Štefan Kuna

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.

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.

Loops Control Structure and Solar System Control of a Multivalent Laboratory under Real-Time Mode

This paper deals with the structure of individual controlled components of the solar system, which is constituted by one of the blocks of the entire heating system of the object. In the introduction of the article, there is briefly characterized the system in a real-time mode. Such systems have to satisfy different requirements due to which they differ from conventional systems. There are several kinds of real-time systems, each of which has its own characteristics highlighted in this contribution. Subsequently, the interconnection of the control system with all blocks of a multivalent laboratory is shown schematically. Of all these blocks, a block of the solar system is described in detail, which, among other things, consists of the installed sensors that provide a control system with the necessary information so that it could then give the command to perform the desired task in response to an event in the system environment. These tasks performing is bounded by a time limit. Non compliance with a time limit would result in incorrect operation of the system, i.e. its degradation from the users aspect.

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.

Real Time Pressure Control in Pneumatic Actuators

This paper explains the design of real-time control system for drives which use a pneumatic artificial muscles. Described is the design of hardware and software equipment, as well as design of these components involvement in the experimental facility with artificial muscles. In this paper are referred experimental measurements on the device aimed at monitoring the changes in observed PAMs characteristics caused by pressure changes in artificial muscles during their operation.

Alternatives for Real Time Positioning Control System in Mechatronic System 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 hardware and software devices, 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.

Energy Yield of Solar Panels in the System of their Position Control

The contribution deals with the climatic conditions in which a solar rotatable structure with flat solar panels was placed on the roof of the building in which the Department of Process Technique is located. There was designed a control system of the structure in order to achieve an increase in efficiency of solar panels. Presented are three ways of the rotatable structure positioning. During the first measurements, the data were obtained and recorded with a fixed position of the solar panels, the second measurements were carried out while the solar panels were rotating along the ecliptic without being dependent on the actual value of the solar radiation intensity, while with the third measurements the rotation was initiated depending on the intensity of the incident solar radiation on the collectors surface. The archived data obtained from individual measurements are presented in the graphs which show the advantage of solar panels rotation in terms of achieving higher temperatures of a solar fluid and a heat transfer medium of an accumulation tank.

Proposal of Linear Drive for Mechatronic Facility of Solar Panels

The paper deals with proposal of synthesis of drive control of solar panels facility. New way of facility control is presented. The facility serves for solar panels rotation according to sun radiation intensity, sun location, and feedback control of position of linear electric drive.

Design of Methodology for Wood Chips Moisture Evaluation

Moisture is an important factor of evaluating of burning process efficiency. Unfavorable moisture increases the requirements for energy/fuel consumption which is needed to evaporate water and in a negative manner affects the volume of exhaust gas, the amount of water vapor in exhaust gas as well as the increase in the temperature of the exhaust gas dew point. Thus, wood chips moisture monitoring is a diagnostics tool suitable for the evaluation of operating parameters and a combustion process. The article deals with the design of an appropriate method of measurement and evaluation of wood chips moisture and compares two methods of moisture determining. The problem of moisture determining consists mainly in selecting a suitable method according to the estimation of content of water in wood chips. Another factor to be considered is the fact that moisture in wood chips due to the ambient conditions (temperature, pressure, humidity) changes over time.