Underwater ultrasonic sensor and underwater robot

Abstract

The invention relates to an underwater ultrasonic sensor and an underwater robot. The underwater ultrasonic sensor comprises a circular piezoelectric ceramic, a sealed shell and a cable, the circular piezoelectric ceramic is arranged in the sealed shell, and the cable penetrates through the sealed shell and is electrically connected with the circular piezoelectric ceramic; the shape of the sealing shell is matched with that of the circular piezoelectric ceramic; the circular piezoelectric ceramic is used for transmitting an ultrasonic signal within a preset angle range in a preset direction under the condition of receiving a control signal transmitted by the cable; the preset direction extends outwards along the radius direction of the circular piezoelectric ceramic; under the condition that an ultrasonic echo signal responding to the ultrasonic signal is received, the ultrasonic echo signal is output through the cable; the preset angle range is a circle center angle range formed by taking the circle center of the circular piezoelectric ceramic as a reference. The underwater ultrasonic sensor can perform large-range detection by transmitting ultrasonic signals in a preset angle range in a preset direction through the circular piezoelectric ceramics.

Description

Technical Field

[0001] This application relates to the field of underwater ultrasonic technology, and particularly to an underwater ultrasonic sensor and an underwater robot. Background Art

[0002] With the development of robot technology, pool robots have emerged. Pool robots are mainly used for regularly cleaning swimming pools. In the prior art, the detection range of the ultrasonic sensors equipped on pool robots is small. Summary of the Invention

[0003] Based on this, in view of the above technical problems, it is necessary to provide an underwater ultrasonic sensor and an underwater robot capable of performing large-range detection.

[0004] In a first aspect, this application provides an underwater ultrasonic sensor, including a circular piezoelectric ceramic, a sealed housing, and a cable, wherein:

[0005] The circular piezoelectric ceramic is disposed inside the sealed housing, and the cable passes through the sealed housing and is electrically connected to the circular piezoelectric ceramic;

[0006] The circular piezoelectric ceramic is configured to, when receiving a control signal transmitted by the cable, emit an ultrasonic signal within a preset angle range in a preset direction; and when receiving an ultrasonic echo signal in response to the ultrasonic signal, output the ultrasonic echo signal through the cable; the preset direction extends outward along the radius direction of the circular piezoelectric ceramic; the preset angle range is a central angle range formed with the center of the circular piezoelectric ceramic as a reference.

[0007] In one embodiment, it further includes:

[0008] The underwater ultrasonic sensor further includes a circuit board, the circuit board is disposed inside the sealed housing, and the cable is connected to the circular piezoelectric ceramic through the circuit board;

[0009] The circuit board is configured to, when receiving a control signal transmitted by the cable, generate a driving signal and transmit it to the circular piezoelectric ceramic;

[0010] The circular piezoelectric ceramic is configured to, when receiving the driving signal, emit an ultrasonic signal within a preset angle range in a preset direction.

[0011] In one embodiment, the circular piezoelectric ceramic is further configured to, when receiving an ultrasonic echo signal in response to the ultrasonic signal, transmit the received ultrasonic echo signal to the circuit board;

[0012] The circuit board is also configured to amplify the ultrasonic echo signal when receiving the ultrasonic echo signal, and output the amplified ultrasonic echo signal through the cable.

[0013] In one embodiment, one end of the cable passes through the sealed housing and is electrically connected to the circular piezoelectric ceramic, and the other end of the cable is connected to an external circuit board; the control signal transmitted by the cable is a driving signal sent by the external circuit board.

[0014] The circular piezoelectric ceramic is configured to emit an ultrasonic signal within a preset angular range in a preset direction when receiving the driving signal; the preset direction extends outward along the radial direction of the circular piezoelectric ceramic; and when receiving an ultrasonic echo signal in response to the ultrasonic signal, output the ultrasonic echo signal to the external circuit board through the cable; the preset angular range is a central angular range formed with the center of the circular piezoelectric ceramic as a reference.

[0015] In one embodiment, the circular piezoelectric ceramic includes an annular piezoelectric ceramic, and the annular piezoelectric ceramic includes an inner ring.

[0016] A protrusion matching the size of the inner ring of the annular piezoelectric ceramic is provided inside the sealed housing, and the height of the protrusion does not exceed a preset constraint value, and the protrusion is used to fix the annular piezoelectric ceramic.

[0017] In one embodiment, the circular piezoelectric ceramic further includes a solid cylindrical piezoelectric ceramic.

[0018] In one embodiment, an adhesive for ultrasonic coupling is filled between the circular piezoelectric ceramic and the sealed housing.

[0019] In one embodiment, the sealed housing includes an upper cover and a lower shell, and the sealing method between the upper cover and the lower shell includes at least one of the following sealing methods: rubber part compression deformation sealing, welding sealing, and potting sealing.

[0020] In one embodiment, the sealing method between the cable and the sealed housing includes at least one of the following sealing methods: rubber part compression deformation sealing and potting sealing.

[0021] In the above underwater ultrasonic sensor, the circular piezoelectric ceramic is arranged inside the sealed housing, and the shape of the sealed housing matches that of the circular piezoelectric ceramic. By emitting ultrasonic signals within a preset angular range in a preset direction through the circular piezoelectric ceramic, the detection range of the underwater ultrasonic sensor can be improved.

[0022] Second aspect, the present application further provides an underwater robot, including an actuator and the underwater ultrasonic sensor as described in the first aspect; the underwater robot receives the ultrasonic echo signal through the underwater ultrasonic sensor, and controls the actuator to perform corresponding actions according to the ultrasonic echo signal.

[0023] The above underwater robot can communicate with a fixed base or a robot cabin at any position or any angle through an underwater ultrasonic sensor that can emit ultrasonic signals within a preset angle range in a preset direction, which can improve the positioning accuracy and action precision of the underwater robot. Description of the Drawings

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0025] Figure 1 It is a schematic cross-sectional structure diagram of an underwater ultrasonic sensor in an embodiment;

[0026] Figure 2 It is a schematic perspective top view structure diagram of an underwater ultrasonic sensor in an embodiment;

[0027] Figure 3 It is a schematic cross-sectional structure diagram of an underwater ultrasonic sensor in another embodiment;

[0028] Figure 4 It is a schematic partial cross-sectional structure diagram between a circular piezoelectric ceramic and a sealed housing in an underwater ultrasonic sensor in an embodiment;

[0029] Figure 5 It is a schematic structure diagram of a sealed housing in an underwater ultrasonic sensor in an embodiment;

[0030] Figure 6 It is a schematic cross-sectional structure diagram of a miniaturized underwater acoustic communication and ranging integrated sensor in an embodiment;

[0031] Figure 7 It is a schematic diagram of the angle range for a ring-shaped piezoelectric ceramic to emit ultrasonic signals at 360°. Detailed Embodiments

[0032] To facilitate the understanding of the present application, the present application will be described more comprehensively below with reference to the relevant drawings. Embodiments of the present application are shown in the drawings. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, these embodiments are provided so that the disclosure of the present application is more thorough and comprehensive.

[0033] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the technical field to which this application belongs. The terms used in the description of this application herein are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0034] It can be understood that the spatial relationship terms used in this application, such as "under", "below", "lower", "beneath", "above", "upper", etc., can be used herein to describe the relationship between one element or feature shown in the figure and other elements or features. It should be understood that in addition to the orientation shown in the figure, the spatial relationship terms also include different orientations of the device during use and operation. For example, if the device in the figure is flipped, the element or feature described as "under other elements" or "beneath it" or "under it" will be oriented "above" other elements or features. Therefore, the exemplary terms "under" and "beneath" can include both the upper and lower orientations. In addition, the device can also include other orientations (such as rotating 90 degrees or other orientations), and the spatial description terms used herein are accordingly interpreted.

[0035] It should be noted that when an element is considered to be "connected" to another element, it can be directly connected to the other element or connected to the other element through an intermediate element. In addition, "connection" in the following embodiments should be understood as "electrical connection", "communication connection", etc. if there is a transmission of electrical signals or data between the connected objects.

[0036] As used herein, the singular forms "a", "an" and "the" may also include the plural forms unless the context clearly indicates otherwise. It should also be understood that the terms "comprising" or "having" or the like specify the presence of the stated features, wholes, steps, operations, components, parts or combinations thereof, but do not preclude the presence or addition of one or more other features, wholes, steps, operations, components, parts or combinations thereof.

[0037] As described in the background art, the ultrasonic sensors in the prior art have the problem of a relatively small detection range. After research by the inventors, it is found that the reason for this problem is that the existing underwater ultrasonic sensors usually use a single piezoelectric ceramic piece as the sensitive element, and the angles for transmitting and receiving ultrasonic signals are limited, resulting in a small detection range and inability to achieve full-range sensing.

[0038] For the above reasons, the present invention provides a solution for underwater acoustic communication or ranging devices, especially sensors applied to submersibles and pool cleaning robots. In one embodiment, as Figure 1 and Figure 2 shown, an underwater ultrasonic sensor is provided, including a circular piezoelectric ceramic 10, a sealed housing 20, and a cable 30. Figure 1 is a schematic cross-sectional view of the above underwater ultrasonic sensor. Figure 2 is a schematic top view of the above underwater ultrasonic sensor. Figure 2 The gap between the circular piezoelectric ceramic 10 and the sealed housing 20 in the figure is only for easy distinction and does not have a practical limitation; wherein: the above circular piezoelectric ceramic 10 is disposed inside the above sealed housing 20, and the above cable 30 passes through the above sealed housing 20 and is electrically connected to the above circular piezoelectric ceramic 10; the shape of the above sealed housing 20 matches the shape of the above circular piezoelectric ceramic 10; the above circular piezoelectric ceramic 10 is configured to emit ultrasonic signals within a preset angle range in a preset direction when receiving a control signal transmitted by the above cable 30; and when receiving an ultrasonic echo signal in response to the above ultrasonic signal, output the above ultrasonic echo signal through the above cable 30; the above preset direction extends outward along the radius direction of the above circular piezoelectric ceramic 10; the above preset angle range is a central angle range formed with the center of the above circular piezoelectric ceramic 10 as the reference.

[0039] Among them, the circular piezoelectric ceramic may refer to a ceramic material with a piezoelectric effect in a circular structure, such as Figure 1 and Figure 2 shown in the cylindrical shape, which can convert an electrical signal into mechanical vibration (transmitting ultrasonic waves) or convert mechanical vibration into an electrical signal (receiving ultrasonic echo signals), that is, it can use the inverse piezoelectric effect (electrical signal converted into mechanical vibration) to transmit ultrasonic waves, and also use the direct piezoelectric effect (mechanical vibration converted into electrical signal) to receive ultrasonic echo signals.

[0040] Among them, the sealed housing may refer to a housing including a circular piezoelectric ceramic, which can be used to isolate the external liquid environment (such as a water environment) and protect the internal electronic components. The shape of the sealed housing needs to match the shape of the circular piezoelectric ceramic, such as Figure 1 and Figure 2The cylindrical shape shown can ensure the installation temperature of the circular piezoelectric ceramic in the underwater ultrasonic sensor, thus not affecting the transmission and reception directions of ultrasonic waves.

[0041] Among them, the cable can refer to a wire used to transmit electrical signals, which can pass through the sealed housing and be connected to the circular piezoelectric ceramic to achieve the electrical connection between external devices (such as a control circuit, a signal processing unit, etc.) and the piezoelectric ceramic.

[0042] Among them, the preset direction can refer to the direction in which the ultrasonic wave is emitted extending outward along the radius direction of the circular piezoelectric ceramic, that is, the direction from the center of the circular piezoelectric ceramic to the circumference, which is also the direction of radial emission. The preset angle range can refer to a sector area with a specific central angle formed with the center of the circular piezoelectric ceramic as the vertex, restricting the ultrasonic wave to be emitted only within this angle range.

[0043] In the above-mentioned underwater ultrasonic sensor, the circular piezoelectric ceramic is arranged inside the sealed housing, and the shape of the sealed housing matches that of the circular piezoelectric ceramic. By emitting ultrasonic signals in the preset direction within the preset angle range through the circular piezoelectric ceramic, the detection range of the underwater ultrasonic sensor can be improved.

[0044] In some embodiments, the specific structural settings of the circular piezoelectric ceramic can be changed to change the ultrasonic emission angle range (preset angle range) of the underwater ultrasonic sensor. For example, the circular piezoelectric ceramic at least includes one layer, and each layer of the circular piezoelectric ceramic can be a solid cylinder or a ring. Multiple layers of circular piezoelectric ceramics can be stacked in the vertical direction (axial direction); one layer of circular piezoelectric ceramic can be obtained by splicing multiple piezoelectric ceramic units; the number of piezoelectric ceramic units can be increased or decreased according to the actual requirements for the emission angle range.

[0045] Among them, the single-layer solid cylindrical circular piezoelectric ceramic can be obtained by splicing sector-shaped piezoelectric ceramic units. A single sector-shaped piezoelectric ceramic unit can refer to a sector-shaped piezoelectric ceramic with a preset central angle. When a single sector-shaped piezoelectric ceramic unit is independently driven, ultrasonic waves can be emitted in a specific radial area (emission angle range). When multiple adjacent sector-shaped piezoelectric ceramic units are driven synchronously, the emission angle range can be combined and expanded.

[0046] Among them, the single-layer ring-shaped circular piezoelectric ceramic can be obtained by splicing piezoelectric ceramic units of a ring sector. A single piezoelectric ceramic unit of a ring sector can refer to a piezoelectric ceramic unit of a ring sector with a preset central angle. The piezoelectric ceramic unit of the ring sector can generate a concentrated sound beam in the preset direction through a radial vibration mode. When multiple adjacent piezoelectric ceramic units of the ring sector are driven synchronously, the emission angle range can be combined and expanded.

[0047] In some other embodiments, a single-layer circular piezoelectric ceramic can be formed by nesting multiple concentric layers of circular piezoelectric ceramics on the same cross-section, that is, the inner diameters of the concentric layers decrease from the outside to the inside. For example, the outer layer is a circular piezoelectric ceramic in the form of a large-radius ring, and the inner layer can be a circular piezoelectric ceramic in the form of a solid cylinder with a small radius or a circular piezoelectric ceramic in the form of a small-radius ring.

[0048] Each piezoelectric ceramic unit of the above-mentioned circular piezoelectric ceramic can be equipped with an independent drive circuit, which is uniformly controlled by a control circuit (such as a circuit board). By selecting and activating the unit combination through a multiplex analog switch, different ultrasonic emission angle ranges can be achieved. For example, for a sensor with multiple-layer circular piezoelectric ceramics, when activating different unit combinations according to actual needs, any piezoelectric ceramic unit combination can be activated for the circular piezoelectric ceramics of different layers. The superimposed effect of the activated piezoelectric ceramic units in different layers in the radial direction can expand the ultrasonic emission angle range, and the superimposed effect in the vertical (axial) direction can enhance the energy intensity of the ultrasonic waves in the corresponding radial direction; that is to say, by controlling the increase or decrease and combination of the piezoelectric ceramic units of the circular piezoelectric ceramic, the flexible adjustment of the ultrasonic emission angle range of the underwater ultrasonic sensor can be realized. For example, if only one piezoelectric ceramic unit is activated in the circular piezoelectric ceramics of different layers, and the piezoelectric ceramic units of each layer are at the same central angle position, narrow-beam high-precision mapping can be achieved, that is, high-precision detection can be realized; if multiple piezoelectric ceramic units are activated in the circular piezoelectric ceramics of different layers, wide-beam environmental perception can be achieved, that is, large-range scanning can be realized.

[0049] In some other embodiments, there may be multiple preset central angles for the above piezoelectric ceramic units, that is, there may be piezoelectric ceramic units with various different central angles. In practical applications, a mobile device using an underwater ultrasonic sensor may have a relatively fixed working mode. For example, when an underwater cleaning robot is cleaning in a pool, the robot base or the robot cabin is generally a fixed device. When the working route of the robot is mainly to move away from the robot base first and then move closer to the robot base, it indicates that the main working movement direction of the robot is mainly the straight-line direction between the robot and the robot base, and there is little lateral movement perpendicular to this straight line. Therefore, the piezoelectric ceramic units of the circular piezoelectric ceramic in the underwater ultrasonic sensor used by this robot can be arranged as follows: in the main working movement direction of the robot, piezoelectric ceramic units with multiple smaller central angles are arranged, and piezoelectric ceramic units with larger central angles can be arranged in other directions. In this embodiment, the robot can make the ultrasonic emission angle match the above current working movement direction by activating the piezoelectric ceramic units with smaller central angles in the current working movement direction. And because the ultrasonic emission angle of the piezoelectric ceramic units with smaller central angles is narrow and the energy is concentrated in the working movement direction, the detection accuracy and detection distance in the working movement direction are improved. While piezoelectric ceramic units with larger central angles are used in other directions, it can achieve rapid scanning of a wider area (such as the side of the robot), timely detect potential lateral obstacles or environmental changes, avoid failures caused by side collisions, and improve the operation safety. There is no need for too high precision in non-main directions. The large central angle can not only meet the basic environmental perception requirements but also avoid the costs (such as increasing the number of ceramic units and complex drive circuits) and energy waste caused by excessive pursuit of precision, realizing the optimal allocation of performance and resources. In the above embodiment, high precision and long detection distance in the main working movement direction ensure the efficient execution of work tasks; large-angle coverage in other directions guarantees all-round environmental perception and safety; at the same time, the energy distribution and cost control of the sensor are optimized, making the underwater ultrasonic sensor more suitable for the actual working mode of the device, improving the overall reliability and practicability, and is especially suitable for underwater robot scenarios with relatively fixed paths.

[0050] In one embodiment, as Figure 3 shown, the above underwater ultrasonic sensor further includes a circuit board 40. The above circuit board 40 is arranged inside the above sealing housing 20, and the above cable 30 is connected to the above circular piezoelectric ceramic 10 through the above circuit board 40; the above circuit board 40 is used for generating a drive signal and transmitting it to the above circular piezoelectric ceramic 10 when receiving the control signal transmitted by the above cable 30; the above circular piezoelectric ceramic 10 is used for emitting an ultrasonic signal within a preset angle range in a preset direction when receiving the above drive signal.

[0051] The control signal may refer to an electrical signal sent from an external device (such as a single-chip microcomputer, industrial computer, etc.) to the circuit board, which is used to specify the ultrasonic emission parameters (such as frequency, pulse width, emission angle range, etc.). The drive signal may refer to an electrical signal of a specific frequency band generated by the circuit board according to the control signal, which is applied to the piezoelectric ceramic to excite vibration.

[0052] The circuit board may refer to a printed circuit board (such as a PCB board) disposed inside a sealed housing, which may be used for signal processing and control. For example, the circuit board may connect a cable and a circular piezoelectric ceramic to realize the input of a control signal and the output of an ultrasonic echo signal. The circuit board may also generate a drive signal (such as a sine wave) through a built-in circuit according to the control signal input from the cable to drive the circular piezoelectric ceramic to vibrate, so as to emit an ultrasonic signal in a preset direction within a preset angle range. The circuit board may also convert the power input from the cable into the drive power required by the circular piezoelectric ceramic.

[0053] In this embodiment, the circuit board is built into a sealed housing to avoid corrosion of the circuit by the external water environment, thereby extending the service life of the sensor; the circuit board converts the control signal into a driving signal and applies it to the circular piezoelectric ceramic to achieve accurate emission of ultrasonic signals.

[0054] In one embodiment, the circular piezoelectric ceramic is also used to transmit the received ultrasonic echo signal to the circuit board when an ultrasonic echo signal in response to the ultrasonic signal is received; the circuit board is also used to amplify the ultrasonic echo signal when the ultrasonic echo signal is received, and output the amplified ultrasonic echo signal through the cable.

[0055] Among them, the ultrasonic echo signal may refer to the ultrasonic signal emitted by the circular piezoelectric ceramic, which is reflected back to the sensor after encountering an obstacle, and then converted into a weak electrical signal by the circular piezoelectric ceramic; in the scenario of using ultrasonic sensors for communication, the ultrasonic echo signal may also refer to the ultrasonic signal emitted by other ultrasonic sensors; or the ultrasonic signal emitted by other ultrasonic sensors after receiving and responding to the ultrasonic signal emitted by the circular piezoelectric ceramic.

[0056] Amplifying the ultrasonic echo signal may refer to a process in which the circuit board amplifies the signal strength of the weak electrical signal output by the circular piezoelectric ceramic.

[0057] The amplified ultrasonic echo signal can be output through a cable to a control module in a device that controls the current underwater ultrasonic sensor for further signal processing.

[0058] In this embodiment, an ultrasonic echo signal is received by a circular piezoelectric ceramic, and then the ultrasonic echo signal is amplified by a circuit board, enhancing the signal quality of the echo signal. Subsequently, the amplified ultrasonic echo signal is output through a cable to improve the accuracy of subsequent signal processing.

[0059] In one embodiment, one end of the cable passes through the sealed housing and is electrically connected to the circular piezoelectric ceramic, and the other end of the cable is connected to an external circuit board; the control signal transmitted by the cable is a drive signal sent by the external circuit board; the circular piezoelectric ceramic is configured to emit an ultrasonic signal within a preset angular range in a preset direction when receiving the drive signal; the preset direction extends outward along the radial direction of the circular piezoelectric ceramic; and when receiving an ultrasonic echo signal in response to the ultrasonic signal, the ultrasonic echo signal is output to the external circuit board through the cable; the preset angular range is a central angular range formed with the center of the circular piezoelectric ceramic as a reference.

[0060] Among them, a current underwater ultrasonic sensor is configured in the device. The external circuit board can be integrated in the controller of the device, or the external circuit board can be integrated in a dedicated controller for the sensor, and the dedicated controller is then connected to the device. For example, two underwater ultrasonic sensors are configured in a device, and the external circuit boards corresponding to the cables of the two underwater ultrasonic sensors are centrally arranged in the controller of the device. Another example is that a device is configured with two underwater ultrasonic sensors, and two external circuit boards corresponding to the two underwater ultrasonic sensors are integrated in an independent controller, then the cables of the two underwater ultrasonic sensors are correspondingly connected to the independent controller, and the independent controller is then connected to the device for being controlled. By concentrating the circuit boards of multiple underwater ultrasonic sensors in the controller, the cost is lower compared to a solution where a circuit board is provided in each underwater ultrasonic sensor, and the loss of signals during transmission of each underwater ultrasonic sensor can be reduced, improving the detection accuracy.

[0061] In this embodiment, only the circular piezoelectric ceramic is arranged inside the sealed housing, without the need to integrate complex circuits in the underwater ultrasonic sensor, which can reduce the volume of the sensor and achieve miniaturization.

[0062] In one embodiment, as Figure 4 shown, the circular piezoelectric ceramic includes a ring-shaped piezoelectric ceramic 101, and the ring-shaped piezoelectric ceramic 101 includes an inner ring; a protrusion 201 matching the size of the inner ring of the ring-shaped piezoelectric ceramic 101 is arranged inside the sealed housing 20, the height of the protrusion 201 does not exceed a preset constraint value, and the protrusion 201 is used to fix the ring-shaped piezoelectric ceramic 101.

[0063] Among them, the annular piezoelectric ceramic may refer to a piezoelectric ceramic element with an annular structure, having a central hollow region (inner ring), a circular cross-section, and a uniform axial height.

[0064] Among them, the protrusion may refer to a columnar or platform-like structure on the inner wall of the sealed housing, whose shape matches the inner ring of the annular piezoelectric ceramic. For example, a cylindrical protrusion fits the inner ring. The height of the protrusion does not exceed a preset constraint value to ensure that the annular piezoelectric ceramic can vibrate freely, avoiding the fixed structure from restricting its telescopic vibration and ensuring the efficiency of the piezoelectric effect.

[0065] In this embodiment, the annular piezoelectric ceramic is fixed by a protrusion that matches the size of the inner ring of the annular piezoelectric ceramic, preventing the annular piezoelectric ceramic from generating displacement. The protrusion only contacts the inner ring and does not contact the outer ring edge of the annular piezoelectric ceramic, avoiding interference with the radial vibration of the annular piezoelectric ceramic; and the height of the protrusion does not exceed the preset constraint value, allowing the annular piezoelectric ceramic to vibrate freely.

[0066] In one embodiment, the above-mentioned circular piezoelectric ceramic further includes a solid cylindrical piezoelectric ceramic. Among them, the solid cylindrical piezoelectric ceramic has no inner ring hollow region, and the vibration energy is concentrated in the direction of the outer diameter of the cylinder, improving the energy utilization rate during the ultrasonic wave emission process.

[0067] In one embodiment, as Figure 4 shown, an adhesive 50 for ultrasonic coupling is filled between the above-mentioned circular piezoelectric ceramic and the above-mentioned sealed housing. Among them, by filling the adhesive between the circular piezoelectric ceramic and the sealed housing, the ultrasonic transmission coefficient can be improved, the emission efficiency and reception efficiency of ultrasonic energy can be improved, energy loss can be reduced, and the sensitivity can be improved.

[0068] In one embodiment, as Figure 5 shown, the above-mentioned sealed housing 20 includes an upper cover 203 and a lower shell 205. The sealing method between the above-mentioned upper cover 203 and the lower shell 205 includes at least one of the following sealing methods: rubber part compression deformation sealing, welding sealing, and potting sealing. Among them, the rubber part compression deformation sealing may refer to that the upper cover 203 and the lower shell 205 adopt a threaded fit, and a rubber part is used as the contact material at the connection. When tightened by the thread, the rubber part is compressed and deformed to achieve the sealing effect. The welding sealing may refer to that the upper cover 203 and the lower shell 205 are sealed by welding. The potting sealing may refer to potting between the upper cover 203 and the lower shell 205 to form a potting layer to achieve the sealing effect.

[0069] In one embodiment, the sealing method between the cable and the sealing housing includes at least one of the following sealing methods: rubber part compression deformation sealing and potting sealing. Among them, the rubber part compression deformation sealing may refer to that a bolt is used in cooperation between the cable and the sealing housing, and a rubber part is used as the contact material at the connection part. When the bolt is tightened, the rubber part is compressed and deformed to achieve the sealing effect. The potting sealing may refer to that the cable passes through the sealing housing, and potting is performed in the gap between the cable and the sealing housing, thereby achieving the sealing effect.

[0070] In one embodiment, as Figure 6 shown, the present application provides a miniaturized underwater acoustic communication and ranging integrated sensor 80, including an annular piezoelectric ceramic 801, a circuit board 802, a cable 803, and a sealing housing (including an upper cover 804 and a lower shell 805); wherein:

[0071] The annular piezoelectric ceramic 801 is the core sensitive element of the sensor, which can generate and receive ultrasonic signals omnidirectionally at 360°. The circuit board 802 drives the annular piezoelectric ceramic 801, receives and amplifies ultrasonic echo signals, and performs communication and ranging algorithm processing, etc. The sealing housing is the protective structure of the sensor, is the acoustic impedance matching layer of the annular piezoelectric ceramic 801, and also plays a role in protecting the circuit board and the piezoelectric ceramic. The cable 803 plays a role in supplying power to the sensor and / or performing wired communication with external devices. By using the annular piezoelectric ceramic 801 as the core sensitive element, ultrasonic signals can be generated and received omnidirectionally at 360°, greatly improving the detection range and accuracy. Through the integrated circuit board 802, various functions such as driving the annular piezoelectric ceramic 801, receiving and amplifying ultrasonic echo signals, and performing communication and ranging algorithm processing can be achieved, with a high degree of functional integration.

[0072] Inside the sealing housing, there is an annular piezoelectric ceramic 801, or a ring-shaped piezoelectric ceramic composed of two or more annular piezoelectric ceramics 801. As Figure 7 shown, the annular piezoelectric ceramic 801 adopts a radial vibration mode, enabling the sensor to receive and transmit ultrasonic signals 360° towards the side wall of the housing.

[0073] In this embodiment, controlling the effective average diameter (such as the outer diameter) of the annular piezoelectric ceramic 801 within the range of 10 mm to 30 mm can make the external dimensions of the sensor smaller; at the same time, the annular piezoelectric ceramic 801 can be made to operate in the low-frequency band (such as between 30 kHz and 70 kHz) through the circuit board 802, which is beneficial to increasing the propagation distance of communication and ranging signals.

[0074] In addition to protecting the internal circuit board 802 and the annular piezoelectric ceramic 801, the side wall of the sealed housing also serves as an acoustic impedance matching layer for the annular piezoelectric ceramic 801. Meanwhile, an adhesive is filled between the side wall of the sealed housing and the annular piezoelectric ceramic 801 for ultrasonic coupling. The formed coupling layer 808 and acoustic impedance matching layer can improve the ultrasonic transmission coefficient, enhance the emission and reception efficiency of ultrasonic energy, reduce energy loss, and improve sensitivity. The sealed housing, as the protective structure of the sensor, is both the matching layer of the annular piezoelectric ceramic 801 and plays a role in protecting the circuit board 802 and the annular piezoelectric ceramic 801, with a reasonable structural design.

[0075] The waterproof and sealing performance of the sensor is excellent and can meet the protection level above IP68, enabling the communication and ranging sensor to work underwater for a long time. The waterproof and sealing methods of the sensor housing include that the upper cover 804 and the lower shell 805 adopt rubber part compression deformation sealing (combined with a threaded fastening structure for compression, that is, as shown in Figure 6 the thread 806 of the upper cover 804 and the rubber part 807), welding sealing of the upper cover 804 and the lower shell 805, potting sealing of the housing, etc.; between the cable 803 and the sealed housing, rubber part compression deformation sealing (combined with bolt fasteners for compression), potting sealing, etc. are adopted. The sensor has excellent waterproof and sealing performance and can meet the protection level above IP68, enabling the communication and ranging sensor to work underwater for a long time, greatly extending the service life. As shown in Figure 6 Figure, a step 809 is formed on the lower shell 805 near the annular piezoelectric ceramic 801. In other embodiments, the lower shell 805 can be adjusted to a straight cylinder shape, thus eliminating the need to set the step 809.

[0076] In the above miniaturized underwater acoustic communication and ranging integrated sensor, the cable 803 can supply power to the sensor and / or conduct wired communication with external devices, which can significantly improve the performance and applicability of the underwater acoustic sensor, especially suitable for applications such as submersibles and pool cleaning robots.

[0077] In one embodiment, the present application further provides an underwater robot, including an actuator and the above-mentioned underwater ultrasonic sensor; the above-mentioned underwater robot receives the above-mentioned ultrasonic echo signal through the above-mentioned underwater ultrasonic sensor and controls the above-mentioned actuator to perform corresponding actions according to the above-mentioned ultrasonic echo signal. Through the above-mentioned underwater ultrasonic sensor that can emit ultrasonic signals within a preset angle range in a preset direction, the underwater robot can communicate with a fixed base or a robot cabin through the ultrasonic sensor at any position or any angle, which can improve the positioning accuracy and action precision of the underwater robot.

[0078] The technical features of the above embodiments can be combined arbitrarily. For the sake of concise description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope recorded in this specification.

[0079] The above-described embodiments merely represent several implementation manners of the present application. The description is relatively specific and detailed, but it should not be construed as a limitation on the scope of the invention patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present application, several modifications and improvements can still be made, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application shall be subject to the appended claims.

Claims

1. An underwater ultrasonic sensor, characterized in that, It includes a circular piezoelectric ceramic, a sealed housing, and a cable, where: The circular piezoelectric ceramic is disposed inside the sealed housing, and the cable passes through the sealed housing and is electrically connected to the circular piezoelectric ceramic; The circular piezoelectric ceramic is configured to emit ultrasonic signals within a preset angular range in a preset direction when receiving the control signal transmitted by the cable; and to output the ultrasonic echo signal through the cable when receiving the ultrasonic echo signal in response to the ultrasonic signal; the preset direction extends outward along the radial direction of the circular piezoelectric ceramic; the preset angular range is a central angular range formed with the center of the circular piezoelectric ceramic as a reference.

2. The underwater ultrasonic sensor according to claim 1, characterized in that, The underwater ultrasonic sensor further includes a circuit board, which is disposed inside the sealed housing, and the cable is connected to the circular piezoelectric ceramic through the circuit board; The circuit board is configured to generate a drive signal and transmit it to the circular piezoelectric ceramic when receiving the control signal transmitted by the cable; The circular piezoelectric ceramic is configured to emit ultrasonic signals within a preset angular range in a preset direction when receiving the drive signal.

3. The underwater ultrasonic sensor according to claim 2, characterized in that, The circular piezoelectric ceramic is further configured to transmit the received ultrasonic echo signal to the circuit board when receiving the ultrasonic echo signal in response to the ultrasonic signal; The circuit board is further configured to amplify the ultrasonic echo signal when receiving the ultrasonic echo signal, and output the amplified ultrasonic echo signal through the cable.

4. The underwater ultrasonic sensor according to claim 1, characterized in that, One end of the cable passes through the sealed housing and is electrically connected to the circular piezoelectric ceramic, and the other end of the cable is connected to an external circuit board; the control signal transmitted by the cable is the drive signal sent by the external circuit board; The circular piezoelectric ceramic is configured to emit ultrasonic signals within a preset angular range in a preset direction when receiving the drive signal; the preset direction extends outward along the radial direction of the circular piezoelectric ceramic; and to output the ultrasonic echo signal through the cable to the external circuit board when receiving the ultrasonic echo signal in response to the ultrasonic signal; the preset angular range is a central angular range formed with the center of the circular piezoelectric ceramic as a reference.

5. The underwater ultrasonic sensor according to any one of claims 1 to 4, characterized in that, The circular piezoelectric ceramic includes an annular piezoelectric ceramic, and the annular piezoelectric ceramic includes an inner ring; A protrusion matching the size of the inner ring of the annular piezoelectric ceramic is provided inside the sealed housing, and the height of the protrusion does not exceed a preset constraint value, and the protrusion is used to fix the annular piezoelectric ceramic.

6. The underwater ultrasonic sensor according to any one of claims 1 to 4, characterized in that The circular piezoelectric ceramic further includes a solid cylindrical piezoelectric ceramic.

7. The underwater ultrasonic sensor according to any one of claims 1 to 4, characterized in that, An adhesive for ultrasonic coupling is filled between the circular piezoelectric ceramic and the sealed housing.

8. The underwater ultrasonic sensor according to any one of claims 1 to 4, characterized in that, The sealed housing includes an upper cover and a lower shell, and the sealing method between the upper cover and the lower shell includes at least one of the following sealing methods: rubber part compression deformation sealing, welding sealing, and potting sealing.

9. The underwater ultrasonic sensor according to any one of claims 1 to 4, characterized in that, The sealing method between the cable and the sealed housing includes at least one of the following sealing methods: rubber part compression deformation sealing and potting sealing.

10. An underwater robot, characterized in that, It includes an actuator and the underwater ultrasonic sensor described in any one of claims 1 to 9; the underwater robot receives the ultrasonic echo signal through the underwater ultrasonic sensor and controls the actuator to perform corresponding actions according to the ultrasonic echo signal.

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