99 results about "Marine technology" patented technology

The present invention relates to the field of marine technology and engineering, and in particular to a floating wind power platform attitude control system. The present invention effectively controls the attitude of the floating wind power platform through the mutual cooperation between a measurement system, a control system, and a platform attitude control system, thereby providing good protection for the safe and stable operation of the floating wind turbine. At the same time, the platform attitude control system is provided with a second tidal energy power generation system to provide electrical energy for the electrical connection between the various systems, without additionally consuming the energy of the floating wind turbine, thereby improving resource utilization.

This invention belongs to the field of marine technology and discloses a hatch cover system and a cargo ship. The hatch cover system includes a hatch cover body rotatably mounted on the deck of the cargo ship, capable of rotating relative to the deck to switch between a covered state, a side enclosure state, and a deck extension state. In the covered state, the hatch cover body covers the upper part of the deck, thus covering the hatch opening of the cargo hold located below the deck. In the side enclosure state, the hatch cover body rotates to an angle with the deck, at which point it forms a side enclosure structure on the deck. In the deck extension state, the hatch cover body rotates to the outside of the cargo ship, at which point it can carry cargo. This hatch cover system can switch between multiple forms to function as a cover, a wall, and an extended deck area, improving functional integration and space utilization.

This application relates to a cargo hold and its control method for rapid loading and unloading of cargo on a transshipment barge, belonging to the field of marine technology. It includes a W-shaped cargo hold with two symmetrical unloading ports along the bow and stern lines of the barge at its bottom, each port equipped with an adjustable-opening hatch assembly; and a cargo distribution detection module installed inside the cargo hold to acquire surface area information of the cargo stack within the hold, calculate the center of gravity position of the hold based on this information, and calculate the opening degree distribution of the unloading ports at the bottom of the hold based on the center of gravity position information; and a controller whose data input terminal is connected to the data output terminal of the cargo distribution detection module, and whose signal output terminal is connected to the signal input terminals of several hatch assemblies, for receiving the opening degree distribution results and adjusting the opening degree of the unloading ports at the bottom of the hold. This application ensures the stability of the barge during the unloading process.

The invention discloses a route planning method and device, electronic equipment and a readable storage medium, and relates to the technical field of ships. The route planning method comprises the following steps: dividing a preset sea area into a plurality of sea area grids; historical sailing data corresponding to each sea area grid are obtained, and the historical sailing data comprise ship parameters of historical ships sailing in the sea area grids, historical slip rates corresponding to the historical ships and historical meteorological parameters; establishing a slip rate data set corresponding to each sea area grid according to historical navigation data; according to the slip rate data set, predicting a predicted slip rate of the target ship corresponding to each sea area grid; determining a plurality of target sea area grids according to the departure place, the destination and the predicted slip rate of the target ship; and planning a target ship route of the target ship according to the plurality of target sea area grids. According to the route planning method, the navigation time and slip rate data of the ship can be considered, and the navigation cost of the target ship in the actual navigation process is effectively reduced.

This invention relates to the field of marine technology, specifically disclosing a bilge structure for an oil spill recovery vessel, including an outer bilge plate, ribs, a sealing plate, a lower bilge elbow plate face panel, a lower bilge elbow plate web, and an upper bilge elbow plate; the two ends of the outer bilge plate are respectively connected to the side plates and the bottom plate, and ribs are provided on the inner side of the outer bilge plate away from the bottom plate; the ribs are located on the inner side of the bottom plate, and the ribs are provided with an inner bottom plate and an inner bottom folded edge plate, forming a groove between the inner bottom folded edge plate and the outer bilge plate; the sealing plate is located above the groove; the lower bilge elbow plate face panel is located at the bottom of the sealing plate; the lower bilge elbow plate web is located in the groove; the upper bilge elbow plate is located above the lower bilge elbow plate face panel and is used to connect the lower bilge elbow plate face panel and the ribs; wherein, the outer bilge plate, the inner bottom folded edge plate, the sealing plate, the lower bilge elbow plate face panel, and the lower bilge elbow plate web together form a closed structure, and the closed structure is filled with filling material. This invention eliminates the bilge grooves in the prior art, thereby improving the efficiency of residual oil extraction and cabin cleaning.

The invention discloses a deep-sea exploration shale gas yield prediction method and system, and belongs to the technical field of ocean, and the method comprises the steps: collecting and processing real-time data of a shale gas field, and then determining the characteristic data of the shale gas field; historical data of the shale gas field are collected, and a shale gas yield prediction model is constructed; the shale gas yield prediction model is adopted to analyze the shale gas field characteristic data, and the shale gas yield in the shale gas field is predicted. According to the method, the problems that in the prior art, the shale gas yield in the shale gas field cannot be effectively predicted, so that the production scheme optimization, the development effect evaluation and the energy scheme making are greatly influenced, and the shale gas field development effect is poor are solved. The shale gas field characteristic data is analyzed and predicted based on the shale gas yield prediction model, the shale gas yield in the shale gas field can be effectively predicted, the production scheme is further optimized, the development effect is evaluated, the energy scheme is formulated, and the shale gas field development effect can be improved.

This invention discloses a connection structure between a marine electric propulsion motor and a rudder, relating to the field of marine technology. It includes a shell containing symmetrically distributed rotating shafts rotatably connected within it. Each shaft has a fixedly mounted inclined push wheel. Symmetrically distributed fixed guide rails are fixedly connected to the inner side of the bottom wall of the shell. A fixed shaft is located inside the shell, with a rotating frame fixedly connected to its top and a rudder fixedly connected to its bottom. An emergency component is mounted on the rotating frame. This invention optimizes the transmission structure and emergency mechanism. Under normal operation, all components rotate collaboratively, ensuring precise and efficient directional adjustment. In abnormal situations, the emergency solution quickly disconnects the lifting sleeve from the rotating frame, simplifying the transmission path, avoiding bearing fatigue damage that could lead to jamming, ensuring safe navigation, and significantly improving the reliability and safety of the rudder system.

The invention belongs to the technical field of ships, and discloses a testing method for a PCTC ship stern ramp load monitoring system, the theoretical maximum load capacity of a stern ramp in the non-starting state of the stern ramp load monitoring system is Wmax1, the theoretical maximum load capacity of the stern ramp in the starting state of the stern ramp load monitoring system is Wmax2, and the theoretical maximum load capacity of the stern ramp in the starting state of the stern ramp load monitoring system is Wmax2. Comprising the following steps that a starting button of a stern ramp load monitoring system is pressed down, a stern ramp is opened, and the included angle between the stern ramp and the wharf ground is smaller than or equal to 6 degrees; a weight-free load test is carried out; carrying out load testing within Wmax1; a load test of a Wmax1 critical value is carried out; a load test of a Wmax2 critical value is carried out; compared with the mode that a crane is used for hoisting the weights one by one and the module vehicle loads and moves the weights, crane resources are saved, the testing efficiency is greatly improved, the influence of testing on the wharf production period is reduced, the influence of water level changes caused by tide rising and tide falling on testing is reduced, and the reliability of testing results is improved.

This invention belongs to the field of information and marine technology, and discloses a method for estimating the DOA (Direction of Aperture) of a UUV (Ultra-UV) hull-side array using conjugate enhancement and virtual extension. This method performs conjugate enhancement processing on the received signal from a parallel coprime array, calculates the augmented statistical matrix including autocorrelation, conjugate autocorrelation, cross-correlation, and conjugate cross-correlation, and constructs an extended correlation matrix through weighted combination. A virtual uniform linear array is constructed using the differential co-array characteristics of the coprime array. A redundant integration matrix is ​​designed to remove redundancy from the covariance matrix, obtaining the equivalent signal of the virtual array. Then, the covariance matrix of the virtual array with a Toeplitz structure is reconstructed. Finally, a dual rotation-invariant subspace algorithm is used to achieve high-precision, automatic pairing estimation of the underwater target's azimuth and pitch angles. This invention extends the array aperture, improves the estimation robustness in low signal-to-noise ratio environments, and eliminates the need for spectral peak search, providing technical support for UUV underwater target positioning.

This utility model belongs to the field of marine technology, specifically relating to a multi-level equalization management system for marine lithium battery packs. It includes a main control chip, a voltage detection circuit, a current detection circuit, a temperature sensor, and an equalization switch array. By employing a voltage detection circuit composed of operational amplifiers and voltage divider resistors, a current detection circuit composed of Hall effect sensors and low-noise amplifiers, temperature sensors arranged at multiple locations within the battery pack, and an equalization switch array composed of transistors, it achieves high-precision acquisition and rapid response control of battery parameters. This solution improves the system's stability and equalization efficiency in complex environments, effectively solving the problems of untimely and inaccurate equalization control caused by insufficient monitoring accuracy and response lag in existing technologies, thereby significantly improving the safety and service life of marine lithium battery packs.

The invention discloses a supporting device for a ship container cargo hold, and belongs to the technical field of ships. The cargo hold comprises a first container position and a second container position which are arranged from bottom to top in the vertical direction, and the front / rear wall of the cargo hold is connected with a guide frame. The first box position and the second box position are step-shaped; the supporting device for the ship container cargo hold comprises a supporting toggle plate, two toggle plate assemblies and two supporting assemblies. The supporting toggle plate is connected to the side, away from the front / rear wall of the cargo hold in the first horizontal direction, of a guide frame. The two toggle plate assemblies are correspondingly arranged on the two sides of the guide frame in the second horizontal direction. One ends of the two supporting assemblies are rotationally connected with the two toggle plate assemblies in a one-to-one correspondence mode, and the other ends of the two supporting assemblies are detachably connected to the supporting toggle plate. The guide frame is arranged in the space defined by the two supporting assemblies and the front / rear wall of the cargo hold in a penetrating mode. When the supporting assembly is connected to the supporting toggle plate, the top face of the supporting assembly is used for supporting a second container loaded into the second container position. The operation period is prevented from being prolonged, and the positioning precision of the guide frame to the container is ensured.

This invention belongs to the field of marine technology and discloses an energy-saving rudder device, a power system, and a ship. The energy-saving rudder device includes a rudder body and a rectifier structure. The rudder body is positioned opposite and spaced apart from the propeller of the power system. The rectifier structure is located at the leading edge of the rudder body relative to the propeller, with a gap between it and the propeller; both ends of the rectifier structure are connected to the leading edge, and the middle portion of the rectifier structure protrudes towards the direction of the propeller, with a gap between it and the leading edge. This energy-saving rudder device enables energy conservation in the ship and increases its sailing speed.

This invention discloses a thick-film high-manganese steel corrugated plate for polar LNG ships, its manufacturing method, and its application, belonging to the field of marine technology. The corrugated plate is made of high-manganese steel plate with a manganese content of 22-25 wt%. The high-manganese steel plate substrate has a first protrusion arranged uniformly and parallel along a first direction and a second protrusion arranged uniformly and parallel along a second direction perpendicular to the first direction. A quadruple rotationally symmetrical star-shaped node is pressed at the position where the first and second protrusions intersect perpendicularly. The quadruple rotationally symmetrical star-shaped node includes a surface opening and a recessed bottom surface. Both the surface opening and the recessed bottom surface have a four-lobed symmetrical profile, composed of two alternating arcs with different radii of curvature. The width between the symmetrical lobes of the surface opening is greater than the width between the symmetrical lobes of the recessed bottom surface. This corrugated plate uses an integrated arc transition, which makes it easier for stress to diffuse evenly throughout the entire node area. Results show that the peak stress at the intersection is reduced by more than 35%.

The invention relates to the technical field of ships, and particularly discloses a ship low-temperature container mounting structure which comprises two saddles used for bearing a low-temperature container, a first discharging opening is formed in the bottom of each saddle, and a first temperature sensor is arranged at the bottom of each saddle; the two ends of the bearing groove are fixedly connected with the two saddles, a second discharging opening is formed in the bottom of the bearing groove, and a second temperature sensor is arranged at the bottom of the bearing groove; the recovery assembly comprises two first branch pipes, a second branch pipe, a main pipe and a recovery tank, the two first branch pipes are communicated with the first discharge ports of the two saddles respectively, each first branch pipe is provided with a first discharge valve, the second branch pipe is communicated with the second discharge port of the receiving groove, and the second branch pipe is provided with a second discharge valve; the first branch pipe and the second branch pipe are communicated with the recovery tank through a main pipe; according to the installation structure of the ship low-temperature container, low-temperature leaks can be collected, the low-temperature leaks are effectively prevented from making contact with a ship body structure, and therefore the ship body structure is protected.

This invention discloses a marine fuel supply and return device and control method, belonging to the field of marine technology. The system includes: a steel fuel storage tank, whose inlet is connected to the fuel day tank via a supply pipeline, and whose return outlet is directly connected to the diesel engine return pipeline; a fuel supply power and metering unit, located on the supply pipeline, including a filter, a fuel pump, and an ultrasonic flow meter connected in sequence; a tank condition monitoring unit, located on the steel fuel storage tank, including at least a level gauge and a density meter or thermometer; a data acquisition and control unit, connected to the fuel pump, ultrasonic flow meter, and tank condition monitoring unit, used to control the start and stop of the fuel pump according to the liquid level, and to collect data on the fuel supply volume, the volume and density of the remaining fuel in the tank, and to calculate fuel consumption; and a data transmission unit for remotely transmitting fuel consumption data to a shore-based platform. This invention replaces the traditional float tank and return oil cooler with an integrated steel oil storage tank, simplifying the system structure and ensuring original factory maintenance of the diesel engine; at the same time, it uses a single ultrasonic flow meter combined with a material balance algorithm to achieve accurate fuel consumption measurement and supports remote data transmission, making it suitable for ship energy efficiency management and carbon intensity index calculation.

The invention relates to the technical field of marine technology and enzyme, and particularly discloses alkaline serine protease and application thereof. The brand-new alkaline serine protease is successfully mined by using a marine-derived microbial metagenome database, the limitation of conventional microbial isolated culture is overcome, and the source selection range of the alkaline serine protease is greatly widened. Moreover, the alkaline serine protease has excellent protease activity and detergent tolerance, and can be effectively used for protein degradation or used as a detergent component.

This application discloses a machine learning-based method for constructing numerical atlases of marine propellers, relating to the field of marine technology. This method uses a viscous flow numerical calculation model to calculate the performance parameters of a propeller with design parameters for each set of samples at various sample infeed velocities. Then, using the design parameters and infeed velocities of each set of samples as input and the corresponding performance parameters as output, a performance surrogate prediction model is trained using multiple sets of sample design parameters based on a machine learning model. This surrogate prediction model can then be used to obtain the performance parameters corresponding to different propeller schemes within the atlas parameter range, thus constructing a numerical atlas of marine propellers. This method combines the high efficiency and high accuracy of viscous flow numerical methods with the superior nonlinear fitting capability of machine learning models. It does not rely on extensive physical model experiments, has a simple construction method, and produces propeller atlases with high numerical accuracy.

The invention relates to the technical field of ocean, and particularly discloses a modular honeycomb floating body unit ocean platform structure and method.The modular honeycomb floating body unit ocean platform structure comprises a floating plate, wave-resistant units, connecting pieces, clamping and embedding blocks, connecting screw rods and fence columns, the wave-resistant units are fixedly connected with the floating plate and located at the lower end of the floating plate, and the two clamping and embedding blocks are arranged on the two sides of the connecting pieces correspondingly; the connecting piece is arranged on one side of the floating plate, one set of clamping and embedding blocks are embedded in the floating plate and detachably connected with the floating plate through connecting screw rods, the number of the fence columns is multiple, and each set of fence columns is in threaded connection with the floating plate and located at the upper end of the floating plate. The modularized structure is adopted for combination, transportation and installation are facilitated, meanwhile, when a single module breaks down, rapid maintenance and upgrading are facilitated, the required number of modules are correspondingly used according to requirements, the modules are flexibly installed and combined to form the required platform shape and structure, and the use and installation flexibility of the ocean platform is improved.

The invention discloses a chemical tanker liquid cargo tank failure risk dynamic assessment method and device, and relates to the technical field of ships, and the method comprises the steps: obtaining a first critical pitting corrosion-free characteristic curve of a liquid cargo tank; collecting real-time characteristic data; identifying a spot corrosion area according to the curve; linearly fitting the spot corrosion area by adopting a spatial adjacency algorithm to obtain a linear corrosion area; diffusing the simulated line corrosion region by adopting a spatial transmissibility algorithm to obtain a surface corrosion region; and performing failure risk weighted evaluation on the surface corrosion area to obtain a failure risk evaluation index. The technical problems that an existing corrosion failure risk assessment method cannot effectively combine real-time environment parameters and material characteristics for dynamic analysis, consequently, the overall failure risk cannot be quantified in real time, and risk identification lags behind are solved. The technical effects that point-to-surface dynamic evolution simulation of the corrosion risk is achieved based on the space adjacency and transmissibility algorithm, and the safety early warning comprehensiveness and accuracy of the liquid cargo tank structure are improved are achieved.

The invention belongs to the technical field of ships, and discloses a protection device, a side thrust system and a ship. The protection device comprises a hydraulic assembly, a transmission connection assembly and a plurality of movable blade assemblies which are parallel to one another and can synchronously rotate. The movable blade assembly is arranged in an end opening of a mounting channel of a bow of a ship. The hydraulic assembly is installed on the inner wall of the end opening. The transmission connecting assembly is in transmission connection between the hydraulic assembly and the movable blade assemblies, and the hydraulic assembly can drive the movable blade assemblies to rotate and make contact with one another through the transmission connecting assembly so as to seal the end opening or drive the movable blade assemblies to rotate and be separated from one another so as to open the end opening. The protection device can be opened and closed, foreign matter can be effectively prevented from entering the side thrust system, the influence of the side thrust system in a non-working state on the streamline of a ship body can be improved, and resistance borne by the ship in the sailing process is reduced.

This invention discloses an automatic cleaning dual oil filter for ships, relating to the field of marine technology. It includes a filter cartridge body, an oil inlet chamber, an oil outlet chamber, and a control box. The oil inlet chamber has a support frame and a differential pressure chamber. The support frame houses a first motor, which is connected to a connecting shaft. The connecting shaft is connected to a pneumatic column, which is connected to a telescopic air bladder. The telescopic air bladder is connected to a pressure air bladder, and the telescopic air bladder has a propulsion column. The connecting shaft has a second sliding groove. The differential pressure chamber has a switch, which is slidably connected to an electrical contact block. The propulsion column is connected to symmetrical levers. A second oil passage pipe is fixedly connected to the filter cartridge body via a flange. A partition is fixedly installed inside the filter cartridge body, and a filter element is installed in the partition. The filter cartridge body also houses a second motor. This invention can automatically switch to another filter cartridge when the pressure drop inside the oil filter reaches a specified value. Simultaneously, a rotating cleaning brush thoroughly cleans the inside of any clogged filter element, ensuring uninterrupted operation of the oil filter and making it suitable for widespread application.

This invention belongs to the field of marine technology and discloses a bulwark structure and a ship. The bulwark structure is connected to the deck body and includes a bulwark body and an air pipe. The bulwark body is connected to the deck body and encloses the deck body to form a first compartment. The air pipe includes a pipe body and a pipe head. The pipe body is located in the first compartment, and the pipe head is located above the first compartment. Thus, placing the pipe body in the first compartment saves space above the deck body, improves the utilization rate of the deck body, and reduces design and layout costs. At the same time, the first compartment also protects the pipe body, preventing it from being exposed to the outside of the deck body and suffering damage from impacts. While ensuring air communication and pressure balance between the inside and outside of the compartment, it also improves the safety performance of the pipe body and extends its service life.

A flexible, stretchable grounding device, belonging to the field of marine technology, includes a grounding structure with connecting shafts at both ends. The grounding structure comprises two sleeves, with a braided wiring strip placed between them. Wire ends are fixedly installed at both ends of the braided wiring strip, and a fixing pad is fixedly installed inside the sleeves. The connecting shafts are fixed between the equipment body and the ship structure using bolts and tightened. Since the sleeves are made of multiple single-wire braids, they have a certain degree of tensile strength, allowing for some displacement when connecting the equipment body and the ship structure. This avoids the possibility of the yellow-green grounding wire breaking off from the equipment body or ship structure without requiring sufficient displacement margin. Furthermore, its surface is coated with a tin-zinc anti-corrosion coating, ensuring conductivity, tensile strength, and good corrosion resistance.

This invention belongs to the field of marine technology and discloses a marine air cooler cleaning device and method. The marine air cooler cleaning device includes a spray assembly, a liquid inlet pipe, and a regulating valve. The spray assembly includes multiple spray pipes, each of which can selectively connect to a cleaning fluid source. The cleaning fluid can be sprayed onto the air cooler core through the multiple spray pipes and their nozzles. The regulating valve is located on the liquid inlet pipe and is communicatively connected to the control system of the marine diesel engine, used to regulate the flow rate of the cleaning fluid in the liquid inlet pipe. This marine air cooler cleaning device can quantitatively clean the air cooler core according to the operating conditions of the marine diesel engine, thereby achieving an effective supply of cleaning fluid. This invention also provides a marine air cooler cleaning method. Using the above-mentioned marine air cooler cleaning device, the air cooler core can be cleaned periodically and quantitatively according to the operating power of the marine diesel engine, thereby achieving an effective supply of cleaning fluid.

The utility model relates to propelling equipment, and relates to the technical field of ships. The utility model provides propelling equipment. The propelling equipment comprises a lithium ion battery pack, a propelling motor, an elastic coupling and a steering oar device, the lithium ion battery pack is electrically connected with the propulsion motor, and the output end of the propulsion motor is connected with the steering oar device through the elastic coupler. Compared with a traditional propulsion motor using a diesel engine, the propulsion equipment adopts the lithium ion battery pack, the lithium ion battery pack drives the propulsion motor through battery discharging, a traditional propulsion shaft system does not need to be arranged, mechanical transmission loss of the propulsion shaft system and loss caused by incomplete combustion of the diesel engine are avoided, the propulsion efficiency is improved, and the energy consumption is reduced. The pollution to the environment is reduced; meanwhile, the lithium ion battery pack and the elastic coupler are arranged, so that noise during navigation is reduced, and a comfortable environment is provided for tourists.

This invention belongs to the field of marine technology and discloses a drainage system for a ro-ro ship deck and the ro-ro ship itself. The drainage system for the ro-ro ship deck connects longitudinal and transverse drainage channels below the vehicle deck, and a sewage well is connected to the longitudinal and / or transverse drainage channels. During cleaning, sewage flows into the drainage channels through the nearest drain outlet and is quickly guided to the sewage well. Sewage no longer flows freely on the deck surface, reducing accumulation and retention on the vehicle deck and preventing sewage from adhering to the deck surface and bulkhead corners after drying, thus reducing the difficulty of cleaning operations. Due to the multiple drain outlets, cleaning can be carried out more efficiently, reducing the time and effort required and improving cleaning efficiency. Furthermore, the cleaning structure effectively removes dirt from the corresponding drainage channels, ensuring drainage effectiveness and further improving cleaning quality and efficiency.

The invention relates to the technical field of oceans, in particular to a coral ecology multi-risk overlay analysis method and system based on a GIS (Geographic Information System), and the method comprises the steps: constructing a marine ecology resistance surface which reflects the interference degree of human activities, and carrying out the spatial overlay operation of each standardized risk intensity grid and the marine ecology resistance surface in a GIS platform, generating a coral ecological risk spatial distribution map comprehensively reflecting coral reef stressed space; identifying a potential ecological corridor connected with the risk interval residual suitability degree raw land; according to the evaluation result of the coral ecological risk spatial distribution map and the corridor fracture risk, coral protection supervision core areas and ecological corridor restoration areas with different priorities are delimited, and targeted supervision suggestions are generated, so that a direct and scientific decision basis can be provided for delimiting differentiated protection subareas and formulating targeted restoration strategies, and the method is suitable for popularization and application. And the refinement level and foresight of coral reef protection management are improved.

This utility model belongs to the field of marine technology, specifically relating to a combined ship hatch cover limiting device. It includes a ship cabin, with a hatch cover contacting the upper end of the cabin. A hinge is fixedly connected to the hatch cover, and the hinge is fixedly connected to the cabin. A handle is fixedly connected to the upper end of the hatch cover. A connecting plate is fixedly connected to the outer side of the hatch cover. An elastic block is fixedly connected to the lower end of the connecting plate, and a fixed plate contacts the lower end of the connecting plate. The fixed plate contacts the elastic block. A fixed plate is fixedly connected to the outer side of the cabin. This utility model, through the design of components such as positive and negative screws, a rotating block, bearings, threaded blocks, guide blocks, and connecting blocks, allows a slider to be pulled out of a slot. Then, rotating the positive and negative screws causes threaded movement between the screws and the threaded block. The movement of the threaded block moves the limiting block and other components, causing the limiting block to move into a groove, thereby limiting the hatch cover and making the device easy to use.

This invention provides a method and apparatus for constructing a safety envelope for a hovercraft, relating to the field of marine technology, and particularly to a technology for assessing and controlling ship navigation safety. More specifically, this invention discloses a method for constructing a safety envelope for a hovercraft that considers multi-degree-of-freedom coupling for different sea states. The method for constructing the safety envelope of a hovercraft includes: obtaining a preset four-degree-of-freedom motion model of the hovercraft, wherein the four-degree-of-freedom motion model is used to characterize the coupling relationship of the hovercraft's sway, roll, heel, and yaw motions; for at least one preset sea state, based on the four-degree-of-freedom motion model, systematically traversing a set of coupled state parameters including longitudinal motion, lateral motion, heel motion, and rotational motion, and judging the motion stability under each parameter combination to determine a set of stable state boundaries under the sea state; and generating a multi-dimensional safety envelope that characterizes the intrinsic correlation of the multiple coupled state parameters and corresponds to the sea state based on the set of stable state boundaries. Through the above steps, this invention can comprehensively consider the high-order nonlinear strongly coupled motion characteristics of the hovercraft and external environmental interference, thereby comprehensively constructing its high-dimensional safety envelope.

The invention provides an underwater rapid shut-off valve, and relates to the technical field of valves in marine technologies, the underwater rapid shut-off valve comprises a valve body and a driver, the upper part of the valve body is provided with a valve cover, and the driver is mounted at the top of the valve cover; the driver comprises a driver shell, a hydraulic driving assembly, a spring cavity oil storage tank and a rapid oil return system. A spring lower support is arranged at the bottom of the driver shell, a top cover is arranged on the top of the driver shell, a hydraulic cylinder is arranged on the top cover, and the spring cavity oil storage tank is arranged on the top cover and communicated with the driver shell through a pipeline. The hydraulic driving assembly is arranged in a sealed space in the driver; and the quick oil return system is arranged on the top cover. According to the structural design, the influence of resistance on oil liquid in a spring cavity of the driver during flowing is greatly reduced; and when hydraulic pressure fails, the control liquid can be quickly discharged into the hydraulic cylinder oil storage tank through the quick discharge valve, so that the valve can be quickly switched off.