Underwater ultrasonic communication and positioning module
By employing an ultrasonic communication and positioning module in an underwater cleaning robot, the issues of reliability and flexibility in underwater communication have been resolved, achieving stable and flexible underwater communication and positioning functions.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- SHENZHEN DIANYINGPU TECH
- Filing Date
- 2025-06-12
- Publication Date
- 2026-06-16
AI Technical Summary
Existing underwater communication technologies suffer from low reliability and poor flexibility in underwater environments. In particular, underwater electromagnetic wave communication requires high power and large antennas, underwater optical communication has high environmental requirements and strict directional requirements, and underwater acoustic communication suffers from unstable signal propagation in complex environments.
The underwater ultrasonic communication and positioning module is adopted. The ultrasonic transducer and circuit board are set in a sealed cavity, filled with potting compound, and the communication lead extends out of the cavity. Combined with multi-stage amplification circuit and boost excitation pulse circuit, stable communication and positioning functions are achieved.
It improves the reliability of underwater communication and the flexibility of operation and control, reduces dependence on the aquatic environment, and enables stable communication and positioning over long distances.
Smart Images
Figure CN224367843U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to an underwater cleaning robot, and more particularly to a communication and positioning component for an underwater cleaning robot. Background Technology
[0002] With increasing demands for higher quality and efficiency in pool cleaning, and the development of artificial intelligence and the Internet of Things (IoT) technologies, pool cleaning robots are gradually evolving towards intelligence. This requires the robots to receive real-time instructions from operators, such as setting cleaning areas and switching cleaning modes, while also providing feedback on their working status and location. Underwater communication is crucial for achieving these functions. Effective communication allows pool cleaning robots to better adapt to different pool environments and cleaning tasks, improving cleaning efficiency and intelligence. However, water has a strong absorption and scattering effect on electromagnetic waves, rendering conventional wireless communication methods such as Bluetooth and Wi-Fi ineffective underwater. Furthermore, pool cleaning robots need to move flexibly in water; traditional wired communication methods limit their range of motion and easily cause cable entanglement. Therefore, underwater communication is essential for effective communication between pool cleaning robots and external devices.
[0003] The existing underwater communication technologies mainly include the following:
[0004] Underwater electromagnetic wave communication: Utilizing the relatively strong penetrating power of low-frequency electromagnetic waves in seawater, communication can be achieved at a certain depth underwater.
[0005] Underwater optical communication: This technology uses optical signals as the carrier of information to achieve communication in an underwater environment. Light signals are emitted by a light source, propagate through seawater, are received by a photodetector, and converted into electrical signals.
[0006] Underwater acoustic communication: After data and information are digitized by an encoder, the transducer converts the electrical signal into an acoustic signal. The acoustic signal is transmitted through the water medium to the receiving transducer, where it is converted back into an electrical signal. After being decoded by a decoder, the receiver restores the data and information.
[0007] The shortcomings of existing underwater communication technologies are:
[0008] Underwater electromagnetic wave communication: 1. High antenna requirements: To achieve long-distance communication, a very long receiving antenna is needed, which is difficult to meet for small underwater nodes. 2. High transmission power: To achieve electromagnetic wave communication over a certain distance underwater, a large transmission power is required. For example, the transmission power of very low frequency (VLF) communication systems is in the megawatt range. This not only places high demands on energy supply but may also lead to large equipment size and increased costs.
[0009] Underwater optical communication has several drawbacks: 1. It is highly sensitive to the aquatic environment. Water quality, currents, dissolved substances, plankton, and suspended particulate matter can all affect the propagation of optical signals, significantly impacting communication performance. 2. It requires high directivity. Underwater optical communication necessitates precise alignment between the transmitter and receiver to maintain a stable relative position for an effective communication link. In complex underwater environments, it is difficult for underwater equipment to maintain a precise relative position for extended periods, placing high demands on the stability and reliability of the communication system.
[0010] Underwater acoustic communication faces significant challenges due to the complex and variable underwater environment, including variations in water temperature, salinity, and depth, currents, and echo reflections. These factors cause signal propagation paths to become curved, exacerbate multipath effects, and easily lead to signal distortion or even communication interruptions. Existing underwater acoustic communication systems often lack sufficient adaptability. They cannot flexibly adjust the receiving gain for communication needs at different distances, nor can they flexibly adjust the data format for transmitting different amounts of data, resulting in low communication efficiency. Summary of the Invention
[0011] The purpose of this invention is to provide an underwater ultrasonic communication and positioning module, and the technical problem to be solved is to improve the reliability of underwater communication and the flexibility of operation and control.
[0012] The present invention adopts the following technical solution: an underwater ultrasonic communication and positioning module, which is provided with a circuit main board and an ultrasonic transducer connected to the circuit main board. The circuit main board and the ultrasonic transducer are arranged in a cavity of a sealed structure, and the cavity is filled with potting compound. A communication lead is connected to the circuit main board and extends out of the cavity.
[0013] The cavity of this utility model consists of a cylindrical sealed structure formed by an outer shell and a rear cover.
[0014] The outer shell of this utility model is cylindrical in shape, with an opening at the top. In the middle of the cylindrical shape, the outer shell wall tapers inward along the radial direction to form a step, and the lower part of the outer shell is a cylinder smaller than the upper part.
[0015] The circuit board of this invention is mounted on a step.
[0016] An ultrasonic transducer is installed at the bottom of the circuit board and cavity of this utility model.
[0017] In this invention, potting compound is used to fill the cavity between the back cover and the main circuit board, and between the main circuit board and the ultrasonic transducer.
[0018] The back cover of this utility model is installed on the outer shell body. The back cover is disc-shaped and has a hole, through which the communication lead extends out.
[0019] The ultrasonic transducer of this invention uses piezoelectric ceramics.
[0020] The communication lead of this invention has an end lead at its tail end, and the end lead has a positioning and synchronization lead.
[0021] The positioning synchronization leads of the two underwater ultrasonic communication and positioning modules are connected in parallel to form a positioning module, which is installed inside the pool cleaning robot. The communication lead of the third underwater ultrasonic communication and positioning module is connected to a base station set on the shore to form a positioning and correction device for the pool cleaning robot.
[0022] Compared with the prior art, the circuit board and ultrasonic transducer of this utility model are set in a cavity of a sealed structure, which is filled with potting compound and the communication lead extends out of the cavity. It is less affected by water environment factors and can work relatively stably in different water environments. It does not require a large antenna, has a small size, and improves the reliability of underwater communication and the flexibility of operation and control. Attached Figure Description
[0023] Figure 1 This is a schematic diagram of the module structure of this utility model.
[0024] Figure 2 This is an exploded view of the module structure of this utility model.
[0025] Figure 3 This is the circuit block diagram of this utility model.
[0026] Figure 4 This is a schematic diagram of the application scenario of this utility model (I).
[0027] Figure 5 This is a schematic diagram of the application scenario of this utility model (II).
[0028] Figure 6 This is a connection diagram of the present invention for positioning and correction.
[0029] Figure 7 This is a schematic diagram of the end lead of the communication lead of this utility model. Detailed Implementation
[0030] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments.
[0031] like Figure 1 and Figure 2 As shown, the underwater ultrasonic communication and positioning module (module) of this utility model is installed inside the pool cleaning robot and is used to receive instructions from the operator's controller, such as setting the cleaning area and switching the cleaning mode, and to communicate its own working status and location information back to the operator's controller.
[0032] The module consists of a cylindrical sealed cavity formed by a main shell 6 and a rear cover 1. In the center of the cavity, the cavity wall tapers radially inward to form a step, which then extends downwards, making the lower part of the cavity smaller than the upper part of the cylinder. A circuit board 4 is mounted on the step, and a communication lead 3 is connected to the circuit board 4, extending beyond the rear cover 1 of the cavity. An ultrasonic transducer 5 is located below the circuit board 4 and at the bottom of the cavity. Encapsulating adhesive 2 is filled between the rear cover 1 and the circuit board 4, and between the circuit board 4 and the ultrasonic transducer 5, within the cavity to achieve IP68 waterproof rating.
[0033] The outer shell body 6 is cylindrical in shape with an opening at the top. In the middle of the cylindrical body 6, the wall of the outer shell body 6 tapers inward along the radial direction to form a step. The lower part of the outer shell body 6 is a cylinder smaller than the upper part. On the left and right sides outside the middle of the cylindrical body, ears extend outward along the radial direction of the cylinder for mounting and fixing.
[0034] The back cover 1 is installed on the outer shell body 6. The back cover 1 is disc-shaped and has 3 round holes arranged along the diameter of the disc.
[0035] The communication lead 3 extends from the hole in the middle of the back cover 1 and is connected to the base station 11 via a wired connection.
[0036] The ultrasonic transducer 5 is a device for converting between acoustic and electrical signals. It contains piezoelectric ceramic and is connected to the main circuit board 4 via wires 7. Encapsulating adhesive 2 is filled between the main circuit board 4 and the cavity, and between the main circuit board 4 and the ultrasonic transducer 5, to protect the ultrasonic transducer. When sound waves act on the piezoelectric ceramic, the material vibrates mechanically, causing relative displacement of the positive and negative charge centers within it, thus generating moving charges and converting the acoustic signal into an electrical signal. Conversely, when an alternating voltage signal is applied across the piezoelectric ceramic, the material undergoes periodic expansion and contraction under the influence of the electric field. This deformation causes vibration of the surrounding medium, thereby converting the electrical signal into an acoustic signal. In this embodiment, the ultrasonic transducer 5 uses a conventional ultrasonic transducer, as shown in Table 1.
[0037] Table 1 Technical parameters of ultrasonic transducers
[0038] Resonant frequency Fs (in air) 70±10%kHz Free capacitance CT (1kHz, 1V) 4200±15%pF Dynamic impedance R1 ＜200 Mechanical quality factor Qm ＞15 Maximum operating voltage pulse wave (50% duty cycle) ＜300V Dielectric loss tanδ (1kHz, 1V) ＜3% angle 360°
[0039] like Figure 3 As shown, the main circuit board 4 is equipped with a processor, which is connected to an electrostatic discharge (ESD) protection circuit, a temperature detection circuit, a boost excitation pulse circuit, and a signal processing circuit. The processor, ESD protection circuit, temperature detection circuit, boost excitation pulse circuit, and signal processing circuit are connected in a stable and interference-resistant structure. The ultrasonic transducer 5 is connected to the boost excitation pulse circuit and the signal processing circuit.
[0040] The voltage signal from the controller is boosted by the excitation pulse circuit and sent to the ultrasonic transducer 5. The voltage signal received by the ultrasonic transducer 5 is then processed by the signal processing circuit, the processor, and the electrostatic discharge protection circuit before reaching the user interface.
[0041] The boost excitation pulse circuit boosts the 5V voltage signal from the controller to the ultrasonic transducer 5 to the required excitation voltage of 110V. By increasing the excitation voltage, the ultrasonic transducer 5 emits louder sound waves, increasing the communication distance and enabling the signal to effectively radiate to over 25 meters. The boost excitation pulse circuit uses existing technology.
[0042] The processor is responsible for encoding the data signal sent from the controller to the ultrasonic transducer 5. The original format is 8-bit data, and the encoded format is frame header + 8-bit data + 4-bit checksum. The processor also decodes the signal received from the ultrasonic transducer 5 after processing by the signal processing circuit. The original format is frame header + 8-bit data + 4-bit checksum, and the decoded format is 8-bit data. This decoded signal is then sent to the controller. The processor is also responsible for coordinating the operation of various circuits to achieve stable communication. The processor uses existing technology.
[0043] The signal processing circuit amplifies and demodulates (decodes) the sinusoidal analog voltage signal received from the ultrasonic transducer 5, restores the envelope signal, and sends it to the processor.
[0044] The signal processing circuit has three stages of amplifier circuits connected in series. The first stage amplifier circuit, the second stage amplifier circuit, and the third stage amplifier circuit are respectively connected to the processor through their respective envelope detection circuits.
[0045] The first-stage amplifier circuit has a gain of 30–50 dB, the second-stage amplifier circuit has a gain of 10–20 dB, and the third-stage amplifier circuit has a gain of 10–20 dB. The envelope detector circuit is used to demodulate the amplified signal and then output it to the processor for decoding.
[0046] Each stage of the signal amplification circuit inputs the amplified signal to the processor via an envelope detector circuit. The processor simultaneously decodes the three input signals with different amplification factors. Communication can be completed as long as one of the three signal stages is successfully decoded. The first, second, and third stage amplification circuits and the envelope detector circuit use existing amplification and envelope detector circuit technologies.
[0047] This invention increases the communication distance to over 25 meters by improving the excitation voltage and using a multi-stage amplification circuit. The multi-stage amplification circuit enhances the module's communication stability and anti-interference capabilities, while also ensuring compatibility with swimming pools of varying sizes.
[0048] Electrostatic discharge (ESD) protection circuits are used to prevent damage to module circuits caused by electrostatic discharge. These ESD protection circuits utilize existing technology.
[0049] Temperature detection circuits are used to detect the current ambient temperature, such as water temperature, using existing technology.
[0050] like Figure 7 As shown, the communication lead 3 is connected to the main board 4 of the circuit with end leads at the tail end. The end leads include a positive power input lead 21, a power ground lead 22, a Universal Serial Data Bus (UART) communication input lead 23, a UART communication output lead 24, and a positioning synchronization lead 25. The end leads at the tail end of the communication lead 3 are used for wired connection with the base station 11.
[0051] like Figure 6 As shown, the positioning synchronization leads 25 of the two modules are connected in parallel to form a positioning module, which is installed inside the pool cleaning robot. A third module is connected to the base station 11 set on the shore via a communication lead 3, forming the positioning and correction device for the pool cleaning robot. Utilizing the transmission time of ultrasonic signals in water, the processor of the positioning module can determine the distance of each of the two modules from the base station and calculate the offset angle between the positioning module and the base station. The pool cleaning robot can adjust its direction according to the offset angle to align its forward direction with the base station, thereby achieving the positioning and correction functions.
[0052] The working process of this utility model is as follows:
[0053] 1. The module is powered on, supplying power to each circuit; 2. The user host sends the data to be transmitted to the transmitting module through base station 11 according to the communication protocol;
[0054] 3. After receiving data from the user interface, the transmitting module encodes the data into an underwater acoustic communication data format through the processor;
[0055] 4. The boost excitation pulse circuit of the transmitting module modulates the transmitted signal according to the data format, and then transmits the signal in a data shift manner through the ultrasonic transducer to complete the transmission process;
[0056] 5. The receiving module waits for the arrival of underwater acoustic data;
[0057] 6. The ultrasonic transducer of the receiving module receives the ultrasonic signal;
[0058] 7. The ultrasonic signal is converted into an electrical signal by the transducer, processed by the signal processing circuit, and then transmitted to the processor for decoding;
[0059] 8. If the decoded underwater acoustic data matches the agreed data format, decoding is successful. Otherwise, decoding fails. If it is communication data, execute step 1; if it is confirmation data, execute step 12.
[0060] 9. The module acquires its current temperature via a temperature acquisition circuit;
[0061] 10. The receiving module sends the received underwater acoustic data to the user host through the base station 11, and then executes step 11;
[0062] 11. The receiving module sends an acknowledgment to the sending module. At this point, the receiving end becomes the sending end, and the sending end becomes the receiving end. Then, return to step 4 to begin execution.
[0063] 12. Complete the process of transmitting and receiving underwater acoustic data.
[0064] Application scenario 1, such as Figure 4 As shown, in a two-way underwater acoustic communication application, one module 14 is installed in the base station 11, and another module 14 is installed in the pool cleaning robot 13 in the pool water 2. The base station is used to relay data or instructions sent by the operator on shore to the two-way underwater acoustic communication module. The module packages the data into underwater acoustic data according to a specified format and then sends it out. After receiving the ultrasonic signal, the two-way underwater acoustic communication module in the pool cleaning robot 13 decodes the ultrasonic signal. After successful decoding, it transmits the data to the pool cleaning robot and sends back an acknowledgment to the base station, indicating that the data reception was successful. The robot then performs actions based on the received data. The base station 11 is existing technology and has a wireless communication module for wirelessly connecting and communicating with the user's host.
[0065] Application scenario 2, such as Figure 5 As shown, in implementing the positioning and return function, a base station 11 is deployed in the pool. Two underwater acoustic communication modules 14 are horizontally aligned at the upper left and upper right corners directly in front of the pool cleaning robot 13, forming the return positioning function. One module 14 serves as the main module, and the other module 14 serves as the secondary module. When the return positioning is initiated, the main module is responsible for the return positioning and serial port data transmission and reception, while the secondary module assists the main module in completing the return positioning. After the return positioning is completed, the main module returns the positioning and return information. The pool cleaning robot adjusts its current course according to the positioning and return information to align with the base station, achieving route planning to return to the base station position with the shortest distance.
Claims
1. An underwater ultrasonic communication and positioning module, comprising a circuit board (4) and an ultrasonic transducer (5) connected to the circuit board (4), characterized in that: The circuit board (4) and the ultrasonic transducer (5) are set in the cavity of the sealed structure, and the cavity is filled with potting compound (2). A communication lead (3) is connected to the circuit board (4) and extends out of the cavity.
2. The underwater ultrasonic communication and positioning module according to claim 1, characterized in that: The cavity is a cylindrical sealed structure consisting of an outer shell body (6) and a rear cover (1).
3. The underwater ultrasonic communication and positioning module according to claim 2, characterized in that: The outer shell body (6) is cylindrical in shape with an opening at the top. In the middle of the cylindrical body, the wall of the outer shell body (6) tapers inward along the radial direction to form a step. The lower part of the outer shell body (6) is a cylinder smaller than the upper part.
4. The underwater ultrasonic communication and positioning module according to claim 3, characterized in that: The circuit board (4) is mounted on the step.
5. The underwater ultrasonic communication and positioning module according to claim 4, characterized in that: An ultrasonic transducer (5) is installed at the bottom of the cavity under the circuit motherboard (4).
6. The underwater ultrasonic communication and positioning module according to claim 5, characterized in that: The cavity is filled with potting compound (2) between the rear cover (1) and the circuit board (4), and between the circuit board (4) and the ultrasonic transducer (5).
7. The underwater ultrasonic communication and positioning module according to claim 6, characterized in that: The back cover (1) is installed on the outer shell body (6). The back cover (1) is disc-shaped and has a hole. The communication lead (3) extends out of the back cover (1).
8. The underwater ultrasonic communication and positioning module according to claim 7, characterized in that: The ultrasonic transducer (5) is made of piezoelectric ceramic.
9. The underwater ultrasonic communication and positioning module according to any one of claims 1 to 8, characterized in that: The communication lead (3) is provided with an end lead at its tail end, and the end lead is provided with a positioning synchronization lead (25).
10. The underwater ultrasonic communication and positioning module according to claim 9, characterized in that: The positioning synchronization leads (25) of the two underwater ultrasonic communication and positioning modules are connected in parallel to form a positioning module, which is installed in the pool cleaning robot. The communication lead (3) of the third underwater ultrasonic communication and positioning module is connected to the base station set on the shore to form a positioning and correction device for the pool cleaning robot.