Anomalous Behavior of Merchant Ship Steering Systems

1970 ◽  
Vol 7 (02) ◽  
pp. 205-215 ◽  
Author(s):  
Robert Taggart
Keyword(s):  
High Speed ◽  
Mechanical Characteristics ◽  
Anomalous Behavior ◽  
Similar Response ◽  
Steering Control ◽  
Unstable Condition ◽  
Ship Steering ◽  
Merchant Ship ◽  
Automatic Steering ◽  
And Control

An unusual combination of circumstances occurring during an Atlantic crossing of a highspeed containership created a situation where the rudder, acting in response to automatic steering control demands, caused excessive ship rolling. Further investigation revealed the existence of an unstable condition due to a combination of asymmetrical hydrodynamic and mechanical characteristics and the interrelationship of ship motion and control actuation. Similar response has been noted on other high-speed vessels and is a cause for major concern in future containership operations. The elements involved in creating these conditions have been examined in detail and a plausible explanation has been evolved as to how they can combine to produce the observed results. With an understanding of the causes of this anomalous behavior it is possible to devise means for preventing its occurrence in future designs.

Energy Losses Related to Automatic Steering of Ships in Waves—Part II: Performance of Controllers Designed to a New Criterion

1983 ◽  
Vol 105 (3) ◽  
pp. 325-332 ◽  
Author(s):  
R. E. Reid ◽  
B. C. Mears ◽  
D. E. Griffin
Keyword(s):  
High Speed ◽  
Load Condition ◽  
Performance Criterion ◽  
Sensitivity Analyses ◽  
Energy Losses ◽  
Steering Control ◽  
Linear Quadratic ◽  
Linear Quadratic Gaussian ◽  
Automatic Steering ◽  
New Criterion

Minimization of energy losses associated with the steering control of modern ship types is discussed on the basis of frequency-domain sensitivity analyses and time-domain simulation studies. A high-speed containership and large tankers in the full-load condition are analyzed. A new performance criterion for minimization of steering-related propulsion losses is presented, and controllers designed to it using linear quadratic Gaussian (LQG) techniques. In the case of the containership, the resulting controller is shown to have the potential to reduce the net losses related to steering below those of the uncontrolled ship through proper use of the rudder in some conditions. While this does not seem possible for the tankers, the results indicate that a controller designed to the new criterion results in lower losses than a controller based on a form of criterion to which new autopilots for tankers are presently being designed. The implications for both autopilot and steering gear servo-design based on these results are discussed.

scholarly journals Ship Steering Control Based on Quantum Neural Network

Complexity ◽  
2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
Wei Guan ◽  
Haotian Zhou ◽  
Zuojing Su ◽  
Xianku Zhang ◽  
Chao Zhao
Keyword(s):  
Neural Network ◽  
Good Control ◽  
Learning Rate ◽  
Steering Control ◽  
Quantum Neural Network ◽  
Planning And Control ◽  
Fast Learning ◽  
Ship Steering ◽  
Learning Capabilities ◽  
And Control

During the mission at sea, the ship steering control to yaw motions of the intelligent autonomous surface vessel (IASV) is a very challenging task. In this paper, a quantum neural network (QNN) which takes the advantages of learning capabilities and fast learning rate is proposed to act as the foundation feedback control hierarchy module of the IASV planning and control strategy. The numeric simulations had shown that the QNN steering controller could improve the learning rate performance significantly comparing with the conventional neural networks. Furthermore, the numeric and practical steering control experiment of the IASV BAICHUAN has shown a good control performance similar to the conventional PID steering controller and it confirms the feasibility of the QNN steering controller of IASV planning and control engineering applications in the future.

Energy Losses Related to Automatic Steering of Ships in Waves—Part I: Losses Under Conventional Autopilot Control

1983 ◽  
Vol 105 (3) ◽  
pp. 318-324 ◽  
Author(s):  
R. E. Reid ◽  
B. C. Mears ◽  
D. E. Griffin
Keyword(s):  
Computer Simulation ◽  
Time Domain ◽  
Energy Losses ◽  
Simulation Studies ◽  
Steering Control ◽  
Ship Steering ◽  
Captive Model Tests ◽  
Automatic Steering ◽  
Computer Simulation Studies ◽  
Hydrodynamic Data

Results are presented relating to energy losses due to ship steering in waves. Propulsion losses related to yawing and rudder activity of ships during open-seas course-keeping are evaluated. Two representative tankers of 250,000 and 400,000 dwt, and an 880 ft (268 m) long containership are examined, using hydrodynamic data resulting from captive model tests. The approach presented involves time-domain computer simulation studies of the yaw-sway-surge-rudder coupled motions of the ships. Evaluation of losses due to both yawing of the uncontrolled ship and those resulting from yawing and rudder effects in the automatically steered case are made. On the basis of the results presented it is shown that under the action of waves yawing of a ship results in significant energy losses. It is also shown that a substantial increase in energy losses occurs under automatic steering control with commonly accepted autopilot specifications.

scholarly journals Rotary steerable systems: mathematical modeling and their case study

2021 ◽  
Vol 11 (6) ◽  
pp. 2743-2761
Author(s):  
Caetano P. S. Andrade ◽  
J. Luis Saavedra ◽  
Andrzej Tunkiel ◽  
Dan Sui
Keyword(s):  
Directional Drilling ◽  
Steering Control ◽  
Fundamental Physics ◽  
Drilling Tools ◽  
Drilling Operations ◽  
Beam Bending ◽  
Extended Reach Drilling ◽  
And Control ◽  
2D And 3D

AbstractDirectional drilling is a common and essential procedure of major extended reach drilling operations. With the development of directional drilling technologies, the percentage of recoverable oil production has increased. However, its challenges, like real-time bit steering, directional drilling tools selection and control, are main barriers leading to low drilling efficiency and high nonproductive time. The fact inspires this study. Our work aims to contribute to the better understanding of directional drilling, more specifically regarding rotary steerable system (RSS) technology. For instance, finding the solutions of the technological challenges involved in RSSs, such as bit steering control, bit position calculation and bit speed estimation, is the main considerations of our study. Classical definitions from fundamental physics including Newton’s third law, beam bending analysis, bit force analysis, rate of penetration (ROP) modeling are employed to estimate bit position and then conduct RSS control to steer the bit accordingly. The results are illustrated in case study with the consideration of the 2D and 3D wellbore scenarios.

Design and control of a high-speed direct-drive manipulator

1989 ◽  
Vol 27 (3) ◽  
pp. 375-394 ◽  
Author(s):  
K. YOUCEF-TOUMI ◽  
A. T. Y. KUO
Keyword(s):  
High Speed ◽  
Direct Drive ◽  
And Control

Effect of Slice Priority for admission control in 5G Wireless Networks: A comparison study for two Fuzzy-based systems considering Software-Defined-Networks

2020 ◽  
Vol 26 (3) ◽  
pp. 169-183
Author(s):  
Phudit Ampririt ◽  
Yi Liu ◽  
Makoto Ikeda ◽  
Keita Matsuo ◽  
Leonard Barolli ◽  
...  
Keyword(s):  
Wireless Networks ◽  
Admission Control ◽  
High Speed ◽  
Additional Parameter ◽  
Fifth Generation ◽  
Efficient Management ◽  
Grade Of Service ◽  
User Request ◽  
Control Decision ◽  
And Control

The Fifth Generation (5G) networks are expected to be flexible to satisfy demands of high-quality services such as high speed, low latencies and enhanced reliability from customers. Also, the rapidly increasing amount of user devices and high user’s requests becomes a problem. Thus, the Software-Defined Network (SDN) will be the key function for efficient management and control. To deal with these problems, we propose a Fuzzy-based SDN approach. This paper presents and compares two Fuzzy-based Systems for Admission Control (FBSAC) in 5G wireless networks: FBSAC1 and FBSAC2. The FBSAC1 considers for admission control decision three parameters: Grade of Service (GS), User Request Delay Time (URDT) and Network Slice Size (NSS). In FBSAC2, we consider as an additional parameter the Slice Priority (SP). So, FBSAC2 has four input parameters. The simulation results show that the FBSAC2 is more complex than FBSAC1, but it has a better performance for admission control.

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