Rearch of Virtual Asmbly for Tunnel Boring Machine Bad on Division
Gong Yadong1, Cheng Jun1, Jiao Zhongjian2, Yang Yuxiang1
1 School of Mechanical Engineering and Automation, Northeastern University, Shenyang 110004, China
2 Changchun railway vehicles co., ltd, Changchun 130062, China
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ABSTRACT: The application background and practical requirement of virtual asmbly system of tunnel boring machine has been discusd in this paper. Software PROE is ud to build the tunnel boring machine model. Application program of virtual asmbly system ba on virtual reality is developed by using Division, The author also studys on key technologies of constructing virtual asmbly system of tunnel boring machine, such as interference detection in virtual environment. The result shows that the work station can be simulated well, and this virtual simulation system can be extended in virtual training and manipulationǃvirtual construction and so on.
KEYWORDS: Tunnel Boring Machine; Virtual reality; Division; Virtual asmbly
I.I NTRODUCTION
Technology of virtual reality is integrated and complex.
It includes computer technology, nsing and measurement technology, simulation technology, microelectronic technology etc. Immersion, Interaction, Imagination are its three important characters[1].More and more virtual simulation systems have been built for many industrial applications bad on technology of virtual reality, such as car, airplane, tank, naval ship etc. Compare with prototype experiment, virtual simulation system has advantages of safety, low cost, without environment constrain.
Tunnel boring machine(TBM) is one of sixteen major projects which are supported by State Department to brace up national equipment manufacturing industry.Design and development of tunnel boring machine are strong supported by Country, mainly aim on prototype trial-production and engineer application. Prototype experiment has good efficiency but is high cost and long period[2].For the virtual experimentation of tunnel boring machine, it is necessary to build a virtual simulation system. Therefore, developing digital mockup and function simulation platform of tunnel boring machine with independent intellectual property, virtual training and manipulation, virtual constr
uction can be carried out in virtual environment. The results from experiment can be ud for tunnel boring machine’s optimal design.
The author builds the virtual asmbly platform bad on Division, SGI Prism Graphic workstation and Christie DLP Projector Mirage S+2K to construct the virtual reality system for virtual asmbly of TBM.
By using this method, designer can directly check the mechanical system and detect whether there has been interferences in product design stage. Thus reduce design costs and improve design quality.
II.R EALIZATION PROCESS OF VIRTUAL ASSEMBLY
Virtual Asmbly is a important part in product digital definition. Rearch on it generally can be divided to two levels.
One is by using asmbly process visualization instruments and interference checking tools, directly display parts’ motion and displacement in product asmbly process, allowing that the ur can control the product three dimension virtual asmbly process interactively, thus product’s asmbling possibility.
The other is constructing virtual product asmbly environment bad on virtual reality technology, giving the operator immersion feeling. The operator can obrve product’s asmbly quence with immersion visual effect[3]. This is new generation method and application of human computer interaction[4]. Literature 5 describes develop status and trend of virtual asmbly, literature 6 propos four bounding box algorithm for interference detection.
Figure 1. Inner structure of TBM in VR
By doing virtual asmbly of tunnel boring machine in virtual environment, the developer can quickly get the influence of design decision to single operation. Completely control the asmbly process of virtual manufacture of tunnel boring machine is very significant to ensuring product quality, reducing product costs, shorten the develop cycle.
Cylinde r
Segment erector Screw conveyor
Screw support
Shield
2009 International Forum on Computer Science-Technology and Applications
Fig.1 is model of tunnel boring machine in virtual environment.
III. V IRTUAL ASSEMBLY SYSTEM FOR TBM A. System Constitution
The virtual system is built ba on EPB(Earth Pressure Balance)Ф6.28m tunnel boring machine. Fig.2 shows hardware ’s structure of system.
Figure 2. Virtual simulation system of tunnel boring machine
Division is a software for virtual reality developed by PTC company, it has features such as web-bas
ed, scalable. Division has mainly function as digital mockup, asmbly layout, motion simulation and human computer engineer. It constitutes the mainstream virtual reality software on the field of mechanical design software with Opticore ǃVis Mockup ǃCatia DMU together. Final implementation of system is working as Fig.3 shows.
Figure 3. Hardware ’s structure of virtual simulation system
Hardware of system mainly includes: Graphic workstation: SGI-Onyx4
Projector: Christie DLP Projector Mirage S+2K Projection screen: flat-plate with double channel Displayer: ViewSonic Professional Series P225f 3D eyeglass: Crystal EYES 3
B. Virtual asmbly
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peculiarities. For example, the head margin in this template
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This paper implements the virtual asmbly of tunnel boring machine, both executive components and the whole machine. Fig.4 is the working station of virtual asmbly of tunnel boring machine. Figure 4. Working station of virtual asmbly
Virtual asmbly of tunnel boring machine can be
divided to veral parts: cutter head, front shield, rear shield, gment conveyor etc. Fig.5 is the process of cutter head ’s virtual asmbly, a is structure part, b is cutters asmbling, c is the supporting part of cutter head, d is driving unit.
a b
c d
a-structural parts. b-cutters. c-supporting parts. d-driving part.
Figure 5. The asmbly of cutter head
Fig.6 is process of the whole machine ’s virtual asmbly. a is front shield, b is middle shield. c is rear shield. d is matching equipment.
a b
c d a-front shield. b-middle shield. c-rear shield. d-matching equipment.
Figure 6. The asmbly of TBM
C. Interference detection Interference detection is basic constitution of virtual
reality system, also the premi of virtual asmbly. Virtual
asmbly of complex component is a multifarious work,
according to parts ’ asmbly motion, three-propelled
interference detection: bounding box level, mi bounding
box level, accurate entity level has been widely ud. Thus
much unnecessary operation can be avoided. The currently widely ud bounding box algorithms are
axis-aligned bounding box(AABB), sphere bounding box,
oriented bounding box(OBB), fixed directions hull(FDH).
AABB and sphere bounding box can satisfy the requirement of simplicity, but poor tightness. OBB is
complicated in calculation but has good tightness. FDH
construct the bounding box through a fixed t of vector
D={ dl , d2 , d3 , Ă, dk } and point t X, D6 (X ) :D6 =
{±(0,0,1),±(0,1, 0),±(1,0,0)}.
By using FDH bounding box algorithm, contact and
interction are checked to detect whether the collision occurred. When a collision happens, in order to make the obrver find the appearance, division provides three modes
to reflect the interference, color changing, blink, audio
remind.
The relationship between virtual asmbly and
interference query is as Fig.7 shows.
Figure 7. The relationship between virtual asmbly and interference
query
The dialog box of interference query is as Fig.8 shows. The part or components of tunnel boring machine can be
pick cho by detect requirement, instantaneous detect is checking the interference detect in static state, persistence detect is dynamic checking interference detect in asmbly process. The result of
interference query is showed as Fig.9. The static interference will be found in the detect result, so the interference part ’s dimension can be modified. Then
repeat cycle above until the model can satisfy design requirement.
D. Motion simulating implementation The model of tunnel boring machine can be ud for motion simulation in virtual reality system after virtual asmbly. The scene is just as Fig.10 shows.
a b a-the whole machine b-detail of rear shield
Figure 10. The Constitute of motion simulation of TBM in Virtual Reality IV. C ONCLUSION
The author according to traditional asmbly ’s high cost, long cycle, low efficiency, study the virtual asmbly, interference detect, motion simulation bad on Division and
virtual reality technology. Virtual asmbly environment has
been constructed and tunnel boring machine ’s asmbly and motion process has been simulated. Thereby increasing asmbly checking efficiency, ensuring product quality, reducing product costs, shorten the develop cycle.
Becau of the complexity technology of tunnel
boring machine in practical construction, how to detailed
simulate the complicated technique in practical construction will be the next rearch pha we focus on. A CKNOWLEDGMENT
This work was supported by Chine 863 foundation. Number is 2008AA04Z119.
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Figure 9. The result of interference query Figure 8. The dialog box of interference query
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