117 results about "Ultra-short baseline" patented technology

In the present invention, a location joint monitoring solution based on the state of a distributed optical fiber and based on an ultra-short baseline is used, and the solution consists of a distributed optical fiber monitoring device, an ultra-short baseline positioning device and a health monitoring host computer. The distributed optical fiber monitoring device consists of a distributed optical fiber cable (300), a distributed optical fiber demodulator (421), etc. The ultra-short baseline positioning device consists of an ultra-short baseline array (200), an underwater beacon (100), a signal processing device (411), etc. The health monitoring host computer (431) can perform signal conditioning, digital signal processing and parameter estimation by means of the signal processing device and the distributed optical fiber demodulator and by using acquired data such as key point locations, deformation and postures, and complete space curve reconstruction of an underwater riser by means of a space curve reconstruction algorithm and an existing finite element analysis software platform, thereby realizing visual outputs of an underwater state of a marine riser.

The invention discloses an underwater robot submarine cable inspection method and system based on two-dimensional image sonar, and relates to the field of submarine cable inspection. The existing submarine cable inspection method has the problems of insufficient detection precision, lack of autonomy, dynamic obstacle avoidance defect and the like. The method comprises the steps of submarine cable feature recognition model construction, underwater robot sensing system configuration, image processing, path planning, obstacle avoidance path generation and detouring. According to the technical scheme, the underwater robot carries the electromagnetic induction sensor, the two-dimensional image sonar and the ultra-short baseline positioning device, and an image processing technology and a path planning algorithm are combined, so that efficient inspection of the submarine cable is realized; when the robot encounters an obstacle, the robot can generate an obstacle point cloud through image processing in combination with prior obstacle information, and performs obstacle avoidance in combination with a local path planning algorithm, so that safe and smooth proceeding of an inspection task is ensured; the detection precision is effectively improved, automatic and efficient inspection is realized, and a powerful guarantee is provided for long-term stable operation of the submarine cable.

The invention discloses a heterogeneous sensor fusion method and system for dynamic covariance optimization, and the method comprises the steps: constructing a multi-source heterogeneous sensor network which comprises an underwater inertial navigation unit, a Doppler velocity sensor, an ultra-short baseline positioning system, a submarine topography matching device and a geomagnetic gradient detector; the method comprises the following steps: designing a distributed integrated navigation system by adopting a hierarchical fusion architecture, establishing a sensor confidence coefficient dynamic evaluation model based on online estimated error covariance matrix eigenvalue analysis, carrying out state prediction on a local filter level by applying Kalman filtering, and then carrying out measurement updating by adopting a novel variational Bayesian algorithm; a sensor autonomous switching and adaptive weighted dual-mode adjustment mechanism is developed on the main filter level, and self-healing improvement of navigation precision in a non-stationary environment is realized, so that the problems of dynamic reliability evaluation and fusion efficiency optimization in underwater multi-sensor multi-source navigation are solved.

The invention discloses an underwater carrier navigation and positioning method considering in-situ sound velocity observation, which belongs to the technical field of navigation and positioning, is used for underwater carrier navigation and positioning, and comprises the following steps: for the position of a GNSS (Global Navigation Satellite System) antenna, adopting attitude observation data obtained by an attitude sensor, implementing attitude correction, and obtaining the position of the center of an ultra-short baseline USBL (Universal Serial Bus Language) array element unit; the method comprises the following steps: acquiring in-situ sound velocity observation information in real time through a CTD acoustic sensor carried by an underwater carrier, and correcting a historical fixed sound velocity profile SVP based on the real-time in-situ sound velocity information; and carrying out sound ray tracking again based on the corrected historical fixed sound velocity profile, and carrying out real-time positioning on the underwater carrier. Compared with the prior art, the time-varying correction of the fixed sound velocity profile is realized by using the sound velocity in-situ observation information carried on the underwater carrier, the influence on the navigation and positioning of the underwater carrier is weakened, and the navigation and positioning precision of the underwater carrier is improved.

The invention discloses a submersible integrated navigation adaptive calibration method based on multi-source confidence evaluation, belongs to the technical field of underwater navigation and data processing, is used for submersible integrated navigation, and comprises the following steps: establishing a confidence evaluation model of a multi-dimensional ultra-short baseline positioning system; a comprehensive confidence index is dynamically calculated through signal quality, geometric accuracy factor quality, environmental parameters and data sequence stability, Kalman filtering observation weight is adaptively adjusted based on the comprehensive confidence index, and a three-level decision mechanism is designed to replace manual judgment. The intelligent fusion of the positioning data of the ultra-short baseline positioning system is realized, the human participation degree is reduced, the navigation and positioning autonomy of the submersible is improved, and the underwater operation efficiency of the submersible is further improved.

The invention discloses an underwater collaborative navigation positioning method based on inertia / ultra-short baseline alternative navigation. The method comprises the following steps: firstly, establishing a navigator motion model; a navigator carries out calculation navigation by using INS, and when the navigator does not receive a prior topographic map, INS / DVL integrated navigation is carried out by using Kalman filtering. When a navigator receives a prior topographic map, INS / DVL / TAN integrated navigation is carried out by using Kalman filtering. And then establishing a follower collaborative navigation model. Then, the navigator carries out distance measurement and angle measurement on the follower through the ultra-short base line, position information, slant distance information and azimuth angle information of the follower are sent to the follower at fixed time intervals, and the follower carries out tight combination based on Kalman filtering through the information; and finally, when the USBL carries out distance measurement and angle measurement, the single navigator carries out tight combination positioning on the follower. When the USBL only carries out distance measurement, simultaneous navigation is set to be alternate navigation, namely, the navigator 1 broadcasts own position and distance information at the moment, and the navigator 2 broadcasts own position and distance information at the next moment.

A split type AUV system comprises an autonomous underwater robot system and a buoy system, the autonomous underwater robot system comprises an electric control sealed cabin, a multi-beam imaging sonar module, a magnetic attraction fixing device, a visual positioning module, an ultra-short baseline USBL transponder beacon, a single-beam sonar module, a depth module, an underwater laser range finder, a battery sealed cabin and a driving unit; the buoy system comprises an ultra-short base line USBL beacon, a floating platform, a cable reel motor, a cable reel, a satellite positioning module, a buoy system electric control cabin, a side scan sonar, an Aruco two-dimensional code plate, a driving unit, a permanent magnet block and a battery cabin; the invention aims to provide an underwater navigation positioning system of a split type AUV (Autonomous Underwater Vehicle), which assists in acquiring the accurate position of an underwater robot.

The invention provides an underwater vehicle docking process position estimation system and method based on reinforcement learning. The problem of position deviation in the underwater vehicle docking process is solved by combining reinforcement learning and Kalman filtering. The reinforcement learning learns filtering gain from historical data including sensor measurement and estimation, and adaptive error compensation of position information in the docking process of the underwater vehicle is realized by using a good starting point provided by Kalman filtering and learnable characteristics of the reinforcement learning. The ultra-short baseline positioning information and the inertial navigation information are fused, the problems of inertial navigation errors accumulated along with time and ultra-short baseline data lag are solved by using the extended Kalman filter algorithm, and the positioning stability and real-time performance are improved. Through simulation verification, the method can effectively compensate the gain of the filter and accurately estimate the position of the underwater vehicle in the docking process.

The invention relates to the technical field of ultra-short baseline positioning, in particular to an ultra-short baseline positioning method and system based on a TDOA observation value and an effective sound velocity, and the method comprises the steps: constructing a spatial geometric distance mathematical relationship between a hydrophone and a sound source target according to a position vector of the hydrophone in a USBL system in a carrier coordinate system, and building an ultra-short baseline TDOA observation equation; unknown parameters of the ultra-short baseline TDOA observation equation comprise an effective sound velocity parameter and a sound source position vector parameter; substituting the effective sound velocity approximate value and the sound source position vector approximate value into an ultra-short baseline TDOA observation equation to linearize the ultra-short baseline TDOA observation equation; and iteratively solving the linearized ultra-short baseline TDOA observation equation by using a least square method criterion, and obtaining a final effective sound velocity and a final sound source target position vector according to a solving result. The method can be suitable for a USBL system with TDOA as an original observation value, can avoid the influence of sound ray bending, is simple in calculation principle, and can be embedded into a novel USBL positioning system for use.

The invention provides an iUSBL installation error calibration method independent of a fixed transponder and related equipment, and relates to the technical field of inverse ultra-short baseline installation errors. The method comprises the following steps: step 1, calculating coordinates of a transponder in an iUSBL coordinate system according to iUSBL direction finding and distance measuring information; step 2, calculating an origin coordinate of an iUSBL coordinate system under a navigation coordinate system by using UUV position and attitude information provided by iUSBL distance measurement information assisted INS integrated navigation and a lever arm; 3, establishing a theoretical relational expression between the coordinates of the transponder and the coordinates of the origin of the iUSBL coordinate system; 4, establishing a difference equation according to the theoretical relational expression; and 5, based on the difference equation, establishing an objective function and calculating an iUSBL installation error parameter by adopting a nonlinear least square solution. According to the iUSBL installation error calibration method, iUSBL installation error calibration without fixing the transponder can be realized, and the applicability and the flexibility of the iUSBL installation error calibration method are improved.

The invention discloses an ultra-short baseline positioning method based on a binary short baseline, and belongs to the technical field of underwater acoustic target navigation positioning. The method comprises the following steps: S1, designing a spread spectrum underwater acoustic communication signal for underwater acoustic communication between an ultra-short baseline transceiver and a transponder; s2, solving ultra-short baseline time delay information by adopting a frequency domain correlation method, and obtaining high-precision time delay information through an interpolation method; s3, two sets of transceivers with known positions are installed at the ship end at a preset interval distance, and the two sets of transceivers form a binary short baseline framework; installing at least one group of transponders at the mobile terminal, and obtaining the distance information of the two groups of transceivers and the transponders and the initial position information of the mobile terminal; and S4, based on the two groups of distance information and the initial position information, performing binary short baseline positioning calculation by adopting an iterative optimization algorithm to obtain high-precision position information of the mobile terminal. The ultra-short baseline positioning method based on the binary short baseline is high in positioning precision and high in stability, and can still realize high-precision target positioning in a low signal-to-noise ratio environment.

The invention belongs to the technical field of navigation, and discloses an inertial navigation method and system based on dual modes and a medium, the dual modes comprise a first navigation mode and a second navigation mode, the first navigation mode adopts a first combined navigation mode formed by combining an inertial unit with an ultra-short baseline acoustic positioning unit and a Doppler velocity measurement unit, and the second navigation mode adopts a second combined navigation mode formed by combining an ultra-short baseline acoustic positioning unit and a Doppler velocity measurement unit. The navigation mode II adopts a second combined navigation mode of combining an inertial unit and a geomagnetic measurement unit. The method comprises the following steps: acquiring the depth of the submersible at the current position; and updating the current position of the submersible in real time by adopting the navigation mode I and / or the navigation mode II according to the depth of the submersible at the current position. The method has high positioning accuracy.

The invention relates to an ultra-short baseline positioning method for solving phase ambiguity based on a vector baseline fusion algorithm. The invention relates to the ultra-short baseline positioning method for solving the phase ambiguity based on the vector baseline fusion algorithm. The objective of the invention is to solve the problems of low ambiguity resolution success rate and high calculation overhead of the existing algorithm. The method comprises the following steps: step 1, in an N-element circular array, calculating a pseudo-fuzzy number combination set in each baseline combination through the phase of a received signal; step 2, obtaining a pseudo-fuzzy number combination of each baseline of the N-element array; 3, establishing a condition judgment loss function; calculating the error of the pseudo-fuzzy number combination; step 4, obtaining a combinatorial optimization model, and defining the combinatorial optimization model as a comprehensive loss function; obtaining a phase difference after ambiguity resolution of the corresponding baseline based on the comprehensive loss function; and step 5, calculating an azimuth function based on the obtained phase difference after ambiguity resolution of the corresponding base line, and solving the azimuth of the target based on the azimuth function. The method is applied to the field of ultra-short baseline positioning.

The invention provides an ultra-short baseline calibration method, device and system, and belongs to the technical field of underwater acoustic measurement, and the ultra-short baseline calibration method comprises the following steps: according to an antenna phase center position, a carrier instantaneous attitude, a distance and azimuth information at each observation moment, and installation parameters of an ultra-short baseline acoustic transducer relative to an inertial navigation system, carrying out calibration on the ultra-short baseline; establishing a distance equation between the ultra-short baseline acoustic transducer and the ultra-short baseline acoustic beacon at each observation moment; establishing a residual equation of each distance equation; and solving the residual equation through a nonlinear least square method to obtain installation parameters. According to the method, the installation parameters of the ultra-short baseline acoustic beacon can be efficiently and accurately calibrated, and the problems that beacon laying and recycling operation is complex, cost is high, the operation period is long, efficiency is low, and the beacon is prone to drifting due to the influence of ocean currents are effectively solved.

The invention belongs to the technical field of marine surveying and mapping and engineering application, and relates to a multi-layer underwater moving target combined measurement device and method. Through the combined measurement equipment and method based on the ultra-short base line and the long base line and a distributed measurement framework under a geodetic coordinate system, high-precision fusion calculation of motion parameters such as the position and the speed of the underwater moving target is realized, a multi-target situation analysis scene under a unified space-time reference condition can be established, and the accuracy of the situation analysis is improved. According to the method, multi-target integrated situation acquisition under multiple working condition dimensions such as horizontal movement, vertical movement, low-speed movement, high-speed movement, a moving target and an underwater environment in an underwater application environment can be realized, and data support and reference basis can be provided for motion state analysis and safety state judgment of the underwater target under an engineering condition; important information foundation support can be provided for digital space mapping underwater operation environment; and practical application support can be provided for a measurement method of multivariate fusion solution.

The invention discloses a real-time positioning system and method of an underwater glider and the underwater glider, and belongs to the technical field of underwater detection equipment. The real-time positioning system comprises an acoustic positioning system, an inertial navigation unit, an electromagnetic ocean current meter and a control unit. The acoustic positioning system is composed of an ultra-short baseline range finder electronic cabin and an ultra-short baseline electroacoustic transducer and used for emitting acoustic signals and carrying out underwater position calculation through a tracking ship. The inertial navigation unit comprises a gyroscope, an accelerometer and a magnetometer; the electromagnetic ocean current meter is used for acquiring ocean current speed data; and the control unit is used for receiving and fusing data of the acoustic positioning system, the inertial navigation unit and the electromagnetic current meter, and optimizing real-time position estimation of the underwater glider through a fusion algorithm based on Kalman filtering. According to the system, the path and the track of the underwater glider for executing the observation task can be accurately obtained, and the ocean observation and detection accuracy is greatly improved.

The invention discloses an underwater acoustic single carrier communication frequency domain array processing method based on an ultra-short baseline array, and belongs to the field of underwater acoustic communication. The problem that an existing communication system based on an ultra-short baseline receiving array is poor in reliability is solved. According to the method, a high-precision time delay estimation method in underwater acoustic positioning is adopted to carry out refined estimation on propagation time delays of M receiving channels, and the influence of different decimal time delays on channel estimation results of all the channels is eliminated. And comparing the signal-to-noise ratio after multi-channel combination with the signal-to-noise ratio of a single channel to obtain condition limitation required during equal gain selection combination of the multiple channels, and judging whether a standard channel and an alternative channel are combined or not according to the condition of channel combination so as to continuously improve the signal-to-noise ratio of a received signal and obtain a space diversity gain. The reliability of a communication system is improved, and the inter-channel interference of a traditional method is effectively avoided. The method can be applied to underwater acoustic single carrier communication frequency domain array processing of an ultra-short baseline array.

The invention relates to the technical field of underwater positioning of unmanned underwater vehicles, in particular to a clock asynchronous inverse ultra-short baseline passive positioning method and system for an unmanned underwater vehicle. The method comprises the following steps: firstly, calculating a beam incident angle and a horizontal azimuth angle by using attitude information provided by an inertial sensor carried on the unmanned underwater vehicle and direction information measured by an inverse ultra-short baseline (iUSBL) positioning system; converting data acquired in the diving process of the unmanned underwater vehicle into sound velocity profile data of the water area by using a sound velocity empirical formula; secondly, reversely tracking a sound wave propagation path by using a sound ray tracking algorithm on the basis of a beam incident angle, the depth of the unmanned underwater vehicle and sound velocity profile data, and calculating a horizontal distance between a sound source and the unmanned underwater vehicle; calculating a plane coordinate increment by using the horizontal azimuth angle and the horizontal distance; and finally, calculating the three-dimensional coordinate of the unmanned underwater vehicle by using the known sound source position and coordinate increment. According to the invention, the dependence of an iUSBL passive positioning technology on clock synchronization can be avoided.

The invention relates to the technical field of submarine mining, in particular to a multi-vehicle cooperative deep-sea mining underwater positioning navigation system and a working method, and the system comprises a wireless communication positioning device, a long baseline positioning assembly, an ultra-short baseline positioning assembly, a communication cable, an inertial navigation system and a Doppler flow velocity log; the long baseline positioning assembly comprises a long baseline positioning node, a long baseline positioning terminal and a long baseline resolving unit; the ultra-short baseline positioning assembly comprises an ultra-short baseline positioning array and an ultra-short baseline positioning terminal. The method can be applied to underwater comprehensive positioning and navigation of a plurality of mining vehicles, conveying hoses, relay stations and conveying vertical pipes in a commercial mining system.

The invention discloses an underwater towed geomagnetic measurement system and a data timing method, and belongs to the field of underwater geomagnetic detection. The system comprises a towing boat, a monitoring control unit and a geomagnetic measurement device, the monitoring control unit is arranged on the towing boat, and the geomagnetic measurement device is connected with the monitoring control unit through a photoelectric composite cable. The monitoring control unit comprises a monitoring computer, a first GNSS antenna, a GNSS taming clock module, a first photoelectric conversion module, a first ultra-short baseline positioning beacon and a shipborne power supply. The geomagnetic measurement device comprises a magnetometer, a second photoelectric conversion module, a controller, inertial navigation equipment, a second GNSS antenna, a depth meter, a Doppler log, a second ultra-short baseline positioning beacon and a power conversion module. According to the underwater towed geomagnetic measurement system and the data timing method provided by the invention, high-precision geomagnetic measurement data can be obtained, accurate timing can be carried out on the geomagnetic measurement data, and the reliability is high.

The invention discloses an ultra-short baseline installation error calibration system and calibration method based on a rotating platform. The system comprises the rotating platform used for fixing an SINS / USBL integrated system on a mother ship; the ROV is used for carrying the fixed transponder to a designated position in water; the rotating platform drives the SINS / USBL integrated system to rotate, the USBL continuously measures the transponder in the rotating process, and the installation error angle of the USBL relative to the SINS is obtained through calculation. According to the scheme, operation is easy and convenient, a mother ship does not need to sail, and the installation error angle of the USBL can be conveniently calibrated through fixing; and a plurality of SINS and USBL integrated systems can be calibrated at the same time, so that the calibration efficiency is greatly improved.

The integrated navigation system is characterized in that a differential satellite navigation positioning system is distributed in a sensor layer and is mounted on a mother ship, and the mother ship provides a power supply for the differential satellite navigation positioning system; an underwater acoustic beacon of the ultra-short baseline positioning system is mounted on an unmanned vehicle in water; the Beidou receiver sends the second pulse signal and UTC time to an atomic clock in the underwater acoustic beacon through an information transmission layer, and the atomic clock carries out time synchronization according to the received satellite navigation time frequency information; the Beidou receivers are distributed in the sensor layer, a DVL log is further distributed in the sensor layer, the atomic clock provides time service signals for the laser inertial navigation and the DVL log, and the information processing layer carries out automatic fault isolation and dynamic information recombination; a Beidou receiver and an ultra-short baseline positioning system of the sensor layer are used for acquiring and utilizing information, optimal position information is sent outwards in a unified mode through laser inertial navigation, and optimal navigation information guarantee is provided for the unmanned vehicle.

The present application relates to the technical field of ultra-short baseline direction measurement data processing, and particularly relates to a direction estimation method of a multi-element stereo hydrophone array. The method approximates sound waves as plane waves and establishes a mathematical relationship between time difference of arrival (TDOA) and a direction vector, takes TDOA as an observation value, calculates a direction vector estimation value according to a weighted least square method, then calculates the equivalent weight of the observation value according to an equivalent weight function, further replaces the original observation value weight array with an equivalent weight array, and recalculates the direction vector according to the weighted least square method, iteratively calculates the equivalent weight and the direction vector, until the difference between the direction vectors of two consecutive times is less than a manually set threshold, and the direction vector is output as the direction of the multi-element stereo hydrophone array. The present application can weaken the influence of the sound ray bending which is not considered in the direction estimation function model, and consider the influence of the array element spacing and the target direction on the direction estimation, thereby improving the accuracy and reliability of the direction estimation of the multi-element stereo hydrophone array.

The invention relates to the technical field of ocean unmanned monitoring and searching, in particular to an ocean searching and underwater monitoring system based on an underwater small robot and a working method of the ocean searching and underwater monitoring system. The underwater robot is used as a core operation carrier, wireless communication, acoustic detection, a dual-module intrinsic safety type battery and an intelligent obstacle avoidance technology are integrated, and comprehensive upgrading of underwater searching and monitoring operation is realized: potential safety hazards of underwater operation of personnel are eliminated, cable dragging interference of a traditional cable control mode is avoided, and limitation of navigation duration and operation distance is broken through; and long-time low-noise monitoring is realized through a dual-module battery design, accurate target detection and autonomous obstacle avoidance are realized by combining acoustic information acquisition and an ultra-short baseline positioning system, and the navigation safety is improved. According to the invention, the intelligence, high efficiency and reliability of underwater unmanned monitoring and searching operation can be obviously improved, and the method has prominent practical value and popularization prospect.

The invention discloses a post-processing method and device for AUV positioning data, a medium and a program product. The method comprises the following steps: acquiring a first measuring point sequence and a second measuring point sequence of the AUV; wherein the first measuring point sequence is a positioning data set determined by a strapdown inertial navigation system, and the second measuring point sequence is a positioning data set determined by an ultra-short baseline underwater positioning system; performing jump point deletion on the second measuring point sequence, performing trajectory fitting, and determining a virtual control point based on a fitting trajectory; constructing a measurement section based on two adjacent virtual control points, and matching the measurement section with each first measurement point in the first measurement point sequence according to time; and for each measurement section, correcting the first measurement point in the measurement section according to the virtual control point to obtain a corrected measurement point, and determining a correction track of the AUV based on each corrected measurement point. According to the technical scheme, the correction of the AUV positioning data is realized by constructing the virtual control point, and the precision of the AUV positioning data is improved, so that the accuracy and applicability of an underwater task are met.

According to the method for searching the underwater object by using the ultra-short baseline of the L-shaped co-prime array, a ship or an aircraft travels and is berthed in a water surface area near the underwater object or on the water surface area, a coordinate system is established by taking a certain point of the ship or the aircraft as a coordinate origin, a base station is arranged on the origin, N + M-2 array elements are respectively arranged on an X axis and a Y axis, N and M are both prime numbers, and M is a prime number; the included angle between the underwater object and the X axis is alpha, the included angle between the underwater object and the Y axis is beta, the included angle between the underwater object and the Z axis is psi, the position of the underwater object in a coordinate system is (X, Y, Z), and the method for searching the underwater object by using the ultra-short baseline of the L-shaped co-prime array comprises the following steps: transmitting and receiving acoustic signals; determining a distance; constructing a received signal model; determining an incident angle to obtain alpha, beta and psi; calculating the position of the underwater object: X = Rcos alpha; y is equal to Rcos beta; according to the invention, the large aperture of the sparse array and the advantages of small array size and convenient installation of the ultra-short baseline positioning system are fully utilized.

The utility model discloses an ultra-short baseline transducer installation angle converter, which relates to the ultra-short baseline field and comprises a base, the top of the base is fixedly connected with a side plate, one side of the side plate is fixedly connected with a motor, an output shaft of the motor is fixedly connected with a rotating rod through a coupler, one end of the rotating rod is fixedly connected with a first bevel gear, and the other end of the rotating rod is fixedly connected with a second bevel gear. A supporting rod is movably connected to the outer wall of the base, a second bevel gear is fixedly connected to the outer wall of the supporting rod, a support is fixedly connected to the outer wall of the supporting rod, and by starting a motor, the first bevel gear fixedly connected to one end of a rotating rod can rotate, the second bevel gear can rotate, and the supporting rod is driven to rotate; the rotating angle of the sleeve fixedly connected with the outer wall of the support is adjusted, the installation angle of the shell of the ultra-short baseline transducer is adjusted, and the effect of conveniently adjusting the installation angle of the ultra-short baseline transducer is achieved.

According to the portable ultra-short baseline transducer array and the underwater acoustic positioning system provided by the invention, the transmitting performance of the transmitting part is adjusted by utilizing the sound reflecting baffle, the mounting, positioning and watertightness of the transducer array are realized, and the transducer array can be used for the portable underwater acoustic positioning system. The portable ultra-short baseline transducer array comprises a sound reflecting baffle, a transmitting ceramic circular ring, a receiving ceramic circular ring, a receiving fixing frame and a receiving top cover plate, one end of the transmitting ceramic circular ring is coaxially arranged on the sound reflecting baffle through an insulating washer, and the other end of the transmitting ceramic circular ring is coaxially arranged with the receiving fixing frame; a plurality of receiving ceramic circular rings are distributed on the surface of the receiving fixing frame in an array manner; therefore, a transducer array main body structure is formed; a watertight layer is arranged outside the transducer array main body structure; and the bottom surface of the sound reflecting baffle is exposed out of the watertight layer and is provided with a wire outlet hole and a positioning mounting structure.

The invention relates to an underwater multi-source autonomous navigation digital twinning and semi-physical simulation test system and method, which are suitable for development and algorithm verification of a multi-source autonomous navigation system of underwater unmanned platforms such as an unmanned underwater vehicle. According to the system, a semi-physical simulation architecture is adopted, and a physical inertial measurement unit (IMU), a three-axis turntable and a computer simulation module are combined; signal simulation, motion scene simulation, sensor error and environmental noise injection, multi-source navigation information fusion and precision evaluation of sensors such as an inertial navigation system, a Doppler log, an ultra-short baseline positioning system and a satellite navigation system are realized. The platform has the simulation capability of two typical underwater scenes of mooring and motion, supports verification of multiple combined navigation modes, can simulate complex underwater acoustic environments such as Gaussian and non-Gaussian noise and abnormal outliers, and provides a highly reliable and high-precision semi-physical simulation verification environment for development and completeness evaluation of an underwater multi-source autonomous navigation algorithm.

The present application provides an ultra-short baseline positioning method and system based on CZT cross-correlation delay difference spectrum, which measures the propagation time and phase change of the sound wave between the target cooperation end and the USBL array composed of multiple hydrophones to obtain the propagation distance, and then estimates the three-dimensional coordinates of the target; the method includes: the target cooperation end amplifies and automatically gains the received data; performs fast Fourier transform and matched filtering on the data, and then performs inverse fast Fourier transform and peak detection to obtain the arrival time estimation of multiple channel target signals, and then estimates the distance between the target cooperation end and the center of the USBL array; calculates the frequency domain output of the matched filtering of multiple channels to obtain the secondary correlation output, and then performs band filtering, performs CZT transformation on the secondary correlation function, uses the peak to find the delay difference, and calculates the coordinates of the target cooperation end according to the delay difference. The advantages of the present application are: accurate target position solution and small amount of calculation.