JPH0420838B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an automatic anchor control device used to protect an anchor of a ship.

(Prior art) It is an important issue for a ship at anchor to maintain its anchor position, that is, to guard the anchor.In principle, if the anchor is stuck in the seabed in a normal state, the ship's position will be fixed. It is uniquely determined by the anchor chain length and external force.

In such a situation, the problem of collision with other ships or obstacles can be avoided by determining the anchoring position in advance in consideration of the positional relationship with other ships or obstacles.

However, when the external force applied to the ship exceeds the holding force determined by the anchor and anchor chain, so-called anchor dragging occurs, in which the anchor moves through the soil on the seabed.

Once the anchor begins to drag, the external force applied to the ship does not decrease rapidly, so this state continues, leading to serious accidents such as collisions.

Conventionally, changes in the bow direction of the ship are observed while looking through fixed objects on the ground, and if the ship continues to move in the same direction, it is determined that the ship is dragging anchor, and the ship's position relative to the ground is determined using ship positioning methods. By measuring this, it is possible to determine whether or not the anchor is dragging, and when the anchor is dragging, the anchor chain can be further extended to increase the anchoring force, the main engine can be operated to generate propulsive force, and at the same time, the atte rudder can be adjusted. It was common to protect the anchor by using countermeasures such as using them together or activating side thrusters.

(Problems to be Solved by the Invention) The conventional guard anchoring method described above is based solely on the experience of the crew without accurately grasping the holding force between the anchor and the anchor chain or the magnitude of the external force acting on the hull. They operated the windlass, main engine, etc. as a guard anchor, or operated the guard anchor based on the experience of the crew only after the anchor was dragged, so they were not dependent on the experience and intuition of the crew. There are many problems, such as the lack of certainty and reliability of guard anchors, and the fact that guard anchors are not suitable for automation.

(Means for Solving the Problem) The automatic guard anchor control device of the present invention includes a seabed soil type detector for detecting the type of seabed soil in the vicinity of own ship, a paid-out anchor chain length detector for detecting the length of the paid-out anchor chain, and a planar An anchor chain angle detector that detects the payout angle of the anchor chain with respect to the own ship's center line when viewed from the ship, an anchor chain tension detector that detects the tension of the anchor chain, a wind direction and wind speed detector that detects the wind direction and wind speed, and tidal currents near the own ship. a tidal current detector that detects the direction and current speed of the river; and a tidal current detector that receives detection signals from these detectors and also receives various signals representing at least water intake, water depth, hull specifications, superstructure dimensions, anchor chain unit weight, anchor type and dimensions. Based on this, we calculate the maximum holding force between the anchor and anchor chain and the external force acting on the ship's hull, and also calculate the longitudinal and horizontal guard anchor control propulsive force necessary to keep the anchor chain tension below the maximum holding force. The control device includes a control device that outputs a control signal corresponding to the controlled propulsive force to at least one of the main engine control device, the swing device control device, and the stuttering control device.

(Function) Since the present invention is configured as described above, the control device uses data such as seabed soil quality, anchor chain tension, length of the anchor chain to be paid out, unit weight of the anchor chain, anchor type and dimensions, and water depth to adjust the relationship between the anchor and the anchor chain. The maximum holding force is calculated, and the external force acting on the ship is calculated using the wind direction and wind speed, the direction and speed of the current, and the hull specifications and superstructure dimensions. A guard anchor control propulsion force in the vertical and horizontal directions necessary to maintain the tension below the maximum holding force is determined, and a control signal for generating this guard anchor control propulsion force is transmitted to the main engine control means, the swing device control means, and the swiveling control means. output to at least one of the control means. In this way, the anchor is controlled to keep the anchor chain tension below the maximum holding force.

Note that the turning device refers to a steering device or a bow thruster.

(Example) Hereinafter, an example of the present invention will be described based on the drawings.

First, the overall structure of this automatic guard anchor control device and mooring device will be explained based on FIG. 1.

A control room 1 located in the superstructure at the rear of the hull is equipped with a control device 2, a gyro 3, and a control console 4 (hereinafter referred to as the operation panel), and a pair of left and right windlass 5 that are remotely controlled from the operation panel 4. are arranged on the upper deck of the front part of the hull, and an anchor chain 6 paid out from each windlass 5 faces the ship side through each hose pipe 7, and an anchor 8 is connected to the tip thereof.

An anchor chain tension detector 9 that detects the tension of the anchor chain 6 using a load cell or the like is provided in conjunction with the anchor chain 6 that is fed out from the windlass 5, and a length of the anchor chain that is detected from the number of rotations of the windlass 5. A detection signal from the detector 10 is output to the control device 2.

An anchor chain angle detector 11 that detects the payout angle θ (see Fig. 3) of the anchor chain 6 with respect to the hull centerline in plan view when the anchor is anchored is mounted on the gunwale above the hose pipe 7. The detection signal is output to the control device 2.

Furthermore, a seabed soil detector 12 is installed at the bottom of the ship, and includes an ultrasonic transmitter 12a that transmits predetermined ultrasonic waves toward the seabed, and an ultrasonic transmitter 12b that receives reflected waves of the ultrasonic waves. A signal is output to the control device 2. Furthermore, this seabed soil detector 1
2 also has the function of a water depth detector 13.

Tidal current detector 1 that uses ultrasonic waves to detect the direction and velocity of tidal currents, which are the basis for calculating external forces acting on the hull.
4 is provided at the bottom of the front part of the hull, and its detection signal is also output to the control device 2. At the same time, a salinity concentration detector 15 and a water temperature sensor 16 are installed at the bottom of the rear part of the hull to respectively detect the salinity concentration and water temperature necessary to correct the detection data of the ultrasonic detectors 12, 13, and 14. These detection signals are also output to the control device 2.

Four stutter meters 17 for electrically detecting stuttering are attached to both sides of the front and rear of the hull, and their detection signals are also output to the control device 2.

A detection signal from a wind direction and speed meter 18 that detects wind direction and wind speed, which are the basis for calculation of an external force acting on the hull, is also output to the control device 2.

Note that 19 is a water ballast pump, 20 is a main engine, and 22 is a ballast thruster.

The control device 2 uses the detection signals from the various detectors 9 to 18 and preset setting data to calculate the maximum holding force that the anchor 8 and the anchor chain 6 can exert, and also calculates the external force ( (wind force and tidal current force), and outputs a control signal to the windlass control means 5a as necessary so that the anchor chain tension T ₀ becomes less than the maximum holding force, thereby controlling the anchor chain 6 to be further paid out. Alternatively, the main engine control means 20 may output a control signal to the water ballast pump 19 and the ballast valve to control the water ballast water control means 19a to inject ballast water to alleviate wind force or tidal current force.
A control signal is output to a to perform guard anchor control using the propeller propulsion force, and at the same time, the steering device control means 2
A control signal is also output to 1a to control the steering angle,
Alternatively, a control signal is output to the balance thruster control means 22a to control the turning propulsive force.

Next, as shown in the block diagram of FIG.
and the control device 2 described above.

The control device 2 includes a detection signal reception processing device 23
, central processing unit 24, timer 25, and ROM
26, a RAM 27, a data setter 28, and a control signal output device 29.

The detection signal reception processing device 23 receives detection signals from the various detectors 9 to 18 and outputs the detection signals to the central processing unit 24 after performing AD conversion, amplification, and waveform shaping as necessary. The detection signal processing signal is received from the .

The signal processed by the detection signal reception processing device 23 is stored in the RAM 27 via the central processing unit 24.

The ROM 26 stores calculation programs for various calculations to be described later that are executed by the central processing unit 24.

The timer 25 outputs an operating signal at a predetermined period to the central processing unit 24, and based on this operating signal, arithmetic processing is executed at a predetermined period.

The data setter 28 stores various data other than data obtained from various detection signals, which are necessary for various calculations such as calculations for calculating anchor chain catenary, calculations for maximum holding force, and calculations for external forces acting on the hull. Data such as hull specifications (L x B x D), superstructure dimensions, anchor chain unit weight (W _c ), anchor type and dimensions, hose pipe friction force, etc. are set and sent digitally to the central processing unit 24. This is what you input. still,
Data such as stuttering and water depth may be input to the data setter 28.

The control signal output device 29 is the central processing unit 24
The windlass control means 5a receives a control signal from the control signal and performs DA conversion or amplification as necessary.
Main engine control means 20a, balance thruster control means 22
a, steering device control means 21a, stuttering control means 19
This is what is output to a.

Next, the calculation of the anchor chain catenary, the calculation of the maximum holding force between the anchor 8 and the anchor chain 6, the calculation of the external force acting on the hull, the calculation of the guard anchor control propulsive force, etc. calculated by the central processing unit 24 will be explained.

First, the maximum holding force is calculated by finding the anchor chain catenary based on the anchor chain catenary theoretical formula.

The anchor chain catenary is calculated as follows using the main parameters such as the length of the anchor chain C, the anchor chain tension T ₀ , and the water depth H obtained as the detection data (4th
(see figure).

S=f ₁ (T, H, d, w _c ) S... Girth length of anchor chain catenary T... Horizontal component of anchor chain tension H... Water depth d... Vertical distance between water surface and hose pipe w _c ... Anchor chain unit weight φ=f ₂ (T ₀ , H, d, w _c ) φ...Anchor chain upper end elevation angle T ₀ ... Anchor chain tension T=T ₀ cosφ Y=f ₃ (T, w _c , S) Y・Horizontal length of anchor chain catenary Z=C-S Z... Length of straight seabed length of anchor chain In addition, as the above T ₀ , the value obtained by adding the hose pipe friction force to the detected anchor chain tension is used.

Note that the above f ₁ , f ₂ , and f ₃ indicate functional relationships obtained from the anchor chain catenary theoretical formula, but since they are generally known theoretical formulas, detailed explanation thereof will be omitted.

Based on the data such as the seabed straight length Z of the anchor chain obtained as described above, the seabed soil quality ρ obtained as the detection data, and the data input as the setting data, the maximum potential of the anchor 8 and the anchor chain 6 is determined. The gripping force T ₀ max is obtained as follows.

T ₀ max = T (ρ) + T (Z) The above T (ρ) is the holding force of the anchor 8 itself determined from the seabed soil quality ρ and the type and dimensions of the anchor, and T (Z) is the length of the straight seabed length of the anchor chain. This is the holding force of the anchor chain 6 determined from Z and the anchor chain unit weight w _c .

Figure 3 shows the forces acting on the hull at anchor, where F is the external force due to wind and current, T is the horizontal component of the anchor chain tension, and F _p is the hull produced by driving the propeller with the main engine. The longitudinal anchor control propulsive force, code _Fs , is the anchor control propulsive force directed perpendicular to the ship's centerline obtained by driving the ballast thruster, or perpendicular to the ship's centerline obtained by ruddering while rotating the propeller. It is a guard anchor control propulsion force that points in the direction.

Here, the conditions for the ship to maintain its position without moving, that is, the conditions for the guard anchor, are as follows based on the balance of forces in the longitudinal and lateral directions.

Fsinα=F _s +Tsinθ Fcosα=F _p +Tcosθ T=T ₀ cosφ T ₀ ≦T ₀ max=T(ρ)+T(Z) The above external forces F and α are the tidal current direction/current velocity, wind direction/wind speed and It is determined using the hull specifications (L×B×D) and superstructure dimensions input as setting data.

The anchor chain angle θ is obtained as detection data, and φ is obtained by calculating the anchor chain catenary.

Therefore, from the above-mentioned equation 4 and the anchor chain catenary theoretical equation, the values of F _p and F _s that satisfy the above-mentioned equation 4 can be determined.

In addition to the balance of forces in the longitudinal and lateral directions as described above, it is also conceivable to consider the balance of moments around the vertical axis. In this case, the moment is balanced by the lateral propulsive force of the ballast thruster 22 and the lateral propulsive force of the atte rudder, or if the ship is not equipped with the ballast thruster 22, the maximum holding force T ₀ is adjusted by letting out the anchor chain. It is also possible to balance the moment by increasing the max and using the horizontal propulsion force from the atte rudder.

In addition, in order to reduce external forces, when the wind force is strong, the stutter is deepened to reduce the surface area of the ship above the water, and when the tidal force is strong, the stutter is made shallower to reduce the area below the water surface. It is also possible to reduce this.

In addition, to find the external force F acting on the hull, use the stutter meter 1.
It is desirable to calculate the external force F by taking into consideration the data such as the wave height, direction, period, and swell height, direction, and period detected in step 7.

The guard anchor control propulsive forces F _p and F _s are determined as described above, and the longitudinal propulsive force F _p and the lateral propulsive force F _s
A control signal for generating the central processing unit 24
The signal is output from the control signal output device 29 to the main engine control means 20a, the bow thruster control means 22a, or the steering device control means 21a, respectively.

In this case, the control signal is
It may be outputted to all of 22a and 22a at the same time, or it may be outputted to any two means, or to any one means.

In some cases, a control signal is also output to the windlass control device 5a in order to extend the anchor chain 6 and increase the maximum holding force T ₀ max, or a control signal is output to the windlass control device 5a to increase the maximum holding force T 0 max by letting out the anchor chain 6. A control signal for controlling the injection and drainage is output to the stuttering control means 19a.

Next, the calculation procedure executed by the central processing unit 24 will be briefly explained with reference to the flowchart shown in FIG. 5, where S1 to S9 indicate each step.

After starting in S1, timer 2 in S2
When the operation signal from 5 is input, the process moves to S3 where various data stored in the RAM 27 are read, and in S4, the anchor chain catenary calculation is performed using the above data and the calculation program stored in the ROM 26. The maximum gripping force T0max is calculated.

In S5, the detected anchor chain tension T0 (strictly speaking, the value obtained by adding the hose pipe friction force to the detected anchor chain tension)
It is determined whether or not is smaller than the maximum gripping force T0max, and if it is smaller, the process moves to S9, and if it is not smaller, the process moves to S6.

In S6, the hull external force F is calculated, in S7 the required anchorage control forces Fp and Fs are calculated, and in S8
A control signal according to Fp and Fs is output at
Move from S8 to S3 and repeat the same steps as above.

In the flowchart of FIG. 5, the logic for outputting control signals to the windlass control means 5a and the water droplet control means 19a is omitted for simplicity of explanation.

(Effects of the Invention) As explained above, in the present invention, detection signals such as seabed soil quality, anchor chain length, anchor chain angle, anchor chain tension, direction and speed of tidal current, wind direction and wind speed are received, and at least , receiving signals representing the hull specifications, superstructure dimensions, anchor chain unit weight, anchor type and dimensions, the control device accurately calculates the maximum holding force and external force acting on the hull, and also calculates the necessary guard anchorage. Since the control propulsion force is determined and a corresponding control signal is output to at least one of the main engine control means, the swing device control means, and the swamp control means,
Effects such as being able to accurately and reliably control the anchor guard using engineering methods without relying on the experience of the crew, and being able to automate the anchor guard control are achieved.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention, and FIG. 1 is a schematic overall configuration diagram of an automatic guard anchor control device and a mooring device;
Figure 2 is a block diagram of the automatic guard anchor control system, Figure 3 is an explanatory diagram of the force acting on the hull under anchor guard control, Figure 4 is an explanatory diagram of the anchor chain catenary, and Figure 5 is a diagram of the system executed by the central processing unit. This is a schematic flowchart of the calculation procedure. 2...Control device, 6...Anchor chain, 8...Anchor, 9...
... Anchor chain tension detector, 10 ... Payout anchor chain length detector, 11 ... Anchor chain angle detector, 12 ... Seabed soil detector, 14 ... Tidal current detector, 18 ... Wind direction and wind speed detector, 19a ... Drifting water Control means, 20a...Main engine control means, 21a...Steering device control means, 22a
...balance thruster control means.

Claims (1)

[Claims] 1. A seabed soil detector that detects the seabed soil quality near own ship, a payout anchor chain length detector that detects the length of the anchor chain that has been paid out, and an anchor chain angle detector that detects the payout angle of the anchor chain with respect to the own ship's center line in plan view. , an anchor chain tension detector that detects the tension of the anchor chain, a wind direction and wind speed detector that detects the wind direction and speed, a tidal current detector that detects the direction and speed of the current near own ship, and the information from these detectors. Receiving the detection signal and receiving various signals representing at least swamp, water depth, hull specifications, superstructure dimensions, anchor chain unit weight, anchor type and dimensions,
The maximum holding force between the anchor and the anchor chain and the external force acting on the ship's hull are calculated, and the guard anchor control propulsive force in the vertical and horizontal directions necessary to maintain the anchor chain tension below the maximum holding force is calculated. 1. An automatic guard anchor control device comprising: a control device that outputs a control signal according to the above to at least one of a main engine control means, a swing device control means, and a swamp control means.