Marcel Fedak

Statistical Process Control Method Based on Weight Percent of Al-Si Alloy for Melting and Holding Process in Die Casting

We proposed a conceptual method of how to control liquid state of Al-Sialloys in holding process of the die casting. Given that, we determine the characteristic of the holding furnace based on weight percent (wt %) of the certain alloys and their elements. An Experimental case study deals with the application of the proposed method in company that produces castings by the die-casting technology.

DEPENDENCE OF HARDNESS OF CONTINUES DIE-CASTING PRODUCTS ON FE CONTENT

Nowadays die-casting is one of the best of metal casting system. Die-casting comparing with the other casting methods is cost preferably, the savings may be 20% of the metal needed for the casting and cost savings of foundry production can be around 30%. In this work we have measure hardness of Al-Si alloy respect to its Fe content. In our experiments we have used digital microhardness tester CV 400D respect to the Vickers hardness test. Samples were processed in dentacryl. We have made a conclusion that content of the Fe in the alloy have some influence on the product’s hardness. Even insignificant difference in chemical composition of the casting products will lead to different hardness characteristics of the products.

Technical and Software Equipment for the Real Time Positioning Control System in Mechatronic Systems with Pneumatic Artificial Muscles

This paper explains the design of real-time control system for control of drives containing the artificial muscles. Described is the design of devices hardware and software, as well as design of their involvement in the experimental device. In this paper are referred experimental measurements on the device, aimed at monitoring the change in observed characteristics caused by position changes in artificial muscles during their operation.

The Synergistic Effect of Thermal Collectors Rotation in relation to Their Energy Efficiency and Stagnation Compared with the Static Thermal System in the Conditions of Central Europe

The presented paper deals with the issue of the efficient use of solar energy potential gained from thermal panels via tracking the Sun’s trajectory. Based on long-term measurements of the selected parameters, the efficiency of the installed system in relation to the ecliptic was evaluated in the static regime as well as in a rotary regime. In the comparison of rotary and fixed system of the collectors the presented results show an increase of the effectiveness of rotary one during the period of the day. On closer view the increase is not constant. During the day it varies: the most significant increase is in the afternoon, while the time from 10:30 a.m. to 1:00 p.m. the effectiveness of both systems almost identical. The utilisation of the rotary system as a suitable instrument for the elimination of the system stagnation was also evaluated.

Adaptive Rejection Filter for the Drives Stabilization of Pressure Die Casting Machines

The presented paper deals with the design of a mathematical model of a rejection filter for the drives stabilization applied to pressure die casting processes. The rejection filter allows the stabilization of electrohydraulic servo drives making use of periodically repeated zero transfer functions while taking advantage of the essence of a parallel joint of the proportional unit and a time delay unit. Consequently, the model of the adaptive rejection filter algorithm with a higher form of electrohydraulic servo drives has been mathematically elaborated. The paper comprises the algorithm description for the models implementation in the process of a servo drive control, which to a sufficiently greater extent can respond to the changes in technological parameters of pressure die casting than a conventional drive system. The introduction of a position feedback or a high-speed feedback allows the elimination of excessive porosity formation. By Introducing additional feedbacks, it is possible to affect the speed of a piston movement in the range of a low pressing speed depending on other technological parameters, for example, a melt temperature in the chamber.

Equation Model of Stabilization of Low Damped Astatic Systems

The paper deals with the stabilization of low damped astatic systems. They show a low value of a relative damping and consequently a high resonance rise of amplitude frequency response. If astatism occurs in an automatic control system, the situation becomes complicated due to the exhaustion of a phase safety of astatic element. In order to achieve the stabilization, a filter with rejections has been designed. The filter is characterized by rapid rejections of logarithmic frequency characteristics that eliminate resonance rise of a low damped astatic system. A functional model of a discrete filter was created to attest the properties of the filter with a continuous low damped astatic system. Experiments have proved the suitability of the filter application. The method of the filter utilization, the stability of the low damped astatic system as well as the stability assessment by the operator W will be described in the paper.

Simulation Study of Two Alternative Workstations for Pressure Die-Casting Process

The paper introduces two ad-hoc experimental models that emulate the real semi-automated and fully automated workstations of the die-casting production company. The simulation study aims to analyze behavior over time of both models. The intention of the paper is to show that the simulation can be used as a tool to support a decision-making process. It also presents effective approach how to forecast the real system performance.

Chilled Ceiling Adaptive Control with Application of Parameters Gained from the Chilled Ceiling System Proposal Algorithm

Chilled ceiling represents air-conditioning system in which a part of heat load is taken away by the ceiling thus decreasing the demand of cooling air amount. Chilled ceiling can only be applied with automatic air-conditioning control. The contribution presents computer program that can serve for either the proposal of chilled ceiling parameters or for chilled ceiling control algorithm.

Experimental Study on Energy Gain of the Solar Collector with Automatic Inclining System in Conditions of Central Europe during Low Solar Potential Periods

The paper presents study on energy gain increase of the solar collectors equipped with automatic system which serves for the purpose of changing inclination of the collectors according to the sun ecliptic. The system effectiveness is compared with fixed collectors energy gain.

Assesment of Material Flow in Foundry Production by Applying Simulation Analysis

In this paper we applied simulation tools to assess the material flow in particular company oriented on die-casting production. The objective of the presented case study is to highlight that detailed data analysis from simulation can help to increase utilization of machinery considerably. Another reason for simulation adoption is to determine deviation of production volume. We have also implicitly outlined the benefits that can be derived from implementing a simulation tools and the additional costs for the implementation.