The Development and Testing of an Optimised Ride Control System for a 102-Metre Trimaran Ferry

2011 ◽  
Author(s):  
T Clarke ◽  
◽  
N A Armstrong ◽  
J Lee ◽  
◽  
...  
Keyword(s):  
Control System ◽  
Ride Control ◽  
Ride Control System

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.

Full-Scale Motions Of A Large High-Speed Catamaran: The Influence Of Wave Environment, Speed And Ride Control System

2012 ◽  
Vol 154 (A3) ◽  
Keyword(s):  
Control System ◽  
Time Domain ◽  
High Speed ◽  
Full Scale ◽  
Pitch Motion ◽  
Motion Response ◽  
Beam Seas ◽  
Ride Control ◽  
Ride Control System ◽  
Vessel Speed

To assess the behaviour of large high-speed catamarans in severe seas, extensive full-scale trials were conducted by the U.S. Navy on an INCAT Tasmania built vessel in the North Sea and North Atlantic region. Systematic testing was done for different speeds, sea states and ride control settings at different headings. Collected data has been used to characterise the ship’s motions and seakeeping performance with respect to wave environment, vessel speed and ride control system. Motion response amplitude operators were derived and compared with results from a two-dimensional Green function time-domain strip theory seakeeping prediction method. An increase of motion response with increasing vessel speed and a decrease with the vessel moving from head to beam seas was found. In higher sea states and headings ahead of beam seas an increasing influence of the centre bow on pitch motion damping was found. Significant motion RAO reduction was also found when the ride control system was active. Its effectiveness increased at higher speeds and contributed to heave and pitch motion RAO reduction. Predicted motion magnitudes with the time domain seakeeping code were consistent with the measured motion responses, but maximum heave was predicted at a rather higher frequency than was evident in the trials.

The development of a ride control system for fast ferries

1995 ◽  
Vol 3 (5) ◽  
pp. 695-702 ◽  
Author(s):  
A.J. Haywood ◽  
A.J. Duncan ◽  
K.P. Klaka ◽  
J. Bennett
Keyword(s):  
Control System ◽  
Ride Control ◽  
Ride Control System

scholarly journals An Experimental Investigation of Ride Control Algorithms for High-Speed Catamarans Part 1: Reduction of Ship Motions

2017 ◽  
Vol 61 (01) ◽  
pp. 35-49
Author(s):  
Javad AlaviMerh ◽  
Jason Lavroff ◽  
Michael R. Davis ◽  
Damien S. Holloway ◽  
Giles A. Thomas
Keyword(s):  
Control System ◽  
Motion Control ◽  
High Speed ◽  
Vertical Acceleration ◽  
Pitch Control ◽  
Model Scale ◽  
Ride Control ◽  
Control Feedback ◽  
Control Surfaces ◽  
Ride Control System

Ride control systems are essential for comfort and operability of high-speed ships, but it remains an open question what is the optimum ride control method. To investigate the motions of a 112-m high-speed catamaran fitted with a ride control system, a 2.5-m model was tested in a towing tank. The model active control system comprised two transom stern tabs and a central T-Foil beneath the bow. Six ideal motion control feedback algorithms were used to activate the model scale ride control system and surfaces in a closed-loop control system: heave control, local motion control, and pitch control, each in a linear and nonlinear version. The responses were compared with the responses with inactive control surfaces and with no control surfaces fitted. The model was tested in head seas at different wave heights and frequencies and the heave and pitch response amplitude operators (RAOs), response phase operators, and acceleration response were measured. It was found that the passive ride control system reduced the peak heave and pitch motions only slightly. The heave and pitch motions were more strongly reduced by their respective control feedback. This was most evident with nonlinear pitch control, which reduced the maximum pitch RAO by around 50% and the vertical acceleration near the bow by about 40% in 60-mm waves (2.69 m at full scale). These reductions were influenced favorably by phase shifts in the model scale system, which effectively contributed both stiffness and damping in the control action.

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