CN105159954A - Three-dimensional electronic nautical chart generating method based on GIS and virtual reality technology - Google Patents

Abstract

The present invention provides a three-dimensional electronic nautical chart generating method based on a GIS and a virtual reality technology, which comprises: establishing a three-dimensional terrain model; establishing a thematic database model; establishing a water surface model and a flow numerical simulation model; establishing a ship model database module; carrying out association and fusion on simulation calculation results of the three-dimensional terrain model, the thematic database model, the water surface model, the flow numerical simulation model and the ship model database module, carrying out comprehensive display on various types of data and constructing a virtual reality scene; and by model analysis and space calculation, providing services for ship navigation. The three-dimensional electronic nautical chart generating method is used for constructing a three-dimensional electronic nautical chart capable of being applied to the actual ship production practice, a virtual and vivid decision-making environment is provided for a driver and shipping safety is improved.

Description

Based on the three-dimensional electronic sea drawing generating method of GIS and virtual reality technology

Technical field

The invention belongs to marine navigation field, especially a kind of sea of the three-dimensional electronic based on GIS and virtual reality technology drawing generating method.

Background technology

In recent years; along with the development of the technology such as GPS/GIS/GSM technology, ship automatic identification system (AIS), electronic chart display and infor mation system (ECDIS); She Hai mechanism of China has carried out the development of the three-dimensional electronic sea chart based on virtual reality successively, achieves certain achievement.But China still also exists following deficiency at present in the system development of three-dimensional electronic sea chart: 1. underwater topography, flow field numerical value, navigational aids planning etc. emulate separately mostly, and synthesis display ability is weak, and mostly rests on the demonstration stage; 2. focus on emulation, fail the model analysis of effective integration GIS and spatial analysis functions, thus lack the quantitative test of science; 3. great majority abroad related system carry out secondary development, lacks independent intellectual property right, and maintenance and the upgrading of system all exist some problems.

Summary of the invention

The technical problem to be solved in the present invention is: provide a kind of three-dimensional electronic based on GIS and virtual reality technology sea drawing generating method, for driver provides a policy setting directly perceived, true to nature, improves the security of shipping.

The present invention for solving the problems of the technologies described above taked technical scheme is: a kind of sea of the three-dimensional electronic based on GIS and virtual reality technology drawing generating method, is characterized in that: it comprises the following steps:

S1, set up three-dimensional terrain model:

Based on GIS and 3dsMax, based on the three-dimensional geographic scenes of high presence, utilize the method establishment sea/riverbed DEM of irregular grid model, and complete the splicing of sea/riverbed DEM and land DEM;

S2, set up thematic data library model:

According to the visual technology of investigational data to scene areas, rediscover, topography and geomorphology true to nature, navigation mark and artificial structure;

S3, set up water surface model and Flow Numerical Simulation model:

Represent water surface real time water level with fixterm and disturbance term two parts, wherein fixterm is depth datum, and disturbance term comprises tide part and non-tide part; Adopt the astronomical tide numerical forecasting model based on tidal table data assimilation to carry out tide-prediction, and then try to achieve the depth information of the instantaneous water surface;

Flow Numerical Simulation model, based on navigation channel CAD figure, measured discharge, water level and than falling information, being set up mass conservation continuity equation and the momentum conservation equation of motion, being carried out numerical simulation to flow field, navigation channel;

S4, set up ship model database module

With the serial data of AIS for input, by resolving the boats and ships element information in AIS original message, match query is carried out to the model of ship model database;

S5, be associated visualization model

The association of the analog computation result of three-dimensional terrain model, thematic data library model, water surface model and Flow Numerical Simulation model, ship model database module is merged, to Various types of data synthesis display, builds virtual reality scenario;

The dynamic ship information display of S6, the water surface

Calculated by model analysis and space, for ship and sea/riverbed, collision between ship and ship provide early warning information;

Resolved by the original message inputted AIS, obtain the element information of boats and ships around, the state of motion of around boats and ships is shown in virtual reality scenario, is superimposed with the Ship dynamic situation relevant to security decision and static information simultaneously.

By such scheme, described S1 adopts the strategy of point layer building solid model, and after having built each gradation entity model, recombinant is integrated; Three levels are divided into the solid model emulation related within the scope of waters: no matter 1. navigation mark, representative ship types is that Geometric Modeling or texture mapping all adopt meticulous mode to make; 2. bridge, harbour, boats and ships, coastal aids buildings, keeps geometric pattern and textural characteristics; 3. other atural objects land, only represent its general profile and geometric shape.

By such scheme, described flow field, S3 navigation channel is made up of current continuity equation and water movement equation:

Current continuity equation:

$\frac{\∂z}{\∂t}+\frac{\∂\[u(z+h)\]}{\∂x}+\frac{\∂\[v(z+h)\]}{\∂y}=0---\left(1\right)$

Water movement equation:

$\frac{\∂u}{\∂t}+u\frac{\∂u}{\∂x}+v\frac{\∂u}{\∂y}=fv-g\frac{\∂z}{\∂x}-g\frac{u\sqrt{u^2+v^2}}{c^2(z+h)}+{\mathrm{\ξ}}_x{\▿}^{2}u+\frac{{\mathrm{\τ}}_x}{(z+h)\mathrm{\ρ}}---\left(2\right)$

$\frac{\∂v}{\∂t}+u\frac{\∂v}{\∂x}+v\frac{\∂v}{\∂y}=-fu-g\frac{\∂z}{\∂y}-g\frac{v\sqrt{u^2+v^2}}{c^2(z+h)}+{\mathrm{\ξ}}_y{\▿}^{2}v+\frac{{\mathrm{\τ}}_y}{(z+h)\mathrm{\ρ}}---\left(3\right)$

Wherein: the flow velocity on u, v (x, y, t)-x, y direction; Z-water level; H-actual depth of water, H=h+z, h are the diagram depth of water; G-acceleration of gravity; ξ _x, ξ _y-turbulent viscosity; F-Corrioli's effect coefficient.

Beneficial effect of the present invention is: in the present invention, and three-dimensional geographical scenario simulation, numerical value flow field simulation and Ship dynamic situation data are the bases for driver provides decision-making assistant information, provides water surface traffic management information, provides the application such as navigation channel assay information for navigation channel department for maritime sector; By utilizing the geography of computer simulation emulation technology to ship's navigation waters, the hydrology of advanced person to carry out three-dimensional artificial and numerical evaluation, disclose the ship-handling reference information that the geographical environment, current, water level etc. in navigation channel are closely bound up with navigation safety visual pattern; By using the model analysis of GIS and spatial analysis functions and passing through AIS packet parsing, for boats and ships front, side direction, the early warning of bottom safety distance, for deck officer provides aid decision making under navigation flow condition complexity, dimensions of the channel rough sledding, thus improve shipping safety.

Accompanying drawing explanation

Fig. 1 is the FB(flow block) of one embodiment of the invention.

Fig. 2 be one embodiment of the invention under water and coastal feature integration build flow process.

Fig. 3 is the water surface dynamic boats and ships three-dimensional artificial display module structural drawing of one embodiment of the invention.

Embodiment

Below in conjunction with instantiation and accompanying drawing, the present invention will be further described.

The invention provides a kind of three-dimensional electronic based on GIS and virtual reality technology sea drawing generating method, as shown in Figure 1, it comprises the following steps:

S1, set up three-dimensional terrain model:

Based on GIS and 3dsMax, based on the three-dimensional geographic scenes of high presence, utilize the method establishment sea/riverbed DEM of irregular grid model, and complete the splicing of sea/riverbed DEM and land DEM;

S2, set up thematic data library model:

According to the visual technology of investigational data to scene areas, rediscover, topography and geomorphology true to nature, navigation mark and artificial structure;

S3, set up water surface model and Flow Numerical Simulation model:

Represent water surface real time water level with fixterm and disturbance term two parts, wherein fixterm is depth datum, and disturbance term comprises tide part and non-tide part; Adopt the astronomical tide numerical forecasting model based on tidal table data assimilation to carry out tide-prediction, and then try to achieve the depth information of the instantaneous water surface;

Flow Numerical Simulation model, based on navigation channel CAD figure, measured discharge, water level and than falling information, being set up mass conservation continuity equation and the momentum conservation equation of motion, being carried out numerical simulation to flow field, navigation channel;

S4, set up ship model database module

With the serial data of AIS for input, by resolving the boats and ships element information in AIS original message, match query is carried out to the model of ship model database;

S5, be associated visualization model

The association of the analog computation result of three-dimensional terrain model, thematic data library model, water surface model and Flow Numerical Simulation model, ship model database module is merged, to Various types of data synthesis display, builds virtual reality scenario;

The dynamic ship information display of S6, the water surface

Calculated by model analysis and space, for ship and sea/riverbed, collision between ship and ship provide early warning information;

Resolved by the original message inputted AIS, obtain the element information of boats and ships around, the state of motion of around boats and ships is shown in virtual reality scenario, is superimposed with the Ship dynamic situation relevant to security decision and static information simultaneously.

As shown in Figure 1, three-dimensional terrain model module, by the collection of dem data source, the extraction of electronic chart bathymetric data, orthography and texture processing, utilizes the method for irregular grid model to realize the integration generation of underwater topography and coastal feature thereof.Thematic data base model module realizes three-dimensional entity model, the element of composition model and the bookkeeping such as quick warehouse-in, deletion, inquiry, coupling of texture thereof by effectively managing.Flow Numerical Simulation module is based on navigation channel CAD figure, measured discharge, water level, than degradation information, sets up mass conservation continuity equation and the momentum conservation equation of motion, carry out numerical simulation to flow field, navigation channel.AIS packet parsing and ship model database module for input, by resolving the boats and ships element information in AIS original message, carry out match query to the model of ship model database with the serial data of AIS.The analog computation result associations such as three-dimensional terrain model, thematic data model, numerical value flow field model, ship model are merged by association visualization model, to Various types of data synthesis display, build virtual reality scenario.The display of three-dimensional navigation channel superposes association attributes, control and information to aid in decision with searching platform module to associating visual result, and is shown and provide query manipulation.Scene walkthrough module can arrange manual roaming, automatic roaming, hawkeye navigation Three models.Interactive query module, on the basis of displaying live view, can carry out terrain information and thematic attribute query.Navigation channel analysis module possesses ship navigation analysis, shallow point identifies automatically and the specific analysis function such as to report to the police.

Fig. 2 be one embodiment of the invention under water and coastal feature integration build process flow diagram, Fig. 3 is the water surface dynamic boats and ships three-dimensional artificial display module structural drawing of one embodiment of the invention.

1, GIS and 3dsMax integrated under the geographical scenario building of three-dimensional.

Three-dimensional electronic sea chart system is based on the three-dimensional geographic scenes of high presence.First the present invention utilizes method establishment sea (river) the bed DEM of irregular grid model, and completes the splicing of sea (river) bed DEM and land DEM; Secondly according to the visual technology of investigational data to scene areas, rediscover, topography and geomorphology true to nature, navigation mark and artificial structure.

The key factor that the integration of underwater topography and coastal feature thereof generates is exactly first to unify the coordinate frame of underwater topography and land terrain data.Under unified framework, the structure of model is just consistent with the structure of general relief block, thus can apply the construction method of general relief block.Under water and coastal feature integration build flow process as shown in Figure 2.Coordinate transferring in order to realize the unitarity of terrain data, by may exist in modeling region each other can not be compatible each coordinate system, unifiedly convert global coordinate system WGS84 to.WGS84 reference ellipsoid as unified vertical reference face, is realized the unitarity of data by unifying datum module.TIN triangulation network generation module adopts Bowyer-Watson algorithm structure based on the DEM model of irregular grid.

In order to improve the real-time of environment viewing, the vivid effect of the what comes into a driver's of not appreciable impact simultaneously, adopt the strategy of point layer building solid model, after having built each gradation entity model, recombinant is integrated.Three levels are divided into the solid model emulation related within the scope of test waters: no matter 1. navigation mark, representative ship types is that Geometric Modeling or texture mapping all adopt meticulous mode to make; 2. bridge, harbour, boats and ships, coastal aids buildings, keeps geometric pattern and textural characteristics; 3. other atural objects land, only need rough making, represent its general profile and geometric shape, do not need point-device grain details.

2, modeling water surface.

Sea, because affect by stormy waves, tide etc., is all changing all the time.For calculating sea real time water level, can represent with fixterm and disturbance term two parts.Fixterm is depth datum, and disturbance term comprises tide part and non-tide part.

I(t)＝G(t)+r(t)

In formula: I (t) represents Instantaneous Sea Level; G (t) represents sea fixterm; R (t) represents sea disturbance item.

Boats and ships in real navigation, in order to ensure that the general depth datum that conservatively adopts of safety represents sea real time water level.And for situations such as the boats and ships taking advantage of tide to navigate by water in some depth of water restricted areas, the depth information of Instantaneous Sea Level has very important practical significance.Obtain the Instantaneous Sea Level degree of depth and mainly contain two kinds of methods: one is the geodetic height utilizing GPS precision positioning Real-time Obtaining Instantaneous Sea Level, then calculate the depth information of Instantaneous Sea Level according to known submarine topography geodetic height; Two is set up oceanic tide forecasting model, by calculating the depth information of Instantaneous Sea Level.The present invention adopts the astronomical tide numerical forecasting model based on tidal table data assimilation to carry out tide-prediction, and then tries to achieve the depth information of Instantaneous Sea Level.

3, Flow Numerical Simulation.

At present, water level, flow velocity and the flow location form change main Two-dimensional mathematical model that adopts in local, engineering section calculates comparatively meticulously, and its fundamental equation is made up of current continuity equation and water movement equation:

Current continuity equation:

$\frac{\∂z}{\∂t}+\frac{\∂\[u(z+h)\]}{\∂x}+\frac{\∂\[v(z+h)\]}{\∂y}=0---\left(1\right),$

Water movement equation:

$\frac{\∂u}{\∂t}+u\frac{\∂u}{\∂x}+v\frac{\∂u}{\∂y}=fv-g\frac{\∂z}{\∂x}-g\frac{u\sqrt{u^2+v^2}}{c^2(z+h)}+{\mathrm{\ξ}}_x{\▿}^{2}u+\frac{{\mathrm{\τ}}_x}{(z+h)\mathrm{\ρ}}---\left(2\right),$

$\frac{\∂v}{\∂t}+u\frac{\∂v}{\∂x}+v\frac{\∂v}{\∂y}=-fu-g\frac{\∂z}{\∂y}-g\frac{v\sqrt{u^2+v^2}}{c^2(z+h)}+{\mathrm{\ξ}}_y{\▿}^{2}v+\frac{{\mathrm{\τ}}_y}{(z+h)\mathrm{\ρ}}---\left(3\right),$

Wherein: the flow velocity on u, v (x, y, t)-x, y direction; Z-water level; H-actual depth of water (H=h+z, h are the diagram depth of water); G-acceleration of gravity; ξ _x, ξ _y-turbulent viscosity; F-Corrioli's effect coefficient.

Navigation channel Flow Numerical Simulation be based on navigation channel CAD figure, measured discharge, water level, than degradation data message.Its analog computation achievement can import the three-dimensional navigation simulating scenes determining region, support real-time, interactive is inquired about, so that deck officer accurately judges main flow, unhurried current and backflow, identify the ship's navigation risks such as pushing stream, inlet flow, Xuan Shui, formulate safe navigation policy in time.

Current numerical model is calculated by scope Su-Tong Brideg upstream and downstream total length being about to 4km, and compares with actual measurement flow velocity, and result shows that these current numerical model has higher precision, meets the requirement of system application completely.

4, the dynamic ship information display of the water surface.

The dynamic ship information display system of the water surface makes full use of all kinds of element informations such as subaqua-tic geomorphology, water surface hydrometeorology and aquatic sports boats and ships situation, calculated by model analysis and space, for ship and sea (river) bed, collision between ship and ship provide early warning information, the navigation safety of effective guarantee boats and ships.

System is resolved by the original message inputted AIS, obtain the element information of boats and ships around, the state of motion of around boats and ships is shown in the three-dimensional navigation environment of virtual emulation, is superimposed with the Ship dynamic situation closely bound up with security decision and static information simultaneously.The water surface dynamic boats and ships three-dimensional artificial display module structure as shown in Figure 3.

This three-dimensional electronic sea chart system is around the virtual emulation of three-dimensional navigation environment and visual, and under three-dimensional artificial navigation environment, provide a series of complete function services, major function comprises: aids to navigation, characteristically object view see display; Navigating ship front, side direction, the early warning of bottom safety distance; Different scene mode (fine day, cloudy day, rainy day, snow sky) switches; Show as required, analyze boats and ships front underwater topography; Direction of ship travel, speed show; Prebriefed pattern shows; Ship's navigation track backup etc.

Above embodiment is only for illustration of design philosophy of the present invention and feature, and its object is to enable those skilled in the art understand content of the present invention and implement according to this, protection scope of the present invention is not limited to above-described embodiment.So all equivalent variations of doing according to disclosed principle, mentality of designing or modification, all within protection scope of the present invention.

Claims (3)

1., based on a three-dimensional electronic sea drawing generating method for GIS and virtual reality technology, it is characterized in that: it comprises the following steps:

S1, set up three-dimensional terrain model:

Based on GIS and 3dsMax, based on the three-dimensional geographic scenes of high presence, utilize the method establishment sea/riverbed DEM of irregular grid model, and complete the splicing of sea/riverbed DEM and land DEM;

S2, set up thematic data library model:

According to the visual technology of investigational data to scene areas, rediscover, topography and geomorphology true to nature, navigation mark and artificial structure;

S3, set up water surface model and Flow Numerical Simulation model:

Represent water surface real time water level with fixterm and disturbance term two parts, wherein fixterm is depth datum, and disturbance term comprises tide part and non-tide part; Adopt the astronomical tide numerical forecasting model based on tidal table data assimilation to carry out tide-prediction, and then try to achieve the depth information of the instantaneous water surface;

Flow Numerical Simulation model, based on navigation channel CAD figure, measured discharge, water level and than falling information, being set up mass conservation continuity equation and the momentum conservation equation of motion, being carried out numerical simulation to flow field, navigation channel;

S4, set up ship model database module

With the serial data of AIS for input, by resolving the boats and ships element information in AIS original message, match query is carried out to the model of ship model database;

S5, be associated visualization model

The association of the analog computation result of three-dimensional terrain model, thematic data library model, water surface model and Flow Numerical Simulation model, ship model database module is merged, to Various types of data synthesis display, builds virtual reality scenario;

The dynamic ship information display of S6, the water surface

Calculated by model analysis and space, for ship and sea/riverbed, collision between ship and ship provide early warning information;

Resolved by the original message inputted AIS, obtain the element information of boats and ships around, the state of motion of around boats and ships is shown in virtual reality scenario, is superimposed with the Ship dynamic situation relevant to security decision and static information simultaneously.

2. the sea of the three-dimensional electronic based on GIS and virtual reality technology according to claim 1 drawing generating method, is characterized in that: described S1 adopts the strategy of point layer building solid model, and after having built each gradation entity model, recombinant is integrated; Three levels are divided into the solid model emulation related within the scope of waters: no matter 1. navigation mark, representative ship types is that Geometric Modeling or texture mapping all adopt meticulous mode to make; 2. bridge, harbour, boats and ships, coastal aids buildings, keeps geometric pattern and textural characteristics; 3. other atural objects land, only represent its general profile and geometric shape.

3. the sea of the three-dimensional electronic based on GIS and virtual reality technology according to claim 1 drawing generating method, is characterized in that: described flow field, S3 navigation channel is made up of current continuity equation and water movement equation:

Current continuity equation:

$\frac{\∂z}{\∂t}+\frac{\∂\[u(z+h)\]}{\∂x}+\frac{\∂\[v(z+h)\]}{\∂y}=0---\left(1\right)$

Water movement equation:

$\frac{\∂u}{\∂t}+u\frac{\∂u}{\∂x}+v\frac{\∂u}{\∂y}=fv-g\frac{\∂z}{\∂x}-g\frac{u\sqrt{u^2+v^2}}{c^2(z+h)}+{\mathrm{\ξ}}_x{\▿}^{2}u+\frac{{\mathrm{\τ}}_x}{(z+h)\mathrm{\ρ}}---\left(2\right)$

$\frac{\∂v}{\∂t}+u\frac{\∂v}{\∂x}+v\frac{\∂v}{\∂y}=-fu-g\frac{\∂z}{\∂y}-g\frac{v\sqrt{u^2+v^2}}{c^2(z+h)}+{\mathrm{\ξ}}_y{\▿}^{2}v+\frac{{\mathrm{\τ}}_y}{(z+h)\mathrm{\ρ}}---\left(3\right)$

Wherein: the flow velocity on u, v (x, y, t)-x, y direction; Z-water level; H-actual depth of water, H=h+z, h are the diagram depth of water; G-acceleration of gravity; ξ _x, ξ _y-turbulent viscosity; F-Corrioli's effect coefficient.