Tom 216 (2019): Zeszyt 1 (March 2019)

In this paper a results of a transient analysis of the linear actuator is presented. The linear actuator consist of the three cylindrical unmovable coils surrounded by a soft ferromagnetic case, a runner made from sequence of ferromagnetic and permanent magnet rings. The model of the linear actuator was implemented into two software: the Comsol Multiphysics and the Matlab-Simulink. Both environments are commonly used in simulation analysis, but the first one uses Finite Element Method (FEM) and the second one uses Ordinary Differential Equations (ODE). Moreover, the dynamic model was analysed in Matlab-Simulink software with value of electromagnetic phenomena implemented from Comsol Multiphysics. Comparison was made due to the time needed for calculation, accuracy of the simulation model as well as the as utility for further optimization process.

The article contains the chosen results of research on the use of energy profiles controlling the operation of a group of devices powered by a hybrid power source. The concept of using alternative energy sources allows to reduce the total weight of the power system and model its behavior during work. Modern fuel cells are characterized with a very high energy density to mass ratio [Wh/kg], and the additional cooperation of supercapacitors and lithium-ion batteries supporting their operation ensures continuous operation and the required dynamics response while maintaining a low mass of the power supply system. The author presented the general configuration of the layout model, as well as the results of tests of individual elements included in the physical implementation of the hybrid power system.

Article presented below is a prelude to the process of autonomous underwater systems positioning. An article include description of positioning methods and guidelines for the operators of autonomous underwater vehicles (AUVs), concerning above mentioned process.

The article discussed aim to introduce readers to the problem matter in connection with the changes taking place within the area related to the issue of metrology in the Armed Forces of the Polish Republic. The article depicts the current situation along with the changes, which took place over the recent years, in the structures of Military Metrology, and it presents the major directions of its development, with particular emphasis on the automation of the calibration process.

The article in the short form presents a problem of protection of human activity in the offshore sector. Authors particularly focused on the analysis and presentation of highly specialized vessels — ERRV (Emergency Response and Rescue Vessels) which are specially designed to ensure safety in the offshore sector; their equipment and its appropriate use. Specific solutions and measures, their capabilities and limitations were presented.

Security of national borders requires utilization of multimedia surveillance systems automatically gathering, processing and sharing various data. The paper presents such a system developed for the Maritime Division of the Polish Border Guard within the STRADAR project. The system, apart from providing communication means, gathers data, such as map data from AIS, GPS and radar receivers, videos and photos from camera or audio from phone calls and SMS messages, from multiple mobile units and stationary points located along the coastline. All gathered data can be visualized on a multidisplay by the personnel that can dynamically select presented data and configure form of presentation. The paper describes system functionalities, its hardware and software implementation, and presents results of acceptance tests that the system have recently passed.

The effectiveness and efficiency of production system is a guarantee of the company’s success, especially in times of dynamic growth of trade (including online trade), as well as increasing customers’ requirements, who want to have goods always available and delivered, preferably on the day of order. A modern customer of services raises the bar high not only for production systems, but also for transport systems. Therefore, IT tools supporting the management process of all areas of its activity are implemented in enterprises. This article describes selected of them, focusing primarily on the support of production planning process.

As the use of IT systems should be preceded by deepening the knowledge of algorithms applied in them, first of all a calculation example of the use of material requirements planning procedure for complex products with a modular structure was presented, and then the characteristics of selected IT tools supporting the processes of material requirements planning and enterprise resource planning have been made.

The company’s success depends on many factors. One of them is the ability to meet the customers’ expectations and adjust to the needs reported by market. Mathematical methods and tools are helpful in assessing demand. Forecasts should take into account all factors shaping the demand for goods and services, but they are often difficult to define, not only because of their large number, but also due to the impact of individual variables, which is difficult to determine. In many cases, the number of placed orders strongly depends on the time at which they are submitted. The needs can vary according to the time of day, week and year. Then we are dealing with the so-called seasonality, the inclusion of which is very important in the company and enables to better adapt its activity to the customers’ requirements.

This article describes the seasonality of demand in a company providing domestic and road transport services with high-tonnage vehicles. The validity of such analyses and potential benefits were indicated.