Tom 206 (2016): Zeszyt 3 (September 2016)

Currently a much higher number of portable devices with improved functionality supporting our job-related and social activities require higher and higher capacity and power offered by sources of power supply. Theoretical analysis of the possibility to achieve exploitation features of currently known portable sources of electric current has led the author to a conclusion that even the best solutions will not meet the desired mass and volume magnitudes in relation to the energy supplied. Therefore, if the sources of energy have reached the physically and economically justified capability limits and they are characterized by significantly varied exploitation properties, a solution combining the advantages of various sources of energy through energy management seems to be sensible. In this connection this article presents the idea of a system of energy control, which using available cells will allow for reducing the weight of power supply systems. The considerations are based on defense-related applications, this, however, does not exclude applications for civilian purposes.

A control system supporting motion of an underwater robotic vehicle along a reference trajectory in the horizontal plane is presented in the paper. A waypoint line-of-sight scheme and nonlinear PD control law are applied to calculate command signals. Parameters of the proposed control law are tuned using genetic algorithms. The validity and advantages of the approach are illustrated through numerical simulation results.

This paper provides the definitions and basic properties related to a discrete state space semi-Markov process. The semi-Markov process is constructed by the so called Markov renewal process that is a special case the two-dimensional Markov sequence. The Markov renewal process is defined by the transition probabilities matrix, called the renewal kernel and an initial distribution or by another characteristics which are equivalent to the renewal kernel. The counting process corresponding to the semi-Markov process allows to determine concept of the process regularity. In the paper are also shown the other methods of determining the semi-Markov process. The presented concepts are illustrated a simple example.

This article presents a summary of years of research of corrosion resistance and corrosive-stress marine materials and their joints. Aluminium alloys and marine steels including the austenitic have been the subject of research in terms of resistance of these materials for electrochemical corrosion in sea environment. Under certain conditions austenitic steels and aluminium alloys show low susceptibility to corrosion due to the protective oxide film which form itself spontaneously on their surfaces and which became a part of monitoring corrosion of these materials. Unfortunately, the real conditions of ship structures loads and the impact conditions of the sea environment show the need to search for the new materials or to modify those already used in order to increase their corrosive-stress resistance. The welded joints of the above mentioned materials were the special subject of corrosive research and nowadays their friction stir welding joints. Modifying the structure of the origin materials by the alloyed elements, changing the parameters of the heat treatment, using the suitable protective paints or selection of the proper adhesives to connect these materials are the methods used in the following research to increase the corrosion resistance of the aluminium alloys. However, monitoring corrosion based on the patent US 2167 23 states a particular point of these research.

The paper presents the issues associated with the domestic construction of unmanned surface vessels, which are in the limelight of western counties as one of the reinforcing elements of internal security and maritime economy. Also discussed are some experiences from construction of the first such vessel named ‘Edredon’, and on the example of Gdansk Bay and the seaport of Gdynia a number of selected tasks that can be carried out by a vessel in the process of state’s maritime services protection, and in monitoring and protection of the seaports and objects of critical infrastructure. Moreover, the directions for further development (autonomous vessels, in particular) that can be accomplished in a short period of time, based on domestic scientific abilities and shipbuilding industry are indicated.

This article presents the results of operations performed by an underwater vehicle in the course of approaching a target across water in which there exist pre-defined obstacles and sea currents. The mathematical model of a self-propelled payload for neutralizing mines type ‘Głuptak’ is used to model the operations performed by the vehicle. Because the underwater vehicle is powered by batteries it is necessary to assess whether there will be enough energy required to continue the approach to the target in the case of changes in the environment. The results presented refer to the effect of interference, caused by the marine environment, on the possibility to use the vehicle for this task. The energy consumption for the mentioned task is optimized with a genetic algorithm.

In the recent years, a dynamical development of an underwater robotics has been noticed. The robotics is developed in several different directions by many foreign and a few national R&D centers. The development is focused on both an improvement of construction and features of the underwater vehicles (a hardware development) and an increase of underwater vehicle autonomy providing to a swarm control (a software development). In the paper, new research area focused on biomimetic underwater robots undertaken at the Institute of Electrical Engineering and Automatics in the recent years is presented. The area concern both hardware and software development of the underwater vehicles. In the paper, the research on biomimetic underwater vehicles developed within national and international projects is described. At the end of the paper, a summary containing foreseen research is included.

The article discusses the construction of a breathing simulator used at the Department of Underwater Works Technology of the Polish Naval Academy in Gdynia for the research on an open-circuit air diving apparatus for compliance with the PN-EN 250:2014 standard.

In order to increase security of the country in the field of new materials and technologies and research methods were developed, patented and implemented: austenitic steel X02CrNiMoMnN21-16-5-4 with electrodes for welding of steel and high-strength bainitic steel 10GHMBA-E620T. The author developed a theoretical and technological basis for the design of marine constructional-ballistic shields, which has implemented a pilot scale and technical support. In addition, he developed an original method for testing ballistic shields and unified position to the research, which studied and co-patented.