Active vibration isolation method, device and equipment based on piezoelectric ceramics, medium and product

Abstract

The invention discloses an active vibration isolation method, device and equipment based on piezoelectric ceramics, a medium and a product, and relates to the technical field of vibration and noise reduction of ship and ocean engineering.The method comprises the steps that the rigidity of a ship body structure is actively adjusted based on an intelligent material-piezoelectric ceramic intelligent toggle plate; the real cabin section provided with the intelligent toggle plate is simulated, and the inherent frequency and sound radiation data of the hull structure are obtained; a prototype performance test is carried out through the intelligent toggle plate, and the inherent frequency and sound radiation data of the hull structure are predicted; and the steps of adjustment, simulation and prediction are repeatedly executed, and when the optimal inherent frequency and the optimal sound radiation data of the hull structure are determined, vibration and noise reduction is completed. Impedance characteristics of the ship body structure can be changed, and vibration and noise reduction of the ship body double-layer bottom structure is achieved.

Description

Technical Field

[0001] The present application relates to the technical field of vibration and noise reduction in ships and marine engineering, and in particular to an active vibration isolation method, device, equipment, medium and product based on piezoelectric ceramics. Background Art

[0002] To reduce vibration interference and the hazards of underwater explosion shock, vibration damping devices and the passive vibration reduction systems they comprise are commonly used on ships. These devices offer advantages such as simple structure, mature manufacturing processes, and low cost. However, their structural characteristics cannot be modified after the components are manufactured, making them ineffective in reducing vibration when the operating environment changes. They are ineffective for complex structural vibration systems subjected to low-frequency, broadband, non-stationary random excitations or whose dynamic characteristics exhibit time-varying uncertainty. Actual shipboard equipment is often subject to vibration and explosion shock, ranging from a few hertz to thousands of hertz, encompassing a wide frequency range. Low-frequency vibration requires high stiffness from the vibration damping device, while high-frequency vibration (such as explosion shock waves) requires low stiffness, a conflicting requirement. Conventional vibration damping devices, due to their constant stiffness, can reduce the overall vibration level across the entire frequency range but struggle to eliminate low-frequency vibration line spectra, thus failing to meet the higher demands of practical engineering applications.

[0003] To enhance the environmental adaptability and performance of structures, sensors, actuators, and controllers are integrated with the main structure, combined with relevant signal processing and electronic circuit systems, to form structural systems with specialized intelligent functions such as structural health self-diagnosis, environmental adaptation, and damage self-healing, thereby enhancing reliability and stability. The research potential and application value of smart materials and structural technologies are enormous, and they have attracted significant attention worldwide in recent years. They have been widely and significantly applied in fields such as aviation, aerospace, civil engineering, biology, medicine, mechanics, and electronics. Active and semi-active control and vibration reduction of ships based on smart structures have great application prospects. By introducing secondary vibration sources into the controlled system and incorporating monitoring strategies, the controlled system's response to the secondary vibration sources is offset by the response to the primary vibration source, thus achieving mutually beneficial effects. However, active control is currently primarily applied to vibration isolation devices for key equipment, with little application in smart ship structures. Summary of the Invention

[0004] The purpose of this application is to provide an active vibration isolation method, device, equipment, medium and product based on piezoelectric ceramics, which can change the impedance characteristics of the hull structure and achieve vibration and noise reduction of the double bottom structure of the ship hull.

[0005] To achieve the above objectives, this application provides the following solutions:

[0006] In a first aspect, the present application provides an active vibration isolation method based on piezoelectric ceramics, comprising:

[0007] Step 1: Actively adjust the stiffness of the hull structure using a smart bracket made of piezoelectric ceramics, a smart material.

[0008] Step 2: Simulate the actual ship cabin section with the smart bracket installed to obtain the natural frequency and sound radiation data of the hull structure;

[0009] Step 3: Conduct prototype performance tests using intelligent brackets to predict the natural frequency and sound radiation data of the hull structure;

[0010] Step 4: Repeat steps 1 to 3. When the optimal natural frequency and optimal sound radiation data of the hull structure are determined, vibration and noise reduction are completed.

[0011] Optionally, step 1 specifically includes:

[0012] Generate control voltage for actuators made of smart materials—piezoelectric ceramics—based on model predictive control algorithms;

[0013] A feedforward-feedback composite linearization control method is used to compensate for the hysteresis effect of piezoelectric ceramics;

[0014] The impedance characteristics of the hull structure are adjusted in real time through intelligent connecting rods.

[0015] Optionally, the model predictive control algorithm includes offline control and online control; the offline control is to obtain the system characteristic data of the control output-control target nonlinear mapping of the hull structure based on finite element simulation, and to obtain the prediction model through neural network system identification and data fitting method; the online control is to combine the reference signal and the feedback vibration signal, calculate the control voltage through the prediction model, and adjust the output voltage in real time based on rolling optimization and feedback correction.

[0016] Optionally, the feedforward-feedback composite linearization control method specifically includes:

[0017] Feedforward compensation of hysteresis displacement of smart material - piezoelectric ceramics based on Bouc-Wen model;

[0018] Correct the error of feedforward compensation through PI feedback control;

[0019] Specifically, the control formula of the feedforward-feedback composite linearization method is:

[0020]

[0021] Where, h(t) is the hysteresis displacement component; A, β, F, n are the parameters of the Bouc-Wen model; u h (t) is the driving voltage after feedforward-feedback composite control, K P is the proportional coefficient of the PI controller, KI is the integral coefficient of the PI controller.

[0022] Optionally, step 2 specifically includes:

[0023] At the location where the smart bracket is installed, the underwater radiated sound pressure under a given excitation load is measured using a hydrophone;

[0024] According to the formula L P =20*log 10 (P / P0), convert the measured underwater radiated sound pressure into sound pressure level data and calculate the relevant total sound pressure level;

[0025] According to the formula SL=L P +20*log 10 (r p ), obtain the acoustic radiation data of the hydrophone measurement model;

[0026] At the location where the smart bracket is installed, an acceleration sensor is used to measure the vibration acceleration under a specific excitation load;

[0027] According to the formula L a =20*log 10 (a / a0), converting vibration acceleration into vibration acceleration level;

[0028] Compare the vibration acceleration level with the vibration acceleration level of the corresponding inspection point obtained by numerical calculation, calculate the absolute error and relative error, and draw the vibration acceleration level spectrum obtained by numerical calculation and experimental measurement;

[0029] Based on the vibration acceleration level spectrum, the natural frequency of the hull structure is determined.

[0030] Optionally, the prototype performance test includes:

[0031] Arrange the accelerometer and hydrophone on the test sample, and connect the vibrator, data acquisition system and power amplifier;

[0032] The reliability of the test device was verified by preloading, and vibration acceleration and sound pressure data were collected at 5 Hz intervals under different working conditions;

[0033] Compare the sound pressure level, vibration acceleration level, and natural frequency of the test and simulation results, and calculate the absolute and relative errors.

[0034] In a second aspect, the present application provides an active vibration isolation device based on piezoelectric ceramics, comprising:

[0035] Active adjustment module, used for actively adjusting the stiffness of the hull structure based on smart brackets made of smart materials—piezoelectric ceramics;

[0036] The simulation module is used to simulate the actual ship cabin section equipped with intelligent brackets to obtain the natural frequency and sound radiation data of the hull structure;

[0037] The prediction module is used to conduct prototype performance tests using intelligent brackets and predict the natural frequency and sound radiation data of the hull structure;

[0038] The output module is used to achieve vibration and noise reduction when determining the optimal natural frequency and optimal sound radiation data of the hull structure.

[0039] In a third aspect, the present application provides a computer device comprising: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement any one of the above-mentioned active vibration isolation methods based on piezoelectric ceramics.

[0040] In a fourth aspect, the present application provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements any one of the above-mentioned active vibration isolation methods based on piezoelectric ceramics.

[0041] In a fifth aspect, the present application provides a computer program product, including a computer program, which, when executed by a processor, implements any one of the above-mentioned active vibration isolation methods based on piezoelectric ceramics.

[0042] According to the specific embodiments provided in this application, this application discloses the following technical effects:

[0043] This application provides an active vibration isolation method, device, equipment, medium, and product based on piezoelectric ceramics. First, the stiffness of the hull structure is actively adjusted using an intelligent bracket based on the smart material piezoelectric ceramics. Subsequently, a simulation is performed on a real ship cabin section equipped with the intelligent bracket to obtain the natural frequency and acoustic radiation data of the hull structure. Next, a prototype performance test is conducted using the intelligent bracket to predict the natural frequency and acoustic radiation data of the hull structure. The above steps are repeated until the optimal natural frequency and optimal acoustic radiation data of the hull structure are determined, thereby achieving vibration and noise reduction. This application can change the impedance characteristics of the hull structure and achieve vibration and noise reduction of the double-bottom structure of the ship hull. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0045] Figure 1This is a diagram of an application environment of an active vibration isolation method based on piezoelectric ceramics in one embodiment of the present application;

[0046] Figure 2 A schematic flow chart of an active vibration isolation method based on piezoelectric ceramics provided in one embodiment of the present application;

[0047] Figure 3 A logic diagram of an active vibration isolation method based on piezoelectric ceramics provided in one embodiment of the present application;

[0048] Figure 4 A schematic diagram of the hoisting of a scaled-down model of a cabin section provided in one embodiment of the present application;

[0049] Figure 5 A diagram showing the installation arrangement of a bracket compartment provided in one embodiment of the present application;

[0050] Figure 6 A block diagram of the piezoelectric ceramic composite linearization control principle provided in one embodiment of the present application;

[0051] Figure 7 A schematic diagram of the structure of a computer device provided in one embodiment of the present application.

[0052] Explanation of symbols:

[0053] 1-water tank, 2-scale model of the cabin, 3-hydrophone, 4-position one, 5-position two, 6-position three, 7-position four, 8-position five. DETAILED DESCRIPTION

[0054] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0055] With the continuous development of shipbuilding, the requirements for ship power performance are becoming increasingly stringent, and the vibration reduction performance of ship equipment is receiving increasing attention. In shipbuilding, both the effects of the ship's own equipment and external environmental loads can affect hull vibration. For naval vessels, due to their unique operating environment, combat exposure to enemy weapons can cause even more severe impact vibration. Vibration with excessive amplitude and frequency not only exacerbates fatigue damage to the hull but also interferes with the normal operation of shipboard equipment, reducing operational accuracy and service life. Furthermore, prolonged exposure to cabin noise caused by hull vibration is extremely detrimental to shipboard personnel. Besides impacting comfort, fatigue, and work efficiency, it can even cause physical injury in severe cases. The importance of vibration reduction performance for naval vessels is self-evident, as the intensity of vibration and noise directly affects the ship's stealth performance, which in turn directly impacts the ship's combat effectiveness. Once a traditional ship structure is designed and manufactured, its dynamic characteristics are determined, making it difficult to make major adjustments in a short period of time. This makes ship vibration and noise a prominent issue. Therefore, it is of great significance to develop more advanced and effective ship vibration reduction equipment and structures and strengthen research on ship vibration control.

[0056] The purpose of this application is to provide an active vibration isolation method, device, equipment, medium and product based on piezoelectric ceramics, which can change the impedance characteristics of the hull structure and achieve vibration and noise reduction of the double bottom structure of the ship hull.

[0057] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the present application is further described in detail below with reference to the accompanying drawings and specific implementation methods.

[0058] The active vibration isolation method based on piezoelectric ceramics provided in the embodiment of the present application can be applied to Figure 1In the application environment shown. Among them, the terminal 102 communicates with the server 104 through the network. The data storage system can store the data that the server 104 needs to process. The data storage system can be set up separately, integrated on the server 104, or placed on the cloud or other servers. The terminal 102 can send the stiffness of the hull structure to the server 104. After the server 104 receives the stiffness of the hull structure, the server 104 actively adjusts the stiffness of the hull structure based on the smart bracket of the smart material - piezoelectric ceramic; simulates the actual ship cabin section installed with the smart bracket to obtain the natural frequency and sound radiation data of the hull structure; conducts a prototype performance test using the smart bracket to predict the natural frequency and sound radiation data of the hull structure; repeats the process, and when the optimal natural frequency and optimal sound radiation data of the hull structure are determined, the vibration reduction and noise reduction are completed. The server 104 can feedback the obtained vibration reduction and noise reduction results to the terminal 102. In addition, in some embodiments, an active vibration isolation method based on piezoelectric ceramics can also be implemented independently by the server 104 or the terminal 102. For example, the terminal 102 can directly process the stiffness of the hull structure, or the server 104 can obtain the stiffness of the hull structure from the data storage system and process the stiffness of the hull structure.

[0059] Terminal 102 may include, but is not limited to, various desktop computers, laptops, smartphones, tablet computers, IoT devices, and portable wearable devices. IoT devices may include smart speakers, smart TVs, smart air conditioners, and smart car devices. Portable wearable devices may include smart watches, smart bracelets, and head-mounted devices. Server 104 may be implemented as a standalone server or a server cluster consisting of multiple servers, or may be a cloud server.

[0060] In an exemplary embodiment, Figure 2 As shown, an active vibration isolation method based on piezoelectric ceramics is provided. The method is executed by a computer device, specifically a computer device such as a terminal or a server, or a terminal and a server. In the embodiment of the present application, the method is applied to Figure 1 Taking the server 104 in the example as an example, the following steps 1 to 4 are included:

[0061] Step 1: Actively adjust the stiffness of the hull structure using a smart bracket made of piezoelectric ceramics, a smart material.

[0062] Step 2: Simulate the actual ship cabin section with the smart bracket installed to obtain the natural frequency and sound radiation data of the hull structure;

[0063] Step 3: Conduct prototype performance tests using intelligent brackets to predict the natural frequency and sound radiation data of the hull structure;

[0064] Step 4: Repeat steps 1 to 3. When the optimal natural frequency and optimal sound radiation data of the hull structure are determined, vibration and noise reduction are completed.

[0065] When executing step 1, the specific steps may be as follows:

[0066] Step 101: Generate a control voltage for an actuator of a smart material (piezoelectric ceramic) based on a model predictive control algorithm;

[0067] Step 102: Using a feedforward-feedback composite linearization control method to compensate for the hysteresis effect of the piezoelectric ceramic;

[0068] Step 103: The impedance characteristics of the hull structure are adjusted in real time through the intelligent connecting rod.

[0069] Among them, the model predictive control algorithm described in step 101 includes offline control and online control; the offline control is to obtain the system characteristic data of the control output-control target nonlinear mapping of the hull structure based on finite element simulation, and to obtain the prediction model through neural network system identification and data fitting method; the online control is to combine the reference signal and the feedback vibration signal, calculate the control voltage through the prediction model, and adjust the output voltage in real time based on rolling optimization and feedback correction.

[0070] Specifically, when executing step 101, an offline step is first performed. Finite element simulation of the entire hull structure is used to obtain system characteristic data, including a nonlinear mapping of control output and control target. A prediction model is then obtained through system identification and data fitting methods such as neural networks. In online control, the control system inputs are a reference signal and a feedback system vibration signal. The prediction model calculates the required control signal, and then outputs the control voltage for the piezoelectric actuator using a designed control law, thereby achieving active stiffness adjustment. Simultaneously, a rolling optimization of the prediction model is performed using the feedback vibration signal and the objective function. The control law adjusts the output in real time based on the deviation of the feedback signal, achieving feedback correction of the controller.

[0071] Among them, piezoelectric ceramics, a smart material, are functional ceramic materials that exhibit the piezoelectric effect. When subjected to an external force, these materials generate charges of opposite sign on their surfaces, a phenomenon known as the piezoelectric effect. Conversely, when a voltage is applied, the material undergoes mechanical deformation, a phenomenon known as the inverse piezoelectric effect. These unique properties make piezoelectric ceramics a type of smart material, widely used in sensors, actuators, and other fields.

[0072] Specifically, when executing step 102, the smart material—piezoelectric ceramics—has a certain amount of hysteresis, which causes significant disturbances in the closed-loop control system. The control system is likely to remain in a transitional state for a long time, unable to enter the desired stable state. The hysteresis displacement of the piezoelectric ceramics is treated as interference, and corrective action is taken before it affects the control results, i.e., feedforward control is performed. However, the hysteresis displacement of the piezoelectric ceramics cannot be directly measured, so a state observer must be established to estimate the hysteresis displacement of the piezoelectric ceramic actuator online. In fact, this feedforward control is subject to errors. First, the Bouc-Wen mathematical model itself has simulation errors, namely the difference between the actual hysteresis calculated previously and the mathematical model. Second, the output of the hysteresis component state observer is an estimated value, which itself has errors. Third, there is interference from external sources. Therefore, using feedforward control alone for piezoelectric ceramic linearization control results in large errors. A feedback loop can be used to correct the errors, i.e., a composite linearization control method combining feedforward and feedback can be used.

[0073] Hybrid control uses Bouc-Wen model feedforward compensation control to compensate for the hysteresis of piezoelectric ceramics, and achieves closed-loop control of piezoelectric ceramics through PI feedback control to compensate for model errors and unmeasured interference. The block diagram of the piezoelectric ceramic composite linearization control principle is as follows: Figure 6 shown.

[0074] From the hybrid control principle diagram, we can see that:

[0075]

[0076] Among them, u h (t) is the driving voltage after feedforward-feedback composite control, K P is the proportional coefficient of the PI controller, K I is the integral coefficient of the PI controller.

[0077] The expression of feedforward-feedback composite control can be obtained:

[0078]

[0079] Among them, when executing step 103, the structural impedance characteristic data of the hull frame is monitored and fed back in real time through vibration detection equipment such as acceleration sensors and displacement sensors, the control system calculates the active control force of the intelligent connecting rod, and outputs the control current of the piezoelectric ceramic through the power amplifier to realize active stiffness adjustment of the hull structure, thereby changing the impedance characteristics of the hull structure and achieving vibration reduction and noise reduction of the double bottom structure of the ship hull.

[0080] In an exemplary embodiment, when executing step 2, the specific steps may be as follows:

[0081] Step 201: At the location where the smart bracket is installed, using a hydrophone, measure the underwater radiated sound pressure under a given excitation load;

[0082] Step 202: According to formula L P =20*log 10 (P / P0), convert the measured underwater radiated sound pressure into sound pressure level data and calculate the relevant total sound pressure level;

[0083] Step 203: According to the formula SL=L P +20*log 10 (r p ), obtain the acoustic radiation data of the hydrophone measurement model;

[0084] Step 204: Using an acceleration sensor at the location where the smart bracket is installed, measuring the vibration acceleration under a specific excitation load;

[0085] Step 205: According to formula L a =20*log 10 (a / a0), converting vibration acceleration into vibration acceleration level;

[0086] Step 206: Compare the vibration acceleration level with the vibration acceleration level of the corresponding inspection point obtained by numerical calculation, calculate the absolute error and relative error, and draw a spectrum diagram of the vibration acceleration level obtained by numerical calculation and experimental measurement;

[0087] Step 207: Determine the natural frequency of the hull structure based on the vibration acceleration level spectrum.

[0088] Specifically, before step 201 , the method further includes: constructing a finite element model.

[0089] Since the objects of assessment are natural frequency and sound radiation, respectively. The calculation of natural frequency is based on the change in the first peak value of the amplitude obtained from the Fourier transform of the vibration response to obtain the change in natural frequency. The obtained natural frequency change result is expressed as the change in natural frequency at the vibration response assessment position. Therefore, the change result obtained by the vibration response on the double bottom is the change result of the natural frequency of the double bottom structure. In addition, different working conditions are set by determining the vibration response assessment position, the excitation load application position, and the actuator output position. Three impact loads of different sizes are selected, and simulation calculations are performed with or without the actuator. The results of natural frequency and sound radiation under different working conditions are obtained and compared. It is found that the low-frequency vibration control effect of the bracket active control technology meets the technical index requirements.

[0090] In an exemplary embodiment, before executing step 3, the following steps may be performed:

[0091] Before starting the performance test of the intelligent bracket prototype, experimental preparations were carried out, including: single cabin structure, cabin bracket, hydrophone bracket and other test supporting structures, multi-channel signal acquisition system, acceleration sensor, displacement sensor, impedance sensor, exciter, power amplifier, excitation signal source, piezoelectric ceramics, programmable power supply, voltage regulator and other instruments.

[0092] like Figure 4 As shown, in the test, elastic ropes are used to hoist and fix the test components, and four-corner hoisting is adopted to simulate free boundary conditions. During hoisting, a cable artificial traction model should be set up on the model to avoid twisting of the steel cable and collision of the model with surrounding equipment. Before hoisting, the acceleration sensor should be arranged and the exciter should be installed at the designated position. The cables of the acceleration sensor and the hydrophone 3 should be bundled and extended from one side of the model and placed on the open deck. When hoisted to the designated position, the cables should be connected to the signal acquisition system. In order to facilitate data collection, the compartment model is hoisted to the longitudinal center of the pool 1. During the test, the hydrophone 3 is suspended in the pool 1 below the model. The cables should be bundled and kept long enough in the pool 1 so as not to affect the horizontal floating state of the hydrophone 3.

[0093] Install the smart bracket in Figure 5 The compartments shown are position one 4, position two 5, position three 6, position four 7, and position five 8.

[0094] Accelerometers should be installed accurately according to the design layout. First, use a marker to mark the measurement point locations and numbers on the test model. Have another researcher check the correct numbering. Once all preparations are complete, secure the accelerometers to the test model using 502 superglue. This connection method is convenient and secure, and provides more accurate test results. First, use 502 glue to secure the accelerometers. Each sensor's signal transmission line should be kept at an appropriate length at the sensor installation location to prevent tension from affecting test measurements or even from being torn or loosened during the test due to disturbances. The remaining transmission line should be bundled and secured to the model structure with tape in one direction. This should be routed out of the cabin model in one direction to avoid excessive data lines that could cause clutter or interfere with test performance. Once the superglue has fully developed and the accelerometers are securely fixed, record the accelerometer model and corresponding measurement point numbers for later data processing.

[0095] The hydrophone 3 is a sensitive component, so it needs to be installed on a well-designed fixed bracket to avoid damage to the performance of the hydrophone 3 when the crane is raised or lowered.

[0096] Number the excitation points, and use a wire rope to hang the vibrator just above the excitation point. Level the vibrator, connect the force sensor to the vibrator workbench, and use a threaded rod to connect the force sensor to the threaded hole at the excitation point on the base.

[0097] Connect the exciter signal output wire to the exciter, and at the same time, use the corresponding wire to connect it to the force sensor. At the same time, connect the wire to the vibration accelerometer, organize the wires together, number each wire, and then lead the above wires out of the model cabin, fix them to the outer plate of the cabin model with tape, and place them on the cabin model. After the model is hoisted into the water pool 1 and placed, it is connected to the test instrument; at the same time, place the hydrophone 3 at the corresponding position near the designed underwater radiation sound pressure measurement point, measure the actual installation position of the hydrophone 3, and connect the hydrophone 3 to the data acquisition system.

[0098] When executing steps 3 and 4, the test contents are as follows:

[0099] 1) Natural frequency test of ship intelligent bracket:

[0100] In order to study the change of the natural frequency after the intelligent bracket controls the ship structure, the natural frequencies of the ship bottom structure with and without the intelligent bracket control are measured under the same impact load conditions.

[0101] 2) Vibration response test of intelligent bracket under simple harmonic excitation load:

[0102] In order to study the vibration and noise reduction effect of the intelligent bracket on the ship structure, a sinusoidal excitation load is applied to the inner bottom plate, and the acceleration changes at the measuring points before and after the real-time control are measured.

[0103] 3) Test the radiated noise before and after the excitation source is working:

[0104] In order to verify the change of mechanical noise of the hull sample after the intelligent bracket is controlled, the acoustic radiation of the excitation source is measured when it is working.

[0105] Specifically, during the test, the cabin scale model 2 test is in progress. The working environment should be kept as quiet as possible. Each group of data transmission lines should be reasonably numbered and sequenced to facilitate the debugging, installation, inspection and maintenance of each system to ensure that the test can proceed smoothly. The main test steps are as follows:

[0106] 1) Connecting the sensor: Before installing the test sample, check the sensor, connect the sensor to the cable, and number both ends of the cable. At the same time, record the sensor model and the corresponding cable number to facilitate subsequent experimental processing.

[0107] 2) Check the test model: Before conducting the test, visually inspect the appearance and defects of the test model and measure the dimensions of the test sample.

[0108] 3) Connecting wires: After the test model is assembled, install the excitation equipment and measuring instruments at the designated locations in the work area, and use data transmission lines to connect the signal amplifier and the exciter, and at the same time connect the signal amplifier and the computer; connect the accelerometer and the data acquisition system, and at the same time connect the data acquisition system and the computer.

[0109] 4) Multi-channel signal acquisition system and transducer power amplifier: Connect the multi-channel signal acquisition system and transducer power amplifier to the power supply, and perform channel balance and zeroing processing, check whether all channels are normal, and if any abnormality is found, find the problem in time.

[0110] 5) Arrange the acceleration sensors and the hydrophones 3: Arrange the acceleration sensors and the hydrophones 3 according to the plan.

[0111] 6) Preload test: Preload each test sample before the formal test begins to check the reliability of the entire test device; check whether all measuring instruments are working properly.

[0112] 7) Loading and Data Collection: Once all the above test preparations are complete, the specimen can be loaded. Start the electrodynamic vibrator to load the specimen. Adjust the transducer power amplifier and measure and collect data at 5 Hz intervals.

[0113] 8) After testing one working condition, repeat the above test process to test the next working condition.

[0114] Among them, after the current working condition test is completed, the test data is processed as follows:

[0115] 1) First, use hydrophone 3 to measure the underwater radiation sound pressure of the model at the relevant measuring points under a given excitation load.

[0116] L P =20*log 10 (P / P0).

[0117] Among them L P is the sound pressure level (dB), P is the measured sound pressure (Pa), P0 is the reference sound pressure, take 10 -12 Pa.

[0118] According to the formula, the sound pressure measured by hydrophone 3 is used to obtain sound pressure level data and the associated total sound pressure level. The experimental sound pressure level and total sound pressure level results are compared with the numerically calculated sound pressure level and total sound pressure level list for the corresponding inspection points, and the absolute and relative errors between the two are calculated.

[0119] SL=L P +20*log 10 (r p ).

[0120] Where SL is the sound source level (dB), r p is the distance between the measurement point and the sound source (m).

[0121] The sound source level of the model is obtained from the sound pressure level. The sound source level spectra obtained by numerical calculation and experimental measurement are plotted, and the differences and similarities between the two are compared and analyzed in the form of curve graphs.

[0122] 2) Use an accelerometer to measure the vibration acceleration of the model under a given excitation load.

[0123] La=20*log 10 (a / a0);

[0124] Among them, L a is the vibration acceleration level (dB), a is the measured vibration acceleration (m / s 2 ), a0 is the reference acceleration (m / s 2 ), take 1*10 -6 m / s 2 .

[0125] Then, it is converted into vibration acceleration level by the above formula, and compared with the vibration acceleration level results of the corresponding inspection points obtained by numerical calculation. The absolute error and relative error of the two are calculated. At the same time, the vibration acceleration level spectrum diagram obtained by numerical calculation and experimental measurement is plotted, and the changes in the vibration acceleration level in the spectrum diagram are observed. The differences and similarities between the two are compared and analyzed, and the natural frequency results of the model are obtained from the vibration acceleration level spectrum diagram.

[0126] The present application also provides an application scenario that applies the above-mentioned active vibration isolation method based on piezoelectric ceramics. Specifically: The active vibration isolation method based on piezoelectric ceramics provided in this embodiment can be applied to the vibration control of the double-bottom structure of a ship. Through the composite control of the intelligent bracket and piezoelectric ceramics, active vibration isolation of the bottom structure of the ship is achieved. In practical applications, this method can significantly reduce the vibration and noise of the hull structure, and improve the stealth and ride comfort of the ship.

[0127] Based on the same inventive concept, embodiments of the present application also provide a piezoelectric ceramic-based active vibration isolation device for implementing the aforementioned problem. The solution provided by this device is similar to the solution described in the aforementioned method. Therefore, the specific limitations in one or more device embodiments provided below can be found in the aforementioned limitations of the piezoelectric ceramic-based active vibration isolation method and will not be further elaborated here.

[0128] In an exemplary embodiment, a piezoelectric ceramic-based active vibration isolation device is provided, comprising:

[0129] Active adjustment module, used for actively adjusting the stiffness of the hull structure based on smart brackets made of smart materials—piezoelectric ceramics;

[0130] The simulation module is used to simulate the actual ship cabin section equipped with intelligent brackets to obtain the natural frequency and sound radiation data of the hull structure;

[0131] The prediction module is used to conduct prototype performance tests using intelligent brackets and predict the natural frequency and sound radiation data of the hull structure;

[0132] The output module is used to achieve vibration and noise reduction when determining the optimal natural frequency and optimal sound radiation data of the hull structure.

[0133] In an exemplary embodiment, Figure 3 As shown in the figure, the logic of the active vibration isolation method based on piezoelectric ceramics is as follows: Vibration detection equipment such as accelerometers and displacement sensors monitor and provide real-time feedback on the structural impedance characteristics of the hull frame. An active variable stiffness control algorithm based on model predictive control is used to calculate the active control force of the intelligent link. The control current of the piezoelectric ceramics is output through a power amplifier to achieve active stiffness adjustment of the hull structure, resulting in an active vibration isolation method based on piezoelectric ceramics. This method was verified through simulations of a scaled-down cabin model and prototype performance experiments.

[0134] In an exemplary embodiment, a computer device is provided. The computer device may be a server or a terminal. The internal structure diagram thereof may be as follows: Figure 7 As shown. The computer device includes a processor, a memory, an input / output interface (Input / Output, abbreviated as I / O) and a communication interface. The processor, memory and input / output interface are connected through a system bus, and the communication interface is connected to the system bus through the input / output interface. The processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program and a database. The internal memory provides an environment for the operation of the operating system and computer program in the non-volatile storage medium. The database of the computer device is used to store processing data. The input / output interface of the computer device is used to exchange information between the processor and an external device. The communication interface of the computer device is used to communicate with an external terminal through a network connection. When the computer program is executed by the processor, an active vibration isolation method based on piezoelectric ceramics is implemented.

[0135] Those skilled in the art will understand that Figure 7The structure shown in the figure is only a block diagram of a part of the structure related to the solution of the present application, and does not constitute a limitation on the computer device to which the solution of the present application is applied. The specific computer device may include more or fewer components than shown in the figure, or combine certain components, or have a different component arrangement.

[0136] In an exemplary embodiment, a computer device is further provided, including a memory and a processor. The memory stores a computer program, and the processor implements the steps in the above method embodiments when executing the computer program.

[0137] In an exemplary embodiment, a computer-readable storage medium is provided, storing a computer program. When the computer program is executed by a processor, the steps in the above-mentioned method embodiments are implemented.

[0138] In an exemplary embodiment, a computer program product is provided, including a computer program. When the computer program is executed by a processor, the steps in the above method embodiments are implemented.

[0139] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, stored data, displayed data, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of relevant data must comply with relevant regulations.

[0140] Those skilled in the art will understand that all or part of the processes in the above-mentioned embodiment methods can be implemented by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to memory, database or other media used in the embodiments provided in this application may include at least one of non-volatile and volatile memory. Non-volatile memory may include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory may include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM may be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM).

[0141] The databases involved in the various embodiments provided herein may include at least one of a relational database and a non-relational database. Non-relational databases may include, but are not limited to, distributed databases based on blockchains. The processors involved in the various embodiments provided herein may include, but are not limited to, general-purpose processors, central processing units, graphics processing units, digital signal processors, programmable logic units, data processing logic units based on quantum computing, and the like.

[0142] The technical features of the above embodiments can be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0143] This document uses specific examples to illustrate the principles and implementation methods of this application. The description of the above examples is only intended to help understand the method and core concept of this application. At the same time, for those skilled in the art, based on the concept of this application, there may be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting this application.

Claims

1. An active vibration isolation method based on piezoelectric ceramics, characterized in that: include: Step 1: Actively adjust the stiffness of the hull structure using a smart bracket made of piezoelectric ceramics, a smart material. Step 2: Simulate the actual ship cabin section with the smart bracket installed to obtain the natural frequency and sound radiation data of the hull structure; Step 3: Conduct prototype performance tests using intelligent brackets to predict the natural frequency and sound radiation data of the hull structure; Step 4: Repeat steps 1 to 3. When the optimal natural frequency and optimal sound radiation data of the hull structure are determined, vibration and noise reduction are completed.

2. The active vibration isolation method based on piezoelectric ceramics according to claim 1, characterized in that: The step 1 specifically includes: Generate control voltage for actuators made of smart materials—piezoelectric ceramics—based on model predictive control algorithms; A feedforward-feedback composite linearization control method is used to compensate for the hysteresis effect of piezoelectric ceramics; The impedance characteristics of the hull structure are adjusted in real time through intelligent connecting rods.

3. The active vibration isolation method based on piezoelectric ceramics according to claim 2, characterized in that: The model predictive control algorithm includes offline control and online control; the offline control is to obtain the system characteristic data of the control output-control target nonlinear mapping of the hull structure based on finite element simulation, and to obtain the prediction model through neural network system identification and data fitting method; the online control is to combine the reference signal and the feedback vibration signal, calculate the control voltage through the prediction model, and adjust the output voltage in real time based on rolling optimization and feedback correction.

4. The active vibration isolation method based on piezoelectric ceramics according to claim 3, characterized in that: The feedforward-feedback composite linearization control method specifically includes: Feedforward compensation of hysteresis displacement of smart material - piezoelectric ceramics based on Bouc-Wen model; Correct the error of feedforward compensation through PI feedback control; Specifically, the control formula of the feedforward-feedback composite linearization method is: Where h(t) is the hysteresis displacement component; A, β, F, and n are the parameters of the Bouc-Wen model; u h (t) is the driving voltage after feedforward-feedback composite control, K P is the proportional coefficient of the PI controller, K I is the integral coefficient of the PI controller.

5. The active vibration isolation method based on piezoelectric ceramics according to claim 1, characterized in that: The step 2 specifically includes: At the location where the smart bracket is installed, the underwater radiated sound pressure under a given excitation load is measured using a hydrophone; According to the formula L P =20*log 10 (P / P0), convert the measured underwater radiated sound pressure into sound pressure level data and calculate the relevant total sound pressure level; According to the formula SL=L P +20*log 10 (r p ), obtain the acoustic radiation data of the hydrophone measurement model; At the location where the smart bracket is installed, an acceleration sensor is used to measure the vibration acceleration under a specific excitation load; According to the formula L a =20*log 10 (a / a0), converting vibration acceleration into vibration acceleration level; Compare the vibration acceleration level with the vibration acceleration level of the corresponding inspection point obtained by numerical calculation, calculate the absolute error and relative error, and draw the vibration acceleration level spectrum obtained by numerical calculation and experimental measurement; Based on the vibration acceleration level spectrum, the natural frequency of the hull structure is determined.

6. The active vibration isolation method based on piezoelectric ceramics according to claim 1, characterized in that: The prototype performance test includes: Arrange the accelerometer and hydrophone on the test sample, and connect the vibrator, data acquisition system and power amplifier; The reliability of the test device was verified by preloading, and vibration acceleration and sound pressure data were collected at 5 Hz intervals under different working conditions; Compare the sound pressure level, vibration acceleration level, and natural frequency of the test and simulation results, and calculate the absolute and relative errors.

7. An active vibration isolation device based on piezoelectric ceramics, characterized in that: include: Active adjustment module, used for actively adjusting the stiffness of the hull structure based on smart brackets made of smart materials—piezoelectric ceramics; The simulation module is used to simulate the actual ship cabin section equipped with intelligent brackets to obtain the natural frequency and sound radiation data of the hull structure; The prediction module is used to conduct prototype performance tests using intelligent brackets and predict the natural frequency and sound radiation data of the hull structure; The output module is used to achieve vibration and noise reduction when determining the optimal natural frequency and optimal sound radiation data of the hull structure.

8. A computer device comprising: A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement an active vibration isolation method based on piezoelectric ceramics according to any one of claims 1 to 6.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, an active vibration isolation method based on piezoelectric ceramics according to any one of claims 1 to 6 is implemented.

10. A computer program product comprising a computer program, characterized in that When the computer program is executed by a processor, an active vibration isolation method based on piezoelectric ceramics according to any one of claims 1 to 6 is implemented.

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