Test method for active positioning test of ship model in wave

Abstract

The invention belongs to the technical field of ship model tests, and particularly relates to an active positioning test method for a ship model in waves. The method comprises the steps that a wireless signal receiver, a motion control unit and a propeller are fixedly arranged on a ship model; dragging the water pool to enable the ship model to perform six-degree-of-freedom motion; the wireless signal receiver receives a control strategy, and the motion control unit adjusts the rotating speed of the propeller according to the control strategy, so that the posture of the ship model is changed; the longitudinal displacement sensor, the transverse displacement sensor, the lifting displacement sensor and the gyroscope are used for detecting the six-degree-of-freedom movement of the ship model in real time; the detected six-degree-of-freedom motion data is compared with a control strategy, and if the navigation attitude of each degree of freedom meets the expected target requirement, the control strategy is output. According to the invention, the development of the ship model active positioning test method is realized, the effectiveness of the active positioning strategy can be verified, and the problem that there is no test method for the ship model active positioning test at present is solved.

Description

Technical Field

[0001] The present invention belongs to the technical field of ship model tests, and particularly relates to a test method for the active positioning test of a ship model in waves. Background Art

[0002] When a full-scale ship or offshore structure is working in actual conditions and is subjected to external environmental loads, the attitude of the ship or offshore structure will change. At this time, corresponding control strategies need to be formulated to maintain the floating position at sea in waves through its own propulsion system, that is, to maintain the stability of multiple degrees of freedom near the reference position. In order to verify the effectiveness of the active positioning control strategy, hydrodynamic tests are required. Correspondingly, in the hydrodynamic test of dynamic positioning, an active positioning test system for model tests needs to be designed to examine the navigation attitude of the ship model in different wave environments and under corresponding control strategies, and to verify the active positioning strategy. However, there is currently no test method for the active positioning test of ship models. Summary of the Invention

[0003] The present invention solves the problem that there is currently no test method for the active positioning test of ship models, and provides a test method for the active positioning test of a ship model in waves.

[0004] The technical solution claimed by the present invention is as follows:

[0005] A test method for the active positioning test of a ship model in waves, which uses a six-degree-of-freedom motion test platform for a ship model in waves to test the active positioning test of a ship model in waves. The platform includes: a ship model, a first measuring device, a second measuring device, a fixed bracket, and a limiting device; a gyroscope is installed inside the bottom of the mounting base of the first measuring device; a lifting displacement sensor, a lateral displacement sensor, and a longitudinal displacement sensor are arranged on the second measuring device; the method includes the following steps:

[0006] S1: A wireless signal receiver for receiving external wireless signals is fixedly arranged on the ship model. A motion control unit connected to the wireless signal receiver by a wired manner and a thruster connected to the motion control unit are provided. The motion control unit is used to control the change of the rotational speed of the thruster.

[0007] S2: The towing tank sets wave parameter disturbances according to the target sea conditions and transmits them to the ship model, causing the ship model to perform six-degree-of-freedom motion.

[0008] S3: The wireless signal receiver receives an externally input control strategy and transmits the control strategy to the motion control unit. The motion control unit adjusts the rotational speed of the thruster according to the control strategy, thereby changing the attitude of the ship model.

[0009] S4: When the attitude of the ship model changes, the longitudinal displacement sensor, the lateral displacement sensor, and the lift displacement sensor respectively detect the displacement of the ship model in the X, Y, and Z directions in real time, and the gyroscope detects the pitching, rolling, and yawing motions of the ship model in real time;

[0010] S5: Compare the six-degree-of-freedom motion data detected in S4 with the externally input control strategy in S3. If the navigation attitude of each degree of freedom meets the expected target requirements, output the control strategy; otherwise, jump to S3 to adjust the externally input control strategy and then continue to execute S3 - S5.

[0011] Preferably, a wave maker is installed in the towing tank.

[0012] Preferably, the longitudinal displacement sensor measures the longitudinal displacement in the X direction; the lateral displacement sensor measures the lateral displacement in the Y direction; the lift displacement sensor measures the vertical displacement in the Z direction.

[0013] Preferably, the six-degree-of-freedom motion of the ship model includes: displacements in the X, Y, and Z directions, roll, pitch, and yaw; the yaw includes the heading angle and the heading angular velocity.

[0014] Preferably, the gyroscope is used to measure roll, pitch, heading angle, and heading angular velocity.

[0015] Preferably, the device parameters of the gyroscope are SHA130 hollow rotary platform, torque 12 NM, rotation speed 200 RPM, and repeat positioning up to ±0.004 degrees.

[0016] Preferably, the ship model is scaled down according to the actual ship. Multiple motion control units and thrusters are arranged on the ship model, and the number of motion control units and thrusters is determined according to the actual ship design.

[0017] Preferably, the number and installation positions of the motion control units and thrusters are exactly the same.

[0018] Preferably, the number of the motion control units is 3, which are respectively installed at the stern and the bow of the ship, and two symmetrically arranged motion control units are installed at the bow.

[0019] Preferably, the expected target requirements in S5 are generally that the displacements in the X, Y, and Z directions are within 1 cm, and the angles of pitching, rolling, and yawing motions are within 3°.

[0020] Beneficial effects:

[0021] The present invention provides a test method for the active positioning experiment of a ship model. The towing tank generates waves with target parameters, enabling the ship model to simulate real sea waves for six-degree-of-freedom motion, ensuring the authenticity and reliability of the subsequent output control strategy. The longitudinal displacement sensor, lateral displacement sensor, lifting displacement sensor, and gyroscope monitor the six-degree-of-freedom motion data of the ship model in real time, thereby realizing the real-time verification of the effectiveness of the control strategy, and the data has good real-time performance. When there are problems with the control strategy, the various thrusters of the ship model can also be controlled in real time through the motion control unit, which is efficient for the process of verifying the control strategy. In summary, the present invention has achieved the development of a test method for the active positioning experiment of a ship model, which can verify the effectiveness of the active positioning strategy and solve the problem that there is currently no test method for the active positioning experiment of a ship model. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of the test system for the active positioning experiment of a ship model in waves according to an embodiment of the present invention.

[0023] Figure 2 It is a schematic diagram of the installation position of the motion control unit according to an embodiment of the present invention.

[0024] Figure 3 It is a flowchart of the test method for the active positioning experiment of a ship model in waves according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0025] The present invention will be described in detail below with reference to the accompanying drawings.

[0026] The present invention provides a test method for the active positioning experiment of a ship model, which uses a six-degree-of-freedom motion test platform for a ship model in waves (a Chinese invention patent with the publication number CN118961141A: A six-degree-of-freedom motion test platform and system for a ship model in waves) to test the active positioning experiment of a ship model in waves. The platform ( Figure 1 ) includes: a ship model, a first measuring device, a second measuring device, a fixed bracket, and a limiting device; a gyroscope is installed inside the bottom of the installation base of the first measuring device; a lifting displacement sensor, a lateral displacement sensor, and a longitudinal displacement sensor are arranged on the second measuring device; as Figure 3 shown, the method includes the following steps:

[0027] S1: A wireless signal receiver for receiving external wireless signals is fixedly installed on the ship model. A motion control unit connected to the wireless signal receiver by wire and a thruster connected to the motion control unit are provided. The motion control unit is used to control the change of the thruster speed; the wireless signal receiver is used to receive the control strategy for controlling the motion of the ship model transmitted externally. In a specific embodiment of the present invention, the user inputs the motion control strategy of the ship model in the ship model control room according to the six-degree-of-freedom motion of the ship model. The ship model control room transmits the motion control strategy of the ship model in the form of wireless signals. The wireless signal receiver receives the wireless signals (control strategy) transmitted by the control room, and the motion control unit controls the change of the thruster speed according to the control strategy so as to adjust the motion attitude of the ship model; the number of the motion control units and thrusters is exactly the same as that designed for the actual ship, that is: if the number of the motion control units and thrusters designed for the actual ship is both N, then the number of the motion control units and thrusters during the model test is both N; in a specific embodiment of the present invention, the number of the motion control units is 3, which are respectively installed at the stern and the bow ( Figure 1 ), and two symmetrically arranged motion control units are installed at the bow ( Figure 2 ). The position of the wireless signal receiver can be reasonably arranged according to the suitability of the ship model installation; to ensure the synchronization of signal transmission and enhance the anti-interference ability, the wireless signal receiver on the ship model is connected to each motion control unit by wire, as Figure 2 shown.

[0028] S2: The towing tank sets wave parameter disturbances according to the target sea conditions and transmits them to the ship model, causing the ship model to perform six-degree-of-freedom motion; the six-degree-of-freedom motion of the ship model includes: displacements in the X, Y, and Z directions, roll, pitch, and yaw; the yaw includes the heading angle and the heading angular velocity; the longitudinal displacement sensor measures the longitudinal displacement along the X direction; the lateral displacement sensor measures the lateral displacement along the Y direction; the lifting displacement sensor measures the vertical displacement along the Z direction; the gyroscope is used to measure the roll, pitch, and yaw motions, and the yaw includes the heading angle and the heading angular velocity; the device parameters of the gyroscope are SHA130 hollow rotary platform, torque 12NM, rotation speed 200RPM, and the repeat positioning accuracy is up to ±0.004 degrees.

[0029] A wave maker is installed in the towing tank. The wave maker is used to generate waves with target parameters and input the wave parameters into the ship model to enable the ship to perform six-degree-of-freedom motion.

[0030] S3: The wireless signal receiver receives the externally input control strategy and transmits the control strategy to the motion control unit. The motion control unit adjusts the speed of the thruster according to the control strategy, so that the attitude of the ship model changes;

[0031] S4: When the attitude of the ship model changes, the longitudinal displacement sensor, the lateral displacement sensor, and the lifting displacement sensor respectively and real-time detect the displacements of the ship model in the X, Y, and Z directions, and the gyroscope real-time detects the pitch, roll, and yaw motions of the ship model;

[0032] S5: Compare the six-degree-of-freedom motion data detected in S4 with the externally input control strategy in S3. If the navigation attitudes of all degrees of freedom meet the target requirements, then output the control strategy; otherwise, jump to S3 to adjust the externally input control strategy and then continue to execute S3 - S5.

[0033] In a specific embodiment of the present invention, a wave maker in the towing tank generates waves with target parameters and transmits them to the ship model, causing the ship model to have six-degree-of-freedom motions; for the waves received by the ship model, an externally input wave control strategy for the target parameters is provided. The wireless signal receiver receives the control strategy through wireless signals, and the motion control unit controls the rotational speed of the thruster to change according to the control strategy to generate a reaction force for offsetting the motions caused by the environmental loads (waves); meanwhile, the longitudinal displacement sensor, the lateral displacement sensor, the lifting displacement sensor, and the gyroscope perform real-time monitoring on the six-degree-of-freedom motions of the navigation attitude of the ship model in the waves. Among them, the displacements in the X, Y, and Z directions of the six-degree-of-freedom motions are measured by the longitudinal displacement sensor, the lateral displacement sensor, and the lifting displacement sensor, and the roll, pitch, and yaw in the six-degree-of-freedom motions are measured by the gyroscope. The monitoring data of the longitudinal displacement sensor, the lateral displacement sensor, the lifting displacement sensor, and the gyroscope are used to measure the motion conditions of the ship model, and the effectiveness of the control strategy is checked according to the motion conditions of the ship model. Specifically: when the waves and the thrust generated by the thruster act on the ship model simultaneously, the navigation attitude of the ship model is output through the motion data detected by the longitudinal displacement sensor, the lateral displacement sensor, the lifting displacement sensor, and the gyroscope. When the navigation attitudes of all degrees of freedom meet the target requirements, the control strategy is considered effective; when the navigation attitude exceeds the expected target (generally, the displacements in the X, Y, and Z directions are within 1 cm, and the angles of the pitch, roll, and yaw motions are within 3°) range, the strategy needs to be readjusted and verified again.

[0034] The above embodiments are only used to illustrate the technical solutions of the present invention and are not restrictive. Although the present invention has been described in detail through the above preferred embodiments, those skilled in the art should understand that various changes can be made in form and details without departing from the scope defined by the claims of the present invention.

Claims

1. Test method for active positioning test of ship model in waves. Using a six-degree-of-freedom motion test platform for ship model in waves to test the active positioning test of ship model in waves. The platform includes: A ship model, a first measuring device, a second measuring device, a fixing bracket, and a limiting device; a gyroscope is installed inside the bottom of the installation base of the first measuring device; a lifting displacement sensor, a lateral displacement sensor, and a longitudinal displacement sensor are arranged on the second measuring device; it is characterized by including the following steps: S1: A wireless signal receiver for receiving external wireless signals is fixedly arranged on the ship model, a motion control unit connected to the wireless signal receiver by a wired manner and a thruster connected to the motion control unit, and the motion control unit is used for controlling the rotation speed of the thruster to change; S2: The towing tank sets wave parameter disturbances according to the target sea conditions and transmits them to the ship model, so that the ship model undergoes six-degree-of-freedom motion; S3: The wireless signal receiver receives an externally input control strategy and transmits the control strategy to the motion control unit, and the motion control unit adjusts the rotation speed of the thruster according to the control strategy, so that the attitude of the ship model changes; S4: When the attitude of the ship model changes, the longitudinal displacement sensor, the lateral displacement sensor, and the lifting displacement sensor respectively detect the displacements of the ship model in the X, Y, and Z directions in real time, and the gyroscope detects the pitching, rolling, and yaw motions of the ship model in real time; S5: Compare the six-degree-of-freedom motion data detected in S4 with the externally input control strategy in S3. If the navigation attitudes of each degree of freedom meet the expected target requirements, output the control strategy; otherwise, jump to S3 to adjust the externally input control strategy and then continue to execute S3 - S5.

2. The wave tank model active positioning test method according to claim 1, wherein A wave maker is installed in the towing tank.

3. The wave tank test method for active positioning of ship model according to claim 1, wherein, The longitudinal displacement sensor measures the longitudinal displacement along the X direction; the lateral displacement sensor measures the lateral displacement along the Y direction; the lifting displacement sensor measures the vertical displacement along the Z direction.

4. The wave tank model active positioning test method according to claim 3, characterized in that The six-degree-of-freedom motion of the ship model includes: displacements in the X, Y, and Z directions, roll, pitch, and yaw; the yaw includes the heading angle and the heading angular velocity.

5. The ship model active positioning test method according to claim 4, wherein The gyroscope is used for measuring roll, pitch, heading angle, and heading angular velocity.

6. The method for testing the active positioning of a ship model according to claim 5, wherein The device parameters of the gyroscope are SHA130 hollow rotary platform, torque 12NM, rotation speed 200RPM, and the repeat positioning is up to ±0.004 degrees.

7. The method for testing the active positioning of a ship model according to claim 1, characterized in that, The ship model is scaled down according to the actual ship, and a plurality of motion control units and thrusters are arranged on the ship model. The number of motion control units and thrusters is determined according to the actual ship design.

8. The ship model active positioning test method according to claim 7, wherein, The number and installation positions of the motion control units and thrusters are exactly the same.

9. The method for testing the active positioning of a ship model according to claim 8, wherein The number of the motion control units is 3, which are respectively installed at the stern and the bow of the ship, and two symmetric motion control units are installed at the bow of the ship.

10. The method for testing the active positioning of a ship model according to claim 8, characterized in that The expected target requirements in S5 are generally that the displacements in the X, Y, and Z directions are within 1 cm, and the angles of pitching, rolling, and yaw motions are within 3°.

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