KR20180046104A - Dynamic positioning system and dynamic positioning corresponding to fault of gps method using the same - Google Patents

Abstract

The present invention relates to a dynamic positioning system to cope with fault of a global positioning system (GPS), capable of predicting an environmental external force affecting a hull from an average thrust value of thrust generated from a thruster in the fault of the GPS to maintain a position of a vessel; and a positioning method using the same. According to one embodiment of the present invention, the method comprises: a step of a dynamic positioning (DP) control unit receiving vessel information including a measured position of the vessel from a DP measurement unit; a step of the DP control unit collecting thrust generated by the thruster to calculate an average thrust value for a predetermined time period; a step of the DP control unit determining whether or not a GPS receiver included in the DP measurement unit is failed based on the received vessel information; a step of the DP control unit selecting the calculated average thrust value as an environmental external force affecting a hull in the fault of the GPS receiver; and a step of the DP control unit applying the selected environmental external force to a mathematical model to determine a thrust of the thruster.

Description

TECHNICAL FIELD [0001] The present invention relates to a dynamic position maintaining system for a ship corresponding to a failure of a GPS, and a position maintenance method using the same. [0002]

The present invention relates to a dynamic position maintaining system for a ship corresponding to a GPS failure and a position maintaining method using the same. More particularly, the present invention relates to a system for predicting an external force exerted on a ship by means of an average value of a thrust generated in a thruster And more particularly, to a system for maintaining a dynamic position of a ship in response to a failure of a GPS capable of maintaining a position and a position maintenance method using the same.

In recent years, due to rapid industrialization and industrial development, limited global resources are gradually getting out of the way, and the stable production and supply of crude oil has become a very important issue.

Recently, along with the development of oil exploration technology on the seabed, large oil companies have felt the necessity of drilling rig with drilling facilities suitable for development of marginal field or deep sea oil field, It is a reality that is actively searching for development.

Floating production storage offloading (FPSO) and drill ship, which can refine and store oil and gas underground in the ocean, are increasing gradually. Because of the nature of these vessels, they carry out long work at a certain position, so that they can develop safer oilfields with less fluctuation due to algae, wind direction, wind velocity, and less change in position. The time and operability required for this is as short as possible and as simple as possible. At this time, the phenomenon that the position changes due to the swinging of the ship due to the algae, wind direction, wind speed, and digging can be solved by a dynamic positioning system (DPS).

Such a DPS is a system for continuously positioning a floating structure at a desired point and is disclosed in Korean Patent Publication No. 10-2009-0020732 (published on May 27, 2009, Dynamic Position Control System) filed by Samsung Heavy Industries, Many other applications are also filed.

The conventional DPS including the above patent is a control system that automatically maintains the position and direction of a ship in an offshore state in which there is an external force such as algae, blue, and wind, and the position of the ship is basically using a gyro sensor and GPS However, we are using Kalman filter to consider update time and error.

The Kalman filter includes a mathematical model of the ship, which calculates the motion from the external force acting on the ship, and corrects the position measurement of the ship through it to predict the position and speed of the actual ship.

If the position of the vessel is not measured due to GPS failure, only the state by the mathematical model of the Kalman filter is estimated.

Korean Patent Publication No. 10-2009-0020732 (2009.05.27) "Dynamic Position Control System"

However, in order to predict the position and speed of a ship through a mathematical model, an external force applied to the ship, a force generated mainly by wind, algae, and waves, and a force generated by the propeller are used as inputs. Basically, Measured via a weather vane, the force of the propeller can be calculated via a feedback signal, but a separate sensor is needed to measure the force by the tide or wave.

Therefore, if the position of the ship is not measured due to the GPS failure, the conventional DPS performs the position prediction using only the force of the wind and the force of the thruster. Therefore, even if the behavior of the mathematical model is similar to the actual one, only a part of the external force exerted on the actual ship is used as the input.

An object of the present invention is to provide a dynamic position maintaining system for a ship corresponding to a failure of a GPS which can maintain the position of the ship by predicting the force and direction of the entire external force applied to the ship by an average value of the thrust generated by the thruster in the event of GPS failure And a position maintaining method using the same.

According to an aspect of the present invention, there is provided a method for controlling a ship, the method comprising: a DP measurement unit for measuring ship information including a position of a ship; a thrust unit for controlling a position of the ship; The present invention provides a dynamic position maintaining method using a dynamic position maintaining system for a ship that includes a DP control unit and maintains a position of a ship such that a current position of the ship does not deviate from a target range, Receiving vessel information including a measured vessel position; The DP control unit collecting thrust generated by the thrust unit and calculating a thrust average value for a predetermined time; Determining whether the DP control unit is a failure of the GPS receiver included in the DP measurement unit based on the received ship information; The DP control unit selecting the calculated thrust average value as an environmental external force on the hull when the GPS receiver fails; And the DP control unit applies the selected environmental external force to the mathematical model to determine the thrust of the thrust unit. The dynamic position maintenance method using the dynamic position maintenance system of a ship is provided.

The thrust mean value may be the sum of the force due to wind, the force due to algae, and the force due to waves.

The determining step may calculate the thrust of the thrust unit by applying the selected environmental external force and the feedback signal of the thrust unit to the mathematical model.

Wherein the DP control unit predicts the position and speed of the ship using the selected environmental external force, a feedback signal of the thrust unit, and a heading angle of the ship measured by the gyro sensor included in the DP measurement unit step; And generating the thrust control signal for controlling the position of the ship through the predicted position and speed of the ship.

According to another embodiment of the present invention, there is provided a DP control system including a DP measurement unit for measuring vessel information including a position of a ship, a thrust unit for controlling the position of the ship, and a DP control unit for outputting a thrust control signal to the thrust unit A system for maintaining a ship's position such that a current position of a ship does not deviate from a predetermined range from a target point, characterized in that the DP control unit comprises: And the thrust of the thrust section is determined by applying the predicted environmental external force to the mathematical model by predicting the mean thrust force for the time as the environmental external force on the hull, and determining the thrust of the thrust section.

According to the embodiment of the present invention, it is possible to maintain the position of the ship by predicting the environmental external force exerted on the hull by the average value of the thrust force of the thrust portion in case of GPS failure. In particular, the thrust can be controlled by applying the external force reflected by the force due to the wave height and the force due to the tidal current which can not be measured by predicting the average value of thrust collected during a certain time in the GPS failure.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a view for explaining a dynamic position maintenance system of a ship corresponding to a failure of a GPS according to an embodiment of the present invention;
FIG. 2 is a view for explaining the DP control unit shown in FIG. 1, and FIG.
3 is a flowchart illustrating a dynamic location maintenance method using a dynamic location maintenance system for a ship corresponding to a GPS failure according to an embodiment of the present invention.

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

FIG. 1 is a view for explaining a ship dynamic position maintaining system corresponding to a failure of a GPS according to an embodiment of the present invention, and FIG. 2 is a view for explaining a DP control unit shown in FIG. 1 have.

Referring to FIG. 1, a ship dynamic position maintaining system corresponding to a failure of a GPS according to an embodiment of the present invention includes a DP measuring unit 110, a DP control unit 120, and a thrust unit 130.

The DP measuring unit 11 includes an anemometer 110, a GPS receiver 112, a GLONASS (Global Navigation Satellite System) 113, a gyro sensor 114, a fan beam 115, , And an acoustic sensor (116).

The anemometer 111 measures the wind direction and the wind speed and outputs the corresponding electrical signal to the DP control unit 120.

The GPS receiver 112 measures the position of the ship and outputs a corresponding electrical signal to the DP control unit 120.

The GLONASS 113 measures the position of the ship and outputs a corresponding electrical signal to the DP control unit 120. The GLONASS 113 serves to correct the position measured by the GPS receiver 112. In the case of polar regions, since there is a large error in the signals received from the satellites, GLONASS (113), which is a positioning system by Russian satellites, is used to correct the errors.

The gyro sensor 114 measures the heading angle of the ship and outputs a corresponding electrical signal to the DP control unit 120.

The fan beam 115 measures a position relative to the ship and outputs a corresponding electrical signal to the DP control unit 120.

The sound sensor 116 outputs data to the DP control unit 120, which can calculate the reference point position of the ship.

The term " vessel " as used herein is intended to include marine structures that are used in a floating manner in the sea.

The DP control unit 120 controls the position of the ship received from the GPS receiver 112, the heading angle of the ship received from the gyro sensor 114, the wind direction and wind speed measured through the anemometer 111 through low- It is processed into a form as possible. The DP control unit 120 may use a Kalman filter.

In order to maintain the position of the hull at a desired position, it is necessary to first determine the current state, that is, the displacement and velocity of the hull. The Kalman filter is used as a state estimator.

The Kalman filter includes a mathematical model of the ship, so that the external force applied to the ship can be applied to predict the movement of the ship, and the thrust of the thrust section 130 can be calculated therefrom.

When the DP control unit 120 receives a failure signal from the GPS satellite or the GPS receiver 112, the DP control unit 120 determines that the GPS is malfunctioning. In addition, the DP control unit 120 determines whether the measurement value measured from the GPS receiver 112 is freeze for a predetermined time, for example, by comparing position measurement values received from the three GPS receivers 112, Is out of the allowable range, it is determined that the GPS is out of order.

If it is determined that the GPS is broken according to such a criterion, the DP control unit 120 selects an environmental external force applied to the hull by using the thrust average value obtained by averaging the thrust of the thrust unit 130 for a predetermined time. At this time, the selected environmental external force is the force by the wind, the force by the current, and the force by the wave. Accordingly, the total environmental external force including the environmental external force (that is, the force due to the crest and the algae), which has not been conventionally measured without installing a separate sensor, is applied to the mathematical model so that the thrust portion 130 ) Can be determined.

The thrust of the thrust section 130 for a predetermined time is a force generated by the thrust section 1320 of the ship in which dynamic maintenance is well performed under the assumption that the sea state is not abruptly changed.

When the Kalman filter is used, the average force and direction generated by the thrust section 130 for a certain period of time are equal to the sum of the external forces exerted on the ship, and the direction is 180 degrees opposite.

The DP control unit 120 generates a control thrust, that is, a control signal, through feedforward control of values such as displacement, velocity, etc. of the hull estimated through the Kalman filter. The control thrust generated as a result is distributed to the thrust section 130 so as to satisfy the optimum efficiency through the thrust distribution section 123 shown in FIG. 2, and the difference between the desired position and the current position is reduced That is, the hull can be moved to a desired position.

Referring to FIG. 2, the controller 121 included in the DP control unit 120 determines whether the wind (including wind direction and wind speed) received from the anemometer 111, the position and velocity predicted by the mathematical model 122, And outputs the determined thrust to the thrust dividing section 123. The thrust dividing section 123 determines the thrust,

The mathematical model 122 applies the mathematical model to the heading angle of the ship received from the gyro sensor 114, the mean value of the thrust force of the thrust section 130 collected for a predetermined time, and the feedback signal of the thrust section 130, And speed.

The mathematical model 122 may be updated with a predetermined period or a new version of the model.

The thrust distributor 123 appropriately distributes the thrust to the propeller (131 in FIG. 1), the thruster (132 in FIG. 1) and the rudder (133 in FIG. 1) in order to minimize fuel consumption.

The DP control unit 120 outputs the position information of the ship received from the DP measurement unit 110 and a control signal (thrust) for maintaining the position determined by the ship on the basis of the wind to the thrust unit 130.

Particularly, when the failure of the GPS for measuring the position of the ship is recognized, the DP control unit 120 selects the average value of the force generated by the thrust unit 130 for a predetermined time period as the environmental external force applied to the ship, The feedback signal of the unit 130 can be applied to the mathematical model 122 to predict the position and speed of the ship. Using the predicted position and velocity of the ship, the thrust of the thrust section 130 for maintaining the predetermined position of the ship is determined and the thrust control signal for the determined thrust is outputted to the thrust section 130.

Accordingly, even if a failure of the GPS occurs, the average value of the thrust force of the thruster 130 for a predetermined time can be selected as the total external environmental force exerted on the hull, so that the position and the speed of the ship can be predicted and the position of the ship can be stably maintained . In addition, the selected environmental external force (force due to wind, force due to algae and force due to wave) can be used as an input to the Kalman filter, so that the behavior of the mathematical model is similar to that of the actual ship, thereby reducing the error.

The thrust section 130 includes a propeller 131, a thruster 132, and a rudder 133.

The propeller 131 maintains its position in the forward and backward directions of the ship, and its thrust is controlled by the DP control unit 120.

The thrusters 132 maintain the position of the ship in the left-right direction, and the thrust is controlled by the DP control unit 120. [

The rudder 133 adjusts the rotation direction of the ship and is controlled by the DP control unit 120. [

3 illustrates a dynamic location maintenance method using a dynamic location maintenance system of a ship corresponding to a GPS failure according to an embodiment of the present invention. A method of maintaining a dynamic position of a ship according to an embodiment of the present invention will now be described in detail with reference to FIGS. 1 and 2. FIG.

Referring to FIG. 3, the DP control unit 120 receives vessel information including the position of the vessel measured by the DP measuring unit 110 installed on the vessel (S11).

 More specifically, the measurement value from the DP measurement section (110 in FIG. 1) is received by the DP control section (120 in FIG. 1). That is, the measurement data on the wind direction and the wind speed are received from the anemometer (111 in FIG. 1), data on the position of the ship is received from the GPS receiver (112 in FIG. 1) and GLONASS (114 in FIG. 1), the relative position data with the other structure is received from the fan beam (115 in FIG. 1), and the acoustic data is received from the acoustic sensor 116. The position value of the ship obtained from the GPS receiver (112 in FIG. 1) is corrected using the position value of the ship obtained from the GLONASS 113. [ Accordingly, it is possible to more precisely measure the position of the ship in the polar region where the error of the signal received from the satellite is large.

The DP control unit 120 collects the thrust of the thrust unit 130 to maintain the target position in the process of maintaining the dynamic position, and calculates a thrust average value for a predetermined time (S13).

The DP control unit 120 determines whether the GPS is faulty based on the received ship information (S15). The information of the ship includes the position of the ship, the wind direction, the wind speed, and the heading angle of the ship. The DP control unit 120 compares the position measurement value of the ship received from the plurality of GPS receivers 112 for a predetermined period of time or compares the position measurement values received from the plurality of GPS receivers 112, If it is outside the allowable range, it is determined that the GPS is out of order. In addition, when an error signal is received from a plurality of GPS receivers 112, it is determined that the GPS is out of order.

If it is determined in step S15 that the GPS is not malfunctioning, the DP control unit 120 may use the ship information including the position of the ship measured from the DP measurement unit 110 (110 in FIG. 1) And generates a signal (S16). The DP control unit (120 in FIG. 1) controls the thrust force control for moving the difference between the required position and the current position of the hull in a direction to reduce the difference based on the ship information including the environmental external force received from the DP measurement unit Signal.

Thereafter, the DP control unit 120 outputs the generated thrust control signal to the thrust unit 130 (S23). To minimize fuel consumption, the thrust is appropriately distributed to the propeller (131 in Fig. 1), the thruster (132 in Fig. 1) and the rudder (133 in Fig. 1).

If it is determined in step S15 that the GPS has failed, the DP controller 120 selects the thrust average value calculated in step S13 as the environmental external force of the sea (S17).

The DP control unit 120 predicts the position and speed of the ship by applying the selected environmental external force, the feedback signal of the thrust unit 130, and the heading angle of the ship measured from the gyro sensor 114 to the mathematical model (S19).

The DP control unit 120 generates a thrust control signal for controlling the position of the ship through the predicted position and speed of the ship (S21).

Thereafter, the controller 121 moves the process to the step S23 described above, and outputs the generated thrust control signal to the thrust section 130.

In this way, even if the failure of the GPS is recognized in order to maintain the position of the ship, the average value of the thrust force of the thrust unit 130 for a predetermined time can be selected as the environmental external force applied to the ship, so that the position and speed of the ship can be predicted. The position can be stably maintained.

The invention being thus described, it will be obvious that the same way may be varied in many ways. Such modifications are intended to be within the spirit and scope of the invention as defined by the appended claims.

100: Dynamic position maintenance system 110: DP measurement unit
111: Anemometer 112: GPS receiver
113: GLONASS 114: Gyroscope
115: Fanbeam 116: Acoustic sensor
120: DP control unit 121:
122: mathematical model 123: thrust distributor
130: Thrust section 131: Propeller
132: Thruster 133: Rudder

Claims (5)

And a DP control unit for outputting a thrust control signal to the thrust unit, wherein a current position of the ship is detected from a target point A dynamic position maintaining method using a dynamic position maintaining system of a ship which maintains a position of a ship so as not to deviate from a predetermined range,
Receiving, by the DP control unit, vessel information including the position of the vessel measured from the DP measurement unit;
The DP control unit collecting thrust generated by the thrust unit and calculating a thrust average value for a predetermined time;
Determining whether the DP control unit is a failure of the GPS receiver included in the DP measurement unit based on the received ship information;
The DP control unit selecting the calculated thrust average value as an environmental external force on the hull when the GPS receiver fails; And
Wherein the DP control unit applies the selected environmental external force to a mathematical model to determine the thrust of the thrust unit. The method according to claim 1,
Wherein the thrust mean value is a sum of forces due to wind, forces due to algae, and forces due to waves. The method according to claim 1,
Wherein the determining step comprises applying the selected environmental external force and a feedback signal of the thrust section to the mathematical model to calculate a thrust of the thrust section. The method of claim 3,
The step of determining
Estimating the position and speed of the ship using the selected environmental external force, the feedback signal of the thrust section, and the heading angle of the ship measured from the gyro sensor included in the DP measurement section; And
And the DP control unit generating a thrust control signal for controlling the position of the ship through the predicted position and speed of the ship. And a DP control unit for outputting a thrust control signal to the thrust unit, wherein the current position of the ship is determined from a target position CLAIMS 1. A dynamic position maintenance system for a ship which maintains the position of the ship so as not to deviate from the range,
The DP control unit predicts an average external force of thrust generated from the thrust unit during a failure of the GPS receiver included in the DP measurement unit as an environmental external force applied to the ship and applies a predicted environmental external force to the mathematical model, Of the vessel is determined.

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