External load measurement method and apparatus for fin stabilizer, and device

Abstract

The present invention provides an external load measurement method and apparatus for a fin stabilizer, and a device. The method comprises: step 1, collecting a fin rotating angular velocity ω(tn) of a single fin stabilizer, a fluid angle of attack αtn, and an oil inlet pressure Pinlettn and an oil outlet pressure Poutlettn of a hydraulic cylinder for driving a single fin stabilizer at moment tn; step 2, constructing a fluid torque coefficient function; and step 3, on the basis of the fluid torque coefficient function, the fin rotating angular velocity ω(tn), the fluid angle of attack αtn, the oil inlet pressure Pinlettn, and the oil outlet pressure Poutlettn, solving for a lift and drag resultant force and a fluid force by means of an iteration method, the lift and drag resultant force and the fluid torque being a measured external load. An identity in respect of driving torque and load torque is established, and an iteration means is used to implement real-time measurement and calculation of the external load of the fin stabilizer, thereby laying an algorithmic foundation for fin stabilizer lift feedback control.

Description

A method, device and apparatus for detecting external load of a fin stabilizer Technical Field

[0001] The present invention relates to the technical field of fin stabilizers, and in particular to a method, device and equipment for detecting an external load of a fin stabilizer. Background Art

[0002] When a ship is subjected to strong external interference such as wind and wave disturbances during navigation, it will have a significant impact on the ship's posture, especially rolling motion, which will affect its seaworthiness. As the most widely used active anti-roll device to date, the effectiveness of the fin stabilizer has been verified on a variety of ship types. Therefore, the reliability evaluation results of the fin stabilizer are particularly important. Generally, the reliability of the fin stabilizer is evaluated by measuring the external loads on the fin during the ship's navigation through sensors. However, since the fin stabilizer is located outside the cabin and the marine environment is relatively harsh, the method of using sensors to directly measure the external load has problems such as poor sensor installation environment and high sensor range requirements, which makes it impossible to accurately measure the external load of the fin stabilizer.

[0003] Summary of the Invention

[0004] The present invention combines indirect measurement with an iterative algorithm, and can perform real-time external load measurement without adding additional sensors.

[0005] The present invention provides a method for detecting external load of a fin stabilizer, comprising: step 1, collecting t n The angular velocity of a single fin stabilizer at the moment ω(t n ), fluid angle of attack Inlet pressure of the hydraulic drive cylinder for driving a single fin stabilizer and outlet pressure 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 angle of attack Oil inlet pressure and outlet pressure The lift-drag resultant force and the fluid moment are solved by an iterative method, and the lift-drag resultant force and the fluid moment are the external loads detected on the fin stabilizer.

[0006] Furthermore, step 1 includes: collecting t via the fin angle transmitter n The fin angular velocity ω(t n ), and obtain the fin angle displayed on the fin angle transmitter as the fluid attack angle Obtain the oil inlet pressure through the pressure sensors at the inlet and outlet and outlet pressure

[0007] Furthermore, step 1 includes: collecting t via the fin angle transmitter n The fin angular velocity ω(t n ), and obtain the corresponding fin angle displayed on the fin angle transmitter Obtain the oil inlet pressure through the pressure sensors at the inlet and outlet and outlet pressure

[0008] Furthermore, the fluid torque coefficient function is:

[0009] Where M(α) is the fluid moment of the fin stabilizer calculated according to the fluid moment function, α represents any fluid angle of attack at any time, 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, constant, V 2 (t n ) is t n The square of the speed at the moment, V(t n ) It also represents the speed of the fin stabilizer relative to the water, which is collected by the sensor. A represents the fin stabilizer area, which is a constant, and b is the chord length of the fin stabilizer, which is a constant.

[0010] Furthermore, the fluid torque is calculated by the fluid torque function, which is expressed as: M(α)=M 油缸 (t n )-M f (α)-M α (t n )

[0011] Among them, M f (α) is the friction torque calculated based on the friction torque function, M α (t n ) is t n At this moment, the torque due to the moment of inertia is M 油缸 (t n ) is the cylinder output torque; where M 油缸 (t n )=P(t n )*S, pressure difference between the inlet and outlet of the cylinder S is the cylinder area, a constant.

[0012] Furthermore, the friction resistance is calculated by the friction resistance function, and the friction resistance torque function is expressed as: M f (α)=μDF(α)

[0013] Where μ is the comprehensive friction coefficient of the frictional resistance torque caused by the O-ring, bearing, etc., constant, D is the outer diameter of the O-ring and bearing, constant, and F(α) is the lift-drag resultant force calculated based on the lift-drag resultant force function.

[0014] 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:

[0015] Where ρ is the density of seawater, constant, V 2 (t n ) is the square of the ship speed at time tn, C(α) is the lift-drag coefficient of the fin stabilizer, which is obtained by fitting the fin test data and is an internal design parameter.

[0016] Furthermore, step 3 includes:

[0017] Step 31, for time tn, let α tn，1 As in t n Enter the value of the first iteration at time , then set x = 1 and execute step 32;

[0018] Step 32: Calculate the lift-drag resultant force according to the fluid torque coefficient function, the lift-drag resultant force function and the fluid torque function. Fluid torque and the fluid torque coefficient C m , based on the fitting data of the corresponding fin-type fluid test and C m The new corresponding fluid attack angle can be obtained

[0019] Step 33, judge With α tn，1 Is the absolute value of the difference less than 10? -5 If it is less than, then output At this time The fluid attack angle calculated in the first round at time tn is obtained, and the output is obtained The corresponding lift-drag resultant force and fluid torque are the external loads detected; otherwise, let x=x+1, and α tn，x As the input of the next loop, enter step 34 to continue the iterative operation;

[0020] Step 34, calculate the lift-drag resultant force according to the fluid torque coefficient function, the lift-drag resultant force function and the fluid torque function Fluid torque and the fluid torque coefficient C m , based on the fitting data of the corresponding fin-type fluid test and Cm The new corresponding fluid attack angle can be obtained

[0021] Step 35, judge With α tn，x Is the absolute value of the difference less than 10? -5 If it is less than, then output At this time The fluid attack angle calculated for the xth round at time tn is obtained, and the output fluid attack angle, the corresponding lift-drag resultant force, and the fluid torque are obtained. The obtained lift-drag resultant force and fluid torque are the detected external loads; otherwise, let x = x + 1, and α tn，x As the input of the next loop, enter step 34.

[0022] In a second aspect, an embodiment of the present invention further provides an external load detection device for a fin stabilizer, comprising: a first processing module for collecting t n The angular velocity of a single fin stabilizer at the moment ω(t n ), fluid angle of attack Inlet pressure of the hydraulic drive cylinder for driving a single fin stabilizer and outlet pressure The second processing module is used to construct a fluid torque coefficient function; the third processing module is used to construct a fluid torque coefficient function according to the fluid torque coefficient function and the fin angular velocity ω(t n ), fluid angle of attack Oil inlet pressure and outlet pressure The lift-drag resultant force and the fluid moment are solved by an iterative method, and the lift-drag resultant force and the fluid moment are the external loads detected on the fin stabilizer.

[0023] In a third aspect, an embodiment of the present invention further provides an electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the program, the steps of the external load detection method for a fin stabilizer as described in the first aspect are implemented.

[0024] In a fourth aspect, an embodiment of the present invention further provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the external load detection method for a fin stabilizer as described in the first aspect.

[0025] In a fifth aspect, an embodiment of the present invention further provides a computer program product having executable instructions stored thereon, which, when executed by a processor, causes the processor to implement the steps of the external load detection method for a fin stabilizer described in the first aspect.

[0026] The beneficial effects achieved by the present invention are as follows: by real-time acquisition of information on the fin angular velocity and the pressure difference of the swing cylinder of a certain type of fin stabilizer device driven by a swing cylinder, an identity between the driving torque and the load torque is established; by utilizing the actual measurement of the lift coefficient, the drag coefficient, and the torque coefficient in the fin-type fluid test, an iterative method is adopted to achieve real-time measurement of the external load of the fin stabilizer, thereby providing a means for improving the reliability measurement of the fin stabilizer and laying a foundation for the lift feedback control algorithm of the fin stabilizer. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] FIG1 is a schematic flow chart of a method for detecting an external load on a fin stabilizer according to the present invention;

[0028] FIG2 is a schematic diagram of the fluid attack angle α of a single fin stabilizer;

[0029] FIG3 is a schematic diagram of a single fin stabilizer.

[0030] Markings in Figure 3: 1: Fin angle transmitter, which can collect the angular velocity and angle of the rotating fin; 2: Cylinder, which is used to output torque; 3: Support seat; 4: Fin shaft, which transmits torque and connects the fin and the cylinder; 5: Fin, which is a component that is directly in the water and forms lift through the angle of attack with the incoming flow to reduce rolling. DETAILED DESCRIPTION

[0031] The technical solutions of the present invention are described in more detail below with reference to the accompanying drawings. The present invention includes but is not limited to the following embodiments.

[0032] The present invention mainly performs load detection on a single fin stabilizer. Referring to FIG1 , as shown in FIG1 , the external load detection method for a fin stabilizer includes the following steps:

[0033] Step 1: Collect t n The angular velocity of a single fin stabilizer at the moment ω(t n ), fluid angle of attack Inlet pressure of the hydraulic drive cylinder for driving a single fin stabilizer and outlet pressure

[0034] Specifically, the fin angle transmitter arranged behind the swing cylinder can be used to collect t n The fin angular velocity ω(t n ) and the corresponding fin angle displayed on the fin angle transmitter is the fluid attack angle The oil inlet pressure can be obtained by the pressure sensor arranged at the oil inlet and outlet of the swing cylinder Oil outlet pressure After subtraction, the pressure difference between the inlet and outlet of the cylinder at that moment is obtained

[0035] Step 2: Construct the fluid torque coefficient function.

[0036] Wherein, step 2 includes:

[0037] Step 21, constructing a lift-drag resultant force function, a friction resistance torque function, and a fluid torque function;

[0038] Step 22: constructing a fluid torque coefficient function according to the lift-drag resultant force function, the friction resistance torque function, and the fluid torque function.

[0039] The lift-drag resultant force F(α) can be calculated by the following formula:

[0040] Among them, the friction resistance torque M f (F)=M f (F(α))=M f (α) can be calculated by the following formula: M f (α)=μDF(α) Formula (2)

[0041] The fluid moment M(α) can be calculated by the following formula: M(α)=M 油缸 (t n )-M f (α)-M α (t n ) Formula (3)

[0042] The fluid torque coefficient can be calculated by the following formula:

[0043] In formula (1-4):

[0044] Both represent the angle of attack between the fin and the flowing water, is the quantity to be solved, and is the angle of attack between the fin and the flowing water at time tn;

[0045] t n represents the nth moment;

[0046] F(α): lift and drag force on the fin stabilizer, a quantity related to the fluid attack angle α;

[0047] ρ: seawater density, constant;

[0048] S is the area of ​​the oil cylinder, a constant;

[0049] The distance from the center of the L fin to the center of the large bearing is constant;

[0050] V(t n ):t n The ship's speed at the moment, which also represents the speed of the fin stabilizer relative to the water, is collected by sensors;

[0051] A: fin stabilizer area, constant;

[0052] C(α): The lift-drag coefficient is a fin parameter, typically obtained through hydrodynamic testing (by fitting fin test data). The lift coefficient is a function positively correlated with α. Within the operating angle of attack range of the fin stabilizer, it is generally considered linear and is an internal design parameter.

[0053] M f (F): Friction torque caused by O-rings, bearings, etc.

[0054] M f (α): Friction resistance torque caused by O-rings, bearings, etc.

[0055] μ: Comprehensive friction coefficient of friction resistance torque caused by O-rings, bearings, etc., constant;

[0056] D: O-ring, bearing outer diameter, constant;

[0057] M(α): The fluid moment on the fin stabilizer, usually a function of α, Since the high-order quantity has little influence on the final value, in order to simplify the calculation, it can be simplified to be only related to α;

[0058] M α (t n ):t n At the moment, the torque caused by the moment of inertia;

[0059] J: moment of inertia J of the minus fin and the fin axis with the fin axis center as the pure rotation center, constant;

[0060] t n At the moment, the derivative of the angular rotation of the fin stabilizer is collected by the sensor;

[0061] C m (α): Fin stabilizer moment coefficient, obtained by fitting fin test data, an internal design parameter

[0062] b: chord length of the fin stabilizer, constant;

[0063] P(t n ): According to the oil inlet pressure Oil outlet pressure The oil cylinder can obtain the inlet and outlet pressure difference P(t n ), according to the pressure difference between the inlet and outlet of the cylinder P(t n ) Determine the fluid torque coefficient C m Specifically, the oil inlet pressure Oil outlet pressure After subtraction, the pressure difference between the inlet and outlet of the cylinder at that moment is obtained in, Indicates t n At this moment, the oil inlet pressure of the oil cylinder is collected by the sensor; Indicates t n At this moment, the oil outlet pressure of the oil cylinder is collected by the sensor; S represents the area of ​​the oil cylinder, a constant; P(t n ) represents t n At this moment, the pressure difference between the inlet and outlet of the cylinder can be calculated by to obtain;

[0064] M 油缸 (t n ):M 油缸 (t n ) represents t n At this moment, the cylinder outputs torque. In an application scenario, t n At any fluid attack angle α (see Figure 2), the cylinder output torque M 油缸 (t n )=P(t n )*S; The external load torque is mainly composed of three parts, friction resistance torque M f (F), fluid torque Torque caused by moment of inertia

[0065] According to the above formula, C m The new corresponding C can be obtained by fitting the data of the corresponding fin-type fluid test (test parameters are internal design parameters and known quantities). m The fluid angle of attack α and the fluid torque coefficient function are linearly related to α, obtained by fitting test data obtained through wind tunnel and water tunnel tests. The fin stabilizer's fin profile, like an aircraft wing, uses a NACA airfoil. The lift, drag, and torque coefficients are typically calculated through wind tunnel and water tunnel tests. Since the test data is discrete and not globally linear, and the angle of attack used by the fin stabilizer is generally within ±30°, these discrete data appear linear. Therefore, it is necessary to fit the data to obtain a linear curve to determine the fluid angle of attack.

[0066] Step 3: According to the fluid torque coefficient function and the fin angular velocity ω(t n ), fluid angle of attack Oil inlet pressure and outlet pressure The lift-drag resultant force and the fluid moment are solved by an iterative method, and the lift-drag resultant force and the fluid moment are the external loads detected on the fin stabilizer.

[0067] Wherein, step 3 includes:

[0068] Step 31, for time tn, let α tn，1 As in t n Always keep going

[0069] Enter the value of the first iteration, then set x = 1 and execute step 32;

[0070] Step 32: Calculate the lift-drag resultant force according to the fluid torque coefficient function, the lift-drag resultant force function and the fluid torque function. Fluid torque and the fluid torque coefficient C m , based on the fitting data of the corresponding fin-type fluid test and C m The new corresponding fluid attack angle can be obtained

[0071] Step 33, judge With α tn，1 Is the absolute value of the difference less than 10? -5 If it is less than, then output At this time The fluid attack angle calculated in the first round at time tn is obtained, and the output is obtained The corresponding lift-drag resultant force and fluid torque are the external loads detected; otherwise, let x=x+1, and α tn，x As the input of the next loop, enter step 34 to continue the iterative operation;

[0072] Step 34, calculate the lift-drag resultant force according to the fluid torque coefficient function, the lift-drag resultant force function and the fluid torque function Fluid torque and the fluid torque coefficient C m , based on the fitting data of the corresponding fin-type fluid test and C m The new corresponding fluid attack angle can be obtained

[0073] Step 35, judge With α tn，x Is the absolute value of the difference less than 10? -5 If it is less than, then output At this time The fluid attack angle calculated for the xth round at time tn is obtained, and the output fluid attack angle, the corresponding lift-drag resultant force, and the fluid torque are obtained. The obtained lift-drag resultant force and fluid torque are the detected external loads; otherwise, let x = x + 1, and α tn，x As the input of the next loop, enter step 34.

[0074] Through the above steps, the lift-drag resultant force and fluid torque are solved by the iterative method based on the fluid torque coefficient function.

[0075] In one embodiment, the lift-drag resultant force is solved by an iterative method. Fluid torque The process is:

[0076] 1) For a certain time t n ;

[0077] Count: Let α tn，x , x represents the number of iterations, and α tn，x As the input of this loop, is the collected fin angle, which serves as the input of the first cycle;

[0078] The lift and drag force can be obtained:

[0079] 2) Calculate the friction resistance torque: M f (α tn，x )=μDF(α tn，x );

[0080] Calculate fluid moment: M(α tn，x )=M 油缸 (t n )-M f (α tn，x )-M α (t n )

[0081] Calculate the fluid moment coefficient:

[0082] 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 as

[0083] 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 water in the external flow field. Otherwise, let x = x + 1, Re-enter step 1) to calculate the lift-drag resultant force and continue the iterative operation. Record the data in the last step of the operation and obtain The corresponding lift-drag force is: Fluid torque This is the external load.

[0084] Based on the above method, the present invention designs a fin stabilizer. As shown in Figure 3, No. 1 is a fin angle transmitter, and the built-in sensor can collect t n The fin angular velocity ω(t n ) and 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 pressure difference P(t n ); Serial number 3 is a support seat, which contains a bearing group and a seal; Serial number 4 is a fin shaft, which is used to transmit the torque from the swing cylinder to the fin, and at the same time transmit the lift-drag force on the fin to the support seat; Serial number 5 is the fin, which bears the external fluid load, including the lift-drag force F and the fluid torque M. As can be seen from Figure 3, the present invention can still be used to detect the fin without any modification. Existing domestic and foreign patents require the modification of the mechanical structure and the addition of sensors on the fin stabilizer device to detect the external load. This method can detect external loads with the help of existing and necessary sensors and structures, creating economic benefits and reducing costs.

[0085] According to the structural schematic diagrams of some embodiments of the external load detection device for fin stabilizers 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 fin stabilizers. These device embodiments correspond to some embodiments of the method shown in Figure 1, and the device can be applied to various electronic devices.

[0086] The external load detection device of the fin stabilizer includes a first processing module, a second processing module, and a third processing module: the first processing module is used to collect t n The angular velocity of a single fin stabilizer at the moment ω(t n ), fluid angle of attack Inlet pressure of the hydraulic drive cylinder for driving a single fin stabilizer and outlet pressure The second processing module is used to construct a fluid torque coefficient function; the third processing module is used to construct a fluid torque coefficient function according to the fluid torque coefficient function and the fin angular velocity ω(t n ), fluid angle of attack Oil inlet pressure and outlet pressure The lift-drag resultant force and the fluid moment are solved by an iterative method, and the lift-drag resultant force and the fluid moment are the external loads detected on the fin stabilizer.

[0087] In an optional implementation of some embodiments, the first processing module is used to: collect t n The fin angular velocity ω(t n ), and obtain the fin angle displayed on the fin angle transmitter as the fluid attack angle Obtain the oil inlet pressure through the pressure sensors at the inlet and outlet and outlet pressure

[0088] In an optional implementation of some embodiments, the first processing module is used to: collect t n The fin angular velocity ω(t n ), and obtain the corresponding fin angle displayed on the fin angle transmitter Obtain the oil inlet pressure through the pressure sensors at the inlet and outlet and outlet pressure

[0089] In an optional implementation of some embodiments, the fluid torque coefficient function is:

[0090] Where M(α) is the fluid moment of the fin stabilizer calculated according to the fluid moment function, α represents any fluid angle of attack at any time, 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, constant, V 2 (t n ) is t n The square of the speed at the moment, V(t n ) It also represents the speed of the fin stabilizer relative to the water, which is collected by the sensor. A represents the fin stabilizer area, which is a constant, and b is the chord length of the fin stabilizer, which is a constant.

[0091] In an optional implementation of some embodiments, the fluid torque is calculated by a fluid torque function, which is expressed as: M(α)=M 油缸 (t n )-M f (α)-M α (t n )

[0092] Among them, M f (α) is the friction torque calculated based on the friction torque function, M α (t n ) is t n At this moment, the torque due to the moment of inertia is M油缸 (t n ) is the cylinder output torque; where M 油缸 (t n )=P(t n )*S, pressure difference between the inlet and outlet of the cylinder S is the cylinder area, a constant.

[0093] In an optional implementation of some embodiments, the friction resistance is calculated by a friction resistance function, and the friction resistance torque function is expressed as: f (α)=μDF(α)

[0094] Where μ is the comprehensive friction coefficient of the frictional resistance torque caused by the O-ring, bearing, etc., constant, D is the outer diameter of the O-ring and bearing, constant, and F(α) is the lift-drag resultant force calculated based on the lift-drag resultant force function.

[0095] In an optional implementation of some embodiments, the lift-drag resultant force may be obtained by lift-drag resultant force calculation, and the lift-drag resultant force function is expressed as:

[0096] Where ρ is the density of seawater, constant, V 2 (t n ) is the square of the ship speed at time tn, C(α) is the lift-drag coefficient of the fin stabilizer, which is obtained by fitting the fin test data and is an internal design parameter.

[0097] In an optional implementation of some embodiments, the third processing module is configured to:

[0098] For time tn, let α tn，1 As in t n Enter the value of the first iteration at time , then set x = 1 and execute step 32;

[0099] The lift-drag resultant force is calculated in turn according to the fluid torque coefficient function, the lift-drag resultant force function and the fluid torque function. Fluid torque and the fluid torque coefficient C m , based on the fitting data of the corresponding fin-type fluid test and C m The new corresponding fluid attack angle can be obtained

[0100] judge With α tn，1 Is the absolute value of the difference less than 10? -5 If it is less than, then output At this time The fluid attack angle calculated in the first round at time tn is obtained, and the output is obtained The corresponding lift-drag resultant force and fluid torque are the external loads detected; otherwise, let x=x+1, and α tn，x As the input of the next loop, enter step 34 to continue the iterative operation;

[0101] The lift-drag resultant force is calculated in turn according to the fluid torque coefficient function, the lift-drag resultant force function and the fluid torque function. Fluid torque and the fluid torque coefficient C m , based on the fitting data of the corresponding fin-type fluid test and C m The new corresponding fluid attack angle can be obtained

[0102] judge With α tn，x Is the absolute value of the difference less than 10? -5 If it is less than, then output At this time The fluid attack angle calculated for the xth round at time tn is obtained, and the output fluid attack angle, the corresponding lift-drag resultant force, and the fluid torque are obtained. The obtained lift-drag resultant force and fluid torque are the detected external loads; otherwise, let x = x + 1, and α tn，x As the input of the next loop, enter step 34.

[0103] It is understandable that the modules described in the device correspond to the steps in the method described with reference to Figure 1. Therefore, the operations, features and beneficial effects described above for the method are also applicable to the device and the modules and units contained therein, and will not be repeated here.

[0104] On the other hand, the present invention also provides a computer program product, which includes a computer program stored on a non-transitory computer-readable storage medium. The computer program includes program instructions. When the program instructions are executed by a computer, the computer can execute the external load detection methods for stabilizer fins provided by the above methods.

[0105] In yet another aspect, the present invention further provides a non-transitory computer-readable storage medium having a computer program stored thereon, which is configured to execute the above-mentioned external load detection methods for fin stabilizers when executed by a processor.

[0106] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, i.e., they may be located in one location or distributed across multiple network units. Some or all of the modules may be selected based on actual needs to achieve the objectives of the present embodiment. Persons of ordinary skill in the art will be able to understand and implement the present invention without inventive effort.

[0107] 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 the necessary general hardware platform, or of course, by hardware. Based on this understanding, the essence of the above technical solution or the part that contributes to the existing technology 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, a magnetic disk, an optical disk, etc., and includes a number of instructions for enabling a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the above methods of each embodiment or certain parts of the embodiments.

[0108] [Corrected on 10.08.2023 according to Rule 91] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A method for detecting external load of a fin stabilizer, characterized in that: The method comprises: Step 1: Collect t n The angular velocity of a single fin stabilizer at the moment ω(t n ), fluid angle of attack Inlet pressure of the hydraulic drive cylinder for driving a single fin stabilizer and outlet pressure Step 2, constructing a fluid moment coefficient function; Step 3: According to the fluid torque coefficient function and the fin angular velocity ω(t n ), fluid angle of attack Oil inlet pressure and outlet pressure The lift-drag resultant force and the fluid moment are solved by an iterative method, and the lift-drag resultant force and the fluid moment are external loads detected on the fin stabilizer.

2. The external load detection method for fin stabilizers according to claim 1, characterized in that: Step 1 includes: collecting t through the fin angle transmitter n The angular velocity of the fin at the moment ω(t n ), and obtain the fin angle displayed on the fin angle transmitter as the fluid attack angle Obtain the oil inlet pressure through the pressure sensors at the oil inlet and outlet and outlet pressure 3. The external load detection method for fin stabilizers according to claim 1, characterized in that: Step 2 includes: Step 21, constructing lift-drag force function, friction resistance torque function and fluid torque function; Step 22: construct a fluid torque coefficient function according to the lift-drag force function, the friction resistance torque function and the fluid torque function.

4. The external load detection method for fin stabilizers according to claim 3, characterized in that: The fluid torque coefficient function is: Where M(α) is the fluid moment of the fin stabilizer calculated according to the fluid moment function, α represents any fluid angle of attack at any time, 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, is a constant, and V 2 (t n ) is t n The square of the speed at the time, V(t n ) also represents the speed of the fin stabilizer relative to the water, which is collected by the sensor. A represents the fin area, which is a constant, and b is the chord length of the fin stabilizer, which is a constant.

5. The external load detection method for fin stabilizers according to claim 3, characterized in that: The fluid 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 friction torque of a single fin stabilizer calculated according to the friction torque function, M α (t n ) is t n At this moment, the torque caused by the moment of inertia is M 油缸 (t n ) is the cylinder output torque; where M 油缸 (t n )=P(t n )*S, pressure difference between inlet and outlet of oil cylinder S is the cylinder area, which is a constant.

6. The external load detection method for fin stabilizers according to claim 5, characterized in that: The friction torque function is expressed as: M f (α)=μDF(α) Among them, μ is the comprehensive friction coefficient of the friction resistance torque caused by the O-ring, bearing, 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.

7. The external load detection method for fin stabilizers according to claim 6, characterized in that: The lift-drag force function is expressed as: Where ρ is the density of seawater, constant, V 2 (t n ) is the square of the ship speed at time tn, C(α) is the lift-drag coefficient of the fin stabilizer, which is obtained by fitting the fin test data and is an internal design parameter.

8. A method for detecting external load of a fin stabilizer according to any one of claims 4 to 7, characterized in that: Step 3 includes: Step 31, for time tn, let α tn，1 As in t n Enter the value of the first iteration at time, then set x=1 and execute step 32; Step 32, 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 torque and fluid moment coefficient C m , 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 Step 33, determine With α tn，1 Is the absolute value of the difference less than 10? -5 If it is less than, then output At this time The fluid attack angle calculated in the first round at time tn is obtained as output. The corresponding lift-drag resultant force and fluid moment are the external loads detected; otherwise, let x=x+1, α tn，x As the input of the next loop, enter step 34 to continue iterative operation; 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 torque and fluid moment coefficient C m , 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 Step 35, determine With α tn，x Is the absolute value of the difference less than 10? -5 If it is less than, then output At this time is the fluid attack angle calculated for the xth round at time tn, and the output fluid attack angle, the corresponding lift-drag resultant force, and fluid torque are obtained. The obtained lift-drag resultant force and fluid torque are the detected external loads; otherwise, let x = x + 1, and α tn，x As the input of the next loop, enter step 34.

9. An external load detection device for a fin stabilizer, characterized in that: include: The first processing module is used to collect t n The angular velocity of a single fin stabilizer at the moment ω(t n ), fluid angle of attack Inlet pressure of the hydraulic drive cylinder for driving a single fin stabilizer and outlet pressure A second processing module is used to construct a fluid moment coefficient function; The third processing module is used to process the fin angular velocity ω(t n ), fluid angle of attack Oil inlet pressure and outlet pressure The lift-drag resultant force and the fluid moment are solved by an iterative method, and the lift-drag resultant force and the fluid moment are external loads detected on the fin stabilizer.

10. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein: When the processor executes the program, the external load detection method for the fin stabilizer according to any one of claims 1 to 8 is implemented.

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