202 results about "Sea state" patented technology

An ocean wave energy device uses large gas filled and surface vented or evacuated flexible containers having rigid movable ends and rigid fixed depth ends connected by flexible bellows, suitably reinforced against external hydrostatic pressure, submerged to a depth below anticipated wave troughs. One or more containers compress and expand as waves and troughs, respectively, pass overhead driving hydraulic or pneumatic, pumping means producing pressurized fluid flow for a common sea bed motor-generator or for other uses or on-board direct drive generators. Mechanical, hydraulic or pneumatic means re-expand said containers when a wave trough is overhead. Power output is augmented by mechanically connecting said rigid moving surfaces to surface floats, which may also provide said surface vent such that as waves lift and troughs lower said floats, said containers are further compressed and re-expanded, respectively. Depth fixing and adjustment means for tides and sea-states are provided.

A target recognition system and method wherein only target amplitude data, i.e., coherent A-scan data, is interrogated for target recognition. Target aspect angle is ignored within the angular segmentation of the feature library without degrading classification performance. Observed signature characteristics are collected at various aspect angles and through unknown and arbitrary roll, pitch and yaw motions of each anticipated target and provided to a neural network as training sets. The neural network forms feature vectors for each target class which are useful for valid classification comparisons in all sea states, especially in calm and littoral waters. These feature vectors are useful for valid classification comparisons over at least 30 degrees of target aspect angle.

Apparatus and a method utilizing correlation interferometer direction finding for determining the azimuth and elevation to an aircraft at long range and flying at low altitudes above water with a transmitting radar while resolving multipath signals. The signals from the radar are received both directly and reflected from the surface of the water using horizontally polarized and vertically polarized antenna arrays, are digitized and are stored in separate covariant matrices. Eigenvalues for the eigenvectors of the matrices processed on signal samples recorded on horizontally polarized X arrays are compared to the eigenvalues for the eigenvectors of the covariance matrices processed on signal samples recorded on vertically polarized X arrays. Incident field polarization is associated with the antenna array measurements that yield the strongest eigenvalue. The eigenvector and eigenvalues for the strongest signal are selected and used for subsequent signal processing. An initial global search assuming mirror sea-state reflection conditions using the signal eigenvector having the strongest eigenvalue is performed to yield an approximate elevation α and azimuth β to the aircraft. The approximate values are then used as the starting point for a subsequent conjugate gradient search to determine accurate elevation α and azimuth β to the aircraft.

For any directed sea waves the rocking propelled ship can reach high speeds if it utilizes an sea waves energy by means of 1. A rocking propulsor, which is a couple of hydrofoils kept elastic cross by pivots on the extreme points of streamline narrow keel-rocker, extended far out off long sizes of the ship and thus wags hydrofoils vertically with a speed and an amplitude being sufficient for its proper work; 2. A "pendulum design" of a rocking propelled ship, described by a light wide body with weight, concentrated in a middle lowest ship's part and having a vertical keel with a heavy bob. This design provides the highest efficiency of an energy transmission from waves to ship rocking. In case of need to increase ship's speed some more its rocker should be rigged by an on-board oscillator, which is a central heavy flywheel, which is alternately twisted up to speed by a serve motor in both directions on cross axle in time (resonance) of ship rocking. In order to accelerate and change revolution directions without energy loss the flywheel is supplied by spring returners. If the ship is assigned to navigate in both sea state cases (high or calm) the oscillator is mounted into the rocking propulsor, which is attached to the ship bottom with a hinger. It can be locked to the bottom to be swinged by a rocking ship hull to propell the ship by wave generated rocking motion. It can be unlocked to be swinged by the board oscillator undependently from the ship hull to propel the ship in case of calm sea.

An antenna including a feed tube with radial fins and circular plates at the ends of the tube and fins thereby forming a boundary for a plurality of resonant cavities. Curved plates, connected to the tube by switches of a switching system, partially encompass and subtend to the length of the tube. Interior to the tube, a transmission line from an end plate terminus conducts radio-frequency energy from the terminus to a hub and onto a switch of the switching system in which the switch is mechanically reactive to and actuated by a righting action of the curved plates when the curved plates encounter a sea state. When actuated, energy from the switch distributes to a proximate resonant cavity and curved plate to form a radiation pattern based on the difference in phase of the resonant cavity and curved plate.

The ship motion simulator as one integral electromechanical apparatus consists of a six-freedom motion platform and large hydraulic cylinder connected serially, and the experiment cabin is fixed to the top of the six-freedom motion platform supported by the large hydraulic cylinder. The present invention can simulate the motion of ship in sea based on the requirement of experiment. The two-stages composite motion simulator of the present invention has great motion range for simulating ship motion state of ship in 1-6 scale of sea state. After one sea state scale, say 6 scale, in the range is given, the control system will give the motion locus of ship in the said sea state, 6 scale of sea state and the simulating platform will move in the given locus under the drive of the hydraulically driven simulating platform.

A method for making a time-lapse seismic survey in a marine environment, the method designed to eliminate multiple surface reflections and changes in sea state and conditions. Seismic sources and receivers are positioned at predetermined conditions for a first set of data in which at least two sets of seismic signals are recorded at each receiver, proximate in time, such that there are insignificant changes in the subsurface formation. At a later point in time the seismic source(s) and receiver(s) are positioned at the same place when the first seismic data set was generated. A seismic source emits a sound wave and the seismic receiver receives what will be called a “monitor signal” and the two-way water travel time is again determined. A model is then developed for the first and second seismic data sets in that includes the subsurface signal, changes in the subsurface signal and the effect of multiple reflections. A set of filter functions are then developed to filter out the multiple reflections based on the two-way water travel times of the first seismic data set. The first seismic data set, the second seismic data set and the filter function are then used to calculate the differences in the subsurface layers over the elapsed period of time between the two seismic data sets.

An electric power generating buoy capable of generating power by scavenging energy from ocean wave motion. The power generating buoy includes float element adapted to float up and down following wave motion and an electric generator system with a spring loaded spool mechanism adapted to drive the rotor of the electric generator. It also includes an anchor element and a tension element attached to an anchor and the spring loaded spool mechanism and adapted to spin the spring loaded spool mechanism to generate electric current when wave action causes the float element to rise relative to the anchor element. Preferred embodiments of the buoy will deliver a minimum of 100 Watts of average power from the wave motion characteristic of moderate sea state (sea state 3), with less power from slight sea state (sea state 2) and more power from higher sea states. The basic power generation scheme will rely on harnessing the mechanical energy of the wave as it repeatedly pushes the buoyant surface float against a ballast force through the distance corresponding to the wave height.

The invention provides a deep learning ship target detection method based on edge candidate region extraction. The deep learning ship target detection method provided by the invention has the following advantages that a remote sensing image under different conditions is subjected to edge detection by utilizing a structured random forest model to obtain purposeful edge detection results, and the influence of sea states, illumination and other situations on the edge detection results is inhibited; candidate regions where targets possibly exist are extracted from the remote sensing image with large width by utilizing a candidate region extraction algorithm based on the edge detection results; the selection results are inputted into a deep learning network, so that the network processing efficiency is improved, and the detection speed is increased.

The invention discloses a target detection method and device under the background of sea clutter based on a ground wave radar, and the method comprises the steps: forming an echo spectrum of the ground wave radar; obtaining synchronous sea state data, building the mapping between the sea state information and the echo scattering of the ground wave radar, and constructing a no-target sea clutter spectrum through combining with the sea state in a radar scattering region and a radar system; extracting a sea clutter spectrum boundary from the echo spectrum of the ground wave radar and the sea clutter sensitive features for target detection; carrying out the abnormal detection of the sea clutter sensitive features and determining a detection threshold value; and outputting a detection result ofa sea clutter target. The device comprises a ground wave radar sea clutter spectrum extraction unit, a no-target echo spectrum reconstruction unit, a threshold generating and target detection unit and a target parameter estimation unit. The invention jumps out of the conventional thinking on clutter inhibition, proposes a strategy for the extraction of a sea clutter boundary and the direct detection. While achieving the detection of an external target of the sea clutter, the invention proposes the direct detection method for the data feature abnormality of ground wave radar, thereby avoidingthe target loss caused by the clutter inhibition.

An ocean wave energy converter (WEC) uses one or more buoyant elongated float(s) mechanically linked to a motion-stabilized, controlled-submergence depth frame by either swing or lever arms or down-sloping tracks defining and orienting the motion of the floats relative to the frame to capture both heave and surge wave energy forces. The submerged depth of the frame and attached float(s) is adjusted for optimal wave energy capture or submerged sufficiently to fully submerge the float(s) during severe sea conditions. The elongated float's compliant wave-impacting forward wall combined with total submergence during severe sea states allows the elongated float(s) to self-orient parallel to oncoming wave fronts to intercept and capture maximum wave energy per unit of WEC volume, weight and cost.

The invention discloses a semi-submersible drilling platform. The semi-submersible drilling platform provided by the invention comprises two floating boxes; at least two upright rods are supported on each floating box; a deck is supported on the upright rods; wherein, at least two wide-wing horizontal braces are connected with the floating boxes; the connection part of the horizontal braces and the floating boxes is positioned right under the upright rods on the floating boxes. The invention is provided with two wide-wing horizontal braces between the floating boxes of the semi-submersible drilling platform and right under the upright rod to connect with the floating boxes; the connection part of the horizontal braces and the floating boxes is positioned right under the upright rod on the floating boxes, which can increase displacement of the platform, enhance strength and capacity of anti stormy wave of the platform, and allows the platform to work under a medium and even wicked sea state; secondly, internal part of the wide-wing brace is divided into at least two watertight compartments; even when the outside compartment is damaged, the undamaged structure can still retain enough loading capacity.

The invention discloses a sea surface flow inversion method based on an X waveband radar image. The method comprises the following steps that: (1), sea clutter images in a time-space domain are collected and are used as a sequence, so that a sub-image sequence is obtained; (2), three-dimensional fourier transform is carried out on the sub-image sequence; (3), a band pass filer is constructed according to a dispersion relation; (4), correction is carried out on a non-linear influence of an image spectrum; (5), a degree of membership is calculated; (6), weighted calculation is carried out; (7),initial flow estimation carried out; (8), iteration flow estimation is carried out. Compared with a current flow inversion algorithm, the sea surface flow inversion method enables a flow inversion accuracy to be improved and especially a flow inversion accuracy at a slow flow speed to be improved; moreover, stability on an inversion result is improved. According to the invention, a dispersion relation band bass filter that depends on a maximum flow speed is utilized to carry out noise filtering on an image spectrum and the denoising capability is strong; besides, correction is carried out on the image spectrum to obtain a sea state spectrum, so that real sea state information can be reflected; and then, the sea state spectrum is utilized as one of weights of a least square method to calculate a flow, so that a flow inversion result approaches a real sea state.

When performing a task at sea, a naval vessel often comes across typhoons or sea waves, or is hit by shells during a fight, so that a naval vessel body tilts at a large angle, and under a serious condition, the naval vessel body even can overturn. In order to predict the tilting range borne by the naval vessel in advance or simulate sea states which can be generated when the naval vessel performs the task, the invention provides a naval vessel sea state dynamic simulator. According to the naval vessel sea state dynamic simulator disclosed by the invention, a method that a three-freedom degree motion platform and a six-freedom degree motion platform are overlaid is adopted; electric-hydraulic servo driving is used; the six-freedom degree motion platform is arranged at the top and the three-freedom degree motion platform for supporting is arranged at the bottom; under the control of an electric-hydraulic servo system, the two platforms are mutually matched, so that the various sea states which probably appear can be simulated; finally, the sea states of 0-9 levels, which can be generated when the naval vessel performs the task at a sea level can be simulated. The naval vessel sea state dynamic simulator disclosed by the invention can have an important effect of simulating detection in the process of designing and manufacturing of the naval vessel.

The invention discloses a pressure and flow composite controlled electro-hydraulic proportion tension control system for a towing winch of a trawl. The system comprises two sets of electro-hydraulic proportion tension control systems with the same structure, and each tension control system comprises a proportional directional-flow valve, a balance valve, a safety valve, a proportional overflow valve, four one-way valves, two hydraulic motors, a controller, a gear box, a torque sensor and a corner encoder. Towing winches in the two tension control systems are respectively connected with one end of each warp, while the other end of the warps is respectively connected with two ends of a netting gear through respective pulley. According to different operation conditions of the towing winch of the trawl, the system realizes proportion control on working tension of the warp, solves the problems of high labor strength, high technical requirement and low operation safety factor when the trawler fishes. The adopted hydraulic system of the towing winch can adapt to atrocious sea state, greatly improves the system safety, and ensures smooth performance of trawl fishing.

The invention discloses an adaptive control method of an autopilot of a ship and relates to the technical field of automatic control of the ship. The method comprises the steps of: firstly, carrying out wave model identification; updating the upper limit and the lower limit of a controller pipeline so as to calculate controlled quantity; further judging that if the wave model is in a still water area, the model validation is not passed; then, carrying out ship model identification; updating a controller; and carrying out the next control. According to the invention, the self-setting function of the autopilot is automatically finished without personnel to participate and can automatically identify the sea state grade, so that adaptive heading control under wave interference is achieved, and the control performance of the heading of the ship is improved.

The invention discloses an unmanned ship cloth releasing and recovering device with a dock ship as the mother ship. The unmanned ship cloth releasing and recovering device comprises a bracket mechanism and a guiding and winding mechanism. The bracket mechanism is arranged on the mother ship. The appearance of the bracket mechanism is matched with the appearance of an unmanned ship. The bracket mechanism is used for wrapping the whole unmanned ship and supporting the unmanned ship. The bracket mechanism is further used for releasing or locking the unmanned ship according to instructions. The guiding and winding mechanism is arranged on the unmanned ship and used for aiming at a cabin of the mother ship and ejecting out a steel cable so that the unmanned ship can drive into the bracket mechanism according to the designated trajectory. Thus, by means of the unmanned ship cloth releasing and recovering device, the 3-tonnage-level (7.5-m-length) unmanned ship can safely and reliably releaseand recover cloth under the 4-level sea state; the unmanned ship cloth releasing and recovering device has the advantages of being reliable in running, simple in structure, high in autonomy and the like; under the complicated marine environment, the efficiency of the unmanned operation ship is improved, the cloth releasing and recovering program of the unmanned ship is simplified, and the space utilization efficiency of the mother ship and the unmanned ship is improved.

The invention aims to provide a semi-physical simulation method for DP-3-level dynamic positioning. The semi-physical simulation method comprises the steps of: firstly, appointing a command power display and control platform in a display and control system, and commanding one of control computers to be a master control computer through the command power display and control platform; after a simulation work station completes the setting of a required sea state, sending motion information of a floating facility to an information conversion intermediate machine once after one simulation beat; then performing resolution on motion control by the control computers respectively, and performing majority voting on a resolution result of each beat to finally determine the control output of the master control computer; and acquiring a simulation control command resolved by the group of the control computers through a serial port by the information conversion intermediate machine, sending digitalsignals to a simulation computer through a network, and simultaneously transmitting the motion information, which is obtained through resolution of the simulation computer, of the current floating facility to the control computers through a serial port so as to ensure that the control computers perform a new round of control command solving according to updated sate information. According to the invention, the system reliability is greatly increased.

The invention discloses a method for detecting floating targets on the sea based on a normalized Doppler spectrum, and relates to the field of radar target detection. The method includes the steps that firstly, radar echo data are divided into blocks, and divided echo data are acquired; secondly, the normalized Doppler spectrum is calculated for the echo data of a unit to be detected; thirdly, the detection statistical amount is constructed according to the normalized Doppler spectrum; fourthly, a false alarm probability is given, and a detection threshold is acquired through a Monte Carlo experiment; fifthly, whether the targets exist or not is judged according to the detection statistical amount and the detection threshold, if the detection statistical amount is larger than the detection threshold, it is judged that the targets exist, or else it is judged that the targets do not exist. The method mainly solves the problems that in the prior art, detection performance is low when radar observation time is short. The method is adaptive, suitable for different sea states and space-time changes, and capable of effectively detecting the floating targets under the seat clutter background.