AiMT Volume 11 (2016), Issue 1

6th INTERNATIONAL CONFERENCE ON MILITARY TECHNOLOGIES

May 31 to June 2, 2017 Brno, Czech Republic

First Call for Papers / Workshop Proposals

Influence of Approtic Solvents on Negative Electrode Material Properties for Lithium-ion Batteries

Libich J., Máca J., Sedlaříková M. and Vondrák J.

The following article focuses on the safety and stability of lithium-ion batteries. This type of aprotic battery is of high quality, and known to offer a number of advantages. Generally, they are used in small portable devices, such as cell phones, laptops and other similar applications. Lithium-ion batteries seem to be suitable for use in electric vehicles, in particular due to their high specific energy density. This unusual application of lithium-ion batteries puts specific demands on their parameters, e.g. high cyclability, temperature stability, etc. In this article, we have focused on materials for negative electrode along with aprotic solvents. Currently, the majority of commercially used lithium-ion batteries have a negative electrode made from graphite material with specific capacity of 372 mAh/g. As an appropriate successor of graphite, it can be considered a spinel Lithium-Titanate-Oxide (LTO), with theoretical capacity of 175 mAh/g. The liquid electrolyte solvents for lithium-ion batteries should be safe in conditions requiring high performance applications. Among important parameters of aprotic solvent belong thermal resistibility, high flash point and compatibility with electrode materials. In our experiments we used organic solvents, ethylene carbonate, dimethyl carbonate and sulfolane.

Keywords: Battery, Lithium, Safety, Capacity, LTO.

Pages: 5 - 12   [References]   [Download Citation]

Sliding Mode Control of Target Tracking System for Two Degree of Freedom Gun Turret Model

Rahmat M. S., Hudha K., Idris A. M. and Amer N. H.

This paper presents the detailed derivation of gun turret modelling along with the estimation of the ideal azimuth and elevation angles for accurate firing. A control strategy for the gun turret is developed to ensure the capability of an actuator to provide sufficient torque and accurate firing angle for the gun platform and turret. A DC motor model is constructed to actuate the gun platform and turret in high accuracy for firing angle according to the desired target angle. The desired target angle is designed based on the three-dimensional (3D) projectile motion to obtain an accurate firing angle by depending on the distance parameter x, y and z plane coordinates. The control structure for the system is controlled using the Propotional Integral Derivative (PID) and sliding mode control (SMC). The controllers are evaluated based on the performance to generate the drive torque and reduce the error of the system in tracking the desired target angle accurately. The simulation result shows that the SMC controller has advantages of high precision and accuracy for tracking the trajectory of firing angle. A comparison between PID and SMC is also presented to indicate the effectiveness of the SMC controller in terms of tracking performance and firing accuracy.

Keywords: Gun turret modelling, control strategy, gun turret target tracking, modelling and simulation.

Pages: 13 - 28   [References]   [Download Citation]

Mathematical Modeling of the Design Process of Additional Aerodynamic Surfaces of the Wing as a Component of the Configuration of a Commercial Airliner

Gorbunov A., Pripadchev A. and Bykova I.

This paper introduces the methodology and the method of automated design of additional aerodynamic surfaces of the wing as a component of the configuration of a commercial airliner, based on the suggested mathematical model. The mathematical model makes it possible to solve a particular task of developing and designing an additional aerodynamic surface of the wing for a commercial airliner and to select the required type of additional aerodynamic surface for a certain aircraft. The decision on the required type of additional aerodynamic surface for a certain aircraft is made using a specialized software product, based on the implementation of a multi-criterial approach to the selection of the method in the process of defining the set tasks. The automation of the design process of additional aerodynamic surfaces of the wing as a component of the configuration of a commercial airliner is achieved by means of the developed software product, written in an objectoriented high-level programming language.

Keywords: Additional aerodynamic surfaces, wing-tip mounted winglets, mathematical modelling, parametric synthesis, commercial airliner, structural optimization, automation of conceptual design, development and design procedures, model of characteristics.

Pages: 29 - 42   [References]   [Download Citation]

Influence of State Space Topology on the Parameter Identification Based on the PSO Method

Dub M. and Štefek A.

Motion control of electromechanical systems still plays a very important role in a wide area of weapon systems. Modern control systems use not only data from various sensors, but also state parameters of controlled system. The article explores the influence of state space topology on parameter identification of real simple electromechanical system based on the Particle Swarm Optimization (PSO) method. Four different but equivalent mathematical models of the second order were used to create different state spaces of the system parameters. A general recommendation for the PSO method setup and two independent program tools were applied to evaluate the state space searching by the PSO method. The PSO simulations were focused on both narrow and wide state spaces around the fitness function global minimum. A novel approach to set the PSO method initial agents’ positions has been introduced since the traditional random uniform distribution failed when wide state spaces were used.

Keywords: Parameter estimation, particle swarm optimization, system identification.

Pages: 43 - 52   [References]   [Download Citation]

Fuel Cell 3-D Modelling Using a Logarithmic Approximation in MATLAB® & Simulink®

Zaplatílek K. and Leuchter J.

The topic of this paper is a building process of a real fuel cell mathematical model, based on the mixed logarithmic and polynomial approximation, focused on the 3-D load characteristics. The model’s input is the values of load resistance and temperature (independent variables), whereas the output is the value of voltage. The coordinates of the operating point are determined analytically, using the double approximation (both transverse and longitudinal). The resulting 3-D model is then implemented in the MATLAB (text source code) and Simulink (block model) system environments. The core of the model is a system of optimal logarithmic approximation functions. The mathematical principle of the method and a numerical example are then presented. The main idea of the paper is to offer an accurate fuel cell model for more extensive computer experiments and to verify the presented original approximation methods.

Keywords: Fuel cell, logarithmic and polynomial approximation, MATLAB® & Simulink®.

Pages: 53 - 62   [References]   [Download Citation]

Critical Flight Conditions at High Angles of Attack, Related to Loss of Control in Lateral Motion

Akhrameev V. I., Glazkov A. A., Shibaev V. M. and Shoulepov D. V.

The paper deals with developing algorithms for stall diagnostics and airplane protection from inadvertently encountering post stall gyration and entering spin modes. It summarizes the results of the linear theory of stall developing as theoretical foundation of nonlinear approach for diagnostics of flight conditions relating to the loss of aircraft control which is understood as a moment when the angular rates exceed some critical (threshold) values, which in general depend on the angle of attack and airspeed and they correspond to control surfaces deflection.

Keywords: Airplane dynamics, high angles of attack, airplane loss-of-control, critical flight modes, stall and spin immunity, warning system, airplane control automation.

Pages: 63 - 86   [References]   [Download Citation]

TECHNICAL INFORMATION
Material Analysis of Selected Parts of the MPM-20 Jet Engine

Čerňan J., Rodziňák D., Semrád K. and Cúttová M.

The article deals with the issue of the material analyses performed on the selected parts of the MPM-20 jet engine, made within the framework of reverse engineering. The analyses were necessitated due to the absence of appropriate technical documentation to the engine. The engine is a result of conversion made on the original TS–20B/21 turbo starter. This device was formerly used for starting up of more powerful military jet engines. The material analyses were focused on the most thermally stressed parts of the engine – combustion chamber consisting of a flame tube and a combustion chamber casing, turbine blades and a turbine outer ring. The findings are expected to be applicable for further technological modifications of the engine assumed to extend its operational time and total engine efficiency.

Keywords: Small jet engine, combustion chamber, turbine blade, material engineering.

Pages: 89 - 100   [References]   [Download Citation]

TECHNICAL INFORMATION
Developments in Pilot’s Instructions for In-Flight Emergencies in Czechoslovak and Czech Republic Jet Combat Aircraft: Fire

Zavila O., Chmelík R. and Kučera P.

Fire on board an aircraft is one of the most serious incidents that may occur during operation. Ever since military jet combat aircraft were equipped with fire protection systems, flight manuals have included instructions to eliminate fire on board as part of the instructions for in-flight emergencies. Emergency abandonment thus was no longer the only and inevitable solution to the occurred situation. Over the sixty years of operation of military combat aircraft equipped with fire protection systems in Czechoslovakia and the Czech Republic, there has been a clearly discernible evolution also in instructing pilots in in-flight fire emergencies. These instructions reflect very well not only the progressive technical development of aircraft, but also the overall concept of safety in military aviation. This article presents a unique comprehensive overview of such emergency procedures, common features, differences and developments in Czechoslovak and Czech Republic military jet combat aircraft since 1951.

Keywords: Army of the Czech Republic, Czechoslovak Army, Czechoslovak People's Army, pilot, instructions, jet combat aircraft, developments, in-flight emergencies.

Pages: 101 - 116   [References]   [Download Citation]

TECHNICAL INFORMATION
Application for Designing Communication Algorithm Using CAN with CANaerospace Protocol

Janů P.

This paper introduces the most common data buses used in on-board aircraft electronic systems focusing on affordable buses and the reason for their use. Controller Area Network (CAN) was selected as the main bus representative. CAN has its special use in avionic systems called CANaerospace. In avionic systems, it is necessary to access the bus at precisely defined time intervals according to the schedule called Cycle Matrix. There is a need to develop an avionic system application for designing Cycle Matrix. Therefore, this paper focuses on mathematical analysis and a detailed description of the user application for designing Cycle Matrix in MATLAB environment. The application is intended for CAN bus specialists and it is supposed to assist with the design of communication algorithm for any avionic system.

Keywords: Bus utilization, CAN, CANaerospace, Communication analysis, Cycle matrix, MATLAB.

Pages: 117 - 125   [References]   [Download Citation]

BOOK REVIEW
Ballistics: Theory and Design of Guns and Ammunition, Second Edition

Carlucci D. E. and Jacobson Sidney S.

Pages: 129 - 130