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Abstract In the phase of multidisciplinary design optimization
of UAV, according to the changes of the design parameters,
structure scheme and the shape of the air-frame need to be
continuously adjusted. The parametric modeling can avoid the
dis-advantages of 3D modeling, such as long time consuming, low
efficient, and poor interaction, and it will be the important
method of UAV of multidisciplinary design optimization. A 3D model
of a UAV airframe by using the parametric modeling in CATIA
software was constructed, which was the base of design and analysis
of UAV.
Keywords Parametricmodel Airframe Knowledge-basedengineering
CATIA
74.1 Introduction
The airframe of UAV, consisted the wing, tail, landing gear, and
engine, is also the platform to assemble all kinds of task devices
and systems. The load on the wing, tail, landing gear, and engine
is transferred to the aircraft body by adaptors, and thus achieve a
balance [1]. The modeling of the aircraft airframe needs to be
updated quickly to satisfy requirements of different parts on
space. Using the tra-ditional 3D modeling, the model modifies
slowly, interact badly; while using the parametric modeling, the
model can modifies quick and expediently. Therefore, it is very
important to conduct the parametric optimization design and
parametric modeling. This paper studies the realization of the
parametric modeling of UAV airframe based on knowledge-based
engineering using the CATIA software.
Gui-yu Zhou and Guan-jun Liu
Chapter 74Parametric Modeling Based on KBE of CATIA
Z. Zhong (ed.), Proceedings of the International Conference on
Information Engineering and Applications (IEA) 2012, Lecture Notes
in Electrical Engineering 217, DOI: 10.1007/978-1-4471-4850-0_74,
Springer-Verlag London 2013
G. Zhou (*) G. Liu Laboratory of Science and Technology on
Integrated Logistics Support, National University of Defense
Technology, Changsha 410073, Chinae-mail: [email protected]
G. Liu e-mail: [email protected]
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582 G. Zhou and G. Liu
74.2 Parametric Technology and Knowledge-Based Engineering
Parametric technology is an important field of modern
engineering design meth-ods. The parameters predefined graphic
geometric constraint set, specify a set of size as a parameter so
that the geometric constraints associated with the set, and all
associated type into the application, and then use humancomputer
interaction through the dialog box to modify the parameters of
size, and ultimately by the program according to the expression of
these parameters the order of implemen-tation to achieve the
modification of the design results [2, 3]. Parametric tech-nology
can greatly improve the efficiency of the model changes, improve
design flexibility, and shorten product development cycle, reflect
the high value. In the future of engineering design, parametric
technology will play an increasingly important role.
Knowledge-based engineering is an artificial intelligence
development inknowledge and information processing. It uses symbol
manipulation techniques based on description of the specific areas
of knowledge, and this knowledge is pre-pared on the basis of
reasoning knowledge of the application. Core discipline of
knowledge-based engineering is relevant knowledge; design standards
and speci-fications, principals of selection of design parameters,
and design history informa-tion are embedded into the design
software, thus achieving an intelligent product design through
logic and reasoning [4].
The basic idea of knowledge-based engineering is to seek and
record the knowledge of different engineering designs and parts
product configuration based on the experience and knowledge in
product design and development process, and to add artificial
intelligence (knowledge base, knowledge of rules, and logic
reasoning, etc.) to this knowledge. Combining knowledge
engineering, paramet-ric design, and the theory of feature-based
modeling will be able to make up for deficiencies in the
traditional parametric design, enabling the product design more
flexible, efficient, and intelligent [5, 6].
74.3 Knowledge-Based Engineering of CATIA
KNOWLEDGEADVISOR is a CATIA product, which allows users to
embedknowledge within design and leverage it to assist in
engineering decisions, in order to reduce errors or automate design
for maximum productivity.
In the CATIA software, the parameters are generally divided into
two categories:
System parameters (internal parameters): parameters represent
the internal properties defined by documents.
User parameters: parameters defined by the designer to add the
node in the characteristics of tree parameters (Parameters). User
parameters and system
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58374 ParametricModelingBasedonKBEofCATIA
parameters are complementary and inseparable; designers can
achieve a perfect combination of system parameters and user
parameters by constraints, formulas, and rules.
In the top-down modeling approach, the parametric model is
essentially built the parametric model; parametric model is
conducted by the association or assem-bly of the location
parameters. The user parameters of part are divided into two
categories: location parameters and feature parameter.
The location parameters are established in the overall assembly,
and the feature parameters are established in constructing the
parts. It is convenient to manage, modify, and improve efficiency.
The parametric model is established through con-straints, formulas,
and rules.
74.4 UAV Airframe Parametric Modeling
74.4.1 Development Environment
This work is based on the CATIAV5R19 as the studying platform,
usesASD(Assembly Design), PDG (Part Design), GSD (Generative Shape
Design,) and
KWA(KnowledgeAdvisor)toconducttheparametricmodeling.
74.4.2 Design Idea
The airframe, a semi-monocoque shell structure, is mainly
composed of skin, frame, and truss components. This work uses the
top-down modeling approach: firstly, a structural tree based on
assembly relation to the parts was established; then, necessary
parameters were constructed; the parametric model through
con-straints, formula, and rules was established; finally,
parametric model satisfaction of requirements was checked. If it
satisfies the requirements, the parametric mod-eling is finished;
otherwise, the model will be modified until the model meets the
requirements. The body structured of the model tree shown in Fig.
74.1.
74.4.3 Realization of the Parametric Model
For complex assemblies, the relative installation positions and
assembly shapes of components are related to each other. If the
overall design parameters are adjusted, or the shape or position of
certain components are changed, the relevant compo-nents may need
to be modified. In the top-down design, all components in the
product can be directly updated.
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584 G. Zhou and G. Liu
In the top-down design, components are designed in the assembly
environ-ment. The modification of parameters in and between
components can be done by the using the interact parameters between
different components. The top-down design approach agrees with the
product design process and thinking process of designers. It is
convenient to facilitate the synergy of multiple subsystems,
shorten production cycles, improve product quality, and design
efficiency.
Fig. 74.1 The model tree
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58574 ParametricModelingBasedonKBEofCATIA
In the top-down design, component design can be switched from
assembly work-bench to the component workbench; the skeleton parts
are constructed in the product module, then, the reference
parameters (point, line, surface, and control variables) are
published. At the same time, under the control of the main
skeleton, subassembly skeletons are constructed. In detailed
design, only the associated release element is selected to avoid
too much reference. In the associated design, only child
relation-ship (no parent relationship) is generated for noncritical
elements. Thus, no system crashes will be caused during conducting
the large assembly. At the same time, spa-tial analysis functions
in the DMU can be used to check the rationality of the design.
Finally, according to the overall UAV design, the UAV parametric
model is established using the parametric modeling approach. The
UAV parametric model is shown in Fig. 74.2.
If parameters were modified, the model would be updated. For
example, when the parameter orientation-distance of
Frame-1#-Airframe-front = 220 mm, the param-eter orientation-angle
of Beam-1#-Airframe-front = 45 , and the parameter
orien-tation-angle of Beam-2#-Airframe-front = 45 ; Fig. 74.3 shows
the model.
Fig. 74.2 The airframe model
Beam2 Frame1Beam1
Fig. 74.3 The airframe model of parameter 1
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586 G. Zhou and G. Liu
Whentheparameterorientation-distanceofFrame-1#-Airframe-front=
400 mm, the parameter orientation-angle of Beam-1#-Airframe-front =
30 , and the parameter orientation-angle of Beam-2#-Airframe-front
= 30 ; Fig. 74.4 shows the model.
74.5 Conclusion
The development and wide application of parametric modeling
technology based on knowledge-based engineering improves the design
and manufacture of UAV and speeds up the overall developing process
of modern UAV. Using the 3D para-metric design method based on
knowledge-based engineering of CATIA, the UAV parametric model is
established, and the model can be updated easily according to
different design requirements. This proves the effectiveness of the
parametric modeling method using knowledge-based engineering of
CATIA.
References
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fanUAVbasedonCATIA. Comput Technol Dev 21(5):187189
Beam2 Frame1Beam1
Fig. 74.4 The airframe model of parameter 2
74 Parametric Modeling Based on KBE of CATIA74.1
Introduction74.2 Parametric Technology and Knowledge-Based
Engineering74.3 Knowledge-Based Engineering of CATIA74.4 UAV
Airframe Parametric Modeling74.4.1 Development Environment74.4.2
Design Idea74.4.3 Realization of the Parametric Model
74.5 ConclusionReferences
