scholarly journals STEP-NC-Compliant Implementation to Support Mixed-Control Technologies Applied to Stone-Processing Machines Based on Industrial Automation Standards

Machines ◽  
2021 ◽  
Vol 9 (12) ◽  
pp. 327
Julio Garrido ◽  
Diego Silva ◽  
Juan Sáez

STEP-NC (Standard for the Exchange of Product Model Data–Numerical Control) for metal milling and turning is not implemented by industrial computer numerical controllers. Solutions reported are prototypes based on post-processing in G-code. Moreover, minority machining processes, such as stone cutting, have not yet been contemplated in the STEP-NC standard. This article takes that sector as a use case. An extended STEP-NC model for circular saw stone-cutting operations is proposed, and a prototype automation implementation is developed to work with this extended model. This article shows how modern technological resources for coordinated axes control provided by many industrial controllers for the automation of general-purpose machines can speed up the processes of implementing STEP-NC numerical controllers. This article proposes a mixed and flexible approach for STEP-NC-based machine automation, where different strategies can coexist when it comes to executing STEP-NC machining files, so controllers do not need to implement the standard in an exhaustive way for all the possible features, but only at selected ones when convenient. This is demonstrated in a prototype implementation which is able to process STEP-NC product files with mixed-feature types: standard milling and non-standard sawblade features for stone processing.

2016 ◽  
Vol 1136 ◽  
pp. 651-654
Hideki Aoyama ◽  
Duo Zhang

It is frequently the case that the feed rate indicated in a numerical control (NC) program does not obtain in actual machining processes and the cutting tool does not path the points indicated in the NC. A reason underlying such problems is that control gains are not optimized, which causes issues with acceleration and deceleration in the control of machine tools. To address these problems, in this paper, we propose a method for the optimization of control gains using the MATLAB and Simulink software by considering the weight of the workpiece, the controlling distance, and the controlling speed. Simulations confirmed the effectiveness of our proposed optimization.

Alexander Grahn ◽  
Eckhard Krepper ◽  
Frank-Peter Weiß ◽  
So¨ren Alt ◽  
Wolfgang Ka¨stner ◽  

The present study aims at modelling the pressure drop of flows across growing cakes of compressible, fibrous materials which may form on the upstream side of containment sump strainers after a loss-of-coolant accident (LOCA). The model developed is based on the coupled solution of a differential equation for the change of the pressure drop in terms of superficial liquid velocity and local porosity of the fibre cake and a material equation that accounts for the compaction pressure dependent cake porosity. Details of its implementation into a general-purpose three-dimensional computational fluid dynamics code (CFD) are given. An extension to this basic model is presented, which simulates the time dependent clogging of the fibre cake due to capturing of suspended particles as they pass trough the cake. The extended model relies on empirical relations which model the change of pressure drop and removal efficiency in terms of particle deposit in the fibre cake.

2019 ◽  
Vol 18 (03) ◽  
pp. 395-411
Samya Dahbi ◽  
Latifa Ezzine ◽  
Haj El Moussami

During machining processes, cutting temperature directly affects cutting performances, such as surface quality, dimensional precision, tool life, etc. Thus, evaluation of cutting temperature rise in the tool–chip interface by reliable techniques can lead to improved cutting performances. In this paper, we present the modeling of cutting temperature during facing process by using time series approach. The experimental data were collected by conducting facing experiments on a Computer Numerical Control lathe and by measuring the cutting temperature by an infrared camera. The collected data were used to test several Autoregressive Integrated Moving Average (ARIMA) models by using Box–Jenkins time series procedure. Then, the adequate model was selected according to four performance criteria: Akaike criterion, Schwarz Bayesian criterion, maximum likelihood, and standard error. The selected model corresponded to the ARIMA (1, 1, 1) and it was tested by conducting a new facing operation under the same cutting conditions (spindle speed, feed rate, depth of cut, and nose radius). It was clearly seen that there is a good agreement between experimental and simulated temperatures, which reveals that this approach simulates the evolution of cutting temperature in facing process with high accuracy (average percentage error [Formula: see text] 0.57%).

2010 ◽  
Vol 97-101 ◽  
pp. 2403-2406
Ya Bo Luo ◽  
Ming Chun Tang

Grouping the similar processes is a good approach to improve the manufacturing efficiency, however, which is facing with two difficulties of the group automation and the constraints coupling. Regarding the numerical control (NC) machines and tasks as a grid system, this paper proposes a similarity-based tactic to solve the above difficulties. First, the methodology for analyzing the similarity among NC tasks is proposed to implement group automation taking the similarity principle as theory foundation. Second, based on the results drawn from the first step, the complex constraints including similarity constraints, delivery date constraints, and serial constraints are coupled to develop an integrated scheduling model. Finally, the integrated model is solved and the optimum solution is gotten using a specialized ants algorithm.

Do Thi Tam ◽  
Tran The Long ◽  
Nguyen Hoang Quan

Aquatex 3180 is the general purpose soluble oil, formulated for use in a wide variety of machining operations. In fact, the natural diffusion in the liquid is very slow, especially the mixing ratio, and the homogeneity of the solution is difficult to achieve according to the manufacturer's recommendation. Hence, the agitator is required to improve the uniformity of the solution in that the obtained cutting fluid can be effectively used in machining processes to fulfill the role of cooling and lubricating. In this work, the application of the similarity method and dimensional analysis for studying agitator model for mixing Aquatex 3180 cutting oil to build the set of input parameters in the experimental process. The results reveal that the input parameters in the study of the agitator model using 9 similarity criterions πi (i = 1 ... 9) instead of 12 independent parameters. In addition, the standard π2 can characterize the displacement properties of the fluid flow considering the influence of gravity. It means that the number of experiments reduce but still ensure that many experimental input parameters are still guaranteed, therefore ensuring proper description of the actual operation of the machine.

2019 ◽  
Vol 13 (5) ◽  
pp. 631-638 ◽  
Takuma Umezu ◽  
Daisuke Kono

Demand for highly productive machining of thin-walled workpieces has been growing in the aerospace industry. Workpiece vibration is a critical issue that could limit the productivity of such machining processes. This study proposes a machining process for thin-walled workpieces that aims to reduce the workpiece vibration during the machining process. The workpiece compliance is measured using an on-machine measurement system to obtain the cutting conditions and utilize the same for suppressing the vibration. The on-machine measurement system consists of a shaker with a force sensor attached on the machine tool spindle, and an excitation control system which is incorporated within the machine tool’s numerical control (NC). A separate sensor to obtain the workpiece displacement is not required for the estimation of the displacement. The system is also capable of automatic measurement at various measurement points because the NC controls the positioning and the preloading of the shaker. The amplitude of the workpiece vibration is simulated using the measured compliance to obtain the cutting conditions for suppressing the vibration. An end milling experiment was conducted to verify the validity of the proposed process. The simulations with the compliance measurement using the developed system were compared to the results of a conventional impact test. The comparison showed that the spindle rotation speed for suppressing the vibration could be successfully determined; but, the axial depth of cut was difficult to be determined because the simulated vibration amplitude was larger than that found in the experimental result. However, this can be achieved if the amplitude is calibrated by one machining trial.

K. C. Morris

Abstract The problem of sharing data has many facets. The need to share data across multiple enterprises, different hardware platforms, different data storage paradigms and systems, and a variety of network architectures is growing. The emerging Standard for The Exchange of Product Model Data (STEP), being developed in the International Organization for Standardization (ISO), addresses this need by providing information models, called application protocols, which clearly and unambiguously describe data. The validity of these information models is essential for success in sharing data in a highly automated engineering environment. This paper describes the Data Probe: a tool for examining, editing, and managing EXPRESS-based data. The Data Probe tool supports the validation of STEP application protocols. The paper includes a description of the software architecture, the initial implementation, and plans for future enhancements. The software is designed as independent components which can be incorporated into other STEP-related systems or software requiring general purpose editing tools for structured information. The initial version of the Data Probe tool is based on two implementation mechanisms defined within STEP: the conceptual modeling language EXPRESS and the STEP exchange file format. Future work will focus on integrating a database system into the software. The software architecture and the use of object-oriented techniques enables code reusability and system extensibility and has been instrumental for a phased implementation. The software is under development at the National Institute of Standards and Technology and is in the public-domain. The software supports the Validation Testing System, part of the Application Protocol Development Environment, at the CALS-sponsored National PDES Testbed. (PDES, Product Data Exchange using STEP, is the U.S. effort in support of the international standard.)

2008 ◽  
Vol 24 (02) ◽  
pp. 92-98 ◽  
Ben Kassel ◽  
Ted Briggs

This paper considers an alternate approach to the exchange of ship product model data based on general-purpose STEP application protocols. The vision is to provide the functionality defined in the shipbuilding application protocols using a combination of STEP AP239, AP214, and reference data libraries. It is expected that AP239 translators will soon be available, thus enabling the exchange of significant portions of ship product model data.

Ahmet Dogrusadik

Thread milling is a new machining process as compared to thread tapping. As a thread making process in use for a long time, thread tapping did not have any alternative processes except the thread turning for limited cases until computer numerical control (CNC) technology had enabled the three axes synchronized motion. Therefore, investigations about the thread milling process are less as compared to other machining processes. In this work, the thread profile in the internal thread milling process was derived analytically. Experimental work was also performed to verify the performance of the analytical model. It was revealed that the thread profile produced by the cutting edge of the tool is not a straight line but a curve, and the average slope through the thread profile is less than the slope of the cutting edge of the tool. Besides, the effective thread profile enlarges along the vertical axis and constricts laterally as the ratio of thread mill diameter to thread diameter increases.

Andy Dong

The act of changing a product by substituting technologies remains a challenging problem for companies with incumbent and dominant designs. This paper describes a new method to quantify the degree of this change based on the graph edit distance of functional models of products. The knowledge structure of a product is represented by its functional model using the ontology of the functional basis. Its knowledge structure is then compared to an equivalent small-world graph, widely regarded as the most efficient structure for information sharing. Finally, the graph edit distance between a product model and its equivalent small-world graph is calculated. This paper demonstrates a general purpose manner to study design innovation through technological transformation.

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