Report on
REVERSE ENGINEERIN G Submitted to
Mr. SAMI MAJEED Submitted by
RAHEEL AKHTAR
FA07-MB-0145
KHAWAJA FAISAL
FA06-MB-0098
SAIM ZAFAR
FA07-MB-0158
WASEEM IDREES
FA07-MB-0203
ABDUL SAMAD BAIG
SP09-MB-0005
MUHAMMAD ATIF KHAN
SP09-MB-0078
RIZWAN RAUF
SP-09-MB-0124
ARIF RATANI
FA07-MB-0018
Introduction Reverse engineering (RE) is the process of discovering the technological principles of a device, object or system through analysis of its structure, function and operation. It often involves taking something (e.g., a mechanical device, electronic component, or software program) apart and analyzing its workings in detail to be used in maintenance, or to try to make a new device or program that does the same thing without copying anything from the original. Reverse engineering has its origins in the analysis of hardware for commercial or military advantage. The purpose is to deduce design decisions from end products with little or no additional knowledge about the procedures involved in the original production. The same techniques are currently being researched for application to legacy software systems, not for industrial or defense ends, but rather to replace incorrect, incomplete, or otherwise unavailable documentation.
Reasons for reverse engineering • •
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Interoperability. Lost documentation: Reverse engineering often is done because the documentation of a particular device has been lost (or was never written), and the person who built it is no longer available. Integrated circuits often seem to have been designed on obsolete, proprietary systems, which means that the only way to incorporate the functionality into new technology is to reverse-engineer the existing chip and then re-design it. Product analysis. To examine how a product works, what components it consists of, estimate costs, and identify potential patent infringement. Digital update/correction. To update the digital version (e.g. CAD model) of an object to match an "as-built" condition. Security auditing. Military or commercial espionage. Learning about an enemy's or competitor's latest research by stealing or capturing a prototype and dismantling it. Removal of copy protection, circumvention of access restrictions. Creation of unlicensed/unapproved duplicates. Academic/learning purposes. Curiosity Competitive technical intelligence (understand what your competitor is actually doing versus what they say they are doing) Learning: learn from others' mistakes. Do not make the same mistakes that others have already made and subsequently corrected
Product Development Life Cycle IDEA
Replaceme nt with New Product
Maintenanc e
Productio n
Designin g
Prototypin g
Manufacturin g
Testing
Reverse engineering for military applications Reverse engineering is often used by militaries in order to copy other nations' technologies, devices or information that have been obtained by regular troops in the fields or by intelligence operations. It was often used during the Second World War and the Cold War. Well-known examples from WWII and later include •
Jerry can : British and American forces noticed that the Germans had gasoline cans with an excellent design. They reverse-engineered copies of those cans. The cans were popularly known as "Jerry cans".
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Tupolev Tu-4 : Three American B-29 bombers on missions over Japan were forced to land in the USSR. The Soviets, who did not have a similar strategic bomber, decided to copy the B-29. Within a few years, they had developed the Tu-4, a near-perfect copy.
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V2 Rocket : Technical documents for the V2 and related technologies were captured by the Western Allies at the end of the war. Soviet and captured German engineers had to reproduce technical documents and plans, working from captured hardware, in order to make their clone of the rocket, the R-1, which began the postwar Soviet rocket program that led to the R-7 and the beginning of the space race.
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K-13/R-3S missile (NATO reporting name AA-2 'Atoll), a Soviet reverse-engineered copy of the AIM-9 Sidewinder, made possible after a Taiwanese AIM-9B hit a Chinese MiG-17 without exploding; amazingly, the missile became lodged within the airframe, the pilot returning to base with what Russian scientists would describe as a university course in missile development.
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BGM-71 TOW Missile : In May 1975, negotiations between Iran and Hughes Missile Systems on co-production of the TOW and Maverick missiles stalled over disagreements in the pricing structure, the subsequent 1979 revolution ending all plans for such coproduction. Iran was later successful in reverse-engineering the missile and are currently producing their own copy: the Toophan .
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China has reversed many examples of Occidental countries and Russian hardware, from fighter aircraft to missiles and HMMWV cars.
Reverse engineering of mechanical devices As computer-aided design (CAD) has become more popular, reverse engineering has become a viable method to create a 3D virtual model of an existing physical part for use in 3D CAD, CAM, CAE and other software[3]. The reverse-engineering process involves measuring an object
and then reconstructing it as a 3D model. The physical object can be measured using 3D scanning technologies like CMMs, laser scanners, structured light digitizers or computed tomography. The measured data alone, usually represented as a point cloud, lacks topological information and is therefore often processed and modeled into a more usable format such as a triangular-faced mesh, a set of NURBS surfaces or a CAD model. The point clouds produced by 3D scanners are usually not used directly since they are very large unwieldy data sets, although for simple visualization and measurement in the architecture and construction world, points may suffice. Most applications instead use polygonal 3D models, NURBS surface models, or editable feature-based CAD models (aka solid modeling). The process of converting a point cloud into a usable 3D model in any of the forms described above is called “ modeling ” . •
POLYGON MESH MODELS : In a polygonal representation of a shape, a curved surface is modeled as many small faceted flat surfaces (think of a sphere modeled as a disco ball). Polygon models -- also called Mesh models, are useful for visualization, for some CAM (i.e., machining), but are generally "heavy" ( i.e., very large data sets), and are relatively un-editable in this form. Reconstruction to polygonal model involves finding and connecting adjacent points with straight lines in order to create a continuous surface. Many applications are available for this purpose (eg. kubit PointCloud for AutoCAD, photomodeler, imagemodel, PolyWorks, Rapidform, Geomagic, Imageware, Rhino, etc.).
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SURFACE MODELS : The next level of sophistication in modeling involves using a quilt of curved surface patches to model our shape. These might be NURBS, TSplines or other representations of curved topology using higher ordered polynomials (i.e, curved, not straight). Using NURBS, our sphere is a true mathematical sphere. Some applications offer patch layout by hand but the best in class offer both automated patch layout and manual layout. These patches have the advantage of being lighter and more manipulable when exported to CAD. Surface models are somewhat editable, but only in a sculptural sense of pushing and pulling to deform the surface. This representation lends itself well to modeling organic and artistic shapes. Providers of surface modelers include NX, Imageware, Rapidform, Geomagic, Rhino, Maya, T Splines etc.
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SOLID CAD MODELS : From an engineering/manufacturing perspective, the ultimate representation of a digitized shape is the editable, parametric CAD model. After all, CAD is the common "language" of industry to describe, edit and maintain the shape of the enterprise's assets. In CAD, our sphere is described by parametric features which are easily edited by changing a value(e.g., centerpoint and radius).
These CAD models describe not simply the envelope or shape of the object, but CAD models also embody the "design intent" (i.e., critical features and their relationship to other features). An example of design intent not evident in the shape alone might be a brake drum's lug bolts, which must be concentric with the hole in the center of the drum. This knowledge would drive the sequence and method of creating the CAD model; a designer with an awareness of this relationship would not design the lug bolts referenced to the outside diameter, but instead, to
the center. A modeler creating a CAD model will want to include both Shape and design intent in the complete CAD model. Vendors offer different approaches to getting to the parametric CAD model. Some export the NURBS surfaces and leave it to the CAD designer to complete the model in CAD(e.g., Geomagic, Imageware, Rhino). Others use the scan data to create an editable and verifiable feature based model that is imported into CAD with full feature tree intact, yielding a complete, native CAD model, capturing both shape and design intent (e.g. Rapidform). Still other CAD applications are robust enough to manipulate limited points or polygon models within the CAD environment (e.g., Catia). Reverse engineering is also used by businesses to bring existing physical geometry into digital product development environments, to make a digital 3D record of their own products or to assess competitors' products. It is used to analyze, for instance, how a product works, what it does, and what components it consists of, estimate costs, and identify potential patent infringement, etc. Value engineering is a related activity also used by businesses. It involves deconstructing and analyzing products, but the objective is to find opportunities for cost cutting.
3D scanner A 3D scanner is a device that analyzes a real-world object or environment to collect data on its shape and possibly its appearance (i.e. color). The collected data can then be used to construct digital, three dimensional models useful for a wide variety of applications. These devices are used extensively by the entertainment industry in the production of movies and video games. Other common applications of this technology include industrial design, orthotics and prosthetics, reverse engineering and prototyping, quality control/inspection and documentation of cultural artifacts. Many different technologies can be used to build these 3D scanning devices; each technology comes with its own limitations, advantages and costs. It should be remembered that many limitations in the kind of objects that can be digitized are still present: for example optical technologies encounter many difficulties with shiny, mirroring or transparent objects. There are however methods for scanning shiny objects, such as covering them with a thin layer of white powder that will help more light photons to reflect back to the scanner. Laser scanners can send trillions of light photons toward an object and only receive a small percentage of those photons back via the optics that they use. The reflectivity of an object is based upon the object's color or terrestrial albedo. A white surface will reflect lots of light and a black surface will reflect only a small amount of light. Transparent objects such as glass will only refract the light and give false three dimensional information. The purpose of a 3D scanner is usually to create a point cloud of geometric samples on the surface of the subject. These points can then be used to extrapolate the shape of the subject (a
process called reconstruction). If color information is collected at each point, then the colors on the surface of the subject can also be determined. 3D scanners are very analogous to cameras. Like cameras, they have a cone-like field of view, and like cameras, they can only collect information about surfaces that are not obscured. While a camera collects color information about surfaces within its field of view, 3D scanners collect distance information about surfaces within its field of view. The “picture” produced by a 3D scanner describes the distance to a surface at each point in the picture. If a spherical coordinate system is defined in which the scanner is the origin and the vector out from the front of the scanner is φ=0 and θ=0, then each point in the picture is associated with a φ and θ. Together with distance, which corresponds to the r component, these spherical coordinates fully describe the three dimensional position of each point in the picture, in a local coordinate system relative to the scanner. For most situations, a single scan will not produce a complete model of the subject. Multiple scans, even hundreds, from many different directions are usually required to obtain information about all sides of the subject. These scans have to be brought in a common reference system, a process that is usually called alignment or registration, and then merged to create a complete model. This whole process, going from the single range map to the whole model, is usually known as the 3D scanning pipeline.
Technology The two types of 3D scanners are contact and non-contact. Non-contact 3D scanners can be further divided into two main categories, active scanners and passive scanners. There are a variety of technologies that fall under each of these categories.
Contact Contact 3D scanners probe the subject through physical touch. A CMM (coordinate measuring machine) is an example of a contact 3D scanner. It is used mostly in manufacturing and can be very precise. The disadvantage of CMMs though, is that it requires contact with the object being scanned. Thus, the act of scanning the object might modify or damage it. This fact is very significant when scanning delicate or valuable objects such as historical artifacts. The other disadvantage of CMMs is that they are relatively slow compared to the other scanning methods. Physically moving the arm that the probe is mounted on can be very slow and the fastest CMMs can only operate on a few hundred hertz. In contrast, an optical system like a laser scanner can operate from 10 to 500 kHz. Other examples are the hand driven touch probes used to digitize clay models in computer animation industry.
Non-Contact Active Active scanners emit some kind of radiation or light and detect its reflection in order to probe an object or environment. Possible types of emissions used include light, ultrasound or x-ray.
Non-contact passive Passive scanners do not emit any kind of radiation themselves, but instead rely on detecting reflected ambient radiation. Most scanners of this type detect visible light because it is a readily available ambient radiation. Other types of radiation, such as infrared could also be used. Passive methods can be very cheap, because in most cases they do not need particular hardware. Time-of-flight
This lidar scanner may be used to scan buildings, rock formations, etc., to produce a 3D model. The lidar can aim its laser beam in a wide range: its head rotates horizontally, a mirror flips vertically. The laser beam is used to measure the distance to the first object on its path . The time-of-flight 3D laser scanner is an active scanner that uses laser light to probe the subject. At the heart of this type of scanner is a time-of-flight laser rangefinder. The laser rangefinder finds the distance of a surface by timing the round-trip time of a pulse of light. A laser is used to emit a pulse of light and the amount of time before the reflected light is seen by a detector is timed. Since the speed of light c is a known, the round-trip time determines the travel distance of the light, which is twice the distance between the scanner and the surface. If t is the roundtrip time, then distance is equal to . The accuracy of a time-of-flight 3D laser scanner depends on how precisely we can measure the t time: 3.3 picoseconds (approx.) is the time taken for light to travel 1 millimetre. The laser rangefinder only detects the distance of one point in its direction of view. Thus, the scanner scans its entire field of view one point at a time by changing the range finder’s direction of view to scan different points. The view direction of the laser rangefinder can be changed by either rotating the range finder itself, or by using a system of rotating mirrors. The latter method is commonly used because mirrors are much lighter and can thus be rotated much faster and with greater accuracy. Typical time-of-flight 3D laser scanners can measure the distance of 10,000~100,000 points every second. In 2009,the Time-of-flight camera became commercially available. In this configuration, a sensor chip has multiple sensors on it like on a Charge-coupled_device. The light pulse can be generated with integrated LED's on the sensor chip itself, or by external LED's located near the sensor. Each sensor pixel on the chip makes an independent time-of-flight distance measurement. See this blog article: New 3D Measurement Tool.
Prototyping A prototype is an original type, form, or instance of something serving as a typical example, basis, or standard for other things of the same category.
Design and modeling In many fields, there is great uncertainty as to whether a new design will actually do what is desired. New designs often have unexpected problems. A prototype is often used as part of the product design process to allow engineers and designers the ability to explore design alternatives, test theories and confirm performance prior to starting production of a new product. Engineers use their experience to tailor the prototype according to the specific unknowns still present in the intended design. For example, some prototypes are used to confirm and verify consumer interest in a proposed design where as other prototypes will attempt to verify the performance or suitability of a specific design approach.
In general, an iterative series of prototypes will be designed, constructed and tested as the final design emerges and is prepared for production. With rare exceptions, multiple iterations of prototypes are used to progressively refine the design. A common strategy is to design, test, evaluate and then modify the design based on analysis of the prototype. In many products it is common to assign the prototype iterations Greek letters. For example, a first iteration prototype may be called an "Alpha" prototype. Often this iteration is not expected to perform as intended and some amount of failures or issues are anticipated. Subsequent prototyping iterations (Beta, Gamma, etc.) will be expected to resolve issues and perform closer to the final production intent. In many product development organizations, prototyping specialists are employed individuals with specialized skills and training in general fabrication techniques that can help bridge between theoretical designs and the fabrication of prototypes.
Basic Prototype Categories There is no general agreement on what constitutes a "prototype" and the word is often used interchangeably with the word "model" which can cause confusion. In general, “prototypes” fall into four basic categories: Proof-of-Principle Prototype (Model) (also called a breadboard). This type of prototype is used to test some aspect of the intended design without attempting to exactly simulate the visual appearance, choice of materials or intended manufacturing process. Such prototypes can be used to “prove” out a potential design approach such as range of motion, mechanics, sensors, architecture, etc. These types of models are often used to identify which design options will not work, or where further development and testing is necessary. Form Study Prototype (Model). This type of prototype will allow designers to explore the basic size, look and feel of a product without simulating the actual function or exact visual appearance of the product. They can help assess ergonomic factors and provide insight into visual aspects of the product's final form. Form Study Prototypes are often hand-carved or machined models from easily sculpted, inexpensive materials (e.g., urethane foam), without representing the intended color, finish, or texture. Due to the materials used, these models are intended for internal decision making and are generally not durable enough or suitable for use by representative users or consumers. Visual Prototype (Model) will capture the intended design aesthetic and simulate the appearance, color and surface textures of the intended product but will not actually embody the function(s) of the final product. These models will be suitable for use in market research, executive reviews and approval, packaging mock-ups, and photo shoots for sales literature. Functional Prototype (Model) (also called a working prototype) will, to the greatest extent practical, attempt to simulate the final design, aesthetics, materials and functionality of the intended design. The functional prototype may be reduced in size (scaled down) in order to reduce costs. The construction of a fully working full-scale prototype and the ultimate test of
concept, is the engineers' final check for design flaws and allows last-minute improvements to be made before larger production runs are ordered.
Differences between a prototype and a production design In general, prototypes will differ from the final production variant in three fundamental ways: Prototypes are often constructed via non-production intent materials. Production materials may require manufacturing processes involving higher capital costs than what is practical for prototyping. Instead, engineers of prototyping specialists will attempt to substitute materials with properties that simulate the intended final material. Prototypes are generally constructed via non-production intent manufacturing processes. Often expensive and time consuming unique tooling is required to fabricate a custom design. Prototypes will often compromise by using more flexible processes. Prototypes are generally constructed from a design that has been developed to a lower level of fidelity than production intent. Final production designs often require extensive effort to capture high volume manufacturing detail. Such detail is generally unwarranted for prototypes as some refinement to the design is to be expected. Often prototypes are built using very limited engineering detail as compared to final production intent.
Mechanical and electrical engineering
A prototype of the Polish economy hatchback car Beskid 106 designed in the 1980s Main article: rapid prototyping
The most common use of the word prototype is a functional, although experimental, version of a non-military machine (e.g., automobiles, domestic appliances, consumer electronics) whose designers would like to have built by mass production means, as opposed to a mockup, which is an inert representation of a machine's appearance, often made of some non-durable substance. An electronics designer often builds the first prototype from breadboard or stripboard or perfboard, typically using "DIP" packages. However, more and more often the first functional prototype is built on a "prototype PCB" almost identical to the production PCB, as PCB manufacturing prices fall and as many components are not available in DIP packages, but only available in SMT packages optimized for placing on a PCB. Builders of military machines and aviation prefer the terms "experimental" and "service test".
Manufacturing CNC MILLING Numerical control (NC) refers to the automation of machine tools that are operated by abstractly programmed commands encoded on a storage medium, as opposed to manually controlled via handwheels or levers or mechanically automated via cams alone. The first NC machines were built in the 1940s and 50s, based on existing tools that were modified with motors that moved the controls to follow points fed into the system on paper tape. These early servomechanisms were rapidly augmented with analog and digital computers, creating the modern computer numerical controlled (CNC) machine tools that have revolutionized the design process. In modern CNC systems, end-to-end component design is highly automated using CAD/CAM programs. The programs produce a computer file that is interpreted to extract the commands needed to operate a particular machine, and then loaded into the CNC machines for production. Since any particular component might require the use of a number of different tools - drills, saws, etc. - modern machines often combine multiple tools into a single "cell". In other cases, a number of different machines are used with an external controller and human or robotic operators that move the component from machine to machine. In either case the complex series of steps needed to produce any part is highly automated and produces a part that closely matches the original CAD design.
CNC lathe / CNC turning center CNC lathes are rapidly replacing the older production lathes (multispindle, etc) due to their ease of setting and operation. They are designed to use modern carbide tooling and fully utilize modern processes. The part may be designed and the toolpaths programmed by the CAD/CAM process, and the resulting file uploaded to the machine, and once set and trialled the machine will continue to turn out parts under the occasional supervision of an operator. The machine is controlled electronically via a computer menu style interface, the program may be modified and displayed at the machine, along with a simulated view of the process. The setter/operator needs a high level of skill to perform the process, however the knowledge base is broader compared to the older production machines where intimate knowledge of each machine was considered essential. These machines are often set and operated by the same person, where the operator will supervise a small number of machines (cell). The design of a CNC lathe has evolved yet again however the basic principles and parts are still recognizable, the turret holds the tools and indexes them as needed. The machines are often totally enclosed, due in large part to Occupational health and safety (OH&S) issues. With the advent of cheap computers, free operating systems such as Linux, and open source CNC software, the entry price of CNC machines has plummeted. For example, Sherline makes a desktop CNC lathe that is affordable by hobbyists.