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1

Linear motion error evaluation of open-loop cnc milling using a laser interferometer

Winarno Agustinus, Prayoga Benidiktus Tulung, Hendaryanto Ignatius Aris

Acta Mechanica et Automatica

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2022

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Vol. 16, no. 2

124--129

EN

The usage of computerised numerical control (CNC) machines requires accuracy verification to ensure the high accuracy of the processed products. This paper introduces an accuracy verification method of an open-loop CNC milling machine using a fringe counting of He–Ne laser interferometry to evaluate the best possible accuracy and functionality. The linear motion accuracy of open-loop CNC milling was evaluated based on the number of pulses from the controller against the actual displacement measured by the He–Ne fringe-counting method. Interval distances between two pulses are also precisely measured using the He–Ne interferometry. The linear motion error and controller error can be simultaneously evaluated in sub-micro accuracy. The linear positioning error due to the micro-stepping driver accuracy of the mini-CNC milling machine was measured with the expanded uncertainty of measurement and was estimated at 240 nm. The experimental results show that linear motion error of the open-loop CNC milling can reach up to 50 μm for 200 mm translation length.

2

Automation design for monorail - based system processes

Besa B., Chanda K. E., Kuruppu M.

Transport Problems

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2016

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T. 11, z. 4

29--41

EN

Currently, conventional methods of decline development put enormous cost pressure on the profitability of mining operations. This is the case with narrow vein ore bodies where current methods and mine design of decline development may be too expensive to support economic extraction of the ore. According to studies, the time it takes to drill, clean and blast an end in conventional decline development can be up to 224 minutes. This is because once an end is blasted, cleaning should first be completed before drilling can commence, resulting in low advance rates per shift. Improvements in advance rates during decline development can be achieved by application of the Electric Monorail Transport System (EMTS) based drilling system. The system consists of the drilling and loading components that use monorail technology to drill and clean the face during decline development. The two systems work simultaneously at the face in such a way that as the top part of the face is being drilled the pneumatic loading system cleans the face. However, to improve the efficiency of the two systems, critical processes performed by the two systems during mining operations must be automated. Automation increases safety and productivity, reduces operator fatigue and also reduces the labour costs of the system. The aim of this paper is, therefore, to describe automation designs of the two processes performed by the monorail drilling and loading systems during operations. During automation design, critical processes performed by the two systems and control requirements necessary to allow the two systems execute such processes automatically have also been identified.

DE

Derzeit haben konventionelle Methoden der Abnahme Entwicklung enormen Kostendruck auf die Rentabilität der Bergbau. Dies ist der Fall mit engen Vene Erzkörper, wo aktuelle Methoden und Mine Design der Entwicklung des Rückgangs kann zu teuer sein, um die wirtschaftliche Extraktion des Erzes zu unterstützen. Studien zufolge kann die Zeit, die zum Bohren, Reinigen und Sprengen eines Endes in einer konventionellen Abnahmeentwicklung benötigt wird, bis zu 224 Minuten dauern. Dies liegt daran, dass, sobald ein Ende gestrahlt wird, sollte die Reinigung zuerst abgeschlossen werden, bevor das Bohren beginnen kann, was zu niedrigen Vorschüben pro Schicht. Verbesserungen bei den Fortschrittsraten bei der Entwicklung des Rückgangs können durch die Anwendung des Elektrohängebahn-systems (EMTS) erreicht werden. Das System besteht aus den Bohr-und Beschickung Komponenten, die Monorail-Technologie zu bohren und zu reinigen das Gesicht bei der Entwicklung des Rückgangs. Die beiden Systeme arbeiten gleichzeitig am Gesichtsfeld so, dass das pneumatische Ladensystem bei der Bohrung des Oberteils des Gesichts das Gesicht reinigt. Um jedoch die Effizienz der beiden Systeme zu verbessern, müssen kritische Prozesse, die von den beiden Systemen im Bergbau durchgeführt werden, automatisiert werden. Die Automatisierung steigert die Sicherheit und Produktivität, reduziert die Ermüdung des Bedienpersonals und reduziert gleichzeitig die Arbeitskosten des Systems. Das Ziel dieser Arbeit ist es daher, Automatisierungskonzepte der beiden Prozesse zu beschreiben, die von den Monorail-Bohr- und Beschickungssystemen während des Betriebs durchgeführt werden. Während des Automatisierungsentwurfs wurden auch kritische Prozesse identifiziert, die von den beiden Systemen durchgeführt wurden, und Kontrollanforderungen, die erforderlich sind, damit die beiden Systeme solche Prozesse automatisch ausführen können.

3

Linear Quadratic Control Problem With Fixed Final State for Discrete-Time Distributed Systems

Chraibi L., Karrakchou J., Ouansafi A., Rachik M.

International Journal of Applied Mathematics and Computer Science

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2000

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Vol. 10, no 3

517-535

EN

The problem considered is that of minimizing a quadratic cost functional for a discrete distributed system with fixed initial and final states. It is shown that under suitable controllability assumptions, there is a close relationship between this problem and that of exact controllability with minimization of a time-varying energy criterion. The HUM technique is then extended to treat the exact controllability problem in the time-varying case and applied to provide an explicit form for the optimal control and the optimal cost.