An AIS-SART-based positioning lifebuoy and its control method

Abstract

The present invention relates to a positioning lifebuoy based on AIS-SART and its control method. After meeting the activation conditions, it performs the following operations: obtaining the longitude and latitude information of the positioning lifebuoy to obtain AIS message data and sending it on an idle AIS channel; in response to receiving AIS data from an external sending source, parsing to obtain the longitude and latitude information, speed information, and course angle information of the sending source; calculating the lifebuoy-sending source distance based on the longitude and latitude information of the sending source and the longitude and latitude information of the lifebuoy; updating the trigger threshold based on the speed information and course angle information of the sending source; determining whether the trigger condition is met based on the lifebuoy-sending source distance and the trigger threshold. If so, triggering the on-lifebuoy integrated sound, light, and smoke device to work. If not, updating the lifebuoy-sending source distance and / or the trigger threshold. The present invention fully considers the positions and navigation information of each sending source close to the swimming ring and decides whether to activate the on-lifebuoy device, thereby increasing the probability of a person falling into the water being discovered.

Description

Technical Field

[0001] The present invention relates to the technical field of marine lifesaving equipment, and in particular to an AIS-SART-based positioning lifebuoy and a control method thereof. Background Art

[0002] In the field of maritime safety, timely rescue of people after they fall into the water is a key link in ensuring life safety. According to authoritative water rescue data statistics, the golden time for water rescue is only 5 minutes. Implementing effective rescue within this time period can greatly increase the chances of survival of people who fall into the water. However, due to the complex weather conditions at sea, severe winds and waves, and the vast water environment, the traditional search and rescue mode faces great challenges in determining the location of distressed ships and survivors. In existing technologies, search and rescue operations often rely on active searches by search and rescue personnel, or positioning through manual signals sent by people in distress, but such methods are extremely inefficient in severe sea conditions, and often lead to rescue delays due to untimely positioning, resulting in serious loss of life and property.

[0003] Chinese patent application publication number CN105197201A discloses a trigger-based, position-based, and launch-based lifesaving device and method. By integrating a radar and anemometer between a waterproof watch and a shore-based lifesaving box, the device automatically adjusts the launch tube angle and launch force, enabling rapid and precise location-based rescue of drowning victims. This addresses the difficulty of efficient rescue efforts in existing lifesaving devices and improves both efficiency and accuracy. However, this solution relies on a shore-based launch module to launch the lifesaving box toward the person, making it unsuitable for use in maritime environments. Even if deployed on a ship, accurately launching the lifesaving box from a moving vessel poses a complex and pressing challenge.

[0004] In summary, there is currently a lack of a lifebuoy for marine rescue scenarios to solve or partially solve the above-mentioned problems. Summary of the Invention

[0005] The purpose of the present invention is to overcome the defects of the above-mentioned prior art and provide a positioning lifebuoy and a control method thereof based on AIS-SART, so as to solve or partially solve the problems that people using lifebuoys in marine environments are difficult to be found, even if positioning information can be sent, they may still not be found due to environmental reasons, are limited by power and smoke-generating materials, and cannot determine the best start-up time of the lifebuoy.

[0006] The purpose of the present invention can be achieved by the following technical solutions:

[0007] One aspect of the present invention provides a method for controlling a positioning lifebuoy based on AIS-SART, which executes the following steps in response to satisfying preset water pressure and / or infrared activation conditions:

[0008] Obtain the longitude and latitude information of the positioning lifebuoy, process it to obtain AIS message data, and send it on an idle AIS channel;

[0009] In response to receiving AIS data from one or more external transmission sources, obtain the longitude and latitude information, speed information, and course angle information of the transmission source through parsing;

[0010] Calculate the lifebuoy-transmission source distance based on the longitude and latitude information of the transmission source and the longitude and latitude information of the lifebuoy;

[0011] Update the trigger threshold based on the speed information and course angle information of the transmission source;

[0012] Determine whether the trigger condition is met based on the lifebuoy-transmission source distance and the trigger threshold. If so, trigger the on-board sound, light, and smoke integrated device to work. If not, update the lifebuoy-transmission source distance and / or the trigger threshold, and repeat this step.

[0013] The trigger threshold is updated using the following formula:

[0014]

[0015]

[0016] where, is the updated trigger threshold, is the preset trigger threshold, is the dynamic adjustment coefficient, is the speed of the transmission source, is the reference speed, is the basic coefficient, is the course change rate of the transmission source, is the acceleration of the transmission source, 、 are the weights.

[0017] As a preferred technical solution, the lifebuoy-transmission source distance is calculated using the following formula:

[0018]

[0019]

[0020]

[0021]

[0022]

[0023] where, is the longitude and latitude of the lifebuoy, is the longitude and latitude of the sending source, is the radius of the earth, is the distance between the lifebuoy and the sending source.

[0024] As a preferred technical solution, when the positioning lifebuoy is in an active state and satisfies any of the following conditions, the trigger judgment is paused within a preset time:

[0025] The deviation angle of the sending source heading is greater than the threshold, and the heading change rate is greater than the threshold;

[0026] The acceleration of the sending source is greater than the threshold.

[0027] As a preferred technical solution, the process of triggering the work of the sound, light, and smoke integrated device on the lifebuoy includes the following steps:

[0028] By obtaining the light intensity data, determine whether it is day or night currently;

[0029] In response to the current being daytime, trigger the smoke generating device to work and emit orange-yellow smoke;

[0030] In response to the current being night, trigger the light-emitting strip to emit red light;

[0031] Trigger the buzzer to work and emit a beeping sound.

[0032] As a preferred technical solution, the trigger condition is that the distance between the lifebuoy and the sending source is less than or equal to the trigger threshold and the duration exceeds the threshold.

[0033] Another aspect of the present invention provides a positioning lifebuoy based on AIS-SART for implementing the foregoing control method. The positioning lifebuoy includes a lifebuoy body formed of a low dielectric constant foam material and a single-chip microcomputer system provided on the lifebuoy body. The single-chip microcomputer system includes:

[0034] A water pressure / infrared data acquisition circuit, including a water pressure sensor and an infrared sensing module;

[0035] A positioning and communication circuit, including a GNSS module and an AIS transmitter / receiver;

[0036] A light-emitting element circuit, including a light-emitting strip, a photosensitive sensor, and a core / auxiliary power supply unit;

[0037] A sound-emitting element circuit, including a buzzer;

[0038] A smoke-emitting element circuit, including a solenoid valve and an orange smoke generating device.

[0039] As a preferred technical solution, the positioning and communication circuit includes:

[0040] A GNSS module, connected to the single-chip microcomputer module, is used to obtain GNSS positioning data in response to a driving signal;

[0041] An inertial navigation module is used to obtain the longitude and latitude information of the positioning lifebuoy based on the GNSS positioning data;

[0042] A Kalman filter calibration and inertial data calculation module is used to perform Kalman filter calibration on the longitude and latitude information of the positioning lifebuoy under good signal conditions, and perform inertial data calculation on the longitude and latitude information in case of signal loss;

[0043] A communication processor module is used to perform compression, encryption, and differential coding on the processed longitude and latitude information of the positioning lifebuoy to obtain AIS message data;

[0044] An AIS transmitter is used to generate an AIS data packet based on the AIS message data and send it on a preset AIS channel through an FPC antenna;

[0045] An AIS receiver is used to receive AIS data from an external transmission source and perform CRC-32 verification. When the verification fails, it triggers a request for retransmission. When the verification is successful, it is transmitted to the single-chip microcomputer module through an optocoupler isolator and an RC low-pass filter.

[0046] As a preferred technical solution, it further includes an annular buckle connected to the lifebuoy body.

[0047] Another aspect of the present invention provides an electronic device, characterized in that it includes one or more processors, a memory, and one or more programs stored in the memory. The one or more programs include instructions for executing the foregoing control method of the AIS-SART-based positioning lifebuoy.

[0048] Compared with the prior art, the present invention has at least one of the following beneficial effects:

[0049] (1) Realize timely positioning of fallen personnel in a maritime environment: The present invention obtains the longitude and latitude information of the positioning lifebuoy, processes it to obtain AIS message data, and sends it on a preset AIS channel, enabling rapid acquisition of position information and continuous external broadcasting, thus greatly shortening the rescue response time.

[0050] (2) Increase the probability of fallen personnel being discovered: The present invention is provided with an on-ring sound, light, and smoke integrated device on the swimming ring, which enables the fallen person to be more easily discovered by other ships and increases the probability of the fallen person being rescued.

[0051] (3) Fully consider the positions and navigation information of each transmission source near the lifebuoy, and decide whether to activate the on-buoy integrated sound, light, and smoke device: Considering the limitations of electric energy and smoke-generating materials, the person falling into the water tends to immediately activate the on-buoy integrated sound, light, and smoke device due to panic. This easily leads to the inability of the on-buoy integrated sound, light, and smoke device to continue working when the rescue ship arrives, affecting the search and rescue of the person falling into the water. The present invention dynamically updates the trigger threshold based on the speed information and course angle information of the transmission source, and then combines the distance between the lifebuoy and the transmission source to determine whether to trigger the on-buoy integrated sound, light, and smoke device to work. By dynamically updating the trigger threshold, it is possible to fully consider whether the course and speed of nearby ships (i.e., transmission sources) are likely to discover the person falling into the water, and trigger the on-buoy integrated sound, light, and smoke device to work at an appropriate time, thereby increasing the probability of the person falling into the water being discovered.

[0052] (4) Long battery life: Considering that when the probability of the transmission source discovering the person falling into the water is small due to mismatched course and speed, the present invention pauses the trigger judgment within a preset time to determine whether the trigger condition is met, which can extend the battery life. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] Figure 1 It is a flowchart of the control method of the positioning lifebuoy based on AIS-SART in the embodiment;

[0054] Figure 2 It is a perspective view of the positioning lifebuoy based on AIS-SART in the embodiment;

[0055] Figure 3 It is a front view of the positioning lifebuoy based on AIS-SART in the embodiment;

[0056] Figure 4 It is a left side view of the positioning lifebuoy based on AIS-SART in the embodiment;

[0057] Figure 5 It is a top view of the positioning lifebuoy based on AIS-SART in the embodiment;

[0058] Figure 6 It is a bottom view of the positioning lifebuoy based on AIS-SART in the embodiment;

[0059] Figure 7 It is an axial sectional perspective view of the positioning lifebuoy based on AIS-SART in the embodiment;

[0060] Figure 8 It is an axial sectional top view of the positioning lifebuoy based on AIS-SART in the embodiment;

[0061] Figure 9 It is a schematic diagram of the single-chip microcomputer system carried by the positioning lifebuoy based on AIS-SART in the embodiment;

[0062] Figure 10 It is a schematic diagram of an electronic device in the embodiment.

[0063] Among them, 1. Lifebuoy body, 2. Ring buckle, 3. Whistle, 4. Light-emitting strip, 5. Orange smoke generating device, 6. GNSS module, 7. AIS transmitter and receiver, 8. Communication processor module, 9. Power supply unit, 10. Microcontroller module. Specific implementation manner

[0064] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0065] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship when the practical invention is usually placed. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation to the present invention. For example, "horizontal" only means that its direction is more horizontal relative to "vertical", and does not mean that the structure must be completely horizontal, but can be slightly inclined.

[0066] In addition, the terms "first" and "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of this application, "a plurality" means two or more, unless otherwise specifically defined.

[0067] Embodiment 1

[0068] In view of the problems existing in the foregoing prior art, this embodiment provides a control method for a positioning lifebuoy based on AIS-SART, aiming to make a decision on whether to activate the on-ring sound, light, and smoke integrated device by fully considering the positions and navigation information of each transmission source close to the swimming ring, and trigger the on-ring sound, light, and smoke integrated device to work at an appropriate time, thereby increasing the probability of a drowning person being discovered.

[0069] See Figure 1 , the method mainly includes the following steps:

[0070] Step S1, meet the preset water pressure and / or infrared activation conditions.

[0071] After a person falls into the water at sea, the person grabs the life buoy. Through a dual activation mechanism of a water pressure sensor and an infrared sensing module (a ToF ranging sensor can be used), when the water depth > 0.5 m for 10 seconds, it is determined that the person has fallen into the water, and the device is automatically activated. If the water pressure trigger fails, when a human body is detected to be approaching, such as when the distance is less than 1 m, it is forcibly activated to ensure that the device can still be started after the person falling into the water loses physical strength and consciousness and falls into a coma.

[0072] The sensor signal is converted into a digital signal by the ADC signal processing module and input into the single-chip microcomputer. Then, the GNSS module is started to start obtaining position data in real time, and the LED indicator starts to flash green light.

[0073] Step S2, obtain the longitude and latitude information of the positioning life buoy, process it to obtain AIS message data, and send it on the preset AIS channel.

[0074] The inertial navigation module obtains the GNSS position information and transmits it to the communication processor module. The latter compresses, encrypts, and encapsulates the position information into the AIS message format, coordinates the AIS channel switching, signal priority allocation, and data retransmission mechanisms, and uses the AIS transmitter to transmit the distress message to other ships and shore station receiving terminals through two international AIS channels, AIS1 and AIS2.

[0075] When selecting a channel, the channel detection module scans the channel occupancy rates of AIS1 (161.975 MHz) and AIS2 (162.025 MHz) in real time. If the signal strength of the current channel > 80%, it automatically jumps to an idle channel to achieve flexible frequency band switching. If an AIS-SART signal in the same frequency band is detected, the transmission is automatically delayed to avoid channel congestion. The sent message can be received and displayed by rescue units within the coverage area. The rescue units can clearly distinguish AIS-SART from other AIS facilities to ensure that the position information of the person falling into the water can be transmitted to the rescue unit in time.

[0076] Step S3, in response to receiving AIS data from one or more external sending sources, obtain the longitude and latitude information, speed information, and heading angle information of the sending source by parsing.

[0077] The rescue unit sees the AIS-SART icon on the AIS terminal display, quickly locates and starts the rescue with the help of a nautical chart, and at the same time turns on its own AIS transmission to send relevant AIS data to achieve two-way perception between the person falling into the water and the rescue unit.

[0078] Step S4, based on the longitude and latitude information of the sending source and the longitude and latitude information of the life buoy, calculate the distance between the life buoy and the sending source.

[0079] During the rescue process, the AIS receiver receives AIS information from rescue vessels and nearby vessels, i.e., the sending sources, parses information such as their MMSI, longitude and latitude, speed, and heading. The longitude and latitude coordinates of the person in the water are obtained in real time through the GNSS module. The AIS data and GNSS data are input into the single-chip microcomputer through the serial port to calculate the great circle distance between the two points. All received vessel AIS data are traversed every 5 seconds, and the distance between each of them and the person in the water is calculated one by one. If the distance of any vessel ≤ the preset value, it is marked as a trigger candidate. The system stability is enhanced through a debounce mechanism. The trigger candidate needs to continuously meet the conditions for 10 seconds to avoid false triggering caused by a short-term approach. For the processing of multiple vessels, only the nearest vessel or the closest vessel is judged for triggering.

[0080] The distance between the lifebuoy and the sending source is calculated using the following formula:

[0081]

[0082]

[0083]

[0084]

[0085]

[0086] Where, is the longitude and latitude of the lifebuoy, is the longitude and latitude of the sending source, is the radius of the earth, is the distance between the lifebuoy and the sending source.

[0087] Step S5, update the trigger threshold based on the speed information and heading angle information of the sending source.

[0088] The preset trigger distance is 2 nautical miles, and dynamic threshold adjustment is performed. Combining the course change rate / s and the acceleration kn / s, the formula is expressed as follows:

[0089]

[0090] Where, the dynamic adjustment coefficient is defined as:

[0091]

[0092] is the basic coefficient, which is taken as 0.05 in this embodiment, is the course change rate weight, which is taken as 0.02 in this embodiment, is the acceleration weight, which is taken as 0.03 in this embodiment, The reference speed is 10 knots in this embodiment.

[0093] During the judgment, if any of the following conditions is met, the trigger judgment is suspended and reset after 5 seconds:

[0094] (1) The course deviation angle Δθ > 30° and the course change rate ∣ω∣ > 5° / s;

[0095] (2) The ship acceleration ∣a∣ > 2 kn / s.

[0096] When the distance between the lifebuoy and the sending source ≤ the dynamic threshold for 10 seconds, the solenoid valve is activated, and emergency manual triggering is also supported.

[0097] Step S6: Based on the distance between the lifebuoy and the sending source and the trigger threshold, determine whether the trigger condition is met. If so, trigger the operation of the on-lifebuoy integrated sound, light, and smoke device; if not, update the distance between the lifebuoy and the sending source and / or the trigger threshold.

[0098] The single-chip microcomputer is connected to the solenoid valve drive circuit through the digital output port. The trigger signal drives the solenoid valve, which in turn ignites the orange smoke device or triggers the fluorescent strobing.

[0099] Orange smoke or LED strobing is emitted. During the day, after the orange smoke device is activated, obvious orange smoke signals are continuously volatilized; at night, after the fluorescent strobing device is activated, dazzling red light is emitted. Regardless of day or night, the buzzer will emit a beeping sound along with the triggering of the orange smoke or strobing device to attract the attention of rescue personnel to the greatest extent and quickly rescue the fallen personnel.

[0100] Embodiment 2 [[ID=2,6]]

[0101] Based on Embodiment 1, this embodiment provides a positioning lifebuoy based on AIS-SART to implement the method of Embodiment 1. The positioning lifebuoy includes a lifebuoy body 1 and a single-chip microcomputer system built in the internal cavity of the lifebuoy body 1.

[0102] See Figures 2 - 8 , at least one annular buckle 2 is connected to the outside of the lifebuoy body 1. Preferably, it includes two oppositely arranged annular buckles. When a large number of people fall into the water, they can be connected to each other through the external annular buckles to achieve aggregation, increase the rescue target, reduce the rescue difficulty, and keep warm with each other, greatly improving the survival rate. In addition, a warning whistle 3 is also connected to the lifebuoy body 1.

[0103] See Figure 9 , the single-chip microcomputer system mainly includes a single-chip microcomputer module, and a water pressure / infrared data acquisition circuit, a light-emitting element circuit, a sound-emitting element circuit, a smoke-emitting element circuit, and a positioning and communication circuit respectively connected to the single-chip microcomputer module. Each part will be described separately below.

[0104] 1. Water pressure / infrared data acquisition circuit.

[0105] It mainly includes a water pressure sensor, an infrared sensing module, and an ADC signal processing module. In this embodiment, the infrared sensing module is implemented by a ToF ranging sensor.

[0106] After a person falls into the water at sea, the person grabs the lifebuoy. Through the dual activation mechanism of the water pressure sensor and the infrared sensing module, when the water depth > 0.5m for 10 seconds, it is determined that the person has fallen into the water, and the device is automatically started. If the water pressure trigger fails, when a human body is detected to be approaching (i.e., < 1m), it is forcibly activated to ensure that the device can still be started after the person falling into the water loses physical strength and consciousness and falls into a coma.

[0107] The sensor signal is converted into a digital signal by the ADC signal processing module and input into the single-chip microcomputer, and then the positioning and communication circuit is started to start acquiring position data in real time, and the LED indicator starts to flash green light.

[0108] 2. Positioning and communication circuit.

[0109] The positioning and communication circuit mainly includes an electronic positioning module for positioning, which is implemented by a GNSS module, and a navigation inertial module, a communication processor module, an AIS transmitter, an FPC antenna, an AIS receiver, an optocoupler isolator, and an RC low-pass filter for sending life-saving information.

[0110] (1) AIS transmitter and receiver.

[0111] The AIS transmitter transmits a message indicating the identification, position, and safety text information of the distress target through the AIS system. The AIS receiver, as a receiving device, can receive the AIS data of the rescue ship from the AIS system and transmit its position information to the single-chip microcomputer. These devices communicate using the VHF band and have good anti-interference ability to ensure effective operation in complex environments. In addition, the device adopts an automatic update mechanism to ensure the accuracy and timeliness of the information.

[0112] (2) Electronic positioning module.

[0113] The electronic positioning module of this embodiment is implemented by a GNSS module, including a low-cost multi-mode GNSS chip, supporting GPS L1 / L5, Beidou B1 / B2, GLONASS L1 / L2, and Galileo E1 / E5 frequency bands, and increasing the number of visible satellites through multi-system combined positioning. Utilize the strong signal penetration characteristics of the L5 / B2 / E5 high-frequency bands to reduce the influence of occlusion by foliage, buildings, etc.

[0114] (3) Inertial navigation module (INS).

[0115] The inertial navigation module forms a nine-degree-of-freedom inertial navigation unit by integrating a six-axis MEMS inertial sensor and a barometer. The module first judges the GNSS signal quality. When the GNSS signal is available, it calibrates the INS error in real time through Kalman filtering; when the GNSS signal is lost, it calculates the short-term displacement based on inertial data. It automatically adjusts the sensitivity of the AIS receiver according to the signal strength, adopting the conventional reception mode in an open environment and the high-sensitivity mode in an occluded environment to capture weak signals. During the transmission of the AIS transmitter, the GNSS module is turned off, and only the INS and the barometer are maintained to operate with low power consumption. Specifically, the data fusion process includes the following steps:

[0116] Step 1, the GNSS outputs real-time latitude, longitude, speed, and time (PVT) data;

[0117] Step 2, the INS calculates the displacement increment through the accelerometer and gyroscope data;

[0118] Step 3, the Kalman filter fuses the GNSS and INS data and outputs jitter-resistant position information;

[0119] Step 4, when the signal is lost, it switches to the INS calculation mode and activates the high-sensitivity GNSS scan.

[0120] Finally, this electronic positioning module can increase the number of visible multi-mode GNSS satellites at low cost, maintain sub-meter-level positioning for a period of time after the signal is lost under the assistance of INS, and can provide real-time and accurate position information under various climate conditions. It is transmitted through the AIS transmitter to ensure that the rescue unit can quickly discover the position of the person falling into the water.

[0121] (4) Communication processor module.

[0122] The communication processor encodes the acquired position information using differential coding, compresses the AIS message length from 256 bytes to 80 bytes, reduces the transmission time and energy consumption, and broadcasts it through the AIS channel to ensure that the information can cover a wide area.

[0123] The processor has data compression and encryption functions to ensure information security and prevent information from being tampered with or lost during transmission. In addition, the processor enhances the stability and reliability of the system through hybrid redundancy design. In the hardware part, a single-processor dual-core architecture is adopted. The main core processes encoding and communication, and the standby core synchronizes the status in real time and monitors the heartbeat of the main core. In the software part, the same message is alternately sent through AIS1 and AIS2 channels and retransmitted with the help of CRC-32 check. At the sending end, the CRC-32 check value of the data is calculated and appended to the end of the data packet. After reaching the receiving end, the CRC-32 check value is recalculated. If the CRC calculated at the receiving end is the same as that in the data packet, it is confirmed that the data is complete and an acknowledgment (ACK) is returned. If they are inconsistent, it is determined that the data is damaged, a negative acknowledgment (NACK) is returned, and a retransmission is requested. If no ACK / NACK response is received, the sending end automatically retransmits after 5 seconds. After the automatic retransmission is triggered, the maximum number of retries is 3 times to avoid channel congestion caused by infinite retransmission, and finally the complete transmission of AIS data is achieved.

[0124] The communication processor module integrates functions such as data encoding, redundancy design, and communication management, realizing efficient, secure, and robust transmission of maritime distress messages.

[0125] (5)FPC antenna.

[0126] The overall material of the lifebuoy is made of low-dielectric-constant foam material, such as foamed polypropylene, which has extremely low attenuation of electromagnetic waves in the VHF band. The area of 50cm×10cm on the outer shell of the lifebuoy corresponding to the antenna radiation direction is replaced with electromagnetic transparent material, such as polycarbonate (PC) coating.

[0127] An independent sealed cabin is set inside the lifebuoy as the antenna cabin for centrally installing the antenna and supporting circuits. The outer layer of the cabin is coated with polycarbonate (PC) to reduce signal reflection, and the inside is filled with low-dielectric foam.

[0128] The main body of the antenna adopts a serpentine-wire flexible inverted-F antenna (FPC). By increasing the equivalent electrical length, it matches the VHF band. The end is loaded with a patch capacitor to compensate for the low-frequency reactance. It can cooperate with the electromagnetic transparent window to meet the transmission power requirements of the AIS transmitter. The width of the radiation arm is 3mm, the spacing is 2mm, and the bending angle is 90°, realizing a compact layout. The antenna is fixed on the inner wall of the cabin, facing the PC coating window, covering the AIS dual band. The antenna includes a π-type matching network of series 22nH inductor - parallel 12pF capacitor - series 15nH inductor, integrated at the feeding point. The measured frequency band covers 161 - 162MHz, VSWR < 1.5, and the bandwidth ≥ 200kHz. Through slotted loading, it is compatible with multiple GNSS frequency bands and supports dual functions of positioning and communication. A tapered microstrip line is used to achieve broadband impedance matching.

[0129] Lay a copper foil grounding plane under the antenna, and connect it to the antenna grounding layer through a gold-plated spring contact. The antenna grounding layer is also connected to the internal metal frame of the lifebuoy through conductive glue, and redundant grounding enhances stability. The antenna is fixed to the inner wall of the lifebuoy by a silica gel pressure strip to prevent it from falling off due to high-frequency vibration.

[0130] 3. The single-chip microcomputer module and the smoke-generating element circuit.

[0131] The smoke-generating element circuit is implemented based on an orange smoke device, and its architecture is: AIS receiver, optocoupler isolator, RC low-pass filter, single-chip microcomputer, actuator, and trigger of the orange smoke device. The specific function implementation is as follows:

[0132] The AIS receiver receives AIS data of rescue ships and nearby ships (i.e., the sending source) through the AIS system.

[0133] The optocoupler isolator is used to suppress noise and surge interference, and the RC low-pass filter is used to eliminate high-frequency interference.

[0134] The integrated single-chip microcomputer is designed with a 4-layer board, with a size of 30mm × 25mm × 1.6mm. The top layer is for signal routing, the first inner layer is the 3.3V power plane, the second inner layer is the grounding plane, and the bottom layer is the solenoid valve drive circuit and interface.

[0135] The input of the single-chip microcomputer module is the AIS position, speed, course angle, etc. of the rescue ship from the AIS receiver and the position data of the person falling into the water from the GNSS. The real-time distance between the two is calculated using the following formula:

[0136]

[0137]

[0138]

[0139]

[0140]

[0141] where is the latitude and longitude of the lifebuoy, is the latitude and longitude of the sending source, is the radius of the earth, about 6371 km, is the distance between the lifebuoy and the sending source.

[0142] When the distance between the sending source and the person falling into the water (i.e., the lifebuoy) meets the dynamic threshold, a trigger signal is generated to trigger the on-board smoke / luminescence / sound device of the lifebuoy to work. The preset trigger distance is 2 nautical miles, combined with the course change rate / s and the acceleration Perform dynamic threshold adjustment at kn / s as follows:

[0143]

[0144] Among them, the dynamic adjustment coefficient is defined as:

[0145]

[0146] is the base coefficient, which is taken as 0.05 in this embodiment, is the heading change rate weight, which is taken as 0.02 in this embodiment, is the acceleration weight, which is taken as 0.03 in this embodiment, is the reference speed, which is taken as 10 knots in this embodiment.

[0147] In the judgment, if any of the following conditions is met, suspend the trigger judgment and reset it after 5 seconds:

[0148] (1) The heading deviation angle Δθ > 30° and the heading change rate ∣ω∣ > 5° / s;

[0149] (2) The ship acceleration ∣a∣ > 2 kn / s.

[0150] Specifically, when the distance ≤ the dynamic threshold for 10 seconds, activate the solenoid valve. At the same time, it supports emergency manual triggering. Specifically, through the integrated waterproof button, long press for more than 3 seconds to activate the emergency mode and quickly manually trigger. The trigger circle activates the smoke-emitting / luminous / sounding device to work simultaneously to ensure the stability and reliability of the system.

[0151] The actuator connects the switch of the orange smoke device with the mechanical firing device of the solenoid valve. After generating a trigger signal, it judges whether it is day or night. The single-chip microcomputer drives the solenoid valve by outputting a 24V / 1A pulse signal, releases the mechanical firing structure to ignite the orange smoke during the day, and triggers the luminous element circuit to enter the stroboscopic mode at night. Regardless of day or night, the PWM signal output by the single-chip microcomputer will drive the buzzer to emit a beeping sound to help rescuers quickly locate the person who has fallen into the water.

[0152] 4. Luminous element circuit.

[0153] It mainly includes a photosensitive sensor for judging whether it is day or night, a lithium thionyl chloride battery for core power supply, and a flexible solar panel for auxiliary power supply, as a power supply unit, and a luminous strip. The luminous strip has a stroboscopic mode, an indicator mode, and a constant-on mode. It enters the indicator mode after detecting a person falling into the water to indicate the start of work, and enters the stroboscopic mode after generating a trigger signal.

[0154] Specifically, the core power supply uses two lithium thionyl chloride batteries in parallel, with a total capacity of 38000 mAh (136.8 Wh). After startup, the battery can provide a 136-hour endurance and is integrated on the side of the lifebuoy. At the same time, a flexible solar panel is used as an auxiliary power supply to extend the endurance. On sunny days, it can supplement about 15 Wh of energy per day. A priority power supply design is adopted: AIS transmitter > GNSS module > sensor module > orange smoke module. When the voltage is lower than 2.8V, non-core devices are cut off, and only the AIS transmission is retained for over-discharge protection. This battery module can achieve long endurance and high-reliability power supply within the effective space of the lifebuoy to adapt to harsh sea weather and extend the waiting time for rescued personnel in the water.

[0155] The luminous light strip uses a silicone-encapsulated LED light strip. The LEDs are configured with a constant-on mode, a strobe mode, and an indicator mode. The constant-on mode emits yellow light, the strobe mode adds red LEDs, and the indicator mode adds green LEDs. A photosensitive sensor is installed on the surface of the lifebuoy to sense changes in external light intensity. The power supply supports dual-mode low-power operation of the fluorescent strip's constant-on and strobe modes through boost conversion and pulse energy distribution. After the device is activated and the GNSS starts to obtain real-time position data, the indicator light flashes green, and the LED brightness is 10%. When the illuminance is <10 Lux, the fluorescent strip starts to glow constantly, and the LED brightness is 30%. When a rescue ship approaches, it is forced to switch to the strobe mode, and the LED emits pulses at 100% brightness. The LED light strip is circumferentially distributed on the outer surface of the lifebuoy, with a total length of 2 meters, a width of 5 cm, and a slot depth of 2 mm. After silicone potting, the surface is smooth.

[0156] 5. Sound-emitting component circuit

[0157] It mainly includes a buzzer module for emitting beeping sounds.

[0158] The buzzer module uses a piezoelectric buzzer with a volume ≥85 dB and a working frequency of 2 kHz - 4 kHz. The drive circuit is directly connected to the PWM output pin of the single-chip microcomputer. When a rescue ship enters the preset distance, the PWM signal activates the buzzer to emit a strong beeping sound. In summary, this application has the following characteristics:

[0159] (1) Strong real-time performance: It can quickly obtain position information through the GNSS module and continuously broadcast it outward through two international AIS channels, AIS1 and AIS2, thus greatly shortening the rescue response time.

[0160] (2) Wide coverage: The application of AIS and dynamic channel switching enable the signal to cover most ships in the sea area, increasing the probability of successful rescue.

[0161] (3) Visual reminder: The orange smoke device provides obvious visual signals at night or in bad weather, greatly increasing the possibility of rescue success compared with single distress devices such as AIS-SART and ordinary life-saving equipment such as lifebuoys.

[0162] (4) Two-way perception: Through the innovative design from the AIS receiver to the orange smoke trigger, sea distance measurement and dynamic threshold adjustment are realized, and a two-way perception mechanism between the rescue unit and the person in distress is constructed.

[0163] Embodiment 3

[0164] Based on the foregoing embodiments, this embodiment provides an electronic device, including: one or more processors and a memory, where the memory stores one or more programs, and the one or more programs include instructions for executing the control method of the AIS-SART-based positioning lifebuoy as described in Embodiment 1.

[0165] As Figure 10 described, at the hardware level, the electronic device includes a processor, an internal bus, a network interface, a memory, and a non-volatile memory. Of course, it may also include other hardware required for other services. The processor reads the corresponding computer program from the non-volatile memory into the memory and then runs it to implement the above Figure 1 described method. Of course, in addition to the software implementation method, the present invention does not exclude other implementation methods, such as logic devices or a combination of software and hardware, etc. That is to say, the execution subject of the following processing flow is not limited to each logic unit, and can also be hardware or a logic device.

[0166] The memory may include non-permanent memory in a computer-readable medium, random access memory (RAM) and / or non-volatile memory in the form of, for example, read-only memory (ROM) or flash memory (flash RAM). The memory is an example of a computer-readable medium.

[0167] A computer-readable medium includes permanent and non-permanent, removable and non-removable media that can implement information storage by any method or technology. The information can be computer-readable instructions, data structures, program modules, or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, compact disc read-only memory (CD-ROM), digital versatile disc (DVD) or other optical storage, magnetic cassette tapes, disk storage or other magnetic storage devices, or any other non-transitory medium that can be used to store information that can be accessed by a computing device. As defined herein, a computer-readable medium does not include transitory computer-readable media, such as modulated data signals and carrier waves.

[0168] As described above, the above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention can easily think of various equivalent modifications or replacements, and these modifications or replacements should be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. A control method for a positioning lifebuoy based on AIS-SART, characterized in that, In response to meeting the preset water pressure and / or infrared activation conditions, perform the following steps: Obtain the longitude and latitude information of the positioning lifebuoy, process it to obtain AIS message data, and send it on an idle AIS channel; In response to receiving AIS data from one or more external transmission sources, parse the longitude and latitude information, speed information, and course angle information of the transmission source; Calculate the lifebuoy-transmission source distance based on the longitude and latitude information of the transmission source and the longitude and latitude information of the lifebuoy; Update the trigger threshold based on the speed information and course angle information of the transmission source; Based on the lifebuoy-transmission source distance and the trigger threshold, determine whether the trigger condition is met. If so, trigger the on-lifebuoy integrated sound, light, and smoke device to work. If not, update the lifebuoy-transmission source distance and / or the trigger threshold, and repeat this step. The trigger threshold is updated using the following formula: ， ， Among them, is the updated trigger threshold, is the preset trigger threshold, is the dynamic adjustment coefficient, is the speed of the sending source, is the reference speed, is the base coefficient, is the heading change rate of the sending source, is the acceleration of the sending source, 、 are weights.

2. The control method of a positioning lifebuoy based on AIS-SART according to claim 1, characterized in that, The lifebuoy-transmission source distance is calculated using the following formula: ， ， ， ， ， Among them, is the longitude and latitude of the lifebuoy, is the longitude and latitude of the sending source, is the radius of the earth, is the distance between the lifebuoy and the sending source.

3. The control method of a positioning lifebuoy based on AIS-SART according to claim 1, characterized in that, When the positioning lifebuoy is in the activated state and meets any of the following conditions, pause the trigger judgment within the preset time: The course deviation angle of the transmission source is greater than the threshold, and the course change rate is greater than the threshold; The acceleration of the transmission source is greater than the threshold.

4. The control method of a positioning lifebuoy based on AIS-SART according to claim 1, wherein The process of triggering the on-lifebuoy integrated sound, light, and smoke device to work includes the following steps: Judge whether it is day or night by obtaining the light intensity data; In response to it being day currently, trigger the smoke generating device to work and emit orange-yellow smoke; In response to it being night currently, trigger the light-emitting strip (4) to emit red light; Trigger the buzzer to work and emit a beeping sound.

5. The control method of a positioning lifebuoy based on AIS-SART according to claim 1, characterized in that, The trigger condition is that the lifebuoy-transmission source distance is less than or equal to the trigger threshold and the duration exceeds the threshold.

6. A positioning lifebuoy based on AIS-SART, characterized in that, For implementing the control method as described in any one of claims 1-5, the positioning lifebuoy includes a lifebuoy body (1) formed of a low dielectric constant foam material and a single-chip microcomputer system provided on the lifebuoy body (1). The single-chip microcomputer system includes components respectively connected to the single-chip microcomputer module (10): A water pressure / infrared data acquisition circuit, including a water pressure sensor and an infrared sensing module; A positioning and communication circuit, including a GNSS module (6) and an AIS transmitter / receiver; A light-emitting element circuit, including a light-emitting strip (4), a photosensitive sensor, and a core / auxiliary power supply unit; A sound-emitting element circuit, including a buzzer; A smoke-emitting element circuit, including a solenoid valve and an orange smoke generating device (5).

7. The positioning lifebuoy based on AIS-SART according to claim 6, characterized in that, The positioning and communication circuit includes: A GNSS module (6), connected to the single-chip microcomputer module (10), for obtaining GNSS positioning data in response to a drive signal; An inertial navigation module, for obtaining the longitude and latitude information of the positioning lifebuoy based on the GNSS positioning data; A Kalman filter calibration and inertial data calculation module, for performing Kalman filter calibration on the longitude and latitude information of the positioning lifebuoy when the signal is good, and performing inertial data calculation on the longitude and latitude information when the signal is lost; A communication processor module (8), for performing compression, encryption, and differential coding processing on the processed longitude and latitude information of the positioning lifebuoy to obtain AIS message data; An AIS transmitter is used to generate an AIS data packet based on AIS message data and transmit it on a preset AIS channel through an FPC antenna; An AIS receiver is used to receive AIS data from an external transmission source, perform CRC-32 verification. When the verification fails, it triggers a request for retransmission. When the verification is successful, it is transmitted to the single-chip microcomputer module (10) through an optocoupler isolator and an RC low-pass filter.

8. A positioning lifebuoy based on AIS-SART according to claim 6, characterized in that, It further includes an annular buckle (2) connected to the lifebuoy body (1).

9. An electronic device, characterized in that, It includes one or more processors, a memory, and one or more programs stored in the memory. The one or more programs include instructions for executing the control method of the AIS-SART-based positioning lifebuoy according to any one of claims 1-5.

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