KR20100074739A - Position control system and method for ships and sea structure - Google Patents

Abstract

PURPOSE: A system and a method for controlling the location of ships and offshore production units are provided to improve the stability of operations by controlling the location based on information from a GPS or a differential GPS(DGPS). CONSTITUTION: Information related to the external force and a location of ships is inputted in a DGPS. Gyrocompasses(20, 30) display the direction of the ship. An anemometer(90) predicts the speed and the acceleration of the ship. A computer analyses the external force and moving information of the ship. Based on the analysis result, thrust information is outputted. The thrust information is transferred to a thruster(60), a propeller(50), and a rudder(70) trough a programmable logic controller.

Description

Position Control System and Method for Ships and Sea Structure

The present invention relates to a position control method and system for attitude control of ships and offshore structures, and more particularly, to a system and method for attitude control of ships and offshore structures. Ships and offshore structures may need to maintain their intended location in order to perform their work. The present invention is to control the attitude of the ship and offshore structures to realize the attitude control of the ship using GYRO, rudder, propeller, GPS provided in the ship when the ship and offshore structures are to maintain the position A position control system and method.

Maintaining a stable attitude of the ship is to maintain the stability of the operation and the feeling of boarding.

However, in the conventional operation of a ship, a captain or pilot operated a thruster, a propeller, and a rudder as a thrust generator to maintain a target posture.

Therefore, conventionally, the posture maintenance of the shelf was inevitably maintained by the captain or pilot.

The present invention is conceived under the above-mentioned background, the specific position of the ship and offshore structures to obtain the information from the GPS or DGPS (Differential GPS) installed on the ship or offshore structure to control the position of the ship or offshore It is an object of the present invention to provide a position control system and method for ship and offshore structures that enable the structure to work stably.

The system according to an embodiment of the present invention, in order to achieve the above object, the DGPS receiving the environmental force and position information of the ship;

GYRO to indicate the bearing of the ship;

Anemometer to predict vessel speed and acceleration information

PC with built-in location information program that receives environmental external force, position information, speed and acceleration information from the DGPS, GYRO, anemometer, and analyzes the appropriate environmental external force and ship motion information and outputs appropriate thrust information;

And a programmable logic controller (PLC) for transmitting the thrust information from the PC to the thruster, propeller, and rudder as electrical signals.

Method according to an embodiment of the present invention, the step of communicating with the DGPS, GRRO, anemometer, mobile reference device, thruster, rudder and propeller

Filtering the high frequencies from the DGPS and GYRO and the anemometer to low frequencies

Calculating the total thrust of the vessel based on the DGPS and GYRO and the signal filtered by the anemometer; and

Distributing the calculated thrust to the thrusters, rudders and propellers.

According to the method of the present invention, by automatically realizing the position control of ships and offshore structures, it is possible to work for a long time without inputting expensive manpower such as captains and pilots, and it is possible to obtain an effect of reducing risk during operation. .

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

1 is a block diagram illustrating a system implementing the method of the present invention, as shown, anemometer 10, DGPS 20, GYRO 30, position control PC 40, propeller 50, It consists of the side thruster 60 and the rudder 70. In the drawing, the information from the anemometer 10, the DGPS 20, and the Gyro 30 is transmitted to the propeller 50, the side thruster 60, and the rudder 70 using the position control PC 40. .

2 is a conceptual diagram illustrating a position control algorithm of a ship of the present invention.

As shown in the figure, the control command for the thrust distribution through the controller 80 based on the measurement position and the measurement wind of the ship in consideration of the environmental external force is supplied to the side thruster 60, the propeller 50 and the rudder. Delivered to 70. The controller 80 may be implemented as a programmable logic controller (PLC).

3 shows a specific flowchart of a position control method for attitude control of a ship and an offshore structure of the present invention.

First, step S100 is a step in charge of communication with the devices, the horizontal coordinate heading angle is input from the DGPS and GYRO (20, 30) (S110), wind direction and wind speed from the anemometer 90 (S120), The attitude is input from the Motion Reference Unit (MRU) 100 (S130), the pitch is input from the thruster 60 (S140), the rudder angle is input from the rudder 70 (S150), and the propeller RPM (Revolution Per Minute) is input from 50 (S160). The attitude, pitch, rudder angle, and RPM input from the MRU 100, the thruster 60, the rudder 70, and the propeller 50 are monitored by the operator and used in the program (S170).

Subsequently, in step S200, filtering is performed. The control signal is changed to a controllable signal, and correction is performed based on the measured value. In the step S110, the horizontal coordinate heading angle has a high frequency, that is, a controllable horizontal surface coordinate heading angle is filtered (S220). Since the wind direction and the wind speed from the step S12O have a high frequency, the wind direction and the wind speed are controlled to have a low frequency, that is, controllable (S220). In this case, a Kalman filter is used as the low pass filter.

Next, in step S300, the thrust sum is automatically calculated, that is, a control step is performed, and the difference between the current position and the target position is controlled (S310), the environmental external force is predicted based on the wind speed information, and the opposite thrust is generated ( S320). Subsequently, a manual input is input, that is, a manual command is input by calculating a total thrust on the value directly input (S330), and the total thrust is calculated (S340).

Then, in step S400, a step of distributing the calculated thrust to the apparatus is performed, that is, the thrust distribution is performed in step S410, the thrust is distributed to the thruster (S420), the thrust is distributed to the rudder (S430), Thrust is distributed to the propeller (S440). Subsequently, communication with the devices is performed again (S500), and the above process is continuously performed in a cyclic manner to perform position control.

가 모션 필터(300)로 입력되어

가 계산되고, 윈드 필터(400)로 풍향

, 풍속

가 입력되어 풍향의 저주파 성분

,풍속의 저주파 성분

가 계산되어 저 주파수가 추출되어 예측이 수행된다(여기서

는 경도, 위도 및 선수각이고,

는 바람 입사각이고,

는 풍속이고,

는 바람입사각의 저주파 성분이고,

는 풍속의 저주파 성분이고, 또한

는 경도의 저주파 성분, 위도의 저주파 성분 및 선수각의 저주파 성분이고,

는 종방향속도의 저주 파 성분, 횡방향 속도의 저주파 성분, 각속도의 저주파성분이다).FIG. 4 is a diagram corresponding to FIG. 3, in which each process is expressed by a formula. Horizontal plane coordinates from DGPS, GYRO (20, 30)

Is input to the motion filter 300

Is calculated, the wind direction with the wind filter 400

, Wind speed

Is input low frequency component of wind direction

Low frequency components of the wind

Is calculated and a low frequency is extracted to make a prediction (where

Is longitude, latitude, and bow angle,

Is the wind angle of incidence,

Is the wind speed,

Is the low frequency component of the wind angle,

Is the low frequency component of the wind speed,

Are low frequency components of longitude, low frequency components of latitude, and low frequency components of bow angle,

Is a low frequency component of the longitudinal velocity, a low frequency component of the lateral velocity, and a low frequency component of the angular velocity).

(여기서, A,B는 시스템 행렬이고, K는 칼만 게인 행렬이고, H는 계측 행렬이고, x는 상태 방정식의 상태변수(Kalman Filter)이고, z는 계측변수이다.) The time is then updated, the measurement is updated, and calibration is performed by the following equation.

(Where A and B are system matrices, K is the Kalman gain matrix, H is the measurement matrix, x is the Kalman Filter of the state equation, and z is the measurement variable.)

(여기서,

는 궤한 추력 명령이고,

는 궤환 제어 이득이다.) Subsequently, feedback control in the opposite direction from the current position to the desired position is executed.

(here,

Is the thrust force command,

Is the feedback control gain.)

으로 표현된다. 한편, 순방향 제어시는

가 성립하는데(

는 순방향 추력 명령이다.), 환경 부하

는

로 구해진다(여기서,

는 풍력이고,

는 조류력이고,

는 파도에 의한 횡 표류력이다.). 또한 풍력은

로 정해진다(여기서

는 공기밀도이고,

는 풍력 계수이고,

는 풍속이고, A는 투영 면적이다.). 한편, 조류력은

로 구해진다(여기서 는

해수밀도,

는 조류계수이고,

는 조류 속도이다.). Where ship's state is

. On the other hand, in forward control

Is true (

Is the forward thrust command), environmental load

Is

Obtained by (here,

Is wind power,

Is the tidal force,

Is the transverse drift force by the waves). Also wind power

It is decided to (where

Is the air density,

Is the wind power factor,

Is the wind speed and A is the projection area. Meanwhile, the tidal force

(Where is

Seawater Density,

Is the tide coefficient,

Is the tide rate.).

로 주어진다(여기서

는 웨이브 스펙트럼이고,

는 전달함수이다.) In addition, the lateral drift force caused by the waves

Is given by

Is the wave spectrum,

Is the transfer function.)

이다. 추력 명령 매트릭스는

로 주어진다(여기서

는 추력 분배 매트릭스 이고,

는 추력 결과 매트릭스이고, 한편, X는 수평면 종방향 힘이고, Y는 수평면 횡방향 힘이고, N은 수평면 모멘트이다.). 이러한 추력 분배 명령은 상기 MRU(100), 트러스터(60), 러더(70) 및 프로펠러(50)로 명령된다. Thrust distribution is then performed,

to be. Thrust command matrix

Is given by

Is the thrust distribution matrix,

Is the thrust result matrix, while X is the horizontal longitudinal force, Y is the horizontal transverse force, and N is the horizontal moment). This thrust distribution command is commanded to the MRU 100, the thruster 60, the rudder 70, and the propeller 50.

In FIG. 4, communication of the main program of step S100, filtering by the Kalman filter of step S200, control of S300, and thrust distribution of S400 are cyclically repeated to perform position maintenance.

One embodiment of the present invention has been described with reference to the drawings, but the present invention is not limited thereto, and various modifications and variations are made by those skilled in the art without departing from the spirit and scope of the appended claims below. Such modifications and variations are intended to be interpreted as falling within the scope of the present invention.

1 is a block diagram illustrating a system implementing the method of the present invention.

2 is a conceptual diagram illustrating a position control algorithm of a ship of the present invention.

Figure 3 shows a specific flowchart of the position control method for control of the ship and offshore structures of the present invention.

4 is a diagram corresponding to FIG. 3, in which each process is expressed by a formula;

* Description of the symbols for the main parts of the drawings *

10; Anemometer 20; DGPS

30; GYRO 40; position control PC

50 propeller 60; side thruster

70; rudder

Claims (7)

DGPS for receiving environmental external force and position information of the ship; GYRO to indicate the bearing of the ship; Anemometer to predict vessel speed and acceleration information A PC having a built-in location information program that receives environmental external force, position information, speed and acceleration information from the DGPS, GYRO, anemometer, and analyzes appropriate environmental external force and vessel motion information and outputs appropriate thrust information; And And a programmable logic controller (PLC) for transmitting the thrust information from the PC to the thrusters, propellers, and rudders as electrical signals. Communication stages communicating with DGPS, GRRO, anemometers, mobile reference units, thrusters, rudders and propellers Filtering the high frequencies from the DGPS and GYRO and the anemometer to low frequencies A control step of calculating a total thrust of the vessel based on the signals filtered by the DGPS and GYRO and the anemometer; And a distribution step of distributing the calculated thrust to thrusters, rudders, and propellers. The method of claim 2, The Kalman Filter (Kalman Filter) is used in the filtering step. The method of claim 2, And filtering the horizontal plane coordinate heading angle and the wind direction wind speed inputted in the communication step by the controllable horizontal plane heading angle and the controllable wind direction wind speed. The method according to claim 2 or 4, And controlling the difference between the current position and the target position based on the filtered heading angle in the filtering step, predicting an external force of the environment based on the filtered wind power information, and generating counter thrust. And method for position control of offshore structures. The method of claim 2, In the control step, the feedback control is the following equation,

(here,

Is the thrust force command,

Is the feedback control gain), and the ship's state is

(here,

Are low frequency components of longitude, low frequency components of latitude, and low frequency components of bow angle, respectively,

Are low frequency components of the longitudinal velocity, low frequency components of the lateral velocity, and low frequency components of the angular velocity.). The method of claim 2, In the control step, the forward control is

Is performed by

Is the forward thrust command,

Environmental load), where environmental load

Is

(here,

Is wind power,

Is the tidal force,

Is the transverse drift force caused by the waves.)

Is defined as (where

Is the air density,

Is the wind power factor,

Is the wind speed, and A is the projection area.)

Is obtained (where

Is the seawater density,

Is the tide coefficient,

Is the tide velocity), the transverse drift force

Given by (where

Is the wave spectrum,

Is a transfer function.) A method of controlling the position of ships and offshore structures.

Images