2. Reverseengineering
• Reverse Engineering is a process of
redesigning an existing product to improve and
broaden its functions, add quality and to
increase its useful life.
• The main aim of reverse engineering is to
reduce manufacturing costs of the new
product, making it competitive in market.
• The duplication is done without the aid of
drawings, documentation or computer model.
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3. why reverseengineering?
• The original producer no longer produces the
product.
• There is inadequate documentation of product.
• Some bad features of the product needs to be
redesigned.
• To update obsolete materials or antiquated
manufacturing processes with more current,
less expensive technologies.
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6. Digitizing
• Collecting data from physical part.
• Used when drawing of object is not available.
• Aim is to generate a 3D mapping of the
product in the form of CAD file.
• This requires acquisition of surface data,
which is large number of points on the product
surface.
• For this two types of processes are used:
contact and non contact method.
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7. Discretizationmethod
Contact method
• Requires contact between
the component surface & a
measuring tool.
• Uses Coordinate Measuring
Machine (CMM),
electromagnetic digitizer or
sonic digitizers to get
desired coordinates.
Non contact method
• Uses light as the main tool
• Uses white light or laser
scanners to scan 3D objects
to generate CAD design.
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8. Manipulationof data
• Basically, after completion of this a CAD
model of product is obtained.
• Used to fit a geometry to the large number of
points obtained from digitizing.
• The surface can be mathematically defined as
algebraic or parametric surface.
• Surface fitting techniques can be of two types:
interpolation and approximation techniques.
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9. Surfacefitting techniques
Interpolation technique
• Surface to be fitted passes
through all the data points.
• Used when the data points
are accurately measured
without any errors.
Approximation technique
• Surface represents a
generalized or best fit to the
data points.
• Used when large number of
data points are to be fitted.
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10. Generationof functional part
• The geometric model obtained, can be used as
the basis for variety of operations.
• Operations such as automated process
planning, automated manufacturing, automated
dimensional inspection and automated
tolerance analysis.
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11. Advantages of reverse engineering
• RE typically starts with measuring an
existing object, so that a solid model
can be deduced in order to make use
of the advantages of
CAD/CAM/CAE technologies.
• CAD models are used for
manufacturing or rapid prototyping
applications.
• Hence we can work on a product
without having prior knowledge of
the technology involved.
Cost saving for developing new
products.
Lesser maintenance costs
Quality improvement
Competitive advantages
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12. Applications
• ManufacturingField: To create a 3D virtual model
of an existing physical part for use in 3D
CAD, CAM, CAE or other software and to
analyze the working of a product.
• Medical Field:Imaging, modeling and replication
(as a physical model) of a patient's bone
structure
• Software engineering: To detect and neutralize
viruses and malware.
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The choice of discretization method is based on speed & performance during digitization and avoidance of damage to the product.
Algebraic function is one which is defined as f(x,y,z)=0 and is for infinite surface whereas parametric function is one which is defined as a finite surface for example: bezier surface, NURBS surface.