A two-dimensional wave-making water channel driven by a voice coil motor with active wave-absorbing function

Abstract

This invention provides a two-dimensional wave-generating water tank with active wave absorption function driven by a voice coil motor, comprising a wave-generating device, a water tank body, and a force feedback active wave-absorbing device. The force feedback active wave-absorbing device and the wave-generating device are rigidly connected to both sides of the water tank body via brackets. Each includes a voice coil linear motor, a small processor, a magnetic grating displacement sensor, a lever amplification mechanism, and a float. The output end of the voice coil linear motor is connected to the lever amplification mechanism, which is connected to the float. The small processor is connected to the magnetic grating displacement sensor signal. The voice coil linear motor is used to apply a wave-absorbing force f to the float based on the data from the magnetic grating displacement sensor. a (t). This invention is applicable to small and medium-sized wave pools, occupies little space, and has high precision, greatly enriching the application scenarios of wave pools. It is convenient for transportation, installation, debugging, and mobile use in different scenarios, providing a foundation for subsequent classroom demonstrations, student experiments, and equipment sharing.

Description

Technical Field

[0001] This invention relates to the field of wave generation experimental technology, and in particular to a two-dimensional wave generation water tank with active wave absorption function driven by a voice coil motor. Background Technology

[0002] In the field of shipbuilding and ocean engineering, researchers often use physical model experiments in wave tanks to study the various properties of marine structures. The key to conducting these experiments is wave generation. Wave-generating equipment uses mechanical transmission to move water and produce waves; common wave-generating equipment includes push-plate and rocker-plate types. These wave-generating devices, due to their use of servo motors and complex mechanical transmission mechanisms, are expensive, difficult to maintain, and require large areas of space. This results in a high barrier to entry for experiments in the shipbuilding and ocean engineering field, making it difficult for ordinary researchers, students, and small research institutions to conduct related experimental research. Therefore, the industry urgently needs miniaturized wave-generating tanks. Compared to the vast ocean environment, the size of the tank is very limited. On the one hand, existing miniaturized experimental wave-generating devices generate waves that are reflected when they reach the boundary. Repeated cycles of reflection can "contaminate" the target wave field, causing wave field turbulence, affecting the accuracy and reliability of the experiment, and leading to experimental failure. On the other hand, existing miniaturized wave-generating devices commonly use wave sensors, but in actual use, the accuracy of the initial zero-point position of the wave sensor cannot be maintained, and zero-point drift occurs over long-term measurements. Summary of the Invention

[0003] The purpose of this invention is to provide a two-dimensional wave-generating water tank with active wave absorption function driven by a voice coil motor, so as to solve the problems mentioned in the background art.

[0004] This invention is achieved through the following technical solution: a two-dimensional wave-generating water tank with active wave absorption function driven by a voice coil motor, comprising a wave-generating device, a water tank body, and a force feedback active wave-absorbing device. The force feedback active wave-absorbing device and the wave-generating device are rigidly connected to both sides of the water tank body via brackets. Each includes a voice coil linear motor, a small processor, a magnetic grating displacement sensor, a lever amplification mechanism, and a float. The output end of the voice coil linear motor is connected to the lever amplification mechanism, which is connected to the float. The small processor is connected to the magnetic grating displacement sensor signal. The voice coil linear motor is used to apply a wave-absorbing force f to the float according to the data from the magnetic grating displacement sensor. a (t).

[0005] Furthermore, the voice coil linear motor includes a motor stator, a motor mover, and a flange connector. The motor mover is slidably connected to the motor stator, and the motor mover is rigidly connected to the flange connector. The flange connector is connected to the lever amplification mechanism.

[0006] Furthermore, the miniature processor and the magnetic grating displacement sensor are mounted on the stator side of the motor.

[0007] Furthermore, the lever amplification mechanism includes: a first lever, a second lever, and a third lever. The first lever is connected to the motor actuator, one end of the second lever is connected to the first lever bearing, and the other end is connected to the third lever bearing. One end of the third lever is connected to the float.

[0008] Furthermore, the water tank is used to perform an active wave absorption method, which includes the following steps:

[0009] S1. Obtain the displacement and velocity signals of the floating body;

[0010] S2. Calculate the wave-absorbing force f based on the displacement signal and velocity signal. a (t), based on the wave-absorbing force f a (t) Adjust the output force of the voice coil motor.

[0011] Furthermore, the wave-absorbing force f is calculated using the following formula. a (t):

[0012] f a (t)=Nz′+CZ

[0013] Where z′ is the velocity of the floating body; Z is the displacement of the floating body; N is the damping coefficient; and C is the restoring force coefficient.

[0014] Furthermore, the optimal absorption coefficient of the external system satisfies the formula:

[0015] C(ω)=ω 2 [M+a]-c, N(ω)=b

[0016] Where C(ω) is the restoring force coefficient of the external control system; ω is the angular frequency; M is the mass of the float; a is the heave-added mass of the float; b is the heave-damping force coefficient of the float; c is the heave-restoring force coefficient of the float; and N(ω) is the damping coefficient of the external control system.

[0017] Compared with the prior art, the beneficial effects achieved by the present invention are as follows:

[0018] This invention provides a two-dimensional wave-generating tank with active wave absorption function driven by a voice coil motor: by setting a lever amplification mechanism, the actual stroke of the wave-generating float is several times or more than ten times the initial stroke of the voice coil motor, effectively reducing the size of the device; adopting a combination of voice coil motor and float, this type of wave generation is installed vertically, occupying only the space in the depth direction of the pool, ensuring the miniaturization of the wave-generating tank; a force feedback active wave absorption device is set up to avoid the zero-point drift problem caused by traditional wave height sensors, ensuring the accuracy of the zero point and increasing the precision of the experiment. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only preferred embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 The present invention provides a structural diagram of a two-dimensional wave-generating water tank with active wave absorption function driven by a voice coil motor.

[0021] Figure 2 for Figure 1 A detailed structural diagram of the wave-generating device.

[0022] Figure 3 for Figure 2 Detailed structural connection diagram of the mid-range coil linear motor and its various components.

[0023] Figure 4 for Figure 1 Working principle diagram of the force feedback active wave absorption device.

[0024] Reference numerals in the attached drawings: 1. Wave-generating device; 2. Water tank body; 3. Force feedback active wave-absorbing device; 4. Mounting plate; 5. Voice coil linear motor; 6. First bracket; 7. First lever; 8. Second lever; 9. Second bracket; 10. Third bracket; 11. Fourth bracket; 12. Float; 13. Third lever; 14. Motor stator; 15. Motor mover; 16. Flange connector; 17. Magnetic grating displacement sensor; 18. Stator mounting plate. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of the present invention more apparent, exemplary embodiments according to the present invention will be described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are merely a part of the embodiments of the present invention, and not all of the embodiments of the present invention. It should be understood that the present invention is not limited to the exemplary embodiments described herein. Based on the embodiments of the present invention described herein, all other embodiments obtained by those skilled in the art without inventive effort should fall within the protection scope of the present invention.

[0026] In the following description, numerous specific details are set forth in order to provide a more thorough understanding of the invention. However, it will be apparent to those skilled in the art that the invention can be practiced without one or more of these details. In other instances, certain technical features well-known in the art have not been described in order to avoid obscuring the invention.

[0027] It should be understood that the invention can be embodied in various forms and should not be construed as being limited to the embodiments set forth herein. Rather, providing these embodiments will make the disclosure thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

[0028] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the invention. When used herein, the singular forms “a,” “an,” and “the” are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the terms “comprising” and / or “including,” when used in this specification, identify the presence of the stated features, integers, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups. When used herein, the term “and / or” includes any and all combinations of the associated listed items.

[0029] To fully understand this invention, a detailed structure will be presented in the following description to illustrate the technical solution proposed by this invention. Optional embodiments of the invention are described in detail below; however, in addition to these detailed descriptions, the invention may have other embodiments.

[0030] See Figure 1-4A two-dimensional wave-generating water tank with active wave absorption function driven by a voice coil motor includes a wave-generating device 1, a water tank body 2, and a force feedback active wave-absorbing device 3. The force feedback active wave-absorbing device 3 and the wave-generating device 1 are rigidly connected to both sides of the water tank body 2. Each includes a voice coil linear motor 5, a small processor, a magnetic grating displacement sensor 17, a lever amplification mechanism, a support, and a float 12. The small processor is signal-connected to the magnetic grating displacement sensor 17. Under the action of the small processor, the voice coil linear motor 5 applies a wave-absorbing force f to the float according to the data from the magnetic grating displacement sensor 17. a (t) to absorb the energy contained in the waves corresponding to time t. It is generally believed that time t is extremely short, that is, when the input frequency of displacement and velocity and the corresponding output frequency of wave absorption force are fast enough, the voice coil linear motor 5 is considered to be in continuous motion over time, so that the wave absorption process can continue. The voice coil linear motor 5 is directly connected to the lever amplification mechanism, the float 12 is connected to the lever amplification mechanism, the voice coil linear motor 5 is connected to the mounting plate 4, the first bracket 6 is perpendicularly connected to the mounting plate 4, the second bracket 9 is rigidly connected to the water tank body 2, and the second bracket 9 is perpendicularly connected to the third bracket 10. The first bracket 6, the second bracket 9, the third bracket 10, and the fourth bracket 11 together form the motor mounting assembly. The lever amplification mechanism plays a role in amplifying torque or stroke, giving full play to the performance of the voice coil linear motor 5.

[0031] In use, after a certain amount of water is injected into the water tank body 2, the voice coil linear motor 5 in the wave-generating device 1 completes the algorithm operation under the action of the small processor. The lever amplification mechanism connected to the motor reduces the displacement of the motor mover and amplifies the output force of the motor, ultimately causing the voice coil linear motor 5 to output periodic motion and transmit the motor motion to the float 12, causing the float 12 to move periodically and generate periodic two-dimensional regular incident waves in the water tank. When the two-dimensional regular incident waves are transmitted to the force feedback active wave-absorbing device 3 through the water tank body 2, the float 12 in the force feedback active wave-absorbing device 3 will generate vertical displacement under the action of the incident waves. The magnetic grating displacement sensor 17 collects the vertical displacement by sensing the change of the lever amplification mechanism, and then obtains the velocity signal by interpolation. The displacement and velocity signals are then transmitted to the small processor for processing, so that the motor applies wave-absorbing force to the float 12 of the wave-absorbing device according to the algorithm, thereby reducing wave pollution.

[0032] Preferably, the voice coil linear motor includes a motor stator 14, a motor mover 15, and a flange connector 16. The motor mover 15 is rigidly connected to the flange connector 16, and the motor mover 15 is slidably connected to the motor stator 14. The flange connector 16 is connected to the lever amplification mechanism. A magnetic grating displacement sensor 17 is also installed on the side of the motor stator 14. The motor stator 14 is connected to a stator mounting plate 18, which is connected to a mounting plate 4. After the module is powered on, the motor mover 15 moves vertically within the motor stator 14. The motor mover 15 is rigidly connected to the flange connector 16, which is connected to the lever amplification mechanism. The lever amplification mechanism transmits the motor motion, amplifying or reducing the displacement or torque stroke. The magnetic grating displacement sensor 17 provides feedback by measuring the displacement of the motor mover of the voice coil linear motor 5 to ensure the accuracy of the movement of the voice coil linear motor 5.

[0033] It should be noted that the selection of the voice coil linear motor 5 model and the lever should be based on a comprehensive consideration of factors such as wave generation capability, the size of the water tank body 2, and cost. This application does not impose any limitations on these factors. Similarly, the specific dimensions of the wave generation device 1, the water tank body 2, and the force feedback active wave absorption device 3 are not specifically limited in this invention.

[0034] Preferably, the lever amplification mechanism includes a first lever 7, a second lever 8, and a third lever 13. The first lever 7 is connected to the voice coil linear motor 5, the second lever 8 is connected to the first lever 7 and the third lever 13 via bearings, and the third lever 13 is connected to the float 12. The first lever 7 is connected below the voice coil linear motor 5 and is responsible for transmitting the periodic motion of the voice coil linear motor 5. The second lever 8 is connected to the first lever 7 via bearings and is responsible for reducing the displacement of the moving part of the voice coil linear motor 5 and amplifying the output force. Finally, the voice coil linear motor 5 outputs periodic motion, which is transmitted to the third lever 13 through the second lever 8. Since the third lever 13 is connected to the float 12, the third lever 13 transmits the motion of the voice coil linear motor 5 to the float 12, causing the float 12 to move periodically and generate periodic two-dimensional regular incident waves in the water tank body 2.

[0035] Preferably, the water tank is used to perform an active wave absorption method, which includes the following steps:

[0036] S1. Obtain the displacement and velocity signals of the floating body;

[0037] S2. Calculate the wave-absorbing force f based on the displacement signal and velocity signal. a (t), based on the wave-absorbing force f a (t) Adjust the output force of the voice coil motor.

[0038] Specifically, when the two-dimensional regular incident wave generated by the wave-generating device 1 is transmitted to the force feedback active wave-absorbing device 3 through the water tank body 2, the float 12 of the force feedback active wave-absorbing device 3 generates a vertical displacement under the action of the incident wave. The vertical displacement is collected by the magnetic grating displacement sensor 17 through the third lever 13 and the velocity signal is obtained by interpolation. The voice coil linear motor 5 in the force feedback active wave-absorbing device 3 will adjust the rotor speed, frequency, etc., through a small processor based on the displacement and velocity signal of its float 12, so as to control the float 12 in the force feedback active wave-absorbing device 3 to effectively absorb waves through the lever amplification mechanism. The voice coil linear motor 5 in the force feedback active wave-absorbing device 3 applies a wave-absorbing force f to its float 12 according to the algorithm processed by the small processor. a (t) is used to absorb the energy contained in the wave corresponding to time t. It is generally believed that time t is extremely short, that is, when the input frequency of displacement and velocity and the corresponding output frequency of wave-absorbing force are fast enough, the motor is considered to be in continuous motion over time, so that the wave-absorbing process can continue.

[0039] Preferably, the wave-absorbing force f is calculated using the following formula. a (t):

[0040] f a (t)=Nz′+CZ (1-1)

[0041] Where z′ is the velocity of the floating body; Z is the displacement of the floating body; N is the damping coefficient and C is the restoring force coefficient. The velocity and displacement of the floating body 12 are obtained by sensor measurement.

[0042] Specifically, the derivation of the absorption coefficient expression is as follows: When a two-dimensional regular incident wave with angular frequency ω is incident from the positive direction of the x-axis, the equation of motion of the floating body 12 is:

[0043]

[0044] In the above formula, M is the mass of the float 12; z(t) is the vertical displacement of the float 12; f r (t) represents the heave radiation force; f w (t) represents the excitation force of the heaving wave; f c (t) represents the control force of the external system;

[0045] in:

[0046]

[0047]

[0048] Where a is the heave-added mass of the float; b is the heave damping force coefficient of the float; c is the heave restoring force coefficient of the float; ω is the angular frequency; C(ω) is the restoring force coefficient of the external control system; N(ω) is the damping coefficient of the external control system; ζ0 is the amplitude of the incident wave. To determine the wave amplitude ratio; To determine the amplitude of the wave amplitude ratio; The phase is used to determine the wave amplitude ratio; k is the wave number; g is the gravitational acceleration; ρ is the density of water.

[0049] Specifically, in order to determine the restoring force coefficient and damping coefficient of the external control system when the system absorbs regular waves, the relevant formula for energy absorption efficiency is derived from the perspective of energy conservation.

[0050]

[0051] The above represents the work done by the fluid on the buoy per unit time, which is the energy absorbed by the external control system per unit time.

[0052] On the other hand, since the amplitude of the incident wave is ζ0, let the group velocity of the wave be C. g Then the energy W2 of the incident wave per unit time is

[0053]

[0054] According to the dispersion relation of infinitely deep water waves ω 2 =gk and group velocity C g =C / 2=ω / (2k) gives us:

[0055]

[0056] Therefore, the absorption efficiency E of the regular wave is

[0057]

[0058] The energy absorption efficiency is:

[0059]

[0060] The external control system can be simplified as a spring-damped system, specifically by applying an external force via an external motor. If, in the absence of an incident wave, the external system provides a displacement z(t) to force oscillation, then the work W3 done by the external control system per unit time is:

[0061]

[0062] When a two-dimensional floating body undergoes heaving motion, waves are generated on both sides of the body. The amplitudes of the waves generated on the left and right sides of the floating body are respectively... and The energy of the waves generated on the left and right sides of the floating body are W respectively. - and W + :

[0063]

[0064]

[0065] According to the law of conservation of energy, we have

[0066] W3 = W - +W + (1-14)

[0067] Substituting formulas (1-11), (1-12), and (1-13) into (1-14), we obtain...

[0068]

[0069] Transforming formula (1-15) yields

[0070] The group velocity formula C of waves g Substituting g / (2ω) into the above equation, we can obtain

[0071]

[0072] because It can be obtained

[0073]

[0074] As can be seen from the above formula, the damping force coefficient of the buoy is directly proportional to the square of the amplitude ratio. Transforming this formula, we can obtain...

[0075]

[0076] In the above formula,

[0077]

[0078] The energy absorption efficiency can be obtained as follows:

[0079]

[0080] To maximize the above expression, the denominator must be minimized, which means that the expression must satisfy the condition...

[0081] -{M+a}ω 2 +{C(ω)+c}=0 (1-21)

[0082] Therefore, the following inequality can be obtained.

[0083]

[0084] The condition for the second equality sign in the above equation to hold is:

[0085] N(ω)=b (1-23)

[0086] This is the condition for achieving maximum wave absorption efficiency. At this point, the maximum wave absorption efficiency is:

[0087]

[0088] The results show that, in order to make E max =1, meaning that an object only needs to generate waves on one side and not on the other. At this point, the external mechanical coefficients determined by the formula can completely absorb the waves.

[0089] Furthermore, to ensure that the two-dimensional heave float completely absorbs the incident regular wave, the float should be half-sized and positioned at the end of the tank. The optimal absorption coefficient of the external system should satisfy the following formula:

[0090] C(ω)=ω 2 [M+a]-c, N(ω)=b (1-25)

[0091] Where C(ω) is the restoring force coefficient of the external control system; ω is the angular frequency; M is the mass of the float; a is the heave-added mass of the float; b is the heave-damping force coefficient of the float; c is the heave-restoring force coefficient of the float; and N(ω) is the damping coefficient of the external control system.

[0092] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A two-dimensional wave tank driven by a voice coil motor with active wave absorption function, characterized in that, The application relates to a wave making device, a water tank body and a force feedback active wave absorbing device, wherein the force feedback active wave absorbing device and the wave making device are rigidly connected to the two sides of the water tank body through a support, and each of the force feedback active wave absorbing device and the wave making device comprises a voice coil linear motor, a small processor, a magnetic grid displacement sensor, a lever amplification mechanism and a float, the output end of the voice coil linear motor is connected with the lever amplification mechanism, the lever amplification mechanism is connected with the float, the small processor is connected with the signal of the magnetic grid displacement sensor, the vertical displacement of the float is collected by the magnetic grid displacement sensor through sensing the change of the lever amplification mechanism, and the voice coil linear motor is used for applying wave absorbing force to the float according to the data of the magnetic grid displacement sensor ​ The wave-absorbing force is calculated by the following formula : wherein, is the velocity of the float; is the displacement of the float; is the damping coefficient, is the restoring force coefficient; The absorption coefficient includes a restoring force coefficient and a damping coefficient, and the formula for calculating the restoring force coefficient is: The formula for calculating the damping coefficient is: wherein is the restoring force coefficient of the external control system; is the angular frequency; is the mass of the floating body; is the heave added mass of the floating body; is the heave damping force coefficient of the floating body; is the heave restoring force coefficient of the floating body; is the damping coefficient of the external control system.

2. The two-dimensional wave water channel with active wave absorption function driven by voice coil motor according to claim 1, characterized in that, The voice coil linear motor includes a motor stator, a motor mover, and a flange connector, the motor mover is slidingly connected to the motor stator, the motor mover is rigidly connected to the flange connector, and the flange connector is connected to the lever amplification mechanism.

3. The two-dimensional wave water channel with active wave absorption function driven by voice coil motor according to claim 2, characterized in that, The small processor and the magnetic grid displacement sensor are installed on the motor stator side.

4. The two-dimensional wave water channel with active wave absorption function driven by voice coil motor according to claim 2, characterized in that, The lever amplification mechanism includes a first lever, a second lever, and a third lever, the first lever is connected to the motor mover, one end of the second lever is connected to the first lever bearing, the other end of the second lever is connected to the third lever bearing, and one end of the third lever is connected to the float.

5. The two-dimensional wave water channel with active wave absorption function driven by voice coil motor according to claim 1, characterized in that, The sink is used to perform an active wave absorption method, and the active wave absorption method includes the following steps: S1, obtaining a displacement signal and a speed signal of a float; S2, calculate an absorption force based on the displacement signal and the velocity signal , based on the absorption force adjust the output force of the voice coil motor.

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