3D Scanning



Reverse Engineering in GeneralReverse engineering?is the?process?of discovering the technological principles of a human made 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 using or simply duplicating (without understanding) the original. In other word, reverse engineering is taking apart an object to see how it works in order to duplicate or enhance the object. The practice, taken from older industries, is now frequently used on computer hardware and software. Software reverse engineering involves reversing a program's?machine code?(the string of 0s and 1s that are sent to the logic processor) back into the?source code?that it was written in, using program language statements.Software reverse engineering is done to retrieve the source code of a program because the source code was lost, to study how the program performs certain operations, to improve the performance of a program, to fix a?bug?(correct an error in the program when the source code is not available), to identify malicious content in a program such as a?virus?or to adapt a program written for use with one microprocessor for use with another. Reverse engineering for the purpose of copying or duplicating programs may constitute a copyright violation. In some cases, the licensed use of software specifically prohibits reverse engineering.Another type of reverse engineering involves producing?3-D?images of manufactured parts when a blueprint is not available in order to remanufacture the part. To reverse engineer a part, the part is measured by a coordinate measuring machine (CMM). As it is measured, a 3-D wire frame image is generated and displayed on a monitor. After the measuring is complete, the wire frame image is dimensioned. Any part can be reverse engineered using these methods.1.0Introduction to 3 Dimensional ScannerScanning means selecting the correct scanning technique, preparing the part to be scanned and performing the actual scanning to capture information that describes all geometric features of the part such as steps, slots, pockets and holes. 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. colour). Three dimensional scanners are employed to scan the part geometry, producing clouds of points, which define the surface geometry. These scanning devices are available as dedicated tools or as add-ons to the existing computer numerically controlled (CNC) machine tools. The collected data can then be used to construct digital,?three dimensional models?useful for a wide variety of applications.?Other common applications of this technology include?industrial design, orthotics and prosthetics,?reverse engineering?and prototyping,?quality control/inspection and documentation of cultural artefacts.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 colour 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 colour information is collected at each point, then the colours 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 colour 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. There are two distinct types of scanners that is contact or non-contact. For this laboratory session, type of scanner that we use is non-contact scanners. A variety of non-contact scanning technologies available on the market capture data with no physical part contact. Non-contact devices use lasers, optics and charge coupled devices (CCD) sensors to capture point data as shown in figure below. 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.Figure 1-Sensors to capture point dataAlthough these devices capture large amounts of data in relative short space of time, there are a number of issues related to this scanning technology. The topical tolerance of non-contact scanning within + 0.025 to 0.2mm.Some of non-contact systems have problems generating data describing surfaces, which are parallel to the axis of the laser.Non-contact devices employ light within the data capture process. This will creates the problems when the light impinges on shiny surfaces, hence some surfaces must be prepared with a temporary coating of fine powder before scanning. 2.0ObjectivesThe objective for doing this laboratory session are as stated below :To expose students on how to use 3-Dimensional scanner.To train students on how to work with one of the reverse engineering software. To identify the relationship of the laboratory session with the reverse engineering. 3.0Product DescriptionProduct use in this 3-Dimensional scanning process is chess as stated below. Figure 2- ChessChess?is a two-player?board game?played on a?chessboard, a square-checkered board with 64?squares arranged in an eight-by-eight grid. Each player begins the game with sixteen?pieces, that is one?king, one?queen, two?rooks, two?knights, two?bishops, and eight?pawns. The object of the game is to?checkmate?the opponent's king, whereby the king is under immediate attack (in "check") and there is no way to remove or defend it from attack on the next move. The game's present form emerged in Europe during the second half of the 15th century, an evolution of an older Indian game,?Shatranj. Theoreticians have developed extensive?chess strategies?and?tactics?since the game's inception. Computers have been used for many years to create?chess-playing programs, and their abilities and insights have contributed significantly to modern chess theory. One,?Deep Blue, was the first machine to overcome a reigning World Chess Champion in playing ability when it?defeated?Garry Kasparov?in 1997.The history of chess, chess was played many centuries ago in China, India, and Persia. No one really knows for sure in which country it originated. Then, in the eighth century, armies of Arabs known as Moors invaded Persia. The Moors learned chess from the Persians. When the Moors later invaded Spain, the soldiers brought the game of chess with them. Soon the Spanish were playing chess, too. From Spain, chess quickly spread throughout all of Europe.Europeans gave chess pieces the names we know today, they probably had trouble pronouncing and spelling the Persian names, so they modernized them to reflect the way they lived. Today, the names certainly aren't modern but a thousand years ago they represented the very way in which both ordinary people and persons of rank lived their lives.The pawns on the chess board represent serfs, or laborers. There are more of them than any other piece on the board, and often they are sacrificed to save the more valuable pieces. In medieval times, serfs were considered no more than property of landowners, or chattel. Life was brutally hard for serfs during this era of history. They worked hard and died young. They were often left unprotected while wars raged around them. They could be traded, used as a diversion, or even sacrificed to allow the landowners to escape harm.The castle piece on a chess board is the home, or the refuge, just as it was a home in medieval times. In chess, each side has two castles, or rooks, as they are sometimes called.The knight on a chess board represents the professional soldier of medieval times whose job it was to protect persons of rank, and there are two of them per each side in a game of chess. Knights in a game of chess are more important than pawns, but less important than bishops, kings, or queens. Their purpose in the game of chess is to protect the more important pieces, and they can be sacrificed to save those pieces just as pawns can.There is a bishop in the game of chess, who represents the church. The church was a rich and mighty force in medieval times, and religion played a large part in every person's life. It is no wonder that a figure that represented the concept of religion found its way into the game. A bishop was the name for a priest in the Catholic church who had risen through the ranks to a more powerful position. In the game of chess, there are two bishops for each side.The queen is the only piece on the board during a chess game that represents a woman, and she is the most powerful piece of the game. In the game of chess, there is only one queen for each side. Many people do not realize that queens in medieval times often held a powerful, yet precarious, position. The king was often guided by her advice, and in many cases the queen played games of intrigue at court. But kings could set wives aside or even imprison them in nunneries with the approval of the church (and without the queen's approval), and many women schemed merely to hold her place at court. The machinations of queens working either for or against their kings are well noted in history throughout medieval times, and often she held more power than the king did.The king is the tallest piece on the board, and is as well defended on the chessboard as in medieval life. In medieval times, the surrender of the king would mean the loss of the kingdom to invading armies and that could mean change for the worse. It was to everyone's advantage, from the lowest serf to the highest-ranking official, to keep the king safe from harm. The king is the most important, but not the most powerful piece in chess. If we do not protect our king, we lose the game.The purpose for this chess was chosen for the product is because there are many shape and geometries. Each group will take a different shape to scan. 4.0PROCEDURE TO USE 3-D SCANNING (SCAN CHESS SET “HORSE”)Clean the product by using rags to remove from the dust.Observe the product and make sure that the colour of the product is not transparent colour or from black because 3-D scanning cannot scan if the product are made from that colour. If the colour are black or transparent, we need to change the colour of the product by using spray colour.Place a small special sticker on to the product. Put at the difficult shape of the product. More sticker are put to the product, the result will get more accurate to the original part. But if we use too much more, it will become waste because the sticker are too expensive.Put the product on the deck. Place it at the centre of the deck.Switch on the laptop and 3-D scanner.Click the icon “ATOS” at the desktop.When the software appear at the screen, click:-FILENEW PRODUCTFILECHOOSE THE LOCATIONNEXTNEXTNEXTFINISHClick the sensor and then initialize the sensor.To start the measurement, click icon “start/stop measurement”.Press space bar to snap the picture.Click displaying measurement and then start measurement.Then, click the icon Project Mode, right click and then select the picture.Follow the steps below:PROJECTCOMPLETE POLOGANIZATIONOKMESHCLOSE HOLECLOSE HOLE INTERACTIVELYCONTROL + LEFT CLICK IN THE SMALL HOLESAPPLYFILEEXPORTSTLOKClick saveRestart the computerFollow the steps below:HOMEUSERGEOMAGIX SOFTWAREPOLYGONREPAIR INTERSECTIONYESPOLYGONFILL HOLECLICK SMALL HOLE16mm-CIRCUMFERENCESOKTo edit, click phase and surface phaseHOMESHAPE PHASECLICK ICON AUTOSURFACEAPPLYOKThe last step are:FILESAVE AS TYPE ”IGES”. 3352800318770457200318770The object after completely scanning process.Figure 1508004521205.0 RESULTFigure 253340391795Figure SEQ Figure \* ARABIC 353340293370Figure SEQ Figure \* ARABIC 4Figure SEQ Figure \* ARABIC 5Figure SEQ Figure \* ARABIC 66.0DISCUSSIONBased on this experiment, we could see that the 3D scanner technology can be applied at any point in a typical manufacturing cycle, saving time, money and material. 3D scanning gives in higher quality, better fitting parts that are less costly to manufacture. However, there are some error or problems that might occur while running this 3D scanning, which is it could not scan the image of material that are shadowed. Instead of that, 3D scanning also could not be able to scan efficiently the object that is in shining colour or black colour. If this happens, the object needs to be sprayed or change the colour into other appropriate colour that might assist the 3D scanner to scan the object perfectly.After accomplishing the scanning procedure, we have to analyze the surface on the result at the computer by using the software. From there, we could see that there is some of the surface that is not covered fully while scanning. In that case, we have to edit the image on the software, in order to gives complete scanned product and could be able to produce it exactly the same as the actual product. 7.0CONCLUSION At the end of this project, we get many information of 3D scanning. Simply put, 3D scanning is a fast and accurate method of putting physical measurements of an object onto the computer in an organized manner, resulting in what is commonly called 3D scan data. Typically, the 3D scan data is represented with a scale digital model or a 3D graphical rendering. Once the scan data is on the computer, all of the dimensions of the physical object can be taken, such as length, width, height, volume, feature size, feature location, surface area, etc. 3D scan data is often used as a bridge between physical objects and modern manufacturing. This is achieved by converting the data into computer-aided design (CAD) models, using it to compare against the "as-designed" ideal of the part, or using it in the seemingly infinite number of computer-aided engineering (CAE) tools available. By using 3D scan data, a physical object can be translated directly to the engineering phase of a project and moved on from there. 3D scan data is often used to perform CFD, CAE, FEA and other engineering analysis on objects that have been manufactured and then physically modified. 3D Scanning Advantages:Quickly capture all of the physical measurements of any physical objectSave time in design workEnsure parts will fit together on the first tryCapture engineering optimizations inherent in manufactured partsUtilize modern manufacturing on parts that were originally manufactured before CADCompare "as-designed" model to "as-built" condition of manufactured partIncrease effectiveness working with complex parts and shapes.Help with design of products to accommodate someone else’s part.If CAD models are outdated, a 3D scan will provide an updated versionReplacement of missing or older parts3D scanning gives some advantage to the anyone in manufacturing, engineering, design, development, surveying or testing. 3D scanning technology can be applied at any point in a typical manufacturing cycle, saving time, money and material. 3D scanning results in higher quality and better fitting parts that are less costly to manufacture. The cost of a typical manufacturing design cycle is reduced by 75% by utilizing 3D scanning. The illustration below outlines a typical manufacturing product cycle. Use physical objects to conceptualize the idea; this is typically done by an industrial designer in clay lead design or foam lead design. 3D scanning can also be applied at the idea concept phase by digitizing objects, then using them as renderings in concept illustrations. 3D scanning can be applied at the design phase by starting with a physical object and using it to design a CAD model. Oftentimes, designers need to design around or fit their design to existing objects. These mating parts can also be scanned and incorporated into the design, resulting in parts that fit better on a consistent basis. The process of using an existing manufactured part to create a CAD model is often referred to as reverse engineering or reverses modelling. By utilizing reverse engineering, new designs can incorporate and improve upon engineering optimization By using 3D scan data, a physical object can be translated directly to the engineering phase of a project and moved on from there. 3D scan data is often used to perform CFD, CAE, FEA and other engineering analysis on objects that have been manufactured and then physically modified. 8.0RECOMMENDATION Make some clear procedure to use this 3D scanning, so when student want to use or make some research it can be done smoothly.UTHM must make improvement to the machine, such as the quantity of machine must be added. So student are able to use it and no need to take long time to wait their turn to finish the project. Other reason why should the 3D scanning should be add because to give a chance to the student handling the scanning in detail and give some experience to student how to handle it.. Other improving such as the movement of the product. The movement should be automatic control so it can be safe a lot of time.Other things that should improve is number of computer that can be use for scanning process should be added. This is because it may help all student can learn and make some editing itself. So it will sure that student achieve that the module objective.REFERENCES analysis and recognition, Second International Conference on Image Analysis and Recognition, ICIAR 2005, held in Toronto, Canada, in September 2005. ................
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