Solid State Phenomena Vol. 196

Abstract: The paper presents the issues related to the probability of surface objects detection. The classical fluctuation models and the new fluctuation model for small floating objects with 10 m2 radar cross section surface are described. The possibilities of detection of examined passive radar reflectors by the radars on board merchant vessels were determined. Probability of detection of passive radar reflectors calculated using the classical fluctuation models was compared with the results obtained using the proposed new fluctuation model.

Abstract: The radar system with automatic radar plotting aid constitutes a source of input data for algorithm determining safe trajectory of a ship. The article introduces radar data transmission details. It also presents the application of computer decision support system in collision situations of passage with greater quantity of met objects on board research and training ship m/v HORYZONT II. The system enables navigational data transmission from radar system and automatic determining of safe manoeuvre or safe trajectory of a ship. Computer programme used for communication with ARPA system was designed in Matlab software.

Abstract: This material presents the results of works implemented so far at the Department of Underwater Work Technology of the Polish Naval Academy in Gdynia, Poland, within the project No. O N502 274039, focused on an attempt to prepare theoretical assumptions for the visual diagnostics system for underwater objects. The main accomplishments until now have been the preparation of a mathematical model allowing specification of dimensions of photographed underwater objects and construction of a prototype underwater photogrammetric camera. The said device is used for collecting data required in the mathematical model. Moreover, the project involved carrying out experiments which provided the basis for determining optical parameters of the constructed camera. In prospect, the works on the application for the operation of the photogrammetric camera will be accompanied by construction works on a visual assessment system allowing for quantitative and qualitative verification of the state of examined underwater objects.

Abstract: Modelling of three-dimensional motion of an underwater vehicle along a time-varying reference trajectory with predefined speed profiles is presented in the paper. A nonlinear mathematical model with unknown nonlinearities describes the vehicle’s dynamics. Command signals are generated by an adaptive autopilot consisting of three independent controllers with a parameter adaptation law implemented. A control performance is guaranteed by suitably choosing design parameters. Selected results of computer simulations are inserted to demonstrate quality and effectiveness of the approach.

Abstract: The paper considers the problems of controlling a course of an Unmanned Surface Vehicle USV. To select proper course controller, following three methods were tested: PID, slide and fuzzy control. Moreover, to counteract sea current two methods were presented and compared by means of numerical research. In the introduction, the USV called edredon is presented. In the next section, principles of operation of the tested controllers are described. Then, the methods for sea current counteracting are inserted. In the end, the results of numerical research and conclusions from carried out comparisons are presented.

Abstract: The paper presents the ways of stabilising and controlling a Ship Anti-Aircraft Rocket Missile Launcher (SAARML) with the use of a Three-Axis Gyroscope-Stabilized Platform (TAGSP). The analysis of the dynamics of the SAARML and TAGSP systems is conducted for the case of searching and tracking a manoeuvring air target in the conditions of interferences and the influence of kinematic forces from the base (ship's deck). Some research results are presented in a graphical form.

Abstract: In this paper we design the fuzzy logic autopilot to precise control and a track-keeping control of the ship. Precise control of ship has known an increasing interest in the last years. The main benefits of usage of autopilot for control of ship can be removing a man from the dangers of the undersea environment and reduction in cost of exploration of deep seas. Currently, it is common to use the special ship to accomplish missions as the inspection of coastal and off-shore structures, cable maintenance, as well as hydrographical surveys. In the military field they are employed in such tasks as surveillance, intelligence gathering, torpedo recovery and mine counter measures. Hence, a problem of its ability to move along a reference path and keep a desired orientation is regarded. A non-linear mathematical model describes the vehicle’s dynamics. Command signals are generated by an autopilot with fuzzy control law implemented. Some results of computer simulations are provided to demonstrate effectiveness, correctness and usefulness of the approach.

Abstract: The paper describes a three-stage framework for modelling of a discrete manufacturing system. It presents the self-configuration procedure for a distributed manufacturing control system with use of this framework. The procedure allows for the construction of the plug and produce distributed manufacturing control system, which requires the integration of unified, easy to reconfigure cooperative agents. Arena simulation environment (by Rockwell Automation) is used for examining the procedure.

Abstract: The main aim of paper is to introduce the results of research concentrated on controlling remotely operated underwater vehicle which task is trajectory tracking with high accuracy. Firstly the problem of trajectory tracking and its formal and mathematical description were introduced. Next the proposed fuzzy autopilot which assure high precision of trajectory tracking by underwater vehicle was presented. At the end the example results of research on trajectory tracking in environment without and with disturbance were presented. The paper is finished by summary which include conclusions derive from results of research.

Abstract: In the paper a trajectory generation algorithm for two robots’ coordinated motion is presented. Two instances of the algorithm, each for one robot, run in the same time and calculate trajectories’ position and orientation coordinates. Initial and end robots’ end-effectors poses are defined and values of linear and angular speeds are programmed. To minimize relative position and orientation errors an idea of corrective motion is introduced. Trajectory coordinates are calculated as the sum of programmed and corrective motion. The algorithm was implemented in a simulation environment and results of simulation are presented. Static accuracy analysis for general case and stability verification for fixed values of robots’ parameters are described. Finally, an outline of proposed procedure of building a virtual environment for reachability verification and collision checking is presented.