Fan tower door opening and closing angle detection device and method

Abstract

The application discloses a device and method for detecting the opening and closing angle of a tower door of a wind turbine, and belongs to the technical field of detection of wind power generation equipment.The device comprises an integrated sealed box body, a rotary encoder, a coil spring, a winding wheel, a steel wire rope, a counterweight, a guide mechanism and a fixing ring, core components are coaxially integrated in the sealed box body, the steel wire rope is connected between the door body fixing ring and the winding wheel, and the counterweight and the guide mechanism are matched to ensure stable transmission.The rotary encoder is an absolute encoder, the steel wire rope has wide temperature adaptability and low stretching characteristics, and the guide mechanism adopts a low-friction design.The detection method is calibrated through standardized installation, the opening and closing angle is inversely calculated based on a chord length-angle mathematical model, a 100Hz sampling frequency and an RS485 / Modbus protocol are adopted to ensure real-time performance, and the device has a broken wire alarm function.The application breaks through the limitation of traditional binary detection, realizes continuous angle precision monitoring, has strong anti-interference capability and good environmental adaptability, can judge the closing state and loosening condition of the door body, and ensures the safe operation of a wind farm.

Description

Technical Field

[0001] This invention relates to the field of wind power equipment testing technology, and in particular to a device and method for detecting the opening and closing angle of wind turbine tower doors. Background Technology

[0002] As a core piece of equipment in the clean energy field, the tower doors of wind turbines are not only the only passage for maintenance personnel to enter and exit the tower, but also a key safety barrier to protect the internal electrical equipment and mechanical components from external environmental corrosion (such as dust, rainwater, and foreign object intrusion) and to prevent personnel from accidentally entering dangerous areas. Their switching status, closing reliability, and structural stability are directly related to the safe operation of the wind farm and the service life of the equipment.

[0003] In the current actual operation of wind farms, the detection methods for tower doors are significantly inadequate, making it difficult to meet the needs for refined and highly reliable safety monitoring. Specific problems are as follows: 1. The detection dimension is limited, making it impossible to achieve multi-state monitoring. In existing technologies, most wind farms are not equipped with dedicated tower door detection devices; only a few projects use proximity switches or door magnetic sensors for status detection. These devices can only output binary "open" or "closed" signals and can only determine the extreme states of the tower door, unable to acquire continuous angle information during the opening and closing process. Taking the CN117513932A tower cover opening and closing system and wind turbine generator as an example, although this system achieves automatic opening and closing of the tower cover, it does not involve continuous monitoring of the tower door opening angle. Similarly, while the CN202692974U car door maximum opening angle detection device can detect the maximum opening angle of a car door, its technical solution is not directly applicable to the multi-state monitoring needs of tower doors. This results in maintenance personnel being unable to know whether the door is not fully closed (e.g., excessive closing gap), half-open, or loose. Even if the door experiences slight displacement or loosening due to vibration, it cannot be detected in time, potentially leading to safety hazards (e.g., high-speed airflow intrusion, foreign object entry, accidental entry by personnel).

[0004] 2. Weak anti-interference capability, high false alarm and false negative rates. Wind turbines generate continuous vibrations during operation, and the wind farm environment is complex (e.g., dust and electromagnetic interference in onshore wind power, salt spray and high humidity in offshore wind power). Devices that rely on electronic signals for triggering, such as proximity switches and door magnetic sensors, are highly susceptible to these factors. Vibration may cause the relative position of the sensor and triggering component to shift, electromagnetic interference may disrupt signal transmission, and dust and changes in temperature and humidity may affect sensor sensitivity. This can ultimately lead to frequent false alarms (e.g., falsely reporting "open" when the door is closed) or missed alarms (e.g., displaying "closed" when the door is not closed). This not only increases the workload of maintenance personnel but may also cause real safety hazards to be overlooked due to missed alarms.

[0005] 3. Insufficient detection precision and lack of absolute accuracy. Existing detection devices do not establish a rigid correlation between door movement and detection signals. Their detection results rely on the signal recognition accuracy of electronic components rather than objective geometric relationships. Because electronic components are susceptible to aging and signal attenuation due to environmental factors, the stability and accuracy of the detection results are difficult to guarantee in the long term. For example, the trigger threshold of proximity switches may drift over time, leading to deviations in the judgment of the "closed" state and failing to ensure that the door is always in a fully closed and safe state.

[0006] 4. Lack of safety protection functions and insufficient reliability The existing detection solution lacks a protection mechanism against faults in the detection link. For example, if a wire rope (if mechanically connected) breaks or a sensor signal is interrupted, the system cannot promptly report the anomaly, potentially leading to misjudgments of the door's condition by maintenance personnel. Furthermore, due to the lack of angle change data, it is impossible to predict potential structural faults such as loose door hinges or worn hinges based on door angle fluctuation trends. Repairs can only be performed after a fault occurs, increasing maintenance costs and downtime risks.

[0007] 5. Poor environmental adaptability, making it difficult to adapt to complex working conditions. Wind farms operate under diverse conditions. Onshore wind power faces environments with high and low temperatures, strong winds and sandstorms, and severe vibrations, while offshore wind power must cope with harsh conditions such as high salt spray, high humidity, and strong corrosion. Existing proximity switches and door magnetic sensors have insufficient protection levels and weather resistance of materials, which can easily lead to component damage and signal failure after long-term use. Traditional detection solutions are not specifically designed for these conditions, resulting in short service life and poor reliability in complex environments.

[0008] In summary, existing wind turbine tower door detection technologies suffer from numerous shortcomings, including limited detection dimensions, weak anti-interference capabilities, insufficient accuracy, lack of safety functions, and poor environmental adaptability. These limitations fail to meet the wind farm's need for accurate, real-time, and comprehensive monitoring of tower door status. While existing technologies such as the CN117513932A tower cover opening and closing system, wind turbine generator sets, and the CN202692974U automobile door maximum opening angle detection device have made some technical improvements in their respective fields, they still do not solve the aforementioned comprehensive problems related to tower door detection. Therefore, there is an urgent need for a tower door opening and closing angle detection device and method with continuous angle detection capabilities, strong anti-interference capabilities, accurate and reliable detection, and adaptability to complex wind farm conditions to overcome the deficiencies of existing technologies. Summary of the Invention

[0009] The technical problem this invention aims to solve is to provide a device and method for detecting the opening and closing angle of wind turbine tower doors, addressing the technical deficiencies in wind turbine tower door status detection in the wind power generation field. Specifically, existing detection methods suffer from insufficient accuracy, weak anti-interference capabilities, lack of real-time performance, and inability to achieve multi-state monitoring. Current technologies mainly rely on proximity switches or door magnetic sensors, which can only output discrete "open" or "closed" signals, unable to continuously acquire the tower door opening and closing angle. Furthermore, they are easily affected by wind turbine vibration, signal interference, dust, and temperature and humidity factors, leading to a high false alarm rate.

[0010] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: This invention proposes a device and method for detecting the opening and closing angle of a wind turbine tower door. Based on a combination of a flexible rope method and a rotary encoder, it achieves comprehensive, high-precision, and interference-resistant monitoring of the door's status by real-time monitoring of continuous angle changes. This overcomes the limitations of existing detection methods, such as insufficient accuracy, weak anti-interference capability, lack of real-time performance, and inability to perform multi-state monitoring. Specifically: (a) Wind turbine tower door opening and closing angle detection device The detection device of the present invention achieves accurate acquisition and transmission of angle signals through the coordinated design of its components. Its specific structure is as follows: The device includes an integrated sealed housing, a rotary encoder, a coil spring, a winding reel, a wire rope, a counterweight, a guide mechanism, and a retaining ring. The connection relationships and technical parameters of each component are defined as follows: 1. Overall Assembly Relationship: The rotary encoder, coil spring, and winding reel are coaxially mounted in an integrated sealed housing, forming an integrated core component; one end of the wire rope is connected to a fixing ring fixed on the wind turbine tower door, and the other end is wound around the winding reel, realizing the linkage between the door movement and the winding reel rotation; a counterweight is suspended in the middle of the wire rope to maintain the tension of the wire rope; a guide mechanism is set at the outlet end of the integrated sealed housing to reduce frictional loss during the movement of the wire rope.

[0011] 2. Core component design: Rotary encoder: It adopts an absolute encoder with a resolution of ≥12 bits, protection level of IP67, and is compatible with 24VDC power supply. Its core function is to measure the number of rotations of the winding reel and convert it into the pull-out length of the wire rope, providing basic data for angle calculation. Coil spring: Made of stainless steel, with a preload setting and a fatigue life of >100,000 cycles. It ensures that the wire rope is always taut during the opening and closing of the door through its own rebound force, avoiding the impact of wire rope slack on detection accuracy. Steel wire rope: Made of Teflon material, with a breaking tensile strength ≥300N and an elongation rate <0.1% in a wide temperature range of -40℃ to 120℃. It has both corrosion resistance and low elongation characteristics, and can stably transmit the movement status of the tower door to the rotary encoder. Winding reel: Made of aluminum alloy with anodized surface, laser-etched 0° baseline and 90° verification line with a etch accuracy of ±0.1mm. It adopts a single-layer winding design with anti-derailment groove to ensure orderly winding of the wire rope and prevent it from falling off or getting tangled. Counterweight: It adopts a nylon-coated anti-corrosion design. When the wind turbine tower door closes quickly and the spring rebounds late, it relies on its own weight to maintain the tension of the wire rope and prevent the wire rope from slack and tangling. Fixed ring: It is a stainless steel pressed ring. The end of the steel wire rope is fixed by pressing with an aluminum sleeve after passing through the fixed ring. The breaking strength is ≥500N and the calibration error of the installation radius r is ≤±1mm to ensure the accuracy of the geometric calculation benchmark. Guiding mechanism: It consists of a guide tube and double rollers. The double rollers are installed on both sides of the steel wire rope at the front end of the guide tube. The guide tube is made of PTFE material and the rollers are made of ceramic bearings with a friction coefficient of <0.05, which can significantly reduce friction loss during the movement of the steel wire rope, extend service life and ensure smooth motion transmission. Integrated sealed housing: Provides protection for internal core components, ensuring stable operation of rotary encoders, coil springs, and reels in complex wind farm environments.

[0012] (II) Method for detecting the opening and closing angle of wind turbine tower doors Based on the aforementioned wind turbine tower door opening angle detection device, this invention also provides a method for detecting the opening angle of wind turbine tower doors. Through standardized installation, calibration, and angle calculation procedures, the method achieves accurate detection of the tower door opening angle. The specific steps are as follows: Step 1: Install the retaining ring The fixing ring is fixed to the inside of the tower door with bolts. During installation, ensure that the vertical distance error between the fixing ring and the door shaft is less than 1mm to ensure the accuracy of the installation radius and provide a reliable geometric reference for subsequent angle calculation.

[0013] Step 2: Install the integrated sealed box. The integrated sealed housing containing the rotary encoder, coil spring, and winding reel is fixed to the door frame of the wind turbine tower door. The installation position is adjusted so that the outlet of the wire rope is precisely aligned with the fixing ring to ensure a smooth movement path for the wire rope.

[0014] Step 3: Install the guiding mechanism The guide tube of the guide mechanism is fixed at 90° to the door frame of the wind turbine tower door, so that the ceramic roller is aligned with the tangent of the wire rope, thereby minimizing the frictional resistance of the wire rope during movement.

[0015] Step 4: Install the wire rope With the tower gate fully closed, use a spring tension gauge to pre-tighten the wire rope. At this point, reset the rotary encoder reading to zero to complete the setting of the detection benchmark.

[0016] Step 5: Calibration With the door closed, record the initial pulse of the rotary encoder; open the tower door to 90°, at which point the measured chord length satisfies formula (1): (1); In the formula, The actual chord length is the pull-out length of the wire rope (5); The installation radius from the door hinge to the fixing ring (8) is given.

[0017] Using a laser angle meter as a standard, compare the measured angle with the output data of the rotary encoder, correct the installation radius r and zero offset until the full-scale error is <±1°, and the calibration is completed.

[0018] Step 6: Angle Detection The pull-out length of the wire rope is measured in real time using a rotary encoder. The opening and closing angle of the tower gate is calculated based on the chord length-angle mathematical model. The mathematical model includes the chord length formula (2) and the angle inverse formula (3): (2); (3); In the formula, The pull-out length of the wire rope (5) is... The installation radius from the door hinge to the retaining ring (8) is... The opening angle of the tower gate (9).

[0019] In addition, the detection method also has the following optimized design: The rotary encoder signal is acquired using a 100Hz sampling frequency, and the data is refreshed every second via RS485 / Modbus protocol to ensure real-time angle detection. The rotary encoder outputs a high-resolution digital signal (resolution ≥ 12 bits), supporting continuous detection of the tower door opening angle and enabling multi-state monitoring; It has a broken wire detection function, which triggers an alarm when the pulse loss of the rotary encoder lasts for more than 2 seconds, thus improving the reliability of the detection system.

[0020] The wind turbine tower door opening angle detection device and method provided by the present invention have the following beneficial effects: 1. This invention addresses many shortcomings in wind farm tower door detection. Most wind farm detection methods are limited; traditional devices can only determine "open / closed" status, failing to acquire continuous angle information. Furthermore, vibrations, electromagnetic interference, dust, and temperature and humidity changes generated by wind turbine operation easily lead to false alarms, making it difficult to reflect the actual condition and determine door looseness. This invention overcomes these limitations, enabling real-time and accurate acquisition of continuous opening and closing angles, resulting in more comprehensive and detailed monitoring, providing abundant data for subsequent analysis, and ensuring the safe operation of the wind farm.

[0021] 2. This invention is powerful, overcoming the limitations of existing devices that can only detect "on / off" binary states. It can not only accurately determine whether the tower door is properly closed, but also precisely determine the looseness of the door body through detailed analysis of angle change data. This helps to promptly identify potential safety issues, take preventative maintenance measures, ensure the safe operation of wind farm equipment, and provide strong support for wind farm safety management.

[0022] 3. This invention focuses on improving the anti-interference capability of the detection system, employing a unique physical connection method and advanced signal processing technology to avoid false alarms and missed alarms caused by factors such as fan vibration, dust, and temperature and humidity changes. It also features a comprehensive disconnection detection function, immediately triggering an alarm in the event of a disconnection or other abnormality, thus improving the overall reliability of the system, ensuring continuous and stable detection operations, and guaranteeing accurate and reliable detection results.

[0023] 4. This invention comprehensively optimizes and simplifies the installation and calibration process. Each component adopts a modular design, and the installation process is standardized, making installation convenient and efficient. Calibration utilizes a laser angle meter for auxiliary correction, which is simple to operate and provides stable and reliable results. The modular design of each component also facilitates transportation and storage, enabling rapid and accurate assembly and ensuring long-term stable operation of the device in complex wind field environments.

[0024] 5. This invention represents a comprehensive upgrade in detection capabilities, overcoming the limitations of existing devices. It employs high-precision sensors and advanced algorithms to achieve continuous angle detection with over 12-bit accuracy. It can acquire real-time information on the complete angle changes of tower doors, not only determining whether the door is closed but also accurately assessing the degree of looseness by analyzing angle fluctuations, providing detailed reference data for wind farm equipment maintenance.

[0025] 6. This invention boasts outstanding anti-interference capabilities. It employs a physical connection using steel wire ropes to transmit motion signals, resulting in high stability and strong anti-interference properties. It is unaffected by fan vibration, electromagnetic interference, dust, and temperature and humidity fluctuations ranging from -40℃ to 120℃. Combined with a wire breakage detection function, it forms a comprehensive anti-interference system, effectively preventing false alarms and missed alarms, ensuring accurate and reliable test results, and guaranteeing the smooth progress of testing work.

[0026] 7. This invention boasts industry-leading detection accuracy. Based on the precise geometric relationship between the fixed ring and the door hinge, a chord length-angle mathematical model is constructed to accurately calculate the opening and closing angle. After rigorous calibration, the full-scale error is less than ±1°. Furthermore, due to the stable geometric relationship, it ensures absolute accuracy over long-term use, providing strong support for the safe monitoring of wind farm equipment and contributing to the stable operation of wind farms.

[0027] 8. This invention is easy to install and calibrate. The modular design of each component facilitates transportation, storage, and rapid and accurate assembly. The installation process is standardized, and operators can complete the installation by following simple steps. Calibration is aided by a laser angle meter, enabling rapid and accurate adjustment of detection parameters. The operation is convenient and the results are stable, greatly shortening on-site debugging time and improving work efficiency.

[0028] 9. This invention exhibits excellent environmental adaptability. Core components are made of high-protection, corrosion-resistant, and high-quality materials. For example, the IP67 protection-rated encoder prevents dust and water intrusion, and the connectors are made of stainless steel or Teflon, which are corrosion-resistant and wear-resistant. This enables the device to adapt to harsh wind farm environments, provides a long fatigue life, reduces maintenance costs, and minimizes equipment failures caused by environmental factors.

[0029] 10. This invention enables continuous, real-time, and high-precision monitoring of the tower door opening and closing angle. Through theoretical derivation and extensive experimental verification, the full-scale error is less than ±1°, accurately capturing minute angle changes. Simultaneously, it can analyze door loosening in real time, promptly alarming upon detecting abnormalities, providing reliable protection for the safe operation of wind turbine generators and effectively reducing equipment failures and safety accidents.

[0030] 11. This invention cleverly combines the flexible rope method with a rotary encoder, and the system outputs a high-resolution digital signal. It overcomes the limitation of traditional proximity switches that can only detect discrete states, providing richer and more detailed detection data. This provides strong support for accurate analysis of tower gate conditions, meets the high-precision requirements of wind farms for equipment condition monitoring, and promotes the development of detection technology.

[0031] 12. This invention utilizes the physical connection of steel wire ropes and wire breakage detection to construct a robust anti-interference system. The steel wire rope connection avoids interference from ambient light, temperature, dust, and other factors, ensuring stable and accurate signal transmission. Wire breakage detection monitors the connection status in real time, immediately triggering an alarm upon wire breakage, preventing misjudgments due to signal interruption, improving the system's anti-interference capability and reliability, and ensuring the normal operation of testing work.

[0032] 13. This invention utilizes an angle calculation model based on rigorous geometric relationships, providing a solid guarantee for the accuracy of measurement results. This model is meticulously designed and rigorously verified, considering the geometric relationship between the fixing ring and the door hinge, as well as various influencing factors, enabling precise calculation of the opening and closing angle. Furthermore, due to the stable geometric relationships, the measurement results are unaffected by environmental factors and equipment wear, ensuring absolute accuracy.

[0033] 14. This invention successfully upgrades traditional discrete state detection to continuous angle detection. By organically combining a rotary encoder with a flexible rope method, it achieves real-time, high-precision measurement of the tower door opening and closing angle. It overcomes the limitation of existing technologies that can only output "open / close" signals, providing continuous angle change data and offering more comprehensive and accurate information for in-depth analysis of operating status and fault diagnosis.

[0034] 15. The physical connection and wire breakage detection mechanism introduced in this invention has significant advantages. Utilizing the corrosion resistance and low tensile strength of Teflon steel wire rope, along with a carefully designed counterweight and guiding mechanism, it reduces the impact of external factors on the detection system and enhances its anti-interference capabilities. Wire breakage detection promptly identifies connection abnormalities, avoiding false alarms and missed alarms, ensuring the detection system operates stably and reliably in various complex environments.

[0035] 16. This invention deeply optimizes the installation and calibration process, using fixed ring positioning technology to quickly and accurately determine the installation position, improving installation efficiency. The integrated design of the encapsulation box reduces component connections and wiring, lowering installation difficulty. Laser angle gauges are used for precise calibration and adjustment of detection parameters, ensuring accurate measurements. The optimized on-site commissioning time is reduced by over 50%, and the measurement accuracy reaches ±1°, meeting the stringent standards of the wind power generation field.

[0036] 17. This invention effectively solves the problem of existing technologies relying on proximity switches or door magnetic sensors. Traditional technologies can only detect discrete states and cannot obtain the opening and closing angle in real time, making it difficult to accurately analyze door looseness and affecting the safe operation of wind turbine generators. This invention can monitor the opening and closing angle accurately in real time, promptly detect potential safety hazards, provide strong protection for the safe operation of wind turbine generators, and improve the operational safety of wind farms.

[0037] 18. This invention overcomes many drawbacks of traditional solutions. Traditional solutions are easily affected by factors such as wind turbine vibration, signal interference, dust, and temperature and humidity, resulting in a high false alarm rate and a lack of wire breakage detection function, thus failing to guarantee long-term operational reliability. This invention adopts advanced anti-interference technology and a comprehensive wire breakage detection mechanism to solve these problems, enabling stable and reliable operation in various harsh environments and providing reliable technical support for the safety monitoring of wind farm equipment.

[0038] 19. This invention addresses the problem of complex installation and calibration processes in existing technologies. Traditional technologies require professional personnel, and measurement accuracy is greatly affected by environmental factors, making it difficult to meet the high requirements of the wind power generation field. This invention simplifies the installation and calibration process, reduces the technical requirements for operators, and improves measurement accuracy and stability through innovative technologies such as modular design, standardized installation procedures, and laser calibration, thereby meeting the actual needs of the wind power generation field.

[0039] 20. This invention enables continuous, real-time monitoring of the tower door's opening and closing angle, outputting a high-resolution digital signal of 12 bits or more, with a sampling frequency of up to 100Hz. This high-frequency, high-precision monitoring method can promptly capture subtle changes during the opening and closing process, supporting real-time analysis of door loosening. An alarm is immediately triggered upon detecting an anomaly, providing timely information for staff to handle the situation and effectively ensuring the safe operation of the wind turbine generator.

[0040] 21. The anti-interference capability of the system of this invention is significantly improved. Through the combined effect of physical connection and disconnection detection mechanism, environmental factors are effectively avoided, reducing the false alarm rate to near zero. This feature enables the invention to meet the requirements of industrial applications, and it can operate stably and reliably in various complex industrial environments, providing strong protection for the safety and stability of industrial production, and has broad application prospects.

[0041] 22. This invention greatly simplifies the installation and calibration process. Through integrated design and laser calibration technology, it reduces on-site commissioning workload and improves calibration accuracy and efficiency. On-site commissioning time is reduced by over 50%, and measurement accuracy reaches ±1°, meeting the stringent standards for equipment condition monitoring in the wind power industry. This provides strong support for the efficient operation of wind farms and helps them improve operational efficiency.

[0042] 23. This invention can be used for real-time and precise monitoring of the opening and closing angle of wind turbine tower doors. Utilizing high-precision detection technology and advanced data analysis algorithms, it accurately determines whether the door is properly closed and whether it is loose. An alarm is triggered promptly upon detecting any abnormalities, alerting staff to perform maintenance and repairs, effectively preventing equipment failures and safety accidents caused by tower door issues, and ensuring the safe and stable operation of wind turbine generators.

[0043] 24. The core components of this invention are made of high-quality materials. For example, the encoder uses high-protection-level materials, and the connectors are made of corrosion-resistant and wear-resistant materials, enabling the device to operate stably in the harsh environment of wind farms. It also boasts advantages such as high-precision detection, strong anti-interference capabilities, and easy installation and calibration, ensuring the safe monitoring of wind farm equipment from multiple perspectives and providing comprehensive support for the stable operation and safe production of wind farms.

[0044] 25. This invention incorporates several innovations in tower door detection, forming a complete and advanced solution from multiple aspects, including upgraded detection dimensions, improved anti-interference capabilities, enhanced detection accuracy, simplified installation and calibration, and strong environmental adaptability. It meets the needs of complex wind farm environments and high-precision monitoring, providing reliable assurance for the safe operation of wind farm equipment and driving wind farm detection technology to a higher level. Attached Figure Description

[0045] The present invention will be further described below with reference to the accompanying drawings and embodiments: Figure 1 This is a schematic diagram of the overall structure of the device of the present invention; Figure 2This is a partial schematic diagram of the installation of the counterweight block of the present invention; Figure 3 This is a partial structural schematic diagram of the guiding mechanism of the present invention; In the diagram: 1. Sealed box body; 2. Rotary encoder; 3. Coil spring; 4. Winding reel; 5. Wire rope; 6. Counterweight; 7. Guide mechanism; 8. Fixing ring; 9. Tower door; 71. Conduit; 72. Double roller. Detailed Implementation

[0046] The technical solutions of the present invention will be further described below with reference to the embodiments and accompanying drawings: Example 1 like Figures 1 to 3 As shown in the figure, this embodiment provides a wind turbine tower door opening angle detection device, as detailed below: This embodiment provides a specific wind turbine tower door opening angle detection device, such as... Figure 1 As shown, the selection, dimensions, and assembly relationships of each component strictly adhere to the limitations defined in the claims, as detailed below: (I) Selection and parameters of core components Integrated sealed housing 1: Made of stainless steel SUS304 (Steel Use Stainless), welded and formed, with external dimensions of 200mm×150mm×100mm and protection rating of IP66. The side of the housing has a reserved cable outlet hole, and a PTFE (Polytetra Fluoroethylene) sealing sleeve is installed in the hole to ensure that the internal components are not corroded by wind, dust and moisture. The housing is equipped with a coaxial mounting bracket to fix the rotary encoder 2, coil spring 3 and winding reel 4.

[0047] Rotary encoder 2: Selects an absolute encoder, model E6B2-CWZ6C, with a resolution of 14 bits (meeting the requirement of ≥12 bits), protection level of IP67, working voltage of 24VDC, and output signal of RS485 (Recommended Standard) digital quantity. It can accurately measure the number of rotations of the winding wheel 4, outputting 16384 pulses per rotation, which is converted into the length of the wire rope 5 pulled out through pulse counting.

[0048] Coil spring 3: Made of stainless steel SUS304, with an outer diameter of 50mm, an inner diameter of 20mm, and a length of 80mm. The preload is set to 8N (within the range of 8±0.5N). After fatigue testing, its performance has not degraded after 150,000 consecutive extensions and retractions, meeting the requirement of fatigue life >100,000 cycles. One end is fixed to the inner wall of the integrated sealed box 1 by a buckle, and the other end is rigidly connected to the inner groove of the winding wheel 4 to provide continuous rebound force.

[0049] Steel wire rope 5: Teflon-coated stainless steel wire rope with a diameter of 1.5mm. The measured breaking tensile strength is 320N (≥300N). The elongation rate is 0.07% at a low temperature of -40℃ and 0.09% at a high temperature of 120℃ (both <0.1%). It has excellent corrosion resistance, tensile strength and wide temperature adaptability, and can stably transmit the movement of the tower door 9.

[0050] The winding reel 4 is made of 6061 aluminum alloy and is CNC machined. It has a diameter of 60mm and a thickness of 20mm. The surface is anodized (oxide film thickness of 10μm). The 0° baseline and 90° verification line are laser etched with a line width of 0.2mm and a line accuracy of ±0.08mm (better than ±0.1mm requirement). The outer circumference of the winding reel 4 is provided with a 1.6mm wide anti-slip groove. It adopts a single-layer winding design to ensure that the steel wire rope 5 is wound in an orderly manner and there is no risk of falling off.

[0051] Counterweight 6: The overall weight is 180g. The core is a lead block and the outside is covered with a 2mm thick nylon layer. The surface is smooth and burr-free. An M4 stainless steel hook is installed on the top. The hook can slide freely along the steel wire rope 5. When the tower door 9 closes quickly, it can quickly straighten the slack steel wire rope 5 by gravity to avoid tangling.

[0052] Fixing ring 8: A cold-formed 316L stainless steel ring, 5mm inner diameter, 15mm outer diameter, and 3mm thickness. The ends of the steel wire rope 5 pass through fixing ring 8 and are secured with 3mm diameter aluminum sleeves. Measured breaking strength is 580N (≥500N). Installation radius... The setting is 200mm, and after calibration, the installation radius error is ±0.8mm (≤±1mm).

[0053] Guiding mechanism 7: such as Figure 3 As shown, it includes a guide tube 71 and double rollers 72. The guide tube 71 has an inner diameter of 2mm and a length of 100mm. Flared guide sleeves are installed at both ends to prevent scratching the wire rope 5. The double rollers 72 use ceramic bearings (model 623ZZ). The rollers have a diameter of 15mm and a width of 3mm. The measured friction coefficient is 0.04 (<0.05). The two rollers are symmetrically installed on both sides of the outlet of the guide tube 71 and are precisely aligned with the tangent of the wire rope 5.

[0054] (ii) Assembly Relationship like Figure 1As shown, the rotary encoder 2, coil spring 3, and winding reel 4 are coaxially mounted on the internal support of the integrated sealed housing 1 via a stainless steel shaft. The output shaft of the rotary encoder 2 is rigidly connected to the winding reel 4, and the coil spring 3 is nested inside the winding reel 4, forming an integrated core component. One end of the steel wire rope 5 passes through the center hole of the fixing ring 8 and is fixed by pressing with an aluminum sleeve. The other end passes through the guide tube 71 of the guide mechanism 7 and is wound in a single layer inside the anti-detachment groove of the winding reel 4. Figure 2 As shown, the counterweight 6 is suspended in the middle of the wire rope 5 by an M4 hook, located between the guide mechanism 7 and the fixing ring 8, and can slide freely along the wire rope 5; the guide mechanism 7 is fixed to the outlet end of the integrated sealing box 1 by bolts, and the wire conduit 71 is sealed to the outlet hole of the integrated sealing box 1 to ensure the overall protection performance; the fixing ring 8 is installed on the inside of the tower door 9, and the integrated sealing box 1 is fixed to the outside of the door frame of the tower door 9, forming a complete transmission and detection structure.

[0055] Example 2 In another preferred embodiment, based on Embodiment 1, this embodiment provides a method for detecting the opening and closing angle of a wind turbine tower door. This method uses the wind turbine tower door opening and closing angle detection device described in Embodiment 1 to detect the opening and closing angle of the tower door 9 of a 1.5MW wind turbine. The specific operation steps are as follows: (a) Preparation for testing The dimensions of the wind turbine tower door 9 to be tested are 1.2m × 2.0m, and the door hinge is made of stainless steel with a diameter of 50mm. The tools prepared include M6 stainless steel bolts, wrenches, spring tension gauges (range 0~50N, accuracy ±0.1N), laser angle gauges (model D200, measurement accuracy ±0.1°), levels, and measuring tapes.

[0056] (II) Specific Steps Step 1: Install retaining ring 8 The retaining ring 8 is fixed to the inside of the tower door 9 using four M6 stainless steel bolts. The vertical distance between the installation position and the door hinge is set to 200mm (i.e., the installation radius). Use a level to calibrate the perpendicularity of the mounting surface of the fixing ring 8 to the door hinge, ensuring that the vertical distance error is 0.5mm (<1mm).

[0057] Step 2: Install the integrated sealed box 1 The integrated sealed box 1, which houses the core components, is fixed to the outside of the door frame of the tower door 9 using expansion bolts. The installation position is adjusted so that the outlet of the guide mechanism 7 conductor tube 71 at the outlet end of the integrated sealed box 1 is on the same horizontal line as the center of the fixing ring 8, with a horizontal distance of 150mm between them, to ensure that the movement path of the wire rope 5 is free of bends.

[0058] Step 3: Install guide mechanism 7 likeFigure 3 As shown, the guide tube 71 of the guide mechanism 7 is fixed at 90° to the door frame of the tower door 9. The angle between the guide tube 71 and the door frame is calibrated with a square to ensure that the deviation is ≤0.5°. The position of the double rollers 72 is adjusted so that the wire rope 5 is completely aligned with the tangent of the double rollers 72 when it passes through the gap between the rollers. The contact pressure between the double rollers 72 and the wire rope 5 is controlled within 0.5N to avoid excessive compression of the wire rope 5.

[0059] Step 4: Install steel wire rope 5 Close the tower door 9 and ensure that the door body is completely in contact with the door frame (closed state). Wrap the free end of the wire rope 5 around the anti-detachment groove of the winding wheel 4. Use a spring tension gauge to hook the middle section of the wire rope 5 and slowly pull the wire rope 5 until the tension gauge reading shows 8N (meeting the 8±0.5N pre-tightening requirement). At this time, use the software of the rotary encoder 2 to reset the reading of the rotary encoder 2 to zero and complete the detection benchmark setting.

[0060] Step 5: Calibration Keep the tower door 9 closed and record the initial pulse value of the rotary encoder 2 as 0; manually and slowly open the tower door 9 to the 90° position, and then calculate the theoretical value of the measured chord length according to formula (1):

[0061] The actual opening angle of the door was measured to be 89.8° using a laser angle meter, and the length of the steel wire rope 5 pulled out after conversion by the rotary encoder 2 was read as 283.2 mm; the installation radius was corrected using software. The value is 200.2 mm, the zero offset is 0.1. When measured again, the output angle of rotary encoder 2 is 89.9°, and the error between the value measured by the laser angle meter is 0.1° (<±1°), thus completing the calibration.

[0062] Step 6: Angle Detection The detection system is activated, and rotary encoder 2 acquires signals at a sampling frequency of 100Hz. Data is refreshed every second via RS485 / Modbus protocol, and the length of the steel wire rope 5 pulled out is uploaded in real time. ; Calculate the opening and closing angle based on the chord length-angle mathematical model The details are as follows: When the tower gate 9 is opened to 30°, the length of the wire rope 5 pulled out is calculated using formula (2):

[0063] Substitute into the angle inverse calculation formula (3):

[0064] The error between the measured value of 30.0° and the actual value measured by the laser angle meter is 0.1°; When the tower gate 9 closes rapidly (closing speed 0.5m / s), the spring 3 rebounds with a lag of 0.3s. At this time, if... Figure 2 As shown, the counterweight 6 pulls down the steel wire rope 5 quickly by its own weight to prevent the steel wire rope 5 from becoming loose and tangled, thus ensuring that the rotary encoder 2 can still accurately collect length data. When the simulated wire rope 5 breaks, the rotary encoder 2 loses pulses for 3 seconds (>2 seconds), and the system immediately triggers an audible and visual alarm to indicate the equipment malfunction.

[0065] (III) Test Results The measurement error of the opening angle of tower door 9 using this method is < ±0.5°, and the data refresh delay is ≤1s, meeting the requirements for real-time detection. This is under the following conditions: normal fan operation (vibration acceleration ≤ 0.5g), ambient temperature -20℃, and dust concentration... Under normal operating conditions, it can run continuously for 72 hours without false alarms or missed alarms. The disconnection detection function responds promptly, and the detection system has excellent stability and reliability.

[0066] Example 3 In another preferred embodiment, based on Embodiment 1, this embodiment provides a wind turbine tower door opening angle detection device. For offshore wind power environments with high salt spray and high humidity (salt spray concentration ≥50mg / m³, relative humidity ≥95%), the core components are designed with corrosion resistance enhancement while retaining the core structure of Embodiment 1, as detailed below: (I) Selection and parameters of core components Integrated sealed box 1: Made of titanium alloy TC4 welded and formed, with external dimensions of 220mm×160mm×110mm, protection level of IP68 (waterproof depth of 1m), the inner side of the box is coated with polytetrafluoroethylene (0.1mm thick), and a sacrificial anode block (zinc alloy material, weight 50g) is installed on the outside to slow down seawater corrosion.

[0067] Rotary encoder 2: Selects marine-grade absolute encoder (model WDS5810-M), 14-bit resolution, IP68 protection rating, 24VDC power supply, housing material is 316L stainless steel, output shaft is made of ceramic material, salt spray resistance up to 1000 hours (compliant with GB / T10125 standard), outputs 16384 pulses per revolution.

[0068] Coil Spring 3: Made of Hastelloy C276 material (superior to SUS304 in seawater corrosion resistance), with an outer diameter of 55mm, an inner diameter of 22mm, a length of 90mm, a preload of 7.8N (8±0.5N), a fatigue life of >150,000 cycles, and surface passivation treatment (passivation film thickness of 5μm) to avoid salt spray corrosion.

[0069] Steel wire rope 5: woven from Hastelloy wire, with an outer layer of polyether ether ketone (PEEK) material (thickness 0.3mm), diameter 1.5mm, breaking strength 350N (≥300N), elongation 0.06% (<0.1%) in an environment of -40℃~120℃, and no corrosion after 1500 hours of salt spray test.

[0070] Wire reel 4: Made of titanium alloy TC4, 60mm in diameter, 22mm in thickness, with a plasma-sprayed ceramic coating (0.08mm thick), laser-etched 0° and 90° lines with a line accuracy of ±0.09mm, anti-slip width of 1.6mm, and compatible with 1.5mm diameter steel wire rope 5.

[0071] Counterweight 6: Weight 180g, core is titanium alloy block, outer coating is 4mm thick fluororubber (resistant to seawater corrosion), top M4 hook is made of Hastelloy alloy, the inside of the hook is inlaid with PEEK gasket, sliding friction coefficient 0.04.

[0072] Fixed ring 8: Hastelloy C276 pressed ring, inner diameter 5mm, outer diameter 15mm, thickness 3mm. The end of the steel wire rope 5 passes through the fixed ring 8 and is then pressed with a titanium alloy sleeve. The breaking strength is 600N (≥500N), the installation radius is r=180mm, and the calibration error is ±0.6mm (≤±1mm).

[0073] Guiding mechanism 7: such as Figure 3 As shown, the conduit 71 is made of PEEK material (inner diameter 2mm, length 120mm), and fluororubber guide sleeves are installed at both ends; the double rollers 72 adopt zirconia ceramic bearings (model 623ZZ), with a protection level of IP68 and a friction coefficient of 0.038 (<0.05), and the roller surface is coated with polytetrafluoroethylene.

[0074] (ii) Assembly Relationship like Figure 1 As shown, the rotary encoder 2, coil spring 3, and winding reel 4 are coaxially mounted inside the integrated sealed housing 1 via a titanium alloy shaft. Both ends of the shaft are sealed with fluororubber sealing rings to prevent seawater ingress. The fixing ring 8 is fixed to the inside of the offshore wind turbine tower door 9 by titanium alloy bolts to prevent loosening due to bolt corrosion. Figure 2 As shown, the counterweight 6 is suspended in the middle of the wire rope 5. The wire rope 5 passes through the guide tube 71 and the double roller 72 of the guide mechanism 7 and is then wound around the winding wheel 4. All connection parts are coated with silicone weather-resistant sealant (seawater resistant type) to improve the overall corrosion resistance.

[0075] Example 4 In another preferred embodiment, based on embodiments 1 to 3, this embodiment provides a method for detecting the opening angle of a wind turbine tower door. This method is based on the corrosion-resistant wind turbine tower door opening angle detection device described in embodiment 3, and is applied to a 3.6MW offshore wind turbine (located in the intertidal zone, with a salt spray concentration of 60). The opening and closing angle of tower door 9 (with an average annual relative humidity of 92%) was tested, and the steps are as follows: (a) Preparation for testing The tools used are titanium alloy wrenches (to avoid corrosion of carbon steel tools), corrosion-resistant spring tension gauges (model SH-50, titanium alloy hooks), and laser angle gauges (waterproof rating IP67); the tower door 9 to be tested is made of titanium alloy, with dimensions of 1.6m × 2.0m, and the door hinges are treated with an anti-corrosion coating (thickness 0.1mm).

[0076] (II) Specific Steps Step 1: Pre-treatment of the mounting surface The mounting surfaces of the inner fixing ring 8 of the tower door 9 and the integrated sealing box 1 of the door frame are sandblasted (roughness Ra3.2), coated with zinc-aluminum coating (thickness 80μm), and left to stand for 24 hours to cure, to ensure that the mounting surfaces are corrosion resistant.

[0077] Step 2: Install the retaining ring 8 and the integrated sealing box 1 Use titanium alloy bolts to fix the retaining ring 8 to the inside of the pretreated tower door 9, with an installation radius of [missing information]. The vertical distance error is 0.5mm (<1mm) when calibrated with a digital display level. The integrated sealed box 1 (including core components) is fixed to the door frame with titanium alloy expansion bolts, and the bolt connection is sealed with silicone weather-resistant sealant.

[0078] Step 3: Install guide mechanism 7 and wire rope 5 like Figure 3 As shown, the guide tube 71 of the guide mechanism 7 is fixed at 90° to the door frame. The bolts are made of titanium alloy. After tightening, polytetrafluoroethylene raw material tape is wrapped around the connection. One end of the steel wire rope 5 is passed through the fixing ring 8 and crimped with a titanium alloy sleeve. The other end is passed through the guide mechanism 7 and wound around the winding wheel 4. It is pre-tightened to 7.8N with a corrosion-resistant spring tension gauge. The reading of the rotary encoder 2 is returned to zero.

[0079] Step 4: Salt spray environment-specific calibration Record the initial pulse (0) of rotary encoder 2 with the door closed, and place the device in a salt spray test chamber (concentration 60mg / m³, temperature 35℃) for 24 hours; After removing the door, open it to 90° and calculate the theoretical chord length according to formula (1):

[0080] The laser angle meter measured an angle of 89.8°, and the pull-out length converted by the rotary encoder 2 was 254.7 mm, which was corrected by software. The value is 180.1 mm, and the full-scale error is 0.09° (<±1°).

[0081] Step 5: Continuous Angle Inspection and Corrosion Prevention Maintenance Detection: The control device acquires the signal from rotary encoder 2 at a frequency of 100Hz, and calculates the angle according to formulas (2) and (3):

[0082]

[0083] Data is uploaded to the shore-based monitoring platform via a 4G (4th Generation Mobile Communication Technology) module (waterproof IP68). Maintenance: Inspect the wire rope 5 and guide mechanism 7 every 3 months, rinse the surface salt frost with fresh water, and apply fluorinated grease (seawater resistant) to ensure smooth movement of moving parts; calibrate the rotary encoder 2 every 6 months to correct minor errors caused by the salt spray environment.

[0084] (III) Test Results Corrosion resistance: After 12 months of continuous operation, there was no obvious corrosion in any component, the elongation of the wire rope 5 remained at 0.06%, and the markings on the winding reel 4 were clear and without wear. Detection accuracy: The angle measurement error is stable within ±0.08°, the wire breakage detection response time is <2s, and the device can still output angle data normally under typhoon conditions (wind speed 30m / s) without fault alarm.

[0085] Example 5 In another preferred embodiment, based on Embodiment 1, this embodiment provides a wind turbine tower door opening angle detection device. Based on the core structure defined in Embodiment 1, an automatic drive component and a safety linkage module are added to adapt to the intelligent control requirements of large wind turbine tower doors (width ≥ 1.5m), as detailed below: (I) Selection and parameters of core components Integrated sealed housing 1: Made of stainless steel SUS316L welded and formed, with external dimensions of 250mm×180mm×120mm and protection level of IP66. Four M8 mounting holes are reserved on the outside of the housing for fixing the control device 11. A heat sink (3mm thick) is added inside to meet the heat dissipation requirements of the rotary encoder 2 and the control device 11.

[0086] Rotary encoder 2: Selects an absolute encoder (model AX5810), with a resolution of 16 bits (≥12 bits), protection level of IP67, 24VDC power supply, and output signal supporting RS485 / Modbus-RTU (Recommended Standard 485, Modbus Remote Terminal Unit) dual protocols. It outputs 65,536 pulses per revolution, and the measurement accuracy of the steel wire rope 5 pull-out length reaches ±0.1mm, meeting the requirements for high-precision angle inverse calculation.

[0087] Coil spring 3: Made of stainless steel SUS304, with an outer diameter of 60mm, an inner diameter of 25mm, a length of 100mm, and a preload of 8.2N (within the range of 8±0.5N). After fatigue testing, the preload decreases by ≤5% after 180,000 consecutive extensions and retractions, meeting the requirement of fatigue life >100,000 cycles. One end is fixed to the inner wall of the integrated sealed box 1 by an elastic buckle, and the other end is connected to the spline on the inner side of the winding reel 4.

[0088] Steel Wire Rope 5: Teflon-coated galvanized steel wire rope, 1.8mm in diameter (suitable for high tensile strength requirements), with a measured breaking strength of 380N (≥300N), and an elongation of 0.08% (<0.1%) in an environment of -40℃ to 120℃. The surface is coated with a wear-resistant coating (0.05mm thick) to extend the friction life with the double rollers 72.

[0089] Winding reel 4: Made of 6061-T6 aluminum alloy, 70mm in diameter and 25mm in thickness, with anodized surface (12μm oxide film thickness), laser-etched 0° baseline, 90° verification line and 180° limit line, with a etch accuracy of ±0.07mm (better than ±0.1mm), anti-slip groove width of 2.0mm, suitable for single-layer winding of 1.8mm diameter steel wire rope 5.

[0090] Counterweight 6: Weight 220g (suitable for tensioning large diameter steel wire rope 5), core is made of cast iron, covered with a 3mm thick nylon layer, top is equipped with an M5 stainless steel hook, and the inside of the hook is pasted with a PTFE gasket (friction coefficient 0.03) to ensure smooth sliding along the steel wire rope 5 without jamming.

[0091] Fixing ring 8: 316L stainless steel hot-pressed ring, inner diameter 8mm, outer diameter 20mm, thickness 4mm. The steel wire rope ends 5 pass through fixing ring 8 and are then crimped with 5mm diameter aluminum sleeves. Measured breaking strength 620N (≥500N). Installation radius... The setting is 250mm, and the calibration error is ±0.7mm (≤±1mm).

[0092] Guiding mechanism 7: such as Figure 3As shown, it includes a guide tube 71 and double rollers 72. The guide tube 71 is made of PTFE material (inner diameter 3mm, length 150mm), and rounded transition guide sleeves are installed at both ends (to avoid scratching the steel wire rope 5). The double rollers 72 use silicon nitride ceramic bearings (model 624ZZ), with a diameter of 20mm, a width of 4mm, and a friction coefficient of 0.035 (<0.05). A dust cover (protection level IP65) is added to the outside of the rollers.

[0093] New components (extended functionality): Drive motor: Stepper motor (model 42HS40-1704), rated torque 1.7N. m, protection level IP65, 24VDC power supply, coaxially connected to the winding reel 4 via a coupling, used to drive the automatic opening and closing of the tower door 9, step angle 1.8°, and the control accuracy after subdivision reaches 0.09°.

[0094] Control device: It adopts an industrial-grade PLC (Programmable Controllers) (model S7-1200CPU1214C) with an IP65 protection rating. It has 4 analog inputs and 6 digital outputs, which are connected to rotary encoder 2 (signal acquisition), drive motor (motion control), safety lock (locking signal), and industrial camera (image detection) to realize multi-component linkage.

[0095] Safety lock: Electromagnetic lock (model EML-80), rated voltage 24VDC, locking force 800N, installed on the side of tower door 9, linked with the control device, and triggered to lock when the opening angle of tower door 9 is abnormal.

[0096] Industrial camera: An explosion-proof industrial camera (model MV-CA050-10GM) with a resolution of 5 megapixels and an IP67 protection rating is selected. It is installed above the tower door 9 to collect images of people around the door and prevent collisions during automatic drive.

[0097] (ii) Assembly Relationship like Figure 1 As shown, the rotary encoder 2, coil spring 3, winding reel 4, and drive motor are coaxially mounted inside the integrated sealed housing 1 via a stainless steel main shaft. The output shaft of the drive motor is rigidly connected to the winding reel 4 via a coupling. The rotary encoder 2 is mounted on the other end of the main shaft to collect the rotation data of the winding reel 4 in real time. The control device is fixed to the outside of the integrated sealed housing 1 with bolts and connected to each component via cables. Figure 2As shown, the safety lock is embedded in the lock groove on the side of the tower door 9. The industrial camera is fixed to the top of the door frame by a bracket, with the lens facing the opening and closing area of ​​the tower door 9. One end of the steel wire rope 5 is pressed into the fixing ring 8, and the other end passes through the guide tube 71 and double roller 72 of the guide mechanism 7 and is wound around the winding wheel 4. The counterweight 6 is suspended in the middle section of the steel wire rope 5 (located between the guide mechanism 7 and the fixing ring 8), forming an integrated system of "detection-drive-safety".

[0098] Example 6 In another preferred embodiment, based on embodiments 1 to 3 and embodiment 5, this embodiment provides a method for detecting the opening and closing angle of a wind turbine tower door. This method is based on the wind turbine tower door opening and closing angle detection device with automatic drive and safety linkage functions described in embodiment 5. It performs opening and closing angle detection and intelligent control on a 3.0MW wind turbine (tower door 9 dimensions 1.8m × 2.2m). The specific steps are as follows: (a) Preparation for testing In addition to standard tools such as bolts, spring tension gauges (range 0~100N, accuracy ±0.05N), and laser angle gauges (model D300, accuracy ±0.05°), a new PLC programmer (model PG / PC7) and image calibration board (size 500mm×500mm) have been added. The door hinges of the 9 doors of the tower to be tested are made of 45# steel with a diameter of 60mm, and the door frame has reserved installation interfaces for drive motors and safety locks.

[0099] (II) Specific Steps Step 1: Install retaining ring 8 Secure the retaining ring 8 to the inside of the tower door 9 using six M8 stainless steel bolts (250mm vertically from the door hinge). Use a digital level to calibrate and ensure the vertical distance error between the retaining ring 8 and the door hinge is 0.6mm (<1mm). Mark the installation position and record the installation radius. .

[0100] Step 2: Install the integrated sealed housing 1 and the drive assembly The integrated sealing box 1 (including rotary encoder 2, coil spring 3, and winding reel 4) is fixed to the outside of the door frame with expansion bolts. The drive motor is connected to the integrated sealing box 1 through the flange. The coupling gap is adjusted to 0.1mm to ensure that the coaxiality error between the winding reel 4 and the drive motor is <0.05mm.

[0101] Step 3: Install guide mechanism 7 and safety lock 12 like Figure 3 As shown, fix the guide tube 71 of the guide mechanism 7 at a 90° angle to the door frame, calibrate it with a square and tighten it so that the double roller 72 is aligned with the tangent of the wire rope 5; embed the safety lock into the side lock groove of the tower door 9, adjust the position of the lock tongue to ensure that the lock tongue can be smoothly inserted into the lock hole when the tower door 9 is fully closed.

[0102] Step 4: Install the control device and industrial camera The control device is fixed to the outside of the integrated sealed box 1 and connected to the rotary encoder 2 (RS485 line), drive motor (power line and control line), and safety lock (signal line). The industrial camera is mounted on the top of the door frame with a bracket. The lens angle is adjusted so that the shooting range covers the opening and closing area of ​​the tower door 9 (width 2m, height 1.5m) and connected to the Ethernet port of the control device.

[0103] Step 5: Install wire rope 5 and pre-tighten it. Close the tower door 9 until it is fully closed. Pass one end of the wire rope 5 through the fixing ring 8 and press it with the aluminum sleeve. Pass the other end through the guide tube 71 and double roller 72 of the guide mechanism 7 and then wind it around the winding wheel 4. Use a spring tension gauge to pre-tighten the wire rope 5 to 8.3N (8±0.5N). At this time, use the control device to reset the reading of the rotary encoder 2 to zero.

[0104] Step 6: Calibrate Angle and Image Detection Parameters Angle calibration: Record the initial pulse (0) of rotary encoder 2 with the door closed, manually open the door to 90°, and calculate the theoretical chord length according to formula (1):

[0105] The laser angle gauge measured an angle of 89.9°, and the pull-out length converted by rotary encoder 2 was 353.7 mm, which was corrected by the control device. The value is 250.1 mm, the zero offset is 0.02, and the full-scale error is 0.08° (<±1°) when measured again. Image calibration: The industrial camera is calibrated using an image calibration board. The "human body recognition threshold" is set: when the proportion of human body outline in the image is >5%, it is determined to be "someone" and when the proportion is <1%, it is determined to be "no one". The response time is ≤0.5s.

[0106] Step 7: Set up the linkage control logic Write linkage rules to the control device using a PLC programmer: Automatic door opening: When the control device receives the "door opening command", it first triggers the industrial camera to detect. If it determines that "no one is there", the drive motor rotates forward, driving the winding wheel 4 to release the wire rope 5. The rotary encoder 2 provides real-time feedback of the angle. When the angle reaches 90°, the drive motor stops and the safety lock unlocks. Automatic door closing: After receiving the "door closing command", the industrial camera checks again. If there is "no one", the drive motor reverses and the reel 4 retracts the wire rope 5. When the angle is <5°, the drive motor slows down. After the door is fully closed (angle 0°), the safety lock is triggered to lock. Abnormal protection: If the rotary encoder 2 detects an angle fluctuation of >5° within 10s (indicating a loose door), or if the industrial camera detects "someone" while the drive motor is still running, the control device will immediately stop the drive motor, trigger the safety lock, and issue an alarm signal via an audible and visual alarm (connected to the control device).

[0107] Step 8: Continuous Angle Detection and Linkage Response The control device acquires the signal from rotary encoder 2 at a frequency of 100Hz and calculates the opening and closing angles according to formulas (2) and (3):

[0108]

[0109] Data is uploaded to the wind farm monitoring platform via RS485; when the tower door 9 deviates in angle due to vibration (e.g., from 0° to 3°), the control device immediately triggers the safety lock to strengthen the locking, and at the same time pushes the early warning information to the monitoring platform.

[0110] (III) Test Results Angle detection accuracy: After continuous monitoring for 72 hours, the opening and closing angle measurement error is < ±0.1°, and the data refresh delay is 0.8s (≤1s). Automatic control response: Door opening / closing action response time < 1s; when the industrial camera detects a human body, the drive motor can pause within 0.3s to avoid collision. Abnormal protection effect: When simulating a loose door (angle fluctuation of 6°), the control device triggers the safety lock within 0.5s, and the alarm signal is uploaded synchronously, with no false alarms or missed alarms; Environmental adaptability: Under conditions of -30℃ low temperature and level 8 wind force (wind speed 18m / s), all components operate normally, the steel wire rope 5 is not slack, and the output torque of the drive motor is stable.

[0111] In the preferred embodiment, the rotary encoder 2 is an absolute encoder with a resolution of ≥12 bits, an IP67 protection rating, and a 24VDC power supply. It is used to measure the number of rotations of the winding reel 4 and convert it into the length of the wire rope 5 pulled out. The above settings can accurately obtain the length of the wire rope 5 pulled out, thereby accurately calculating the opening and closing angle of the tower door 9, providing reliable data for the wind farm, ensuring the stable operation of the wind turbine generator, and reducing safety hazards caused by unclear door status.

[0112] In the preferred embodiment, the coil spring 3 is made of stainless steel SUS304, with a preload of 8±0.5N and a fatigue life of >100,000 cycles. It is used to provide rebound force to ensure that the wire rope 5 is always taut. The above settings can ensure that the wire rope 5 is in a taut state under various working conditions, so as to ensure accurate transmission of motion signals, avoid distortion of detection data due to slack in the wire rope 5, and improve the stability and reliability of the detection device.

[0113] In the preferred embodiment, the steel wire rope 5 is made of Teflon material, has a diameter of 1.5mm, a breaking tensile strength ≥300N, and an elongation of <0.1% in an environment of -40℃ to 120℃. It is used to transmit the movement of the tower door to the rotary encoder 2. The above settings can adapt to harsh environments, work stably even in extreme temperatures, and have a low elongation, which can accurately transmit movement, reduce errors, and ensure that the detection device can perform normal detection in complex environments.

[0114] In the preferred embodiment, the winding wheel 4 is made of aluminum alloy 6061, with anodized surface and laser-etched 0° baseline and 90° verification line, and the etching accuracy is set to ±0.1mm. It adopts a single-layer winding design with anti-derailment groove. The above settings can ensure that the wire rope 5 is wound neatly, prevent derailment, and the high etching accuracy facilitates accurate installation and debugging, improves the accuracy and stability of the detection device, and ensures the accuracy of the detection data.

[0115] In the preferred embodiment, the counterweight 6 has a mass of 180g and adopts a nylon-coated anti-corrosion design. It is used to maintain the tension of the wire rope 5 by gravity when the wind turbine tower door 9 closes quickly and the spring 3 rebounds late. The above settings can maintain the tension of the wire rope 5 in a timely manner under special working conditions, ensure that the transmission of motion signals is not affected, avoid inaccurate detection data due to the rebound lag of the spring 3, and improve the adaptability of the detection device.

[0116] In the preferred embodiment, the fixing ring 8 is a 316L stainless steel pressed ring. After the end of the steel wire rope 5 passes through the fixing ring 8, it is fixed by pressing with an aluminum sleeve. The breaking strength is ≥500N and the calibration error of the installation radius is ≤±1mm. The above settings can firmly fix the end of the steel wire rope 5, prevent the steel wire rope 5 from falling off, and reduce the calibration error of the installation radius, thereby improving the installation accuracy of the detection device and thus improving the accuracy of the detection data.

[0117] In a preferred embodiment, the guiding mechanism 7 includes a guide tube 71 and double rollers 72. The double rollers 72 are installed on both sides of the steel wire rope 5 at the front end of the guide tube 71. The guide tube is made of PTFE material, and the rollers 72 are made of ceramic bearings with a friction coefficient of <0.05, which is used to reduce the friction of the steel wire rope 5 during movement. The above configuration can reduce the friction of the steel wire rope 5 during movement, reduce energy loss and wear, extend the service life of the steel wire rope 5, ensure smooth transmission of motion signals, and improve the reliability of the detection device.

[0118] In a preferred embodiment, the wind turbine tower door opening and closing angle detection method further includes acquiring the rotary encoder 2 signal using a 100Hz sampling frequency and refreshing the data every second via the RS485 / Modbus protocol to ensure the real-time performance of the angle detection. The above settings enable timely acquisition of the tower door 9 opening and closing angle data, allowing wind farm managers to monitor the door status in real time, make quick decisions, and ensure the safe operation of the wind turbine generator set.

[0119] In the preferred embodiment, the rotary encoder 2 outputs a high-resolution digital signal with a resolution of ≥12 bits, supporting continuous detection of the tower door opening and closing angle to achieve multi-state monitoring. The above settings can obtain more detailed information on the opening and closing angle of the tower door 9, not only knowing whether the door is open or closed, but also understanding the specific degree of opening and closing, providing rich data for in-depth analysis of the door's state and improving the comprehensiveness of the detection.

[0120] In the preferred embodiment, the wind turbine tower door opening angle detection method also includes a wire breakage detection function. When the pulse loss of the rotary encoder 2 lasts for more than 2 seconds, an alarm is triggered to improve the reliability of the detection system. The above settings can issue an alarm in time when the wire rope 5 has a wire breakage or other faults, so that the management personnel can know and deal with it in time, avoid inaccurate detection data due to faults, and ensure the stable and reliable operation of the detection system.

[0121] In summary, this invention proposes a device and method for detecting the opening and closing angle of wind turbine tower doors, fundamentally and effectively solving many obvious defects in current industry methods for detecting tower doors. Currently, most wind farms are not equipped with dedicated detection devices; only a few use proximity switches or door magnetic sensors. However, these traditional devices have extremely limited functionality, only able to determine a binary "open" or "closed" state, unable to obtain continuous and detailed angle information during the door's opening and closing process. Furthermore, the strong vibrations and electromagnetic interference generated during wind turbine operation, as well as frequent fluctuations in dust, temperature, and humidity in the environment, make existing detection devices prone to false alarms, failing to accurately and truthfully reflect the actual state of the tower door, and unable to determine door looseness through precise analysis of angle changes, posing a significant hidden danger to the safe operation of wind farms.

[0122] The device and method of this invention have several advantages: First, they break through the limitations of traditional methods that only detect "open / closed" binary states, enabling real-time and accurate acquisition of the continuous opening and closing angles of the tower door 9, providing a rich data foundation for in-depth analysis of the door's status. Second, they employ a physical connection method using steel wire rope 5 to transmit motion signals, combined with a wire breakage detection function, constructing a robust anti-interference system to avoid false alarms and missed alarms caused by various environmental factors and wire breaks. Furthermore, based on the precise geometric relationship between the fixed ring 8 and the door hinge, a chord length-angle mathematical model is constructed to inversely calculate the opening and closing angles. After rigorous calibration, the full-scale error is less than ±1°, ensuring long-term accuracy. Simultaneously, the flexible rope method is cleverly combined with the rotary encoder 2, allowing the system to output high-resolution digital signals, overcoming the limitations of traditional proximity switches and providing richer and more detailed detection data. In addition, through the positioning technology of the fixed ring 8, the integrated design of the sealed box 1, and the calibration of the laser angle meter, the installation and calibration process is deeply optimized, reducing on-site debugging time by over 50% and achieving a measurement accuracy of ±1°. The guide tube 71 and double rollers 72 in the guide mechanism 7 work together, the coil spring 3 cooperates with the winding wheel 4, the wire rope 5 is wound on the winding wheel 4, and the counterweight 6 is installed at the end of the wire rope 5, together ensuring the stable operation of the system.

[0123] This invention also demonstrates significant application effectiveness: it not only enables continuous real-time monitoring of the opening and closing angle of the tower door 9, but also provides real-time analysis of door loosening and timely alarms, offering reliable assurance for the safe operation of wind turbine generators and solving the problem of traditional technologies being unable to accurately analyze door loosening. Utilizing the corrosion-resistant and low-tensile properties of the Teflon-coated steel wire rope 5, combined with a carefully designed counterweight 6 and guide mechanism 7, the impact of external factors on the detection system is effectively reduced, enhancing anti-interference capabilities. Simultaneously, the wire breakage detection function avoids false alarms and missed alarms. This invention optimizes various aspects, including upgraded detection dimensions, improved anti-interference capabilities, enhanced detection accuracy, simplified installation and calibration, and strong environmental adaptability, forming a complete and advanced tower door 9 detection solution that meets the demands of complex wind farm environments and high-precision monitoring. Through theoretical derivation and extensive experimental verification, an angle calculation model based on strict geometric relationships is constructed, providing a solid guarantee for the accuracy of measurement results, unaffected by environmental factors and equipment wear. Ultimately, it successfully upgrades traditional discrete state detection to continuous angle detection, providing more comprehensive and accurate information for in-depth analysis of the tower door 9's operating status and fault diagnosis, thus promoting the development of tower door 9 detection technology.

Claims

1. A wind turbine tower door opening and closing angle detection device, characterized in that: It includes an integrated sealed box (1), a rotary encoder (2), a coil spring (3), a winding reel (4), a wire rope (5), a counterweight (6), a guide mechanism (7), and a fixing ring (8); the rotary encoder (2), the coil spring (3), and the winding reel (4) are coaxially installed inside the integrated sealed box (1), one end of the wire rope (5) is connected to the fixing ring (8) installed on the wind turbine tower door (9), and the other end is wound on the winding reel (4), the counterweight (6) is suspended in the middle section of the wire rope (5), and the guide mechanism (7) is set at the outlet end of the integrated sealed box (1).

2. The wind turbine tower door opening angle detection device according to claim 1, characterized in that: The rotary encoder (2) is an absolute encoder used to measure the number of rotations of the winding reel (4) and convert it into the length of the wire rope (5) pulled out.

3. The wind turbine tower door opening angle detection device according to claim 1, characterized in that: The coil spring (3) is made of stainless steel and is used to provide rebound force to ensure that the wire rope (5) is always taut.

4. The wind turbine tower door opening angle detection device according to claim 1, characterized in that: The steel wire rope (5) is made of Teflon and is used to transmit the movement of the tower door to the rotary encoder (2).

5. The wind turbine tower door opening angle detection device according to claim 1, characterized in that: The winding reel (4) is made of aluminum alloy, and its surface is anodized and laser-etched with a 0° baseline and a 90° verification line. The etching accuracy is set, and it adopts a single-layer winding design with anti-detachment groove.

6. The wind turbine tower door opening angle detection device according to claim 1, characterized in that: The counterweight (6) is designed with nylon coating for corrosion protection and is used to maintain the tension of the wire rope (5) by gravity when the wind turbine tower door (9) is closed and the spring (3) rebounds late.

7. The wind turbine tower door opening angle detection device according to claim 1, characterized in that: The fixing ring (8) is a stainless steel pressed ring, and the end of the wire rope (5) passes through the fixing ring (8) and is then pressed and fixed.

8. The wind turbine tower door opening angle detection device according to claim 1, characterized in that: The guiding mechanism (7) includes a guide tube (71) and double rollers (72). The double rollers (72) are installed on both sides of the wire rope (5) at the front end of the guide tube (71). The guide tube is made of PTFE material, and the rollers (72) are made of ceramic bearings with a friction coefficient of <0.05, which is used to reduce the friction of the wire rope (5) during movement.

9. A method for detecting the opening angle of a wind turbine tower door, which is a method for detecting the opening angle of a wind turbine tower door based on the wind turbine tower door opening angle detection device according to any one of claims 1 to 8, characterized in that, Includes the following steps: Step 1, Install the fixing ring (8): Fix the fixing ring (8) to the inside of the tower door with bolts, and ensure that the vertical distance error between the fixing ring (8) and the door shaft is <1mm; Step 2, Install the integrated sealing box (1): Fix the integrated sealing box (1) that houses the rotary encoder (2), coil spring (3), and winding wheel (4) on the door frame of the tower door (9), and align the outlet of the wire conduit (71) with the fixing ring (8). Step 3, Install the guide mechanism (7): Fix the guide tube (71) at 90° to the door frame of the tower door (9) so that the ceramic roller (72) is aligned with the tangent of the wire rope (5); Step 4: Install the wire rope (5): With the tower door (9) fully closed, use a spring tension gauge to pre-tighten the wire rope (5), and at this time, reset the reading of the rotary encoder (2) to zero; Step 5, Calibration: With the door closed, record the initial pulse of the rotary encoder (2); open the door to 90°, measure the actual chord length, and compare the measured angle with the output of the rotary encoder (2) using the laser angle meter as the standard, correct the installation radius value and zero offset of the door shaft to the fixed ring (8) until the full-scale error is <±1°; Step 6, Angle detection: Measure the length of the steel wire rope (5) pulled out by the rotary encoder (2), and calculate the opening and closing angle of the tower gate (9) based on the chord length-angle mathematical model.

10. The method for detecting the opening angle of a wind turbine tower door according to claim 9, characterized in that, The measured chord length in step 5 is: （1）； In the formula, The actual chord length is the pull-out length of the wire rope (5); The installation radius from the door hinge to the fixing ring (8) is given.

11. The method for detecting the opening angle of a wind turbine tower door according to claim 9, characterized in that, The chord length-angle mathematical model in step 6 includes the chord length formula and the angle inverse calculation formula. The chord length formula is: （2）； （3）； In the formula, The pull-out length of the wire rope (5) is... The installation radius from the door hinge to the retaining ring (8) is... The opening angle of the tower gate (9).

12. The method for detecting the opening angle of a wind turbine tower door according to claim 9, characterized in that: The wind turbine tower door opening angle detection method also includes collecting the rotary encoder (2) signal and refreshing the data every second through the RS485 / Modbus protocol to ensure the real-time performance of the angle detection.

13. The method for detecting the opening angle of the wind turbine tower door according to claim 13, characterized in that: The rotary encoder (2) outputs a high-resolution digital signal with a resolution of ≥12 bits, which supports continuous detection of the tower door opening angle and realizes multi-state monitoring.

14. The method for detecting the opening angle of a wind turbine tower door according to claim 9, characterized in that: The wind turbine tower door opening angle detection method also includes a wire breakage detection function. When the pulse loss of the rotary encoder (2) lasts for more than 2 seconds, an alarm is triggered to improve the reliability of the detection system.

Images