding from ordinary optical fiber. The buffer layer is mainly removed by cutting, while the cladding is removed by soaking and wiping with a polyethylene solution.

[0062] In this embodiment, the sensor base 5 is made of PLA (polylactic acid), a biodegradable polymer material formed by the condensation polymerization of lactic acid monomers. It has good resistance to seawater corrosion, does not pollute the environment, and is simple to manufacture. It can be manufactured by 3D printing, which improves production efficiency and design flexibility. The artificial ciliary cantilever beam 1 is made of flexible thermoplastic polyurethane (TPU), a high-performance polymer with excellent elasticity and flexibility. It can deform within a large range without losing its original shape and has good wear resistance and oil resistance, ensuring that the sensor can maintain stable performance during long-term use.

[0063] Preferably, the flow velocity of the flow field can be obtained based on the light signal received by the light source receiver, using the following formula:

[0064] max{|y4-y2|,|y3-y1|}=Ax 3 +Bx 2 +Cx+D

[0065] In the formula: y1, y2, y3, and y4 are the voltage signals received by the first, second, third, and fourth light source receivers, respectively, arranged sequentially in a clockwise direction; x represents the flow velocity. A, B, C, and D represent the cubic coefficient, square coefficient, linear coefficient, and constant term, respectively.

[0066] In one specific embodiment of the present invention,

[0067] max{|y4-y2|,|y3-y1|}=0.608x 3 +0.0092x 2 +0.0536x+0.0022

[0068] The flow velocity of the flow field is thus obtained. Specifically, in this embodiment, the optical fiber integrates the input and output of light into a single artificial ciliated cantilever beam 1 through a bent structure, simplifying the sensor structure. When the flow field causes the artificial ciliated cantilever beam 1 to deform, the direction of the output light will change. That is, the cantilever beam bends in the direction of the flow field, and the output light moves in the opposite direction of the flow field. As a result, the light intensity received by the light source receiver 6 in the direction of the flow field will increase, and the light intensity received by the light source receiver 6 in the opposite direction of the flow field will decrease. The flow field direction can be distinguished based on the change in light intensity signal.

[0069] Specifically, the voltage signals received by the four light source receivers in this embodiment are as follows: Figure 6 As shown.

[0070] Specifically, the sensor is installed in the flow field to be measured, and the input optical fiber 2 is connected to the light source. The flow velocity in the flow field to be measured acts on the artificial ciliary cantilever beam 1, causing it to deform, and the acquisition circuit records the voltage changes in four directions;

[0071] For example, the water flow from direction 1 acts on the artificial ciliary cantilever beam 1, causing it to bend in the opposite direction. This causes the output optical fiber 3 to shift towards direction 1, resulting in an increase in the voltage collected in direction 1 and a decrease in the voltage in the opposite direction. The direction is determined by the change in the signal, and the magnitude of the change is determined by the magnitude of the speed.

[0072] Preferably, the salinity of the flow field can be obtained from the light signal received by the light source receiver, using the following formula:

[0073] y1=an f +b

[0074] Where y1 is the voltage signal received by the first light source receiver, and n fLet be the refractive index of the liquid, a be the voltage decreasing coefficient with respect to refractive index, and b be the initial voltage signal received by the first light source.

[0075] In one specific embodiment of the present invention, the relationship between the voltage signal received by the light source receiver and the refractive index of the liquid is expressed as follows: Figure 5 As shown:

[0076] This sensor detects salinity by measuring light intensity attenuation based on the difference in refractive index between the inside and outside of an optical fiber. When a light beam is reflected within the exposed fiber core, some light is refracted at the interface and enters the water, causing light intensity attenuation. The degree of light intensity attenuation is closely related to the liquid's refractive index; increased salinity increases the water's refractive index, thus exacerbating light loss. By monitoring changes in light intensity, the refractive index can be inferred, and the salinity can be further calculated using the approximately linear relationship between the liquid's refractive index and salinity. Within a salinity range of 0‰ to 40‰, the approximate relationship between refractive index and salinity is as follows:

[0077] n f =n0+k·S

[0078] Where, n f Let n be the refractive index of the liquid, n0 be the refractive index of pure water, S be the salinity, and k be the refractive index variation coefficient of salinity. By combining the relationship between light intensity and refractive index, a quantitative correlation between light intensity and salinity can be indirectly established.

[0079] Specifically, the deformation of the artificial fiber cantilever beam 1 causes deformation of the input fiber 2 and the output fiber 3. The deformation of the output fiber 3 changes the direction of the output light, thus affecting the light intensity received by the four receivers of the light source receiver 6 in the sensor base 5, each receiving light intensity in its corresponding direction. When the light beam flows through the bare fiber 4 (after removing the fiber sheath), it experiences loss; the loss varies depending on the salinity of the liquid, resulting in a general decrease in the light intensity received by the light source receiver 6. In this embodiment, the salinity determination process and usage use one voltage as the basis for judgment. Since the changes in the four directions are consistent when the voltage decreases simultaneously, the refractive index can be calculated by substituting the voltage signal of any one light source receiver into its light intensity refractive index formula, thereby calculating the salinity. The salinity measurement method of the bent fiber multi-parameter sensor in this embodiment includes the following steps:

[0080] The sensor is installed in fluids with different salinity, and the input optical fiber 2 is connected to the light source to record the voltage output of the current acquisition circuit.

[0081] Light propagates in an optical fiber via total internal reflection, which maintains signal transmission. However, since the fiber core of the bare optical fiber 4 is in direct contact with the fluid, it is affected by the fluid's refractive index, resulting in light loss. The degree of light loss varies for fluids with different salinities. Therefore, the salinity information of the fluid can be obtained by comparing the voltage output of the acquisition circuit.

[0082] Specifically, the sensor in this embodiment can also obtain the direction information of the flow field. The method of obtaining the direction information of the flow field based on the four electrical signals converted from the signal received by the light source receiver is a common method in the field, which will not be described in detail here.

[0083] A specific application scenario of this embodiment is as follows:

[0084] Single sensors are suitable for scenarios with clear flow direction and simple local environment, such as monitoring the direction of fluid in pipes and optimizing cooling systems.

[0085] For example, in environmental monitoring scenarios at aquaculture farms, this sensor is used to detect water flow velocity, direction, and salinity in real time. It can be deployed at multiple key locations within the farm (such as inlets, outlets, and within the aquaculture area), achieving multi-point monitoring through low-cost deployment. By monitoring flow velocity and direction, the sensor ensures that fresh water flows into the aquaculture area in the expected direction, avoiding oxygen deficiency caused by excessively low flow rates and preventing water pollution from wastewater backflow. The salinity monitoring function can detect minute changes in water salinity in real time; once an anomaly is detected, the sensor can quickly issue an alert and assist in adjusting water conditions.

[0086] The fiber optic sensor in this embodiment also features resistance to electromagnetic interference and low cost, maintaining stable performance even in nearshore or high-density industrialized aquaculture farms. The sensor is small and flexible, suitable for large-scale deployment in aquaculture farms. By deploying multiple points to form a complete environmental monitoring network, it can quickly locate the problem area if flow velocity or salinity is abnormal, providing precise control measures, significantly reducing the operation and maintenance costs of aquaculture farms, while improving production efficiency and the stability of the aquaculture environment.

[0087] The sensor mimics the lateral line sensing system of fish, using a curved, biomimetic cantilever beam structure combined with multi-directional fiber optic detection to sense the direction and intensity of water flow. This structural design effectively enhances the sensor's directional sensing capability, a relatively weak point in existing technologies.

[0088] The "multi-parameter" aspect of this invention is reflected in the fact that the sensor can not only detect the flow velocity of water (including the magnitude and direction of the velocity), but also detect the salinity of the fluid through the contact between the exposed optical fiber portion and the water body.

[0089] Flow velocity detection: The sensor uses a biomimetic cantilever beam structure to detect changes in water flow velocity. Under the influence of the water flow, the cantilever beam deforms, which in turn affects the light intensity signals in the optical fibers in various directions. By analyzing these light intensity signals, the magnitude and direction of the flow velocity can be determined, thus achieving comprehensive detection of water flow speed.

[0090] Salinity detection: When the exposed portion of the optical fiber comes into contact with a fluid, the varying salinity of the fluid causes changes in light intensity loss. By comparing the light intensity signals received from different directions, the salinity of the fluid can be detected.

[0091] The biomimetic lateral wire-based bending fiber multi-parameter sensor of this embodiment has the following advantages:

[0092] 1. Directional Sensing Capability: This sensor mimics the lateral line hair cell structure of fish, employing a vertical, flexible artificial ciliate cantilever beam as its core sensing element. This cantilever beam deforms under the shear stress of the flow field, thereby altering the direction of the beam emitted from the output fiber. This results in changes in the light intensity signals received by the light source receiver from four different directions, effectively distinguishing the flow field direction and achieving precise sensing of the optical signal from the shear stress of the water flow.

[0093] 2. Anti-interference and anti-corrosion capabilities: The sensor of this invention is made of quartz material, which has good corrosion resistance and anti-electromagnetic interference capabilities. It can work stably in complex and harsh marine environments, extend the service life of the sensor, and overcome the shortcomings of existing microelectromechanical system sensors that are easily damaged when used in seawater.

[0094] 3. Multi-parameter detection capability: This invention can not only detect the shear stress of water flow, but also detect the salinity of the fluid by utilizing the difference in the fluid's refractive index through direct contact between the exposed optical fiber and the fluid. By comparing the light intensity signal received at the light source receiver, the degree of light intensity loss can be accurately calculated, thereby obtaining the fluid's salinity information and realizing multi-parameter detection functionality.

[0095] The biomimetic lateral line-based bending fiber multi-parameter sensor of this embodiment has strong directional sensing capability, excellent anti-interference and anti-corrosion capabilities, and rich multi-parameter detection functions. It can meet the requirements of modern marine monitoring networks for high-precision, low-cost, anti-interference, and long-life sensor devices, and is an ideal marine monitoring device.

[0096] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A multi-parameter sensor based on a biomimetic lateral line bending optical fiber, characterized in that, include: Artificial fiber cantilever beam (1), sensor base (5), input fiber (2), output fiber (3), bare fiber (4), multiple light source receivers (6). The artificial cilia cantilever beam (1) is provided with a first through hole (11) and a second through hole (12), and the axes of the first through hole (11) and the second through hole (12) are both parallel to the axis of the artificial cilia cantilever beam (1). One end of the input optical fiber (2) is connected to the light source emitting end, and the other end passes through the sensor base (5) and through the artificial ciliary cantilever beam (1) via the first through hole (11), and is fixedly connected to the exposed optical fiber (4). The other end of the exposed optical fiber (4) is fixedly connected to one end of the output optical fiber (3); The other end of the output optical fiber (3) passes through the artificial ciliary cantilever beam (1) via the second through hole (12) and is communicatively connected to the light source receiver (6) to obtain the flow field direction, flow field velocity and flow field salinity based on the voltage signal received by the light source receiver. The artificial cilia cantilever beam (1) is fixedly connected to the sensor base (5); The sensor base (5) is provided with a groove (56) along its axial direction. The groove (56) is provided with a third through hole (51), a fourth through hole (52), a fifth through hole (53), a sixth through hole (54) and a seventh through hole (55) coaxial with the groove (56). The input optical fiber (2) passes through the sensor base (5) via the third through hole (51); a light source receiving end is fixedly installed in the fourth through hole (52), the fifth through hole (53), the sixth through hole (54) and the seventh through hole (55); The fourth through hole (52), the fifth through hole (53), the sixth through hole (54) and the seventh through hole (55) are evenly arranged with the axis of the output optical fiber (3) as the center; The artificial cilia cantilever beam (1) includes a first artificial cilia cantilever beam segment (13) and a second artificial cilia cantilever beam segment (14); the first artificial cilia cantilever beam segment (13) and the second artificial cilia cantilever beam segment (14) are coaxially fixed. One end of the input optical fiber (2) passes through the first through hole (11) and sequentially through the first artificial fiber cantilever beam segment (13) and the second artificial fiber cantilever beam segment (14). The outer wall of the first artificial ciliary cantilever beam segment (13) is fixedly connected to the inner wall of the groove (56), and a space for optical signal transmission is formed between the bottom surface of the first artificial ciliary cantilever beam segment (13) and the bottom surface of the groove (56). The artificial fibrous cantilever beam (1) is made of flexible thermoplastic polyurethane material; The formula used to obtain the flow velocity in the flow field is as follows: In the formula: , , , These are the voltage signals received by the first light source receiver, the second light source receiver, the third light source receiver, and the fourth light source receiver, respectively, with the first, second, third, and fourth light source receivers arranged sequentially in a clockwise direction. x The flow velocity is represented by A, B, C, and D, which represent the cubic coefficient, square coefficient, linear coefficient, and constant term, respectively.

2. The multi-parameter sensor based on a biomimetic lateral line of a bent optical fiber according to claim 1, characterized in that, The artificial fibrous cantilever beam (1) is a cylindrical structure.

3. The multi-parameter sensor based on a biomimetic lateral line of a bent optical fiber according to claim 1, characterized in that, The formula used to obtain the salinity of the flow field is as follows: in, This refers to the voltage signal received by the first light source receiver. Let be the refractive index of the liquid. denoted as the voltage decreases with refractive index, and b is the initial voltage signal received by the first light source; in, Let be the refractive index of the liquid. Let be the refractive index of pure water. Salinity This is the coefficient of refractive index variation for salinity.

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