Water surface wake test method for underwater vehicle model

Abstract

A water surface wake test method for an underwater vehicle model is characterized in that the model is connected with a trailer above a test pool through a first thin cable, a second thin cable, a third thin cable and a fourth thin cable so as to transmit traction force, and the test method comprises the following steps: debugging in a static state, enabling the model to be immersed in water, and enabling a heeling angle, a trim angle and a drift angle to be zero in the static state; the model moves in water, the heeling angle, the trim angle and the drift angle of the model during movement are detected, and the displacement of the model relative to the trailer is detected; when the heeling angle, the trim angle and the drift angle of the model moving in water and the displacement of the model relative to the trailer are all zero, a water surface wake test can be carried out, when the heeling angle, the trim angle and the drift angle are not zero, the positions of tying points of the first thin cable, the second thin cable, the third thin cable and the fourth thin cable on the trailer are adjusted through a pre-bias method, and then motion state detection is carried out again. Therefore, the moving posture of the underwater vehicle model is guaranteed, the influence of a traditional dragging mechanism on the water surface wake of the underwater vehicle is avoided, and the accuracy of water surface wake test measurement is improved.

Description

Technical Field

[0001] The invention relates to the technical field of ship and ocean engineering, in particular to a water surface wake test method for an underwater vehicle model. Background Art

[0002] Underwater vehicles generate internal waves, surface waves, turbulence, vortices and other wakes during their submerged motion. At a certain diving depth and speed, microwaves, visible light, infrared and other means can be used to detect the surface wake characteristics. With the continuous improvement of vibration reduction and noise reduction technology, the difficulty of noise detection for underwater vehicles is increasing. By using the surface wake characteristics of underwater vehicles, the position, speed and direction of underwater vehicles can be detected, judged and identified, and the target detection of underwater vehicles can be achieved. It is very necessary to study the surface wake characteristics of underwater vehicles from the perspective of wake detection and stealth, and model test research is an indispensable and important means. The installation and towing motion of the underwater vehicle wake test model are important links in the model test.

[0003] In traditional hydrodynamic tests of underwater vehicles, one or two vertical swords are usually used to connect and fix the model. However, in this installation method, the vertical sword is above the model, and the wake generated by the movement of the sword, especially the surface wake of the sword, directly interferes with the surface wake of the underwater vehicle model, which has an adverse effect on the experimental research on the surface wake characteristics of the underwater vehicle. Summary of the invention

[0004] In view of the shortcomings in the above-mentioned existing production technology, the applicant provides a method for testing the water surface wake of an underwater vehicle model, thereby ensuring the movement posture of the underwater vehicle model, avoiding the influence of the traditional towing mechanism on the water surface wake of the underwater vehicle, and improving the accuracy of the water surface wake test measurement.

[0005] The technical solution adopted by the present invention is as follows:

[0006] A method for testing the surface wake of an underwater vehicle model.

[0007] The model is connected to a trailer above the test pool by a first thin cable, a second thin cable, a third thin cable and a fourth thin cable to transmit traction, the first thin cable and the second thin cable are respectively connected to both sides of the front end of the model, the third thin cable and the fourth thin cable are respectively connected to both sides of the rear end of the model, and the first thin cable and the third thin cable are located on the same side of the model;

[0008] The test method comprises the following steps:

[0009] Static state debugging: when the model is immersed in water and in a static state, the heel angle, pitch angle and drift angle of the model are all zero;

[0010] Motion state detection: starting the trailer, causing the model to move in the water under the traction of the first thin cable, the second thin cable, the third thin cable and the fourth thin cable, detecting the heel angle, the pitch angle and the drift angle of the model during movement, and detecting the displacement of the model relative to the trailer;

[0011] Motion state judgment: When the heel angle, pitch angle and drift angle of the model moving in the water and the displacement of the model relative to the trailer are all zero, a water surface wake test can be carried out.

[0012] When any one or more of the heel angle, the pitch angle and the drift angle of the model when it moves in the water and the displacement of the model relative to the trailer are not zero, performing motion state detection again after pre-biasing the anchor point;

[0013] Pre-biasing of the tie points: adjusting the positions of the tie points of the first thin cable, the second thin cable, the third thin cable and the fourth thin cable on the trailer by the pre-biasing method.

[0014] The cyclic iterative process of motion state detection, motion state judgment and tie point pre-biasing is carried out when the trailer tows the model to move.

[0015] Establishing a traveling coordinate system fixed relative to the trailer;

[0016] In the motion state detection step, the heel angle, pitch angle, and drift angle of the detected model during motion are θ xop ,θ yop and θ zop ;

[0017] θ xop >0 means the model rotates counterclockwise around the axis.

[0018] θ yop >0 means the head of the model is raised.

[0019] θ zop >0 means that the head swing direction of the model is toward the positive direction of the y-axis;

[0020] The overall displacement of the model relative to the trailer is Δ xop , Δ yop , Δ zop ;

[0021] Δ xop >0 means the moving direction is the same as the positive direction of the x-axis.

[0022] Δ yop >0 means the moving direction is the same as the positive direction of the y-axis.

[0023] Δ zop >0 means the moving direction is the same as the positive direction of the z-axis.

[0024] The tie point pre-biasing method includes the following steps:

[0025] When the static debugging step is completed, the first thin cable, the second thin cable, the third thin cable and the fourth thin cable are tied to the point A on the trailer. 1s , A 2s , A 3s , A 4s The coordinates are represented by A is (x is ,y is , z is ), where i = 1, 2, 3, 4;

[0026] The static posture parameters of the tie points on the model 5 in the static state are obtained. The static posture parameters include:

[0027] The heel motion radius R of the four tie points Bix , R Bix Angle θ with the horizontal plane Bix ,

[0028] The radius of pitch motion R of the four tie points Biy , R Biy Angle θ with the horizontal plane Biy ,

[0029] Yaw motion radius R of the four tie points Biz , R Biz Angle θ with the vertical plane Biz ,

[0030] Wherein, i = 1, 2, 3, 4;

[0031] According to the detection data in the motion state detection step, θ xop ,θ yop ,θ zop and Δ xop , Δ yop , Δ zop Calculate the offset of the model tie points and obtain the pre-biased coordinates A of the four tie points in (x in ,y in , z in ).

[0032] Pre-biased coordinates A of the tie point in (x in ,y in , z in )middle,

[0033] x in =x is -Δ xop -(R Biy×θ yop )×sinθ Biy -(R Biz ×θ zop )×sinθ Biz i=1,2,3,4

[0034] y in =y is -Δ yop +(R Bix ×θ xop )×sinθ Bix -(R Biz ×θ zop )×cosθ Biz i=1,2

[0035] y in =y is -Δ yop +(R Bix ×θ xop )×sinθ Bix +(R Biz ×θ zop )×cosθ Biz i=3,4

[0036] z in =z is -Δ zop +(R Bix ×θ xop )×cosθ Bix -(R Biy ×θ yop )×cosθ Biy i=1

[0037] z in =z is -Δ zop -(R Bix ×θ xop )×cosθ Bix -(R Biy ×θ yop )×cosθ Biy i=2

[0038] z in =z is -Δ zop +(R Bix ×θ xop )×cosθ Bix +(R Biy ×θ yop )×cosθ Biy i=3

[0039] zin =z is -Δ zop -(R Bix ×θ xop )×cosθ Bix +(R Biy ×θ yop )×cosθ Biy i=4

[0040] In the above formula, θ xop ,θ yop ,θ zop The unit is radians.

[0041] The x-axis of the accompanying coordinate system is parallel to the axis of the model in the static state, and the positive direction of the x-axis is opposite to the navigation direction.

[0042] The y-axis of the accompanying coordinate system is perpendicular to the axis of the static model and is located in the same horizontal plane as the x-axis. The positive direction of the y-axis is toward the right side of the navigation direction.

[0043] The positive direction of the z-axis of the accompanying coordinate system points vertically upward.

[0044] The model is in a negative buoyancy state in water, and a ballast is provided in the model to ensure the net weight of the model in water, so that the first thin cable, the second thin cable, the third thin cable, and the fourth thin cable are in a tensioned state when conducting a water surface wake test.

[0045] The model is provided with a posture sensor for detecting the roll angle, pitch angle and drift angle of the model, and also includes a model position detection system for detecting the displacement of the model relative to the trailer.

[0046] The model position detection system includes a visual sensor fixedly mounted on the trailer, and feature points are arranged on the upper surface of the model. The visual sensor identifies the positions of the feature points and calculates the horizontal displacement of the model relative to the trailer. The system also includes a first water pressure sensor mounted on the bow of the model and a second water pressure sensor mounted on the tail of the model. The vertical displacement of the model is obtained by calculating the pressure change.

[0047] The trailer is equipped with four sets of moving mechanisms, corresponding to the first thin cable, the second thin cable, the third thin cable and the fourth thin cable respectively;

[0048] The single-group moving mechanism includes a vertical moving module fixedly mounted on the body of the trailer, the moving end of the vertical moving module is installed with a lifting base plate, the lifting base plate is provided with a lateral moving module and a longitudinal moving module, the moving end of the lateral moving module is installed with the longitudinal moving module, the moving end of the longitudinal moving module is installed with a lifting point base plate, the lifting point base plate is provided with a trailer tie point, and the trailer tie point is used to connect the model.

[0049] The beneficial effects of the present invention are as follows:

[0050] The invention has a compact and reasonable structure and is easy to operate. By adopting four thin cables to connect the model with the trailer from the front, back, left and right respectively, the interference of the traditional sword body fixed above the model and dragging the model to the underwater wake and the water surface wake of the model is greatly reduced. Before the model is subjected to the water surface wake test, it is ensured that the posture of the model is stable after being subjected to the hydrodynamic force, and the position of the thin cable fastening point on the trailer can be adjusted and corrected, thereby ensuring the movement posture of the underwater vehicle model, avoiding the influence of the traditional towing mechanism on the water surface wake of the underwater vehicle, and improving the accuracy of the water surface wake test measurement.

[0051] At the same time, the present invention also has the following advantages:

[0052] The servo drives on the lateral moving module, longitudinal moving module and vertical moving module record the position of each thin cable hanging point and transmit the position to the measurement and control computer. The measurement and control computer controls the lateral moving module, longitudinal moving module and vertical moving module according to the calculated pre-biased coordinates, thereby changing the position of the tie point on the trailer, thereby achieving fast and precise adjustment of the pre-bias of the tie points of the first thin cable, the second thin cable, the third thin cable and the fourth thin cable on the trailer. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] Figure 1 It is a structural schematic diagram (front view) of the present invention.

[0054] Figure 2 It is a schematic structural diagram (top view) of the present invention.

[0055] Figure 3 It is a schematic diagram of the model lifting process of the present invention.

[0056] Figure 4 It is a stereogram of the model of the present invention.

[0057] Figure 5 The figure is a schematic diagram of the posture of the model of the present invention when performing heeling motion.

[0058] Figure 6 The figure is a schematic diagram of the posture of the model of the present invention performing longitudinal tilting motion.

[0059] Figure 7The figure is a schematic diagram of the posture of the model of the present invention performing yaw motion.

[0060] Figure 8 It is a structural schematic diagram of a single group of moving mechanisms of the present invention.

[0061] Fig. 9 It is a schematic structural diagram of the vertical moving module of the present invention.

[0062] in:

[0063] 1. First thin cable; 2. Second thin cable; 3. Third thin cable; 4. Fourth thin cable; 5. Model; 6. Ballast;

[0064] 71. First water pressure sensor; 72. Second water pressure sensor; 8. Posture sensor; 9. Measurement and control line;

[0065] 101, hanging rope; 102, tension sensor; 11, feature point; 12, visual sensor;

[0066] 13. Vertical moving module; 131. Electric cylinder; 132. Guide rod; 133. Organ cover;

[0067] 14. Hoisting base plate; 15. Lateral moving module; 151. First rack; 152. First guide rail; 153. First servo motor;

[0068] 16. longitudinal moving module; 161. second rack; 162. second guide rail; 163. second servo motor;

[0069] 17. Suspension point base plate; 18. Machine body. DETAILED DESCRIPTION

[0070] The specific implementation of the present invention will be described below in conjunction with the accompanying drawings.

[0071] Embodiment 1:

[0072] In the underwater vehicle model water surface wake test method of this embodiment, the connection structure between the model 5 and the trailer is as follows: Figure 1 , Figure 2 As shown, the model 5 is connected to the trailer above the test pool by the first thin cable 1, the second thin cable 2, the third thin cable 3 and the fourth thin cable 4 to transmit the traction force. The first thin cable 1 and the second thin cable 2 are respectively connected to the two sides of the front end of the model 5, the third thin cable 3 and the fourth thin cable 4 are respectively connected to the two sides of the rear end of the model 5, and the first thin cable 1 and the third thin cable 3 are located on the same side of the model 5;

[0073] The underwater vehicle model water surface wake test method of this embodiment comprises the following steps:

[0074] Static state debugging: when the model 5 is immersed in water and in a static state, the heel angle, pitch angle and drift angle of the model 5 are all zero;

[0075] Motion state detection: start the trailer, and the model 5 moves in the water under the traction of the first thin cable 1, the second thin cable 2, the third thin cable 3 and the fourth thin cable 4, and detect the heel angle, pitch angle and drift angle of the model 5 during movement, and detect the displacement of the model 5 relative to the trailer;

[0076] Motion state judgment: when the heel angle, pitch angle and drift angle of the model 5 moving in the water and the displacement of the model 5 relative to the trailer are all zero, the water surface wake test can be carried out; when any one or more of the heel angle, pitch angle and drift angle of the model 5 moving in the water and the displacement of the model 5 relative to the trailer are not zero, the motion state detection is carried out again after the anchor point pre-biasing;

[0077] Pre-biasing of the tie points: The positions of the tie points of the first thin cable 1, the second thin cable 2, the third thin cable 3 and the fourth thin cable 4 on the trailer are adjusted by the pre-biasing method.

[0078] One end of each thin cable is connected to the trailer, and the other end is fixedly connected to the underwater model 5. The distance (width) between the intersection of the front and rear sets of thin cables and the water surface is greater than the width of the wake area of ​​the underwater vehicle. The four thin cables are tied to the model at the front, back, left and right of the model 5. When the trailer moves, the four thin cables pull the model 5 forward together. Figure 1 , Figure 2 As shown, each adjacent thin cable of the first thin cable 1, the second thin cable 2, the third thin cable 3 and the fourth thin cable 4 is in an inverted figure eight shape, and the four thin cables are radially arranged from bottom to top.

[0079] The first thin cable 1, the second thin cable 2, the third thin cable 3 and the fourth thin cable 4 are made of cables with a larger elastic coefficient and a smaller diameter to reduce the disturbance of the thin cable to the water surface and reduce the tension deformation of the thin cable.

[0080] For the streamlined slender body model 5, the hydrodynamic force it receives when it moves at a uniform speed underwater is relatively stable. During the water surface wake test of the underwater vehicle model, under the hydrodynamic conditions, it can be approximately considered that the heel angle, pitch angle and drift angle of the model 5 remain unchanged during the movement. The hydrodynamic force is generated by the relative uniform motion of the model 5 and the water.

[0081] Under the action of hydrodynamic force, if the posture of model 5 changes, the displacement and posture of model 5 are corrected from the displacement angle of the four thin cable tie points, that is, the tie point pre-bias. Specifically, the attitude angle and position of model 5 are preset by the displacement of the tie points of each thin cable on the trailer to offset the position offset and angle deflection of model 5 caused by hydrodynamic interference when model 5 moves.

[0082] Four thin cables are used to connect the model 5 with the trailer from the front, back, left and right respectively, which greatly reduces the interference of the traditional sword body fixed above the model 5 and dragging the model 5 to the underwater wake and water surface wake of the model. Before the model 5 is subjected to the water surface wake test, it is ensured that the posture of the model 5 is stable after being subjected to the hydrodynamic force, and the position of the thin cable fastening point on the trailer can be adjusted to correct the deviation, thereby ensuring the movement posture of the underwater vehicle model, avoiding the influence of the traditional towing mechanism on the water surface wake of the underwater vehicle, and improving the accuracy of the water surface wake test measurement.

[0083] In a specific embodiment, when any one or more of the heel angle, pitch angle and drift angle of the model 5 when moving in the water and the displacement of the model 5 relative to the trailer are not zero, before the pre-biasing of the tie point, the trailer is stopped and the position of the tie point is adjusted, and then the motion state detection and motion state judgment are performed again.

[0084] In another specific embodiment, in the above test method, the iterative process of motion state detection, motion state judgment and pre-biasing of the tie point is performed during the process of the trailer towing the model 5. The test efficiency is improved by synchronous adjustment with the movement of the trailer in the water. The motion state detection, motion state judgment and pre-biasing of the tie point are iterated until the heel angle, pitch angle, drift angle and displacement of the model 5 relative to the trailer are zero when the model 5 moves in the water, and then the iterative cycle is stopped.

[0085] like Figure 5 As shown, if the heel angle θ xop >0, that is, when the trailer moves at a constant speed, the model 5 tilts counterclockwise. To this end, when the trailer is stationary, the first thin cable 1 and the third thin cable 3 are simultaneously moved rightward and upward to the trailer tie point A. 1s , A 3s , and at the same time move the trailer tie point A of the second thin cable 2 and the fourth thin cable 4 downward to the right 2s , A 4s , so that the trailer is stationary θ xop <0 to compensate for the heeling of the model 5 caused by the hydrodynamic force when the trailer moves.

[0086] like Figure 6 As shown, if the pitch angle θ yop >0, that is, when the trailer moves at a constant speed, the model 5 is tilted forward (head high and tail low), then when the trailer is stationary, the first thin cable 1 and the second thin cable 2 trailer tie point A are lowered simultaneously 1s , A 2s At the same time, the towing tie point A of the third thin cable 3 and the fourth thin cable 4 is increased. 3s , A 4s height, achieving the preset pitch angle θ yop <0 to compensate for the bow tilt caused by the hydrodynamic force on the model 5 when the trailer moves.

[0087] like Figure 7 As shown, if the drift angle θ zop >0, that is, when the trailer moves at a constant speed, the model 5 deflects clockwise in the horizontal plane. To this end, when the trailer is stationary, the first thin cable 1 and the second thin cable 2 trailer tie point A are moved counterclockwise at the same time. 1s , A 2s , and at the same time move the trailer tie point A of the third thin cable 3 and the fourth thin cable 4 counterclockwise 3s , A 4s , so that the trailer is stationary θ zop <0 to compensate for the drift angle caused by the hydrodynamic force on the model when the trailer moves.

[0088] The heel angle, pitch angle and drift angle of the detected model 5 during motion are θ xop ,θ yop and θ zop , the overall displacement of model 5 relative to the trailer is Δ xop , Δ yop , Δ zop The point B on the model 5 can be calculated based on the size and direction of the above detection parameters 1s , B 2s , B 3s , B 4s The position changes, such as Figure 5-Figure 6 As shown, a simplified calculation is performed, provided that the attitude angle θ xop ,θ yop and θ zop The value is small (generally less than or equal to 10°).

[0089] Taking the heeling motion of model 5 as an example, the position of the tie point of model 5 when it is stationary is B 1s , the position of the tie point after the movement is B 1p , the tie point position after reverse pre-bias is B 1n , B 1s C 1x and B 1n C 1x The angle between 1s Move to B 1p The heel angle θ at position xop Equal, B 1n With B 1s The distance between them is approximately the heel angle θ xop The corresponding arc length is Figure 5 Middle triangle ΔB 1s C 1x B 1n Simplified calculation is performed in and RTΔOB is obtained 1s B 1n The two right-angled sides OB 1s and OB 1n Length.

[0090] like Figure 1-Figure 2 As shown, the model 5 is in a negative buoyancy state in the water, and a ballast 6 is provided in the model 5 to ensure the net weight of the model 5 in the water, so that the first thin cable 1, the second thin cable 2, the third thin cable 3, and the fourth thin cable 4 are in a tensioned state when conducting a water surface wake test.

[0091] Model 5 maintains a certain net weight, and the four thin cables bear the net weight of model 5 in static state, and maintain a certain tension reserve to overcome the hydrodynamic interference during the movement of model 5. In static state, through the allocation of the gravity G and buoyancy B of model 5, the residual gravity ΔG=GB>0, and ΔG / G is not less than a certain ratio, that is, the gravity of model 5 is greater than the buoyancy and a certain margin is maintained. By adjusting the position of ballast 6, the center of gravity and the center of buoyancy of model 5 are both in the middle longitudinal section, and the height of the center of gravity is lower than the center of buoyancy.

[0092] like Figure 1-Figure 2 As shown, the model 5 is provided with a posture sensor 8 for detecting the roll angle, pitch angle and drift angle of the model 5 . The model position detection system is also included for detecting the displacement of the model 5 relative to the trailer.

[0093] The attitude sensor 8 and the model position detection system are connected to the measurement and control computer on the trailer through the measurement and control line 9, and the measurement and control line 9 is fixed on the thin cable. The attitude sensor 8 and the model position detection system are located inside the model 5 to sense the model position and attitude information such as the diving depth, pitch angle, drift angle, and heel angle of the model 5 in real time. The measurement and control line 9 is led out from the inside of the model 5 along the thin cable to the measurement and control computer on the trailer to transmit electrical signals.

[0094] Furthermore, the model position detection system includes a visual sensor 12 fixedly mounted on the trailer. Feature points 11 are provided on the upper surface of the model 5. The visual sensor 12 identifies the position of the feature points 11, and then calculates the horizontal displacement of the model 5 relative to the trailer. It also includes a first water pressure sensor 71 installed at the bow of the model 5 and a second water pressure sensor 72 installed at the tail of the model 5. The vertical displacement of the model 5, that is, the change in diving depth, is calculated through the pressure change.

[0095] The first water pressure sensor 71 and the second water pressure sensor 72 are installed on the model 5 , which is also convenient for detecting the immersion depth of the model 5 and facilitating the installation and debugging of the model 5 .

[0096] Embodiment 2:

[0097] In order to quickly obtain the tie point and offset adjustment amount on the trailer, based on the first embodiment:

[0098] The underwater vehicle model water surface wake test method of this embodiment comprises the following steps:

[0099] Step 1, static state debugging: When the model 5 is immersed in water and in a static state, the heel angle, pitch angle and drift angle of the model 5 are all zero;

[0100] Step 2: Establish a fixed accompanying coordinate system relative to the trailer. Specifically:

[0101] The x-axis of the accompanying coordinate system is parallel to the axis centerline of the static model 5, and the positive direction of the x-axis is opposite to the navigation direction.

[0102] The y-axis of the accompanying coordinate system is perpendicular to the axis of the stationary model 5 and is located in the same horizontal plane as the x-axis. The positive direction of the y-axis is toward the right side of the navigation direction.

[0103] The positive direction of the z-axis of the accompanying coordinate system points vertically upward.

[0104] Step 3, motion state detection: start the trailer, and the model 5 moves at a constant speed in the water under the traction of the first thin cable 1, the second thin cable 2, the third thin cable 3 and the fourth thin cable 4, and detect the heel angle, pitch angle and drift angle of the model 5 during movement, and detect the displacement of the model 5 relative to the trailer;

[0105] In the motion state detection step, the heel angle, pitch angle, and drift angle of the detected model 5 during motion are θ xop ,θ yop and θ zop ;

[0106] θ xop >0 means that the model 5 rotates counterclockwise around the axis.

[0107] θ yop >0 means the head of model 5 is raised.

[0108] θ zop >0 means that the head swing direction of model 5 is toward the positive direction of the y-axis;

[0109] The overall displacement of model 5 relative to the trailer is Δ xop , Δ yop , Δ zop ;

[0110] Δ xop >0 means the moving direction is the same as the positive direction of the x-axis.

[0111] Δ yop >0 means the moving direction is the same as the positive direction of the y-axis.

[0112] Δ zop >0 means the moving direction is the same as the positive direction of the z-axis.

[0113] Step 4, motion state judgment: when the heel angle, pitch angle and drift angle of the model 5 moving in the water and the displacement of the model 5 relative to the trailer are all zero, a water surface wake test can be performed; when any one or more of the heel angle, pitch angle and drift angle of the model 5 moving in the water and the displacement of the model 5 relative to the trailer are not zero, the motion state detection is performed again after the anchor point pre-biasing;

[0114] The tie point pre-biasing method includes the following steps:

[0115] S1: When the static state debugging step is completed, the first thin cable 1, the second thin cable 2, the third thin cable 3 and the fourth thin cable 4 are tied to the point A on the trailer. 1s , A 2s , A 3s , A 4s The coordinates are represented by A is (x is ,y is , z is )where, i=1, 2, 3, 4; A 1s , A 2s , A 3s , A 4s Their coordinates are all known quantities.

[0116] S2: Obtain the static posture parameters of the tie points on the model 5 in the static state. The static posture parameters include:

[0117] The heel motion radius R of the four tie points Bix , R Bix Angle θ with the horizontal plane Bix ,

[0118] The radius of pitch motion R of the four tie points Biy , R Biy Angle θ with the horizontal plane Biy ,

[0119] Yaw motion radius R of the four tie points Biz , R Biz Angle θ with the vertical plane Biz ,

[0120] Among them, i = 1, 2, 3, 4, corresponding to the point B respectively. 1s , B 2s , B 3s , B 4s ,like Figure 1-Figure 2 As shown, B 1s , B 2s , B 3s , B 4s Corresponding to the first thin cable 1, the second thin cable 2, the third thin cable 3 and the fourth thin cable 4 respectively;

[0121] According to the detection data in the motion state detection step, θ xop ,θ yop ,θ zop and Δ xop , Δ yop , Δ zop Calculate the offset of the model tie points and obtain the pre-biased coordinates A of the four tie points in (x in ,y in , z in ).

[0122] In step S2, the method for obtaining the static posture parameters is as follows:

[0123] like Figure 4 As shown, in the static state, the deflection center point C1 of the model 5 and the model axis, the longitudinal motion axis and the yaw motion axis can be determined according to the geometric shape and mass distribution of the model 5, and the lengths of the first thin cable 1, the second thin cable 2, the third thin cable 3 and the fourth thin cable 4 are not changed. 1s , B 2s , B 3s , B 4s The position on the model 5 is unchanged and known, and the static posture parameters can be obtained. Figure 5 B 1p and B 1n Represents the two positions of the tie points during inference.

[0124] Based on point B 1s For example:

[0125] For the tie point B 1s like Figure 5 As shown, C 1x For B 1s The intersection of the cross section and the centerline of the model 5, R B1x That is line segment B 1s C 1x ,θ B1x That is line segment B 1s C 1x Angle with y axis, point B 2s , B 3s , B 4s Same reason.

[0126] For the tie point B 1s like Figure 6 As mentioned above, C 1y For B 1s The intersection of the vertical plane and the longitudinal tilt axis of model 5, R B1y That is line segment B 1s C 1y ,θ B1yThat is line segment B 1s C 1y The angle with the x-axis. 2s , B 3s , B 4s Same reason.

[0127] For the tie point B 1s like Figure 7 As mentioned above, C 1z For B 1s The intersection of the horizontal plane and the axis of the yaw motion of model 5, R Biz That is line segment B 1s C 1z ,θ Biz That is line segment B 1s C 1z The angle with the x-axis. 2s , B 3s , B 4s Same reason.

[0128] S3: Obtain the coordinates of the points that need to be pre-biased by coordinate calculation.

[0129] Pre-biased coordinates A of the tie point in (x in ,y in , z in )middle,

[0130] x in =x is -Δ xop -(R Biy ×θ yop )×sinθ Biy -(R Biz ×θ zop )×sinθ Biz i=1,2,3,4

[0131] y in =y is -Δ yop +(R Bix ×θ xop )×sinθ Bix -(R Biz ×θ zop )×cosθ Biz i=1,2

[0132] y in =y is -Δ yop +(R Bix ×θ xop )×sinθ Bix +(R Biz ×θ zop)×cosθ Biz i=3,4

[0133] z in =z is -Δ zop +(R Bix ×θ xop )×cosθ Bix -(R Biy ×θ yop )×cosθ Biy i=1

[0134] z in =z is -Δ zop -(R Bix ×θ xop )×cosθ Bix -(R Biy ×θ yop )×cosθ Biy i=2

[0135] z in =z is -Δ zop +(R Bix ×θ xop )×cosθ Bix +(R Biy ×θ yop )×cosθ Biy i=3

[0136] z in =z is -Δ zop -(R Bix ×θ xop )×cosθ Bix +(R Biy ×θ yop )×cosθ Biy i=4

[0137] In the above formula, θ xop ,θ yop ,θ zop The unit is radians.

[0138] The various calculation items in the above formula can be obtained by combining the following decomposition situations.

[0139] Case 1: Δ xop , Δ yop , Δ zop One of them is not equal to 0

[0140] x in =x is -Δxop ,y in =y is -Δ yop , z in =z is -Δ zop , i=1,2,3,4;

[0141] Case 2:

[0142] Heel angle θ xop ≠0, the x-coordinates of points A1, A2, A3, and A4 remain unchanged.

[0143] y in =y is +(R Bix ×θ xop )×sinθ Bix , i=1,2,3,4;

[0144] z in =z is +(R Bix ×θ xop )×cosθ Bix , i=1,3;

[0145] z in =z is -(R Bix ×θ xop )×cosθ Bix , i=2,4;

[0146] Case 3:

[0147] Pitch angle θ yop ≠0, the y coordinates of points A1, A2, A3, and A4 remain unchanged

[0148] x in =x is -(R Biy ×θ yop )×sinθ Biy , i=1,2,3,4;

[0149] z in =z is -(R Biy ×θ yop )×cosθ Biy , i=1,2;

[0150] z in =z is +(R Biy ×θ yop )×cosθ Biy , i=3,4;

[0151] Case 4:

[0152] Drift angle θ zop ≠0, the z coordinates of points A1, A2, A3, and A4 remain unchanged

[0153] x in =x is -(R Biz ×θ zop )×sinθ Biz , i=1,2,3,4;

[0154] y in =y is -(R Biz ×θ zop )×cosθ Biz , i=1,2;

[0155] y in =y is +(R Biz ×θ zop )×cosθ Biz , i=3,4;

[0156] It is possible to determine in turn whether there is a position or posture change in the above situations, and then perform offset superposition.

[0157] In the above formula, Δ xop , Δ yop , Δ zop Distinguish between positive and negative, θ xop ,θ yop ,θ zop The unit is radian, and it can be positive or negative. According to different deflection and movement directions, the system point A 1s , A 2s , A 3s , A 4s The position of is offset in the opposite direction to compensate for the changes in the heel angle, pitch angle and drift angle caused by the hydrodynamic force of the model 5 when the trailer moves, and the pre-biased coordinate A is obtained. in (x in ,y in , z in ).

[0158] In the above calculation process, if Figure 5-Figure 7 As shown, at θ xop ,θ yop ,θ zop When the corresponding central angle is small (generally less than or equal to 10°), the above calculation method can be used equivalently.

[0159] Steps 3 and 4 are iterated in a loop until the heel angle, pitch angle and drift angle of the model 5 when moving in the water and the displacement of the model 5 relative to the trailer are all zero, and then a water surface wake test is performed.

[0160] Further, in order to facilitate the adjustment of the tie point position on the trailer, such as Figure 8 , Fig. 9 As shown, four sets of moving mechanisms are installed on the trailer, corresponding to the first thin cable 1, the second thin cable 2, the third thin cable 3 and the fourth thin cable 4 respectively;

[0161] The single-group moving mechanism includes a vertical moving module 13 fixedly mounted on a body 18 of a trailer, a lifting base plate 14 being mounted on the moving end of the vertical moving module 13, a transverse moving module 15 and a longitudinal moving module 16 being arranged on the lifting base plate 14, a longitudinal moving module 16 being mounted on the moving end of the transverse moving module 15, a lifting point base plate 17 being mounted on the moving end of the longitudinal moving module 16, a trailer tie point being arranged on the tie point base plate 17, and the trailer tie point being used to connect the model 5.

[0162] The lateral moving module 15 includes a pair of first guide rails 152 arranged in parallel on the hanging base plate 14, and a first rack 151 is arranged on one side of one of the first guide rails 152. The longitudinal moving module 16 includes a second guide rail 162, and a second rack 161 is fixedly installed on one side of the second guide rail 162. A first servo motor 153 is installed at one end of the second guide rail 162. Both ends of the second guide rail 162 are respectively slidably connected to the first guide rail 152, and the first servo motor 153 is transmission connected to the first rack 151. A hanging point base plate 17 is slidably installed on the second guide rail 162, and a second servo motor 163 is installed on the hanging point base plate 17. The second servo motor 163 is transmission connected to the second rack 161.

[0163] The vertical moving module 13 includes an electric cylinder 131 fixedly mounted on the body 18, the piston rod of the electric cylinder 131 is connected to the lifting base plate 14, the lifting base plate 14 is slidably connected to the body 18 through a guide rod 132, there are four guide rods 132, which are located on the outer periphery of the electric cylinder 131, an accordion cover 133 is arranged on the outer periphery of the guide rod 132, one end of the accordion cover 133 is connected to the body 18, and the other end of the accordion cover 133 is connected to the lifting base plate 14.

[0164] The servo drives on the transverse moving module 15, the longitudinal moving module 16 and the vertical moving module 13 record the position of the corresponding suspension point substrate 17 (i.e. the position of each thin cable suspension point), and transmit the position to the measurement and control computer. The measurement and control computer controls the transverse moving module 15, the longitudinal moving module 16 and the vertical moving module 13 according to the calculated pre-biased coordinates, thereby changing the position of the tie point on the trailer, thereby achieving rapid and precise adjustment of the pre-bias of the tie points of the first thin cable 1, the second thin cable 2, the third thin cable 3 and the fourth thin cable 4 on the trailer.

[0165] Embodiment three:

[0166] Step S110:

[0167] The layout design of the first thin cable 1, the second thin cable 2, the third thin cable 3 and the fourth thin cable 4 on the trailer is preliminarily performed, that is, the positions of the tie points of the four thin cables on the trailer are selected, and the positions of the four tie points of the thin cables on the model 5 are selected at the same time. Tie points B of the four thin cables on the model 5 1s , B 2s , B 3s , B 4s , distributed in front, behind, left and right of model 5, that is, any two thin cables maintain a certain distance between their tie points on model 5.

[0168] Select cables made of materials with larger elastic coefficients and smaller diameters to reduce the disturbance of the thin cables to the water surface and at the same time reduce the tension and deformation of the thin cables.

[0169] Step S120:

[0170] The ballast 6, attitude sensor 8, first water pressure sensor 71, and second water pressure sensor 72 are installed inside the model 5. Distinct feature points 11 are marked on the upper surface of the model 5 to coordinate with the visual sensor 12 (CCD camera) to align the underwater model 5 and measure the position and front, back, left, and right deviations of the model 5.

[0171] like Figure 3 As shown, the model is hoisted on the trailer using a sling 101, and at this time, all thin cables are in a relaxed state. The model 5 is weighed in the air using the tension sensor 102 on the sling 101, and the weight of the model 5 is recorded as G; the model 5 is weighed in the water, and this weight is recorded as △G, and the buoyancy of the model 5 is obtained as: B=G-ΔG, and the net weight ΔG>0 is ensured, and ΔG / G is kept at a certain ratio, so as to reserve a certain thin cable tension to resist the hydrodynamic interference when the model moves.

[0172] Step S130:

[0173] The first thin cable 1 , the second thin cable 2 , the third thin cable 3 , the fourth thin cable 4 and the model 5 are connected.

[0174] Step S140:

[0175] The suspension rope 101 is gradually lowered, and the model 5 gradually enters the water. The diving depth information of the model 5 can be obtained in real time according to the first water pressure sensor 71 and the second water pressure sensor 72. After reaching the predetermined depth, the model 5 stays still for a period of time until it stabilizes. The suspension rope 101 is released, and the four thin cables are tightened. The net weight of the model 5 is borne by the four thin cables.

[0176] Check whether the front and rear, left and right positions of the model 5 are in place, that is, whether the diving depth is in place and the attitude angle is zero. If not, adjust the front and rear, left and right positions of the tie points of each thin cable on the trailer.

[0177] Record the tie points A of the first thin cable 1, the second thin cable 2, the third thin cable 3, and the fourth thin cable 4 on the trailer 1s , A 2s , A 3s , A 4s The coordinates are represented by A is (x is ,y is , z is ), collect and record the pressure signals P of the first water pressure sensor 71 and the second water pressure sensor 72 at the trailer speed. 1s , P 2s , the subscript s represents that the model is at rest.

[0178] Step S150:

[0179] The trailer starts to accelerate, and the model 5 is dragged by the first thin cable 1, the second thin cable 2, the third thin cable 3 and the fourth thin cable 4. After the trailer moves at a constant speed, the pressure signals P of the first water pressure sensor 71 and the second water pressure sensor 72 at the speed of the trailer are collected and recorded. 1p , P 2p , the roll θ measured by attitude sensor 8 xop , pitchθ yop , drift angle θ zop The subscript p represents the displacement and deflection of the model 5 under the action of hydrodynamic force when the trailer moves at a constant speed. Strictly speaking, the above parameters change with time. Here, small fluctuations are ignored and the average of each parameter is taken. By photographing the surface feature points 11 of the model 5 through the visual sensor 12 (CCD camera), the front-to-back and left-to-right displacement Δ of the model 5 can be tested. xop , Δ yop , the pressure signals P of the first water pressure sensor 71 and the second water pressure sensor 72 are 1p , P 2p The vertical offset Δ of model 5 can be obtained zop .

[0180] Step S160:

[0181] After the trailer stops, adjust the position of each thin cable tie point on the trailer, denoted as A. in (x in ,y in , z in The principle of adjustment is the same as the method of balancing when the trailer is stationary, except that the reverse pre-adjustment is required at this time. The goal is to make the average position change of the model 5 times Δ when the trailer moves at a constant speed. xop , Δ yop , Δzop is zero, the attitude angle deflection θ xop ,θ yop ,θ zop is zero.

[0182] Step S170:

[0183] After the above adjustment process is completed, enter step S150 to test run again. If Δ xop , Δ yop , Δ zop is zero, the attitude angle deflection θ xop ,θ yop ,θ zop is zero, then go to step S160 until the trailer movement Δ xop , Δ yop , Δ zop is zero, the attitude angle deflection θ xop ,θ yop ,θ zop Then, the wake test of the underwater vehicle model can be officially started.

[0184] During the test, the pressure signals P of the first water pressure sensor 71 and the second water pressure sensor 72 at the trailer speed are collected and recorded. 1p , P 2p , the roll θ measured by attitude sensor 8 xop , pitchθ yop , drift angle θ zop , the CCD camera records the position of the surface feature points 11 of the model 5 to realize dynamic monitoring of the model state during the test and ensure the accuracy of the test measurement results.

[0185] Step S180:

[0186] After the test, when the trailer is stationary, first slowly move the thin cable trailer tie points upward to gradually lift the model 5. When the model 5 reaches the water surface but has not yet emerged from the water, the lifting rope 101 hooks the model 5 and gradually exerts force, while gradually loosening the first thin cable 1, the second thin cable 2, the third thin cable 3 and the fourth thin cable 4, and finally the model 5 is lifted by the lifting rope 101.

[0187] The above description is an explanation of the present invention, not a limitation of the present invention. The scope of the present invention is defined in the claims. Any form of modification may be made within the scope of protection of the present invention.

Claims

1. A method for testing the surface wake of an underwater vehicle model, characterized in that: The model (5) is connected to a trailer above the test pool by a first thin cable (1), a second thin cable (2), a third thin cable (3) and a fourth thin cable (4) to transmit traction, the first thin cable (1) and the second thin cable (2) are respectively connected to both sides of the front end of the model (5), the third thin cable (3) and the fourth thin cable (4) are respectively connected to both sides of the rear end of the model (5), and the first thin cable (1) and the third thin cable (3) are located on the same side of the model (5); The test method comprises the following steps: Static state debugging: the model (5) is immersed in water and in a static state, the heel angle, the pitch angle and the drift angle of the model (5) are all zero; Movement state detection: starting the trailer, causing the model (5) to move in the water under the traction of the first thin cable (1), the second thin cable (2), the third thin cable (3) and the fourth thin cable (4), detecting the heel angle, the pitch angle and the drift angle of the model (5) during movement, and detecting the displacement of the model (5) relative to the trailer; Motion state judgment: When the heel angle, pitch angle and drift angle of the model (5) when moving in the water and the displacement of the model (5) relative to the trailer are all zero, a water surface wake test can be carried out. When any one or more of the heel angle, the pitch angle and the drift angle of the model (5) when moving in the water and the displacement of the model (5) relative to the trailer are not zero, the motion state detection is performed again after the anchor point is pre-biased; Pre-biasing of the tie points: The positions of the tie points of the first thin cable (1), the second thin cable (2), the third thin cable (3) and the fourth thin cable (4) on the trailer are adjusted by the pre-biasing method.

2. The underwater vehicle model water surface wake test method according to claim 1, characterized in that: The cyclic iteration process of motion state detection, motion state judgment and tie point pre-biasing is carried out when the trailer tows the model (5) to move.

3. The underwater vehicle model water surface wake test method according to claim 1, characterized in that: Establishing a traveling coordinate system fixed relative to the trailer; In the motion state detection step, the heel angle, pitch angle, and drift angle of the detected model (5) during motion are θ xop ,θ yop and θ zop ; θ xop >0 means that the model (5) rotates counterclockwise around the axis. θ yop >0 means that the head of the model (5) is raised, θ zop >0 means that the head swing direction of the model (5) is toward the positive direction of the y-axis; The overall displacement of the model (5) relative to the trailer is Δ xop , Δ yop , Δ zop ; Δ xop >0 means the moving direction is the same as the positive direction of the x-axis. Δ yop >0 means the moving direction is the same as the positive direction of the y-axis. Δ zop >0 means the moving direction is the same as the positive direction of the z-axis.

4. The method for testing the water surface wake of an underwater vehicle model according to claim 3, characterized in that: The tie point pre-biasing method includes the following steps: When the static state debugging step is completed, the first thin cable (1), the second thin cable (2), the third thin cable (3) and the fourth thin cable (4) are tied to the point A on the trailer. 1s , A 2s , A 3s , A 4s The coordinates are represented by A is (x is ,y is , z is ), where i=1, 2, 3, 4; The static posture parameters of the tie points on the model 5 in the static state are obtained. The static posture parameters include: The heel motion radius R of the four tie points Bix , R Bix Angle θ with the horizontal plane Bix , The radius of pitch motion R of the four tie points Biy , R Biy Angle θ with the horizontal plane Biy , Yaw motion radius R of the four tie points Biz , R Biz Angle θ with the vertical plane Biz , Wherein, i = 1, 2, 3, 4; According to the detection data in the motion state detection step, θ xop ,θ yop ,θ zop and Δ xop , Δ yop , Δ zop Calculate the offset of the model tie points and obtain the pre-biased coordinates A of the four tie points in (x in ,y in , z in ).

5. The method for testing the water surface wake of an underwater vehicle model according to claim 4, characterized in that: Pre-biased coordinates A of the tie point in (x in ,y in , z in )middle, x in =x is -Δ xop -(R Biy ×θ yop )×sinθ Biy -(R Biz ×θ zop )×sinθ Biz i=1,2,3,4 y in =y is -Δ yop +(R Bix ×θ xop )×sinθ Bix -(R Biz ×θ zop )×cosθ Biz i=1,2 y in =y is -Δ yop +(R Bix ×θ xop )×sinθ Bix +(R Biz ×θ zop )×cosθ Biz i=3,4 z in =z is -Δ zop +(R Bix ×θ xop )×cosθ Bix -(R Biy ×θ yop )×cosθ Biy i=1 z in =z is -Δ zop -(R Bix ×θ xop )×cosθ Bix -(R Biy ×θ yop )×cosθ Biy i=2 z in =z is -Δ zop +(R Bix ×θ xop )×cosθ Bix +(R Biy ×θ yop )×cosθ Biy i=3 z in =z is -Δ zop -(R Bix ×θ xop )×cosθ Bix +(R Biy ×θ yop )×cosθ Biy i=4 In the above formula, θ xop ,θ yop ,θ zop The unit is radians.

6. The method for testing the water surface wake of an underwater vehicle model according to claim 3, characterized in that: The x-axis of the accompanying coordinate system is parallel to the axis of the stationary model (5), and the positive direction of the x-axis is opposite to the navigation direction. The y-axis of the accompanying coordinate system is perpendicular to the axis of the stationary model (5) and is located in the same horizontal plane as the x-axis. The positive direction of the y-axis is toward the right side of the navigation direction. The positive direction of the z-axis of the accompanying coordinate system points vertically upward.

7. The method for testing the water surface wake of an underwater vehicle model according to claim 1, characterized in that: The model (5) is in a negative buoyancy state in water, and a ballast (6) is provided in the model (5) for ensuring the net weight of the model (5) in water, so that the first thin cable (1), the second thin cable (2), the third thin cable (3), and the fourth thin cable (4) are in a tensioned state when conducting a water surface wake test.

8. The method for testing the water surface wake of an underwater vehicle model according to claim 1, characterized in that: The model (5) is provided with a posture sensor (8) for detecting the heel angle, pitch angle and drift angle of the model (5), and also includes a model position detection system for detecting the displacement of the model (5) relative to the trailer.

9. The method for testing the water surface wake of an underwater vehicle model according to claim 8, characterized in that: The model position detection system comprises a visual sensor (12) fixedly mounted on the trailer, a feature point (11) being arranged on the upper surface of the model (5), the visual sensor (12) identifying the position of the feature point (11), and then calculating the horizontal displacement of the model (5) relative to the trailer, and further comprising a first water pressure sensor (71) mounted on the bow of the model (5) and a second water pressure sensor (72) mounted on the tail of the model (5), and obtaining the vertical displacement of the model (5) by calculating the pressure change.

10. The underwater vehicle model water surface wake test method according to claim 1, characterized in that: The trailer is equipped with four sets of moving mechanisms, corresponding to the first thin cable (1), the second thin cable (2), the third thin cable (3) and the fourth thin cable (4) respectively; The single-group moving mechanism comprises a vertical moving module (13) fixedly mounted on a body (18) of the trailer, a lifting base plate (14) being mounted on the moving end of the vertical moving module (13), a lateral moving module (15) and a longitudinal moving module (16) being arranged on the lifting base plate (14), a longitudinal moving module (16) being mounted on the moving end of the lateral moving module (15), a lifting point base plate (17) being mounted on the moving end of the longitudinal moving module (16), a trailer tie point being arranged on the lifting point base plate (17), and the trailer tie point being used to connect the model (5).

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