Development of 3D Image Measurement System for Large Area (original) (raw)
Image Processing in 3D Profilomerty Measurement Based on MATLAB
Proceedings of The 6th IIAE International Conference on Intelligent Systems and Image Processing 2018, 2018
Phase-shifting profilometry (PSP) combined with gray-code patterns projected onto the object surface have been widely used to 3D shape measurement. Because of the change of the 3D surface, the distortion stripes appear when the sinusoidal grating or gray-code pattern is projected onto the object surface, which includes information about the 3D surface profilometry. The deformed grating pattern is taken into a computer by CCD camera and processed by a series of procedure: image pre-process (cropping and filtering), fractal image coding, thresholding and morphology process. Then according to the corresponding mathematics model and arithmetic of digital image process analyze to obtain the unwrapped phase of the superficial of the measured object.
3D Measurement - Comparison of CMM and 3D Scanner
DAAAM Proceedings, 2020
Continuous improvement and optimization of products, which is the most often reflected in more complex geometrical and dimensional characteristics of products and increasing market demands for quality, lead to the development of new solutions in quality control. In industry today, the control of geometric characteristics is most often performed by the tactile method of probe stylus, i.e. using 3D coordinate measuring machines (CMM). Coordinate measuring machines have long been the only option in quality control of various products and have become generally accepted in industrial quality. In recent years, the development of digital technologies, i.e. the development of a new generation of hardware and software, has enabled the development of other methods of 3D measurement such as 3D scanner, which has proven to be a good alternative to CMM machines. The aim of this review is to provide insight into the areas of application of both devices as well as their advantages and disadvantages and possible future solutions and application of devices in this area.
Precision measurement technology and application based on machine vision
Presently, the precision measurement technology based on machine vision has applied to all kinds of fields such as electron, motorcar, weave, glass and metalworking. It can also work effectively in many occasions that many old methods are difficult to check and measure. The levels of production automation and intelligent detection system have been improved greatly. In this paper, the basic principle and application of the machine vision system is introduced firstly, and then the application of small modulus gear precision measurement technology based on machine vision is taken as an example to show the feasibility of this method in precision measurement. The results revealed the advantages of machine vision method that the measurement efficiency is improved and the artificial error is reduced.
A novel three-dimensional shape measurement method based on a look-up table
Optik - International Journal for Light and Electron Optics, 2014
Three-dimensional profile measurement Fringe projection profilometry Look-up table a b s t r a c t Fringe projection profilometry is widely used for three-dimensional shape measurement. In an obliqueangle projection, the fringe cycle is broadened on the reference plane. Phase errors are mainly caused by the nonlinear gamma of the projector and fringe cycle broadening. This study describes a phase error compensation method to eliminate these phase errors. A look-up table that stores phase errors is constructed for phase error compensation. Based on it, a new height equation is proposed. The experimental results show that the proposed method can compensate for the phase errors of the fringe projection profilometry, thereby improving the measurement accuracy significantly.
The International Journal of Advanced Manufacturing Technology, 2019
Optical coordinate measuring is a highly functional tool for application in metrology laboratories, in areas of quality control and reverse engineering due to its versatility in terms of non-contact measurements. However, with the increasing requirements for high accuracy results in these areas, it is necessary to guarantee the traceability of this type of equipment using standards with compatible uncertainty. In order to provide traceability to these measurement systems, this research shows a method for calibration of dimensional length standard in image metrology. In this way, two lasers are used to measure the displacement of xand y-axes simultaneously and the measurement values are applied in a mathematical model together with pixel positions from the images of a standard. The methodology shows advantages using high magnifications to visualize the standards, showing in each image just a small part of the area. The method provides uncertainties around 0.10 μm, showing that this method is capable of providing traceability for this kind of standard.
Construction of 3D Shape Measurement Equipment Using Gray Codes Pattern
Encoded structured light is among reliable techniques for 3D imaging and shape measurements in academic and industry. The paper presents some of results on construction of a propotyping of 3D shape measurement using binary codes by an LCD EPSon X12 projector and a full HD Logitec camera to measure and recover 3D profile of part. The depth is estimated by triangulation method. The experiment have, built calip camera method to determine conventional pixel size of camera in hardware experiment system and affect of illuminance of reference strip on the reference plane to gray lever in 3D map building.
2018
3D optical scanning systems have been gaining considerable space in metrology, being largely applied in industry sectors and in the cultural heritage domain. The amount of available sensors on the market has grown considerably. Thereby, deciding for the right technique that fits-to-a-purpose or the most cost efficient technology, is a challenging task. When deciding in which technology to invest, the user often relies on the manufacturer's instructions. However, manufacturers generally do not state under which conditions such values were acquired and thus, the system's reproducibility is not assured. If measurements could be traced back to a common standard, this problem could be easily addressed. As such a solution is still not available, specialist often tend to solve this issue by associating terms like precision, accuracy and uncertainty to a measurement. Nowadays, the most applicable solution to define the accuracy of a system relies on the VDI/VDE 2634. This master thesis aims to develop a common solution to assess accuracy for different geometric 3D data acquisition models, considering the specifications of the VDI/VDE 2634 Part 3. The methodology proposed here encompasses the entire process from the acquisition to its processing stage. The study-case comprehend triangulated methods, as photogrammetry and laser line sensor. During the acquisition, a calibrated probing body and adapted test are proposed. The processing stage includes a best-fit algorithm and an evaluation of measurement uncertainty. The result comprehends the quality parameters together with the visualization of measurement uncertainty supporting the entire system. Therefore, providing to the end user enough information about the capability of the evaluated system.
Rapid 3D measurement using digital video cameras
2008
I, the undersigned, hereby declare that the work contained in this thesis is my own original work and that I have not previously in its entirety or in part submitted it at any university for a degree.
Technology Development to Measure Vertical Height and High Aspect Ratio Using Chromatic Confocal
International Journal of Engineering and Technology
Electronic parts are becoming small and thin parts are very precise and refined accordingly, requiring measurement of part shapes. In particular, parts structures that have high aspect ratio and dozens of millimeters high vertical resolution need to be measured in the 3D measurement area. To measure 3D shape of high vertical resolution, the study suggested measuring technology with synchronization of stage and chromatic confocal. It also suggested the chromatic confocal with high NA value to measure high aspect ratio structures with high slope and technology to measure the sample by inclining and fixing this. The suggestion would make real time 3D shape measurement possible of the sample with high vertical resolution and high aspect ratio without surface treatment. Convergence of measurement probe would also enable shape measurement of nano-size structure surface in various fields. Keyword-Aspect ratio, Chromatic confocal, Multi probe, Stage, High vertical resolution, 3D shape I. INTRODUCTION Measurement is needed to verify parts in industrial area. Electronic goods are becoming small and their parts are very precise and refined accordingly. As the parts also rapidly become highly precise and large in the display industry, they call for shape measurement. Optical measurement, or two-dimensional geometric measurement, uses a microscope and CCD camera. However, 3D shape measurement technology is emerging to measure the micro shape in the semiconductor and display industry. Since the micro shape has very large aspect ratio, thus requiring high spatial resolution to observe 3D shape, scanning electron microscope or scanning probe microscope is used. This method measures a very small area after surface treatment of the sample and has its limit to measure without changing the form of the sample. Therefore, industries use confocal and white light microscope that can measure it without sample deformation. Besides, the optical measurement technology we have now has its limit to observe the shape height of the high aspect ratio. With increasing sales of IT goods in particular, there is also increasing need to measure structures having high aspect ratio and parts requiring scope of about 20mm vertical resolution. Composite measurement of the increasingly precise and large mold to manufacture the parts is also on the rise (1). Combining with sensors submicron non-contact probes, a multipurpose device that can measure highly precise shapes and structures with high aspect ratio in the 3D measurement area, the study developed high-speed/high-precision multi probe measurement system that has precise shape measurement function in the same location for 3D large area measuring scope. However, measuring shape of high aspect ratio has its limit (2). The study discussed the technology that is able to measure longitudinal and high aspect ratio of structures to overcome such limit.
Stitching of 3- D Image Position Measurement System with ID Direction-sensitive Devices
2001
We previously proposed prnctical calibrntion of 3-D bright spot position measurement system using 3 I-D direction-sensitive devices. The proposed calibrntion en- ables easy setup of I-D direction-sensitive devices to con- stmct 3-D position sensing system; then the applicable fields and cireUIDStances are extended extremely. The method is based on mathematical techniques which the situation of each I-D mam direction sensitive device is deteln1ined automatically by referencing coonlinates with 7 referential points. Here, we are proposing the stitching of measurement space of high-precision 3-D position sensing with I-D mam direction-sensitive devices to ex- pand measured space furthec Our proposed method is essentially iterntive application of calibrntion: reference coonlinates are trnnslated and rotated to include both ad- jacent measurement spaces step by step, calibrntion is executed, and the position and situation of each I-D di- rection-sensitive device are found systematically....
A NEW APPROACH FOR 3D MEASUREING USING SINGLE IMAGE WITH A MIRROR IN CLOSE RANGE PHOTOGRAMMETRY
The close-range photogrammetry has a wide use in measuring the three dimensions of the objects. This needs to have at least two photos for the object and for certain cases multiimages of the object may be needed. Single image has been used for measuring some dimensions of the objects, but the measurements must be in a plan (two dimensions) by making a rectification for the single image by using some of the ground control points. To make some three dimensions measurements from a single image, an additional condition must be found. This paper presents a new approach for three dimensions measuring system by using a mirror that lies in a position to reflect the object and appear with it in the single image. The mathematical model of this approach has been developed and tested theoretically and practically and it gave promising results. This paper will concentrate on the special case that the camera axis is horizontal and the mirror plan is vertical.
Optics and Lasers in Engineering, 2016
In order to determine Dynamic 3-D shape with vertical measurement mode, a fast modulation measuring profilometry (MMP) with a cross grating projection and single shot is proposed. Unlike the previous methods, in our current projection system, one cross grating is projected by a special projection lens consisting of a common projection lens and a cylindrical lens. Due to the characteristics of cylindrical lens, the image of the vertical component and the horizontal component of the cross grating is separated in the image space, and the measuring range is just the space between the two image planes. Through a beam splitter, the CCD camera can coaxially capture the fringe pattern of the cross grating modulated by the testing object's shape. In one fringe pattern, by applying Fourier transform, filtering and inverse Fourier transform, the modulation corresponding to the vertical and horizontal components of the cross grating can be obtained respectively. Then the 3-D shape of the object can be reconstructed according to the mapping relationship between modulation and height, which was established by calibration process in advance. So the 3-D shape information can be recorded at the same speed of the frame rate of the CCD camera. This paper gives the principle of the proposed method and the setup for measuring experiment and system calibration. The 3-D shape of a still object and a dynamic process of liquid vortex were measured and reconstructed in the experiments, and the results proved the method's feasibility. The advantage of the proposed method is that only one fringe pattern is needed to extract the modulation distribution and to reconstruct the 3-D shape of the object. Therefore, the proposed method can achieve high speed measurement and vertical measurement without shadow and occlusion. It can be used in the dynamic 3-D shape measurement and vibration analysis.
Three Dimensional Measurement Based on Image Shift and Its Applications in Object Inspection
A novel three-dimensional measurement method is proposed in this paper based on images shifted to a preset position. The proposed measuring system with a simple architecture can be easily established with very low installation costs as long as two images shifted by a certain window frame can be obtained. To show the effectiveness of the proposed approach, an object inspection system for use in a production line based on the measuring method is demonstrated in this paper, where a single CCD camera is used to capture images with the help of two position sensors to obtain non-contact 3-dimensional measurements for objects on a conveyer. Because a single scan line of images is only used for calculating the measurements including distance from the object and length and width of the object under inspection, the proposed measuring method has demonstrated itself as an efficient yet cost-effective method in achieving the objectives of sorting or screening defects of objects. Simulation resul...
3D Optical Measuring Systems and Laser Technologies for
2013
Modern industry and science require novel 3D optical measuring systems and laser technologies with micro/nanometer resolution for solving actual problems. Such systems, including the 3D dimensional inspection of ceramic parts for electrotechnical industry, laser inspection of wheel pair diagnostic for running trains and 3D superresolution low-coherent micro-/nanoprofilometers are presented. The newest results in the field of laser technologies for high-precision synthesis of microstructures by updated image generator using the semiconductor laser are given. The measuring systems and the laser image generator developed and produced by TDI SIE and IAE SB RAS have been tested by customers and used in different branches of industry and science.
Measurement of 3D-line shaped objects
Pattern Recognition Letters, 1994
We present a software tool for the analysis of 3D-line shaped objects in a 3D grey valued image. We discuss the extraction of the object from the image, the measurement of its shape features and its display.
Optical measurement techniques for mobile and large-scale dimensional metrology
Optics and Lasers in Engineering, 2009
Dimensional inspection tasks are often carried out on conventional coordinate measuring machines (CMMs). These CMMs can differ in layout and size depending on the application area. They can have measurement volumes up to 100 m 3 . However, when measuring large objects it is not always possible to bring a large object to these conventional CMMs. That is why for these applications mobile measuring systems are an ideal solution. These systems often measure the dimensions through optical techniques, like interferometry and optical triangulation. After a short survey of common optical measurement techniques for mobile and large-scale measurements, this paper focuses on two industrial cases where different techniques were used to solve a measurement problem. The first case covers the measurement of a large iron casting with an optical LED-based triangulation system. It was possible to predict problems that would occur with the machining of the part, like unfinished surfaces after milling due to material shortage, and adapt the alignment of the part to prevent these problems. The second case covers the measurement of a double-decker train by means of photogrammetry, as an alternative for the currently used total station. Despite some specific drawbacks of photogrammetry systems it was possible to obtain the same accuracy and to reduce the overall inspection time significantly in comparison with the current situation.
Method and Device Based on Multiscan for Measuring the Geometric Parameters of Objects
Processes, 2020
The article deals with the issues of improving the accuracy of measurements of the geometric parameters of objects by optoelectronic systems, based on a television multiscan. A mathematical model of a multiscan with scanistor activation is developed, expressions for its integral output current and video signal are obtained, and the mechanism of their formation is investigated. An expression for the video signal is obtained that reflects the dual nature of the discrete–continuous multiscan structure: the video signal can have a discrete (pulse) or analog (continuous) form, depending on the step voltage between the photodiode cells of the multiscan. A Vernier discrete–analog method for measuring the parameters of the light zone on a multiscan is proposed, in which in order to increase the accuracy of the measurements, the location of the video pulse is determined relative to the neighboring reference pulses of a rigid geometric raster due to the slope of the discrete structure of the ...