Ship anti-collision early warning device and method based on terahertz radar

Abstract

The invention discloses a ship anti-collision early warning device and method based on a terahertz radar. The device comprises terahertz radar antenna units and a comprehensive processing platform, the terahertz radar antenna units are installed at monitoring nodes, and transmission of target data and control information is achieved through network communication equipment and the comprehensive processing platform; the comprehensive processing platform controls the terahertz radar antenna unit, displays radar video information and track data, and performs small target detection and fusion situation generation according to monitoring information of the terahertz radar antenna unit to realize a collision avoidance alarm function. Unmanned detection and anti-collision early warning are carried out by adopting terahertz radar and photoelectric monitoring information fusion, and all-weather non-blind-area and high-precision unmanned detection and anti-collision early warning of the ship are achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of radar design and manufacturing, and in particular to a ship anti-collision warning device and method based on terahertz radar. Background Art

[0002] The future trend for ships is toward unmanned operation, miniaturization, larger scale, and faster speeds. This trend makes small unmanned ships difficult to detect from a safe distance, their high relative speeds making them difficult to evade. Large unmanned ships, however, are difficult to brake due to their high inertia, and their high kinetic energy creates significant damage from impacts. Given the unpredictable and harsh conditions at sea, the radar-based navigation systems used by automated vehicles on land cannot be directly applied to automated ships. Furthermore, radar sensors prevent remote operators from obtaining information about the ship's surroundings through the most direct means—visual perception. Furthermore, the long voyages of ships require operators to maintain a constant all-around vigilance, requiring numerous personnel on duty in shifts and consuming considerable energy. This often leads to delays in detecting dangerous situations due to fatigue or negligence. This necessitates the need for automated collision warning and navigation systems not only for unmanned ships but also for conventional vessels.

[0003] To meet the navigation safety requirements of future unmanned and intelligent ships, shipborne radars are required to possess all-weather, high-resolution, intelligent identification and tracking, and intelligent collision avoidance and prediction capabilities. Invention patent CN 108303078 A discloses an omnidirectional ship collision avoidance warning and navigation system based on stereo vision. This system uses multiple sets of conventional cameras and a stabilized gimbal to provide omnidirectional collision avoidance warning and navigation for ships in marine environments. This improves the stability of image output in marine environments such as strong winds and waves, or when the ship is moving at high speed or making sharp turns. However, this vision-based solution is sensitive to light and is significantly affected by adverse weather conditions such as fog and rain, failing to provide all-weather, high-resolution collision avoidance and prediction capabilities.

[0004] Compared to laser radar and optoelectronic devices, microwave radar has better penetration capabilities in adverse weather conditions such as fog and rain. Compared to microwave radar, terahertz radar has many technical advantages: (1) It has a very large signal bandwidth, which can achieve higher resolution; (2) It has a shorter wavelength, which can achieve a narrow antenna beam and obtain better angular resolution; (3) It has a wider detection field of view and better search capability under the same size antenna.

[0005] The technical characteristics of terahertz radar make it extremely advantageous for target imaging and acquiring detailed information about target features, enabling precise shape recognition of the target. Because terahertz radar can achieve a greater Doppler shift for targets with low radial velocities, it can be used to detect and identify slow-moving or peristaltic targets. Furthermore, target recognition typically requires a high data rate. The small size and light weight of terahertz radar facilitate rapid antenna scanning, thus providing a high data rate. These characteristics give terahertz radar a leading advantage in target early warning detection, and it holds a very broad prospect in security and counterterrorism, vehicle collision avoidance, meteorological cloud measurement, biomedicine, and other fields.

[0006] Terahertz radars enable high-resolution, all-weather situational awareness and intelligent target identification and tracking. Networking multiple terahertz radars around a ship's hull enables high-resolution collision avoidance warnings with no blind spots. Currently, there are no terahertz-band marine radars available, either domestically or internationally. Therefore, a device using terahertz radar for ship collision avoidance warning is urgently needed to achieve high-precision, high-resolution, all-weather, unmanned detection and collision avoidance warning capabilities. Summary of the Invention

[0007] The object of the present invention is to provide a ship anti-collision warning device and method based on terahertz radar, which does not require target structural information and has good attack concealment and attack effect.

[0008] The technical solution to achieve the purpose of the present invention is: a terahertz radar-based ship collision warning device, including a terahertz radar antenna unit and an integrated processing platform;

[0009] The terahertz radar antenna unit is installed at each monitoring node, and the target data and control information are transmitted through the network communication equipment and the integrated processing platform;

[0010] The comprehensive processing platform controls the terahertz radar antenna unit, displays radar video information and track data, detects small targets and generates fusion situations based on the monitoring information of the terahertz radar antenna unit, and realizes the collision avoidance alarm function.

[0011] Furthermore, the terahertz radar antenna unit includes an optoelectronic device, an antenna extension, a transceiver extension, and a servo extension;

[0012] The photoelectric equipment includes a long-range photoelectric monitoring lens and a short-range photoelectric monitoring lens, which are used to collect photoelectric video images;

[0013] The antenna extension includes an antenna and a feeder, is not equipped with a radome, and is used to transmit and receive radio frequency signals;

[0014] The transceiver extension is composed of a microwave module, including a TR component and a frequency combiner, which realizes the functions of transmitting, receiving, frequency conversion and amplification of radio frequency signals;

[0015] The servo extension includes a servo control assembly and a servo drive assembly. The servo control assembly includes a servo control board and a status detection board; the servo drive assembly includes an azimuth driver and a pitch driver, which are used to control the rotation of the antenna and complete the azimuth and pitch scanning of the antenna.

[0016] Furthermore, the integrated processing platform includes a signal processing extension, a data processing extension, a display and control extension, and a power extension;

[0017] The signal processing sub-unit includes a sampling board and a comprehensive processing board, which are used to complete AD sampling, non-coherent accumulation, CFAR, and output digital video signals;

[0018] The data processing sub-unit and the signal processing sub-unit share a comprehensive processing board for completing point track processing, track processing and filtering, and outputting point track and track information;

[0019] The display and control extension includes an integrated display and control unit for controlling the radar and optoelectronic equipment as a whole and displaying detection information;

[0020] The power extension includes a power box and a secondary power supply. The power box converts the externally provided AC220V power into DC48V and sends it to the secondary power supply. The secondary power supply is used to power the terahertz radar antenna unit.

[0021] Furthermore, the number of the terahertz radar antenna units is 4, which are installed at each monitoring node on the ship respectively, and adopt the terahertz frequency band and continuous wave large frequency modulation bandwidth mode; in the continuous wave large frequency modulation bandwidth mode, a low-power solid-state transmitter, digital filtering and FFT processing are used to identify the target's shape, obtain the target's characteristic structure details, and realize target detection and collision avoidance without blind spots.

[0022] Furthermore, the antenna adopts a dual-antenna reflector to meet the requirements for transmit and receive isolation during continuous wave operation; the antenna's inverse cosecant square is shaped to -50°, the elevation beam width is 2.2°, and the antenna is mechanically scanned with a period of 2s and ±120°.

[0023] Four terahertz radar antenna units are networked, and each radar covers an azimuth range of ±90°, achieving complementary visual field blind spots: azimuth 0-360°, pitch coverage range -80° to 15°, and pitch instantaneous range -45° to 5°.

[0024] Furthermore, the terahertz radar antenna unit adopts an integrated two-axis structure with an optoelectronic monolithic design, with a width × height × depth = 432mm × 685mm × 407mm;

[0025] Each terahertz radar antenna unit adopts a full-frame structure form, and the antenna pedestal is installed in a hoisting manner, with the pitching and azimuth axes intersecting vertically at one point; the weight distribution of the devices is optimized during the design of the structural parts and the module combination layout of the entire antenna pedestal to achieve torque balance.

[0026] Furthermore, in the terahertz radar antenna unit, the antenna reflector and the front cover plate of the box are integrally processed and formed, and the whole is used as the front cover of the frame; a feed support arm and a fine-tuning mechanism are provided to connect the feed section of the component to the antenna reflecting surface to form a frame structure.

[0027] Furthermore, the terahertz radar antenna unit operates in the frequency-modulated continuous wave mode, with the working range set to 1 km, the frequency modulation bandwidth of 8 G, the working frequency band of 139.5 GHz to 148.5 GHz, and the three frequency points are 143.5 GHz, 144 GHz, and 144.5 GHz respectively.

[0028] Furthermore, the frequency domain allocation of the terahertz radar antenna unit is as follows:

[0029] t sd is the transmission time, that is, the signal duration, Δt is the period of the entire transmission waveform, where Δt is equal to the beam dwell time, that is, the time to complete the target measurement within a single beam. There are n consecutive sawtooth waveforms with a period of T within Δt, and the gap between the two sets of transmitted signals is Δt - t sd is used for signal processing and data processing;

[0030] The propagation delay of the radar signal satisfies t d <<T, and the maximum echo delay t of the LFMCW radar d necessarily satisfies t d <T / 2, where T is the frequency modulation period;

[0031] The maximum frequency deviation of the echo signal, that is, the difference frequency signal F if is F if =B / T*t d , where B represents the signal bandwidth;

[0032] Detection distance f bav is the frequency deviation of the target, and c represents the speed of light;

[0033] Adopting the same maximum frequency deviation value under different ranges to meet the system distance resolution requirements;

[0034] The determination of the maximum frequency deviation value and the echo delay finally determines the frequency modulation period T, and two transmission time widths of 1200 μs and 600 μs are reserved as radar design parameters:

[0035] Table 1

[0036]

[0037] The radar parameters are shown in Table 1.

[0038] A terahertz radar-based ship collision avoidance warning method, which uses the terahertz radar-based ship collision avoidance warning device. The process of the warning method is as follows:

[0039] The signal processing timer controls the working sequence of the terahertz radar. The frequency synthesizer generates a pulse frequency modulation signal, which is up-converted to the X-band and then connected to the terahertz signal transceiver module. The signal is up-converted to the terahertz frequency band and then amplified and output to the terahertz antenna.

[0040] The echo signal is mixed, filtered, and amplified to the X-band through the receiving channel, and then sent to the baseband signal transceiver module for mixing, filtering, amplification, and then AD digitization to complete signal accumulation processing;

[0041] Data processing and signal processing share the same integrated processing board hardware. After completion, the track and video are output to the display and control program through the network;

[0042] The integrated display and control machine controls the entire radar, displays radar video information and track data, integrates radar information and optoelectronic information, and has collision avoidance alarm functions.

[0043] Compared with the existing technology, the present invention has the following significant advantages: (1) It adopts terahertz radar and optoelectronic monitoring information fusion for unmanned detection and anti-collision warning, has a wider detection field of view and better search capability, and realizes all-weather, high-precision unmanned detection and anti-collision warning of ships without blind spots; (2) The terahertz radar antenna unit adopts a miniaturized, optoelectronic and co-integrated design, which reduces the overall weight of the antenna base; (3) The terahertz band can be isolated from the X and S bands commonly used by navigation radars in the frequency band, and there is no interference between the spectrums, which improves the electromagnetic compatibility between different devices. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 This is a structural block diagram of a ship anti-collision warning device based on terahertz radar in the present invention.

[0045] Figure 2 The figure is a schematic diagram of the working process of a ship anti-collision warning device based on terahertz radar according to the present invention.

[0046] Figure 3 Schematic diagram of the system airspace coverage and configuration of the anti-collision warning device in the present invention.

[0047] Figure 4 Schematic diagram of the three-dimensional structure of the antenna base of the ship collision avoidance warning device in an embodiment of the present invention.

[0048] Figure 5 Schematic diagram of the three-dimensional structure of the antenna feed system of the ship anti-collision warning device in an embodiment of the present invention.

[0049] Figure 6 This is a linear frequency modulation waveform diagram of the ship anti-collision warning device in an embodiment of the present invention.

[0050] Figure 7 This is a radar timing diagram of the ship anti-collision warning device in an embodiment of the present invention. DETAILED DESCRIPTION

[0051] Combine Figure 1 , the present invention provides a ship anti-collision warning device based on terahertz radar, including a terahertz radar antenna unit and an integrated processing platform;

[0052] The terahertz radar antenna unit is installed at each monitoring node, and the target data and control information are transmitted through the network communication equipment and the integrated processing platform;

[0053] The comprehensive processing platform controls the terahertz radar antenna unit, displays radar video information and track data, detects small targets and generates fusion situations based on the monitoring information of the terahertz radar antenna unit, and realizes the collision avoidance alarm function.

[0054] As a specific example, the terahertz radar antenna unit includes an optoelectronic device, an antenna extension, a transceiver extension, and a servo extension;

[0055] The photoelectric equipment includes a long-range photoelectric monitoring lens and a short-range photoelectric monitoring lens, which are used to collect photoelectric video images;

[0056] The antenna extension includes an antenna and a feeder, is not equipped with a radome, and is used to transmit and receive radio frequency signals. The horizontal beam width is 0.62; the elevation main beam is 2.2°, pointing to -1.0°, and the cosecant square is shaped to -45°;

[0057] The transceiver extension is composed of a microwave module, containing a TR component and a frequency combiner, which realizes the functions of transmitting and receiving, frequency conversion and amplification of radio frequency signals;

[0058] The servo extension includes a servo control assembly and a servo drive assembly. The servo control assembly includes a servo control board and a status detection board; the servo drive assembly includes an azimuth driver and a pitch driver, which are used to control the rotation of the antenna and complete the azimuth and pitch scanning of the antenna.

[0059] As a specific example, the integrated processing platform includes a signal processing extension, a data processing extension, a display and control extension, and a power extension;

[0060] The signal processing sub-unit includes a sampling board and a comprehensive processing board, which are used to complete AD sampling, non-coherent accumulation, CFAR, and output digital video signals;

[0061] The data processing sub-unit and the signal processing sub-unit share a comprehensive processing board for completing point track processing, track processing and filtering, and outputting point track and track information;

[0062] The display and control extension includes an integrated display and control unit for controlling the radar and optoelectronic equipment as a whole and displaying detection information;

[0063] The power extension includes a power box and a secondary power supply. The power box converts the externally provided AC220V power into a stable and usable DC48V and sends it to the secondary power supply. The secondary power supply is used to power each module in the terahertz radar antenna unit.

[0064] As a specific example, Figure 3 As shown, there are four terahertz radar antenna units, which are installed at various monitoring nodes on the ship. The target data and control information are transmitted through network communication equipment and the integrated processing platform, and the display control and low-altitude target alarm are implemented through the display and control all-in-one machine. The terahertz radar antenna unit transmits information to the outside through the network to achieve complementary visual airspace blind spots: azimuth 0-360°, pitch coverage range -80°~15°, pitch instantaneous range -45°~5°.

[0065] As a specific example, the terahertz radar antenna unit adopts a miniaturized, optoelectronically co-existing design, an integrated two-axis structure, and has a width × height × depth of 432mm × 685mm × 407mm. The entire platform adopts a full-frame structure, and the antenna base is installed by hoisting, with the pitch and azimuth axes intersecting perpendicularly at a point. To minimize unbalanced torque, the entire antenna base takes into account the weight distribution of the device when designing the structural components and combining the modules. The center of gravity offset is within an acceptable range, avoiding the counterweight design and reducing the overall weight of the antenna base.

[0066] The terahertz radar antenna unit uses a low-power solid-state transmitter, which can achieve short-range small target detection and collision avoidance without blind spots. At the same time, the terahertz frequency band is conducive to target imaging and obtaining target characteristic structure details. The 8G frequency modulation bandwidth is used to accurately identify the target's shape.

[0067] As a specific example, the terahertz radar antenna unit adopts digital and networked communication technology to reduce the complexity of the system architecture, facilitate system expansion and docking with other systems.

[0068] As a specific example, the antenna reflector and the front cover of the box are integrally processed and formed, and the whole serves as the front cover of the frame; in order to ensure the positioning accuracy, a feed support arm and a fine-tuning mechanism are designed to connect the component feed section with the antenna reflecting surface to form a frame structure, thereby achieving the effect of reinforcement and fine-tuning.

[0069] As a specific example, the antenna adopts the form of a reflecting surface dual antenna, which meets the technical requirements for transmit and receive isolation during continuous wave operation; the antenna system's inverse cosecant square is shaped to -50°, the pitch beam width is 2.2°, and the antenna is mechanically scanned with a period of 2s and ±120°.

[0070] As a specific example, Figure 2 As shown, the working process of the ship anti-collision warning device based on terahertz radar is as follows:

[0071] The terahertz radar system is controlled by a signal processing timer to control the working timing of the system. The frequency synthesizer generates a pulse frequency modulation signal, which is up-converted to the X-band and then connected to the terahertz signal transceiver module, up-converted to the terahertz frequency band, and output to the terahertz antenna after amplification. The echo signal is mixed, filtered, and amplified to the X-band through the receiving channel, and then sent to the baseband signal transceiver module for mixing, filtering, amplification, and AD digitization to complete the signal accumulation processing. Data processing and signal processing share the integrated processing board hardware. After completion, the track and video are output to the display and control program through the network. The display and control integrated machine completes the control of the radar system, and the radar video information and track data are displayed. The radar information and optoelectronic information are integrated and the collision avoidance alarm function is provided.

[0072] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0073] Example

[0074] like Figure 1 As shown, this embodiment provides a ship collision avoidance warning device based on terahertz radar, including a terahertz radar antenna unit and an integrated processing platform;

[0075] The terahertz radar antenna unit is installed at each monitoring node, and the target data and control information are transmitted through the network communication equipment and the integrated processing platform;

[0076] The comprehensive processing platform controls the terahertz radar antenna unit, displays radar video information and track data, detects small targets and generates fusion situations based on the monitoring information of the terahertz radar antenna unit, and realizes the collision avoidance alarm function.

[0077] As a specific example, the terahertz radar antenna unit includes an optoelectronic device, an antenna extension, a transceiver extension, and a servo extension;

[0078] The photoelectric equipment includes a long-range photoelectric monitoring lens and a short-range photoelectric monitoring lens, which are used to collect photoelectric video images;

[0079] The antenna extension includes an antenna and a feeder, is not equipped with a radome, and is used to transmit and receive radio frequency signals. The horizontal beam width is 0.62; the elevation main beam is 2.2°, pointing to -1.0°, and the cosecant square is shaped to -45°;

[0080] The transceiver extension is composed of a microwave module, containing a TR component and a frequency combiner, which realizes the functions of transmitting and receiving, frequency conversion and amplification of radio frequency signals;

[0081] The servo extension includes a servo control assembly and a servo drive assembly. The servo control assembly includes a servo control board and a status detection board; the servo drive assembly includes an azimuth driver and a pitch driver, which are used to control the rotation of the antenna and complete the azimuth and pitch scanning of the antenna.

[0082] As a specific example, the integrated processing platform includes a signal processing extension, a data processing extension, a display and control extension, and a power extension;

[0083] The signal processing sub-unit includes a sampling board and a comprehensive processing board, which are used to complete AD sampling, non-coherent accumulation, CFAR, and output digital video signals;

[0084] The data processing sub-unit and the signal processing sub-unit share a comprehensive processing board for completing point track processing, track processing and filtering, and outputting point track and track information;

[0085] The display and control sub-station includes an integrated display and control unit, which uses an integrated processing computer and a 23-inch display to control the radar and optoelectronic equipment and display detection information;

[0086] The power extension includes a power box and a secondary power supply. The power box converts the externally provided AC220V power into a stable and usable DC48V and sends it to the secondary power supply. The secondary power supply is used to power each module in the terahertz radar antenna unit.

[0087] As a specific example, Figure 3 As shown, Figure 3 (a) is a schematic diagram of the installation height of the anti-collision warning device; Figure 3 (b) is a schematic diagram of the airspace coverage of the anti-collision warning device; Figure 3(c) is a schematic diagram of the installation location of the anti-collision warning device. The terahertz radar antenna units consist of four, installed at various monitoring nodes on the vessel. Target data and control information are transmitted via network communications equipment and an integrated processing platform. Display control and low-altitude target warnings are implemented via the integrated display and control unit. The terahertz radar antenna units transmit information externally via the network, complementing the visual field's blind spots: 0-360° in azimuth, -80° to 15° in elevation, and -45° to 5° in instantaneous elevation.

[0088] As a specific example, Figure 4 As shown, the terahertz radar antenna unit adopts a miniaturized, optoelectronically co-existing design, an integrated two-axis structure, and measures 432mm x 685mm x 407mm in width x height x depth. The entire platform adopts a full-frame structure, and the antenna base is hoisted, with the elevation and azimuth axes intersecting perpendicularly at a point. To minimize unbalanced torque, the weight distribution of the components is considered during the structural design and module combination layout of the entire antenna base. The center of gravity offset is within an acceptable range, avoiding counterweight design and reducing the overall weight of the antenna base.

[0089] The terahertz radar antenna unit uses a low-power solid-state transmitter, which can achieve short-range small target detection and collision avoidance without blind spots. At the same time, the terahertz frequency band is conducive to target imaging and obtaining target characteristic structure details. The 8G frequency modulation bandwidth is used to accurately identify the target's shape.

[0090] As a specific example, the terahertz radar antenna unit adopts digital and networked communication technology to reduce the complexity of the system architecture, facilitate system expansion and docking with other systems.

[0091] As a specific example, Figure 5 As shown, the antenna reflector and the front cover of the box are integrally formed and serve as the front cover of the frame. To ensure positioning accuracy, a feed support arm and a fine-tuning mechanism are designed to connect the component feed section with the antenna reflector surface to form a frame structure, thereby achieving reinforcement and fine-tuning effects.

[0092] As a specific example, the antenna adopts the form of a reflecting surface dual antenna, which meets the technical requirements for transmit and receive isolation during continuous wave operation; the antenna system's inverse cosecant square is shaped to -50°, the pitch beam width is 2.2°, and the antenna is mechanically scanned with a period of 2s and ±120°.

[0093] The terahertz radar utilizes a terahertz frequency band and a continuous wave (CW) wide frequency modulation bandwidth system. Since antenna size is related to frequency, terahertz band antennas and microwave components are relatively small. Using a smaller antenna size allows for a narrower beam. Furthermore, the terahertz band is frequency-isolated from the X and S bands commonly used in navigation radars, eliminating cross-spectral interference and improving electromagnetic compatibility between different devices. The CW system enables blind-spot detection and collision avoidance of small, short-range targets. The terahertz band facilitates target imaging and acquisition of target structural details. The present invention utilizes an 8GHz CW bandwidth, enabling precise target shape recognition.

[0094] As a specific example, the workflow of the terahertz radar-based ship collision warning device is as follows:

[0095] The terahertz radar system is controlled by a signal processing timer to control the working timing of the system. The frequency synthesizer generates a pulse frequency modulation signal, which is up-converted to the X-band and then connected to the terahertz signal transceiver module, up-converted to the terahertz frequency band, and output to the terahertz antenna after amplification. The echo signal is mixed, filtered, and amplified to the X-band through the receiving channel, and then sent to the baseband signal transceiver module for mixing, filtering, amplification, and AD digitization to complete the signal accumulation processing. Data processing and signal processing share the integrated processing board hardware. After completion, the track and video are output to the display and control program through the network. The display and control integrated machine completes the control of the radar system, and the radar video information and track data are displayed. The radar information and optoelectronic information are integrated and the collision avoidance alarm function is provided.

[0096] In continuous wave mode, the radar uses a low-power solid-state transmitter, digital filtering, and FFT processing. Its characteristics include low peak power, low intercept characteristics, and the use of linear frequency modulation sawtooth waveforms. This system is simple to implement and has high accuracy and resolution.

[0097] (1) Frequency domain allocation

[0098] When the radar operates in FMCW mode, the operating range is set to 1km, the FM bandwidth is 8GHz, and the operating frequency bands and frequencies are shown in Table 1.1:

[0099] Table 1.1 Radar operating frequency table

[0100]

[0101] (2) Time domain allocation

[0102] like Figure 6 As shown in the figure, T is the frequency modulation time width, t sdis the emission time, that is, the signal duration; Δt is the period of the entire emission waveform, where Δt is approximately equal to the beam dwell time, that is, the time to complete the target measurement within a single beam. There are n consecutive sawtooth waveforms with a period of T within Δt, and the gap between two sets of transmitted signals is Δt - t sd It can be used for signal processing and data processing.

[0103] The propagation delay of the radar signal generally satisfies t d <<T, and the maximum echo delay t of the LFMCW radar d necessarily satisfies t d <T / 2, where T is the sweep period.

[0104] The maximum frequency deviation of the echo signal, that is, the difference frequency signal is:

[0105] F if =μ * t d =B / T * t d

[0106] The detection distance R is:

[0107]

[0108] In the formula, f bav is the frequency deviation of the target.

[0109] The maximum frequency deviation value is related to the filter design and the AD sampling rate. Considering reducing the complexity of the receiver design and the actual radar application situation, the maximum frequency deviation value under different ranges is uniformly set to meet the system distance resolution requirements.

[0110] The determination of the maximum frequency deviation value and the echo delay finally determines the frequency modulation period T. Two transmit time widths of 1200u and 600us are reserved as radar design parameters, as shown in Table 1.2, and the timing relationship is as Figure 7 shown:

[0111] Table 1.2 Radar parameter table

[0112]

[0113] The above is only the preferred implementation mode of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. A ship anti-collision warning device based on terahertz radar, characterized in that: Includes terahertz radar antenna unit and integrated processing platform; The terahertz radar antenna unit is installed at each monitoring node, and the target data and control information are transmitted through the network communication equipment and the integrated processing platform; The comprehensive processing platform controls the terahertz radar antenna unit, displays radar video information and track data, detects small targets and generates fusion situations based on the monitoring information of the terahertz radar antenna unit, and realizes the collision avoidance alarm function.

2. The ship collision avoidance warning device based on terahertz radar according to claim 1, characterized in that: The terahertz radar antenna unit includes an optoelectronic device, an antenna extension, a transceiver extension, and a servo extension; The photoelectric equipment includes a long-range photoelectric monitoring lens and a short-range photoelectric monitoring lens, which are used to collect photoelectric video images; The antenna extension includes an antenna and a feeder, is not equipped with a radome, and is used to transmit and receive radio frequency signals; The transceiver extension is composed of a microwave module, including a TR component and a frequency combiner, which realizes the functions of transmitting, receiving, frequency conversion and amplification of radio frequency signals; The servo extension includes a servo control assembly and a servo drive assembly. The servo control assembly includes a servo control board and a status detection board; the servo drive assembly includes an azimuth driver and a pitch driver, which are used to control the rotation of the antenna and complete the azimuth and pitch scanning of the antenna.

3. The ship anti-collision warning device based on terahertz radar according to claim 2, characterized in that: The comprehensive processing platform includes a signal processing extension, a data processing extension, a display and control extension, and a power supply extension; The signal processing sub-unit includes a sampling board and a comprehensive processing board, which are used to complete AD sampling, non-coherent accumulation, CFAR, and output digital video signals; The data processing sub-unit and the signal processing sub-unit share a comprehensive processing board for completing point track processing, track processing and filtering, and outputting point track and track information; The display and control extension includes an integrated display and control unit for controlling the radar and optoelectronic equipment as a whole and displaying detection information; The power extension includes a power box and a secondary power supply. The power box converts the externally provided AC220V power into DC48V and sends it to the secondary power supply. The secondary power supply is used to power the terahertz radar antenna unit.

4. The ship collision avoidance warning device based on terahertz radar according to claim 3, characterized in that: The terahertz radar antenna units are four in number, installed at each monitoring node on the ship, using the terahertz frequency band and continuous wave large frequency modulation bandwidth mode. In the continuous wave large frequency modulation bandwidth mode, a low-power solid-state transmitter, digital filtering and FFT processing are used to identify the target's shape, obtain the target's characteristic structural details, and achieve target detection and collision avoidance without blind spots.

5. The ship anti-collision warning device based on terahertz radar according to claim 4 is characterized in that: The antenna adopts a reflector dual antenna form to meet the requirements of transmitting and receiving isolation during continuous wave operation; The antenna's inverse cosecant square is shaped to -50°, the elevation beamwidth is 2.2°, and the antenna is mechanically scanned with a period of 2s and ±120°. Four terahertz radar antenna units are networked, and each radar covers an azimuth range of ±90°, achieving complementary visual field blind spots: azimuth 0-360°, pitch coverage range -80° to 15°, and pitch instantaneous range -45° to 5°.

6. The ship collision avoidance warning device based on terahertz radar according to claim 5, characterized in that: The terahertz radar antenna unit adopts an integrated two-axis structure with an optoelectronic integrated design, with a width × height × depth of 432mm × 685mm × 407mm; Each terahertz radar antenna unit adopts a full-frame structure, and the antenna base is installed by hoisting, with the pitch and azimuth axes intersecting vertically at one point; the entire antenna base optimizes the device weight distribution during the structural design and module combination layout to balance the torque.

7. The ship collision avoidance warning device based on terahertz radar according to claim 6, characterized in that: In the terahertz radar antenna unit, the antenna reflector and the front cover of the box are integrally processed and formed, and the whole serves as the front cover of the frame; a feed support arm and a fine-tuning mechanism are provided to connect the component feed section with the antenna reflector surface to form a frame structure.

8. The ship collision avoidance warning device based on terahertz radar according to claim 7, characterized in that: The terahertz radar antenna unit operates in frequency-modulated continuous wave mode, with a working range set to 1 km, a frequency modulation bandwidth of 8G, an operating frequency band of 139.5GHz to 148.5GHz, and three frequency points of 143.5GHz, 144GHz, and 144.5GHz respectively.

9. The ship anti-collision warning device based on terahertz radar according to claim 8, characterized in that: The frequency domain allocation of the terahertz radar antenna unit is as follows: t sd is the transmission time, i.e., the duration of the signal, and Δt is the period of the entire transmission waveform, where Δt is equal to the beam dwell time, i.e., the time to complete the target measurement in a single beam. Δt contains n consecutive sawtooth waveforms with a transmission period of T. The gap between the two groups of transmission signals is Δt-t sd For signal processing and data processing; The propagation delay of the radar signal satisfies t d << T, and the maximum echo delay t of the LFMCW radar d must satisfy t d < T / 2, where T is the frequency modulation period; The maximum frequency deviation of the echo signal is the difference frequency signal F if F if =B / T*t d , B represents the signal bandwidth; Detection distance f bav is the frequency deviation of the target, c represents the speed of light; The maximum frequency deviation value under different ranges is used to meet the system distance resolution requirements; The maximum frequency deviation value and echo delay were determined, and the frequency modulation period T was finally determined. Two transmission time widths of 1200μs and 600μs were reserved as radar design parameters: Table 1 The radar parameters are shown in Table 1.

10. A ship collision avoidance warning method based on terahertz radar, characterized in that: The method adopts the terahertz radar-based ship collision avoidance warning device according to any one of claims 1 to 9, and the process of the warning method is as follows: The signal processing timer controls the working sequence of the terahertz radar. The frequency synthesizer generates a pulse frequency modulation signal, which is up-converted to the X-band and then connected to the terahertz signal transceiver module. The signal is up-converted to the terahertz frequency band and then amplified and output to the terahertz antenna. The echo signal is mixed, filtered, and amplified to the X-band through the receiving channel, and then sent to the baseband signal transceiver module for mixing, filtering, amplification, and then AD digitization to complete signal accumulation processing; Data processing and signal processing share the same integrated processing board hardware. After completion, the track and video are output to the display and control program through the network; The integrated display and control machine controls the entire radar, displays radar video information and track data, integrates radar information and optoelectronic information, and has collision avoidance alarm functions.

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