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Direct digital prototyping and manufacturing
Published in Fuewen Frank Liou, Rapid Prototyping and Engineering Applications, 2019
The reverse engineering machines require very high precision, and thus, there are some standard procedures to ensure that the machine is well qualified before it is used. For example, the CMM is an accurate measuring device used to verify dimensions to ensure part quality. A CMM can be used to measure features in 2D and 3D, although 2D features cannot be measured directly. For example, a line is a 2D feature and can be defined by the intersection of a plane to the reference plane. While a plane is a 3D feature, a line can be indirectly defined by defining two planes using a CMM. Most CAD models are made up of simple geometric elements such as planes, edges, cylinders, spheres, and cones, created by machining or forming. Distance, symmetry, intersection, angle, and projection cannot be directly measured, but must be constructed mathematically from measured features. A projection is the reproduction of a part feature on another feature, for example, projecting a circle or a line on a plane or a point onto a line. An intersection is where two existing geometric elements meet and cross each other. For example, the points are created by the intersection of two lines, or of a line and a plane; and the lines are created by the intersection of two planes.
Advanced Measurement Techniques in Surface Metrology
Published in Salah H. R. Ali, Automotive Engine Metrology, 2017
Advances in software during the 1980s allowed CMMs to have error corrections and provided geometric computations [8,9]. Now, the CMM technique is one challenge for advanced coordinate metrology in modern engineering applications. The basic function of CMM is to measure the actual geometrical shape of object compared to desired shape and evaluating the collected data using metrological aspects of size, form, location, and orientation [10]. The actual shape is obtained by probing the surface of the object at definite measuring points. Figure 2.1 illustrates four common different types of developed CMMs. Additionally, the advantage of developed CMM techniques is to convert the data of the measured object into 3D image suitable for other CAD/CAM systems.
Three-Dimensional Vision
Published in Richard L. Shell, Ernest L. Hall, Handbook of Industrial Automation, 2000
Scales and calipers are traditional contact measurement devices that require a human operator. When the operator is a computer, the measuring device would be a co-ordinate measuring machine (CMM). A CMM is a rectangular robot that uses a probe to acquire three-dimensional positional data. The probe senses contact with a surface using a force transducer. The CMM records the three-dimensional position of the sensor as it touches the surface point.
A region segmentation method to measure multiple features using a tactile scanning probe
Published in International Journal of Computer Integrated Manufacturing, 2019
Feng Li, Joseph Hiley, Tauseef Mohammed Syed, Carl Hitchens, Miguel Garcia Lopez-Astilleros
A CMM is a measuring system with the means to move a probing system and capability of determining the spatial coordinates of points on the surface of a workpiece. In a CMM system, the probe sensor is one of the most important elements and is crucial for the overall accuracy of a measurement result (Weckenmann et al. 2004). The most common probes for dimensional measurements are tactile and optical probing sensors, depending on whether the probes contact the surfaces of a workpiece. In addition, multi-sensor approaches have also been developed for coordinate metrology and the digitization of the surfaces of workpieces (Weckenmann et al. 2009; Lu and Wang 2015). The major focus of this paper is on exploring the application of tactile probing systems for coordinate measurements. The working principle of tactile probes is based on a mechanical interaction with the workpiece and they usually measure in more than one direction.
Morphological Box Classification Framework for supporting 3D scanner selection
Published in Virtual and Physical Prototyping, 2018
W. L. K. Nguyen, A. Aprilia, A. Khairyanto, W. C. Pang, G. G. L. Seet, S. B. Tor
To ensure that the experiment is reliable, an as-built model is required for the rack being scanned. The original CAD model provided by KHK cannot be used, as it only includes three effective teeth, whereas there are in total of five teeth physically presented on the rack. In addition, the CAD model may not accurately represent the as-built part. Hence, for this experiment, a coordinate measuring machine (CMM) machine is used to produce the as-built model. CMM machine is commonly used as an industrial standard for inspection due to its high accuracy. The CMM used in this paper is a three-axis CMM, the Mitutoyo Beyond-Crysta C544 with PH10M Indexing Head and TP200 Probe, and is used together with the accompanying software MCOSMOS v2.4 with SCANPAK.
Adaptive restoration strategy based on non-rigid matching for repairing damaged complex parts
Published in Journal of Industrial and Production Engineering, 2020
At present, based on whether the measuring equipment comes into contact with the object that needs measuring or not, the measurement method can be classified into two types, namely, touch-measuring method and non-touch measuring method. CMM is a typical touch-measuring equipment which can obtain 3D data by using a probe to touch the surface of the measured object. According to the principle of measurement, non-touch measurement can be classified into optical and non-optical types. The former includes the optical triangle method, laser method, and stereo vision measurement method. Industrial computed tomography (CT) scanning, ultrasonic, and nuclear magnetic resonance (NMR) method, etc., belong to the non-optical method.