Wyniki wyszukiwania - BazTech

1

An approximate method for calculating the resistance of a transport ship model

Szelangiewicz Tadeusz, Żelazny Katarzyna

Zeszyty Naukowe Akademii Morskiej w Szczecinie

|

2019

|

nr 60 (132)

64--71

EN

The article presents regression formulas for calculating the friction resistance RF and the total resistance RT of ship models in the 2.0–10.0 m range. The method for calculating the total resistance is novel and applies to the design models of an unmanned surface vessel (USV) for experimental testing of autonomous control. For both regression models (RF and RT), statistical and substantive tests were performed (the results of the calculations were compared with the experimental measurements). In both cases, convincing results were obtained, which have confirmed the possibility of their use at the preliminary design stage of unmanned ship models.

2

The prospect for the launche of a mini unmanned aerial vehicle from an unmanned surface vehicle

Jurczyk K.

Zeszyty Naukowe Akademii Marynarki Wojennej

|

2018

|

R. 59 nr 1 (212)

5--26

EN

Due to the growing interest in the problems of cooperation among unmanned vehicles, in the article the proposition of the system for launching a mini unmanned aerial vehicle (mini-UAV) from an unmanned surface vehicle (USV) has been presented. The solution differs from the previously used in this that instead of the commonly used rotorcrafts it concerns the ability to start the mini aircraft with the help of pneumatic or rubber launcher. The results of the computer simulation have confirmed the possibility of implementation of that kind of system.

PL

W związku z rosnącym na świecie zainteresowaniem problemami współpracy między pojazdami bezzałogowymi w artykule przedstawiona została propozycja systemu pozwalającego na start małego bezzałogowego statku powietrznego (UAV) z małego bezzałogowego pojazdu nawodnego (USV). Rozwiązanie to różni się od dotychczasowych tym, iż zamiast stosowanych powszechnie wiropłatów rozpatrzono możliwość startu płatowca przy użyciu wyrzutni pneumatycznej lub gumowej wspomagającej start. Wyniki symulacji komputerowej potwierdziły możliwość realizacji takiego systemu.

3

Path following control of the underactuated USV based on the improved line-of-sight guidance algorithm

Liu T., Dong Z., Du H., Song L., Mao Y.

Polish Maritime Research

|

2017

|

nr 1

3--11

EN

The path following control problem of the underactuated unmanned surface vessel (USV) is studied in this paper. An improved line-of-sight (LOS) guidance algorithm is proposed which can adjust adaptively based on the path following error. The global asymptotically stable path following controller is designed based on the nonlinear backstepping method and the Lyapunov stability theory. Firstly, the USV path following error model is established in the Serret-Frenet (SF) coordinate frame. The path following error in the inertial coordinate frame is transformed into the SF coordinate frame, which is used to define the path following control problem. Secondly, inspired by the traditional LOS guidance algorithm, the longitudinal path following error in the SF coordinate frame is introduced into the improved LOS guidance algorithm. This allows the algorithm to adjust adaptively to the desired path. Thirdly, in order to solve the underactuated problem of the USV path following control system, the tangential velocity of the desired path is designed as a virtual input. The underactuated problem is converted to a virtual fully actuated problem by designing the virtual control law for the tangential velocity. Finally, by combining backstepping design principles and the Lyapunov stability theory, the longitudinal thrust control law and the yaw torque control law are designed for the underactuated USV. Meanwhile, the global asymptotic stability of the path following error is proved. Simulation experiments demonstrate the effectiveness and reliability of the improved LOS guidance algorithm and the path following controller.

4

The Human Element and Autonomous Ships

Ahvenjärvi S.

TransNav : International Journal on Marine Navigation and Safety of Sea Transportation

|

2016

|

Vol. 10, no. 3

517--521

EN

The autonomous ship technology has become a “hot” topic in the discussion about more efficient, environmentally friendly and safer sea transportation solutions. The time is becoming mature for the introduction of commercially sensible solutions for unmanned and fully autonomous cargo and passenger ships. Safety will be the most interesting and important aspect in this development. The utilization of the autonomous ship technology will have many effects on the safety, both positive and negative. It has been announced that the goal is to make the safety of an unmanned ship better that the safety of a manned ship. However, it must be understood that the human element will still be present when fully unmanned ships are being used. The shore-based control of a ship contains new safety aspects and an interesting question will be the interaction of manned and unmanned ships in the same traffic area. The autonomous ship technology should therefore be taken into account on the training of seafarers. Also it should not be forgotten that every single control algorithm and rule of the internal decision making logic of the autonomously navigating ship has been designed and coded by a human software engineer. Thus the human element is present also in this point of the lifetime navigation system of the autonomous ship.