An autonomous visual bionic lateral line sensor and its preparation method

Abstract

The present invention discloses an autonomous visual bionic lateral line sensor and a preparation method thereof, wherein the sensor comprises: a sensing component, a support frame, a sealing mechanism and a lighting component; wherein the sensing component comprises a flexible gel tentacle, a gel protective layer and a hard sleeve, wherein the flexible gel tentacle is mounted on a transparent support plate via a flexible substrate, the gel protective layer evenly covers the surface of the flexible gel tentacle, and the hard sleeve is wrapped and mounted on the outside of the flexible gel tentacle with the gel protective layer; the support frame is fixedly connected to the sensing component via a sealing mechanism, the support frame comprises a hollow cavity, and the lighting component is arranged in the hollow cavity; an internal camera is also arranged in the hollow cavity, for real-time capturing the flexible gel tentacle to convert flow field vector information into geometric deformation information of an elastic body. The present invention realizes high-resolution flow field vector information sensing, and solves the problem that the existing lateral line sensor is difficult to directly measure the distribution of high-resolution flow field vectors.

Description

Technical Field

[0001] The invention belongs to the field of underwater sensors, and in particular relates to an autonomous visual bionic lateral line sensor and a preparation method thereof. Background Art

[0002] Flow field perception is of great significance to the navigation, positioning, and coordination of underwater robots, and plays an important role in improving navigation accuracy and efficiency, optimizing control strategies and saving energy, enhancing environmental adaptability and safety, imitating biological behavior, and improving intelligence. Flow field sensors used in traditional marine engineering, such as Doppler velocimeters and acoustic Doppler current profilers, are mostly difficult to detect local flow fields, are greatly affected by the environment, have poor measurement timeliness, and are expensive, bulky, and have high energy consumption.

[0003] In nature, fish have evolved excellent flow field perception capabilities, mainly relying on lateral line organs to perceive the surrounding environment and obtain flow field information, and based on this, they realize intelligent behaviors such as obstacle avoidance, predation, and school swimming. By imitating the lateral line system of fish, the researchers designed the artificial lateral line (ALL) sensor, which has the advantages of fast measurement, small size, and low energy consumption. It is more suitable for use in bionic underwater robots with compact internal space, energy consumption constraints, and complex working environments. This is especially important in the ocean, where the flow field is complex and changeable and the light is degraded. It improves the adaptability of underwater robots to the external environment, enables them to respond more flexibly to complex underwater environmental changes, and improves their application performance in underwater detection, surveying and other tasks, which has important application value.

[0004] Most of the existing research on bionic lateral line sensors focuses on the measurement of flow velocity in one direction, while the perception of the flow field direction is mainly estimated by multi-sensor information fusion, and it is difficult to directly measure the high-resolution flow field vector distribution. This limitation affects the perception ability and application scenarios of the lateral line sensors, and also makes it difficult for bionic underwater robots to perceive the surrounding turbulent and laminar flow information. In order to enable bionic underwater robots to perceive the surrounding flow field distribution and better understand the underwater flow field environment, it is very important to explore the principle and structural design of new high-resolution bionic lateral line sensors and realize accurate sensing and detection of flow field vector velocity distribution information. Summary of the invention

[0005] In order to solve the above technical problems, the present invention provides an autonomous visual bionic lateral line sensor and a preparation method thereof, which realizes high-resolution flow field vector velocity distribution information perception and can be widely used in flow field perception tasks of underwater robots.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] An autonomous visual bionic lateral line sensor comprises: a sensing component, a supporting frame, a sealing mechanism and a lighting component; wherein:

[0008] The sensor assembly includes a flexible gel tentacle, a gel protective layer, and a hard sleeve. The flexible gel tentacle is installed on a transparent support plate via a flexible substrate. The gel protective layer evenly covers the surface of the flexible gel tentacle. The hard sleeve wraps and is installed on the outside of the flexible gel tentacle with the gel protective layer.

[0009] The support frame is fixedly connected to the sensor assembly through a sealing mechanism, the support frame includes a hollow cavity, and the lighting assembly is arranged in the hollow cavity;

[0010] An internal camera is also arranged in the hollow cavity to capture in real time the conversion of flow field vector information by the flexible gel tentacles into geometric deformation information of the elastomer.

[0011] Furthermore, a plurality of sensing components constitute a bionic sensing whisker array of the bionic lateral line sensor.

[0012] Furthermore, the field of view of the internal camera covers the area where the bionic sensing tentacle array is located in the hollow cavity.

[0013] Furthermore, the support frame includes a main frame and a rear shell, and the rear shell, the main frame and the transparent support plate are connected and fixed by fixing parts to form a hollow cavity.

[0014] Furthermore, a sealing mechanism is designed between the rear shell, the main frame and the transparent support plate of the sensor, annular grooves are provided on the contact surfaces at both ends of the main frame, and static sealing is performed using an O-shaped rubber sealing ring.

[0015] Furthermore, the lighting assembly provides lighting for the hollow cavity.

[0016] Furthermore, the lighting assembly includes a flexible LED light strip and a shading cover. The lamp beads in the flexible LED light strip are spaced at a certain distance. The flexible LED light strip forms a circle of dense light sources in the main frame close to the transparent support plate. The shading cover surrounds the flexible LED light strip along the inner wall of the main frame.

[0017] On the other hand, the present invention also provides a method for preparing an autonomous visual bionic lateral line sensor, comprising:

[0018] Step 1, assembling the gel protective layer mold, the flexible gel tentacle mold and the transparent support plate into a gel mold, placing the support frame into the gel mold and fixing it; mixing the transparent gel material in a 1:1 ratio, pouring it into the gel mold, and solidifying it at room temperature in the gel mold for 6 hours, and using the mold turning technology to form the flexible gel tentacle and the flexible substrate;

[0019] Step 2, mixing a gel adhesive, silver light-shielding pigment particles, and a diluent in a ratio of 1:1:3 to obtain a light-shielding gel spray material; spraying the spray material evenly on the surface of the flexible gel tentacles and the flexible substrate by a spray gun to form a gel protective layer;

[0020] Step 3, using resin material to prepare a hard sleeve through photocuring 3D printing technology, and fixing it to the outside of the flexible gel tentacle with a gel protective layer through a gel adhesive to complete the preparation of the bionic lateral line sensor.

[0021] Beneficial effects of the present invention:

[0022] The bionic lateral line sensor based on autonomous vision of the present invention has a simple structure and a simple manufacturing process. It utilizes a surface flexible bionic sensing tentacle array to convert flow field vector information into geometric deformation information of the elastomer. The deformation image of the bionic sensing tentacle array is captured by the autonomous vision system inside the sensor, thereby realizing high-resolution flow field vector sensing with rich information and stable perception. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a comparison diagram of the lateral line neuromast of fish and the principle of an autonomous visual bionic lateral line sensor of the present invention;

[0024] Figure 2 This is a schematic diagram of the structure of an autonomous visual bionic lateral line sensor of the present invention;

[0025] Figure 3 This is an exploded diagram of the structure of an autonomous visual bionic lateral line sensor of the present invention;

[0026] Figure 4 This is a structural diagram of the gel mold and support frame of the present invention;

[0027] Figure 5 This is a flow chart of a method for preparing an autonomous visual bionic lateral line sensor of the present invention;

[0028] Figure 6 This is a schematic diagram of the actual processing of an autonomous visual bionic lateral line sensor of the present invention;

[0029] Figure 7 A diagram of the bionic lateral line sensor experimental environment provided by an embodiment of the present invention;

[0030] Figure 8 This is a comparison diagram of the deflection angles of the bionic sensing tentacles of the present invention at different flow rates;

[0031] Fig. 9 It is a schematic diagram of the deformation of the bionic sensing tentacles of the present invention under different flow velocities;

[0032] Fig.10This is a schematic diagram of flow field sensing of the bionic lateral line sensor of the present invention.

[0033] Reference numerals:

[0034] 101. Glial top; 102. Motile cilia; 103. Static cilia; 104. Hair cells; 105. Epidermal cells; 106. Mantle cells; 107. Support cells; 109. Hard mantle; 110. Flexible gel tentacles; 111. Gel protective layer; 112. Transparent support plate; 113. Internal camera; 114. Main frame; 115. Back shell; 116. Flexible LED light strip; 117. Light shield; 118. Gel protective layer mold; 119. Flexible gel tentacle mold; 120. Sealing rubber ring; 121. Bionic sensing tentacle array. DETAILED DESCRIPTION

[0035] The preferred embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood by those skilled in the art that these embodiments are only used to explain the technical principles of the present invention and are not intended to limit the protection scope of the present invention.

[0036] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0037] Figure 1The present invention shows a bionic object (fish lateral line neuromast), sensing principle and sensing structure of a bionic lateral line sensor based on autonomous vision. The lateral line neuromast is the sensory functional unit of the mechanical receptor of the fish lateral line system, which is mainly composed of four cells: hair cells 104 (hair cell), epidermal cells 105 (periderm cell), supporting cells 107 (supporting cell) and mantle cells 106 (mantle cell). Among them, the hair cell 104 has the function of sensing mechanical vibration waves. When it senses the mechanical stimulation caused by the water flow, it can convert the stimulation into a neuro-electrophysiological signal and transmit it to the central nervous system. The epidermal cell 105 plays a role in protecting the lateral line neuromast. The supporting cell 107 and the mantle cell 106 play an important role in the regeneration and repair of the hair cell 104. They are used to secrete a double-layer gelatinous cupula (gelatinous cupula) on the outside of the neuromast, which protects the hair cell 104 and drives the deflection of the ciliary bundle. The sensory unit of the neuromast hair cell is a ciliary bundle composed of kinocilium 102 and stereocilia 103. When the neuromast is stimulated by fluid in a certain direction, the swing of the glial top 101 drives the ciliary bundle to deflect in a certain direction, inducing changes in the internal and external potentials of the hair cell 104 membrane, generating neuroelectrophysiological signals and transmitting the signals to the central nervous system through afferent nerves. Finally, the fish processes the electrical signals in the central nervous system to realize the perception of the flow field.

[0038] By imitating the structure and perception principle of the lateral line neuromasts of fish, such as Figure 1As shown, the sensing components of the bionic lateral line sensor of the present invention mainly include: flexible gel tentacles 110, gel protective layers 111, and hard sleeves 109. Among them, the flexible gel tentacles 110 have an appearance that imitates the lateral line neuromast, which is thin at the top and thick at the bottom, and the bottom is smoothly connected to the flexible substrate (not shown in the figure). A transparent support plate 112 is installed at the bottom of the flexible substrate. The flexible gel tentacles 110 are deformed when in contact with the water flow, and the flow field vector information is converted into geometric deformation information of the elastic body, so as to realize efficient sensing of the flow velocity and direction information of the local flow field; the gel protective layer 111 is made of wear-resistant light-shielding material, and is evenly covered on the surface of the flexible gel tentacles 110, playing a protective function similar to that of the glial top 101 in the lateral line neuromast, and can block external light while protecting the flexible gel tentacles 110. The line enters the interior of the tentacle, providing a stable internal light field condition for the sensor; the hard sleeve 109 is wrapped and installed on the outside of the flexible gel tentacle 110 with the gel protective layer 111, which plays a role in protecting the sensing tentacles and improving the sensing sensitivity; the field of view of the internal camera 113 covers the bottom of the flexible gel tentacle 110, and after the flexible gel tentacle 110 converts the flow field vector information into the geometric deformation information of the elastomer, the internal camera 113 captures the deformation of the bionic tentacle in real time to realize local flow field perception, and multiple sensing components are arranged in an orderly manner to form a bionic sensing tentacle array 121 of the bionic lateral line sensor of the present invention.

[0039] The structural schematic diagram and structural explosion view of the bionic lateral line sensor FlowSight according to the embodiment of the present invention are respectively as follows: Figure 2 , Figure 3 As shown in the figure, the bionic lateral line sensor FlowSight is mainly composed of a sensor component, a support frame, a sealing mechanism and a lighting component.

[0040] As mentioned above, multiple sensing components serve as the bionic sensing tentacle array 121 of the bionic lateral line sensor, and a single sensing component mainly includes: flexible gel tentacles 110, gel protective layer 111, and hard sleeve 109, wherein multiple flexible gel tentacles 110 constitute the bionic sensing tentacle array 121, which are evenly arranged vertically on the transparent support plate 112 to sense the flow field distribution information.

[0041] In some preferred embodiments, a single bionic sensing tentacle can convert flow field vector information into geometric deformation information of the elastic body to perform local flow field vector information sensing.

[0042] In some preferred embodiments, the flexible gel tentacle 110 has an appearance imitating a lateral line neuromast that is thin at the top and thick at the bottom, and the bottom is smoothly connected to the flexible base in an integral manner, and a transparent support plate 112 is installed at the bottom of the flexible base.

[0043] The support frame includes: a main frame 114 and a rear shell 115, which are used to install various parts of the sensor and play a role in fixing the entire mechanism. The hollow main frame 114 is connected and fixed to the transparent support plate 112 through a fixing piece, and then the main frame 114 is fixedly connected to the rear shell 115 to form a hollow cavity. The transparent support plate 112 is made of acrylic and plays a role in fixing the flexible gel tentacles 110. The internal camera 113 is installed in the hollow cavity. The internal camera 113 includes a high-resolution camera, whose field of view covers the area where the bionic sensing tentacle array 121 is located in the hollow cavity, and is used to capture the geometric deformation information of the bionic sensing tentacle array.

[0044] A sealing mechanism is designed between the rear shell 115, the main frame 114 and the transparent support plate 112 of the sensor. Annular grooves are set on the contact surfaces at both ends of the main frame 114 for placing the sealing rubber ring 120. The grooves are used for static sealing by using the O-ring rubber sealing ring 120, so that the inside of the sensor is in a dry and sealed state.

[0045] The lighting component mainly includes: a flexible LED light strip 116 and a light shield 117. There is a certain distance between the lamp beads in the flexible LED light strip 116. The flexible LED light strip 116 forms a circle of dense light sources near the main frame 114 near the transparent support plate 112. At the same time, the light shield 117 is used to generate a uniform light field inside the hollow cavity of the sensor to ensure a stable and clear field of vision. The light shield 117 surrounds the flexible LED light strip 116 along the inner wall of the main frame 114.

[0046] On the other hand, the present invention also provides a method for preparing a bionic lateral line sensor based on autonomous vision, which is used to prepare the bionic lateral line sensor FlowSight in the above embodiment.

[0047] like Figure 4 , showing the structure diagram of the gel mold and support frame of the bionic lateral line sensor FlowSight according to an embodiment of the present invention. In the embodiment of the present invention, resin is used as the main material of the gel protective layer mold 118 and the support frame, and high-precision resin is used as the flexible gel tentacle mold 119. The gel protective layer mold 118, the flexible gel tentacle mold 119 and the support frame are manufactured by using photocuring 3D printing technology; a smooth acrylic plate is used as the transparent support plate 112 to support the flexible gel tentacle mold 119.

[0048] Figure 5 The preparation process of the bionic lateral line sensor FlowSight according to an embodiment of the present invention is exemplarily shown, and Figure 6 , is a schematic diagram of the actual processing of the bionic lateral line sensor of the present invention, the preparation method comprises:

[0049] Step 1, first assemble the gel protective layer mold 118, the flexible gel tentacle mold 119 and the transparent support plate 112 into a gel mold, put the main support frame 114 into the gel mold and fix it; mix the transparent gel material according to the AB component in a 1:1 ratio, pour it into the 3D printed gel mold, and solidify it at room temperature in the gel mold for 6 hours, and use the mold turning technology to form the flexible gel tentacle 110 and the flexible base layer.

[0050] In one example, a transparent gel material with a Shore hardness of 0031 is used, and optionally, materials with different hardnesses may be selected;

[0051] Step 2, using gel adhesive, silver light-proof pigment particles and diluent in a ratio of 1:1:3 to obtain a light-proof gel spray material for making the gel protective layer 111; spraying the spray material evenly on the surface of the flexible gel tentacles 110 and the flexible substrate through a spray gun to form the gel protective layer 111 and provide a stable internal light field environment.

[0052] In step 3, the hard sleeve 109 is prepared by using resin material through photocuring 3D printing technology, and fixed to the outside of the flexible gel tentacles 110 with gel protective layer 111 through gel adhesive, so as to protect the bionic sensing tentacles and improve the sensing sensitivity.

[0053] In one example, the number of the flexible gel tentacles 110 is 25, and the bionic sensing tentacles array 121 is composed of 5 5 A total of 25 flexible gel tentacles 110 are evenly distributed on a transparent support plate 112.

[0054] In one example, the hard sleeve 109 is made of hard non-light-transmitting resin;

[0055] In one example, the transparent support plate 112 is a transparent acrylic plate, fixed to the flexible gel tentacles 110 by a gel adhesive;

[0056] In one example, the distance between the lamp beads in the flexible LED light strip 116 is 0.5 mm;

[0057] In one example, the internal camera 113 uses a 2-megapixel 1080p color imaging camera module with a power supply voltage of 5V;

[0058] In one example, the main frame 114 and the rear shell 115 are made of 3D printed non-transparent material resin;

[0059] In one example, Figure 7Schematic diagram of the experimental environment of the autonomous visual bionic lateral line sensor provided in an embodiment of the present invention. The experimental environment uses the SW10150 swimming lane. The water speed of the SW10150 swimming lane in the test area can be adjusted. Since the actual flow direction of the water flow is fixed, in order to indicate the change in the water flow direction, the sensor is driven to rotate by using a digital servo to change the direction of the sensor relative to the water flow. Therefore, the angle of the sensor relative to the initial state can indicate the direction of the water flow.

[0060] In one example, Figure 8 A diagram showing the deformation of the bionic tentacles of the autonomous visual bionic lateral line sensor provided by an embodiment of the present invention, where the horizontal axis is the square of the water flow velocity , the vertical axis is the sensor whisker deformation , where θ is the deflection angle of the current position of the bionic tentacle relative to the position of the bionic tentacle in the static state of the water flow. Figure 8 It can be seen that the square of the flow velocity is linearly related to the deformation of the sensor tentacles, and its linearity It is 0.9727.

[0061] In one example, Fig. 9 The diagram is a diagram of the deformation of the bionic tentacle of the autonomous visual bionic lateral line sensor provided in an embodiment of the present invention under different flow velocities, including a side view of the sensor tentacle, a view of the internal camera 113, and a sensing diagram. In still water, the flexible gel tentacle 110 is in the center, and the internal camera 113 can sense the circular root of the flexible gel tentacle 110 and the circular bottom of the hard sleeve 109. When the water flows at the first speed and the first direction, the center root of the flexible gel tentacle 110 shifts in position. When the water flows at the second speed and the second direction, the center root of the flexible gel tentacle 109 shifts in different directions, and the degree of the shift is different (see Fig. 9 The second column), and its perception is shown in the third column.

[0062] In one example, Fig.10 A schematic diagram of flow field sensing of an autonomous visual bionic lateral line sensor provided in an embodiment of the present invention; Fig.10 The left side shows the vector velocity distribution at a certain moment. According to the velocity and direction information of each tentacle, the velocity and direction flow field distribution is obtained through a series of frame vector velocity distribution diagrams, such as Fig.10 High-resolution flow field perception map shown on the right.

[0063] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0064] The specific embodiments described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. An autonomous visual bionic lateral line sensor, characterized in that: include: Sensing component, supporting frame, sealing mechanism and lighting component; wherein, The sensing component comprises a flexible gel tentacle, a gel protective layer, and a hard sleeve. The flexible gel tentacle is mounted on a transparent support plate via a flexible substrate. The gel protective layer evenly covers the surface of the flexible gel tentacle. The hard sleeve wraps and is mounted on the outside of the flexible gel tentacle with the gel protective layer. The support frame is fixedly connected to the sensor assembly through a sealing mechanism, the support frame includes a hollow cavity, and the lighting assembly is arranged in the hollow cavity; An internal camera is also arranged in the hollow cavity to capture in real time the conversion of flow field vector information by the flexible gel tentacles into geometric deformation information of the elastomer.

2. The autonomous visual bionic lateral line sensor according to claim 1, characterized in that: A plurality of sensing components constitute the bionic sensing whisker array of the bionic lateral line sensor.

3. The autonomous visual bionic lateral line sensor according to claim 2, characterized in that: The field of view of the internal camera covers the area where the bionic sensing whisker array is located in the hollow cavity.

4. The autonomous visual bionic lateral line sensor according to claim 1, characterized in that: The support frame includes a main frame and a rear shell, and the rear shell, the main frame and the transparent support plate are connected and fixed by fixing parts to form a hollow cavity.

5. The autonomous visual bionic lateral line sensor according to claim 4, characterized in that: A sealing mechanism is designed between the rear shell, the main frame and the transparent support plate of the sensor, annular grooves are arranged on the contact surfaces at both ends of the main frame, and static sealing is performed using an O-shaped rubber sealing ring.

6. The autonomous visual bionic lateral line sensor according to claim 1, characterized in that: The lighting assembly provides lighting for the hollow cavity.

7. An autonomous visual bionic lateral line sensor according to claim 4 or 5, characterized in that: The lighting assembly includes a flexible LED light strip and a light shield. The lamp beads in the flexible LED light strip are spaced at a certain distance. The flexible LED light strip forms a circle of dense light sources in the main frame close to the transparent support plate. The light shield surrounds the flexible LED light strip along the inner wall of the main frame.

8. A method for preparing an autonomous visual bionic lateral line sensor, characterized in that: include: Step 1, assembling the gel protective layer mold, the flexible gel tentacle mold and the transparent support plate into a gel mold, placing the support frame into the gel mold and fixing it; After the transparent gel material is mixed, it is poured into a gel mold and solidified at room temperature in the gel mold, and a flexible gel tentacle and a flexible substrate are formed by using a mold turning technology; Step 2, mixing a gel adhesive, silver light-shielding pigment particles and a diluent to obtain a light-shielding gel spray material; spraying the spray material evenly on the surface of the flexible gel tentacles and the flexible substrate by a spray gun to form a gel protective layer; Step 3, using resin material to prepare a hard sleeve through photocuring 3D printing technology, and fixing it to the outside of the flexible gel tentacle with a gel protective layer through a gel adhesive to complete the preparation of the bionic lateral line sensor.

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