JPH01254482A - Control method for fin stabilizer - Google Patents

Abstract

PURPOSE:To prevent production of an irregular swing angular velocity, by a method wherein movement of a fine or a flap for a fin stabilizer is smoothed approximately at a maximum working angle. CONSTITUTION:A lateral swing angle theta detected by a swing angle detector 3 is inputted to a first synchronous output circuit 13, and after it is converted into a lateral swing angular velocity theta' by means of a differentiating circuit 10, it is inputted to a second synchronous output circuit 14. Further, after it is converted into a lateral swing angular velocity theta'' by means of a differentiating circuit 11, it is inputted to a third synchronous output circuit 15. Thereafter, a fin command angle phi1 is determined by an adding circuit, a fin angle stabilizer phi2 after control of smoothing of a waveform is determined by a waveform smoothing computing circuit 17, and further a final fin angle command angle phic is outputted through a limiter 18. This method enables prevention of production of an irregular lateral swing angular velocity, and prevention of worsening of seasickness.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an improvement in a method for controlling a fin stabilizer.

[Prior art]

Ships, especially passenger ships, have a number of motion reduction devices to reduce motion in order to prevent passengers from getting seasick and to provide comfortable accommodation.In particular, large cruise ships use fin stabilizers to prevent the ship from rolling. The angles of the fins and flaps are adjusted to reduce lateral sway.

However, in the past, when the ship's rolling became large, the fins were controlled in a Bang-Bang control (Bang-Bang control), that is, the relationship between the fin angle Φ and the time t was square, as shown by the broken line in Fig. 4. This results in irregular roll angular acceleration, which is in addition to roll. This also causes seasickness to worsen.

[Purpose of the invention]

The present invention has been made in order to eliminate such conventional drawbacks, and by smoothing the angle adjustment of the fins or flaps in the fin stabilizer when the rolling angle of the ship becomes large, the irregular rolling angle can be improved. The purpose is to prevent the occurrence of yaw angular acceleration, thereby preventing the deterioration of seasickness and the like.

[Structure of the invention]

In order to achieve the above object, the fin stabilizer control method of the present invention is characterized in that the movement of the fins or flaps in the fin stabilizer is smoothed before and after the maximum operating angle.

〔Example〕

Hereinafter, the present invention will be explained in detail with reference to the drawings.

In FIG. 1, reference numeral 1 denotes a hull, and a fin 2a for a fin stabilizer is disposed on the port side of the hull 1, and a fin 2b is disposed on the starboard side. These fins 2a and 2b can be rotated clockwise a and counterclockwise, respectively. Also, inside the hull 1, a rolling angle detector 3, a control device 4, a motor 5a with a transmission,
5b is installed and, for example, when the hull 1 is tilted to the left,
The fin command angle φC calculated by the control device 4 based on the roll angle θ from the roll angle detector 3 is the fin command angle φC of the transmission device motor 5a.
, 5b, the motor 5a rotates the fin 2a on the port side counterclockwise as shown in FIG. 2, and the motor 5b on the starboard side rotates the fin 2b clockwise a. When the fins 2a and 2b are rotated, a restoring force is generated in these fins 2a and 2b to restore the hull 1 to the right.

In this case, if the fins are controlled in a wide range as in the past when the ship's rolling angle becomes large, this may actually worsen seasickness, but in the present invention, the fins can be moved in order to prevent seasickness from worsening. is controlled so that it is smooth before and after the maximum operating angle.

That is, FIG. 3 is an example of a detailed diagram of the control device 4 according to the present invention, and shows the rolling angle θ detected by the rolling angle detector 3.
is input to the first synchronous output circuit 13, and the above-mentioned roll angle θ is converted into a roll angular velocity J by a differentiating circuit 1O, and then input to the second synchronous output circuit 14. The angular velocity θ is converted into a rolling angular acceleration i by the second-order differentiator 11, and then input to the third synchronization output circuit 15.

A control gain is determined for each synchronous output circuit, and the fin command angle Φ1 is determined based on the gain. The synchronous output circuit 13 sets the roll angle deviation gain to 1, and the second synchronous output circuit 14 sets the roll angular velocity deviation gain KZ%.
Furthermore, the roll angle acceleration deviation gain in the third synchronization output circuit 15 is set to 3.

Thereafter, after the fin command angle Φ1 is determined by the adder circuit 16, it is normally output as is through the limiter 18, but in the present invention, a waveform smoothing calculation circuit is inserted here. That is, the waveform smoothing calculation circuit 17 determines the fin angle stabilizer φ2 after waveform smoothing control, and further outputs the final fin angle command angle φC via the limiter 18. This fin command angle ΦC is
When inputted to , the relationship between the fin angle φ and the time t exhibits a smooth waveform as shown by the solid line in FIG. 4, and irregular rolling angular acceleration no longer occurs.

Here, the fin command angle riser Φ2 after waveform smoothing control is calculated from equations (2) and (3).

That is, Φ2=Φt/(1+TφS) ・・・・・・・・・ (
2) [However, Tφ is a time constant] Tφ= (φ2−Φ5et)/β (Φmax −φ
5et)・・・・・・・・・(3) [However, β is a constant, S is the Laplace transformer, Φmax is the maximum inclination angle of the fin, and Φset is the angle at which smooth fin control starts] In the above explanation, Although the case where the fin of the fin stabilizer itself rotates has been described, similar control is possible for the flap of the fin stabilizer.

〔Effect of the invention〕

As described above, according to the present invention, it is possible to prevent irregular rolling angular acceleration from occurring when adjusting the angle of the fins or flaps in the fin stabilizer. Therefore, worsening of seasickness and the like can be prevented.

[Brief explanation of the drawing]

Figure 1 is a cross-sectional view of the hull with fin stabilizers;
FIG. 2 is a side view of the fin stabilizer, FIG. 3 is a detailed view of the control device, and FIG. 4 is a diagram showing how the fin stabilizer is controlled. 1...hull, 2a, 'lb...fin, θ...rolling angle. Agent Patent Attorney Nobuo Ogawa −

Claims (1)

[Claims] A method for controlling a fin stabilizer, comprising smoothing the movement of a fin or a flap in the fin stabilizer before and after a maximum operating angle.