KR100868849B1 - System of optimum course selection for ship's speed trial and method thereof - Google Patents

Abstract

The present invention relates to a method for selecting an optimal course for speed test operation of a ship, and in particular, modeling a steering motion equation in a control unit; Starting the ship's turning and zigzag operation test; Logarithmic speed detected by the speed log sensor during turning and zigzag operation, ground speed detected by DGPS, propeller rotation speed (RPM) of the ship input from engine power, and rudder angle detected by the rudder angle in real time through the interface Receiving an input and storing the same in a storage unit in the controller; Analyzing the velocity and direction of the ocean current using the data; Measuring wind speed and wind direction through a wind vane; Inputting and storing data on the calculated currents and winds; Calculating the rudder angle and the drift angle for each course according to the current and wind; Selecting an optimal course based on the degree of occurrence of rudder angle and drift angle for each course caused by the influence of the calculated current and wind; And performing a speed trial run along the selected optimal course.

Therefore, the direction and speed of currents are estimated using the bow angle at this time, including the ground speed detected by DGPS, the log speed detected by speed log, and the difference, while performing the actual zigzag and turning operation of the constructed ship. Using this estimated current and wind speed and direction, the course can be selected to minimize the generation of rudder angles and drift angles, which can greatly improve the reliability of the ship's performance.

Speed Log, Gyro, DGPS, Engine Power, Rudder Angle, Algebra & Ground Speed

Description

System of optimum course selection for ship's speed trial and method

1 is a block diagram of a system to which the method of the present invention is applied.

Figure 2 is a state diagram for calculating the logarithmic speed difference between the DGPS speed (earth speed) and the speed log using the system to which the present invention is applied.

3 is a flowchart for explaining the method of the present invention.

Figure 4 is a graph showing the difference between the logarithmic speed and the ground speed when the vessel is rotated 180 degrees to which the present invention is applied.

5 is a graph showing the difference between the logarithmic speed and the ground speed when the vessel to which the present invention is applied in zigzag operation.

6 is a screen showing a result of inputting the basic specifications of the ship for modeling the steering motion equation for executing the speed test run course selection program.

7 is a screen showing a state in which the velocity and direction of the measured current and the wind speed and wind direction obtained from the wind vane are inputted into the speed trial run course selection program by external force.

8 is a screen displaying the direction of the course by calculating the course to minimize the use and drift angle of the rudder under a given external force.

Explanation of symbols on the main parts of the drawings

1: ship 2: speed log

3: gyro 4: DGPS

5: engine power 6: rudder angle

7: interface unit 8: control unit

The present invention relates to a method for selecting an optimal course for ocean current measurement and speed trial operation of a vessel using a precision global positioning system (hereinafter, abbreviated as "DGPS") and a speed log. Through the zigzag and turning of the vessel, the direction and velocity of the currents are estimated using the difference between the DGPS speed (ground speed), the logarithmic speed of the speed log, and the bow angle at this time, and the wind speed measured from the estimated currents and wind vanes. It is invented to select a course that minimizes the occurrence of rudder angle and drift angle using and directions.

In general, to test and verify the speed performance of the ship after the ship is built, the speed trial run is carried out at sea.

The speed performance of the ship at the time of contract means the performance in the water without waves, wind, and currents, but the external force is always present in the sea where the actual speed test is performed.

In order to compensate for these external forces, waves and winds reflect the effects of the increase in ship resistance according to the prescribed rules, and the effects of the currents are reflected by measuring round trips and averaging them.

However, in the case of the current, the impact can be compensated by measuring the reciprocation when it meets from the front, but when the current or the wind meets the side or at an angle, the force is generated in the transverse direction of the vessel. In some cases, the ship may be operated with a drifting angle occurring.

This phenomenon reduces the speed performance of the ship, but it can be said that there is practically no compensation for the effect.

On the other hand, for speed test operation of the ship, the direction of the ship is designated, and the direction is maintained by using the automatic navigation device.

At this time, the rudder is used to maintain the direction, and the International Organization for Standardization (ISO) describes a method of compensating the use of the rudder and the angle of drift for maintaining the course.

However, most ship owners do not accept such compensation, so it is necessary to select the course of the ship in such a way as to minimize the use of rudders and the occurrence of drift angles.

Therefore, the most objective measurement of the ship's speed performance is among the constants, but if not, it is more effective to perform mainly in the forward and reverse directions of the current.

However, although it may not be easy to find the direction of the currents changing seasonally in the sea where the actual test run is performed, conventionally, the optimal course selection system considering the influence of the current and wind on the speed test run of such a ship And no method has been developed.

The present invention has been made in order to solve such a conventional problem, the ground speed detected by the DGPS and the speed difference detected by the speed log while the actual ship zigzag and turning operation and the bow angle at this time To estimate the direction and speed of the sea current using the heading angle) and to minimize the occurrence of the rudder angle (drift angle) and the drift angle using the estimated speed and direction of the wind from the current and the wind vane. The purpose is to provide a method for selecting an optimal course for speed test operation of ships.

The present invention for achieving the above object is a speed log installed on the bottom of the ship to detect the log speed, which is the relative speed of the sailing ship and sea water; A gyro for detecting the bow angle of the ship in zigzag and turning operation in real time; A DGPS that detects coordinates (latitude and longitude), ground speed, and direction of the ship's current position in zigzag and orbit using real-time data received through a GPS positioning receiver in real time; Engine power for detecting the propeller rotational speed (RPM) of the ship in real time; A rudder angle for detecting an angle of a rudder provided at the rear of the ship; An interface unit for collecting data output from the components and transmitting the collected data to the control unit; Analyze the speed and direction of currents by inputting various data through the interface unit, measure wind direction and wind speed, select the optimal course by calculating rudder angle and drift angle for each course by using current and wind data. Control unit for performing a speed trial run using this.

The present invention for achieving the above object comprises the steps of modeling a steering motion equation in the control unit; Starting the ship's turning and zigzag operation test; Logarithmic speed detected by the speed log sensor during turning and zigzag operation, ground speed detected by DGPS, propeller rotation speed (RPM) of the ship input from engine power, and rudder angle detected by the rudder angle in real time through the interface Receiving an input and storing the same in a storage unit in the controller; Analyzing the velocity and direction of the ocean current using the data; Measuring wind speed and wind direction through a wind vane; Inputting and storing data on the calculated currents and winds; Calculating the rudder angle and the drift angle for each course according to the current and wind; Selecting an optimal course based on the degree of occurrence of rudder angle and drift angle for each course caused by the influence of the calculated current and wind; And performing a speed trial run along the selected optimal course.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a block diagram of a system to which the present invention method is applied, and FIG. 2 is a state diagram for calculating a logarithmic speed difference between a DGPS speed (ground speed) and a speed log using the system to which the present invention method is applied. 3 shows a flowchart for explaining the method of the present invention.

In addition, Figure 4 shows a graph showing the difference between the logarithmic speed and the ground speed when the vessel is applied to the present invention 180 degrees, Figure 5 shows the logarithmic speed and the ground when the vessel to which the present invention is applied in zigzag A graph showing the difference in speed is shown.

In addition, Figure 6 shows a screen showing the result of inputting the basic specifications of the ship for modeling the steering motion equation for executing the speed test run course selection program, Figure 7 is the velocity and direction of the measured current flow and the wind speed obtained from the wind vane And a screen showing a state in which the wind direction is input to the speed test driving course selection program as an external force, and FIG. 8 shows a screen displaying the direction of the course by calculating a course that minimizes the use of another rudder and the drift angle under a given external force. .

According to this, the system to which the method of the present invention is applied comprises: a speed log (2) installed at the bottom of the vessel (1) to detect a logarithmic speed, which is a relative speed of the sailing vessel and the sea water;

A gyro (3) for detecting in real time the bow angle of the ship 1 in zigzag and turning operation;

A DGPS (4) for detecting in real time the coordinates (latitude and longitude), the earth speed, and the direction of the current position of the ship in zigzag and orbit using the data received through the GPS system;

Engine power 5 for detecting in real time the propeller rotational speed (RPM) of the ship;

A rudder angle 6 for detecting an angle of a rudder provided at the rear of the ship;

An interface unit 7 which collects data output from the respective components and transmits the collected data to the control unit 8;

Analyze the speed and direction of the current by receiving various data through the interface unit 7, measure the wind, calculate the rudder angle and the drift angle for each course using the current and the data of the wind, and select the optimal course. It is characterized in that consisting of; control unit 8 for performing a speed trial run using this.

In addition, the method of the present invention, the step (S1) for modeling the steering motion equation in the control unit (8);

Starting the turning and zigzag operation test of the vessel 1 (S2);

In the logarithmic speed detected by the speed log 2 during turning and zigzag operation, the ground speed detected by the DGPS 4, the propeller rotational speed (RPM) of the ship input from the engine power 5, the rudder angle 6 Receiving the detected rudder angle in real time through the interface unit 7 and storing the detected rudder angle in a storage unit in the control unit 8 (S3);

Analyzing the velocity and direction of the current using the data (S4);

Measuring wind through the wind vane (S5);

Inputting and storing data on the calculated currents and winds (S6);

Calculating the steering angle and the drifting angle for each course according to the current and wind (S7);

Selecting an optimal course based on the rudder angle and the drift angle for each course using the calculated currents and winds (S8);

Characterized in that consisting of; step (S9) for performing a speed trial run according to the selected optimal course.

Referring to the operation and effect of the present invention made of such a configuration and steps as follows.

First, the system to which the method of the present invention is applied is largely divided into a speed log 2, a gyro 3, a DGPS 4, an engine power 5, a rudder angle 6, an interface 7 and a controller 8. What is done is the main technical component.

At this time, the speed log 2 is installed at the bottom of the vessel 1 detects the logarithmic speed and transmits it to the controller 8 through the interface unit 7.

In addition, the gyro 3 detects the bow angle (direction of the bow) of the ship 1 in zigzag and turning operation in real time, and transmits it to the controller 8 through the interface unit 7.

In addition, the DGPS 4 uses the data received through the satellite positioning system (GPS) receiver in real time to coordinate (latitude and longitude), earth speed and direction for the current position of the ship in zigzag operation and turning. It is detected and transmitted to the control unit 8 through the interface unit 7.

At this time, the DGPS (4), which is a precision satellite positioning system, is known, the relative positioning method for applying the error contained in the data measured at the normal reference point to the measured data at a position away from the reference point. In other words, by comparing the position data of the reference point and the position data measured by the GPS receiver at the reference point that knows the position accurately, the error component is detected.The actual measurement of the point 100 ~ 200km away from the reference point is detected. Since the error of the value is similar to the error of the reference point, removing the error component of the reference point from the measured data significantly improves the accuracy of the measurement position.In this case, the carrier method or data link may be used to transmit error information to correct the data at the reference point. There is a near-precision satellite positioning system (DGPS) and a low-precision long-range DGPS that provide high-precision services according to the method of transmitting simultaneous processing position correction information from the reference point.

In addition, the engine power 5 detects how many times the propeller of the ship rotates in one minute and detects the rotational speed (RPM) of the propeller during the voyage of the ship in real time, and transmits it to the controller 8, and the rudder angle (6) continues to detect the angle of the rudder installed at the rear of the ship during navigation and transmits it to the control unit (8).

In addition, the various data output from each of the above components are collected in real time by the interface unit 7 and transmitted to the control unit 8, the control unit 8 that received various data through the interface unit 7 in this way ), The vessel analyzes the speed and direction of the current through zigzag and turning operation, measures the wind direction and wind speed through the wind vane, and calculates the rudder angle and the drifting angle for each course using the current and wind data. Once selected, it is used to perform speed commissioning.

On the other hand, the method of the present invention is the step (S1) of modeling the steering motion equation in the control unit 8, the step of starting the turning and zigzag operation test of the vessel (S2), the log speed and the ground during the turning and zigzag operation Coordinate position change data, gyro heading, ship propeller rotational speed (RPM) and rudder angle of the ship in real time through the interface unit (7), and storing (S3) the current using the data. Analyze the speed and direction of the step (S4), measuring the wind direction and wind speed through the wind vane (S5), the step of inputting and storing the data about the current and wind calculated above (S6), Calculating the rudder angle and the drift angle for each course according to the speed and direction (S7), selecting the optimal course based on the calculated current, wind, rudder angle and the drift angle for each course (S8) and the selected optimal course Speed along And that comprising the step (S9) that performs the operation as a key technology configure a base.

At this time, Figure 2 shows a method for calculating the logarithm speed difference between the DGPS speed (ground speed) and the speed log, the speed of the current can be said to be the difference between the ground speed and the log speed.

For example, if a ship is anchored and currents flow below the ship at a speed of "2" knots, the earth speed will be "0" knots, but the log speed will appear as "2" knots.

The difference between the earth speed and the logarithmic speed is maximum when the current is in the forward or reverse direction.

In addition, if you turn 180 degrees to know the direction of the sea current in the sea area where you will be commissioning or perform zigzag navigation around the direction that is expected to be estimated in advance, you can know the exact direction of the current. The difference between the speed and the ground speed is as shown in the graph shown in FIG.

In Fig. 4, the horizontal axis is the bow angle and the vertical axis is the speed difference detected by the DGPS 4 and the speed log 2, respectively.

For example, if the vessel is facing in the 180 degree direction, the speed detected by the speed log 2 is about 0.8 kts fast, and the speed difference between negative and negative is between 180 and 200 degrees.

This means that currents are flowing between 180 and 200 degrees and the vessel is operating in reverse, and the speed of the current is about 0.7 kts.

If you turn from 200 to 20 degrees, the speed difference between 0 and 20 degrees will be the largest positive.

This means that the vessel is running smoothly, and the direction is likewise the current flows between 180 and 200 degrees.

Therefore, it is not necessary to make a 360 degree turn, and a 200 degree turn can measure the direction and speed of the current.

In addition, when the zigzag operation is performed, the difference between the logarithmic speed and the ground speed is shown in the graph shown in FIG.

After all, the heading of the gyro with the largest difference between log speed and earth speed is the direction of the current, and the difference is the speed of the current.

At this time, the zigzag operation is performed to compensate for the above problems of the turning test.

The turning test is sometimes a bad effect on the speed log (2) on the bottom of the ship due to the rapid rotation of the ship.

Therefore, the zigzag operation is effective around the expected current direction to measure stable signals.

Referring to FIG. 5, in this case, the zigzag operation was performed at 160 degrees to 200 degrees, and when the temperature was 160 degrees, the data was acquired while maintaining 160 degrees for a while. It is measured to 200 degrees (red).

In addition, for stable measurement of the data, it is measured again in the same way while descending from 200 degrees to 160 degrees (blue), and then the direction and velocity of the current are determined using the average speed difference.

5, the average speed difference is shown for each bow angle at the top.

That is, the average velocity is -1.096 kts in the 160-degree direction and -1.494 kts in the 200-degree direction. As the speed difference is the largest, the current is 200 degrees and the speed is about 1.49 kts.

On the other hand, Figure 6 is a screen showing the result of inputting the basic specifications of the ship for modeling the steering motion equation for executing the speed trial run course selection program, which is based on the basic specifications of the ship, the fluid force coefficient of the control equation Empirically and automatically estimate and use them to simulate vessel motion.

In addition, Figure 7 is a screen showing the state of the measured velocity and direction of the current and the wind speed and wind direction obtained from the wind vane as an external force input to the speed trial run course selection program, along with the hydrodynamic coefficient of the steering motion equation This is to calculate the speed and direction of the ship as an external force term and to calculate the ship's motion to maintain the course under this external force.

In addition, Figure 8 shows a screen displaying the direction of the course by calculating the course to minimize the use and drift angle of the rudder under a given external force, input the external force to the speed trial run course selection program and at the same time to suit the steering characteristics of each ship Solve the modeled steering equation and perform speed trial run simulation for each course under the given external force, calculate the use of the rudder and the drift angle caused by the external force for each course, and consider the increase in the resistance of the ship. The optimal course is selected by calculating the loss and minimizing the speed loss.

As can be seen in FIG. 8, it can be seen that under a given current and wind, the course of 35 degrees to 215 degrees (which always reciprocates 180 degrees) is most appropriate.

Although the above-described embodiments have been described with respect to the most preferred embodiments of the present invention, it is not limited to the above embodiments, and it will be apparent to those skilled in the art that various modifications can be made without departing from the technical spirit of the present invention.

As described above, according to the present invention, using the bow angle at this time, including the ground speed detected by the DGPS, the log speed detected by the speed log, and the difference while performing the actual zigzag and turning operation of the constructed ship. It is possible to estimate the direction and velocity of the current and to select a course that minimizes the occurrence of the rudder angle (drift angle) and the drift angle using the estimated current and wind velocity and direction. It is a very useful invention that can be improved.

Claims (2)

delete Modeling a steering motion equation at the control unit; Starting the ship's turning and zigzag operation test; Log speed and ground speed detected by speed log and DGPS during turning and zigzag operation, bow angle detected by gyro, propeller rotation speed (RPM) of ship input from engine power, rudder angle detected in rudder angle Receiving the input in real time through the interface unit and storing it in a storage unit in the controller; Interpreting the velocity and direction of the ocean current using the data; Measuring wind direction and wind speed through a wind vane; Inputting and storing data on the calculated currents and winds; Calculating the rudder angle and the drift angle for each course according to the current and wind; Selecting an optimal course based on the calculated current, wind, course angle and drifting angle; And performing speed trial run according to the selected optimal course.

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