A search and location system and method for a search and rescue aircraft

Abstract

The application discloses a search positioning system and method for a search and rescue type aircraft, and relates to the technical field of search and rescue type aircrafts. The system comprises a task management subsystem, a radio search subsystem, a radar search subsystem, an optical-electric search subsystem and a sea condition measurement subsystem; the task management subsystem is connected with the radar search subsystem, the optical-electric search subsystem, the radio search subsystem and the sea condition measurement subsystem in data mode, and is used for guiding the flight of the search and rescue type aircraft; the radio search subsystem is used for AIS search and direction search; the radar search subsystem is used for long-distance search; the optical-electric search subsystem is used for target tracking and identification; and the sea condition measurement subsystem is used for sea condition measurement. The method can improve the efficiency and success rate of the search for a marine distress target.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of marine emergency rescue, in particular to a search positioning system and method for search and rescue aircraft. BACKGROUND

[0002] With the continuous development of marine economy, transportation, island tourism and mariculture and other related industries are also booming. However, compared with land operations, marine operations face more complex marine conditions, such as hurricanes, tsunamis, etc. Therefore, marine rescue faces the problems of variable search and rescue environment, difficult target positioning, and time requirement for rescuing the distressed personnel, and the rapid positioning of the person falling into the sea has become a key problem.

[0003] Although the marine rescue capability of China is continuously strengthened, and performs well in various emergency drills, the rescue process often encounters problems such as long manual intervention time and insufficient intelligent rescue system. The emergence of unmanned aerial vehicles and other aircrafts helps to solve such problems. First, it can reduce manual intervention, autonomously search and locate marine targets and return, which helps to speed up the rescue speed and improve the success rate of rescue. Therefore, building an efficient search and positioning system based on aircrafts has become an urgent task. SUMMARY

[0004] The technical problem to be solved by the present application is to provide a search and positioning system and method for search and rescue aircrafts, which can improve the efficiency and success rate of search for marine distress targets.

[0005] To solve the above technical problems, the first aspect of the embodiment of the present application discloses a search and positioning system for search and rescue aircrafts, which comprises a task management subsystem, a radio search subsystem, a radar search subsystem, an optical-electric search subsystem and a sea state measurement subsystem.

[0006] The task management subsystem is in data connection with the radar search subsystem, the optical-electric search subsystem, the radio search subsystem and the sea state measurement subsystem, and is used for trajectory prediction and guiding the flight of the search and rescue aircraft.

[0007] The radio search subsystem is used for AIS search and bearing search.

[0008] The radar search subsystem is used for long-distance search.

[0009] The optical-electric search subsystem is used for target tracking and identification.

[0010] The sea state measurement subsystem is used for sea state measurement.

[0011] As an optional implementation, in the first aspect of the embodiment of the present application, the radio search subsystem comprises a first search unit and a second search unit;

[0012] The first search unit comprises an AIS transceiver and an AIS antenna, and is configured to perform AIS search;

[0013] The AIS antenna is in data connection with the AIS transceiver, and is configured to transceive AIS signals;

[0014] The AIS transceiver is in data connection with the task management subsystem, and is configured to forward the AIS signals and decode the AIS signals to obtain a distress position;

[0015] The second search unit comprises a directional instrument antenna and a directional instrument, and is configured to perform bearing search;

[0016] The directional instrument antenna is in data connection with the directional instrument, and is configured to receive radio distress signals;

[0017] The directional instrument is in data connection with the task management subsystem, and is configured to process the radio distress signals to obtain a distress direction angle.

[0018] As an optional implementation, in the first aspect of the embodiment of the present application, the radar search subsystem comprises a radar antenna, a radar servo unit and a radar signal processing unit;

[0019] The radar antenna is fixedly connected with the radar servo unit, and is in data connection with the radar signal processing unit, and is configured to emit radar search signals and receive radar echo signals;

[0020] The radar signal processing unit is in data connection with the radar servo unit and the task management subsystem, and is configured to generate control information and the radar search signals, and process the radar search signals and the radar echo signals to obtain a radar search position; the radar search position comprises a longitude value and a latitude value;

[0021] The radar servo unit is configured to adjust the direction of the radar antenna by using the control information.

[0022] As an optional implementation, in the first aspect of the embodiment of the present application, the sea state measurement subsystem comprises a wave height meter antenna, a wave height meter transceiver and a plurality of sea state measurement buoys;

[0023] The wave height meter antenna is in data connection with the wave height meter transceiver, and is configured to emit measurement pulses and receive echo pulses;

[0024] The wave height gauge transceiver is connected with the task management subsystem, and is used for generating the measuring pulse and processing the measuring pulse and the echo pulse to obtain a wave height value.

[0025] The sea state measuring buoy is connected with the task management subsystem, and is used for measuring a sea state to obtain water surface information; the water surface information includes a wind speed value, a wind direction angle, an ocean current speed value, a wave length value and an ocean current direction angle.

[0026] To solve the above technical problems, a second aspect of the embodiment of the present application discloses a search and positioning method for a search and rescue aircraft, the method comprising:

[0027] S1, the task management subsystem, the radio search subsystem, the radar search subsystem, the photoelectric search subsystem and the sea state measuring subsystem are respectively arranged on a preset search and rescue aircraft;

[0028] S2, the first search unit of the radio search subsystem, the sea state measuring subsystem, the task management subsystem, the search and rescue aircraft and the photoelectric search subsystem are used to carry out a first passive search;

[0029] S3, the second search unit of the radio search subsystem, the task management subsystem, the search and rescue aircraft, the photoelectric search subsystem are used to carry out a second passive search;

[0030] S4, the radar search subsystem, the sea state measuring subsystem, the task management subsystem, the photoelectric search subsystem and the search and rescue aircraft are used to carry out an active search;

[0031] S5, S2-S4 are repeated until an externally input search and rescue stop signal is received;

[0032] S6, the task management subsystem is used to guide the search and rescue aircraft to return.

[0033] As an optional implementation, in the second aspect of the embodiment of the present application, the first search unit of the radio search subsystem, the sea state measuring subsystem, the task management subsystem, the search and rescue aircraft and the photoelectric search subsystem are used to carry out a first passive search, comprising:

[0034] S21, the first search unit is used to carry out AIS search to obtain a distress position;

[0035] The distress position information is judged;

[0036] When the distress position information is empty, S3 is executed;

[0037] setting a target position as the distress position when the distress position information is not empty;

[0038] S22, processing the target position by using the sea state measuring sub-system, the task management sub-system, the search and rescue type aircraft and the photoelectric search sub-system to obtain a current recognition result;

[0039] judging the current recognition result;

[0040] when the current recognition result is successful, performing S6;

[0041] when the current recognition result is unsuccessful, performing S23;

[0042] S23, repeating S21-S22 until a first stop signal inputted from outside is received; performing S3.

[0043] As an optional implementation, in the second aspect of the embodiment of the present application, the second passive search by using the second search unit of the radio search sub-system, the task management sub-system, the search and rescue type aircraft and the photoelectric search sub-system comprises:

[0044] S31, conducting a bearing search by using the second search unit to obtain a distress direction angle; judging the distress direction angle;

[0045] when the distress direction angle is empty, performing S4;

[0046] when the distress direction angle is not empty, performing S32;

[0047] S32, guiding the search and rescue type aircraft to fly according to the distress direction angle by using the task management sub-system;

[0048] S33, conducting target tracking and recognition by using the photoelectric search sub-system to obtain a photoelectric recognition result;

[0049] judging the photoelectric recognition result;

[0050] when the photoelectric recognition result is successful, performing S6;

[0051] when the photoelectric recognition result is unsuccessful, performing S34;

[0052] S34, repeating S31-S33 until a second stop signal inputted from outside is received; performing S4.

[0053] As an optional implementation, in the second aspect of the embodiment of the present application, the active search by the radar search subsystem, the sea state measurement subsystem, the task management subsystem, the photoelectric search subsystem and the search and rescue aircraft includes:

[0054] S41, performing long-distance search by the radar search subsystem to obtain a radar search position;

[0055] judging the radar search position;

[0056] when the radar search position is empty, performing S5;

[0057] when the radar search position is not empty, setting a target position as the radar search position; and performing S42;

[0058] S42, processing the target position by the sea state measurement subsystem, the task management subsystem, the search and rescue aircraft and the photoelectric search subsystem to obtain a current recognition result;

[0059] judging the current recognition result;

[0060] when the current recognition result is successful, performing S6;

[0061] when the current recognition result is unsuccessful, performing S43;

[0062] S43, repeating S41-S42 until a third stop signal input from outside is received; and performing S5.

[0063] As an optional implementation, in the second aspect of the embodiment of the present application, the processing of the target position by the sea state measurement subsystem, the task management subsystem, the search and rescue aircraft and the photoelectric search subsystem to obtain a current recognition result includes:

[0064] A1, performing sea state measurement by the sea state measurement subsystem to obtain a wave height value and water surface information;

[0065] A2, performing trajectory prediction processing on the target position, the wave height value and the water surface information by the task management subsystem to obtain a position sequence and a time sequence;

[0066] A3, guiding the search and rescue aircraft to fly according to the position sequence and the time sequence by the task management subsystem;

[0067] A4, performing target tracking and recognition by the photoelectric search subsystem to obtain a photoelectric recognition result;

[0068] A5, determining that the current recognition result is the photoelectric recognition result.

[0069] As an optional implementation, in the second aspect of the embodiment of the present application, the trajectory prediction processing on the target position, the wave height value and the water surface information to obtain a position sequence and a time sequence comprises:

[0070] A21, presetting a time step Δt and a prediction step number N;

[0071] A22, initializing a current cycle number n as 1, setting a current position as the target position, and initializing the position sequence as only including the target position;

[0072] A23, acquiring a current time, and initializing a time sequence as only including the current time;

[0073] A24, processing the wave height value and the water surface information to obtain a moving speed

[0074] A25, processing the time step Δt by using a random offset calculation model to obtain a random offset

[0075] The random offset calculation model is:

[0076]

[0077] wherein U is a random number in the interval [-1, 1] obeying a uniform distribution, c is a preset random coefficient, is a unit vector with a random direction;

[0078] A26, according to a current position update model, processing the moving speed and the random offset to update the current position to obtain an updated current position;

[0079] The current position update model is:

[0080]

[0081] wherein, and are the current position before and after the update respectively;

[0082] A27, inserting the current position at the end of the position sequence, and updating the time sequence by using the time step Δt;

[0083] A28, increasing the value of n by 1;

[0084] A29, repeat A25-A28 until n is greater than N.

[0085] Compared with the prior art, the embodiment of the present application has the following beneficial effects:

[0086] By sequentially circulating the passive AIS search and bearing search, and the active long-distance search, the success rate of the search can be improved while the search efficiency is taken into account. Meanwhile, the influence of the complex sea conditions on the position of the distress target can be considered in the search process, so as to improve the success rate of the search. BRIEF DESCRIPTION OF DRAWINGS

[0087] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the embodiments will be briefly introduced as follows. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without any creative effort on the basis of these drawings.

[0088] Figure 1 is a structural schematic diagram of a search and positioning system for a search and rescue aircraft according to an embodiment of the present application.

[0089] Figure 2 is a structural schematic diagram of a radio search subsystem of a search and positioning system for a search and rescue aircraft according to an embodiment of the present application.

[0090] Figure 3 is a structural schematic diagram of a radar search subsystem of a search and positioning system for a search and rescue aircraft according to an embodiment of the present application.

[0091] Figure 4 is a structural schematic diagram of a sea condition measuring subsystem of a search and positioning system for a search and rescue aircraft according to an embodiment of the present application.

[0092] Figure 5 is a flow schematic diagram of a search and positioning method for a search and rescue aircraft according to an embodiment of the present application. DETAILED DESCRIPTION

[0093] The technical solutions in the embodiments of the present application will be described clearly and completely with reference to the drawings of the embodiments of the present application. Obviously, the described embodiments are only some embodiments of the present application, but not all the embodiments. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without any creative effort fall within the scope of protection of the present application.

[0094] In the description of the present application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" and the like indicate the orientation or positional relationship shown in the drawings, which are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation of the present application. In addition, the terms "first", "second", "third" are only for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0095] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connection" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0096] Embodiment one

[0097] Please refer to Figures 1-4 . Figure 1 is a structural schematic diagram of a search and positioning system for a search and rescue aircraft disclosed by an embodiment of the present application. Figure 2 is a structural schematic diagram of a radio search subsystem of a search and positioning system for a search and rescue aircraft disclosed by an embodiment of the present application. Figure 3 is a structural schematic diagram of a radar search subsystem of a search and positioning system for a search and rescue aircraft disclosed by an embodiment of the present application. Figure 4 is a structural schematic diagram of a sea state measurement subsystem of a search and positioning system for a search and rescue aircraft disclosed by an embodiment of the present application. Figure 1 The search and positioning system for a search and rescue aircraft described is applied to the field of maritime emergency rescue, such as search and rescue of a distressed ship, and the embodiment of the present application is not limited.

[0098] As Figure 1 shown, the system includes a task management subsystem, a radio search subsystem, a radar search subsystem, an optical-electric search subsystem and a sea state measurement subsystem.

[0099] The above-mentioned task management subsystem is in data connection with the radar search subsystem, the optical-electric search subsystem, the radio search subsystem and the sea state measurement subsystem, and is used for trajectory prediction and guiding the search and rescue aircraft to fly.

[0100] It should be noted that the above-mentioned search and rescue aircraft can be an amphibious aircraft, and the embodiment of the present application is not limited.

[0101] The radio search sub-system is used for AIS search and bearing search.

[0102] The radar search sub-system is used for long-range search.

[0103] The photoelectric search sub-system is used for target tracking and identification.

[0104] The sea state measurement sub-system is used for sea state measurement.

[0105] In an optional embodiment, as shown in Figure 2 The radio search sub-system comprises a first search unit and a second search unit.

[0106] The first search unit comprises an AIS transceiver and an AIS antenna, and is used for AIS search.

[0107] The AIS antenna is in data connection with the AIS transceiver, and is used for transmitting and receiving AIS signals.

[0108] The AIS transceiver is in data connection with the mission management sub-system, and is used for forwarding AIS signals and decoding AIS signals to obtain distress positions.

[0109] It is to be noted that the forwarding of AIS signals is to enhance the AIS signals received by the AIS antenna from the distress target by using the AIS transceiver, and then send the AIS signals to the surrounding area again through the AIS antenna.

[0110] It is to be noted that the AIS signals can be TDMS (Time Division Multiple Access) signals, and work at two VHF frequencies of 161.975 MHz (87B channel) and 162.025 MHz (88B channel), which are not limited in the embodiments of the present application.

[0111] It is to be noted that the AIS system (Automatic Identification System) is an automatic tracking system, which is used for exchanging AIS signals between ships and between ships and shore-based stations, so as to improve the safety, efficiency of sea navigation and accuracy of ship management. When a ship is in distress, it can report its distress position by actively sending AIS signals.

[0112] It can be seen that, with the help of AIS signals, the distress target can be quickly identified and located in the sea area with dense ships; further, the AIS signals are forwarded to the surrounding area, so as to inform other ships to actively avoid collision with the distress target, and ensure the safety of the search and rescue action.

[0113] The second search unit comprises a direction finder antenna and a direction finder, and is configured to perform a bearing search.

[0114] The direction finder antenna is connected to the direction finder, and is configured to receive the radio distress signal.

[0115] It should be noted that the direction finder antenna can be single-polarized or dual-polarized, and can be a Yagi antenna, a log-periodic antenna or a parabolic antenna, and the embodiments of the present application are not limited thereto.

[0116] The direction finder is connected to the mission management subsystem, and is configured to process the radio distress signal to obtain a distress direction angle.

[0117] It should be noted that the direction finder determines the bearing of the distress target by measuring the direction of arrival of the radio distress signal, thereby obtaining the distress direction angle.

[0118] It can be seen that when the distress target cannot accurately know its own distress position, or the AIS system carried by the distress target is damaged, the distress target cannot actively report its own distress position through the AIS signal, and the direction finder antenna and the direction finder can be used to receive the radio distress signal sent by the distress target to the surrounding sea area to determine the target bearing of the distress target. Further, since the direction finder can cover a wide frequency range, the distress target can use a plurality of devices operating in different frequency bands to transmit the radio distress signal, thereby improving the success rate of the search and rescue action.

[0119] Optionally, the AIS transceiver can receive the AIS signal conforming to the GB / T 20068-2017 standard.

[0120] Optionally, the direction finder can satisfy the following conditions: (a) the airborne direction finder should be able to receive the 406.0-406.1 MHz distress information of the COSPAS-SARSAT system; (b) the airborne direction finder should be able to measure the relative bearing of the 121.2-123.2 MHz distress signal source of the COSPAS-SARSAT system; (c) the airborne direction finder should be able to measure the relative bearing of the 241.2-245.1 MHz distress signal source of the COSPAS-SARSAT system; (d) the airborne direction finder should be able to measure the relative bearing of the 156.8 MHz (VHF 16 channel) maritime distress signal source; and (e) when the airborne direction finder calculates the bearing or receives the distress information, a prompt audio should be given.

[0121] In another optional embodiment, as shown in FIG. 2, the radar search subsystem comprises a radar antenna, a radar servo unit and a radar signal processing unit. Figure 3

[0122] ​The aforementioned radar antenna is fixedly connected to the radar servo unit and data-connected to the radar signal processing unit, and is used to transmit radar search signals and receive radar echo signals.

[0123] The aforementioned radar signal processing unit is connected to the radar servo unit and the mission management subsystem for generating control information and radar search signals, as well as processing the radar search signals and radar echo signals to obtain the radar search position; the aforementioned radar search position includes longitude and latitude values.

[0124] It should be noted that the radar search locations mentioned above represent the locations of the distressed targets as detected by the radar search subsystem.

[0125] The aforementioned radar servo unit is used to adjust the direction of the radar antenna using control information.

[0126] It should be noted that the radar signal processing unit described above obtains the radar search position by calculating the time difference between the radar search signal and the radar echo signal.

[0127] Optionally, the radar antenna and signal processing unit are cooled by their own low-power fan.

[0128] In yet another alternative embodiment, such as Figure 4 As shown, the above-mentioned sea state measurement subsystem includes a wave altimeter antenna, a wave altimeter transceiver, and several sea state measurement buoys.

[0129] The aforementioned altimeter antenna is connected to the altimeter transceiver for transmitting measurement pulses and receiving echo pulses.

[0130] It should be noted that both the measurement pulse and the received echo pulse mentioned above are microwave pulses. The frequency of the microwave pulses varies within a specific frequency band, such as the K-band or the C-band, and this embodiment of the invention does not impose any limitation on this.

[0131] The aforementioned wave height transceiver is connected to the task management subsystem for generating measurement pulses and processing the measurement pulses and echo pulses to obtain the wave height value.

[0132] It should be noted that the above-mentioned wave height transceiver determines the wave height value by analyzing the shape change of the echo pulse relative to the measurement pulse.

[0133] The aforementioned sea state measurement buoy is connected to the mission management subsystem for data transmission and is used to measure sea state and obtain water surface information. This water surface information includes wind speed, wind direction angle, ocean current speed, wavelength, and ocean current direction angle.

[0134] Optionally, the above water surface information may also include air temperature, air pressure, and water temperature.

[0135] It should be noted that the sea state measuring buoy can communicate with the task management subsystem through wireless methods such as LoRa or maritime radio, and the embodiments of the present application are not limited.

[0136] The wireless method is connected with the task management subsystem.

[0137] It can be seen that the sea state measuring subsystem can obtain sea state information such as wave height value and water surface information.

[0138] Preferably, the wave height meter antenna and the wave height meter transceiver have the following functions: a) measuring and calculating the wave height of the sea surface; b) correcting the measured wave height value; c) sea condition identification function; d) external information transmission function; e) self-detection function.

[0139] Preferably, the sea state measuring buoy is designed to meet the following requirements: a) the sampling frequency is 4Hz; b) the detection is carried out by air dropping, and there is no special requirement for dropping; c) the design of the unturned doll is adopted, and the water balance is automatically balanced in the test state after entering the water.

[0140] In another optional embodiment, the photoelectric search subsystem is a photoelectric turret; the photoelectric turret comprises a turret, a television camera, an infrared camera and a tracking and identification unit; the turret comprises a fixed part and a rotating part; the television camera and the infrared camera are both fixed on the fixed part; the tracking and identification unit is used for processing the television image and the infrared image photographed by the television camera and the infrared camera to obtain a photoelectric identification result.

[0141] It should be noted that the photoelectric turret can use television imaging and infrared imaging at close range, automatically detect and track the distress target, and obtain target distance information through laser ranging. When the distress target is successfully detected and tracked, the tracking and identification unit outputs a successful photoelectric identification result, otherwise the tracking and identification unit outputs an unsuccessful photoelectric identification result.

[0142] Optionally, the photoelectric search subsystem has the following functions: a) it has the function of detecting and identifying sea surface, island reefs and onshore targets; b) it has the function of day and night wide-area search; c) it has the function of automatic video tracking; d) it has the function of target geographical positioning; e) it has the function of high-precision stabilization of the sighting line and image; f) it has the function of image enhancement (electronic fog penetration); g) it can automatically prompt multiple targets in the field of view, and manually select the main target; h) it can output information such as sighting line angle position, angular velocity and target geographical coordinates; i) it has a self-detection function.

[0143] Optionally, the photoelectric turret is also equipped with a photoelectric operating handle for controlling the photoelectric turret under the operation of the search personnel.

[0144] In yet another optional embodiment, the above-mentioned task management subsystem includes a trajectory prediction unit and a navigation unit.

[0145] The above-mentioned trajectory prediction unit is in data connection with the wave height meter transceiver, the sea state measuring buoy, the first search unit, the radar signal processing unit and the navigation unit, and is used for trajectory prediction processing on the wave height value and the water surface information, and the target position from the first search unit or the radar signal processing unit, to obtain a position sequence.

[0146] The above-mentioned navigation unit is in data connection with the second search unit, and is used for guiding the search and rescue aircraft to fly according to the distress direction angle or the position sequence.

[0147] Optionally, the above-mentioned task management subsystem further includes a comprehensive management unit; the above-mentioned comprehensive management unit has the following three types of functions:

[0148] a) screen display and control:

[0149] 1) having the function of displaying and controlling the working state of each device;

[0150] 2) having the functions of displaying radar detection signal display and photoelectric detection video display;

[0151] 3) having the function of displaying a digital map.

[0152] b) tactical task processing:

[0153] 1) having the function of correlating radar detection data and AIS data;

[0154] 2) having the function of water surface search auxiliary decision;

[0155] c) comprehensive alarm:

[0156] 1) having the function of search and rescue task system alarm calculation;

[0157] 2) having the functions of sound and light alarm.

[0158] d) data management:

[0159] 1) having the function of recording bus data and audio data;

[0160] 2) having the function of task data loading;

[0161] 3) having the function of quickly unloading data through a cache card.

[0162] e) system management:

[0163] 1) having the function of self-detection;

[0164] 2) having the function of time management;

[0165] 3) With the function of margin management.

[0166] It can be seen that the search and positioning system for search and rescue aircraft described in the embodiments of the application can comprehensively utilize the radio search subsystem, the radar search subsystem, the photoelectric search subsystem and the sea state measurement subsystem, and can simultaneously carry out actions in multiple search modes, and can simultaneously utilize the task management subsystem to perform trajectory prediction and guide the search and rescue aircraft to fly.

[0167] Embodiment two

[0168] Please refer to Figure 5 , Figure 5 is a flowchart of a search and positioning method for search and rescue aircraft disclosed by the embodiments of the application. Wherein, Figure 5 The search and positioning method described for search and rescue aircraft can be applied to the field of marine emergency rescue, such as search and rescue of a distressed ship, and the embodiments of the application are not limited. As Figure 5 shown, the search and positioning method for search and rescue aircraft includes:

[0169] S1, the task management subsystem, the radio search subsystem, the radar search subsystem, the photoelectric search subsystem and the sea state measurement subsystem are respectively arranged on a preset search and rescue aircraft.

[0170] S2, the first search unit of the radio search subsystem, the sea state measurement subsystem, the task management subsystem, the search and rescue aircraft and the photoelectric search subsystem are utilized to carry out the first passive search.

[0171] S3, the second search unit of the radio search subsystem, the task management subsystem, the search and rescue aircraft, the photoelectric search subsystem are utilized to carry out the second passive search.

[0172] S4, the radar search subsystem, the sea state measurement subsystem, the task management subsystem, the photoelectric search subsystem and the search and rescue aircraft are utilized to carry out the active search.

[0173] S5, S2-S4 are repeated until an externally input search and rescue stop signal is received.

[0174] S6, the task management subsystem is utilized to guide the search and rescue aircraft to return.

[0175] It should be noted that the task management subsystem records the initial position of the search and rescue aircraft before takeoff, and guides the search and rescue aircraft to return after the search task is completed.

[0176] It can be seen that through the cyclic utilization of passive AIS search and bearing search and active long-distance search, various methods can be comprehensively utilized to search and position the target in distress.

[0177] Preferably, the radar antenna and the radar servo unit are fixedly installed in the radome of the head of the search and rescue aircraft, and are cooled by forced air cooling provided by the search and rescue aircraft.

[0178] Preferably, the radar signal processing unit is fixedly arranged at the front end of the search and rescue aircraft.

[0179] Preferably, the photoelectric search subsystem is fixedly arranged at the lower end of the head of the search and rescue aircraft.

[0180] Preferably, the photoelectric search subsystem satisfies the following indexes: a) the azimuth angle range is -90°~+90°; b) the pitch angle range is -110°~0°; and c) the weight is not greater than 35 kg.

[0181] Preferably, the AIS antenna and the directional instrument antenna are respectively fixedly arranged below the wings on both sides of the search and rescue aircraft.

[0182] Preferably, the wave height meter antenna is fixedly arranged on the tail on both sides of the search and rescue aircraft.

[0183] In an optional embodiment, the first search unit using the radio search subsystem, the sea state measurement subsystem, the task management subsystem, the search and rescue aircraft, and the photoelectric search subsystem are used to carry out the first passive search, which includes:

[0184] S21, AIS search is carried out by using the first search unit to obtain a distress position;

[0185] The distress position information is judged.

[0186] When the distress position information is empty, S3 is executed.

[0187] When the distress position information is not empty, the target position is set as the distress position.

[0188] It should be noted that the distress position information being empty means that the first search unit fails to successfully obtain the distress position; and the distress position information not being empty means that the first search unit successfully obtains the distress position.

[0189] S22, the target position is processed by using the sea state measurement subsystem, the task management subsystem, the search and rescue aircraft, and the photoelectric search subsystem to obtain a current recognition result.

[0190] The current recognition result is judged.

[0191] When the current recognition result is successful, S6 is executed.

[0192] When the current recognition result is unsuccessful, S23 is executed.

[0193] S23, repeating S21-S22 until receiving a first stop signal input from outside; performing S3.

[0194] It should be noted that the first stop signal can be input by a search and rescue personnel on the search and rescue aircraft when the AIS search time exceeds the preset search time threshold, or according to the order of the superior, and the embodiments of the present application are not limited.

[0195] It should be noted that since the distress target has obtained its own position, it can be directly received through AIS search, so that the efficiency of AIS search is much higher than that of bearing search and long-distance search.

[0196] It can be seen that through passive AIS search, the distress target's own position information actively sent by the AIS system can be quickly obtained, so as to quickly lock the distress target and improve the search efficiency.

[0197] In another optional embodiment, the second passive search using the radio search subsystem, the task management subsystem, the search and rescue aircraft, and the optical-electric search subsystem includes:

[0198] S31, using the second search unit to perform bearing search to obtain a distress direction angle;

[0199] judging the distress direction angle;

[0200] When the distress direction angle is empty, performing S4;

[0201] When the distress direction angle is not empty, performing S32.

[0202] It should be noted that the distress bearing angle being empty indicates that the second search unit fails to successfully obtain the distress direction angle; and the distress bearing angle being not empty indicates that the second search unit successfully obtains the distress direction angle.

[0203] S32, using the task management subsystem to guide the search and rescue aircraft to fly according to the distress direction angle.

[0204] S33, using the optical-electric search subsystem to perform target tracking and identification to obtain an optical-electric identification result;

[0205] judging the optical-electric identification result;

[0206] When the optical-electric identification result is successful, performing S6;

[0207] When the optical-electric identification result is unsuccessful, performing S34.

[0208] S34, repeating S31-S33 until receiving a second stop signal input from outside; performing S4.

[0209] It should be noted that the first stop signal can be input by a search and rescue personnel on the search and rescue aircraft when the azimuth search time exceeds the preset search time threshold, or according to the superior order, and the embodiments of the present application are not limited.

[0210] It should be noted that, due to the azimuth search, only the target azimuth needs to be determined according to the existing radio distress signal, and the target position does not need to be determined, so the search process is faster than the long-distance search.

[0211] It can be seen that in the case of AIS search failure, the passive azimuth search can quickly obtain the radio distress signal of various frequencies actively sent by the distress target, so as to quickly lock the azimuth of the distress target.

[0212] In another optional embodiment, the active search using the radar search subsystem, the sea state measurement subsystem, the task management subsystem, the photoelectric search subsystem and the search and rescue aircraft includes:

[0213] S41, using the radar search subsystem to perform long-distance search to obtain a radar search position;

[0214] judging the radar search position;

[0215] When the radar search position is empty, S5 is executed;

[0216] When the radar search position is not empty, the target position is set as the radar search position, and S42 is executed.

[0217] It should be noted that the radar search position being empty means that the long-distance search fails to successfully obtain the radar search position, and the radar search position being not empty means that the long-distance search successfully obtains the radar search position.

[0218] S42, using the sea state measurement subsystem, the task management subsystem, the search and rescue aircraft and the photoelectric search subsystem to process the target position to obtain a current identification result;

[0219] judging the current identification result;

[0220] When the current identification result is successful, S6 is executed;

[0221] When the current identification result is unsuccessful, S43 is executed.

[0222] S43, repeating S41-S42 until a third stop signal input from outside is received; and executing S5.

[0223] It should be noted that, since the active long-distance search, no acquisition of distress target sent effective position information, need to search in a number of directions and a large distance range, so this search method consumes the longest time.

[0224] It can be seen that, in the case of further failure of the bearing search, the position of the distress target can be actively acquired through long-distance search, further improving the success rate of the search.

[0225] In another optional embodiment, the above-mentioned target position processing system, task management subsystem, search and rescue aircraft and photoelectric search subsystem are used to process the target position to obtain the current recognition result or the current recognition result, comprising:

[0226] A1, using the sea state measurement subsystem to measure the sea state to obtain the wave height value and the water surface information.

[0227] It should be noted that the sea state measurement buoy of the above-mentioned sea state measurement subsystem needs to be air-dropped to the water surface by the search and rescue aircraft during measurement.

[0228] A2, using the task management subsystem to process the target position, the wave height value and the water surface information for trajectory prediction to obtain the position sequence and the time sequence.

[0229] A3, using the task management subsystem to guide the search and rescue aircraft flight according to the position sequence and the time sequence.

[0230] A4, using the photoelectric search subsystem to track and identify the target to obtain the photoelectric recognition result.

[0231] A5, determining the current recognition result or the current recognition result as the photoelectric recognition result.

[0232] It can be seen that, in the trajectory prediction processing, the target position and the wave height value and the water surface information obtained by the sea state measurement subsystem are comprehensively considered, which can make the obtained position sequence fully consider the current sea state and improve the accuracy of the position sequence. In addition, during the search and rescue aircraft going to the distress target, the distress target can be automatically locked by the photoelectric search subsystem, avoiding the defects that the human eye recognition is easily affected by fatigue and weather environment.

[0233] In another optional embodiment, the above-mentioned trajectory prediction processing of the target position, the wave height value and the water surface information to obtain the position sequence and the time sequence comprises:

[0234] A21, presetting the time step Δt and the prediction step number N.

[0235] Preferably, the time step Δt is 0.1 seconds.

[0236] Preferably, the prediction step number N is 1000.

[0237] A22, initialize the current cycle number n as 1; set the current position as the target position; initialize the position sequence as only including the target position.

[0238] A23, obtain the current time; initialize the time sequence as only including the current time.

[0239] It should be noted that the current time can be obtained through a GPS or Beidou satellite navigation system, and the embodiments of the present application are not limited.

[0240] A24, process the wave height value and the water surface information to obtain the moving speed

[0241] A25, process the time step Δt by using a random offset calculation model to obtain the random offset

[0242] The random offset calculation model is as follows:

[0243]

[0244] In the formula, U is a random number in the interval [-1, 1] obeying a uniform distribution, c is a preset random coefficient, is a unit vector in a random direction.

[0245] Preferably, c is 0.02.

[0246] It should be noted that the random offset calculation model takes into account the randomness of the change of the current position of the target in distress under complex sea conditions. In addition, due to the introduction of randomness, the longer the position sequence, the greater the cumulative random error introduced, and therefore the product of N and Δt should not be too large, for example, the product value can be set to 100.

[0247] A26, update the current position according to a current position update model by using the moving speed the time step Δt and the random offset update the current position to obtain the updated current position.

[0248] The current position update model is as follows:

[0249]

[0250] In the formula, and are the current positions before and after the update respectively.

[0251] A27, insert the current position into the end of the position sequence; update the time sequence by using the time step Δt.

[0252] A28, add 1 to the value of n.

[0253] A29, repeat A25-A28 until n is greater than N.

[0254] In yet another optional embodiment, the wave height value and the water surface information are processed to obtain the moving speed comprises:

[0255] A241, processing the wind speed value, the wind direction angle, the ocean current speed value and the ocean current direction angle by using a static speed calculation model to obtain a static speed

[0256] The static speed calculation model is:

[0257]

[0258] wherein a is a preset ocean current correction coefficient; the size of the static speed is the wind speed value, the direction of the static speed is along the direction indicated by the wind direction angle; the size of the static speed is the ocean current speed value, the direction of the static speed is along the direction indicated by the ocean current direction angle.

[0259] It should be noted that the operation in the static speed calculation model is a vector operation.

[0260] Preferably, the ocean current correction coefficient a is 0.03.

[0261] A242, processing the wave height value H, the wave length value λ and the ocean current direction angle by using an additional speed calculation model to obtain an additional speed

[0262] The additional speed calculation model is:

[0263]

[0264] wherein b is a preset additional speed correction coefficient, g is the gravitational acceleration, is a unit vector along the direction indicated by the ocean current direction angle.

[0265] Preferably, the additional speed correction coefficient is 0.01.

[0266] A243, calculating the vector sum of the static speed and the additional speed to obtain the moving speed

[0267] In yet another optional embodiment, the updating the time sequence by using the time step Δt comprises:

[0268] A271, set the time to be updated as the last element of the time sequence.

[0269] A272, calculate the sum of the time to be updated and Δt to obtain the updated time.

[0270] A273, insert the updated time at the end of the time sequence to complete the update of the time sequence.

[0271] It should be noted that after the step A29 is completed, the time sequence and the position sequence both contain N elements, and the elements in the time sequence and the position sequence correspond to each other. Through the time sequence and the position sequence, the position of the target in distress at different time points can be obtained, so as to guide the search and rescue aircraft to the target in distress. For example, when the search and rescue aircraft is delayed due to weather conditions, the position of the target in distress needs to be reacquired, at this time, the task management subsystem only needs to find the closest updated time in the time sequence and the corresponding current position in the position sequence, and guide the search and rescue aircraft to fly to the corresponding current position.

[0272] It can be seen that the search and positioning method for the search and rescue aircraft described in the embodiment of the present application can first quickly lock the target in distress through passive AIS search, improve the search efficiency; in the case of AIS search failure, the bearing of the target in distress is quickly locked through passive bearing search; in the case of further failure of bearing search, the position of the target in distress is actively acquired through long-distance search, and the success rate of search is further improved. Further, by sequentially and circularly using the above three search methods, the success rate of search can be improved while the efficiency is taken into account. In addition, in the trajectory prediction, the target position and the current sea conditions are comprehensively considered, which can improve the accuracy of the position sequence and the time sequence, and further improve the success rate of search.

[0273] The device embodiments described above are only schematic, and the modules illustrated as separate components can or can not be physically separated, and the components illustrated as modules can or can not be physical modules, i.e. they can be located in one place or distributed on multiple network modules. Part or all of the modules can be selected to achieve the purpose of the embodiment scheme according to actual needs. Those skilled in the art can understand and implement it without creative labor.

[0274] Those skilled in the art can clearly understand the implementation of the various embodiments by means of software and necessary general hardware platforms through the above specific description of the embodiments, and of course, the embodiments can also be implemented by hardware. Based on such understanding, the above technical solutions, essentially or in other words, the part of the prior art that makes a contribution, can be embodied in the form of a software product. The computer software product can be stored in a computer readable storage medium, and the storage medium includes a read-only memory (ROM), a random access memory (RAM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), a one-time programmable read-only memory (OTPROM), an electrically erasable programmable read-only memory (EEPROM), a compact disc read-only memory (CD-ROM) or other optical disk storage, a magnetic disk storage, a magnetic tape storage, or any other computer readable medium that can be used to carry or store data.

[0275] Finally, it should be noted that: the search positioning system for search and rescue aircraft disclosed by the embodiments of the present application is only the preferred embodiment of the present application, and is used to illustrate the technical solutions of the present application, but not to limit it; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: the technical solutions recorded in the foregoing embodiments can still be modified, or some technical features can be replaced by equivalents; and these modifications or replacements do not make the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A search and location system for a search and rescue aircraft, characterized in that, The task management subsystem, the radar search subsystem, the photoelectric search subsystem, the radio search subsystem and the sea state measurement subsystem are connected with each other in data, and the task management subsystem is used for trajectory prediction and guiding the search and rescue aircraft to fly. The radio search subsystem is used for AIS search and bearing search, and the radio search subsystem comprises a first search unit and a second search unit. The first search unit comprises an AIS transceiver and an AIS antenna, and is used for AIS search. The AIS antenna is connected with the AIS transceiver in data, and is used for transmitting and receiving AIS signals. The AIS transceiver is connected with the task management subsystem in data, and is used for forwarding the AIS signals and decoding the AIS signals to obtain a distress position. The second search unit comprises a direction finder antenna and a direction finder, and is used for bearing search. The direction finder antenna is connected with the direction finder in data, and is used for receiving radio distress signals. The direction finder is connected with the task management subsystem in data, and is used for processing the radio distress signals to obtain a distress direction angle. The radar search subsystem is used for long-distance search. The photoelectric search subsystem is used for target tracking and identification. The sea state measurement subsystem is used for sea state measurement, and comprises a wave height meter antenna, a wave height meter transceiver and a plurality of sea state measurement buoys. The wave height meter antenna is connected with the wave height meter transceiver in data, and is used for transmitting measurement pulses and receiving echo pulses. The wave height meter transceiver is connected with the task management subsystem in data, and is used for generating the measurement pulses and processing the measurement pulses and the echo pulses to obtain a wave height value. The sea state measurement buoys are connected with the task management subsystem in data, and are used for sea state measurement to obtain water surface information, and the water surface information comprises a wind speed value, a wind direction angle, an ocean current speed value, a wave length value and an ocean current direction angle. The radar search subsystem comprises a radar antenna, a radar servo unit and a radar signal processing unit.

2. A search and rescue aircraft search positioning system according to claim 1, characterised in that, The radar antenna is fixedly connected with the radar servo unit and connected with the radar signal processing unit in data, and is used for transmitting radar search signals and receiving radar echo signals. The radar signal processing unit is connected with the radar servo unit and the task management subsystem in data, and is used for generating control information and the radar search signals, and processing the radar search signals and the radar echo signals to obtain a radar search position; the radar search position comprises a longitude value and a latitude value. The radar servo unit is used for adjusting the direction of the radar antenna by using the control information. The method is applied to the search and positioning system for the search and rescue aircraft, and the method comprises the following steps:

3. A search and location method for a search and rescue aircraft, characterized in that, S1, the task management subsystem, the radio search subsystem, the radar search subsystem, the photoelectric search subsystem and the sea state measurement subsystem are respectively arranged on the preset search and rescue aircraft. ​ S2, using the first search unit of the radio search sub-system, the sea state measurement sub-system, the task management sub-system, the search and rescue aircraft and the photoelectric search sub-system, carrying out a first passive search; S3, using the second search unit of the radio search sub-system, the task management sub-system, the search and rescue aircraft, the photoelectric search sub-system, carrying out a second passive search; S4, using the radar search sub-system, the sea state measurement sub-system, the task management sub-system, the photoelectric search sub-system and the search and rescue aircraft, carrying out an active search; S5, repeating S2-S4 until receiving an externally input search and rescue stop signal; S6, using the task management sub-system, guiding the search and rescue aircraft to return.

4. The search and rescue method for an aerial search vehicle according to claim 3, wherein, The first passive search using the first search unit of the radio search sub-system, the sea state measurement sub-system, the task management sub-system, the search and rescue aircraft and the photoelectric search sub-system, includes: S21, using the first search unit to carry out AIS search to obtain a distress position; Judging the distress position information; When the distress position information is empty, executing S3; When the distress position information is not empty, setting the target position as the distress position; S22, using the sea state measurement sub-system, the task management sub-system, the search and rescue aircraft and the photoelectric search sub-system, processing the target position to obtain a current identification result; Judging the current identification result; When the current identification result is successful, executing S6; When the current identification result is unsuccessful, executing S23; S23, repeating S21-S22 until receiving an externally input first stop signal; executing S3.

5. The search and rescue method for an aerial search vehicle according to claim 3, wherein, The second passive search using the second search unit of the radio search sub-system, the task management sub-system, the search and rescue aircraft, the photoelectric search sub-system, includes: S31, using the second search unit to carry out bearing search to obtain a distress direction angle; Judging the distress direction angle; When the distress direction angle is empty, executing S4; When the distress direction angle is not empty, executing S32; S32, using the task management sub-system to guide the search and rescue aircraft to fly according to the distress direction angle; S33, using the photoelectric search sub-system to carry out target tracking identification to obtain a photoelectric identification result; Judging the photoelectric identification result; When the photoelectric identification result is successful, executing S6; When the photoelectric identification result is unsuccessful, executing S34; S34, repeating S31-S33 until receiving an externally input second stop signal; executing S4.

6. The search and rescue method for an aerial search vehicle according to claim 3, wherein, The active search using the radar search sub-system, the sea state measurement sub-system, the task management sub-system, the photoelectric search sub-system and the search and rescue aircraft, includes: S41, using the radar search sub-system to carry out long-distance search to obtain a radar search position; Judging the radar search position; When the radar search position is empty, executing S5; When the radar search position is not empty, setting a target position as the radar search position; performing S42; S42, processing the target position by using the sea state measurement sub-system, the task management sub-system, the search and rescue type aircraft and the photoelectric search sub-system to obtain a current recognition result; Judging the current recognition result; When the current recognition result is successful, performing S6; When the current recognition result is unsuccessful, performing S43; S43, repeating S41-S42 until a third stop signal inputted from outside is received; performing S5.

7. A search and location method for a search aircraft according to claim 4 or 6, characterized in that, The processing of the target position by using the sea state measurement sub-system, the task management sub-system, the search and rescue type aircraft and the photoelectric search sub-system to obtain a current recognition result comprises: A1, measuring a sea state by using the sea state measurement sub-system to obtain a wave height value and water surface information; A2, performing trajectory prediction processing on the target position, the wave height value and the water surface information by using the task management sub-system to obtain a position sequence and a time sequence; A3, guiding the search and rescue type aircraft to fly according to the position sequence and the time sequence by using the task management sub-system; A4, performing target tracking and recognition by using the photoelectric search sub-system to obtain a photoelectric recognition result; A5, determining the current recognition result as the photoelectric recognition result.

8. The search and rescue method for an aerial search vehicle according to claim 7, wherein, The trajectory prediction processing on the target position, the wave height value and the water surface information to obtain a position sequence and a time sequence comprises: A21, preset time step and predicted step number N ; A22. set current loop count to 1 n initialize to 1; set current position to target position; initialize the sequence of positions to include only the target position; A23, obtaining a current time; initializing the time sequence as containing only the current time; A24, processing the wave height value and the water surface information to obtain a moving speed ; A25, using the random offset calculation model, processing the time step to obtain a random offset ; The random offset calculation model is: In the formula, U is a random number in the interval [-1, 1] obeying a uniform distribution, c is a preset random coefficient, is a unit vector with a random direction. A26、according to a current position update model, updating the current position by using the moving speed , the time step , and the random offset to obtain an updated current position; The current position update model is: In the formula, and respectively, the current position before and after the update; A27. inserting said current position at the end of said sequence of positions; using said time step updating said time sequence; A28、will n the value of i is incremented by 1; A29. Repeat A25-A28 until n greater than N .

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