Krzysztof Kluszczynski

Two module electromagnetic launcher with pneumatic assist: Modelling, computer simulations and laboratory investigations

Purpose – The purpose of this paper is to present a new concept of a multi-module electromagnetic launcher with pneumatic assist. The authors focus on the problem of modelling a two-module electromagnetic launcher consisting of a coil-gun (module C) and a rail-gun (module R), as well as on the key problem of determining their position-dependent parameters, i.e. the resistances and inductances of discharging electrical circuits connected with the both modules. Special attention is paid to the possibility of influencing the missile’s flight via basic controller variation of the initial voltage values across the terminals of the capacitor batteries supplying current to both modules C and R. Design/methodology/approach – Analysis of the electromagnetic launcher has been based on the circuit-field approach. Differential equations describing movement of the missile have been drawn from circuit theory. The Finite Element Method and the Comsol Multiphysic program were used to determine position-dependent paramete...

SMA actuators: theory, performance curves and design problems

Purpose – The main purpose of the paper is to develop model basing on the modified and properly‐adopted Fermi‐Dirac equation which combines proper accuracy with adequate simplicity as well as to show how steady state and transient curves resulting from this model can be applied for solving design task.Design/methodology/approach – The standard Fermi‐Dirac equation was modified and extended. Full performance cycle for the SMA actuator was characterized by double‐valued function describing the actuator activation and the actuator deactivation. All these functions and parameters can be easily determined by analysis of measurement data or with use of Hooke‐Jeeves optimization algorithm.Findings – SMA linear actuator can be used in mechatronic systems as a special non‐standard drive when ultra‐light mass and very simple mechanical construction of power feed system is required. The proposed steady‐state and transient performance curves as well as operation diagram constitute sufficient base for effective design...

How to convert a factory-manufactured induction motor into rotary-linear motor ? Part 1 Constructional issues

Induction motors with two degrees of freedom are unconventional drives offering broader possibilities of different movements than traditional drives. There is general opinion that construction of a machine with 2 degrees of freedom (2DoF machine) is much more complicated and expensive than a machine with one degree of freedom. In the paper the authors show that it is possible to construct in easy way (even in an university laboratory workshop) a 2DoF 2-module induction motor using components of a factory-manufactured 3-phase squirrel-cage motor. The presented solution is one of many possibilities and should be treated as the exemplary case elaborated and tested at the Silesian University of Technology in Gliwice.

Analysis of Magnetic Field Distribution and Mechanical Vibration of Magnetic Field Exciter under Different Voltage Supply

The aim of the study performed in the Department of Biophysics of Nicolaus Copernicus University is to investigate the effect of extremely low frequency electromagnetic field (ELF-EMF) exposure on animal nervous system function. American cockroach (Periplaneta americana) serves as a model in experiments. Insects are placed into the chamber inside the coil (electromagnetic field exciter) designed and manufactured by ,,Elektronika i Elektromedycyna Sp. J.”. Before starting the exposure it is necessary to determine: (1) what kind of field is applied, (2) the parameters of exposure and (3) the area of homogenous field. Only well established set-up characteristics can provide correct and comparable conditions of exposure to EMF. As well as, before starting the observation of the EMF influence on insects it is necessary to exclude factors which are associated with EMF exposure (such as temperature changes and vibrations) and could affect the organism function (behavior of animal). Especially cockroaches are very sensitive to vibrations and mechanical disturbances. Thermal conditions during the whole period of EMF exposure have been established earlier 1. The research that has been conducted by the authors so far included methodology of measurements of mechanical vibration spectrum and magnetic field distribution in interior part of electromagnetic field exciter on insects putted into research chamber. The vibration of electromagnetic field exciter occurs due to current flow by the exciter windings 2,3, and they acts on it in radial and longitudinal direction. In this paper the vibration and field distribution of field exciter measurements results are presented.

Rotary-linear induction motor based on the standard 3-phase squirrel cage induction motor – constructional and technological features

Rotary-linear induction motor based on the standard 3-phase squirrel cage induction motor – constructional and technological features

Hybrid electromagnetic launcher with pneumatic assist - influence of input supply data upon final velocity missile

The purpose of this paper is to present simplified graphical representation of the missile velocity for the hybrid electromagnetic launcher with pneumatic assist. The presented simplified graphical method is oriented at describing clearly influence of supply data upon velocity of the missile in the form of the so-called control strategy trees in consecutive modules of the hybrid launcher: air-gun, coil-gun and rail-gun.

How to convert a factory-manufactured induction motor into rotary-linear motor? Part 2 design issues from viewpoint of educational purposes and industrial demands

2DoF rotary-linear motor is perfect study case to show that both circuit and field methods are very helpful and effective in mastering design abilities. The proposed circuit design method is termed “transformation of structure” method. Its essence is to change step by step the basic 3-phase induction motor into the desired rotary module of the 2DoF induction motor. What is important, “transformation of structure” is accompanied by detailed analytical study showing in simultaneous way conversion of the most significant curves from one phase into the another. The calculations are based on the modified equivalent circuit. As regards field design method, it employs Maxwell and FEMM program. Comparison of the results obtained with the help of circuit and field methods shows evidently advantages and disadvantages of each method, as well as confirms, in general, their equivalency.

Study on 3-winding system with angular asymmetry part I - current zero-components and 2-axis transformation

This The main purpose of this paper is to generalize the definition of current zero-component for a 3-phase system of windings with angular asymmetry and to elaborate procedure that enable to calculate value of this zero-component for the asymmetrical 3-winding system using the two different methods, respectively.

Dynamic model of hybrid electromagnetic launcher for simulations in LabVIEW environment

The paper presents dynamic model of a hybrid electromagnetic launcher consisting of three modules: air-gun, coil-gun and rail-gun. The model was elaborated and implemented in LabVIEW environment. It enables us to present easily in graphical way different dynamic curves, as well static characteristics. The model was verified by laboratory investigations performed for the selected cases. Final aim is to include the elaborated LabVIEW model in the modified automatic control system.

Study on 3-winding system with angular asymmetry part II - eigenvalues of inductance matrix and transformation αβ0

One of the most frequently-used coordinate system in theory of electrical circuits is the coordinate system spanned on eigenvectors which leads to diagonal structure of matrix relation between input and output variables. So far, this coordinate system has not been considered in details in relation to a 3-phase system of windings with angular asymmetry. In the paper the characteristic equation is formulated and eigenvalues are determined as function of angles between consecutive windings. The paper is enriched by graphical presentation of equivalent schemes and discussion on possible physical models of 3-winding asymmetrical system in coordinates αβ0 linked with eigenvector coordinate system.