An underwater robot vector environment detection device based on ultrasonic waves and PVDF material

Abstract

The application discloses an underwater robot vector environment detection device based on ultrasonic waves and PVDF material, which is composed of an ultrasonic detection cabin, a PVDF flow field detection area and a data processing cabin; the ultrasonic detection cabin is composed of an ultrasonic detection cabin cover, an ultrasonic detection cabin body, a fastening nut, an ultrasonic detection head and a wiring tube; the PVDF flow field detection area is composed of a PVDF flow field detection sensor, a sensor support and a support; the data processing cabin is composed of a data processing cabin body and a base; on the overall structure, the ultrasonic detection cabin and the data processing cabin are connected by the PVDF flow field detection area; the device arranges sensors in six directions and can accurately measure and calculate the underwater vector environment; a four-electrode PVDF material flow field sensor is designed, so that the device can simultaneously detect the resultant force and force couple in the transverse X, Y and longitudinal Z directions; meanwhile, the device serves as a robot module, and the device can be vertically installed by only manufacturing corresponding installation structures and connecting the device with the robot.

Description

Technical Field

[0001] This invention relates to the field of underwater robot technology, specifically to an underwater robot vector environment detection device based on ultrasonic waves and PVDF materials. Background Technology

[0002] Underwater robots, as important tools for human exploration of the underwater environment, have always been valued by various countries and have played a significant role in marine resource development and deep-sea exploration in recent years. Meanwhile, the application of underwater robots in my country's water conservancy industry is also constantly developing and being explored, currently mainly used in reservoir searches, dam inspections, and safety checks. Due to the unique environment of underwater inspections or operations, environmental perception is particularly important for underwater robots to achieve more stable and reliable control. For non-vector environmental factors such as temperature and depth, general-purpose sensors can usually be used and carried by the underwater robot into the working environment for perception. However, for the detection of vector environmental factors in underwater space (this invention relates to spatial obstacle detection and flow force detection), it is difficult to achieve by using general-purpose sensors alone. Currently, underwater ultrasonic detection can measure distance in one direction, but it cannot provide more accurate spatial feedback for the intelligent operation of underwater robots. Researchers have mostly used parallel biomimetic structures for flow field detection, but these structures are not suitable for the structure of underwater robots due to their special shapes. Therefore, we propose an underwater robot vector environment detection device based on ultrasonic waves and PVDF materials to solve the above-mentioned problems. Summary of the Invention

[0003] The purpose of this invention is to provide an underwater robot vector environment detection device based on ultrasonic waves and PVDF materials, so as to solve the problems mentioned in the background art.

[0004] To achieve the above objectives, the present invention provides the following technical solution:

[0005] An underwater robot vector environment detection device based on ultrasonic waves and PVDF materials includes an ultrasonic detection chamber, a PVDF flow field detection area, and a data processing chamber. The ultrasonic detection chamber comprises an ultrasonic detection chamber cover, an ultrasonic detection chamber body, fastening nuts, ultrasonic detection heads, and wiring conduits. The PVDF flow field detection area comprises PVDF flow field sensors, sensor supports, and a bracket. The data processing chamber comprises a data processing chamber body and a base. The ultrasonic detection chamber and the data processing chamber are connected by the PVDF flow field detection area. Six ultrasonic detection heads are provided, mounted on six sides of the ultrasonic detection chamber body, and secured by a fastening nut. The nuts are tightened, and the wires of the ultrasonic detection head are led through conduits into the data processing compartment to connect to the main control chip therein. The PVDF flow field detection area consists of six PVDF flow field detection sensors arranged on six sides and connected to a bracket. Four wires are led out from the four electrodes of each PVDF flow field detection sensor and directly enter the data processing compartment through holes on the data processing compartment body, connecting to the main control chip therein. The main control chip is placed in the data processing compartment. The main control chip is used to process the data from the six ultrasonic detection heads and the six PVDF flow field detection sensors. The main control chip is connected to the underwater robot body through a data cable to provide underwater vector environment data.

[0006] As a further aspect of the present invention: the ultrasonic detection chamber is located at the top of the device and is used to detect lateral obstacles in the horizontal direction. The ultrasonic detection chamber has six sides, and each side is equipped with an ultrasonic detection head and is fixed by a fastening nut.

[0007] As a further aspect of the present invention: the ultrasonic detection head is model L042M4W, the working voltage is 5-24V, the output method is RS485, and the detection range is 6m.

[0008] As a further aspect of the present invention: the PVDF flow field detection area consists of six sets of PVDF flow field detection sensors, and their arrangement is structurally consistent with that of the ultrasonic detection chamber.

[0009] As a further aspect of the present invention: the PVDF flow field detection sensor is a four-electrode PVDF piezoelectric fiber flexible sensor with PVDF as the material surface, based on the charge generated by the piezoelectric effect on the surface of the PVDF piezoelectric fiber; the preparation method of the four-electrode PVDF piezoelectric fiber flexible sensor is as follows: PDVF particles are heated to a molten state at 200°C, allowing them to cover the surface of metal fibers to form a PDVF coating layer. After complete cooling in air, a section of PVDF piezoelectric fiber with a metal core is obtained, wherein the metal wire is precisely located at the center of the pressed fiber; the piezoelectric fiber is polarized to give it piezoelectric properties, and in PVDF… Four electrodes are uniformly coated on the surface of the piezoelectric fiber. During polarization, the metal core acts as the negative electrode, and the four electrodes act as the positive electrode. The piezoelectric fiber is placed in an oil temperature chamber containing silicone oil at 150°C and an applied voltage of 0.5kV for 45 minutes for polarization. After cooling to room temperature, it is taken out. After polarization, the electrode-covered area of ​​the piezoelectric fiber is piezoelectric, while the area not covered by the four electrodes is not piezoelectric. That is, a four-electrode PVDF piezoelectric fiber with a conductive silver paint coating on the surface is charged and the uncoated area is uncharged is prepared. Under the action of external force, the charge density on the surface of the PVDF fiber changes. The surface coated with conductive silver paint collects the charge and outputs it as an electrical signal.

[0010] As a further aspect of the present invention, the specific implementation method for installing the PVDF flow field detection sensor is as follows: the metal core of the processed PDVF piezoelectric fiber is removed, and it is cut to a suitable size. The metal core is replaced with an optical fiber similar to animal whiskers, which makes the sensor more flexible. Considering the waterproofing of the piezoelectric fiber surface, the piezoelectric fiber is wrapped with a soft rubber sleeve and mounting holes are made in the rubber sleeve. It is then installed on the sensor support, and four wires are used to lead out two pairs of electrodes and connect them to the main control unit in the data processing compartment.

[0011] As a further aspect of the present invention: the six PDVF flow field detection sensors are mounted on sensor supports, which are then fixed as crossbeams on two adjacent brackets.

[0012] As a further aspect of the present invention: the data processing cabin is an important part used to house the data processing chip and support the upper sensing structure, and consists of a data processing cabin body and a base.

[0013] Compared with the prior art, the beneficial effects of the present invention are: the underwater robot vector environment detection device based on ultrasonic waves and PVDF materials can accurately measure and calculate the underwater vector environment (obstacle orientation, flow field force); a four-electrode PVDF material flow field sensor is designed, which enables the device to simultaneously detect the resultant force and couple in the transverse X, Y and longitudinal Z directions; at the same time, as a robot module, the device can be connected to the robot simply by manufacturing the corresponding mounting structure and vertically installing the device. Attached Figure Description

[0014] Figure 1 This is an overall exploded view of the present invention.

[0015] Figure 2 This is a disassembled diagram of the PVDF flow field detection sensor in this invention.

[0016] Figure 3 This is a schematic diagram of the force acting on the X-axis of the PVDF flow field detection sensor in this invention.

[0017] Figure 4 This is a schematic diagram of the forces acting on the X and Z axes of the PVDF flow field detection sensor in this invention.

[0018] Figure 5 This is a cross-sectional view of the material composition of the PVDF flow field detection sensor in this invention.

[0019] Figure 6 This is a projection view of the entire invention along the X and Y axes.

[0020] Figure 7 This is a Z-axis projection view of the present invention.

[0021] Figure 8 This is a schematic diagram of the overall structure of the present invention.

[0022] The components include: 1. Ultrasonic testing chamber; 101. Ultrasonic testing chamber cover; 102. Ultrasonic testing chamber body; 103. Fastening nut; 104. Ultrasonic testing head; 105. Cable routing pipe; 2. PVDF flow field detection area; 201. PVDF flow field detection sensor; 202. Sensor support; 203. Bracket; 3. Data processing chamber; 301. Data processing chamber body; 302. Base. Detailed Implementation

[0023] In one embodiment, such as Figures 1-8 As shown, an underwater robot vector environment detection device based on ultrasonic waves and PVDF materials includes three main parts: ultrasonic detection chamber 1, PVDF flow field detection area 2, and data processing chamber 3.

[0024] In the ultrasonic testing chamber 1, the ultrasonic testing chamber body 102 has six sides, and an ultrasonic testing head 104 is installed on each side. The head is fixed to the side by fastening nuts 103 through holes on the side of the ultrasonic testing chamber body 102. The ultrasonic testing chamber cover 101 is installed on the upper part of the ultrasonic testing chamber body 102 and is connected and sealed by six mounting holes. The upper end of the wire conduit 105 is also connected to the ultrasonic testing chamber body 102, and the lower end is connected to the data processing chamber 301. It is used to guide the wires of the ultrasonic testing head 104 in the ultrasonic testing chamber 1 into the data processing chamber 3.

[0025] The overall structure of the PVDF flow field detection area 2 is based on the ultrasonic detection chamber 1. PDVF flow field detection components are arranged in six directions. In each component, the PVDF flow field detection sensor 201 is mounted on the sensor support 202 through the positioning hole on the top. The support 202 is fixed on two adjacent brackets 203 as a crossbeam. Each PVDF flow field detection sensor 201 has four electrode wires, and these four electrode wires pass directly through the data processing chamber 301 and are connected to the chip in the data processing chamber 3.

[0026] Six brackets 203 are used to connect and support the ultrasonic testing chamber 1 and the data processing chamber 3, and a PVDF flow field detection sensor is installed in every two brackets 203.

[0027] The data processing compartment 3 consists of a data processing compartment body 301 and a base 302, which are assembled through six mounting holes. A power cable is led out from the base to power the device, and a data cable is led out to transmit the calculated sensor data to the underwater robot. When the robot is used with this device, it is only necessary to manufacture a mounting structure on the robot that corresponds to the base and ensure that the device is placed vertically.

[0028] like Figure 2 As shown, the PVDF flow field detection sensor 201 consists of a four-electrode PVDF piezoelectric fiber a, a soft rubber sleeve b, and a soft rubber cover c. The four-electrode PVDF piezoelectric fiber a is used to sense the flow field force in two directions; the soft rubber sleeve b is used for waterproofing and also mounts the sensor on the sensor support 202; the soft rubber cover c is used for waterproofing, and the beam structure at the front end is used to increase the force-bearing area and assist deformation in the two specified directions.

[0029] like Figure 3 and Figure 4 The force diagram of the PVDF flow field detection sensor 201 shown illustrates the direction of the flow field force that the flow field sensor can detect. The PVDF flow field detection sensor 201 can detect the flow field force in both the x and z directions.

[0030] like Figure 5 As shown, the internal materials of the PVDF flow field detection sensor 201 consist of I, II, III and IV. I is a soft rubber that wraps the internal sensor and is mainly used for waterproofing; II is PVDF material (polyvinylidene fluoride), which generates charges through piezoelectric effect on its surface; III is PVDF material coated with conductive silver paint, which is used to form four electrodes after polarization; IV is an optical fiber, which is highly similar to animal whiskers, giving the sensor better flexibility.

[0031] When the piezoelectric fiber portion of the PVDF flow field detection sensor 201 deforms, the charge generated on the electrode is calculated using the first-type piezoelectric equation. After substituting the boundary conditions into the equation, the electric displacement in the PVDF layer can be expressed as:

[0032]

[0033] In the formula: Dr is the electric displacement; SZZ is the axial strain; s11E is the elastic compliance coefficient when the electric field strength is 0; d is the piezoelectric constant.

[0034] When subjected to force, the charge on one electrode of each pair of surface electrodes can be expressed as:

[0035]

[0036]

[0037] In the formula: l is the length of the PVDF piezoelectric fiber; α is the wrap angle of the surface electrode; M(x) is the bending moment along the length direction; E is the elastic modulus; I is the moment of inertia; RC is the radius of the surface electrode; x is the length direction; and is the central angle. This sensor has four electrodes, each pair of electrodes is symmetrical, and the generated charges are equal and opposite. Let the charge difference between the electrodes in the x-direction be Qa, and the charge difference between the electrodes in the z-direction be Qb, then:

[0038] Q a =2Q1

[0039] Q b =2Q2

[0040] like Figure 6 and Figure 7 The overall projection view of the device shown is used to represent the direction of the flow field force that the device as a whole can detect. Since each PVDF flow field detection sensor 201 can detect the force in the x and z directions, the resultant force and couple in the transverse X and Y directions and the longitudinal Z direction can be obtained by mechanical calculation for the whole.

[0041] An underwater robot vector environment detection device based on ultrasonic waves and PVDF materials is described. During operation, six ultrasonic detection heads 104 detect obstacle information in six directions and transmit the data to the chip in the data processing cabin 3 to accurately determine the direction and distance of the obstacles.

[0042] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. An underwater robot vector environment detection device based on ultrasonic waves and PVDF materials, characterized in that, The system includes an ultrasonic testing chamber (1), a PVDF flow field testing area (2), and a data processing chamber (3). The ultrasonic testing chamber (1) consists of an ultrasonic testing chamber cover (101), an ultrasonic testing chamber body (102), a fastening nut (103), an ultrasonic testing head (104), and a wiring conduit (105). The PVDF flow field testing area (2) consists of a PVDF flow field testing sensor (201), a sensor support (202), and a bracket (203). The data processing chamber (3) consists of a data processing chamber body (301) and a base (302). The ultrasonic testing chamber (1) and the data processing chamber (3) are connected by the PVDF flow field testing area (2). Six ultrasonic testing heads (104) are provided, and the six ultrasonic testing heads (104) are installed on six sides of the ultrasonic testing chamber body (102). On the surface, it is fastened by a fastening nut (103), and the wires of the ultrasonic detection head (104) are introduced into the data processing cabin (3) through the conduit (105) to connect to the main control chip therein; the PVDF flow field detection area (2) is arranged on six sides by six PVDF flow field detection sensors and connected to the bracket (203). Four wires are led out from the four electrodes of each PVDF flow field detection sensor (201) and directly enter the data processing cabin (3) through the hole on the data processing cabin body (301) to connect to the main control chip therein; the main control chip is placed in the data processing cabin (3). The main control chip is used to process the data of the six ultrasonic detection heads (104) and the six PVDF flow field detection sensors (201). The main control chip is connected to the underwater robot body through the data line to provide underwater vector environment data.

2. The underwater robot vector environment detection device based on ultrasonic waves and PVDF material according to claim 1, characterized in that, The ultrasonic detection chamber (1) is located at the top of the device and is used to detect lateral obstacles in the horizontal direction. The ultrasonic detection chamber body (102) has six sides, each of which is equipped with an ultrasonic detection head (104) and fixed by a fastening nut (103).

3. The underwater robot vector environment detection device based on ultrasonic waves and PVDF material according to claim 1, characterized in that, The ultrasonic testing head (104) is model L042M4W, with a working voltage of 5-24V, an output mode of RS485, and a detection range of 6m.

4. The underwater robot vector environment detection device based on ultrasonic waves and PVDF material according to claim 1, characterized in that, The PVDF flow field detection area (2) consists of six sets of PVDF flow field detection sensors (201), and their arrangement is structurally consistent with that of the ultrasonic detection chamber (1).

5. The underwater robot vector environment detection device based on ultrasonic waves and PVDF material according to claim 1, characterized in that, The PVDF flow field detection sensor (201) is a four-electrode PVDF piezoelectric fiber flexible sensor with PVDF as the material surface, based on the charge generated by the piezoelectric effect on the surface of the PVDF piezoelectric fiber. The preparation method of the four-electrode PVDF piezoelectric fiber flexible sensor is as follows: PVDF particles are heated to a molten state at 200°C, allowing them to cover the surface of metal fibers to form a PVDF coating layer. After complete cooling in air, a section of PVDF piezoelectric fiber with a metal core is obtained, wherein the metal wire is precisely located at the center of the pressed fiber. The piezoelectric fiber is polarized to give it piezoelectric properties. Four electrodes are uniformly coated on the surface of the piezoelectric fiber. During polarization, the metal core acts as the negative electrode, and the four electrodes act as the positive electrode. The piezoelectric fiber is placed in an oil temperature chamber containing silicone oil at 150°C and an applied voltage of 0.5kV for 45 minutes for polarization. After cooling to room temperature, it is taken out. After polarization, the electrode-covered area of ​​the piezoelectric fiber is piezoelectric, while the area not covered by the four electrodes is not piezoelectric. That is, a four-electrode PVDF piezoelectric fiber with a conductive silver paint coating is charged and the uncoated area is uncharged is prepared. Under the action of external force, the surface charge density of the PVDF fiber changes. The surface coated with conductive silver paint collects the charge and outputs it as an electrical signal.

6. The underwater robot vector environment detection device based on ultrasonic waves and PVDF material according to claim 1, characterized in that, The specific implementation method for installing the PVDF flow field detection sensor (201) is as follows: the metal core of the processed PVDF piezoelectric fiber is removed, and it is cut to a suitable size. The metal core is replaced with an optical fiber, which makes the sensor more flexible. Considering the waterproofness of the piezoelectric fiber surface, the piezoelectric fiber is wrapped with a soft rubber sleeve and the sleeve is made into an installation hole. It is installed on the sensor support (202). Four wires lead out two pairs of electrodes and connect them to the main control in the data processing cabin (3).

7. The underwater robot vector environment detection device based on ultrasonic waves and PVDF material according to claim 1, characterized in that, The six PVDF flow field detection sensors (201) are mounted on sensor supports (202), which are fixed as crossbeams on two adjacent brackets (203).

8. The underwater robot vector environment detection device based on ultrasonic waves and PVDF material according to claim 1, characterized in that, The data processing compartment (3) is an important part used to house the data processing chip and support the upper sensing structure. It consists of a data processing compartment body (301) and a base (302).

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