JPS628896A - Steering method using wave energy - Google Patents

Abstract

PURPOSE:To enhance the propelling efficiency of a ship, by reducing a resistance acting upon the ship with the use of wave energy when the ship is steered during cruising. CONSTITUTION:When a gyro signal from a gyro compass 1 has a waveform in which high frequency components due to waves are superpose with low frequency components due to external distervance such as, for example, the high frequency components alone are allowed to path through a filter 3 so that a high frequency signal psi' is delivered from the filter 3. Meanwhile, the direction and cyclic period of waves, optimum phase shift value alpha and gain K are set in the set means 4, and an adjusting means 5 shifts the phase of the high frequency signal psi' by the phase shift value alpha to convert the signal into the phase shift high frequency signal psi*, and the latter is multiplied by K. Thus, the adjusting means 5 delivers an adjusting steering control signal Kpsi*.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides a steering method using wave energy that reduces resistance acting on a sailing ship by using wave energy when steering the ship. Regarding.

[Conventional technology]

Generally, a ship is equipped with a gyro compass, an autopilot, etc., and the autopilot keeps the ship's course constant based on gyro signals from the gyro compass.

By the way, even if the autopilot keeps the ship on a constant course, the ship (S) will normally be affected by waves, wind, etc.
For example, as shown in FIG. 4, the following steering method is used to prevent the propulsion efficiency of a ship from decreasing due to the effects of waves, wind, etc. when the ship is sailing in a meandering manner. In other words, (1) For high-frequency course errors caused by waves, even if you perform steering such as counter rudder to correct the errors, the steering resistance will only increase and propulsion efficiency will decrease. High frequency heading error due to

In other words, the autopilot is prevented from responding to high frequency components of the gyro signal from the gyro compass.

(11) Steer to suppress low-frequency movement of the ship due to disturbances such as wind.

[Problem that the invention seeks to solve]

However, with the above-mentioned steering method, although it is possible to suppress the decline in the propulsion efficiency of the ship, it is not possible to improve the propulsion efficiency itself, and there is a problem that it is difficult to say that it is an optimal steering method. .

[Means for resolving gaps and points of interest]

This invention was made with the above points in mind,
A bypass filter extracts a high frequency signal, which is a motion component of the ship due to waves, from a gyro signal of a gyro compass installed on the ship, and an adjustment means extracts the wave direction, wave period, and size of the ship. The amplitude and phase of the high frequency signal are adjusted based on the gain and phase shift amount set according to the above, and the output means outputs the high frequency signal with the adjusted amplitude and phase as a steering signal to the steering system of the ship. This is a steering method using wave energy, characterized in that the wave energy is outputted to reduce the resistance acting on the vessel during navigation.

[Effect]

Therefore, in the present invention, a high-frequency signal, which is a motion component of the ship due to waves, is extracted from a gyro signal of a gyro compass by a bypass filter, and the amplitude and phase of the high-frequency signal are adjusted based on a predetermined gain and phase shift amount, thereby steering the vehicle. The wave energy is used to propel the ship by combining the movement of the ship due to waves with the movement of the steering so that the centrifugal force that is output to the ship acts as a thrust force that reduces resistance to the ship. It turns out.

〔Example〕

Next, the present invention will be explained in detail with reference to FIGS. 1 to 3 showing an embodiment thereof.

First, the principle of this invention will be explained using FIG.

As shown in the figure, when the direction of the bow of a ship (S) that is sailing in a meandering manner while repeating high-frequency motion due to waves changes from the state shown by the solid line in the figure to the state shown by the dashed-dotted line, Assuming that a centrifugal force F is acting on the ship (S) in a direction perpendicular to the bow and stern line before the bow direction changes, the centrifugal force F changes as the bow direction changes. A force V in a direction parallel to the bow-stern line L' of the rear vessel (S) and a force in a direction perpendicular to the bow-stern line L' act on the vessel (8), and the latter force acts on the vessel (8). r is a ship (S
) becomes a centrifugal force.

On the other hand, if the former mold is directed towards the stern of the ship (8), it will act as resistance, and if it is towards the bow, it will act as thrust.
A ship that navigates while repeating high-frequency motion due to waves (S
) By appropriately adjusting the steering of the ship (S), it is possible to make the centrifugal force act as thrust on the ship (S), as described in the Society of Shipbuilding Proceedings vol.

122, which was already reported in 1967 in Takeo Koyama's ``Study on Optimal Automatic Steering System for Ships Sailing on the Ocean''.

As mentioned above, the resistance X that acts on a ship sailing while repeating periodic motion such as high-frequency motion caused by waves is expressed as: X = (M+My) U p r Ot) -1-R
Denoted as J − (j), where M ,
My is the mass of the ship and the lateral additional mass of the ship, U is the ship speed, 7 is the amplitude of the ship's crossflow angle β and the amplitude of the ship's turning angular velocity r, respectively, and φ is the crossflow angle β and the turning angular speed r, respectively. The phase difference, RJ, is the resistance due to steering, and the stern direction is positive.

Therefore, (9)φ in the first term on the right side of the above equation 0 is negative,
That is, by steering the vessel so that φ is 90° and φ<270°, the resistance X acting on the vessel is reduced, and the propulsion efficiency of the vessel is improved.

Next, FIG. 1 showing the block configuration will be explained.

In the figure, (1) is a gyro compass installed on the ship, and (2) is a gyro compass installed on the ship.
1) an autopilot that outputs a course-keeping steering signal δa based on the gyro signal; (3) a bypass filter that extracts a high-frequency signal ψ, which is a motion component of the ship due to waves, from the gyro signal of the gyro compass (1); (4
) is a setting means for inputting and setting the gain and the phase shift amount α according to the direction of the waves, the period of the waves, the size of the ship, etc.;
5) is an adjusting means for adjusting the amplitude and phase of the high frequency signal ψ′ based on the gain set in the setting means (4) and the phase shift amount α, and outputting ψ as an adjustment steering signal;
) is 9* for the course-keeping steering signal δa and the adjustment steering signal.
(7) is a steering gear of the ship, which performs steering based on the combined signal δC from the signal combining means (6).

For example, if the gyro signal from the gyro compass (1) has a waveform in which a high frequency component due to waves is superimposed on a low frequency component due to disturbance such as wind, as shown in FIG. 2(a), the filter (3) Only the high-frequency components are filtered, and a high-frequency signal ψ' as shown in FIG. 3(b) is output from the filter (3).

On the other hand, the optimum phase shift amount α and gain K are set in the setting means (4) according to the direction of the waves, the period of the waves, and the size of the ship, so that the gradient φ of the above equation 0 becomes negative, Adjustment means (5)
The phase of the high-frequency signal ψ' is shifted by the phase shift amount α and converted into a phase-shifted high-frequency signal, and the phase-shifted high-frequency signal is multiplied by the gain, that is, adjusted by the adjusting means (5). - is output to the steering signal.

By determining the lateral flow angle β, the lateral flow angle β is determined.Furthermore, since the lateral flow angle β is the initial phase of the turning angular velocity r, the phase difference φ between the lateral flow angle β and the turning angular velocity r is inevitably determined. , by optimally setting the phase shift amount α, the phase difference −
can be set so that φ<270° by 90°, and the resistance X acting on the ship can be reduced by making φ in equation 0 negative (2).

〔Effect of the invention〕

As described above, according to the wave energy steering method of the present invention, the movement of the ship caused by waves and the movement caused by steering are combined so that the component of centrifugal force on the ship acts as a thrust force that reduces resistance to the ship. This makes it possible to improve the propulsion efficiency of ships by using wave energy for ship propulsion.

[Brief explanation of drawings]

1 to 3 show one embodiment of the steering method using wave energy of the present invention, FIG. 1 is a block diagram, and FIG. 2 (a
) and (b) are waveform diagrams of a gyro signal and a high frequency signal, respectively, FIG. 3 is a diagram for explaining the principle, and FIG. 4 is a diagram for explaining the normal running state of a ship. (1)...Gyro compass, (3)...Bypass filter, (5)...Adjusting means, (6)...Synthesizing means, (7)...Steering gear (8)...・Ships.

Claims (1)

[Claims] (1) A bypass filter extracts a high frequency signal which is a motion component of the ship due to waves from a gyro signal of a gyro compass installed on the ship, and an adjustment means extracts a high frequency signal that is a motion component of the ship due to waves.
The amplitude and phase of the high frequency signal are adjusted based on the gain and phase shift amount set according to the direction of the waves, the wave period, the size of the ship, etc., and the amplitude and phase are adjusted by the output means. A steering method using wave energy, characterized in that a high frequency signal is output as a steering signal to a steering machine of the ship to reduce resistance acting on the ship during navigation.