Method for water surface wake test of underwater vehicle model

Abstract

A kind of underwater vehicle model water surface wake test method, model is connected by first fine cable, second fine cable, third fine cable and fourth fine cable trailer above test tank in turn to transfer traction, test method includes the following steps: static state debugging, so that model is immersed in water, static state is zero for roll angle, pitch angle and drift angle;Model moves in water, detects the roll angle, pitch angle, drift angle when model moves, detects the displacement of model relative to trailer;When the roll angle, pitch angle and drift angle when model moves in water and the displacement of model relative to trailer are all zero, water surface wake test can be carried out, when not, after adjusting the position of the point of first fine cable, second fine cable, third fine cable and fourth fine cable on trailer by pre-biased method, motion state detection is carried out again, to guarantee the motion posture of underwater vehicle model, avoid the influence of traditional towing mechanism on underwater vehicle water surface wake, improve the accuracy of water surface wake test measurement.

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 wakes such as internal waves, surface waves, turbulence, and vortices during their submerged motion. At a certain diving depth and speed, the surface wake characteristics can be detected using microwaves, visible light, infrared, and other means. With the continuous advancement of vibration and noise reduction technology, the difficulty of detecting noise from underwater vehicles is increasing. However, the surface wake characteristics of underwater vehicles can be used to detect, determine, and identify the position, speed, and direction of underwater vehicles, enabling target detection of underwater vehicles. It is necessary to study the surface wake characteristics of underwater vehicles from the perspective of wake detection and stealth, and model testing is an indispensable and important means of this. The installation and towing of the underwater vehicle wake test model are important steps in the model testing.

[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 swords are placed above the model. The wake generated by the movement of the swords, especially the surface wake of the swords, 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 response to the shortcomings of the above-mentioned existing production technology, the applicant provides a method for testing the 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 surface wake of the underwater vehicle, and improving the accuracy of the surface wake test measurement.

[0005] The technical solutions adopted in the present invention are as follows:

[0006] A water surface wake test method for underwater vehicle models.

[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, and the third thin cable and the fourth thin cable are respectively connected to both sides of the rear end of the model. 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, the water surface wake test can be carried out.

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

[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 a pre-biasing method.

[0014] The cyclic iterative process of motion state detection, motion state judgment and tie point pre-bias is carried out while the trailer is pulling the model.

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

[0016] In the motion state detection step, the roll 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 indicates that the head of the model is swinging in 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-bias method includes the following steps:

[0025] When the static state commissioning 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 as A is (x is ,y is , z is ), where i = 1, 2, 3, 4;

[0026] Obtain the static posture parameters of the tie point on the model 5 in the static state. 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 pitch motion radius 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] Where 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's tie points and obtain the pre-biased coordinates A of the four tie points in (x in ,y in , z in ).

[0032] Pre-biased coordinate 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 stationary model and is located in the same horizontal plane as the x-axis. The positive direction of the y-axis is to the right 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. The model 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. Feature points are provided 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 calculated through pressure changes.

[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 transverse moving module and a longitudinal moving module, the moving end of the transverse 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 present invention has a compact and reasonable structure and is easy to operate. By adopting four thin cables to connect the model to 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 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 hydrodynamic force. The position of the thin cable tie 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-bias coordinates, thereby changing the position of the tie point on the trailer, and realizing 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 structural schematic 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 three-dimensional diagram of the model of the present invention.

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

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

[0059] Figure 7This 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] Figure 9 It is a structural schematic diagram of the vertical movable 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. Attitude sensor; 9. Measurement and control line;

[0065] 101. Suspension rope; 102. Tension sensor; 11. Feature point; 12. Vision sensor;

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

[0067] 14. Hoisting base plate; 15. Lateral movement 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 embodiments of the present invention will be described below with reference to the accompanying drawings.

[0071] Example 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 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 the two sides of the front end of the model 5, and 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. The first thin cable 1 and the third thin cable 3 are located on the same side of the model 5.

[0073] The water surface wake test method of the underwater vehicle model of this embodiment includes 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. 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, drift angle, and displacement of the model 5 relative to the trailer are all zero, a water wake test can be performed. If any one or more of the heel angle, pitch angle, drift angle, and displacement of the model 5 relative to the trailer are not zero, perform a pre-biased anchor point and then conduct another motion state test.

[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 underwater vehicle's wake area. The four thin cables are attached 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. 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 materials with a large elastic coefficient and a small diameter to reduce the disturbance of the thin cable to the water surface and reduce the tension deformation of the thin cable.

[0080] The hydrodynamic forces acting on the streamlined, slender model 5 during its uniform underwater motion are relatively stable. During the surface wake test of the underwater vehicle model, under hydrodynamic conditions, it can be assumed that the heel, pitch, and drift angles of the model 5 remain constant during its motion. The hydrodynamic forces are generated by the uniform relative motion of the model 5 and the water.

[0081] If the attitude of model 5 changes due to hydrodynamic forces, the displacement of the four thin cables' tie points is used to correct the displacement and attitude of model 5. This is known as tie point pre-biasing. Specifically, the displacement of each thin cable's tie point on the trailer achieves a pre-set offset in the attitude angle and position of model 5. This offset offsets the position and angle of model 5 caused by hydrodynamic interference during its movement.

[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 hydrodynamic force, and the position of the thin cable tie 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, drift angle, and displacement of the model 5 relative to the trailer when the model 5 moves in the water is not zero, before performing the anchor point pre-bias, the trailer is stopped and the anchor point position is adjusted, and then the motion state detection and motion state judgment are performed again.

[0084] In another specific embodiment, the iterative process of motion state detection, motion state determination, and tie point pre-biasing in the aforementioned test method is performed while the trailer is pulling the model 5. This process is synchronized with the trailer's motion in the water, improving test efficiency. The iterative process of motion state detection, motion state determination, and tie point pre-biasing continues until the heel, pitch, and drift angles of the model 5, as well as the displacement of the model 5 relative to the trailer, are zero while the model 5 is moving in the water. The iterative process then ceases.

[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 to the right and upward to the trailer tie point A. 1s 、A 3s , while moving the trailer tie point A of the second thin cable 2 and the fourth thin cable 4 to the right and downward 2s 、A 4s , so that the trailer can be stationary xop <0 to compensate for the roll caused by the hydrodynamic force on the model 5 when the trailer moves.

[0086] like Figure 6 As shown, if the pitch angle θ yop >0, that is, when the trailer is moving 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 are lowered at the trailer tie point A at the same time. 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 of the model 5 caused by the hydrodynamic force when the trailer moves.

[0087] likeFigure 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 are simultaneously moved counterclockwise to the trailer tie point A. 1s 、A 2s , while moving the trailer tie point A of the third and fourth thin cables 3 and 4 counterclockwise 3s 、A 4s , so that the trailer can be stationary 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 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 According to the size and direction of the above detection parameters, the point B on the model 5 can be calculated. 1s 、B 2s 、B 3s 、B 4s Position changes, such as Figures 5-6 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 Perform simplified calculations in and obtain RTΔOB 1s B 1n The two right-angled sides OB 1s and OB 1n length.

[0090] like Figures 1-2 As shown, the model 5 is in a negative buoyancy state in the water. 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 constant net weight. The four thin cables bear the net weight of model 5 in the static state and maintain a certain reserve of tension to overcome the hydrodynamic disturbances during model 5's movement. In the static state, the balance between model 5's gravity G and buoyancy B ensures that the residual weight ΔG = GB > 0, and that ΔG / G does not fall below a certain ratio. This means that the weight of model 5 exceeds its buoyancy with a certain margin. By adjusting the position of ballast 6, the center of gravity and center of buoyancy of model 5 are both located in the mid-longitudinal section, with the center of gravity lower than the center of buoyancy.

[0092] like Figures 1-2 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 5 also includes a model position detection system for detecting the displacement of the model 5 relative to the trailer.

[0093] Attitude sensor 8 and the model position detection system are connected to the tracking and control computer on the trailer via a tracking and control cable 9, which is fixed to a thin cable. Position sensor 8 and the model position detection system are located inside model 5 and provide real-time information about model 5's position and attitude, including its depth, pitch, drift, and roll angles. Tracking and control cable 9 extends from inside model 5 along a thin cable to the tracking and control computer on the trailer, transmitting 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 calculates the horizontal displacement of the model 5 relative to the trailer. It also includes 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. The vertical displacement of the model 5, that is, the change in diving depth, is calculated by 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] Example 2:

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

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

[0099] Step one, static state debugging: when the model 5 is submerged in water and in a static state, the roll angle, pitch angle and drift angle of the model 5 are all zero;

[0100] Step two, establishing a traveling coordinate system fixed relative to the trailer, specifically:

[0101] The x-axis of the traveling coordinate system is parallel to the axis of the model 5 in a static state, and the positive direction of the x-axis is opposite to the sailing direction,

[0102] The y-axis of the traveling coordinate system is perpendicular to the axis of the model 5 in a static state and is in the same horizontal plane as the x-axis, and the positive direction of the y-axis is towards the right side of the sailing direction,

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

[0104] Step three, motion state detection: start the trailer, and under the traction of the first fine cable 1, the second fine cable 2, the third fine cable 3 and the fourth fine cable 4, the model 5 moves uniformly in water, the roll angle, pitch angle and drift angle of the model 5 when moving are detected, and the displacement of the model 5 relative to the trailer is detected;

[0105] In the motion state detection step, the roll angle, pitch angle and drift angle of the model 5 when moving are θ xop , θ yop and θ zop , respectively;

[0106] θ xop > 0 indicates that the model 5 rotates counterclockwise with the axis as the center,

[0107] θ yop > 0 indicates that the bow of the model 5 is lifted,

[0108] θ zop > 0 indicates that the swing direction of the bow of the model 5 is towards the positive direction of the y-axis;

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

[0110] Δ xop > 0 indicates that the moving direction is the same as the positive direction of the x-axis,

[0111] Δ yop > 0 indicates that the moving direction is the same as the positive direction of the y-axis,

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

[0113] Step 4: Determine the motion state: When the heel angle, pitch angle, drift angle, and displacement of the model 5 relative to the trailer are all zero, a surface wake test can be performed. When any one or more of the heel angle, pitch angle, drift angle, and displacement of the model 5 relative to the trailer are not zero, perform a pre-biased anchor point and then perform motion state detection again.

[0114] The tie point pre-bias 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 as 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 point 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 pitch motion radius 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] Where i = 1, 2, 3, 4, corresponding to the point B respectively 1s 、B 2s 、B 3s 、B 4s ,like Figures 1-2 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's 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 pitch axis and the yaw 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 in 1p and B 1n Represents the two positions of the tie point during inference.

[0124] Take point B 1s For example:

[0125] For 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 axis, R B1x That is line segment B 1s C 1x ,θ B1x That is line segment B 1s C 1x Angle with the y-axis, point B 2s 、B 3s 、B 4s Same thing.

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

[0127] For 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 Angle with the x-axis. 2s 、B 3s 、B 4s Same thing.

[0128] S3: Obtain the coordinates of the system point that needs to be pre-biased through coordinate calculation.

[0129] Pre-biased coordinate 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) x cos θ Biz i = 3, 4

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

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

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

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

[0137] In the above formula, θ xop , θ yop , θ zop are in radian.

[0138] Each calculation term of the above formula can be synthesized according to the following several decomposition cases.

[0139] Case 1: Δ xop , Δ yop , Δ zop are 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 two:

[0142] When the roll angle θ xop ≠ 0, the x coordinates of the points A1, A2, A3, A4 are unchanged

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

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

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

[0146] Case three:

[0147] When the pitch angle θ yop ≠ 0, the y coordinates of the points A1, A2, A3, A4 are unchanged

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

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

[0150] z in = z is + (R Biy × θ yop ) × cos θ 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, which can be positive or negative. According to different deflection and movement directions, the point A 1s 、A 2s 、A 3s 、A 4s The position of the model 5 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 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 Figures 5-7 As shown, in 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 as an equivalent method.

[0159] Steps three and four are iterated until the roll angle, pitch angle and yaw angle of the model 5 when moving in water and the displacement of the model 5 relative to the trailer are all zero, and the water surface wake test is performed.

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

[0161] A single set of moving mechanisms includes a vertical moving module 13 fixedly installed on the body 18 of the trailer, a lifting base plate 14 installed at the moving end of the vertical moving module 13, a transverse moving module 15 and a longitudinal moving module 16 provided on the lifting base plate 14, the longitudinal moving module 16 installed at the moving end of the transverse moving module 15, and a lifting point base plate 17 installed at the moving end of the longitudinal moving module 16, on which a trailer tie point is provided for connecting the model 5.

[0162] The transverse moving module 15 includes a pair of first guide rails 152 provided in parallel on the lifting base plate 14, and a first rack 151 provided on one side of one of the first guide rails 152, the longitudinal moving module 16 includes a second guide rail 162, one side of which is fixedly installed with a second rack 161, one end of the second guide rail 162 is installed with a first servo motor 153, and both ends of the second guide rail 162 are slidably connected with the first guide rails 152, the first servo motor 153 is in transmission connection with the first rack 151, the lifting point base plate 17 is slidably installed on the second guide rail 162, and the lifting point base plate 17 is installed with a second servo motor 163, which is in transmission connection with the second rack 161.

[0163] The vertical moving module 13 includes an electric cylinder 131 fixedly installed on the body 18, the piston rod of the electric cylinder 131 is connected with the lifting base plate 14, the lifting base plate 14 is slidably connected with the body 18 through guide rods 132, the number of the guide rods 132 is four, which are located at the outer periphery of the electric cylinder 131, an organ case 133 is provided at the outer periphery of the guide rods 132, one end of the organ case 133 is connected with the body 18, and the other end of the organ case 133 is connected with the lifting base plate 14.

[0164] The positions of the lifting point base plates 17 (i.e. the positions of each fine cable lifting point) on the servo drive records of the transverse moving module 15, the longitudinal moving module 16 and the vertical moving module 13 are recorded, and the positions are transmitted 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 pre-offset coordinates calculated, thereby changing the position of the tie point on the trailer, and realizing the rapid and accurate adjustment of the pre-offset of the first fine cable 1, the second fine cable 2, the third fine cable 3 and the fourth fine cable 4 on the tie point on the trailer.

[0165] Example 3:

[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 carried out, that is, the positions of the four thin cables' tie points on the trailer are selected, and the positions of the four thin cables' tie points on the model 5 are selected at the same time. 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 on the water surface and at the same time reduce the tensile 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 model 5. Distinctive feature points 11 are marked on the top surface of model 5 to facilitate alignment between the visual sensor 12 (CCD camera) and the underwater model 5, thereby measuring the position and fore / aft / lateral offset of model 5.

[0171] like Figure 3 As shown, the model is hoisted from a trailer using a sling 101, with all the thin cables in a slack state. Using tension sensor 102 on sling 101, model 5 is weighed in air, with its weight recorded as G. The model is then weighed in water, with this weight recorded as ΔG. The buoyancy of model 5 is then calculated as: B = G - ΔG. Ensure that the net weight ΔG is greater than 0, and maintain a constant ratio of ΔG / G to maintain a certain amount of cable tension to resist hydrodynamic interference during model movement.

[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 first and second water pressure sensors 71 and 72 provide real-time information on the model 5's diving depth. After reaching the predetermined depth, the model 5 remains stationary for a period of time until it stabilizes. The suspension rope 101 is released, and the four thin cables are tightened, so that the net weight of the model 5 is borne by the four thin cables.

[0176] Check the position of the model 5, whether the depth is in place, the attitude angle is zero, if not, adjust the position of the fine cable in the trailer.

[0177] Record the coordinates of the first fine cable 1, the second fine cable 2, the third fine cable 3, and the fourth fine cable 4 in the trailer 1s , A 2s , A 3s , A 4s The coordinates of the first fine cable 1, the second fine cable 2, the third fine cable 3, and the fourth fine cable 4 in the trailer is (x is , y is , z is ) are recorded, and the pressure signals P 1s , P 2s of the first water pressure sensor 71 and the second water pressure sensor 72 at the speed of the trailer are collected and recorded, and the subscript s represents that the model is in a static state.

[0178] Step S150:

[0179] The trailer starts to accelerate, and the model 5 is dragged to move under the common traction of the first fine cable 1, the second fine cable 2, the third fine cable 3, and the fourth fine cable 4. After the trailer moves at a constant speed, the pressure signals P 1p , P 2p of the first water pressure sensor 71 and the second water pressure sensor 72 at the speed of the trailer are collected and recorded, and the roll θ xop , pitch θ yop , and yaw θ zop tested by the attitude sensor 8. The subscript p represents that the trailer moves at a constant speed, and the model 5 generates a deviation and a deflection under the action of water power. Strictly speaking, the above parameters change with time, and here the small fluctuations are ignored, and the mean values of the parameters are taken. The front and rear, left and right deviation amounts Δ xop , Δ yop of the model 5 can be tested and obtained by photographing the surface feature points 11 of the model 5 through the visual sensor 12 (CCD camera), and the vertical deviation amount Δ zop of the model 5 can be obtained through the pressure signals P 1p , P 2p of the first water pressure sensor 71 and the second water pressure sensor 72.

[0180] Step S160:

[0181] After the trailer stops, the positions of the fine cables in the trailer are adjusted, and are recorded as A in (x in , y in , z in ). The principle of adjustment is consistent with the leveling method when the trailer is static, but at this time, the pre-adjustment is reversed, and the target is to make the model 5 change the position Δ 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, step S150 is entered for re-commissioning, and if Δ xop , Δ yop , Δ zop is zero, the attitude angle deflection θ xop , θ yop , θ zop is zero, step S160 is entered until Δ xop , Δ yop , Δ zop is zero, the attitude angle deflection θ xop , θ yop , θ zop is zero. Then, the underwater vehicle model wake test can be formally started.

[0184] During the test, the pressure signals P 1p , P 2p of the first water pressure sensor 71 and the second water pressure sensor 72 at the speed of the tow vehicle are collected and recorded, the roll θ xop , the pitch θ yop , the yaw θ zop tested by the attitude sensor 8, and the position of the feature point 11 on the upper surface of the model 5 recorded by the CCD camera, so as 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 is completed, the tow vehicle is in a stationary state, and first, each fine cable tow vehicle connection point is slowly moved upward, and the model 5 is gradually lifted. When the model 5 reaches the water surface and has not yet emerged, the lifting rope 101 hooks the model 5 and gradually becomes difficult, while the first fine cable 1, the second fine cable 2, the third fine cable 3, and the fourth fine cable 4 are gradually loosened, and finally the model 5 is lifted by the lifting rope 101.

[0187] The above description is an explanation of the present application, not a limitation of the invention, and the scope of the present application is defined with reference to the claims. Within the protection scope of the present application, any form of modification can be made.

Claims

1. A method for testing the wake of an underwater vehicle model on a water surface, characterized by: 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 is in a static state, and the heel angle, pitch angle and drift angle of the model (5) are all zero; Motion state detection: the trailer is started, and the model (5) moves in 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 the heel angle, the pitch angle and the drift angle of the model (5) during the movement are detected, and the displacement of the model (5) relative to the trailer is detected; Motion state judgment: When the heel angle, pitch angle and drift angle of the model (5) when moving in 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, pitch angle and drift angle of the model (5) when moving in water and the displacement of the model (5) relative to the trailer is not zero, performing a pre-biasing of the anchor point and then performing a motion state detection again; Pre-biasing of the tie points: adjusting 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 by a pre-biasing method; Establishing a trailing coordinate system fixed relative to the trailer; In the motion state detection step, the roll angle, pitch angle and drift angle of the detected model (5) are 、 and ; >0 means that the model (5) rotates counterclockwise around the axis. >0 means that the head of the model (5) is raised, >0 indicates 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 、 、 ; >0 means the moving direction is the same as the positive direction of the x-axis. >0 means the moving direction is the same as the positive direction of the y-axis. >0 means the moving direction is the same as the positive direction of the z axis; The tie point pre-bias 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 trailer. 、 、 、 The coordinates are expressed as , where i=1, 2, 3, 4; Obtain the static attitude parameters of the tie point on the model (5) in the static state. The static attitude parameters include: Heel motion radius of the four tie points , Angle with the horizontal plane , Pitch motion radius of the four tie points , Angle with the horizontal plane , Yaw motion radius of the four tie points , Angle with the vertical plane , Where i=1, 2, 3, 4; According to the detection data in the motion state detection step: 、 、 and 、 、 Calculate the offset of the model's tie points and obtain the pre-biased coordinates of the four tie points ; Pre-biased coordinates of the tie points middle, In the above formula, 、 、 The unit is radians.

2. The method for testing the water surface wake of an underwater vehicle model according to claim 1, wherein: The cyclic iterative process of motion state detection, motion state judgment and tie point pre-bias is carried out while the trailer is pulling the model (5) in motion.

3. The method for testing the water surface wake of an underwater vehicle model according to claim 1, wherein: 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.

4. The method for testing the water surface wake of an underwater vehicle model according to claim 1, wherein: 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 performing a water surface wake test.

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

6. The method for testing the water surface wake of an underwater vehicle model according to claim 5, wherein: The model position detection system includes a visual sensor (12) fixedly mounted on the trailer, a feature point (11) is provided on the upper surface of the model (5), and the visual sensor (12) identifies the position of the feature point (11), thereby calculating the horizontal displacement of the model (5) relative to the trailer. The system also includes a first water pressure sensor (71) mounted on the head of the model (5) and a second water pressure sensor (72) mounted on the tail of the model (5), and the vertical displacement of the model (5) is calculated by pressure changes.

7. The method for testing the water surface wake of an underwater vehicle model according to claim 1, wherein: 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); 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 a 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 moving end of the lateral moving module (15) being mounted on the longitudinal moving module (16), 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).

Images