A 3D simulation model for ships

Abstract

The present invention relates to the technical field of simulation models, and specifically discloses a three-dimensional simulation model for ships, including a self-ship simulation module, a cooperative ship simulation module, a target ship simulation module, a sea condition simulation system, a 3DGIS three-dimensional geographical simulation module, and a cluster management system. The present invention can achieve the synchronization of vision radar, reproduce complex sea conditions, improve the training effect of relevant personnel of tugboats, and enhance the safety and efficiency of offshore operations.

Description

Technical Field

[0001] The present invention relates to the technical field of simulation models, and more specifically, the present invention relates to a three-dimensional simulation model for ships. Background Art

[0002] With the increasing size of ships, the berthing and unberthing operations of large ships, the towing of non-powered ships or floating objects, and the dynamic positioning of offshore platforms all rely on the assistance of tugboats. As an auxiliary maneuvering means, tugboats play a very important role in sea towing, sea or ice area rescue, salvage, drilling platform supply, and assisting large ships in berthing and unberthing. Tugboats are small in tonnage, flexible, and have good maneuverability and relatively large thrust or towing force. For safety reasons, large ships or dangerous ships generally have the assistance of tugboats when entering and leaving ports. Therefore, tugboats are essential in maritime transportation.

[0003] At present, tugboats play an important role in the entry and exit of large ships, the berthing and unberthing of dangerous goods ships, and the emergency rescue in strong winds and waves. They are an important guarantee and prerequisite for port safety production. Tugboat simulators are widely used in the skills training of tugboat drivers, pilots, and ship operators. The main function of such simulators is to help trainees master the maneuvering skills, emergency fault handling capabilities, and cooperative operations of tugboats through simulation training, so as to improve the safety and efficiency in actual operations. At present, the tugboat simulators on the market are usually used to simulate the operations between tugboats and target ships. However, the visual scenes and radar images between ships on the market are not dynamically synchronized, and the relative positions and navigation states cannot be displayed in real time. The dynamic interaction between the tugboat and the towed ship cannot be synchronously shown. At the same time, the prior art cannot fully reproduce complex sea conditions. Summary of the Invention

[0004] In order to overcome the above-mentioned defects of the prior art, the present invention provides a three-dimensional simulation model for ships. By dynamically synchronizing the visual scenes and radar images between ships, the dynamic towing interaction three-dimensional model can calculate the relative motion between the tugboat and the towed ship and achieve safe and efficient interaction. The sea condition simulation system can establish a dynamic sea condition simulation model to reproduce complex sea conditions, so as to improve the operation skills of trainees and solve the problems raised in the above background art.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] A three-dimensional simulation model for ships, used for real-time interactive pushing and towing operations between a tugboat and other ships, includes a self-ship simulation module, a cooperative ship simulation module, a target ship simulation module, a sea condition simulation system, a 3DGIS three-dimensional geographical simulation module, and a cluster management system; the sea condition simulation system establishes a dynamic sea condition simulation model to reproduce complex sea conditions, and the steps are as follows:

[0007] Step Z1, based on the directional wave spectrum function to describe the wave energy distribution under wind force and wind direction, the directional wave spectrum function is expressed as: , where is the frequency spectrum of the wave, describing the distribution of wave energy with frequency; is the direction distribution function, indicating the distribution of wave energy in different propagation directions;

[0008] Step Z2, the frequency spectrum of the wave adopts the JONSWAP spectrum, and the calculation formula is: , where is the spectral peak factor, depending on the intensity and duration of the wind force; is the gravitational acceleration; is the wave frequency; is the peak frequency, corresponding to the frequency of the maximum wave energy; is the wave crest enhancement factor, reflecting the non-linear enhancement effect of the wave; is the frequency distribution width parameter; the direction distribution function has the calculation formula of: , where is the wave propagation direction, is the wind direction;

[0009] Step Z3, based on the directional wave spectrum, the dynamic sea condition simulation model generates a three-dimensional sea wave surface through the Fourier superposition method, and the height of the sea wave surface has the calculation formula of: , where is the wave height at the position at time ; is the wave amplitude; is the component of the wave number vector in the direction; is the component of the wave number vector in the direction; is the angular frequency of the wave, calculated through the dispersion relation: , is the water depth; is the random phase of the wave; is the number of segments of the wave frequency; is the number of segments of the wave wind direction;

[0010] Step Z4, in real-time simulation, the dynamic sea condition simulation model dynamically updates the wave height , combined with wind speed and direction, generates a dynamic three-dimensional sea wave field, and adjusts the wave simulation parameters in real time to meet the requirements of tugboat operations; when the tugboat and the towed vessel enter an area with increasing wind force, the dynamic sea condition simulation model will increase the wave crest enhancement factor to enhance the nonlinear characteristics of the waves; when the tidal current speed increases, the dynamic sea condition simulation model will adjust the wave number and angular frequency to reflect the acceleration effect of wave propagation.

[0011] As a further solution of the present invention, the vessel simulation module includes a three-dimensional visual scene unit, a tugboat operation module, and a training sea area database, including the following specific contents: The vessel simulation module constructs a three-dimensional simulated hull, which interacts with sea waves, cables, and sea winds, and simultaneously receives left and right rudder control signals and acts on the hull. The three-dimensional visual scene unit consists of a 180-degree cylindrical screen, including computer imaging technology, virtual reality technology, and seamless stitching wide field-of-view annular screen projection technology, enabling the simulator to present a realistic three-dimensional visual scene effect. The three-dimensional visual scene unit selects a high-performance microcomputer hardware platform and is equipped with a high-end three-dimensional graphics acceleration board to ensure the efficiency and stability of computing and processing. At the same time, the entire three-dimensional visual scene unit is based on the Windows10 operating system and is developed using C++ and a professional real-time visual scene management software platform to ensure smooth visual scene effects in a complex real-time computing environment. The visual scene effect can present the six-degree-of-freedom motion mathematical model of the ship and meet most navigation simulation requirements. Its image update rate is greater than 50 frames per second to ensure visual fluency during the simulation process, and most of the indicators are better than the DNV standard.

[0012] The tugboat operation module includes a tugboat operation equipment unit, a comprehensive information display unit, an electronic chart unit, and a simulated radar unit; the tugboat operation equipment unit includes rudder control, telegraph control, control of the vessel's own cable, control of the vessel's own anchor, and control of the vessel's navigation lights and sound signals; the rudder control includes three modes: manual steering, follow-up steering, and automatic steering, and the control parameters of each mode can be adjusted to meet different operation requirements. The manual steering mode allows the operator to manually control the rudder according to the actual situation to adjust the vessel's course; the follow-up steering mode automatically adjusts the rudder angle according to the vessel's current course and speed to ensure the stability and smoothness of the vessel during navigation; in the automatic steering mode, the rudder angle is automatically calculated and adjusted according to the preset waterway and target point to make the vessel sail along the optimal path. The telegraph control is used to adjust the propulsion operation of the tugboat. The control of the vessel's own cable is used to manage the cable operation between the tugboat and the towed vessel, including the mooring, unmooring, and warping operations of the main cable. The control of the vessel's own anchor controls the left and right anchors through an anchor operation panel, supports various anchor operation functions, including anchoring, weighing anchor, paying out, and stopping, and can dynamically display the length and tension of the anchor chain to ensure that the operator can monitor the anchor chain status in real time, thereby controlling the anchor operation. The control of the vessel's navigation lights and sound signals is operated through a control panel, supports the setting of various navigation lights and shapes, and the control of the sound signals supports the manual sounding of the bow bell and the stern gong.

[0013] The functions of the comprehensive information display unit include the solution of the ship motion mathematical model and sound simulation. The comprehensive information display unit designs the motion mathematical models of two ship types, namely the container outer hull and the cargo ship, and covers models of different tonnages and loading conditions. At the same time, the sound simulation function includes the simulation of the ship's sound signal system (supporting foghorns, bells, gongs, and automatic cycle settings), engine room noise, sea waves, sirens, telegraphs, and other operation sound effects. The comprehensive information display unit also provides detailed ship dynamic information, including rudder and propeller data, true wind direction and speed, compass course, and basic parameters such as ship type, displacement, length, width, draft, and loading status. In addition, the comprehensive information display unit has a fault alarm function, covering faults of key components such as the main engine, steering gear, autopilot, radar, GPS, log, as well as alarm information such as collision, grounding, stranding, and dragging anchor.

[0014] The functions of the electronic chart unit include electronic chart display and vessel dynamic display based on ECDIS (Electronic Chart Display and Information System). The electronic chart display has multiple functions, including real-time chart information display, chart data update and modification, positioning and navigation, nautical information query, radar image overlay display and target tracking, route design and monitoring, course keeping, voyage record and hazard avoidance functions. The dynamic display function based on ECDIS can present the dynamic positions of the own vessel, target vessels and tugboats on the system interface in real time, and automatically adjust the display scale according to the vessel tonnage. The simulated radar unit can simulate radar systems in 10 cm and 3 cm bands and support operations in relative motion mode and true motion mode. The training sea area database covers charts and radar charts, as well as a three-dimensional visual scene database of the training sea area based on these two.

[0015] As a further aspect of the present invention, the cooperative vessel simulation module constructs a three-dimensional simulated hull that interacts with sea waves, cables and sea winds, and also has an audio simulation function. It receives the rudder signals simulated by the left and right handles and acts on the hull.

[0016] As a further aspect of the present invention, the vessel types in the target vessel simulation module include container ships, bulk carriers and ro-ro passenger ships. It has an audio simulation function and is physically simulated under the action of a tugboat.

[0017] As a further aspect of the present invention, the visual scenes and radar images between vessels are dynamically synchronized. When the tugboat and the towed vessel operate in their respective simulators, their relative positions and navigation states are displayed in real time. By establishing a dynamic towing interaction three-dimensional model, the relative motion between the tugboat and the towed vessel is calculated and dynamically adjusted to achieve the interaction between the tugboat and the towed vessel. The steps of the dynamic towing interaction three-dimensional model are as follows:

[0018] Step S1, obtain the real-time state data of the tugboat and the towed vessel, and calculate the force on the cable. The calculation formula for the force on the cable is: , where is the total force on the cable; is the elastic coefficient of the cable; is the dynamic stretching length of the cable, that is, the difference between the current cable length and the original length; is the damping coefficient of the cable, reflecting the damping effect of the cable during dynamic stretching; is the cable stretching speed; is the self-weight of the cable; is the towing angle, that is, the angle between the cable and the horizontal plane; is the external disturbing force, and the disturbing force includes wind-wave-current force and underwater frictional force , the wind-wave-current force satisfies ,in, is the water density; is the drag coefficient of the cable; is the projected area of ​​the cable in the fluid; is the relative water flow velocity; the underwater friction satisfy ,in, is the friction coefficient between the cable and the water; is the normal force of the cable;

[0019] Step S2, the force exerted by the tugboat on the towed ship is determined by the components of the cable tension in the horizontal direction and the vertical direction, and the force is expressed by the following decomposition formula: ,in, is the horizontal force exerted by the tugboat on the towed ship; It is the vertical force exerted by the tugboat on the towed vessel; is the towing direction angle of the cable in the horizontal direction, that is, the angle between the cable and the moving direction of the tugboat; the interaction force between the tugboat and the towed ship is solved by the force balance formula, and the force balance equation of the tugboat is: ; The force balance equation of the towed ship is: ,in, is the horizontal component of the tugboat thrust, is the vertical component of the tugboat thrust, is the horizontal component of the external force on the towed ship, is the vertical component of the external force on the towed vessel, is the water resistance of the hull in the horizontal direction, is the water resistance of the hull in the vertical direction, is the mass of the tugboat, is the mass of the towed vessel, is the speed of the tugboat, is the speed of the towed vessel, is the acceleration of the tugboat, is the acceleration of the towed vessel;

[0020] Step S3: Based on the above formula, the dynamic towing interactive 3D model uses a real-time feedback control mechanism to adjust the parameters of the cable and the hull. Exceeding the preset total force threshold of the safety cable When the propulsion force of the tugboat is reduced Or increase the heading angle of the towed vessel ; By adjusting the towing angle ,make sure and The components reach the optimum within the target direction; utilize the ship speed difference Dynamically adjust the propulsion force of the tugboat to avoid over-pulling or slackening of the cable. Through the above formulas and adjustment strategies, the dynamic towing interaction 3D model can not only calculate the relative motion during the towing process, but also cope with complex sea conditions and dynamic changes, realizing efficient and safe interaction between the tugboat and the towed ship.

[0021] As a further solution of the present invention, the 3DGIS 3D geographical simulation module simulates the port area, terrain and buildings, has a coordinate unified management system, and establishes a spatial coordinate system and a geodetic coordinate system.

[0022] As a further solution of the present invention, the cluster management system uniformly manages all computer devices, enabling data and visual scenes to be synchronized.

[0023] Technical effects and advantages of a 3D simulation model for ships according to the present invention: The present invention presents a realistic visual scene through a variety of advanced technologies, with a high visual scene update rate. Its tugboat operation module has rich and diverse functions, covering various control modes and operation functions. The comprehensive information display unit can calculate ship motion parameters, simulate sounds and provide detailed information and fault alarms, and the electronic chart unit has complete functions; the cooperative ship simulation module and the target ship simulation module can construct 3D simulation hulls of cooperative ships and target ships; the visual scenes and radar images between ships are dynamically synchronized, and the dynamic towing interaction 3D model can calculate the relative motion between the tugboat and the towed ship and achieve safe and efficient interaction; the sea condition simulation system can establish a dynamic sea condition simulation model to reproduce complex sea conditions and improve the operation skills of trainees; the 3DGIS 3D geographical simulation module can simulate the port area, etc. and establish a coordinate system; the cluster management system ensures the synchronization of data and visual scenes. The present invention overcomes the problems in the prior art such as asynchronous visual scenes and radars, and inability to reproduce complex sea conditions, effectively improving the training effect of tugboat-related personnel and enhancing the safety and efficiency of offshore operations. Description of the Drawings

[0024] Figure 1 It is a structural schematic diagram of a 3D simulation model for ships according to the present invention.

[0025] Figure 2 It is a structural diagram of the tugboat operation module of the present invention.

[0026] Figure 3 It is a schematic diagram of the anchor operation panel for the ship's anchor control of the present invention.

[0027] Figure 4 It is a schematic diagram of the navigation light control panel for the control of the ship's navigation lights and sound signals of the present invention.

[0028] Figure 5 It is a schematic diagram of the signal shape control panel for the control of the ship's navigation lights and sound signals of the present invention. Detailed Implementation Modes

[0029] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0030] Embodiment 1

[0031] Referring to Figure 1 the structural schematic diagram shown, the embodiment of the present invention provides a three-dimensional simulation model for a ship, which includes a self-ship simulation module, a cooperative ship simulation module, a target ship simulation module, a sea condition simulation system, a 3DGIS three-dimensional geographic simulation module, and a cluster management system.

[0032] Furthermore, the self-ship simulation module includes a three-dimensional visual scene unit, a tugboat operation module, and a training sea area database, including: the self-ship simulation module constructs a three-dimensional simulation hull, interacts with sea waves, cables, and sea winds, and simultaneously receives left and right rudder control signals and acts on the hull. The three-dimensional visual scene unit consists of a 180-degree cylindrical screen, including computer imaging technology, virtual reality technology, and seamless stitching wide-angle annular screen projection technology, enabling the simulator to present a realistic three-dimensional visual scene effect. The three-dimensional visual scene unit selects a high-performance microcomputer hardware platform and is equipped with a high-end three-dimensional graphics acceleration board to ensure the efficiency and stability of computing and processing. At the same time, the entire three-dimensional visual scene unit is based on the Windows 10 operating system and is developed using C++ and a professional real-time visual scene management software platform to ensure a smooth visual scene effect in a complex real-time computing environment. The visual scene effect can present the six-degree-of-freedom motion mathematical model of the ship and meet most navigation simulation requirements. Its image update rate is greater than 50 frames per second to ensure visual fluency during the simulation process, and most of the indicators are better than the DNV standard.

[0033] Referring to Figure 2The structure diagram shown, the tugboat operation module includes a tugboat operation equipment unit, a comprehensive information display unit, an electronic chart unit, and a simulated radar unit; the tugboat operation equipment unit includes rudder control, telegraph control, control of the ship's own cable, control of the ship's own anchor, and control of the ship's navigation lights and sound signals; the rudder control includes three modes: manual steering, follow-up steering, and automatic steering, and the control parameters of each mode can be adjusted to meet different operation requirements. The manual steering mode allows the operator to manually control the rudder according to the actual situation and adjust the ship's course; the follow-up steering mode automatically adjusts the rudder angle according to the current course and speed of the ship to ensure the stability and smoothness of the ship during navigation; in the automatic steering mode, the rudder angle is automatically calculated and adjusted according to the preset waterway and target point to make the ship sail along the optimal path. The telegraph control is used to adjust the propulsion operation of the tugboat and can simulate the preparation of the main engine, completion of the engine, stopping, slow ahead, ahead one, ahead two, ahead three, slow astern, astern one, astern two, and full astern. The control of the ship's own cable is used to manage the cable operation between the tugboat and the towed ship, including the mooring, unmooring, and warping operations of the main cable. Refer to Figure 3 The schematic diagram shown, the control of the ship's own anchor is to control the left and right anchors through the anchor operation panel, supporting a variety of anchor operation functions, including anchoring, heaving in the anchor, paying out, and stopping, etc., and can dynamically display the length and tension of the anchor chain to ensure that the operator can monitor the status of the anchor chain in real time, so as to control the operation of the anchor. Refer to Figure 4 and Figure 5 The schematic diagram shown, the control of the ship's navigation lights and sound signals is operated through the control panel, supporting the setting of a variety of navigation lights and shapes, supporting the setting of a variety of navigation lights and shapes, the navigation lights include forward and after masthead lights, port and starboard side lights, stern light, forward anchor light, and after anchor light; the omnidirectional lights include three white lights and three red lights, and can also control the display of shapes in specific situations, specifically including: when the ship is at anchor, a black ball is displayed on the forward mast; when the ship is aground, three black balls are displayed on the after mast; when the ship is out of control, two black balls are displayed on the after mast; when the ship's maneuverability is restricted, two black balls and a diamond are displayed on the main mast; when the ship's draft is restricted, a cylinder is displayed on the main mast; in case of poor visibility, the fog signal can be sounded manually or automatically, and the automatic fog signal includes the following sounds: one long blast, two long blasts, one long and two short blasts, one long and three short blasts, one short, one long, one short blast, one long and four short blasts, and five short blasts; the control of the sound signal supports the manual sounding of the bow bell and the stern gong.

[0034] The functions of the comprehensive information display unit include the solution of the ship motion mathematical model and acoustic simulation. The comprehensive information display unit has designed the motion mathematical models of two ship types, namely the container outer hull and the cargo ship, and covers models with different tonnages and loading conditions. The ship motion mathematical model takes into account many influencing factors, such as vehicle, rudder, anchor, cable, wind, current, tugboat, bank effect, ship-to-ship effect and shallow water effect, etc. By real-time solving these operation and environmental data (such as wind speed, water current, tide), it dynamically calculates and outputs motion parameters such as ship position, course, speed, course change rate and acceleration. At the same time, the acoustic simulation function includes the simulation of the ship's sound signal system (supporting foghorn, bell, gong and automatic cycle setting), engine room noise, sea wave sound, siren, telegraph and other operation sound effects. The comprehensive information display unit also provides detailed ship dynamic information, including rudder and propeller data, true wind direction and speed, compass course, as well as basic parameters such as ship type, displacement, ship length, ship width, draft and loading status. In addition, the comprehensive information display unit has a fault alarm function, covering faults of key components such as main engine, steering gear, autopilot, radar, GPS, log, etc., as well as alarm information such as collision, grounding, stranding and dragging anchor.

[0035] The functions of the electronic chart unit include electronic chart display and ship dynamic display based on ECDIS (Electronic Chart Display and Information System). The electronic chart display has multiple functions, including real-time chart information display, chart data update and modification, positioning and navigation, nautical information query, radar image overlay display and target tracking, route design and monitoring, course keeping, navigation record and collision avoidance function. The dynamic display function based on ECDIS can present the dynamic positions of the own ship, target ship and tugboat on the system interface in real time, and automatically adjust the display scale according to the ship's tonnage. The simulated radar unit can simulate radar systems in 10 cm and 3 cm bands and supports operations in relative motion mode and true motion mode. The training sea area database covers nautical charts and radar charts, as well as a three-dimensional visual scene database of the training sea area based on these two.

[0036] The radar simulation of the simulated radar unit meets the requirements of IMO specifications. The display system is consistent with the actual ship equipment. It can simulate radar systems in 10 cm and 3 cm, and can select relative motion mode and true motion mode for operation. Its main performance indicators are as follows: 1. Radar image: It shows the echoes of target ships, and the shape of the echoes will change according to the size, distance and relative bearing of the target ships; it can simulate rain, snow clutter and sea clutter and ensure that they conform to the actual situation. 2. Radar functions: The radar is simulated using the popular radar models on current ships. The main functions include: automatic and manual target acquisition, capable of tracking at least 20 targets, with a coverage range of 0.3 nautical miles to 32 nautical miles; display of target ship data, including target ship number, distance, bearing, true course, true speed.

[0037] Furthermore, the cooperative vessel simulation module constructs a three-dimensional simulated hull that interacts with sea waves, cables, and sea breeze, and also has an audio simulation function. It receives the rudder signals simulated by the left and right handles and acts on the hull. The vessel types in the target vessel simulation module include container ships, bulk carriers, and ro-ro passenger ships. It has an audio simulation function and is physically simulated under the action of a tugboat.

[0038] Furthermore, the visual scenes and radar images between vessels are dynamically synchronized. When the tugboat and the towed vessel operate in their respective simulators, their relative positions and navigation states are displayed in real time. By establishing a dynamic towing interaction three-dimensional model, the relative motion between the tugboat and the towed vessel is calculated and dynamically adjusted to achieve the interaction between the tugboat and the towed vessel. The steps of the dynamic towing interaction three-dimensional model are as follows:

[0039] Step S1, obtain the real-time state data of the tugboat and the towed vessel, and calculate the force on the cable. The calculation formula for the force on the cable is: , where is the total force on the cable; is the elastic coefficient of the cable; is the dynamic stretching length of the cable, that is, the difference between the current cable length and the original length; is the damping coefficient of the cable, reflecting the damping effect of the cable during dynamic stretching; is the cable stretching speed; is the self-weight of the cable; is the towing angle, that is, the angle between the cable and the horizontal plane; is the external disturbing force, and the disturbing force includes wind-wave-current force and underwater friction force , the wind-wave-current force satisfies , where is the water density; is the resistance coefficient of the cable; is the projected area of the cable in the fluid; is the relative water flow velocity; the underwater friction force satisfies , where is the friction coefficient between the cable and the water body; is the normal force on the cable;

[0040] Step S2, the force exerted by the tugboat on the towed vessel is determined by the horizontal and vertical components of the cable tension. The force is expressed by the following decomposition formula: , where is the force exerted by the tugboat on the towed vessel in the horizontal direction; is the force exerted by the tugboat on the towed vessel in the vertical direction; is the towing direction angle of the cable in the horizontal direction, that is, the angle between the cable and the moving direction of the tugboat; the interaction force between the tugboat and the towed ship is solved by the force balance formula, and the force balance equation of the tugboat is: ; The force balance equation of the towed ship is: ,in, is the horizontal component of the tugboat thrust, is the vertical component of the tugboat thrust, is the horizontal component of the external force on the towed ship, is the vertical component of the external force on the towed vessel, is the water resistance of the hull in the horizontal direction, is the water resistance of the hull in the vertical direction, is the mass of the tugboat, is the mass of the towed vessel, is the speed of the tugboat, is the speed of the towed vessel, is the acceleration of the tugboat, is the acceleration of the towed vessel;

[0041] Step S3: Based on the above formula, the dynamic towing interactive 3D model uses a real-time feedback control mechanism to adjust the parameters of the cable and the hull. Exceeding the preset total force threshold of the safety cable When the propulsion force of the tugboat is reduced Or increase the heading angle of the towed vessel ; By adjusting the towing angle ,make sure and The component of is optimal in the target direction; using the ship speed difference Dynamically adjust the propulsion force of the tugboat to avoid over-pulling or loosening the cable. Through the above formula and adjustment strategy, the dynamic towing interaction three-dimensional model can not only calculate the relative motion during the towing process, but also cope with complex sea conditions and dynamic changes, and realize efficient and safe interaction between the tugboat and the towed ship.

[0042] Furthermore, the sea condition simulation system comprehensively considers the wave height, wave period, wave direction, wind force and wind direction physical parameters to establish a dynamic sea condition simulation model for reproducing complex sea conditions to simulate the real ocean environment in ship towing operations. The specific steps of the dynamic sea condition simulation model are:

[0043] Step Z1, using the directional spectrum function Based on the wind force and the wave energy distribution in the wind direction, the directional wave spectrum function is expressed as: , where is the frequency spectrum of the wave, describing the distribution of wave energy with frequency; is the direction distribution function, indicating the distribution of wave energy in different propagation directions;

[0044] Step Z2, the frequency spectrum of the wave adopts the JONSWAP spectrum, and the calculation formula is: , where is the spectral peak factor, depending on the intensity and duration of the wind force; is the acceleration due to gravity; is the wave frequency; is the peak frequency, corresponding to the frequency of the maximum wave energy; is the wave crest enhancement factor, reflecting the non-linear enhancement effect of the wave; is the frequency distribution width parameter; the direction distribution function has the calculation formula: , where is the wave propagation direction, is the wind direction;

[0045] Step Z3, based on the directional wave spectrum, the dynamic sea condition simulation model generates a three-dimensional sea wave surface through the Fourier superposition method, and the height of the sea wave surface has the calculation formula: , where is the position at time of the wave height; is the wave amplitude; is the component of the wave number vector in the direction; is the component of the wave number vector in the direction; is the angular frequency of the wave, calculated through the dispersion relation: , is the water depth; is the random phase of the wave; is the number of segments of the wave frequency; is the number of segments of the wave wind direction;

[0046] Step Z4, in the real-time simulation, the dynamic sea condition simulation model dynamically updates the wave height , and combines the wind speed and wind direction to generate a dynamic three-dimensional sea wave field, and adjusts the wave simulation parameters in real time to meet the requirements of the tugboat operation; when the tugboat and the towed ship enter the area with increasing wind force, the dynamic sea condition simulation model will increase the wave crest enhancement factor , to enhance the non - linear characteristics of the waves; when the tidal current velocity increases, the dynamic sea condition simulation model will adjust the wave number and angular frequency to reflect the acceleration effect of wave propagation. By updating the wave height, the dynamic sea condition simulation model can ensure a high degree of consistency between the simulated sea conditions and the actual environment. Finally, the three - dimensional sea wave field generated by the dynamic sea condition simulation model is integrated into the tugboat visual system, and trainees can clearly observe the impact of sea waves on the tugboat and the cable during the training process. Through the three - dimensional simulation of the dynamic sea condition simulation model, trainees can proficiently master the tugboat operation and towing operation skills under various complex sea conditions, improving the safety and efficiency of offshore operations.

[0047] Furthermore, the 3DGIS three - dimensional geographic simulation module simulates the port area, terrain, and buildings, has a coordinate unified management system, and establishes a spatial coordinate system and a geodetic coordinate system. The cluster management system uniformly manages all computer devices, enabling data and visual scenes to be synchronized.

[0048] The present invention presents a realistic visual scene through a variety of advanced technologies, with a high visual scene update rate. Its tugboat operation module has rich and diverse functions, covering a variety of control modes and operation functions. The comprehensive information display unit can calculate ship motion parameters, simulate sounds, and provide detailed information and fault alarms. The electronic chart unit has complete functions; the cooperative vessel simulation module and the target vessel simulation module can construct three - dimensional simulation hulls of cooperative vessels and target vessels; the visual scenes and radar images between vessels are dynamically synchronized, and the dynamic towing interaction three - dimensional model can calculate the relative motion between the tugboat and the towed vessel and achieve safe and efficient interaction; the sea condition simulation system can establish a dynamic sea condition simulation model to reproduce complex sea conditions and improve trainees' operation skills; the 3DGIS three - dimensional geographic simulation module can simulate the port area, etc. and establish a coordinate system; the cluster management system ensures data and visual scene synchronization. The present invention overcomes the problems in the prior art such as unsynchronized visual scene radar and inability to reproduce complex sea conditions, effectively improving the training effect of tugboat - related personnel and enhancing the safety and efficiency of offshore operations.

[0049] The above - mentioned is only the specific implementation manner of this application, but the protection scope of this application is not limited thereto. Any person skilled in the art within the technical scope disclosed by this application can easily think of changes or substitutions, which should all be covered within the protection scope of this application. Therefore, the protection scope of this application should be subject to the protection scope of the claims.

[0050] Finally: The above - mentioned is only the preferred embodiment of the present invention and is not used to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A three-dimensional simulation model for ships, used for real-time interactive pushing and towing operations between tugboats and other ships, characterized in that: It includes a ship simulation module, a collaborative ship simulation module, a target ship simulation module, a sea condition simulation system, a 3DGIS three-dimensional geographic simulation module and a cluster management system; the vision and radar images between the ships are dynamically synchronized, a dynamic towing interactive three-dimensional model is established, the relative motion between the tugboat and the towed ship is calculated, and dynamic adjustments are made to realize the interaction between the tugboat and the towed ship. The steps of the dynamic towing interactive three-dimensional model are: Step S1, obtain the real-time status data of the tugboat and the towed ship, calculate the force of the cable, and the calculation formula of the cable force is: ,in, is the total force on the cable, is the elastic modulus of the cable, is the dynamic expansion and contraction length of the cable, is the damping coefficient of the cable, is the cable extension and retraction speed; The cable is deadweight; is the towing angle, is an external disturbance force, which includes wind, wave and current forces and underwater friction , the wind, wave and current force satisfy ,in, is the water density; is the drag coefficient of the cable; is the projected area of ​​the cable in the fluid; is the relative water flow velocity; the underwater friction satisfy ,in, is the friction coefficient between the cable and the water; is the normal force of the cable; Step S2, the force exerted by the tugboat on the towed ship is determined by the components of the cable tension in the horizontal direction and the vertical direction, and the force is expressed by the following decomposition formula: ,in, is the horizontal force exerted by the tugboat on the towed ship, is the vertical force exerted by the tugboat on the towed ship, is the towing direction angle of the cable in the horizontal direction. The interaction force between the tugboat and the towed ship is solved by the force balance formula. The force balance equation of the tugboat is: ; The force balance equation of the towed ship is: ,in, is the horizontal component of the tugboat thrust, is the vertical component of the tugboat thrust, is the horizontal component of the external force on the towed ship, is the vertical component of the external force on the towed vessel, is the water resistance of the hull in the horizontal direction, is the water resistance of the hull in the vertical direction, is the mass of the tugboat, is the mass of the towed vessel, is the speed of the tugboat, is the speed of the towed vessel, is the acceleration of the tugboat, is the acceleration of the towed vessel; Step S3: Based on the above formula, the dynamic towing interactive 3D model uses a real-time feedback control mechanism to adjust the parameters of the cable and the hull. Exceeding the preset total force threshold of the safety cable When the propulsion force of the tugboat is reduced Or increase the heading angle of the towed vessel ; Use the speed difference of the ship Dynamically adjust the tugboat's propulsion.

2. A three-dimensional simulation model for a ship according to claim 1, characterized in that ,The sea condition simulation system is used to establish a dynamic sea condition ,simulation model to reproduce complex sea conditions. ,The steps are as follows: Step Z1, using the directional spectrum function Based on the wind force and the wave energy distribution in the wind direction, the directional wave spectrum function is expressed as: ,in, is the frequency spectrum of the wave; is the direction distribution function; Step Z2, frequency spectrum of waves Using the JONSWAP spectrum, the calculation formula is: ,in, is the peak factor, is the acceleration due to gravity, is the wave frequency, is the peak frequency, is the peak enhancement factor, is the frequency distribution width parameter; directional distribution function The calculation formula is: ,in, is the wave propagation direction, for wind direction; Step Z3, based on the directional wave spectrum, the dynamic sea condition simulation model generates a three-dimensional wave surface through the Fourier superposition method. The calculation formula is: ,in, For location In time The wave height; is the wave amplitude; is the wave number vector in Directional weight; is the wave number vector in Directional weight; is the angular frequency of the wave, calculated by the dispersion relation: , for water depth; is the random phase of the wave; is the number of segments of the wave frequency; is the number of segments of wave wind direction.

3. A three-dimensional simulation model for a ship according to claim 1, characterized in that The ship simulation module includes a three-dimensional vision unit, a tugboat maneuvering module and a training sea area database. The three-dimensional vision unit consists of a 180-degree cylindrical screen. It is based on the Windows 10 operating system and is developed using C++ and a professional real-time vision management software platform. The image update rate is greater than 50 frames per second, presenting a mathematical model of the ship's six-degree-of-freedom motion.

4. A three-dimensional simulation model for a ship according to claim 3, characterized in that: The tugboat control module includes a tugboat control equipment unit, a comprehensive information display unit, an electronic chart unit and a simulated radar unit. The tugboat control equipment unit includes rudder control, clock control, control of the ship's cable, control of the ship's anchor, and control of the ship's navigation lights and sound signals.

5. A three-dimensional simulation model for a ship according to claim 4, characterized in that The rudder control includes three modes: manual steering, follow-up steering and automatic steering, and the control parameters of each mode can be adjusted. In the manual steering mode, the servo is manually controlled to adjust the heading. The follow-up steering mode automatically adjusts the rudder angle according to the heading and speed. The automatic steering mode automatically calculates and adjusts the rudder angle according to the preset course and target point.

6. A three-dimensional simulation model for a ship according to claim 4, characterized in that The clock control is used to adjust the tugboat propulsion operation and simulate the main engine operation status. The ship's cable control is used to manage the cable operation between the tugboat and the towed ship. The ship's anchor control supports the anchor operation function and dynamically displays the length and tension of the anchor chain. The ship's navigation lights and sound signal control supports the setting of light signal types and manual sounding of sound signals.

7. A three-dimensional simulation model for a ship according to claim 4, characterized in that The electronic chart unit has the functions of electronic chart display and ECDIS-based ship dynamic display. The electronic chart display functions include real-time chart information display, chart data update and modification, positioning and navigation, navigation information query, radar image overlay display and target tracking, route design and monitoring, track keeping, navigation record and risk avoidance. The dynamic display function based on ECDIS presents the dynamic positions of the ship, target ship and tugboat in real time and automatically adjusts the display ratio.

8. A three-dimensional simulation model for a ship according to claim 4, characterized in that The simulated radar unit can simulate 10 cm and 3 cm band radar systems, support relative motion mode and true motion mode operations, and the training sea area database covers nautical charts, radar charts and training sea area three-dimensional visual database.

9. A three-dimensional simulation model for a ship according to claim 1, characterized in that The collaborative ship simulation module constructs a three-dimensional simulated hull, interacts with waves, cables and sea breeze, has an acoustic simulation function, and receives the left and right handles to simulate the rudder signal to act on the hull; the target ship simulation module can construct a three-dimensional simulated hull of the target ship. The ship types in the target ship simulation module include container, bulk cargo and passenger and vehicle ferries, and have an acoustic simulation function.

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