Triangulation Device Research Articles

Laser triangulation as a fast and reliable method for determining ribbon solid fraction; focus on accuracy, precision, and measurement time

Roller compaction and dry granulation represent well-established unit operations in the pharmaceutical industry. The ribbon solid fraction is classified as a critical quality attribute, that directly impacts final product quality and performance. The development and evaluation of novel methods measuring ribbon solid fraction represent a subject of current research, since novel analyses strategies need to be established for at-, on–, or in-line process monitoring to overcome limitations of end product testing and to set the course for continuous manufacturing. In this study, a novel analytical device, using the principle of laser triangulation, was investigated to asses its potential being used as at-line process analytical technology tool during a roller compaction process. To this end, the laser triangulation device was compared with X-ray micro-computed tomography and powder based volume displacement measurement techniques using different statistical evaluation methods. Special focus was given to accuracy, precision, and total measurement time. The laser triangulation device was confirmed as highly accurate and precise, enabling the shortest total measurement time compared to the other methods. The findings of this study support the idea of implementing the laser triangulation device as a novel at-line process analytical technology tool into a roller compaction process.

Optical Setup for Error Compensation in a Laser Triangulation System.

Absolute distance measurement is a field of research with a large variety of applications. Laser triangulation is a well-tested and developed technique using geometric relations to calculate the absolute distance to an object. The advantages of laser triangulation include its simple and cost-effective setup with yet a high achievable accuracy and resolution in short distances. A main problem of the technology is that even small changes of the optomechanical setup, e.g., due to thermal expansion, lead to significant measurement errors. Therefore, in this work, we introduce an optical setup containing only a beam splitter and a mirror, which splits the laser into a measurement beam and a reference beam. The reference beam can then be used to compensate for different error sources, such as laser beam dithering or shifts of the measurement setup due to the thermal expansion of the components. The effectiveness of this setup is proven by extensive simulations and measurements. The compensation setup improves the deviation in static measurements by up to 75%, whereas the measurement uncertainty at a distance of 1 m can be reduced to 85 μm. Consequently, this compensation setup can improve the accuracy of classical laser triangulation devices and make them more robust against changes in environmental conditions.

Effect of artificial soil compaction in landfill capping systems on anisotropy of air‐permeability

AbstractSoil air permeability is an important parameter which governs the aeration in soils that significantly promotes the root growth of field and grassland species and leads, in turn, to higher levels of evapotranspiration. The German Landfill Directive (2009) requires a rigid or a minimal shrinking capping system that ensures a high evapotranspiration rate to decrease the infiltration rate through the underlying waste body and therefore the leachate generation. This research is focussed on the questions if compacted glacial till can ensure the required rigidity and if and how air permeability is affected by soil compaction.The objective was to compare air‐filled porosity and the direction‐dependency of air permeability of a capping soil when assuming rigid and non‐rigid conditions considering a shrinkage factor. Intact soil cores were sampled in vertical and horizontal direction in 0.05, 0.2, 0.5, and 0.8 m depths at two profiles of a mineral landfill capping system at the Rastorf landfill in Northern Germany. Desiccation experiments were carried out on differently‐compacted soils and soil shrinkage was measured with a 3D laser triangulation device, while the air permeability was estimated with an air flow meter.The results indicate that the “engineered” soil structure which was predominately platy due to a layered installation, led to a more anisotropic behaviour and therefore to higher air permeability in horizontal than in vertical direction. The compacted installation of the capping system seems to be effective and observes the statutory required more‐or‐less rigid system, otherwise, soil shrinkage would lead to vertical cracks and a more pronounced isotropic behaviour.

Fűszegélynyíró rezgésvizsgálata

This paper explores the possible sources of vibration in a strimmer. Within this, the linear vibrational finite element equations of a strimmer line as a taut string are discussed in detail. The vortex detachments of the high-speed strimmer line are examined using the Strouhal number and the vibrational formula. The other vibration sources of the device are analysed by measurements. An optical method is used to determine the revolution per minute. The displacement-time curve is measured with a laser triangulation device, which is analysed by Fast Fourier Transform.

Palliative psychiatric care and inquiry about pain in patients with schizophrenia: A study based on two clinical cases

Summary Objective This study was part of a comprehensive perspective, and aiming to propose a draft protocol for assessing the severity of pain in schizophrenic patients suffering from somatic pathology, to see the characteristics of non-reactive to pain. Patients, materiel and methods This paper reports the observation from two clinical case that took place at the Saint-Vincent-de-Paul hospital in Dschang (Cameroon). Documentary research was conducted using Google, Google Scholar, Scielo, PubMed, Medline and Interagency Pain Research Portfolio as main search engines and databases. The main keywords were schizophrenia, pain, and psychosis, psychotic, schizophrenic. A clinical experimental protocol with control cases and respect of ethical rules was used. Result The patients with schizophrenia also showed insensitivity/low sensitivity to pain. Control cases showed a reaction indicating that the pain was severe. Conclusion The present study concludes on the proposal of a triangulation device for the evaluation of pain in schizophrenic patients with somatic pathologies.

Repeatability and Agreement of Various High-Speed Macrotexture Measurement Devices

Five high-speed macrotexture measurement devices were tested on a variety of asphalt and Portland cement concrete pavement surfaces to evaluate their repeatability and their pairwise agreement. Experiments were run under three speed conditions: highway speed, varying constant speeds, and various acceleration and deceleration profiles. Data were processed and reduced per current industry standards. A novel approach for outlier removal from line laser devices was developed. The pairwise device agreement was evaluated using a limits of agreement analysis. The results demonstrate good repeatability for each of the devices tested. The agreement analysis showed that not all high-speed distance triangulation devices can be used interchangeably for all pavement surfaces. Data acquisition speed was found to be a factor in macrotexture parameter calculation for two of the five devices. The effect of speed was found to be worse on randomly textured surfaces than on transversely textured surfaces. Finally, acceleration was shown to have an effect on the parameters produced by one of the devices, giving further credence to the fact that care should be taken to gather high-quality datasets for the critical pavement characteristic of macrotexture.

Automated identification of defect geometry for metallic part repair by an additive manufacturing process

This paper presents a method to partially automate the repair process of metallic parts, such as aluminum castings, by using a machine vision system and an additive manufacturing process such as LMD (laser metal deposition). This method is based on a modified RANSAC (RANdom SAmple Consensus) algorithm and an intersection operation that enables the automated segmentation of repair volumes of canonical shape within a range dataset. To illustrate the working principle of the present method, an experiment is described where a 2D laser triangulation device scans a cavity machined in an aluminum workpiece. Despite the inevitable errors and noise in the range data, the repair volume and its edge features are robustly and accurately extracted. Scan paths can then be generated and turned into machine code for refilling the repair volume by an LMD additive manufacturing process.

광삼각법을 이용한 임계치수 측정용 단순 장비 및 신호 처리용 소프트웨어의 개발

광삼각법을 이용한 임계치수 측정용 단순 장비 및 신호 처리용 소프트웨어의 개발

Data-Driven Learning for Calibrating Galvanometric Laser Scanners

State-of-the-art calibration very often constructs models motivated by a real-world device. Recently, artificial neural networks (ANNs) have been proposed as a more universal, accurate, and practical black-box approach. For a galvanometric triangulation device based on two mirrors, we embrace this proposal and set it into context with other supervised data-driven approaches: 1) ridge regression; 2) support vector regression; and 3) Gaussian processes. We show that they outperform available model-based approaches and yield similar performance compared with a memorizing lookup table calibration. The results demonstrate that an off-the-shelf usage of ANNs may run into generalization problems. Restricting the space of functions using kernel-based learning has proven to be advantageous. Finally, all approaches and distinct properties are discussed in a broader context, since each application entails differently relevant requirements for its calibration. This also holds for any calibration other than the considered triangulation device.

Reconfiguration based model for matrix triangulation and hardware device creation concept

This research article based on the dynamic partial reconfiguration process gives a new orientation to the idea behind the matrix inverse computation method. The conventional way of computing matrix inverse uses the "Gauss's Methods" or any optimized variant of it. This research extends the classical method limited to the optimal "Gauss's Derivative Algorithms". The new algorithm based on the "Reconfiguration Concept" has been applied and provides matrix inverse without using "Gauss's Analysis". Instead, the computation idea will be based on the reconfigured "RLP". A wide range of $$n \times n$$n×n matrix computations have been tested for their feasibility and correctness. In this paper, we assume that such an algorithm exists that can compute the inverse matrices using the partial reconfiguration concept; we then use this idea to develop a reconfiguration-based model for matrix factorization and matrix reduction. Our reconfiguration model neither utilizes any standard algorithm to achieve the decomposition or the reduction nor any related matrix concept that factorizes matrices. However, it will use the reconfiguration matrix inverse computation to triangulate matrices. The model is described by a "Vector-Matrix Equation" reconfigured from the recursive dynamic process. Since the assumptions of our model are derived from the reconfiguration matrix inverse computations, it correctly computes the triangulated matrices. Another contribution of our work is the reduction of matrices into trivial identity matrices. Our model produces triangular matrices that avoid computational failures due to matrix inverse singularity conditions; thus,this matrix factorization management approach offers a new matrix-based computation standard.

Mo1531 Feasibility of Using a Novel Triangulation Device to Perform Flexible Endoscopic Suturing in a Porcine Model

Endoscopic suturing was reported recently but full thickness gastric sutures are still challenging due to the complexity of suturing maneuvers and lack of instrumental handiness, the latter could be reduced with a flexible triangulation system.

Assessment of behavioral changes associated with oral meloxicam administration at time of dehorning in calves using a remote triangulation device and accelerometers

BackgroundDehorning is common in the cattle industry, and there is a need for research evaluating pain mitigation techniques. The objective of this study was to determine the effects of oral meloxicam, a non-steroidal anti-inflammatory, on cattle behavior post-dehorning by monitoring the percent of time spent standing, walking, and lying in specific locations within the pen using accelerometers and a remote triangulation device. Twelve calves approximately ten weeks of age were randomized into 2 treatment groups (meloxicam or control) in a complete block design by body weight. Six calves were orally administered 0.5 mg/kg meloxicam at the time of dehorning and six calves served as negative controls. All calves were dehorned using thermocautery and behavior of each calf was continuously monitored for 7 days after dehorning using accelerometers and a remote triangulation device. Accelerometers monitored lying behavior and the remote triangulation device was used to monitor each calf’s movement within the pen.ResultsAnalysis of behavioral data revealed significant interactions between treatment (meloxicam vs. control) and the number of days post dehorning. Calves that received meloxicam spent more time at the grain bunk on trial days 2 and 6 post-dehorning; spent more time lying down on days 1, 2, 3, and 4; and less time at the hay feeder on days 0 and 1 compared to the control group. Meloxicam calves tended to walk more at the beginning and end of the trial compared to the control group. By day 5, the meloxicam and control group exhibited similar behaviors.ConclusionsThe noted behavioral changes provide evidence of differences associated with meloxicam administration. More studies need to be performed to evaluate the relationship of behavior monitoring and post-operative pain. To our knowledge this is the first published report demonstrating behavioral changes following dehorning using a remote triangulation device in conjunction with accelerometers.

Extraction of Building Facades in Urban Space and Texture Mapping to 3D Polygon Map by Using In-Vehicle Camera

Due to the wide diffusion of 3D maps, supporting tool for constructing the 3D maps are required. Individual information necessary for constructing the 3D maps is gathered by some measurement instruments. For example, 3D information and wall textures are acquired by triangulation (or GPS measurement) and optical devices, respectively. Building polygons in a 3D map can be constructed easily by combining the 3D (height) information and a 2D map. It is, however, difficult to obtain an appropriate texture for an arbitrary building polygon by combining those measurements information. In general, the texture mapping with the acquired image is performed manually. However, it takes huge costs to perform in a wide area. Therefore, the demand of the automation is extremely high. In this study, we aim to automatize the texture mapping by image information from the in-vehicle camera. An in-vehicle camera has the advantage that it is possible to take a picture of the building wall while driving over the broad area. But, the vibration and the traffic have influences on the photography environment. As a result, it is difficult to specify the building area in the image. In the proposed method, tracks of the camera are calculated from the acquired continuous image, the building area that corresponds to the polygon on the map is specified. In this paper, we described our observation about the result of a miniature model.

Study of the precision characteristics of algorithms for measuring the coordinates in triangulation devices

The rms deviation of the coordinate of the center of the light mark on a CCD detector has been measured for a triangulation-measuring device in which the surface being monitored is illuminated along the normal and at an angle. The coordinate of the center was calculated by processing the video signal read from the CCD detector by various algorithms. The measurements were carried out for samples that differ in surface structure and roughness. © 2005 Optical Society of America

Design of optical triangulation devices

This paper presents the derivation of the precise relation between the displacement of a light spot on an object's surface and the displacement of its image on the detector in an optical triangulation device, along with applications of the design of triangulation devices. Based on this relation, improved designs of optical triangulation devices, including devices of adjustable configurations, are proposed and discussed.

A simple method for the mensuration of body contour.

Accurate measurement of body contour and the transposition of this contour to the plotting board are integral but tedious parts of all but the most simplified forms of planning for radiation therapy. The use of a rotation therapy unit and a light-beam triangulation device ordinarily employed to measure source-to-skin distances has been found to provide an easy and convenient substitute of comparable accuracy for the more time-consuming conventional methods. The usual technics for the mensuration of body contour, such as those which employ the bending of malleable wire or solder about the part, the use of plaster-cast contours, the spoke-and-wheel device which employs movable radii of measured length, and even the more elaborate projection methods in which cross-sectional contours of the body are projected against a patient's dimensions on the plotting board, are too well known to warrant elaboration here. All are time-consuming procedures which have inherent inaccuracies, probably the most important of which is due to the need for transposing onto the plotting board the location of the tumor to simulate actual conditions of treatment. A system which employs the actual location of the tumor as a fixed point of reference for the measurement of varying tumor-skin radii bypasses some of the inaccuracies of the conventional methods. The body contour and its relationship to the underlying mass are mapped directly on the patient, the only prerequisites being a rotational therapy device capable of 360° rotation and a light-beam source-to-skin measuring device such as that shown in the accompanying figure. This light-beam device is capable of measuring source-to-skin distances of 40 to 60 cm. by adjustment of the light-beam spot to the cross-hair shadow of the field lights, the source-to-skin distance being read directly from the scale on the device. The skin-tumor radius of any desired vector is obtained directly by the simple expedient of positioning the tumor at the axis of rotation. With our unit, which employs a rotational radius of 55 cm., the source-to-skin distance is determined with the light beam and this value is subtracted from 55 cm., the difference representing the skin-tumor radius of the particular vector. The same process is repeated every 30° around the circumference of the part, and within a short time an accurate cross-sectional contour is obtained. Accurate localization of the area to be treated is, of course, essential, but since this is a necessary step preliminary to any technic of body-contour plotting, it need not enter into special consideration with the particular method under description. Once the necessary markings are placed on the skin, conforming to the anteroposterior and lateral co-ordinates of the tumor area, obtained either by localizing roentgenograms or fluoroscopy, the patient is placed exactly as for rotational therapy.