Three-Dimensional Geometrical Modelling of Wild Boar Head by Reverse Engineering Technology

In this paper, a wild boar head was taken as the bionic research object for the development of new ridgers, a kind of plough. The reverse engineering technology was adopted to obtain the surface geometrical information of the head. Several three-dimensional （3D） point clouds of the head were captured first using a non-touch laser scanner, and an integrated point cloud was generated by aligning these point clouds using UG/Imageware. Then, the digital surface model of the head was rebuilt by means of CATIA. The characteristic curves of the surface model were analyzed. The results show that the average error between the rebuilt surface and the point cloud is -0.431 ram. The max curvature of the ridge on the neb of the head is 0.187 mm^-1, and the max and rain Gauss curvatures on the surface are 0.008 mm^-2 and -0.002 mm^-2. These geometrical information are the essential parameters for biomimetics study of the ridger.

Color 3D Reverse Engineering

This paper presents a principle and a method of col or 3D laser scanning measurement. Based on the fundamental monochrome 3D measureme nt study, color information capture, color texture mapping, coordinate computati on and other techniques are performed to achieve color 3D measurement. The syste m is designed and composed of a line laser light emitter, one color CCD camera, a motor-driven rotary filter, a circuit card and a computer. Two steps in captu ring object’s images in the measurement process: First, the color CCD camera ta kes the color picture of the object to be used for texture mapping in post proce ssing. Secondly, the monochrome data of the object is taken. The laser light emi tter is started; the light plane and the surface of the object intersect to form an undulate line, which forms an image on the CCD sensor. After the optic- electronics transformation, the electronic signals are captured and send to the computer. A new color 3D measurement model was derived, and a rapid calibra ting method to measure the system parameters was proposed--optical plane equat ion calibrating method. A calibrating drone was designed and built. 3D color sca nning system not only provides an object’s individual point information in the 3D coordinate, in the mean time, it provides the color information of each indiv idual point. This paper also advances a multi-frame auto-merging method, i.e. several frames of color 3D digital images measured are merged quickly according to their curvature characteristics and RGB information. Initial matching and fin e tune of the registration are completely performed by the computer; initial mat ching is via user interface in helping computer to find the transformation matri x. The transformation matrix is found according to the geometric characteristics chosen by hand. After the initial transformation matrix is found, fine tune of the registration is preformed to do the optimum adjustment to achieve a complete color textured 3D model. The system can be broadly used in the fields of produc t design, mold manufacture, multimedia, game development, animation, medical eng ineering, antique digitization, etc.

LEAST-SQUARES METHOD-BASED FEATURE FITTING AND EXTRACTION IN REVERSE ENGINEERING

The main purpose of reverse engineering is to convert discrete data pointsinto piecewise smooth, continuous surface models. Before carrying out model reconstruction it issignificant to extract geometric features because the quality of modeling greatly depends on therepresentation of features. Some fitting techniques of natural quadric surfaces with least-squaresmethod are described. And these techniques can be directly used to extract quadric surfaces featuresduring the process of segmentation for point cloud.

Reverse Engineering of Machine-tool Settings with Modified Roll for Spiral Bevel Pinions

Although a great deal of research has been dedicated to the synthesis of spiral bevel gears, little related to reverse engineering can be found. An approach is proposed to reverse the machine-tool settings of the pinion of a spiral bevel gear drive on the basis of the blank and tooth surface data obtained by a coordinate measuring machine(CMM). Real tooth contact analysis(RTCA) is performed to preliminary ascertain the contact pattern, the motion curve, as well as the position of the mean contact point. And then the tangent to the contact path and the motion curve are interpolated in the sense of the least square method to extract the initial values of the bias angle and the higher order coefficients(HOC) in modified roll motion. A trial tooth surface is generated by machine-tool settings derived from the local synthesis relating to the initial meshing performances and modified roll motion. An optimization objective is formed which equals the tooth surface deviation between the real tooth surface and the trial tooth surface. The design variables are the parameters describing the meshing performances at the mean contact point in addition to the HOC. When the objective is optimized within an arbitrarily given convergence tolerance, the machine-tool settings together with the HOC are obtained. The proposed approach is verified by a spiral bevel pinion used in the accessory gear box of an aviation engine. The trial tooth surfaces approach to the real tooth surface on the whole in the example. The results show that the convergent tooth surface deviation for the concave side on the average is less than 0.5 μm, and is less than 1.3 μm for the convex side. The biggest tooth surface deviation is 6.7 μm which is located at the corner of the grid on the convex side. Those nodes with relative bigger tooth surface deviations are all located at the boundary of the grid. An approach is proposed to figure out the machine-tool settings of a spiral bevel pinion by way of reverse engineering without having known the theoretical tooth surfaces and the corresponding machine-tool settings.

DELAUNAY-BASED SURFACE RECONSTRUCTION ALGORITHM IN REVERSE ENGINEERING

Triangulation of scattered points is the first important section duringreverse engineering. New concepts of dynamic circle and closed point are put forward based oncurrent basic method. These new concepts can narrow the extent which triangulation process shouldseek through and optimize the triangles during producing them. Updating the searching edgesdynamically controls progress of triangulation. Intersection judgment between new triangle andproduced triangles is changed into intersection judgment between new triangle and searching edges.Examples illustrate superiorities of this new algorithm.

METHOD TO EXTRACT BLEND SURFACE FEATURE IN REVERSE ENGINEERING

A new method of extraction of blend surface feature is presented. It contains two steps: segmentation and recovery of parametric representation of the blend. The segmentation separates the points in the blend region from the rest of the input point cloud with the processes of sampling point data, estimation of local surface curvature properties and comparison of maximum curvature values. The recovery of parametric representation generates a set of profile curves by marching throughout the blend and fitting cylinders. Compared with the existing approaches of blend surface feature extraction, the proposed method reduces the requirement of user interaction and is capable of extracting blend surface with either constant radius or variable radius. Application examples are presented to verify the proposed method.

Aspect-oriented software reverse engineering

To solve the identification and comprehension problem of crosscutting concerns in existing legacy software system, a framework of aspect-oriented software reveme engineering is proposed. An approach on re-modularizing traversal features of legacy system is presented based on various unified modeling language （UML） diagrams. While modeling crosscutting concerns in UML use case diagrams, the non-functional requirements that affect several use case modules can be enveloped into aspect modules with a stereotype mechanism. The recurring message transmission patterns can be re-modularized as aspects in UML sequence diagrams with UML collaborations. Standard UML activity diagram notations are extended and modified by node fusion and addition, which support the graphical composition operation between crosscutting behaviors and primary business roles of concurrent systems. Case study indicates that travernal features of software system can be extracted and re-modularized from various perspectives in aspect-oriented reverse engineering, which improves comprehensibility and maintainability of legacy systems.

Fringe Projection Measurement System in Reverse Engineering

Acquisition of physical data with high precision is a key step in reverse engineering (RE). It is an important stimulative for the progress of reverse engineering with which various digitizing devices are invent ed, developed and made applicable. This paper introduces a three dimensional opt ical measurement method based on digital fringe projection technique in RE to im prove the technique through its application. A practical example is presented an d the result demonstrates the applicability and feasibility of the measurement s ystem as well as the reliability and validity of relevant methods and algorithms .

Reverse Engineering Based Methodology for Redesigning Contour Milling Tools

Reverse Engineering (RE) involves the use of techniques aimed to retrieve information about manufactured products, not only regarding geometries, but also materials and functionality. Today, even if several RE techniques are known, many of them still leave the object unusable to analyze. Nevertheless, other alternatives to this problem allows for obtaining a Digital or Virtual Model (VM) via the three-dimen- sional scanning. Getting the VM of an item, via scanning or not, can offer many possibilities to digital analysis (FEM). Furthermore, starting from VM, it is possible to achieve the physical reproduction of an element, part or workpiece—in the same or different materials—using Additive Manufacturing (AM) technologies. This enables to improve the product through a redesign process. In this paper, a RE based methodology is proposed for redesigning a tool for contour milling, after comparing different microscopy based techniques, 3D-Scanner tools and CAD-CAGD utilities for generating a Virtual Model of the newly designed mill.

A Modified SOFM Method for Point Cloud Segmentation in Reverse Engineering

The purpose of reverse engineering is to convert a large point cloud into a CAD model. In reverse engineering, the key issue is segmentation, i.e. studying how to subdivide the point cloud into smaller regions, where each of them can be approximated by a single surface. Segmentation is relatively simple, if regions are bounded by sharp edges and small blends; problems arise when smoothly connected regions need to be separated. In this paper, a modified self-organizing feature map neural network （SOFM） is used to solve segmentation problem. Eight dimensional feature vectors （3-dimensional coordinates, 3-dimensional normal vectors, Gaussian curvature and mean curvature） are taken as input for SOFM. The weighted Euclidean distance measure is used to improve segmentation result. The method not only can deal with regions bounded by sharp edges, but also is very efficient to separating smoothly connected regions. The segmentation method using SOFM is robust to noise, and it operates directly on the point cloud. An examples is given to show the effect of SOFM algorithm.

Slicing Method for Reverse Engineering Based on Image Mosaic

Reverse engineering dealing with images is traditionally based on image processing and contour recognition. A new method is presented based on the combination of sectional slicing with image mosaic. Sectional contours of the target object are generated by colorful liquid or laser scanning, these images from different views are fused into a set of complete cross-sectional images, thereby the whole practical model is reconstructed in 3D space.

Integrated Product and Process Design Using a Reverse Engineering System

Computer-integrated manufacturing (CIM) and revers e engineering (RE) have changed drastically the concept of product re-design, pla nning and manufacture of components. However, the main problems currently facing the developers of reverse engineering system, is the time consuming digitis ation of 3D data and the conversion of large amounts of data into a concise and manageable format and linking it to a CAD/CAM system. Automated 3-D profile gen eration, measurements and inspection of manufactured component represents one of the important functions in reverse engineering and in the improvements in produ ct quality in rapid product developments. The paper presents a novel methodology for the development of a reverse enginee ring technique for use in the rapid product development in a CIM environment . The system developed provides integration, data capture and manipulation, dat a transfer between a CAD, CAM, Computer-aided inspection (CAI) and a 3-D profi le scanning system. An efficient scanning strategy has been developed for scann ing and surfaces data acquisition. The products were scanned using a laser scann ing system with a dedicated scan control card and the associated software packag es. A versatile rig was developed for the ease of data gathering of the profile scanning process. The surface data collected was then used to build a mathematic al surface model, which was then used to develop a virtual 3-D model of the pro duct. The resulting surface model provides the geometrical input to the subseque nt machining operation using either a CNC system or other manufacturing operatio n e.g. dies casting/mould casting etc. The prototypes developed were inspected u sing a state-of-the art CNC-CMM that was integrated to the CAD/CAM system. Si nce the scanning/digitised data captured by laser scanning probes requires no ma nual editing, significant time saving over most non-contact probe systems was a chieved. Since the creation of an accurate CAD model of a redesigned component o r a prototype constitute a major element of the total turnaround time; maximum r eturn can be achieved by increasing the efficiency of the redesigning process. T he paper also outlines with a case study the application of the developed system . The system developed offers the flexibility of using the concept of reverse en gineering of a variety of components with the complimentary facility of integrat ion between CAD/CAM Computer-aided Inspection (CAI) systems and a scanning syst em. The developed reverse engineering application in an integrated manufacturing system can increase the consistency, improve cost-efficiency, reduce produ ct turn around and skill levels required to redesign, reengineer and prototyping components and products.

ANALYSIS AND RESEARCH OF COMPUTER-AIDED MODEL OF HIP JOINT BASED ON REVERSE ENGINEERING

Former research work about the modeling of hip joint focus on the uppersegment of femoral, and assumes the acetabulum cup is sphere concave, and the acetabulum prosthesesis semisphere. A method of acquiring the point data on the surface of the hipbone using the reverseengineering technology is presented. After analyzing the acetabulum surface fitting error, arotation ellipsoid CAD model is applied to fit the acetabulum surface, and then optimizationtechnique is used to find the geometric parameters of the model. The fitting error between thesphere and rotation ellipsoid is compared and gets the result that the fitting error of rotationellipsoid is smaller than sphere, and the rotation ellipsoid can describe the shape of theacetabulum better.

Reverse Engineering of Mobile Banking Applications

Software reverse engineering is the process of analyzing a software system to extract the design and implementation details.Reverse engineering provides the source code of an application,the insight view of the architecture and the third-party dependencies.From a security perspective,it is mostly used for finding vulnerabilities and attacking or cracking an application.The process is carried out either by obtaining the code in plaintext or reading it through the binaries or mnemonics.Nowadays,reverse engineering is widely used for mobile applications and is considered a security risk.The Open Web Application Security Project(OWASP),a leading security research forum,has included reverse engineering in its top 10 list of mobile application vulnerabilities.Mobile applications are used in many sectors,e.g.,banking,education,health.In particular,the banking applications are critical in terms of security as they are used for financial transactions.A security breach of such applications can result in huge financial losses for the customers as well as the banks.There exist various tools for reverse engineering of mobile applications,however,they have deficiencies,e.g.,complex configurations,lack of detailed analysis reports.In this research work,we perform an analysis of the available tools for reverse engineering of mobile applications.Our dataset consists of the mobile banking applications of the banks providing services in Pakistan.Our results indicate that none of the existing tools can carry out the complete reverse engineering process as a standalone tool.In addition,we observe significant differences in terms of the execution time and the number of files generated by each tool for the same file.

An Application Study of Transition Surface Reconstruction in Reverse Engineering

the reconstruction of transition surface is one of time consuming activities during surface modeling in reverse engineering. Yet currently available software applications suffer from shortcoming in processing the connection among free form surfaces. In this paper, a new method is put forward combining Surfacer with Unigraphics to resolve this problem: Curves and surfaces are first constructed in Surfacer, then, the finished data is imported into Unigraphics based on IGES fonnat. At last, the transition surface can be reconstructed in Unigraphics. The application of this method in transition surface reconstruction is illustrated by means of two case studies, showing the connection between free form surfaces; filleting and rounding among multiple surfaces: transition surface between two sets of surfaces.

Multi-View Point Clouds Registration without Feature Extraction for Use in Reverse Engineering of CAD Models

For reverse engineering a CAD model, it is necessary to integrate measured points from several views of an object into a common reference frame. Given a rough initial alignment of point cloud in different views with point-normal method, further refinement is achieved by using an improved iterative closest point (ICP) algorithm. Compared with other methods used for mult-view registration, this approach is automatic because no geometric feature, such as line, plane or sphere needs to be extracted from the original point cloud manually. A good initial alignment can be acquired automatically and the registration accuracy and efficiency is proven better than the normal point-point ICP algorithm both experimentally and theoretically.

Automatic protocol reverse engineering for industrial control systems with dynamic taint analysis

Proprietary(or semi-proprietary)protocols are widely adopted in industrial control systems(ICSs).Inferring protocol format by reverse engineering is important for many network security applications,e.g.,program tests and intrusion detection.Conventional protocol reverse engineering methods have been proposed which are considered time-consuming,tedious,and error-prone.Recently,automatical protocol reverse engineering methods have been proposed which are,however,neither effective in handling binary-based ICS protocols based on network traffic analysis nor accurate in extracting protocol fields from protocol implementations.In this paper,we present a framework called the industrial control system protocol reverse engineering framework(ICSPRF)that aims to extract ICS protocol fields with high accuracy.ICSPRF is based on the key insight that an individual field in a message is typically handled in the same execution context,e.g.,basic block(BBL)group.As a result,by monitoring program execution,we can collect the tainted data information processed in every BBL group in the execution trace and cluster it to derive the protocol format.We evaluate our approach with six open-source ICS protocol implementations.The results show that ICSPRF can identify individual protocol fields with high accuracy(on average a 94.3%match ratio).ICSPRF also has a low coarse-grained and overly fine-grained match ratio.For the same metric,ICSPRF is more accurate than AutoFormat(88.5%for all evaluated protocols and 80.0%for binary-based protocols).

Personalized Cranium Defects Restoration Technique Based on Reverse Engineering

The purpose of this paper is to overcome the limitations of the traditional cranial defects restoration technique and better satisfy the aesthetic and comfort demands of different patients. An arithmetic profile curve blending technique was used based on a well-proportioned points cloud data obtained by analyzing computer tomography (CT) images of the patients. This technique uses reverse engineering technique to reconstruct a model of the defective cranium, taking all the characteristics of the protruding cranium into consideration to check the form and appropriateness of the restoration and to adjust the surface in real time to obtain the ideal shape. Then, the model is transferred to a multiple-point forming (MPF) pressure machine to produce a titanium alloy restoration model. The system has greater flexibility, shorter production cycles, and lower cost through the use of digital production technology, guarantees the quality of the cranial defects restoration model, reduces the surgical risks, and alleviates the patients’ pain. In addition, an improved contour curved bridge algorithm technique is used to repair any cranium defects on the contour curve to make the contour more complete and closed.

A New Algorithm for Feature Matching in Reverse Engineering

Feature recognition and surface reconstruction from point clouds are difficulties in reverse engineering. A new surface reconstruction algorithm for slicing point cloud was presented. The contours of slice were extracted. Then, the intersection of two adjacent curve segments in the contour was obtained and curves feature was extracted. Finally, adjacent section contours were matched directly with Fourier-Mellin curve matching method for feature extraction. An example of 3-D model reconstruction shows the reliability and application of the algorithm.

FORMING FREEFORM SURFACE SHEET METAL USING INTEGRATED REVERSE ENGINEERING TECHNOLOGY

This paper presented a model of integrated reverse engineering system and set up its various data output flowchart, which is easy to be associated with other systems. The idea of integrated reverse engineer is introduced to the system of forming sheet metal with complex surface and using IDEF0 method sets up the function model of the system. The freeform surface reconstruction and CAD modeling of the system are described and decomposed. This paper discussed some problems, such as the feature expression, feature modeling and feature translation of the sheet parts and dies.