321 results about "Underwater navigation" patented technology

The invention relates to the technical field of underwater navigation, and discloses a real-time attitude estimation method of an underwater inertial navigation system. The method comprises the steps that the underwater vehicle collects multi-axis angular velocity and linear acceleration data through an inertial measurement unit and uploads the data to a central processing module, and the central processing module conducts kinematics modeling on the data to generate attitude change initial feature vectors; receiving water flow velocity data of a Doppler velocimeter and pressure data of a depth sensor, and performing flow field interference compensation optimization on the attitude change initial feature vector based on the data to generate an anti-interference attitude feature vector; fusing the anti-interference attitude feature vector and a historical attitude estimation result to generate space-time fusion attitude state representation, and then resolving a real-time Euler angle through a nonlinear filter; and matching a corresponding attitude stability control instruction from the navigation strategy library according to the real-time Euler angle, and issuing the attitude stability control instruction to a propeller execution unit. The method can effectively cope with underwater complex environment interference and guarantee stable operation of the underwater vehicle.

The invention discloses an AUV (Autonomous Underwater Vehicle) path planning and control integrated method for a complex marine environment, and provides an intelligent path control scheme integrating reinforcement learning and local obstacle avoidance mainly aiming at underwater navigation problems such as submarine topography fluctuation, frequent ocean current disturbance and uncertain dynamic obstacle distribution. According to the method, a realistic three-dimensional ocean grid environment is constructed, an improved Q-learning algorithm is utilized to complete global path planning, a group of optimal path point sequences are generated, and it is ensured that the AUV has the macroscopic navigation capability. Local obstacle avoidance is performed in combination with a three-dimensional dynamic window method (3D DWA), and sudden obstacles are dynamically avoided through speed sampling and trajectory prediction. A DDPG control strategy based on deep reinforcement learning is further introduced, end-to-end training of path planning and control execution is realized, and the system can directly output a control instruction according to a real-time sensing state. A cosine attenuation learning rate, a self-adaptive exploration mechanism, an energy consumption penalty function and a dynamic obstacle prediction and control action filtering technology are fused in the method, so that the intelligence of path planning, the stability of control output and the robustness of obstacle avoidance response are effectively improved. According to the invention, the autonomous navigation capability, the environmental adaptability and the safety task completion efficiency of the AUV in a complex marine environment can be obviously enhanced, and reliable intelligent control technical support is provided for underwater operation.

The invention relates to the technical field of cable sealing, and provides a cabin-penetrating sealing device and an installation method of the cabin-penetrating sealing device applied to an underwater vehicle, and the cabin-penetrating sealing device comprises a pipe body which divides a pipe cavity into a first sealing groove and a second sealing groove; the first sealing structure comprises a first sealing filler which fills a gap between the pipe body and the linear entity in the first sealing groove; the first fastener compresses the first sealing filler; the second sealing structure comprises a second sealing filler which is used for filling a gap between the pipe body and the linear entity in the second sealing groove; the second fastener compresses the second sealing filler; the third sealing structure comprises a third sealing filler which tightly holds the second fastener and the linear entity and wraps the second fastener in a sealed mode. And the fourth sealing structure comprises a first sealing mold, covers the third sealing structure and the outboard part of the pipe body, and is filled with fourth sealing filler. Multiple sealing ensures that the linear entity is fixed and sealed without leakage in the underwater navigation process, and the sealing effect is safe and reliable.

The invention provides an anti-interference sound signal data extraction method based on energy data perception, and belongs to the technical field of underwater sound signal processing, and the method comprises the steps: carrying out the A / D sampling and digital orthogonal demodulation of a received sound signal, and obtaining a baseband signal; performing low-pass filtering and downsampling on the baseband signal to obtain a preprocessed signal; performing matched filtering on the pre-processed signal by using a reference signal; the key improvement lies in that a local energy estimation function of a preprocessed signal is calculated, and normalization processing is carried out on a matched filtering result and the energy estimation function to obtain a normalized detection signal. The method effectively suppresses the shielding effect of a strong interference signal on a weak target signal under a non-orthogonal reference signal and a strong near-end and weak far-end scene, remarkably reduces the misrecognition probability, and improves the accuracy and reliability of the extraction of a long-distance and low-signal-to-noise-ratio target beacon signal in a complex underwater acoustic environment. The method is suitable for underwater navigation, positioning and communication systems.

The invention discloses a new-configuration cross-medium aircraft based on blade tip jet rotors and a working method thereof, the aircraft has an air flight mode, an underwater navigation mode and a cross-medium mode, and comprises a fuselage; the main rotor system comprises an electric centrifugal compressor which is arranged on the fuselage in a jacking manner and a blade tip air injection main rotor blade which is connected with an air path of the electric centrifugal compressor; the auxiliary lift system comprises lift units arranged on the fuselage in a distributed mode, and the lift units can be independently controlled; in the air flight mode, the propeller tip jets air, the main rotor rotates, and the auxiliary lift system works to realize air flight; and in the underwater navigation mode, the blade tip jets air, the main rotor stops rotating, the blades on the single side are overturned around the fixed axis till the blade nozzles face the advancing rear portion, and the underwater water jet propulsion device is formed. The novel-configuration cross-medium aircraft disclosed by the invention adopts a distributed lift force layout, has relatively large take-off weight and good maneuverability, can realize continuous medium crossing, and is small in water entering and exiting impact.

The invention discloses a magnetic coupling speed-adjustable propeller and a control method thereof, and belongs to the technical field of underwater navigation and electric propulsion. A motor, a driving assembly and a driven assembly of the propeller are arranged in a cabin, a motor driving shaft is connected with the driving assembly, and a plurality of first permanent magnets are arranged on the driving assembly; a plurality of second permanent magnets are arranged on the driven assembly, and the first permanent magnets are in magnetic fit with the second permanent magnets; an impeller is arranged outside the cabin body and is connected with a driven assembly; the magnetic controller comprises a disc and electromagnets, the disc is rotationally connected with the driving assembly, the multiple electromagnets are detachably arranged on the disc and arranged between the first permanent magnet and the second permanent magnet, and when the driving assembly drives the driven assembly to rotate, the states of the electromagnets are changed, and the speed of the impeller can be adjusted. According to the propeller, friction loss in traditional mechanical transmission is eliminated, so that the propeller has a multi-mode speed regulation function and can adapt to more application scenes, and the transmission efficiency is improved.

The invention relates to the technical field of underwater navigation and positioning, and particularly discloses a wide-area very-low-frequency radio navigation and underwater sound combined underwater navigation and positioning method, which comprises the following steps that: a very-low-frequency navigation transmitting station transmits a very-low-frequency radio navigation time service signal; the semi-submersible acoustic beacon receives a very-low-frequency radio navigation time service signal; performing position calibration and time synchronization; the semi-submersible acoustic beacon emits an underwater acoustic navigation signal, and the underwater carrier calculates the three-dimensional coordinates of the underwater carrier according to the received underwater acoustic navigation signal. According to the invention, a shore-based very-low-frequency radio navigation and underwater sound combined navigation mode is adopted, and a very-low-frequency radio navigation time service signal has a certain underwater entry depth, so that the problem of time synchronization between semi-submersible acoustic beacons is solved, and auxiliary calibration of the positions of the semi-submersible acoustic beacons is provided; the semi-submersible acoustic beacon emits an underwater navigation signal to realize navigation and positioning of a deepwater underwater carrier, and reliable navigation service with wide area coverage, high precision and low power consumption is provided for the underwater carrier.

The invention provides a sonar-assisted underwater navigation positioning method and system, and the method comprises the steps: carrying out dead reckoning according to an attitude angle outputted by an IMU and a speed outputted by a DVL, and obtaining a dead reckoning odometer factor; after the first frame is set as the key frame, if the time difference between the current frame and the previous key frame is greater than a time difference threshold value or the pose change of the current frame relative to the previous key frame is greater than a pose change threshold value, the current frame is set as the key frame; performing filtering, feature extraction and matching on the sonar image; performing pose extraction according to the matched feature points to obtain a sonar odometer factor; key frames in a preset range are searched for loopback detection, and a loopback constraint factor is obtained through matching; and performing back-end optimization on the to-be-optimized pose by using a factor graph optimization method. According to the method, dead reckoning results of the IMU and the DVL are adopted as odometer factors, and calculation of back-end optimization can be greatly simplified.

The invention discloses a portable underwater vehicle throwing device which comprises a control device and further comprises a hoisting assembly (1), and the upper portion of the hoisting assembly (1) is used for being connected with a marine crane (9) for use; the lifting assembly (2) is detachably installed in the middle of the lower portion of the hoisting assembly (1), and the lower portion of the lifting assembly (2) is connected with an underwater navigation body (7) for use; the supporting assemblies (3) are symmetrically connected to the two sides of the lower portion of the hoisting assembly (1); the two ends of the upper portion of the supporting frame (4) are detachably connected with the lower portions of the corresponding supporting assemblies (3) through adapters (5) respectively; wherein the hoisting assembly (1) is wirelessly connected with the control equipment. The system is easy to operate, stable and reliable, pre-tightening constraint of the underwater vehicle can be stable and controllable in the using and releasing process, and the releasing function of the underwater vehicle can be conveniently and rapidly completed by controlling the middle remote control cordless detacher.

The invention discloses a self-adaptive integrated navigation method based on geometric accuracy factors, which belongs to the technical field of underwater navigation and positioning, is used for underwater navigation and positioning, and comprises the following steps: initializing an inertial navigation system and an integrated navigation filter, and setting a state vector and a noise covariance matrix; predicted navigation parameters of the recursive carrier are mechanically arranged through inertial navigation, and the state transition matrix is used for state prediction; and dynamically adjusting an observation noise covariance matrix according to the geometric precision factor value, further calculating a Kalman gain, performing optimal estimation and correction on a prediction state by fusing acoustic observation information, and finally outputting a high-precision carrier position, speed and attitude. According to the method, the statistical characteristics of observation noise are dynamically remodeled by calculating and feeding back geometric precision factor values in real time, so that the Kalman filter has the capabilities of knowing the own geometric situation and adjusting the trust degree of each information source, and the global optimal navigation precision and reliability are realized under any motion track.

The invention provides an underwater integrated navigation method and system based on speed prediction, and relates to the technical field of underwater navigation.The underwater integrated navigation method comprises the steps that observation data of an inertial navigation system (INS), a Doppler log (DVL) and a pressure sensor (PS) are obtained, and when the observation speed of the Doppler log (DVL) fails or meets the gross error condition, the pressure sensor (PS) is determined; predicting the observation speed based on the corrected rotating speed of the propeller; based on the observation data, calculating an IMU pre-integration factor, a DVL factor and a PS factor, constructing a factor graph, and fusing the observation data through a factor graph optimization method to obtain a final underwater vehicle state, including position coordinates, speed, attitude, accelerometer and gyroscope zero offset errors; according to the method, the pseudo DVL factor constructed by the speed predicted value replaces the DVL factor to participate in the navigation framework, so that the navigation precision divergence is effectively inhibited in the DVL failure state.

The invention discloses a deep sea node instrument laying device and laying method. The deep sea node instrument laying device comprises a computer control unit arranged on a surface ship, an underwater power transmission and distribution unit connected with the computer control unit and a surface ship power supply system through multifunctional cables, and an underwater robot connected with the underwater power transmission and distribution unit. The underwater robot comprises an OBN storage matrix, a plurality of propellers and a plurality of sensors, wherein the propellers are assembled on the OBN storage matrix and used for achieving underwater navigation, and the sensors are distributed on the OBN storage matrix and used for monitoring the navigation state and the underwater environment. By means of the device, an aerial seeding type operation mode is provided, high-precision continuous laying of the OBN on the seabed is achieved, the laying speed of the OBN can be greatly increased, that is, the computer control unit controls the underwater robot to submerge continuously at a constant speed in a water layer which is a certain distance away from the seabed, the OBN is controlled to be released continuously during constant-speed submerging, and therefore the underwater robot can stably lay the OBN on the seabed. And precisely sinking at a preset laying point position of the seabed along a parabolic path.

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 belongs to the technical field of underwater navigation, and particularly relates to a multi-AUV (Autonomous Underwater Vehicle) collaborative SLAM (Simultaneous Localization and Mapping) method based on multi-beam water depth measurement data, which comprises the following steps: a plurality of AUVs synchronously run in a task area, and a multi-beam depth sounding sonar is respectively used for acquiring local water depth data and generating an internal water depth sub-graph set; each AUV performs sparse processing on the internal water depth sub-graph; the AUV receiving the sub-graph performs interpolation reconstruction on the sparse sub-graph by using a GPR algorithm; each AUV constructs a collaborative SLAM factor graph containing a pushing factor, an internal water depth closed-loop factor, an external water depth closed-loop factor and an inter-AUV distance observation factor based on self navigation data, the internal water depth sub-graph and the external water depth sub-graph; and solving the factor graph through a distributed optimization algorithm, and outputting an optimized pose and a global map of each AUV. According to the method, the positioning precision and reliability of the underwater SLAM are remarkably improved.

The invention provides a butt joint device based on electromagnetic connection and an underwater navigation device, and relates to the technical field of underwater vehicles, the butt joint device comprises a first butt joint assembly and a second butt joint assembly, the first butt joint assembly comprises a first nut and a magnetic driving part arranged on the first nut in a sleeving mode, the second butt joint assembly comprises a telescopic rod, a connecting rod, a second nut and a magnetic response part, one end of the connecting rod is connected with the telescopic end of the telescopic rod, the other end is in threaded connection with the second nut, and the magnetic response part sleeves the periphery of the second nut. The magnetic driving part is used for attracting the magnetic response part to preliminarily butt the first butt joint assembly and the second butt joint assembly, the fixed end of the telescopic rod is driven to rotate to drive the connecting rod to rotate, and the connecting rod rotates and moves in the axial direction of the second nut to be in threaded connection with the inner wall of the first nut so as to secondarily butt the first butt joint assembly and the second butt joint assembly. Radial and axial wandering is eliminated, the stability and anti-disturbance capability after butt joint are enhanced, and the overall operation quality and efficiency are improved.

The invention discloses an underwater navigation positioning method and system based on supercontinuum laser intensity correlation. The system comprises a master control system, a transmitting end underwater base station and a receiving end underwater carrier. The method comprises the following steps: firstly, a main control system generates a super-continuum laser signal with pseudo-random code information, the super-continuum laser signal is separated into optical signals of different wavelength channels through a light splitting module, and the optical signals are respectively sent to underwater base stations uniquely corresponding to the wavelength channels and are emitted; then the underwater carrier receives optical signals from a plurality of base stations, identifies a signal source base station according to wavelength identification, performs correlation operation with a locally copied pseudo-random code sequence, determines signal arrival time TOA and calculates a pseudo-range; and finally, resolving the three-dimensional coordinate and local clock error result of the underwater carrier by combining the pseudo-ranges, absolute positions and transmission delays of the underwater carrier and the at least four base stations. According to the invention, high-precision and high-robustness absolute positioning of the underwater environment is realized, and the reliability of long-time positioning and navigation of the underwater robot is enhanced.

The invention belongs to the technical field of artificial intelligence, and relates to an underwater navigation method and system based on panoramic visual perception and language model reasoning. The method comprises the following steps: acquiring a 360-degree panoramic video sequence when an underwater robot runs, pre-processing the 360-degree panoramic video sequence, dividing the 360-degree panoramic video sequence into sub-views, extracting visual features, combining position and action embedding information, and aggregating the sub-views into a space-time trajectory feature flow through a Transform network. An adaptive module is embedded in a language model, and visual track features are injected into a language hidden space by using a cross attention mechanism, so that visual-language information fusion and content reasoning are realized. Meanwhile, semantic scene representation is constructed through three-dimensional scene modeling, illusion landmarks are inhibited by means of a landmark uncertainty evaluation module, and finally reasoning output of a language model is mapped into a structured control instruction. According to the method, autonomous semantic navigation based on content understanding in an underwater environment is realized.

The invention discloses a master-slave USV collaborative navigation method based on corner net condition adjustment, and belongs to the technical field of autonomous underwater navigation, and the method comprises the following steps: using a strapdown inertial navigation system to obtain a navigation state of a USV to be positioned at an initial moment, receiving a current position shared by other USV data in a USV formation by the USV to be positioned, converting the current position into a two-dimensional coordinate, and carrying out navigation on the two-dimensional coordinate; the USV to be positioned obtains the relative distance measurement information # imgabs0 # and the relative azimuth angle # imgabs1 # between the USV to be positioned and other USVs according to the equipped sensor, establishes a state equation and a measurement equation for describing the USV to be positioned, establishes a corner net condition adjustment mathematical model, processes measurement vectors, obtains a measurement vector adjustment value and a variance matrix thereof, sets an observation noise variance matrix, and obtains the measurement vector adjustment value of the USV to be positioned according to the measurement information # imgabs0 # and the relative azimuth angle # imgabs1 # of the USV to be positioned. And measurement updating is carried out in combination with DVL speed measurement information. By adopting the corner net condition adjustment-based master-slave USV collaborative navigation method disclosed by the invention, high-precision estimation and collaborative correction of the navigation state of the USV to be positioned can be realized.

The present invention belongs to the field of marine underwater positioning, navigation and timing. Disclosed are an underwater navigation and communication integrated position service system and method. The system comprises a buoy base station, a submerged buoy base station, a seabed base station and a shore-based operation and control unit, and the system utilizes a three-dimensional base station network observation mode combining the buoy base station, the submerged buoy base station and the seabed base station. The position service system and method in the present invention have the capabilities of underwater acoustic navigation and communication, satellite positioning and communication, atomic clock timekeeping, hydrological measurement and responding to instructions of a shore-based operation and control unit, have the functions of autonomous, real-time and online base station position and clock calibration and sound velocity field correction, have the functions of base station position and clock calibration, and sound velocity field correction and control based on the shore-based operation and control unit, and can expand the range and functions of underwater position services, and provide accurate positioning, navigation and timing services for water-surface / underwater users.

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 belongs to the technical field of water-air amphibious inspection, and discloses a water-air amphibious inspection robot for offshore wind power, the water-air amphibious inspection robot comprises variable force propellers and bionic empennages, the variable force propellers are mounted around the robot, each variable force propeller is driven to rotate by an independent motor, the maneuverability and flexibility of the robot are improved, and the robot can be driven by the bionic empennages to rotate. The variable force propeller is composed of four blades, the four blades are installed on a central bevel gear, the inclination angles of the blades are adjusted through rotation of the central bevel gear, and the problems of thrust difference and unstable navigation caused by switching of the aerial working environment and the underwater working environment of the robot can be solved. The bionic empennages are mounted at the tail of the robot, and the two bionic empennages can synchronously swing along with the action of ocean current in the underwater navigation process of the inspection robot, so that the navigation stability of the robot is improved.

The invention provides a trigger type folding-stretching linkage wing structure for a seaplane. The trigger type folding-stretching linkage wing structure comprises a wing assembly, a driving assembly, a linkage assembly and a limiting assembly. The wing assembly comprises a wing seat, two wing groups and two guide units, the wing groups can stretch out and draw back, the two ends of each wing group are connected with an inner connecting plate and an outer connecting plate correspondingly, and the inner connecting plates are rotationally installed on the wing seat; the guide unit comprises a telescopic rod and a reset spring, the two ends of the telescopic rod are connected with the inner connecting plate and the outer connecting plate correspondingly, and the telescopic rod is sleeved with the reset spring. The driving assembly comprises a first sliding block and a connecting rod; two ends of the connecting rod are respectively hinged with the first slide block and one end of the wing group close to the wing seat; the linkage assembly comprises a traction rope and a pulley block; the limiting assembly comprises a first limiting unit and a second limiting unit. The first sliding block moves in the direction away from the wing base, sweepback and contraction of the wing set are synchronously achieved, the cross sectional area and the wetted area of the wing can be reduced at the same time during underwater navigation, and fluid resistance is remarkably reduced.

The invention relates to the technical field of underwater navigation, in particular to an underwater intelligent matching method and device based on a self-adaptive variable scale domain. The method comprises the following steps: selecting a local small domain center through a variable scale domain coarse positioning mechanism of an adaptive particle swarm optimization algorithm, and realizing high-precision repositioning of a real position of a submersible vehicle through a local small domain fine positioning mechanism of an optimal evaluation value. Simulation results show that the method can effectively improve the positioning efficiency and out-of-domain matching performance of underwater gravity matching navigation. In the test of four tracks, the occurrence of out-of-domain mismatching is completely avoided, and the average improvement ratios of the out-of-domain average matching precision and the out-of-domain worst matching precision are 83% and 85% respectively. The superiority of the method provided by the invention in matching performance is effectively verified, and a new method is provided for realizing long-endurance and high-precision underwater gravity matching navigation under the global ocean background.

The invention discloses an inertial navigation system periodic oscillation suppression method based on time-frequency transformation, and relates to the technical field of underwater navigation, and the method comprises the following steps: S1, modeling an error propagation model of an INS, and defining coordinate systems required by INS navigation, including an inertial coordinate system, a navigation coordinate system and a body coordinate system; based on the INS navigation equation, obtaining an INS error model, and carrying out time domain analysis to obtain an analytical solution of time domain error divergence; s2, designing a time-frequency transformation NTFT, proposing a normal phase time-frequency transformation method, and constructing a complete observation equation; s3, substituting a null method into a calculated longitude and latitude result, and accurately extracting frequency, phase and instantaneous amplitude in inertial navigation longitude and latitude; and S4, establishing a resolving framework of the inertial navigation system periodic oscillation suppression method based on time-frequency transformation, and constructing a negative feedback loop through input gyroscope and acceleration information to suppress periodic errors.

The invention discloses a water-air cross-medium unmanned aerial vehicle and a flight method, and belongs to the technical field of unmanned aerial vehicles. The unmanned aerial vehicle comprises a sealed cabin body composed of an upper cabin body and a lower cabin body, symmetrical vehicle arms, a tail steering engine, a rudder, a left steering engine, a right steering engine, an elevator, an underwater propeller and various types of sensors (a binocular camera, a sonar, a water quality sensor and the like). Air flight is achieved in a four-rotor mode, and underwater sneaking is driven in a fixed-wing mode. The control method comprises the stages of takeoff, air flight, air-water transition (a water surface hovering automatic switching mode), underwater navigation, water-air transition and landing, and complete-process autonomous cross-medium conversion is achieved by combining layered rate descent and multi-sensor fusion judgment states. The device has the advantages of being compact in structure, reliable in sealing and accurate in cross-domain control, and is suitable for ocean exploration, environment monitoring, underwater reconnaissance and other scenes.

The invention relates to a sea-land-air triphibian aircraft which is composed of an aircraft head, an aircraft body and foldable wings, each wing comprises a fixing part, a folding part and a driving part, and unfolding and folding of the wings are controlled through hydraulic jacks. The aircraft is provided with a propeller engine and a propeller thruster which provide lift force and propulsive force respectively, and air flight, underwater navigation and land advancing are achieved. The driving system assembly comprises a submarine engine and an aircraft star-shaped engine, and the submarine engine is connected with and drives propellers to rotate through gears to provide power; the aircraft star-shaped engine is mainly used for air flight. The triphibian aircraft has multifunctionality, high flexibility and wide applicability, and is suitable for various scenes such as emergency rescue, military reconnaissance and environment monitoring. Special materials and design endow the robot with concealment and maneuverability, the robot can quickly respond and avoid potential threats during task execution, and the robot shows powerful comprehensive performance and wide application potential.

The invention discloses a navigation method for an aircraft in a water-air multi-medium environment, which is based on a water-air cross-medium integrated navigation system consisting of an IMU inertial navigation device, a GNSS receiver, a magnetometer, a water depth pressure sensor and DVL equipment, and comprises the following steps: firstly, determining a state equation of the navigation system, and then determining a measurement equation of the integrated navigation system; seamless switching between an overwater navigation mode and an underwater navigation mode is realized; according to the invention, an IMU inertial navigation device is taken as a core, a GNSS receiver is combined to provide pseudo-range position observation when used on water, a magnetometer provides course information, a water depth pressure sensor provides depth observation, and DVL equipment is used underwater to provide speed observation, so that the navigation problem in a water-air multi-medium environment is mainly solved; the system has the functions of acquiring navigation information on water and underwater and realizing switching between the water mode and the underwater mode.

The invention discloses a satellite underwater acoustic inertial optical tight combination underwater robot positioning method, and belongs to the technical field of underwater navigation. According to the method, optical positioning data are innovatively and effectively fused into an underwater tight combination positioning system, the positioning precision is further optimized through joint calculation of overwater and underwater tight combination, and data provided by an optical sensor are added, so that the method not only expands multi-source data which can be used for calculation, but also improves the positioning precision of the underwater tight combination positioning system. The positioning capability of the underwater robot in a complex environment is also remarkably enhanced, especially for the error accumulation problem existing in an inertial navigation system, real-time compensation of optical data can effectively improve the positioning accuracy and reliability, and further, through combination of overwater and underwater tight combination calculation, the method has the advantages that the calculation resources are optimized, and meanwhile the positioning accuracy and reliability of the underwater robot are improved. The consistency and the stability of a positioning result in different working environments are guaranteed, and particularly, high-precision navigation positioning can still be guaranteed in deepwater or other complex water area environments with weak signals.

The invention provides an automatic compensation method for underwater buoyancy of an AUV (Autonomous Underwater Vehicle), which meets the navigation depth control requirement caused by the change of seawater density in the navigation process of the underwater vehicle. Comprising the following steps: step 1, acquiring seawater temperature, salinity and navigation depth data of a current sea area; 2, according to the obtained seawater temperature, salinity and navigation depth data, the seawater density rho1 of the position where the AUV is located is calculated, and meanwhile the current liquid level of an AUV buoyancy adjusting device is collected through a liquid level sensor; 3, calculating the weight M1 of the AUV according to the seawater density rho1 and the volume V of the AUV, and comparing the weight M1 with the initial weight M0 to obtain weight change; 4, after the water amount of the AUV is adjusted, a proper liquid level value H1 is obtained, and the AUV stores the liquid level value to serve as the balance liquid level for depth control during underwater navigation of the AUV.

The invention relates to the technical field of wave power generation, in particular to a self-retractable spherical friction nanometer power generation underwater navigation device and an application method. The spherical friction nanometer power generation device and the underwater vehicle are ingeniously and innovatively integrated, through reasonable mechanical structure design, flexible retraction and release of the spherical power generation device in the underwater vehicle are achieved, and the dual requirements of energy self-sufficiency and navigation performance of the underwater vehicle can be met; powerful guarantee is provided for autonomous operation and long-time operation of the underwater vehicle; the multi-direction spherical friction nanometer power generation device can collect wave energy in all directions, has high energy collection and conversion efficiency under the low-frequency sea wave condition, is simple in structural design and small in size, can be ingeniously integrated in an underwater vehicle, solves the problem that an existing underwater vehicle cannot supply energy autonomously and underwater, and is suitable for being popularized and applied. And a brand new path is opened up for energy supply of the underwater vehicle.