CN104598290A

CN104598290A - Virtual vehicle emulation technique based on Java 3D technology

Info

Publication number: CN104598290A
Application number: CN201310531742.2A
Authority: CN
Inventors: 不公告发明人
Original assignee: ZHENJIANG HUAYANG INFORMATION TECHNOLOGY CO LTD
Current assignee: ZHENJIANG HUAYANG INFORMATION TECHNOLOGY CO LTD
Priority date: 2013-11-02
Filing date: 2013-11-02
Publication date: 2015-05-06

Abstract

Virtual vehicle emulation is a brand new technology for building a system by means of the java 3D technology. Three-dimensional traffic simulation is an effective method for analyzing and assessing an intelligent traffic system. The technology can be well combined with environments, a distributed structure is supported, the problem of platform independence is solved, and system transportability is enhanced. By means of a three-dimensional design method constructing a scene graph through Java 3D, virtual scene design is more visual and flexible, design and development of three-dimensional programs are simplified, the problems of scene construction, vehicle moving, viewpoint moving and the like in virtual traffic scenes are well solved, the virtual vehicle emulation system can simulate conditions of the intelligent traffic system visually, and the conditions of the intelligent traffic system can be conveniently analyzed and assessed.

Description

Based on the virtual vehicle emulation technology of Java 3D technology

Technical field

Simulation technical field in one java 3D in computer realm is virtual.

Background technology

In intelligent transportation, the acquisition of information and process are the important topics of the research of intelligent transportation nearly ten years.In the management of Modern City Traffic with in controlling, the data volume utilizing various technological means and modern devices to obtain is day by day huge.Along with electronic technology

Development and the becoming stronger day by day of computer function, the processing power of transport information is also constantly strengthened.Particularly along with the raising of computer graphical processing ability, the researchist of many intelligent transportation is devoted to the visualize display of transport information and traffic data, has done a large amount of work.Real-time traffic data can be shown by department of computer science's graphic display system of unifying by the emulation of intelligent transportation system intuitively, thus enable traffic administration and controllers obtain the operation conditions of urban transportation easily, send traffic control instruction timely and accurately, ensure the safety of urban transportation and unimpeded.

Virtual vehicle emulation is a kind of microscopic traffic simulation based on intelligent transportation system.It with each vehicle for elementary cell, acquisition urban traffic control and control in real time for information about, utilize computer system simulation human pilot to the response of various Real-time Traffic Information and traffic control, for human pilot provides the real-time analysis to judgement various in information process and decision-making.From microcosmic angle, comprehensive information processing and display being carried out to Traffic Systems, providing prediction scheme analysis and Scheme Choice for relieving traffic congestion better.

Virtual vehicle analogue system mainly comprises three-dimensional traffic scene, Virtual Driving Platform and driver's decision behavior and simulates several part.System obtains the geography information such as traffic environment, geographic entity from GIS infosystem, the control status etc. as corresponding road traffic control information, other vehicle conditions and intelligent transportation systems such as traffic grade is obtained from intellectual traffic control analogue system, driver's decision behavior of coupling system itself again, adopt 3-D technology to show the operation conditions of intelligent transportation system intuitively, achieve the three-dimensional drive interface display at visual angle in car.

In recent years, the R and D of virtual vehicle analogue system have attracted the attention of numerous company and research institution, have dropped into the research and development for this respect of a large amount of manpowers and fund, as the VISSIM of German PVT company, and the AIMSUN2 of TSS company of Spain.But these systems also exist does not support distributed parallel computing, the problems such as platform independence is bad.Three-dimensional design exploitation is wherein use the low layer three-dimensional function storehouses such as OPENGL or Direct3d mostly, and use C Plus Plus exploitation, programming efficiency is low, portable poor.And use Java language in conjunction with Java3D technology to build virtual vehicle analogue system, greatly can improve development efficiency and system portability, support Distributed Design better, accomplish that real platform is independent, be a kind of new development and Design approach.

Summary of the invention

Utilize the correlation technique based on Java 3D, complete the overall design of virtual vehicle analogue system, achieving transport information, the coordination of control information and vehicle drive information and unification, providing an outstanding display platform for studying urban traffic control and control model better.

First describe the design of virtual vehicle analogue system Scene structure, then specifically describe the realization of three-dimensional scenic and the generation of Virtual Driving Platform.

One, scene structure design;

Scene graph basis is the structure foundation of whole scene structure, for scene provides three-dimensional Virtual Space, and imparts position, scene graph accurate insertion point, thus the connection realized one or more scene graph objects and control.Comprise node Node and data object NodeComponent in scene graph, node is divided into again group node Group and leaf node Leaf.Group node is for the child node under organizing, controlling it, and leaf node is endpoint node, contains the core semantic primitive forming scene graph, as geometry of objects, behavior etc.Data object then comprises the data message needed for leaf node, and leaf node is by providing its semantic data message to be expressed to quoting of data object.Leaf node and data object coordinate can construct the three dimensional object such as three-dimensional body, light.According to the difference of comprised information, scene graph can be divided into again content branch and look branch.

Two, three-dimensional scenic realizes;

1. static scene generates; Set up three-dimensional traffic scene, first will realize static three-dimensional scene.In three-dimensional traffic scene, static scene includes all scenery be not subjected to displacement relative to ground in scene, and relevant data and information, is mainly divided into environment and the stationary body such as house, road.Therefore by completing the foundation of static three-dimensional scene to the structure of environment and stationary body branching diagram.

Set up static scene and first want physical environment that is virtually reality like reality, structure comprises the environment branch of light and background, provides the environmental element that sunshine, surround lighting, light, sky etc. are necessary, virtual scene is normally shown.

It is secondary places stationary body according to the position determined.Need to determine the accurate location of each three-dimensional body in scene and the conversion of position, implementation space during structure branching diagram.

In construction process, the branching diagram of stationary body adopts the method for point class formation.This is due in three-dimensional scenic, and object can be divided into two parts again according to the state existed: immutable part and variable part.The part that immutable part can not change after referring to scene foundation again, as road, house, road sign etc.; Variable part is the part that state likely changes after scene is set up, as traffic lights (its color can change).Because three-dimensional traffic scene is very complicated huge, therefore should be optimized the structure of scene as far as possible, improve rendering efficiency.

System, from after GIS infosystem obtains related data and information, produces each static scene branching diagram, is joined by branching diagram on scene basis, just complete the structure to three-dimensional static scene.

2. moving vehicle generates; In traffic scene, the motion state of vehicle is very complicated, speed is different, is a continuous print process.The motion of simulating vehicle in traffic scene, auto model be made in virtual scene, can to carry out complicated continuous motion according to the control information obtained in real time, and concrete implementation method is as follows:

(1) realize auto model motion: be connected to by auto model node on transfering node TransfromGroup, arranged by position, the direction changing transfering node, make vehicle produce corresponding motion.

(2) compound movement of vehicle: realize with the combination of simple motion.The motion of vehicle can be divided into displacement and rotate two large class simple motions, wherein displacement includes straight line, curvilinear motion, rotates and includes level, vertical rotary.Realize these simple motions of three-dimensional body and combined, just can generate the compound movement of vehicle.

(3) vehicle moves continuously according to the control information obtained in real time from intellectual traffic control analogue system: vehicle branch wants according to the specific time interval, to obtain the motion control information of vehicle.Simultaneously because information is that interval obtains, also need discontinuous control information to produce continuous print motion.If use the method arranging transfering node, certain interval of time converts a upper/lower positions and carrys out simulating vehicle motion, and program design can be made very complicated, and operational efficiency is low, causes the discontinuous of motion.Therefore the interpolater Interpolator using Java 3D to provide and Alpha Conjugative tiansfer node are to control the motion of object continuous print.Interpolater can produce corresponding motion continuously according to given a series of positions, directional information, Alpha then control interpolater produce the speed of motion.The Alpha that can produce ohject displacement and the interpolater self rotated and control rate is used to be configured to a movement node (MyInterpolator), and structure obtains the part of motion control information in real time, make it can produce motion according to the control information obtained in real time wherein.Movement node is connected on transfering node, so just can controls transfering node motion, solve the problem generating the real-time complexity controlled and move continuously.

Three, Virtual Driving Platform generates:

Virtual Driving Platform is contained in virtual vehicle analogue system.By this driving platform, the operation conditions of three-dimensional traffic system can be observed.Perceived model according to Java 3D designs the generation that can complete Virtual Driving Platform depending on branching diagram.

1. Java3D perceived model; The virtual world that a window formed to observe scene graph is provided depending on branching diagram.。Depending on platform model, whole scene is divided into two parts, virtual world and physical world.Virtual world refers in scene graph structure, the virtual scene that all branching diagrams are formed.Physical world refers to the real world at observer place, comprises display device etc.Two worlds is connected by inherent corresponding relation, becomes a unified space.

2. Virtual Driving Platform design; Divide two parts to the design of Virtual Driving Platform, first generate and look branching diagram, look platform in the constructing virtual world, regeneration View, Ganvas3D, Screen 3D etc. provides concrete spatial cue, thus draws out scene on the physical devices.Wherein, be main part to the structure depending on branching diagram in virtual world.

Claims

1., based on the virtual vehicle emulation technology of Java 3D technology, it is characterized in that mainly scene structure design, three-dimensional scenic realizes, and Virtual Driving Platform generates.

2. design according to claim 1 scene structure; Java 3D adopts the scene enterprise schema of scene graph structure (Scene Graph Structure), is made up of scene graph (Scene Graph) and scene graph basis (Scene Graph Structure) two parts.

3. according to claim 2 item, the three-dimensional design of virtual vehicle analogue system is divided into two parts: three-dimensional traffic Scenario Design and Virtual Driving Platform design.

4. according to the claim 3 item feature according to Java 3D scene graph structure, the method for classification can be adopted, set up three-dimensional traffic scene by design content branching diagram, look branching diagram constructing virtual driving platform by design.

5. realize setting up three-dimensional traffic scene according to claim 1 three-dimensional scenic, first will realize static three-dimensional scene; In three-dimensional traffic scene, static scene includes all scenery be not subjected to displacement relative to ground in scene, and relevant data and information, is mainly divided into environment and the stationary body such as house, road.

6. set up static scene according to claim 4 and first want physical environment that is virtually reality like reality, structure comprises the environment branch of light and background, provides the environmental element that sunshine, surround lighting, light, sky etc. are necessary, virtual scene is normally shown.

7. according to claim 4, stationary body will be placed according to the position determined by it.

8. generate according to claim 1 moving vehicle; (1) auto model motion is realized: auto model node is connected to transfering node TransfromGroup) on, arranged by position, the direction changing transfering node, make vehicle produce corresponding motion; (2) compound movement of vehicle: realize with the combination of simple motion.

9. the motion of vehicle can be divided into displacement and rotate two large class simple motions, wherein displacement includes straight line, curvilinear motion, rotates and includes level, vertical rotary.

10. realize these simple motions of three-dimensional body and combined, just can generate the compound movement of vehicle; (2) vehicle moves continuously according to the control information obtained in real time from intellectual traffic control analogue system: vehicle branch wants according to the specific time interval, to obtain the motion control information of vehicle.