Control method of frog mouth type bilge keel

Abstract

The invention relates to a control method of a frog mouth type bilge keel. A main structure of the frog mouth type bilge keel comprises a fixed clamshell structure (2) and a rotary clamshell structure (1). The rotary clamshell structure (1) is connected with the fixed clamshell structure (2) through a rotary shaft system. The control method of the frog mouth type bilge keel includes the steps that when a ship sails, the rolling angle, the angular speed and the angular accelerated speed of the ship are monitored, ship draught information is obtained, and the ship stability change is checked; if any index of the three parameters including the rolling angle, the angular speed and the angular accelerated speed continuously exceeds the upper limit of a corresponding safety threshold value within a set time, a motor is used for driving the rotary shaft system to unfold the rotary clamshell structure of the bilge keel; and if the three parameters including the rolling angle, the angular speed and the angular accelerated speed are continuously lower than the lower limit of the corresponding safety threshold value within the set time, the motor is used for driving the rotary shaft system to fold the rotary clamshell structure of the bilge keel. By the adoption of the control method of the frog mouth type bilge keel, the bilge keel can be intelligently controlled to be unfolded and folded; and the rolling damping of the ship can be increased, rolling of the ship is effectively reduced, and rolling stability is enhanced.

Description

technical field [0001] The invention relates to marine equipment for reducing rolling, a bilge keel that can change shape according to sea conditions, that is, a bilge keel used for anti-sinking, anti-rolling, and anti-overturning of ships. Background technique [0002] The swaying motion of the ship is a harmful ship motion, which has adverse effects on the crew, hull structure, mechanical equipment, etc. Ship swaying motions include six types: roll, pitch, yaw, surge, sway and heave, among which roll has the greatest impact on ship performance, followed by pitch. In order to slow down or reduce the sway of the ship, an anti-rolling device can be added to the ship. [0003] According to the essential classification of the force constituting the stabilizing moment, the anti-rolling device can be divided into three types: gravity action type, fluid dynamic action type, and rotary force action type; according to the control form, it can be divided into passive type and active...

AI Technical Summary

Problems solved by technology

However, the existing bilge keel structure has the following defects and deficiencies: it is vulnerable to damage; it produces certain navigational resistance to the ship; it can only reduce roll, but not pitch

Moreover, limited by the size of the bilge keel, the damping moment of the anti-rolling is limited, and the ability of anti-rolling (reducing the swing amplitude) is limited. The anti-rolling effect is generally around 10% to 20%, which is difficult to meet the demand

In addition, for a certain bilge keel, due to the fixed shape and size of the bilge keel, dynamic adjustments cannot be made in response to changes in sea conditions, roll angles and accelerations, which greatly affects its application range

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