An external load detection method, device and equipment for fin stabilizers

Abstract

The present invention provides a method, device and equipment for detecting external load of a fin stabilizer. The method comprises: step 1, collecting t n The angular velocity of a single fin stabilizer at the moment ω(t n ), fluid attack angle #imgabs0#, oil inlet pressure #imgabs1# and oil outlet pressure #imgabs2# of the hydraulic drive cylinder used to drive a single anti-roll fin, step 2, constructing a fluid torque coefficient function; step 3, according to the fluid torque coefficient function, the fin angular velocity ω(t n ), fluid attack angle #imgabs3# oil inlet pressure #imgabs4# and oil outlet pressure #imgabs5#, the lift-drag resultant force and fluid force are solved by iteration method, and the lift-drag resultant force and fluid moment are the detected external load. The identity between the driving torque and the load torque is established, and the real-time measurement of the external load of the fin stabilizer is realized by iterative means, providing the algorithm basis for the lift feedback control of the fin stabilizer.

Description

Technical Field

[0001] The present invention relates to the technical field of fin stabilizers, and particularly to an external load detection method, device and equipment for fin stabilizers. Background Art

[0002] When a ship is sailing and is subjected to strong external disturbances such as wind and wave disturbances, it will have a great impact on the ship's attitude, especially the rolling motion, which affects seaworthiness. As the most widely used active anti-rolling device so far, the effectiveness of fin stabilizers has been verified on various ship types. Therefore, the reliability evaluation result of fin stabilizers is particularly important. Generally, the reliability of fin stabilizers is evaluated by detecting the external load received by fin stabilizers during ship navigation through sensors. However, since fin stabilizers are located outside the cabin and the marine environment is relatively harsh, the method of directly measuring the external load using sensors has problems such as poor sensor installation environment and high sensor range requirements, resulting in the inability to accurately measure the external load of fin stabilizers. Summary of the Invention

[0003] The present invention combines indirect calculation with an iterative algorithm to perform real-time external load calculation without additional sensors.

[0004] The present invention provides an external load detection method for fin stabilizers, including: Step 1, collecting the fin rotation angular velocity ω(t n ) of a single fin stabilizer at time t n , the fluid angle of attack the inlet pressure of the hydraulic drive cylinder for driving a single fin stabilizer and the outlet pressure Step 2, constructing a hydrodynamic moment coefficient function; Step 3, according to the hydrodynamic moment coefficient function, the fin rotation angular velocity ω(t n ), the fluid angle of attack the inlet pressure and the outlet pressure solve the lift-drag resultant force and the hydrodynamic moment by the iterative method, and the lift-drag resultant force and the hydrodynamic moment are the detected external load of the fin stabilizer.

[0005] Further, Step 1 includes: collecting the fin rotation angular velocity ω(t n ) at time t through a fin angle transmitter, and obtaining the fin angle displayed on the fin angle transmitter as the fluid angle of attack n Obtaining the inlet pressure and the outlet pressure through the pressure sensors at the inlet and outlet

[0006] Further, Step 1 includes: collecting the fin rotation angular velocity ω(t nThe angular velocity ω(t n ) of the fin at a moment, and obtain the corresponding fin angle displayed on the fin angle transmitter Obtain the inlet pressure through the pressure sensor at the inlet and outlet and the outlet pressure

[0007] Furthermore, the hydrodynamic moment coefficient function is:

[0008]

[0009] where M(α) is the hydrodynamic moment of the anti-rolling fin calculated according to the hydrodynamic moment function, α represents any hydrodynamic angle of attack at any moment, the hydrodynamic angle of attack is the angle between the fin and the flowing water in the external flow field, ρ is the density of seawater, a constant, V 2 (t n ) is the square of the ship speed at time t n , V(t n ) also represents the speed of the anti-rolling fin relative to the water, collected by the sensor, A represents the area of the anti-rolling fin, a constant, b is the chord length of the anti-rolling fin, a constant.

[0010] Furthermore, the hydrodynamic moment is calculated through the hydrodynamic moment function, and the hydrodynamic moment function is expressed as:

[0011] M(α) = M 油缸 (t n ) - M f (α) - M α (t n )

[0012] where M f (α) is the frictional drag moment calculated according to the frictional drag moment function, M α (t n ) is the torque caused by the moment of inertia at time t n , M 油缸 (t n ) is the output torque of the oil cylinder; where M 油缸 (t n ) = P(t n ) * S, the pressure difference between the inlet and outlet of the oil cylinder S is the area of the oil cylinder, a constant.

[0013] Furthermore, the frictional drag is calculated through the frictional drag function, and the frictional drag moment function is expressed as:

[0014] M f (α) = μDF(α)

[0015] Among them, μ is the comprehensive friction coefficient of the frictional resistance torque caused by O-rings, bearings, etc., which is a constant, D is the outer diameter of the O-ring and the bearing, which is a constant, and F(α) is the lift-drag resultant force calculated according to the lift-drag resultant force function.

[0016] Furthermore, the lift-drag resultant force can be calculated from the lift-drag resultant force, and the lift-drag resultant force function is expressed as:

[0017]

[0018] Among them, ρ is the density of seawater, which is a constant, V 2 (t n ) is the square of the ship speed at time tn, C(α) is the lift-drag resultant force coefficient of the anti-rolling fin, which is obtained by fitting the fin type test data and is an internal design parameter.

[0019] Furthermore, step 3 includes:

[0020] Step 31, for time tn, let Take α tn，1 as the value entering the first iteration at time t n , then, let x = 1, and execute step 32;

[0021] Step 32, successively calculate the lift-drag resultant force hydrodynamic torque and the hydrodynamic torque coefficient C m according to the hydrodynamic torque coefficient function, the lift-drag resultant force function and the hydrodynamic torque function. The new corresponding fluid angle of attack can be obtained through the fitting data of the corresponding fin type fluid test and C m can be obtained.

[0022] Step 33, judge Whether the absolute value of the difference from α tn，1 is less than 10 -5 . If it is less, output The at this time is the fluid angle of attack obtained by the first round of calculation at time tn. Obtain the corresponding lift-drag resultant force and hydrodynamic torque of the output . The obtained lift-drag resultant force and hydrodynamic torque are the detected external loads; otherwise, let x = x + 1, and take α tn，x as the input for the next cycle, and enter step 34 to continue the iterative calculation;

[0023] Step 34, successively calculate the lift-drag resultant force hydrodynamic torque and the hydrodynamic torque coefficient C m, the root obtains the new corresponding fluid angle of attack that can be obtained through the fitting data corresponding to the fin-type fluid test and C m The new corresponding fluid angle of attack can be obtained

[0024] Step 35, judge The absolute value of the difference from α tn，x Is it less than 10 -5 If it is less, output At this time Is the fluid angle of attack obtained in the x-th round of calculation at time tn. Obtain the output fluid angle of attack, the corresponding lift-drag resultant force, and the fluid moment. The obtained lift-drag resultant force and fluid moment are the detected external load; otherwise, let x = x + 1, and use α tn，x As the input for the next loop, enter step 34.

[0025] In a second aspect, an embodiment of the present invention further provides an external load detection device for a fin stabilizer, including: a first processing module for collecting the fin rotation angular velocity ω(t n At a moment) of a single fin stabilizer, the fluid angle of attack n ), the inlet pressure Of the hydraulic drive cylinder for driving a single fin stabilizer And the outlet pressure A second processing module for constructing a fluid moment coefficient function; a third processing module for according to the fluid moment coefficient function, the fin rotation angular velocity ω(t n ), the fluid angle of attack The inlet pressure And the outlet pressure Solve the lift-drag resultant force and the fluid moment by the iteration method. The lift-drag resultant force and the fluid moment are the detected external load of the fin stabilizer.

[0026] In a third aspect, an embodiment of the present invention further provides an electronic device, including a memory, a processor, and a computer program stored on the memory and executable on the processor. When the processor executes the program, it implements the steps of the external load detection method for a fin stabilizer as described in the first aspect.

[0027] In a fourth aspect, an embodiment of the present invention further provides a non-transitory computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, it implements the steps of the external load detection method for a fin stabilizer as described in the first aspect.

[0028] In a fifth aspect, an embodiment of the present invention further provides a computer program product, on which an executable instruction is stored. When the instruction is executed by a processor, it causes the processor to implement the steps of the external load detection method for a fin stabilizer as described in the first aspect.

[0029] The beneficial effects achieved by the present invention are as follows: By collecting in real time the fin rotation angular velocity information and the swing cylinder pressure difference information of a certain type of fin stabilizer driven by a swing cylinder, an identity equation between the driving torque and the load torque is established. Using the actual measurement of the lift coefficient, drag coefficient, and torque coefficient in the fin type fluid experiment, and adopting an iterative method, the real-time measurement of the external load of the fin stabilizer is realized, providing a means for improving the reliability measurement of the fin stabilizer and a basis for the lift feedback control algorithm of the fin stabilizer. Description of the Drawings

[0030] Figure 1 is a schematic flow chart of a method for detecting the external load of a fin stabilizer according to the present invention;

[0031] Figure 2 is a schematic diagram of the fluid angle of attack α of a single fin stabilizer;

[0032] Figure 3 is a schematic diagram of a single fin stabilizer.

[0033] Figure 3 Markings in

[0034] 1: Fin angle transmitter, which can collect the fin rotation angular velocity and angle;

[0035] 2: Oil cylinder, which is used to output torque;

[0036] 3: Support base;

[0037] 4: Fin shaft, which transmits torque and connects the fin and the oil cylinder;

[0038] 5: Fin, which is directly in the water and forms a lift force with the oncoming flow through the angle of attack to reduce rolling. Detailed Embodiments

[0039] The technical solution of the present invention will be described in more detail below with reference to the drawings. The present invention includes but is not limited to the following embodiments.

[0040] The present invention mainly conducts load detection on a single fin stabilizer. Please refer to Figure 1 , as Figure 1 shown, the method for detecting the external load of a fin stabilizer includes the following steps:

[0041] Step 1, collect the fin rotation angular velocity ω(t n ) of a single fin stabilizer at time t n , the fluid angle of attack the inlet pressure of the hydraulic drive oil cylinder for driving a single fin stabilizer

[0042] Specifically, the angular velocity ω(t n ) of the fin rotation at time t can be collected by a fin angle transmitter arranged behind the swing cylinder, and the corresponding fin angle displayed on the fin angle transmitter is used as the fluid angle of attack n . The inlet pressure can be obtained by a pressure sensor arranged at the inlet and outlet of the swing cylinder . The outlet pressure . After subtraction, the pressure difference between the inlet and outlet of the oil cylinder at this moment can be obtained .

[0043] Step 2: Construct the fluid force moment coefficient function.

[0044] Among them, Step 2 includes:

[0045] Step 21: Construct the lift-drag resultant force function, the frictional drag moment function, and the fluid force moment function;

[0046] Step 22: Construct the fluid force moment coefficient function according to the lift-drag resultant force function, the frictional drag moment function, and the fluid force moment function.

[0047] Among them, the lift-drag resultant force F(α) can be calculated by the following formula:

[0048]

[0049] Among them, the frictional drag moment M f (F) = M f (F(α)) = M f (α) can be calculated by the following formula:

[0050] M f (α) = μDF(α) Formula (2)

[0051] Among them, the fluid force moment M(α) can be calculated by the following formula:

[0052] M(α) = M 油缸 (t n ) - M f (α) - M α (t n ) Formula (3)

[0053] Among them, the fluid force moment coefficient can be calculated by the following formula:

[0054]

[0055] In Formulas (1-4):

[0056] All represent the angle of attack between the fin and the flowing water, which is the quantity to be solved, and is the angle of attack between the fin and the flowing water at time tn;

[0057] tn Representing the nth moment;

[0058] F(α): The resultant lift and drag force on the fin stabilizer, a quantity related to the fluid angle of attack α;

[0059] ρ: Seawater density, a constant;

[0060] S is the area of the oil cylinder, a constant;

[0061] L: The distance from the fin center to the center of the large bearing, a constant;

[0062] V(t n ): The ship speed at time t, which also represents the speed of the fin stabilizer relative to the water, collected by sensors; n

[0063] A: The fin area of the fin stabilizer, a constant;

[0064] C(α): The lift and drag force coefficient is a fin type parameter, generally obtained through hydrodynamic tests (fitted from fin type test data). The lift coefficient is a function positively correlated with α. In the range of the angle of attack of the fin stabilizer, it is generally regarded as linear and is an internal design parameter;

[0065] M f (F): The frictional resistance torque caused by O-rings, bearings, etc.;

[0066] M f (α): The frictional resistance torque caused by O-rings, bearings, etc.;

[0067] μ: The comprehensive friction coefficient of the frictional resistance torque caused by O-rings, bearings, etc., a constant;

[0068] D: The outer diameter of the O-ring, bearing, etc., a constant;

[0069] M(α): The hydrodynamic torque on the fin stabilizer, usually a quantity related to α, all related. Since the influence of higher-order quantities on the final value is very small, for the sake of simplifying the calculation amount, it can be simplified to be only related to α;

[0070] M α (t n ): The torque caused by the moment of inertia at time t; n

[0071] J: The moment of inertia J of the fin and the fin shaft with the center of the fin shaft as the pure rotation center, a constant;

[0072] t n The derivative of the angle of rotation of the fin stabilizer at time t, collected by sensors;

[0073] Cm (α): The fin stabilizer moment coefficient, obtained by fitting the fin type test data, is an internal design parameter

[0074] b: The chord length of the fin stabilizer, a constant;

[0075] P(t n ): According to the inlet pressure Outlet pressure The pressure difference between the inlet and outlet of the oil cylinder P(t can be obtained n ), According to the pressure difference P(t between the inlet and outlet of the oil cylinder n ) to determine the hydrodynamic moment coefficient C m . Specifically, the inlet pressure Outlet pressure After subtraction, the pressure difference between the inlet and outlet of the oil cylinder at this moment is obtained Among them, Indicates t n At the moment, the inlet pressure of the oil cylinder, collected by the sensor; Indicates t n At the moment, the outlet pressure of the oil cylinder, collected by the sensor; S represents the area of the oil cylinder, a constant; P(t n ) indicates t n At the moment, the pressure difference between the inlet and outlet of the oil cylinder, which can be obtained from Obtained;

[0076] M 油缸 (t n ): M 油缸 (t n ) represents t n At the moment, the output torque of the oil cylinder. In an application scenario, t n At the moment, there is any fluid angle of attack α (refer to Figure 2 ), The output torque of the oil cylinder M 油缸 (t n ) = P(t n ) * S; The external load torque mainly consists of three parts, the frictional resistance torque M f (F), hydrodynamic torque The torque caused by the moment of inertia

[0077] The C calculated according to the above formula m Can be obtained from the fitting data of the corresponding fin type fluid test (test parameters, internal design parameters, known quantities) to obtain the new corresponding C mThe fluid angle of attack α, and the hydrodynamic moment coefficient function is a function linearly related to α fitted from the test data obtained through wind tunnel and water tunnel tests. The fin type of the anti-rolling fin is like an airplane wing, adopting the NACA airfoil. Generally, the lift and drag coefficients and the moment coefficient are measured through wind tunnel and water tunnel tests. Since the data obtained from the tests are discrete points and are not linear globally, and the angle of attack range used for the anti-rolling fin is generally within ±30°, these discrete data show linearity. Therefore, it is necessary to fit the data to obtain a linear curve to obtain the fluid angle of attack.

[0078] Step 3, according to the hydrodynamic moment coefficient function, the fin rotation angular velocity ω(t n ), the fluid angle of attack inlet pressure and the outlet pressure solve for the lift-drag resultant force and the hydrodynamic moment by the iterative method, and the lift-drag resultant force and the hydrodynamic moment are the detected external loads of the anti-rolling fin.

[0079] Among them, step 3 includes:

[0080] Step 31, for the moment tn, let Take α tn，1 as the value entering the first iteration at time t n . Then, let x = 1 and execute step 32;

[0081] Step 32, successively calculate the lift-drag resultant force hydrodynamic moment and the hydrodynamic moment coefficient C m according to the hydrodynamic moment coefficient function, the lift-drag resultant force function and the hydrodynamic moment function. Based on the fitting data of the corresponding fin type fluid test and C m the new corresponding fluid angle of attack can be obtained

[0082] Step 33, judge Whether the absolute value of the difference from α tn，1 is less than 10 -5 . If it is less, output The at this time is the fluid angle of attack obtained in the first round of calculation at time tn, and obtain the output The corresponding lift-drag resultant force and hydrodynamic moment. The obtained lift-drag resultant force and hydrodynamic moment are the detected external loads; otherwise, let x = x + 1, and take α tn，x as the input for the next cycle and enter step 34 to continue the iterative calculation;

[0083] Step 34, calculate the lift-drag resultant force according to the fluid moment coefficient function, lift-drag resultant force function, and fluid moment function in sequence Fluid moment and fluid moment coefficient C m , and obtain the new corresponding fluid angle of attack that can be obtained through the fitting data of the corresponding fin type fluid test and C m

[0084] Step 35, judge Whether the absolute value of the difference from α tn，x is less than 10 -5 , if less, output The current is the fluid angle of attack calculated in the x-th round at time tn. Obtain the output fluid angle of attack, the corresponding lift-drag resultant force, and fluid moment. The obtained lift-drag resultant force and fluid moment are the detected external loads; otherwise, let x = x + 1, and use α tn，x as the input for the next loop, and enter Step 34.

[0085] Through the above steps, the lift-drag resultant force and fluid moment are solved by the iterative method according to the fluid moment coefficient function.

[0086] In one embodiment, the process of solving the lift-drag resultant force fluid moment by the iterative method is as follows:

[0087] 1) For a certain moment t n ;

[0088] Count: Let α tn，x , x represents the number of iterations, and use α tn，x as the input for this loop, where is the fin angle collected and used as the input for the first loop;

[0089] The lift-drag resultant force can be obtained:

[0090] 2) Calculate the frictional moment: M f (α tn，x ) = μDF(α tn，x );

[0091] Calculate the fluid moment: M(α tn，x ) = M 油缸 (t n ) - M f (α tn，x ) - M α (t n )

[0092] ​Calculate the fluid moment coefficient:

[0093] 3) Through the known C m Parameter spectrum, you can find out the C obtained in this step m (α tn，x ) is the only corresponding angle value in the spectrum, denoted by

[0094] 4) Add judgment, if α tn，x , The absolute value of the difference is less than 10 -5 , if it is less than, then let the output α tn，x , at this time α tn，x That is, the true angle between the fin and the flowing water in the external flow field. Otherwise, let x = x + 1, Reenter step 1) to calculate the lift-drag force and continue iterating. Record the data from the last step. and obtain The corresponding lift-drag force is: Fluid torque This is the external load.

[0095] Based on the above method, the present invention designs a fin stabilizer. Figure 3 As shown in the figure, No. 1 is the fin angle transmitter, and the built-in sensor can collect t n The angular velocity of the fin at the moment ω(t n ) and the corresponding fin angle No. 2 is the fin torque provided by the swing cylinder. The inlet and outlet pressures can be obtained by the pressure sensors arranged at the inlet and outlet of the swing cylinder. The inlet and outlet pressures of the cylinder at that moment can be obtained by subtracting them. n ); No. 3 is the support seat, which contains a bearing group and a seal; No. 4 is the fin shaft, which is used to transmit the torque from the swing cylinder to the fin, and at the same time transmit the lift and drag force on the fin to the support seat; No. 5 is the fin, which bears the external fluid load, including the lift and drag force F and the fluid torque M. Figure 3 It can be seen that the present invention can still be used to detect the load without any modification to the fin stabilizer. However, existing domestic and foreign patents require modifying the mechanical structure and adding sensors to the fin stabilizer device to detect the external load. This method can detect the external load based on the existing and necessary sensors and structures, creating economic benefits and reducing costs.

[0096] According to the structural schematic diagram of some embodiments of the external load detection device for the fin stabilizer provided by the present invention, as an implementation of the methods shown in the above figures, the present invention also provides some embodiments of the external load detection device for the fin stabilizer, and these device embodiments are similar to Figure 1The embodiments of some of the methods described correspond, and the device can be applied to various electronic devices.

[0097] Regarding the external load detection device for a stabilizer fin, it includes a first processing module, a second processing module, and a third processing module: The first processing module is used to collect the n fin rotation angular velocity ω(t n ) of a single stabilizer fin at a moment t, the fluid angle of attack the inlet pressure of the hydraulic drive cylinder used to drive a single stabilizer fin and the outlet pressure The second processing module is used to construct a fluid moment coefficient function; the third processing module is used to solve the lift-drag resultant force and fluid moment through an iterative method according to the fluid moment coefficient function, the fin rotation angular velocity ω(t n ) and the fluid angle of attack the inlet pressure and the outlet pressure The lift-drag resultant force and fluid moment are the detected external load of the stabilizer fin.

[0098] In an alternative implementation of some embodiments, the first processing module is used to: collect the fin rotation angular velocity ω(t n ) at a moment t through a fin angle transmitter, and obtain the fin angle displayed on the fin angle transmitter as the fluid angle of attack n Obtain the inlet pressure through the pressure sensors at the inlet and outlet, and the outlet pressure and the outlet pressure

[0099] In an alternative implementation of some embodiments, the first processing module is used to: collect the fin rotation angular velocity ω(t n ) at a moment t through a fin angle transmitter, and obtain the corresponding fin angle displayed on the fin angle transmitter n Obtain the inlet pressure through the pressure sensors at the inlet and outlet, and the outlet pressure and the outlet pressure

[0100] In an alternative implementation of some embodiments, the fluid moment coefficient function is:

[0101]

[0102] Wherein, M(α) is the fluid moment of the stabilizer fin calculated according to the fluid moment function, α represents any fluid angle of attack at any moment, the fluid angle of attack is the angle between the fin and the flowing water in the external flow field, ρ is the seawater density, a constant, V 2 (t n ) is at time t nThe square of the ship speed at a certain moment, V(t n ) also represents the speed of the anti-rolling fin relative to the water. It is collected by sensors. A represents the area of the anti-rolling fin, which is a constant, and b is the chord length of the anti-rolling fin, which is a constant.

[0103] In an alternative implementation of some embodiments, the hydrodynamic moment is calculated through a hydrodynamic moment function, and the hydrodynamic moment function is expressed as:

[0104] M(α) = M 油缸 (t n ) - M f (α) - M α (t n )

[0105] Wherein, M f (α) is the frictional resistance moment calculated according to the frictional resistance moment function, and M α (t n ) is the torque caused by the moment of inertia at time t n , M 油缸 (t n ) is the output torque of the oil cylinder; wherein, M 油缸 (t n ) = P(t n ) * S, the pressure difference between the inlet and outlet of the oil cylinder S is the area of the oil cylinder, a constant.

[0106] In an alternative implementation of some embodiments, the frictional resistance is calculated through a frictional resistance function, and the frictional resistance moment function is expressed as:

[0107] M f (α) = μDF(α)

[0108] Wherein, μ is the comprehensive friction coefficient of the frictional resistance moment caused by O-rings, bearings, etc., a constant, D is the outer diameter of the O-ring and bearing, a constant, and F(α) is the lift-drag resultant force calculated according to the lift-drag resultant force function.

[0109] In an alternative implementation of some embodiments, the lift-drag resultant force can be calculated through a lift-drag resultant force function, and the lift-drag resultant force function is expressed as:

[0110]

[0111] Wherein, ρ is the density of seawater, a constant, V 2 (t n ) is the square of the ship speed at time tn, and C(α) is the lift-drag resultant force coefficient of the anti-rolling fin, which is obtained by fitting the fin type test data and is an internal design parameter.

[0112] In an alternative implementation of some embodiments, the third processing module is configured to:

[0113] For the time tn, let Take α tn，1 As the value entering the first iteration at time t n Then, let x = 1 and execute step 32;

[0114] Calculate the lift - drag resultant force, Fluid moment And the fluid - moment coefficient C m In turn according to the fluid - moment coefficient function, lift - drag resultant - force function, and fluid - moment function. Based on the fitting data of the corresponding fin - type fluid test and C m Find the new corresponding fluid angle of attack that can be obtained

[0115] Judge Whether the absolute value of the difference from α tn，1 Is less than 10 -5 If it is less, output The current As the fluid angle of attack calculated in the first round at time tn, obtain the output The corresponding lift - drag resultant force and fluid moment. The obtained lift - drag resultant force and fluid moment are the detected external loads; otherwise, let x = x + 1, and take α tn，x As the input for the next loop and enter step 34 to continue the iterative operation;

[0116] Calculate the lift - drag resultant force, Fluid moment And the fluid - moment coefficient C m In turn according to the fluid - moment coefficient function, lift - drag resultant - force function, and fluid - moment function. Based on the fitting data of the corresponding fin - type fluid test and C m Find the new corresponding fluid angle of attack that can be obtained

[0117] Judge Whether the absolute value of the difference from α tn，x Is less than 10 -5 If it is less, output The current As the fluid angle of attack calculated in the x - th round at time tn, obtain the output fluid angle of attack, the corresponding lift - drag resultant force and fluid moment. The obtained lift - drag resultant force and fluid moment are the detected external loads; otherwise, let x = x + 1, and take α tn，x As the input for the next loop and enter step 34.

[0118] It can be understood that each module described in the device corresponds to each step in the method described in the reference Figure 1 description. Thus, the operations, features, and beneficial effects described above for the method also apply to the device and the modules and units contained therein, and will not be elaborated here.

[0119] On the other hand, the present invention also provides a computer program product. The above computer program product includes a computer program stored on a non-transitory computer-readable storage medium. The above computer program includes program instructions. When the above program instructions are executed by a computer, the computer can execute the external load detection method for fin stabilizers provided by the above various methods.

[0120] On yet another aspect, the present invention also provides a non-transitory computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, it is implemented to execute the external load detection method for fin stabilizers provided by the above various methods.

[0121] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed to multiple network units. Some or all of the modules can be selected according to actual needs to achieve the purpose of the solution of this embodiment. Those of ordinary skill in the art can understand and implement it without creative efforts.

[0122] Through the description of the above embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus a necessary general hardware platform, and of course, it can also be implemented by hardware. Based on this understanding, the essence of the above technical solution, or the part that contributes to the prior art, can be embodied in the form of a software product. The computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to enable a computer device (which can be a personal computer, a server, or a network device, etc.) to execute each embodiment or some parts of the above methods of the embodiments.

[0123] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An external load detection method for fin stabilizers, characterized in that, The method includes: Step 1, collect t n The angular velocity ω(t n ) of a single fin stabilizer at a moment, the fluid angle of attack The inlet pressure of the hydraulic drive cylinder for driving a single fin stabilizer and the outlet pressure Step 2: Construct a hydrodynamic moment coefficient function according to... Step 3, according to the hydrodynamic moment coefficient function, the angular velocity ω(t n ), the fluid angle of attack inlet pressure and the outlet pressure solve the lift-drag resultant force and the hydrodynamic moment by the iterative method, and the lift-drag resultant force and the hydrodynamic moment are the detected external loads of the fin stabilizer Wherein, Step 1 includes: collecting, by a fin angle transmitter, the angular velocity ω(t n ) of the fin rotation at time t, and obtaining the fin angle displayed on the fin angle transmitter as the fluid angle of attack n ) Obtaining the inlet pressure through a pressure sensor at the inlet and outlet ports and the outlet pressure Step 2 includes: Step 21: Construct a lift-drag resultant force function, a frictional drag moment function, and a hydrodynamic moment function; Step 22: Construct a hydrodynamic moment coefficient function according to the lift-drag resultant force function, the frictional drag moment function, and the hydrodynamic moment function. The hydrodynamic moment coefficient function is: Among them, M(α) is the hydrodynamic moment of the fin stabilizer calculated according to the hydrodynamic moment function, α represents any hydrodynamic angle of attack at any moment, the hydrodynamic angle of attack is the angle between the fin and the flowing water in the external flow field, ρ is the seawater density, which is a constant, V 2 (t n ) is the square of the ship speed at time t n , and V(t n ) also represents the speed of the fin stabilizer relative to the water, which is collected by sensors. A represents the fin area of the fin stabilizer, which is a constant, and b is the chord length of the fin stabilizer, which is a constant; Step 3 includes: Step 31, for the tn moment, let Take α tn，1 as the value entering the first iteration at time t n Then, let x = 1 and execute Step 32; Step 32, calculate the lift-drag resultant force according to the fluid moment coefficient function, lift-drag resultant force function, and fluid moment function in sequence Fluid moment and the fluid moment coefficient C m , and obtain the new corresponding fluid angle of attack that can be obtained through the fitting data of the corresponding fin type fluid test and C m ​ Step 33, determine whether the absolute value of the difference from α tn，1 is less than 10 -5 . If it is less, output the current as the fluid angle of attack obtained in the first round of calculation at time tn, and obtain the output the corresponding lift-drag resultant force and fluid moment. The obtained lift-drag resultant force and fluid moment are the detected external loads; otherwise, let x = x + 1, and use α tn，x as the input for the next iteration, and enter Step 34 to continue the iterative calculation; Step 34, calculate the lift-drag resultant force according to the fluid moment coefficient function, the lift-drag resultant force function, and the fluid moment function in sequence Fluid moment and the fluid moment coefficient C m , and obtain the new corresponding fluid angle of attack that can be obtained through the fitting data of the corresponding fin-type fluid test and C m ​ Step 35, determine whether the absolute value of the difference from α tn，x is less than 10 -5 . If it is less, output the current fluid angle of attack calculated in the x-th round at time tn, obtain the output fluid angle of attack, the corresponding lift-drag resultant force, and the fluid moment. The obtained lift-drag resultant force and fluid moment are the detected external load; otherwise, let x = x + 1, and use α tn，x as the input for the next loop and enter Step 34.

2. The external load detection method for fin stabilizers according to claim 1, characterized in that The hydrodynamic moment function is expressed as: M(α) = M 油缸 (t n ) - M f (α) - M α (t n ) Among them, M f (α) is the frictional resistance moment received by a single fin stabilizer calculated according to the frictional resistance moment function, M α (t n ) is the torque caused by the moment of inertia at time t n . M 油缸 (t n ) is the output torque of the oil cylinder; among them, M 油缸 (t n ) = P(t n ) * S, where P is the pressure difference between the inlet and outlet of the oil cylinder S is the area of the oil cylinder and is a constant.

3. The external load detection method for fin stabilizers according to claim 2, wherein The frictional drag moment function is expressed as: M f (α) = μDF(α) Wherein, μ is the comprehensive friction coefficient of the frictional drag moment caused by O-rings, bearings, etc., a constant, D is the outer diameter of the O-ring and the bearing, a constant, and F(α) is the lift-drag resultant force calculated according to the lift-drag resultant force function.

4. The external load detection method for fin stabilizers according to claim 3, wherein The lift-drag resultant force function is expressed as: where ρ is the seawater density, a constant, and V 2 (t n ) is the square of the ship speed at time tn, and C(α) is the lift-drag resultant force coefficient of the anti-rolling fin, obtained by fitting the fin type test data and is an internal design parameter.

5. An external load detection device for a fin stabilizer, characterized in that, Including: The first processing module is used to collect n the angular velocity ω(t n ) of a single fin stabilizer at time t, the fluid angle of attack the inlet pressure of the hydraulic drive cylinder for driving a single fin stabilizer and the outlet pressure A second processing module, configured to construct a hydrodynamic moment coefficient function and execute the method steps of Step 2 in Claim 1; The third processing module is configured to solve the lift-drag resultant force and the hydrodynamic moment by an iterative method according to the hydrodynamic moment coefficient function, the angular velocity ω(t n ), the fluid angle of attack the inlet pressure and the outlet pressure , where the lift-drag resultant force and the hydrodynamic moment are the detected external loads of the fin stabilizer, and are used to execute the steps in step 3 of claim 1.

6. An electronic device, comprising a memory, a processor, and a computer program stored on the memory and executable on the processor, characterized in that, When the processor executes the program, it implements the external load detection method for fin stabilizers as described in Claim 1.

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