scholarly journals Geometric Measurements on a CNC Machining Device as an Element of Closed Door Technology

Sensors ◽  
2021 ◽  
Vol 21 (14) ◽  
pp. 4852
Author(s):  
Grzegorz Bomba ◽  
Artur Ornat ◽  
Piotr Gierlak

The article discusses the quality testing of a measuring system consisting of a CNC machine with measuring probes. The research was conducted in a broader context regarding the implementation of the closed door technology, i.e., production without human intervention, in an aviation plant manufacturing aircraft gearbox systems. This technology may involve automated measuring operations performed in machining centers, and not in measuring laboratories, provided that the quality of the measurements is appropriate. The aim of the study was to investigate whether the CNC machining device can be used to measure the geometric features of aircraft gearbox housing. For this purpose, measurement experiments were carried out with the use of three different probes. Measurements were carried out using four sequences of increasing complexity, so that, after error analysis, it was possible to find the causes of possible irregularities. A reference ring with known dimensions and position in the working space of the machine was used for the measurements performed as part of the assessment of the measurement system. The quality of the measurements was evaluated with the use of repeatability and reproducibility testing and statistical process control. The analysis results showed that the tested measurement system ensures adequate accuracy and repeatability, and the measurement process is characterized with adequate efficiency in relation to the manufacturing tolerance of the components produced using the machine. Thus, it was proven that the measurement process can be carried out on a machining device, which enables its integration into the closed door technology.

2012 ◽  
Vol 214 ◽  
pp. 939-943
Author(s):  
Jing Ping Liu ◽  
Yu Zhong Li

CNC machine tools and programming is a professional core curriculum of the vocational colleges in machinery manufacturing and automation, and CNC machining technology. This course involves teaching and professional practice, which requires us to improve teaching methods, improve the quality of teaching to promote students 'understanding of CNC machine tools and programming course and mastery, in order to develop students' practical capacity. In this paper, we use the conception, design, implementation, and operation of the CDIO model implementation of teaching reform, providing engineering teaching model with a new teaching ideas, and this also plays an active role in the training to cultivate innovative talents.


2018 ◽  
Vol 224 ◽  
pp. 01048 ◽  
Author(s):  
Roman Nekrasov ◽  
Ulyana Putilova ◽  
Yulia Tempel

The quality of the part is characterized by precision of its processing. A good fit of the product parts and, as a consequence, its reliability in general depends on how accurately the size and shape of the part is maintained during machining. In this connection, the article considers the problem of ensuring the accuracy during machining of work pieces using CNC machines. Within the identified problem, the analysis of known technical solutions in this area was carried out and three main areas were identified: optimization of cutting conditions, improvement of the treated surface area according to the criteria for increasing the resistance of the cutting tool, as well as error tracking and correction during machining. The main disadvantages of the analyzed methods and inventions are complexity of their implementation, the need to equip the CNC machine with an adaptive control system, and a limited field of application. Therefore, a method for controlling the accuracy of shaft processing using mathematical and finite element modeling is proposed.


Author(s):  
Angel Lengerov ◽  
Galina Nikolcheva ◽  
Julieta Kaleycheva ◽  
Lyubomir Lazov

Statistical process control (SPC) can help manufacturers improve the quality of their products. This paper describes a relatively simple and effective method and algorithm to adjust the accuracy of parts produced on CNC machine tools using the methods of statistical process control. Examined the possibilities of the proposed method by computer simulation of the process. By using the proposed algorithm scattering of size is placed in the middle of the tolerance zone. Various variants carrying out the method are proposed adequate on the machining time during processing details in the sample. This can optimize the total time for processing of the batch.


Polymers ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 353
Author(s):  
Kun-Cheng Ke ◽  
Ming-Shyan Huang

Conventional methods for assessing the quality of components mass produced using injection molding are expensive and time-consuming or involve imprecise statistical process control parameters. A suitable alternative would be to employ machine learning to classify the quality of parts by using quality indices and quality grading. In this study, we used a multilayer perceptron (MLP) neural network along with a few quality indices to accurately predict the quality of “qualified” and “unqualified” geometric shapes of a finished product. These quality indices, which exhibited a strong correlation with part quality, were extracted from pressure curves and input into the MLP model for learning and prediction. By filtering outliers from the input data and converting the measured quality into quality grades used as output data, we increased the prediction accuracy of the MLP model and classified the quality of finished parts into various quality levels. The MLP model may misjudge datapoints in the “to-be-confirmed” area, which is located between the “qualified” and “unqualified” areas. We classified the “to-be-confirmed” area, and only the quality of products in this area were evaluated further, which reduced the cost of quality control considerably. An integrated circuit tray was manufactured to experimentally demonstrate the feasibility of the proposed method.


Energies ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 673
Author(s):  
Augustyn Wójcik ◽  
Piotr Bilski ◽  
Robert Łukaszewski ◽  
Krzysztof Dowalla ◽  
Ryszard Kowalik

The paper presents the novel HF-GEN method for determining the characteristics of Electrical Appliance (EA) operating in the end-user environment. The method includes a measurement system that uses a pulse signal generator to improve the quality of EA identification. Its structure and the principles of operation are presented. A method for determining the characteristics of the current signals’ transients using the cross-correlation is described. Its result is the appliance signature with a set of features characterizing its state of operation. The quality of the obtained signature is evaluated in the standard classification task with the aim of identifying the particular appliance’s state based on the analysis of features by three independent algorithms. Experimental results for 15 EAs categories show the usefulness of the proposed approach.


2010 ◽  
Vol 166-167 ◽  
pp. 357-362
Author(s):  
Shahed Shojaeipour

In this article, a new method for rapid tool movement in CNC machines is presented. Firstly, a single digital camera, installed on the Z-axis, captures the image of the workpiece on the work table. Image processing techniques, implemented using MATLAB, are then used to convert the image into a binary black and white image. This allows the locations of protruding edge sections on the workpiece, which could impede tool movement, to be identified. Quadtree decomposition is then performed on the binary image, and possible paths from the tool current location to its target location are found. These paths are then analysed based on the tool diameter clearance and the distance to the goal, and the shortest path with sufficient tool clearance is selected. A Visual Basic program then converts the selected path into G-code commands that provides instructions to the CNC machine tool such that this path is followed. With this method, the workpiece fixture location would not have to be precise as the imaging system would be able to automatically identify the target location with respect to the tool current location, along with the optimal path to reach it.


Author(s):  
Bryan W. Schlake ◽  
Brian S. Daniel ◽  
Ron Voorheis

In pursuit of improved safety, Norfolk Southern Corp. (NS) has partnered with Amberg Technologies to explore the potential benefits of a laser-based measurement system for measuring over dimensional freight rail shipments. Shipments that do not fall within a standard geometric envelope, denoted as Plate B in the Association of American Railroads (AAR) Open Top Loading Rules [1], are considered to be over dimensional, or High-Wide Loads (HWLs). Extending beyond the limits of the Plate B diagram, these loads are not permitted in unrestricted interchange service. Instead, they must be measured both at points of origin and at interchange points. For US Class I Railroads, the de facto method for measuring HWLs requires mechanical personnel to either climb on the equipment or use a ladder and physically measure the overall height and width of the load. Using a tape measure, plumb line, and 6-foot level, car inspectors, or carmen, must often make multiple measurements to determine the height or width of a critical point on the load. The summation of these measurements can be subject to mathematical human error. In addition to the inherent limitations with regards to accuracy and efficiency, this method of measurement presents considerable safety challenges. The objective of the project was to develop a portable, cost-effective and accurate measurement system to improve the day-to-day operational process of measuring HWLs and reduce human exposure to railyard hazards. Norfolk Southern worked closely with Amberg Technologies to provide a clear overview of the current measuring methods, requirements, challenges and risks associated with HWLs. Amberg then developed a prototype system (with patent pending) and successful tests have been completed at both a point of origin for NS shipments and at a location where HWLs are received at interchange. The measuring system consists of a tripod mounted laser, a specially designed track reference target (TRT) and software designed specifically for HWL measurements. The system allows car inspectors to take measurements from a safe, strategic location away from the car. As a result, this system eliminates the need to climb on the equipment or a ladder and greatly reduces the amount of time spent on and around live tracks. In addition, initial tests indicate that this technology reduces the labor time required to measure HWLs by as much as one half while improving measurement accuracy. These tests have demonstrated that a laser-based system has the potential to greatly improve the safety, efficiency and accuracy associated with measuring HWLs.


Author(s):  
Hourieh Foroutan ◽  
Amirhossein Amiri ◽  
Reza Kamranrad

In most statistical process control (SPC) applications, quality of a process or product is monitored by univariate or multivariate control charts. However, sometimes a functional relationship between a response variable and one or more explanatory variables is established and monitored over time. This relationship is called “profile” in SPC literature. In this paper, we specifically consider processes with compositional data responses, including multivariate positive observations summing to one. The relationship between compositional data responses and explanatory variables is modeled by a Dirichlet regression profile. We develop a monitoring procedure based on likelihood ratio test (lrt) for Phase I monitoring of Dirichlet regression profiles. Then, we compare the performance of the proposed method with the best method in the literature in terms of probability of signal. The results of simulation studies show that the proposed control chart has better performance in Phase I monitoring than the competing control chart. Moreover, the proposed method is able to estimate the real time of a change as well. The performance of this feature is also investigated through simulation runs which show the satisfactory performance. Finally, the application of the proposed method is illustrated based on a real case in comparison with the existing method.


Author(s):  
В.А. Гвоздев ◽  
Л.В. Леонов ◽  
О.Н. Рублевская

Качество услуг водоснабжения и водоотведения за первые двадцать лет XXI века вывело на новый уровень развития ГУП «Водоканал Санкт-Петербурга» благодаря внедрению инновационных технологий в системах водоснабжения и водоотведения. Использование технологий, таких как двухступенчатое обеззараживание питьевой воды, дезодорирование полигонов, геотубирование, применение центрифуг «Флоттвег», порошкообразного однокомпонентного флокулянта, порошкообразного активированного угля, внедрение системы измерения осадков, осуществлялись при активном участии Федора Ивановича Лобанова – помощника генерального директора ГУП «Водоканал Санкт-Петербурга» по работе с промышленностью, которому в ноябре 2021 г. исполнилось 80 лет. The quality of water supply and wastewater disposal services over the first twenty years of the 21st century has brought SUE «Vodokanal of St. Petersburg» to a new level of development owing to the introduction of innovative technologies in water supply and wastewater disposal systems. The use of technologies, such as two-stage disinfection of drinking water, odor control of landfills, geotubing, the use of Flottweg centrifuges, powdered one-component flocculant, powdered activated carbon, the introduction of a precipitation measurement system, were carried out with the active participation of Fedor Ivanovich Lobanov, Assistant to the General Director of SUE «Vodokanal of St. Petersburg» on dealing with industries, who turned 80 in November 2021.


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