Super-large L-shaped high-sea-condition high-precision absorption type wave maker system and wave simulation method

Abstract

The invention relates to a super-large L-shaped high-sea-condition high-precision absorption type wave maker system and a wave simulation method.The wave maker system comprises a central control layer, an equipment control layer and an execution mechanism layer which are sequentially connected, and the central control layer is characterized in that a main control computer operates wave making control software; a target wave time calendar curve is generated, theoretical motion instructions needing to be executed by the wave making plates are synchronously deduced, the main PLC conducts format conversion and time sequence synchronization processing on the theoretical motion instructions, and wave making plate displacement curve instructions are generated and issued; the equipment control layer is used for calculating active absorption compensation from the PLC and generating a motor motion instruction; the executing mechanism layer comprises a super-large L-shaped wave making unit, a fan-shaped driving arm, a plurality of motors and other assemblies to execute wave making motion and feed back wave height information, and the motors drive the fan-shaped driving arm to drive a wave making plate to swing around a hinge assembly and drive the wave making plate to execute compensation action opposite to the phase of incident waves; high-sea-condition wave simulation and high-precision wave active absorption are realized, and a full-wave-direction test with navigational speed is supported.

Description

Technical Field

[0001] The present invention relates to the technical field of ship hydrodynamic test equipment, and in particular to an ultra-large L-shaped high-sea-state high-precision absorption wave maker system and a wave simulation method. Background Art

[0002] As a core testing facility in the field of ship hydrodynamics research, the Ship Maneuvering and Seakeeping Tank plays an irreplaceable role in ship model maneuverability and seakeeping tests, shipping safety assessments, and energy efficiency optimization. This facility is primarily used to conduct research on the hydrodynamic characteristics of ships and other surface and underwater moving bodies, including but not limited to key areas such as maneuverability analysis, seakeeping testing, energy efficiency assessments, and stability studies.

[0003] Wave machines simulate specific sea conditions in a water tank environment, providing essential testing conditions for research activities such as hydrodynamic performance studies of ships and marine engineering structures and shipping safety assessments. However, most existing wave-making systems used in seakeeping tanks suffer from significant technical limitations: limited wave-making capacity, insufficient wave-making plates, an inability to conduct full-wave-direction seakeeping tests at speed, and a lack of active absorption capabilities. These technical bottlenecks severely restrict test accuracy, making it difficult to accurately predict the seakeeping performance of actual ships under real-world sea conditions. Therefore, improving the comprehensive performance of wave-making systems, particularly enhancing their multi-directional wave-making capabilities, expanding their frequency range, and implementing active absorption capabilities, has become a core focus of upgrading and renovating ship hydrodynamic test facilities.

[0004] Specifically, the existing technology can be divided into the following key issues:

[0005] (1) Currently, many small wave generators used in seakeeping tanks have a significant problem of insufficient wave height generation capacity, which directly leads to the forced increase of the scale ratio (actual ship size / ship model size) of ship model tests. Excessive scale ratio will introduce significant scale effects, seriously affecting the accuracy of test results, and thus reducing the accuracy of the prediction of the actual ship's seakeeping performance. This technical bottleneck limits the application value of tanks in high-precision ship hydrodynamic performance research.

[0006] (2) The existing wave-making system configuration of some maneuvering and seakeeping tanks has obvious defects. Only a single-sided wave maker is arranged on one side of the tank, which only has the ability to generate waves on one side. This configuration cannot meet the requirements of full-wave wavekeeping tests under speed conditions, including the simulation of various wave direction conditions such as following waves, bow oblique waves, stern oblique waves, beam waves and head waves. This seriously restricts the comprehensiveness and reliability of the tank's research on ship maneuverability and seakeeping under complex sea conditions.

[0007] (3) Currently, many L-shaped wave makers used in maneuvering wave-keeping tanks generally have the problem of insufficient scale, with the number of wave-making plates being less than 200. This causes the transient waves (non-propagating morphological waves) generated by the short-side wave makers to interfere with the flow field near the ship model, and the long-side wave makers are inefficient when conducting irregular wave tests. A single wave condition often requires multiple, or even ten, split tests to complete. In addition, the pool boundary effect is more significant in small-scale wave maker systems, further reducing the scope of the effective test area and seriously affecting the quality and reliability of the test data. These technical defects highlight the urgent need to improve the scale of wave makers and the overall performance of the pool. Summary of the Invention

[0008] To address the problems of existing wave-making systems, such as limited wave-making capacity, insufficient wave-making plate configuration, inability to conduct full-speed, all-wave-direction seakeeping tests, and lack of active wave absorption, this invention proposes an ultra-large L-shaped, high-sea-state, high-precision absorption wave-making system. This system improves the scale and stability of wave-making, achieves high-precision wave simulation and absorption, and possesses multi-directional wave-making capabilities and active absorption functions, supporting full-speed, all-wave-direction testing. The invention also relates to a wave simulation method for this ultra-large L-shaped, high-sea-state, high-precision absorption wave-making system.

[0009] The technical solutions of the present invention are as follows:

[0010] An ultra-large L-shaped high-sea-state high-precision absorption wave maker system, characterized by comprising a central control layer, a device control layer and an actuator layer connected in sequence,

[0011] The central control layer includes a main control cabinet and a main control computer and main PLC configured in the main control cabinet. The main control computer runs wave-making control software, generates a target wave history curve based on high sea state target parameters, and simultaneously derives theoretical motion instructions to be executed by each wave-making board. The main PLC performs format conversion and timing synchronization on the theoretical motion instructions, generates wave-making board displacement curve instructions that can be recognized by the equipment control layer, and sends them to the equipment control layer according to the communication timing. At the same time, the target wave history curve is synchronously sent as a wave morphology verification benchmark.

[0012] The equipment control layer includes several wave-making machine electrical control cabinets, each of which is equipped with a slave PLC and several drivers. Each slave PLC receives the wave-making plate displacement curve instruction issued by the master PLC, analyzes it into a control signal for the corresponding driver, and outputs the drive signal to the motor of the actuator layer through the driver; collects the wave-making plate motion state signal in real time, compares it with the wave-making plate displacement curve instruction issued by the master PLC, and dynamically adjusts the driver output to achieve high-precision wave-making plate motion closed-loop control; collects wave height meter data in real time, compares it with the wave shape verification benchmark to calculate the active absorption compensation value, and then converts it into a reverse motion instruction for the wave-making plate. The reverse motion instruction is converted into a control signal by the driver and sent to the motor of the actuator layer, and the active absorption compensation value is fed back to the central control layer;

[0013] The actuator layer includes an extra-large L-shaped wave-making unit, a hinge assembly, a wave height meter in front of the board, a fan-shaped drive arm, a fork arm support and a frame support, and several motors. Each motor corresponds to the driver of the equipment control layer one by one. The extra-large L-shaped wave-making unit is vertically spliced ​​into an L shape by a short-side wave-making mechanism and a long-side wave-making mechanism. The short-side wave-making mechanism is arranged along the width direction of the experimental water pool, and includes M wave-making plates spliced ​​end to end along its own length direction; the long-side wave-making plate mechanism is arranged along the length direction of the experimental water pool, and includes N wave-making plates spliced ​​end to end along its own length direction, M+N≥400, and each wave-making plate is arranged vertically in the initial state; the lower end of each wave-making plate is hinged to the frame support through a hinge assembly, and the middle section of the back of each wave-making plate is connected to the frame support. It is fixedly connected to one end of the fan-shaped driving arm, the other end of the fan-shaped driving arm is hinged to one end of the fork arm support, and the other end of the fork arm support is hinged to the bottom of the wave-making board, so that the wave-making board, the fan-shaped driving arm and the fork arm support form a triangular stable structure; the wave height meter in front of the board is arranged vertically in front of each wave-making board for real-time collection of wave height meter data; the motor output shaft is fixedly connected to the root of the fan-shaped driving arm, and the rotation centers of the two coincide, driving the fan-shaped driving arm to drive the wave-making board to swing around the hinge assembly to realize high sea state wave simulation; at the same time, the reverse motion instruction generated by the equipment control layer drives the motor action to be transmitted to the wave-making board through the fan-shaped driving arm, driving the wave-making board to perform a compensation action with a phase opposite to the incident wave, thereby realizing high-precision active wave absorption.

[0014] Preferably, the wave-making control software run by the main control computer in the central control layer establishes a mathematical relationship between the swing angle of the wave-making plate and the target wave height based on the micro-wave theory and the Stokes wave theory, and generates any combination of regular waves, irregular waves, white noise waves, second-order waves, single-point focused waves, multi-point focused waves, deformed waves and broken waves. The irregular waves include PM spectra, JONSWAP spectra, ITTC spectra, and ITTC dual-parameter spectra. The focusing time error of the single-point focused wave is ≤±0.1 seconds, and the wave height magnification factor of the focused point is ≥3 times. The wave height of the deformed wave exceeds 2 times the effective wave height, and the duration is ≥3 wave cycles.

[0015] Preferably, the device control layer collects wave height meter data from the PLC in real time, performs frequency domain analysis based on the IIR filter model, separates the incident wave and reflected wave components, and extracts the frequency, amplitude and phase parameters of the waves; based on the extracted frequency, amplitude and phase parameters of the waves, the wave morphology calibration benchmark is compared, and the active absorption compensation value is iteratively calculated using a recursive reweighted Gauss-Newton algorithm.

[0016] Preferably, the equipment control layer includes 30 wave-making machine electrical control cabinets, each of which is equipped with a slave PLC and 16 drivers, thereby forming a distributed control architecture consisting of 1 master PLC and 30 slave PLCs. The 30 slave PLCs communicate data and exchange commands through EL6695 real-time Ethernet to achieve multi-axis synchronous control, so that the swing synchronization error of each wave-making plate is ≤20 microseconds.

[0017] Preferably, the actuator layer includes a transmission assembly, and the root of the sector drive arm is fixedly connected to the corresponding motor through the transmission assembly; the transmission assembly includes a reducer, a driving pulley, a toothed synchronous belt, and a driven pulley; wherein, the output shaft of the motor of the actuator layer is connected to the reducer, and after deceleration and torque increase by the reducer, its output shaft is fixedly connected to the driving pulley; the driving pulley is meshed with the sector drive arm through the toothed synchronous belt, and the toothed synchronous belt is tensioned and guided by the driven pulley;

[0018] When the central control layer issues a displacement curve instruction for the wave-making plate, the slave PLC of the equipment control layer parses the instruction and generates a motor drive signal through the driver to drive the motor of the actuator layer to rotate. The power of the motor is input to the reducer, and the reducer converts high speed and low torque into low speed and high torque through a gear set. The output shaft drives the active pulley to rotate, and the active pulley engages with the driven pulley through a toothed synchronous belt to transmit the rotational motion to the reciprocating swing of the fan-shaped drive arm. The fan-shaped drive arm drives the wave-making plate to swing around the hinge assembly to achieve wave generation and active absorption.

[0019] Preferably, in the actuator layer, the short-side wave-making mechanism includes 88 wave-making plates spliced ​​end to end along its own length direction; the long-side wave-making mechanism includes 392 wave-making mechanisms spliced ​​end to end along its own length direction, and the immersion depth of each wave-making plate is 2.0 meters and the dry chord height is 0.8 meters; the actuator is configured with a limit switch at the extreme swing angle position of the wave-making plate. When the wave-making plate triggers the limit switch, the limit switch feeds back a signal to the PLC, and the driver cuts off the power supply to the motor.

[0020] Preferably, in the actuator layer, the fan-shaped driving arm drives the wave-making plate to swing around the hinge assembly to achieve high sea state wave simulation with a wave direction angle of 0° to 165°; wherein the wave direction angle is the angle between the wave propagation direction and the length direction of the experimental pool, including:

[0021] 0° head-on wave condition: the wave propagation direction is opposite to the sailing direction of the ship model;

[0022] 45°~135° bow / stern oblique wave condition: the waves hit the bow or stern of the ship model in an oblique direction;

[0023] 90° beam wave condition: the waves are perpendicular to the sailing direction of the ship model;

[0024] 165° wave-following condition: the angle between the wave propagation direction and the sailing direction of the ship model is ≤15°.

[0025] A wave simulation method for an ultra-large L-shaped high-sea-state high-precision absorption wave maker system, characterized by comprising the following steps:

[0026] System construction steps: vertically splice the short-side wave-making mechanism and the long-side wave-making mechanism into an L-shaped super-large L-shaped wave-making unit. The short-side wave-making mechanism is arranged along the width direction of the experimental pool, and includes M wave-making plates spliced ​​end to end along its own length direction. The long-side wave-making mechanism is arranged along the length direction of the experimental pool, and includes N wave-making plates spliced ​​end to end along its own length direction. M+N≥400. The wave-making plates are arranged vertically in the initial state; the super-large L-shaped wave-making unit is assembled with the hinge assembly, the wave height meter in front of the board, the fan-shaped drive arm, the fork arm support, the frame support and the servo motor to build the actuator layer, and the wave-making plates, the fan-shaped drive arm and the fork arm support form a triangular stable structure. The electrical connection and mechanical assembly between the actuator layer and the equipment control layer and the central control layer are completed respectively;

[0027] System initialization steps: Start the central control layer's main control computer and main PLC, load the wave-making control software; set the initial parameters to a wave-making plate immersion depth of 2.0 meters and a freeboard height of 0.8 meters through the human-computer interface; the main PLC sends initialization instructions to the equipment control layer, and the slave PLCs in the equipment control layer drive the servo motors in the actuator layer to adjust the wave-making plate to the vertical zero position; the wave height meter in front of the board completes zero-point calibration, and the real-time collected data is fed back to the central control layer as the initial value of the wave shape verification benchmark;

[0028] Instruction generation and issuance steps: The main control computer in the central control layer runs the wave-making control software. Based on the high-sea target parameters, micro-amplitude wave theory and Stokes wave theory, it establishes a mathematical relationship between the wave-making board's swing angle and the target wave height, generates a target wave time history curve, and simultaneously derives the theoretical motion instructions required for each wave-making board. The main PLC converts the theoretical motion instructions and performs timing synchronization processing to generate and issue the wave-making board displacement curve instructions.

[0029] Instruction execution and closed-loop control steps: The slave PLC at the equipment control layer receives displacement curve instructions and interprets them into corresponding driver control signals to drive the servo motor. The wave-making plate motion status signal is collected in real time and compared with the wave-making plate displacement curve instructions issued by the master PLC. The driver output is dynamically adjusted to achieve high-precision closed-loop control of the wave-making plate motion. Wave height meter data is also collected and frequency-domain analysis is performed based on an IIR filter model. A recursive reweighted Gauss-Newton algorithm is used to calculate the active absorption compensation value, generating a reverse motion instruction to drive the servo motor.

[0030] Wave generation and active absorption steps: The servo motor at the actuator layer drives the fan-shaped drive arm and wave-making plate to swing through the transmission assembly, generating waves according to the instructions; and performing a compensation action opposite to the phase of the incident wave according to the reverse motion instruction, completing high-precision active wave absorption.

[0031] Preferably, in the system construction step, the equipment control layer is configured with 30 wave maker electrical control cabinets, and each wave maker electrical control cabinet is configured with a slave PLC and 16 drivers, thereby forming a distributed control architecture consisting of 1 master PLC and 30 slave PLCs;

[0032] In the instruction generation and issuance steps, the master PLC issues instructions to 30 slave PLCs based on the EtherCAT protocol by configuring the real-time Ethernet architecture of the EL6695 EtherCAT master module. Each slave PLC uses the EtherCAT distributed clock to compensate for network transmission delays and responds to clock synchronization calibration instructions to calibrate the initial offset, achieving multi-axis synchronous control and ensuring that the instruction execution time deviation of the 30 slave PLCs is ≤20μs.

[0033] Preferably, in the instruction execution and closed-loop control steps, the device control layer parses the instructions from the PLC and generates a motor drive signal through the driver to drive the motor of the actuator layer to rotate; in the wave generation and active absorption steps, the power of the motor is input to the reducer, and the reducer converts high speed and low torque into low speed and high torque through a gear set, and the output shaft drives the driving pulley to rotate, and the driving pulley is engaged with the driven pulley through a toothed synchronous belt to transmit the rotational motion to the reciprocating swing of the fan-shaped drive arm, and the fan-shaped drive arm drives the wave-making plate to swing around the hinge assembly to achieve wave generation and active absorption.

[0034] The technical effects of the present invention are as follows:

[0035] The present invention relates to an extra-large L-shaped high-sea-state high-precision absorption wave maker system, which is a new type of wave maker with strong wave maker capacity, high wave simulation accuracy, large wave maker scale, and active absorption function, and can solve the problems encountered in current wave simulation in water pools. Its central control layer generates the target wave time history curve based on the high sea condition target parameters through the main control computer, accurately derives the theoretical motion instructions of the wave-making board, and combines the format conversion and timing synchronization processing of the instructions by the main PLC to realize the precise instruction source output of the coordinated movement of multiple wave-making boards, laying the control foundation for the simulation of complex wave forms in high sea conditions and ensuring the matching degree between the wave time history curve and the target sea condition; it simultaneously sends down the wave form verification benchmark, builds a "target-feedback" verification system for wave-making accuracy, provides a precise reference for subsequent active absorption compensation, and improves the sea condition reproduction capability of the wave-making system from the control source; its equipment control layer parses instructions from the PLC to drive the motor of the actuator layer, collects the wave-making board motion state signal in real time to realize closed-loop control, dynamically adjusts the driver output, controls the wave-making board motion deviation within ±0.1°, ensures the motion accuracy of a single wave-making board, and provides support for the consistency of the overall wave form; it calculates the active absorption compensation value based on the wave height meter data and the verification benchmark, converts the reverse motion instruction and feeds back, forming a "wave-making-wave-breaking" control closed loop, effectively suppressing the second The secondary reflected waves ensure the stability of the wave field in the pool and meet the needs of continuous and precise test environment under high sea conditions; its actuator layer includes an ultra-large L-shaped wave-making unit with a layout of M short-side wave-making plates + N long-side wave-making plates, totaling more than 400 plates (such as 88 short-side wave-making plates + 392 long-side wave-making plates), covering the width and length of the pool, combined with the vertical arrangement of head-to-tail splicing, to construct a large-scale, continuously controllable wave-making surface, realizing the full-domain simulation of multi-directional and complex waves under high sea conditions (wave direction covers 0°-180°), wave-making plates, fan-shaped The driving arm and fork arm support form a triangular stable structure, which, together with the articulated design of the hinge assembly, improves the structural stiffness of the wave-making board during swinging (lateral displacement ≤ 2mm), ensures the stability of the mechanical structure during the wave-making process, and supports long-term reliable operation under high sea conditions and heavy loads; the wave height meter in front of the board collects data in real time and cooperates with the reverse motion command to drive the wave-making board's compensation action to achieve active wave absorption. The execution end accurately responds to the control layer's instructions, ensures the timeliness and accuracy of wave absorption, and synergistically improves the system's simulation and control capabilities for complex sea conditions.The present invention can simulate extreme sea conditions with wave height ≥1m and period 0.5-10s through precise command generation and synchronous scheduling of the central control layer, closed-loop motion control and active absorption compensation of the equipment control layer, and coordination of the ultra-large L-shaped layout and stable mechanical structure of the actuator layer. It covers various wave forms such as regular waves and irregular waves, and meets the wave resistance test requirements of ships, marine structures, etc. under high sea conditions; the wave-making plate motion synchronization error is ≤20μs, the wave crest straightness error is ≤±5mm / m, and the wave stability accuracy after active absorption (wave height deviation ≤±1.5%) ensures the accuracy and reliability of the test data; the ultra-large L-shaped wave-making unit constructs a full-area wave-making surface, combined with the active absorption function, effectively suppresses wave reflection interference, and provides a precise wave environment with integrated "generation-absorption" for marine engineering experiments, breaking through the limitations of traditional wave-making systems in sea condition reproduction range, control accuracy and wave field stability, and facilitating the research and development and performance verification of marine equipment under high sea conditions.

[0036] The present invention has an extra-large L-shaped layout. By combining more than 400 long and short-side wave-making plates, for example, 88 short-side plates + 392 long-side plates = 480 plates, an L-shaped structure covering the width and length of the pool is formed, significantly expanding the wave-making area. Compared with traditional unidirectional wave-making systems, it can simulate more complex wave forms (such as oblique waves and multi-directional waves). In the central control layer, wave time history curves are generated according to high-sea-state target parameters. Combined with the triangular stabilization structure of the actuator, the system can withstand greater wave loads and achieve high-sea-state simulation with a wave height of ≥1m and a period range of 0.5-10s. It has high sea-state adaptability and breaks through the capacity limitations of traditional wave-making systems in extreme sea conditions. The total configuration of more than 400 wave-making boards far exceeds that of conventional wave-making systems (usually less than 200 boards), and adopts a modular splicing design (spliced ​​end to end along its own length), which can be flexibly expanded according to the size of the pool, solving the problems of low wave simulation accuracy and limited coverage area caused by the insufficient number of wave-making boards in the existing system; each wave-making board is independently equipped with a motor and driver, and independent closed-loop control of each wave-making board is achieved through the equipment control layer. Distributed drive can achieve more precise wave shape control compared to traditional centralized drive systems. The short-side and long-side wave-making mechanisms are vertically spliced ​​to form an L-shaped orthogonal layout, which can generate waves from two directions simultaneously, realizing the wave resistance test of ships under different wave directions (including oblique waves and transverse waves), and making up for the defect that traditional single-direction wave-making systems can only test head-on or following wave conditions; the timing synchronization processing of the central control layer and the displacement curve instructions of the equipment control layer form multi-board collaborative control, ensuring the coordinated action of wave-making boards in different positions, which can accurately simulate the wave field under complex sea conditions and support the full wave direction test requirements with speed. By collecting wave data in real time through the wave height meter in front of the board, the device control layer calculates the active absorption compensation value and drives the wave-making board to perform a compensation action opposite to the phase of the incident wave, forming a complete "perception-calculation-execution" closed-loop control architecture, realizing active wave absorption and effectively suppressing the interference of reflected waves on test results. Combined with the high rigidity support and ±0.1° swing accuracy provided by the triangular stabilization structure, the system can quickly respond to wave changes and achieve efficient energy absorption, solving the inefficiency problem of traditional wave-making systems relying on passive wave-breaking flats. Therefore, the ultra-large L-shaped layout + triangular stabilization structure of the ultra-large L-shaped high-sea-state high-precision absorption wave-making machine system of the present invention improves the scale and stability of wave-making; distributed closed-loop control + timing synchronization realizes high-precision wave simulation and absorption; multi-directional wave-making capability + active absorption function supports full-wave direction testing at speed. These improvements make the wave-making machine system significantly superior to existing technologies in terms of wave-making capability, configuration flexibility, and test function integrity, making it particularly suitable for the high-sea-state and high-precision testing requirements in the field of marine engineering.

[0037] Furthermore, the wave-making control software run by the main control computer in the central control layer adopts the global wave pool wave-making theory, combined with advanced wave analysis and calculation methods (based on the micro-wave theory and Stokes wave theory to establish the mathematical relationship between the wave-making plate motion swing angle and the target wave height) to generate wave-making control signals, which can accurately simulate various complex wave forms such as regular waves and irregular waves and their combinations. By setting multiple spectral types of irregular waves, the focusing time error and wave height amplification coefficient of single-point focused waves, and the wave height and duration parameters of deformed waves, the system can reproduce real wave scenes under different sea conditions, meet the diverse needs of ship wave resistance tests, marine structure performance tests, etc., and significantly improve the simulation accuracy and application range of the wave-making machine system for complex sea conditions.

[0038] Furthermore, the PLC in the equipment control layer uses an IIR filter model to perform frequency domain analysis on the wave height meter data, accurately separating the incident wave from the reflected wave, extracting key wave parameters, and providing a reliable data basis for active absorption. The application of the recursive reweighted Gauss-Newton algorithm can iteratively calculate the optimal active absorption compensation value based on the extracted parameters, effectively suppressing wave reflections, improving the stability of the wave field in the water tank, and achieving an absorption rate of ≥80% for secondary reflected waves, thereby ensuring the accuracy of high sea wave simulation and the accuracy of test data. By comparing the target wave spectrum with the wave height meter feedback data in real time, the adaptive algorithm is used to dynamically calculate the compensation wave parameters and seamlessly superimpose them on the target wave file, ultimately achieving internationally advanced wave simulation accuracy. This technological breakthrough provides an unprecedentedly precise simulation environment for marine engineering experiments.

[0039] Furthermore, the equipment control layer adopts a 1-master-30-slave distributed control architecture, combined with EL6695 real-time Ethernet communication technology, to achieve multi-axis synchronous control, controlling the swing synchronization error of each wave-making board to ≤20 microseconds. This technical solution ensures a high degree of coordination between the multiple wave-making boards during movement, making the wave crest straightness error ≤10°, effectively improving the consistency and stability of the wave shape, and meeting the strict requirements of high-precision wavemaking in severe sea conditions.

[0040] Furthermore, the transmission component of the actuator layer adopts a transmission structure of "reducer-driving pulley-toothed synchronous belt-driven pulley". Through the reduction gear reduction and torque increase, the high speed and low torque of the motor is converted into low speed and high torque suitable for driving the fan-shaped drive arm. Combined with the precise transmission of the toothed synchronous belt, the rotational motion of the motor can be efficiently and stably converted into the reciprocating swing of the fan-shaped drive arm, thereby driving the wave-making plate to achieve precise wave generation and active absorption action, ensuring the reliability of the wave-making machine operation and the accuracy of power transmission.

[0041] Furthermore, the actuator layer clarifies the layout of the wave-making plates with 88 pieces on the short side and 392 pieces on the long side. Combined with the design of 2.0-meter immersion depth and 0.8-meter dry chord height, the effective wave-making area of ​​the wave maker is expanded, and the ability to drive the water body to generate waves is improved, meeting the simulation requirements of high-energy waves under high sea conditions. The limit switch set at the extreme swing angle position can be triggered in time when the swing of the wave-making plate reaches the critical angle, cutting off the power supply to the motor to prevent the wave-making plate from swinging excessively and causing damage to the mechanical structure, effectively ensuring the operational safety and service life of the wave-making machine equipment.

[0042] The present invention also relates to a wave simulation method for an ultra-large L-shaped high-sea-state high-precision absorption wave maker system, which corresponds to the ultra-large L-shaped high-sea-state high-precision absorption wave maker system of the present invention. It can be understood as the wave simulation method for the ultra-large L-shaped high-sea-state high-precision absorption wave maker system, including system construction steps, system initialization steps, instruction generation and issuance steps, instruction execution and closed-loop control steps, and wave generation and active absorption steps. Through the coordinated movement of ultra-large-scale L-shaped wave-making units (≥400 panels) and the three-layer intelligent control frame The system combines global wave theory to generate target wave instructions, uses IIR filter frequency domain analysis and recursive reweighted Gauss-Newton algorithm to calculate compensation values ​​in real time, and ultimately achieves accurate wave simulation in high sea conditions (regular wave height 1.0m / irregular wave significant wave height 0.5m) and all wave directions (0°-165°). It also simultaneously completes active absorption with a reflected wave absorption rate of ≥80%, with an effective test area exceeding 150 meters. This completely solves the boundary effect, large synchronization error (≤20μs after compensation), and reflected wave interference problems caused by the insufficient scale of traditional wave-making systems. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 This is a structural diagram of the super-large L-shaped high-sea-state high-precision absorption wave maker system of the present invention.

[0044] Figure 2 This is a working principle diagram of the super-large L-shaped high-sea-state high-precision absorption wave maker system of the present invention.

[0045] Figure 3a and Figure 3b All of them are schematic diagrams of the wave-making control software interface of the present invention.

[0046] Figure 4 This is a flow chart of the recursive reweighted least squares method used by the slave PLC in the device control layer of the present invention.

[0047] Figure 5 Schematic diagram of the arrangement of the super-large L-shaped wave-making unit of the present invention.

[0048] Figure 6 Schematic diagram of the preferred structure of the components of the actuator layer of the present invention.

[0049] Figure 7 for Figure 6 Schematic diagram of the structure from another angle.

[0050] Figure 8 This is a schematic diagram of the disassembled structure of the components of the actuator layer of the present invention.

[0051] Figure 9 、 10 Schematic diagram of the structure of the components of the actuator layer of the present invention in different working states.

[0052] Figure 11 It is a schematic diagram of the transmission component structure in the actuator layer of the present invention.

[0053] Figure 12 This is a schematic diagram of the triangular stable structure formed by the wave-making plate, fan-shaped driving arm, and fork back support of the present invention.

[0054] Examples of the labels in the figure are as follows:

[0055] 1—motor and transmission components; 101—motor; 102—reducer; 103—driving pulley; 104—toothed synchronous belt; 105—driven pulley; 2—top support; 3—limit switch; 4—wave height meter; 5—wave maker; 6—hinge (shaft); 7—spindle; 8—spindle; 9—spindle; 10—spindle; 11—spindle; 12—spindle; 13—spindle; 14—spindle; 15—spindle; 16—spindle; 17—spindle; 18—spindle; 19—spindle; 20—spindle; 21—spindle; 22—spindle; 23—spindle; 24—spindle; 25—spindle; 26—spindle; 27—spindle;

[0056] —Frame support; 8—Fork arm support; 9—Fan-shaped drive arm. DETAILED DESCRIPTION

[0057] The present invention will be described below with reference to the accompanying drawings.

[0058] The present invention relates to an ultra-large L-shaped high-sea-state high-precision absorption wave maker system, such as Figure 1 The structure shown includes a central control layer, a device control layer, and an actuator layer connected in sequence. The central control layer and the device control layer are connected via an Ethernet communication system. The device control layer and the actuator layer are connected via cables.

[0059] 1. Central Control Layer: This includes the main control cabinet, the main control computer, and the main PLC located within. The main control computer runs the wavemaking control software, generates target wave history curves based on high sea state target parameters, and simultaneously derives the theoretical motion instructions required for each wavemaking board. The main PLC converts the theoretical motion instructions and synchronizes their timing to generate wavemaking board displacement curve instructions that can be recognized by the equipment control layer. These instructions are then sent to the equipment control layer according to the communication timing sequence. The target wave history curves are also sent to the layer simultaneously as a benchmark for wave morphology verification.

[0060] Specifically, if Figure 2As shown in the working principle, the main control computer runs the wave-making control software to generate a wave-making file, that is, to generate a target wave time history curve based on the high sea state target parameters, and simultaneously derive the theoretical motion instructions that each wave-making board needs to execute. Furthermore, the wave-making control software includes wave-making simulation and wave-making control. The wave-making simulation is aimed at the wave-making needs of the entire wave pool. Based on the micro-wave theory and Stokes wave theory, a mathematical relationship between the swing angle of the wave-making board and the target wave height is established, and a wave-making machine control transfer function is constructed to generate regular waves, irregular waves, white noise waves, second-order waves, single-point focused waves, multi-point focused waves, deformed waves and broken waves in any combination of wave forms, wherein the irregular waves include PM spectrum, JONSWAP spectrum, ITTC spectrum, ITTC dual-parameter spectrum and other functions; the focusing time error of the single-point focused wave is ≤±0.1 seconds, and the wave height magnification factor of the focused point is ≥3 times; the wave height of the deformed wave exceeds 2 times the effective wave height, and the duration is ≥3 wave cycles. As Figure 3a The main interface of the wave control software shown in the figure includes the regular wave parameter settings, which can set parameters such as wave height, period, water depth, direction, data interval, etc., and perform wave starting, zero sampling, data collection and storage, and the interface displays the wave curve; Figure 3b The main interface of the wave-making control software shown in the figure is used to set the parameters of the unidirectional irregular wave.

[0061] In other words, the present invention is a global wave maker that adopts the global wave pool wave making theory and combines it with advanced wave analysis and calculation methods to generate wave making control signals, which can realize the simulation of wave forms such as regular waves, irregular waves, white noise waves, second-order waves, single-point focused waves, multi-point focused waves, deformed waves, and breaking waves.

[0062] The wave machine control is to synchronously derive the theoretical motion instructions that each wave-making board needs to execute; the main PLC converts the format and performs timing synchronization on the theoretical motion instructions, generates wave-making board displacement curve instructions that can be recognized by the equipment control layer, and sends them to the equipment control layer according to the communication timing. At the same time, the target wave history curve is synchronously sent as a wave morphology verification benchmark.

[0063] 2. Equipment Control Layer: This layer includes several electrical control cabinets for wavemakers, each equipped with a slave PLC and several drivers. The slave PLCs calculate active absorption compensation and generate motor motion instructions based on the wavemaking file instructions and received wave height feedback signals. Specifically, each slave PLC receives the wavemaking plate displacement curve instructions issued by the master PLC, parses them into control signals for the corresponding drivers, and outputs the drive signals to the motors in the actuator layer through the drivers. The wavemaking plate motion status signals are collected in real time, compared with the wavemaking plate displacement curve instructions issued by the master PLC, and the driver output is dynamically adjusted to achieve high-precision closed-loop control of the wavemaking plate motion. Wave height meter data is collected in real time and compared to the wave shape calibration benchmark to calculate active absorption compensation values, which are then converted into reverse motion instructions for the wavemaking plate. These reverse motion instructions are converted into control signals by the drivers and sent to the motors in the actuator layer, with the active absorption compensation values ​​fed back to the central control layer.

[0064] Preferably, the equipment control layer includes 30 wave machine electrical control cabinets, each of which is equipped with a slave PLC and 16 drivers, thus forming a distributed control architecture consisting of 1 master PLC and 30 slave PLCs. Figure 1 and Figure 2 As shown, slave PLCs #1 to #30 (programmable logic controllers, also referred to as slave PLC controllers) calculate active absorption compensation and generate motor motion commands, respectively. Data communication and command exchange between the slave PLCs occurs via the EL6695 real-time Ethernet network, enabling multi-axis synchronous control and maintaining a swing synchronization error of ≤20 microseconds for each wave-making board. This multi-axis synchronous wave-making machine utilizes 31 controllers (1 master and 30 slaves) (each slave controls 16 boards) for a total of 480 wave-making boards. Equipped with the EL6695 control technology, this control maintains the synchronization error of the wave-making boards within 20 microseconds, effectively ensuring the wave crest straightness accuracy. The slave PLCs are responsible for converting the time history curve instructions received from each board into displacement curve instructions (number of motor revolutions) for the motor above each board. These instructions are then sent to the corresponding drivers, controlling and monitoring the board's operation, achieving closed-loop control of the board's motion. They are also responsible for receiving signals from the wave height meter on each wave-making board and calculating active absorption compensation values.

[0065] The present invention adopts a one-master-thirty-slave multi-controller architecture, and the communication structure adopts the form of Ethernet. The data transmission part with high real-time requirements adopts EtherCAT industrial Ethernet; while the data transmission control part that is not sensitive to the clock is constructed using ordinary Ethernet with a standard TCP protocol. The EtherCAT-P protocol is used to transmit wave height information and proximity position sensor signals from the super-large L-shaped wave-making unit for the feedback signal of the active absorption function. The wave height sensor (analog signal) and proximity position sensor (digital signal) on the wave-making unit are both connected to the EtherCAT-P bus through an acquisition box, realizing signal transmission and sensor power supply at the same time. The uploaded wave height / position data is used for the active absorption algorithm in the main PLC to adjust the swing angle of the wave-making plate in real time to offset wave reflection.

[0066] To ensure synchronization between 30 slave PLCs, the system utilizes EtherCAT distributed clock technology based on the selected controllers to compensate for transmission delay and dynamic drift. The addition of an EL6695 module compensates for initial clock offset, keeping inter-slave PLC delays within design requirements and improving oscillator synchronization. Specifically, to ensure precise synchronization of 30 slave controllers in the multi-axis synchronous control of a wave generator, the present invention utilizes an EtherCAT-based distributed clock (DC) technology solution. This solution effectively addresses network transmission delay and clock drift issues through a hardware-level timestamp mechanism and a precise clock compensation algorithm. Specifically, the system integrates the EL6695 EtherCAT bridge module, which utilizes a high-precision clock synchronization protocol that compensates for initial clock offsets down to nanoseconds. Through this series of precise time synchronization measures, the system successfully controls inter-slave synchronization errors within strict engineering design requirements. Rigorous laboratory testing confirmed that, before implementing these synchronization measures, the inter-slave PLCs experienced a 2 millisecond synchronization error. After implementing the optimized solution, the system's synchronization accuracy was significantly improved to within 20 microseconds. This technological breakthrough not only significantly improves the synchronization of the rocking plate movement, but also lays a solid foundation for achieving high-precision wave simulation.

[0067] Active wave absorption technology is an advanced wave control method. Its core principle is to eliminate secondary reflected waves in the tank through real-time monitoring and feedback control, thereby simulating ideal open water conditions. Specifically, the system uses an array of wave height sensors deployed in the tank to collect real-time wave height meter data, including parameters such as the amplitude and phase of the incident and reflected waves. Based on this data, the control system calculates a compensation wave with an opposite phase and equal amplitude to the reflected wave, and generates this compensation wave through the precise movement of the wave-making plate. In other words, active wave absorption technology represents the highest level of modern wave simulation technology. It achieves precise elimination of reflected waves through a real-time closed-loop control system, thereby simulating the wave environment under real-world conditions. This system uses distributed wave height sensors (one wave height meter per wave plate) to collect real-time holographic wave field data, accurately capturing the amplitude, phase, and spectral characteristics of the incident and reflected waves. Utilizing advanced digital signal processing technology, the system calculates a compensation wave with a 180° phase difference and equal amplitude to the reflected wave in real time. A high-precision servo system drives the wave-making plate to achieve submillimeter motion control, ensuring accurate wave simulation.

[0068] Furthermore, wave height meter data is collected in real time from the PLC, and frequency domain analysis is performed based on the IIR filter model to separate the incident and reflected wave components, extracting the wave frequency, amplitude, and phase parameters. Based on the extracted wave frequency, amplitude, and phase parameters, the wave morphology calibration benchmark is compared, and the active absorption compensation value is iteratively calculated using a recursive reweighted Gauss-Newton algorithm. The specific calculation is as follows:

[0069] (1) Active absorption control equation of wave maker

[0070]

[0071] where η p (t) is the wave-making plate motion x gen (t) the height of the traveling wave generated, is the corresponding transient wave height. r (t) is the height of the reflected wave, η rr (t) is the height of the secondary reflected wave. Assuming the reflection coefficient of the wave-making plate is 1, then η r (t) = η rr (t). Absorb motion for the wave board x abs (t) The compensation wave height generated is different from the secondary reflection wave height η rr (t) are equal and 180° out of phase. is the transient wave height generated by the wave-making plate during this process. According to the linear wave-making theory, we know that:

[0072]

[0073] In formula (2), i represents the i-th frequency component, c0 and c n is the hydrodynamic transfer function of the wave maker, which is related to the water depth, wave frequency and wave plate type. The control equations composed of (1) and (2) describe the relationship between the wave plate motion and the wave height in front of the wave plate in the active absorption mode. When there is no reflected wave transmitted to the wave plate, At this time, the absorption motion x of the wave-making plate abs (t) = 0, and formula (1) is the standard linear wave theory.

[0074] (2) Frequency domain solution of the active absorption control equation of the wave maker

[0075]

[0076] in

[0077]

[0078] The output on the left side of formula (3) That is the frequency domain complex amplitude of the wave-making plate stroke required to absorb the reflected wave. p,0 -A0 is the frequency domain complex amplitude of the input wave height, A0 is the high frequency domain value of the feedback wave obtained by the wave height sensor in front of the board, A p,0 is the high-frequency domain value of the target wave in front of the board calculated by linear wave theory, including the traveling wave term A p and transient wave terms F is the absorption transfer function, which specifies the input A p,0 -A0 and output The frequency domain relationship between them.

[0079] (3) Time domain implementation method of active absorption by wave maker

[0080] The wave generator system is a digital control system composed of a computer and a motion controller. It is a typical linear time-invariant (LTI) discrete-time system. The output time series in the time domain can be represented by the convolution of its unit impulse response and the input time series. If the unit impulse response h(t) of the LTI system is an infinite-length sequence, the system is called an "infinite-length unit impulse response system," or IIR system for short. It is generally normalized to a0 = 1 and can be expressed as Equation (6). To obtain y(t) in the difference equation, y(tn) must be fed back individually, so it is also called a recursive system.

[0081]

[0082] (4) Solving IRR filter parameters based on recursive reweighting algorithm

[0083] For an IIR filter, its system function H(z) can be expressed in various forms, among which the polynomial form is as follows:

[0084]

[0085] To achieve active absorption, we need to design the system function H(e jω )≈F(e jω ) of the IIR filter and stabilize it, where F(e jω ) is the active absorption transfer function. In mathematical methods, linear least squares is often used to solve optimization problems such as function approximation and fitting. n , b m It is updated iteratively by recursive reweighted least squares method. The target frequency response F(e jω ) at L>M+N+1 frequency pointsω i Discretize above, where i = 0, 1, ..., L-1. Then the filter design problem can be described as a constrained least squares optimization problem, as shown in Equation (8):

[0086]

[0087] Where E(ω)=F(e jω )-H(e jω ) is the complex domain error function.

[0088] The recursive reweighting method is used to solve equation (8) to obtain the parameters of the IIR filter and complete the calculation of the active absorption transfer function of the wave maker. The solution process is as follows: Figure 4 As shown, it starts with the initial estimated value, uses the Gauss-Newton method to solve the parameters, and determines whether to iterate based on whether the parameter change is less than the threshold. If it is not satisfied, it continues after reweighting, and ends when it is satisfied, thus achieving filter parameter optimization.

[0089] Therefore, the present invention is an active absorption wave generator. This wave generator's active absorption algorithm module, which utilizes an advanced control algorithm based on an IIR filter model and a recursive reweighted Gauss-Newton algorithm, can absorb over 80% of secondary reflected waves, ensuring wave stability and simulation accuracy in the pool. This algorithm module, integrated into the PLC controller (lower computer) within the electrical control cabinet, is responsible for comparing the target wave with the wave feedback from the wave height meter. If there is a deviation, a supplementary wave is calculated and superimposed onto the target wave file, providing a high level of wave simulation accuracy. Specifically, by comparing the target wave spectrum with the wave height meter feedback data in real time, an adaptive algorithm is used to dynamically calculate the compensation wave parameters, which are seamlessly superimposed onto the target wave file. Ultimately, this achieves internationally advanced wave simulation accuracy. This technological breakthrough provides an unprecedentedly precise simulation environment for marine engineering experiments.

[0090] 3. Actuator layer: executes wave-making machines and other processes to achieve wave-making and feedback real-time wave signals. It includes an extra-large L-shaped wave-making unit, a hinge assembly, a wave height meter in front of the board, a fan-shaped drive arm, a fork arm support and a frame support, as well as several motors. Each motor corresponds to the driver of the equipment control layer one by one. The extra-large L-shaped wave-making unit is vertically spliced ​​into an L shape by a short-side wave-making mechanism and a long-side wave-making mechanism. The short-side wave-making mechanism is arranged along the width direction of the experimental pool, and includes M wave-making plates spliced ​​end to end along its own length direction; the long-side wave-making plate mechanism is arranged along the length direction of the experimental pool, and includes N wave-making plates spliced ​​end to end along its own length direction, M+N≥400, M and N are both positive integers, and each wave-making plate is arranged vertically in the initial state; the lower end of each wave-making plate is hinged to the frame support through a hinge assembly, and the middle section of the back of each wave-making plate is connected to the fan-shaped drive arm. One end of the arm is fixedly connected, the other end of the fan-shaped driving arm is hinged to one end of the fork arm support, and the other end of the fork arm support is hinged to the bottom of the wave-making board, so that the wave-making board, the fan-shaped driving arm and the fork arm support form a triangular stable structure; the wave height meter in front of the board is arranged vertically in front of each wave-making board for real-time collection of wave height meter data; the motor output shaft is fixedly connected to the root of the fan-shaped driving arm, and the rotation centers of the two coincide, driving the fan-shaped driving arm to drive the wave-making board to swing around the hinge assembly to realize high sea state wave simulation; at the same time, the reverse motion instruction generated by the equipment control layer drives the motor action to be transmitted to the wave-making board through the fan-shaped driving arm, driving the wave-making board to perform a compensation action opposite to the phase of the incident wave, realizing high-precision active wave absorption, and feeding back the actively absorbed wave height to the equipment control layer.

[0091] Specifically, if Figure 5 The schematic diagram of the layout of the super-large L-shaped wave-making unit is shown in the figure. The short-side wave-making mechanism and the long-side wave-making mechanism are vertically spliced ​​into an L shape, with a total of 120 groups. Each group corresponds to a hinge assembly, a wave height meter in front of the board, a fan-shaped drive arm, a fork arm support and a frame support and 16 motors, which together constitute a wave-making machine module. Figure 1 The wave maker modules 1# through 120# are shown. Each module performs wave-making processes, generates waves, and provides real-time wave signals. The short-side wave-making mechanism, arranged along the width of the experimental tank, consists of 88 wave-making plates (22 groups of 4 plates each), connected end-to-end along its length. The long-side wave-making plate mechanism, arranged along the length of the experimental tank, consists of 392 wave-making plates (98 groups of 4 plates each), connected end-to-end along its length, for a total of 480 plates. Initially, each plate is arranged vertically, with an immersion depth of 2.0 meters and a dry chord height of 0.8 meters. In other words, the present invention provides a super-multi-plate wave maker, with a short-side wave maker of 44 meters and 88 plates, and a long-side wave maker of 196 meters and 392 plates. The sufficient width of the short-side wave maker and the short side of the pool ensures that the ship model will not be affected by the transient waves of the wave maker when conducting transverse and oblique wave tests, thereby ensuring the accuracy of transverse and oblique wave tests; the sufficient length of the short-side wave maker and the pool ensures that when conducting tests along all wave directions, the ship model has an effective test area of ​​more than 150 meters, which can achieve a qualitative improvement in test efficiency and data processing. The core innovation of the wave maker system suitable for high sea state simulation provided by the present invention lies in the optimization of the geometric parameters and motion performance of the wave maker plate. The wave maker of the present invention adopts a precisely designed rocking plate structure with an immersion depth set to 2.0 meters (i.e., the height from the center of the hinge axis to the water surface when the rocking plate is in a vertical state), and is configured with a dry chord height of 0.8 meters. This rigorously calculated structural parameter ensures that the wave maker can maintain excellent wave-making performance under various working conditions, achieving a wider bandwidth wave generation capability. The system can accurately simulate regular waves with a maximum wave height of 1.0 meter and irregular waves with a maximum significant wave height of 0.5 meter, meeting the requirements of high-sea-state testing. Furthermore, the system can support ship model navigation safety assessment testing, providing a reliable testing platform for studying ship performance in extreme sea conditions.

[0092] Figure 6 This is a schematic diagram of the preferred structure of the wave-making machine module of the actuator layer of the present invention. The figure shows a group of wave-making plates in the super-large L-shaped wave-making unit, which can be a group of wave-making plates in the short-side wave-making mechanism or a group of wave-making plates in the long-side wave-making mechanism. In this embodiment, a group of wave-making plates consists of 4 pieces. Figure 7 , which is Figure 6 Another angle diagram can more intuitively show a set of 4 wave-making plates. Figure 6Also shown are the motor and transmission assembly 1, the top support 2, the limit switch 3, the wave height meter 4 in front of the board, the hinge assembly - the hinge (shaft) 6, the frame support 7, the fork arm support 8 and the fan-shaped drive arm 9. The actuator layer includes the frame support 7 and the top support 2. The motor and transmission assembly 1 is fixed to the top support 2. The lower end of each wave-making plate 5 is hinged to the frame support 7 through the hinge assembly. The core component of the hinge assembly is the hinge (shaft) 6. The middle section of the back of each wave-making plate 5 is fixedly connected to one end of the fan-shaped drive arm 9. The other end of the fan-shaped drive arm 9 is hinged to one end of the fork arm support 8. The other end of the fork arm support 8 is hinged to the bottom of the wave-making plate 5. Thus, the wave-making plate 5, the fan drive arm 9 and the fork arm support 8 form a triangular stable structure. Figure 12 As shown, in terms of structural design, an innovative triangular stable structure is adopted, that is, the rocker plate, fan-shaped drive arm and fork arm support form a stable triangular mechanical structure. This design not only significantly improves the rigidity of the overall structure, but also ensures the stability and durability of the equipment in long-term operation. Figure 8 For the disassembly structure diagram, the triangular stable structure is disassembled through the hinge assembly to separate it from the frame support 7 and other components. The wave height meter 4 is arranged vertically in front of each wave maker 5 to collect wave height meter data in real time; the structure of the transmission assembly is as follows Figure 11 As shown, it includes a reducer 102, a driving pulley 103, a toothed synchronous belt 104 and a driven pulley 105. That is to say, the transmission form of the wave maker is a toothed synchronous belt drive, and the power source is a motor (preferably a servo motor). The servo motor is connected to the reducer and the driving pulley (the driving pulley is installed on the output shaft of the reducer). The driving pulley is connected to the fan-shaped driving arm through a toothed belt and is guided by two driven pulleys. When the servo motor drives the reducer to rotate, it drives the driving pulley synchronous belt to rotate, and drives the fan-shaped driving arm and the rocker plate to rotate around the hinge axis. Specifically, the output shaft of the motor 101 is connected to the reducer 102. After deceleration and torque increase by the reducer 102, its output shaft is fixedly connected to the driving pulley 103; the driving pulley 103 is engaged with the fan-shaped driving arm through the toothed synchronous belt 104, and the toothed synchronous belt 104 is tensioned and guided by the driven pulley 105; that is, the output shaft of the motor 101 is indirectly fixedly connected to the root of the fan-shaped driving arm 9 through the transmission component, and the rotation centers of the two coincide, driving the fan-shaped driving arm 9 to drive the wave-making plate 5 to swing around the hinge (axis) 6, thereby realizing high sea condition wave simulation; at the same time, the reverse motion instruction generated by the equipment control layer drives the motor 101 to move and is transmitted to the wave-making plate 5 through the fan-shaped driving arm 9, driving the wave-making plate 5 to perform a compensation action opposite to the phase of the incident wave, thereby realizing high-precision active wave absorption.

[0093] When the central control layer issues a wave-making plate displacement curve instruction, the slave PLC of the device control layer parses the instruction and generates a motor drive signal through the driver to drive the motor of the actuator layer to rotate. The power of the motor 101 is input to the reducer 102. The reducer 102 converts high speed and low torque into low speed and high torque through the gear set. The output shaft drives the active pulley 103 to rotate. The active pulley 103 engages with the driven pulley 105 through the toothed synchronous belt 104, converting the rotational motion into the reciprocating swing of the fan-shaped drive arm 9. The fan-shaped drive arm 9 drives the wave-making plate 5 to swing around the hinge assembly, as shown in FIG. Figure 9 and Figure 10 The structure shown in different operating states shows a fan-shaped drive arm 9 driving the wave-making plate 5 to swing around the hinge assembly to different angles, achieving both wave generation and active wave absorption. The actuator is equipped with a limit switch 3 at the extreme swing angles of the wave-making plate 5. When the wave-making plate 5 triggers the limit switch 3, it sends a signal to the PLC, causing the driver to cut off power to the motor 101.

[0094] Furthermore, the fan-shaped driving arm drives the wave-making plate to swing around the hinge assembly, which can realize high sea condition wave simulation with a wave direction angle of 0° to 165°; wherein, the wave direction angle is the angle between the wave propagation direction and the length direction of the experimental water tank, including the simulation of various wave direction conditions such as following waves, bow oblique waves, stern oblique waves, transverse waves, and head waves. For example, 0° head wave condition: the wave propagation direction is opposite to the sailing direction of the ship model; 45° to 135° bow / stern oblique wave condition: the wave hits the bow or stern of the ship model in an oblique direction; 90° transverse wave condition: the wave is perpendicular to the sailing direction of the ship model; 165° following wave condition: the angle between the wave propagation direction and the sailing direction of the ship model is ≤15°. That is to say, the super-large L-shaped high-sea-state high-precision absorption wave maker system of the present invention can simulate waves with wave direction angles of 0° to 165° while ensuring wave accuracy, can carry out full-wave direction seakeeping tests with ship speed, and can carry out wave tests according to any wave direction interval, which is convenient for all-round ship model seakeeping test research.

[0095] The present invention also relates to a wave simulation method for an ultra-large L-shaped high-sea-state high-precision absorption wave maker system, which corresponds to the ultra-large L-shaped high-sea-state high-precision absorption wave maker system of the present invention. It can be understood as the wave simulation method for the ultra-large L-shaped high-sea-state high-precision absorption wave maker system, which sequentially includes a system construction step, a system initialization step, an instruction generation and issuance step, an instruction execution and closed-loop control step, and a wave generation and active absorption step. Specifically,

[0096] System construction steps: vertically splice the short-side wave-making mechanism and the long-side wave-making mechanism into an L-shaped super-large L-shaped wave-making unit. The short-side wave-making mechanism is arranged along the width direction of the experimental pool, and includes M wave-making plates spliced ​​end to end along its own length direction. The long-side wave-making mechanism is arranged along the length direction of the experimental pool, and includes N wave-making plates spliced ​​end to end along its own length direction. M+N≥400. The wave-making plates are arranged vertically in the initial state; the super-large L-shaped wave-making unit is assembled with the hinge assembly, the wave height meter in front of the board, the fan-shaped drive arm, the fork arm support, the frame support and the servo motor to build the actuator layer, and the wave-making plates, the fan-shaped drive arm and the fork arm support form a triangular stable structure. The electrical connection and mechanical assembly between the actuator layer and the equipment control layer and the central control layer are completed respectively;

[0097] System initialization steps: Start the central control layer's main control computer and main PLC, load the wave-making control software; set the initial parameters to a wave-making plate immersion depth of 2.0 meters and a freeboard height of 0.8 meters through the human-computer interface; the main PLC sends initialization instructions to the equipment control layer, and the slave PLCs in the equipment control layer drive the servo motors in the actuator layer to adjust the wave-making plate to the vertical zero position; the wave height meter in front of the board completes zero-point calibration, and the real-time collected data is fed back to the central control layer as the initial value of the wave shape verification benchmark;

[0098] Instruction generation and issuance steps: The main control computer in the central control layer runs the wave-making control software. Based on the high-sea target parameters, micro-amplitude wave theory and Stokes wave theory, it establishes a mathematical relationship between the wave-making board's swing angle and the target wave height, generates a target wave time history curve, and simultaneously derives the theoretical motion instructions required for each wave-making board. The main PLC converts the theoretical motion instructions and performs timing synchronization processing to generate and issue the wave-making board displacement curve instructions.

[0099] Instruction execution and closed-loop control steps: The slave PLC at the equipment control layer receives displacement curve instructions and interprets them into corresponding driver control signals to drive the servo motor. The wave-making plate motion status signal is collected in real time and compared with the wave-making plate displacement curve instructions issued by the master PLC. The driver output is dynamically adjusted to achieve high-precision closed-loop control of the wave-making plate motion. Wave height meter data is also collected and frequency-domain analysis is performed based on an IIR filter model. A recursive reweighted Gauss-Newton algorithm is used to calculate the active absorption compensation value, generating a reverse motion instruction to drive the servo motor.

[0100] Wave generation and active absorption steps: The servo motor at the actuator layer drives the fan-shaped drive arm and wave-making plate to swing through the transmission assembly, generating waves according to the instructions; and performing a compensation action opposite to the phase of the incident wave according to the reverse motion instruction, completing high-precision active wave absorption.

[0101] Furthermore, in the system construction step, the equipment control layer is configured with 30 wave maker electrical control cabinets, each of which is equipped with a slave PLC and 16 drivers, thereby forming a distributed control architecture consisting of 1 master PLC and 30 slave PLCs;

[0102] In the instruction generation and issuance steps, the master PLC issues instructions to 30 slave PLCs based on the EtherCAT protocol by configuring the real-time Ethernet architecture of the EL6695 EtherCAT master module. Each slave PLC uses the EtherCAT distributed clock to compensate for network transmission delays and responds to clock synchronization calibration instructions to calibrate the initial offset, achieving multi-axis synchronous control and ensuring that the instruction execution time deviation of the 30 slave PLCs is ≤20μs.

[0103] Furthermore, in the instruction execution and closed-loop control steps, the device control layer parses the instructions from the PLC and generates a motor drive signal through the driver to drive the motor of the actuator layer to rotate; in the wave generation and active absorption steps, the power of the motor is input to the reducer, and the reducer converts high speed and low torque into low speed and high torque through a gear set, and the output shaft drives the driving pulley to rotate, and the driving pulley is engaged with the driven pulley through a toothed synchronous belt to transmit the rotational motion, converting the rotational motion into the reciprocating swing of the fan-shaped drive arm, and the fan-shaped drive arm drives the wave-making plate to swing around the hinge assembly to achieve wave generation and active absorption.

[0104] It should be noted that the specific embodiments described above can enable those skilled in the art to more fully understand the present invention, but do not limit the present invention in any way. Therefore, although this specification has described the present invention in detail with reference to the drawings and embodiments, those skilled in the art should understand that the present invention can still be modified or replaced with equivalents. In short, all technical solutions and improvements that do not depart from the spirit and scope of the present invention should be included in the scope of protection of the patent for the present invention.

Claims

1. An ultra-large L-shaped high-sea-state high-precision absorption wave maker system, characterized in that: It includes the central control layer, equipment control layer and actuator layer connected in sequence. The central control layer includes a main control cabinet and a main control computer and main PLC configured in the main control cabinet. The main control computer runs wave-making control software, generates a target wave history curve based on high sea state target parameters, and simultaneously derives theoretical motion instructions to be executed by each wave-making board. The main PLC performs format conversion and timing synchronization on the theoretical motion instructions, generates wave-making board displacement curve instructions that can be recognized by the equipment control layer, and sends them to the equipment control layer according to the communication timing. At the same time, the target wave history curve is synchronously sent as a wave morphology verification benchmark. The equipment control layer includes several wave-making machine electrical control cabinets, each of which is equipped with a slave PLC and several drivers. Each slave PLC receives the wave-making plate displacement curve instruction issued by the master PLC, analyzes it into a control signal for the corresponding driver, and outputs the drive signal to the motor of the actuator layer through the driver; collects the wave-making plate motion state signal in real time, compares it with the wave-making plate displacement curve instruction issued by the master PLC, and dynamically adjusts the driver output to achieve high-precision wave-making plate motion closed-loop control; collects wave height meter data in real time, compares it with the wave shape verification benchmark to calculate the active absorption compensation value, and then converts it into a reverse motion instruction for the wave-making plate. The reverse motion instruction is converted into a control signal by the driver and sent to the motor of the actuator layer, and the active absorption compensation value is fed back to the central control layer; The actuator layer includes an extra-large L-shaped wave-making unit, a hinge assembly, a wave height meter in front of the board, a fan-shaped drive arm, a fork arm support and a frame support, and several motors. Each motor corresponds to the driver of the equipment control layer one by one. The extra-large L-shaped wave-making unit is vertically spliced ​​into an L shape by a short-side wave-making mechanism and a long-side wave-making mechanism. The short-side wave-making mechanism is arranged along the width direction of the experimental water pool, and includes M wave-making plates spliced ​​end to end along its own length direction; the long-side wave-making plate mechanism is arranged along the length direction of the experimental water pool, and includes N wave-making plates spliced ​​end to end along its own length direction, M+N≥400, and each wave-making plate is arranged vertically in the initial state; the lower end of each wave-making plate is hinged to the frame support through a hinge assembly, and the middle section of the back of each wave-making plate is connected to the frame support. It is fixedly connected to one end of the fan-shaped driving arm, the other end of the fan-shaped driving arm is hinged to one end of the fork arm support, and the other end of the fork arm support is hinged to the bottom of the wave-making board, so that the wave-making board, the fan-shaped driving arm and the fork arm support form a triangular stable structure; the wave height meter in front of the board is arranged vertically in front of each wave-making board for real-time collection of wave height meter data; the motor output shaft is fixedly connected to the root of the fan-shaped driving arm, and the rotation centers of the two coincide, driving the fan-shaped driving arm to drive the wave-making board to swing around the hinge assembly to realize high sea state wave simulation; at the same time, the reverse motion instruction generated by the equipment control layer drives the motor action to be transmitted to the wave-making board through the fan-shaped driving arm, driving the wave-making board to perform a compensation action with a phase opposite to the incident wave, thereby realizing high-precision active wave absorption.

2. The ultra-large L-shaped high-sea-state high-precision absorption wave maker system according to claim 1 is characterized in that: The wave-making control software run by the main control computer in the central control layer establishes a mathematical relationship between the swing angle of the wave-making plate and the target wave height based on the micro-wave theory and the Stokes wave theory, and generates any combination of regular waves, irregular waves, white noise waves, second-order waves, single-point focused waves, multi-point focused waves, deformed waves and broken waves. The irregular waves include PM spectra, JONSWAP spectra, ITTC spectra, and ITTC dual-parameter spectra. The focusing time error of the single-point focused wave is ≤±0.1 second, and the wave height magnification factor of the focused point is ≥3 times. The wave height of the deformed wave exceeds twice the effective wave height, and the duration is ≥3 wave cycles.

3. The ultra-large L-shaped high-sea-state high-precision absorption wave maker system according to claim 1 is characterized in that: The device control layer collects wave height meter data from the PLC in real time, performs frequency domain analysis based on the IIR filter model, separates the incident wave and reflected wave components, and extracts the frequency, amplitude, and phase parameters of the waves; based on the extracted wave frequency, amplitude, and phase parameters, the wave morphology calibration benchmark is compared, and a recursive reweighted Gauss-Newton algorithm is used to iteratively calculate the active absorption compensation value.

4. The ultra-large L-shaped high-sea-state high-precision absorption wave maker system according to any one of claims 1 to 3, characterized in that: The equipment control layer includes 30 wave-making machine electrical control cabinets, each equipped with a slave PLC and 16 drivers, forming a distributed control architecture consisting of one master PLC and 30 slave PLCs. The 30 slave PLCs communicate data and exchange commands via EL6695 real-time Ethernet, achieving multi-axis synchronous control and ensuring that the swing synchronization error of each wave-making plate is ≤20 microseconds.

5. The ultra-large L-shaped high-sea-state high-precision absorption wave maker system according to any one of claims 1 to 3, characterized in that: The actuator layer includes a transmission assembly, and the root of the sector drive arm is fixedly connected to the corresponding motor through the transmission assembly; the transmission assembly includes a reducer, a driving pulley, a toothed synchronous belt, and a driven pulley; wherein, the output shaft of the motor of the actuator layer is connected to the reducer, and after deceleration and torque increase by the reducer, its output shaft is fixedly connected to the driving pulley; the driving pulley is meshed with the sector drive arm through the toothed synchronous belt, and the toothed synchronous belt is tensioned and guided by the driven pulley; When the central control layer issues a displacement curve instruction for the wave-making plate, the slave PLC of the equipment control layer parses the instruction and generates a motor drive signal through the driver to drive the motor of the actuator layer to rotate. The power of the motor is input to the reducer, and the reducer converts high speed and low torque into low speed and high torque through a gear set. The output shaft drives the active pulley to rotate, and the active pulley engages with the driven pulley through a toothed synchronous belt to transmit the rotational motion to the reciprocating swing of the fan-shaped drive arm. The fan-shaped drive arm drives the wave-making plate to swing around the hinge assembly to achieve wave generation and active absorption.

6. The ultra-large L-shaped high-sea-state high-precision absorption wave maker system according to claim 5 is characterized in that: In the actuator layer, the short-side wave-making mechanism includes 88 wave-making plates spliced ​​end to end along its own length; the long-side wave-making mechanism includes 392 wave-making plates spliced ​​end to end along its own length, with each wave-making plate having an immersion depth of 2.0 meters and a dry chord height of 0.8 meters. The actuator is equipped with a limit switch at the extreme swing angle position of the wave-making plate. When the wave-making plate triggers the limit switch, the limit switch feeds back a signal to the PLC, and the driver cuts off the power supply to the motor.

7. The ultra-large L-shaped high-sea-state high-precision absorption wave maker system according to any one of claims 1 to 3, characterized in that: In the actuator layer, the fan-shaped drive arm drives the wave-making plate to swing around the hinge assembly to achieve high sea state wave simulation with a wave direction angle of 0° to 165°; wherein the wave direction angle is the angle between the wave propagation direction and the length direction of the experimental pool, including: 0° head-on wave condition: the wave propagation direction is opposite to the sailing direction of the ship model; 45°~135° bow / stern oblique wave condition: the waves hit the bow or stern of the ship model in an oblique direction; 90° beam wave condition: the waves are perpendicular to the sailing direction of the ship model; 165° wave-following condition: the angle between the wave propagation direction and the sailing direction of the ship model is ≤15°.

8. A wave simulation method for an ultra-large L-shaped high-sea-state high-precision absorption wave maker system, characterized in that: The following steps are involved: System construction steps: vertically splice the short-side wave-making mechanism and the long-side wave-making mechanism into an L-shaped super-large L-shaped wave-making unit. The short-side wave-making mechanism is arranged along the width direction of the experimental pool, and includes M wave-making plates spliced ​​end to end along its own length direction. The long-side wave-making mechanism is arranged along the length direction of the experimental pool, and includes N wave-making plates spliced ​​end to end along its own length direction. M+N≥400. The wave-making plates are arranged vertically in the initial state; the super-large L-shaped wave-making unit is assembled with the hinge assembly, the wave height meter in front of the board, the fan-shaped drive arm, the fork arm support, the frame support and the servo motor to build the actuator layer, and the wave-making plates, the fan-shaped drive arm and the fork arm support form a triangular stable structure. The electrical connection and mechanical assembly between the actuator layer and the equipment control layer and the central control layer are completed respectively; System initialization steps: Start the central control layer's main control computer and main PLC, load the wave-making control software; set the initial parameters to a wave-making plate immersion depth of 2.0 meters and a freeboard height of 0.8 meters through the human-computer interface; the main PLC sends initialization instructions to the equipment control layer, and the slave PLCs in the equipment control layer drive the servo motors in the actuator layer to adjust the wave-making plate to the vertical zero position; the wave height meter in front of the board completes zero-point calibration, and the real-time collected data is fed back to the central control layer as the initial value of the wave shape verification benchmark; Instruction generation and issuance steps: The main control computer in the central control layer runs the wave-making control software. Based on the high-sea target parameters, micro-amplitude wave theory and Stokes wave theory, it establishes a mathematical relationship between the wave-making board's swing angle and the target wave height, generates a target wave time history curve, and simultaneously derives the theoretical motion instructions required for each wave-making board. The main PLC converts the theoretical motion instructions and performs timing synchronization processing to generate and issue the wave-making board displacement curve instructions. Instruction execution and closed-loop control steps: The slave PLC at the equipment control layer receives displacement curve instructions and interprets them into corresponding driver control signals to drive the servo motor. The wave-making plate motion status signal is collected in real time and compared with the wave-making plate displacement curve instructions issued by the master PLC. The driver output is dynamically adjusted to achieve high-precision closed-loop control of the wave-making plate motion. Wave height meter data is also collected and frequency-domain analysis is performed based on an IIR filter model. A recursive reweighted Gauss-Newton algorithm is used to calculate the active absorption compensation value, generating a reverse motion instruction to drive the servo motor. Wave generation and active absorption steps: The servo motor at the actuator layer drives the fan-shaped drive arm and wave-making plate to swing through the transmission assembly, generating waves according to the instructions; and performing a compensation action opposite to the phase of the incident wave according to the reverse motion instruction, completing high-precision active wave absorption.

9. The wave simulation method according to claim 8, characterized in that: In the system construction step, the equipment control layer is configured with 30 wave machine electrical control cabinets, each of which is equipped with a slave PLC and 16 drivers, thus forming a distributed control architecture consisting of 1 master PLC and 30 slave PLCs; In the instruction generation and issuance steps, the master PLC issues instructions to 30 slave PLCs based on the EtherCAT protocol by configuring the real-time Ethernet architecture of the EL6695 EtherCAT master module. Each slave PLC uses the EtherCAT distributed clock to compensate for network transmission delays and responds to clock synchronization calibration instructions to calibrate the initial offset, achieving multi-axis synchronous control and ensuring that the instruction execution time deviation of the 30 slave PLCs is ≤20μs.

10. The wave simulation method according to claim 8 or 9, characterized in that: In the instruction execution and closed-loop control step, the device control layer parses the instruction from the PLC and generates a motor drive signal through the driver to drive the motor of the actuator layer to rotate; in the wave generation and active absorption step, the power of the motor is input to the reducer, and the reducer converts high speed and low torque into low speed and high torque through a gear set. The output shaft drives the active pulley to rotate, and the active pulley engages with the driven pulley through a toothed synchronous belt to transmit the rotational motion to the reciprocating swing of the fan-shaped drive arm, and the fan-shaped drive arm drives the wave-making plate to swing around the hinge assembly to achieve wave generation and active absorption.

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