Photovoltaic tracking support and control method thereof

Abstract

The invention discloses a photovoltaic tracking support and a control method thereof.The photovoltaic tracking support comprises a mounting bracket for mounting a photovoltaic module, a main shaft is fixed to the mounting bracket through at least two connecting parts, one end of the main shaft is movably connected to a second stand column, and the other end of the main shaft is provided with an azimuth angle adjusting mechanism; the bottom of the azimuth angle adjusting mechanism is movably connected with an electric telescopic rod; an ultrasonic anemorumbometer and a plurality of photosensitive diodes are arranged at the top of the photovoltaic module, and an attitude measurement sensor is arranged at the input end of the main shaft. The photovoltaic tracking support is simple in structure, good in anti-wind stability, high in control precision and capable of adapting to different collection environments, disturbance response is more timely in cooperation with a control method based on HOSMD-ADRC, real-time adjustment of the azimuth angle and the pitch angle of the support can be achieved, and the stability of the support is improved. Therefore, the photovoltaic module can receive the optimal sunlight irradiation at different times in one day, so that the photoelectric conversion efficiency is improved to the maximum extent.

Description

Technical Field

[0001] The present invention relates to the technical field of photovoltaic power generation, and in particular to a photovoltaic tracking bracket and a control method thereof. Background Art

[0002] As global demand for renewable energy continues to increase, solar energy, as a clean, green, and renewable energy source, has become an important component of the energy structure transformation. In particular, under the pressure of addressing climate change and reducing greenhouse gas emissions, solar photovoltaic technology has been widely used.

[0003] Photovoltaic brackets can be mainly divided into two categories: fixed brackets and tracking brackets. The emergence of tracking brackets has significantly improved the photoelectric conversion efficiency of solar photovoltaic panels. Among the existing tracking brackets, single-axis tracking brackets are the most common type, which mainly adjust the changes in the pitch angle of the sun within a day to achieve tracking of the solar radiation angle. Although this bracket has improved the photoelectric conversion efficiency to a certain extent, since it cannot effectively track the changes in the azimuth angle of the sun, there is still a lot of room for improvement, especially in optimizing the azimuth angle tracking and system control algorithms. Patent document CN118889972A discloses a photovoltaic tracking bracket with self-adjusting slope, which uses a self-adjusting mechanism to make the main shaft swing up and down around its end, thereby adapting to the slope; the drive assembly uses the transmission assembly and the extension arm to drive the main shaft to rotate around its axis to achieve tracking of the sun, but this bracket can only adjust one angle of the photovoltaic panel and cannot track the azimuth and pitch angle of the sun at the same time. Patent document CN117013935A discloses a dual-axis solar tracking bracket, which uses a rotary drive device installed on a column to achieve tracking of the solar azimuth angle; the push rod is used to drive the rotation mechanism to achieve tracking of the elevation angle, thereby increasing the effective area facing the sun. However, the push rod tracking is subject to certain limitations on the rotation angle of the photovoltaic panel and is difficult to accurately control. When the angle is large, the push rod is prone to locking. Patent document CN119045540A discloses a photovoltaic tracking bracket and its control system and control method, wherein the angle adjustment mechanism cooperates with the drive motor through a worm gear transmission system, enabling the bracket to adjust the azimuth and pitch angle in the horizontal and vertical directions respectively to achieve dual-axis tracking of the sun, and the rotation of the photovoltaic panel can be adjusted within a large angle range, greatly improving tracking accuracy and light energy conversion efficiency. However, the angle adjustment mechanism has a complex structure, the adjustment accuracy is affected by the assembly accuracy, and the installation is difficult. In addition, the use of a single support column has poor structural stability. The aforementioned existing photovoltaic brackets still have the following problems: 1. Existing photovoltaic brackets use a single-column support structure. Under the influence of long-term wind and gravity, or in blizzards, the bracket is prone to significant tilt or deformation, affecting tracking accuracy and reliability. At the same time, the single-column design usually cannot effectively share the load, increasing the local stress of the bracket structure, which may lead to material fatigue or failure risks. 2. Most existing photovoltaic brackets can only track one of the sun's azimuth and pitch angles. It is necessary to track both azimuth and pitch angles simultaneously, and the existing tracking bracket structure is relatively complex. 3. The commonly used control methods for existing photovoltaic brackets are PID and fuzzy control. The fixed parameters of PID are difficult to adapt to strong disturbances such as wind disturbances and sudden changes in cloud cover, which can easily lead to tracking lag and overshoot oscillation; and fuzzy control relies on expert experience, the design of the empirical rule base is complex, and the dynamic response is slow. Summary of the Invention

[0004] In response to the above-mentioned deficiencies in the prior art, the present invention provides a photovoltaic tracking bracket and a control method thereof, which solve the problems of poor wind resistance, insufficient control accuracy, weak environmental adaptability and delayed disturbance response of the existing photovoltaic tracking bracket. Through the collaborative design of structural optimization and intelligent control, real-time adjustment of the bracket's azimuth and pitch angles is achieved, ensuring that the photovoltaic modules can receive optimal sunlight at different times of the day, thereby maximizing the improvement of the photoelectric conversion efficiency.

[0005] In order to achieve the above-mentioned object of the invention, the technical solution adopted by the present invention is: Provided are a photovoltaic tracking bracket and a control method thereof, comprising a mounting bracket for mounting a photovoltaic module, wherein the mounting bracket is fixed with a main shaft via at least two connecting components, one end of the main shaft being movably connected to a second column, and the other end of the main shaft being provided with an azimuth adjustment mechanism, the azimuth adjustment mechanism being used to drive the main shaft to rotate, and the bottom of the azimuth adjustment mechanism being movably connected to an electric telescopic rod; an ultrasonic anemometer and a plurality of photosensitive diodes being provided on the top of the photovoltaic module, an attitude measurement sensor being provided at the input end of the main shaft, and the ultrasonic anemometer, the photosensitive diode and the attitude measurement sensor being all electrically connected to a control system.

[0006] Furthermore, the telescopic end of the electric telescopic rod is provided with a connecting ball, the bottom of the azimuth adjustment mechanism is provided with an upper ball socket that cooperates with the connecting ball, and the lower side of the connecting ball is provided with a connecting ball socket, which is fixedly connected to the bottom of the azimuth adjustment mechanism, and the connecting ball is installed in the lower ball socket through the connecting ball socket.

[0007] Furthermore, a strip arc groove is provided in the upper ball socket, and a sliding protrusion that cooperates with the strip arc groove is provided on the connecting ball. When the connecting ball rotates in the connecting ball socket, the sliding protrusion can slide in the strip arc groove.

[0008] Furthermore, the sliding direction of the sliding protrusion is the same as the lifting direction of the main shaft lifting end.

[0009] Furthermore, the azimuth angle adjustment mechanism includes an adjustment motor, a worm, a turbine meshing with the worm, a three-stage reduction gearbox and a housing. The motor is connected to the worm through a coupling. The other end of the worm is rotatably mounted on the second bearing seat. The bottom of the second bearing seat is fixedly connected to the housing. A rolling bearing for mounting the worm is provided on the second bearing seat. The turbine is fixedly mounted on the input shaft of the three-stage reduction gearbox, and the output end of the three-stage reduction gearbox is connected to the main shaft.

[0010] Furthermore, a first bearing seat is provided on the second column, and a joint bearing is provided on the main shaft, in which the first bearing seat and the joint bearing cooperate with each other.

[0011] Furthermore, photosensitive diodes are provided at four locations, and the four photosensitive diodes are evenly distributed at the four corners of the top of the photovoltaic module.

[0012] The control system is a HOSMD-ADRC controller, which includes a high-order sliding mode differentiator, an extended state observer, and a nonlinear state error feedback control law.

[0013] A control method for a photovoltaic tracking bracket comprises the following steps: S1: Use an ultrasonic anemometer to collect the wind speed and direction in the current environment, and adjust the sun-facing angle of the photovoltaic tracking bracket according to the collected wind speed; specifically: When the wind speed in the current environment detected by the ultrasonic anemometer is greater than 25m / s, the safety response mechanism is activated. Based on the collected wind direction data, the electric telescopic rod and azimuth adjustment mechanism are controlled to adjust the bottom surface of the mounting bracket to be consistent with the wind direction; When the wind speed in the current environment detected by the ultrasonic anemometer is greater than or equal to 10m / s and less than or equal to 5m / s, the photovoltaic tracking bracket maintains the current state, and the electric push rod and worm gear remain in the self-locking state; When the wind speed in the current environment detected by the ultrasonic anemometer is less than 10m / s, the photovoltaic tracking bracket operates normally, and the next step is executed to adjust the optimal collection angle of the photovoltaic bracket; S2: A GPS module is installed on the photovoltaic tracking bracket to obtain the current geographic location and time information of the photovoltaic tracking bracket through the GPS module, and the azimuth angle and pitch angle of the sun at the current location of the photovoltaic tracking bracket are obtained as the target azimuth angle and target pitch angle to which the photovoltaic tracking bracket needs to be adjusted; S3: The actual azimuth and pitch angles of the photovoltaic tracking bracket are acquired through the attitude measurement sensor; S4: Compare the target azimuth angle with the actual azimuth angle, and the target pitch angle with the actual pitch angle to determine whether it is necessary to perform a coarse adjustment on the angle of the photovoltaic tracking bracket. The coarse adjustment includes azimuth adjustment and pitch angle adjustment. The specific method for adjusting the azimuth angle of the photovoltaic tracking bracket is as follows: S41: Determine whether the target azimuth angle is equal to the actual azimuth angle; if the target azimuth angle is not equal to the actual azimuth angle, execute step S42 to adjust the angle of the photovoltaic tracking bracket; if the target azimuth angle is equal to the actual azimuth angle, execute step S5; S42: The azimuth angle of the photovoltaic tracking bracket is coarsely adjusted by controlling the rotation of the motor to drive the main axis to rotate toward the target azimuth angle; the pitch angle of the photovoltaic tracking bracket is coarsely adjusted by controlling the extension and retraction of the electric telescopic rod to drive the main axis to rotate toward the target pitch angle; S43: Collect the actual azimuth and actual pitch angles of the photovoltaic tracking bracket after rough adjustment, and then call the HOSMD-ADRC controller to assist in achieving precise adjustment of the azimuth and pitch angles of the photovoltaic tracking bracket; S44: Repeat steps S42-S43, replace the target azimuth angle and the actual azimuth angle with the target pitch angle and the actual pitch angle, and adjust the pitch angle of the photovoltaic tracking bracket; S5: Based on the collected actual azimuth angle after coarse adjustment and the target azimuth angle, as well as the target pitch angle and the actual pitch angle after coarse adjustment, it is determined whether the photovoltaic support is facing the sun, and the azimuth angle or pitch angle of the photovoltaic tracking support is fine-tuned using a photodiode; Specifically, when the electrical signals sent by the four photosensitive diodes are consistent, it is determined that the photovoltaic tracking bracket is facing the sun, and the angle adjustment of the photovoltaic tracking bracket is completed; when the electrical signals sent by the four photosensitive diodes are inconsistent, it is determined that the photovoltaic tracking bracket is not facing the sun. At this time, the angle of the photovoltaic tracking bracket is fine-tuned in conjunction with the photosensitive diodes until the electrical signals sent by the four photosensitive diodes are consistent, and the angle adjustment of the photovoltaic tracking bracket is completed.

[0014] Furthermore, step S43 specifically includes the following steps: S431: Using a high-order sliding mode differentiator to perform high-precision and rapid tracking of the target azimuth and target pitch angles, obtaining a smoothed target angle and a smoothed target angular velocity. The target angle includes the smoothed target azimuth and target pitch angles, and the target angular velocity includes the smoothed target azimuth angular velocity and target pitch angular velocity. Specifically, the formulas for calculating the smoothed target angle and the smoothed target angular velocity are as follows: ;

[0015] Where: Input signal , is the original signal of the target azimuth and / or target elevation, i.e. the target angle of the elevation or the target angle of the azimuth, Noise interference includes encoder quantization error, photoelectric sensor noise and mechanical vibration noise. Tracking moments for angles; The original signal The estimated value of The original signal The first-order differential estimate of The original signal The second-order differential estimate of is an estimated value The differential value of is the first-order differential estimate The differential value of is the second-order differential estimate The differential value of is an estimated value The approximate value of , that is, the target angle after smoothing, is the first-order differential estimate The approximate value of , that is, the target angular velocity after smoothing; is the second-order differential estimate The approximate value of , that is, the target angular acceleration after smoothing; is the second-order differential estimate The approximation of the differential value of ; is the parameter that controls the convergence speed of the angle error, is the parameter that controls the convergence strength of the angular velocity error, is the parameter that controls the robustness of angular acceleration; is a symbolic function, is the variable of the symbolic function; S432: Using an expanded state observer to observe the feedback signal collected by the photovoltaic tracking bracket, and expanding the total disturbance of the system into an expanded state variable, and performing real-time estimation to establish a disturbed expanded system. Specifically, the disturbed expanded system is as follows: ; in, The feedback signal collected by the photovoltaic tracking bracket is the pitch angle or azimuth angle collected in real time by the attitude measurement sensor. The actual pitch angle or actual azimuth angle collected by the attitude measurement sensor, It is the actual pitch angular velocity or actual azimuth angular velocity collected by the attitude measurement sensor. for The differential value of for The differential value of is the expansion state variable; is the unknown nonlinear system function including disturbance, is the gain coefficient of the control quantity, that is, the gain coefficient of the actual pitch angle or the actual azimuth angle; For The estimated value of , which is the compensation factor that determines the strength of error compensation; is the actual control quantity; S433: Introduce the gain coefficient and combine it with the feedback acquisition signal obtained in step S432 , we can get the observed value of pitch angle or azimuth angle, the observed value of pitch angular velocity or azimuth angular velocity and the estimated value of total disturbance of the system. Specifically, the calculation formula is as follows: ; ; in, is the error between the estimated value of the actual pitch angle and the pitch angle collected in real time by the attitude measurement sensor, or the error between the estimated value of the actual azimuth angle and the pitch angle collected in real time by the attitude measurement sensor, is the observed value of the elevation angle or azimuth angle, is the observed value of the pitch angular velocity or azimuth angular velocity, is the estimated value of the total disturbance of the system, through Compensate the control amount to effectively suppress the interference effect; for The differential value of for The differential value of for The differential value of and is the gain coefficient; To control the nonlinear response curve shape of the angle error feedback, To control the nonlinear response curve shape of the angular velocity error feedback, is the observation error feedback gain coefficient, which is used to realize the extended state observer to quickly and accurately approximate the true state of the system, where is the feedback gain of the angle error, is the nonlinear feedback gain of the angular velocity error, is the feedback gain of the disturbance term, is the step length; is the moment of inertia of the photovoltaic module, is the mechanical damping coefficient, and Used to suppress the observation lag caused by rotational inertia; for Function expressions; S434: Combining the smoothed target angle and smoothed target angular velocity obtained in step S431, the observed value of the pitch angle or azimuth angle, the observed value of the pitch angular velocity or azimuth angular velocity, and the estimated value of the total system disturbance obtained in step S433, the total disturbance is compensated using a nonlinear state error feedback control law to obtain an error feedback control variable. Specifically: First, by comparing the tracking signal and differential signal of the high-order sliding mode differentiator with the state signal estimated by the extended state observer, the error between the actual angle and the target angle, and the error between the actual angular velocity and the target angular velocity are obtained; then, the error between the actual angle and the target angle, and the error between the actual angular velocity and the target angular velocity are nonlinearly combined to obtain a nonlinear state error feedback control law. The error feedback control quantity is calculated through the nonlinear state error feedback control law. Specifically, the formula for calculating the error feedback control quantity is as follows:

[0016] is the error between the actual pitch angle or azimuth angle and the target angle, is the error between the actual pitch angular velocity or azimuth angular velocity and the target angular velocity; is the error feedback gain coefficient in the control law, which determines the response degree of the control law to the angle and angular velocity errors; is the feedback gain of the angle error, is the feedback gain of angular velocity error; To control the nonlinear response curve shape of the angle error feedback, To control the nonlinear response curve shape of angular velocity error feedback; S435: Feedback control quantity based on error , the estimated value of the total disturbance of the system and compensation factor , and get the actual control quantity of the system , actual control quantity The specific calculation formula is as follows: .

[0017] The beneficial effects of the present invention are: The photovoltaic tracking mount of the present invention adjusts the azimuth angle of the photovoltaic tracker by controlling a motor to rotate the main shaft toward a target azimuth angle. The pitch angle of the photovoltaic tracker is adjusted by controlling a motorized telescopic rod to rotate the main shaft toward a target pitch angle. By combining the motorized telescopic rod with the azimuth adjustment mechanism, the azimuth angle of the photovoltaic module can be adjusted within a range of -120° to 120°, and the pitch angle can be adjusted within a range of at least -45° to 60°, making it suitable for most latitude and longitude regions.

[0018] This invention significantly improves the stability, tracking accuracy, and environmental adaptability of photovoltaic tracking systems under complex operating conditions through the collaborative design of structural optimization and intelligent control. The distributed piles and dual-column structure enhance the support's anti-overturning capability. The azimuth angle of the photovoltaic modules can be adjusted within a range of -120° to 120°, and the pitch angle can be adjusted within a range of at least -45° to 60°, making the system adaptable to a wide range of geographic locations.

[0019] The control method of this invention utilizes a composite HOSMD-ADRC control structure, effectively improving the system's tracking accuracy, enhancing its ability to suppress disturbances such as rain, snow, and sandstorms, and enhancing the system's steady-state performance in inclement weather. Combining a hierarchical control strategy of "coarse angle adjustment + fine optical signal adjustment," a highly robust control system with self-sensing and adaptive capabilities is constructed, significantly reducing tracking error and improving system response speed. This invention achieves breakthroughs in structural strength, environmental perception, control accuracy, and system reliability, providing key technical support for efficient, safe, and intelligent photovoltaic tracking systems.

[0020] The photovoltaic tracking bracket of this invention utilizes a distributed load-bearing structure. By optimizing the buried depth and spacing of the four foundation piles, the bracket's overall anti-overturning stability and dynamic wind load adaptability are enhanced. Furthermore, the dual-column structure, positioned on either side of the photovoltaic module, reduces obstruction of the module's backside by the support and drive mechanisms, thereby increasing the utilization of the module's backside.

[0021] The present invention realizes the adjustment of azimuth and pitch angle respectively through main shaft rotation and electric telescopic rod, wherein the main shaft rotation is almost unrestricted, and the reciprocating movement of the electric push rod is limited by the inner ring diameter of the outer spherical surface of the joint bearing, the outer ring diameter of the inner spherical surface and the bearing width. However, by adjusting the structural parameters of the joint bearing, the maximum value of the pitch angle is still adjustable, so the azimuth and pitch angle adjustment range of the photovoltaic module is large, and can adapt to most longitude and latitude areas.

[0022] The present invention introduces a three-stage reducer into the azimuth angle adjustment mechanism. By increasing the equivalent inertia of the transmission system and reducing the angular velocity of the moving parts, the control resolution of the drive motor is doubled, thereby improving the control accuracy of the rotation angle to ±0.1°, meeting the engineering requirements of high-precision solar tracking.

[0023] The present invention utilizes the self-locking property of the worm gear and the dynamic and static hybrid locking characteristics of the electric push rod, and couples it with a dynamic compensation strategy based on HOSMD-ARDC to effectively ensure the stability and anti-interference performance of the bracket structure, so that the bracket can still maintain reliable and stable operation when facing complex and severe weather such as rain, snow, wind and sand.

[0024] This invention utilizes a hierarchical control strategy combining "coarse angle adjustment + fine optical signal adjustment" for the control of photovoltaic tracking brackets. An integrated attitude measurement unit (IMU) fuses multi-source data from a gyroscope (angular velocity), an accelerometer (gravity direction), and a magnetometer (geomagnetic direction) to calculate the bracket's attitude angle in real time during movement, preventing interference from dynamic acceleration or column tilt on a single sensor. Furthermore, the gyroscope provides high-precision angular velocity feedback, enabling autonomous azimuth correction in the event of magnetic interference. Furthermore, it enables the controller to proactively detect the bracket's motion trends, improving dynamic response and effectively suppressing tracking jitter caused by wind disturbances. The high-precision sensitivity of a photodiode compensates for the accumulated errors of the GPS and IMU, enabling dynamic fine adjustment of the bracket's angle and minimizing tracking deviation. Furthermore, an ultrasonic anemometer monitors wind speed and direction. Excessive wind speed triggers a safety response mechanism to mitigate damage to the bracket structure caused by dynamic wind loads.

[0025] This invention designs a composite control architecture based on a second-order nonlinear high-order sliding mode differentiator-active disturbance rejection control (HOSMD-ADRC) controller. Leveraging the robustness and high precision of the HOSMD, it accurately extracts differential information from discontinuous measurement signals, effectively overcoming the drawbacks of traditional differentiators, such as noise amplification and phase distortion, when processing discontinuous signals. Combining the ESO and NLSEF to construct a comprehensive disturbance observation system and dynamic compensation model enables rapid and accurate compensation and tracking of unmodeled internal system dynamics and external unknown disturbances, thereby improving the dynamic response speed and control accuracy of the photovoltaic tracker and the overall efficiency of the photovoltaic power generation system.

[0026] Compared with the existing photovoltaic bracket, the present invention has the following advantages: (1) Existing photovoltaic brackets adopt a double-sided design, that is, both the front and back sides of the photovoltaic module have photoelectric conversion functions. The traditional support and drive structure based on a single column is usually set in the middle of the back of the photovoltaic module. Not only is the structural stability poor, but it also blocks a large area of ​​the back of the photovoltaic panel, which to a certain extent reduces the photoelectric conversion efficiency. The present invention adopts a distributed load-bearing structure in combination with a double-column structure, which can improve the anti-overturning stability and dynamic wind load adaptability of the bracket. The double-column structure is arranged on both sides of the photovoltaic module, reducing the shading of the back of the photovoltaic module by the support and drive mechanism, which can improve the utilization rate of the back of the photovoltaic module.

[0027] (2) Existing photovoltaic tracking brackets have certain structural limitations: On the one hand, some brackets can only track a single angle in azimuth or pitch, and cannot achieve dual-axis linkage tracking, resulting in limited efficiency in capturing sunlight. On the other hand, when relying on the push rod to extend and retract to drive the rotation mechanism to track the pitch angle, the rotation angle of the photovoltaic panel is limited and precise control is difficult. In large-angle adjustment scenarios, the push rod is prone to locking, affecting the bracket's tracking performance and stability.

[0028] (3) In terms of the control of existing photovoltaic tracking brackets, the commonly used control method is PID control. However, its reliance on the error integration mechanism leads to response lag, and fixed parameters are difficult to adapt to sudden changes in irradiation intensity and nonlinear mechanical structure. In addition, the integration link is prone to overshoot and oscillation under strong disturbances such as cloud cover, and its anti-disturbance ability is weak. ADRC does not rely on the precise model of the system, has good nonlinear processing capabilities and disturbance estimation capabilities, and is particularly robust when facing uncertainty and external disturbances. However, the traditional linear ESO has a phase lag problem in estimating high-frequency disturbances. Therefore, the introduction of HOSMD on the basis of ADRC to replace the TD module can achieve the purpose of eliminating phase lag and enhancing noise suppression to a certain extent, effectively eliminate the chattering phenomenon, and improve the system's estimation rate and tracking accuracy for high-frequency disturbances. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 The overall structure of the photovoltaic tracking bracket in the present invention is shown in FIG. Figure 1 ; Figure 2 The overall structure of the photovoltaic tracking bracket in the present invention is shown in FIG. Figure 2 ; Figure 3 Schematic diagram of the structure of the azimuth adjustment mechanism; Figure 4 This is a flow chart of the photovoltaic tracking bracket control method; Figure 5 This is the structural schematic diagram of the HOSMD-ADRC controller; The main components in the figure are described as follows: 1. Photovoltaic module; 2. Mounting bracket; 3. Connecting parts; 4. Main shaft; 5. Azimuth adjustment mechanism; 6. Connecting ball socket; 7. Connecting sphere; 8. Electric telescopic rod; 9. First column; 10. Second column; 11. Spherical bearing; 12. First bearing seat; 13. Attitude measurement sensor; 14. Photosensitive diode; 15. Ultrasonic anemometer; 51. Adjustment motor; 52. Coupling; 53. Worm; 54. Turbine; 55. Rolling bearing; 56. Second bearing seat; 57. Three-stage reduction gearbox; 58. Input shaft; 59. Box body. DETAILED DESCRIPTION

[0030] The specific embodiments of the present invention are described below to facilitate understanding of the present invention by those skilled in the art. However, it should be clear that the present invention is not limited to the scope of the specific embodiments. For those skilled in the art, as long as various changes are within the spirit and scope of the present invention as defined and determined by the appended claims, these changes are obvious, and all inventions and creations utilizing the concepts of the present invention are protected.

[0031] like Figure 1 and 2 As shown, a photovoltaic tracking bracket includes a mounting bracket 2 for mounting a photovoltaic module 1. The upper portion of the mounting bracket 2 is a concave groove for supporting the photovoltaic module 1. The bottom of the concave groove is a hollow structure, so that the back of the photovoltaic module 1 can also perform photoelectric conversion. The lower portion of the mounting bracket 2 is three U-shaped beams, and two sets of connecting components 3 are fixed below each U-shaped beam. The connecting components 3 are divided into upper and lower parts. The upper portion is fixed to the mounting bracket 2, and the lower portion is screwed to achieve an interference fit with the main shaft 4. The mounting bracket 2 is fixed with a main shaft 4 through the two sets of connecting components 3. One end of the main shaft 4 is movably connected to the second column 10, and the other end of the main shaft 4 is provided with an azimuth adjustment mechanism 5. The azimuth adjustment mechanism 5 is used to adjust the azimuth angle of the photovoltaic tracking bracket. The azimuth adjustment mechanism 5 is used to drive the main shaft 4 to rotate. The bottom of the azimuth adjustment mechanism 5 is movably connected to an electric telescopic rod 8, which is used to adjust the pitch angle of the photovoltaic tracking bracket.

[0032] The top of the photovoltaic module 1 is equipped with an ultrasonic anemometer 15 and several photodiodes 14. The input end of the main shaft 4 is equipped with an attitude measurement sensor 13. These instruments, photodiodes 14, and attitude measurement sensor 13 are all electrically connected to the control system. The control system is preferably a HOSMD-ADRC controller, which includes a high-order sliding mode differentiator (HOSMD), an extended state observer (ESO), and a nonlinear state error feedback control law (NLSEF). Four photodiodes 14 are located evenly at the four corners of the top of the photovoltaic module 1. The electrical signals collected by these photodiodes 14 are used to determine whether the photovoltaic tracking bracket is at the optimal sun-facing angle. The connecting component 3 consists of an upper and lower part. The upper part is fixed to the mounting bracket 2, while the lower part is screwed to achieve an interference fit with the main shaft 4. One end of the main shaft 4 is connected to the output end of the reduction gear system 5, and the other end is fixed to the spherical bearing 11.

[0033] The telescopic end of the electric telescopic rod 8 is equipped with a connecting ball 7. The bottom of the azimuth adjustment mechanism 5 is provided with an upper socket that mates with the connecting ball 7. A connecting socket 6 is located below the connecting ball 7, which is fixedly connected to the bottom of the azimuth adjustment mechanism 5. The connecting ball 7 is mounted within the lower socket via the connecting socket 6. The upper socket is provided with a bar-shaped arc groove. The connecting ball 7 is equipped with a sliding protrusion that mates with the bar-shaped arc groove. When the connecting ball 7 rotates in the connecting socket 6, the sliding protrusion slides within the bar-shaped arc groove. The sliding protrusion slides in the same direction as the lifting end of the main shaft 4. The bar-shaped arc groove and the sliding protrusion cooperate to restrict the swing of the connecting ball 6 to the direction of the groove of the connecting ball 7 (i.e., the lifting direction of the main shaft 4). The photovoltaic tracking bracket structure includes an attitude measurement sensor 13 (IMU), a photodiode 14, and an ultrasonic anemometer 15. Among them, the attitude measurement sensor 13 is used to measure the azimuth and pitch angles of the photovoltaic module and is installed on the main shaft 4 of the bracket. Since the bottom surface of the mounting bracket is parallel to the main shaft axis, the measured main shaft attitude angle is the attitude angle of the photovoltaic module. The photosensitive diode 14 is used to detect the intensity of sunlight. Four diodes are set and fixed in parallel on the upper part of the mounting bracket 2, and a conical light shield is set in the center of the four diodes. The light shield is used to detect whether the bracket is facing the sun. If it is not facing, the shadow surfaces generated on the four diodes when the sunlight shines on the light shield are different, which causes the electrical signals sent by the diodes to be inconsistent. The ultrasonic anemometer 15 is used to detect the wind speed and direction in the environment. It is fixed on the upper part of the mounting bracket 2. When the wind speed is detected to be too high, the safety response mechanism is automatically triggered to reduce the risk of impact and damage to the photovoltaic bracket structure by dynamic wind loads.

[0034] like Figure 3As shown, the azimuth angle adjustment mechanism 5 includes an adjustment motor 51, a worm 53, a turbine 54 meshing with the worm 53, a three-stage reduction gearbox 57 and a housing 59. The motor 51 is connected to the worm 53 through a coupling 52. The other end of the worm 53 is rotatably mounted on the second bearing seat 56. The bottom of the second bearing seat 56 is fixedly connected to the housing 59. A rolling bearing 55 for mounting the worm 53 is provided on the second bearing seat 56. The end of the worm 53 is interference fit with the second bearing seat 56. The turbine 54 is fixedly mounted on the input shaft 58 of the three-stage reduction gearbox 57. The output end of the three-stage reduction gearbox 57 is connected to the main shaft 4. A coordinated transmission scheme of a worm gear and a three-stage reducer is designed into the azimuth adjustment mechanism. Leveraging the self-locking properties of the worm gear mechanism, it achieves mechanical self-locking at any position, effectively suppressing unexpected displacement caused by external disturbances such as wind, and improving the mechanism's wind resistance. The introduction of the three-stage reducer doubles the control resolution of the drive motor by increasing the equivalent inertia of the transmission system and reducing the angular velocity of the moving parts, thereby improving the control accuracy of the rotation angle to ±0.1°, meeting the engineering requirements of high-precision solar tracking. This composite transmission structure balances dynamic stability and motion accuracy, providing reliable mechanical support for all-weather solar tracking.

[0035] A first bearing seat 12 is provided on the second column 10, and a spherical bearing 11 is provided on the main shaft 4. The first bearing seat 12 is fixed to the top of the second column 10 by screws, and the spherical bearing 11 is installed inside the first bearing seat 12 to support the main shaft 4. A first column 9 is provided at the bottom of the electric telescopic rod 8. The electric telescopic rod 8 is fixed to the top of the first column 9 by screws. The end of the electric telescopic rod 8 has an interference fit with the bottom circular hole of the connecting sphere 7. The height of the first column 9 is lower than that of the second column 10. The first column 9 and the second column 10 are anchored to the foundation surface through a rigid fixing method. Four foundation piles are configured at the bottom of each column and vertically embedded into the underground matrix to ensure the overall stability and wind resistance of the photovoltaic tracking bracket.

[0036] The specific working principle of the photovoltaic tracking bracket: The photovoltaic tracking bracket of the present invention drives the main shaft 4 to rotate toward the target azimuth angle by controlling the motor 51, thereby achieving azimuth adjustment of the photovoltaic tracking bracket. The main shaft 4 is driven to rotate toward the target pitch angle by controlling the electric telescopic rod 8, thereby achieving pitch adjustment of the photovoltaic tracking bracket. Through the cooperation of the electric telescopic rod 8 and the azimuth adjustment mechanism 5, the azimuth angle of the photovoltaic module 1 can be adjusted within the range of -120° to 120°, and the pitch angle can be adjusted within the range of at least -45° to 60°, which is suitable for most longitude and latitude areas. Among them, the maximum pitch angle depends on the inner ring diameter of the outer spherical surface of the joint bearing 11, the outer ring diameter of the inner spherical surface, and the bearing width. Specifically: When tracking the pitch angle of the sun, by controlling the electric telescopic rod 8 to extend and retract, the connecting ball 7, the connecting ball socket 6, and the electric telescopic rod 8 are driven in turn, causing these components to produce coordinated up and down displacement, thereby driving the left end of the main shaft 4 to rotate clockwise or counterclockwise around the joint bearing 11 to achieve adjustment of the pitch angle of the tracking bracket. When tracking the solar azimuth, the motor 51 is controlled to drive the worm 53 to rotate, and the worm 53 engages with the turbine 54, thereby driving the turbine 54 to rotate, and driving the input shaft 58 and the three-stage reduction gearbox 57 to rotate, and finally driving the main shaft 4 and the mounting bracket 2 and photovoltaic module 1 fixed on the main shaft 4 to rotate, so as to achieve the adjustment of the azimuth of the tracking bracket.

[0037] In the pitch angle adjustment mechanism, the electric push rod 8 serves as the core actuator. It converts rotational motion into linear displacement output via a servo motor-driven precision ball screw pair. It features high axial thrust, adjustable axial linear velocity, and high control accuracy. Furthermore, it possesses unique static self-locking and dynamic retention properties, which can, to a certain extent, resist external disturbances and ensure that the push rod's axial position remains unchanged. Together with the worm gear in the azimuth angle adjustment mechanism, it forms a dual anti-disturbance system. Furthermore, the concave-convex groove structure formed by the connecting ball socket 6 and the connecting ball 7 precisely limits the motion trajectory of the main shaft 4 and photovoltaic module 1, restricting them to rotational motion within the longitudinal plane around the spherical bearing 11 as the rotation center. This effectively ensures the bracket's tracking accuracy for the pitch angle and the stability of its operation.

[0038] like Figure 4 This is a flow chart of a photovoltaic tracking bracket control method, a photovoltaic tracking bracket control method, comprising the following steps: S1: Using the ultrasonic anemometer 15 to collect the wind speed and direction in the current environment, and adjusting the sun-facing angle of the photovoltaic tracking bracket according to the collected wind speed; specifically: When the wind speed in the current environment detected by the ultrasonic anemometer 15 is greater than 25m / s, the safety response mechanism is activated. According to the collected wind direction data, the electric telescopic rod 8 and the azimuth adjustment mechanism 5 are controlled to adjust the bottom surface of the mounting bracket 2 to be consistent with the wind direction; When the wind speed in the current environment detected by the ultrasonic anemometer 15 is greater than or equal to 10m / s and less than or equal to 5m / s, the photovoltaic tracking bracket maintains the current state, and the electric push rod and the worm gear maintain a self-locking state; When the wind speed in the current environment detected by the ultrasonic anemometer 15 is less than 10m / s, the photovoltaic tracking bracket operates normally, and the next step is executed to adjust the optimal collection angle of the photovoltaic bracket; S2: A GPS module is installed on the photovoltaic tracking bracket to obtain the current geographic location and time information of the photovoltaic tracking bracket through the GPS module, and the azimuth angle and pitch angle of the sun at the current location of the photovoltaic tracking bracket are obtained as the target azimuth angle and target pitch angle to which the photovoltaic tracking bracket needs to be adjusted; S3: The actual azimuth angle and actual pitch angle of the photovoltaic tracking bracket are acquired by the attitude measurement sensor 13; S4: Compare the target azimuth angle with the actual azimuth angle, and the target pitch angle with the actual pitch angle to determine whether it is necessary to perform a coarse adjustment on the angle of the photovoltaic tracking bracket. The coarse adjustment includes azimuth adjustment and pitch angle adjustment. The specific method for adjusting the azimuth angle of the photovoltaic tracking bracket is as follows: S41: Determine whether the target azimuth angle is equal to the actual azimuth angle; if the target azimuth angle is not equal to the actual azimuth angle, execute step S42 to adjust the angle of the photovoltaic tracking bracket; if the target azimuth angle is equal to the actual azimuth angle, execute step S5; S42: The azimuth angle of the photovoltaic tracking bracket is coarsely adjusted by controlling the rotation of the motor 51 to drive the main shaft 4 to rotate toward the target azimuth angle; the electric telescopic rod 8 is then controlled to extend and retract to drive the main shaft 4 to rotate toward the target pitch angle, thereby coarsely adjusting the pitch angle of the photovoltaic tracking bracket; S43: Collect the actual azimuth and actual pitch angles of the photovoltaic tracking bracket after rough adjustment, and then call the HOSMD-ADRC controller to assist in achieving precise adjustment of the azimuth and pitch angles of the photovoltaic tracking bracket; Figure 5 This is the structural schematic diagram of the HOSMD-ADRC controller; Step S43 specifically includes the following steps: S431: Using a high-order sliding mode differentiator to perform high-precision and rapid tracking of the target azimuth and target pitch angles, obtaining a smoothed target angle and a smoothed target angular velocity. The target angle includes the smoothed target azimuth and target pitch angles, and the target angular velocity includes the smoothed target azimuth angular velocity and target pitch angular velocity. Specifically, the formulas for calculating the smoothed target angle and the smoothed target angular velocity are as follows: ;

[0039] Where: Input signal , is the original signal of the target azimuth and / or target elevation, i.e. the target angle of the elevation or the target angle of the azimuth, Noise interference includes encoder quantization error, photoelectric sensor noise and mechanical vibration noise. Tracking moments for angles; The original signal The estimated value of The original signal The first-order differential estimate of The original signal The second-order differential estimate of is an estimated value The differential value of is the first-order differential estimate The differential value of is the second-order differential estimate The differential value of is an estimated value The approximate value of , that is, the target angle after smoothing, is the first-order differential estimate The approximate value of , that is, the target angular velocity after smoothing; is the second-order differential estimate The approximate value of , that is, the target angular acceleration after smoothing; is the second-order differential estimate The approximation of the differential value of ; is the parameter that controls the convergence speed of the angle error, is the parameter that controls the convergence strength of the angular velocity error, is the parameter that controls the robustness of angular acceleration; is a symbolic function, is the variable of the symbolic function; S432: Using an expanded state observer to observe the feedback signal collected by the photovoltaic tracking bracket, and expanding the total disturbance of the system into an expanded state variable, and performing real-time estimation to establish a disturbed expanded system. Specifically, the disturbed expanded system is as follows: ; in, The feedback signal collected by the photovoltaic tracking bracket is the pitch angle or azimuth angle collected in real time by the attitude measurement sensor. The actual pitch angle or actual azimuth angle collected by the attitude measurement sensor, It is the actual pitch angular velocity or actual azimuth angular velocity collected by the attitude measurement sensor. for The differential value of for The differential value of is the expansion state variable; is the unknown nonlinear system function including disturbance, is the gain coefficient of the control quantity, that is, the gain coefficient of the actual pitch angle or the actual azimuth angle; For The estimated value of , which is the compensation factor that determines the strength of error compensation; is the actual control quantity; S433: Introduce the gain coefficient and combine it with the feedback acquisition signal obtained in step S432 , we can get the observed value of pitch angle or azimuth angle, the observed value of pitch angular velocity or azimuth angular velocity and the estimated value of total disturbance of the system. Specifically, the calculation formula is as follows: ; ; in, is the error between the estimated value of the actual pitch angle and the pitch angle collected in real time by the attitude measurement sensor, or the error between the estimated value of the actual azimuth angle and the pitch angle collected in real time by the attitude measurement sensor, is the observed value of the elevation angle or azimuth angle, is the observed value of the pitch angular velocity or azimuth angular velocity, is the estimated value of the total disturbance of the system, through Compensate the control amount to effectively suppress the interference effect; for The differential value of for The differential value of for The differential value of and is the gain coefficient; To control the nonlinear response curve shape of the angle error feedback, To control the nonlinear response curve shape of the angular velocity error feedback, is the observation error feedback gain coefficient, which is used to realize the extended state observer to quickly and accurately approximate the true state of the system, where is the feedback gain of the angle error, is the nonlinear feedback gain of the angular velocity error, is the feedback gain of the disturbance term, is the step length; is the moment of inertia of the photovoltaic module, is the mechanical damping coefficient, and Used to suppress the observation lag caused by rotational inertia; for Function expressions; S434: Combining the smoothed target angle and smoothed target angular velocity obtained in step S431, the observed value of the pitch angle or azimuth angle, the observed value of the pitch angular velocity or azimuth angular velocity, and the estimated value of the total system disturbance obtained in step S433, the total disturbance is compensated using a nonlinear state error feedback control law to obtain an error feedback control variable. Specifically: First, by comparing the tracking signal and differential signal of the high-order sliding mode differentiator with the state signal estimated by the extended state observer, the error between the actual angle and the target angle, and the error between the actual angular velocity and the target angular velocity are obtained; then, the error between the actual angle and the target angle, and the error between the actual angular velocity and the target angular velocity are nonlinearly combined to obtain a nonlinear state error feedback control law. The error feedback control quantity is calculated through the nonlinear state error feedback control law. Specifically, the formula for calculating the error feedback control quantity is as follows:

[0040] is the error between the actual pitch angle or azimuth angle and the target angle, is the error between the actual pitch angular velocity or azimuth angular velocity and the target angular velocity; is the error feedback gain coefficient in the control law, which determines the response degree of the control law to the angle and angular velocity errors; is the feedback gain of the angle error, is the feedback gain of angular velocity error; To control the nonlinear response curve shape of the angle error feedback, To control the nonlinear response curve shape of angular velocity error feedback; S435: Feedback control quantity based on error , the estimated value of the total disturbance of the system and compensation factor , and get the actual control quantity of the system , actual control quantity The specific calculation formula is as follows: .

[0041] S44: Repeat steps S42-S43, replacing the target azimuth angle and the actual azimuth angle with the target pitch angle and the actual pitch angle, and adjusting the pitch angle of the photovoltaic tracking bracket; S5: Based on the collected actual azimuth angle after coarse adjustment and the target azimuth angle, as well as the target pitch angle and the actual pitch angle after coarse adjustment, it is determined whether the photovoltaic support is facing the sun, and the azimuth angle or pitch angle of the photovoltaic tracking support is fine-tuned using a photodiode; Specifically, when the electrical signals sent by the four photosensitive diodes are consistent, it is determined that the photovoltaic tracking bracket is facing the sun, and the angle adjustment of the photovoltaic tracking bracket is completed; when the electrical signals sent by the four photosensitive diodes are inconsistent, it is determined that the photovoltaic tracking bracket is not facing the sun. At this time, the angle of the photovoltaic tracking bracket is fine-tuned in conjunction with the photosensitive diodes until the electrical signals sent by the four photosensitive diodes are consistent, and the angle adjustment of the photovoltaic tracking bracket is completed.

[0042] The design of the second-order nonlinear HOSMD-ADRC controller not only improves control accuracy, enhances the energy capture efficiency of the photovoltaic system, and enhances the operational reliability of the structure under complex working conditions, but also has the following three main effects on the control of the photovoltaic tracking bracket structure: (1) High-precision trajectory tracking: The HOSMD module smoothes the input signal to generate a continuously differentiable tracking trajectory, avoiding the phase lag problem caused by traditional differentiators and improving dynamic tracking accuracy. The ESO module observes and dynamically compensates for the total system disturbance in real time, effectively suppressing the impact of wind load disturbances, mechanical resonance, and sensor errors on tracking performance.

[0043] (2) Strong anti-interference capability: Under environmental factors such as wind speed disturbance, the ESO module can realize disturbance estimation and control the angle offset within the design threshold through the feedforward compensation mechanism; at the same time, the sliding mode control also enhances the system's robustness to parameter perturbations.

[0044] (3) Adaptability to complex environments: In response to intermittent irradiance changes in cloudy weather, the ESO module can estimate these disturbances in real time and optimize the observer's response speed by dynamically adjusting the bandwidth, achieving rapid disturbance suppression of solar irradiance changes. In addition, by dynamically adjusting the control gain according to the irradiance intensity and reducing the motor power consumption, it can effectively solve the problem of deteriorating energy efficiency ratio of traditional control systems under low-light conditions.

Claims

1. A photovoltaic tracking bracket, characterized in that: The invention comprises a mounting bracket (2) for mounting a photovoltaic module (1), wherein the mounting bracket (2) is fixed with a main shaft (4) via at least two connecting parts (3), one end of the main shaft (4) is movably connected to a second column (10), and the other end of the main shaft (4) is provided with an azimuth adjustment mechanism (5), the azimuth adjustment mechanism (5) is used to drive the main shaft (4) to rotate, and the bottom of the azimuth adjustment mechanism (5) is movably connected to an electric telescopic rod (8); An ultrasonic wind speed and direction meter (15) and a plurality of photosensitive diodes (14) are provided on the top of the photovoltaic assembly (1), an attitude measurement sensor (13) is provided at the input end of the main shaft (4), and the ultrasonic wind speed and direction meter (15), the photosensitive diode (14) and the attitude measurement sensor (13) are all electrically connected to a control system.

2. The photovoltaic tracking bracket according to claim 1, characterized in that: The telescopic end of the electric telescopic rod (8) is provided with a connecting ball (7), the bottom of the azimuth angle adjustment mechanism (5) is provided with an upper ball socket that cooperates with the connecting ball (7), the lower side of the connecting ball (7) is provided with a connecting ball socket (6), the connecting ball socket (6) is fixedly connected to the bottom of the azimuth angle adjustment mechanism (5), and the connecting ball (7) is installed in the lower ball socket through the connecting ball socket (6).

3. The photovoltaic tracking bracket according to claim 2, characterized in that: A strip arc chute is provided in the upper ball socket, and a sliding protrusion cooperating with the strip arc chute is provided on the connecting ball (7). When the connecting ball (7) rotates in the connecting ball socket (6), the sliding protrusion can slide in the strip arc chute.

4. The photovoltaic tracking bracket according to claim 3, characterized in that: The sliding direction of the sliding protrusion is the same as the lifting direction of the lifting end of the main shaft (4).

5. The photovoltaic tracking bracket according to claim 1, characterized in that: The azimuth angle adjustment mechanism (5) includes an adjustment motor (51), a worm (53), a turbine (54) meshing with the worm (53), a three-stage reduction gearbox (57) and a housing (59), wherein the motor (51) is connected to the worm (53) via a coupling (52), the other end of the worm (53) is rotatably mounted on a second bearing seat (56), the bottom of the second bearing seat (56) is fixedly connected to the housing (59), and a rolling bearing (55) for mounting the worm (53) is provided on the second bearing seat (56), the turbine (54) is fixedly mounted on an input shaft (58) of the three-stage reduction gearbox (57), and the output end of the three-stage reduction gearbox (57) is connected to the main shaft (4).

6. The photovoltaic tracking bracket according to claim 1, characterized in that: A first bearing seat (12) is provided on the second column (10), and a joint bearing (11) is provided on the main shaft (4) in which the first bearing seat (12) and the joint bearing (11) cooperate.

7. The photovoltaic tracking bracket according to claim 1, characterized in that: The photosensitive diodes (14) are arranged at four locations, and the photosensitive diodes (14) are evenly distributed at the four corners of the top of the photovoltaic assembly (1).

8. The photovoltaic tracking bracket according to claim 1, characterized in that: The control system is a HOSMD-ADRC controller, which includes a high-order sliding mode differentiator, an extended state observer, and a nonlinear state error feedback control law.

9. A control method for the photovoltaic tracking bracket according to any one of claims 1 to 8, characterized in that: The steps include: S1: Using an ultrasonic wind speed and direction meter (15) to collect the wind speed and direction in the current environment, and adjusting the sun-facing angle of the photovoltaic tracking bracket according to the collected wind speed; specifically: When the wind speed in the current environment detected by the ultrasonic wind speed and direction meter (15) is greater than 25 m / s, the safety response mechanism is activated, and based on the collected wind direction data, the electric telescopic rod (8) and the azimuth adjustment mechanism (5) are controlled to adjust the bottom surface of the mounting bracket (2) to be consistent with the wind direction; When the wind speed in the current environment detected by the ultrasonic anemometer (15) is greater than or equal to 10 m / s and less than or equal to 5 m / s, the photovoltaic tracking bracket maintains the current state, and the electric push rod and the worm gear maintain a self-locking state; When the wind speed in the current environment detected by the ultrasonic wind speed and direction meter (15) is less than 10 m / s, the photovoltaic tracking bracket operates normally, and the next step is executed to adjust the optimal collection angle of the photovoltaic bracket; S2: A GPS module is installed on the photovoltaic tracking bracket to obtain the current geographic location and time information of the photovoltaic tracking bracket through the GPS module, and the azimuth angle and pitch angle of the sun at the current location of the photovoltaic tracking bracket are obtained as the target azimuth angle and target pitch angle to which the photovoltaic tracking bracket needs to be adjusted; S3: acquiring the actual azimuth angle and actual pitch angle of the photovoltaic tracking bracket through the attitude measurement sensor (13); S4: Compare the target azimuth angle with the actual azimuth angle, and the target pitch angle with the actual pitch angle, to determine whether it is necessary to perform a coarse adjustment on the angle of the photovoltaic tracking bracket, wherein the coarse adjustment includes an azimuth adjustment and a pitch angle adjustment; The azimuth adjustment method of the photovoltaic tracking bracket is specifically as follows: S41: Determine whether the target azimuth angle is equal to the actual azimuth angle; if the target azimuth angle is not equal to the actual azimuth angle, execute step S42 to adjust the angle of the photovoltaic tracking bracket; if the target azimuth angle is equal to the actual azimuth angle, execute step S5; S42: controlling the motor (51) to rotate and drive the main shaft (4) to rotate toward the target azimuth angle, thereby achieving a coarse adjustment of the azimuth angle of the photovoltaic tracking bracket; then controlling the electric telescopic rod (8) to extend and retract and drive the main shaft (4) to rotate toward the target pitch angle, thereby achieving a coarse adjustment of the pitch angle of the photovoltaic tracking bracket; S43: Collect the actual azimuth and actual pitch angles of the photovoltaic tracking bracket after rough adjustment, and then call the HOSMD-ADRC controller to assist in achieving precise adjustment of the azimuth and pitch angles of the photovoltaic tracking bracket; S44: Repeat steps S42-S43, replace the target azimuth angle and the actual azimuth angle with the target pitch angle and the actual pitch angle, and adjust the pitch angle of the photovoltaic tracking bracket; S5: Based on the collected actual azimuth angle after coarse adjustment and the target azimuth angle, as well as the target pitch angle and the actual pitch angle after coarse adjustment, it is determined whether the photovoltaic support is facing the sun, and the azimuth angle or pitch angle of the photovoltaic tracking support is fine-tuned using a photodiode; Specifically, when the electrical signals sent by the four photosensitive diodes are consistent, it is determined that the photovoltaic tracking bracket is facing the sun, and the angle adjustment of the photovoltaic tracking bracket is completed; when the electrical signals sent by the four photosensitive diodes are inconsistent, it is determined that the photovoltaic tracking bracket is not facing the sun. At this time, the angle of the photovoltaic tracking bracket is fine-tuned in conjunction with the photosensitive diodes until the electrical signals sent by the four photosensitive diodes are consistent, and the angle adjustment of the photovoltaic tracking bracket is completed.

10. The control method of the photovoltaic tracking bracket according to claim 9, characterized in that: Step S43 specifically includes the following steps: S431: Using a high-order sliding mode differentiator to perform high-precision and rapid tracking of the target azimuth and target pitch angles, obtaining a smoothed target angle and a smoothed target angular velocity. The target angle includes the smoothed target azimuth and target pitch angles, and the target angular velocity includes the smoothed target azimuth angular velocity and target pitch angular velocity. Specifically, the formulas for calculating the smoothed target angle and the smoothed target angular velocity are as follows: ； Where: Input signal , is the original signal of the target azimuth and / or target elevation, i.e. the target angle of the elevation or the target angle of the azimuth, Noise interference includes encoder quantization error, photoelectric sensor noise and mechanical vibration noise. Tracking moments for angles; The original signal The estimated value of The original signal The first-order differential estimate of The original signal The second-order differential estimate of is an estimated value The differential value of is the first-order differential estimate The differential value of is the second-order differential estimate The differential value of is an estimated value The approximate value of , that is, the target angle after smoothing, is the first-order differential estimate The approximate value of , that is, the target angular velocity after smoothing; is the second-order differential estimate The approximate value of , that is, the target angular acceleration after smoothing; is the second-order differential estimate The approximation of the differential value of ; is the parameter that controls the convergence speed of the angle error, is the parameter that controls the convergence strength of the angular velocity error, is the parameter that controls the robustness of angular acceleration; is a symbolic function, is the variable of the symbolic function; S432: Using an expanded state observer to observe the feedback signal collected by the photovoltaic tracking bracket, and expanding the total disturbance of the system into an expanded state variable, and performing real-time estimation to establish a disturbed expanded system. Specifically, the disturbed expanded system is as follows: ； in, The feedback signal collected by the photovoltaic tracking bracket is the pitch angle or azimuth angle collected in real time by the attitude measurement sensor. The actual pitch angle or actual azimuth angle collected by the attitude measurement sensor, It is the actual pitch angular velocity or actual azimuth angular velocity collected by the attitude measurement sensor. for The differential value of for The differential value of is the expansion state variable; is the unknown nonlinear system function including disturbance, is the gain coefficient of the control quantity, that is, the gain coefficient of the actual pitch angle or the actual azimuth angle; For The estimated value of , which is the compensation factor that determines the strength of error compensation; is the actual control quantity; S433: Introduce the gain coefficient and combine it with the feedback acquisition signal obtained in step S432 , we can get the observed value of pitch angle or azimuth angle, the observed value of pitch angular velocity or azimuth angular velocity and the estimated value of total disturbance of the system. Specifically, the calculation formula is as follows: ； ； in, is the error between the estimated value of the actual pitch angle and the pitch angle collected in real time by the attitude measurement sensor, or the error between the estimated value of the actual azimuth angle and the pitch angle collected in real time by the attitude measurement sensor, is the observed value of the elevation angle or azimuth angle, is the observed value of the pitch angular velocity or azimuth angular velocity, is the estimated value of the total disturbance of the system; for The differential value of for The differential value of for The differential value of is the gain coefficient; To control the nonlinear response curve shape of the angle error feedback, To control the nonlinear response curve shape of the angular velocity error feedback, is the feedback gain of the angle error, is the nonlinear feedback gain of the angular velocity error, is the feedback gain of the disturbance term, is the step length; is the moment of inertia of the photovoltaic module, is the mechanical damping coefficient, and Used to suppress the observation lag caused by rotational inertia; for Function expressions; S434: Combining the smoothed target angle and smoothed target angular velocity obtained in step S431, the observed value of the pitch angle or azimuth angle, the observed value of the pitch angular velocity or azimuth angular velocity, and the estimated value of the total system disturbance obtained in step S433, the total disturbance is compensated using a nonlinear state error feedback control law to obtain an error feedback control variable. Specifically: First, by comparing the tracking signal and differential signal of the high-order sliding mode differentiator with the state signal estimated by the extended state observer, the error between the actual angle and the target angle, and the error between the actual angular velocity and the target angular velocity are obtained; then, the error between the actual angle and the target angle, and the error between the actual angular velocity and the target angular velocity are nonlinearly combined to obtain a nonlinear state error feedback control law. The error feedback control quantity is calculated through the nonlinear state error feedback control law. Specifically, the formula for calculating the error feedback control quantity is as follows: is the error between the actual pitch angle or azimuth angle and the target angle, is the error between the actual pitch angular velocity or azimuth angular velocity and the target angular velocity; is the error feedback gain coefficient in the control law; where, is the feedback gain of the angle error, is the feedback gain of angular velocity error; To control the nonlinear response curve shape of the angle error feedback, To control the nonlinear response curve shape of angular velocity error feedback; S435: Feedback control quantity based on error , the estimated value of the total disturbance of the system and compensation factor , and get the actual control quantity of the system , actual control quantity The specific calculation formula is as follows: 。

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