A static pressure balance type underwater self-driven flexible touch pressure finger and a pressure measurement method

Abstract

The application provides a static pressure balance type underwater self-driven flexible touch pressure sensing finger, which comprises a touch pressure sensing unit, a hydraulic cylinder, a pressure transmission unit, a piezoelectric transducing unit, a transducing unit support, a platinum electrode and a base, the touch pressure sensing unit and the pressure transmission unit are connected with the hydraulic cylinder through bolts, and the oil cavity between the piston end faces is filled with hydraulic oil; the piezoelectric transducing unit is inserted into the stepped through hole in the cylinder wall of the transducing unit support; the pressure transmission unit and the base are connected with the transducing unit support through a flange and a threaded pair; the platinum electrode is fixed in the lead hole of the piezoelectric transducing unit, and the lead of the platinum electrode is led out from the lead hole of the base and connected to a pressure detection circuit. Based on the area effect of Pascal's principle and the solid-liquid interface double electric layer principle, the application can convert the tiny pressure detected by the finger tip into a larger elastic deformation of the flexible hose, so as to generate a high-amplitude ionic current signal and transmit it to the pressure detection circuit, and realize the sensing, amplification and measurement of the pressure signal.

Description

Technical Field

[0001] This invention relates to the field of deep-sea tactile sensor technology, and more particularly to a hydrostatically balanced underwater self-driven flexible tactile sensor and a pressure measurement method. Background Technology

[0002] The vast ocean harbors abundant natural resources, including biological, mineral, chemical, and energy resources. With ever-increasing societal demands, the scale of ocean development is expanding, and exploration has extended into the deep sea. Underwater robots, as tools to replace humans in arduous underwater tasks, play a crucial role in deep-sea development. Underwater robots typically possess observation equipment such as cameras, sonar, and lighting, operational equipment such as robotic arms, and various sensors, enabling real-time observation of the underwater environment while operating. However, the deep-sea environment is not only complex in topography but also has extremely low visibility, making it difficult for underwater robots to respond promptly to avoid obstacles based on images and echoes. To address this, by installing tactile sensors on underwater robotic arms, combined with visual and auditory perception for obstacle detection, the operational efficiency and safety of underwater robots can be effectively ensured.

[0003] Common tactile sensors mainly include piezoresistive, capacitive, elastic, and piezoelectric sensors. The first three detect external pressure by measuring changes in resistance, capacitance, and elastic deformation of the sensing material under pressure, respectively. Traditional piezoelectric sensors utilize the piezoelectric effect, where the piezoelectric material polarizes under pressure, generating a charge on its surface to detect external pressure. In deep-sea environments, these sensors typically need to be sealed. Under the extremely high pressure difference between the inside and outside, the sensors exceed their operating range and cannot perform normal pressure sensing. Therefore, designing a tactile sensor that can eliminate interference from deep-sea hydrostatic pressure and integrating it with an underwater manipulator can further improve the obstacle avoidance capabilities of underwater robots and has significant practical value. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention provides a hydrostatically balanced underwater self-driven flexible pressure sensor and a pressure measurement method. This invention combines a piezoelectric transducer and a Pascal's stroke amplification mechanism, converting the minute pressure detected by the sensor tip into a larger elastic deformation of the flexible hose. Based on the solid-liquid interface double-layer principle, a high-amplitude ion current signal is generated and input to the pressure detection circuit, enabling the sensing, amplification, and measurement of the pressure signal.

[0005] The technical means employed in this invention are as follows:

[0006] A hydrostatically balanced underwater self-propelled flexible pressure-sensitive finger includes: a pressure sensing unit, a hydraulic cylinder, a pressure transmission unit, a piezoelectric transducer unit, a transducer unit support, a platinum electrode, and a base, wherein:

[0007] The touch sensing unit and the pressure transmission unit are connected to the hydraulic cylinder by bolts, and the oil chamber between the piston end faces is filled with hydraulic oil.

[0008] The piezoelectric transducer is installed in the stepped through hole in the cylinder wall of the transducer support, and is positioned using a slot and a threaded pair;

[0009] The pressure transmission unit and the base are connected to the transducer unit bracket via flanges and threaded pairs;

[0010] The platinum electrode is fixed inside the wire hole of the piezoelectric transducer unit, and the wire of the platinum electrode is led out from the wire hole of the base and connected to the pressure detection circuit.

[0011] Furthermore, the pressure sensing unit includes a flexible finger sleeve, a pressure sensing contact, a pressure sensing spring, a finger sleeve retaining ring, a linear bearing, a short-stroke piston bearing seat, and a short-stroke piston, wherein:

[0012] The flexible finger sleeve is installed on the finger sleeve fixing ring by a ring-shaped clip;

[0013] The pressure sensing contact is provided with an axial through hole, a smooth hole near the arc end and a threaded hole near the flat end. The interior of the pressure sensing contact has 6 flow channels arranged circumferentially to connect the flat end with the smooth hole.

[0014] The pressure sensing spring is fixed between the pressure sensing contact and the spring base of the short-stroke piston bearing housing; the end face of the short-stroke piston bearing housing has 6 open holes.

[0015] Six open holes are made circumferentially in the annular groove of the finger sleeve fixing ring cylinder wall, and annular filter plates are installed in the groove;

[0016] The piston head of the short-stroke piston is equipped with a sealing ring; the piston rod of the short-stroke piston is fixed to the short-stroke piston bearing seat by a linear bearing, so that the piston can slide freely relative to the bearing seat; the threaded end of the short-stroke piston is screwed into the pressure sensing contact.

[0017] Furthermore, the oil chamber of the hydraulic cylinder is stepped, with the inner diameter of the larger hole being twice the inner diameter of the smaller hole.

[0018] Furthermore, the pressure transmission unit includes a long-stroke piston, a long-stroke piston bearing housing, a linear bearing, a pressure transmission spring, and a pressure transmission contact, wherein:

[0019] The piston head of the long-stroke piston is equipped with a sealing ring; the piston rod of the long-stroke piston is fixed to the long-stroke piston bearing seat by a linear bearing, so that the piston can slide freely relative to the bearing seat; the threaded end of the long-stroke piston is screwed into the pressure transmission contact.

[0020] The end face of the long-stroke piston bearing housing has 6 open holes;

[0021] The pressure transmission spring is fixed between the pressure transmission contact and the spring base of the long-stroke piston bearing seat;

[0022] The pressure transmission contact is provided with an axial through hole, a smooth hole near the arc end and a threaded hole near the flat end. Six flow channels are arranged circumferentially inside the contact to connect the flat end with the smooth hole.

[0023] Furthermore, the piezoelectric transducer unit includes a spiral ring, a circular filter, a flexible tube support, and a flexible tube, wherein:

[0024] The circular filter elements are arranged in pairs and fixed at both ends of the flexible hose.

[0025] One end of the hose bracket has an H-shaped groove, and the other end engages with a screw ring via a threaded pair;

[0026] The flexible hose is fixed to the hose support, and the wire hole of the flexible hose and the wire hole of the hose support are coaxial.

[0027] Furthermore, the cylindrical wall of the transducer unit support is provided with stepped through holes; an open hole is opened circumferentially in the annular groove of the cylindrical wall, and an annular filter is installed in the groove.

[0028] Furthermore, one side of the base is a knuckle structure, and a wire hole is opened on the end face.

[0029] This invention also provides a pressure measurement method based on the above-mentioned hydrostatic balance underwater self-driven flexible pressure sensor, comprising:

[0030] When the current pressure sensor is working in a deep-sea environment, the external seawater passes through the finger sleeve fixing ring, the transducer unit bracket and the filter of the piezoelectric transducer unit to remove impurities and then enters the interior of the current pressure sensor through the openings and channels on each shell. This allows the seawater to contact the inner surface of the flexible hose to form a double electric layer, balancing the deep-sea static pressure and ensuring the relative stability of the measurement zero point when the sensor is not subjected to external force.

[0031] When the fingertip of the current pressure sensing finger touches an underwater obstacle, the pressure sensing contact will be subjected to the pressure of the obstacle wall through the flexible finger sleeve, pushing the short-stroke piston to move quickly by a distance Δl, causing the hydraulic oil in the hydraulic cylinder to flow from the large-diameter end to the small-diameter end, and the pressure sensing spring is compressed to a state of force balance.

[0032] Based on the area effect of Pascal's principle, the hydraulic oil simultaneously pushes the long-stroke piston to move 4Δl, amplifying the fingertip stroke. The pressure transmission spring is stretched to a state of force equilibrium, and the pressure transmission contact compresses the flexible hose to produce elastic deformation. The solid-liquid contact area on the inner surface of the flexible hose changes ΔS accordingly. Ions in the seawater undergo directional movement, enter the double layer and form an ionic current, and form a potential difference between the pressure position and the platinum electrode, thereby generating a conduction current in the wire. The magnitude of the current signal is positively correlated with the deformation of the flexible hose.

[0033] The current signal is transmitted through a wire to the pressure detection circuit to be converted into a pressure signal, thus completing the measurement of fingertip pressure.

[0034] Compared with the prior art, the present invention has the following advantages:

[0035] 1. The hydrostatic balance underwater self-driven flexible pressure sensor provided by this invention is based on the area effect of Pascal's principle and the double electric layer principle of the solid-liquid interface. It can convert the small pressure detected by the fingertip into a large elastic deformation of the flexible hose to generate a high-amplitude ion current signal and transmit it to the pressure detection circuit to realize the sensing, amplification and measurement of the pressure signal.

[0036] 2. The hydrostatic balance underwater self-driven flexible pressure sensor provided by this invention has an open structure, which can balance the pressure inside and outside the sensor and eliminate the influence of deep-sea hydrostatic pressure to ensure the relative stability of the measurement zero point.

[0037] 3. The hydrostatically balanced underwater self-driven flexible tactile finger provided by this invention is compact in size and exquisite in structure. It is suitable for deep-sea environments and can be combined with various underwater manipulators in the form of a fingertip as a tactile sensor to assist underwater robots in sensing deep-sea objects and avoiding obstacles. It has good practical value.

[0038] Based on the above reasons, this invention can be widely applied in fields such as deep-sea tactile sensors. Attached Figure Description

[0039] 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.

[0040] Figure 1 This is an overall assembly diagram of the hydrostatically balanced underwater self-driven flexible touch finger of the present invention.

[0041] Figure 2 This is a cross-sectional view of the hydrostatically balanced underwater self-driven flexible touch finger of the present invention.

[0042] Figure 3 This is a structural diagram of the touch pressure sensing unit of the present invention.

[0043] Figure 4 This is a structural diagram of the hydraulic cylinder of the present invention.

[0044] Figure 5 This is a structural diagram of the pressure transmission unit of the present invention.

[0045] Figure 6 This is a structural diagram of the piezoelectric transducer unit of the present invention.

[0046] Figure 7 This is a structural diagram of the transducer unit support of the present invention.

[0047] Figure 8 This is a structural diagram of the base of the present invention.

[0048] Figure 9 This is a schematic diagram illustrating the pressure measurement principle of the present invention.

[0049] In the diagram: 1. Static pressure balanced underwater self-driven flexible pressure-sensitive finger; 2. Pressure sensing unit; 3. Hydraulic cylinder; 4. Pressure transmission unit; 5. Piezoelectric transducer unit; 6. Transducer unit bracket; 7. Platinum electrode and its wires; 8. Base; 9. Hydraulic oil; 10. Flexible finger sleeve; 11. Pressure sensing contact; 12. Pressure sensing spring; 13. Finger sleeve retaining ring; 14. Linear bearing; 15. Short-stroke piston bearing seat; 16. Short-stroke piston; 17. Sealing ring; 18. Opening hole; 19. Annular filter; 20. Flow channel; 21. Axial through hole; 22. Long-stroke piston; 23. Long-stroke piston bearing seat; 24. Pressure transmission spring; 25. Pressure transmission contact; 26. Screw ring; 27. Circular filter; 28. Hose bracket; 29. ​​Flexible hose; 30. Wire hole; 31. Stepped through hole; 32. Underwater obstacle; 33. Double electric layer; 34. Pressure detection circuit. Detailed Implementation

[0050] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0051] 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, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. 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.

[0052] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0053] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps described in these embodiments do not limit the scope of the invention. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following figures denote similar items; therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0054] In the description of this invention, it should be understood that the orientation or positional relationship indicated by directional terms such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" is generally based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing this invention and simplifying the description. Unless otherwise stated, these directional terms do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the scope of protection of this invention. The directional terms "inner" and "outer" refer to the inner and outer contours relative to the outline of each component itself.

[0055] For ease of description, spatial relative terms such as "above," "over," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation besides the orientation of the device as described in the figures. For example, if the device in the figures is inverted, a device described as "above" or "above" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0056] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore should not be construed as limiting the scope of protection of this invention.

[0057] like Figure 1 , 2 As shown, this invention provides a hydrostatically balanced underwater self-driven flexible pressure sensor 1, which includes: a pressure sensing unit 2, a hydraulic cylinder 3, a pressure transmission unit 4, a piezoelectric transducer unit 5, a transducer unit bracket 6, a platinum electrode 7, and a base 8. Specifically: the pressure sensing unit 2 and the pressure transmission unit 4 are connected to the hydraulic cylinder 2 by bolts, and the oil chamber between the piston end faces is filled with hydraulic oil 9; the piezoelectric transducer unit 5 is inserted into a stepped through hole 31 in the cylinder wall of the transducer unit bracket 6, and is positioned using a slot and threaded joint; the pressure transmission unit 4 and the base 8 are connected to the transducer unit bracket 6 via a flange and a threaded joint; the platinum electrode 7 is fixed in a wire hole 30 of the piezoelectric transducer unit 5, and the wire of the platinum electrode 7 is led out from the wire hole 30 of the base 8 and externally connected to the pressure detection circuit 32.

[0058] In specific implementation, as a preferred embodiment of the present invention, such as Figure 3As shown, the pressure sensing unit 2 includes a flexible finger sleeve 10, a pressure sensing contact 11, a pressure sensing spring 12, a finger sleeve retaining ring 13, a linear bearing 14, a short-stroke piston bearing seat 15, and a short-stroke piston 16. The flexible finger sleeve 10 is mounted on the finger sleeve retaining ring 13 via an annular clip. The pressure sensing contact 11 has an axial through hole 21, with a smooth hole near the curved end and a threaded hole near the flat end. Six flow channels 20 are arranged circumferentially inside the pressure sensing contact 11, connecting the flat end to the smooth hole. The pressure sensing spring 12 is fixed... Between the pressure sensing contact 11 and the spring base of the short-stroke piston bearing seat 15; six open holes 18 are opened on the end face of the short-stroke piston bearing seat 15; six open holes 18 are opened circumferentially in the annular groove of the finger sleeve fixing ring 13 cylinder wall, and an annular filter 19 is installed in the groove; a sealing ring 17 is installed on the piston head of the short-stroke piston 16; the piston rod of the short-stroke piston 16 is fixed to the short-stroke piston bearing seat 15 through a linear bearing 14, so that the piston can slide freely relative to the bearing seat, and the threaded end of the short-stroke piston 16 is screwed into the pressure sensing contact 11.

[0059] In specific implementation, as a preferred embodiment of the present invention, such as Figure 4 As shown, the oil chamber of the hydraulic cylinder 3 is stepped, and the inner diameter of the large hole is twice the inner diameter of the small hole.

[0060] In specific implementation, as a preferred embodiment of the present invention, such as Figure 5 As shown, the pressure transmission unit 4 includes a long-stroke piston 22, a long-stroke piston bearing seat 23, a linear bearing 14, a pressure transmission spring 24, and a pressure transmission contact 25. Specifically: the piston head of the long-stroke piston 22 is fitted with a sealing ring 17; the piston rod of the long-stroke piston 22 is fixed to the long-stroke piston bearing seat 23 via the linear bearing 14, allowing the piston to slide freely relative to the bearing seat; the threaded end of the long-stroke piston 22 engages with the pressure transmission contact 25; six open holes 18 are formed on the end face of the long-stroke piston bearing seat 23; the pressure transmission spring 24 is fixed between the pressure transmission contact 25 and the spring base of the long-stroke piston bearing seat 23; the pressure transmission contact 25 is provided with an axial through hole 21, with a smooth hole near the curved end and a threaded hole near the flat end; six flow channels 20 are arranged circumferentially inside the contact, connecting the flat end to the smooth hole.

[0061] In specific implementation, as a preferred embodiment of the present invention, such as Figure 6 As shown, the piezoelectric transducer 5 includes a screw ring 26, a circular filter 27, a flexible tube support 28, and a flexible tube 29. The circular filter 27 is configured as a pair and fixed at both ends of the flexible tube 29. One end of the flexible tube support 28 is an H-shaped groove, and the other end is screwed into the screw ring 26 through a threaded pair. The flexible tube 29 is fixed on the flexible tube support 28, and the wire hole 30 of the flexible tube 29 and the wire hole 30 of the flexible tube support 28 are coaxial.

[0062] In specific implementation, as a preferred embodiment of the present invention, such as Figure 7 As shown, the cylindrical wall of the transducer unit support 6 is provided with stepped through holes 31; six open holes 18 are opened circumferentially in the annular groove of the cylindrical wall, and annular filter plates 19 are installed in the groove.

[0063] In specific implementation, as a preferred embodiment of the present invention, such as Figure 8 As shown, one side of the base 8 is a knuckle structure, and a wire hole 30 is opened on the end face.

[0064] In a specific implementation, as a preferred embodiment of the present invention, all springs and all rigid parts are made of stainless steel, the flexible finger sleeve 10 is made of platinum silicone, the flexible hose 29 is made of thermoplastic elastomer, and the piston seal ring 17 is made of nitrile.

[0065] like Figure 9 As shown, the present invention provides a pressure measurement method based on the above-mentioned hydrostatic balance underwater self-driven flexible pressure sensor, comprising:

[0066] When the current-type pressure sensing finger 1 operates in a deep-sea environment, external seawater, after being filtered by the filter plates of the finger sleeve fixing ring 13, the transducer unit bracket 6, and the piezoelectric transducer unit 5 to remove impurities, enters the interior of the current-type pressure sensing finger 1 through the openings 18 and flow channels 20 on each housing. This causes the seawater to contact the inner surface of the flexible hose 29, forming a double electric layer 33, balancing the deep-sea static pressure, and ensuring the relative stability of the measurement zero point when the finger is not subjected to external force. When the fingertip of the current-type pressure sensing finger 1 touches the underwater obstacle 32, the pressure sensing contact 11 will be subjected to the pressure of the obstacle wall through the flexible finger sleeve 10, pushing the short-stroke piston 16 to move rapidly a distance Δl, causing the hydraulic oil 9 in the hydraulic cylinder 3 to flow from the large-diameter end to the small-diameter end, and the pressure sensing spring... 12 is compressed to a state of force equilibrium; based on the area effect of Pascal's principle, the hydraulic oil 9 simultaneously pushes the long-stroke piston 22 to move 4Δl, amplifying the fingertip stroke, the pressure transmission spring 24 is stretched to a state of force equilibrium, the pressure transmission contact 25 compresses the flexible hose 29 to produce elastic deformation, the solid-liquid contact area on the inner surface of the flexible hose 29 changes ΔS accordingly, ions in the seawater undergo directional movement, enter the double electric layer 33 and form an ion current, and form a potential difference between the pressure position and the platinum electrode, thereby generating a conduction current in the wire, and the magnitude of the current signal is positively correlated with the deformation of the flexible hose 29; the current signal is transmitted to the pressure detection circuit 34 through the wire to be converted into a pressure signal, completing the measurement of fingertip pressure.

[0067] 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 hydrostatically balanced underwater self-propelled flexible touch-sensitive finger, characterized in that, The hydrostatically balanced underwater self-propelled flexible pressure-sensitive finger (1) includes: a pressure sensing unit (2), a hydraulic cylinder (3), a pressure transmission unit (4), a piezoelectric transducer (5), a transducer bracket (6), a platinum electrode (7), and a base (8), wherein: The touch-sensing unit (2) and the pressure transmission unit (4) are connected to the hydraulic cylinder (2) by bolts, and the oil chamber between the piston end faces is filled with hydraulic oil (9). The piezoelectric transducer (5) is inserted into the stepped through hole (31) in the cylinder wall of the transducer bracket (6) and positioned by the slot and thread pair; The pressure transmission unit (4) and the base (8) are connected to the transducer unit bracket (6) via a flange and a threaded pair; The platinum electrode (7) is fixed in the wire hole (30) of the piezoelectric transducer (5), and the wire of the platinum electrode (7) is led out from the wire hole (30) of the base (8) and connected to the pressure detection circuit (32). The pressure sensing unit (2) includes a flexible finger sleeve (10), a pressure sensing contact (11), a pressure sensing spring (12), a finger sleeve retaining ring (13), a linear bearing (14), a short-stroke piston bearing seat (15), and a short-stroke piston (16), wherein: The flexible finger sleeve (10) is installed on the finger sleeve fixing ring (13) by a ring clip; The pressure sensing contact (11) is provided with an axial through hole (21), with a light hole near the arc end and a threaded hole near the flat end. The interior of the pressure sensing contact (11) has 6 flow channels (20) arranged circumferentially to connect the flat end with the light hole. The pressure sensing spring (12) is fixed between the pressure sensing contact (11) and the spring base of the short-stroke piston bearing seat (15); the end face of the short-stroke piston bearing seat (15) has 6 open holes (18). Six open holes (18) are opened circumferentially in the annular groove of the finger sleeve fixing ring (13) cylinder wall, and annular filter plates (19) are installed in the groove. The piston head of the short-stroke piston (16) is fitted with a sealing ring (17); the piston rod of the short-stroke piston (16) is fixed to the short-stroke piston bearing seat (15) by a linear bearing (14), so that the piston can slide freely relative to the bearing seat; the threaded end of the short-stroke piston (16) is screwed into the pressure sensing contact (11). The piezoelectric transducer unit (5) includes a spiral ring (26), a circular filter (27), a flexible tube support (28), and a flexible tube (29), wherein: The circular filter discs (27) are arranged in pairs and fixed at both ends of the flexible hose (29); One end of the hose bracket (28) is an H-shaped groove, and the other end is screwed into the screw ring (26) through a threaded pair; The flexible hose (29) is fixed on the hose support (28), and the wire hole (30) of the flexible hose (29) and the wire hole (30) of the hose support (28) are coaxial; The cylinder wall of the transducer unit support (6) is provided with stepped through holes (31); six open holes (18) are opened in the annular groove of the cylinder wall along the circumferential direction, and annular filter plates (19) are installed in the groove.

2. The hydrostatically balanced underwater self-propelled flexible touch-sensitive finger according to claim 1, characterized in that, The oil chamber of the hydraulic cylinder (3) is stepped, and the inner diameter of the large hole is twice the inner diameter of the small hole.

3. The hydrostatically balanced underwater self-propelled flexible touch-sensitive finger according to claim 1, characterized in that, The pressure transmission unit (4) includes a long-stroke piston (22), a long-stroke piston bearing seat (23), a linear bearing (14), a pressure transmission spring (24), and a pressure transmission contact (25), wherein: The piston head of the long-stroke piston (22) is fitted with a sealing ring (17); the piston rod of the long-stroke piston (22) is fixed to the long-stroke piston bearing seat (23) by a linear bearing (14), so that the piston can slide freely relative to the bearing seat; the threaded end of the long-stroke piston (22) is screwed into the pressure transmission contact (25); The end face of the long stroke piston bearing housing (23) has 6 open holes (18). The pressure transmission spring (24) is fixed between the pressure transmission contact (25) and the spring base of the long stroke piston bearing seat (23); The pressure transmission contact (25) is provided with an axial through hole (21), a smooth hole near the arc end and a threaded hole near the flat end. Six flow channels (20) are arranged circumferentially inside the contact so that the flat end is connected to the smooth hole.

4. The hydrostatically balanced underwater self-propelled flexible touch-sensitive finger according to claim 1, characterized in that, One side of the base (8) is a finger joint structure, and a wire hole (30) is opened on the end face.

5. A pressure measurement method based on the hydrostatic balance underwater self-propelled flexible pressure sensor as described in any one of claims 1-4, characterized in that, include: When the current pressure sensor (1) is working in a deep-sea environment, the external seawater is filtered through the filter of the finger sleeve fixing ring (13), the transducer unit bracket (6) and the piezoelectric transducer unit (5) to remove impurities and then enters the interior of the current pressure sensor (1) through the opening (18) and flow channel (20) on each shell, so that the seawater comes into contact with the inner surface of the flexible hose (29) to form a double electric layer (33), which balances the deep-sea static pressure and ensures the relative stability of the measurement zero point when the sensor is not subjected to external force. After the fingertip of the current-type pressure sensing finger (1) touches the underwater obstacle (32), the pressure sensing contact (11) will be subjected to the pressure of the obstacle wall through the flexible finger sleeve (10), pushing the short-stroke piston 16 to move rapidly. The distance causes the hydraulic oil (9) in the hydraulic cylinder (3) to flow from the large diameter end to the small diameter end, and the pressure sensing spring (12) is compressed to a state of force balance. Based on Pascal's principle and the area effect, the hydraulic oil (9) simultaneously pushes the long-stroke piston (22) to move. With the fingertip travel increased, the pressure transmission spring (24) is stretched to a state of force equilibrium, and the pressure transmission contact (25) compresses the flexible hose (29) to produce elastic deformation. The solid-liquid contact area on the inner surface of the flexible hose (29) changes accordingly. Ions in seawater undergo directional movement, enter the double layer (33) and form an ionic current, and form a potential difference between the pressure position and the platinum electrode, thereby generating a conduction current in the wire, and the magnitude of the current signal is positively correlated with the deformation of the flexible hose (29). The current signal is transmitted to the pressure detection circuit (34) via a wire to be converted into a pressure signal, thus completing the measurement of fingertip pressure.

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