Offshore photovoltaic system power generation performance dynamic simulation experiment platform and control method

Abstract

The invention discloses an offshore photovoltaic system power generation performance dynamic simulation experiment platform and a control method. The platform comprises a wave making experiment subsystem, a floating body assembly, an inclination angle measurement module, a data acquisition and communication module, a main control unit, a double-shaft adjustable photovoltaic support controller, a motor driving circuit, a pitch shaft and azimuth shaft driving unit, a double-shaft adjustable support, a support attitude sensor and a signal processing module. A limiting and safety protection module; and a power supply and voltage stabilization module. The offshore photovoltaic experiment platform can be built in the land outdoor environment, the postures of the photovoltaic array and the floating body in the ocean wave environment can be reproduced in a high-fidelity mode, the experiment system is relatively simple in structure, stable in control and high in safety, the experiment cost of the offshore photovoltaic system is greatly reduced, and the experiment efficiency is improved. The device is suitable for attitude simulation and performance test of an offshore photovoltaic support and other ocean floating structures.

Description

Technical Field

[0001] This invention belongs to the field of wave load simulation and attitude control technology, and particularly relates to a dynamic simulation experimental platform and control method for the power generation performance of a marine photovoltaic system. Background Technology

[0002] With the rapid development of marine renewable energy sources such as offshore wind power and offshore photovoltaics, the motion characteristics of floating structures under wave action and their impact on the operating conditions of upper equipment are receiving increasing attention. Taking offshore photovoltaics as an example, photovoltaic modules are usually installed on floating bodies or flexible support structures, and are constantly exposed to the combined effects of waves and wind currents. Their pitch, roll, and other attitude changes not only affect structural safety and fatigue life, but also influence the incident angle of sunlight, electrical connection status, and power generation performance evaluation results. Therefore, the controlled reproduction of wave conditions under laboratory conditions, and the subsequent correlation tests on support attitude, stress, and power generation performance, have become important research methods in related fields.

[0003] Some existing technologies target photovoltaic (PV) tracking power plants, focusing on improving the operational reliability and power generation efficiency of PV arrays in natural environments. Chinese patent application CN113992127B discloses a PV tracking bracket rotation system and controller. This system acquires images of the components and the environment through an image acquisition device, utilizes a neural network to identify weather conditions such as rain, snow, or hail, and controls the tracking bracket to rotate to a position to avoid snow and hail or to utilize rainwater to clean accumulated dust, thereby improving operational performance under adverse weather conditions. Chinese patent application CN223414834U proposes a dual-axis tracking PV panel bracket, which achieves dual-axis tracking of the solar altitude and azimuth angles through a slewing bearing, electric push rod, and modular connecting components, while also considering lightweight structure and ease of installation and maintenance. Although the above technologies involve dual-axis bracket structures and rotation control, their application scenarios are all onshore or fixed power plant conditions, focusing on solar tracking and protection issues, and do not specifically address the need for reproducing the floating body's attitude under wave excitation.

[0004] On the other hand, general-purpose equipment such as six-degree-of-freedom motion platforms and industrial robots are also used to simulate wave loads or attitudes. However, these devices are expensive, and their control systems are mainly based on general trajectory control. When using measured wave attitude data, complex coordinate transformations and trajectory reconstructions are often required. Furthermore, their mechanical structure and load-bearing methods differ significantly from actual photovoltaic supports, leading to discrepancies between experimental results and engineering applications. In addition, existing devices mostly rely on simplified motion with single or few degrees of freedom, and do not adequately consider issues such as coordinated control of pitch and azimuth dual degrees of freedom, attitude decoupling, smooth trajectory generation under high-frequency wave conditions, and full-process safety protection. This can easily result in large attitude tracking errors, discontinuous motion, or impact overtravel. Summary of the Invention

[0005] Purpose of the Invention: The purpose of this invention is to address the problems existing in current wave simulation experiments, such as the difficulty in accurately reproducing the attitude of floating bodies on land platforms, the lack of dedicated control methods for dual-axis supports under wave conditions, and insufficient attitude tracking smoothness and safety. This invention proposes a dynamic simulation system and control method for dual-axis supports based on wave attitude drive. This system can use measured or preset wave attitude sequences as input to perform high-fidelity dynamic reproduction of the floating body attitude in both pitch and azimuth degrees of freedom. It achieves integrated mapping and closed-loop control from "wave-floating body attitude-dual-axis support attitude," balancing attitude tracking accuracy, motion stability, and operational safety. This provides a convenient and controllable experimental means for the structural design and performance evaluation of support structures for marine engineering equipment such as offshore photovoltaic systems.

[0006] Technical solution: The present invention provides a dynamic simulation experimental platform for the power generation performance of a marine photovoltaic system, comprising: a wave-generating experimental subsystem, a floating body assembly, an inclination measurement module, a data acquisition and communication module, a main control unit, a dual-axis adjustable photovoltaic support controller, a motor drive circuit, pitch and azimuth axis drive units, a dual-axis adjustable support, a support attitude sensor, a signal processing module, a limit and safety protection module, and a power supply and voltage regulation module. In the wave and attitude acquisition section, the wave generator controller sends drive commands to the wave generator actuator to generate regular or irregular waves with set wave height, period, and waveform within the water tank. A floating model is positioned at a designated location within the water tank; its geometry and mass distribution can be designed similarly to the target offshore photovoltaic support foundation or floating platform. An inclination measurement module is fixedly installed on the floating body. Acceleration and angular velocity sensors within the module collect the linear acceleration and angular velocity signals of the floating body under wave action in real time. After attitude calculation, continuous pitch and roll attitude data are generated. The attitude signal processing and mapping section consists of a data acquisition and communication module and a main control unit. The data acquisition and communication module receives the attitude data output from the inclination measurement module, performs frame parsing, buffering, and integrity verification on the data, and forwards it to the main control unit according to a predetermined communication protocol. The main control unit internally incorporates attitude preprocessing and mapping algorithms. After filtering, resampling, and outlier handling of the attitude sequence, it converts the pitch and roll attitudes of the floating body into target control quantities for the dual-axis adjustable support in the pitch and azimuth directions based on pre-calibrated coordinate relationships. Simultaneously, based on the maximum allowable angular velocity and maximum angular acceleration of the dual-axis adjustable support, it performs trajectory planning for the target control quantities, generating a smooth target angle curve, which serves as the reference input for subsequent drive control. The dual-axis adjustable support execution and feedback section includes the dual-axis adjustable support mechanism, motors and their drive circuits for driving the pitch and azimuth axes, and support attitude sensors mounted on the dual-axis adjustable support. The main control unit outputs control commands to the dual-axis adjustable support controller based on the target angle curve. The dual-axis adjustable support controller then sends the control quantities to the motor drive circuit. The motor drive circuit adjusts the drive voltage and current of the motors, driving the pitch and azimuth axes to rotate, enabling the dual-axis adjustable support to follow the target attitude changes in two degrees of freedom. The support attitude sensor collects the current pitch and azimuth angles of the dual-axis adjustable support in real time, and sends them to the signal processing module for filtering and decoding to obtain the actual attitude information. The main control unit compares this actual attitude with the target angle curve to form an attitude error signal, and corrects the control commands in subsequent control cycles to achieve closed-loop attitude tracking of the dual-axis support. In the safety and power supply section, a dual mechanical and electronic limit structure and an emergency stop control circuit are set up to constrain the rotation range of the pitch and azimuth axes, and monitor the drive current, equipment temperature rise, and abnormal attitude. When an over-limit or abnormal operating condition is detected, the drive signal can be automatically reduced or cut off to keep the support in a preset safe attitude. The power supply and voltage regulation module provides multiple stable DC power supplies for the tilt measurement module, data acquisition and communication module, main control unit, motor drive circuit, support attitude sensor, etc., and improves the overall anti-interference capability and operational reliability of the system through isolation and protection measures.

[0007] Based on the aforementioned platform structure, this invention also proposes a dynamic simulation method for the power generation performance of a marine photovoltaic system. This method includes: setting target wave parameters and generating a corresponding wave field on a wave-generating experimental platform; acquiring the pitch and roll attitude sequences of the floating body using an attitude measurement module installed on the floating body; filtering, interpolating, and reconstructing the time axis of the attitude sequences to obtain attitude reference signals for control; converting the attitude reference into the pitch and azimuth target angles of the dual-axis support according to the attitude mapping relationship, and performing trajectory planning; executing closed-loop control in both the pitch and azimuth channels to make the dual-axis support move according to the target trajectory; continuously updating the error using the support attitude feedback signal and performing safety monitoring during the control process, thereby achieving high-precision and controllable simulation of the floating body attitude under wave conditions.

[0008] Furthermore, the tilt measurement module includes a triaxial accelerometer or angular velocity sensor, and is equipped with a temperature compensation circuit and a zero-bias calibration unit. It filters and fuses the measured signals through a built-in attitude calculation algorithm to output attitude data characterizing the pitch and roll attitude of the floating body component.

[0009] Furthermore, the data acquisition and communication module includes a data parsing unit, a buffer unit, a verification unit, a multi-threaded processing structure, and a communication interface circuit. The data parsing unit is used to perform protocol parsing, format conversion, and field extraction on the attitude data output by the tilt measurement module, splitting the raw data stream into information frames with timestamps, attitude parameters, and status flags. The buffer unit is used to perform queue-style storage and read / write scheduling of the parsed information frames, adapting to the differences between different sampling frequencies and transmission bandwidths, and preventing data loss under high-frequency sampling conditions. The verification unit performs integrity checks on the received data frames by setting frame header and frame tail flags, data length verification, and CRC verification mechanisms, and performs verification within the specified time. When an anomaly is detected, a retransmission request or packet loss flag is triggered; a multi-threaded processing structure is used to complete data reception, buffering, verification, and transmission tasks in parallel within the same module, enabling real-time reception, format conversion, data reconstruction, and timing alignment of high-frequency attitude data; by setting sliding window filtering, mutation point suppression, and data integrity check mechanisms, drift, jitter, packet loss, and delay deviation under high fluctuation conditions are limited to a controllable range; the communication interface circuit adopts one or more of serial port, CAN bus, RS485, or Ethernet, and the baud rate, node address, and data frame format are configured according to experimental requirements to stably send the preprocessed attitude data to the main control unit according to the predetermined communication protocol.

[0010] Furthermore, the main control unit is equipped with an attitude analysis and decomposition module and a target control quantity generation module. The attitude analysis and decomposition module is used to decompose the spatial attitude of the floating body component into attitude components in the pitch and azimuth directions of the corresponding dual-axis adjustable support based on the angle information contained in the attitude data. The target control quantity generation module calculates the corresponding pitch and azimuth target control quantities based on the decomposed attitude components and outputs them to the pitch and azimuth axis drive units in the form of digital control commands.

[0011] Furthermore, the dual-axis adjustable bracket includes a pitch rotating component arranged along a first rotation axis and an azimuth rotating component arranged along a second rotation axis orthogonal to the first rotation axis. The pitch rotating component and the azimuth rotating component are supported by each other through bearing assemblies and form two mutually orthogonal rotational degrees of freedom, used to support photovoltaic modules, test boards or other objects to be simulated. The pitch axis and azimuth axis drive units respectively include a motor body and a transmission structure connecting the motor output shaft to the corresponding rotating shaft of the dual-axis adjustable bracket. The motor drive circuit adjusts the speed and direction of the motor according to the control command output by the main control unit, thereby driving the dual-axis adjustable bracket of the corresponding axis to achieve a specified angle of rotation.

[0012] Furthermore, the support attitude sensor includes one or more of an angle encoder, gyroscope, or inertial measurement unit, used to acquire the actual angle information of the dual-axis adjustable support in the pitch and azimuth directions, and output it to the signal processing module in the form of electrical signals; the power supply and voltage regulation module includes a main power input unit, a voltage regulation conversion unit, and an isolation protection unit. The main power input unit is used to receive external power supply, the voltage regulation conversion unit is used to convert the main power supply into multiple DC voltage outputs adapted to the main control unit, sensor module, and drive unit, and the isolation protection unit is used to electrically isolate the control logic circuit and the power drive circuit, and provide overcurrent, overvoltage, and short circuit protection.

[0013] This invention also discloses a control method for a dynamic simulation experimental platform for the power generation performance of an offshore photovoltaic system, used to dynamically follow an external wave attitude reference signal for a support structure with two rotational degrees of freedom, pitch and azimuth. The method includes the following steps: Step 1: Obtain wave attitude reference signal. Record the attitude information of the floating body or the object under test that produces pitch and roll motion under the action of waves in the form of time series as attitude reference data. Step 2: Filter, denoise and reconstruct the time axis of the attitude reference data to remove outliers and jitter components, and obtain a smooth and time-continuous attitude reference sequence. Step 3: Based on the attitude parameters contained in the attitude reference sequence, decompose the reference attitude into target attitude components that act on the pitch and azimuth degrees of freedom of the support respectively. Step 4: For each degree of freedom, construct a target angle trajectory with velocity and acceleration constraints based on the corresponding target attitude components, so that the target angle trajectory remains continuous in terms of angle, angular velocity and angular acceleration. Step 5: During the dual closed-loop control process, the target angle trajectories in the pitch and azimuth directions are compared with the current support feedback attitude to obtain their respective attitude error signals, and the drive control quantity is calculated based on the attitude error signals and their changing trends. Step 6: Convert the drive control quantity into a control signal that adapts to the actuator, drive the pitch and azimuth degrees of freedom to move synchronously, so that the actual attitude of the dual-axis adjustable support follows the target angle trajectory in real time. Step 7: During the operation of the dual-axis adjustable support, continuously collect the current attitude as feedback information to participate in subsequent control cycles, and set monitoring conditions for attitude exceeding limits, sudden increase in error and abnormal drive. Once an abnormal state that meets the preset conditions is detected, limit or stop the output of the target angle trajectory or drive control quantity to keep the dual-axis adjustable support in a safe state.

[0014] Further, step 2 specifically involves: the attitude reference sequence being generated by an inertial measurement unit (IMU) or a numerical simulation module. The IMU collects the triaxial acceleration, triaxial angular velocity, and magnetic field information of the object under wave conditions and converts it into a sequence of data describing the attitude change over time using an attitude calculation algorithm. The attitude calculation algorithm includes one or more of quaternion calculation, direction cosine matrix calculation, or Euler angle calculation, ensuring that the obtained attitude reference sequence contains at least pitch angle, roll angle, and their corresponding timestamp information.

[0015] Furthermore, the signal processing module includes a filtering unit and an error calculation unit. The filtering unit performs denoising, smoothing, and compensation processing on the actual angle information output by the support attitude sensor. The actual angle information includes at least the actual pitch angle and the actual azimuth angle. The filtering unit suppresses high-frequency noise caused by mechanical vibration, electromagnetic interference, and quantization errors through low-pass filtering, moving average filtering, wavelet denoising, Kalman filtering, or a combination thereof. It can also optionally calibrate and compensate for the zero-point deviation and proportional coefficient of the support attitude sensor, ensuring that the filtered actual angle information is continuous in time, stable in value, and consistent with the dual-axis support. The actual attitude is consistent with the actual attitude. The error calculation unit is used to compare the actual angle information processed by the filtering unit with the target control quantity output by the main control unit one by one, calculate the attitude deviation in the pitch direction and azimuth direction respectively, and obtain the attitude error signal for control adjustment. The attitude error signal can be in scalar form or vector form, and can include one or more of angle error, error change rate or weighted comprehensive error. The error calculation unit feeds the attitude error signal back to the main control unit or the dual-axis adjustable support controller so that it can correct the output of the pitch axis and azimuth axis drive unit in real time according to the error magnitude and change trend during the closed-loop control process.

[0016] Furthermore, the denoising and smoothing processing of the original attitude reference sequence includes: firstly, based on the wave change frequency band and sampling frequency contained in the attitude reference sequence, selecting one or more combinations of low-pass filtering, sliding window averaging filtering, wavelet denoising, or Kalman filtering to perform multi-stage filtering processing on the original sequence. The low-pass filtering is used to suppress high-frequency noise components higher than the main wave frequency band; the sliding window averaging filtering is used to weaken short-period oscillations caused by mechanical jitter and quantization errors; wavelet denoising is used to locally suppress sudden noise in the time-frequency domain; and Kalman filtering is used to estimate and compensate for random noise while considering the dynamic characteristics of attitude changes, thereby reducing the amplitude of high-frequency oscillations while maintaining the attitude change trend and phase characteristics as much as possible; subsequently, by setting amplitude thresholds and rate of change thresholds... A comparative analysis of the attitude reference sequences before and after filtering is performed to identify and mark data points that exhibit significant abrupt changes within a short period and are clearly inconsistent with the physical characteristics of waves. These data points are discarded as outliers or replaced with interpolated neighboring data. Then, under a unified time reference, the remaining attitude reference data undergoes interpolation and resampling. This resampling employs one or more of the following methods: linear interpolation, cubic spline interpolation, or other polynomial interpolation. This reconstructs the attitude reference data, which originally had uneven sampling intervals or missing samples, into a sequence with a fixed sampling period. Through this process, the attitude reference progresses monotonically on the time axis, with uniform sampling intervals, and exhibits continuous, smooth, and consistent numerical characteristics with actual wave changes, providing a stable input basis for subsequent two-degree-of-freedom decomposition and target trajectory generation.

[0017] Further, step 3 specifically involves: establishing an attitude mapping relationship between the global coordinate system of the attitude reference description and the local coordinate system adopted by the dual-axis support body, and projecting the attitude reference sequence onto two orthogonal directions corresponding to the pitch and azimuth degrees of freedom; the attitude mapping relationship is obtained by a predetermined attitude calibration experiment, and the conversion from global attitude to local attitude is achieved by using rotation matrix, direction cosine matrix or quaternion transformation, so that the obtained pitch direction target attitude component and azimuth direction target attitude component are mathematically independent, thereby avoiding coupling interference between the two degrees of freedom during the control process; Step 4 specifically involves: acquiring the target attitude components at the current control time and several future times within each control cycle; using discrete target attitude points as interpolation nodes; and generating the corresponding target angle trajectory using one or more combinations of cubic spline interpolation, quintic polynomial trajectory planning, or S-curve trajectory planning. Cubic spline interpolation ensures the continuity of adjacent interpolation segments in terms of angle and first derivative; quintic polynomial trajectory planning achieves a smooth transition from the initial attitude to the target attitude under the condition that the angle, first derivative, and second derivative are all continuous; and S-curve trajectory planning limits the rate of change of acceleration while controlling angular velocity, angular acceleration, and angular jerk, thereby reducing the impact of the trajectory on the support mechanism. Regarding trajectory constraints, the maximum permissible angular velocity, maximum permissible angular acceleration, and optional maximum permissible angular jerk are preset for each degree of freedom of the support mechanism. The angular velocity rise time and deceleration time constraint parameters can be set according to the desired operational smoothness or comfort requirements. During the generation of the target angle trajectory, the candidate trajectory is constrained and verified. When the angular velocity or angular acceleration of the trajectory at a certain moment exceeds the preset limit, the trajectory is corrected by adjusting the interpolation node interval, resolving the polynomial coefficients, or adding a transition segment, so that the corrected trajectory always meets the above constraint conditions.

[0018] Furthermore, step 5 specifically involves: setting up closed-loop controllers for pitch and azimuth degrees of freedom respectively; in each control cycle, the closed-loop controller compares the target angle trajectory with the current actual attitude to obtain the attitude error and its rate of change, and calculates the drive control quantity using at least a combination of proportional-integral-derivative control and feedforward compensation; wherein, proportional-integral-derivative control is used to eliminate steady-state error and suppress dynamic error, and feedforward compensation is used to respond in advance to the changing trend of the target trajectory, thereby improving the dynamic performance of the support in tracking the target attitude when wave conditions change. Step 6 specifically involves: the feedback sampling frequency is preferably set to be more than twice the control cycle frequency; the states of attitude exceeding limits, sudden increase in error, and control signal saturation are comprehensively judged by threshold comparison and duration judgment; when attitude exceeding limits is detected, the target angle trajectory is truncated or limited; when the error is detected to continuously increase in a short period of time and exceed the preset threshold, the rate of change of the target trajectory is reduced or the drive control quantity is reduced; when the control signal is detected to be continuously in the saturation range, the protection logic is triggered to stop the output of drive control quantity and keep the support in a safe attitude position, thereby taking into account both tracking accuracy and operational safety during wave attitude tracking control.

[0019] Beneficial effects: Compared with the prior art, the present invention has the following significant advantages: 1. This invention establishes a dedicated mapping relationship and control process from wave attitude reference to dual-axis support attitude. It can directly use the measured or simulated attitude sequence of the floating body under wave conditions as input, and continuously reproduce its motion process in the two degrees of freedom of pitch and azimuth. Compared with the pendulum device that can only perform simplified single-degree-of-freedom reciprocating motion, and the scheme that relies on a general six-degree-of-freedom platform for complex trajectory programming, this invention can more realistically reflect the attitude changes in the wave environment and significantly improve the consistency between experimental results and actual engineering scenarios.

[0020] 2. This invention introduces attitude preprocessing, two-degree-of-freedom decomposition, and trajectory planning with velocity / acceleration constraints into the control method. Closed-loop controllers and feedforward compensation structures are configured in the pitch and azimuth channels respectively, so that the target angle, angular velocity, and angular acceleration remain continuous in time. This ensures that the support movement remains smooth even under high-frequency and wide-amplitude wave conditions, avoiding sudden velocity changes and impact overtravel problems. Compared with traditional control methods that do not consider trajectory smoothing and dynamic constraints, this invention significantly reduces attitude tracking error and improves the dynamic response performance of the system.

[0021] 3. The system structure of this invention is specially designed around the specific application scenario of "floating platform attitude - dual-axis support". It retains only the two necessary degrees of freedom of pitch and azimuth, and adopts a modular support mechanism, execution drive unit and data processing unit. Compared with the general six-degree-of-freedom motion platform or the solution of setting up a complete floating photovoltaic system on site, the mechanical structure is simpler, the footprint is smaller, the control implementation difficulty and equipment investment cost are significantly reduced, and it is easy to build and promote under ordinary laboratory conditions.

[0022] 4. This invention incorporates mechanical limit switches, electronic limit switches, and emergency stop circuits on the dual-axis support mechanism. The control software includes multiple criteria such as attitude exceeding limits, sudden error increases, and drive signal saturation to monitor the support's motion state and drive load in real time. In the event of an anomaly, automatic measures such as deceleration, amplitude limiting, or drive disconnection are implemented to return the support to or maintain it within a safe attitude range. Compared to existing devices lacking a systematic protection mechanism, this invention is more suitable for conducting long-term, multi-condition wave attitude simulation tests, offering higher system safety and reliability.

[0023] 5. Although the system structure and control method proposed in this invention are typically applied to the attitude research of marine photovoltaic support, its core idea is to transform the wave attitude reference into the dynamic following motion of the two-degree-of-freedom mechanical support. Therefore, it is also applicable to the attitude simulation of other marine structures, observation equipment or test vehicles. At the same time, the system reserves a variety of sensor interfaces and load installation interfaces, and the test components can be replaced or measurement modules can be added according to different research needs, which has good versatility and expandability. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the experimental platform structure of the wave attitude-driven dual-axis support dynamic simulation system of the present invention; in the figure, the wave generator controller is 1, the wave generator actuator is 2, the floating body assembly is 3, the tilt angle measurement module is 4, the data acquisition and communication module is 5, the dual-axis adjustable photovoltaic support controller is 6, the motor drive circuit is 7, the pitch axis and azimuth axis drive unit is 8, the dual-axis adjustable support is 9, the support attitude sensor is 10, and the power supply and voltage stabilization module is 11.

[0025] Figure 2 This is a control system block diagram of the wave attitude-driven dual-axis support dynamic simulation system of the present invention; Figure 3 This is a flowchart illustrating the overall process of the dual-axis support attitude control method based on wave attitude drive according to the present invention. Figure 4 This is a schematic diagram of the wave generator control process based on wave attitude drive according to the present invention; Figure 5 This is a schematic diagram of the attitude reference and trajectory preprocessing process based on wave attitude driving according to the present invention; Figure 6 This is a schematic diagram of the dual-axis decoupling and dual-channel control process based on wave attitude driving according to the present invention. Detailed Implementation

[0026] The technical solution of the present invention will be further described below with reference to the accompanying drawings.

[0027] like Figure 1 , Figure 2As shown, the wave attitude-driven dual-axis support dynamic simulation system of this invention includes: a wave-generating experimental platform, a floating body component 3, an inclination measurement module 4, a data acquisition and communication module, a main control unit, a dual-axis adjustable support 9, a pitch axis and azimuth axis drive unit 8, a support attitude sensor 10, a signal processing module, a limit and safety protection module, and a power supply and voltage regulation module 11, etc.

[0028] The wave-generating experimental platform can be a linear or reflux tank, with a wave generator at one end and a wave-damping device at the other. The wave generator outputs regular or irregular waves based on preset wave height, period, and wave direction parameters, forming a repeatable target wave field. The floating body assembly 3 is arranged in the wave field and can adopt a rectangular box, cylindrical, or multi-floating body splicing structure. Internal counterweights are installed to adjust resilience and draft, enabling it to produce representative pitch and roll attitude responses under the target wave conditions. Those skilled in the art can design similar floating body geometry and mass distribution based on the research object, such as a marine photovoltaic array unit or an observation platform model.

[0029] The tilt measurement module 4 is fixedly mounted on the floating body assembly 3, preferably near the geometric center or center of mass to reduce the impact of local structural vibrations on the measurement results. In this embodiment, the tilt measurement module 4 adopts an integrated inertial measurement unit, which integrates a three-axis accelerometer and a three-axis gyroscope, and optionally includes a magnetometer to provide attitude reference in the geographic coordinate system. The inertial measurement unit has built-in temperature compensation and zero-point calibration programs to reduce temperature drift and long-term drift; its sampling frequency can be set to 50-200Hz, and it periodically outputs data frames including pitch angle, roll angle, three-axis acceleration, three-axis angular velocity, and timestamps via serial port or CAN bus.

[0030] The data acquisition and communication module is electrically connected to the tilt measurement module 4 to receive, preprocess, and transmit attitude data. Specifically, the data acquisition and communication module internally includes a data parsing unit, a buffer unit, a verification unit, and a multi-threaded processing structure. The data parsing unit identifies the frame header, splits fields, and converts the format of received data frames, extracting information such as pitch angle, roll angle, and timestamp into a unified data structure. The buffer unit stores a certain amount of attitude data in a circular queue, which can adapt to fluctuations in the processing speed of the host computer and act as a buffer in case of momentary communication interruptions. The verification unit confirms data integrity through length checks, CRC checks, etc., and discards or marks erroneous frames. The multi-threaded processing structure enables parallel execution of data reception, buffer organization, and uplink transmission, ensuring real-time data transmission even under high sampling frequency conditions. The data acquisition and communication module can be connected to the main control unit using serial port, RS485, CAN, or Ethernet communication methods, depending on the available laboratory conditions.

[0031] The main control unit can be implemented using a combination of an industrial computer, a host computer, and an embedded control board, or a high-performance microcontroller / ARM controller. In this embodiment, the main control unit includes an attitude analysis and mapping module, a trajectory generation module, and a dual-channel control module. The attitude analysis and mapping module first filters and interpolates the attitude sequence from the data acquisition and communication module to reduce measurement noise and unify the sampling period. Then, based on the azimuth relationship between the pre-calibrated floating body coordinate system and the dual-axis adjustable support coordinate system, it decomposes the overall attitude reference into target attitude quantities in the pitch and azimuth directions using rotation matrix or quaternion operations. The trajectory generation module generates target angle trajectories for each of the two degrees of freedom using cubic splines, fifth-order polynomials, or S-curves, based on the target attitude change trend and constraints such as the maximum angular velocity and maximum angular acceleration allowed by the dual-axis adjustable support assembly, ensuring that the angle, angular velocity, and angular acceleration are continuous in time. The dual-channel control module reads the target angle and the feedback angle of the dual-axis adjustable support at the current moment in each control cycle, calculates the attitude error and its rate of change, and calls the set control algorithm to obtain the respective drive control quantities of the pitch axis and azimuth axis.

[0032] The dual-axis adjustable support assembly is mounted on a rigid land base and consists of an azimuth turntable and a pitch rocker arm. The azimuth turntable is connected to the base via a slewing bearing and can rotate about a vertical axis. The pitch rocker arm is connected to the azimuth turntable via supports on both sides and can rotate about a horizontal axis. The dummy load of the photovoltaic module under test or other test pieces is mounted on the upper mounting plate of the pitch rocker arm. The pitch axis drive unit is connected to the rotation shaft of the pitch rocker arm, and the azimuth axis drive unit is connected to the internal or external gear ring of the slewing bearing of the azimuth turntable. Both can be driven by servo motors with reducers or electric actuators, and a coupling and encoder bracket are provided at the output shaft end for easy debugging and maintenance.

[0033] The support attitude sensor 10 is installed on the rotating part of the dual-axis adjustable support assembly to acquire the current pitch and azimuth angles of the dual-axis adjustable support in real time. In this embodiment, absolute encoders are preferably installed on the pitch and azimuth axes respectively, but a small IMU can also be attached to the pitch rocker arm to synchronously detect angular velocity. The signal processing module performs counting decoding, zero-point correction, and digital filtering on the encoder or IMU output signal to obtain the actual attitude data for feedback control, and provides it to the main control unit through the internal bus.

[0034] The limit and safety protection module includes mechanical limit blocks, limit switches, and software limit logic. The mechanical limit blocks are set at the extreme travel positions of the pitch arm and azimuth turntable to prevent the dual-axis adjustable support from rotating beyond a safe angle in extreme cases. The limit switches are connected to the control circuit and issue a warning or stop signal when the dual-axis adjustable support approaches its extreme position. The software limit logic is implemented within the main control unit, setting the maximum allowable range for the attitude reference and target angle trajectory, and comprehensively judging the drive current, error magnitude, and duration. If an abnormality occurs, it reduces output or triggers an emergency stop. The power supply and voltage regulation module provides multiple DC power supplies to the main control unit, support attitude sensors, actuators, and other electronic units. It internally uses isolated power supply modules and voltage regulator chips, and is equipped with overcurrent, overvoltage, and short-circuit protection.

[0035] Based on the above hardware structure, the control method of the present invention can be combined with Figures 3-6 Please provide an explanation.

[0036] like Figure 3 As shown, the control calculation unit first reads the attitude reference sequence during operation and performs data preprocessing on it, including noise filtering, outlier removal and time resampling, to obtain a smooth attitude reference signal with a uniform sampling period; then, according to the attitude mapping relationship, the reference signal is converted into pitch target angle and azimuth target angle.

[0037] like Figure 5 As shown, the preprocessing process can adopt a combination of multi-level filtering and sliding window statistics: first, high-frequency noise is suppressed by low-pass or Kalman filtering, then unreasonable jump points are identified by amplitude threshold and rate of change threshold, and they are corrected by interpolation or neighborhood averaging; finally, the attitude reference is interpolated according to the control cycle to obtain the target sequence sampled at equal intervals.

[0038] like Figure 6 As shown, in the dual-axis decoupling and control process, the pitch and azimuth channels each perform trajectory planning and closed-loop control. For each channel, the control calculation unit generates a smooth trajectory based on the target angle at the current moment and several future moments, and calculates the drive control quantity under the constraints of this trajectory. The pitch and azimuth axis drive units 8 and azimuth axis drive units receive their respective control quantities and drive the motors to rotate, causing the dual-axis adjustable support assembly to move along the planned trajectory. The actual angle collected in real time by the support attitude sensor 10 is returned to the main control unit, compared with the target angle, and the error signal is updated. This process is repeated cyclically within a fixed sampling period, thereby achieving continuous tracking of the wave attitude.

[0039] Throughout the control process, the limit and safety protection module continuously monitors the attitude, drive current, and system operating status of the dual-axis adjustable bracket. When it detects that the dual-axis adjustable bracket is approaching the set limit angle, the error increases rapidly in a short period of time, or the drive control quantity is in a saturated state for a long time, the main control unit will reduce the target trajectory change speed or stop the output directly. If necessary, it will trigger the emergency stop relay to cut off the motor power supply, keeping the dual-axis adjustable bracket assembly in a safe position and ensuring the safety of the test personnel and equipment.

[0040] As can be seen from the above specific embodiments, the present invention can use a dual-axis adjustable support to perform high-precision and repeatable dynamic reproduction of the attitude of a floating body in waves on a land platform. Moreover, the system has a clear structure and a sound control strategy, making it suitable for widespread use in various application scenarios such as offshore photovoltaic supports and marine observation platforms.

[0041] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A dynamic simulation experiment platform for power generation performance of a marine photovoltaic system, characterized in that, The application relates to a wave making experiment subsystem, a floating body assembly (3), an inclination measuring module (4), a data acquisition and communication module (5), a main control unit, a two-axis adjustable photovoltaic support controller (6), a motor driving circuit (7), a pitching shaft and azimuth shaft driving unit (8), a two-axis adjustable support (9), a support posture sensor (10), a signal processing module, a position limiting and safety protection module and a power supply and voltage stabilizing module (11). The wave making experiment subsystem comprises a wave maker controller (1) and a wave maker execution end (2) connected with the wave maker controller (1) through signals, and the wave maker execution end (2) is installed at one end of a water tank; the floating body assembly (3) is arranged in a wave field formed by the wave making experiment subsystem; the inclination measuring module (4) is fixedly installed on the floating body assembly (3) and is installed in parallel relative to the bottom surface of the floating body and is connected with the data acquisition and communication module (5) to output inclination data representing posture changes of the floating body to the data acquisition and communication module (5); the data acquisition and communication module (5) is electrically connected with the inclination measuring module (4) and is further connected to the main control unit to collect, pretreat and communicate and package posture data and send the posture data to the main control unit; the main control unit generates target control amounts of the two-axis adjustable support (9) in the pitching direction and the azimuth direction according to received posture information and outputs corresponding control instructions to the motor driving circuit (7), the motor driving circuit (7) generates driving voltage and driving current according to the control instructions and sends the driving voltage and the driving current to the pitching shaft and azimuth shaft driving unit (8) so that the two-axis adjustable support (9) rotates in the pitching shaft and azimuth shaft directions; the two-axis adjustable support (9) has a pitching shaft and an azimuth shaft arranged in perpendicular to each other and is used for carrying a simulated object and realizing posture adjustment in two rotation degrees of freedom; the pitching shaft and azimuth shaft driving unit (8) is connected with the main control unit and is in transmission connection with the pitching shaft and the azimuth shaft in the two-axis adjustable support (9) respectively, drives corresponding shafts S to rotate according to the control instructions output by the main control unit, and makes the two-axis adjustable support (9) produce posture changes corresponding to the target control amounts; the support posture sensor (10) is installed on the two-axis adjustable support (9) and is used for feeding back actual posture information of the two-axis adjustable support (9) to the signal processing module; the signal processing module is used for processing the actual posture information output by the support posture sensor (10) and providing processing results to the main control unit, and the main control unit controls adjustment based on the deviation between the actual posture and the target control amounts; the position limiting and safety protection module and the power supply and voltage stabilizing module (11) are arranged on the two-axis adjustable support (9) and a driving circuit thereof; the power supply and voltage stabilizing module (11) provides required working power for the inclination measuring module (4), the data acquisition and communication module (5), the main control unit, the pitching shaft and azimuth shaft driving unit (8), the support posture sensor (10) and the signal processing module, and performs voltage stabilization, isolation and overload protection on power supply. ​ 2. The dynamic simulation experiment platform for the performance of a marine photovoltaic system according to claim 1, characterized in that, The inclination measuring module (4) comprises a three-axis acceleration sensor or an angular velocity sensor, and is provided with a temperature compensation circuit and a zero offset calibration unit. The measured signals are filtered and fused by a built-in attitude solving algorithm, and attitude data representing the pitch and roll attitude of the floating body assembly are output.

3. The dynamic simulation experiment platform for the performance of a marine photovoltaic system according to claim 1, characterized in that, The data acquisition and communication module (5) comprises a data analysis unit, a buffer unit, a verification unit, a multi-thread processing structure and a communication interface circuit. The data analysis unit is used for protocol analysis, format conversion and field extraction of the attitude data output by the inclination measuring module (4), and the original data stream is split into information frames with time stamp, attitude quantity and state flag. The buffer unit is used for queue storage and read-write scheduling of the analyzed information frames, and is adapted to the difference between different sampling frequencies and transmission bandwidths, and prevents data loss under high-frequency sampling conditions. The verification unit checks the integrity of the received data frames by setting frame header and frame tail flags, data length check and CRC check mechanism, and triggers retransmission request or packet loss marking when an exception is detected. The multi-thread processing structure is used to complete the data receiving, buffering, verification and sending tasks in parallel in the same module, and the real-time receiving, format conversion, data reconstruction and time sequence alignment of high-frequency attitude data. The drift, jitter, data packet loss and delay deviation under high fluctuation state are limited within a controllable range by setting sliding window filtering, mutation point suppression and data integrity checking mechanism. The communication interface circuit adopts one or several of serial port, CAN bus, RS485 or Ethernet, and configures baud rate, node address and data frame format according to experimental requirements, so as to stably send the preprocessed attitude data to the main control unit according to the predetermined communication protocol.

4. The dynamic simulation experiment platform for the performance of a marine photovoltaic system according to claim 1, characterized in that, The main control unit is internally provided with an attitude analysis and decomposition module and a target control quantity generation module. The attitude analysis and decomposition module is used to decompose the spatial attitude of the floating body assembly (3) into attitude components corresponding to the pitch direction and azimuth direction of the double-axis adjustable support (9) according to the angle information contained in the attitude data. The target control quantity generation module calculates the corresponding pitch direction target control quantity and azimuth direction target control quantity according to the decomposed attitude components, and outputs them to the pitch axis and azimuth axis driving unit (8) in the form of digital control instructions.

5. The dynamic simulation experiment platform for the performance of a marine photovoltaic system according to claim 1, characterized in that, The double-axis adjustable support (9) comprises a pitch rotating member arranged along a first rotation axis and an azimuth rotating member arranged along a second rotation axis orthogonal to the first rotation axis. The pitch rotating member and the azimuth rotating member are supported by a bearing assembly and form two mutually orthogonal rotation degrees of freedom for carrying photovoltaic modules, test boards or other objects to be simulated. The pitch axis and azimuth axis driving unit (8) respectively comprises a motor body and a transmission structure connecting the motor output shaft and the corresponding rotating shaft of the double-axis adjustable support (9). The motor driving circuit adjusts the speed and direction of the motor according to the control instructions output by the main control unit, so as to drive the double-axis adjustable support (9) in the corresponding axis to rotate at a specified angle.

6. The dynamic simulation experiment platform for the performance of a marine photovoltaic system according to claim 1, characterized in that, The support posture sensor (10) includes one or more of an angle encoder, a gyroscope or an inertial measurement unit, for acquiring actual angle information of the two-axis adjustable support (9) in the pitch direction and the azimuth direction, and outputting to the signal processing module in the form of an electrical signal; the power supply and voltage stabilizing module (11) includes a main power input unit, a voltage stabilizing conversion unit and an isolation protection unit, the main power input unit is used for receiving external power supply, the voltage stabilizing conversion unit is used for converting the main power into a plurality of direct current voltage outputs suitable for the master control unit, the sensor module and the driving unit, and the isolation protection unit is used for electrically isolating the control logic circuit and the power driving circuit and providing overcurrent, overvoltage and short circuit protection.

7. A control method of a dynamic simulation experiment platform for power generation performance of a marine photovoltaic system, characterized in that, The method for the support structure with two rotational degrees of freedom of pitch and azimuth to dynamically follow the external wave posture reference signal, the method comprises the following steps: Step 1, acquiring the wave posture reference signal, recording the posture information of the floating body or the measured object subjected to the pitch and roll motion under the action of the wave in the form of time sequence as the posture reference data; Step 2, filtering, denoising and time axis reconstruction processing are performed on the posture reference data, abnormal points and jitter components are removed, and a smooth and continuous posture reference sequence in time is obtained; Step 3, according to the posture parameters contained in the posture reference sequence, the reference posture is decomposed into target posture components respectively acting on the pitch degree of freedom and the azimuth degree of freedom of the support; Step 4, on each degree of freedom, a target angle trajectory with speed constraint and acceleration constraint is constructed according to the corresponding target posture component, so that the target angle trajectory remains continuous on three levels of angle, angular velocity and angular acceleration; Step 5, in the double closed-loop control process, the target angle trajectories in the pitch direction and the azimuth direction are compared with the current support feedback posture respectively, the respective posture error signals are obtained, and the driving control quantity is calculated based on the posture error signals and their trends; Step 6, the driving control quantity is converted into a control signal suitable for the actuator, and the pitch degree of freedom and the azimuth degree of freedom are driven to move synchronously, so that the actual posture of the two-axis adjustable support follows the target angle trajectory in real time; Step 7, the current posture is continuously collected as feedback information during the operation of the two-axis adjustable support to participate in the subsequent control cycle, and monitoring conditions of posture overrun, error sudden increase and driving abnormality are set, and once the abnormal state meeting the preset condition is detected, the target angle trajectory or the driving control quantity is limited or stopped to output, so that the two-axis adjustable support is in a safe state.

8. The control method of a dynamic simulation experiment platform for the performance of a marine photovoltaic system according to claim 7, characterized in that, Step 2 is specifically: the posture reference sequence is generated by an inertial measurement device or a numerical simulation module, the three-axis acceleration, three-axis angular velocity and magnetic field information of the measured object under the wave working condition are collected by the inertial measurement device, and a posture solving algorithm is used to convert them into sequence data describing the change of the posture with time, the posture solving algorithm includes one or more of quaternion solving, direction cosine matrix solving or Euler angle solving, so that the obtained posture reference sequence at least includes the pitch angle, the roll angle and the corresponding time stamp information.

9. The control method of the offshore photovoltaic system power generation performance dynamic simulation experiment platform according to claim 7, characterized in that, Step 3 is specifically: projecting the attitude reference sequence to two orthogonal directions corresponding to the pitch degree of freedom and the azimuth degree of freedom by establishing an attitude mapping relationship between the global coordinate system described by the attitude reference and the local coordinate system adopted by the two-axis adjustable support body; the attitude mapping relationship is obtained by a pre-determined attitude calibration experiment, and the conversion from the global attitude to the local attitude is realized by using a rotation matrix, a direction cosine matrix or a quaternion transformation, so that the obtained pitch direction target attitude component and the azimuth direction target attitude component are mathematically independent of each other, thereby avoiding the coupling interference of the two degrees of freedom in the control process; Step 4 is specifically: obtaining the target attitude components at the current control time and several future times in each control period, taking the discrete target attitude points as interpolation nodes, and generating the corresponding target angle trajectory by using one or a combination of several of the following: cubic spline interpolation, quintic polynomial trajectory planning or S-curve trajectory planning; wherein the cubic spline interpolation is used to ensure the continuity of adjacent interpolation segments in angle and first-order derivative, the quintic polynomial trajectory planning is used to realize smooth transition from the initial attitude to the target attitude under the condition that the angle, the first-order derivative and the second-order derivative are all continuous, and the S-curve trajectory planning is used to limit the acceleration change rate under the premise of control angular velocity, angular acceleration and angular jerk, thereby reducing the impact of the trajectory on the support mechanism; In terms of trajectory constraints, the maximum allowed angular velocity, the maximum allowed angular acceleration and the optional maximum allowed angular jerk of the support mechanism are pre-set for each degree of freedom, and the constraint parameters of the angular velocity rise time and the deceleration time can be set according to the desired running stability or comfort requirements; in the process of generating the target angle trajectory, the candidate trajectory is checked for constraints, and when the angular velocity or the angular acceleration of the trajectory at a certain time exceeds the pre-set limit value, the trajectory is modified by adjusting the interval between the interpolation nodes, recalculating the polynomial coefficients or adding a transition segment, so that the modified trajectory always satisfies the above constraint conditions.

10. The control method of the offshore photovoltaic system power generation performance dynamic simulation experiment platform according to claim 7, characterized in that, Step 5 is specifically: setting a closed-loop controller for the pitch degree of freedom and the azimuth degree of freedom respectively, the closed-loop controller compares the target angle trajectory with the current actual attitude in each control period to obtain the attitude error and its rate of change, and at least adopts the combination of proportional-integral-derivative control and feedforward compensation to calculate the driving control quantity; wherein the proportional-integral-derivative control is used to eliminate steady-state error and suppress dynamic error, and the feedforward compensation is used to respond to the trend of the target trajectory in advance, thereby improving the dynamic performance of the support in tracking the target attitude when the wave condition changes. The step 6 specifically comprises: the feedback sampling frequency is preferably set to be greater than twice of the control cycle frequency, the states of the attitude overrun, the error sudden increase and the control signal saturation are comprehensively judged through threshold comparison and duration judgment; when the attitude overrun is detected, the target angle trajectory is truncated or limited in amplitude; when the error continuously increases in a short time and exceeds the preset threshold, the change rate of the target trajectory or the driving control amount is reduced; when the control signal continuously stays in the saturation interval, the protection logic is triggered to stop outputting the driving control amount and keep the support in the safe attitude position, so as to simultaneously consider the tracking accuracy and the operation safety in the wave attitude tracking control process.

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