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Title:
SYSTEM TO CONTROL AND SUPERVISE SHIP MOVEMENTS AND EQUIPMENT FOR IT
Document Type and Number:
WIPO Patent Application WO/2003/053775
Kind Code:
A1
Abstract:
The invention concerns a system and a device to control and monitor the hull stress on a ship regarding at least pitch and roll with the aid of a number of sensors and a device for making calculations on basis of the controls. According to the invention a number of sensors (2) are to be attached to the ship (1) in question. Each sensor is composed of plates that are combined two by two at a relative distance from each other. The said sensors (2) are to be connected to a computer (PC) which is connected to a monitor screen. The computer will receive the measure values from the said sensors and on the basis of these values and with the aid of a software program, it will calculate the desired conditions for the vessel in question. The calculated values will then be visualized on the monitor screen.

Inventors:
Vestin, Karl Helge (Bälggatan 6, Varberg, S-432 31, SE)
Application Number:
PCT/SE2002/001711
Publication Date:
July 03, 2003
Filing Date:
September 23, 2002
Export Citation:
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Assignee:
Vestin, Karl Helge (Bälggatan 6, Varberg, S-432 31, SE)
International Classes:
B63B39/14; (IPC1-7): B63B39/14
Foreign References:
US4872118A
US4524710A
US4566336A
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Claims:
1. P a t e n t C.
2. a i m s 1. The said system is designed to control and monitor the stress on a vessel (1), as well as pitch and roll, with the aid of a number of sensors (2) and a computer which puts in order the calculations according to the made controls. The system, characterized in, by the following: that at least one sensor (2), which is made of plates held in pairs at a relative distance from each other, and that is intended to be mounted on the ship (1), that acceleration measuring of forces in x and/or y and/or z direction/directions is measured by the said sensor, that the said sensor (2) is arranged to be connected to a computer (3) that is attached to a monitor screen (4), that the said computer (3) is arranged to receive the measure values from the said sensor (2), that the said computer (3) is set up to calculate the desired maritime parameters for the ship (1) in question, with the aid of a software program, and that the calculated values are to be visualized on the monitor screen (4). *& 2.
3. The said system, within the patent claim 1, characterized in, that the calculated values are to be visualized graphically on the monitor screen (4).*& 3.
4. The said system, within the patent claim 2, characterized in, that the ship's movements, such as pitch and roll, are to be visualized on the monitor screen.*& 4.
5. The said system, within any of the patent claims 23, characterized in, that a ring (5) with different colours on the outer (6) and inner (7) circumference edge is used to visualize pitch and roll, and whereas the total inclination is also arranged to be shown on the monitor screen (4).*& 5.
6. The said system, within any of the patent claims 24, characterized in, that a point (8) is arranged to be shown on the screen, and that it indicates the total pitch and roll of the ship or any other condition you wish to control.*& 6.
7. The said system, within the patent claim 5, characterized in, that the diameter (h) of the said point (8) is programmed to vary, whereas the diameter (h) is used to report the value of the ship's actuated forces.*& 7.
8. The said system, within the patent claim 6, characterized in, that the point (8) is programmed to move on the monitor screen (4) in the same direction as the ship's effected forces are moving, whereas the movement of the point (8) is directly proportinal with the acceleration, and that a warning is arranged to be effected when the point crosses the outer ring (6) as shown on the monitor screen.*& 8.
9. The said system, within any of the above mentioned patent claims, characterized in, that at least two sensors (2) are attached to the ship (1) at a distance from each other to enable measuring and, with the aid of the said measure values, to calculate the stresses of the ship regarding torsion and deflection.*& 9.
10. The said system, within the patent claim 8, characterized in, that one of the two sensors (2) is arranged to be placed in the foreship of the vessel, and the other of the two sensors (2) is to be placed in the stern of the vessel.*& 10.
11. A device to be used in connection with the said system to control and monitor the stresses of the ship (1) regarding at least pitch and roll, and with the aid of a number of sensors (2). A device to put into order the calculations on the basis of the made controls, according to any of the above mentioned patent claims 19, characterized in, that the sub units of the sensor (2) are composed of covered plates, that are combined two by two at a relative distance from each other, and to be used as an accelerometer to measure up to three different perpendicular directions (x, y and z). With the said sensor (s) are to be measured the speeds, rotations, positions, deformations and stresses of the ship. Furthermore there is a device to be used for attaching the sensor (2) to the ship (1), and that there is a PC with a monitor screen (4) and a software program to be connected to the said sensor (2). The software is made to be able to receive information about different measure values for making subsequent calculations of the desired functions, and to monitor these calculated conditions graphically on a monitor screen (4).
Description:
System to Control and Supervise, Ship Movements and Equip- ment for it.

The invention in question is a system designed to monitor and control ship motions regarding at least pitch and roll with the aid of a number of specially designed sensor (s) and a PC to put in order the calculations on the basis of the made controls.

As modern ships become larger and faster with quicker turnarounds and smaller crews, pressure and stress are taking their toll leading increasingly to mistakes and accidents.

Although technology has come to the'aid of seafarers in the shape of hardware and software designed to facilitate navigation and monitoring :., engine room performance, there are relatively few systems currently available which give information and data on the effects weather and sea conditions have on ships and their cargoes.

The following are examples of such measuring equipment for ships : GB 2094476 A shows an example of stress monitoring equipment where several measuring devices are'used to measure the deflection of a ship. In this case, a PC and monitor are used to define the maximum stress by using a suitable algorithm of curves as applied by the PC. In this example, a large amount of measuring equipment must be used and the stress estimate must be worked on continuously.

US 4, 872, 118 A is of a measuring system for trim and -s-t-ability-control. This system works well when the ship is anchored during loading and discharging, but is not so useful during transport.

WO 87/07876 is of a device and method to control the charge distribution on a ship. Many measuring devises are required to make this method work, including measuring devices to control the water. pressure on the ship. However, this method is not exact and requires numerous measurements as well as points of measuring.

US 5,547, 327 A is of a control system that is to be used when loading a ship. This system is also very complicated and demands a lot of measuring devices as well.

An important aspect of the newly invented said system is that it will easily solve the above mentioned problems efficiently and without the complicated mounting of a large amount of equipment.

Said aspect will be reached with the system according to the invention in question, that is mainly characterized thereby, that at least one sensor that is meant to be mounted on the vessel. The sensor is composed of covered plates, that are combined two by two at a relative distance from each other.

The acceleration measurement of forces in x and/or y and/or z direction/directions can be measured with the said sensor. The said sensor is also meant to be connected to a computer that is communicating with a monitor and the said computer is arranged to receive the measurement results from the said sensor.

The said computer is set up to determine the desired conditions of the vessel in question, on the basis of the received measurement test results and, with the help of a software program, to visualize the calculated values on the monitor.

Said system consists in its basic form of one sensor usually mounted in the forepart of the vessel and linked by cable to a computer on the bridge giving a visual real-time display and analysis of the ship's motions when at sea or, when in port, to calculate the relationship between the centre of gravity and the metacenter. At least two sensors are required to measure the torsion and hull stresses. One in the bow and the other fitted towards the stern.

Measuring the angle and period of roll and pitch together with 3D acceleration makes it possible to estimate the forces on lashings and containers during the voyage thereby reducing the risk of accidents. Graphic analysis of all historic movements can be recorded over a period of up to 30 days continuously.

Of course, there is no real substitute for good practical seamanship but, when combined with a system according to the present invention, the system will help the crew to make more informed decisions particularly since it will also give predictive sea-state information enabling preventative action to be taken. The primary function of the system is therefore to assist the ship's officer of the watch to improve sea-keeping in rough weather by displaying the data in easily understandable graphics. An audible and visual alarm is given when pre-set alarm levels are reached.

Another purpose will be achieved by a device that is mainly characterized by the sensor, which is composed of covered plates that are combined in pairs at a relative distance from each other.

Additionally, there is a device to connect the sensor to the ship and that a computer complete with monitor and software is available to be connected to the said sensor. The software enables reception of information, of different measured values, to be used for the subsequent calculation of the desired results and that the calculated results are subsequently displayed graphically on the monitor.

The invention will be described as follows, in a number of examples of applications, with the reference to the enclosed drawings: Fig. 1 is a perspective view of a sensor.

Fig. 2 is a picture of the PASA window.

Fig. 3 is a picture of the SAMP window.

Fig. 4 is a picture of the HSC window.

Fig. 5 shows part of the PASA window in Fig. 2 during a measuring exercise.

Fig. 6 shows a graphic picture of pitch and roll from the PASA window.

Fig. 7 shows a picture of different choices in the program menu.

Fig. 8 shows a picture of the SAMP display.

Fig. 9 shows various readings of the sensor that are logged and are shown on screen in the shape of a curve.

Fig. 10 shows various alarm function readings during a particular period and that have been stored in tables.

Fig. 11 shows the division of onboard container stacks within the cargo hold (of the vessel) as well as their stresses at different measuring points.

This invention, which concerns a system designed to monitor and control ship motion (1), will use at least one sensor (2) when controlling and monitoring pitch and roll.

However, when controlling and monitoring torsion and deflection, it will use at least two or more sensors (2) and also when putting into order the calculations according to the controls that have been made. The system consists of at least one sensor (2), that is composed of plates, that are combined two by two at a relative distance from each other and, that is meant to be mounted on the ship (1). The sensor (2) will measure the acceleration of forces in one, two or three dimensions in relation to each other at perpendicular angles x, y and z.

The sensor (2) consists of one, two or three internal sensor units. Each sensor unit consists of two plates, one being stationary and the other being movable.

When the movable plate is influenced by gravity the distance between the two plates will change, depending on the angle of the sensor in relation to the direction of gravity or acceleration on the sensor. An electrical field is also measured between the two plates.

When the sensor moves or angles accordingly, the distance between the plates will change and the resulting signal can be analysed as a sum of the changes in angle and acceleration. The signal is analyzed along a time axis and can therefore be separated as acceleration and angle.

Accordingly, it is possible to measure the changes in acceleration and angle with one sensor. When there are three sensors mounted at an angle towards each other (X, Y, Z) all incurred angles and motions can be measured.

The measure values from the sensor can be applied directly to the control systems of the ship or alternatively to a PC. With a PC, the motions will be shown graphically (as described below).

The said sensor (2) shall be connected to a PC (3) that is connected to a monitor (4) or to another similar device. The PC (3) shall receive the measured values from the said sensor (2) and according to these values, it shall calculate, with the aid of a software program, the desired conditions for the vessel (1). Preferably these calculated values shall be shown graphically on a monitor screen (4).

On the screen (4) shall be visualized the motions of the ship, such as pitch and roll as per Fig. 2. There is a ring (5) with different colours on the outer (6) and inner (7) circumference edge, made to clearly visualize the pitch and roll of the ship (1). The total pitch is displayed on screen (4). Preferably the colours are red for the outer ring and yellow for the inner ring, 6 and 7 respectively.

One point (8) is shown on screen (4) to display the pitch and roll of the ship or other conditions that are to be monitored. The diameter (h) on the said point (8) is programmed to display the value of the influenced forces on the ship graphically.

The said point (8) is programmed to move on the screen (4) in the same direction as the forces that are bearing on the vessel. Hereby the motion of the point 8 is directly proportional to the acceleration. Also, there will be made a warning of some kind when the point crosses the outer ring (6) on the screen.

At least two sensors (2) of the above mentioned type are attached to the ship (1), at a relative distance from each other, to measure the movements of the ship. With the aid of the said measured values, it will enable a calculation of the stresses on the ship regarding torsion and deflection. In this situation, one of the two sensors 2 is to be placed in the foreship while the second one of the two sensors is to be placed in the stern.

The said invention enables the use of a system, of the type mentioned above, to control and monitor the stress on a vessel. The said invention also controls and monitors at least pitch and roll with the aid of one or more sensors (2) that enable the system to make calculations from the measured readings of the sensor (s). The sub units of the said sensor (2) are composed of plates that are combined two by two at a relative distance from each other. The said sensor has a shut in the cover that enable it to be used as an accelerometer to measure up to three different perpendicular directions (x, y and z) and that the speeds, movements, positions, deformations and stresses can be measured by the said sensor (2).

Furthermore, there is a device (9) with holes for fixing screws, and a PC with a monitor screen (4) and a software program, to be connected to the said sensor (2). The software is made to be able to receive information about different measure values for making subsequent calculations of the desired functions, and to monitor these calculated conditions graphically on a monitor screen (4).

The present invention which shortly has been described above is called S. M. C. which means Ship Motion Controller and which is further described below. The sensors 2 which are used by the present invention are meant for: Angle and shock analyzer.

Hull stress control.

Lash control.

"Sea-state"prediction.

Stability control system.

Tank level program.

Basic design of sensors The measure system makes it possible to connect one or more sensors depending on the function desired. Each sensor measures an angle, movement speed, movement direction and shocks in three degrees of freedom. The sensor signals will be transformed to a data communication signal that makes the signal transmission to the signal transformer possible without any disturbance.

Number of sensors One sensor is normally enough for measuring a ship's movement. When there are special circumstances, more than one sensor could be necessary. Example is control of loading capacity in several separate cargo spaced. For measuring torsion and deflection there will be two sensors needed.

Hardware installation The sensor has been cast in epoxy plastic and the sensor house is made of stainless steel to avoid moisture damage. Although the sensor is well protected we recommend installation in a splash proof box. The sensor must be installed close to the centre line of the ship and at the prow and the sensor shall be installed with the disc horizontal.

The arrows marked"Y"3 on the top of the sensor must be mounted in accordance with the direction of the ship.

Base Windows The base side will show all the measuring functions of the program. The program window has been designed in two parts. In the upper part are shown the basic information of the ship's current movements as per the figure 7. The information is made in bars as well as numerically under each bar. The rightmost bar shows the temperature inside the sensor body.

PASA Power Angle and Shock Analyzer Displays and analyses wave interaction. Adds angles and shocks in 3D-axis.

PASA is built up with two circles 6,7, a red and a yellow, and one point 8, a green in a system of coordinates.

The two centric circles move in the diagram of in relation to the movements of the ship. Both angle and direction is shown.

Thickness of the circles 6,7 corresponds to alarm levels. The point 8 illustrates shocks, which the ship is exposed to. This ring will move in the system of coordinates in proportion to the acceleration. When the rings touch each other alarm will be given. The event will be registered in"Events"and the alarm will sound. All maximum values are adjustable by the bar controls.

PASA gives you a graphic picture of the pitch and roll of the ship shown in Figs 2 and 6.

The inner yellow circle 7 shows'low level alarm".

The red outer circle 6 shows"high level alarm". The yellow and the red circles move in the system of coordinates with the current movements of the ship. The pitch will be described by the moving of the Y-direction in the system of coordinates.

The roll will be described by the moving of the X-direction.

The total angle of inclination will be shown automatically.

The setting of the maximum allowed pitch is the same as the one on the angle bar above. The diameter of the green 8 point will be changed according to the G-force. Higher G-force gives a bigger diameter of the point. The point has its ground position in the centre of the coordinates. When accelerating laterally the green point 8 will move in the same direction as the force of acceleration. The movement of the point 8 is directly proportional to the acceleration. When the green point moves and touch the yellow 7 or red 6 field there will be an event registered in the"*, Events" and the alarm will be given.

Real Time Measurement See Fig 5.

7 = Interior Alarm ring (low alarm level) 6 = Exterior Alarm ring (high alarm level) 8 = Centre point symbolizes shock d = The total angle of inclination of the ship e = The pith angle of the ship f = The angle of rolling g = Acceleration force (shown as distance to origin of coordinates) The direction of the arrow shows the direction of the acceleration.

H = The diameter of the point corresponds to the size shock value.

Shock Circle The function resembles the PASA but is a definite analysis of shock and acceleration in 3-dimensions.

SAMP-Ship's Average Movement Position Optimises and simplifies trim control through an integrated ballast tank level system. Optimises economic fuel consumption and diminishes hull stess. The program calculates the average value of each rolling period for Roll and Pitch.

Thereafter, by one point in the diagram, the average value is calculated in 30 minutes periods. This point in the diagram shall be in origo of coordinates when the ship is running optimal. In the point there is an arrow showing the direction of the deviation. The size of the arrow symbolizes the deviation speed but without any scale of degrees. The 0- position (home position) deviates from the 0-point of the sensor and therefore this 0-point should be set separately.

The optimal 0-point will vary depending on the speed and cargo of the ship as well as weather conditions.

When two sensors are connected to the software, it is possible to measure the difference between the indicated angles. The angle difference in the measuring points of the sensors will give Torsion and Deflection. See Fig 4.

Trend-Prediction The curve is divided into two parts. The left one (History) shows the events during the previous hour. The signal Predictions show the expected average curve for the coming hour. The Prediction Curve is estimated from an average value"Average Force"from the previous hour. The Alarm levels "Max Limit"and"Warn Limit"are the same as the set values in "PASA".

This is not shown on any fig.

Events Historic Alarm Table Alarm levels that have been set in the bar instrument will be stored in the Event table.

See Fig. 10 Scale Division will change automatically to the curve requirements. Graphic Analyses of all historic movements and movement combinations of the ship can have down to 0,1 second resolution.

Rectify (the right button in the lower menu row) transforms the graphic negative values to positive. This means that the negative values will be moved to the positive scale and you can compare the positive peaks with the negative peaks.

See Fig 9.

Acceleration, shock and speed of movement are dependent on the distance between the Centre point of Torsion, the Sensors Measuring point and the actual point (the actual container.

In the window"Option"under"Sensor"is correction made between Sensor och the Centre point of Torsion to determine the powers of different locations at the ship, the distance between Measuring point and Centre point of Torsion must be programmed.

Calculations 1. The distances between sensor and Centre point is programmed. location of the Centre Point are programmed.

3. The program calculates the distance to all measuring points on the ship.

4. The program calculates acceleration and inclination for all measuring points on the ship in compliance with the given distances and sensor values.

Control of cargo, its contents and also lashing Calculations can be done on each desired point and be used afterwards for analyses of transport damages. Real Time Monitoring Supervision is made in"PASA".

Container The program is designed for maximum number of containers according to: Bay 0-35 Pcs, Pow/column 0-20 Pcs, Number of container height 0-10 Pcs. See Fig 11.

All columns that have its weight noted (in tons) for a container will automatically be transferred into force tables. (Bay, Row, Stack).

In the table also alarm limitations will be noted.

All notices will be stored under table"Events". See Fig 11.

Power of moving Stress on different parts of a ship and its cargo becomes a combination of acceleration shock and angle of inclination.

Force analyse of measure points The program calculates the distance to all containers on board. The program calculates acceleration and inclination for all containers on board in compliance with the given distances and sensor values.

When the movement is known in one point on the ship it will be possible to estimate the powers of all the points on the ship. It chould be observed that these results are theoretical and must be used only as a recommendation.

The said invention is not limited to the above mentioned description and to the applications in the included drawings. Modifications are possible, especially concerning the construction of the different parts, by using similar techniques of equal nature without patent evasion in the protected area for the invention, such as defined in the patent demands.