JP5965142B2 - Azimuth control device, floating body, and shaking reduction method - Google Patents

Description

  The present invention relates to an azimuth control device for controlling the azimuth of a ship and other floating structures (hereinafter referred to as “floating bodies”) so as to reduce the shaking. Moreover, it is related with the floating body provided with this azimuth | direction control apparatus. Furthermore, the present invention relates to a shaking reduction method for reducing shaking of a floating body.

  Regardless of whether the floating body is moving or stays at a predetermined position, the floating body is affected by waves (wind and swell) as long as it floats on the water. In order to reduce the influence of this wave, Patent Document 1 proposes an automatic steering device for a ship that predicts the state of impact of a wave on the hull and reduces the force received when the hull collides with the wave. Yes.

JP 59-220497 A

  However, the automatic steering device described above is intended only to reduce the “shock” of the hull due to a wave collision, and does not directly reduce the “sway” of the hull. The large impact force received from the waves of the hull is not unrelated to the large shaking of the hull, but they are not necessarily the same. Even if the hull is hardly affected by waves, there may be situations where the hull is greatly shaken. For example, a work ship such as a crane ship needs to work in a stable state, but it is not sufficient to reduce the impact received by the hull. Rather, in this case, it is important to reduce the hull motion.

  This invention is made | formed in view of this situation, and it aims at providing the azimuth | direction control apparatus which can reduce the shaking of the floating body by a wave.

  An azimuth control apparatus according to an embodiment of the present invention is an azimuth control apparatus that controls the azimuth of a floating body that fluctuates due to waves. Wave analysis that calculates the wave characteristics and traveling azimuth of each wave that constitutes the waves Based on the wave characteristics and traveling direction of each wave, a suitable direction calculation unit for calculating a suitable direction of the floating body that reduces fluctuation, and turning the floating body in the preferred direction A control unit. According to such a configuration, the water levitation body main body is directed in a suitable direction, so that the sway of the water levitation body main body due to waves can be reduced.

  Further, in the above azimuth control device, further comprising a response storage device in which a wave response function representing the magnitude of the sway of the floating body when a wave having a certain wave characteristic is received from a certain direction is stored, The wave characteristic is a wave spectrum representing a frequency component of the wave and its energy, and the preferred azimuth calculating unit is configured to calculate from the wave response function based on the wave spectrum of each wave and the traveling azimuth of each wave. It is also possible to calculate the direction of the floating body with the smallest fluctuation and set the direction as the preferred direction. According to this configuration, since the preferred orientation is calculated using the wave response function, the most appropriate preferred orientation can be calculated under various conditions.

  Further, in the above azimuth control device, the wave characteristic is a wave height, and the preferred azimuth calculation unit includes a traveling direction of a wave having the largest wave height among the waves and a longitudinal length of the floating body. It is also possible to calculate the azimuth of the floating body that is parallel to the direction and set the azimuth as the preferred azimuth. According to such a configuration, it is possible to calculate the preferred orientation with a very simple calculation.

  In the azimuth control device, the wave analysis unit may calculate the wave spectrum of each wave from the model function of the wave spectrum based on the wave height of each wave and the encounter period of each wave. Good. According to such a configuration, the spectrum of the entire wave including irregularities can be calculated by a relatively simple calculation.

  In the azimuth control apparatus, the wave analysis unit may calculate a wave spectrum of each wave by performing a Fourier transform on a time signal obtained by observing each wave.

  The azimuth control device further includes a wave data input unit for inputting wave data relating to wind and swell, and the wave height of each wave is obtained from the wave height of the wave and swell obtained from the wave data, The frequency of the wave may be calculated based on the wave and swell period obtained from the wave data.

  In the above azimuth control apparatus, a fixed point holding control unit for holding the floating body at a predetermined target position may be further provided.

  Furthermore, the floating body according to an embodiment of the present invention includes the above-described azimuth control device.

  Further, the method of reducing the levitation of a floating body according to an embodiment of the present invention is a method of reducing the levitation of a floating body that receives a wave force, and calculates the wave characteristics and traveling direction of each wave constituting the wave. Then, based on the wave characteristics and traveling direction of each wave, the preferred orientation of the floating body is calculated such that the fluctuation is small, and the floating body is directed to the preferred direction.

  As described above, according to the azimuth control device of the present invention, it is possible to reduce the shaking of the floating body main body due to waves.

FIG. 1 is a schematic side view of a floating body according to the first embodiment of the present invention. FIG. 2 is a schematic plan view of the floating body according to the first embodiment of the present invention. FIG. 3 is a block diagram of a configuration related to the control of the first embodiment of the present invention. FIG. 4 is a control flow diagram of the floating body according to the first embodiment of the present invention. FIG. 5 is a block diagram of a configuration related to the control of the second embodiment of the present invention. FIG. 6 is a block diagram of a configuration related to the control of the third embodiment of the present invention. FIG. 7 is a block diagram of a configuration related to the control of the fourth embodiment of the present invention. FIG. 8 is a block diagram of a configuration related to the control of the fifth embodiment of the present invention.

  Hereinafter, embodiments of the present invention will be described. In the following description, the same or corresponding components are denoted by the same reference symbols throughout the drawings, and redundant description is omitted.

(First embodiment)
First, with reference to FIG. 1 thru | or FIG. 3, the structure of the floating body 100 which concerns on 1st Embodiment of this invention is demonstrated. FIG. 1 is a schematic side view of a floating body 100 according to the present embodiment, FIG. 2 is a schematic plan view of the floating body 100 according to the present embodiment, and FIG. 3 is a block diagram of a configuration relating to control according to the present embodiment. FIG. The floating body 100 according to the present embodiment is a ship that navigates (moves) offshore. However, here, for ease of explanation, it is assumed that the floating body 100 has a constant moving speed and moving direction. As shown in FIG. 1, the floating body 100 includes a floating body main body 10, a power unit 20, a wave radar 30, a gyrocompass 40, and an azimuth control device 50. Hereinafter, each of these components will be described in order. In the following, “azimuth” refers to an absolute direction such as east, west, south, and north, and is distinguished from a mere “direction” including relative ones.

  The floating body 10 is a portion that floats on the water and serves as a base of the floating body 100. The “levitation” here includes not only the case of floating without moving but also the case of floating while moving. The floating body 10 is a portion corresponding to the hull of a ship, and is shaken by receiving a force from waves. In addition, “the direction of the floating body (main body)” refers to the heading when there is a bow, and the direction of a predetermined reference point when there is no bow.

  The power unit 20 is a part that moves the floating body 10 and changes (turns) the orientation of the floating body 10. As shown in FIG. 2, the power unit 20 includes four propulsion devices 21. The propulsion device 21 of this embodiment can adjust the magnitude of the thrust by changing the rotation speed of the propeller 22. The propeller 22 may be a variable pitch propeller (Controllable Pitch Propeller) or a fixed pitch propeller (Fixed Pitch Propeller). When the propeller 22 is a variable pitch propeller, the magnitude of the thrust can be adjusted also by changing the pitch (blade angle). Further, the propulsion device 21 can change the thrust direction by turning itself. Since the power unit 20 of the present embodiment is configured as described above, the floating body 10 can be moved in an arbitrary direction without changing the orientation of the floating body 10. Moreover, the power unit 20 can arbitrarily change the orientation of the floating body 10 without changing the moving direction of the floating body 10. That is, the moving direction of the floating body 10 and the direction of the floating body 10 do not necessarily match. The propulsion device 21 that constitutes the power unit 20 is not limited to that described above, and a propulsion device having a water jet pump or a propulsion device having a rudder may be adopted.

  The wave radar 30 is a device that is provided in the floating body 10 and detects each wave constituting the wave. As the wave radar, for example, WAVEX manufactured by MIROS can be used. The wave radar 30 can detect the wave height, encounter period, and traveling direction (hereinafter referred to as “relative traveling direction”) of each wave viewed from the floating body 10. Here, ocean waves are composed of “wind waves” and “swells”. “Wind waves” refer to waves generated by the wind blowing in the area, and “swells” refer to waves transmitted to areas where wind does not blow. Each wave is not a simple sine wave, but is composed of many frequency components. As shown in FIG. 3, the wave radar 30 transmits a signal relating to the detected wave height, encounter period, and traveling direction of each detected wave to a wave analysis unit 52 described later.

  The gyrocompass 40 is a device that is mounted on the floating body 10 and detects the orientation of the floating body 10. As shown in FIG. 3, the gyrocompass 40 transmits a signal related to the detected orientation of the floating body 10 to a wave analysis unit 52 and a turning control unit 55 described later.

  The azimuth control device 50 is a device that controls the azimuth of the floating body 10 so that the shaking of the floating body 10 is reduced. As shown in FIG. 3, the direction control device 50 is mainly configured by a wave storage unit 51, a wave analysis unit 52, a response storage unit 53, a preferred direction calculation unit 54, and a turning control unit 55. Yes.

  The wave storage unit 51 is a part that stores a model function of a wave spectrum. The “wave spectrum model function” here refers to a distribution of what frequency component a wave having a certain wave characteristic has and how much energy the frequency component has (hereinafter, “wave function”). A model function representing a spectrum. As the input of the model function of the wave spectrum, for example, a significant wave height and a zero cross frequency are used. Of these, the “significant wave height” can be calculated from the wave height, and the “zero cross frequency” can be calculated from the wave encounter period. That is, if the wave height and the encounter period of each wave are known, the wave spectrum of each wave can be obtained by the model function of the wave spectrum. The model function of the wave spectrum has a specific shape depending on the sea area and the like, and typical examples include the Modified Pierson-Moskowitz spectrum and the JONSWAP spectrum.

  The wave analysis unit 52 is a part that calculates the wave spectrum of each wave and the traveling direction (traveling direction in the absolute coordinate system) of each wave. Of these, the wave spectrum can be obtained by a model function of the wave spectrum if the wave height and the encounter period are known, as described above. The wave analysis unit 52 calculates the wave spectrum based on the wave height and encounter period of each wave detected by the wave radar 30 and the model function of the wave spectrum stored in the wave storage unit 51. Further, the traveling direction of each wave can be calculated based on the relative traveling direction of each wave detected by the wave radar 30 and the direction of the floating body 10 when the relative traveling direction is detected. The orientation of the floating body 10 can be detected by the gyrocompass 40. Signals related to the wave spectrum and traveling direction of each wave calculated as described above are transmitted from the wave analysis unit 52 to the preferred direction calculation unit 54.

  The response storage unit 53 is a part that stores a wave response function. Here, the “wave response function” refers to a function representing the degree to which the floating body 10 is shaken when receiving a wave having a certain wave characteristic from a certain relative direction. The wave characteristic here is the above-described wave spectrum. That is, if the wave spectrum, wave traveling direction, and direction of the floating body 10 are known, the degree of shaking of the floating body 10 can be calculated from the wave response function. As a specific calculation result, a fluctuation value for each frequency is obtained. The wave response function is unique to each floating body and is called RAO (Response Amplitude Operator). In addition, the wave response function of each floating body 10 can be obtained by numerical calculation from the specific shape and the like of the floating body 10.

  The preferred azimuth calculation unit 54 is a part that calculates the preferred azimuth of the floating body 10 so that the fluctuation is small. As described above, based on the wave spectrum of each wave, the traveling direction of each wave, and the orientation of the floating body 10, the magnitude of the shaking of the floating body 10 can be calculated by the wave response function. Here, in this embodiment, since the floating body 10 is based on the premise that the moving speed and moving direction are constant, the wave spectrum of each wave calculated based on the wave height and the encounter period is constant. It is. Also, the traveling direction of each wave is constant. Therefore, by calculation, only the azimuth value (azimuth angle) of the floating body 10 is changed to find the direction in which the shaking of the floating body 10 is minimized. Then, the direction in which the fluctuation is the smallest is taken as the preferred direction.

More specifically, as shown in FIG. 2, it is assumed that the waves at the floating position of the floating body 10 are composed of two waves, which are a first wave 101 and a second wave 102, respectively. Then, using the wave response function RAO, if the azimuth angle of the floating body 10 is Ψ, the sway of the floating body 10 by the first wave 101 can be expressed as RAO ₁ (Ψ), and the second wave The shaking of the floating body 10 due to 102 can be expressed as RAO ₂ (Ψ). Then, the sway J (Ψ) of the floating body 10 due to the entire wave can be obtained by the following equation, and therefore the magnitude of the sway J (Ψ) of the floating body 10 due to the entire wave becomes the smallest. What is necessary is just to calculate the azimuth angle Ψ of the levitation body 10. Here, how to evaluate the magnitude of the shaking depends on the use of the floating body 100, but the highest shaking value may be the shaking magnitude, and the value obtained by adding the shaking values at all frequencies (integral value). May be the size of the sway, and other than this may be the size of the sway.

  The turning control unit 55 is a part that operates the power unit 20 and directs the floating body 10 to a suitable direction. Specifically, the turning control unit 55 obtains the preferred orientation from the preferred orientation calculation unit 54 and obtains the current orientation (hereinafter referred to as “current orientation”) of the floating body 10 from the gyrocompass 40. Then, based on the difference between the preferred orientation and the current orientation, a control signal for turning (turning) the floating body 10 is generated, and the control signal is transmitted to the power unit 20. As a result, the turning control unit 55 can control the power unit 20 and direct the floating body 10 to the preferred direction calculated by the preferred direction calculation unit 54.

  Next, with reference to FIG. 4, operation | movement of the floating body 100 which concerns on this embodiment is demonstrated. FIG. 4 is a flowchart of the operation of the floating body 100 according to the present embodiment. The operation described below is performed under the control of the direction control device 50. Since the approximate operation has already been described, a brief description will be given here.

  First, the azimuth control device 50 uses the wave spectrum model function stored in the wave storage unit 51 based on the wave height and the encounter period of each wave detected by the wave radar 30 by the wave analysis unit 52. Calculate the spectrum. Similarly, the wave analysis unit 52 determines the traveling direction of each wave based on the relative traveling direction of each wave detected by the wave radar 30 and the orientation of the floating body 10 when the relative traveling direction is detected. Calculate (step S1). The orientation of the floating body 10 can be detected by the gyrocompass 40.

  Subsequently, the floating body with the smallest fluctuation is obtained by the wave response function stored in the response storage unit 53 based on the wave spectrum and traveling direction of each wave calculated by the wave analysis unit 52 by the preferred direction calculation unit 54. The orientation of the main body 10 is calculated, and the orientation is set as a preferred orientation (step S2).

  Subsequently, the turning control unit 55 operates the power unit 20 based on the preferred orientation calculated by the preferred orientation calculation unit 54 and the current orientation of the floating body 10 detected by the gyrocompass 40, and the floating body The main body 10 is turned to a suitable orientation (step S3).

  The above is the operation of the floating body 100 according to the present embodiment. Thus, according to the present embodiment, based on the result of analyzing the waves arriving at the floating body 10, the floating body 10 is directed in the direction in which the fluctuation is minimized, so the floating body 10 ( The shaking of the floating body 100) can be effectively reduced.

(Second Embodiment)
Next, the floating body 200 according to the second embodiment of the present invention will be described with reference to FIG. FIG. 5 is a block diagram of a configuration relating to control of the floating body 200 according to the present embodiment. As shown in FIG. 5, the floating body 200 according to the present embodiment does not include the wave storage unit 51 (see FIG. 3) that stores the model function of the wave spectrum, and the floating body according to the first embodiment. 100 and the configuration is different. That is, in this embodiment, the wave spectrum is calculated without using the model function of the wave spectrum. The other points are basically the same as the floating body 100 according to the first embodiment.

  Specifically, in the present embodiment, the wave radar 30 detects a time change of the wave height of each wave (wave time signal), and the wave analysis unit 52 performs Fourier transform on the wave time signal to directly generate the wave. Calculate the spectrum. Other than that, in the same manner as in the first embodiment, the wave analysis unit 52 calculates the traveling direction of the waves, the preferable direction calculation unit 54 calculates the preferable direction, and the turning control unit 55 calculates the floating body 10. To the preferred orientation.

(Third embodiment)
Next, with reference to FIG. 6, the floating body 300 which concerns on 3rd Embodiment of this invention is demonstrated. FIG. 6 is a block diagram of a configuration related to the control of the floating body 300 according to the present embodiment. As shown in FIG. 6, the floating body 300 according to the present embodiment includes a wave storage unit 51 that stores a model function of a wave spectrum and a response storage unit 53 that stores a wave response function (both refer to FIG. 3). The structure differs from the floating body 100 according to the first embodiment. That is, in the present embodiment, the preferred orientation is calculated without using the wave spectrum model function or wave response function. The other points are basically the same as the floating body 100 according to the first embodiment.

First, the wave analysis unit 52 of this embodiment calculates the traveling direction of each wave as in the first embodiment, but does not calculate the wave spectrum of each wave unlike the case of the first embodiment. However, the wave analysis unit 52 acquires the wave height of each wave not used for calculation from the wave radar 30 here. Then, the wave analysis unit 52 transmits a signal related to the calculated traveling azimuth of each wave to the preferred azimuth calculation unit 54 and transfers a signal related to the wave height of each wave detected by the wave radar 30 to the preferred azimuth calculation unit 54 as it is. .

  The preferred azimuth calculation unit 54 acquires the wave height and traveling azimuth of each wave arriving at the floating body 10 from the wave analysis unit 52. In the present embodiment, the wave height of each wave is a wave characteristic for calculating a preferred direction. Subsequently, the wave analysis unit 52 selects a wave having the largest wave height among the waves. Then, the direction opposite to the traveling direction of the wave having the largest wave height is set as a preferred direction. For example, when the traveling direction of the wave with the highest wave height is south, the preferred direction is north. Thereafter, as in the case of the first embodiment, the power control unit 55 is controlled by the turning control unit 55 so that the floating body 10 is directed in a suitable direction. When the bow of the floating body 300 is not present, the preferred direction is such that the traveling direction of the wave having the highest wave height is parallel to the longitudinal direction of the floating body 10, and the floating body 10 In this preferred orientation.

  According to the present embodiment, the floating body 10 is directed in the direction opposite to the traveling direction of the wave having the largest wave height (the traveling direction of the wave having the largest wave height is parallel to the longitudinal direction of the floating body 10). Therefore, it is possible to suppress the shaking of the floating body 10 due to the wave having the largest wave height. As a result, the shaking of the floating body 10 due to the entire wave (combined wave of each wave) can also be reduced. In this embodiment, calculation using a wave response function is not performed, so that it is easier to calculate a suitable orientation than in the case of the first embodiment, and the wave response function is obtained in advance by numerical calculation or the like. There is no need to keep it.

(Fourth embodiment)
Next, with reference to FIG. 7, the floating body 400 which concerns on 4th Embodiment of this invention is demonstrated. FIG. 7 is a block diagram of a configuration related to the control of the floating body 400 according to the present embodiment. As shown in FIG. 7, the floating body 400 according to the present embodiment does not include the wave radar 30 (see FIG. 3). Instead, the wave data input unit 60, the position detection device 70, and the main body The configuration differs from the floating body 100 according to the first embodiment in that the movement calculating unit 56 is provided. The other points are basically the same as the floating body 100 according to the first embodiment. Hereinafter, the description will focus on the wave data input unit 60, the position detection device 70, the main body movement calculation unit 56, and the wave analysis unit 52.

  The wave data input unit 60 is a part for inputting wave data. The “wave data” here includes data on wind and swell. As described above, since a wave in the ocean can be regarded as a combined wave of wind and swell, a preferred direction can be calculated with relatively high accuracy. The specific values of the wave data are the wave height, the wave traveling direction, and the wave cycle of the sea forecast and the wave measured by the Japan Meteorological Agency in each country. In the present embodiment, the operator inputs the wave data to the wave data input unit 60. However, the wave data input unit 60 may be configured to be input automatically.

  The position detection device 70 is mounted on the floating body 10 and is a device that detects the position of the floating body 10. As the position detection device 70, for example, a GPS (Global Positioning System) can be used. As shown in FIG. 7, a signal related to the position of the floating body 10 detected by the position detection device 70 is transmitted to the body movement calculation unit 56.

  The main body movement calculating unit 56 is a component of the azimuth control device 50 and is a part that calculates the moving speed and moving direction of the floating body 10. The main body movement calculation unit 56 acquires the position of the floating body 10 from the position detection device 70 every moment, and compares the position of the floating body 10 at a certain time with the position of the floating body 10 after a predetermined time. By doing so, the moving speed and moving direction of the floating body 10 can be calculated. As shown in FIG. 7, a signal related to the moving speed and moving direction of the floating body 10 calculated by the main body movement calculation unit 56 is transmitted to the wave analysis unit 52.

  The wave analysis unit 52 according to the present embodiment acquires the wave data input by the wave data input unit 60, and analyzes the waves that arrive at the floating body 10 based on the wave data. Specifically, the wave spectrum and traveling direction of the waves and the wave spectrum and traveling direction of the swell are calculated. Of these, the traveling direction of each wave (wind and swell) is directly input from the wave data input unit 60, so that no substantial calculation is required. That is, there is no need to consider the orientation of the floating body 10, and no signal from the gyrocompass 40 is input to the wave analysis unit 52. On the other hand, in order to calculate the wave spectrum, an encounter cycle is necessary. However, what can be acquired from the wave data is a simple wave cycle. To calculate the encounter cycle, the moving speed of the floating body 10 is further increased. And moving direction is required. Therefore, the wave analysis unit 52 of the present embodiment acquires the moving speed and moving direction of the floating body 10 from the main body movement calculation unit 56, and calculates the encounter period of each wave based on these and the period of each wave. The wave spectrum is then calculated.

  Then, after calculating the wave spectrum and traveling direction of the waves and the wave spectrum and traveling direction of the swell, the operation is the same as in the first embodiment. In other words, the preferred azimuth calculation unit 54 calculates the preferred azimuth by the wave response function stored in the response storage unit 53 based on the wave spectrum and traveling azimuth of each wave (wind and swell). And the power control part 20 is controlled by the turning control part 55, and the floating body 10 is orient | assigned to a suitable direction. As described above, according to the present embodiment, the preferred azimuth can be calculated without using the wave radar 30, and therefore the floating body 300 can be configured relatively simply.

(Fifth embodiment)
Next, with reference to FIG. 8, the floating body 500 which concerns on 5th Embodiment of this invention is demonstrated. FIG. 8 is a block diagram of a configuration relating to control of the floating body 500 according to the present embodiment. As shown in FIG. 8, the floating body 500 according to the present embodiment includes a position detection device 70 (see FIG. 7), a target position setting unit 80 that sets a target position (fixed position), and a floating surface at the target position. The structure differs from the floating body 100 according to the first embodiment in that it includes a fixed point holding control unit 57 that holds the body body 10 at a fixed point. The other points are basically the same as the floating body 100 according to the first embodiment. Hereinafter, the target position setting unit 80 and the fixed point holding control unit 57 will be mainly described.

  The target position setting unit 80 is a part for inputting a target position (fixed point) necessary for the fixed point holding control. In the present embodiment, the target position setting unit 80 is configured so that an operator can input coordinates. The target position setting unit 80 sets the target position based on the coordinates input by the operator.

  The fixed point holding control unit 57 is a component of the azimuth control device 50, and is a part that controls the power unit 20 and holds the floating body 10 at a predetermined target position. The fixed point holding control unit 57 acquires the target position from the target position setting unit 80 and acquires the current position of the floating body 10 from the position detection device 70. The fixed point holding control unit 57 controls the power unit 20 based on the difference between the target position and the current position of the floating body 10 to move or hold the floating body 10 to the target position (fixed point). Hold control.

  As described above, in the floating body 500 of the present embodiment, fixed point holding control is performed in addition to the control for reducing the shaking of the floating body main body 10 described in the first embodiment. That is, according to this embodiment, the floating body main body 10 is held at a fixed point, and the floating body 10 is prevented from shaking. For example, in the case of a floating body that requires both the floating body 10 not to deviate from a predetermined position and not to shake, such as a work boat, it is very effective to combine both controls.

  As mentioned above, although the floating body 100, 200, 300, 400, 500 which concerns on 1st thru | or 5th embodiment of this invention was demonstrated, a concrete structure is not restricted to these embodiment, The summary of this invention Any change in design and the like without departing from the scope of the invention is also included in the present invention. For example, although the case where the floating body is a ship has been described above, the floating body other than a suspended ship such as a mega float is also included in the present invention.

  In addition, although the case where the moving direction and moving speed of the floating body 10 are constant has been described above, the wave spectrum of each wave is calculated under the condition when there is a desired moving direction and moving speed. Then, the preferred orientation may be calculated.

  According to the azimuth control device according to the present invention, it is possible to reduce the sway of the floating body due to the waves, which is beneficial in the technical field of floating bodies.

DESCRIPTION OF SYMBOLS 10 Water floating body 20 Power part 30 Wave radar 40 Gyrocompass 50 Direction control apparatus 51 Wave storage part 52 Wave analysis part 53 Response storage part 54 Suitable direction calculation part 55 Turning control part 56 Main body movement calculation part 57 Fixed point holding | maintenance control part 60 Wave data input unit 70 Position detection device 80 Target position setting unit 100, 200, 300, 400, 500 Floating body

Claims (9)

An azimuth control device that controls the azimuth of a floating body that is shaken by waves,
A wave analysis unit for calculating the wave characteristics and traveling direction of each wave constituting the wave;
On the basis of the wave characteristics and heading of each wave, the preferred orientation calculation unit that upset calculates the preferred orientation of the smallest such the water flotation body,
A turning control unit for directing the floating body in the preferred orientation;
An azimuth control device comprising: A response storage device that stores a wave response function that represents the magnitude of the sway of the floating body when a wave having a certain wave characteristic is received from a certain direction;
The wave characteristic is a wave spectrum representing the frequency component of the wave and its energy,
The preferred azimuth calculation unit calculates the azimuth of the floating body with the smallest fluctuation from the wave response function based on the wave spectrum of each wave and the traveling azimuth of each wave, and the azimuth is calculated as the preferred azimuth. The direction control device according to claim 1. The wave characteristic is the wave height,
The preferred azimuth calculating unit calculates the azimuth of the floating body main body in which the traveling direction of the wave having the highest wave height among the waves and the longitudinal direction of the floating levitation body are parallel, and the azimuth is calculated. The azimuth | direction control apparatus of Claim 1 set as the said suitable azimuth | direction.   The azimuth control device according to claim 2, wherein the wave analysis unit calculates a wave spectrum of each wave from a model function of the wave spectrum based on a wave height of each wave and an encounter period of each wave.   The azimuth control device according to claim 2, wherein the wave analysis unit calculates a wave spectrum of each wave by performing Fourier transform on a time signal obtained by observing each wave. A wave data input unit for inputting wave data relating to wind and swell;
The wave height of each wave is obtained by the wave height and swell wave height obtained from the wave data,
The direction control device according to claim 4, wherein the frequency of each wave is calculated based on a wind and swell period obtained from the wave data.   The azimuth | direction control apparatus as described in any one of Claims 1 thru | or 6 further provided with the fixed point holding | maintenance control part which hold | maintains the said floating body in a predetermined target position.   A floating body comprising the azimuth control device according to any one of claims 1 to 7. A method for reducing sway of a floating body that receives the power of waves,
Calculate the wave characteristics and traveling direction of each wave constituting the wave,
On the basis of the wave characteristics and heading of each wave, and calculates a preferred orientation of the water buoyant body such upset is minimized,
A method for reducing sway of a floating body, wherein the floating body is directed in the preferred direction.

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