Reverse Engineering• Systematic evaluation of a product with the purpose of replication. Design of a new part Copy of an existing part Recovery of a damaged or broken part• An important step in the product development cycle.
Importance• We cannot start from the very beginning to develop a new product every time.• We need to optimize the resources available in our hands and reduce the production time keeping in view the customers’ requirements.• For such cases, RE is an efficient approach to significantly reduce the product development cycle. For example: Impeller Pump Design
Suppose there is a impellor pump which had an original pumpingcapacity of 20000 cubic feet of water per minute; now, after a year ofuse, the pump manufacturing company finds that it is pumping 19000cubic feet per minute. They need to figure out what happened to thatextra 1 thousand cubic feet in performance. The pump manufacturerscans the year-old impeller into the CAD system. Once thosemeasurements are captured, engineers can compare themeasurements taken from the actual impeller against the original, as-designed part. This helps determine exactly how and where the parthas degraded. With that information in hand, engineers can redesignthe impeller to avoid future loss in pumping capability.
Advantages• RE typically starts with measuring an Cost saving for developing existing object, so that a solid model can new products. be deduced in order to make use of the advantages of CAD/CAM/CAE technologies. Lesser maintenance costs• CAD models are used for manufacturing or rapid prototyping applications. Quality improvement• Hence we can work on a product without having prior knowledge of the technology Competitive advantages involved.
RE ProcessI. Digitization of the object/ Data Capturing (using CMM, scanners etc.)II. Processing of measured dataIII. Creation of CAD modelIV. Prototype
Rapid Prototyping in combination with RE• A group of techniques to quickly fabricate a scale model of a physical part or assembly using 3D CAD data• Integration of reverse engineering and rapid prototyping is being used for getting product to the market quickly by resolving a long-standing conflict between design and manufacturing
a b c CAD model generation using laser scanner:(a) wooden pattern, (b) cloud of points, and (c) 3D CAD model Fabricated RP Model
Areas of ApplicationDesign of a new componentReproduction of an existing componentImproving quality & efficiency of existing parts
Manufacturing Engineering• To create a 3D virtual model of an existing physical part for use in 3D CAD, CAM, CAE or other software• To make a digital 3D record of own products• To assess competitors products• To analyze the working of a product• To identify potential patent infringement etc.
Software Engineering• To extract design & implementation information• To detect and neutralize viruses and malware Chemical Engineering• To determine chemical composition• To substitute or improve recipes to stimulate or improve the products performance
Film-Entertainment Industry• Animated objects are imparted motion using the reverse engineered human skeletons
Medical Field• Applications in orthopedic, dental & reconstructive surgery• Imaging, modeling and replication (as a physical model) of a patients bone structure• Models can be viewed & physically handled before surgery, benefiting in evaluation of the procedure & implant fit in difficult cases• Less risk to the patient and reduced cost through saving in theatre time
A Case StudyAdapted from “Reverse engineering in thedesign of turbine blades-a case study inapplying the MAMDP” by Liang-Chia Chen, GrierC.I. Lin
• The large amount of surface data generated from the fast 3D digitizers is not easily modeled by current CAD/CAM systems. Inadequate data reduction methods are not only time consuming, but lose surface characteristic points.• Consequently, the reconstructed surfaces could lose their true shape in the design cycle. The time required for reprocessing in this case would be unacceptable to the manufacturing industry and thereby be unusable for further steps.
• The study describes how the developed reverse engineering approach MAMDP was successfully applied to design of turbine blades and the existing problems encountered in reverse engineering processes were overcome.• MAMDP stands for Modified Adaptive Model- based Digitizing Process
A 3D initial triangular patch of a subdivided surface patch generated by IVSTP The surface triangular patch of a The surface model of a subdivided surfacesubdivided surface patch of the turbine patch of the turbine blade (before surface trimming)
The surface model of the measured turbine blades.
Generation of initial surface triangular patches of turbine blades• A charge-coupled device (CCD) camera is used to rapidly detect the objects position and measure its surface boundary coordinates, to establish exploration paths for further automatic surface digitization of a touch probe.
• Free-form surface subdivided into an adequate number of individual surface patches• 3D stereo detection method is applied to automatically detect 3D surface boundaries• Initial triangular patch by applying Triangulation process• A 3D initial triangular surface patch can be rapidly generated & used for probe exploration paths in the following MAMDP
Automatic surface digitization &surface modeling by using the MAMDP• The surface model is used to calculate the new exploration points at the approximate midpoints between the vertices of the initial triangular patch.• CMM then automatically digitizes these exploration targets
• Adaptive approach evaluates the digitizing accuracy by calculating the deviations between the target points and the digitized points• New exploration targets will be generated at the estimated midpoints between vertices of those triangular patches where deviations are higher than the user-specified tolerance• This iterative digitizing loop will continue until all new digitized deviations are within the specified tolerance
• Totally 786 surface characteristic points were automatically digitized by a touch-triggered probe in CMM. The time spent for this job was 45 min. The digitizing accuracy can be controlled within 0.25 mm and the maximum fitted error in the resulting surface model is reduced to 0.030 mm using a least-squares fitting method.• To generate a complete CAD surface model of turbine blades, the individual surface models generated from the MAMDP have to be merged, according to their geometric relationship. (Using CAD/CAM package ANVIL5000)
Future Scope & PossibilitiesWith the advent of RE & RP, we can hope to seecommercial and domestic use of these technologiesto manufacture desired products at home and officeswhich will be revolutionary in coming time.Possibilities of use of this technology is onlyrestricted by boundaries of human thinking.
• 3D laser scanners as robot eye for scanning objects specially in space missions.• Scanning technology can be integrated with mobile phones/cameras and can be used for 3D printing at domestic level.• Tissue engineering applications where organs and body parts are built using inkjet techniques. Layers of living cells are deposited onto a gel medium or sugar matrix and slowly built up to form three dimensional structures including vascular systems.• Availability of 3D printers at every home as is now of the normal printers.
Around the World…• Wiki Weapon Project Aims To Create A Gun Anyone Can 3D-Print At Home.• The open source Fab@Home project has developed printers for general use which can use anything squirtable through a nozzle, from chocolate to silicon sealant and chemical reactants.• Some companies offer an on-line 3D printing service open both to consumers and to industry.
RE of trans tunnel by Macomb College Students Video
References• Eyup Bagci, Reverse engineering applications for recovery of broken or worn parts and re-manufacturing: Three case studies, Advances in Engineering Software 40 (2009) 407–418• Yu Zhang, Research into the engineering application of reverse engineering technology, Journal of Materials Processing Technology 139 (2003) 472–475• Liang-Chia Chen, Grier C.I. Lin, Reverse engineering in the design of turbine blades}a case study in applying the MAMDP, Robotics and Computer Integrated Manufacturing 16 (2000) 161-167• http://en.wikipedia.org/wiki/Reverse_engineering• http://www.asme.org/kb/news---articles/articles/computational-methods--- modeling/the-rise-of-reverse-engineering• R. Schenker, Novel combination of RE & RP in medicine, South African Journal of Science, 95, August 1999• Wiki Weapon Project Aims To Create A Gun Anyone Can 3D-Print At Home- http://www.forbes.com/sites/andygreenberg/2012/08/23/wiki-weapon-project- aims-to-create-a-gun-anyone-can-3d-print-at-home/