scholarly journals Research advance of damage load of surface ship cabin explosion

2021 ◽  
Vol 51 (12) ◽  
pp. 124605
Author(s):  
Lei ZHANG ◽  
ZhiPeng DU ◽  
Peng GAO ◽  
Ying LI
Keyword(s):  
Surface Ship ◽  
Research Advance

Research advance on the instrumental analysis methods of fluoride

2016 ◽  
Vol 34 (10) ◽  
pp. 942
Author(s):  
Chengzhu NI ◽  
Xinhua JIANG ◽  
Gang LI ◽  
Jiajie ZHANG ◽  
Peimin ZHANG ◽  
...  
Keyword(s):  
Instrumental Analysis ◽  
Analysis Methods ◽  
Research Advance

Research Advance in Harmful Effects and Removal of Impurity Fe from Al and Al Alloys

2011 ◽  
Vol 295-297 ◽  
pp. 751-759 ◽  
Author(s):  
Hua Shen ◽  
Wei Dong Yang ◽  
He Liang ◽  
Guang Chun Yao
Keyword(s):  
Mechanical Properties ◽  
Aluminum Alloys ◽  
Pure Aluminum ◽  
Al Alloys ◽  
Precipitation Method ◽  
Filtration Method ◽  
Purification Methods ◽  
Research Advance ◽  
Harmful Effects

The presence of Fe and harmful effects on mechanical properties of pure aluminum and aluminum alloys are introduced. Several purification methods are reviewed, but all of them are of definite limitations. It is effective that precipitation method, filtration method and centrifugal division method are integrated.

scholarly journals Modified Vector Field Path-Following Control System for an Underactuated Autonomous Surface Ship Modelin the Presence of Static Obstacles

2021 ◽  
Vol 9 (6) ◽  
pp. 652
Author(s):  
Haitong Xu ◽  
Miguel A. Hinostroza ◽  
C. Guedes Guedes Soares
Keyword(s):  
Control System ◽  
Vector Field ◽  
Path Following ◽  
Field Method ◽  
Integrated System ◽  
Ship Model ◽  
Surface Ship ◽  
Path Following Control ◽  
Exponentially Stable ◽  
Vector Field Method

A modified path-following control system using the vector field method for an underactuated autonomous surface ship model is proposed in the presence of static obstacles. With this integrated system, autonomous ships are capable of following the predefined path, while avoiding the obstacles automatically. It is different from the methods in most published papers, which usually study path-following and obstacle collision avoidance, separately. This paper considers the coupled path following and collision avoidance task as a whole. Meanwhile, the paper also shows the heading control design method in the presence of static obstacles. To obtain a strong stability property, a nonlinear autopilot is designed based on the manoeuvring tests of the free-running ship model. The equilibrium point of the controller is globally exponentially stable. For the guidance system, a novel vector field method was proposed, and the proof shows the coupled guidance and control system is uniform semi-global exponentially stable (USGES). To prevent the obstacles near the predefined path, the proposed guidance law is augmented by integrating the repelling field of obstacles so that it can control the ship travel toward the predefined path through the obstacles safely. The repelling field function is given considering the obstacle shape and collision risk using the velocity obstacle (VO) algorithm. The simulations and ship model test were performed to validate the integrated system of autonomous ships.

scholarly journals Towards a Framework of Operational-Risk Assessment for a Maritime Autonomous Surface Ship

Energies ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3879
Author(s):  
Cunlong Fan ◽  
Jakub Montewka ◽  
Di Zhang
Keyword(s):  
Expert Knowledge ◽  
Safety Evaluation ◽  
Manual Control ◽  
Operational Mode ◽  
Surface Ship ◽  
Open Questions ◽  
Study Results ◽  
Operational Modes ◽  
Mass Case

Global research interest in the domain of maritime autonomous surface ships (MASS) is dramatically increasing. With new prototypes planned to be set to the seas where various operational modes (OMs) are claimed, the issue of the safety evaluation of an MASS, and criteria for selecting the appropriate OM for given conditions remain open questions. This paper proposes a four-step risk-informed framework to assess risk in a scenario for an MASS operating at one of three OMs: manual control (MC), remote control (RC), and autonomous control (AC). To this end, the concept of risk priority numbers (RPNs), adopted from failure mode and effects analysis (FMEA), is utilized. The required parameters to defined RPNs are obtained in the course of analyzing a model MASS accident with expert knowledge. The applicability of the proposed framework is demonstrated via a model MASS case study. Results reveal that, in the same scenario, the risk of MASS varied across the analyzed OMs. On the basis of the aggregated results for each operational mode, suggestions for OM switching are put forward.

Research advance abstracts

1982 ◽  
Vol 14 (4) ◽  
pp. 72-83
Author(s):  
SIGACT News Staff
Keyword(s):  
Research Advance
Sign in / Sign up

Export Citation Format

Share Document