Decoupled cushion control in ride control systems for air cushion catamarans

2000 ◽  
Vol 8 (2) ◽  
pp. 191-203 ◽  
Author(s):  
Daniele Bertin ◽  
Sergio Bittanti ◽  
Sergio M. Savaresi
Keyword(s):  
Control Systems ◽  
Ride Control ◽  
Air Cushion

The Decoupled Cushion Control in Ride Control Systems for Air Cushion Catamarans

1998 ◽  
Vol 31 (30) ◽  
pp. 217-222
Author(s):  
Daniele Bertin ◽  
Sergio Bittanti ◽  
Sergio M. Savaresi
Keyword(s):  
Control Systems ◽  
Ride Control ◽  
Air Cushion

Operation of Ride Control Systems to Minimise Slamming of Wave-Piercing Catamarans

2021 ◽  
Vol 163 (A1) ◽  
pp. 29-40
Author(s):  
M R Davis
Keyword(s):  
Control Systems ◽  
High Speed ◽  
Vertical Motion ◽  
Ship Motions ◽  
Wave Surface ◽  
Active Motion ◽  
Ride Control ◽  
Heave Motion ◽  
Control Feedback ◽  
Active Controls

Wave slam produces dynamic loads on the centre bow of wave piercing catamarans that are related to the relative vertical motion of the bow to the encountered wave surface. Rapid slam forces arise when the arch sections between centre bow and main hulls fill with rising water. In this paper time domain solutions for high speed ship motion in waves, including the action of active motion controls, are used to compute the slam forces. Slamming occurs at specific immersions of the bow whilst the peak slam force is characterised by the maximum relative vertical velocity of the bow during bow entry. Vertical motions of bow and encountered wave are in antiphase at encounter frequencies where slamming is most severe. The range of encounter frequencies where slamming occurs increases with wave height. Wave slam loads reduce ship motions, the heave motion being most reduced. Deployment of a fixed, inactive T-foil can reduce slamming loads by up to 65 %. With active controls peak slamming loads on the bow can be reduced by up to 73% and 79% in 4 m and 3 m seas, local control feedback being marginally the most effective mode of control for reduction of slamming.

Recent Developments in Ride Control

2015 ◽  
Author(s):  
Alan J. Haywood ◽  
Benton H. Schaub ◽  
Chris M. Pappas
Keyword(s):  
Control Systems ◽  
High Speed ◽  
New Technologies ◽  
Early Adoption ◽  
Wide Range ◽  
Ride Control ◽  
Recent Developments ◽  
Material Choice ◽  
Maintenance Requirements ◽  
Broad Understanding

The use of ride control systems on high speed vessels has become the norm within many industries, producing better seakeeping that in turn provides a more comfortable and operationally effective vessel. Commercial ferry designers have been at the forefront of adoption of new technologies notably with early adoption of T-foils and interceptors. These devices have been taken up by others, for example offshore crew boats and frontline naval warships. The range of vessel types has also expanded with more industries adopting different hull designs including catamarans and trimarans. Ride control systems have developed alongside innovative designers producing for example combined lifting foil and ride control systems, lifting T-foil systems, retractable T-foils. This paper will review the different ride control devices including fins, trim tabs, interceptors, T-foils (including retractable T-foils) and lifting foils. As well as technical aspects, the discussion will consider costs, ease of installation, operational and maintenance requirements and material choice. Extensive examples from a wide range of industries will be presented. By the end of the talk, delegates will have a broad understanding of the options available to them in improving the seakeeping of their vessels.

RESPONSE OF A HIGH-SPEED WAVE-PIERCING CATAMARAN TO AN ACTIVE RIDE CONTROL SYSTEM

2021 ◽  
Vol 158 (A4) ◽  
Author(s):  
J AlaviMehr ◽  
M R Davis ◽  
J Lavroff ◽  
D S Holloway ◽  
G A Thomas
Keyword(s):  
Control System ◽  
Control Systems ◽  
High Speed ◽  
Control Surface ◽  
Control Algorithms ◽  
Active Centre ◽  
Ride Control ◽  
Control Step ◽  
Set Up ◽  
Ride Control System

Ride control systems on high-seed vessels are an important design features for improving passenger comfort and reducing motion sickness and dynamic structural loads. To investigate the performance of ride control systems a 2.5m catamaran model based on the 112m INCAT catamaran was tested with an active centre bow mounted T-Foil and two active stern mounted trim tabs. The model was set-up for towing tank tests in calm water to measure the motions response to ride control step inputs. Heave and pitch response were measured when the model was excited by deflections of the T-Foil and the stern tab separately. Appropriate combinations of the control surface deflections were then determined to produce pure heave and pure pitch response. This forms the basis for setting the gains of the ride control system to implement different control algorithms in terms of the heave and pitch motions in encountered waves. A two degree of freedom rigid body analysis was undertaken to theoretically evaluate the experimental results and showed close agreement with the tank test responses. This work gives an insight into the motions control response and forms the basis for future investigations of optimal control algorithms.

scholarly journals An experimental investigation on slamming kinematics, impulse and energy transfer for high-speed catamarans equipped with Ride Control Systems

2019 ◽  
Vol 178 ◽  
pp. 410-422 ◽  
Author(s):  
Javad AlaviMehr ◽  
Jason Lavroff ◽  
Michael R. Davis ◽  
Damien S. Holloway ◽  
Giles A. Thomas
Keyword(s):  
Experimental Investigation ◽  
Energy Transfer ◽  
Control Systems ◽  
High Speed ◽  
Ride Control

Dynamic Hull Vane – A Solution for active Pitch Motion Reduction and Resistance Reduction of ships

2021 ◽  
Author(s):  
Alan Haywood ◽  
Andrew Ricks ◽  
Bruno Bouckaert ◽  
Julian Hofman
Keyword(s):  
Energy Saving ◽  
Control Systems ◽  
Upward Flow ◽  
Pitch Motion ◽  
Resistance Reduction ◽  
Ride Control ◽  
Lift Forces

The Dynamic Hull Vane® is an actively controlled version of the Hull Vane®, a patented energy-saving and seakeeping device which consists of a submerged wing mounted on the aft ship. The Hull Vane is positioned in the upward flow aft of the ship, to develop forward thrust and reduce the stern wave. Naiad Dynamics US Inc, is a supplier of ride control systems and has worked with Hull Vane BV to develop the Dynamic Hull Vane®. By enabling the Hull Vane® to rotate, it can produce variable lift forces which when suitably controlled can reduce the pitching motions of a vessel in a seaway. This paper describes some of the research carried out on the AMECRC series 13, a generic fast displacement hull.

VI—Hovercraft and the Collision Regulations

1962 ◽  
Vol 15 (4) ◽  
pp. 383-386
Author(s):  
J. H. Hardwick
Keyword(s):  
Control Systems ◽  
First Generation ◽  
Point Of View ◽  
Present Generation ◽  
Air Cushion ◽  
Air Cushion Vehicle ◽  
The Mind

The preceding papers have shown that the present generation of hovercraft being used mainly on overwater routes should be considered as ships. The problems of operating these very fast craft in the same media as conventional vessels is receiving a lot of thought at the present time and perhaps a few more words on this subject would not be amiss.In framing operational rules for hovercraft it has been proposed that they obey the Regulations for Preventing Collision at Sea in so far as their size and construction will permit. This is in fact the point of view which has been put forward by the Hovercraft Operational Requirements Panel, representing Hovercraft Developments Ltd. and the industry, in their provisional British Air-Cushion Vehicle Operational Rules.If this approach is accepted, three questions immediately spring to the mind of the mariner;(1) How manœuvrable are these machines that skid around on a cushion of air? The present papers have shown very clearly how well the turning circles and stopping distances of hovercraft compare with conventional ships. Control systems have improved tremendously since the first generation of machines and they are now far more manœuvrable than ships proceeding at a fraction of their speed. Experience in driving these craft has shown that this problem causes, little trouble, and as a result of various hovercraft demonstrations their manœuvrability at speed now seems to be generally accepted as satisfactory.

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