A ship motion detection system and method

Abstract

This invention discloses a ship motion detection system, including a ship motion angular displacement detection system comprising a lateral tilt sensor, a longitudinal tilt sensor, and a heading sensor installed on the ship; a target tracking and observation system comprising a target tracking servo gimbal and a target observer installed on the ship; and a data acquisition, calculation, and storage system for acquiring and storing the ship's roll, pitch, and bow signal data measured by the ship motion angular displacement detection system, and for calculating and storing the ship's sway, pitch, and heave motion data. This invention also discloses a ship motion detection method based on the above system. This invention enables highly reliable and accurate measurement of ship motion data in waves, further improving the compensation accuracy of wave compensation boarding bridges on wind power maintenance vessels.

Description

Technical Field

[0001] This invention relates to the field of ship motion detection, and in particular to a ship motion detection system and method. Background Technology

[0002] Offshore wind power maintenance vessels require regular inspections, repairs, and maintenance of offshore wind farms, making boarding ramps essential equipment. Due to the high waves and strong currents at offshore wind farms, accessing and alighting wind towers is extremely dangerous. Therefore, boarding ramps equipped with wave motion compensation functions are the most effective way to improve the safety of personnel accessing and alighting wind towers, ensuring relative stability amidst waves. Boarding ramps with wave motion compensation functions primarily work by detecting the six degrees of freedom of the wind power maintenance vessel's motion in the waves and then driving a compensation hydraulic mechanism to move in the opposite direction of the vessel's wave motion, achieving mutual cancellation of motion and thus maintaining relative stability of the boarding ramp. As can be seen from the above, obtaining high-precision vessel motion data is the primary task to achieve effective wave motion compensation for wind power maintenance vessels. Traditional ship motion detection methods use motion reference units (MRUs) to collect ship motion data. However, this method mainly utilizes inertial technology to obtain the ship's linear displacement motion data through the quadratic integration of acceleration. This method suffers from problems such as error accumulation, drift, phase inaccuracy, and poor reliability under complex sea conditions. Therefore, relying solely on motion reference units to detect ship motion data is insufficient to meet the high-precision compensation control requirements of wave-compensated boarding bridges. How to achieve more effective and high-precision ship motion data detection and acquisition has become an urgent engineering need. Summary of the Invention

[0003] In order to overcome the above-mentioned shortcomings and deficiencies of the prior art, the purpose of this invention is to provide a ship motion detection system that can perform highly reliable and high-precision measurement of ship motion data in waves, so as to further improve the compensation accuracy of the wave compensation boarding bridge of the wind power operation and maintenance vessel.

[0004] Another object of the present invention is to provide a detection method based on the above-mentioned ship motion detection system.

[0005] The objective of this invention is achieved through the following technical solution:

[0006] A ship motion detection system, including

[0007] The ship motion angular displacement detection system includes a lateral tilt sensor, a longitudinal tilt sensor, and a heading sensor installed on the ship, which are used to measure the angles of the ship's roll, pitch, and bow respectively;

[0008] The target tracking and observation system includes a target tracking servo gimbal and a target observer installed on a ship; the target tracking servo gimbal is used to drive the target observer to rotate 360 ​​degrees and adjust the vertical elevation angle; the target observer is used to track and align with a target point on a fixed object at sea, and to measure the straight-line distance from the target observer to the target point on the fixed object at sea.

[0009] The data acquisition, calculation, and storage system is used to calculate the three-dimensional coordinate values ​​of the target observer at different times based on the measurement results of the ship motion angular displacement detection system and the target tracking observation system. The change value of the three-dimensional coordinate values ​​of the target observer is used as the linear displacement of the ship's motion. The coordinate transformation of the ship's linear displacement is performed to obtain the ship's sway, pitch, and heave data, and then the data is stored.

[0010] Preferably, the data acquisition, calculation, and storage system includes a ship roll, pitch, and bow roll acquisition and storage unit and a ship sway, pitch, and heave calculation and storage unit; the ship roll, pitch, and bow roll acquisition and storage unit is used to acquire and store the ship's roll, pitch, and bow roll signal data measured by the ship motion angular displacement detection system; the ship sway, pitch, and heave calculation and storage unit is used to calculate and store the ship's sway, pitch, and heave motion data.

[0011] Preferably, the target tracking and observation system is equipped with an observation azimuth sensor and an observation tilt sensor; the observation azimuth sensor is used to detect the observation horizontal azimuth angle of the target observer; the observation tilt sensor is used to detect the observation elevation angle of the target observer in the vertical plane.

[0012] Preferably, the target observer includes an observation camera and a rangefinder; the observation camera is used to photograph the target point on the fixed object at sea; the rangefinder is used to measure the straight-line distance from the target observer to the target point on the fixed object at sea.

[0013] Preferably, the offshore fixed object is an offshore wind turbine column.

[0014] The ship motion detection method of the aforementioned ship motion detection system includes the following steps:

[0015] The ship motion angular displacement detection system measures the angles of the ship's roll, pitch, and bow.

[0016] The target tracking and observation system tracks and aligns with a target point on a fixed object at sea, and measures the straight-line distance from the target observer to the target point on the fixed object at sea;

[0017] The data acquisition, calculation, and storage system calculates and stores the ship's sway, pitch, and heave motion data based on the measurement results from the ship motion angular displacement detection system and the target tracking observation system.

[0018] The calculated data for the ship's sway, pitch, and heave motions are as follows:

[0019] Taking the location of the target observer as ship observation point A, based on the measurement results of the ship motion angular displacement detection system and the target tracking observation system, calculate and record the three-dimensional coordinates (x, y, y) of ship observation point A at different times. A ,y A ,z A ), calculate the change (Δx) in the three-dimensional coordinates of the ship observation point A at adjacent time intervals. A ,Δy A ,Δz A ), by adjusting (Δx) A ,Δy A ,Δz A Perform ship coordinate transformation to obtain the sway, pitch, and heave data values ​​of point A on the ship at the adjacent time.

[0020] Preferably, the three-dimensional coordinates (x, y, z) of the ship observation point A are... A ,y A ,z A The calculation process for ) is as follows:

[0021] The vertical distance h and horizontal distance l between the ship's observation point A and the target point B on the fixed object at sea are calculated based on the straight-line distance d from the target observer to the target point on the fixed object at sea and the observation elevation angle α of the target observer in the vertical plane, where h = d·sinα and l = d·cosα.

[0022] Based on the horizontal azimuth of the target observer and the horizontal distance l between the ship's observation point A and the target point B on the fixed object at sea, the horizontal coordinates (x, y, y) of the ship's observation point A are obtained. A ,y A );

[0023] Based on the vertical distance h from ship observation point A to target point B on the fixed object at sea and the horizontal coordinate (x) of ship observation point A... A ,y A ), thus obtaining the three-dimensional coordinates (x, y) of observation point A on the ship. A ,y A ,z A ).

[0024] Preferably, the horizontal coordinates (x, y) of the ship observation point A are obtained based on the horizontal azimuth angle observed by the target observer and the horizontal distance l between the ship observation point A and the target point B on the fixed object at sea. A ,y A Specifically:

[0025] With target point B on the fixed object at sea as the origin of the coordinate system, the east direction is the x-axis, the north direction is the y-axis, and the vertical upward direction is the z-axis.

[0026] Based on the angle β between the axis of the target observer and true north, and the horizontal distance l from the ship's observation point A to the target point B on the fixed object at sea, the horizontal coordinates (x, y) of the ship's observation point A are obtained. A ,y A ), where x A = -l·sinβ, y A = -l·cosβ.

[0027] Preferably, the method is based on the vertical distance h from the ship observation point A to the target point B on the fixed object at sea and the horizontal coordinate value (x) of the ship observation point A. A ,y A ), thus obtaining the three-dimensional coordinates (x, y) of observation point A on the ship. A ,y A ,z A Specifically:

[0028] Calculate the vertical coordinate z of observation point A based on the vertical distance h between observation point A and target point B on the fixed object at sea. A =-h, combined with the horizontal coordinates (x) of ship observation point A A ,y A ), thus obtaining the three-dimensional coordinates (x, y) of observation point A on the ship. A ,y A ,z A ).

[0029] Preferably, the target tracking and observation system tracks and aligns with a target point on a fixed object at sea, specifically as follows:

[0030] The target tracking and observation system's camera captures images of target point B on a fixed object at sea. Then, it uses target recognition to obtain the position coordinates of target point B in the captured image. These position coordinates are used as feedback signals to control the target tracking servo gimbal to dynamically adjust the horizontal azimuth and vertical tilt angles of the target observer, so that target point B is exactly at the center of the image captured by the camera. This enables the target observer to automatically track and align target point B.

[0031] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0032] (1) The ship motion detection system and method of the present invention measures the angles of roll, pitch, and bow of the ship, and simultaneously measures the horizontal azimuth, vertical azimuth, and distance of a target point on a fixed object at sea. Then, based on the vertical azimuth and distance information, the vertical position coordinates of the ship's observation point are calculated, and based on the horizontal azimuth and distance information, the horizontal position coordinates of the ship's observation point are calculated, thereby obtaining the three-dimensional position coordinates of the ship's observation point. Next, based on the changes in the three-dimensional position coordinates of the ship's observation point at different times, the motion linear displacement information at the ship's observation point is obtained. Finally, through ship coordinate transformation, the sway, pitch, and heave data at the ship's observation point are obtained. The present invention overcomes the problems of error accumulation, drift, and phase inaccuracy existing in traditional inertial detection methods using motion reference units, and has advantages such as high accuracy and good reliability.

[0033] (2) The ship motion detection system and detection method of the present invention can be applied to the detection of the six degrees of freedom motion of the offshore wind power maintenance vessel in the waves. The detection result is used as the input signal of the wave motion compensation boarding bridge on the wind power maintenance vessel to control the compensation hydraulic mechanism of the boarding bridge to generate the opposite direction of motion to counteract the ship motion and achieve the purpose of keeping the boarding bridge relatively stable. Attached Figure Description

[0034] Figure 1 This is a block diagram of a ship motion detection system according to an embodiment of the present invention.

[0035] Figure 2 This is a schematic diagram illustrating the working principle of a ship motion detection system in the vertical plane according to an embodiment of the present invention.

[0036] Figure 3 This is a schematic diagram illustrating the working principle of a ship motion detection system on a horizontal plane according to an embodiment of the present invention. Detailed Implementation

[0037] The present invention will be further described in detail below with reference to the embodiments, but the implementation of the present invention is not limited thereto.

[0038] Example

[0039] like Figure 1 As shown, one embodiment of the present invention provides a ship motion detection system, which is mainly used for detecting the six degrees of freedom motion (i.e., roll, pitch, bow roll, sway, heave and sway) of offshore wind power maintenance vessels in waves. The system includes a ship motion angular displacement detection system, a target tracking observation system, and a data acquisition, calculation and storage system.

[0040] The ship motion angular displacement detection system includes a lateral tilt sensor, a longitudinal tilt sensor, and a heading angle sensor installed on the wind power operation and maintenance vessel, which are used to measure the roll, pitch, and bow angles of the wind power operation and maintenance vessel, respectively.

[0041] The target tracking and observation system can automatically adjust its angle and orientation through target recognition to achieve automatic target tracking and alignment. It includes a target tracking servo gimbal and a target observer installed on a wind turbine operation and maintenance vessel. The target tracking servo gimbal is used to drive the target observer to rotate 360 ​​degrees and adjust the vertical elevation angle. The target observer is used to track and align with the target point on the offshore wind turbine column and to measure the straight-line distance from the target observer to the target point on the offshore wind turbine column.

[0042] The data acquisition, calculation, and storage system includes a ship roll, pitch, and bow acquisition and storage unit and a ship sway, pitch, and heave calculation and storage unit. The ship roll, pitch, and bow acquisition and storage unit is used to acquire and store the roll, pitch, and bow signal data of the wind power maintenance vessel measured by the ship motion angular displacement detection system. The ship sway, pitch, and heave calculation and storage unit is used to calculate and store the sway, pitch, and heave motion data of the wind power maintenance vessel.

[0043] In this embodiment, the target tracking and observation system is equipped with an observation azimuth sensor and an observation tilt sensor; the observation azimuth sensor is used to detect the observation horizontal azimuth angle (i.e., the orientation angle of the southeast, northwest, and northeast) of the target observer; the observation tilt sensor is used to detect the observation elevation angle of the target observer in the vertical plane (i.e., the angle between the central axis of the observation optical path of the target observer and the horizontal plane).

[0044] In this embodiment, the target observer includes an observation camera and a rangefinder; the observation camera is used to capture images of the target point on the offshore wind turbine column; the rangefinder is used to measure the straight-line distance from the target observer to the target point on the offshore wind turbine column.

[0045] In this embodiment, the data acquisition, calculation, and storage system calculates the vertical position coordinates of the observation point on the wind power operation and maintenance vessel based on the distance data measured by the rangefinder and the tilt angle data measured by the tilt angle sensor. Then, it calculates the horizontal position coordinates of the observation point based on the horizontal azimuth angle measured by the azimuth sensor, thereby obtaining the three-dimensional position coordinates of the observation point. Next, based on the changes in the three-dimensional position coordinates of the observation point at different times, the linear displacement information of the ship's motion at the observation point is obtained. Finally, the sway, pitch, and heave data of the observation point are obtained through ship coordinate transformation.

[0046] In one embodiment, when the ship motion detection system is used for nighttime measurements, the target observer can be a thermal imaging camera. In this case, a temperature control device is installed on the offshore wind turbine column to make the temperature of the target point different from the ambient temperature, making it easier to identify.

[0047] In one embodiment, a laser rangefinder is used to obtain higher measurement accuracy.

[0048] In one embodiment, the specific process of the target observer tracking and aligning with the target point on the offshore wind turbine column is as follows: The observation camera of the target tracking observation system takes a picture of the target point B on the offshore wind turbine column, and then uses target recognition to obtain the position coordinates of the target point B in the captured image. Using the position coordinates as a feedback signal, the target tracking servo gimbal is controlled to dynamically adjust the horizontal azimuth angle and vertical tilt angle of the target observer, so that the target point B is exactly at the center of the image captured by the observation camera, thereby realizing the automatic tracking and alignment of the target observer with the target point B.

[0049] Another embodiment of the present invention provides a method for detecting ship motion, comprising the following steps:

[0050] The ship motion angular displacement detection system measures the roll, pitch, and bow angles of the wind power maintenance vessel;

[0051] The target tracking and observation system tracks and aligns with the target point on the offshore wind turbine column, and measures the straight-line distance d from the target observer to the target point on the offshore wind turbine column;

[0052] The data acquisition, calculation and storage system calculates and stores the sway, pitch and heave motion data of the wind power maintenance vessel based on the measurement results of the ship motion angular displacement detection system and the target tracking observation system;

[0053] The calculated data for the sway, pitch, and heave motions of the wind turbine maintenance vessel are as follows:

[0054] Calculate and record the three-dimensional coordinates (x, y, z) of observation point A on the wind power operation and maintenance vessel at different times. A ,y A ,z A ), calculate the change (Δx) in the three-dimensional coordinates of observation point A at adjacent time points. A ,Δy A ,Δz A The change in its three-dimensional coordinates (Δx) A ,Δy A ,Δz A This represents the linear displacement of point A at that adjacent moment. This linear displacement is the absolute displacement of point A relative to the ground. Therefore, by considering (Δx) A ,ΔyA ,Δz A By performing ship coordinate transformation, the sway, pitch, and heave data values ​​at observation point A at that adjacent moment can be obtained.

[0055] Figure 2 This is a schematic diagram illustrating the working principle of a ship motion detection system in a vertical plane, as shown in one embodiment. The diagram depicts a wind power maintenance vessel 1, a target tracking servo gimbal 2, a target observer 3, and an offshore wind turbine support column 4. Figure 2 It can be seen that, based on the straight-line distance d from the target observer 3 to the target point B on the offshore wind turbine column 4 and the observation elevation angle α of the target observer 3 in the vertical plane, the vertical distance h and horizontal distance l from the observation point A to the target point B on the offshore wind turbine column can be calculated, where h = d·sinα and l = d·cosα.

[0056] Figure 3 This is a schematic diagram illustrating the working principle of a ship motion detection system on a horizontal plane, as shown in one embodiment. The diagram depicts a wind turbine maintenance vessel 1, a target observer 3, and an offshore wind turbine column 4. Taking the target point B on the offshore wind turbine column 4 as the origin, east is the x-axis, north is the y-axis, and vertically upward is the z-axis. Based on the angle β between the target observer's axis and north, and the horizontal distance l from the ship's observation point A to the target point B on the offshore wind turbine column, the horizontal coordinate value (x, y, z) of the ship's observation point A is calculated. A ,y A ), where x A = -l·sinβ, y A = -l·cosβ.

[0057] Furthermore, based on the vertical distance h between observation point A on the ship and target point B on the offshore wind turbine column, the vertical coordinate z of point A is calculated. A =-h, combined with the horizontal coordinates (x) of ship observation point A A ,y A ), to obtain the three-dimensional coordinates (x, y) of point A. A ,y A ,z A ).

[0058] The ship motion detection system and method of the present invention are applied to the detection of the six degrees of freedom motion of the offshore wind power maintenance vessel in waves. The detection results are used as the input signal for the wave motion compensation boarding bridge on the wind power maintenance vessel, so as to control the compensation hydraulic mechanism of the boarding bridge to generate the opposite direction of motion to counteract the ship motion and achieve the purpose of keeping the boarding bridge relatively stable.

[0059] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the embodiments described above. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A ship motion detection system, characterized in that, include The ship motion angular displacement detection system includes a lateral tilt sensor, a longitudinal tilt sensor, and a heading sensor installed on the ship, which are used to measure the angles of the ship's roll, pitch, and bow respectively; The target tracking and observation system includes a target tracking servo gimbal and a target observer mounted on a ship. The target tracking servo gimbal is used to drive the target observer to rotate 360 ​​degrees and adjust its vertical elevation angle. The target observer is used to track and align with a target point on a fixed object at sea, and to measure the straight-line distance from the target observer to the target point on the fixed object. The target tracking and observation system is equipped with an observation azimuth sensor and an observation tilt sensor. The observation azimuth sensor is used to detect the horizontal azimuth angle of the target observer. The observation tilt sensor is used to detect the vertical elevation angle of the target observer. The data acquisition, calculation, and storage system is used to calculate the three-dimensional coordinate values ​​of the target observer at different times based on the measurement results of the ship motion angular displacement detection system and the target tracking observation system. The change value of the three-dimensional coordinate values ​​of the target observer is used as the linear displacement of the ship's motion. The coordinate transformation of the ship's linear displacement is performed to obtain the ship's sway, pitch, and heave data, and then the data is stored.

2. The ship motion detection system according to claim 1, characterized in that, The data acquisition, calculation, and storage system includes a ship roll, pitch, and bow acquisition and storage unit and a ship sway, pitch, and heave calculation and storage unit. The ship roll, pitch, and bow acquisition and storage unit is used to acquire and store the ship's roll, pitch, and bow signal data measured by the ship motion angular displacement detection system. The ship sway, pitch, and heave calculation and storage unit is used to calculate and store the ship's sway, pitch, and heave motion data.

3. The ship motion detection system according to claim 1, characterized in that, The target observer includes an observation camera and a rangefinder; The observation camera is used to photograph target points on fixed objects at sea; The rangefinder is used to measure the straight-line distance from the target observer to the target point on the fixed object at sea.

4. The ship motion detection system according to claim 1, characterized in that, The offshore fixed structure is an offshore wind turbine support column.

5. The ship motion detection method of the ship motion detection system according to any one of claims 1 to 4, characterized in that, Includes the following steps: The ship motion angular displacement detection system measures the angles of the ship's roll, pitch, and bow. The target tracking and observation system tracks and aligns with a target point on a fixed object at sea, and measures the straight-line distance from the target observer to the target point on the fixed object at sea; The data acquisition, calculation, and storage system calculates and stores the ship's sway, pitch, and heave motion data based on the measurement results from the ship motion angular displacement detection system and the target tracking observation system. The calculated data for the ship's sway, pitch, and heave motions are as follows: Taking the location of the target observer as ship observation point A, based on the measurement results of the ship motion angular displacement detection system and the target tracking observation system, calculate and record the three-dimensional coordinates (x, y, y) of ship observation point A at different times. A ,y A ,z A ), calculate the change (Δx) in the three-dimensional coordinates of the ship observation point A at adjacent time intervals. A ,Δy A ,Δz A ), by adjusting (Δx) A ,Δy A ,Δz A Perform ship coordinate transformation to obtain the sway, pitch, and heave data values ​​of point A on the ship at the adjacent time.

6. The ship motion detection method according to claim 5, characterized in that, The three-dimensional coordinates (x, y) of the ship observation point A A ,y A ,z A The calculation process for ) is as follows: The vertical distance h and horizontal distance l between the ship's observation point A and the target point B on the fixed object at sea are calculated based on the straight-line distance d from the target observer to the target point on the fixed object at sea and the observation elevation angle α of the target observer in the vertical plane, where h = d·sinα and l = d·cosα. Based on the horizontal azimuth of the target observer and the horizontal distance l between the ship's observation point A and the target point B on the fixed object at sea, the horizontal coordinates (x, y, y) of the ship's observation point A are obtained. A ,y A ); Based on the vertical distance h from ship observation point A to target point B on the fixed object at sea and the horizontal coordinate (x) of ship observation point A... A ,y A ), thus obtaining the three-dimensional coordinates (x, y) of observation point A on the ship. A ,y A ,z A ).

7. The ship motion detection method according to claim 6, characterized in that, The horizontal coordinates (x, y) of the ship's observation point A are obtained based on the horizontal azimuth angle observed by the target observer and the horizontal distance l between the ship's observation point A and the target point B on the fixed object at sea. A ,y A Specifically: With target point B on the fixed object at sea as the origin of the coordinate system, the east direction is the x-axis, the north direction is the y-axis, and the vertical upward direction is the z-axis. Based on the angle β between the axis of the target observer and true north, and the horizontal distance l from the ship's observation point A to the target point B on the fixed object at sea, the horizontal coordinates (x, y) of the ship's observation point A are obtained. A ,y A ), where x A = -l·sinβ, y A = -l·cosβ.

8. The ship motion detection method according to claim 6, characterized in that, The vertical distance h from ship observation point A to target point B on the fixed object at sea and the horizontal coordinate (x) of ship observation point A are used as the basis for this. A ,y A ), thus obtaining the three-dimensional coordinates (x, y) of observation point A on the ship. A ,y A ,z A Specifically: Calculate the vertical coordinate z of observation point A based on the vertical distance h between observation point A and target point B on the fixed object at sea. A =-h, combined with the horizontal coordinates (x) of ship observation point A A ,y A ), thus obtaining the three-dimensional coordinates (x, y) of observation point A on the ship. A ,y A ,z A ).

9. The ship motion detection method according to claim 6, characterized in that, The target tracking and observation system tracks and aligns with target points on fixed objects at sea, specifically as follows: The target tracking and observation system's camera captures images of target point B on a fixed object at sea. Then, it uses target recognition to obtain the position coordinates of target point B in the captured image. These position coordinates are used as feedback signals to control the target tracking servo gimbal to dynamically adjust the horizontal azimuth and vertical tilt angles of the target observer, so that target point B is exactly at the center of the image captured by the camera. This enables the target observer to automatically track and align target point B.

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