Positioning life buoy based on AIS-SART and control method thereof

Abstract

The invention relates to a positioning life buoy based on AIS-SART and a control method thereof, after an activation condition is met, the following steps are executed: acquiring latitude and longitude information of the positioning life buoy, obtaining AIS telegraph text data, and sending the AIS telegraph text data on an idle AIS channel; responding to received AIS data of an external sending source, and obtaining longitude and latitude information, navigational speed information and course angle information of the sending source through analysis; calculating a life buoy-sending source distance based on the longitude and latitude information of the sending source and the longitude and latitude information of the life buoy; updating a trigger threshold value based on the navigational speed information and the course angle information of the sending source; and judging whether a triggering condition is met or not based on the life buoy-sending source distance and the triggering threshold value, if so, triggering the ring-loaded sound, light and cigarette integrated equipment to work, and if not, updating the life buoy-sending source distance and / or the triggering threshold value. According to the invention, the position and navigation information of each sending source close to the swim ring are fully considered, whether to start the ring loading equipment is decided, and the probability that drowning personnel are found is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of marine lifesaving equipment, and in particular to a positioning lifebuoy based on AIS-SART 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, the golden time for water rescue is only 5 minutes. Effective rescue during this period can greatly increase the chance of survival of people who fall into the water. However, due to the complex weather conditions at sea, severe winds and waves, and vast water environments, the traditional search and rescue mode faces great challenges in determining the location of distressed ships and survivors. In the existing technology, 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 rescue is often delayed due to untimely positioning, resulting in serious loss of life and property.

[0003] Chinese patent application publication number CN105197201A discloses a life-saving device and method for triggering positioning and launching, which automatically adjusts the angle and projection force of the launch tube by combining a radar and anemometer between a waterproof watch and a life-saving box on the shore, thereby realizing rapid and accurate positioning and rescue of drowning accident personnel, solving the problem that the life-saving device in the prior art is difficult to rescue efficiently, and improving the rescue efficiency and accuracy. However, its solution relies on the launch module on the shore to launch the life-saving box to the personnel, which is not suitable for the marine environment. Even if it is set on a ship, how to accurately launch from the moving ship to the personnel is also a complex problem that needs to be solved urgently.

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

[0006] The purpose of the present invention can be achieved by the following technical solutions: One aspect of the present invention provides a method for controlling a positioning lifebuoy based on AIS-SART, and in response to satisfying a preset water pressure and / or infrared activation condition, performs the following steps: Obtain the latitude and longitude information of the lifebuoy, obtain AIS message data through processing, and send it on an idle AIS channel; In response to receiving AIS data from one or more external transmission sources, the longitude and latitude information, speed information, and heading angle information of the transmission source are obtained by parsing; Based on the longitude and latitude information of the transmission source and the longitude and latitude information of the lifebuoy, the lifebuoy-transmission source distance is calculated; Based on the speed information and heading angle information of the transmission source, the trigger threshold is updated; Based on the lifebuoy-transmission source distance and the trigger threshold, it is determined whether the trigger condition is met. If so, the on-board sound, light, and smoke integrated device of the lifebuoy is triggered to work. If not, the lifebuoy-transmission source distance and / or the trigger threshold are updated, and this step is repeated. The trigger threshold is updated using the following formula:

[0007]

[0008] 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 base coefficient, is the heading change rate of the transmission source, is the acceleration of the transmission source, , are the weights.

[0009] As a preferred technical solution, the lifebuoy-transmission source distance is calculated using the following formula:

[0010]

[0011]

[0012]

[0013]

[0014] where, is the longitude and latitude of the lifebuoy, is the longitude and latitude of the transmission source, is the radius of the earth, is the lifebuoy-transmission source distance.

[0015] As a preferred technical solution, when the lifebuoy is in the activated state and any of the following conditions is met, the trigger judgment is paused within the preset time: The heading deviation angle of the sending source is greater than the threshold, and the heading change rate is greater than the threshold; The acceleration of the sending source is greater than the threshold.

[0016] As a preferred technical solution, the process of triggering the lifebuoy-acoustic, optical, and smoke integrated device to work includes the following steps: By obtaining the light intensity data, determine whether it is day or night currently; In response to the current being daytime, trigger the smoke generating device to work and emit orange-yellow smoke; In response to the current being night, trigger the light-emitting strip to emit red light; Trigger the buzzer to work and emit a beeping sound.

[0017] As a preferred technical solution, the triggering condition is that the distance between the lifebuoy and the sending source is less than or equal to the triggering threshold and the duration exceeds the threshold.

[0018] 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: 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 and an AIS transmitter / receiver; A light-emitting element circuit, including a light-emitting strip, 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.

[0019] As a preferred technical solution, the positioning and communication circuit includes: A GNSS module, connected to the single-chip microcomputer module, for obtaining GNSS positioning data in response to a driving 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 in the case of good signal, and performing inertial data calculation on the longitude and latitude information in the case of signal loss; A communication processor module, 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 AIS data packets based on AIS message data and transmit them 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 through an optocoupler isolator and an RC low-pass filter.

[0020] As a preferred technical solution, it further includes an annular buckle connected to the lifebuoy body.

[0021] Another aspect of the present invention provides an electronic device, which is characterized by including 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.

[0022] Compared with the prior art, the present invention has at least one of the following beneficial effects: (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 transmits it on a preset AIS channel, enabling rapid acquisition of position information and continuous external broadcasting, thereby greatly shortening the rescue response time.

[0023] (2) Increase the probability of fallen personnel being discovered: The present invention installs a sound, light, and smoke integrated device on the swimming ring, enabling the fallen person to be more easily discovered by other ships and increasing the probability of the fallen personnel being rescued.

[0024] (3) Fully consider the positions and navigation information of various transmission sources close to the swimming ring and decide whether to activate the sound, light, and smoke integrated device on the ring: Considering the limitations of electric energy and smoke-generating materials, and the fact that fallen persons tend to immediately activate the sound, light, and smoke integrated device due to panic, which easily leads to the inability of the sound, light, and smoke integrated device to continue working when the rescue ship arrives, affecting the search and rescue of fallen personnel. The present invention dynamically updates the trigger threshold based on the speed information and heading angle information of the transmission source, and then combines the distance between the lifebuoy and the transmission source to determine whether to trigger the operation of the sound, light, and smoke integrated device on the ring. By dynamically updating the trigger threshold, it can fully consider whether the nearby ships (i.e., transmission sources) are likely to discover the fallen person, and trigger the operation of the sound, light, and smoke integrated device at an appropriate time, thereby increasing the probability of the fallen personnel being discovered.

[0025] (4) Long battery life: Considering that when the probability of the transmission source discovering the fallen person is small due to mismatched heading and speed, the present invention pauses the trigger judgment within a preset time to determine whether the trigger condition is met, which can increase the battery life. Brief Description of the Drawings

[0026] Figure 1 Flow chart of the control method of the positioning lifebuoy based on AIS-SART in the embodiment; Figure 2 Stereogram of the positioning lifebuoy based on AIS-SART in the embodiment; Figure 3 Front view of the positioning lifebuoy based on AIS-SART in the embodiment; Figure 4 Left side view of the positioning lifebuoy based on AIS-SART in the embodiment; Figure 5 Top view of the positioning lifebuoy based on AIS-SART in the embodiment; Figure 6 Bottom view of the positioning lifebuoy based on AIS-SART in the embodiment; Figure 7 Axial sectional stereogram of the positioning lifebuoy based on AIS-SART in the embodiment; Figure 8 Axial sectional top view of the positioning lifebuoy based on AIS-SART in the embodiment; Figure 9 Schematic diagram of the single-chip microcomputer system carried by the positioning lifebuoy based on AIS-SART in the embodiment; Figure 10 Schematic diagram of the electronic device in the embodiment, wherein, 1. lifebuoy body, 2. annular 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. single-chip microcomputer module. Specific implementation manners

[0027] 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. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0028] 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 drawings, or the orientation or positional relationship in which the utility model is customarily placed during use. 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 should not be construed 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.

[0029] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance or implicitly specifying 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 the present application, the meaning of "a plurality" is two or more, unless otherwise specifically defined.

[0030] Embodiment 1 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 transmitting source close to the lifebuoy, and trigger the on-ring sound, light, and smoke integrated device to work at an appropriate time, thereby increasing the probability of a person falling into the water being discovered.

[0031] See Figure 1 , the method mainly includes the following steps: Step S1, meet the preset water pressure and / or infrared activation conditions.

[0032] After a person falls into the water at sea, the person grabs the lifebuoy. 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 close, such as when the distance is less than 1 m, it is forcibly activated to ensure that the device can still be activated after the person falling into the water loses physical strength and becomes unconscious.

[0033] 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 activated to start obtaining position data in real time, and the LED indicator starts to flash green light.

[0034] Step S2, obtain the longitude and latitude information of the positioning lifebuoy, process it to obtain AIS telegram data, and send it on a preset AIS channel.

[0035] The inertial navigation module obtains GNSS position information and transmits it to the communication processor module, which compresses, encrypts, and encapsulates the position information into the AIS message format, coordinates the AIS channel switching, signal priority allocation, and data retransmission mechanism, and transmits the distress message through two international AIS channels, AIS1 and AIS2, to other ships and shore station receiving terminals with the help of the AIS transmitter.

[0036] 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 will automatically jump to the idle channel to achieve flexible frequency band switching. If an AIS-SART signal in the same frequency band is detected, the transmission will be automatically delayed to avoid channel congestion. The transmitted message can be received and displayed by the rescue units within the coverage area, and 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 units in time.

[0037] Step S3, in response to receiving AIS data from one or more external transmission sources, obtain the longitude and latitude information, speed information, and heading angle information of the transmission source by parsing.

[0038] The rescue unit sees the AIS-SART icon on the AIS terminal display, quickly locates and launches a rescue with the help of the 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.

[0039] Step S4, based on the longitude and latitude information of the transmission source and the longitude and latitude information of the life buoy, calculate the life buoy - transmission source distance.

[0040] During the rescue process, the AIS receiver receives AIS information from the rescue ship and nearby ships, that is, the transmission source, parses its MMSI, longitude and latitude, speed, heading, etc. information, obtains the longitude and latitude coordinates of the person falling into the water in real time through the GNSS module, inputs the AIS data and GNSS data into the single-chip microcomputer through the serial port, calculates the great circle distance between the two points, traverses all the received ship AIS data every 5 seconds, and calculates the distance between each ship and the person falling into the water one by one. If the distance of any ship ≤ the preset value, it is marked as a trigger candidate. The system stability is enhanced through the debounce mechanism, and the trigger candidate needs to continuously meet the conditions for 10 seconds to avoid false triggering caused by a short-term approach. For multi-ship processing, only the nearest ship or the closest ship is judged for triggering.

[0041] The life buoy - transmission source distance is calculated using the following formula:

[0042]

[0043]

[0044]

[0045]

[0046] 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.

[0047] Step S5, update the trigger threshold based on the speed information and course angle information of the sending source.

[0048] Preset the trigger distance to 2 nautical miles and perform dynamic threshold adjustment. Combining the course change rate / s and the acceleration kn / s, the formula is expressed as follows:

[0049] Among them, the dynamic adjustment coefficient is defined as:

[0050] 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, is the reference speed, which is taken as 10 knots in this embodiment.

[0051] In the judgment, if any of the following conditions is met, suspend the trigger judgment and reset it after 5 seconds: (1) The course deviation angle Δθ > 30° and the course change rate ∣ω∣ > 5° / s; (2) The ship acceleration ∣a∣ > 2 kn / s.

[0052] When the distance between the lifebuoy and the sending source ≤ the dynamic threshold for 10 seconds, activate the solenoid valve, and at the same time support emergency manual triggering.

[0053] Step S6, judge whether the trigger condition is met based on the distance between the lifebuoy and the sending source and the trigger threshold. If so, trigger the on-board sound, light, and smoke integrated device to work. If not, update the distance between the lifebuoy and the sending source and / or the trigger threshold.

[0054] The single-chip microcomputer is connected to the solenoid valve drive circuit through the digital output port. The trigger signal drives the solenoid valve, and then ignites the orange smoke device or triggers the fluorescent strobing.

[0055] Emit orange smoke or LED strobing. During the day, after the orange smoke device is activated, obvious orange smoke signals are continuously emitted; 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 drowning person.

[0056] Embodiment 2 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.

[0057] See Figures 2 - 8 , at least one annular buckle 2 is externally connected to 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 police whistle 3 is also connected to the lifebuoy body 1.

[0058] 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.

[0059] 1. Water pressure / infrared data acquisition circuit.

[0060] It mainly includes a water pressure sensor, an infrared induction module, and an ADC signal processing module. In this embodiment, the infrared induction module is implemented by a ToF ranging sensor.

[0061] 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 induction 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, it is forcibly activated when a human body is detected to be close (i.e., < 1m) to ensure that the device can still be started after the drowning person loses physical strength and falls into a coma.

[0062] The sensor signal is converted into a digital signal by the ADC signal processing module, input into the single-chip microcomputer, and then the positioning and communication circuit is started to start obtaining position data in real time, and the LED indicator starts to flash green.

[0063] 2. Positioning and communication circuit.

[0064] 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.

[0065] (1) AIS transmitter and receiver.

[0066] 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 capabilities to ensure effective operation in complex environments. In addition, the devices adopt an automatic update mechanism to ensure the accuracy and timeliness of the information.

[0067] (2) Electronic positioning module.

[0068] The electronic positioning module of this embodiment is implemented by a GNSS module, including a low-cost multi-mode GNSS chip that supports GPS L1 / L5, Beidou B1 / B2, GLONASS L1 / L2, and Galileo E1 / E5 frequency bands. The number of visible satellites is increased through multi-system combined positioning. Utilize the strong penetrability of the L5 / B2 / E5 high-frequency band signals to reduce the influence of occlusion by foliage, buildings, etc.

[0069] (3) Inertial navigation module (INS).

[0070] 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 quality of the GNSS signal. When the GNSS signal is available, the INS error is calibrated in real time through Kalman filtering; when the GNSS signal is lost, the short-term displacement is estimated based on inertial data. Automatically adjust the sensitivity of the AIS receiver according to the signal strength, adopt the conventional receiving mode in the open environment, and adopt the high-sensitivity mode in the 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 in low power consumption. Specifically, the data fusion process includes the following steps: Step 1, the GNSS outputs real-time latitude, longitude, speed, and time (PVT) data; Step 2, the INS calculates the displacement increment through the accelerometer and gyroscope data; Step 3, the Kalman filter fuses the GNSS and INS data and outputs anti-jitter position information; Step 4, when the signal is lost, switch to the INS estimation mode and activate the high-sensitivity GNSS scan.

[0071] Finally, the electronic positioning module can increase the number of visible satellites of multi-mode GNSS at low cost, maintain sub-meter positioning for a period of time after signal loss with INS assistance, and 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.

[0072] (4) Communication processor module.

[0073] 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.

[0074] 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, through a hybrid redundancy design, the stability and reliability of the system are enhanced. In the hardware part, a single-processor dual-core architecture is adopted, where the main core processes encoding and communication, and the standby core synchronizes the status in real time and monitors the main core heartbeat; in the software part, the same message is alternately sent through the 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 triggering the automatic retransmission, the maximum number of retries is 3 times to avoid infinite retransmission causing channel congestion, and finally the complete transmission of AIS data is achieved.

[0075] The communication processor module integrates functions such as data encoding, redundancy design, and communication management, realizing efficient, secure, and robust transmission of maritime distress information.

[0076] (5) FPC antenna.

[0077] The overall material of the life buoy 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 50 cm × 10 cm area of the life buoy shell corresponding to the antenna radiation direction is replaced with an electromagnetic transparent material, such as polycarbonate (PC) coating.

[0078] An independent sealed cabin is set inside the life buoy as the antenna cabin for centrally installing the antenna and supporting circuits. The outer layer of the cabin is coated with polycarbonate (PC), and the inside is filled with low-dielectric foam to reduce signal reflection.

[0079] The antenna body adopts a serpentine 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 transmitting power requirements of the AIS transmitter. The width of the radiation arm is 3 mm, the spacing is 2 mm, and the bending angle is 90°, achieving a compact layout. The antenna is fixed on the inner wall of the cabin, facing the PC-coated window, covering the AIS dual band. The antenna includes a π-type matching network of series 22 nH inductor - parallel 12 pF capacitor - series 15 nH inductor, integrated at the feeding point. The measured frequency band covers 161 - 162 MHz, VSWR < 1.5, and the bandwidth ≥ 200 kHz. Through slotted loading, it is compatible with multiple GNSS bands and supports dual functions of positioning and communication. A tapered microstrip line is used to achieve broadband impedance matching.

[0080] A copper foil grounding plane is laid under the antenna and connected 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 adhesive, and the redundant grounding enhances stability. The antenna is fixed to the inner wall of the lifebuoy through a silicone pressure strip to prevent it from falling off due to high-frequency vibration.

[0081] 3. The single-chip microcomputer module and the smoke-generating element circuit.

[0082] The smoke-generating element circuit is 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 functions are realized as follows: The AIS receiver receives AIS data of the rescue ship and nearby ships (i.e., the sending sources) through the AIS system.

[0083] The optocoupler isolator is used to suppress noise and surge interference, and the RC low-pass filter is used to eliminate high-frequency interference.

[0084] The integrated single-chip microcomputer is designed with a 4-layer board, with dimensions of 30 mm × 25 mm × 1.6 mm. 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.

[0085] The input of the single-chip microcomputer module is the AIS position, speed, heading angle, etc. information 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:

[0086]

[0087]

[0088]

[0089]

[0090] 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, about 6371 km, is the distance between the lifebuoy and the sending source.

[0091] When the distance between the sending source and the person falling into the water (i.e., the lifebuoy) meets the dynamic threshold condition, a trigger signal is generated to trigger the on-ring smoke / luminescence / sound device to work. The preset trigger distance is 2 nautical miles, combined with the course change rate / s and the acceleration kn / s for dynamic threshold adjustment, expressed as follows:

[0092] Among them, the dynamic adjustment coefficient is defined as:

[0093] 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, is the reference speed, which is taken as 10 knots in this embodiment.

[0094] In the judgment, if any of the following conditions is met, the trigger judgment is suspended and reset after 5 seconds: (1) The course deviation angle Δθ > 30° and the course change rate ∣ω∣ > 5° / s; (2) The ship acceleration ∣a∣ > 2 kn / s.

[0095] Specifically, when the distance ≤ the dynamic threshold lasts for 10 seconds, the solenoid valve is activated, and at the same time, emergency manual triggering is supported. Specifically, by integrating a waterproof button, pressing and holding for more than 3 seconds activates the emergency mode for quick manual triggering, and the on-ring smoke / luminescence / sound device is triggered to work simultaneously to ensure the stability and reliability of the system.

[0096] 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. During the day, it releases the mechanical firing structure to ignite the orange smoke, and at night, it triggers the luminescence element circuit to enter the stroboscopic mode. Regardless of day or night, the PWM signal output by the single-chip microcomputer drives the buzzer to emit a beeping sound to help the rescue personnel quickly locate the person falling into the water.

[0097] 4. Light-emitting element circuit.

[0098] 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 as auxiliary power supply, serving as a power supply unit, and a light-emitting strip. The light-emitting strip has a stroboscopic mode, an indicator light mode, and a constant-on mode. After detecting a person falling into the water, it enters the indicator light mode to indicate the start of work, and enters the stroboscopic mode after generating a trigger signal.

[0099] Specifically, the core power supply uses 2 lithium thionyl chloride batteries in parallel, with a total capacity of 38000 mAh (136.8 Wh). After startup, the battery life reaches 136 hours 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 battery life, and about 15 Wh of energy can be supplemented every sunny day. A priority power supply design is adopted: AIS transmitter > GNSS module > sensor module > orange smoke module. When the voltage is lower than 2.8 V, non-core devices are cut off, and only AIS transmission is retained for over-discharge protection. This battery module can achieve long-term and highly reliable power supply within the effective space of the lifebuoy to adapt to harsh sea weather and extend the waiting time of the person falling into the water.

[0100] The light-emitting strip uses a silicone-encapsulated LED strip. The LED is configured with a constant-on mode, a stroboscopic mode, and an indicator light mode. The constant-on mode emits yellow light, the stroboscopic mode adds red LEDs, and the indicator light mode adds green LEDs. The photosensitive sensor is installed on the surface of the lifebuoy to sense the change of external light intensity. The power supply supports dual-mode low-power operation of the fluorescent strip in constant-on and stroboscopic 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 blinks green, and the LED brightness is 10%; when the illuminance < 10 Lux, the fluorescent strip starts to be constantly on, and the LED brightness is 30%; when the rescue ship approaches, it is forced to switch to the stroboscopic mode, and the LED emits pulses at 100% brightness. The LED 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. The surface is smooth after silicone potting.

[0101] 5. Sound-emitting element circuit.

[0102] It mainly includes a buzzer module for emitting a buzzing sound.

[0103] 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 the rescue ship enters the preset distance, the PWM signal activates the buzzer to emit a strong buzzing sound. In summary, the present application has the following characteristics: (1)Strong real-time performance: It can quickly obtain location information through the GNSS module and continuously broadcast it outward through two international AIS channels, namely AIS1 and AIS2, thus greatly shortening the rescue response time.

[0104] (2)Wide coverage: The application of AIS and dynamic channel switching enable the signal to cover most ships within the sea area, increasing the probability of rescue success.

[0105] (3)Visual reminder: The orange smoke device provides obvious visual signals at night or in bad weather. Compared with single distress devices such as AIS-SART and ordinary life-saving equipment like lifebuoys, it greatly increases the possibility of rescue success.

[0106] (4)Two-way perception: Through the innovative design from the AIS receiver to the orange smoke trigger, it realizes sea distance measurement and dynamic threshold adjustment, and constructs a two-way perception mechanism between the rescue unit and the person in distress.

[0107] Embodiment 3 Based on the foregoing embodiments, this embodiment provides an electronic device, including: one or more processors and a memory. 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.

[0108] 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. 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.

[0109] The memory may include non-permanent memory in the 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 the computer-readable medium.

[0110] A computer-readable medium includes permanent and non-permanent, removable and non-removable media and 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.

[0111] 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 substitutions, and these modifications or substitutions 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 sending sources, parse the longitude and latitude information, speed information, and heading angle information of the sending source; Based on the longitude and latitude information of the sending source and the longitude and latitude information of the lifebuoy, calculate the lifebuoy-sending source distance; Update the trigger threshold based on the speed information and heading angle information of the sending source; Based on the lifebuoy-sending 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-sending 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 basic coefficient, is the course 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-sending 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 activation state and meets any of the following conditions, suspend the trigger judgment within the preset time: The deviation angle of the sending source heading is greater than the threshold, and the heading change rate is greater than the threshold; The acceleration of the sending source is greater than the threshold.

4. The control method of a positioning life buoy based on AIS-SART according to claim 1, characterized in that The process of triggering the on-lifebuoy integrated sound, light, and smoke device to work includes the following steps: By obtaining the light intensity data, determine whether it is day or night currently; 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-sending source distance is less than or equal to the trigger threshold and the duration exceeds the threshold.

6. An AIS-SART-based positioning lifebuoy, 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: 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 in the case of good signal, and performing inertial data calculation on the longitude and latitude information in the case of signal loss; 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, which 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, which is used to receive AIS data from an external transmission source, perform CRC-32 verification, trigger a request for retransmission when the verification fails, and transmit it to the single-chip microcomputer module (10) through an optocoupler isolator and an RC low-pass filter when the verification is successful.

8. The 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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